LUTEINIZING-HORMONE HUMAN CHORIONIC-GONADOTROPIN RECEPTORS IN BREAST-CANCER

Recent studies have suggested that human choriogonadotropin (hCG), in addition to its function in regulating steroidogenesis, may also play a role as a growth factor. Immunocytochemistry using two different mon oclonal antibodies (LHR29 and LHR1055) raised against the human lutein izing hormone/human chorionic gonadotropin (LH/hCG) receptor allowed u s to detect this receptor in breast cancer cell lines (T47D, MCF7, and ZR75) in individual cancer biopsies and in benign breast lesions. The receptor was also present in epithelial cells of normal human and sow breast, In the latter, its concentration increased after ovulation. T he presence of LH/hCG receptor mRNA was confirmed by reverse transcrip tion-PCR using primers extending over exons 2-4, 5-11, and 9-11. The p roportion of LH/hCG-receptor positive cells and the intensity of the i mmunolabeling varied in individual biopsies, but there was no obvious correlation with the histological type of the cancer. These results ar e compatible with previous studies suggesting that during pregnancy, h CG is involved in the differentiation of breast glandular epithelium a nd that this hormone may play an inhibitory role in mammary carcinogen esis and in the growth of breast tumors.