Chemokine CXCL16 Expression Suppresses Migration and Invasiveness and Induces Apoptosis in Breast Cancer Cells

Abstract

Background.Increasing evidence argues that soluble CXCL16 promotes proliferation, migration, and invasion of cancer cellsin vitro. However, the role of transmembrane or cellular CXCL16 in cancer remains relatively unknown. In this study, we determine the function of cellular CXCL16 as tumor suppressor in breast cancer cells.Methods.Expression of cellular CXCL16 in breast cancer cell lines was determined at both RNA and protein levels.In vitroandin vivostudies that overexpressed or downregulated CXCL16 were conducted in breast cancer cells.Results.We report differential expression of cellular CXCL16 in breast cancer cell lines that was negatively correlated with cell invasiveness and migration. Overexpression of CXCL16 in MDA-MB-231 cells led to a decrease in cell invasion and migration and induced apoptosis of the cells; downregulation of CXCL16 in MCF-7 cells increased cell migration and invasiveness. Consistent with thein vitrodata, CXCL16 overexpression inhibited tumorigenesisin vivo.Conclusions.Cellular CXCL16 suppresses invasion and metastasis of breast cancer cellsin vitroand inhibits tumorigenesisin vivo. Targeting of cellular CXCL16 expression is a potential therapeutic strategy for breast cancer.