Brevinin-2R is a novel non-hemolytic defensin that was isolated from the skin of the frog Rana ridibunda. It exhibits preferential cytotoxicity towards malignant cells, including Jurkat (T-cell leukemia), BJAB (B-cell lymphoma), HT29/219, SW742 (colon carcinomas), L929 (fibrosarcoma), MCF-7 (breast adenocarcinoma), A549 (lung carcinoma), as compared to primary cells including peripheral blood mononuclear cells (PBMC), T cells and human lung fibroblasts. Jurkat and MCF-7 cells overexpressing Bcl2, and L929 and MCF-7 over-expressing a dominant-negative mutant of a pro-apoptotic BNIP3 (ΔTM-BNIP3) were largely resistant towards Brevinin-2R treatment. The decrease in mitochondrial membrane potential (ΔΨm), or total cellular ATP levels, and increased reactive oxygen species (ROS) production, but not caspase activation or the release of apoptosis-inducing factor (AIF) or endonuclease G (Endo G), were early indicators of Brevinin-2R-triggered death. Brevinin-2R interacts with both early and late endosomes. Lysosomal membrane permeabilization inhibitors and inhibitors of cathepsin-B and cathepsin-L prevented Brevinin-2R-induced cell death. Autophagosomes have been detected upon Brevinin-2R treatment. Our results show that Brevinin-2R activates the lysosomalmitochondrial death pathway, and involves autophagy-like cell death.
Abstract.Objectives : The phosphatidylinositol 3-kinase (PI3-K)/Akt pathway is well known for the regulation of cell survival, proliferation, and some metabolic routes. Meterials and Methods : In this study, we document a novel role for the PI3-K/Akt pathway during cell death induced by apoptin, a tumour-selective inducer of apoptosis. Results : We show for the first time that apoptin interacts with the p85 regulatory subunit, leading to constitutive activation of PI3-K. The inhibition of PI3-K activation either by chemical inhibitors or by genetic approaches severely impairs cell death induced by apoptin. Downstream of PI3-K, Akt is activated and translocated to the nucleus together with apoptin. Direct interaction between apoptin and Akt is documented. Co-expression of nuclear Akt significantly potentiates cell death induced by apoptin. Thus, apoptin-facilitated nuclear Akt, in contrast to when in its cytoplasmic pool, appears to be a positive regulator, rather than repressor of apoptosis. Conclusions : Our observations indicate that PI3-K/Akt pathways have a dual role in both survival and cell death processes depending on the stimulus. Nuclear Akt acts as apoptosis stimulator rather than as a repressor, as it likely gains access to a new set of substrates in the nucleus. The implicated link between survival and cell death pathways during apoptosis opens new pharmacological opportunities to modulate apoptosis in cancer, for example through the manipulation of Akt's cellular localization.
For over 35 years shock wave lithotripsy has proven to be an effective, safe and truly minimally invasive option for the treatment of nephrolithiasis. Various technical factors as well as patient selection can impact the success of the procedure. We used published work focusing on outcomes of shock wave lithotripsy, risk of complications, and strategies for improving stone fragmentation to create this review. Multiple patient and technical factors have been found to impact success of treatment. Skin to stone distance, stone density and composition, size and location of the stone within the urinary system all influence stone free rates. A slower rate with a gradual increasing voltage, precise targeting, proper coupling will improve stone fragmentation and decrease risk of complications. The selection of appropriate patients through a shared decision making process and attention to the technical factors that improve stone free rates is key to providing an effective treatment and patient satisfaction.
While single-treatment success rates may not equal those of ureteroscopy or percutaneous nephrolithotomy, with proper patient selection, optimization of SWL technique, and use of adjunctive treatment after SWL, success rates can be maximized while further reducing the already low rate of serious complications. SWL remains an excellent treatment option for calculi even in 2017.
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