PRODUCTION OF MODULATORS OF CELL PROLIFERATION

THE LONG-TERM OBJECTIVE OF THIS PROJECT IS TO ESTABLISH A STABLE SOURCE OF PURE ENDOGENOUS HEPATIC PROLIFERATION INHIBITOR (HPI) AND OTHER RELATED MODULATORS OF CELL DIVISION. THESE IMPORTANT PROBES CAN THEN BE MADE AVAILABLEFOR FUNDAMENTAL RESEARCH INTO THE REGULATION OF CELL PROLIFERATION AND DIFFERENTIATION, WHICH MAY BE A COMMON DENOMINATOR FOR MALIGNANT DISEASES AND AGING. PHASE I STUDIES INVOLVE: 1. IMPROVEMENT IN THE YIELD OF ENDOGENOUS HPI FROM RAT LIVER ACHIEVED BY SOLUBILIZING CELL MEMBRANES AND BY EXPLOITING THE RELATIVE RESISTANCE OF HPI TO HEAT IN ORDER TO REMOVE THE BULK OF INERT PROTEINS. 2. PREPARATION OF CDNA CLONES ENCODING RAT HPI WILL BE PERFORMED THROUGH ISOLATION OF THE MESSAGE FOR HPI FROM RAT LIVER AND/OR IMMUNOLOGICAL SCREENING OF CDNA EXPRESSION LIBRARIES AS WELLAS THE CONSTRUCTION OF APPROPRIATE EXPRESSION VECTORS. 3. PRODUCTION OF MONOCLONAL ANTIBODIES AGAINST HPI AND ITS RECEPTOR WILL BE ACCOMPLISHED USING HYBRIDOMA TECHNOLOGY. DURING PHASE I, A SMALL AMOUNT OF ENDOGENOUS HPI WILL BE PRODUCED; A MORE SENSITIVE ASSAY FOR HPI ACTIVITY WILL BE STANDARDIZED; PARTIAL SEQUENCE ANALYSIS WILL BE COMPLETED; AND, USING THE PRESENTLY AVAILABLE POLYCLONAL ANTIBODIES TO HPI, THE MRNA APPROACH TO CLONING THE DNA WILL BE PERFORMED.SUCCESS IN THESE ENDEAVORS WILL ENSURE THE FEASIBILITY OF THE OVERALL PROGRAM, PAVE THE WAY FOR THE DEVELOPMENTAL STUDIES OF PHASE II, AND PROMOTE THE EVENTUAL PRODUCTION OF THESE BIOLOGICAL MODULATORS ON A COMMERCIAL SCALE.