Gene expression of the invasive phenotype of TNF-α-treated MCF-7 cells

Background and objectivesTNF-α secreted by tumor cells and macrophages that have infiltrated into the micro-environment of a tumor may promote the metastasis of a variety of malignant cancers, including breast cancer. The present study was designed to detect gene expression changes in metastatic MCF-7 cells treated with a low dose of TNF-α (20 ng/mL), and to further explore the mechanisms by which TNF-α can contribute to metastasis.MethodsTranswell assays were performed to evaluate the invasive phenotype of MCF-7 cells. Samples for cDNA array analysis were collected 3 h and 24 h after pre-treatment with TNF-α and changes in gene expression were quantitated.ResultsThe invasive phenotype of MCF-7 cells was enhanced by the exposure of MCF-7 cells to a low dose of TNF-α. Gene expression profiles of 39 genes significantly increased or decreased after treatment with TNF-α, 6 of which were genes not previously associated with regulation by TNF-α. Genes to promote metastasis, as well as to inhibit metastasis, were identified with some changes being time dependent.ConclusionsTNF-α can enhance the invasive capacity of MCF-7 cells by affecting the expression of a group of genes that have roles in various steps of metastasis. Mechanistic insights into the role of TNF-α in tumor cell metastasis are discussed.