MicroRNA-506 Inhibits Malignancy of Colorectal Carcinoma Cells by Targeting LAMC1

Objective: To investigate the effects of microRNA-506 (miR-506) on malignancy of colorectal carcinoma (CRC) cells and to elucidate the underlying mechanism.

Methods: Human colorectal carcinoma cell lines SW480, SW620, HCT116, and HT29 were served as model. Five experimental groups are established in this study, including cell control, pcDNA3 blank vector control, miR-506 over-expression, pSIH1 blank vector control, and miR-506 suppression groups. Quantitative reverse transcription PCR (qRT-PCR) assay was performed to measure miR-506 level. Transwell, Cell counting kit8 (CCK-8), and colony formation assays were performed to detect migration and invasion, viability, and colony formation abilities of CRC cell lines, 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 CRC cell lines. The LAMC1 mRNA and protein levels were detected by qRT-PCR and Western blot, respectively.

Results: In the CRC cell lines, miR-506 level increased in the miR-506 over-expression group (P<0.05), compared with the blank vector control group. In the miR-506 over-expression group, cellular viability was significantly reduced (P<0.05). Migrated and invasive cell numbers and cell colony numbers were decreased (P<0.05). LAMC1 mRNA and protein levels in the miR-506 over-expression groups were lower than those in the control groups (P<0.05). However, there were no difference on the above indexes between pSIH1 blank vector control and miR-506 suppression groups.

Conclusion: miR-506 acts as a tumor suppressor and inhibits malignancy of colorectal cancer cells through directly targeting LAMC1.