The objective of this study is to characterize a recently identified tumor-associated gene, HBXAP (also known as Rsf-1), that is amplified in ovarian cancer. Over the past years, we have applied genome-wide analyses to delineate molecular genetic changes in ovarian cancer, and have identified a new amplified gene, HBXAP (Rsf-1), in ovarian carcinomas. Amplification and overexpression of HBXAP are significantly associated with the most aggressive type of ovarian cancer in clinical specimens. It has been known that HBXAP interacts with hSNF2H to form a chromatin remodeling complex. Indeed, we demonstrated that HBXAP co-immunoprecipitated with hSNF2H in ovarian caner cells, and expression of HBXAP promoted tumor cell growth and survival in p53 mutated cells but not in p53 wild-type cells. Based on the above findings, we hypothesize that p53 mutation facilitates cells to evade from the oncogene-induced growth suppression and apoptosis, and in the p53 mutant cells, increased HBXAP levels contributes to tumor progression by its binding to hSNF2H. Furthermore, HBXAP may serve as a potential therapeutic target in a preclinical mouse tumor model. To test the above hypotheses, we propose four closely integrated aims.
Aim 1 : Determine if formation of the HBXAP and hSNF2H chromatin remodeling complex is required for survival in ovarian cancer cells with HBXAP overexpression.
Aim 2 : Assess the roles of p53 mutations in HBXAP-induced tumor promotion.
Aim 3 : Assess if overexpression of HBXAP in combination with mutant p53 is essential for tumorigenesis and/or tumor progression.
Aim 4 : Determine the anti-tumor effects by targeting HBXAP in mouse ovarian cancer xenografts. Revealing the molecular context in deciphering the functions of a tumor-promoting gene is essential to understand the pathogenesis of cancer development and may have translational implications for new cancer therapy.

Public Health Relevance

Previous studies have shown that amplification and overexpression of HBXAP, a chromatin remodeling gene, are significantly associated with the most aggressive type of ovarian cancer. The objective of the current study is to characterize how HBXAP upregulation contributes to the development and progression of ovarian cancer. Revealing the molecular context in deciphering the functions of a tumor-promoting gene is essential to understand the pathogenesis of cancer development and may have translational implications for new cancer therapy.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Project (R01)
Project #
5R01CA129080-03
Application #
7760912
Study Section
Tumor Cell Biology Study Section (TCB)
Program Officer
Watson, Joanna M
Project Start
2008-04-01
Project End
2013-01-31
Budget Start
2010-02-01
Budget End
2011-01-31
Support Year
3
Fiscal Year
2010
Total Cost
$340,300
Indirect Cost
Name
Johns Hopkins University
Department
Pediatrics
Type
Schools of Medicine
DUNS #
001910777
City
Baltimore
State
MD
Country
United States
Zip Code
21218
Suryo Rahmanto, Yohan; Jung, Jin-Gyoung; Wu, Ren-Chin et al. (2016) Inactivating ARID1A Tumor Suppressor Enhances TERT Transcription and Maintains Telomere Length in Cancer Cells. J Biol Chem 291:9690-9
Guan, Bin; Rahmanto, Yohan Suryo; Wu, Ren-Chin et al. (2014) Roles of deletion of Arid1a, a tumor suppressor, in mouse ovarian tumorigenesis. J Natl Cancer Inst 106:
Wu, Ren-Chin; Ayhan, Ayse; Maeda, Daichi et al. (2014) Frequent somatic mutations of the telomerase reverse transcriptase promoter in ovarian clear cell carcinoma but not in other major types of gynaecological malignancy. J Pathol 232:473-81
Guan, Bin; Magomi, Tae; Wang, Tian-Li et al. (2013) Establishing isogenic inducible cell lines using founder reporter lines and recombinase-mediated cassette exchange. Biotechniques 55:233-42
Sheu, Jim Jinn-Chyuan; Choi, Jung Hye; Guan, Bin et al. (2013) Rsf-1, a chromatin remodelling protein, interacts with cyclin E1 and promotes tumour development. J Pathol 229:559-68
Mao, Tsui-Lien; Ardighieri, Laura; Ayhan, Ayse et al. (2013) Loss of ARID1A expression correlates with stages of tumor progression in uterine endometrioid carcinoma. Am J Surg Pathol 37:1342-8
Kuhn, Elisabetta; Kurman, Robert J; Soslow, Robert A et al. (2012) The diagnostic and biological implications of laminin expression in serous tubal intraepithelial carcinoma. Am J Surg Pathol 36:1826-34
Guan, Bin; Gao, Min; Wu, Chen-Hsuan et al. (2012) Functional analysis of in-frame indel ARID1A mutations reveals new regulatory mechanisms of its tumor suppressor functions. Neoplasia 14:986-93
Thiaville, Michelle M; Stoeck, Alexander; Chen, Li et al. (2012) Identification of PBX1 target genes in cancer cells by global mapping of PBX1 binding sites. PLoS One 7:e36054
Jones, Siân; Wang, Tian-Li; Kurman, Robert J et al. (2012) Low-grade serous carcinomas of the ovary contain very few point mutations. J Pathol 226:413-20

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