Expression of miR-31 in rectal cancer patients and its effect on proliferation ability of rectal cancer cells SW837

J.-F. Mu, X.-D. Wang, P.-D. Sun

Department of Gastric Colorectal Surgery, The First Hospital of Jilin University, Changchun, P.R. China. spd52291@163.com

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• Oncology

OBJECTIVE: This study aimed to investigate the expression of miR-31 in rectal cancer patients and its effect on the proliferation and invasion ability of human rectal cancer cells SW837.

PATIENTS AND METHODS: 55 rectal cancer cancerous tissue specimens and 55 corresponding adjacent tissue (tissue adjacent to carcinoma) specimens were collected from rectal cancer patients treated in The First Hospital of Jilin University from March 2014 to March 2015. Real Time-quantitative Polymerase Chain Reaction was used for detecting the expression level of miR-31 in cancerous tissue and corresponding adjacent tissues. Differences in the expression of miR-31 were compared between the two groups. Different miR-31 expression vectors were established and rectal cancer cells SW837 were transfected. MTT was used for detecting the proliferation ability of the cells in the miR-31-mimics group, miR-31-inhibitor group and miR-control group.

RESULTS: The expression level of miR-31 was significantly higher in rectal cancer tissues than that in the adjacent tissues (p<0.05). The expression of miR-31 was higher in the miR-31-mimics group (23.6±4.6) than that in the miR-control group (1.63±0.65), while the expression of miR-31 was lower in the miR-31-inhibitor group (0.65±0.23) than that in the miR-control group. The proliferation ability of cells at the 6th, 12th, 24th, 48th, and 72nd hours was higher in the miR-31-mimics group than in the miR-31-inhibitor group, while that of cells was significantly lower in the miR-31-inhibitor group than in the miR-control group, with statistically significant differences (p<0.05). The number of invasive membrane cells (cell membrane number) counted under a microscope was (84.2±10.6) cells in the miR-31-mimics group, (12.3±4.1) cells in the miR-31-inhibitor group, and (45.2±10.6) cells in the miR-control group. The invasion ability in vitro of SW837 cells significantly increased after the overexpression of miR-31 (p<0.05).

CONCLUSIONS: miR-31 is increasingly expressed in rectal cancer. Low expression of miR31 can inhibit the proliferation and invasion ability of the cells. MiR-31 is expected to become a current biotherapeutic target.

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