MicroRNA-204 modulates colorectal cancer cell sensitivity in response to 5-fluorouracil-based treatment by targeting high mobility group protein A2.

MicroRNAs (miRNAs) are a conserved class of ∼22 nucleotide RNAs that playing important roles in various biological processes including chemoresistance. Recently, many studies have revealed that miR-204 is significantly attenuated in colorectal cancer (CRC), suggesting that this miRNA may have a function in CRC. However, whether miR-204 modulates chemosensitivity to 5-fluorouracil (5-Fu) in colorectal cancer is still unclear. In our present study, we discuss this possibility and the potential mechanism exerting this effect. We identified high mobility group protein A2 (HMGA2) as a novel direct target of miR-204 and showed that miR-204 expression was decreased while HMGA2 expression was increased in CRC cell lines. Additionally, both MiR-204 overexpression and HMGA2 inhibition attenuated cell proliferation, whereas forced expression of HMGA2 partly restored the inhibitory effect of miR-204 on HCT116 and SW480 cells. Moreover, the miR-204/HMGA2 axis modulated the resistance of tumor cells to 5-Fu in HCT-116 and SW480 colon cancer cells via activation of the PI3K/AKT pathway. These results demonstrate that the miR-204/HMGA2 axis could play a vital role in the 5-Fu resistance of colon cancer cells. Taken together, our present study elucidated that miR-204 upregulated 5-Fu chemosensitivity via the downregulation of HMGA2 in colorectal cancer and provided significant insight into the mechanism of 5-Fu resistance in colorectal cancer patients. More importantly, our present study suggested that miR-204 has potential as a therapeutic strategy for 5-Fu-resistant colorectal cancer.