Purpose:We investigated whether BRCA1mRNA expression levels may represent a biomarker of survival in sporadic epithelial ovarian cancer following chemotherapy treatment. Experimental Design: The effect of loss of BRCA1 expression on chemotherapy response in ovarian cancer was measured in vitro using dose inhibition assays and AnnexinV flow cytometry. Univariate and multivariate analyses were done to evaluate the relationship between BRCA1 mRNA expression levels and survival after chemotherapy treatment in 70 fresh frozen ovarian tumors. Results: We show that inhibition of endogenous BRCA1 expression in ovarian cancer cell lines results in increased sensitivity to platinum therapy and decreased sensitivity to antimicrotubule agents. In addition, we show that patients with low/intermediate levels of BRCA1 mRNA have a significantly improved overall survival following treatment with platinum-based chemotherapy in comparison with patients with high levels of BRCA1mRNA (57.2 versus18.2 months; P = 0.0017; hazard ratio, 2.9). Furthermore, overall median survival for higher-BRCA1-expressing patients was found to increase following taxane-containing chemotherapy (23.0 versus 18.2 months; P = 0.12; hazard ratio, 0.53). Conclusions: We provide evidence to support a role for BRCA1 mRNA expression as a predictive marker of survival in sporadic epithelial ovarian cancer.The BRCA1 tumor suppressor gene is associated with susceptibility to both hereditary breast and ovarian cancer (1,2). Approximately 5% to 15% of ovarian cancers are inherited and BRCA1 germ-line mutations account for 90% of these cases conferring a cumulative lifetime risk of 54% compared with 1.8% within the general population (3, 4). Although somatic mutations of BRCA1 are uncommon in sporadic ovarian tumors (5), down-regulation of BRCA1 has been reported in >72% of high-grade sporadic ovarian cancers, suggesting that BRCA1 may also play a major role in the development of sporadic epithelial ovarian cancer (6, 7). Epigenetic inactivation of BRCA1 is at least partially due to hypermethylation of the BRCA1 promoter, which has been observed in up to 15% of cases (8,9).Several preclinical breast cancer studies have indicated that BRCA1 is an important determinant of response to both DNAdamaging and taxane-based chemotherapy. Evidence that BRCA1 deficiency, whether through inherited mutation or epigenetic down-regulation, confers marked sensitivity to DNAdamaging agents is derived from numerous in vitro studies (10 -15). Furthermore, several retrospective breast cancer clinical studies are in agreement with these preclinical findings. It has been shown that BRCA1 mutation carriers gain a significant survival advantage from DNA damage -based chemotherapy compared with non -mutation carriers (16,17). In addition, reduced BRCA1 protein expression in sporadic epithelial ovarian cancer was found to correlate with improved survival (18). Finally, a retrospective analysis of BRCA1 mRNA levels in a cohort of sporadic lung tumors showed that low-BRCA1-expressing ...

Background/Aims: Myocardial ischemia/reperfusion injury is a major cause of morbidity and mortality associated with coronary heart disease. Many studies have demonstrated that natural products are promising chemotherapeutic drugs counteracting the loss of cardiomyocytes. Thus, the purpose of the present study was to investigate the effects of geniposide, a traditional Chinese herb extract from Gardenia jasminoides J. Ellis, on cardiomyocyte apoptosis induced by hypoxia/reoxygenation (H/R) in H9c2 cells, and their underlying mechanisms. Methods: Cell viability and apoptosis ratio were assessed using the cell counting kit-8 assay and Annexin V/propidium iodide (PI) staining. The concentrations of lactate dehydrogenase (LDH), intracellular total superoxide dismutase (T-SOD), and malondialdehyde (MDA) were detected by microplate reader. The production of reactive oxygen species/reactive nitrogen species (ROS/RNS), the level of mitochondrial calcium, and mitochondrial membrane potential depolarization were measured by confocal laser scanning microscopy. Mitochondrial morphology was visualized using transmission electron microscopy. The expressions of Bcl-2 mRNA and Caspase-3 mRNA were measured by reverse transcription-polymerase chain reaction (RT-PCR). The protein levels of cleaved caspase-3, Bcl-2, Bax, AKT, p-AKT^serine473, cytochrome-c were detected by western bloting. Results: Geniposide pretreatment increased cell viability, decreased LDH levels in the supernatant, and inhibited cardiomyocyte apoptosis caused by H/R. Furthermore, geniposide reversed mitochondrial dysfunction by decreasing oxidative stress products (ROS/RNS and MDA), increasing anti-oxidative enzyme (T-SOD) level, improving mitochondrial morphology, attenuating mitochondrial calcium overload and blunting depolarization of mitochondrial membrane. Moreover, geniposide pretreatment increased Bcl-2 level and decreased Bax level, thus enhancing the Bcl-2/Bax ratio. Consistent with the above result, Bcl-2 mRNA expression was upregulated and caspase-3 mRNA expression was downregulated by geniposide. In addition, geniposide decreased the protein expression of cleaved caspase-3 and cytochrome-c and increased the level p-AKT^serine473. The protective effects of geniposide were partially reversed by glucagon-like pepitide-1 receptor antagonist exendin-(9-39) and the phosphatidylinositol 3 kinase (PI3K) inhibitor LY294002. Conclusions: Our results suggest that geniposide pretreatment inhibits H/R-induced myocardial apoptosis by reversing mitochondrial dysfunction, an effect in part due to activation of GLP-1R and PI3K/AKT signaling pathway.

Myocardial ischemia/reperfusion (MI/R) leads to oxidative stress, which may in turn lead to myocardial injury. In the present study, we investigated the effects of exenatide, a glucagon-like peptide-1 (GLP-1) analogue, on oxidative stress-induced injury in vitro and in vivo. In in vitro experiments, H9c2 cells were incubated with exenatide to determine the direct cytoprotective effects of exenatide following exposure to hydrogen peroxide (H2O2). Pre-treatment with exenatide (1 nM), prior to H2O2 exposure, increased cell viability and inhibited H2O2-induced reactive oxygen species (ROS) production. Exenatide also decreased the levels of lactate dehydrogenase (LDH) and creatine kinase-MB (CK-MB) in the cultured supernatants, as well as those of malondialdehyde (MDA) in the H9c2 cells and increased the total superoxide dismutase (T-SOD) levels in the H9c2 cells. In in vivo experiments, an animal model of MI/R was induced by coronary occlusion. Pre-treatment with exenatide (10 µg/kg/day) protected the rat hearts from MI/R-induced injury by decreasing the levels of LDH and CK-MB in plasma, increasing the levels of catalase, T-SOD and glutathione peroxidase (GSH-Px) in the heart and decreasing the MDA levels in the rats with MI/R-induced injury. Exenatide also reduced the infarct size and enhanced cardiac function in the rats with MI/R-induced injury. Moreover, pre-treatment with exenatide inhibited cardiomyocyte apoptosis, increased Aktserine473 and Badserine136 phosphorylation and decreased cleaved caspase-3 expression in vitro and in vivo; however, these effects were attenuated by the phosphoinositide 3-kinase (PI3K) inhibitor, LY294002. Our results suggest that exenatide exerts significant cardioprotective effects against oxidative stress-induced injury in vitro and in vivo. The mechanisms involved may be attributed to the scavenging of oxidative stress products, such as ROS, the increase in the concentrations of antioxidant defense enzymes and the inhibition of cardiomyocyte apoptosis. The anti-apoptotic effects of exenatide were, at least in part, associated with the activation of the PI3K/Akt signaling pathway.

TMZ improved cardiac function, alleviated myocardial injury and oxidative stress, and reduced the myocardial infarct area and apoptosis. TMZ inhibited MI/R-induced myocardial autophagy, H/R-induced H9c2 cell apoptosis, and autophagy flux. The effect of TMZ on autophagy was repressed by LY294002. TMZ protected against MI/R injury by inhibiting excessive autophagy via activating the AKT/mTOR pathway.

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