Background-Autophagy is a molecular process that breaks down damaged cellular organelles and yields amino acids for de novo protein synthesis or energy provision. Mechanical unloading with a left ventricular assist device (LVAD) decreases the energy demand of the failing human heart. We tested the hypothesis that LVAD support reverses activation of autophagy. Methods and Results-Paired biopsy samples of left ventricular myocardium were obtained from 9 patients with idiopathic dilated cardiomyopathy (mean duration of LVAD support, 214 days) at the time of implantation and explantation of the LVAD. Transcript and protein levels of markers and mediators of autophagy and apoptosis were measured by quantitative reverse-transcription polymerase chain reaction and Western blotting. TUNEL assays, C9 immunohistochemistry, and 20S proteasome activity assays were also performed. Mechanical unloading significantly decreased mRNA transcript levels of Beclin-1, autophagy-related gene 5 (Atg5), and microtubule-associated protein-1 light chain-3 (MAP1-LC3 or LC3; PϽ0.02). Protein levels of Beclin-1, Atg5-Atg12 conjugate, and LC3-II were also significantly reduced after LVAD support (PϽ0.05). A significant increase in 20S proteasome activity was observed with unloading, in parallel to the decrease in autophagic markers. Although BNIP3 and the ratio of activated caspase 3 to procaspase 3 increased after LVAD support, Bcl-2 and TUNEL-positive nuclei were not significantly different between samples. Conclusions-Mechanical unloading of the failing human heart decreases markers of autophagy. These findings suggest that autophagy may be an adaptive mechanism in the failing heart, and this phenomenon is attenuated by LVAD support. (Circulation. 2009;120[suppl 1]:S191-S197.)
The prevalence of human papilloma virus (HPV)-16 in patients with cervical cancer, the physical status of HPV-16 in patients with cervical lesions, and the role of HPV-16 integration in cervical carcinogenesis were investigated. HPV genotyping was performed by using PCR approach with the primer GP5+/GP6+ and type-specific primer on biopsy specimens taken operatively from 198 women. Multiple PCR was done to detect physical status of HPV-16 in a series of cervical liquid-based cytology samples and biopsy specimens obtained from different cervical lesions with HPV-16 infection, including 112 specimens with cervical cancer, 151 specimens with CIN I, 246 specimens with CIN and 120 specimens with CINIII. The results showed that there were 112 cervical cancer samples (56.57% of total cervical cancer patients) with HPV-16 infection. The frequency of HPV-16 pure integration was 65.18% (73/112), 56.57% (47/120), 23.58% (58/246) and 7.95% (12/151) in cervical cancer, CINIII, CINII and CINI patients respectively. In situ hybridization was performed on some paraffin-embedded sections of CINII, CINIII and cervical cancer to verify the physical status of HPV-16 infection. Significant difference was observed between cervical cancer and CIN I, CINII, CINIII in the frequency of HPV-16 integration (P<0.01). It is suggested that HPV-16 is the most prevalent type and is associated with cervical cancer. In the case of HPV-16 infection there are close associations between the severity of cervical lesions and the frequency of HPV-16 integration. The application of testing HPV genotyping and physical status based on detection of HC-II HPV DNA would be in favor of predicting the prognosis of cervical precancerosis and enhancing the screening accuracy of cervical cancer.
Lung cancer is one of the most prevalent causes of morbidity and mortality in both men and women across the globe. The disease has a quiet phenotype at first, which leads to chronic tumor development. Non-small cell lung cancer (NSCLC) is the most common kind of lung cancer, accounting for 85 percent of all lung malignancies. Autophagy has been described as an intracellular "recycle bin" where damaged proteins and molecules are degraded. Autophagy regulation is mainly dependent on signaling pathways such as phosphoinositide 3-kinases (PI3K), AKT, and the mammalian target of rapamycin (mTOR). In the context of NSCLC, studies on these signaling pathways are inconsistent, but our literature review suggests that the inhibition of mTOR, PI3K/AKT, and epidermal growth factor receptor signaling pathways by different medications can active autophagy and inhibit NSCLC progression. In conclusion, signaling pathways related to autophagy are effective therapeutic approaches for the treatment of NSCLC.
Although a combination of platinum- and taxane-based chemotherapy is recommended for at least 70% patients with ovarian cancer as treatment subsequent to surgery, the initial response to the chemotherapy is not durable and tumors become resistant. Histone deacetylase and proteasome inhibitors are novel therapeutic agents. However, the moderate antitumoral effect of the inhibitors has restricted their clinical use when used as single agents. The aim of the present study was to investigate the synergistic activity of trichostatin A (TSA) and PS-341 in ovarian cancer cells, along with the investigation of the molecular mechanisms of taxane resistance. The taxane-sensitive ovarian cancer A2780 cell line and its resistant variant, A2780T, were treated with taxane, TSA and PS-341 at various concentrations. An Annexin V assay was performed to determine the levels of cell viability and apoptosis, while flow cytometry and immunofluorescence staining for the mitotic phase-specific protein phosphorylated-histone H3 (Ser10) were used for cell cycle detection. The effects of combined TSA and PS-341 on cell cycle-associated proteins were tested by western blot analysis. Furthermore, the present study examined the apoptosis and cell cycle arrest induced by the 3 agents subsequent to overexpression or downregulation of cyclin B1 in A2780 and A2780T cells, respectively. It was found that TSA interacted synergistically with PS-341, resulting in a marked increase in apoptosis and the rate of G2/M arrest in A2780T cells. A lower basal level of cyclin B1 expression and the incompetence of the upregulation of the cyclin may explain the taxane resistance found in A2780T cells. Collectively, the combination of TSA and PS-341 increased cyclin B1 expression level regardless of the basal expression level, resulting in the proliferation inhibition and apoptosis in A2780 and A2780T cells, which raised the possibility that a combination of the two drugs may represent a novel strategy for the treatment of ovarian cancer, particularly in taxane-resistant ovarian cancer.
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