When grown in nude mice, cultured renal carcinoma cells from a hypercalcemic patient produced marked hypercalcemia that was reversed by resection of tumor. Conditioned medium from this cell line contained a protein with activity in a renal adenylate cyclase bioassay for parathyroid hormone (PTH) which was blocked by the competitive PTH antagonist [8norleucyl, 18norleucyl, 34tyrosinyl]bPTH (3-34)amide. However, the biologically active protein was eluted from gel filtration columns as a larger molecular size component that PTH and was not recognized by any of four region-specific PTH antisera. The properties of this factor resemble those of the postulated PTH-like substance(s) in humoral hypercalcemia of malignancy.
G J Strewler, R D Williams, R A Nissenson
The Editorial Board will only consider comments that are deemed relevant and of interest to readers. The Journal will not post data that have not been subjected to peer review; or a comment that is essentially a reiteration of another comment.