Serpentine transmembrane antigens expressed in human cancers and uses thereof

Abstract

Described is a novel family of cell surface serpentine transmembrane antigens. Two of the proteins in this family are exclusively or predominantly expressed in the prostate, as well as in prostate cancer, and thus members of this family have been termed “STEAP” (Six Transmembrane Epithelial Antigen of the Prostate). Four particular human STEAPs are described and characterized herein. The human STEAPs exhibit a high degree of structural conservation among them but show no significant structural homology to any known human proteins. The prototype member of the STEAP family, STEAP-1, appears to be a type IIIa membrane protein expressed predominantly in prostate cells in normal human tissues. Structurally, STEAP-1 is a 339 amino acid protein characterized by a molecular topology of six transmembrane domains and intracellular N- and C-termini, suggesting that it folds in a “serpentine” manner into three extracellular and two intracellular loops. STEAP-1 protein expression is maintained at high levels across various stages of prostate cancer. Moreover, STEAP-1 is highly over-expressed in certain other human cancers.

1 . A STEAP-2 protein having an amino acid sequence shown in FIG. 9A-D (SEQ ID NO: 8).  
     
     
         2 . A STEAP-2 polypeptide that includes at least 10 contiguous amino acids of an amino acid sequence selected from the group consisting of amino acids 1-245, 2-204, 100-108, 121-454, 153-165, 182-454, 183-387, 227-235, 276-453, 306-314, 307-315, 345-358, 402-410, and 419-454 of the amino acid sequence shown in FIGS.  9 A-D (SEQ ID NO: 8).  
     
     
         3 . A polypeptide comprising an amino acid sequence which is at least 90% identical to the amino acid sequence shown in FIGS.  9 A-D (SEQ ID NO: 8) over its entire length.  
     
     
         4 . A polynucleotide selected from the group consisting of (a) a polynucleotide having the sequence as shown in FIGS.  9 A-D (SEQ ID NO: 7), wherein T can also be U; (b) a polynucleotide encoding a STEAP-2 polypeptide whose sequence is encoded by the cDNA contained in plasmid 98P4B6-GTD3 as deposited with American Type Culture Collection as Accession No. PTA-311; (c) a polynucleotide encoding the STEAP-2 protein of  claim 1;  and (d) a polynucleotide which is fully complementary to a polynucleotide of (a)-(c).  
     
     
         5 . A polynucleotide that encodes the fragment of  claim 2 .  
     
     
         6 . A recombinant expression vector which contains a polynucleotide according to  claim 4  or  5 .  
     
     
         7 . A host cell which contains an expression vector according to  claim 6 .  
     
     
         8 . A polynucleotide according to  claim 4  or  5  which is labeled with a detectable marker.  
     
     
         9 . A process for producing a STEAP-2 protein comprising culturing a host cell of  claim 7  under conditions sufficient for the production of the polypeptide and recovering the STEAP-2 protein from the culture.  
     
     
         10 . An antibody or fragment thereof which specifically binds to an epitope within amino acids 1-245, 2-204, 100-108, 121-454, 153-165, 182-454, 183-387, 227-235, 276-453, 306-314, 307-315, 345-358, 402-410, or 419-454 of the STEAP-2 protein of  claim 1 .  
     
     
         11 . The antibody or fragment thereof of  claim 10  which is monoclonal.  
     
     
         12 . A recombinant protein comprising the antigen binding region of a monoclonal antibody of  claim 11 .  
     
     
         13 . The antibody or fragment thereof of  claim 10  or  11 , or the recombinant protein of  claim 12 , which is labeled with a detectable marker.  
     
     
         14 . The antibody or fragment thereof or recombinant protein of  claim 13 , wherein the detectable marker comprises a radioisotope, metal chelator, enzyme or fluorescent, bioluminescent or chemiluminescent compound.  
     
     
         15 . The antibody fragment of  claim 13 , which is an Fab, F(ab′)2, Fv or Sfv fragment.  
     
     
         16 . The antibody or fragment thereof of any one of claims  10 ,  11 ,  13  or  14 , which is a human antibody.  
     
     
         17 . The antibody of any one of claims  10 ,  11 ,  13  or  14 , which comprises murine antigen binding region residues and human antibody residues.  
     
     
         18 . A transgenic animal producing a monoclonal antibody of  claim 11 .  
     
     
         19 . A hybridoma producing a monoclonal antibody of  claim 11 .  
     
     
         20 . A single chain monoclonal antibody that comprises the variable domains of the heavy and light chains of a monoclonal antibody of  claim 11 .  
     
     
         21 . A vector comprising a polynucleotide encoding a single chain monoclonal antibody of  claim 20 .  
     
     
         22 . The monoclonal antibody or fragment thereof of  claim 11  which is conjugated to a toxin, a radioisotope or a therapeutic agent.  
     
     
         23 . The monoclonal antibody or fragment thereof of  claim 22 , wherein the toxin comprises ricin, ricin A-chain, doxorubicin, daunorubicin, a maytansinoid, taxol, ethidium bromide, mitomycin, etoposide, tenoposide, vincristine, vinblastine, colchicine, dihydroxy anthracin dione, actinomycin, diphtheria toxin, Pseudomonas exotoxin (PE) A, PE40, abrin, abrin A chain, modeccin A chain, alpha-sarcin, gelonin, mitogellin, retstrictocin, phenomycin, enomycin, curicin, crotin, calicheamicin, sapaonaria officinalis inhibitor, or a glucocorticoid.  
     
     
         24 . The monoclonal antibody or fragment thereof of  claim 22 , wherein the radioisotope comprises  212 I,  131 I,  131 In,  90 Y, or  186 Re.  
     
     
         25 . An assay for detecting the presence of a STEAP-2 protein in a biological sample comprising contacting the sample with an antibody of  claim 13 , and detecting the binding of STEAP-2 protein in the sample thereto.  
     
     
         26 . An assay for detecting the presence of a STEAP-2 polynucleotide in a biological sample, comprising: 
 (a) contacting the sample with a polynucleotide probe which specifically hybridizes to a polynucleotide of  claim 4;  and    (b) detecting the presence of a hybridization complex formed by the hybridization of the probe with STEAP-2 polynucleotide in the sample,    wherein the presence of the hybridization complex indicates the presence of STEAP-2 polynucleotide within the sample.    
     
     
         27 . An assay for detecting the presence of STEAP-2 mRNA in a biological sample comprising: 
 (a) producing cDNA from the sample by reverse transcription using at least one primer;    (b) amplifying the cDNA so produced using STEAP-2 polynucleotides as sense and antisense primers to amplify STEAP-2 cDNAs therein;    (c) detecting the presence of the amplified STEAP-2 cDNA,    wherein the STEAP-2 polynucleotides used as the sense and antisense primers are capable of amplifying the polynucleotide shown in FIGS.  9 A-D (SEQ ID NO: 7).    
     
     
         28 . A pharmaceutical composition comprising an antibody or fragment thereof according to  claim 10 ,  11 ,  15 ,  16  or  17 , a STEAP-2 protein according to  claim 1  or  2 , or a STEAP-2 polynucleotide according to  claim 4  or  5 , and a physiologically acceptable carrier.  
     
     
         29 . A vaccine composition comprising a STEAP-2 protein according to  claim 1  or  2 , or a STEAP-2 polynucleotide according to  claim 4  or  5 , and a physiologically acceptable carrier.  
     
     
         30 . A method of inhibiting the development or progression of a cancer expressing STEAP-2 in a patient, comprising administering to the patient an effective amount of the vaccine composition of  claim 29 .  
     
     
         31 . A method of inhibiting the growth of cells expressing STEAP-2 in a patient, comprising administering to the patient an effective amount of the vaccine composition of  claim 29 .  
     
     
         32 . A method of killing cells that express STEAP-2 in a patient, comprising administering to the patient an effective amount of the vaccine composition of  claim 29 .  
     
     
         33 . A method of treating a patient with a cancer that expresses STEAP-2, which comprises administering to said patient a vector encoding a single chain monoclonal antibody that comprises the variable domains of the heavy and light chains of a monoclonal antibody that specifically binds to a STEAP-2 protein of  claim 2 , such that the vector delivers the single chain monoclonal antibody coding sequence to the cancer cells and the encoded single chain antibody is expressed intracellularly therein.  
     
     
         34 . A method of inhibiting growth of cells that express STEAP-2, which comprises administering to said patient a vector encoding a single chain monoclonal antibody that comprises the variable domains of the heavy and light chains of a monoclonal antibody that specifically binds to a STEAP-2 protein of  claim 2 , such that the vector delivers the single chain monoclonal antibody coding sequence to the cancer cells and the encoded single chain antibody is expressed intracellularly therein.  
     
     
         35 . A method of killing cells that express STEAP-2, which comprises administering to said patient a vector encoding a single chain monoclonal antibody that comprises the variable domains of the heavy and light chains of a monoclonal antibody that specifically binds to a STEAP-2 protein of  claim 2 , such that the vector delivers the single chain monoclonal antibody coding sequence to the cancer cells and the encoded single chain antibody is expressed intracellularly therein.  
     
     
         36 . A STEAP-3 protein having an amino acid sequence shown in FIGS.  10 A-E (SEQ ID NO: 10).  
     
     
         37 . A polypeptide of at least 10 contiguous amino acids of the protein of  claim 36 .  
     
     
         38 . A polypeptide comprising an amino acid sequence which is at least 90% identical to the amino acid sequence shown in FIGS.  10 A-E (SEQ ID NO: 10) over its entire length.  
     
     
         39 . A polynucleotide selected from the group consisting of (a) a polynucleotide having the sequence as shown in FIGS.  10 A-E (SEQ ID NO: 9), wherein T can also be U; (b) a polynucleotide encoding the STEAP-3 protein of  claim 1;  and (c) a polynucleotide which is fully complementary to a polynucleotide of (a) or (b).  
     
     
         40 . An antibody or fragment thereof which specifically binds to the STEAP-3 protein of  claim 36 .  
     
     
         41 . The antibody or fragment thereof of  claim 40  which is monoclonal.  
     
     
         42 . A recombinant protein comprising the antigen binding region of a monoclonal antibody of  claim 41 .  
     
     
         43 . The antibody or fragment thereof of  claim 40  or  41  which is labeled with a detectable marker.  
     
     
         44 . The antibody or fragment thereof or recombinant protein of  claim 43 , wherein the detectable marker comprises a radioisotope, metal chelator, enzyme or fluorescent, bioluminescent or chemiluninescent compound.  
     
     
         45 . The monoclonal antibody or fragment thereof of  claim 41  which is conjugated to a toxin, a radioisotope or a therapeutic agent.  
     
     
         46 . The monoclonal antibody or fragment thereof of  claim 41 , wherein the toxin comprises ricin, ricin A-chain, doxorubicin, daunorubicin, a maytansinoid, taxol, ethidium bromide, mitomycin, etoposide, tenoposide, vincristine, vinblastine, colchicine, dihydroxy anthracin dione, actinomycin, diphtheria toxin, Pseudomonas exotoxin (PE) A, PE40, abrin, abrin A chain, modeccin A chain, alpha-sarcin, gelonin, mitogellin, retstrictocin, phenomycin, enomycin, curicin, crotin, calicheamicin, sapaonaria officinalis inhibitor, or a glucocorticoid.  
     
     
         47 . The monoclonal antibody or fragment thereof of  claim 41 , wherein the radioisotope comprises  212 Bi,  131 I,  131 In,  90 Y, or  186 Re.  
     
     
         48 . The antibody fragment of  claim 41 , which is an Fab, F(ab′)2, Fv or Sfv fragment.  
     
     
         49 . The antibody or fragment thereof of any one of claims  40 ,  41 , and  43 - 48 , which is a human antibody.  
     
     
         50 . The antibody or fragment thereof of any one of claims  40 ,  41 , and  43 - 48 , which comprises murine antigen binding region residues and human antibody residues.  
     
     
         51 . A transgenic animal producing a monoclonal antibody of  claim 41 .  
     
     
         52 . A hybridoma producing a monoclonal antibody of  claim 41 .  
     
     
         53 . A single chain monoclonal antibody that comprises the variable domains of the heavy and light chains of a monoclonal antibody of  claim 41 .  
     
     
         54 . A vector comprising a polynucleotide encoding a single chain monoclonal antibody of  claim 53 .  
     
     
         55 . An assay for detecting the presence of a STEAP-3 protein in a biological sample comprising contacting the sample with an antibody of  claim 43  or  44 , and detecting the binding of STEAP-3 protein in the sample thereto.  
     
     
         56 . An assay for detecting the presence of a STEAP-3 polynucleotide in a biological sample, comprising 
 (a) contacting the sample with a polynucleotide probe which specifically hybridizes to a polynucleotide of  claim 39  or its complement; and    (b) detecting the presence of a hybridization complex formed by the hybridization of the probe with STEAP-3 polynucleotidc in the sample,    wherein the presence of the hybridization complex indicates the presence of STEAP-3 polynucleotide within the sample.    
     
     
         57 . An assay for detecting the presence of STEAP-3 mRNA in a biological sample comprising: 
 (a) producing cDNA from the sample by reverse transcription using at least one primer;    (b) amplifying the cDNA so produced using STEAP-3 polynucleotides as sense and antisense primers to amplify STEAP-3 cDNAs therein;    (c) detecting the presence of the amplified STEAP-3 cDNA,    wherein the STEAP-3 polynucleotides used as the sense and antisense primers are capable of amplifying the polynucleotide of FIGS.  10 A-E (SEQ ID NO: 9).    
     
     
         58 . A pharmaceutical composition comprising an antibody or fragment thereof or recombinant protein of any one of claims  40 - 50 , a STEAP-3 protein according to  claim 36 , or a STEAP-3 polynucleotide according to  claim 39 , and a physiologically acceptable carrier.