Prostate carcinogenesis predictor

Abstract

A method of detecting prostate tumorigenesis in a subject, the method including the steps of (a) obtaining a sample from the prostate of the human subject, (b) detecting quantitatively or semi-quantitatively in the sample a level of expression for PKC-ι and (c) comparing the expression level in (b) to a level of expression in a normal control, wherein overexpression of PKC-ι, with respect to the control, indicates the presence of prostate cancer in the subject. The present invention is based upon the discovery that PKC-ι levels are elevated during prostate tumorigenesis. Furthermore, the proliferation rate of the tumor correlates with the level of PKC-ι. The invention also provides methods of treating prostate cancer by administering to the subject a compound that inhibits the expression of PKC-ι. The compound can be a small interfering RNA (siRNA) molecule.

1 . A method of detecting prostate cancer in a subject comprising:
 (a) obtaining a sample from the prostate of a human subject;   (b) detecting quantitatively or semi-quantitatively in the sample a level of expression for PKC-ι; and   (c) comparing the expression level in (b) to a level of expression in a normal control, whereby overexpression of PKC-ι with respect to the control indicates the presence of prostate cancer.   
     
     
         2 . The method according to  claim 1  wherein the detecting detects the quantitative level of expression of PKC-ι in a sample tissue whereby the relative level of expression of PKC-ι in the sample as compared to the control correlates with the proliferation rate of the prostate cancer cells. 
     
     
         3 . The method according to  claim 1  wherein the comparing step includes:
 contacting a sample from the prostate of a subject with an antibody which recognizes PKC-ι protein; and   detecting the complex between the antibody and the PKC-ι protein.   
     
     
         4 . The method according to  claim 3  wherein said antibody is a monoclonal antibody. 
     
     
         5 . The method according to  claim 3  wherein said antibody is a polyclonal antibody. 
     
     
         6 . The method according to  claim 3  wherein said protein is contacted with said antibody in an immunoassay selected from the group consisting of radioimmunoassay, western blot assay, immunofluorescent assay, enzyme immunoassay, immunoprecipitation, chemiluminescent assay, immunohistochemical assay, dot blot assay and slot blot assay. 
     
     
         7 . The method according to  claim 4  wherein said immunoassay is a western blot assay. 
     
     
         8 . A method of diagnosing the presence of prostate tumorigenesis in a subject, comprising:
 (a) obtaining a sample from the prostate of a human subject;   (b) detecting quantitatively or semi-quantitatively in the sample a level of expression for PKC-ι protein or PKC-ι-specific mRNA; and   (c) comparing the expression level in (b) to a level of expression in a normal control, wherein overexpression of PKC-ι protein or PKC-ι-specific mRNA, with respect to the control, indicates the presence of prostate tumorigenesis in the subject.   
     
     
         9 . The method according to  claim 8  wherein the step of detecting detects the quantitative level of expression of PKC-ι in a sample tissue wherein the relative level of expression of PKC-ι in the sample as compared to the control correlates with the proliferation rate of the tumor. 
     
     
         10 . A diagnostic kit for the detection of prostate tumorigenesis comprising in combination;
 an anti-PKC-ι antibody;   a labeled secondary antibody capable of immunocomplexing with the anti-PKC-ι antibody;   a positive control derived from a tissue sample of a prostate tumor; and   a negative control derived from a normal prostate tissue sample.   
     
     
         11 . The diagnostic kit according to  claim 10  further comprising a suitable diluent for the prostate tissue sample to be tested. 
     
     
         12 . The diagnostic kit according to  claim 10  wherein the label of the secondary antibody is selected from the group consisting of a fluorescent label, an enzyme label and a radioactive label. 
     
     
         13 . A method of treating a prostate tumor in a subject comprising the step of administering to the subject a substance that inhibits PKC-ι. 
     
     
         14 . The method according to  claim 13  wherein the substance is a small interfering RNA molecule. 
     
     
         15 . The method according to  claim 14  wherein a strand of the siRNA comprises a sequence selected from the group consisting of PKC-ι siRNA: 663 5′-CAAGCCAAGCGUUUCAACA-3′ (SEQ ID NO: 1); 5′-UGUUGAAACGCUUGGCUU G-3′ (SEQ ID NO: 2); 739 5′-GGAACGAUUGGGUUGUCAU-3′ (SEQ ID NO: 3); 5′-AUGACAACCCAAUCGUUUCC-3′ (SEQ ID NO: 4); 2137 5′-CCCAAUAUCUUCUCUUGUA-3′ (SEQ ID NO: 5); 5′-UACAAGAGAAGAUAUUGGG3′ (SEQ ID NO: 6); PKC-ζ siRNA: 5′-AAGACGACACAUGUCUCUCACCCUGUCUC-3′ (SEQ ID NO: 7); 5′-AUACAUUUCU ACAGCUAGC-3′ (SEQ ID NO: 8) antisense; 5′-GAGACAGGGUGAGAGACAUGUGUCGUCUU-3′ (SEQ ID NO: 9); 5′-GCUAGC UGUAGAAAUGUAU-3′ (SEQ ID NO: 10) sense; PKC-δ siRNA: 5′-UCAUAAAUCAGUUUCUCAC-3′ (SEQ ID NO: 11) antisense; 5′-AUGACAAAGAAAUUCUGAC-3′ (SEQ ID NO: 12) antisense; 5′-GUGAGAAACUGAUUUAUGA-3′ (SEQ ID NO: 13) sense; 5′-GUCAGAAUUUCUUUGUCAU-3′ (SEQ ID NO: 14) sense. 
     
     
         16 . The method of  claim 14  wherein the siRNA is administered in conjunction with a delivery agent. 
     
     
         17 . The method of  claim 16  wherein the delivery agent is selected from the group consisting of lipofectin, lipofectamine, cellfectin, polycations, and liposomes. 
     
     
         18 . The method of  claim 17  wherein the delivery agent is a liposome. 
     
     
         19 . The method of  claim 13 , wherein the substance is ICA-1. 
     
     
         20 . A method of detecting prostate cancer in a subject, comprising:
 (a) obtaining a sample from the prostate of the human subject;   (b) detecting quantitatively or semi-quantitatively in the sample a level of expression for PKC-ι; and   (c) comparing the expression level in (b) to a level of expression in one or more controls wherein the controls are selected from the group consisting of a negative control, a positive control and a combination thereof.   
     
     
         21 . A method of inducing prostate carcinoma cell apoptosis comprising contacting prostate carcinoma cells with a PKC-ι inhibiting substance. 
     
     
         22 . The method according to  claim 21 , wherein the substance is a small interfering RNA molecule. 
     
     
         23 . The method according to  claim 22  wherein a strand of the siRNA comprises a sequence selected from the group consisting of PKC-ι siRNA: 663 5′-CAAGCCAAGCGUUUCAACA-3′ (SEQ ID NO: 1); 5′-UGUUGAAACGCUUGGCUU G-3′ (SEQ ID NO: 2); 739 5′-GGAACGAUUGGGUUGUCAU-3′ (SEQ ID NO: 3); 5′-AUGACAACCCAAUCGUUUCC-3′ (SEQ ID NO: 4); 2137 5′-CCCAAUAUCUUCUCUUGUA-3′ (SEQ ID NO: 5); 5′-UACAAGAGAAGAUAUUGGG3′ (SEQ ID NO: 6); PKC-ζ siRNA: 5′-AAGACGACACAUGUCUCUCACCCUGUCUC-3′ (SEQ ID NO: 7); 5′-AUACAUUUCU ACAGCUAGC-3′ (SEQ ID NO: 8) antisense; 5′-GAGACAGGGUGAGAGACAUGUGUCGUCUU-3′ (SEQ ID NO: 9); 5′-GCUAGC UGUAGAAAUGUAU-3′ (SEQ ID NO: 10) sense; PKC-δ siRNA: 5′-UCAUAAAUCAGUUUCUCAC-3′ (SEQ ID NO: 11) antisense; 5′-AUGACAAAGAAAUUCUGAC-3′ (SEQ ID NO: 12) antisense; 5′-GUGAGAAACUGAUUUAUGA-3′ (SEQ ID NO: 13) sense; 5′-GUCAGAAUUUCUUUGUCAU-3′ (SEQ ID NO: 14) sense. 
     
     
         24 . The method according to  claim 21 , wherein the substance is ICA-1.