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Abstract Canolol (4-vinylsyringol), extracted form crude canola oil, is the promising drug toward cancer prevention and treatment. The current studies focus on the role of COX-2 signaling pathway in canolol-induced apoptosis in cancer cells. It is still unknown whether mitochondria and MAPK signaling pathways are involved. To elucidate the roles of above signaling pathways in canolol-induced apoptosis in cancer cells, human cervical carcinoma cell line HeLa and HeLa xenograft tumor model are adopted. Canolol induced apoptosis of HeLa cells and inhibited tumor growth with low systemic adverse effect, accompanying with excess generation of intracellular ROS and lysosome rupture. The results in vitro and in vivo confirmed that MAPK signaling pathways mediated mitochondrial signaling pathway activation were involved in canolol-induced apoptosis. In conclusion, these data showed that canolol induced apoptosis in HeLa cells through ROS-MAPK mediated mitochondrial signaling pathway, providing a view of the potential application of canolol as an anticancer agent. Highlights • Canolol inhibited cell survival and induced apoptosis in HeLa cells. • Canolol activated MAPK and mitochondrial signaling pathways in HeLa cells. • Canolol had less cytotoxicity in vitro and low systemic adverse effect in vivo. [ABSTRACT FROM AUTHOR]

The Journal of Biological Chemistry (JBC) has been a major vehicle for disseminating and recording the discovery and characterization of proteolytic enzymes. The pace of discovery in the protease field accelerated during the 1971-2010 period that Dr. Herb Tabor served as the JBC's editor-in-chief. When he began his tenure, the fine structure and kinetics of only a few proteases were known; now thousands of proteases have been characterized, and over 600 genes for proteases have been identified in the human genome. In this review, besides reflecting on Dr. Tabor's invaluable contributions to the JBC and the American Society for Biochemistry and Molecular Biology (ASBMB), I endeavor to provide an overview of the extensive history of protease research, highlighting a few discoveries and roles of proteases in vivo. In addition, metalloproteinases, particularly meprins of the astacin family, will be discussed with regard to structural characteristics, regulation, mechanisms of action, and roles in health and disease. Proteases and protein degradation play crucial roles in living systems, and I briefly address future directions in this highly diverse and thriving research area. [ABSTRACT FROM AUTHOR]

Loss-of-function mutations in the SIL1 gene are linked to Marinesco-Sjögren syndrome (MSS), a rare multisystem disease of infancy characterized by cerebellar and skeletal muscle degeneration. SIL1 is a ubiquitous adenine nucleotide exchange factor for the endoplasmic reticulum (ER) chaperone BiP. The complexity of mechanisms by which loss of SIL1 causes MSS is not yet fully understood. We used HeLa cells to test the hypothesis that impaired protein folding in the ER due to loss of SIL1 could affect secretory trafficking, impairing the transport of cargoes essential for the function of MSS vulnerable cells. Immunofluorescence and ultrastructural analysis of SIL1-knocked-down cells detected ER chaperone aggregation, enlargement of the Golgi complex, increased autophagic vacuoles, and mitochondrial swelling. SIL1-interefered cells also had delayed ER-to-plasma membrane transport with retention of Na + /K + -ATPase and procollagen-I in the ER and Golgi, and increased apoptosis. The PERK pathway of the unfolded protein response was activated in SIL1-interfered cells, and the PERK inhibitor GSK2606414 attenuated the morphological and functional alterations of the secretory pathway, and significantly reduced cell death. These results indicate that loss of SIL1 is associated with alterations of secretory transport, and suggest that inhibiting PERK signalling may alleviate the cellular pathology of SIL1 -related MSS. [ABSTRACT FROM AUTHOR]

We investigated the effects of Stattic, an important signal transducer and activator of transcription 3 (STAT3) inhibitor, on enhancing the anti-proliferative and apoptotic effects of docetaxel in lung A549 and prostate cancer DU145 cells. Cell proliferation, cellular apoptosis and expression of STAT3 target genes were evaluated by DAPI staining, Annexin V/PI staining, cell cycle analysis and Real Time PCR. The anticancer effects of docetaxel and Stattic combination therapy induced synergistic effects in A549 and DU145 cells with combination indices of 0.71 and 0.52, respectively. Annexin V/PI demonstrated that there was a 2-fold increase in the proportion of apoptotic cells in cells treated with docetaxel and Stattic in A549 and DU145 cell lines, compared with control groups. Compared with cells treated with either docetaxel or Stattic alone, the results of the current study identified a significant decrease in the transcript levels of the anti-apoptotic proteins Bcl-2 and Bcl-xl and a marked increase in the level of the pro-apoptotic protein, Bax in cells that underwent combination therapy with docetaxel and Stattic combination (P < 0.05). These results suggest that combination of a STAT3 inhibitor and taxan derivatives may be developed as a promising therapeutic strategy to treat patients with lung and prostate cancer. [ABSTRACT FROM AUTHOR]

Esophageal squamous cell carcinoma (ESCC) is one of the most common cancers worldwide due to its chemoresistance and poor prognosis. Currently, there is a lack of effective small molecule drugs for the treatment of ESCC. Microtubules are an attractive target for cancer therapy since they play a central role in various fundamental cell functions. We investigated the anti-ESCC activity and mechanisms of the small molecule tubulin ligands, SL-3-19 and SL-1-73, which are two carbazole sulfonamide derivatives, in vitro and in vivo for the first time. These drugs were previously screened from a small molecule library with over 450 compounds and optimized for high aqueous solubility [1,2]. Here, we reveal the promising activities of these compounds against esophageal cancer. Mechanistically, both SL-3-19 and SL-1-73 inhibited ESCC cell growth by inducing cell apoptosis and arresting the cell cycle at G2/M phase in a dose-dependent manner. These drugs effectively inhibited microtubule assembly, greatly disrupted microtubule maturation by down-regulating acetylated α-tubulin, and significantly disrupted the vascular structure by obstructing the formation of capillary-like tubes in vitro. Consistent with their in vitro activities, SL-3-19 and SL-1-73 inhibited the growth of ESCC xenografts and inhibited the microvessel density in vivo. In summary, SL-3-19 and SL-1-73 are novel microtubule-destabilizing agents that have a potential antitumor effect on ESCC both in vitro and in vivo, and SL-3-19 had a higher activity than SL-1-73, with a low IC50 value and an observable antitumor activity in vivo. These results indicate that SL-3-19 may be a new therapeutic candidate for ESCC treatment. [ABSTRACT FROM AUTHOR]

Maintenance of tissue organization is crucial to ensure normal organ function and organism viability. Tissues are loaded with the ability to sense the available space, measuring cell density and adapting their behaviour accordingly. To keep homeostasis, compression pressure generated by local cell density increment triggers cell elimination. During mechanical cell competition, winner cells compress the neighbouring cells, promoting tissue crowding, which leads to cell elimination. Thus, the hypersensitivity to crowding may confer a loser status, whereas resistance to mechanical-induced elimination may favour a winner status. Here we analyse the emerging field of mechanical cell competition, describing the mechanotransducers implicated in cell elimination. Furthermore, we highlight the dual role of mechanical cell competition (MCC) as tumour suppression or expansion mechanisms. [ABSTRACT FROM AUTHOR]

Although methylene blue (MB) has showed strong antioxidant effect, its effect related with heme oxygenase-1 (HO-1) is still unclear. Thus, we investigated the effects of MB on HO-1 protein content and enzyme activity, and its protective effect against hydrogen peroxide (H 2 O 2 )-induced oxidative damage in RAW264.7 macrophage. The cell viability and the release of lactate dehydrogenase of RAW264.7 were determined. The mitochondrial functions were valuated through these indexes: content of adenosine triphosphate, superoxide dismutase, concentration of reactive oxygen species and mitochondrial membrane potential. Meanwhile, high content screening tested generation of ROS, MMP and intracellular concentration of calcium ion. qRT-PCR valuated macrophage phenotype markers expression. Lastly, flow cytometry and caspase-3 detection analyzed RAW264.7 apoptosis. Our data showed that (1) Both pretreatment and posttreatment of MB increased HO-1 protein content and enzyme activity; (2) MB rescued cells from H 2 O 2 -induced mitochondrial dysfunction; (3) High content screening revealed that MB alleviated the changes including generation of reactive oxygen species, mitochondrial membrane potential and intracellular concentration of calcium ion in H 2 O 2 exposed RAW264.7; (4) MB attenuated H 2 O 2 -induced apoptosis; (5) MB pretreatment decreased the expression of M1 macrophage markers ( Tnf and Nos2 ) while increasing the expression of M2 macrophage markers ( Mrc1 and Il10 ); (6) The beneficial effect of MB was abolished by zinc protoporphyrin IX (HO-1 activity inhibitor) or HO-1 siRNA. In summary, MB protects RAW264.7 cells from H2O2-induced injury through up-regulation HO-1. [ABSTRACT FROM AUTHOR]

Prostate cancer is the most frequently diagnosed cancer and is one of the leading causes of male cancer death in the world. Recently, in the course of our screening for a novel anticancer compound, we synthesized carbocyclic analogs of pyrrolo[2,3- d ]pyrimidine nucleoside; compounds 5 , and 6 . In the current study, we report the effects of compound 5 on pleiotropic induction of cell death via up-regulation of AR-associated p21 Cip1 protein in prostate cancer cells with different androgen responsiveness, such as LNCaP (androgen-dependent and -sensitive), LNCaP C4-2 (androgen-independent and -sensitive; androgen-refractory), and DU145 (androgen-independent and -insensitive) cells. The treatment of LNCaP cells with 6 μM compound 5 for 24 h stimulated the androgen receptor (AR) activity and dramatically up-regulated transcription (56-fold) of p21 Cip1 , which, in turn, induces typical apoptosis in the cells. However, induction of apoptosis through up-regulation (23-fold) of AR-associated p21 Cip1 achieved in LNCaP C4-2 cells was possible by intensive cell treatment with compound 5 (9 μM, 48 h), because the cells are less sensitive and independent to androgen than LNCaP cells. Furthermore, 6 μM compound 5 -treated DU145 cells, which exhibit extremely low AR activation due to no androgen responsiveness and dependency, showed neither up-regulation of p21 Cip1 nor apoptotic induction. Instead, a different type of cell death, autophagy-like death through the LC3B-associated autophagosome formation, was obviously induced in DU145 cells. Taken together, our results suggest that pleiotropic induction of prostate cancer cell death by compound 5 is determined by how efficiently and how abundantly androgen-dependent activation of the AR occurs, whereas compound 6 shows no induction of apoptosis in LNCaP cells. [ABSTRACT FROM AUTHOR]

Neonatal bronchopulmonary dysplasia (BPD) might lead to an increased risk for brain injury. The present study aims to investigate the effects of neonatal BPD on neuronal apoptosis in the hippocampus and cognitive function and to explore the underlying mechanisms. The results revealed that BPD model rat pups exhibited more apoptotic cells in the hippocampus and longer escape latencies in the Morris maze test. Both the caspase-dependent and caspase-nondependent signal pathways were activated. Further examinations showed an elevated p53 level by BPD via HIF-1α induction, while the caspase-3 in the hippocampus was suppressed by both HIF-1α and p53 inhibitor. These findings suggested that neonatal BPD caused impaired cognitive function and neuron apoptosis in hippocampus via p53 and HIF-1α. Although the precise mechanism requires further investigation, this study provided new evidence for and an explanation of the impaired CNS developmental outcomes of BPD. [ABSTRACT FROM AUTHOR]

A novel cyclometalated iridium(III) complex, [Ir(CˆN) 2 (HPIP)]Cl (IrC) was synthesized and characterized. IrC exhibited about 10-fold higher cytotoxicity than cisplatin against A549 cancer cell line. Interestingly, a cisplatin-resistant cell line, A549-CP/R showed sensitivity to IrC. Further study suggested that IrC induced apoptosis via negatively regulated the nuclear factor-kappa B (NF-κB) pathway, which involved reactive oxygen species (ROS) generation, Bcl-2 and caspase family members activation. Taken together, these results suggest that IrC is able to overcome chemoresistance and may be an effective treatment for platinum-resistant cancer therapy. [ABSTRACT FROM AUTHOR]

Xanthohumol (XN), a prenylflavonoid derived from the hop plant ( Humulus lupulus L.) has been found to exhibit a broad spectrum of biological properties, including anti-cancer activity. In this study, the mechanisms involved in anti-cancer activity of XN in human RK33 and RK45 larynx cancer cell lines were investigated. The effect of XN on the viability of larynx cancer and normal cells (human skin fibroblasts HSF and rat oligodendroglia-derived cells, OLN-93) was compared. Additionally, the influence of XN on proliferation, cell cycle progression, induction of apoptosis in larynx cancer cells, as well as the molecular mechanisms underlying in these processes were analyzed. XN promoted the reduction of cell viability in cancer cells, but showed low cytotoxicity to normal cells. The decrease in cell viability in the cancer cells was coupled with induction of apoptosis via two pathways. The mechanisms involved in these effects of XN were associated with cell growth inhibition by induction of cell cycle arrest in the G 1 phase, increased p53 and p21/WAF1 expression levels, downregulation of cyclin D1 and Bcl-2, and activation of caspases-9, -8, and -3. Moreover, this compound inhibited phosphorylation of ERK1/2, suggesting a key role of the ERKs pathway in the XN-mediated growth suppressing effects against the studied cells. These results indicate that XN could be used as a potential agent for the treatment of patients with larynx cancer. [ABSTRACT FROM AUTHOR]

Ganoderic acids (GAs) produced by Ganoderma lucidum possess anticancer activities with the generation of reactive oxygen species (ROS). However, the role of oxidative stress in apoptotic process induced by GAs is still undefined. In this study, the effects of four structurally related GAs, i.e. GA-T, GA-Mk, and two deacetylated derivatives of GA-T (GA-T1 and GA-T2) on the antioxidant defense system and induced apoptosis in cervical cancer cells HeLa were investigated in vitro . Our results indicated that the tested GAs (5–40 μM) induced apoptotic cell death through mitochondrial membrane potential decrease and activation of caspase-9 and caspase-3. Furthermore, GAs increased the generation of intracellular ROS and attenuated antioxidant defense system by decreasing glutathione (GSH) level, superoxide dismutase (SOD) and glutathione peroxidase (GPX) activities. The above effects were remarkably blocked by the exogenous antioxidants, i.e. N -acetylcysteine, catalase and diphenyleneiodonium chloride. The potency of the four GAs toward induced apoptosis, generation of ROS and suppression of antioxidant defense system was in the order of: GA-T > GA-Mk ≈ GA-T1 > GA-T2 in HeLa cells. These findings suggest that GAs induced mitochondria-dependent cell apoptosis in HeLa cells are mediated via enhancing oxidative stress and depressing antioxidant defense. Additionally, the acetylation of hydroxyl groups in GAs may contribute to their pro-oxidant activities and cytotoxicity, which is helpful to the development of novel chemotherapy agents. [ABSTRACT FROM AUTHOR]

The epithelial–mesenchymal transition (EMT) is an important cellular process during which epithelial polarized cells become motile mesenchymal-appeared cells, which, in turn, induces the metastatic of cancer. Geraniin is a polyphenolic component isolated from Phyllanthus amarus , which exhibits a wide range of pharmacological and physiological activities, such as antitumor, anti-hyperglycemic, anti-hypertensive, antimicrobial, and antiviral activities. However, the possible role of geraniin in the EMT is unclear. We investigated the effect of geraniin on the EMT. Transforming growth factor-beta 1 (TGF-β1) induces the EMT to promote lung adenocarcinoma migration, invasion, and anoikis resistance. To understand the suppressive role of geraniin in lung cancer migration, invasion, and anoikis resistance, we investigated the use of geraniin as inhibitors of TGF-β1-induced EMT in A549 lung cancer cells in vitro. Here, we show that geraniin remarkably increased expression of the epithelial marker E-cadherin and repressed Snail upregulation and expression of the mesenchymal marker N-cadherin and vimentin during the TGF-β1-induced EMT. Geraniin also inhibited the TGF-β1-induced increase in cell migration, invasion, and anoikis resistance of A549 lung cancer cells. Additionally, geraniin markedly inhibited TGF-β1-regulated activation of Smad2. Taken together, our findings provide new evidence that geraniin suppresses lung cancer migration, invasion, and anoikis resistance in vitro by inhibiting the TGF-β1-induced EMT. [ABSTRACT FROM AUTHOR]

The capacity to injure infected cells is a widespread property of viruses. Usually, this cytopathic effect (CPE) is ascribed to viral hijacking of cellular resources to fulfill viral needs. However, evidence is accumulating that CPE is not necessarily directly coupled to viral reproduction but may largely be due to host defensive and viral antidefensive activities. A major part in this virus–cell interaction appears to be played by a putative host-encoded program with multiple competing branches, leading to necrotic, apoptotic, and, possibly, other types of cell suicide. Manifestations of this program are controlled and modulated by host, viral, and environmental factors. [ABSTRACT FROM AUTHOR]

Reactive oxygen species (ROS), continuously generated as by-products of respiration, inflict more damage on the mitochondrial (mt) than on the nuclear genome because of the nonchromatinized nature and proximity to the ROS source of the mitochondrial genome. Such damage, particularly single-strand breaks (SSBs) with 5′-blocking deoxyribose products generated directly or as repair intermediates for oxidized bases, is repaired via the base excision/SSB repair pathway in both nuclear and mt genomes. Here, we show that EXOG, a 5′-exo/endonuclease and unique to the mitochondria unlike FEN1 or DNA2, which, like EXOG, has been implicated in the removal of the 5′-blocking residue, is required for repairing endogenous SSBs in the mt genome. EXOG depletion induces persistent SSBs in the mtDNA, enhances ROS levels, and causes apoptosis in normal cells but not in mt genome-deficient rho0 cells. Thus, these data show for the first time that persistent SSBs in the mt genome alone could provide the initial trigger for apoptotic signaling in mammalian cells. [ABSTRACT FROM AUTHOR]

Abstract: Chrysin exists widely in plants, honey and propolis. The anti-cancer property of chrysin has been demonstrated though the molecular mechanism is not clear. In this study, we found that pre-treatment with chrysin could promote the cell death induced by TRAIL according to the morphological changes and appearance of sub-G1 peak in four human cancer cell lines. In HCT-116 cells, the results of flow cytometry analysis showed that the percentage of sub-G1 reached (38.89±3.78) % when pre-treatment of chrysin was used at 40μM, but that was only (2.53±0.10) % in the untreated group and (13.22±0.20) % in TRAIL alone group. The differences between the combination and the untreated or TRAIL alone group were all significant (P <0.05) and dose-dependent effect was obvious. Similar results were obtained in CNE1 cells. In the search of molecular mechanisms, we found that pre-treatment with chrysin could increase TRAIL-induced degradation of caspase 3, caspase 8, PARP proteins. Z-VAD-fmk, which is a pan-caspase inhibitor, could inhibit the apoptosis enhanced by the combination of chrysin and TRAIL. All data indicate that chrysin can enhance the apoptosis induced by TRAIL, and the apoptosis is caspase-dependent and related to the activation of caspase 8. [Copyright &y& Elsevier]

Abstract: Complex behavioural disabilities, as well as pain, characterise neuropathic pain conditions for which clinical treatment is sought. In rats, chronic constriction injury (CCI) of the sciatic nerve evokes, allodynia and hyperalgesia as well as three distinct patterns of disability, characterised by changes in social and sleep-wake behaviours: (i) Pain & Disability; (ii) Pain & Transient Disability and (iii) Pain alone. Importantly, the degree of allodynia and hyperalgesia is identical for each of these groups. Social-interactions and sleep-wake behaviours are regulated by neural networks, which converge on the periaqueductal grey (PAG). Rats with Pain & Disability show astrocyte activation restricted to the lateral and ventrolateral PAG. Reactive astrocytes are a hallmark of cell death (apoptosis and necrosis). Quantitative real-time RT-PCR for the mRNAs encoding Bax, Bcl-2, heat shock protein 60 (HSP60), mitogen activated kinase kinase (MEK2) and iNOS was performed on the dorsal midbrains of individual, disability characterised rats, extending our earlier Gene-Chip data, showing a select up-regulation of Bax and MEK2 mRNA, and a down-regulation of HSP60 mRNA, in Pain & Disability rats. The anatomical location of TUNEL and cleaved-caspase-3 immunoreactive profiles in the midbrain was also identified. Rats with Pain & Disability showed: (i) pro-apoptotic ratios of Bax:Bcl-2 mRNAs; (ii) decreased HSP60 mRNA; (iii) increased iNOS and MEK2 mRNAs; (iv) TUNEL-positive profiles in the lateral and ventrolateral PAG; and (v) caspase-3 immunoreactive neurons in the mesencephalic nucleus of the trigeminal nerve. Cell death in these specific midbrain regions may underlie the disabilities characterising this subgroup of nerve-injured rats. [Copyright &y& Elsevier]

The evidence that biologically active food components are key environmental factors affecting the incidence of many chronic diseases is overwhelming. However, the full extent of such components in our diet is unknown, as is our understanding of their mechanisms of action. Beyond the interaction of these food components with the gut and intestinal immune functions, whey proteins such as lactoferrin are being tested as anticancer agents. Lactoferrin is an iron-binding protein that has been reported to inhibit several types of cancer. In the present work, the effects of bovine milk lactoferrin on human breast cancer HS578T and T47D cells were studied. The cells were either untreated or treated with lactoferrin concentrations ranging from 0.125 to 125 μM. Lactoferrin decreased the cell viability of HS578T and T47D by 47 and 54%, respectively, and increased apoptosis about 2-fold for both cell lines. Proliferation rates decreased by 40.3 and 63.9% for HS578T and T47D, respectively. For the T47D line, cell migration decreased in the presence of the protein. Although the mechanisms of action are not fully known, the results gathered in this work suggest that lactoferrin interferes with some of the most important steps involved in cancer development. [ABSTRACT FROM AUTHOR]

Abstract: Oxidative stress, an imbalance toward the prooxidant side of the prooxidant/antioxidant homeostasis, occurs in several brain neurodegenerative disorders. The protective effect of 3-butyl-6-bromo-1(3H)-isobenzofuranone (Br-NBP), a derivative compound of l-3-n-butylphthalide (NBP), on the hydrogen peroxide(H2O2)- induced oxidative damage was investigated in PC12 cells. Following exposure of the cells to H2O2, there was a significant reduction in cell survival,activities of glutathione peroxidase (GSH-px) and mitochondria membrane potential(MMP), in contrast, the increased levels in the leakage of lactate dehydrogenase (LDH), malondialdehyde (MDA) contents, nitric oxide (NO) productions, intracellular reactive oxygen species (ROS), intracellular Ca2+ concentration ([Ca2+]i), as well as cell apoptosis were observed. However, pretreatment of cells with Br-NBP prior to H2O2 exposure attenuated all the changes mentioned above in a concentration-dependent manner except no effect on activities of GSH-px. Br-NBP exhibited the protective effect against H2O2-induced cytotoxicity in PC12 cells, suggesting that the compound may be a potential therapeutic agent for diseases induced by oxidative damage. [Copyright &y& Elsevier]

Abstract: We previously reported the effect of a selective inducer of BiP (a BiP inducer X; BIX) after permanent middle cerebral artery occlusion (MCAO) in mice. However, in acute stroke, almost all drugs have been used clinically after the onset of events. We evaluated the effect of post-treatment of BIX after permanent MCAO in mice, and examined its neuroprotective properties in in vivo mechanism. BIX (intracerebroventricular injection at 20μg) administered either at 5min or 3h after occlusion reduced both infarct volume and brain swelling, but at 6h after occlusion there was no reduction. BIX protected against the decrease in a dose-dependent manner. Furthermore, BIX reduced the number of terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL)-positive cells induced by the ischemia in ischemic penumbra. These findings indicate that post-treatment with BIX after ischemia has neuroprotective effects against acute ischemic neuronal damage in mice even when given up to 3h after MCAO. BIX may therefore be a potential drug for stroke. [Copyright &y& Elsevier]

Abstract: Oropouche (OROV) is a single-stranded RNA arbovirus of the family Bunyaviridae, genus Orthobunyavirus, which has caused over half a million cases of febrile illness in Brazil in the past 30 years. OROV fever has been registered almost exclusively in the Amazon region, but global warming, deforestation and redistribution of vectors and animal reservoirs increases the risk of Oropouche virus emergence in other areas. OROV causes a cytolytical infection in cultured cells with characteristic cytopathic effect 48h post-infection. We have studied the mechanisms of apoptosis induced by OROV in HeLa cells and found that OROV causes DNA fragmentation detectable by gel electrophoresis and by flow cytometric analysis of the Sub-G1 population at 36h post-infection. Mitochondrial release of cytochrome C and activation of caspases 9 and 3 were also detected by western blot analysis. Lack of apoptosis induced by UV-inactivated OROV reveals that virus-receptor binding is not sufficient to induce cell death. Results obtained in cells treated with chloroquine and cycloheximide indicated that viral uncoating and replication are required for apoptosis induction by OROV. Furthermore, treatment of the cells with pan-caspase inhibitor prevented OROV-induced apoptosis without affecting virus progeny production. The results show that OROV infection in vitro causes apoptosis by an intracellular pathway involving mitochondria, and activated by a mechanism dependent on viral replication and protein synthesis. [Copyright &y& Elsevier]

Abstract: Japanese encephalitis virus (JEV), a mosquito-borne Flavivirus, is a major cause of acute encephalitis, and neurons have been proposed to be the principle JEV target cells in the central nervous system. However, clinically, infection with JEV leads to increased levels of cytokines and chemokines in the serum and cerebrospinal fluid (CSF) the levels of which correlate with the mortality rate of patients. This research aimed to study the role of microglial cells in JEV infection. Mouse microglial cells (BV-2) supported the replication of JEV with extracellular production of virus by 10h post-infection, and virus titer reached a maximum (2.55×1010 pfu/ml) by day 3 post-infection. While apoptosis was induced in response to virus infection, no alteration in nitric oxide production was observed. Microglial cells remained productively infected with JEV for up to 16weeks without significant morphological alterations, and the released virions were infectious to mouse neuroblastoma (NA) cells. The high virus production and long persistence of JEV in microglial cells suggests that these cells may serve as viral reservoirs for the infection of neurons in the CNS. [Copyright &y& Elsevier]

Abstract: Tritrichomonas foetus is an extracellular parasite of the reproductive tract in cattle. To investigate the cytopathic effects of T. foetus in deeper parts of the reproductive tract, a bovine primary oviduct epithelial cell system (BOECs) was developed. Reproductive tracts were obtained from cows and the effect of co-incubating T. foetus with BOECs was analyzed by scanning electron, transmission electron and fluorescence microscopy. Viability tests were performed using colorimetric methods, TUNEL (Terminal deoxynucleotidyltransferase-mediated dUTP nick-end labeling), fluorescein diacetate, propidium iodide, JC-1 and annexin-V. The results demonstrate that: (1) the in vitro oviduct epithelium is useful for interaction experiments with T. foetus; (2) T. foetus adheres to the BOECs as single separate cells, and later on the cells aggregate as large clusters; (3) the posterior region of the cell initiates the process of adhesion and forms filopodia and digitopodia; (4) T. foetus severely damages BOECs leaving imprints in the epithelial cells, wide intercellular spaces, and large lesions in the epithelium; and (5) T. foetus provokes bovine oviduct cell death by apoptosis and secondary necrosis. Our observations indicate the possibility that T. foetus can move through the reproductive tract to the oviduct and that infertility in cows can be mediated by an attack on the oviduct cells by T. foetus. [Copyright &y& Elsevier]

Abstract: The severe acute respiratory syndrome-coronavirus (SARS-CoV) caused an outbreak of atypical pneumonia in 2003. The SARS-CoV viral genome encodes several proteins which have no homology to proteins in any other coronaviruses, and a number of these proteins have been implicated in viral cytopathies. One such protein is 3a, which is also known as X1, ORF3 and U274. 3a expression is detected in both SARS-CoV infected cultured cells and patients. Among the different functions identified, 3a is a capable of inducing apoptosis. We previously showed that caspase pathways are involved in 3a-induced apoptosis. In this study, we attempted to find out protein domains on 3a that are essential for its pro-apoptotic function. Protein sequence analysis reveals that 3a possesses three major protein signatures, the cysteine-rich, Yxxϕ and diacidic domains. We showed that 3a proteins carrying respective mutations in these protein domains exhibit reduced pro-apoptotic activities, indicating the importance of these domains on 3a''s pro-apoptotic function. It was previously reported that 3a possesses potassium ion channel activity. We further demonstrated that the blockade of 3a''s potassium channel activity abolished caspase-dependent apoptosis. This report provides the first evidence that ion channel activity of 3a is required for its pro-apoptotic function. As ion channel activity has been reported to regulate apoptosis in different pathologic conditions, finding ways to modulate the ion channel activity may offer a new direction toward the inhibition of apoptosis triggered by SARS-CoV. [Copyright &y& Elsevier]

Abstract: Objectives: To investigate the pathophysiology of postprostatectomy erectile dysfunction (pPED) in a rat model of bilateral cavernous nerve ablation (BCNA) and to assess the effects of local bone marrow mononuclear cell (BMMNC) injection on erectile dysfunction (ED) and cavernosal cellular abnormalities caused by BCNA. Design, setting, and participants: This was an experimental study in Fisher rats with BCNA. Intervention: Intervention included BNCA, electrical stimulation of the pelvic ganglion, and local BMMNC injection. Measurements: Erectile responses to electric pelvic ganglion stimulation were studied. Cavernous tissue was examined to determine the cell types undergoing apoptosis and to detect changes in protein and gene expression of neuronal nitric oxide synthase (nNOS) and endothelial nitric oxide synthase (eNOS) using real-time quantitative polymerase chain reaction (RTQ-PCR) and Western blotting. The effects of local BMMNC injection on these parameters were studied. Results and limitations: Diffuse apoptosis was noted in the connective tissue mesenchymal cells and vascular smooth muscle and endothelial cells. Compared with sham-operated controls, nNOS and eNOS levels were decreased after 3 wk and were normal (eNOS) or increased (nNOS) after 5 wk, suggesting spontaneous nerve regeneration. Despite nNOS recovery, erectile responses to electrical stimulation remained impaired after 5 wk, when mesenchymal cell apoptosis was the main persistent biologic abnormality. BMMNC injection decreased apoptotic cell numbers, accelerated the normalisation of nNOS and eNOS, and partially restored erectile responses at week 5. Conclusions: Massive cell apoptosis may play a key role in the pathophysiology of pPED. In this animal model, apoptosis persisted despite spontaneous nerve regeneration, suggesting that the course of BCNA-induced cell dysfunction was independent of reinnervation. BMMNC improved erectile function by inhibiting apoptosis and may hold promise for repairing penile cell damage caused by radical prostatectomy (RP). [Copyright &y& Elsevier]

The article discusses the suicidal roles of lysosomes, that are described as suicide bags, in cellular processes. It states that lysosomes are linked to three major morphologically distinct pathways of cell death including apoptosis, type II programmed cell death or autophagic cell death, and necrosis. Furthermore, it mentions that lysosomes, regardless of their destructive potential, should not be called suicide bags because cell death happens mainly during pathologies.

Abstract: 2(±)-7,8,3′,4′,5′-pentamethoxyflavan (PMF), a synthetic flavan racemate, showed growth inhibitory effect on various kinds of tumor cells. The present study is to investigate the molecular mechanisms of action of PMF in human leukemia HL60 cells. Anti-proliferative effect of PMF on HL60 cells was associated with G2/M cell cycle arrest, which was mediated by regulating the expression of Cdc25C, cyclin A and p21 proteins and inhibiting the phosphorylation of Cdc2 at Thr161. PMF also induced apoptosis of HL60 cells via death receptor and mitochondria apoptotic pathways, which was characterized by DNA fragmentation, cleavage of poly (ADP-ribose) polymerase, caspase-3, caspase-8 and caspase-9, changes of Bcl-2 and Bax expression, cytochrome c release from mitochondria and a decrease in the mitochondrial membrane potential (MMP). These data suggest that PMF produces anti-tumor effect via induction of G2/M cell cycle arrest and apoptosis. [Copyright &y& Elsevier]

Abstract: The velogenic Newcastle disease virus (NDV) causes highly infectious and economically significant Newcastle disease (ND) in birds of various species. In cell culture NDV induces cytopathic effect (CPE) characterized by rounding, vacuolation, syncytia formation and cell death. Aside from cell to cell fusion caused by the F and HN glycoprotein of the virus molecular events leading to cell death are not known. In the current study, NDV-infected Vero cells, at 48h p.i., showed nuclear condensation, cytoplasm blebbing, DNA fragmentation, and phosphatidylserine translocation to the cell surface. In addition, virus-infected cells demonstrated decreased DNA content and an increased Bax to Bcl-2 ratio, p53 level and caspase 3, 8, 9 expression compared to mock-infected cells. Based on these results, it was concluded that CPE in NDV-infected cells was caused by to the induction of apoptosis with the involvement of p53 and the Bax, dependent apoptotic pathways. [Copyright &y& Elsevier]

Apoptotic cell death is considered to be an underlying mechanism in immunosuppression and multiple organ dysfunction after trauma–hemorrhage and sepsis. Although studied intensively over the last decade, the role of other cell death mechanisms under similar pathophysiological conditions has remained elusive. Recently, autophagy has emerged as an important mediator of programmed cell death pathways. Here, we review recent advances in our understanding of apoptosis and autophagy and the crosstalk between these processes. We explore the coexistence of these two processes and the effects of autophagy on apoptosis after trauma–hemorrhage and sepsis. The inter-relationship between autophagy and apoptosis might unveil novel therapeutic approaches for the detection and treatment of trauma–hemorrhage and sepsis. [Copyright &y& Elsevier]

Ardipusilloside I, a triterpenoid saponin isolated from Ardisia pusilla A. DC, suppresses the growth of a variety of cancer cells, and has certain immunomodulative properties. Herein, we investigated its effect on glioblastoma cell line U87MG cells and primary cultured human glioblastoma cells, and examined the underlying mechanism of action. Ardipusilloside I substantially decreased the number of viable cells of both cell lines in a time- and concentration-dependent manner, with a similar IC50 of 4.05μM. Microscopy revealed apoptotic characteristics, including chromatin condensation and cell nucleus fragmentation, demonstrating that ardipusilloside I-induced apoptosis. Ardipusilloside I exposure also gradually increased the sub-G1 fraction (the apoptotic cell population) and an S phase-arrest of both glioblastoma cells. Furthermore, ardipusilloside I increased the expression of Fas and its ligand (FasL), and enhanced the activation of caspase-8 and caspase-3. Additionally, we observed a significant decreased apoptosis after the trigger effection of FasL was abolished by the neutralization antibody anti-FasL antibody and an unchanged apoptosis level when the activation of caspase-8 was interrupted by specific inhibitor z-IETD-fmk, which suggested that a casepase-8 independent FasL/Fas-signaling-mediated death receptor pathway is involved. These data suggested that ardipusilloside I could be developed as a chemotherapeutic agent for the management of gliomas. [Copyright &y& Elsevier]

Abstract: Oxidative stress is an important component of the cytopathology of equine spermatozoa undergoing storage as liquid or frozen semen. Damage to chromatin, membranes and proteins of sperm are important components of oxidative damage to sperm. Similarly, sperm are exposed to a variety of osmotic stresses during storage that result from exposure to hypertonic media or result as a consequence of osmotic changes induced during freezing. A number of changes induced during processing and storage of equine sperm also appear to induce apoptotic-like changes which may adversely affect sperm survival and function. These processes appear in many cases to be interrelated, and this review will examine current understanding of these processes on the equine sperm function. [Copyright &y& Elsevier]

The essential hallmarks of cancer are intertwined with an altered cancer cell-intrinsic metabolism, either as a consequence or as a cause. As an example, the resistance of cancer mitochondria against apoptosis-associated permeabilization and the altered contribution of these organelles to metabolism are closely related. Similarly, the constitutive activation of signaling cascades that stimulate cell growth has a profound impact on anabolic metabolism. Here, we review the peculiarities of tumor cell metabolism that might be taken advantage of for cancer treatment. Specifically, we discuss the alterations in signal transduction pathways and/or enzymatic machineries that account for metabolic reprogramming of transformed cells. [Copyright &y& Elsevier]

Hsp27 inhibits mitochondrial injury and apoptosis in both normal and cancer cells by an unknown mechanism. To test the hypothesis that Hsp27 decreases apoptosis by inhibiting Bax, Hsp27 expression was manipulated in renal epithelial cells before transient metabolic stress, an insult that activates Bax, induces mitochondrial injury, and causes apoptosis. Compared with control, enhanced Hsp27 expression inhibited conformational Bax activation, oligomerization, and translocation to mitochondria, reduced the leakage of both cytochrome c and apoptosis-inducing factor, and significantly improved cell survival by >50% after stress. In contrast, Hsp27 down-regulation using RNA-mediated interference promoted Bax activation, increased Bax translocation, and reduced cell survival after stress. Immunoprecipitation did not detect Hsp27-Bax interaction before, during, or after stress, suggesting that Hsp27 indirectly inhibits Bax. During stress, Hsp27 expression prevented the inactivation of Akt, a pro-survival kinase, and increased the interaction between Akt and Bax, an Akt substrate. In contrast, Hsp27 RNA-mediated interference promoted Akt inactivation during stress. Hsp27 up- or down-regulation markedly altered the activity of phosphatidylinositol 3-kinase (PI3-kinase), a major regulator of Akt. Furthermore, distinct PI3-kinase inhibitors completely abrogated the protective effect of Hsp27 expression on Akt activation, Bax inactivation, and cell survival. These data show that Hsp27 antagonizes Bax-mediated mitochondrial injury and apoptosis by promoting Akt activation via a PI3-kinase-dependent mechanism. [ABSTRACT FROM AUTHOR]

Abstract: A systematic study was designed to elucidate differences in cytostatic activity in vitro between HPMA-based doxorubicin conjugates synthesized using different polymerization techniques and differing in peptidyl side chain. A polymer–drug conjugate containing doxorubicin (DOX) bound to HPMA copolymer backbone through the enzymaticaly non-cleavable sequence GlyGly shows low but significant cytotoxicity in vitro in seven cancer cell lines of mouse (EL4, 38C13, 3T3, BCL1) and human (SW620, Raji, Jurkat) origin. The low cytotoxicity can be considerably increased by the presence of additional drug-free GlyPheLeuGly side chains. P1 conjugate, i.e. non-targeted HPMA copolymer bearing doxorubicin bound via a biodegradable GlyPheLeuGly sequence, synthesized by direct copolymerization of HPMA with monomeric doxorubicin and thus without additional drug-free GlyPheLeuGly sequences is less effective compared to PK1 synthesized by polymer analogous reaction and thus containing extra drug-free GlyPheLeuGly sequences. Significant activity-enhancing effect was not seen with other amino acid/oligopeptide sequences (e.g., Gly or GlyGly). The activity-enhancing effect of GlyPheLeuGly sequences is more obvious in the conjugate containing doxorubicin bound to HPMA through GlyGly sequence. Derivatization of the terminal carboxyl group of the extra GlyPheLeuGly side chains (amide, N-substituted amide, free carboxyl) does not significantly influence the cytotoxicity of the conjugates. The presence of the GlyPheLeuGly sequence in the conjugate structure increases its rate of intracellular accumulation. Normal cells (Balb/c splenocytes) accumulate less polymer–doxorubicin conjugate compared to cancer cells (T cell lymphoma EL4, B cell lymphoma Raji and T cell leukemia JURKAT). [Copyright &y& Elsevier]

Abstract: Berberine is known to possess a wide variety of pharmacological activities, including pro-apoptotic activity. However, its molecular targets are not elucidated at present. NAG-1 and ATF3 are induced by several dietary compounds associated with pro-apoptotic activity. Berberine induces cell growth arrest, apoptosis, NAG-1, and ATF3 in human colorectal cancer cells. ATF3 induction by berberine is mediated in a p53-dependent manner, whereas NAG-1 induction by berberine is mediated by multiple signaling pathways. Our results suggest that berberine facilitates apoptosis and that NAG-1 and ATF3 expression plays an important role in berberine-induced apoptosis. [Copyright &y& Elsevier]

The BCL-2 homologue MCL-1 plays an important role in the regulation of cell fate by blocking apoptosis as well as regulating cell cycle. MCL-1 has an unusual N-terminal extension, which contains a PEST domain and several phosphorylation sites that have been suggested to regulate its turnover. Here we report that the first 79 amino acids of MCL-1 regulate its subcellular localization. Deletion of this domain impairs both its mitochondrial localization and its anti-apoptotic activity. Conversely, expression of the N terminus of MCL-1 promotes both the association of MCL-1 with mitochondria and cell survival in a fashion that is dependent on the presence of endogenous MCL-1. In addition, the N terminus of MCL-1 has an antagonistic effect on proliferation. Although MCL-1 decreases proliferation through binding to proliferating cell nuclear antigen and cyclin-dependent kinase 1 in the nucleus, the N terminus of MCL-1 accelerates cell division. On the other hand, deletion of this region further increases the anti-proliferative activity of MCL-1. These results suggest that the N terminus of MCL-1 plays a major regulatory role, regulating coordinately the mitochondrial (anti-apoptotic) and nuclear (anti-proliferative) functions of MCL-1. [ABSTRACT FROM AUTHOR]

Abstract: Objectives: Emerging evidence indicates that prostatic inflammation may contribute to prostate growth either in terms of hyperplastic (benign prostatic hyperplasia [BPH]) or neoplastic (prostate cancer [PCa]) changes. We propose two questions: Does prostate inflammation represent a significant factor for the development and the progression of both BPH and PCa? Are data available now to sustain the identification of prostate inflammation as a risk factor for prostate diseases? Methods: We reviewed the recent international literature using a PubMed search to analyze new findings supporting a role for inflammation in BPH and PCa growth and progression. Results: On histologic examinations from patients with BPH, inflammatory aspects are present in approximately 40% of cases. The men with inflammatory aspects inside the prostate have a significantly higher risk for BPH progression and acute urinary retention. Evidence shows that a cyclooxygenase-2 (COX-2) inhibitor can increase the apoptotic activity in human BPH tissue. Analyses on the bacterial colonization in PCa and normal prostate tissue showed a highly suggestive correlation between bacterial colonization/chronic inflammation and the diagnosis of PCa. Evidence from genetic studies supports the hypothesis that prostate inflammation may be a cause of PCa development. Proliferative inflammatory atrophy has been considered as an early histologic precursor to prostatic intraepithelial neoplasia and PCa. Conclusion: The concept that inflammation can promote chronic prostatic diseases, such as BPH or PCa, is actually supported by several new significant findings; however, no specific oncologic surveillance for these cases is justified at the moment. [Copyright &y& Elsevier]

Propionyl.-L-carnitine (PLC) has been introduced among the therapeutic approaches of peripheral arterial disease, and more recently, an increase of intimal cell apoptosis has been demonstrated to contribute to its effectiveness in rabbit carotid postinjury myointimal hyperplasia prevention. How PLC mediates these effects on vascular smooth muscle cells (SMCs) remains poorly understood. We investigated the role of NF-κB in PLC-induced arterial remodeling. In vivo, daily PLC treatment 15 days after injury resulted in a reduction of relative rat aortic intimal volume, an increase of apoptosis, Bar up-regulation without changing the Bcl-2 level, and a reduction of NF-κB, vascular cell adhesion molecule-1, monocyte chemotactic protein-1, and survivin in myointimal thickening compared with controls. In the presence of 10% serum, a reduced G1 -→ S phase progression preceded PLC-induced intimal cell apoptosis; in 0.1% serum cultures, in a dose-dependent manner, PLC rapidly induced intimal cell apoptosis and reduced p65, p50, lAP-1, and IAP-2 expression. Inhibiting NF-κB activation through SN50 increased apoptotic rate and Bax expression in intimal but not in medial SMCs, and successive PLC treatment failed to induce a further increase in apoptotic rate. Bax antisense oligodeoxynucleotide reduced PLC-induced intimal cell apoptosis and cytochrome c release. The PLC-induced attenuation of NF-κB activity in intimal cells was also due to the increase of IκB-α bioavailability, as the result of a parallel induction of IκB-α synthesis and reduction of phosphorylation and degradation. Collectively, these findings document that NF-κB activity inhibition contributes to PLC-induced proliferative arrest and Bax-related apoptosis of intimal SMCs. [ABSTRACT FROM AUTHOR]

Summary: Cancer cells are typically characterized by increased resistance towards apoptosis. Livin (alternatively called ML-IAP or KIAP) is an anti-apoptotic protein which is expressed in several cancer forms. Using real-time reverse transcription-polymerase chain reaction (RT-PCR), we confirmed livin expression in a significant portion of non-small cell lung cancer (NSCLC) tissue samples and, in addition, detected livin expression in a number of NSCLC cell lines. In order to elucidate whether livin contributes to the apoptotic resistance of lung cancer cells, we silenced endogenous livin expression in a panel of cancer-derived NSCLC cell lines by RNA interference (RNAi). We observed that the targeted inhibition of livin strongly sensitized NSCLC cells to different pro-apoptotic stimuli, such as UV-irradiation or the chemotherapeutic drug etoposide. In addition, long-term silencing of livin blocked the outgrowth of NSCLC cells in colony formation assays. These effects of small interfering (si)RNA were specific for livin-expressing tumor cells. Our results indicate that Livin is an important contributor to the apoptosis resistance of NSCLC cells and may serve as a novel molecular target for therapeutic inhibition in NSCLC. [Copyright &y& Elsevier]

Abstract: Non-pylori helicobacter infections are associated with gastritis, gastric ulcers and MALT lymphomas in man. Approximately 50% of these are caused by helicobacters commonly found in dogs and cats, including Helicobacter felis, Helicobacter bizzozeronii and H. salomonis. In contrast to Helicobacter pylori, the virulence mechanisms of these species are unknown. In this study the virulence of H. felis, H. bizzozeronii and H. salomonis was investigated in Mongolian gerbils. Female SPF gerbils were inoculated intragastrically with H. felis, H. bizzozeronii or H. salomonis and sacrificed 3 weeks later. Fundus and antrum samples were taken for bacterial detection by PCR. A longitudinal strip covering all stomach regions was taken for histology. Gastric colonization, inflammation, apoptosis, loss of parietal cells and cell proliferation were assessed. Controls and H. salomonis inoculated gerbils were negative in PCR. H. felis and H. bizzozeronii inoculated animals were positive. H. felis inoculated animals showed loss of parietal cells extending from the limiting ridge into the fundus. A high cell proliferation rate was noticed in the mucosal area devoid of parietal cells. A dense band of apoptotic cells and large numbers of Helicobacter bacteria were seen at the transition zone between affected and normal parietal cells. In H. bizzozeronii infected gerbils, this was less pronounced. Focal apoptotic loss of gastric epithelial cells was spatially associated with the presence of bacteria especially in H. felis and to a lesser extent in H. bizzozeronii infected gerbils. This loss of cells may lead to intestinal metaplasia. [Copyright &y& Elsevier]

Abstract: Interscapular brown adipose tissue (IBAT) hyperplasia involves a new metabolic and structural profile, resulting from acclimation of animals to a cold environment. Cold-induced changes of several antioxidative defense (AD) components in IBAT and their interrelationship with uncoupling protein 1 (UCP1), sympathetic innervation and apoptosis were studied using cold-acclimated adult rat males (4±1 °C, 45 days). Their age-matches were maintained at 22±1 °C serving as the controls. In cold-adapted rats, activities of CuZn- and Mn-superoxide dismutase (SOD) and apoptosis were reduced, while catalase (CAT), glutathione peroxidase (GSH-Px), glutathione S-transferase (GST) activities and glutathione (GSH) content were increased compared to the control. IBAT mass, protein content, plasma free fatty acid (FFA) concentration, sympathetic innervation and UCP1 level were significantly increased in cold-acclimated group compared to the corresponding control. These results suggest that decreased CuZn and MnSOD activities in IBAT represent an adaptive response due to UCP1-induced mitochondrial uncoupling. Additionally, intensive fatty acid oxidation led to an increased H2O2 production which resulted in increased CAT, GSH-Px and GST activities and GSH level. Generally speaking, cold-induced changes of AD in the IBAT are closely connected with newly established metabolic profile in this tissue, thus making an important part of the entire tissue homeostasis including cell survival. [Copyright &y& Elsevier]

BAY 43-9006 is a kinase inhibitor that induces apoptosis in a variety of tumor cells. Here we report that treatment with BAY 43-9006 results in marked cytochrome c and AIF release into the cytosol, caspase-9, -8, -7, and -3 activation, and apoptosis in human leukemia cells (U937, Jurkat, and K562). Pronounced apoptosis was also observed in blasts from patients with acute myeloid leukemia. These events were accompanied by ERK1/2 inactivation and caspase-independent down-regulation of Mcl-1. Inducible expression of a constitutively active MEK1 construct did not prevent Mcl-1 down-regulation, suggesting that this event is not related to MEK/ERK pathway inactivation. Furthermore, BAY 43-9006 did not induce major changes in Mcl-1 mRNA levels monitored by real-time PCR or Mcl-1 promoter activity demonstrated by luciferase reporter assays, but it did enhance Mcl-1 down-regulation in actinomycin D-treated cells. Inhibition of protein synthesis by cycloheximide or proteasome function with MG132 and pulse-chase studies with [35S]methionine demonstrated that BAY 43–9006 did not diminish Mcl-1 protein stability, nor did it enhance Mcl-1 ubiquitination, but instead markedly attenuated Mcl-1 translation in association with the rapid and potent dephosphorylation of the elF4E translation initiation factor. Finally, ectopic expression of Mcl-1 in leukemic cells markedly inhibited BAY 43-9006-mediated cytochrome c cytosolic release, caspase-9, -7, and -3 activation, as well as cell death, indicating that Mcl-1 operates upstream of cytochrome c release and caspase activation. Together, these findings demonstrate that BAY 43-9006 mediates cell death in human leukemia cells, at least in part, through down-regulation of Mcl-1 via inhibition of translation. [ABSTRACT FROM AUTHOR]

Treatment with the protein kinase C activator 12-O-tetradecanoylphorbol 12-acetate (TPA) enables radiation-resistant LNCaP human prostate cancer cells to undergo radiation-induced apoptosis, mediated via activation of the enzyme ceramide synthase (CS) and de novo synthesis of the sphingolipid ceramide (Garzotto, M., Haimovitz­Friedman, A., Liao, W. C., White­Jones, M., Huryk, R, Heston, D. W. Wo, Cardon­Cardo, C., Kolesnick, R., and Fuks, Z. (1999) Cancer Res. 59, 5194–5201). Here, we show that TPA functions to decrease the cellular level of the ATM (ataxia telangiectasia mutated) protein, known to repress CS activation (Liao, W.-C., Haimovitz­ Friedman, A., Persaud, R., McLoughlin, M., Ehleiter, D., Zhang, N., Gatei, M., Lavin, M., Kolesnick, R., and Fuks, Z. (1999) J. Biol. Chem. 274, 17908–17917). Gel shift analysis in LNCaP and CWR22-Rv1 cells demonstrated a significant reduction in DNA binding of the Sp1 transcription factor to the ATM promoter, and quantitative reverse transcription-PCR showed a 50% reduction of ATM mRNA between 8 and 16 h of TPA treatment, indicating that TPA inhibits ATM transcription. Furthermore, treatment of LNCaP, CWR22-Rv1, PC-3, and DU-145 human prostate cells with antisense-ATM oligonucleotides, which markedly reduced cellular ATM levels, significantly enhanced radiation-induced CS activation and apoptosis, leading to apoptosis at doses as a low as 1 gray. These data suggest that the CS pathway initiates a generic mode of radiation-induced apoptosis in human prostate cancer cells, regulated by a suppressive function of ATM, and that ATM might represent a potential target for pharmacologic inactivation with potential clinical applications in human prostate cancer. [ABSTRACT FROM AUTHOR]

NAG-1 (nonsteroidal anti-inflammatory drug-activated gene), a member of the transforming growth factor β superfamily, is involved in cellular processes such as inflammation, apoptosis/survival, and tumorigenesis and is regulated by p53, Sp1, and Egr-1. In the current study, the regulation of NAG-1 expression in LNCaP human prostate carcinoma cells by 12-O-tetradecanoyl-phorbol-13-acetate (TPA) was examined. TPA treatment increased NAG-1 protein and mRNA levels in a time- and concentration-dependent manner as well as NF-κB binding/transcriptional activity in LNCaP cells. Pretreatment with protein kinase C (PKC) inhibitor blocked the TPA-induced increase in NAG-1 protein levels and NF-κB binding/transcriptional activity, whereas an inhibition of p38, JNK, MEK activity had no effect on TPA-induced NAG-1 levels and NF-κB transcriptional activity. Expression of constitutively active PKCs induced an increase in NF-κB transcriptional activity and NAG-1 protein levels in LNCaP cells. The expression of NF-κB p65 induced NAG-1 promoter activity, and chromatin immunoprecipitation assay for p65 showed that NF-κB binds the NAG-1 promoter in LNCaP cells. Inhibition of TPA-induced NAG-1 expression by NAG-1 short interfering RNA blocked TPA-induced apoptosis in LNCaP cells, suggesting induction of NAG-1 negatively affects LNCaP cell survival. These results demonstrate that NAG-1 expression is up-regulated by TPA in LNCaP cells through a PKC-dependent pathway involving the activation of NF-κB. [ABSTRACT FROM AUTHOR]

Caspase-3-deficient 129/Sv mice show hyperplasia of the brain at embryonic (E) day 10.5–12.5, but caspase-3-deficient C57L/B6 mice do not. We examined the relationship between activation of caspase-3 and programmed cell death (PCD) during forebrain development of various mouse strains (129/Sv, ICR, C57L/B6, and CBA) using terminal deoxytransferase-mediated deoxyuridine triphosphate nick-end labeling (TUNEL) and immunostaining with antiserum against the caspase-3 (anti-m3D175) cleavage site. A number of anti-m3D175 positive cells and TUNEL positive cells were detected in the ventral side of the forebrain of 129/Sv and ICR mice at E8.5–9 but not in C57L/B6 and CBA mice. Ac-DEVD-MCA cleavage activity, a caspase-3-like activity, also suggests the preferential activation of caspase-3 in the ventral forebrain of ICR mice but not in C57L/B6 mice. Developmental changes of TUNEL and anti-m3D175 reactivities were essentially similar during brain morphogenesis of ICR and 129/Sv mice. The number of TUNEL/anti-m3D175 positive cells decreased in the neuroepithelium of the ventral forebrain at E9.5 before generation of the medial ganglionic eminence (MGE). TUNEL and/or anti-m3D175 reactivity was slightly detectable in the MGE at E10.5, from which neuroprogenitor cells follow a tangential migratory route to the cortex. Activation of caspase-9 was also immunohistochemically detected in the ventral forebrain at E8.5–9, suggesting that activation of caspase-3 and caspase-9 occurs in the PCD of this region. Thus, it is likely that decreased cell death in the ventral forebrain of caspase-3- and caspase-9-deficient 129/Sv mice increases the number of neuroprogenitor cells in the MGE, leading to hyperplasia of the forebrain. [Copyright &y& Elsevier]

Apoptotic cell death has been involved as a cytopathologic mechanism in response to dengue (DEN) virus infection. Little information exists about how DEN virus replication triggers apoptosis in infected cells. We reported that a nine-residue sequence of the DEN M protein referred to as ApoptoM has proapoptotic properties in transformed and tumor cells of various origins. The aim of the present study was to investigate whether ApoptoM-induced apoptosis is associated to mitochondrial dysfunction and requires caspase activation. Intracellular expression of ApoptoM provokes the disruption of the mitochondrial transmembrane potential without subsequent generation of reactive oxygen species. We showed that ApoptoM-induced apoptosis involves the activation of a caspase-like protease pathway. Caspase-3 like activity was detected in ApoptoM-expressing cells. However, there was no role for caspase-9 in ApoptoM-mediated cell death. Our data suggest that a particular mitochondrion-dependent apoptotic pathway may be involved in induction of apoptosis by ApoptoM. [Copyright &y& Elsevier]

In this issue of Cancer Cell, Hatley et al., by using several tour-de-force in vivo approaches, reported a miR-21-mediated oncogenic pathway through inhibition of negative regulators of the Ras/MEK/ERK pathway and inhibition of apoptosis in lung cancers models. Targeting miR-21 could be a promising therapeutic strategy in lung cancers. [Copyright &y& Elsevier]

The mortality rate caused by colorectal cancer is increasing. The current treatment options not only do not produce optimal results but also cause various side effects. Nowadays, herbal plants have been shown to be one of many treatment options, one of which is the Kersen plant ( Muntingia calabura L). This study aimed to evaluate the growth inhibitory effects and apoptosis induction ability of the methanolic extract on the WiDr colorectal cancer cell line, and also determine some of the secondary metabolites constituents. Antiproliferative activity was measured by 3-(4-dimethylthiazolyl)2, 5-diphenyl-tetrazolium bromide (MTT) assay and apoptosis induction was detected by fluorescence microscopy (acridine orange/ethidium bromide, double staining method). Secondary metabolite content was evaluated by using spectrophotometry and thin layer chromatography (TLC). Alkaloids, flavonoids, saponin, and triterpenoids were identified in the methanolic extract. The methanolic extract was found to be cytotoxic to WiDr cells in a dose-dependent manner with IC 50 values from two experiments of 39.21 μg/mL and 40.22 μg/mL. The extract also caused typical apoptotic morphological changes in the WiDr colorectal cancer cell line. The results indicate that Muntingia calabura L may constitute a promising anticancer therapy in colorectal cancer. [ABSTRACT FROM AUTHOR]