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.
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.
|Colden, Melissa; Dar, Altaf A; Saini, Sharanjot et al. (2017) MicroRNA-466 inhibits tumor growth and bone metastasis in prostate cancer by direct regulation of osteogenic transcription factor RUNX2. Cell Death Dis 8:e2572|
|Imai-Sumida, Mitsuho; Chiyomaru, Takeshi; Majid, Shahana et al. (2017) Silibinin suppresses bladder cancer through down-regulation of actin cytoskeleton and PI3K/Akt signaling pathways. Oncotarget 8:92032-92042|
|Bucay, N; Sekhon, K; Yang, T et al. (2017) MicroRNA-383 located in frequently deleted chromosomal locus 8p22 regulates CD44 in prostate cancer. Oncogene 36:2667-2679|
|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|
|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|
|Nip, Hannah; Dar, Altaf A; Saini, Sharanjot et al. (2016) Oncogenic microRNA-4534 regulates PTEN pathway in prostate cancer. Oncotarget 7:68371-68384|
|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; Shahryari, Varahram; Majid, Shahana et al. (2015) miRNA Expression Analyses in Prostate Cancer Clinical Tissues. J Vis Exp :|
|Hirata, Hiroshi; Hinoda, Yuji; Shahryari, Varahram et al. (2015) Long Noncoding RNA MALAT1 Promotes Aggressive Renal Cell Carcinoma through Ezh2 and Interacts with miR-205. Cancer Res 75:1322-31|
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