title: Biochemical disorders associated with antiproliferative effect of dehydroepiandrosterone in hepatoma cells as revealed by LC-based metabolomics.
abstract: DHEA is known to have chemopreventive and antiproliferative activities, and was initially thought to be mediated by inhibition of G6PD. Our previous study has shown that DHEA may act through interference with energy metabolism. To study the effect of pharmacological dose of DHEA on cellular metabolism, and to further delineate the mechanism underlying its antiproliferative effect, we applied a metabolomic approach to globally profile the changes in metabolites in SK-Hep1 cells underexpressing G6PD (Sk-Gi) and control cells (Sk-Sc) after DHEA treatment. RRLC-TOF-MS was used to identify metabolites, and tandem mass spectrometry was used to confirm their identity. DHEA induced changes in glutathione metabolism, lipid metabolism, s-adenosylmethionine (SAM) metabolism, as well as lysine metabolism. Elevation in level of glutathione disulfide, together with a concomitant decrease in level of reduced glutathione, was indicative of increased oxidative stress. Depletion of carnitine and its acyl derivatives reflected decline in fatty acid catabolism. These changes were associated with mitochondrial malfunction and reduction in cellular ATP content. Cardiolipin (CL) and phosphatidylcholine (PC) levels decreased significantly, suggesting that alterations in lipid composition are causally related to decline in mitochondrial function after DHEA treatment. The decline in cellular SAM content was accompanied by decreased expression of methionine adenosyltransferase genes MAT2A and MAT2B. SAM supplementation partially rescued cells from DHEA-induced growth stagnation. Our findings suggest that DHEA causes perturbation of multiple pathways in cellular metabolism. Decreased SAM production, and cardiolipin depletion and the resulting mitochondrial dysfunction underlie the antiproliferative effect of DHEA.
authors.affiliation: Department of Medical Biotechnology and Laboratory Science, Chang Gung University, 259, Wen-Hwa 1st Rd., Kwei-San, Tao-Yuan, Taiwan. chengm@mail.cgu.edu.tw
authors.forename: Mei-Ling
authors.initials: ML
authors.lastname: Cheng
authors.forename: Ming-Shi
authors.initials: MS
authors.lastname: Shiao
authors.forename: Daniel Tsun-Yee
authors.initials: DT
authors.lastname: Chiu
authors.forename: Shiue-Fen
authors.initials: SF
authors.lastname: Weng
authors.forename: Hsiang-Yu
authors.initials: HY
authors.lastname: Tang
authors.forename: Hung-Yao
authors.initials: HY
authors.lastname: Ho
mesh_terms: D016588:Anticarcinogenic Agents / Q000494:pharmacology*; D000970:Antineoplastic Agents / Q000494:pharmacology*; D006528:Carcinoma, Hepatocellular; D049109:Cell Proliferation / Q000187:drug effects; D002853:Chromatography, Liquid; D003687:Dehydroepiandrosterone / Q000494:pharmacology*; D005954:Glucosephosphate Dehydrogenase / Q000378:metabolism; D006801:Humans; D008113:Liver Neoplasms; D055442:Metabolome; D008716:Methionine Adenosyltransferase / Q000378:metabolism; D008928:Mitochondria / Q000187:drug effects / Q000502:physiology; D018384:Oxidative Stress / Q000187:drug effects; D010713:Phosphatidylcholines / Q000378:metabolism; D010767:Phosphorylcholine / Q000378:metabolism; D012436:S-Adenosylmethionine / Q000494:pharmacology
chemical_list: D016588:Anticarcinogenic Agents; D000970:Antineoplastic Agents; D010713:Phosphatidylcholines; D010767:Phosphorylcholine; D003687:Dehydroepiandrosterone; D012436:S-Adenosylmethionine; D005954:Glucosephosphate Dehydrogenase; C527161:MAT2A protein, human; C527162:MAT2B protein, human; D008716:Methionine Adenosyltransferase