Calcitonin Secretion by Monolayer Cultures of Human C-Cells Derived from Medullary Thyroid Carcinoma

Abstract

Monolayer cultures of human calcitonin-secreting cells (C-cells) have been derived from medullary thyroid carcinomas. The cultures were prepared from cell suspensions obtained by enzymatic digestion of surgical specimens of the tumor. Human calcitonin (hCT) secretion by these cells was studied using a specific radioimmunoassay for the hormone. The cultures could be used for reproducible secretion studies up to 40 days after their initiation; they demonstrated a linear rate of hormone secretion in the basal state for at least 4 h. Calcium, pentagastrin, and prostaglandin E2 (PGE2) each produced a marked increase (up to 7-fold) in hormone secretion. Magnesium had no apparent secretory effect; and compared to PGE2, PGF2alpha had only a small secretory effect. In addition to responding to specific secretagogues shown to regulate calcitonin secretion in vivo, the secretory effects of each of the secretagogues could be raipdly reversed. Therefore, these cultures of human C-cells exhibit secretory responses which are quantitatively and qualitatively similar to C-cells in vivo. Accordingly, such cultures provide a useful model to study the regulation of calcitonin secretion in human C-cells.

Primary Tissue Cultures of Benign and Malignant Human Thyroid Tumors: Effect of TSH

“…8 17.8 f 1.8 19.8 f 1. 6 16.3 f 1.5 3 0 9 % 3 2 2 0 5 % 2 0 9 1 9 % 8 9 7 2 9 % 6 8 1075 f 2 0 3 61 5 % 1 3 2 1467 k 1 2 5 1 2 6 2 k 11 2 111 9 f 1 0 1 9 5 7 k 8 3 120 1 5 clusters could usually be observed after 24 hours incubation. In the majority of cases, a confluent monolayer developed (Fig.…”

Chromosomal localization of the type-I 15-PGDH gene to 4q34-q35

“…In addition, this syndrome is sometimes associated with low calcitonin secretion during calcium infusion (Culler et al 1985). Prostaglandins of the E 2 series have been shown to be involved in both vitamin D metabolism (Yamada et al 1985) and the regulation of calcitonin expression (Roos et al 1974). Thus, defects in the type-I 15-PGDH gene (most likely leading to an overexpression) could be involved in the disturbance of vitamin D metabolism and implicated in this syndrome.…”

The effects of forskolin and calcium ionophore A23187 on secretion and cytoplasmic RNA levels of Chromogranin-A and calcitonin

“…(~~~~'~~~' The lack of an effect of A23187 in the MTC line remains unexplained. In contrast to this finding, the rat MTC cell line rMTC 6-23 and perfused porcine thyroid glands both respond to A23 187 treatment with increased secretion of CT. (26*33) Furthermore, the rMTC line and primary cultures of human MTC tissue respond to increased extracellular calcium with enhanced secretion of CT. (34)(35) In contrast, secretion of CT from the human MTC cell line is not enhanced by increased extracellular calcium (data not shown). However, disparities in responsiveness to A23 187 between cells of similar origin but different degrees of transformation have been described.…”