The combination of RAD001 and MK-2206 exerts synergistic cytotoxic effects against PTEN mutant gastric cancer cells: involvement of MAPK-dependent autophagic, but not apoptotic cell death pathway

Dongmei Ji; Zhe Zhang; Lei Cheng; Jinjia Chang; Shanshan Wang; Biqiang Zheng; Rongliang Zheng; Zuojun Sun; Chenchen Wang; Zhiqing Zhang; Rujiao Liu; Xiaowei Zhang; Xin Liu; Xiaofeng Wang; Jin Li

doi:10.1371/journal.pone.0085116

The combination of RAD001 and MK-2206 exerts synergistic cytotoxic effects against PTEN mutant gastric cancer cells: involvement of MAPK-dependent autophagic, but not apoptotic cell death pathway

PLoS One. 2014 Jan 9;9(1):e85116. doi: 10.1371/journal.pone.0085116. eCollection 2014.

Authors

Affiliations

¹ Department of Medical Oncology, Fudan University Shanghai Cancer Center, Shanghai Medical College, Fudan University, Shanghai, China.
² Department of Interventional Radiology, Suzhou Hospital Affiliated to Nanjing Medical University, Suzhou, Jiangsu, China.
³ Department of Gastric Cancer and Soft Tissue Sarcomas, Fudan University Shanghai Cancer Center, Shanghai Medical College, Fudan University, Shanghai, China.
⁴ Institute of Neuroscience, Soochow University, Suzhou, Jiangsu, China.

Abstract

In the current study, we showed that the combination of mammalian target of rapamycin (mTOR) inhibitor RAD001 (everolimus) and Akt inhibitor MK-2206 exerted synergistic cytotoxic effects against low-phosphatase and tensin homolog (PTEN) gastric cancer cells (HGC-27 and SNU-601 lines). In HGC-27 cells, RAD001 and MK-2206 synergistically induced G1/S cell cycle arrest, growth inhibition, cell death but not apoptosis. RAD001 and MK-2206 synergistically induced light chain 3B (LC3B) and beclin-1 expression, two important autophagy indicators. Meanwhile, the autophagy inhibitor 3-methyladenine (3-MA) and chloroquine inhibited the cytotoxic effects by RAD001 and MK-2206, suggesting that autophagic, but not apoptotic cell death was important for the cytotoxic effects by the co-administration. We observed that the combination of RAD001 and MK-2206 exerted enhanced effects on Akt/mTOR inhibition, cyclin D1 down-regulation and ERK/MAPK(extracellular signal-regulated kinase/mitogen-activated protein kinases) activation. Intriguingly, MEK/ERK inhibitors PD98059 and U0126 suppressed RAD001 plus MK-2206-induced beclin-1 expression, autophagy induction and cytotoxicity in HGC-27 cells. In conclusion, these results suggested that the synergistic anti-gastric cancer cells ability by RAD001 and MK-2206 involves ERK-dependent autophagic cell death pathway.

Publication types

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

MeSH terms

Adenine / analogs & derivatives
Adenine / pharmacology
Antineoplastic Agents / pharmacology*
Apoptosis
Apoptosis Regulatory Proteins / antagonists & inhibitors
Apoptosis Regulatory Proteins / genetics
Apoptosis Regulatory Proteins / metabolism
Autophagy / drug effects*
Beclin-1
Butadienes / pharmacology
Cell Line, Tumor
Chloroquine / pharmacology
Cyclin D1 / antagonists & inhibitors
Cyclin D1 / genetics
Cyclin D1 / metabolism
Drug Synergism
Everolimus
Flavonoids / pharmacology
Gastric Mucosa / drug effects
Gastric Mucosa / metabolism
Gastric Mucosa / pathology
Gene Expression Regulation, Neoplastic*
Heterocyclic Compounds, 3-Ring / pharmacology*
Humans
Membrane Proteins / antagonists & inhibitors
Membrane Proteins / genetics
Membrane Proteins / metabolism
Microtubule-Associated Proteins / antagonists & inhibitors
Microtubule-Associated Proteins / genetics
Microtubule-Associated Proteins / metabolism
Mitogen-Activated Protein Kinases / antagonists & inhibitors
Mitogen-Activated Protein Kinases / genetics*
Mitogen-Activated Protein Kinases / metabolism
Nitriles / pharmacology
PTEN Phosphohydrolase / antagonists & inhibitors
PTEN Phosphohydrolase / genetics*
PTEN Phosphohydrolase / metabolism
Proto-Oncogene Proteins c-akt / antagonists & inhibitors
Proto-Oncogene Proteins c-akt / genetics
Proto-Oncogene Proteins c-akt / metabolism
Signal Transduction
Sirolimus / analogs & derivatives*
Sirolimus / pharmacology
TOR Serine-Threonine Kinases / antagonists & inhibitors
TOR Serine-Threonine Kinases / genetics
TOR Serine-Threonine Kinases / metabolism

Substances

Antineoplastic Agents
Apoptosis Regulatory Proteins
BECN1 protein, human
Beclin-1
Butadienes
CCND1 protein, human
Flavonoids
Heterocyclic Compounds, 3-Ring
MAP1LC3B protein, human
MK 2206
Membrane Proteins
Microtubule-Associated Proteins
Nitriles
U 0126
Cyclin D1
3-methyladenine
Chloroquine
Everolimus
MTOR protein, human
Proto-Oncogene Proteins c-akt
TOR Serine-Threonine Kinases
Mitogen-Activated Protein Kinases
PTEN Phosphohydrolase
PTEN protein, human
Adenine
2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one
Sirolimus

Grants and funding

The source of funding for this study was the Construction of new drug clinical research technology platform, grant number JKB1101-1 (http://www.nmp.gov.cn/). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.