Effects of integrins on laminin chemotaxis by hepatocellular carcinoma cells

Abstract

To quantitatively evaluate the effects of integrins α1b1, α2β1, α3β1, α4β1, α5β1, and α6β1 on the chemotaxis of hepatocelluar carcinoma (HCC) cell line SMMC-7721 to laminin (LN).Amodified dual-micropipette system was used to dynamically and quantitatively monitor the formation of pseudopod protrusion of HCC cells toward LN in the presence or absence of specific antibodies against integrins α1, α2, α3, α4, α5, α6, and β1. Additionally, the expression levels of different integrin subunits on the surface of the cells were determined via flow cytometry analysis. In response to equal concentrations of LN in both micropipettes, HCC cells form symmetrical pseudopod protrusions on both sides. Addition of antibodies against α3, α6, or β1 into one micropipette leads to significant reduction of pseudopod formation on that side, while antibodies against α1, α2, α4, and α5 do not affect the symmetrical formation of pseudopods in either micropipette. The percentages of HCC cells positive for expression of integrins α1, α2, α3, α4, α5, α6, and β1 were 95.07, 23.17, 95.55, 2.47, 34, 14.29, and 95.78%, respectively. Integrins a3b1 and a6b1 are important cell surface receptors that mediate the chemotaxis of HCC cells toward LN. © Springer Science+Business Media B.V. 2009.