The leukocyte protein L‐plastin induces proliferation, invasion and loss of E‐cadherin expression in colon cancer cells

L‐plastin, a gene that codes for an actin‐bundling protein, is upregulated in the metastatic colon cancer cell line SW620, when compared to its premetastatic counterpart SW480. The aim of our study was to characterise the effect of L‐plastin overexpression on SW480 cells in the context of the acquisition of a metastatic phenotype. SW480 cell lines overexpressing L‐plastin were established (SW480‐LPL). Analysis of these cell lines revealed significantly higher rates of proliferation and invasion than the control cell line (SW480‐Ctrl). In addition, the expression of E‐cadherin was lost from SW480‐LPL cells. Treatment of SW480‐LPL cells with cytochalasin B, an inhibitor of endocytosis, attenuated the loss of E‐cadherin expression in these cells. The association of L‐plastin overexpression with an increased rate of proliferation and invasion, and loss of E‐cadherin expression in the SW480 colon cancer cell line indicates that L‐plastin plays an important mechanistic role in colorectal cancer metastasis (supplementary material for this article can be found on the International Journal of Cancer website at http://www.interscience.wiley.com/jpages/0020‐7136/suppmat/index.html). © 2005 Wiley‐Liss, Inc.