NR2F2 inhibits Smad7 expression and promotes TGF-β-dependent epithelial-mesenchymal transition of CRC via transactivation of miR-21.

Metastasis is one of the most decisive factors influencing CRC patient prognosis and current studies suggest that a molecular mechanism known as EMT broadly regulates cancer metastasis. NR2F2 is a key molecule in the development of CRC, but the roles and underlying mechanisms of NR2F2 in TGF-β induced EMT in CRC remain largely unknown. In the current study, we were interested to examine the role of NR2F2 in the TGF-β-induced EMT in CRC. Here, we found NR2F2 was upregulated in CRC cells and promotes TGF-β-induced EMT in CRC. Using comparative miRNA profiling TGF-β pre-treated CRC cells in which NR2F2 had been knocked down with that of control cells, we identified miR-21 as a commonly downregulated miRNA in HT29 cells treated with TGF-β and NR2F2 siRNA, and its downregulation inhibiting migration and invasion of CRC cells. Moreover, we found NR2F2 could transcriptional activated miR-21 expression by binding to miR-21 promoter in HT29 by ChIP and luciferase assay. In the last, our data demonstrated that Smad7 was the direct target of miR-21 in CRC cells. Thus, NR2F2 could promote TGF-β-induced EMT and inhibit Smad7 expression via transactivation of miR-21, and NR2F2 may be a new common therapeutic target for CRC.

Wang H ，Nie L ，Wu L ，Liu Q ，Guo X ... -  《-》

MiR-382 inhibits cell growth and invasion by targeting NR2F2 in colorectal cancer.

Colorectal cancer (CRC) is one of the leading causes of cancer death worldwide. MiR-382 has been found to have a decreased expression and the ability to suppress tumorigenesis in certain cancers. However, the role of miR-382 in CRC has not been sufficiently investigated. NR2F2 (also known as COUP-TFII), a member of the steroid/thyroid receptor superfamily, is often aberrantly activated in various tumors, but it is currently unclear whether NR2F2 may be a target of miR-382. In the present study, we investigated the role of miR-382 in CRC and identified the regulation of NR2F2 by miR-382. We observed that miR-382 was aberrantly downregulated in CRC. Transfection with miR-382 mimics impeded the growth, migration, and invasion of CRC cells. The direct binding of miR-382 to the 3' untranslated region (3' UTR) of NR2F2 was confirmed using a luciferase reporter gene assay. We showed that the relative expression levels of NR2F2 were significantly higher in CRC tissues compared with normal adjacent mucosa. A Kaplan-Meier analysis indicated that patients with high NR2F2 expression had a poor overall survival. Knockdown of NR2F2 inhibited CRC cell growth, migration, and invasion. Ectopic expression of NR2F2 mitigated miR-382 suppression of CRC cell proliferation, migration, and invasion. In conclusion, the present study describes a potential mechanism underlying a miR-382/NR2F2 link contributing to CRC development. Our results demonstrate that miR-382 represents a potential strategy against CRC. © 2016 Wiley Periodicals, Inc.

Zhou B ，Song J ，Han T ，Huang M ，Jiang H ，Qiao H ，Shi J ，Wang Y ... -  《-》

miR-4775 promotes colorectal cancer invasion and metastasis via the Smad7/TGFβ-mediated epithelial to mesenchymal transition.

Zhao S ，Sun H ，Jiang W ，Mi Y ，Zhang D ，Wen Y ，Cheng D ，Tang H ，Wu S ，Yu Y ，Liu X ，Cui W ，Zhang M ，Sun X ，Zhou Z ，Peng Z ，Yan D ... -  《Molecular Cancer》

miR-367 promotes epithelial-to-mesenchymal transition and invasion of pancreatic ductal adenocarcinoma cells by targeting the Smad7-TGF-β signalling pathway.

Zhu Z ，Xu Y ，Zhao J ，Liu Q ，Feng W ，Fan J ，Wang P ... -  《-》

miR-21 overexpression enhances TGF-β1-induced epithelial-to-mesenchymal transition by target smad7 and aggravates renal damage in diabetic nephropathy.

Epithelial-to-mesenchymal transition (EMT) plays an important role in renal interstitial fibrosis (RIF) with diabetic nephropathy (DN). Smad7 (a inhibitory smad), a downstream signaling molecules of TGF-β1, represses the EMT. The physiological function of miR-21 is closely linked to EMT and RIF. However, it remained unclear whether miR-21 over-expression affected TGF-β1-induced EMT by regulating smad7 in DN. In this study, real-time RT-PCR, cell transfection, luciferase reporter gene assays, western blot and confocal microscope were used, respectively. Here, we found that miR-21 expression was upregulated by TGF-β1 in time- and concentration -dependent manner. Moreover, miR-21 over-expression enhanced TGF-β1-induced EMT(upregulation of a-SMA and downregulation of E-cadherin) by directly down-regulating smad7/p-smad7 and indirectly up-regulating smad3/p-smad3, accompanied by the decrease of Ccr and the increase of col-IV, FN, the content of collagen fibers, RTBM, RTIAW and ACR. Meantime, the siRNA experiment showed that smad7 can directly regulate a-SMA and E-cadherin expression. More importantly, miR-21 inhibitor can not only inhibit EMT and fibrosis but also ameliorate renal structure and function. In conclusion, our results demonstrated that miR-21 overexpression can contribute to TGF-β1-induced EMT by inhibiting target smad7, and that targeting miR-21 may be a better alternative to directly suppress TGF-β1-mediated fibrosis in DN.

Wang JY ，Gao YB ，Zhang N ，Zou DW ，Wang P ，Zhu ZY ，Li JY ，Zhou SN ，Wang SC ，Wang YY ，Yang JK ... -  《-》