Role and possible mechanism of miR-21 on the regulation of anoikis resistance in human colon carcinoma

Abstract:

Objective：To investigate the role and possible mechanism of miR-21 on the regulation of anoikis in human colon carci－noma. Methods：The expression level of miR-21 in 30 cases of colon cancer was examined by qRT-PCR，and its correlation with clinicopathologic features and prognosis was further analyzed. HT-29 cells and its derivative HT-29/AR（subpopulation of HT-29 cells that acquired resistance to anoikis） were used to explore the relationship between the expression of miR-21 and anoikis resis－tance. Western blot was used to detect changes of PDCD4 and PTEN，and dual-luciferase reporter assay was applied to verify the di－rect conjunction of miR-21 to its 3’UTR. Results：Expression of miR-21 in human colon carcinoma tissues was higher than that in adjacent tissues；was significantly correlated with poor differentiation，lymph node metastasis and TNM stage；patients with high ex－pression of miR-21 had poor prognosis. Compared with HT-29 cells，miR-21 expression in HT-29/AR cells was significantly in－creased and transfection of miR-21 mimics was able to promote the anoikis resistance of HT-29 cells. Western blot and dual-lu－ciferase reporter assay demonstrated that miR-21 was able to increase the anoikis resistance of colon carcinoma cells by inhibiting expression of PDCD4 and PTEN. Conclusion：The miR-21 can participate in regulating anoikis in human colon carcinoma cells by targeted inhibiting PDCD4 and PTEN.