title: Expression and epigenetic regulation of angiogenesis-related factors during dormancy and recurrent growth of ovarian carcinoma.
abstract: The initiation of angiogenesis can mark the transition from tumor dormancy to active growth and recurrence. Mechanisms that regulate recurrence in human cancers are poorly understood, in part because of the absence of relevant models. The induction of ARHI (DIRAS3) induces dormancy and autophagy in human ovarian cancer xenografts but produces autophagic cell death in culture. The addition of VEGF to cultures maintains the viability of dormant autophagic cancer cells, thereby permitting active growth when ARHI is downregulated, which mimics the "recurrence" of growth in xenografts. Two inducible ovarian cancer cell lines, SKOv3-ARHI and Hey-ARHI, were used. The expression level of angiogenesis factors was evaluated by real-time PCR, immunohistochemistry, immunocytochemistry and western blot; their epigenetic regulation was measured by bisulfite sequencing and chromatin immunoprecipitation. Six of the 15 angiogenesis factors were upregulated in dormant cancer cells (tissue inhibitor of metalloproteinases-3, TIMP3; thrombospondin-1, TSP1; angiopoietin-1; angiopoietin-2; angiopoietin-4; E-cadherin, CDH1). We found that TIMP3 and CDH1 expression was regulated epigenetically and was related inversely to the DNA methylation of their promoters in cell cultures and in xenografts. Increased H3K9 acetylation was associated with higher TIMP3 expression in dormant SKOv3-ARHI cells, while decreased H3K27me3 resulted in the upregulation of TIMP3 in dormant Hey-ARHI cells. Elevated CDH1 expression during dormancy was associated with an increase in both H3K4me3 and H3K9Ac in two cell lines. CpG demethylating agents and/or histone deacetylase inhibitors inhibited the re-growth of dormant cancer cells, which was associated with the re-expression of anti-angiogenic genes. The expression of the anti-angiogenic genes TIMP3 and CDH1 is elevated during dormancy and is reduced during the transition to active growth by changes in DNA methylation and histone modification.
authors.affiliation: Department of Gynecology; Shanghai Key Laboratory of Female Reproductive Endocrine-Related Diseases, Obstetrics and Gynecology Hospital; Fudan University; Shanghai, PR China; Shanghai Key Laboratory of Female Reproductive Endocrine-Related Diseases, Obstetrics and Gynecology Hospital; Fudan University; Shanghai, PR China.
authors.forename: Tianjiao
authors.initials: T
authors.lastname: Lyu
authors.affiliation: Department of Gynecology; Shanghai Key Laboratory of Female Reproductive Endocrine-Related Diseases, Obstetrics and Gynecology Hospital; Fudan University; Shanghai, PR China; Shanghai Key Laboratory of Female Reproductive Endocrine-Related Diseases, Obstetrics and Gynecology Hospital; Fudan University; Shanghai, PR China.
authors.forename: Nan
authors.initials: N
authors.lastname: Jia
authors.affiliation: Department of Gynecology; Shanghai Key Laboratory of Female Reproductive Endocrine-Related Diseases, Obstetrics and Gynecology Hospital; Fudan University; Shanghai, PR China; Shanghai Key Laboratory of Female Reproductive Endocrine-Related Diseases, Obstetrics and Gynecology Hospital; Fudan University; Shanghai, PR China.
authors.forename: Jieyu
authors.initials: J
authors.lastname: Wang
authors.affiliation: Department of Gynecology; Shanghai Key Laboratory of Female Reproductive Endocrine-Related Diseases, Obstetrics and Gynecology Hospital; Fudan University; Shanghai, PR China; Shanghai Key Laboratory of Female Reproductive Endocrine-Related Diseases, Obstetrics and Gynecology Hospital; Fudan University; Shanghai, PR China.
authors.forename: Xiaohui
authors.initials: X
authors.lastname: Yan
authors.affiliation: Department of Gynecology; Shanghai Key Laboratory of Female Reproductive Endocrine-Related Diseases, Obstetrics and Gynecology Hospital; Fudan University; Shanghai, PR China; Shanghai Key Laboratory of Female Reproductive Endocrine-Related Diseases, Obstetrics and Gynecology Hospital; Fudan University; Shanghai, PR China; Department of Experimental Therapeutics; University of Texas, M.D. Anderson Cancer Center; Houston, TX USA.
authors.forename: Yinhua
authors.initials: Y
authors.lastname: Yu
authors.affiliation: Department of Experimental Therapeutics; University of Texas, M.D. Anderson Cancer Center; Houston, TX USA.
authors.forename: Zhen
authors.initials: Z
authors.lastname: Lu
authors.affiliation: Department of Experimental Therapeutics; University of Texas, M.D. Anderson Cancer Center; Houston, TX USA.
authors.forename: Robert C
authors.initials: RC
authors.lastname: Bast
authors.affiliation: Department of Gynecology; Shanghai Key Laboratory of Female Reproductive Endocrine-Related Diseases, Obstetrics and Gynecology Hospital; Fudan University; Shanghai, PR China; Shanghai Key Laboratory of Female Reproductive Endocrine-Related Diseases, Obstetrics and Gynecology Hospital; Fudan University; Shanghai, PR China.
authors.forename: Keqin
authors.initials: K
authors.lastname: Hua
authors.affiliation: Department of Gynecology; Shanghai Key Laboratory of Female Reproductive Endocrine-Related Diseases, Obstetrics and Gynecology Hospital; Fudan University; Shanghai, PR China; Shanghai Key Laboratory of Female Reproductive Endocrine-Related Diseases, Obstetrics and Gynecology Hospital; Fudan University; Shanghai, PR China.
authors.forename: Weiwei
authors.initials: W
authors.lastname: Feng
mesh_terms: D000107:Acetylation; D000818:Animals; D001343:Autophagy; D000077216:Carcinoma, Ovarian Epithelial; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D019175:DNA Methylation; D044127:Epigenesis, Genetic; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D064593:Heterografts; D006657:Histones / Q000378:metabolism; D006801:Humans; D051379:Mice; D008819:Mice, Nude; D009364:Neoplasm Recurrence, Local / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D009368:Neoplasm Transplantation; D009375:Neoplasms, Glandular and Epithelial / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D009389:Neovascularization, Pathologic / Q000235:genetics* / Q000378:metabolism; D010051:Ovarian Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D011401:Promoter Regions, Genetic
chemical_list: D006657:Histones
keywords: angiogenesis; dormancy; histone modification; methylation; ovarian cancer; recurrence