Over-expression of pemt2 into rat hepatoma cells contributes to the mitochondrial apoptotic pathway.

Abstract

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.

• Authors: Yali Li, Wei Zou, Qiu Yan, Yuefei Xu, Quan Xia, Zhaochun Tsui, Keli Ma
• Journal: IUBMB life (IUBMB Life) Vol. 61 Issue 8 Pg. 846-52 (Aug 2009) ISSN: 1521-6551 [Electronic] England
• PMID: 19517528 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Phosphatidylcholines
• Cytochromes c
• Phosphatidylethanolamine N-Methyltransferase

Topics

• Animals
• Apoptosis (drug effects, physiology)
• Blotting, Western
• Cell Line, Tumor
• Chromatography, Gas
• Chromatography, Thin Layer
• Cytochromes c (metabolism)
• Mitochondrial Membranes (drug effects, metabolism)
• Phosphatidylcholines (metabolism)
• Phosphatidylethanolamine N-Methyltransferase (metabolism, pharmacology)
• Rats