WO1999060115A2

WO1999060115A2 - Proteins and genes useful as tumor markers

Info

Publication number: WO1999060115A2
Application number: PCT/EP1999/003374
Authority: WO
Inventors: Fred Van Leuven
Original assignee: Vlaams Interuniversitair Instituut Voor Biotechnologie Vzw
Priority date: 1998-05-18
Filing date: 1999-05-17
Publication date: 1999-11-25
Also published as: AU4362199A; WO1999060115A3

Abstract

The current invention concerns a human protein, its cDNA and its gene that is located on chromosome 19q12. The invention also concerns its mouse counterpart. The invention further relates to the use of monitoring the expression of said gene as tumor marker in general and especially as marker for Reed-Sternberg cells of Hodgkin's disease.

Description

PROTEINS AND GENES USEFUL AS TUMOR MARKERS

Field of the invention

The present invention relates to a novel human protein, to its cDNA and to its gene located on chromosome 19q12. The invention also concerns its mouse counterpart. The invention further relates to the use of monitoring the expression of said gene as tumor marker in general and especially as marker for Reed-Sternberg cells of Hodgkin's disease.

Background of the invention The etiology of Hodgkin's disease has not yet been elucidated. There is good evidence that Hodgkin's disease is heterogeneous with respect to the cell lineage of the Reed-Sternberg cells, which are the neoplastic cells of Hodgkin's disease. Investigations into the immunophenotype, the clonal nature and the karyotype of the Reed-Sternberg cells as well as studies on the role of Epstein-Barr virus and known oncogenes in Hodgkin's disease point to the heterogeneous nature of the disease and justify the usage of the term "Hodgkin's syndrome" (Diehl et al., 1990; Stein et al., 1991 ; Drexler, H.G. 1992). Nevertheless, there are some common denominators in Hodgkin's disease. Reed-Stemberg cells express activation associated markers such as CD25, CD30 and CD71 in addition to major histocompatibility class II antigens and the accessory molecules CD54, CD58 and B7/BB1. Interestingly, the expression of activation associated antigens and accessory molecules is also a feature of the malignant cells of anaplastic large cell lymphoma, a non-Hodgkin's lymphoma of B, T or null cell lineage.

Delabie et al. (1992) demonstrated that also Restin is highly expressed in Reed- Sternberg cells and in anaplastic large-cell lymphoma (so-called Ki-1 lymphoma), but not in normal tissues, in non-Hodgkin's lymphoma or in nonlymphoid tumors. Restin was identified and characterized as a 170 kDa cytoplasmic protein coded by the RSN gene located on chromosome 12q24.3 (Hilliker et al., 1994). Restin or CLIP 170 was proposed to control the shuttling of endocytic vesicles in the cytoplasm (Pierre et al., 1992; Rickard and Kreis, 1996). Although its role in Hodgkin's pathology is still unknown, Restin can be used as marker for Reed-Sternberg cells and for anaplastic large-cell lymphoma.

Summary of the invention Following the isolation and identification by N-terminal and internal protein sequencing of two novel proteins (Van Leuven et al., 1993) the molecular cloning of the corresponding cDNA was initiated by PCR amplification. Several of the prominent amplicons obtained, were cloned and sequenced as the primary characterization, and revealed that the majority represented unknown human genes. One particular amplicon, designated NNX3, was consistently and prominently encountered. Moreover, the partially sequenced open reading frame predicted a protein with some intriguing features, not related to any known protein or structural domain. The subsequent more complete molecular characterization confirmed these initial findings and led to a comprehensive molecular analysis, from molecular cloning of the human and mouse cDNA and the encoding genes and chromosomal and physical mapping of the human gene.

Sequenced fragments corresponding to both the human and mouse NNX3 cDNA sequences are listed in the EST database, in total more than 70 entries. However, these sequences do not give any information about any coding sequence, the protein composition or the function of the protein. Moreover, the complete nucleotide sequence of the cDNA cannot be derived unambiguously on the basis of the EST sequences. They are only helpful in revealing the many different sources from which the cDNA sequences and clones were generated. The results identified NNX3 as a novel cytoplasmic protein, encoded by a gene located on human chromosome 19q12: the inventive protein is also called c19orf2. Apart from the cloning and characterization of the human gene and protein, the murine counterpart has been characterized too. This confirmed in another species the unique nature of NNX3, and allowed to analyze its expression in vivo at the mRNA and protein level. The molecular findings and the analysis of expression in mouse and human tissues indicate that NNX3 may be an useful marker for different types of tumors, including lung tumors. Surprisingly, an unexpected parallel was found in expression of NNX3 to Restin in the Reed-Sternberg cells of Hodgkin's disease (Chan and Delabie, 1995), which makes of NNX3 an interesting marker for Reed-Stemberg cells.

Therefore one aspect of the invention is to offer a novel maker for tumors, including lung tumors. The detection of the expression may be situated on mRNA level or on protein level. Methods for detection are known to the people skilled in the art and include any nucleotide based amplification technique, Northern blotting, Western blotting, ELISA-based techniques, immunohistochemistry and immunofluorescence.

A preferred embodiment of the invention is a novel marker for Hodgkin's disease and/or Reed-Sternberg ceils.

Another embodiment of the invention is a protein comprising the amino acid sequence represented in SEQ ID NO.2.

Another embodiment of the invention is a protein comprising the amino acid sequence represented in SEQ ID NO.4.

A further aspect of the invention relates to antibodies produced against above mentioned proteins. Another aspect of the invention comprises DNA molecules encoding the above mentioned proteins.

Still another aspect of the invention is an expression vector for above mentioned proteins, for the expression of the gene and/or the production of the proteins in prokaryotic and/or eukaryotic cells. This includes the expression in bacterial cells, such as Escherichia coli, Bacillus or Lactobacillus, expression in actinomycetes such as Streptomyces, expression in yeasts such as Saccharomyces, expression in insect cells, expression in plant cells, expression in human or animal cells, transgenic plants or transgenic animals. Transformation methods and suitable promoters are known to a person skilled in the art. Another aspect of the invention are mice in which the expression of the gene is altered, inactivated or restricted to certain cells, tissues or time points during embryonal or adult life. Techniques to change structure of the gene by homologous recombination in ES cells are known to people skilled in the art.

Aims and description of the invention

The invention thus concerns an isolated purified protein comprising an amino acid sequence with 70-100 % homology to the sequence depicted in SEQ ID NO. 2 and/or a functional fragment thereof. In addition part of the current invention is an isolated purified protein comprising an amino acid sequence with 70-100 % homology to the sequence depicted in SEQ ID NO. 4 and/or a functional fragment thereof. To the invention also belongs a nucleic acid sequence encoding above captioned protein(s) or functional fragments thereof, more particularly a nucleic acid sequence with about 70-100% homology to the sequence depicted in SEQ ID NO.1 but also in the alternative a nucleic acid sequence with about 70-100% homology to the sequence depicted in SEQ ID NO. 3.

Furthermore a specific probe based on a nucleic acid sequence comprising at least 15 contiguous nucleotides selected from a nucleic acid sequence according to the invention as well as antibodies directed against said protein according to the invention or an antigenic fragment thereof all belong to the scope of the current invention.

To the invention also relates an assay for screening the expression of a nucleic acid sequence and/or the production of a protein according to the invention but also an assay comprising the immunological detection of said protein or an antigenic fragment thereof or an assay comprising the detection and/or amplification of a nucleic acid sequence according to the present invention.

Expression vectors may comprise a nucleic acid molecule having at least 15 contiguous nucleotides of a nucleic acid sequence according to the current invention operably linked to a promoter sequence; said vector can transform and/or transfect (recombinant) host cells selected from the group consisting of bacterial, mammalian, plant, fungal or insect cells.

Transgenic, non human, animals in which the expression of a nucleic acid sequence according to the invention is upregulated, downregulated or eliminated in a specified tissue and/or in cells in embryonic and/or adult life can be constructed accordingly. The NNX3 mRNA and/or protein derived therefrom can be used as a tumor marker, in particular for lung tumors, but also as a marker for Hodgkin's disease. Consequently the isolated purified protein and/or a functional fragment thereof according to the invention can be used as a medicament. A pharmaceutical composition may comprise one or more isolated purified proteins and/or a functional fragment thereof and pharmaceutically acceptable carrier material. Said protein according to the invention and/or a functional fragment thereof can be used for the manufacture of a pharmaceutical composition to treat lung

A tumors, but also to treat Hodgin's disease.

DEFINITIONS

The following definitions are set forth to illustrate and define the meaning and scope of the various terms used to describe the invention herein and the meaning is further elaborated hereunder for sake of clarity.

"Nucleic acid" or "nucleic acid sequence" means genomic DNA, cDNA, double stranded or single stranded DNA, messenger RNA or any form of nucleic acid sequence known to a skilled person. "Antibody" means polyclonal antibody, monoclonal antibody, single chain antibody, chimeric antibody, camilid antibody, diabody, heterodimeric or heteromultimeric antibody, immunotoxin or any molecule with a similar activity known to the people skilled in the art. "Antigenic fragment" means any epitope of a protein against which antibodies can be raised. This fragment may be used as a purified peptide, or as an epitope in a larger protein, or it may be presented on an antigen presenting structure as known to the people skilled in the art.

"Specific probe" means any nucleic acid binding molecule, recognizing only or mainly (at least 60 %) of the nucleic acid used as target sequence under the conditions used. Specific probes can be used for hybridization under different stringency conditions, or as primer for any nucleic acid sequence amplification technique such as the so-called polymeric chain reaction.

"Homology" in the context of amino acid sequences means identical or similar to the referenced sequence while obvious replacements/modifications of any of the amino acids provided, are included as well. A homology search in this respect can be performed with the BLAST-P (Basic Local Alignment Search Tool) program well known to a person skilled in the art. For the corresponding nucleic acid sequence homology is referred to the BLASTX and BLASTN programs known in the art. Homology in this context means that the respective nucleic acid molecules or encoded proteins are functionally and/or structurally equivalent. The nucleic acid molecules that are homologous to the nucleic acid molecules described above and that are derivatives of said nucleic acid molecules are, for example, variations of said nucleic acid molecules which represent modifications having the same biological function, in particular encoding proteins with the same or substantially the same biological function. They may be naturally occurring variations, such as sequences from other varieties or species, or mutations. These mutations may occur naturally or may be obtained by mutagenesis techniques. The allelic variations may be naturally occurring allelic variants as well as synthetically produced or genetically engineered variants.

The proteins encoded by the various derivatives and variants of the above-described nucleic acid molecules have similar common characteristics, such as biological activity, molecular weight, immunological reactivity, conformation, etc., as well as physical properties, such as electrophoretic mobility, chromatographic behavior, sedimentation coefficients, pH optimum, temperature optimum, stability, solubility, spectroscopic properties, etc.

As mentioned the present invention also relates to vectors, particularly plasmids, cosmids, viruses, bacteriophages and other vectors used conventionally in genetic engineering that contain a nucleic acid molecule according to the invention. Methods which are well known to those skilled in the art can be used to construct various plasmids and vectors; see, for example, the techniques described in Sambrook, Molecular Cloning A Laboratory Manual, Cold Spring Harbor Laboratory (1989) N.Y. Alternatively, the nucleic acid molecules and vectors of the invention can be reconstituted into liposomes for delivery to target cells.

In a preferred embodiment the nucleic acid molecule present in the vector is operably linked to (a) control sequence(s) which allow the expression of the nucleic acid molecule in prokaryotic and/or eukaryotic cells. The term "control sequence" refers to regulatory DNA sequences which are necessary to affect the expression of coding sequences to which they are ligated. The nature of such control sequences differs depending upon the host organism. In prokaryotes, control sequences generally include promoter, ribosomal binding site, and terminators. In eukaryotes generally control sequences include promoters, terminators and, in some instances, enhancers, transactivators or transcription factors. The term "control sequence" is intended to include, at a minimum, all components the presence of which are necessary for expression, and may also include additional advantageous components. The term "operably linked" refers to a juxtaposition wherein the components so described are in a relationship permitting them to function in their intended manner. A control sequence "operably linked" to a coding sequence is ligated in such a way that expression of the coding sequence is achieved under conditions compatible with the control sequences. In case the control sequence is a promoter, it is obvious for a skilled person that double-stranded nucleic acid is used. Thus, the vector of the invention is preferably an expression vector. An "expression vector" is a construct that can be used to transform a selected host cell and provides for expression of a coding sequence in the selected host. Expression vectors can for instance be cloning vectors, binary vectors or integrating vectors. Expression comprises transcription of the nucleic acid molecule preferably into a translatable mRNA. Regulatory elements ensuring expression in prokaryotic and/or eukaryotic cells are well known to those skilled in the art. The present invention furthermore relates to host cells comprising a vector as described above or a nucleic acid molecule according to the invention wherein the nucleic acid molecule is foreign to the host cell.

By "foreign" it is meant that the nucleic acid molecule is either heterologous with respect to the host cell, this means derived from a cell or organism with a different genomic background, or is homologous with respect to the host cell but located in a different genomic environment than the naturally occurring counterpart of said nucleic acid molecule. This means that, if the nucleic acid molecule is homologous with respect to the host cell, it is not located in its natural location in the genome of said host cell, in particular it is surrounded by different genes. In this case the nucleic acid molecule may be either under the control of its own promoter or under the control of a heterologous promoter. The vector or nucleic acid molecule according to the invention which is present in the host cell may either be integrated into the genome of the host cell or it may be maintained in some form extrachromosomaliy. In this respect, it is also to be understood that the nucleic acid molecule of the invention can be used to restore or create a mutant gene via homologous recombination (Paszkowski (ed.), Homologous Recombination and Gene Silencing in Plants. Kluwer Academic Publishers (1994)). The host cell can be any prokaryotic or eukaryotic cell, such as bacterial, insect, fungal, plant or animal ceils. Preferred fungal cells are, for example, those of the genus Saccharomyces, in particular those of the species S. cerevisiae. Another subject of the invention is a method for the preparation of the inventive proteins which comprises the cultivation of host cells according to the invention which, due to the presence of a vector or a nucleic acid molecule according to the invention, are able to express such a protein, under conditions which allow expression of the protein and recovering of the so-produced protein from the culture. The term "expression" means the production of a protein or nucleotide sequence in the cell. However, said term also includes expression of the protein in a cell-free system. It includes transcription into an RNA product, post-transcriptional modification and/or translation to a protein product or polypeptide from a DNA encoding that product, as well as possible post-translational modifications. Depending on the specific constructs and conditions used, the protein may be recovered from the cells, from the culture medium or from both. For the person skilled in the art it is well known that it is not only possible to express a native protein but also to express the protein as fusion polypeptides or to add signal sequences directing the protein to specific compartments of the host cell, e.g., ensuring secretion of the peptide into the culture medium, etc. Furthermore, such a protein and fragments thereof can be chemically synthesized and/or modified according to standard methods.

The terms "protein" and "polypeptide" used in this application are interchangeable. "Polypeptide" refers to a polymer of amino acids (amino acid sequence) and does not refer to a specific length of the molecuie. Thus peptides and oligopeptides are included within the definition of polypeptide. This term does also refer to or include post-translational modifications of the polypeptide, for example, glycosylations, acetylations, phosphorylations and the like. Included within the definition are, for example, polypeptides containing one or more analogs of an amino acid (including, for example, unnatural amino acids, etc.), polypeptides with substituted linkages, as well as other modifications known in the art, both naturally occurring and non- naturally occurring.

The present invention furthermore relates to proteins encoded by the nucleic acid molecules according to the invention or produced or obtained by the above- described methods, and to functional and/or immunologically active fragments of such proteins. The proteins and polypeptides of the present invention are not necessarily translated from a designated nucleic acid sequence; the polypeptides may be generated in any manner, including for example, chemical synthesis, or expression of a recombinant expression system, or isolation from a suitable viral system. The polypeptides may include one or more analogs of amino acids, phosphorylated amino acids or unnatural amino acids. Methods of inserting analogs of amino acids into a sequence are known in the art. The polypeptides may also include one or more labels, which are known to those skilled in the art. In this context, it is also understood that the proteins according to the invention may be further modified by conventional methods known in the art. By providing the proteins according to the present invention it is also possible to determine fragments which retain biological activity, namely the mature, processed form. This allows the construction of chimeric proteins and peptides comprising an amino sequence derived from the protein of the invention, which is crucial for its binding activity. The other functional amino acid sequences may be either physically linked by, e.g., chemical means to the proteins of the invention or may be fused by recombinant DNA techniques well known in the art. The term "functional fragment of a sequence" or " functional part of a sequence" means a truncated sequence of the original sequence referred to. The truncated sequence (nucleic acid or protein sequence) can vary widely in length; the minimum size being a sequence of sufficient size to provide a sequence with at least a comparable function and/or activity of the original sequence referred to, while the maximum size is not critical, in some applications, the maximum size usually is not substantially greater than that required to provide the desired activity and/or function(s) of the original sequence. Typically, the truncated amino acid sequence will range from about 5 to about 60 amino acids in length. More typically, however, the sequence will be a maximum of about 50 amino acids in length, preferably a maximum of about 30 amino acids. It is usually desirable to select sequences of at least about 10, 12 or 15 amino acids, up to a maximum of about 20 or 25 amino acids.

Furthermore, folding simulations and computer redesign of structural motifs of the protein of the invention can be performed using appropriate computer programs (Olszewski, Proteins 25 (1996), 286-299; Hoffman, Comput. Appl. Biosci. 11 (1995), 675-679). Computer modeling of protein folding can be used for the conformational and energetic analysis of detailed peptide and protein models (Monge, J. Mol. Biol. 247 (1995), 995-1012; Renouf, Adv. Exp. Med. Biol. 376 (1995), 37-45). In particular, the appropriate programs can be used for the identification of interactive sites of the inventive protein , its receptor, its ligand or other interacting proteins by computer assistant searches for complementary peptide sequences (Fassina, Immunomethods 5 (1994), 114-120. Further appropriate computer systems for the design of protein and peptides are described in the prior art, for example in Berry, Biochem. Soc. Trans. 22 (1994), 1033-1036; Wodak, Ann. N. Y. Acad. Sci. 501 (1987), 1-13; Pabo, Biochemistry 25 (1986), 5987-5991. The results obtained from the above-described computer analysis can be used for, e.g., the preparation of peptidomimetics of the protein of the invention or fragments thereof. Such pseudopeptide analogues of the natural amino acid sequence of the protein may very efficiently mimic the parent protein (Benkirane, J. Biol. Chem. 271 (1996), 33218-33224). For example, incorporation of easily available achiral -amino acid residues into a protein of the invention or a fragment thereof results in the substitution of amide bonds by polymethylene units of an aliphatic chain, thereby providing a convenient strategy for constructing a peptidomimetic (Banerjee, Biopolymers 39 (1996), 769-777). Superactive peptidomimetic analogues of small peptide hormones in other systems are described in the prior art (Zhang, Biochem. Biophys. Res. Commun. 224 (1996), 327-331). Appropriate peptidomimetics of the protein of the present invention can also be identified by the synthesis of peptidomimetic combinatorial libraries through successive amide alkylation and testing the resulting compounds, e.g., for their binding and immunological properties. Methods for the generation and use of peptidomimetic combinatorial libraries are described in the prior art, for example in Ostresh, Methods in Enzymology 267 (1996), 220-234 and Dorner, Bioorg. Med. Chem. 4 (1996), 709-715. Furthermore, a three-dimensional and/or crystallographic structure of the protein of the invention can be used for the design of peptidomimetic inhibitors of the biological activity of the protein of the invention (Rose, Biochemistry 35 (1996), 12933-12944; Rutenber, Bioorg. Med. Chem. 4 (1996), 1545-1558). Furthermore, the present invention relates to antibodies specifically recognizing the protein(s) according to the invention or parts, i.e. specific fragments or epitopes, of such a protein. The antibodies of the invention can be used to identify and isolate other related proteins and genes in any organism. These antibodies can be monoclonal antibodies, polyclonal antibodies, camelid antibodies or synthetic antibodies as well as fragments of antibodies, such as Fab, Fv or scFv fragments etc. Monoclonal antibodies can be prepared, for example, by the techniques as originally described in Kόhler and Milstein, Nature 256 (1975), 495, and Galfre, Meth. Enzymol. 73 (1981 ), 3, which comprise the fusion of mouse myeloma cells to spleen cells derived from immunized mammals. Furthermore, antibodies or fragments thereof to the aforementioned peptides can be obtained by using methods which are described, e.g., in Harlow and Lane "Antibodies, A Laboratory Manual", CSH Press, Cold Spring Harbor, 1988. These antibodies can be used, for example, for the immunoprecipitation and immunolocalization of proteins according to the invention as well as for the monitoring of the synthesis of such proteins, for example, in recombinant organisms, and for the identification of compounds interacting with the protein according to the invention. For example, surface plasmon resonance as employed in the BIAcore system can be used to increase the efficiency of phage antibodies selections, yielding a high increment of affinity from a single library of phage antibodies which bind to an epitope of the protein of the invention (Schier, Human Antibodies Hybridomas 7 (1996), 97-105; Malmborg, J. Immunol. Methods 183 (1995), 7-13). In many cases, the binding phenomena of antibodies to antigens is equivalent to other ligand/anti-ligand binding. The invention also relates to a diagnostic composition comprising at least one of the aforementioned nucleic acid molecules, vectors, proteins, antibodies or compounds and optionally suitable means for detection.

Said diagnostic compositions may be used for methods for detecting expression of related proteins as described in the current invention by detecting the presence of the corresponding mRNA which comprises isolation of mRNA from a cell and contacting the mRNA so obtained with a probe comprising a nucleic acid probe as described above under hybridizing conditions, detecting the presence of mRNA hybridized to the probe, and thereby detecting the expression of the protein in the cell. Further methods of detecting the presence of a protein according to the present

H invention comprises immunotechniques well known in the art, for example enzyme linked immunosorbent assay.

The terms "gene(s)", "polynucleotide", "nucleic acid sequence", "nucleotide sequence", "DNA sequence" or "nucleic acid molecule(s)" as used herein refers to a polymeric form of nucleotides of any length, either ribonucleotides or deoxyribonucleotides. This term refers only to the primary structure of the molecule. Thus, this term includes double- and single-stranded DNA, and RNA. It also includes known types of modifications, for example, methylation, "caps" substitution of one or more of the naturally occuring nucleotides with an analog. Preferably, the DNA sequence of the invention comprises a coding sequence encoding the above defined X3-protein.

A "coding sequence" is a nucleotide sequence which is transcribed into mRNA and/or translated into a polypeptide when placed under the control of appropriate regulatory sequences. The boundaries of the coding sequence are determined by a translation start codon at the 5'-terminus and a translation stop codon at the 3'- terminus. A coding sequence can include, but is not limited to mRNA, cDNA, recombinant nucleotide sequences or genomic DNA, while introns may be present as well under certain circumstances. As used herein, the term "composition" refers to any composition such as a pharmaceutical composition comprising as an active ingredient an isolated functional protein according to the present invention possibly in the presence of suitable excipients known to the skilled man and may thus be administered in the form of any suitable composition as detailed below by any suitable method of administration within the knowledge of a skilled man. The preferred route of administration is parenterally. In parenteral administration, the compositions of this invention will be formulated in a unit dosage injectable form such as a solution, suspension or emulsion, in association with a pharmaceutically acceptable excipient. Such excipients are inherently nontoxic and nontherapeutic. Examples of such excipients are saline, Ringer's solution, dextrose solution and Hank's solution. Nonaqueous excipients such as fixed oils and ethyl oleate may also be used. A preferred excipient is 5% dextrose in saline. The excipient may contain minor amounts of additives such as substances that enhance isotonicity and chemical stability, including buffers and preservatives. The isolated functional protein of the invention is administered at a concentration that is therapeutically effective to prevent allograft rejection, GVHD, allergy and autoimmune diseases. The dosage and mode of administration will depend on the individual. Generally, the compositions are administered so that the isolated functional protein is given at a dose between 1 μg/kg and 10 mg/kg, more preferably between 10 μg/kg and 5 mg/kg, most preferably between 0.1 and 2 mg/kg. Preferably, it is given as a bolus dose. Continuous short time infusion (during 30 minutes) may also be used. The compositions comprising the isolated functional protein according to the invention may be infused at a dose between 5 and 20 μg/kg/minute, more preferably between 7 and 15 μg/kg/minute.

According to a specific case, the "therapeutically effective amount" of the isolated functional protein according to the invention needed should be determined as being the amount sufficient to cure the patient in need of treatment or at least to partially arrest the disease and its complications. Amounts effective for such use will depend on the severity of the disease and the general state of the patient's health. Single or multiple administrations may be required depending on the dosage and frequency as required and tolerated by the patient.

BRIEF DESCRIPTION OF THE FIGURES

Fig. 1. Alignment of the predicted protein sequence of human NNX3 with the mouse NNX3.

Numbering of the amino acid residues of the deduced NNX3 gene is indicated at the end of each line. Human NNX3 sequence is shown in the upper line ( total of 458 amino acids), while the mouse sequence is depicted in the lower line (total of 457 amino acids). In the figure a bipartite motif for nuclear targeting is underlined. Also indicated are a stretch of acidic residues (underlined), consisting of 16 to 18 aspartic acid residues and most mismatches which are concentrated in 4 areas (boxed).

Fig. 2. Physical maps of the human and mouse NNX3 genes.

The maps displays the position of the nine identified exons (filled blocks) for the human NNX3 and the mouse NNX3 genes. The restriction pattern was obtained with

1S the YAC clone, YAC 91 E10 and the lambda phage clones indicated by λ FM4.1 ; λ FM1.1 ; λ FM5.1 with the following restriction enzymes: EcoRI (E), Hindill (H), BamHI (B). The numbers in the open boxes represent the approximate sizes of the restriction fragments in kilobases. The scale is indicated by the bar (upper right-hand corner).

Fig. 3. Expression of Human NNX3 and Mouse NNX3 in COS-1 cells.

Panel A. Western blotting of COS-1 ceils transfected with pSG5 (lane 3, control) and constructs containing the cDNA coding for human NNX3 (lane 2) and mouse NNX3 (lane 1 ). Cell extracts were electrophoresed on a 4-20 % gradient acrylamide gel and transferred to nitrocellulose membrane. Polyclonal F17 antibody against human NNX3 was used to detect mouse and human NNX3. Molecular size markers are indicated at the left in kDa. Panel B. COS-1 cells transfected with a plasmid coding for human NNX3 were metabolically labeled with f³⁵ Sjmethionine for 4 h. Cells were solubilized and NNX3 was immunoprecipitated with 5 μl of antiserum F17 (lane 1 ) or 10 μl of antiserum F17 (lane 2) . Immunoprecipitates were resolved by 4-20% gradient SDS-PAGE. COS-1 cells transfected with pSG5 were labeled, extracted and immunoprecipitated with 5 μl of antiserum F17 (lane 3, control). Panel C. Analysis of NNX3 phosphorylation. COS-1 cells transfected with pSG5 (lane 1 ) and constructs containing the cDNA coding for human NNX3 (lane 2) and mouse NNX3 (lane 3) were labeled with [³²P] orthophosphate and NNX3 was immunoprecipitated using antiserum F17 and resolved by 4-20 % gradient acrylamide gel. Panel D. Thin layer chromatography of hydrolyzed human NNX3 identifying serine as the phosphorylated residue. The mobility of phosphoserine (S), phosphothreonine (T), or phosphotyrosine (Y), as detected by ninhydrin staining, is indicated by the dotted lines.

Fig. 4. Immunofluorescent staining of human NNX3 in transfected COS-1 cells.

COS-1 cells transfected with plasmids coding for human NNX3 (A), human NNX3 trunc.1 (stop signal created in the human NNX3 cDNA sequence at position 828- 830, fig. 1 ) (B) and human NNX3 trunc.2 (stop signal created in the human NNX3 cDNA sequence at position 915-917, fig. 1 ) (C) were fixed and permeabilized with acetone. Immunostaining was done with affinity purified antiserum, against human NNX3 protein, followed by the appropriate FITC conjugated secondary antibody. A perinuclear staining was observed in all three forms of human NNX3 constructs.

Fig. 5. Intracellular distribution of mouse NNX3 in neurons.

Cortex neurons were fixed and the intracellular distribution of NNX3 expression in neurons was done by immunofluorescence using the F17 polyclonai antibody against human NNX3 (B) and a control by using only GAR-FITC as second antibody (A).

Fig. 6. Analysis of mRNA expression of NNX3 and Restin in human cells, tissues and cancer cell lines. Multiple Tissue Northern (MTN ™) blots (Clontech) with poly A RNA from human tissues (heart, brain , placenta, lung, liver, sceletal, muscle, kidney, pancreas, uterus, colon, small intestine, bladder, stomach and prostate) and human cancer cell lines, were hybridized with the human NNX3 cDNA probe (A, B, C) and with Restin cDNA probe (D, E). A pronounced expression in skeletal muscle is seen for NNX3 as well as for Restin. A strong signal is obtained in the cell line Colorectal adenocarcinoma SW480 and lung carcinoma A-549 for NNX3 as well for Restin.

Fig. 7. Analysis of mRNA expression of NNX3 in mouse tissues and embryos at different stages. Northern blotting of mRNA extracts of adult mouse tissues (brain, liver, heart, lung, kidney and muscle) (panel A) and whole embryos at stages E6, E7, E8.5 (panel B) E1 1 , E13, E15, E17, E19, P1 and P2 (panel C) were hybridized with the mouse NNX3 cDNA probe. A mouse NNX3 message of 2.9 kb was detected in most adult mouse tissues and in whole embryos with highest levels in brain, kidney and muscle. The mRNA marker is indicated at the left in kilobases. EXAMPLES

Example 1 : cDNA cloning of human and mouse NNX3.

Partial cDNA fragments coding for human NNX3 were obtained by PCR amplification with degenerated primers based on the N-terminal and the internal amino acid sequences of a previously isolated and characterized, novel human plasma protein (Van Leuven et al., 1993). Among others, one amplicon of about 1kB was prominently and consistently present in PCR reactions performed on different cDNA libraries generated from human embryonal and adult tissues, i.e. liver, brain, kidney and placenta. Similarly, the same amplicon was observed in RT-PCR reactions on total or purified mRNA, extracted from human cells and tissues. The 1 kB amplicon was cloned and sequenced, demonstrating that it did not represent the desired cDNA but a completely novel cDNA, designated NNX3. Human NNX3 cDNA clones were isolated from a human liver cDNA library (Uni-Zap, Stratagene, La Jolla, CA). Positive clones were excised, handled and characterized by restriction analysis and complete sequencing as described (Van Leuven et al., 1995). The complete human NNX3 cDNA was obtained as a Sstll-Xhol restriction fragment and ligated into the adapted multiple cloning site of the pSG5-plasmid (Stratagene, La Jolla, CA). Screening of the library yielded 6 clones with inserts from 1.8 to 2.2 kb, producing a consensus cDNA sequence of 2174 bp, tailed by 28 adenosines and containing a single open reading frame of 458 codons.

Mouse NNX3 cDNA was isolated by PCR amplification of a mouse brain cDNA library (Uni-Zap, Stratagene, La Jolla, CA) with forward primer 5'- CGGGy4TCCCAAGAGAGGCTGAGGACC-3', wherein the italics denote a BamHI restriction site and with reverse primer 5' GAΛG>4TC7TCCCAATGCCACTGATAA 3', in which italics denote a Bglll restriction site. The resulting 1.6 kb amplicon was restricted and ligated in a modified and adapted BamHI-Bglll pSG5-plasmid (Stratagene, La Jolla, CA). The mouse and human NNX3 cDNA sequences are 76% identical, while the mouse open reading frame contains 1 codon less, i.e. only 457 codons. The predicted proteins has 75% sequence identity and 82% sequence similarity with most differences concentrated in 4 smaller areas (boxed in fig 1). Human NNX3 protein contains 7 cysteine residues of which only 3 are positionally conserved in mouse NNX3. One conserved cysteine marks the sequence CSDTSES, present twice in human NNX3 but only once in mouse NNX3 (position 343) leaving open the functional importance, if any, of the extra copy in human NNX3.

The predicted protein structures do not reveal hydrophobic regions qualifying either as signal peptide or as transmembrane domain. Most remarkable in the sequence is the stretch of acidic residues in the middle of both proteins, and consisting of 16 aspartic acid residues in human NNX3 interrupted by 2 uncharged residues and of 18 aspartic and glutamic acids in mouse NNX3 (fig 1 ). This region must be exposed and mobile, separating or hinging two structural half-molecules. The N-terminal domains are most identical in human and mouse NNX3 with a strong α-helical propensity. Positions 44 to 60 are predicted as a bipartite nuclear targeting motif, i.e. an interrupted cluster of basic residues (underlined in fig 1 )(Dingwall and Laskey, 1991 ). A less clear-cut, but possible second nuclear localization signal might be conserved at positions 284 to 293. Predictions about the structure of the carboxy- terminal domain are equivocal, combining regions with α-helical and β-sheet propensity and many possible turns and coils. The carboxy-terminal domain displays less sequence identity between human and mouse NNX3, although the mismatches are again concentrated in two larger areas as in the N-terminal domain (boxed in fig 1 ). Many other signatures and motifs (i.e. glycosylation, phosphorylation and myristoylation) are predicted by the Prosite software program, of which phosphorylation was experimentally verified (see below).

Example 2: Cloning of the human and mouse NNX3 gene Human YAC screening and subcloning. The CEPH human YAC library (Albertsen et al., 1990) was screened by pulsed field gel electrophoresis and southern blotting of pooled YAC clones (Mendez et al., 1991 ). Positive clones were purified by standard colony hybridization techniques as previously detailed (Hilliker et al, 1992). Restriction digests of YAC clones in agarose blocks were separated on 0.7 or 1% agarose gels in O.δxTBE (45 mM Tris, 45 mM sodium borate, 1 mM EDTA, pH 8.3), transferred to nylon membranes and hybridized with radiolabeled probes as described (Hilliker et al., 1994). The screening of the YAC library produced 5 YAC clones. Restrictions with EcoRI, BamHI and Hindlll demonstrated all YAC clones to contain the NNX3 gene, but 3 clones were recombinant or hybrids. Only YAC clones 91 E10 and 854D2 contained the human NNX3 gene in identical large restriction fragments. EcoRI and Hindlll fragments were subcloned for exon identification by a combination of restriction digests, southern blotting and sequencing of the exon-intron boundaries. The size of the introns was determined by PCR and by restriction analysis. Subclones and digests were mapped and arranged by southern blotting with small human NNX3 cDNA probes, in comparison with digests of YAC 91E10 and of human genomic DNA. Nine exons were thus identified, representing the entire open reading frame identified in human NNX3 cDNA (fig 2, table 1).

Mouse genomic DNA lambda phage library screening

The mouse NNX3 gene was cloned from a lambda genomic library, screened with human NNX3 cDNA probes. Lambda phage libraries (lambdaGEMH , Stratagene, La Jolla, CA) plated on E. coli KW251 on NZYDT-agar substrates were replicated on nylon filters, hybridized with radiolabeled NNX3 cDNA probes, essentially as described (Van Leuven et al., 1995). After post hybridization washes at the appropriate stringency, filters were exposed at -70°C (Hyperfilm-MP, Amersham, UK). Positive plaques were isolated and rescreened until purity. Inserts from single clones were analyzed by restriction analysis and southern blotting and subcloned as EcoRI and HindDIII restriction fragments into pUC and pBS plasmids for sequencing (Van Leuven et al., 1993; Van Leuven et al., 1995).

The screening resulted in 3 and 6 clones, respectively representing the 5' and 3' parts of the gene. Comparative mapping by restriction and southern blotting yielded lambda clones FM1.1 , FM4.1 and FM5.1 containing the exons of the murine NNX3 gene. Subcloning in plasmids for exon-intron boundary sequencing and intron sizing was performed as described for the human gene.

Intron-exon analysis

The nine exons in both genes were completely sequenced on subcloned genomic DNA without revealing conflicts with human and mouse cDNA sequences. The resulting genes were very similar if not identical in overall structure with only minor differences in size of introns. Alignment of the protein sequences and comparison with the exon structure underlined that the same exons code for the same domains in both genes. Intron 2 was not completely cloned from the human YAC 91 E10, nor was it retrieved in the lambda clones representing the mouse gene. The size of intron 2 was estimated by pulsed field gel electrophoresis to equal about 50 kB in both genes. The position of YAC 854D2 in a well-defined contig on chromosome 19q (Gordon et al., 1995; Stubbs et al., 1996; chromosome 19 map at www- bio. llnl.gov/bbrp/genome/genome. html). This was confirmed by FISH with YAC 91 E10 derived probes, mapping the human NNX3 gene to 19q12.

Example 3: bacterial expression, isolation of NNX3 protein and generation of antisera.

A partial cDNA fragment of the human NNX3 cDNA, i.e. a 1.4 kB EcoRI fragment, positions 198 to 1577) was ligated in the pGEMEXI vector and expressed in JM109(DE3) cells, induced with IPTG as instructed (Promega, Madison, Wisconsia). Bacterial pellets were extracted with 1% SDS in 45 mM Tris, 45 mM sodium borate (pH 8.3) and the 50 kDa fusion protein separated by electrophoresis in 3% Nusieve- GTG-agarose (FMC, Rockiand, ME). The gel was cut in 1 mm slices and the fractions containing pure fusion protein as identified by SDS PAGE, homogenized in complete Freund's adjuvant and used to immunize rabbits intradermally 4 times with two-week intervals. Blood was taken by heart-puncture and the anti-serum collected and tested by western blotting on recombinant fusion proteins and on transfected COS ceils. For immunofluorescence analysis and immunohistochemistry, the antiserum was affinity-purified by adsorption on the recombinant NNX3 fusion protein immobilized by electro-transfer on nylon membranes ( Rybicki et al., 1986; Olmsted et al., 1981).

Example 4: expression in transfected COS cells

Human and mouse NNX3 proteins were expressed by transfection in COS1 cells and analyzed by western blotting and immunoprecipitation with polyclonal antisera raised in rabbits against a recombinant bacterial fusion protein of part of human NNX3.

Therefore, human and mouse NNX3 cDNA was ligated in pSG5 plasmid for transfection into COS1 cells by DEAE-dextran and lipofectamine methods as indicated. After 48 h, cells were metabolically labeled for 4 hours with 100 mCi/ml [³⁵S]methionine in methionine-free medium or with 500 mCi/ml [³²P]phosphoric acid. Cells were washed, collected by scraping and extracted by homogenization with 0.5% Triton-X-100 in 50 mM Tris (pH 8.0) containing 0.15 M NaCI, 100 mg/ml aprotinin, 1 mg/ml pepstatin, 1 mM sodium vanadate, 5 mM EDTA, 5 mM EGTA, 20 mM NaF. After centrifugation (150.000 g, 15 min, 4°C), immunoprecipitation was performed with specified antisera (final dilution of 1/200, 4°C, 1 hour). Immune complexes were collected on protein A-sepharose beads (Pharmacia, Uppsala, Sweden) by continuous mixing (overnight, 4°C). The pelleted immunoprecipitates were washed three times with cold IP-buffer, i.e. 10 mM Tris, pH 8.3 containing 0.15 M NaCI, 1 %(v/v) Triton-X-100, 1 %(w/v) deoxycholate, 0.1 %(w/v) SDS. The proteins were solubilized by boiling in 1 % (w/v) SDS and 1 % (v/v) 2-mercaptoethanol before separation on 4-20% SDS-PAGE gels (Novex, San Diego, CA). The gels were dried and processed for autoradiography. For western immunoblotting, transfected COS cells were solubilized in 10 mM Tris, 0.15 M NaCI, 1 % (w/v) SDS by boiling for 5 min. The proteins were separated and transferred to nitrocellulose membranes (Hybond-C, Amersham, UK). Primary antisera and affinity-purified fractions were diluted as indicated, incubated with the membranes overnight at 4°C, and revealed with affinity-purified peroxidase labeled goat anti-rabbit antibodies (diluted 1/10000; Biorad Labs, Hercules, CA) using the ECL system (Amersham, UK). Affinity-purified antisera revealed human NNX3 protein to migrate as a closely spaced doublet of equally intense bands of 64-66 kDa (Fig 3A), considerably higher than the predicted value of about 51 kDa. Similar experiments with mouse NNX3 cDNA confirmed the aberrant slow migration, but revealed only one major protein species of about 70 kDa (Fig 3A). A weakly reacting protein was always detected at about 62 kDa, equal in size to the smaller human NNX3 isoform (fig 3A). The secondary antibody used, reacted weakly and aspecifically with a 50 kDa protein in western blots also in untransfected COS1 cells (fig 4). Immunoprecipitation of human NNX3 from transfected COS cells after metabolic labeling with [35S]methionine also yielded the doublet of 62-66 kDa proteins (fig 3B). Incorporation of radioactive [32]phosphate in transfected COS1 cells and immunoprecipitation resulted in a stronger labeling of the largest 66 kDa isoform of human NNX3, while mouse NNX3 labeled very weakly with radioactive phosphate (fig 3C). Hydrolysis of the radiolabeled bands identified mainly phosphoserine, while phosphotyrosine was not detected (fig 3C).

Localization of NNX3 in the cell was carried out using immunofiuorescence microscopy.

Transfected COS1 cells, cultured on chamber slides, were fixed and permeabilized with cold acetone for 10 min. After washing and blocking with 10% swine serum in PBS, slides were incubated with affinity purified anti-NNX3 for 30 min, washed and incubated with FITC-conjugated swine anti-rabbit IgG antibodies (1/500 in PBS with 10% swine serum). Mouse organs were flushed and fixed by trans-cardiac perfusion of anesthesized animals with saline and 4% paraformaldehyde, respectively. Organs were dissected and fixed overnight at 4°C. Vibratome sections of 50 mm were stored in PBS with 0.1 % sodium azide at 4 °C until used. Mouse embryos of gestational days 12 to 18 were fixed overnight in 4% paraformaldehyde, dehydrated and embedded in paraffin for sectioning. Microtome sections (5mm) were dewaxed, rehydrated, treated with hydrogen peroxide (1 %) to eliminate endogenous peroxidase activity and microwaved in 10 mM citrate buffer pH 6 for 15 min at 450 W. After blocking with 5% goat serum in 50 mM Tris (pH 8.0), 0.15 M NaCI, 0.1 % Triton-X100, sections were incubated overnight at 4°C with affinity purified rabbit anti-NNX3, followed by peroxidase-conjugated goat anti-rabbit antibodies (dilution 1/100). Immune complexes were detected with 0.075 % 3,3-diaminobenzidine and 0.01 % hydrogen peroxide. Primary cultures of mouse embryonal neurons were maintained for up to 14 days to allow differentiation, before being fixed and treated for NNX3 immunoreactivity, performed as described previously (de Hoop et al., 1995; Tiennari et al., 1996; De Strooper et al., 1997).A series of sections from normal human tissues and tumors was screened for expression of NNX3 by immunohistochemistry. The samples were obtained for routine diagnosis at the pathology department and remnant tissue was used for this study. Cells and tissues were frozen and stored at -70 °C until used. Sections (5 mm) were used routinely for immunohistochemical detection of NNX3, as for the analysis of mouse tissues, with the exception that colorimetric detection was performed with amino-ethyl carbasole and hydrogen peroxide.

Immunofiuorescence microscopy on transfected COS cells with affinity-purified antibodies to human NNX3 protein, revealed a typical cytoplasmic staining pattern with some tendency for association with the endoplasmic reticulum (fig 4). Untransfected COS1 cells stained only very weakly, corroborating western blotting and immunoprecipitation data and demonstrating that the monkey equivalent of NNX3 was not expressed in the COS1 cell-line used. Cell-fractionation experiments confirmed that human and mouse NNX3 proteins were recovered mainly in the post- microsomal supernatant, with less than 5 and 10% recovered in the nuclear and microsomal pellets, respectively, in parallel studies, however, a nuclear staining in neurons in embryonal mouse brain was noticed (see below). To exclude artifacts from culture conditions or manipulation induced changes, COS ceils were transfected with two different versions of a truncated NNX3 protein, i.e. the N- terminal domain containing the predicted bipartite nuclear targeting signal, with and without the "acid-hinge" region. Both of these truncated proteins were, however, located in the cytoplasm, very similar to the parent, full-length human NNX3 protein (fig 4). Primary cultures of mouse embryonal cortical and hippocampal neurons were analyzed for endogenous mouse NNX3 by immunofiuorescence with the same affinity purified antibody. Mouse NNX3 protein was detected in the cytoplasm both in the nerve cell bodies and in the dendritic processes, leaving the nucleus essentially unstained (fig 5).

Example 5: Analysis of expression of NNX in human and mouse tissues. Cells and tissue RNA was extracted with trizol reagent and RNA was analyzed by northern blotting with radiolabeled human and mouse NNX3 cDNA probes, essentially as described (Lorent et al., 1995; Overbergh et al., 1995). Lung carcinoma specimens and established human SCLC cell lines were processed as described (Roebroek et al, 1993). Multiple Tissue Northern blots (MTN™, Clontech, Palo Alto, CA) carrying poly-adenylated mRNA from different human tissues and from human cancer cell-lines, were hybridized as instructed with radiolabeled NNX3 or Restin cDNA (Delabie et al., 1993).

Northern blots of RNA extracted from different human tissues demonstrated NNX3 mRNA to be expressed as a 2.6 kB mRNA transcript in many tissues, but most pronounced in skeletal muscle on two independent northern blots, and lesser signals in brain, hart and pancreas (fig 5). The same blots were also probed for Restin mRNA (about 7kB, Delabie et al., 1992) revealing a remarkable parallel in expression relative to that of NNX3 in normal human tissues (fig 6). The equivalent mouse NNX3 mRNA was similarly detected in many adult mouse tissues analyzed, with highest levels in brain and kidney (fig 7). Extracts of mRNA from whole mouse embryos at stages E6 to P2 revealed that the NNX3 gene was active relatively early in development, with highest expression in the second week of gestation (Fig 7).

Affinity-purified antibodies to NNX3 immunostained many mouse tissues. Most intense staining was evident in the system including the developing brain, spinal cord, ganglia, choroid plexus and olfactory epithelium (fig. 8). Also skin (mainly the stratum germinativrum), lung, kidney, testis and muscular structures displayed high immunoreactivity. On both cardiac and skeletal muscle, especially the cross- striations were heavily stained (fig. 8). On the liver megakaryocytes stained strongly while the number of immunopositive hepatocytes decreased with increasing embryonic age. Remarkable was the strong immunoreactivity of epithelia, including intestinal stomach and tongue epithelium, and of ductular structures such as bronchi and bronchioli in the lung, submandibular and sublingual ducts, proximal and distal convoluted tubules as well as collecting tubules in the kidney, ureter, urethra and vas deferens (fig. 8). The expression of NNX3 analyzed in the available samples of human tissues, largely that in mouse tissues, with expression particularly strong in skeletal muscle and ganglion cells.

In adult mouse brain, immunoreactivity was concentrated in neuronal somata and the proximal neurites, while dendrites were stained over their entire length in the cortex and the hippocampus. Neurons (interneurons), in stratum oriens, stratum radiatum and stratum moleculare lacunsum displayed prominent staining, while the most definite immunostaining was present in neurons in the posterior thalamic nuclei, the geniculate nuclei, in substantia nigra and zona incerta. Weak staining of granular cells in the dentate gyrus contrasted with strong staining of neurons in the hilus. Finally, ependymal cells were clearly stained, while reaction with celis in white matter, presumably microglia, was weak.

Corroborating the strong immunoreactivity in mouse lung, NNX3 mRNA was expressed at relatively high levels in a variety of cell lines derived from human small ceil lung carcinoma (SCLC) patients (Roebroek et al, 1989). Expression of NNX3 mRNA was detected in all SCLC cell lines while non-SCLC primary tumors or cell- lines were negative (Table 2 and 3). Interestingly, NNX3 was not detected in many common human tumor specimens when analyzed by immunohistochemistry, i.e. NNX3 was absent in non-Hodgkin's lymphomas, malignant melanomas and soft tissue tumors, including rhabdomyosarcoma. Surprisingly, NNX3 protein was clearly expressed in Reed-Sternberg cells in Hodgkin's disease (fig 8). The specific staining for NNX3 in most of these specimens demonstrated conclusively that NNX3 must be regarded as a new marker for at least a subset of these tumors, and eventually of other tumors. It is unclear at the moment why the NNX3 protein was expressed at easily detectable levels in many cultured tumor derived cell lines and not in many primary tumor tissues.

ZA TABLE 1

Exon-intron Structure and Boundary Sequences of the Human NX3 and the Mouse NNX3 Genes

Human NNX3 gene

-1 -lll-(-77) ttcatgacag GTGGTCACTA <35bp) TCCAGCATTG gtgagtgaaa (5.0kb)

1 -76-3 cctgtcacag GAAGAAGGTA (79bp) TAATATAATG gtatgtctgg (l.Okb)

2 4-139 taaacaatag GTACCATTTG (136bp) CGGAAAGAAC gtaggtaccc (>12.5kb

3 140-231 attgtttcag ATGTAAGAAA (92bp) AATGAGCGAT gtgagtattt (198b)

4 232-294 taaaaaccag GCTGCAGGTG (63bp) GAATTTAAAG gtaagcagta (2.1kb)

5 295-463 ttctaaatag CAAAACACCG (169bp) AACTTGATAG gtaagcctga (1.4kb)

6 464-809 tccttgctag TAAGCCTGAT (346bp) GCCTAAGAGG gtttgtatac (1.7kb)

7 810-952 gaaattttag GTCCGAATAA (143bp) ACATTTACAG gtgggaggcg (l.lkb)

8 953-1199 aacatcacag AGCCTTTGTT (247bp) AACACCTGAG gtgtgtgtgt (2.2kb)

9 1200- tgttttctag GCTTTTTCTG

Mouse NNX3 gene

1 -76-3 tcctcatcag GGAGAAAGTA (79bp) CGCAGTCATG gtatgctcac (1. ,0kb)

2 4-139 aaaccaatag GTACCATTCG (136bp) CGGAAAGAAC gtaggtacct (?)

3 140-231 gtgttttcag ATGTAAGAAA (92bp) GATGAGTGAT gtgggtattg (168b)

4 232-294 taaaaattag GCTGCAGGTG (63bp) GAATTTAAAG gtaagtaatg (2. ,0kb)

5 295-463 ttttaaacag GAAAACAACG (169bp) AACTTGAAAG gtgcttaatg (2. , Okb)

6 464-811 catcatctag TAAACCTGAT (348bp) ACCTAAAAGG gtttgtatac (1. , 6kb)

7 812-951 ttaattttag GTTCGAATAA (140bp) ATATTTACAG gtgcgtgatg (0. .6kb)

8 952-1195 aatgctgtag AGTCTTCGTG (244bp) AGTGTCTGAG gtgtgtgtct (0. .45kb)

9 1196- tgtcttacag GCTTTTTCTG

Note: Each exon is numbered in the first column and is tabulated with its location in the cDNA sequences. Also given are the sequences of the exon-intron boundaries, with intron sequences in lowercase and exon sequences in uppercase, taking the first base of the ATG codon as position 1. The size of each exon is given m basepairs as determined by sequencing of the subcloned genomic DNA. In the last column the sizes of the intervening sequences, as determined by restriction analysis and mterexon PCR, are listed.

TABLE 2

Expression of NNX3 gene in human lung carcinoma cell lines

Lung cancer cells Classification NNX3 expression

GLC-1-M13 SCLC-C ++

SCLC-21H SCLC-C ++

SCLC-22H SCLC-C ++

SCLC-16C SCLC-C ++ NCI-H249 SCLC-C +

GLC-1 SCLC-V SCLC-16V SCLC-V

NCI-H82 SCLC-V

NCI-N417 SCLC-V

NCI-H524 SCLC-V

NCI-H526 SCLC-V NCI-H446 SCLC-V

NL-SCLC3 SCLC-V

TABLE 3

Expres sion of NNX3 gene m primary human lung tumors

Primary tumors Tumors Level of NNX3 express ion

Tested + ++ ( * ) + ( * ) -

SCLCs 6 3 0 3 0 non-SCLCs

-adenocarcmomas 6 0 4 2 0 -squamous cell carcinomas 7 0 4 3 0

Carcmoid tumors 4 0 2 1 1

^r) After prolonged (120h) exposure of X-ray film

REFERENCES

Albertsen, H.M., Abderrahim, H., Cann, H.M., Dausset, J., Le Postier, D, and Cohen, D. (1990). Construction and characterization of a yeast artificial chromosome library containing seven haploid human genome equivalents. Proc. Natl. Acad. Sci. USA 87 (11), 4256-4260.

Chan, W. O, and Delabie, J., (1995). Hodgkin's Disease . Amer. J. Clin. Pathol. 104, 368-370.

de Hoop, M., von Poser, O, Lange, O, Ikonen, E., Hunziker, W. and Dotti, C.G. (1995). Intracellular Routing of Wild-Type and Mutated Polymeric Immunoglobulin Receptor in Hippocampal Neurons in Culture. Journ. Cell Biology 13, 1447-1459.

Delabie, J., Shipman, R., Brϋggen, J., De Strooper, B., Van Leuven, F., Tarcsay, N., Cerletti, N., Odink, K., Diehl, V., Bilbe, G. and De Wolf-Peeters, C. (1992a). Expression of the novel intermediate filament-associated protein Restin in Hodgkin's disease and anaplastic large-cell lymphoma. Blood, 80, 2891 -2896.

Delabie, J., Bilbe, G., Brϋggen, J., Van Leuven, F. and De Wolf-Peeters, C. (1993). Restin in Hodgkin's Disease and Anaplastic Large Cell Lymphoma. Leukemia and Lymphoma 12, 21 -26.

De Strooper, B., Contreras, B., Levesque, L., Crassaerts, K., Cordell, B., Moechars, D., Bollen, M., Fraser, P., St. Georg-Hyslop, P. and Van Leuven, F. (1997). Phosphorylation, subceiluiar localization and membrane orientation of the Alzheimer's Disease associated Presenilins. J. Biol. Chem.272, 3590-3598.

Diehl, V., von Kail, O, Fonatsch, C, Tesch, H., Jϋecker, M and Schaadt, M. (1990). The cell of origin in Hodgkin's disease. Sem. One. 6, 660-672.

Dingwall, O, Laskey, R.A. (1991 ). Nuclear targeting sequences - a consensus? Trends Biochem. Sci. 16(12), 478-481.

Drexler, H.G. (1992). Recent results on the biology of Hodgkin and Reed-Sternberg cells. I; Biopsy Material. Leuk. Lymph. 8, 283-313.

Gordon, L.A., Bergmann, A., Christensen, M., Danganan, L., Lee, D. A., Ashworth, L. K., Nelson, D. O., Olsen, A.S., Mohrenweiser, H. W., Carrano, A. V., and Brandriff, B. F. (1995) A 30-Mb Metric Fluorescence in Situ Hybridization Map of Human Chromosome 19q. Genomics 30, 187-192.

Hilliker, C, Overbergh, L., Van Leuven, F. and Van Den Berghe, H. (1992). Assignment of mouse alpha-2-macroglobulin gene to chromosome 6 band F1-G3. Mamm. Genome 3, 469-471. Hilliker.O, Delabie, J., Speleman, F., Bilbe, G., Bruggen, J., Van Leuven, F. and Van Den Berghe, H. (1994). Localization of the gene (RSN) coding for restin, a marker for Reed-Sternberg cells in Hodgkin's Disease, to human chromosome band 12q24.3 and YAC cloning of the locus. Cytogenet. Cell Genet. 65, 172-176.

Lorent, K., Overbergh, L., Moechars, D., De Strooper, B., Van Leuven, F. and Van Den Berghe, H. (1995) Expression in mouse embryos and in adult mouse brain of three members of the amyloid precursor protein family, of the alpha-2-macroglobulin receptor/low density lipoprotein receptor-related protein and of its ligans apolipoprotein E, lipoprotein lipase, alpha-2-macroglobulin and the 40,000 molecular weight receptor- associated protein. Neurosci. 65, 1009-1025.

Mendez, M.J., Klaphols, S., Brownstein, B., H. and Gemmill, R.M. (1991 ). Rapid screening of a YAC library by pulsed-field gel Soutern blot analysis of pooled YAC clones. Genomics 10, 661-665.

Olmsted, J.B., (1981 ). Affinity purification of antibodies from diazotized paper blots of heterogeneous protein samples. J. Biol. Chem. 256, 1 1955-1 1957.

Overbergh L., Lorent, K., Torrekens, S., Van Leuven, F. and Van Den Berghe, H. (1995). Analysis of expression of the Alpha-2-Macroglobulin proteinase inhibitors, the Lipoprotein Receptor Related Protein, the Receptor Associated Protein, the Low Density Lipoprotein Receptor, Apolipoprotein E and Lipoprotein Lipase during pregnancy and development of the mouse. J. Lipid. Res. 36, 1501-1513.

Pierre, P., Scheel, J., Rickard, J.E. and Kreis, T.E. (1992) CLIP-170 Links Endocytic Vesicles to Microtubules. Cell 70, 887-900.

Rickard, J.E. and Kreis, T.E. (1996). CLIPs for organellemicrotubule interactions. Cell Biology 6, 178-183.

Roebroek, A.J., Martens, G.J., Duits, A.J., Schalken, J.A., Van Bokhoven, A., Wagenaar, S.S. and Van de Ven, W.J.M. (1989). Differential expression of the gene encoding the novel pituitary polypeptide 7B2 in human lung cancer cells. Cancer Res. 49, 4154-4158.

Stein, H. Herbst, H. Anagnostopoulos, I., Niedobitek,G., Dallenbach, F. And Kratsch, H.-C. (1991 ). The nature of Hodgkin's and Reed-Sternberg celis, thei association with EBV and their relationship to anaplastice large cell lymphoma. Ann. One, 2, 33s-38s.

Stubbs, L., Carver, E.A., Shannon, M.E., Kim, J., Geisler, J., Generosa, E.E., Stanford, B.G., Dunn, W.C., Mohrenweiser, H., Zimmermann, W., Watt, S.M. and Ashmorth, L.K. (1996). Detailed Comparative Map of Human Chromosome 19q and Related Regions of the Mouse Genome. Genomics 35, 499-508. Rybicki, E.P. (1986). Affinity purification of specific antibodies from plant virus capsid protein immobilised on nitrocellulose. Journal of Phytopathology 116, 30-38.

Stubbs, L., Carver, E.A., Shannon, M.E., Kim, J., Geisler, J., Generosa, E.E., Stanford, B.G., Dunn, W.C., Mohrenweiser, H., Zimmermann, W., Watt, S.M. and Ashmorth, L.K. (1996). Detailed Comparative Map of Human Chromosome 19q and Related Regions of the Mouse Genome. Genomics 35, 499-508 .

Tienari, P.J., De Strooper, B., Ikonen, E., Simons, M., Weidemann, A., Czech, C, Hartmann, T., Ida, N., Multhaup, G., Masters, C.L., Van Leuven, F., Beyreuther, K. and Dotti, C.G. (1996). The β-amyloid domain is essential for axonal sorting of amyloid precursor protein. EMBO Journal 15(19), 5218-5229.

Van Leuven, F., Torrekens, S., Van Damme, E., Peumans, W. and Van Den Berghe, H. (1993). Mannose specific lectins binds A2M and an unknown protein from human plasma. Protein Science 2, 255-263.

Van Leuven, F., Stas, L., Hilliker, C, Lorent, K., Umans, L., Serneels, L., Overbergh, L.,Torrekens, S., Moechars, D., De Strooper, B. and Van Den Berghe, H. (1995). Structure of the gene LRP1 coding for the human Alpha-2-macroglobulin/Lipoprotein receptor related protein. Genomics 24, 78-89.

Claims

1. An isolated purified protein comprising an amino acid sequence with 70-100 % homology to the sequence depicted in SEQ ID NO. 2 and/or a functional fragment thereof.

2. An isolated purified protein comprising an amino acid sequence with 70-100 % homology to the sequence depicted in SEQ ID NO. 4 and/or a functional fragment thereof.

3. A nucleic acid encoding a protein according to claim 1 or 2.

4. A nucleic acid with about 70-100% homology to the sequence depicted in SEQ ID NO.1 .

5. A nucleic acid with about 70-100% homology to the sequence depicted in SEQ ID NO. 3.

6. A specific probe based on a nucleic acid sequence according to any of the claims 3 to 5.

7. A specific probe according to claim 6 comprising at least 15 contiguous nucleotides selected from a nucleic acid sequence according to any claims 3 to 5.

8. Antibodies directed against a protein according to claim 1 or 2 or an antigenic fragment thereof.

9. An assay for screening the expression of a nucleic acid according to any of the claims 3 to 5 and/or the production of a protein according to claim 1 or 2.

10. An assay according to claim 9 comprising the immunological detection of a protein according to claim 1 or 2 or an antigenic fragment thereof.

1 1. An assay according to claim 9 comprising the detection and/or amplification of a nucleic acid according to any of the claims 3 to 5.

12. An expression vector comprising a nucleic acid molecule comprising at least 15 contiguous nucleotides of a nucleic acid sequence according to any of the claims 3 to 5 operably linked to a promoter sequence.

13. A (recombinant) host cell wherein said host cell has been transformed and/or transfected with an expression vector according to claim 12.

14. The host cell of claim 13 wherein said host cell is selected from the group consisting of bacterial, mammalian, plant, fungal or insect cells.

15. Transgenic, non human animal, in which the expression of a nucleic acid according to any of the claims 3 to 5 is upregulated, downregulated or eliminated in a specified tissue and/or in cells in embryonic and/or adult life.

16. Use of NNX3 mRNA and/or protein as a tumor marker, in particular for lung tumors.

17. Use of NNX3 mRNA and/or protein as a marker for Hodgkin's disease.

18. Use of an isolated purified protein and/or a functional fragment thereof according to claims 1 or 2 as a medicament.

19. A pharmaceutical composition comprising one or more isolated purified proteins according to claims 1 or 2 and/or a functional fragment thereof and pharmaceutically acceptable carrier material.

20. Use of a protein according to claims 1 or 2 and/or a functional fragment thereof for the manufacture of a pharmaceutical composition to treat lung tumors and/or Hodgkin's disease.