Effects of miR-506 on proliferation of colorectal carcinoma cells and its mechanism

ZU Caihua; ZHANG Guoliang; LIU Tao

doi:10.3969/j.issn.1002-266X.2016.40.002

Abstract：Objective To investigate the effects of microRNA-506 (miR-506) on proliferation of colorectal carcinoma cells and to identify the target gene for miR-506.Methods The colorectal carcinoma SW620 cells were respectively divid-ed into pcDNA3 group, miR-506 group, pSIH1 group and TuD-506 group according to different tranfection plasmids.The real-time fluorescent quantitative PCR was used to detect the expression of miR-506.Cell viability and colony-forming abili-ty was measured by CCK8 and colony formation assays, respectively.Furthermore, bioinformatics method was applied to predict potential target genes of miR-506.Green fluorescent protein ( GFP) reporter assays were used to verify the direct regulation of miR-506 on target mRNA in SW620 cells.The LAMC1 mRNA and protein levels were detected by quantitative reverse transcription polymerase chain reaction ( qRT-PCR) and Western blotting, respectively.Results Compared with the pcDNA3 group, the relative expression of miR-506 in the miR-506 group was significantly higher, while the activity and colony formation ability of the miR-506 group was significantly decreased (all P<0.01).No statistically significant differ-ence was found in the relative expression of miR-506, cell viability and colony forming ability between the TuD-506 group and pSIH1 group (all P>0.05).LAMC1 was predicted to be a potential target gene of miR-506, and GFP reporter assays verified miR-506 directly targeted LAMC1 mRNA and negatively regulated its expression.The expression of miR-506 in the miR-506 group was significantly lower than that of the pcDNA3 group (all P<0.05).No statistically significant difference was found in the LAMC1 mRNA and protein expression between the TuD-506 group and pSIH1group (all P>0.05).Con-clusion miR-506 plays a tumor suppressor role in SW620 cells by inhibiting cell viability and colony formation, LAMC1 is a direct target gene for miR-506, and miR-506 inhibits proliferation of colorectal cancer cells by down-regulating the ex-pression of LAMC1.