ABSTRACT
[Objective] To investigate the expression of microRNA-200c (miR-200c) in colorectal carcinomas (CRC),and analyze its role on tumor cell migration and invasion.[Methods] The expression levels of miR-200c in CRC tissues and adjacent normal mucosa were assessed by real-time quantitative RT-PCR (qRT-PCR).miR-200c mimics were transiently transfected into human colorectal cancer cells,and their roles on cell migration and invasion were analyzed by Transwell assay.Cell proliferation was measured using the Cell Counting kit-8.The expression levels of epithelial and mesenchymal markers as well as related transcription factor ZEB1 were detected by Western blotting.[Results] Lower miR-200c expression was found in primary CRC tissues with lymph node metastasis compared to those without lymph node metastasis and adjacent normal mucosa.Transfection of miR-200c mimics suppressed proliferation,and reduced invasion and migration in SW620 cells.Furthermore,up-regulation of miR-200c inhibited ZEB1,and resulted in increased E-cadherin and reduced Vimentin gene expression.[Conclusion] miR-200c was associated with invasive and metastatic behavior of CRC.These effects may be mediated through regulation of epithelial-mesenchymal transition.
ABSTRACT
AIM:To investigate the clinical characteristics of microRNA(miR)-196b in colorectal cancer(CRC)and to study its biological function in 5-fluorouracil(5-FU)resistance.METHODS:miRNA sequence dataset and the corresponding clinical data of CRC patients were downloaded from The Cancer Genome Atlas(TCGA).Expression level and clinical characteristics of miR-196b in CRC patients were analyzed using SPSS 17.0.CRC cell line overexpres-sing miR-196b was established using transient transfection method.MTS test was used to evaluate the effect of miR-196b overexpression on 5-FU resistance.RESULTS:miR-196b expression was associated with lymph node metastasis and TNM stage(P<0.05),but not related with age and sex.Lymph node metastasis and distant metastasis were independent prog-nostic factors for rectal patients(P<0.05).The expression level of miR-196b was not associated with survival condition of rectal patients.The viability of the cells overexpressing miR-196b treated with different concentrations of 5-FU was signifi-cantly higher than that in control group(P<0.05).CONCLUSION:miR-196b may be a potential biomarker of TNM stage and lymph node metastasis in CRC.miR-196b increases the 5-FU resistance of CRC cells.