mTOR regulation of metabolism in hematologic malignancies

Neoplastic cells rewire their metabolism, acquiring a selective advantage over normal cells and a protection from therapeutic agents. The mammalian Target of Rapamycin (mTOR) is a serine/threonine kinase involved in a variety of cellular activities, including the control of metabolic processes. mTOR is hyperactivated in a large number of tumor types, and among them, in many hematologic malignancies. In this article, we summarized the evidence from the literature that describes a central role for mTOR in the acquisition of new metabolic phenotypes for different hematologic malignancies, in concert with other metabolic modulators (AMPK, HIF1α) and microenvironmental stimuli, and shows how these features can be targeted for therapeutic purposes

The Influence of Temperature on the Low-Velocity Impact Response of Polyamide 6/Basalt Plain Fabric Laminates

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The IMiDs targets IKZF-1/3 and IRF4 as novel negative regulators of NK cell-activating ligands expression in multiple myeloma

Immunomodulatory drugs (IMiDs) have potent anti-tumor activities in multiple myeloma (MM) and are able to enhance the cytotoxic function of natural killer (NK) cells, important effectors of the immune response against MM. Here, we show that these drugs can enhance the expression of the NKG2D and DNAM-1 activating receptor ligands MICA and PVR/CD155 in human MM cell lines and primary malignant plasma cells. Depletion of cereblon (CRBN) by shRNA interference strongly impaired upregulation of these ligands and, more interestingly, IMiDs/CRBN-mediated downregulation of the transcription factors Ikaros (IKZF1), Aiolos (IKZF3) and IRF4 was critical for these regulatory mechanisms. Indeed, shRNA knockdown of IKZF1 or IKZF3 expression was both necessary and sufficient for the upregulation of MICA and PVR/CD155 expression, suggesting that these transcription factors can repress these genes; accordingly, the direct interaction and the negative role of IKZF1 and IKZF3 proteins on MICA and PVR/CD155 promoters were demonstrated. Finally, MICA expression was enhanced in IRF4-silenced cells, indicating a specific suppressive role of this transcription factor on MICA gene expression in MM cells. Taken together, these findings describe novel molecular pathways involved in the regulation of MICA and PVR/CD155 gene expression and identify the transcription factors IKZF-1/IKZF-3 and IRF4 as repressors of these genes in MM cells

Inhibition of bromodomain and extra-terminal (BET) proteins increases NKG2D ligand MICA expression and sensitivity to NK cell-mediated cytotoxicity in multiple myeloma cells. role of cMYC-IRF4-miR-125b interplay

Background: Anticancer immune responses may contribute to the control of tumors after conventional chemotherapy and different observations have indicated that chemotherapeutic agents can induce immune responses resulting in cancer cell death and immune-stimulatory side effects. Increasing experimental and clinical evidence highlight the importance of Natural Killer (NK) cells in immune responses toward Multiple Myeloma (MM) and combination therapies able to enhance the activity of NK cells against MM are showing promise in treating this hematologic cancer. The epigenetic readers of acetylated histones Bromodomain and Extra-Terminal (BET) proteins are critical regulators of gene expression. In cancer, they can upregulate transcription of key oncogenes such as cMYC, IRF4, BCL-2 and others. In addition, the activity of these proteins can regulate the expression of osteoclastogenic cytokines during cancer progression. Here, we investigated the effect of BET-bromodomain proteins inhibition, on the expression of Natural Killer (NK) cell-activating ligands in Multiple Myeloma (MM) cells. Methods: Five MM cell lines [SKO-007(J3), U266, RPMI-8226, ARP-1, JJN3] and CD138+ MM cells isolated from MM patients were used to investigate the activity of BET bromodomain inhibitors (BETi) (JQ1 and I-BET-151) and of the selective BRD4-degrader PROTAC (Proteolysis Targeting Chimera) (ARV-825), on the expression and function of several NK cell activating ligands (NKG2DLs and DNAM-1Ls), using Flow Cytometry, Real-Time PCR, transient transfections and degranulation assays. Results: Our results indicate that inhibition of BET proteins via small molecule inhibitors or their degradation via a hetero-bifunctional Proteolysis Targeting Chimera (PROTAC) probe can enhance the expression of MICA, a ligand of the NKG2D receptor, in human MM cell lines and primary malignant plasma cells, rendering myeloma cells more efficient to activate NK cell degranulation. Noteworthy, similar results were obtained using selective CBP/EP300 bromodomain inhibition. Mechanistically, we found that BETi-mediated inhibition of cMYC correlates with the upregulation of miR-125b-5p and the downregulation of the cMYC/miR-125b-5p target gene IRF4, a transcriptional repressor of MICA. Conclusions: These findings provide new insights on the immuno-mediated antitumor activities of BETi and further elucidate the molecular mechanisms that regulate NK cell-activating ligand expression in MM

Hepatitis C Virus infections trends in Italy, 1996-2006

BACKGROUND: The World Health Organization (WHO) estimates that about 180 million people, 3% of the world population, are infected with the hepatitis C virus (HCV). In Italy, the prevalence in the general population is reported to be greater than 5% and 9% among households of HCV-positive patients. OBJECTIVES: The aim of this study was to estimate the trends of HCV infection in Italy in the period 1996-2006. MATERIALS AND METHODS: The formula ln (rate) = b 7 years was applied for logarithmic transformation of the incidence rates to obtain time trends of HCV infection, using the join-point regression program software version 3.3.1. Linear graphs representing trends and the annual percentage change (APC) were considered for each joinpoint. Time changes are expressed as expected annual percentage change (EAPC) with the respective 95% confidence intervals (CIs); significance levels of time trends are also reported. The null hypothesis was tested using a maximum of 3 changes in slope with an overall significance level of 0.05 divided by the number of joinpoints in the final model. RESULTS: Considering all age groups, the incidence rate decreased from 2.02 to 0.55 per 100,000. The join-point analysis showed a statistically significant decrease in the incidence rates of HCV infection. No join-points were found in any age groups. Our data show that the incidence rates of HCV infections have considerably decreased in each age group throughout the studied period (1996-2006). CONCLUSIONS: This decreasing trend in HCV infections is, in part, attributable to behavioral and social changes. Improved hygiene, use of precautions in medical settings, blood screening, and sexual educational campaigns seem to have contributed to reduce the transmission of infection during the last 10 years

23-valent pneumococcal polysaccharide vaccine (PPV23) for the prevention of invasive pneumococcal diseases (IPDs) in the elderly: is it really effective?

Introduction. Incidence of invasive pneumococcal diseases (IPDs) in Italy is constantly increasing and that is particularly true among the elderly. 23-valent polysaccharide pneumococcal vac- cine (PPV23) is recommended to this age group and offered in all Italian regions. However, efficacy of PPV23 on preventing IPDs is debated. We therefore performed a review of the most recent avail- able meta-analyses in order to assess the efficacy of PPVs. Methods. The literature search was conducted using PubMed and Scopus search engines. We used the following keywords: ?pneu- mococcal?, ?polysaccharide?, ?vaccine?, ?efficacy?, ?elderly?, ?meta analysis?. Only meta-analyses published in the last 7 years were selected. We examined the results of the selected meta-anal- yses and assessed their quality according to the PRISMA recom- mendations. Results. The search returned 16 results in PubMed and 12 in Scopus: among them we selected 3 meta-analyses. According to our quality assessment, all meta-analyses showed generally posi- tive results and almost all items of the PRISMA checklist were respected. However, the research protocol and the registration number were absent in all the 3 revisions and the flow-chart was not shown in Moberley?s and Melegaro?s works. In the study by Huss et al. the relative risk of developing IPDs among vaccinated subjects was 0.90 (95%CI: 0.46-1.77, I2 4.9%), indicating a very slight benefit after vaccination. This contrasts with the results of the Cochrane Review by Moberley et al., in which the PPVs showed a protective efficacy in reducing the risk of IPDs of 74% (OR 0.26, 95%CI: 0.15-0.46) with no statistical heterogeneity (I2 0%). Melegaro et al. found a reduction not statistically signifi- cant of the incidence of IPD of 65% (OR 0.35; 95%CI 0.08-1.49) among healthy elderly, while the global estimate of vaccine efficacy among high risk elderly was minimal (OR 0.80; 95%CI 0.22-2.88). Conclusions. Most of the studies suggest that the PPVs confer low protection against IPDs. Anyhow, their methodological het- erogeneity does not allow definitive conclusions. While waiting to see the results of new trials about the efficacy of PPVs, in particular of PPV23, and the extension of the use of conjugate vaccine among the population over 65, stakeholders should be aware of the results of the meta-analyses discussed in this paper during the implementation of the vaccination programs for the elderly in Public Health. The full article is free available on www.jpmh.or

Cohort study of electronic cigarette use: effectiveness and safety at 24 months

OBJECTIVE: To evaluate the safety and effectiveness of e-cigarettes, by comparing users of only e-cigarettes, smokers of only tobacco cigarettes and dual users. DESIGN: Prospective cohort study. We update previous 12-month findings and report the results of the 24-month follow-up. DATA SOURCES: Direct contact and questionnaires by phone or via internet. METHODS: Adults (30-75 years) were classified as: (1) tobacco smokers, if they smoked ≥1 tobacco cigarette/day, (2) e-cigarette users, if they inhaled ≥50 puffs/week of any type of e-cigarette and (3) dual users, if they smoked tobacco cigarettes and also used e-cigarettes. Carbon monoxide levels were tested in 50% of those declaring tobacco smoking abstinence. Hospital discharge data were used to validate possibly related serious adverse events in 46.0% of the sample. MAIN OUTCOME MEASURES: Sustained abstinence from tobacco cigarettes and/or e-cigarettes after 24 months, the difference in the number of tobacco cigarettes smoked daily between baseline and 24 months, possibly related serious adverse events. RESULTS: Data at 24 months were available for 229 e-cigarette users, 480 tobacco smokers and 223 dual users (overall response rate 68.8%). Of the e-cigarette users, 61.1% remained abstinent from tobacco (while 23.1% and 26.0% of tobacco-only smokers and dual users achieved tobacco abstinence). The rate (18.8%) of stopping use of either product (tobacco and/or e-cigarettes) was not higher for e-cigarette users compared with tobacco smokers or dual users. Self-rated health and adverse events were similar between all groups. Among those continuing to smoke, there were no differences in the proportion of participants reducing tobacco cigarette consumption by 50% or more, the average daily number of cigarettes and the average self-rated health by baseline group. Most dual users at baseline abandoned e-cigarettes and continued to smoke tobacco. Those who continued dual using or converted from tobacco smoking to dual use during follow-up experienced significant improvements in the 3 outcomes compared with those who continued or switched to only smoking tobacco (p<0.001). CONCLUSIONS: E-cigarette use alone might support tobacco quitters remaining abstinent from smoking. However, dual use did not improve the likelihood of quitting tobacco or e-cigarette use, but may be helpful to reduce tobacco consumption. Adverse event data were scarce and must be considered preliminary. TRIAL REGISTRATION NUMBER: NCT01785537

PARP inhibitor ABT-888 affects response of MDA-MB-231 cells to doxorubicin treatment, targeting Snail expression

To overcome cancer cells resistance to pharmacological therapy, the development of new therapeutic approaches becomes urgent. For this purpose, the use of poly(ADP-ribose) polymerase (PARP) inhibitors in combination with other cytotoxic agents could represent an efficacious strategy. Poly(ADP-ribosyl)ation (PARylation) is a post-translational modification that plays a well characterized role in the cellular decisions of life and death. Recent findings indicate that PARP-1 may control the expression of Snail, the master gene of epithelial-mesenchymal transition (EMT). Snail is highly represented in different resistant tumors, functioning as a factor regulating anti-apoptotic programmes. MDA-MB-231 is a Snail-expressing metastatic breast cancer cell line, which exhibits chemoresistance properties when treated with damaging agents. In this study, we show that the PARP inhibitor ABT-888 was capable to modulate the MDA-MB-231 cell response to doxorubicin, leading to an increase in the rate of apoptosis. Our further results indicate that PARP-1 controlled Snail expression at transcriptional level in cells exposed to doxorubicin. Given the increasing interest in the employment of PARP inhibitors as chemotherapeutic adjuvants, our in vitro results suggest that one of the mechanisms through which PARP inhibition can chemosensitize cancer cells in vivo, is targeting Snail expression thus promoting apoptosi

Co-targeting of Bcl-2 and mTOR pathway triggers synergistic apoptosis in BH3 mimetics resistant acute lymphoblastic leukemia

Several chemo-resistance mechanisms including the Bcl-2 protein family overexpression and constitutive activation of the PI3K/Akt/mTOR signaling have been documented in acute lymphoblastic leukemia (ALL), encouraging targeted approaches to circumvent this clinical problem. Here we analyzed the activity of the BH3 mimetic ABT-737 in ALL, exploring the synergistic effects with the mTOR inhibitor CCI-779 on ABT-737 resistant cells. We showed that a low Mcl-1/Bcl-2 plus Bcl-xL protein ratio determined ABT-737 responsiveness. ABT-737 exposure further decreased Mcl-1, inducing apoptosis on sensitive models and primary samples, while not affecting resistant cells. Co-inhibition of Bcl-2 and the mTOR pathway resulted cytotoxic on ABT-737 resistant models, by downregulating mTORC1 activity and Mcl-1 in a proteasome-independent manner. Although Mcl-1 seemed to be critical, ectopic modulation did not correlate with apoptosis changes. Importantly, dual targeting proved effective on ABT-737 resistant samples, showing additive/synergistic effects. Together, our results show the efficacy of BH3 mimetics as single agent in the majority of the ALL samples and demonstrate that resistance to ABT-737 mostly correlated with Mcl-1 overexpression. Co-targeting of the Bcl-2 protein family and mTOR pathway enhanced drug-induced cytotoxicity by suppressing Mcl-1, providing a novel therapeutic approach to overcome BH3 mimetics resistance in ALL