Activation of the PI3K–AKT–mTOR signaling pathway promotes DEHP-induced Hep3B cell proliferation

• Published in: Food and chemical toxicology Vol. 59; pp. 325 - 333
• Main Authors: Chen, Xi, Qin, Qizhi, Zhang, Wenjuan, Zhang, Youjian, Zheng, Hongyan, Liu, Chuanyao, Yang, Yuqing, Xiong, Wei, Yuan, Jing
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01-09-2013; Elsevier
• Subjects: Biological and medical sciences; Carcinogens, Environmental - chemistry; Carcinogens, Environmental - toxicity; cell cycle; Cell Line, Tumor; cell proliferation; Cell Proliferation - drug effects; Cell Survival - drug effects; cell viability; Chromones; Di-(2-ethylbexyl) phthalate; Diethylhexyl Phthalate - antagonists & inhibitors; Diethylhexyl Phthalate - toxicity; DNA Damage; DNA replication; Enzyme Inhibitors; gene expression regulation; Gene Expression Regulation, Neoplastic - drug effects; genes; Hepatocytes - drug effects; Hepatocytes - enzymology; Hepatocytes - metabolism; Humans; Medical sciences; membrane potential; Membrane Potential, Mitochondrial - drug effects; messenger RNA; mitochondrial membrane; Morpholines; Neoplasm Proteins - agonists; Neoplasm Proteins - antagonists & inhibitors; Neoplasm Proteins - genetics; Neoplasm Proteins - metabolism; Osmolar Concentration; oxidation; Oxidative stress; Oxidative Stress - drug effects; phosphatidylinositol 3-kinase; Phosphatidylinositol 3-Kinase - antagonists & inhibitors; Phosphatidylinositol 3-Kinase - chemistry; Phosphatidylinositol 3-Kinase - genetics; Phosphatidylinositol 3-Kinase - metabolism; PI3K–AKT–mTOR pathway; Plasticizers - chemistry; Plasticizers - toxicity; Proliferation; Proto-Oncogene Proteins c-akt - agonists; Proto-Oncogene Proteins c-akt - genetics; Proto-Oncogene Proteins c-akt - metabolism; Ribosomal Protein S6 Kinases, 70-kDa - chemistry; Ribosomal Protein S6 Kinases, 70-kDa - metabolism; signal transduction; Signal Transduction - drug effects; TOR Serine-Threonine Kinases - chemistry; TOR Serine-Threonine Kinases - genetics; TOR Serine-Threonine Kinases - metabolism; Toxicology; Tumor Suppressor Protein p53 - genetics; Tumor Suppressor Protein p53 - metabolism; GSSG; Oxidative stress; p70S6K; PI3K–AKT–mTOR pathway; DMSO; Di-(2-ethylbexyl) phthalate; TBST; AKT; Proliferation; PPAR; PI3K; DEHP; ROS; mTOR; GSH; 8-OHdG; Cell proliferation; Signal transduction; PI3K―AKT―mTOR pathway; Endocrine disruptor; Activation; In vitro; glutathione; oxidized glutathione; 8-hydroxy-2′-deoxyguanosine; 40S ribosomal protein S6 kinase; di-(2-ethylhexyl) phthalate; mammalian target of rapamycin; dimethyl sulfoxide; reactive oxygen species; peroxisome proliferators-activated receptor; protein kinase B; buffered saline with tween 20; phosphoinositide 3-kinase
• ISSN: 0278-6915; 1873-6351
• DOI: 10.1016/j.fct.2013.06.016

•DEHP increased ROS-induced DNA damage in Hep3B cells.•DEHP increased mitochondrial membrane potential in Hep3B cells.•DEHP increased DNA replication rate and accelerated the cell cycle in Hep3B cells.•LY294002 could attenuate DEHP-induced oxidative stress in Hep3B cells.•PI3K–AKT–mTOR pathway involved in DEHP-induced Hep3B cell abnormal proliferation.
Hep3B cells were treated with DEHP at various concentrations (62.5, 125.0, 250.0, 500.0 and 1000.0μM). After 24h exposure to DEHP only, increased Hep3B cell viability was observed (p<0.05 or p<0.01). However, after 24h co-exposure to DEHP at indicated concentrations plus 50.0μM LY294002 (PI3K inhibitor), cell viability was significantly decreased compared to the corresponding DEHP treated groups. DEHP increased mitochondrial membrane potential level and induced oxidative DNA damage in Hep3B cells, DEHP also increased DNA replication rate and accelerated the cell cycle. The PI3K inhibitor LY294002 could recover the mitochondrial membrane potential and attenuate the oxidative stress in Hep3B cells; however, it could not protect the cells from oxidation of DNA damage. The findings showed that LY294002 attenuated DEHP-induced up-regulation of the selected genes (pi3k, akt, mtor and p70s6k) involved in PI3K–AKT–mTOR signaling pathway at both mRNA and protein levels thus inhibited the cell abnormal proliferation.