55 research outputs found

    Designing a broad-spectrum integrative approach for cancer prevention and treatment

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    Targeted therapies and the consequent adoption of "personalized" oncology have achieved notablesuccesses in some cancers; however, significant problems remain with this approach. Many targetedtherapies are highly toxic, costs are extremely high, and most patients experience relapse after a fewdisease-free months. Relapses arise from genetic heterogeneity in tumors, which harbor therapy-resistantimmortalized cells that have adopted alternate and compensatory pathways (i.e., pathways that are notreliant upon the same mechanisms as those which have been targeted). To address these limitations, aninternational task force of 180 scientists was assembled to explore the concept of a low-toxicity "broad-spectrum" therapeutic approach that could simultaneously target many key pathways and mechanisms. Using cancer hallmark phenotypes and the tumor microenvironment to account for the various aspectsof relevant cancer biology, interdisciplinary teams reviewed each hallmark area and nominated a widerange of high-priority targets (74 in total) that could be modified to improve patient outcomes. For thesetargets, corresponding low-toxicity therapeutic approaches were then suggested, many of which werephytochemicals. Proposed actions on each target and all of the approaches were further reviewed forknown effects on other hallmark areas and the tumor microenvironment. Potential contrary or procar-cinogenic effects were found for 3.9% of the relationships between targets and hallmarks, and mixedevidence of complementary and contrary relationships was found for 7.1%. Approximately 67% of therelationships revealed potentially complementary effects, and the remainder had no known relationship. Among the approaches, 1.1% had contrary, 2.8% had mixed and 62.1% had complementary relationships. These results suggest that a broad-spectrum approach should be feasible from a safety standpoint. Thisnovel approach has potential to be relatively inexpensive, it should help us address stages and types ofcancer that lack conventional treatment, and it may reduce relapse risks. A proposed agenda for futureresearch is offered

    Resveratrol increases rate of apoptosis caused by purine analogues in malignant lymphocytes of chronic lymphocytic leukemia

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    In this study, we attempted to assess the interactions of resveratrol, a natural compound present in various plant species, with the purine analogues fludarabine and cladribine in terms of their effects on DNA damage and apoptosis in chronic lymphocytic leukemia (CLL) cells. The experiments were performed ex vivo using short-term cell cultures of blood and bone marrow cells from newly diagnosed untreated patients. We analyzed the expression of active caspase-3 and the BCL-2/BAX ratio as markers of apoptosis and the expression of phosphorylated histone H2AX (γH2AX) and activated ATM kinase, which are reporters of DNA damage. The results of our study revealed that resveratrol induced apoptosis in CLL cells in a tumor-specific manner but did not affect non-leukemic cells, and apoptosis was associated with a decreased BCL2/BAX ratio. Here, we report for the first time that both resveratrol + fludarabine and resveratrol + cladribine caused a higher rate of apoptosis in comparison to the rate caused by a single drug. The percentage of apoptotic cells induced by resveratrol alone was higher in the group of patients with better prognostic markers than in those with worse prognostic markers. However, the rates of apoptosis caused by resveratrol combined with purine analogues were independent of ZAP-70 and CD38 expression and the clinical state of the disease; they were only dependent on the presence of high-risk cytogenetic abnormalities. We also observed an increase in γH2AX expression together with a rise in activated ATM in most of the analyzed samples. The obtained results indicate that resveratrol might warrant further study as a new therapeutic option for CLL patients. This naturally occurring substance may be used as a single agent, especially in older persons for whom there are some limitations for the use of aggressive treatment. On the other hand, a lower purine analogue dose could potentially be used in combination with resveratrol because of their combined effect. One of the mechanisms of action of resveratrol is the induction of DNA damage, which ultimately leads to apoptosis

    Simvastatin and purine analogs have a synergic effect on apoptosis of chronic lymphocytic leukemia cells

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    Despite many therapeutic regimens introduced recently, chronic lymphocytic leukemia (CLL) is still an incurable disorder. Thus, there is an urgent need to discover novel, less toxic and more effective drugs for CLL patients. In this study, we attempted to assess simvastatin, widely used as a cholesterol-lowering drug, both as a single agent and in combination with purine analogs—fludarabine and cladribine—in terms of its effect on apoptosis and DNA damage of CLL cells. The experiments were done in ex vivo short-term cell cultures of blood and bone marrow cells from newly diagnosed untreated patients. We analyzed expression of active caspase-3 and the BCL-2/BAX ratio as markers of apoptosis and the expression of phosphorylated histone H2AX (named γH2AX) and activated ATM kinase (ataxia telangiectasia mutated kinase), reporters of DNA damage. Results of our study revealed that simvastatin induced apoptosis of CLL cells concurrently with lowering of BCL-2/BAX ratio, and its pro-apoptotic effect is tumor-specific, not affecting normal lymphocytes. We observed that combinations of simvastatin+fludarabine and simvastatin+cladribine had a synergic effect in inducing apoptosis. Interestingly, the rate of apoptosis caused by simvastatin alone and in combination was independent of markers of disease progression like ZAP-70 and CD38 expression or clinical stage according to Rai classification. We have also seen an increase in γH2AX expression in parallel with activation of ATM in most of the analyzed samples. The results suggest that simvastatin can be used in the treatment of CLL patients as a single agent as well as in combination with purine analogs, being equally effective both in high-risk and good-prognosis patients. One of the mechanisms of simvastatin action is inducing DNA damage that ultimately leads to apoptosis

    Berberine enhances inhibition of glioma tumor cell migration and invasiveness mediated by arsenic trioxide

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    <p>Abstract</p> <p>Background</p> <p>Arsenic trioxide (As<sub>2</sub>O<sub>3</sub>) exhibits promising anticarcinogenic activity in acute promyelocytic leukemic patients and induces apoptosis in various tumor cells <it>in vitro</it>. Here, we investigated the effect of the natural alkaloid berberine on As<sub>2</sub>O<sub>3</sub>-mediated inhibition of cancer cell migration using rat and human glioma cell lines.</p> <p>Methods</p> <p>The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay was used to determine the viability of rat C6 and human U-87 glioma cells after treatment with As<sub>2</sub>O<sub>3 </sub>or berberine, and after co-treatment with As<sub>2</sub>O<sub>3 </sub>and berberine. The wound scratch and Boyden chamber assays were applied to determine the effect of As<sub>2</sub>O<sub>3 </sub>and berberine on the migration capacity and invasiveness of glioma cancer cells. Zymography and Western blot analyses provided information on the effect of As<sub>2</sub>O<sub>3 </sub>and berberine on the intracellular translocation and activation of protein kinase C (PKC), and some PKC-related downstream factors. Most assays were performed three times, independently, and data were analyzed using ANOVA.</p> <p>Results</p> <p>The cell viability studies demonstrated that berberine enhances As<sub>2</sub>O<sub>3</sub>-mediated inhibition of glioma cell growth after 24 h incubation. Untreated control cells formed a confluent layer, the formation of which was inhibited upon incubation with 5 μM As<sub>2</sub>O<sub>3</sub>. The latter effect was even more pronounced in the presence of 10 μM berberine. The As<sub>2</sub>O<sub>3</sub>-mediated reduction in motility and invasion of glioma cells was enhanced upon co-treatment with berberine. Furthermore, it has been reported that PKC isoforms influence the morphology of the actin cytoskeleton, as well as the activation of metalloproteases MT1-MMP and MMP-2, reported to be involved in cancer cell migration. Treatment of glioma cells with As<sub>2</sub>O<sub>3 </sub>and berberine significantly decreased the activation of PKC α and ε and led to actin cytoskeleton rearrangements. The levels of two downstream transcription factors, myc and jun, and MT1-MMP and MMP-2 were also significantly reduced.</p> <p>Conclusion</p> <p>Upon co-treatment of glioma cells with As<sub>2</sub>O<sub>3 </sub>and berberine, cancer cell metastasis can be significantly inhibited, most likely by blocking the PKC-mediated signaling pathway involved in cancer cell migration. This study is potentially interesting for the development of novel chemotherapeutic approaches in the treatment of malignant gliomas and cancer development in general.</p

    Salivary Markers for Oral Cancer Detection

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    Oral cancer refers to all malignancies that arise in the oral cavity, lips and pharynx, with 90% of all oral cancers being oral squamous cell carcinoma. Despite the recent treatment advances, oral cancer is reported as having one of the highest mortality ratios amongst other malignancies and this can much be attributed to the late diagnosis of the disease. Saliva has long been tested as a valuable tool for drug monitoring and the diagnosis systemic diseases among which oral cancer. The new emerging technologies in molecular biology have enabled the discovery of new molecular markers (DNA, RNA and protein markers) for oral cancer diagnosis and surveillance which are discussed in the current review

    Future-oriented analysis of battery technologies

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    This article aims to develop a model of forward-looking management of battery technologies. For the construction of this model the methodology of Future-Oriented Technology Analysis has been adapted. The article first examines the available energy storage technologies, then selects and synthetically characterizes the future, emerging technologies requiring carrying out the development path with a time horizon of several years. Next, based on the methodology of Future-oriented Technology Analyses, a proprietary model created of forward-looking management of battery technologies. Also, a preliminary route of development of these technologies has been constructed based on a review of literature and research projects related to these technologies. Also, further research in this area has been proposed. The paper is of review-theoretical character and is the beginning of further work in this area

    Constitutive histone H2AX phosphorylation and ATM activation are strongly amplified during mitogenic stimulation of lymphocytes

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    OBJECTIVES: We recently postulated that constitutive activation of Ataxia Telangiectasia, Mutated (CAA) and constitutive histone H2AX phosphorylation (CHP) seen in cells not treated with genotoxic agents are the events triggered by DNA damage caused by endogenous reactive oxygen species (ROS), the product of mitochondrial oxidative metabolism. The aim of this study was to seek further evidence in support of this postulate, namely to test whether the levels of CAA and CHP correlate with cells metabolic activity. MATERIALS & METHODS: Peripheral blood lymphocytes are non-cycling (G(0)) cells characterized by minimal rate of oxidative metabolism. A dramatic rise in transcriptional and translational activity, an increase in number of mitochondria, and induction of DNA replication, occur during their mitogenic stimulation. This classic model of cell activation was chosen to study a possible correlation between CAA and CHP versus metabolic activity and generation of ROS. RESULTS: The levels of CAA and CHP in lymphocytes were increased many-fold during their stimulation. This increase was paralleled by the rise in extent of endogenously generated ROS. The growth of stimulated lymphocytes in the presence glucose antimetabolite 2-deoxy-D-glucose led to markedly lowered translational activity, decreased ROS generation and correspondingly attenuated CHA and CAA. CONCLUSIONS: The present data are consistent with our postulate that CHP and CAA report DNA damage by endogenous oxidants whose level correlates with metabolic activity. Because cumulative DNA damage by ROS generated via oxidative metabolism is considered the key mechanism responsible for cell ageing and senescence the data imply that these processes are delayed in G(0) quiescent lymphocytes or stem cells as compared with proliferating cells
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