scholarly journals The miRNA Pull Out Assay as a Method to Validate the miR-28-5p Targets Identified in Other Tumor Contexts in Prostate Cancer

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Milena Rizzo ◽  
Gabriele Berti ◽  
Francesco Russo ◽  
Monica Evangelista ◽  
Marco Pellegrini ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Cell Proliferation ◽  
Tumor Suppressor ◽  
Protein Level ◽  
Mirna Targets ◽  
Pull Out ◽  
General Terms ◽  
Specific Tumor ◽  
Context Specific ◽  
Tumor Types

miR-28-5p is an intragenic miRNA which is underexpressed in several tumor types showing a tumor suppressor (TS) activity. Routinely, the known miR-28-5p targets are validated in specific tumor contexts but it is unclear whether these targets are also being regulated in other tumor types. To this end, we adopted the miRNA pull out assay to capture the miR-28-5p targets in DU-145 prostate cancer (PCa) cells. Firstly, we demonstrated that miR-28-5p acts as a TS-miRNA in PCa, affecting cell proliferation, survival, and apoptosis. Secondly, we evaluated the enrichment of the 10 validated miR-28-5p targets in the pull out sample. We showed that E2F6, TEX-261, MAPK1, MPL, N4BP1, and RAP1B but not BAG1, OTUB1, MAD2L1, and p21 were significantly enriched, suggesting that not all the miR-28-5p targets are regulated by this miRNA in PCa. We then verified whether the miR-28-5p-interacting targets were regulated by this miRNA. We selected E2F6, the most enriched target in the pull out sample, and demonstrated that miR-28-5p downregulated E2F6 at the protein level suggesting that our approach was effective. In general terms, these findings support the miRNA pull out assay as a useful method to identify context-specific miRNA targets.

scholarly journals MiR-5195-3p Functions as a Tumor Suppressor in Prostate Cancer via Targeting CCNL1

2020 ◽  
Author(s):  
Xing Zeng ◽  
Zhiquan Hu ◽  
Yuanqing Shen ◽  
Xian Wei ◽  
Jiahua Gan ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Cell Cycle ◽  
Cell Proliferation ◽  
Tumor Suppressor ◽  
Clinical Significance ◽  
Cox Regression ◽  
Tumor Formation ◽  
Luciferase Reporter ◽  
Cell Cycle Distribution ◽  
Survival Prognosis

Abstract BackgroundAccumulating evidence indicates miR-5195-3p exerts tumor suppressive role in several tumors. However, there is limited research on the clinical significance and biological function of miR-5195-3p in prostate cancer (PCa).MethodsExpression levels of miR-5195-3p and Cyclin L1 (CCNL1) were determined using quantitative real-time PCR. The clinical significance of miR-5195-3p in PCa patients was evaluated using Kaplan-Meier survival analysis and Cox regression models. Cell proliferation and cell cycle distribution were measured by CCK-8 assay and flow cytometry, respectively. The association between miR-5195-3p and CCNL1 was analyzed by luciferase reporter assay.ResultsMiR-5195-3p expression levels were significantly downregulated in 69 paired PCa tissues compared with matched adjacent normal tissues. The decreased miR-5195-3p expression was associated with Gleason score and TNM stage, as well as worse survival prognosis. The in vitro experiments showed that miR-5195-3p overexpression suppressed the proliferation and cell cycle G1/S transition in PC-3 and DU145 cells. Elevated miR-5195-3p abundance was also demonstrated to impair tumor formation in vivo using PC-3 xenografts. Mechanistically, Cyclin L1 (CCNL1) was a direct target of miR-5195-3p in PCa cells, which was inversely correlated with miR-5195-3p in PCa tissues. Importantly, CCNL1 knockdown imitated, while overexpression reversed the effects of miR-5195-3p overexpression on PCa cell proliferation and cell cycle G1/S transition.ConclusionsOur data suggests that miR-5195-3p functions as a tumor suppressor via downregulating G1/S related CCNL1 expression in PCa.

scholarly journals Nuclear receptor HNF4α performs a tumor suppressor function in prostate cancer via its induction of p21-driven cellular senescence

Oncogene ◽  
2019 ◽  
Vol 39 (7) ◽  
pp. 1572-1589 ◽  
Author(s):  
Zhu Wang ◽  
Youjia Li ◽  
Dinglan Wu ◽  
Shan Yu ◽  
Yuliang Wang ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Cell Proliferation ◽  
Tumor Suppressor ◽  
Cancer Cells ◽  
Nuclear Receptor ◽  
Cellular Senescence ◽  
Xenograft Model ◽  
Tumor Suppressor Function ◽  
Prostate Cancer Cells ◽  
Suppressor Function

Abstract Hepatocyte nuclear factor 4α (HNF4α, NR2A1) is a highly conserved member of the nuclear receptor superfamily. Recent advances reveal that it is a key transcriptional regulator of genes, broadly involved in xenobiotic and drug metabolism and also cancers of gastrointestinal tract. However, the exact functional roles of HNF4α in prostate cancer progression are still not fully understood. In this study, we determined the functional significance of HNF4α in prostate cancer. Our results showed that HNF4α exhibited a reduced expression pattern in clinical prostate cancer tissues, prostate cancer cell lines and xenograft model of castration-relapse prostate cancer. Stable HNF4α knockdown not only could promote cell proliferation and suppress doxorubicin (Dox)-induced cellular senescence in prostate cancer cells, but also confer resistance to paclitaxel treatment and enhance colony formation capacity and in vivo tumorigenicity of prostate cancer cells. On the contrary, ectopic overexpression of HNF4α could significantly inhibit the cell proliferation of prostate cancer cells, induce cell-cycle arrest at G2/M phase and trigger the cellular senescence in prostate cancer cells by activation of p21 signal pathway in a p53-independent manner via its direct transactivation of CDKN1A. Together, our results show that HNF4α performs a tumor suppressor function in prostate cancer via a mechanism of p21-driven cellular senescence.

miR-671 promotes prostate cancer cell proliferation by targeting tumor suppressor SOX6

2018 ◽  
Vol 823 ◽  
pp. 65-71 ◽  
Author(s):  
Yin Yu ◽  
Zhixin Wang ◽  
Daju Sun ◽  
Xueying Zhou ◽  
Xin Wei ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Cell Proliferation ◽  
Tumor Suppressor ◽  
Cancer Cell ◽  
Prostate Cancer Cell ◽  
Cancer Cell Proliferation

scholarly journals Human BRE1 Is an E3 Ubiquitin Ligase for Ebp1 Tumor Suppressor

2009 ◽  
Vol 20 (3) ◽  
pp. 757-768 ◽  
Author(s):  
Zhixue Liu ◽  
Sang-Muk Oh ◽  
Masashi Okada ◽  
Xia Liu ◽  
Dongmei Cheng ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Tumor Suppressor ◽  
Ubiquitin Ligase ◽  
Protein Level ◽  
E3 Ubiquitin Ligase ◽  
E3 Ligase ◽  
Suppressive Activity ◽  
Cancer Proliferation ◽  
Repressive Effect ◽  
Receptor Binding Protein

Human Bre1, an E3 ligase for H2B monoubiquitination, binds p53 and enhances activator-dependent transcription. Ebp1, an ErbB3 receptor-binding protein, inhibits cell proliferation and acts as a tumor suppressor. Here, we show that hBre1 acts as an E3 ubiquitin ligase for Ebp1 tumor suppressor and promotes its polyubiquitination and degradation. Ebp1 is polyubiquitinated in cancer cells, which is regulated by its phosphorylation. We identified hBre1 acting as an E3 ligase for Ebp1 and increasing its polyubiquitination. Depletion of hBre1 blocks Ebp1's polyubiquitination and elevates its protein level, preventing cancer proliferation. hBre1 binds Ebp1 and suppresses its repressive effect on E2F-1. Moreover, Ebp1 protein level is substantially diminished in human cancers. It is robustly phosphorylated and localized in the nucleus of primary gliomas, correlating with hBre1 subcellular residency. Thus, hBre1 inhibits Ebp1's tumor suppressive activity through mediating its polyubiquitination and degradation.

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