Diallyl trisulfide-induced apoptosis of bladder cancer cells is caspase-dependent and regulated by PI3K/Akt and JNK pathways

Diallyl trisulfide (DATS) is one of the major organosulfur components of garlic (Allium sativum L.), which inhibits the proliferation of various cancer cells, but the exact mechanisms of this action in human bladder cancer cells still remain largely unresolved. In this study, we investigated how DATS induces apoptosis in T24 human bladder cancer cells in vitro. Treatment of T24 cells with DATS resulted in potent anti-proliferative activity. Additionally, some typical apoptotic characteristics, such as chromatin condensation and an increase in the population of sub-G1 hypodiploid cells, were observed. With respect to the mechanism underlying the induction of apoptosis, DATS reduced the expression of anti-apoptotic Bcl-2 and Bcl-xL, and inhibitor of apoptosis protein family proteins, but the expression of pro-apoptotic Bax and death receptor-related proteins was increased compared with the controls. DATS also activated caspase-8 and -9, the respective initiator caspases of the extrinsic and the intrinsic apoptotic pathways. The increase in mitochondrial membrane depolarization was correlated with activation of effector caspase-3 and cleavage of poly-ADP-ribose polymerase, a vital substrate of activated caspase-3. Blockage of caspase activation through treatment with a pan-caspase inhibitor consistently inhibited apoptosis and abrogated growth inhibition in DATS-treated T24 cells. The study further investigated the roles of the phosphatidylinositol 3-kinase (PI3K)/Akt and mitogen-activated protein kinases (MAPKs) pathways with respect to the apoptotic effect of DATS, and showed that DATS deactivates Akt. Additionally, DATS activates extracellular signal-regulated kinase (ERK) and c-Jun N-terminal protein kinase (JNK), but not p38 MAPK, in T24 cells. Unlike ERK, JNK inhibitors reversed DATS-induced apoptosis and growth inhibition; however, inhibition of PI3K/Akt notably enhanced the apoptotic action of DATS. The results suggest that the pro-apoptotic activity of DATS is probably regulated by a caspase-dependent cascade through the activation of both intrinsic and extrinsic signaling pathways, which is mediated through the blocking of PI3K/Akt and the activation of the JNK pathway.     

Antimalarial drugs - what is in use and what is in the pipeline

Malaria continues to be a potentially fatal threat to almost half of the world's population. In light of this threat, the armory to fight this disease is rather limited. Resistance against the most common and affordable antimalarials is widespread. Only few new drugs are in clinical development, most of them belong to long used classes of antimalarial drugs. This review will concisely cover the drugs which are currently in use, and describe the drug candidates which are in clinical evaluation.     

Modern multiple sclerosis treatment - what is approved, what is on the horizon

In the mid-1990s, the implementation of the immunomodulatory drugs interferon-beta and glatiramer acetate offered the first evidence-based treatment option for multiple sclerosis (MS). These new drugs were beneficial in a huge number of MS patients worldwide, leading to a delay in disease-related disability. Moreover, MS was suddenly the focus not only of patients and their physicians but also of pharmaceutical companies, with a tremendous increase in interest by scientists. As a result of these efforts the first monoclonal antibody treatment has recently been implemented in MS. It will presumably be followed by several other more specific, more effective and more comfortable therapies within the next few years. Here, we will show the current MS treatment options as well as recent progress in the field, and we will introduce the potential new treatment options for future MS therapy.     

T cell selective apoptosis by a novel immunosuppressant,FTY720, is closely regulated with Bcl-2

1. A novel immunosuppressant FTY720 caused a significant decrease in peripheral T lymphocytes, but not in B lymphocytes upon oral administration. This decrease was mainly a result of FTY720-induced apoptosis. In this study, we confirmed FTY720-induced T cell selective apoptosis using lymphoma cell lines in vitro. 2. Viability loss, DNA fragmentation, Annexin V binding, and caspases activation (caspase-3, -8, and -9) were observed in Jurkat cells (T lymphoma cells), but not significantly in BALL-1 cells (B lymphoma cells). These results indicated that FTY720 selectively induced apoptosis in T cell lymphoma to a greater extent than in B cell lymphoma, a finding that is similar to the result observed when FTY720 was treated with T lymphocytes and B lymphocytes in vitro. 3. FTY720 released cytochrome c from mitochondria in Jurkat intact cells as well as from isolated Jurkat mitochondria directly, but not from mitochondria in BALL-1 cells nor from isolated BALL-1 mitochondria. 4. BALL-1 cells and B cells had more abundant mitochondria-localized anti-apoptotic protein Bcl-2 than did Jurkat cells and T cells. 5. FTY720-induced apoptosis is inhibited by the overexpression of Bcl-2, suggesting that the cellular Bcl-2 level regulates the sensitivity to FTY720.     

Capsaicin-induced apoptosis is regulated by endoplasmic reticulum stress- and calpain-mediated mitochondrial cell death pathways

Capsaicin, a pungent compound found in hot chili peppers, induces apoptotic cell death in various cell lines, however, the precise apoptosis signaling pathway is unknown. Here, we investigated capsaicin-induced apoptotic signaling in the human breast cell line MCF10A and found that it involves both endoplasmic reticulum (ER) stress and calpain activation. Capsaicin inhibited growth in a dose-dependent manner and induced apoptotic nuclear changes in MCF10A cells. Capsaicin also induced degradation of tumor suppressor p53; this effect was enhanced by the ER stressor tunicamycin. The proteasome inhibitor MG132 completely blocked capsaicin-induced p53 degradation and enhanced apoptotic cell death. Capsaicin treatment triggered ER stress by increasing levels of IRE1, GADD153/Chop, GRP78/Bip, and activated caspase-4. It led to an increase in cytosolic Ca²⁺, calpain activation, loss of the mitochondrial transmembrane potential, release of mitochondrial cytochrome c, and caspase-9 and -7 activation. Furthermore, capsaicin-induced the mitochondrial apoptotic pathway through calpain-mediated Bid translocation to the mitochondria and nuclear translocation of apoptosis-inducing factor (AIF). Capsaicin-induced caspase-9, Bid cleavage, and AIF translocation were blocked by calpeptin, and BAPTA and calpeptin attenuated calpain activation and Bid cleavage. Thus, both ER stress- and mitochondria-mediated death pathways are involved in capsaicin-induced apoptosis.     

Retinoids, apoptosis and cancer

Retinoids are a class of natural and synthetic vitamin A analogs structurally related to all-trans-retinoic acid (ATRA). Natural retinoids are involved in the physiology of vision and as morphogenic agents during embryonic development; they are also known to play a major role in regulating growth and differentiation of a wide variety of normal and malignant cell types, and, indeed, they can in various ways inhibit cell proliferation, induce differentiation and cell death by apoptosis. The development of new active retinoids and the identification of two distinct families of retinoid receptors has led to an increased understanding of the cellular effects of activation of these receptors and of mechanisms involved in the retinoid-induced apoptosis. In this review a brief summary of cellular pathways relevant to programmed cell death is given together with therapeutic potentialities of retinoids having apoptotic activity. Structure-activity relationship studies concerning the importance of different stereochemistry at the C9 double bond of retinoids in conferring apoptotic activity will be described. It will be also described the preparation and the potent cytotoxic and apoptotic activity of a novel class of heterocycle-bridged arotinoids.     

Estrogens in the wrong place at the wrong time: Fetal BPA exposure and mammary cancer

Iatrogenic gestational exposure to diethylstilbestrol (DES) induced alterations of the genital tract and predisposed individuals to develop clear cell carcinoma of the vagina as well as breast cancer later in life. Gestational exposure of rodents to a related compound, the xenoestrogen bisphenol-A (BPA) increases the propensity to develop mammary cancer during adulthood, long after cessation of exposure. Exposure to BPA during gestation induces morphological alterations in both the stroma and the epithelium of the fetal mammary gland at 18 days of age. We postulate that the primary target of BPA is the fetal stroma, the only mammary tissue expressing estrogen receptors during fetal life. BPA would then alter the reciprocal stroma-epithelial interactions that mediate mammogenesis. In addition to this direct effect on the mammary gland, BPA is postulated to affect the hypothalamus and thus in turn affect the regulation of mammotropic hormones at puberty and beyond.     

Current research in empirical therapy for febrile neutropenia in cancer patients: what should be necessary and what is going on

Introduction: Fever is an important complication in neutropenic patients and standard of care calls for empirical broad-spectrum antibiotics, followed by ‘empirical' antifungal therapy in persisting fever. Emergence of infections due to resistant bacteria, especially Gram-negatives, and usefulness of empirical antifungal therapy represent the major concerns in this field.

Areas covered: Clinical trials registered in 5 international databases were referred for randomized clinical trials (RCTs) of empirical antibacterial therapy or empirical antifungal therapy in neutropenic cancer patients. The majority of RCTs compared antibiotics without major differences in the spectrum of activity, especially in the wake of the present epidemiology with an increase of infections and mortality due to resistant Gram-negatives; oral therapy and home care were analyzed in 3 RCTs. As regards empirical antifungal therapy, 1 ongoing study is comparing ‘standard' empirical treatment vs diagnostic-driven approach.

Expert opinion: In an era of increasing antibiotic resistance the comparison of different strategies more than that of different drugs will probably represent the future in studies in this field. The next future will tell us if a diagnostic-driven approach is safe for fungal infections, or if we should continue to treat them only on the basis of the persistence of febrile neutropenia.     

人脐带内皮细胞受到血流剪切应力刺激后表达凋亡蛋白X连锁抑制物(英文)

目的　生理水平的血流剪切应力有抑制内皮细胞凋亡等作用 ,进而发挥抗动脉粥样硬化作用 ,本研究的目的是阐明血流剪切应力抑制血管内皮细胞凋亡的分子机制。方法　人脐静脉内皮细胞培养于DMEM培养液 ,当细胞融合时将细胞暴露于 2 0dyne·cm-2 的剪切应力 ,分别用免疫印迹杂交及实时聚合酶链反应法检测凋亡蛋白X连锁抑制物 (X linkedinhibitorofapoptosisprotein ,XIAP)mRNA及蛋白的表达。结果　 2 0dyne·cm-2 的剪切应力刺激 1～ 4h ,可诱导内皮细胞产生XIAPmRNA ,4h时表达最多。 2 0dyne·cm-2 剪切应力刺激 6,1 2和 2 4h ,XI AP蛋白表达明显增加。结论　生理水平的剪切应力明显诱导内皮细胞XIAPmRNA和蛋白的表达 ,这可能是剪切应力抑制内皮细胞凋亡 ,发挥抗动脉粥样硬化作用的机制之一     

The BH3-only protein, PUMA, is involved in oxaliplatin-induced apoptosis in colon cancer cells

Oxaliplatin, the first line chemotherapeutic of colon cancer, induces damage to tumors via induction of apoptosis. PUMA (p53 up-regulate modulator of apoptosis) is an important pro-apoptotic member of Bcl-2 family and regulated mainly by p53. Here we investigated the role of PUMA in oxalipaltin-induced apoptosis and the potential mechanism. We showed that oxaliplatin-induced PUMA expression in a time- and dose-dependent manner and suppression of PUMA expression by stable transfecting anti-sense PUMA plasmid decreased oxaliplatin-induced apoptosis in colon cancer cells. By abrogating the function of p53, we further demonstrated that the induction was p53-independent. We also found that oxaliplatin could inactivate ERK and suppression of ERK activity by its specific inhibitor (PD98059), and dominant negative plasmid (DN-MEK1) enhanced the oxaliplatin-induced PUMA expression and apoptosis in a p53-independent manner. Taken together, our data suggest that PUMA plays an important role in oxaliplatin-induced apoptosis and the induction could be both p53-dependent and p53-independent. Moreover, PUMA expression and apoptosis in oxaliplatin-treated colon cancer cells could be regulated partly by ERK inactivation. Identification of the molecular components involved in regulating the cellular sensitivity to oxaliplatin may provide potential targets for development of novel compounds that may be useful in enhancement of oxaliplatin cytotoxicity in p53 deficient colon cancer.     

Even when regulated, advertising is still advertising

The Swiss authorities have tried to make drug advertising less misleading by insisting that it be evidence-based. However, a study conducted 3 years after the legislation was enacted showed that half of the claims made in drug ads were not backed up by the references cited or were based on biased information.     

Reactive oxygen species-dependent apoptosis by gugulipid extract of Ayurvedic medicine plant Commiphora mukul in human prostate cancer cells is regulated by c-Jun N-terminal kinase

Gugulipid (GL), extract of Indian Ayurvedic medicinal plant Commiphora mukul, has been used to treat a variety of ailments. We report an anticancer effect and mechanism of GL against human prostate cancer cells. Treatment with GL significantly inhibited the viability of human prostate cancer cell line LNCaP (androgen-dependent) and its androgen-independent variant (C81) with an IC(50) of ～1 μM (24-h treatment), at pharmacologically relevant concentrations standardized to its major active constituent z-guggulsterone. The GL-induced growth inhibition correlated with apoptosis induction as evidenced by an increase in cytoplasmic histone-associated DNA fragmentation and sub-G(0)/G(1)-DNA fraction, and cleavage of poly(ADP-ribose) polymerase. The GL-induced apoptosis was associated with reactive oxygen species (ROS) production and c-Jun NH(2)-terminal kinase (JNK) activation. The induction of proapoptotic Bcl-2 family proteins Bax and Bak and a decrease of antiapoptotic Bcl-2 protein Bcl-2 were observed in GL-treated cells. SV40 immortalized mouse embryonic fibroblasts derived from Bax-Bak double-knockout mice were significantly more resistant to GL-induced cell killing compared with wild-type cells. It is interesting to note that a representative normal prostate epithelial cell line (PrEC) was relatively more resistant to GL-mediated cellular responses compared with prostate cancer cells. The GL treatment caused the activation of JNK that functioned upstream of Bax activation in apoptosis response. The GL-induced conformational change of Bax and apoptosis were significantly suppressed by genetic suppression of JNK activation. In conclusion, the present study indicates that ROS-dependent apoptosis by GL is regulated by JNK signaling axis.     

Nuclear factor-kappa B, cancer, and apoptosis

The role of nuclear factor (NF)-kappa B in the regulation of apoptosis in normal and cancer cells has been extensively studied in recent years. Constitutive NF-kappa B activity in B lymphocytes as well as in Hodgkin's disease and breast cancer cells protects these cells against apoptosis. It has also been reported that NF-kappa B activation by tumor necrosis factor (TNF)-alpha, chemotherapeutic drugs, or ionizing radiations can protect several cell types against apoptosis, suggesting that NF-kappa B could participate in resistance to cancer treatment. These observations were explained by the regulation of antiapoptotic gene expression by NF-kappa B. However, in our experience, inhibition of NF-kappa B activity in several cancer cell lines has a very variable effect on cell mortality, depending on the cell type, the stimulus, and the level of NF-kappa B inhibition. Moreover, in some experimental systems, NF-kappa B activation is required for the onset of apoptosis. Therefore, it is likely that the NF-kappa B antiapoptotic role in response to chemotherapy is cell type- and signal-dependent and that the level of NF-kappa B inhibition is important. These issues will have to be carefully investigated before considering NF-kappa B as a target for genetic or pharmacological anticancer therapies.     

ROS在奥沙利铂诱导PUMA表达致肠癌细胞凋亡过程中的作用

目的探讨活性氧分子在奥沙利铂诱导凋亡相关基因PUMA表达致肠癌细胞凋亡过程中的作用及影响。方法采用过氧化氢做为体外氧化应激的模型,WesternBlot检测过氧化氢处理后PUMA蛋白的表达,Hoechst33258荧光染色法检测过氧化氢处理后肠癌细胞的凋亡,MTT法检测在联合应用奥沙利铂和抗氧化剂后肠癌细胞的增殖率。结果一定量的过氧化氢可以诱导肠癌细胞的凋亡及PUMA的表达;抑制PUMA的表达可以减小过氧化氢诱导的肠癌细胞的凋亡;抗氧化剂可以减弱奥沙利铂对肠癌细胞中PUMA表达的诱导;抗氧化剂可以增加奥沙利铂处理后肠癌细胞的增殖率。结论PUMA在氧化应激诱导的肠癌细胞的凋亡过程中具有重要作用;氧化应激在奥沙利铂诱导肠癌细胞凋亡的过程中具有一定作用;奥沙利铂可能部分通过增加活性氧分子的产生而诱导PUMA的表达,从而诱导肠癌细胞发生凋亡。     

Harm reduction: what it is and is not

The meaning of the term “harm reduction” has changed over the decades of its existence but it is now increasingly being aligned with public health approaches. An agreed meaning for the term would be helpful and should be sought. Antecedents are easy to find. Emphasis on small achievable steps is an important element; neither inherently supportive of prohibition nor of legalization, harm reduction is essentially pragmatic and tends to favour regulatory approaches. HIV has focused attention on harm reduction but even in the illicit drug field, a strong tradition of research and policy with an identical philosophical framework can be traced back well before the AIDS era. Harm reduction primary prevention educational approaches are more open, honest and respectful of responsible decision making processes. With current illicit drug users, harm reduction emphasizes the need to understand existing individual control mechanisms. The concept can be well understood if contrasted with prevailing approaches to drugs which generally emphasize punishment, lack of regulation and often augment harm.     

Thapsigargin induces apoptosis when autophagy is inhibited in HepG2 cells and both processes are regulated by ROS-dependent pathway

Thapsigargin (TG), is widely used to induce endoplasmic reticular stress. Treated with TG for a long time, cells suffer the unfolded protein response (UPR) to elude apoptosis, but may activate autophagy. However, the switch between autophagy and apoptosis is unclear. To clarify the key signal for selection of these two protective responses, we studied the correlation of autophagy and apoptosis in HepG2 cells exposed to TG with time. TG induced apoptosis in HepG2 cells was evidenced by typical cell morphological changes and the activation of caspase-12, caspase-9 and caspase-3. Meanwhile, cytochrome c was released following with the dissipation of mitochondrial membrane potential (MMP), and the ratio of Bax/Bcl-2 was increased. TG-induced autophagy was confirmed by the accumulation of MDC, GFP-LC3 staining autophagic vacuoles, and the improved expression of LC3 II and Beclin-1. Additionally, inhibited autophagy via chloroquine (CQ) markedly enhanced the apoptosis induced by TG, which was linked to the Bcl-2 family. Furthermore, TG induced the generation of reactive oxygen species (ROS), and the ROS scavenger effectively suppressed TG-induced apoptosis and autophagy. All these results proved that restraint of autophagy may enhance TG-induced apoptosis through increasing the Bax/Bcl-2 ratio and both processes were regulated by ROS.