MiR-30c exerts tumor suppressive functions in colorectal carcinoma by directly targeting BCL9

Colorectal carcinoma (CRC) remains a leading health threat worldwide due to its high mortality. MicroRNA (miR-30c) is an important tumor suppressor in various cancers. B cell lymphoma 9 (BCL9) is one of the candidate genes for cancers. The synergistic effects of miR-30c and BCL9 in CRC progression remain to be carefully elucidated.

Fifty pairs of CRC samples and matched adjacent non-tumor tissues were collected from Yantai Yuhuangding Hospital between 2015 and 2017. MiR-30c and BCL9 expression levels were measured by quantitative Real-time polymerase chain reaction (qRT-PCR) in CRC tissues and cell lines. The 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was performed to determine the influence of miR-30c on the proliferation ability of CRC cells. Target Scan was used to predict the potential target of miR-30c. Then, luciferase assay was performed to confirm the prediction. In addition, we also investigated the biological influence of BCL9 on miR-30c-mediated functions in CRC.

We found that miR-30c was significantly decreased in CRC tissues and cell lines while the BCL9 expression level was prominently increased in CRC tissues and cells. Additionally, the miR-30c expression was negatively correlated with BCL9 expressions in CRC tissues. Furthermore, the findings of this study also showed that BCL9 was a direct target of miR-30c in CRC and miR-30c could inhibit the CRC proliferation by binding to its 3'-UTR.

This study showed that miR-30c overexpression inhibited CRC proliferation via the regulation of BCL9, suggesting that miR-30c may be a new molecular therapeutic target for CRC.