Long-term selective culture of hamster pulmonary endocrine cells

We describe, for the first time, the development of a technique for a long-term selective culture of endocrine (PE) cells from the lungs of normal animals. Epithelial cells were isolated from 1-day-old hamster lungs through mechanical and enzymatic dissociation with collagenase type II. Cells were then cultured in HITES medium which contained RPMI 1640, hydrocortisone, insulin, transferrin, estradiol, sodium selenite, and supplemented with 5% fetal bovine serum (FBS), or medium which contained HITES medium supplemented with bovine serum albumin, phosphoethanolamine, arginine vasopressin, bombesin, and 2% FBS (9N). HITES medium, originally developed for establishment and long-term culture of human small cell lung cancer (SCLC) cell lines, allowed propagation of normal hamster PE cells up to 12 months as a mixed floating-attached cell culture. No difference was noted in the results using HITES or 9N. By 3 months, 80% of the cultured cells contained characteristic dense-core (endocrine type) granules. The cultured PE cells also expressed creatine kinase brain isoenzyme, and general NE markers including neuron specific enolase, and amine handling enzyme activity within the range of SCLC cell lines. Moreover, cultured PE cells contained and secreted immunoreactive calcitonin (iCT) which had a molecular profile similar to that of intact hamster lung. This long-term culture technique should markedly assist in elucidating the role of PE cells in health and disease.