miR-222 can inhibit the autophagy of renal cell carcinoma cells through down-regulating the expression of DDIT4
10.3969/j.issn.1007-3969.2015.03.001
- VernacularTitle:miR-222通过下调DDIT4抑制肾癌细胞自噬
- Author:
Xiaochen NI
;
Zhihong ZHAO
;
Yongliang MA
;
Zongtao REN
;
Bin LIU
;
Aili ZHANG
- Publication Type:Journal Article
- Keywords:
miR-222;
Renal cell carcinoma;
DDIT4;
Autophagy
- From:
China Oncology
2015;(3):161-166
- CountryChina
- Language:Chinese
-
Abstract:
Background and purpose:MicroRNA (miRNA, miR) plays an important regulatory role in cancer. miR-222 is reported to be up-regulated in various tumors, but its role in renal cell carcinoma (RCC) remains unclear. In this study, we detected the expression of miR-222 in both RCC and adjacent tissue samples. The aim of this study was to investigate the role of miR-222 in RCC. Methods:The expression levels of miR-222 in RCC tissue samples were quantified by quantitative real-time polymerase chain reaction (qRT-PCR). DDIT4 and LC3-Ⅱ protein expressions were determined by Western blot. Dual luciferase assay was performed to verify the target of miR-222. EGFP-LC3 microscopy assay was performed to assess autophagy. Results:Results from qRT-PCR showed that the expression of miR-222 was up-regulated in RCC tissues. Knockdown of miR-222 with speciifc antagomiR decreased the cell viability of 786-O cells, whereas overexpression of miR-222 increased the cell viability (P<0.01). The levels of DDIT4 were up-regulated in 786-O cells transfected with miR-222 antagomiR, whereas overexpression of miR-222 induced the down-regulation of DDIT4 expression. Data from dual luciferase assay indicated that miR-222 directly targeted the expression of DDIT4. Consistently, the expression of DDIT4 in RCC tissues was down-regulated compared with adjacent tissues. Knockdown of miR-222 in 786-O cells induced a signiifcant increase of autophagosome formation and LC3 lipidation.These results supported that miR-222 could inhibit autophagy in RCC cells, which may affect the clinical characteristcs of RCC. Conclusion: miR-222 is up-regulated in RCC and can inhibit the autophagy of RCC cells through down-regulating the expression of DDIT4.
