OBJECTIVE:To investigate the effect of Ruyanneixiao cream(RYNX) on the expression of hypoxia inducible factor-1α(HIF-1α), hexokinase 2(HK2),phosphofructokinase(PFK), and pyruvate kinase M2(PKM2) mRNA and protein in MCF-10 AT cells and in an animal model of precancerous mammary lesions.METHODS:Following treatment of MCF-10 AT cells with RYNX, tamoxifen(TAM) and YC-1 for 48 h,HIF-1α, HK2, PFK, PKM2 mRNA and protein expression was analyzed.Fifty female SD rats were randomly divided into control, model, TAM, and highand low-dose RYNX groups, with 10 rats in each group.A precancerous mammary lesion model was established for all groups except the control group.High-and low-dose RYNX cream containing TAM was coated on the breasts of animals in the corresponding groups.The rat mammary tissue was removed in the 10 th week and HIF-1α, HK2, PFK,PKM2 mRNA and protein was analyzed.RESULTS:In vitro analyses demonstrated that, compared with the matrix group, HIF-1α, HK2, PFK,PKM2 mRNA and protein expression was significantly decreased in the RYNX group(P < 0.05).Compared with the YC-1 + RYNX group, HK2, PFK,and PKM2 protein expression was significantly reduced in the RYNX group.HIF-1α, HK2, PFK, and PKM2 protein expression was increased significantly in the model group(P < 0.05) compared with the control group, while HIF-1α, HK2, PFK, and PKM2 mRNA and protein expression was significantly decreased in both the high-and low-dose RYNX groups(P < 0.05), with the effect being greater in the high-dose group.CONCLUSION:RYNX can block precancerous breast lesions by decreasing the expression of HK2,PFK, and PKM2 mRNA and protein via inhibition of HIF-1α mRNA and protein overexpression in a dose-dependent manner.