RESUMO
Poly(ADP-ribose) polymerase (PARP)-1 and PARP2 function as ADP-ribosylases involved in DNA repair. PARP1/2 is highly expressed in cancers and emerged as an attractive target for antitumor drug. In this study, we investigated the antitumor activity of a novel PARP1/2 inhibitor YHP-743 in vitro and in vivo. The results showed that YHP-743 had potent enzymatic inhibitory activity against PARP1 and PARP2 to down-regulate the PAR level. YHP-743 not only inhibited breast cancer cells with genes deficiency of homologous recombination repair, but also potentiated chemotherapy agent's cytotoxicity, such as temozolomide, topotecan, cisplatin and doxorubicin. YHP-743 elicited good antitumor activity in combination with temo-zolomide in vivo.
RESUMO
AIM:To investigate the expression of poly(ADP-ribose) polymerase-2 (PARP-2) during rat car-diac hypertrophy in vitro and in vivo, and to explore the effects of PARP-2 on the cardiac hypertrophy.METHODS:Ab-dominal aortic coarctation ( AAC) was performed to establish a model of pressure overload-induced cardiac hypertrophy in SD rats.The expression of PARP-2 at mRNA and protein levels in the myocardium was determined by real-time PCR and Western blot.The hypertrophy model of the cardiomyocytes was induced by treating the cells with angiotensinⅡ( AngⅡ) . PARP-2 was knocked down by siRNAs in neonatal rat cardiomyocytes and the cardiomyocyte hypertrophy was evaluated by measuring the mRNA levels of ANF, BNP, and β-MHC and the cellular surface area.RESULTS: The expression of PARP-2 at mRNA and protein levels was both increased in the AAC rats as compared with those in the sham animals.The expression of PARP-2 at mRNA and protein levels was also increased in a time-and concentration-dependent manner in AngⅡ-induced hypertrophy model of the cardiomyocytes.In the neonatal rat cardiomyocytes, knockdown of PARP-2 ex-pression by siRNA attenuated AngⅡ-induced cardiac hypertrophy of the cardiomyocytes, indicating that endogenous PARP-2 played a positive regulatory role in cardiac hypertrophy.CONCLUSION:The mRNA and protein levels of PARP-2 in-crease in the in vitro and in vivo models of cardiac hypertrophy.Knockdown of PARP-2 protects cardiomyocytes from hyper-trophy.