RLIP76 Blockade by siRNA Inhibits Proliferation, Enhances Apoptosis, and Suppresses Invasion in HT29 Colon Cancer Cells

RLIP76, a multidomain protein which is a downstream effector of the small GTP ases RalA and RalB, is known to play a role in biological activities in a variety of malignant cancer cells. However, little study has been done on the role of RLIP76 in CRC. In this study, a RLIP76-targeted siRNA-containing vector was used to investigate the effect of RLIP76 knockdown on cellular functions in human CRC cell line HT29. Quantitative RT-PCR and Western blot analysis revealed that the expression levels of RLIP76 mRNA and protein in HT29 cells were significantly suppressed after transfection. Our results indicated that RLIP76 downregulation in HT29 CRC cells suppressed cell growth, enhanced cell apoptosis, induced cell cycle arrest, and inhibited cell invasion by decreasing MMP2 expression. Although the mechanisms through which RLIP76 regulates the cellular functions needs further investigation, our results indicate that RLIP76 may represent as a potential target of gene therapy for CRC treatment.