title: O-linked GlcNAcylation elevated by HPV E6 mediates viral oncogenesis.
abstract: High-risk human papillomaviruses (HPVs) are causative agents of anogenital cancers and a fraction of head and neck cancers. The mechanisms involved in the progression of HPV neoplasias to cancers remain largely unknown. Here, we report that O-linked GlcNAcylation (O-GlcNAc) and O-GlcNAc transferase (OGT) were markedly increased in HPV-caused cervical neoplasms relative to normal cervix, whereas O-GlcNAcase (OGA) levels were not altered. Transduction of HPV16 oncogene E6 or E6/E7 into mouse embryonic fibroblasts (MEFs) up-regulated OGT mRNA and protein, elevated the level of O-GlcNAc, and promoted cell proliferation while reducing cellular senescence. Conversely, in HPV-18-transformed HeLa cervical carcinoma cells, inhibition of O-GlcNAc with a low concentration of a chemical inhibitor impaired the transformed phenotypes in vitro. We showed that E6 elevated c-MYC via increased protein stability attributable to O-GlcNAcylation on Thr58. Reduction of HPV-mediated cell viability by a high concentration of O-GlcNAc inhibitor was partially rescued by elevated c-MYC. Finally, knockdown of OGT or O-GlcNAc inhibition in HeLa cells or in TC-1 cells, a mouse cell line transformed by HPV16 E6/E7 and activated K-RAS, reduced c-MYC and suppressed tumorigenesis and metastasis. Thus, we have uncovered a mechanism for HPV oncoprotein-mediated transformation. These findings may eventually aid in the development of effective therapeutics for HPV-associated malignancies by targeting aberrant O-GlcNAc.
authors.affiliation: Key Laboratory of Pathobiology, Ministry of Education, Norman Bethune College of Medicine, Jilin University, Changchun 130021, China; Division of Hematology and Oncology, Comprehensive Cancer Center, University of Alabama at Birmingham, Birmingham, AL 35294;
authors.forename: Qinghua
authors.initials: Q
authors.lastname: Zeng
authors.affiliation: Division of Hematology and Oncology, Comprehensive Cancer Center, University of Alabama at Birmingham, Birmingham, AL 35294;
authors.forename: Rui-Xun
authors.initials: RX
authors.lastname: Zhao
authors.affiliation: Division of Hematology and Oncology, Comprehensive Cancer Center, University of Alabama at Birmingham, Birmingham, AL 35294;
authors.forename: Jianfeng
authors.initials: J
authors.lastname: Chen
authors.affiliation: Division of Hematology and Oncology, Comprehensive Cancer Center, University of Alabama at Birmingham, Birmingham, AL 35294;
authors.forename: Yining
authors.initials: Y
authors.lastname: Li
authors.affiliation: Division of Hematology and Oncology, Comprehensive Cancer Center, University of Alabama at Birmingham, Birmingham, AL 35294;
authors.forename: Xiang-Dong
authors.initials: XD
authors.lastname: Li
authors.affiliation: Division of Hematology and Oncology, Comprehensive Cancer Center, University of Alabama at Birmingham, Birmingham, AL 35294;
authors.forename: Xiao-Long
authors.initials: XL
authors.lastname: Liu
authors.affiliation: Division of Hematology and Oncology, Comprehensive Cancer Center, University of Alabama at Birmingham, Birmingham, AL 35294;
authors.forename: Wei-Ming
authors.initials: WM
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Pathobiology, Ministry of Education, Norman Bethune College of Medicine, Jilin University, Changchun 130021, China;
authors.forename: Cheng-Shi
authors.initials: CS
authors.lastname: Quan
authors.affiliation: Key Laboratory of Pathobiology, Ministry of Education, Norman Bethune College of Medicine, Jilin University, Changchun 130021, China;
authors.forename: Yi-Shu
authors.initials: YS
authors.lastname: Wang
authors.affiliation: Key Laboratory of Pathobiology, Ministry of Education, Norman Bethune College of Medicine, Jilin University, Changchun 130021, China;
authors.forename: Ying-Xian
authors.initials: YX
authors.lastname: Zhai
authors.affiliation: Key Laboratory of Pathobiology, Ministry of Education, Norman Bethune College of Medicine, Jilin University, Changchun 130021, China;
authors.forename: Jian-Wei
authors.initials: JW
authors.lastname: Wang
authors.affiliation: Key Laboratory of Pathobiology, Ministry of Education, Norman Bethune College of Medicine, Jilin University, Changchun 130021, China;
authors.forename: Mariam
authors.initials: M
authors.lastname: Youssef
authors.affiliation: Department of Pharmacology and Experimental Therapeutics, Boston University School of Medicine, Boston, MA 02118;
authors.forename: Rutao
authors.initials: R
authors.lastname: Cui
authors.affiliation: Department of Systems Biology, University of Texas MD Anderson Cancer Center, Houston, TX 77030;
authors.forename: Jiyong
authors.initials: J
authors.lastname: Liang
authors.affiliation: Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, AL 35294.
authors.forename: Nicholas
authors.initials: N
authors.lastname: Genovese
authors.affiliation: Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, AL 35294 ltchow@uab.edu ylli@jlu.edu.cn zhixiangxu@uabmc.edu.
authors.forename: Louise T
authors.initials: LT
authors.lastname: Chow
authors.affiliation: Key Laboratory of Pathobiology, Ministry of Education, Norman Bethune College of Medicine, Jilin University, Changchun 130021, China; ltchow@uab.edu ylli@jlu.edu.cn zhixiangxu@uabmc.edu.
authors.forename: Yu-Lin
authors.initials: YL
authors.lastname: Li
authors.affiliation: Key Laboratory of Pathobiology, Ministry of Education, Norman Bethune College of Medicine, Jilin University, Changchun 130021, China; Division of Hematology and Oncology, Comprehensive Cancer Center, University of Alabama at Birmingham, Birmingham, AL 35294; ltchow@uab.edu ylli@jlu.edu.cn zhixiangxu@uabmc.edu.
authors.forename: Zhi-Xiang
authors.initials: ZX
authors.lastname: Xu
mesh_terms: D000818:Animals; D063646:Carcinogenesis; D045744:Cell Line, Tumor; D005260:Female; D016259:Genes, myc; D006801:Humans; D051379:Mice; D008810:Mice, Inbred C57BL; D017351:N-Acetylglucosaminyltransferases / Q000502:physiology*; D009856:Oncogene Proteins, Viral / Q000502:physiology*; D050725:Papillomavirus E7 Proteins / Q000502:physiology; D012097:Repressor Proteins / Q000502:physiology*; D002583:Uterine Cervical Neoplasms / Q000209:etiology* / Q000821:virology
chemical_list: C068651:E6 protein, Human papillomavirus type 16; D009856:Oncogene Proteins, Viral; D050725:Papillomavirus E7 Proteins; D012097:Repressor Proteins; C059731:oncogene protein E7, Human papillomavirus type 16; D017351:N-Acetylglucosaminyltransferases; C449880:O-GlcNAc transferase
keywords: HPV E6; HPV oncogenicity; O-linked GlcNAcylation; c-MYC; cervical cancer