Basic Study
Copyright ©The Author(s) 2023. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Sep 14, 2023; 29(34): 5038-5053
Published online Sep 14, 2023. doi: 10.3748/wjg.v29.i34.5038
Suberoylanilide hydroxamic acid upregulates reticulophagy receptor expression and promotes cell death in hepatocellular carcinoma cells
Jia-Yao Li, Tian Tian, Bing Han, Ting Yang, Yi-Xin Guo, Jia-Yu Wu, Yu-Si Chen, Qin Yang, Ru-Jia Xie
Jia-Yao Li, Bing Han, Ting Yang, Yi-Xin Guo, Jia-Yu Wu, Yu-Si Chen, Qin Yang, Ru-Jia Xie, Guizhou Provincial Key Laboratory of Pathogenesis and Drug Research on Common Chronic Diseases, College of Basic Medical Sciences, Guizhou Medical University, Guiyang 550025, Guizhou Province, China
Jia-Yao Li, Bing Han, Ting Yang, Yi-Xin Guo, Jia-Yu Wu, Yu-Si Chen, Qin Yang, Ru-Jia Xie, Department of Pathophysiology, College of Basic Medical Sciences, Guizhou Medical University, Guiyang 550025, Guizhou Province, China
Tian Tian, Department of Eugenic Genetics, Guiyang Maternal and Child Health Care Hospital, Guiyang 550003, Guizhou Province, China
Author contributions: Xie RJ and Yang Q contributed to the experimental conception and design; Li JY, Tian T, and Han B conducted the experiments; Yang T and Guo YX collected and assembled the experimental data; Li JY, Chen YS, and Wu JY contributed to data analysis and interpretation; Li JY and Xie RJ wrote the article; All authors approved the final manuscript. Li JY, Tian T, and Han B contributed equally to this work.
Supported by the National Natural Science Foundation of China, No. 82260127; Guizhou Provincial Science and Technology Projects, No. Qiankehe Jichu-ZK[2021]365 and Qiankehe Jichu-ZK[2021]364; National Natural Science Foundation Cultivation Project of Guizhou Medical University, No. 20NSP016; Guizhou Provincial Natural Science Foundation, No. [2021]4029 and [2022]4017; and Science and Technology Foundation of Guizhou Provincial Health Commission, No. gzwjkj2019-1-102.
Institutional review board statement: This study did not involve human subjects or living animals.
Conflict-of-interest statement: All the authors report having no relevant conflicts of interest for this article.
Data sharing statement: The data used to support the findings of this study are available from the corresponding author at 592153968@qq.com upon request.
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 NonCommercial (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: Ru-Jia Xie, MD, Academic Research, Department of Pathophysiology, College of Basic Medical Sciences, Guizhou Medical University, Dongqing Road, Guiyang 550025, Guizhou Province, China. 592153968@qq.com
Received: March 23, 2023
Peer-review started: March 23, 2023
First decision: June 17, 2023
Revised: July 15, 2023
Accepted: August 15, 2023
Article in press: August 15, 2023
Published online: September 14, 2023
Processing time: 169 Days and 6.8 Hours
Abstract
BACKGROUND

Hepatocellular carcinoma (HCC) is a common clinical condition with a poor prognosis and few effective treatment options. Potent anticancer agents for treating HCC must be identified. Epigenetics plays an essential role in HCC tumorigenesis. Suberoylanilide hydroxamic acid (SAHA), the most common histone deacetylase inhibitor agent, triggers many forms of cell death in HCC. However, the underlying mechanism of action remains unclear. Family with sequence similarity 134 member B (FAM134B)-induced reticulophagy, a selective autophagic pathway, participates in the decision of cell fate and exhibits anticancer activity. This study focused on the relationship between FAM134B-induced reticulophagy and SAHA-mediated cell death.

AIM

To elucidate potential roles and underlying molecular mechanisms of reticulophagy in SAHA-induced HCC cell death.

METHODS

The viability, apoptosis, cell cycle, migration, and invasion of SAHA-treated Huh7 and MHCC97L cells were measured. Proteins related to the reticulophagy pathway, mitochondria-endoplasmic reticulum (ER) contact sites, intrinsic mitochondrial apoptosis, and histone acetylation were quantified using western blotting. ER and lysosome colocalization, and mitochondrial Ca2+ levels were characterized via confocal microscopy. The level of cell death was evaluated through Hoechst 33342 staining and propidium iodide colocalization. Chromatin immunoprecipitation was used to verify histone H4 lysine-16 acetylation in the FAM134B promoter region.

RESULTS

After SAHA treatment, the proliferation of Huh7 and MHCC97L cells was significantly inhibited, and the migration and invasion abilities were greatly blocked in vitro. This promoted apoptosis and caused G1 phase cells to increase in a concentration-dependent manner. Following treatment with SAHA, ER-phagy was activated, thereby triggering autophagy-mediated cell death of HCC cells in vitro. Western blotting and chromatin immunoprecipitation assays confirmed that SAHA regulated FAM134B expression by enhancing the histone H4 lysine-16 acetylation in the FAM134B promoter region. Further, SAHA disturbed the Ca2+ homeostasis and upregulated the level of autocrine motility factor receptor and proteins related to mitochondria-endoplasmic reticulum contact sites in HCC cells. Additionally, SAHA decreased the mitochondrial membrane potential levels, thereby accelerating the activation of the reticulophagy-mediated mitochondrial apoptosis pathway and promoting HCC cell death in vitro.

CONCLUSION

SAHA stimulates FAM134B-mediated ER-phagy to synergistically enhance the mitochondrial apoptotic pathway, thereby enhancing HCC cell death.

Keywords: Suberoylanilide hydroxamic acid, Histone H4 lysine-16, Reticulophagy, Apoptosis, Autophagic cell death, Hepatocellular carcinoma

Core Tip: Family with sequence similarity 134 member B (FAM134B) is considered to be a tumor suppressor protein that can play a pivotal role in inhibiting hepatocellular carcinoma (HCC) cells. In addition, FAM134B acts as a putative reticulophagy receptor in the regulation of the reticulophagy process. Furthermore, suberoylanilide hydroxamic acid (SAHA) upregulates FAM134B expression in HCC cells and promotes apoptosis and autophagy-mediated cell death. Thus, FAM134B-mediated reticulophagy synergizes with SAHA to induce HCC cell death. Our findings offer novel insights into the mechanism underlying SAHA-induced HCC cell death.