Vemurafenib is a selective and potent small molecule inhibitor of the V600 
mutant form of the BRAF protein used in the treatment of melanoma and colorectal 
cancer. However, vemurafenib has less effect in BRAF mutant colorectal cancer 
due to the resistance of tumor cell to vemurafenib. To verify whether or not 
miR-145, a short RNA molecule of microRNA which has been supposed to be a tumor 
suppressor, is involved in this process, we established vemurafenib-resistant 
cell line colo205/V and found that the miR-145 expression was significantly 
downregulated in colo205/V cells compared to normal colo205 cells. Moreover, the 
overexpression of miR-145 could increase the sensitivity of colo205/V cells to 
vemurafenib both in vitro and in vivo. In conclusion, miR-145 might be used as a 
therapeutic target in the treatment of colorectal cancer patients with BRAF 
V600E mutation.