Basic Study
Copyright ©The Author(s) 2022. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Aug 28, 2022; 28(32): 4600-4619
Published online Aug 28, 2022. doi: 10.3748/wjg.v28.i32.4600
Sirolimus increases the anti-cancer effect of Huai Er by regulating hypoxia inducible factor-1α-mediated glycolysis in hepatocellular carcinoma
Lin Zhou, Yang Zhao, Li-Chao Pan, Jing Wang, Xian-Jie Shi, Guo-Sheng Du, Qiang He
Lin Zhou, Yang Zhao, Jing Wang, Qiang He, Department of Hepatobiliary and Pancreaticosplenic Surgery, Beijing ChaoYang Hospital, Capital Medical University, Beijing 100020, China
Li-Chao Pan, Xian-Jie Shi, Guo-Sheng Du, Faculty of Hepato-Pancreato-Biliary Surgery, Chinese PLA General Hospital, Beijing 100853, China
Author contributions: Zhou L, Zhao Y, and Pan LC contributed equally to this work; Zhou L, Shi XJ, and He Q contributed to conception and design; Du GS, Shi XJ, and He Q contributed to administrative support; He Q and Du GS contributed to provision of study materials; Zhou L, Pan LC, and Wang J contributed to experimental manipulation; Zhao Y, Wang J, and Zhou L contributed to collection and assembly of data; Wang J and Zhao Y contributed to data analysis and interpretation; all authors contributed to manuscript writing and final approval.
Supported by the Natural Science Foundation of Capital Medical University, No. PYZ20014 and No. PYZ21074.
Institutional review board statement: The study was reviewed and approved by the Ethics Committee of Beijing Chaoyang Hospital, No. 2021-1-19-3; and PLA General Hospital, No. S2108-013-01.
Informed consent statement: All study participants, or their legal guardians, provided written informed consent for personal and medical data collection prior to study enrolment.
Conflict-of-interest statement: The authors have no conflicts of interest to declare.
Data sharing statement: The data used and analysed in this study are included in the article or are available from the corresponding and first authors upon reasonable request.
ARRIVE guidelines statement: The authors have read the ARRIVE guidelines, and the manuscript was prepared and revised according to the ARRIVE guidelines.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: https://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Guo-Sheng Du, MD, Professor, Faculty of Hepato-Pancreato-Biliary Surgery, Chinese PLA General Hospital, No. 28 Fuxing Road, Haidian District, Beijing 100853, China. duguosheng309@126.com
Received: November 10, 2021
Peer-review started: November 10, 2021
First decision: January 9, 2022
Revised: January 11, 2022
Accepted: July 16, 2022
Article in press: July 16, 2022
Published online: August 28, 2022
Abstract
BACKGROUND

Glycolysis caused by hypoxia-induced abnormal activation of hypoxia inducible factor-1α (HIF-1α) in the immune microenvironment promotes the progression of hepatocellular carcinoma (HCC), leading to enhanced drug resistance in cancer cells. Therefore, altering the immunosuppressive microenvironment by imp-roving the hypoxic state is a new goal in improving cancer treatment.

AIM

To analyse the role of HIF-1α, which is closely related to tumour proliferation, invasion, metastasis, and angiogenesis, in the proliferation and invasion of liver cancer, and to explore the HIF-1α pathway-mediated anti-cancer mechanism of sirolimus (SRL) combined with Huai Er.

METHODS

Previous studies on HCC tissues identified the importance of HIF-1α, glucose transporter 1 (GLUT1), and lactate dehydrogenase A (LDHA) expression. In this study, HepG2 and Huh7 cell lines were treated, under hypoxic and normoxic conditions, with a combination of SRL and Huai Er. The effects on proliferation, invasion, cell cycle, and apoptosis were analysed. Proteomics and genomics techniques were used to analyze the HIF-1α-related signalling pathway during SRL combined with Huai Er treatment and its inhibition of the proliferation of HCC cells.

RESULTS

High levels of HIF-1α, LDHA, and GLUT-1 were found in poorly differentiated HCC, with lower patient survival rates. Hypoxia promoted the proliferation of HepG2 and Huh7 cells and weakened the apoptosis and cell cycle blocking effects of the SRL/Huai Er treatment. This was achieved by activation of HIF-1α and glycolysis in HCC, leading to the upregulation of LDHA, GLUT-1, Akt/mammalian target of rapamycin (mTOR), vascular endothelial growth factor (VEGF), and Forkhead box P3 and downregulation of phosphatase and tensin homolog deleted on chromosome ten (PTEN) and p27. The hypoxia-induced activation of HIF-1α showed the greatest attenuation in the SRL/Huai Er (S50 + H8) group compared to the drug treatments alone (P < 0.001). The S50 + H8 treatment significantly downregulated the expression of mTOR and HIF-1α, and significantly reduced the expression of VEGF mRNA. Meanwhile, the combined blocking of mTOR and HIF-1α enhanced the downregulation of Akt/mTOR, HIF-1α, LDHA, and GLUT-1 mRNA and resulted in the downregulation of PTEN, p27, and VEGF mRNA (P < 0.001).

CONCLUSION

SRL increases the anti-cancer effect of Huai Er, which reduces the promotion of hypoxia-induced HIF-1α on the Warburg effect by inhibition of the PI3K/Akt/mTOR-HIF-1α and HIF-1α-PTEN signalling pathways in HCC.

Keywords: Hepatocellular carcinoma, Sirolimus, Huai Er, Warburg effect, Hypoxia inducible factor-1α

Core Tip: Hypoxia-mediated glycolysis is associated with poorly differentiated hepatocellular carcinoma (HCC) and a poor prognosis. Hypoxia inducible factor-1α (HIF-1α), induced by hypoxia, promotes the growth of HepG2 and Huh7 cells and weakens the anti-cancer effect of sirolimus (SRL) and Huai Er. SRL increased the anti-cancer effect of Huai Er, which reduced the promotion of hypoxia-induced HIF-1α on the Warburg effect by inhibiting the PI3K/Akt/mammalian target of rapamycin-HIF-1α and HIF-1α-phosphatase and tensin homolog deleted on chromosome ten signalling pathways in HCC.