Differential cyclic AMP responses to calcitonin among human ovarian carcinoma cell lines: a calcitonin-responsive line derived from a rare tumor type.

Several human tumor cell lines have been reported to have specific receptors for calcitonin (CT) and CT-responsive adenylate cyclase. In order to correlate patterns of responsiveness to CT, parathyroid hormone (PTH) and prostaglandin E2 (PGE2) with tumor morphology and intermediate filament protein expression, we examined four human ovarian tumor cell lines (BIN-16, BIN-22, BIN-53, BIN-67) which had been cultured from cells of metastatic foci. In two cell lines (BIN-53 and -16) there were small increases in cAMP content after exposure to CT and in three cell lines (BIN-53, -16, and -22) larger increases with PGE2. There was no cAMP response in any of the cells to PTH. In BIN-67 cells, however, CT induced a striking (greater than 20-fold) increase in cAMP content. Histologically, the CT-nonresponsive tumor lines were derived from serous adenocarcinomas while the CT-responsive tumor line was from a rare small cell carcinoma. Gel electrophoretic and immunofluorescence microscopic analyses had previously disclosed that the CT-nonresponsive cell lines contained high levels of simple epithelial keratins and no or very low levels of vimentin (characteristic of ovarian surface epithelial cells), while the CT-responsive cell line contained almost exclusively vimentin. Thus, cells cultured from a rare type of ovarian tumor were CT-responsive and were distinguishable from CT-nonresponsive ovarian tumor cells by initial tumor histology and intermediate filament protein expression.