RESUMO
As a natural flavonol, fisetin has significant inhibitory effects on many cancers. Although fisetin can inhibit kidney cancer, its effects on kidney renal stem cells (HuRCSCs) remain unknown. Our study found that renal cancer tissues and CD44+/CD105+ HuRCSCs both show high TET1 protein expression. Both in vivo and in vitro experiments showed that fisetin can effectively inhibit HuRCSC cell division and proliferation, invasion, in vivo tumourigenesis and angiogenesis. Our findings showed that fisetin can significantly decrease TET1 expression levels in HuRCSCs and overall 5hmC levels in the genomes of these cells. At the same time, ChIP-PCR results showed that fisetin can effectively inhibit 5hmC modification levels at the CpG islands in cyclin Y (CCNY) and CDK16 and reduce their transcription and activity. Thus, we conclude that fisetin inhibits the epigenetic mechanism in renal cancer stem cells, that is, fisetin inhibits TET1 expression and reduces 5hmC modification in specific loci in the promoters of CCNY/CDK16 in HuRSCs. This in turn inhibits transcription of these genes, causing cell cycle arrest and ultimately inhibiting renal cancer stem cell activity.
Assuntos
Proliferação de Células/efeitos dos fármacos , Quinases Ciclina-Dependentes/genética , Ciclinas/genética , Flavonoides/farmacologia , Oxigenases de Função Mista/genética , Células-Tronco Neoplásicas/efeitos dos fármacos , Regiões Promotoras Genéticas/efeitos dos fármacos , Proteínas Proto-Oncogênicas/genética , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Pontos de Checagem do Ciclo Celular/genética , Proliferação de Células/genética , Células Cultivadas , Ilhas de CpG/efeitos dos fármacos , Epigênese Genética/efeitos dos fármacos , Flavonóis , Humanos , Neoplasias Renais/tratamento farmacológico , Neoplasias Renais/genética , Invasividade Neoplásica/genética , Invasividade Neoplásica/patologia , Regiões Promotoras Genéticas/genética , Transcrição Gênica/efeitos dos fármacosRESUMO
Cardiac fibrosis is pathological damage associated with nearly all forms of heart disease. AMP-activated protein kinase (AMPK) is an evolutionary conserved energy-sensing enzyme. Emerging evidences indicate that AMPK plays an important role in cardiac fibrosis and cell proliferation. However, less is known about the detailed mechanism of AMPK activation on cardiac fibrosis. In this study, we found the AMPK activation improved the impaired cardiac function of cardiac fibrosis rats and decreased interstitial fibrosis. Further results indicated AMPK activation promoted p21 and p27 and inhibited CDK2 and cyclin E protein expressions both in vivo and in vitro. Moreover, AMPK activation repressed downstream transcription factor hepatocyte nuclear factor 4 alpha (HNF-4α) expression and decreased the binding of HNF-4α to TGF-ß1 promoters, which eventually resulted in TGF-ß1 downregulation and miR-29 family upregulation. Furthermore, miR-29, in turn, inhibited the progression of cardiac fibrosis through suppressing its target CDK2. Taken together, activation of AMPK, on the one hand, upregulated p21 and p27 expression, further inhibited CDK2 and cyclin E complex, and finally suppressed the progression of cardiac fibrosis, and, on the other hand, repressed HNF-4α expression, further downregulated the activity of TGF-ß1 promoter, promoted miR-29 expression, and finally prevented the development of cardiac fibrosis.
RESUMO
Objective The purpose of this study is to investigate the apoptosis mechanisms of glioblasto-ma cell line U87 induced by sodium cantharidinate ( SCA) in vitro.Methods Growth inhibition of U87 by 0.625μg/mL,1.25μg/mL,2.5μg/mL,5μg/mL SCA at 24 h,48 h,72 h were analyzed by MTT assay respec-tively.Morphological changes of U 87 nuclear were detected by fluorescence microscope .U87 cell apoptosis and cell cycle arrest were detected after SCA treatment for 24 h and 48 h by flow cytometry.The changes of apoptosis-related genes Bcl -2,Bax,Caspase-3 expression were analyzed after 24 h of SCA treatment by RT -PCR as-say.Results MTT assay showed that growth inhibition of U 87 cell induced by SCA was accompanied with the in-creased drug concentration ,Hoechst33258 staining showed the morphology of apoptotic U 87 cells nucleui ,chromo-some condensation ,nuclear condensation ,some nuclear fragmentation and formation of apoptotic bodies .Flow cy-tometry showed that SCA could induce cell cycle arrest at the G 2/M phase,and could induce apoptosis of U87.RT-PCR results showed that after 24 h of SCA treatment caspase -3,bax expression of U87 was significantly higher than the control group(P0.05).Conclusion Our results demonstrate that SCA can inhibit U87 pro-liferation and induce apoptosis of U 87 .
