J Cancer 2021; 12(16):4830-4840. doi:10.7150/jca.58494

Research Paper

Shikonin Inhibits Tumor Growth of ESCC by suppressing PKM2 mediated Aerobic Glycolysis and STAT3 Phosphorylation

Qiqi Zhang1, Qing Liu1, Shutao Zheng1, Tao Liu2, Lifei Yang3, Xiujuan Han1, Xiaomei Lu1✉

1. State Key Laboratory of Pathogenesis, Prevention and Treatment of High Incidence Diseases in Central Asia, Clinical Medical Research Institute, The First Affiliated Hospital of Xinjiang Medical University, Urumqi, Xinjiang Uygur Autonomous Region, China.
2. Department of Clinical Laboratory, First Affiliated Hospital of Xinjiang Medical University, Urumqi, Xinjiang Uygur Autonomous Region, China.
3. Cancer Hospital Affiliated of Xinjiang Medical University, Urumqi, Xinjiang Uygur Autonomous Region, China.

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Citation:
Zhang Q, Liu Q, Zheng S, Liu T, Yang L, Han X, Lu X. Shikonin Inhibits Tumor Growth of ESCC by suppressing PKM2 mediated Aerobic Glycolysis and STAT3 Phosphorylation. J Cancer 2021; 12(16):4830-4840. doi:10.7150/jca.58494. Available from https://www.jcancer.org/v12p4830.htm

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Abstract

Background: Shikonin, a small molecule inhibitor of pyruvate kinase 2 (PKM2), has been demonstrated to play the antitumor effect in various cancers. However, the specific effects and related regulatory mechanism of Shikonin in esophageal squamous cell carcinoma (ESCC) have not been clearly declared.

Materials and methods: Cell viability was valued through 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Glucose consumption, lactate production, glycolytic intermediates and pyruvate kinase enzymatic activity were measured using corresponding assay kits. Patient-derived xenograft (PDX) models were constructed to observe the anti-ESCC effect of Shikonin in vivo. PKM2, p-PKM2, signal transducer and activator of transcription 3 (STAT3), p-STAT3, glucose transporter 1 (GLUT1) and hexokinase 2 (HK2) in ESCC tissues were assessed by western blot. The expression of PKM2, p-PKM2, p-STAT3, GLUT1 and HK2 was assessed by immunohistochemistry (IHC) in ESCC tissue based on PDXs.

Results: Shikonin effectively inhibited cell proliferation in dose-dependent and time-dependent manner compared with the control group. The detection of glycolysis showed that Shikonin suppressed the glucose consumption, lactate production, glycolytic intermediates and pyruvate kinase enzymatic activity. Furthermore, Shikonin not only inhibited the growth of ESCC, but also decreased the expression of p-PKM2 and p-STAT3 in vivo. Finally, Shikonin suppressed the expression of GLUT1 and HK2 proteins which are related to glycolysis.

Conclusion: Shikonin has a significant antitumor effect in the ESCC by suppressing PKM2 mediated aerobic glycolysis and regulating PKM2/STAT3 signal pathway.

Keywords: Shikonin, Pyruvate kinase 2 (PKM2), Aerobic glycolysis, Esophageal squamous cell carcinoma (ESCC)