ABSTRACT
Aim To study the reversal effect of albiflorin(AL)on multidrug resistance of human ovarian cancer and the potential mechanism. Methods The drug resistance reversal effect of AL on SKOV3/DDP cells was detected by CCK-8 kit,and the effect of AL on P-glycoprotein(P-gp)function was detected by flow cytometry. The effects of AL on MYC,WWP1 and ABCB1 in SKOV3/DDP cells were detected by RT-qPCR and Western blot. The MYC-knockdown SKOV3/DDP cell line was constructed by RNA interference technology,and its drug resistance,P-gp function and related gene and protein expression changes were investigated. Results AL had a drug resistance reversal effect on SKOV3/DDP cells and a concentration-dependent inhibitory effect on P-gp function. The inhibitory effects of AL 25,50 and 100 μmol·L-1 on ABCB1/P-gp,MYC and WWP1 were gradually enhanced. The inhibitory effect of MYCi975,a MYC inhibitor,on ABCB1/P-gp,MYC and WWP1 was stronger than or equivalent to that of AL 100 μmol·L-1 group. After knockdown of MYC in SKOV3/DDP cells,cell drug resistance,P-gp function,and related gene and protein expression were inhibited. Conclusions The drug resistance reversal effect of AL on SKOV3/DDP cells may be related to the inhibition of P-gp function and the expression of ABCB1/P-gp,MYC and WWP1,which provides an experiment base for the development of AL as a drug resistance reversal agent for the clinical treatment of ovarian cancer.
ABSTRACT
The success rate of mechanism-based drug discovery depends on the drug targets. With the rapid development of genomics and proteomics, a lot of nonenzymic proteins have been identified as potential drug targets. However, these nonenzymic proteins cannot be regulated by occupying the active site, which were recognized as undruggable targets. Direct regulation of the concentration of these proteins in cells by the innate ubiquitin-proteasome is a potential approach to target these proteins. The ubiquitination of target protein by E3 ligase is the key step for ubiquitin-proteasome mediated protein degradation. Proteolysis targeting chimeras (PROTACs) can facilitate the assembly of complex that consists of the target protein and E3 ligase. The target protein will be ubiquitinated, leading to the degradation by proteasome. This type of regulation mechanism can expand the scope of potential drug targets, and the development of PROTACs may be an innovative strategy in drug discovery.
ABSTRACT
AIM:To explore the role of ubiquitin E3 ligase tripartite motif 10 (TRIM10) in the development of cardiomyocyte hypertrophy .METHODS: Primary cultured neonatal rat cardiomyocytes ( NRCMs ) were infected with siRNA-TRIM10, siRNA-control, Ad-TRIM10 or Ad-GFP for 24 h respectively, and then stimulated with phenylephrine ( PE) for additional 24 h.The protein levels of TRIM10, AKT and ERK1/2 were determined by Western blot .The size of the NRCMs was measured by immunofluorescence staining .The mRNA expression of atrial natriuretic peptide ( ANP) and brain natriuretic peptide ( BNP) was detected by RT-qPCR.RESULTS:Compared with the control , PE treatment signifi-cantly increased the protein expression of TRIM 10.Moreover, transfection of NRCMs with siRNA-TRIM10 markedly inhibi-ted cardiomyocyte size , the mRNA expression of ANP and BNP , and the phosphorylation levels of AKT and ERK as com-pared with siRNA-control after PE treatment.In contrast, overexpression of TRIM10 significantly enhanced PE-induced hy-pertrophic effect on NRCMs above .CONCLUSION:TRIM10 regulates cardiomyocyte hypertrophy partially through AKT and ERK signaling pathways .
ABSTRACT
AIM:To explore the role of ubiquitin E3 ligase tripartite motif 10 (TRIM10) in the development of cardiomyocyte hypertrophy .METHODS: Primary cultured neonatal rat cardiomyocytes ( NRCMs ) were infected with siRNA-TRIM10, siRNA-control, Ad-TRIM10 or Ad-GFP for 24 h respectively, and then stimulated with phenylephrine ( PE) for additional 24 h.The protein levels of TRIM10, AKT and ERK1/2 were determined by Western blot .The size of the NRCMs was measured by immunofluorescence staining .The mRNA expression of atrial natriuretic peptide ( ANP) and brain natriuretic peptide ( BNP) was detected by RT-qPCR.RESULTS:Compared with the control , PE treatment signifi-cantly increased the protein expression of TRIM 10.Moreover, transfection of NRCMs with siRNA-TRIM10 markedly inhibi-ted cardiomyocyte size , the mRNA expression of ANP and BNP , and the phosphorylation levels of AKT and ERK as com-pared with siRNA-control after PE treatment.In contrast, overexpression of TRIM10 significantly enhanced PE-induced hy-pertrophic effect on NRCMs above .CONCLUSION:TRIM10 regulates cardiomyocyte hypertrophy partially through AKT and ERK signaling pathways .