Modulation of miR‐34a in curcumin‐induced antiproliferation of prostate cancer cells

: Curcumin is a phytochemical which exhibits significant inhibitory effect in multiple cancers including prostate cancer. MicroRNA-34a (miR-34a) was found to be a master tumor suppressor miRNA and regulated the growth of cancer cells. To date, however, the role of miR-34a in the anticancer action of curcumin against prostate cancer has been rarely reported. In the present study, we showed that curcumin altered the expression of cell cycle-related genes (cyclin D1, PCNA, and p21) and inhibited the proliferation of prostate cancer cells. Furthermore, we found that curcumin significantly upregulated the expression of miR-34a, along with the downregulated expression of β-catenin and c-myc in three prostate cancer cell lines. Inhibition of miR-34a activated β-catenin/c-myc axis, altered cell cycle-related genes expression and significantly suppressed the antiproliferation effect of curcumin in prostate cancer cells. Findings from this study revealed that miR-34a plays an important role in the antiproliferation effect of curcumin in prostate cancer.