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

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.

• Authors: S L Leng, K S Leeding, R H Whitehead, L A Bach
• Journal: Molecular and cellular endocrinology (Mol Cell Endocrinol) Vol. 174 Issue 1-2 Pg. 121-7 (Mar 28 2001) ISSN: 0303-7207 [Print] Ireland
• PMID: 11306178 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

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

Topics

• 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, genetics)
• RNA, Messenger (metabolism)
• Tumor Cells, Cultured