title: Selective effects of insulin and hydrocortisone on colony formation and chemosensitivity of human tumors in soft agar.
abstract: Because low plating efficiencies of most human cancers severely limit the number of successful chemosensitivity tests that can be performed, we studied the growth-enhancing effects of insulin and hydrocortisone on a variety of solid tumors. Colony formation in soft agar was significantly increased in 23/49 (47%) tumors treated with 3 U/ml insulin, whereas fewer colonies were observed in 7 (14%). These effects were highly selective for tumor type. Colony growth for ovarian, lung, and colon carcinomas increased by 123%, 37% and 28%, respectively. In contrast, insulin inhibited the growth of melanoma, kidney, and breast tumors. Hydrocortisone at 0.05 microgram/ml increased colony numbers in 23/45 (51%) tumors, while in 7 (16%) colony numbers were decreased. Growth of ovarian, lung, breast, and kidney carcinomas was increased by 136%, 126%, 78% and 69%, respectively, whereas melanomas, sarcomas, and colon tumors were inhibited by hydrocortisone. In vitro chemosensitivities were relatively unchanged by the hormones. In 168 (134 paired) drug/tumor tests, sensitivity to standard antineoplastic drugs in the presence or absence of hormones was concordant 82% of the time (correlation coefficient, 0.71). However, in 20 tests (15%), significant enhancement of chemosensitivity was observed. We concluded that cloning efficiencies of many common human tumor types can be improved with hormones, and that these growth-enhancing effects are selective for tumor type.
mesh_terms: D002478:Cells, Cultured; D003114:Colony-Forming Units Assay; D003470:Culture Media; D004351:Drug Resistance; D006133:Growth Substances / Q000494:pharmacology*; D006801:Humans; D006854:Hydrocortisone / Q000494:pharmacology*; D007328:Insulin / Q000494:pharmacology*; D009369:Neoplasms / Q000473:pathology*; D014410:Tumor Stem Cell Assay
chemical_list: D003470:Culture Media; D006133:Growth Substances; D007328:Insulin; D006854:Hydrocortisone