Abstract: Objective  To observe the influence of N-myc downstreamregulated gene 2 (NDRG2) on the growth and invasive ability of human colon cancer cell line SW620, and to explore its mechanism. MethodspcDNA3.1NDRG2 and siRNANDRG2 were transfected transiently respectively into SW620 by Lipofectamine TM 2000, untreated cells as the control group. Western blotting was used to investigate the expression of NDRG2 and matrix metalloproteinase-2(MMP-2). Matrigel invasion assay was used to study the invasive abilities of SW620 cells in all groups. The growth curve was determined through 3(4,5dimethyl2thiazoly)2,5diphenyl2Htetrazolium bromide method. ResultAfter transfecting pcDNA3.1NDRG2 into the SW620 cells, the protein level of NDRG2 increased and the expression of MMP-2 declined markedly. After transfecting siRNANDRG2 into the SW620 cells, the protein level of NDRG2 declined and the expression of MMP2 increased markedly. In addition, compared with the control group (75.80 ±4.82), the numbers of transmembrane cells in pcDNA3.1 group (56.20 ±7.40) and in siRNA group (94.20 ±9.23) were significantly different (t=13.102, P=0.000; t=11.820, P=0.000). The growth curve showed that: compared with the control group (0.67±0.01), the absorbance of the fifth day after transfection in pcDNA3.1 group (0.46±0.01) and in siRNA group (0.91±0.02) were different significantly (t=9.561, P=0.000; t=10.922, P=0.000). ConclusionNDRG2 can reduce the invasion and proliferation ability of colon cancer cell SW620, and its mechanism may be related to the downregulation of MMP-2 expression.

Key words: Colonic neoplasms, Blotting, Western, Transfection, NDRG2 gene