title: PE‑induced apoptosis in SMMC‑7721 cells: involvement of Erk and Stat signalling pathways.
abstract: Emerging evidence indicates that the redistribution of phosphatidylethanolamine (PE) across the bilayer of the plasma membrane is an important molecular marker for apoptosis. However, the effect of PE on apoptosis and the underlying mechanism of PE remain unclear. In the current study, MTT and flow cytometric assays were used to examine the effects of PE on apoptosis in SMMC‑7721 cells. The level of mitochondrial membrane potential (ΔΨm) and the expression of Bax, Bcl‑2, caspase‑3, phospho‑Erk and phospho‑Stat1/2 in SMMC‑7721 cells that were exposed to PE were also investigated. The results showed that PE inhibited proliferation, caused G0/G1 phase cell cycle arrest and induced apoptosis in SMMC‑7721 cells in a dose‑dependent manner. Rhodamine 123 staining showed that the treatment of SMMC‑7721 cells with different concentrations of PE for 24 h significantly decreased the level of ΔΨm and exerted dose‑dependent effects. Using immunofluorescence and western blotting, we found that the expression of Bax was upregulated, whereas that of Bcl‑2 was downregulated in PE‑induced apoptotic cells. In addition, these events were accompanied by an increase in caspase‑3 expression in a dose‑dependent manner following PE treatment. PE‑induced apoptosis was accompanied by a decrease in Erk phospho-rylation and by the activation of Stat1/2 phosphorylation in SMMC‑7721 cells. In conclusion, the results suggested that PE‑induced apoptosis is involved in upregulating the Bax/Bcl‑2 protein ratio and decreasing the ΔΨm. Moreover, the results showed that the Erk and Stat1/2 signalling pathways may be involved in the process of PE‑induced apoptosis.
authors.affiliation: Forensic Medicine College of Xi'an Jiaotong University, Key Laboratory of the Health Ministry for Forensic Medicine, Key Laboratory of the Ministry of Education for Environment and Genes Related to Diseases, Xi'an, Shaanxi 710061, P.R. China.
authors.forename: Li
authors.initials: L
authors.lastname: Xue
authors.affiliation: Department of Cardiovascular Surgery, The First Affiliated Hospital of Medical College of Xi'an Jiaotong University, Xi'an, Shaanxi 710061, P.R. China.
authors.forename: Ming
authors.initials: M
authors.lastname: Li
authors.affiliation: Forensic Medicine College of Xi'an Jiaotong University, Key Laboratory of the Health Ministry for Forensic Medicine, Key Laboratory of the Ministry of Education for Environment and Genes Related to Diseases, Xi'an, Shaanxi 710061, P.R. China.
authors.forename: Teng
authors.initials: T
authors.lastname: Chen
authors.affiliation: Tumour Hospital of Shaanxi Province, Xi'an, Shaanxi 710061, P.R. China.
authors.forename: Haifeng
authors.initials: H
authors.lastname: Sun
authors.affiliation: Forensic Medicine College of Xi'an Jiaotong University, Key Laboratory of the Health Ministry for Forensic Medicine, Key Laboratory of the Ministry of Education for Environment and Genes Related to Diseases, Xi'an, Shaanxi 710061, P.R. China.
authors.forename: Jie
authors.initials: J
authors.lastname: Zhu
authors.affiliation: VIP Internal Medicine Department, Lanzhou University Second Hospital, Lanzhou, Gansu 730030, P.R. China.
authors.forename: Xia
authors.initials: X
authors.lastname: Li
authors.affiliation: Graduate Teaching and Experimental Centre, Xi'an Jiaotong University School of Medicine, Xi'an, Shaanxi 710061, P.R. China.
authors.forename: Feng
authors.initials: F
authors.lastname: Wu
authors.affiliation: Department of Immunology and Pathogenic Biology, Xi'an Jiaotong University School of Medicine, Xi'an, Shaanxi 710061, P.R. China.
authors.forename: Biao
authors.initials: B
authors.lastname: Wang
authors.affiliation: School of Public Security, Northwest University of Politics and Law, Xi'an, Shaanxi 710063, P.R. China.
authors.forename: Juping
authors.initials: J
authors.lastname: Li
authors.affiliation: Department of Immunology and Pathogenic Biology, Xi'an Jiaotong University School of Medicine, Xi'an, Shaanxi 710061, P.R. China.
authors.forename: Yanjiong
authors.initials: Y
authors.lastname: Chen
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D002453:Cell Cycle / Q000187:drug effects; D045744:Cell Line, Tumor; D004305:Dose-Response Relationship, Drug; D048049:Extracellular Signal-Regulated MAP Kinases / Q000235:genetics* / Q000378:metabolism; D015972:Gene Expression Regulation, Neoplastic; D022781:Hepatocytes / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D006801:Humans; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism; D010714:Phosphatidylethanolamines / Q000494:pharmacology*; D010766:Phosphorylation / Q000187:drug effects; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics / Q000378:metabolism; D050794:STAT1 Transcription Factor / Q000235:genetics* / Q000378:metabolism; D050795:STAT2 Transcription Factor / Q000235:genetics* / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects*
chemical_list: D000970:Antineoplastic Agents; D010714:Phosphatidylethanolamines; D019253:Proto-Oncogene Proteins c-bcl-2; D050794:STAT1 Transcription Factor; C494079:STAT1 protein, human; D050795:STAT2 Transcription Factor; C494084:STAT2 protein, human; C483858:phosphatidylethanolamine; D048049:Extracellular Signal-Regulated MAP Kinases