Polydatin Exerts an Antitumor Effect Through Regulating miR-382/PD-L1 Axis in Colorectal Cancer.

Background: Colorectal cancer (CRC) is considered as one of the most lethal malignancies worldwide. However, the effective therapies remain limited. Polydatin, a main effective component of the Chinese herb Polygonum cuspidatum, has multiple antitumor activities; however, whether Polydatin has anti-CRC activity is not fully understood. Materials and Methods: CRC cell proliferation and apoptosis were measured after treatment of Polydatin using Cell Counting Kit-8 assay, colony formation assay, and flow cytometer assay. The expression of miR-382 and programmed cell death ligand 1 (PD-L1) were determined in CRC cell lines by quantitative real-time polymerase chain reaction and Western blot, respectively. Furthermore, dual-luciferase reporter assay was conducted to determine the target of miR-382. Moreover, loss-of-functional experiments were used to identify the effect of Polydatin on miR-382. Finally, tumor xenograft experiments were conducted to determine the effect of Polydatin in vivo. Results: As a result, Polydatin effectively inhibited cell proliferation and promoted cell apoptosis in CRC cell lines. PD-L1 was confirmed as a direct target of miR-382. Furthermore, Polydatin could suppress the expression of PD-L1 by upregulating miR-382. Moreover, Polydatin inhibits proliferation and promotes apoptosis of CRC cells by regulating miR-382 and suppressing CRC tumor growth in vivo. Conclusion: Polydatin inhibits CRC cell proliferation and promotes apoptosis by regulating miR-382/PD-L1 axis. Polydatin could be a potential compound to synthesize novel antitumor drugs.