SIRT1 and cancer: Further, p53 regulates several miRNAs that control metabolism in cancer; it also modulates the expression of miR-34, the miR-194/miR-215 cluster, let-7 and miR-107, which further inhibits the expression of their target genes, including LDHA, MYC and sirtuin-1 (SIRT1), as well as HIF [22,56,57].