MONOCLONAL ANTIBODIES AGAINST RETINOBLASTOMA GENE PRODUCT

RECENT EVIDENCE SUGGESTS THAT MUTATIONAL INACTIVATION OF SPECIFIC "CANCER SUPPRESSOR" GENES CONTRIBUTES TO THE FORMATION OF SEVERAL HUMAN CANCER TYPES INCLUDING RETINOBLASTOMA (RB), OSTEOSARCOMA, AND ADENOCARCINOMAS OF BREAST AND COLON. IN THE CASE OF RETINOBLASTOMA, THE CONTROLLING CANCER SUPPRESSOR GENE (RB GENE) HAS BEEN CLONEDAND SEQUENCED. BOTH ALLELES OF THIS GENE HAVE BEEN SHOWN TOBE INACTIVATED IN VIRTUALLY ALL RETINOBLASTOMAS. USING POLYCLONAL RABBIT ANTISERA, LEE ET AL. HAVE DEMONSTRATED THAT THE RB GENE PRODUCT IS A NUCLEAR PHOSPHOPROTEIN OF 110-114 KD MOLECULAR WEIGHT WITH DNA BINDING ACTIVITY. THE PRIMARY GOAL OF THIS PROPOSAL IS TO PRODUCE MONOCLONAL ANTIBODIES (MCABS) AGAINST THE RB GENE PRODUCT FOR USE IN SENSITIVE AND SPECIFIC DIAGNOSTIC TESTS FOR RETINOBLASTOMA AND OTHER RB-RELATED CANCERS. THESE MCABS WILL BE USEFUL FOR ASSESSING THE FUNCTION OF THE RB PROTEIN IN HUMAN NEOPLASIA AND DIAGNOSING RB-RELATED TUMORS. THE SPECIFIC AIMS OF THIS PROPOSAL ARE: 1. TO GENERATE MCABS SPECIFIC TO RB PROTEIN; 2. TO CHARACTERIZE THE EPITOPES RECOGNIZED BY THESE MCABS; 3. TO DEVELOP SENSITIVE AND SPECIFIC IMMUNOLOGICAL TESTS FOR CANCER DIAGNOSIS. THE KNOWLEDGE DERIVED AND THE TEST(S) DEVELOPED FROM THESE MCABS WILL BE VERY IMPORTANT FOR PHASE II CLINICAL APPLICATIONS SUCH AS PROSPECTIVE OR PROGNOSTIC STUDIES.