title: Modifying metabolically sensitive histone marks by inhibiting glutamine metabolism affects gene expression and alters cancer cell phenotype.
abstract: The interplay of metabolism and epigenetic regulatory mechanisms has become a focal point for a better understanding of cancer development and progression. In this study, we have acquired data supporting previous observations that demonstrate glutamine metabolism affects histone modifications in human breast cancer cell lines. Treatment of non-invasive epithelial (T-47D and MDA-MB-361) and invasive mesenchymal (MDA-MB-231 and Hs-578T) breast cancer cell lines with the glutaminase inhibitor, Compound 968, resulted in cytotoxicity in all cell lines, with the greatest effect being observed in MDA-MB-231 breast cancer cells. Compound 968-treatment induced significant downregulation of 20 critical cancer-related genes, the majority of which are anti-apoptotic and/or promote metastasis, including AKT, BCL2, BCL2L1, CCND1, CDKN3, ERBB2, ETS1, E2F1, JUN, KITLG, MYB, and MYC. Histone H3K4me3, a mark of transcriptional activation, was reduced at the promoters of all but one of these critical cancer genes. The decrease in histone H3K4me3 at global and gene-specific levels correlated with reduced expression of SETD1 and ASH2L, genes encoding the histone H3K4 methyltransferase complex. Further, the expression of other epigenetic regulatory genes, known to be downregulated during apoptosis (e.g., DNMT1, DNMT3B, SETD1 and SIRT1), was also downregulated by Compound 968. These changes in gene expression and histone modifications were accompanied by the activation of apoptosis, and decreased invasiveness and resistance of MDA-MB-231 cells to chemotherapeutic drug doxorubicin. The results of this study provide evidence to a link between cytotoxicity caused by inhibiting glutamine metabolism with alterations of the epigenome of breast cancer cells and suggest that modification of intracellular metabolism may enhance the efficiency of epigenetic therapy.
authors.affiliation: Division of Biochemical Toxicology, National Center for Toxicological Research, Jefferson, AR, USA.
authors.forename: Natalie E
authors.initials: NE
authors.lastname: Simpson
authors.forename: Volodymyr P
authors.initials: VP
authors.lastname: Tryndyak
authors.forename: Marta
authors.initials: M
authors.lastname: Pogribna
authors.forename: Frederick A
authors.initials: FA
authors.lastname: Beland
authors.forename: Igor P
authors.initials: IP
authors.lastname: Pogribny
mesh_terms: D017209:Apoptosis / Q000187:drug effects / Q000235:genetics; D053119:Benzophenanthridines / Q000494:pharmacology; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000235:genetics* / Q000473:pathology; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects / Q000235:genetics; D000076123:DNA (Cytosine-5-)-Methyltransferase 1; D004248:DNA (Cytosine-5-)-Methyltransferases / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics; D004791:Enzyme Inhibitors / Q000494:pharmacology; D044127:Epigenesis, Genetic / Q000187:drug effects; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D005972:Glutaminase / Q000037:antagonists & inhibitors; D005973:Glutamine / Q000235:genetics / Q000378:metabolism*; D011495:Histone-Lysine N-Methyltransferase / Q000235:genetics; D006657:Histones / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D009687:Nuclear Proteins / Q000235:genetics; D011401:Promoter Regions, Genetic; D056564:Sirtuin 1 / Q000235:genetics; D014157:Transcription Factors / Q000235:genetics; D000097584:DNA Methyltransferase 3B
chemical_list: D053119:Benzophenanthridines; D000076123:DNA (Cytosine-5-)-Methyltransferase 1; D004248:DNA (Cytosine-5-)-Methyltransferases; D004268:DNA-Binding Proteins; D004791:Enzyme Inhibitors; D005972:Glutaminase; D005973:Glutamine; D011495:Histone-Lysine N-Methyltransferase; D006657:Histones; D009687:Nuclear Proteins; D056564:Sirtuin 1; D014157:Transcription Factors; D000097584:DNA Methyltransferase 3B; C485622:ASH2L protein, human; C000598981:compound 968; C000619380:DNMT1 protein, human; C526068:Setd1A protein, human; C447939:SIRT1 protein, human