UHRF1 is overexpressed in many tumours and is an epigenetic regulator required for DNA methylation (DNAm) by recruiting all DNMTs to methylation sites. UHRF1 is also crucial for histone modifications, epigenetic gene silencing and has an important impact on prostate cancer pathogenesis and progression. Here we studied whether UHRF1 could exert its role in the epigenetic of cancer by changes in microRNA (miRNA) levels in prostate transformed cells. MiRNAs are small non-coding RNAs that negatively control gene expression and play crucial functions in all cellular processes. Growing evidences indicate their deregulated expression in human cancer, proposing miRNAs as oncogenes or tumour suppressors. Besides, miRNAs can induce gene silencing via epigenetic mechanisms e.g. by targeting a specific gene region for DNAm and histone modifications or by regulating expression of epigenetic enzymes. MiRNAs expression profile of siRNA-UHRF1 PC3 cells showed both increased and decreased miRNA levels. Using different target predictive software, Dnmt3a appeared as a target of two new miRNAs (miRNA-a and miRNA-b) overexpressed in siRNA-UHRF1 PC3 cells. Levels of miRNA-a and -b were confirmed by RT-QPCR in siRNA-UHRF1 PC3 and in LNCaP cells (with UHRF1 and Dnmt3a lower levels than PC3) and the binding of the two new miRNAs to the Dnmt3a3’UTR and its inhibitory effect were validated by reporter luciferase system. We studied the effect of the overexpression of miRNA-a and -b in PC3 finding a decrease of Dnmt3a mRNA and protein, and a decrease in PC3 proliferation. We studied the effects of miRNA silencing in LNCaP finding an increase of Dnmt3a mRNA and protein, and an increase in LNCaP proliferation. These data show the role of miRNA-a and -b in the modulation of Dnmt3a and propose their involvement in prostate cancer progression. Next goal is to study their promoters evaluating the role of UHRF1 in miRNAs transcription.
UHRF1-miRNAs modulate Dnmt3a expression in prostate transformed cells
BABBIO, FEDERICA;ZANETTI, VALENTINA;CASTIGLIONI, ILARIA;MANDRUZZATO, MARTINA;MAGNANI, ELENA;BONAPACE, IAN MARC;
2013-01-01
Abstract
UHRF1 is overexpressed in many tumours and is an epigenetic regulator required for DNA methylation (DNAm) by recruiting all DNMTs to methylation sites. UHRF1 is also crucial for histone modifications, epigenetic gene silencing and has an important impact on prostate cancer pathogenesis and progression. Here we studied whether UHRF1 could exert its role in the epigenetic of cancer by changes in microRNA (miRNA) levels in prostate transformed cells. MiRNAs are small non-coding RNAs that negatively control gene expression and play crucial functions in all cellular processes. Growing evidences indicate their deregulated expression in human cancer, proposing miRNAs as oncogenes or tumour suppressors. Besides, miRNAs can induce gene silencing via epigenetic mechanisms e.g. by targeting a specific gene region for DNAm and histone modifications or by regulating expression of epigenetic enzymes. MiRNAs expression profile of siRNA-UHRF1 PC3 cells showed both increased and decreased miRNA levels. Using different target predictive software, Dnmt3a appeared as a target of two new miRNAs (miRNA-a and miRNA-b) overexpressed in siRNA-UHRF1 PC3 cells. Levels of miRNA-a and -b were confirmed by RT-QPCR in siRNA-UHRF1 PC3 and in LNCaP cells (with UHRF1 and Dnmt3a lower levels than PC3) and the binding of the two new miRNAs to the Dnmt3a3’UTR and its inhibitory effect were validated by reporter luciferase system. We studied the effect of the overexpression of miRNA-a and -b in PC3 finding a decrease of Dnmt3a mRNA and protein, and a decrease in PC3 proliferation. We studied the effects of miRNA silencing in LNCaP finding an increase of Dnmt3a mRNA and protein, and an increase in LNCaP proliferation. These data show the role of miRNA-a and -b in the modulation of Dnmt3a and propose their involvement in prostate cancer progression. Next goal is to study their promoters evaluating the role of UHRF1 in miRNAs transcription.
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