Salvia Miltiorrhiza Inhibited Lung Cancer Through HKII-Dependent Aerobic Glycolysis Suppression

Abstract

Background: Cancer cells can still take in the glucose and produce lactic acid under the condition of sufficient oxygen. This unique metabolic mode is known as aerobic glycolysis, also known as the 'Warburg effect'. Inhibition of tumor aerobic glycolysis promotes anti-tumor immunity and is a potential cancer treatment strategy. Salvia miltiorrhiza is a classical Chinese herbal medicine and has effective activity against human cancer. However, its role in interfering with aerobic glycolysis remains to be elucidated.

Methods: C57BL/6J tumor-bearing model was established, and CCK-8 staining, Annexin V/PI staining, and colony formation test were performed. In vitro and in vivo experiments were conducted to jointly evaluate the anti-lung cancer efficacy of water extract (DSAE), ethanol extract (DSEE) of Salvia miltiorrhiza and its active components Danshensu (DSS) and dihydrotanshinone I (DHI). The effects of DSAE, DSEE, DSS, and DHI on aerobic glycolysis were studied using metabolite kits and the Seahorse method. in Key enzymes during aerobic glycolysis were detect with immunofluorescence, western blotting, immunohistochemistry. Chemical antagonists and molecular cloning technology were used to determine the role of key enzyme hexokinase-II (HK-II) in the antitumor effect of Salvia miltiorrhiza’s in lung cancer cells.

Results: Inhibition of cell proliferation, reduction of colonies number, decreased tumor volume, and increased apoptotic cells suggested that Salvia miltiorrhiza and its active components exerted an anti-lung cancer effect. Metabolites (ATP, lactic acid, and pyruvate content）production was inhibited, Seahorse indexes changed, such as the decrease of basic glycolysis. The data suggested that DSAE, DSEE, DSS, and DHI impaired the aerobic glycolysis of lung cancer cells. HK-II antagonists (2-Deoxy-D-glucose,2-DG; 2-Deoxy-D-glucose,3-BP) and HK-II silencing could enhance the intervention effects of DSS and DHI on aerobic glycolysis and the sensitivity of lung cancer cells to DSS and DHI, while HK-II high level expression showed an opposite effect.

Conclusions: Salvia miltiorrhiza played anti-lung cancer effect via suppressing aerobic glycolysis in a HK-II dependent manner.This study not only provides a new paradigm for Salvia miltiorrhiza in the treatment of cancer but also highlights the important role of mitochondrial HK-II in the link between glucose metabolism and Salvia miltiorrhiza in promoting blood circulation and removing blood stasis.

Keywords: Lung cancer, Salvia miltiorrhiza, Warburg effect, HKII