IN VITRO SCREENING TEST FOR DETECTING ANTIESTROGENS

THE OVERALL OBJECTIVE OF THIS PROPOSAL IS TO DEVELOP A RELIABLE IN VITRO TEST SYSTEM USING HUMAN CELL LINES TO SCREEN COMPOUNDS FOR THEIR CYTOTOXICITY AND ANTIESTROGENIC ACTIVITY. CURRENTLY, A NUMBER OF IN VITRO SCREENING TESTS ARE USED TO IDENTIFY POTENTIAL CHEMOTHERAPEUTIC DRUGS. MOST OF THESE TESTS UTILIZE NONHUMAN (MOSTLY RODENT) CELL LINES THAT MAY NOT DISTINGUISH SPECIES-SPECIFIC DIFFERENCES IN TOXICITY OF CHEMICALS BETWEEN HUMANS AND RODENTS. ALTHOUGH A FEW HUMAN CELL LINES (HT-29, A549, KB) ARE CURRENTLY USED TO SCREEN CHEMICALS FOR THEIR CYTOTOXICITIES, NONE OF THEM ARE RESPONSIVE TO ESTROGENS OR ANTIESTROGENS. BECAUSE IN RECENTYEARS PATIENTS WITH HORMONE-RESPONSIVE SOLID TUMORS HAVE BEEN TREATED WITH BOTH ENDOCRINE DRUGS (ANTIESTROGENS) AND OTHER CHEMOTHERAPEUTIC AGENTS, IT IS ESSENTIAL TO DEVELOP ANIN VITRO SCREENING TEST WITH APPROPRIATE HUMAN ESTROGEN-SENSITIVE AND ESTROGEN-NONSENSITIVE CELL LINES. USE OF HUMAN CELL LINES WILL ALSO BE MORE RELEVANT IN VIEW OF THE DIFFERENCES IN THE SPECIES-SPECIFIC CYTOTOXICITY OF ANUMBER OF COMPOUNDS. SITEK RESEARCH LABORATORIES PROPOSES TO DEVELOP A RELIABLE PROTOCOL FOR A RAPID, IN VITRO TEST USING ESTROGEN-RESPONSIVE AND ESTROGEN-NONRESPONSIVE HUMAN CELL LINES. SUCH A TEST WILL BE SENSITIVE, RELATIVELY INEXPENSIVE, AND ALLOW THE EVALUATION OF A NUMBER OF SAMPLESAT THE SAME TIME. IN ADDITION, THE TEST WILL DISTINGUISH THE TOXICITY CAUSED BY THE ANTIESTROGENS FROM THE NONSPECIFIC CYTOTOXICITY OR TOXICITY CAUSED BY OTHER CHEMOTHERAPEUTIC DRUGS.