HINT2 triggers mitochondrial Ca2+ influx by regulating the mitochondrial Ca2+ uniporter (MCU) complex and enhances gemcitabine apoptotic effect in pancreatic cancer

Linghui Chen; Qiang Sun; Dongkai Zhou; Wei Song; Qifan Yang; Bingjie Ju; Lufei Zhang; Haiyang Xie; Lin Zhou; Zhenhua Hu; Hangping Yao; Shusen Zheng; Weilin Wang

doi:10.1016/j.canlet.2017.09.020

HINT2 triggers mitochondrial Ca²⁺ influx by regulating the mitochondrial Ca²⁺ uniporter (MCU) complex and enhances gemcitabine apoptotic effect in pancreatic cancer

Cancer Lett. 2017 Dec 28:411:106-116. doi: 10.1016/j.canlet.2017.09.020. Epub 2017 Sep 23.

Authors

Linghui Chen¹, Qiang Sun², Dongkai Zhou², Wei Song³, Qifan Yang¹, Bingjie Ju¹, Lufei Zhang², Haiyang Xie⁴, Lin Zhou⁴, Zhenhua Hu², Hangping Yao⁵, Shusen Zheng⁶, Weilin Wang⁷

Affiliations

¹ Key Laboratory of Precision Diagnosis and Treatment for Hepatobiliary and Pancreatic Tumor of Zhejiang Province, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310003, Zhejiang, China; Key Laboratory of Combined Multi-Organ Transplantation, Ministry of Public Health, Hangzhou 310003, Zhejiang, China; Division of Hepatobiliary and Pancreatic Surgery, Department of Surgery, First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310003, Zhejiang, China.
² Key Laboratory of Precision Diagnosis and Treatment for Hepatobiliary and Pancreatic Tumor of Zhejiang Province, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310003, Zhejiang, China; Division of Hepatobiliary and Pancreatic Surgery, Department of Surgery, First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310003, Zhejiang, China.
³ Key Laboratory of Precision Diagnosis and Treatment for Hepatobiliary and Pancreatic Tumor of Zhejiang Province, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310003, Zhejiang, China.
⁴ Key Laboratory of Combined Multi-Organ Transplantation, Ministry of Public Health, Hangzhou 310003, Zhejiang, China.
⁵ Key Laboratory of Precision Diagnosis and Treatment for Hepatobiliary and Pancreatic Tumor of Zhejiang Province, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310003, Zhejiang, China; State Key Laboratory & Collaborative Innovation Center for Diagnosis and Treatment of Infectious Disease, Zhejiang University, Hangzhou 310003, Zhejiang, China.
⁶ Key Laboratory of Combined Multi-Organ Transplantation, Ministry of Public Health, Hangzhou 310003, Zhejiang, China; Division of Hepatobiliary and Pancreatic Surgery, Department of Surgery, First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310003, Zhejiang, China; State Key Laboratory & Collaborative Innovation Center for Diagnosis and Treatment of Infectious Disease, Zhejiang University, Hangzhou 310003, Zhejiang, China. Electronic address: shusenzheng@zju.edu.cn.
⁷ Key Laboratory of Precision Diagnosis and Treatment for Hepatobiliary and Pancreatic Tumor of Zhejiang Province, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310003, Zhejiang, China; Division of Hepatobiliary and Pancreatic Surgery, Department of Surgery, First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310003, Zhejiang, China; State Key Laboratory & Collaborative Innovation Center for Diagnosis and Treatment of Infectious Disease, Zhejiang University, Hangzhou 310003, Zhejiang, China. Electronic address: wam@zju.edu.cn.

PMID: 28947137
DOI: 10.1016/j.canlet.2017.09.020

Abstract

In early studies, it was shown that HINT2, which sensitizes cells to mitochondrial apoptosis, is down-regulated in hepatocellular carcinoma (HCC) cells (Martin et al., 2006). However, the molecular mechanism of this effect is unknown. Immunohistochemistry revealed that HINT2 expression is relatively low in pancreatic cancer tissues, compared to that in adjacent tissues (P < 0.05). Furthermore, its expression was related to pathological grade and lymph node metastasis (P = 0.0161 and 0.0108, respectively); in addition, down-regulation of HINT2 was found to be associated with relatively poor prognosis in pancreatic cancer patients. Up-regulation of HINT2 was shown to trigger pancreatic cancer cell apoptosis, decrease mitochondrial membrane potential (ΔΨm), promote intracellular reactive oxygen species (ROS) production, and elevate mitochondrial Ca²⁺ levels. However, co-treatment of HINT2 overexpressing BxPC-3 cells with ruthenium red partially inhibited HINT2-induced apoptosis, which was associated with a reduction in ΔΨm and an increase in intracellular ROS and mitochondrial Ca²⁺. According to our results, mitochondrial calcium uptake1 and 2 (MICU1 and MICU2) were down-regulated and the essential MCU regulator (EMRE) was up-regulated in cells transduced with Adv-HINT2. Therefore, we deduced that HINT2 triggers apoptosis in pancreatic cancer cells by regulating mitochondrial Ca²⁺ influx through the mitochondrial calcium uniporter (MCU). In addition, we found that HINT2 can sensitize BxPC-3 and L3.6pl cells to gemcitabine-induced apoptosis and that gemcitabine up-regulates HINT2 expression. This indicates that gemcitabine-induced apoptosis is related to HINT2 levels.

Keywords: Apoptosis; HINT2; MCU complex; Mitochondrial Ca(2+); Pancreatic cancer.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animals
Antimetabolites, Antineoplastic / pharmacology*
Apoptosis / drug effects
Calcium / metabolism
Calcium Channels / metabolism*
Deoxycytidine / analogs & derivatives*
Deoxycytidine / pharmacology
Gemcitabine
Heterografts
Humans
Male
Mice
Mice, Inbred BALB C
Mice, Nude
Mitochondria / metabolism*
Mitochondrial Proteins / biosynthesis
Mitochondrial Proteins / metabolism*
Pancreatic Neoplasms / drug therapy*
Pancreatic Neoplasms / genetics
Pancreatic Neoplasms / metabolism*

Substances

Antimetabolites, Antineoplastic
Calcium Channels
Hint2 protein, human
Mitochondrial Proteins
mitochondrial calcium uniporter
Deoxycytidine
Calcium
Gemcitabine