Multiple autocrine factors including an extracellular matrix protein are required for the proliferation and spreading of human colon carcinoma cells in vitro

Abstract

The human colon carcinoma cell line LIM1215 proliferates and changes morphology (spread) in a cell density-dependent manner in response to epidermal growth factor (EGF). At high density, production of autocrine transforming growth factor-α enables the cells to proliferate and spread in the absence of exogenous EGF or serum. At low cell density (< 1 x 104/cm2) EGF alone fails to elicit a mitogenic or morphological response and requires the presence of conditioned medium (derived from high cell density serum-free culture of the same cells) to exert its effects. This synergy between EGF and LIM1215 conditioned medium was investigated further. Using a low cell density assay and fractionated LIM1..