MicroRNA-99a Promotes Proliferation And Migration Of Colon Cancer Cell And Its Anti-tumor Mechanism

Colon cancer is one of the common malignant tumor,is the third and second most common types of cancer in men and women,with different incidence rates in different countries,and leads serious threat to human life and health.But the process of colon cancer is complex,with multiple genes and factors involved.Its pathogenesis is not fully illuminated with poor outcome.Many scholars have paid much attention to gene expression of colorectal cancer.Micro RNA are a class of small molecular non-coding RNAs.They negatively regulate gene expression through basic pairing with the 3' untranslated region(3'UTR)of target m RNAs,which results in m RNA degradation and/or translation repression.Numerous studies have found that a variety of mi RNAs with different expression,associated with gastric cancer,colon cancer,liver cancer,lung cancer,breast cancer,and others,as cancer promoter or tumor suppressor,and closely related to the occurrence and progression,and metastasis of malignant tumor.To investigate the interaction mechanism between micro RNA and colon cancer may provide a theoretical basis for the prevention and treatment of colon cancer.Objective:To investigate the expression of micro RNA-99 a in the tumor tissues of colon cancer patients and its effect on cancer cell proliferation and migration.Methods:49 pairs of cancer tissue and adjacent tissue(5cm away from cancer tissue)from colon cancer patients that treated in Gastrointestinal Center of Affiliated Changzhou Second Hospital of Nanjing Medical University,and colon cancer cell lines(HT-29,HCT-116,SW480,Caco-2)as well as normal epithelial Hcoe Pic cell line were selected for our research.Quantitative real-time PCR was used to detect the levels of micro RNA-99 a in tumor tissues,adjacent tissues and tumor cells;After transfection of mciro RNA-99 a inhibitor,we used CCK-8 to test the cell proliferation,transwell assay to observe the cell migration,and Western blot to examine the levels of FGFR3 in HT-29 cells.Results:The expression of micro RNA-99 a in the cancer tissues was significantly higher than that in normal para-cancerous tissues(6.27±0.48 vs 1.34±0.54,P<0.05),and its expression in tumor cells was significantly higher than that in normal colon epithelial cells(5.48±0.34,7.67±0.24,5.78±0.22,6.28±0.44 vs 1.45±0.37,P<0.05).After micro RNA-99 a inhibitor transfection,cell proliferation and migration of HT-29 cells were significantly decreased(P<0.05);in the meanwhile,the m RNA and protein levels of FGFR3 were significantly decreased in HT-29 cells(P<0.05).Conclusion:micro RNA-99 a was highly expressed in the tumor tissue of colon cancer patients and colon cancer cells,and low expression of micro RNA-99 a may weaken the proliferation and migration ability of cancer cells,which might be accomplished through FGFR3 signaling pathway.