Insulin-like growth factor (IGF)-binding protein-6 inhibits IGF-II-induced but not basal proliferation and adhesion of LIM 1215 colon cancer cells

Mol Cell Endocrinol. 2001 Mar 28;174(1-2):121-7. doi: 10.1016/s0303-7207(00)00444-5.

Abstract

IGF-II is an autocrine growth factor for many colon cancer cells. This study aimed to determine the role of IGF-II in proliferation and adhesion of LIM 1215 colon cancer cells. RT-PCR demonstrated expression of IGF-I and IGF-II mRNA. Addition of IGF-I or -II increased monolayer proliferation in a dose-dependent manner. Although addition of IGFBP-6 had no effect on basal proliferation, coincubation of IGFBP-6 decreased IGF-II but not IGF-I-induced proliferation. Colony formation in agar was increased by IGF-II, an effect inhibited by coincubation with IGFBP-6. IGFBP-6 alone significantly decreased colony formation. Preincubation of cells with IGF-II increased adhesion to type IV collagen, fibronectin and laminin. IGFBP-6 had no effect on basal cell adhesion but completely inhibited the effects of IGF-II. LIM 1215 colon cancer cells are therefore IGF-responsive but IGF-II is not a major autocrine factor for these cells in monolayer, suggesting heterogeneity between colon carcinoma cell lines with respect to the role of the IGF system.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Autocrine Communication
  • Cell Adhesion / drug effects
  • Cell Division / drug effects
  • Colonic Neoplasms / pathology*
  • Extracellular Matrix / metabolism
  • Humans
  • Insulin-Like Growth Factor Binding Protein 6 / pharmacology*
  • Insulin-Like Growth Factor I / genetics
  • Insulin-Like Growth Factor II / antagonists & inhibitors*
  • Insulin-Like Growth Factor II / genetics
  • RNA, Messenger / metabolism
  • Tumor Cells, Cultured

Substances

  • Insulin-Like Growth Factor Binding Protein 6
  • RNA, Messenger
  • Insulin-Like Growth Factor I
  • Insulin-Like Growth Factor II