EXPRESSION OF THE INTEGRIN ALPHA-5 SUBUNIT IN HT29 COLON-CARCINOMA CELLS SUPPRESSES APOPTOSIS TRIGGERED BY SERUM DEPRIVATION

It is clear that certain integrins can regulate the growth of tumors, probably by contributing to signal transduction processes. In the pres ent study we have used HT29 human colon carcinoma cells stably transfe cted with human cDNA for the integrin alpha 5 subunit and studied the effects of alpha 5 expression on the induction of apoptosis, We observ e that apoptosis can be triggered in HT29 cells by removal of serum an d that this process can be suppressed by the stable expression of full -length integrin alpha 5 subunits. While the mechanism underlying this effect is still unclear, these observations suggest that the alpha 5 beta 1 integrin plays an important role in modulating tumor cell respo nses to growth factors and nutrients. (C) 1996 Academic Press, Inc.