MicroRNAs in the progression of prostate cancer. The main goal of this project is to investigate the role of a set of microRNAs (miRNAs) in the progression of prostate cancer. The rationale of this project is that miRNAs regulate gene expression by repressing translation or directing sequence-specific degradation of complementary mRNA, and our preliminary results have provided a novel concept that miRNAs and non-coding double stranded RNAs can also activate various genes. Based on these novel observations, we hypothesize that down-regulation of a set of microRNAs can inhibit tumor suppressor genes or activate oncogenes and re-expression of these miRNAs can reverse these effects thereby regulating prostate cancer progression. These hypotheses will be tested by pursuing the following three specific aims.
Specific Aim # 1. To investigate the expression of a set of miRNAs in human prostate cancer tissues and also analyze whether miRNAs can regulate cell proliferation and progression using prostate cancer cell lines. Based on our preliminary data, we have identified a set of miRNAs that are significantly downregulated in prostate cancer. We will analyze the expression of these miRNAs in human prostate cancer samples. We will over-express a defined set of individual miRNAs in prostate cancer cell lines and the modulation of targeted genes will be evaluated at both the mRNA and protein levels using real-time PCR and Western analysis, respectively. The miRNAs-mediated repression of oncogenes or activation of tumor suppressor genes will be analyzed by luciferase assays using 3'UTR or 5'UTR sequence constructs, respectively. Changes in cell growth will be analyzed by monitoring proliferation, cell cycle distribution, apoptosis and in vitro invasion. Assays to be used include cell proliferation, flow cytometry, migration, clonogenic survival, in vitro invasion and TUNEL-based ELISA apoptosis assays.
Specific Aim #2 : To investigate the molecular mechanisms of microRNA inactivation in prostate cancer cells. We will test the hypothesis that specific miRNAs are inactivated through epigenetic pathways. Human prostate cancer tissues will be used for analysis of methylation of miRNAs. CpG methylation in putative promoter regions of miRNAs will be examined by sodium bisulfite methylation techniques and confirm by direct DNA sequencing. We will also investigate whether histone acetylation, chromatin remodeling and associated enzymes (histone deacetylases and histone acetyltransferases) play a role in controlling expression of specific miRNAs.
Specific Aim #3 : Investigate whether microRNAs can inhibit growth and proliferation of human xenograft prostate tumors in a nude mouse model. To validate our in vitro results, we will also use an in vivo model of mouse xenografts with human prostate cancer cells.

Public Health Relevance

Successful completion of these experiments will demonstrate the functional role of specific microRNAs in the suppression of prostate cancer growth and also the mechanism of inactivation of these genes in prostate cancer. In the future, these results may provide better strategies for the management of prostate cancer.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Project (R01)
Project #
1R01CA138642-01A1
Application #
7782806
Study Section
Tumor Progression and Metastasis Study Section (TPM)
Program Officer
Snyderwine, Elizabeth G
Project Start
2010-04-08
Project End
2015-01-31
Budget Start
2010-04-08
Budget End
2011-01-31
Support Year
1
Fiscal Year
2010
Total Cost
$549,290
Indirect Cost
Name
University of California San Francisco
Department
Urology
Type
Schools of Medicine
DUNS #
094878337
City
San Francisco
State
CA
Country
United States
Zip Code
94143
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Shiina, Marisa; Hashimoto, Yutaka; Kato, Taku et al. (2017) Differential expression of miR-34b and androgen receptor pathway regulate prostate cancer aggressiveness between African-Americans and Caucasians. Oncotarget 8:8356-8368
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Bucay, Nathan; Bhagirath, Divya; Sekhon, Kirandeep et al. (2017) A novel microRNA regulator of prostate cancer epithelial-mesenchymal transition. Cell Death Differ 24:1263-1274
Hashimoto, Yutaka; Shiina, Marisa; Kato, Taku et al. (2017) The role of miR-24 as a race related genetic factor in prostate cancer. Oncotarget 8:16581-16593
Sekhon, Kirandeep; Bucay, Nathan; Majid, Shahana et al. (2016) MicroRNAs and epithelial-mesenchymal transition in prostate cancer. Oncotarget 7:67597-67611
Mitsui, Yozo; Chang, Inik; Kato, Taku et al. (2016) Functional role and tobacco smoking effects on methylation of CYP1A1 gene in prostate cancer. Oncotarget 7:49107-49121
Bucay, Nathan; Sekhon, Kirandeep; Majid, Shahana et al. (2016) Novel tumor suppressor microRNA at frequently deleted chromosomal region 8p21 regulates epidermal growth factor receptor in prostate cancer. Oncotarget 7:70388-70403
Shahryari, Varahram; Nip, Hannah; Saini, Sharanjot et al. (2016) Pre-clinical Orthotopic Murine Model of Human Prostate Cancer. J Vis Exp :

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