Zebularine induces apoptosis of esophageal cancer cells via demethylation SFRP2/Dkk3 to regulate Wnt/β-catenin signaling pathway / 药学学报

To explore the effect and mechanisms of demethylation drug zebularine on esophageal cancer cells apoptosis, ECA109 cells and KYSE170 cells were treated with zebularine at different concentrations (25, 50, 100, 200, and 400 μmol·L-1). The cell viability was measured by CCK-8. Flow cytometry was used to detect the cell apoptosis rate, Western blot was performed to determine the expression of apoptosis protein (Bcl-2, Bax, cleaved-caspase-3, and cleaved-PARP) and Wnt signal pathway molecules (β-catenin, cyclin D1, and c-Myc), real-time quantitative PCR was used to detect the expression level of negative regulatory genes of Wnt signaling pathway, methylation specific PCR (MSP) was used to detect the methylation status of secreted frizzled related protein 2 (SFRP2) and dickkopf 3 (Dkk3) genes. After knockdown of SFRP2 and Dkk3, the effect of zebularine on apoptosis was detected. The studies showed that zebularine could inhibit the activity of ECA109 and KYSE170 cells in a dose-dependent and time-dependent manner; zebularine could induce cell apoptosis, down-regulate the expression of Bcl-2 protein, up-regulate the expression of Bax, cleaved-caspase-3, and cleaved-PARP protein, and inhibit the expression of β-catenin, cyclin D1, and c-Myc protein (P < 0.05); the mRNA expression levels of Dkk3 and SFRP2 were significantly up-regulated by zebularine, while the methylation levels of SFRP2 and Dkk3 promoters were decreased; knockdown of SFRP2 and Dkk3 could reduce the apoptosis induced by zebularine. In summary, zebularine could reduce the methylation level of SFRP2 and Dkk3 gene promoter, promote the expression of SFRP2 and Dkk3 gene, and then induce the apoptosis of esophageal cancer cells by inhibiting Wnt/β-catenin signaling pathway.

Buckwheat rutin inhibits angII-induced cardiomyocyte hypertrophy via blockade of CaN-dependent signal pathway

Buckwheat rutin has been found to be able to inhibit angiotensin II [AngII] - induced hypertrophy in cultured neonatal rat cardiomyocytes, but the mechanism remains uncertain. In this study, myocardial hypertrophy model was made by adding AngII to the medium of cardiac myocytes of neonatal rats; meanwhile, different concentrations of buckwheat rutin were applied to observe their effects. Intracellular Ca[2]+ level was detected by Hitachi - 850 fluorospectrophotometer, calcineurin [CaN] activity was measured by colorimetric method, the expression of CaN protein was observed with immunocytochemistry, and the proto - oncogene c - fos mRNA expression was assessed with reverse transcription polymerase chain reaction [RT - PCR]. Compared with control group, AngII could greatly stimulate the increase of intracellular Ca[2]+ level, the activities and protein expression of cardiomyocytes CaN, and the expression of proto - oncogene c - fos mRNA in cultured neonatal rat cardiomyocytes, which could be effectively decreased by buckwheat rutin. Our results demonstrated that buckwheat rutin exhibited inhibitory effect on AngII - induced hypertrophy in cultured neonatal rat cardiomyocytes via Ca[2]+ antagonism action thus block the CaN - dependent signal pathway