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Over‐expression of pemt2 into rat hepatoma cells contributes to the mitochondrial apoptotic pathway
Author(s) -
Li Yali,
Zou Wei,
Yan Qiu,
Xu Yuefei,
Xia Quan,
Tsui Zhaochun,
Ma Keli
Publication year - 2009
Publication title -
iubmb life
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.132
H-Index - 113
eISSN - 1521-6551
pISSN - 1521-6543
DOI - 10.1002/iub.222
Subject(s) - apoptosis , phosphatidylethanolamine , cytochrome c , mitochondrial apoptosis induced channel , mitochondrion , microbiology and biotechnology , biology , transfection , western blot , phosphatidylcholine , chemistry , biochemistry , phospholipid , membrane , gene
We previously established a line of phosphatidylethanolamine N ‐methyltransferase 2 (pemt2) ‐stably transfected CBRH‐7919 hepatoma cells, and showed that pemt2 over‐expression inhibited cell proliferation and induced apoptosis. This study was aimed to further elucidate the cellular mechanisms leading to this apoptosis in these cells. Fatty acid compositions of phosphatidylcholine (PC) in pemt2 over‐expressed cells and control cells, and the location of PC synthesized by PEMT2 pathway were analyzed with lipid extraction, high‐performance thin layer chromatography, high‐performance gas chromatography (HPGC), and [ 3 H]‐ethanolamine tracing. The effects of pemt2 over‐expression on the mitochondrial membrane fluidity, the release of cytochrome C from mitochondria, and the activity of caspases were determined by Western blot. Newly synthesized PC by PEMT2 contained more acyl groups of oleic acid ( P < 0.01) and was mainly located in mitochondria; pemt2 over‐expression increased the mitochondrial membrane fluidity and the release of cytochrome C from the mitochondria into the cytoplasma, which in turn activated caspase‐9 and caspase‐3, the key molecules in the mitochondrial apoptotic pathway. We demonstrated that, in rat hepatoma cells, PEMT2‐induced apoptosis proceeds through mitochondria. © 2009 IUBMB IUBMB Life, 61(8): 846–852, 2009