title: H3K9 Trimethylation Silences Fas Expression To Confer Colon Carcinoma Immune Escape and 5-Fluorouracil Chemoresistance.
abstract: The Fas-FasL effector mechanism plays a key role in cancer immune surveillance by host T cells, but metastatic human colon carcinoma often uses silencing Fas expression as a mechanism of immune evasion. The molecular mechanism under FAS transcriptional silencing in human colon carcinoma is unknown. We performed genome-wide chromatin immunoprecipitation sequencing analysis and identified that the FAS promoter is enriched with H3K9me3 in metastatic human colon carcinoma cells. The H3K9me3 level in the FAS promoter region is significantly higher in metastatic than in primary cancer cells, and it is inversely correlated with Fas expression level. We discovered that verticillin A is a selective inhibitor of histone methyltransferases SUV39H1, SUV39H2, and G9a/GLP that exhibit redundant functions in H3K9 trimethylation and FAS transcriptional silencing. Genome-wide gene expression analysis identified FAS as one of the verticillin A target genes. Verticillin A treatment decreased H3K9me3 levels in the FAS promoter and restored Fas expression. Furthermore, verticillin A exhibited greater efficacy than decitabine and vorinostat in overcoming colon carcinoma resistance to FasL-induced apoptosis. Verticillin A also increased DR5 expression and overcame colon carcinoma resistance to DR5 agonist drozitumab-induced apoptosis. Interestingly, verticillin A overcame metastatic colon carcinoma resistance to 5-fluorouracil in vitro and in vivo. Using an orthotopic colon cancer mouse model, we demonstrated that tumor-infiltrating cytotoxic T lymphocytes are FasL(+) and that FasL-mediated cancer immune surveillance is essential for colon carcinoma growth control in vivo. Our findings determine that H3K9me3 of the FAS promoter is a dominant mechanism underlying FAS silencing and resultant colon carcinoma immune evasion and progression.
authors.affiliation: Department of Biochemistry and Molecular Biology, Medical College of Georgia, Georgia Regents University, Augusta, GA 30912; Cancer Center, Georgia Regents University, Augusta, GA 30912; Charlie Norwood Veterans Affairs Medical Center, Augusta, GA 30904;
authors.forename: Amy V
authors.initials: AV
authors.lastname: Paschall
authors.affiliation: Department of Biochemistry and Molecular Biology, Medical College of Georgia, Georgia Regents University, Augusta, GA 30912;
authors.forename: Dafeng
authors.initials: D
authors.lastname: Yang
authors.affiliation: Department of Biochemistry and Molecular Biology, Medical College of Georgia, Georgia Regents University, Augusta, GA 30912;
authors.forename: Chunwan
authors.initials: C
authors.lastname: Lu
authors.affiliation: Cancer Center, Georgia Regents University, Augusta, GA 30912; Department of Biostatistics and Epidemiology, Medical College of Georgia, Georgia Regents University, Augusta, GA 30912;
authors.forename: Jeong-Hyeon
authors.initials: JH
authors.lastname: Choi
authors.affiliation: College of Life Sciences, Zhejiang University, Hangzhou 310027, China;
authors.forename: Xia
authors.initials: X
authors.lastname: Li
authors.affiliation: College of Life Sciences, Zhejiang University, Hangzhou 310027, China; Kliu@gru.edu liuf64@zju.edu.cn.
authors.forename: Feiyan
authors.initials: F
authors.lastname: Liu
authors.affiliation: Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, Greensboro, NC 27402;
authors.forename: Mario
authors.initials: M
authors.lastname: Figueroa
authors.affiliation: Department of Chemistry and Biochemistry, University of North Carolina at Greensboro, Greensboro, NC 27402;
authors.forename: Nicholas H
authors.initials: NH
authors.lastname: Oberlies
authors.affiliation: Mycosynthetix, Inc., Hillsborough, NC 27278; and.
authors.forename: Cedric
authors.initials: C
authors.lastname: Pearce
authors.affiliation: Charlie Norwood Veterans Affairs Medical Center, Augusta, GA 30904; Department of Physiology, Medical College of Georgia, Georgia Regents University, Augusta, GA 30912.
authors.forename: Wendy B
authors.initials: WB
authors.lastname: Bollag
authors.affiliation: Cancer Center, Georgia Regents University, Augusta, GA 30912;
authors.forename: Asha
authors.initials: A
authors.lastname: Nayak-Kapoor
authors.affiliation: Department of Biochemistry and Molecular Biology, Medical College of Georgia, Georgia Regents University, Augusta, GA 30912; Cancer Center, Georgia Regents University, Augusta, GA 30912; Charlie Norwood Veterans Affairs Medical Center, Augusta, GA 30904; Kliu@gru.edu liuf64@zju.edu.cn.
authors.forename: Kebin
authors.initials: K
authors.lastname: Liu
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D045744:Cell Line, Tumor; D003110:Colonic Neoplasms / Q000188:drug therapy / Q000209:etiology* / Q000473:pathology; D019175:DNA Methylation; D004195:Disease Models, Animal; D019008:Drug Resistance, Neoplasm / Q000235:genetics*; D053222:Fas Ligand Protein / Q000378:metabolism; D005472:Fluorouracil / Q000494:pharmacology; D020869:Gene Expression Profiling; D020868:Gene Silencing; D055106:Genome-Wide Association Study; D006649:Histocompatibility Antigens / Q000378:metabolism; D000076983:Histone Methyltransferases; D011495:Histone-Lysine N-Methyltransferase / Q000037:antagonists & inhibitors / Q000378:metabolism; D006657:Histones / Q000378:metabolism*; D006801:Humans; D007211:Indoles / Q000494:pharmacology; D020128:Inhibitory Concentration 50; D008099:Liver / Q000187:drug effects / Q000378:metabolism; D008745:Methylation / Q000187:drug effects; D008780:Methyltransferases / Q000378:metabolism; D051379:Mice; D011401:Promoter Regions, Genetic; D012097:Repressor Proteins / Q000378:metabolism; D019139:Tumor Escape / Q000235:genetics* / Q000276:immunology*; D023041:Xenograft Model Antitumor Assays; D019014:fas Receptor / Q000235:genetics*
chemical_list: D053222:Fas Ligand Protein; D006649:Histocompatibility Antigens; D006657:Histones; D007211:Indoles; D012097:Repressor Proteins; D019014:fas Receptor; C009654:verticillins; C407843:SUV39H1 protein, human; D000076983:Histone Methyltransferases; D008780:Methyltransferases; C445405:EHMT2 protein, human; D011495:Histone-Lysine N-Methyltransferase; C515701:SUV39H2 protein, human; D005472:Fluorouracil