Insulin-like growth factor-II expression in carcinoma in colon cell lines: implications for autocrine actions.

摘要: BACKGROUND: In the gastrointestinal tract, insulin-like growth factor-II (IGF-II) messenger RNA (mRNA) is localized mainly in mesenchymal cells, and more abundant fetus than adult. The purposes of this study are to characterize gene expression IGF-II at mRNA protein level seven different epithelial cell lines derived from colon carcinomas determine action IGF-receptors on a carcinoma line. STUDY DESIGN: Insulin-like mRNAs were examined by Northern analysis; conditioned media cells concentrated, chromatographed, specific radioreceptor assay. factor receptors radioligand binding assays. mitogenic role was determined 3-(4,5-dimethylthiazol-2yl)-2,5-diphenyltetrazolium bromide RESULTS: Multiple sizes expressed all tested (six human lines: HCT116, COLO 205, 320 DM, LoVo, DLD-1, HT29, one mouse line: MC-26). 205 HCT116 7.5 kilodaltons high molecular form (IGF-II IGF complex) detected. Both Type I II present whose stimulated IGF-II. Addition anti-IGF-I receptor anti-IGF-II antibody culture significantly depressed line presence or absence exogenous CONCLUSIONS: lines, which may induce production significant amount biologically active protein. secreted stimulate an autocrine fashion through receptors.