Objective:To investigate the effect of silencing the PLD2(phospholipases D2)gene expression on cell proliferation and migration of colon cancer cell lines and to explore the underline molecular mechanisms. Methods:The small interfering RNA(si RNA)targeted PLD2 was transfected into SW480 and SW620 cells by adenovirus. Expression levels of PLD2 m RNA and protein were measured by q RT-PCR and Western blot

respectively. Plate clone formation assay and transwell chamber were used to detect the proliferation and migration ability of colon cancer cells. Finally

the expressions of Cyclin D1 and metalloproteinase-2(MMP-2)protein were measured by Western blot in both cell lines. Results:PLD2 si RNA greatly inhibited the expression of PLD2 in colon cancer cells at both m RNA and protein levels(all P<0.01). Down-regulated the PLD2 expression significantly suppressed the proliferation and migration ability of SW480 and SW620 cells and also inhibited the expression of Cyclin D1 and MMP-2 proteins in both cell lines(all P=0.000). Conclusion:Down- regulated PLD2 gene expression can clearly inhibit the proliferation and migration of colon cancer cells

which may closely associate with the decreased expression of Cyclin D1 and MMP-2

indicating a way of gene therapy for colon cancer.