ABSTRACT
A new human pancreatic cancer (HPAC) cell line was established from a nude mouse xenograft (CAP) of a primary human pancreatic ductal adenocarcinoma. In culture, HPAC cells form monolayers of morphologically heterogenous, polar epithelial cells, which synthesize carcinoembryonic antigen, CA 19-9, CA-125, cytokeratins, antigens for DU-PAN-2, HMFG1, and AUA1, but do not express chromogranin A or vimentin indicative of their pancreatic ductal epithelial cell character. In the presence of serum, HPAC cell DNA synthesis was stimulated by insulin, insulin growth factor-I, epidermal growth factor, and TGF-α but inhibited by physiologic concentrations of hydrocortisone and dexamethasone. Dose-dependent inhibition of DNA synthesis was limited to steroids with glucocorticoid activity. The inhibitory effect of dexamethasone was abolished by the glucocorticoid antagonist RU 384862 Binding of [3H] dexamethasone to cytosolic proteins was specific and saturable at 4 degrees C. Scatchard analysis of binding data demonstrated a single class of high-affinity binding sites (K(d) = 3.8 ± 0.9 nM; B(max) = 523 ± 128 fmol/mg protein). Western blot analysis revealed a major protein band that migrated at a M(r) of 96 kDa. Northern blot analysis identified an mRNA of approximately 7 kilobases which hybridized with a specific glucocorticoid receptor complementary-DNA probe (OB7). These findings support a role for glucocorticoids in the regulation of human malignant pancreatic cell function.
