MTOR cross-talk in cancer and potential for combination therapy

The mammalian Target of Rapamycin (mTOR) pathway plays an essential role in sensing and integrating a variety of exogenous cues to regulate cellular growth and metabolism, in both physiological and pathological conditions. mTOR functions through two functionally and structurally distinct multi-component complexes, mTORC1 and mTORC2, which interact with each other and with several elements of other signaling pathways. In the past few years, many new insights into mTOR function and regulation have been gained and extensive genetic and pharmacological studies in mice have enhanced our understanding of how mTOR dysfunction contributes to several diseases, including cancer. Single-agent mTOR targeting, mostly using rapalogs, has so far met limited clinical success; however, due to the extensive cross-talk between mTOR and other pathways, combined approaches are the most promising avenues to improve clinical efficacy of available therapeutics and overcome drug resistance. This review provides a brief and up-to-date narrative on the regulation of mTOR function, the relative contributions of mTORC1 and mTORC2 complexes to cancer development and progression, and prospects for mTOR inhibition as a therapeutic strategy

Dry bone and virtual modality interchangeability for the estimation of sex on the human pelvis and skull

Background: Traditional osteological methods are typically based on visual and tactile observational approaches. However, the tactile sensation is excluded when investigating skeletal remains in virtual reality. This raises the question of the actual comparability of data obtained from osteological analysis on analogous versus virtual modality. The aim of this work is to address this topic and quantify the deviation between the scoring on dry bone and virtual models of sexually dimorphic features on the human pelvis and skull. Materials and methods: We applied seven widely used sex estimation methods to 200 archaeological pelves and 223 skulls. We scored and measured each method-specific trait on dry bone and computed tomographic (CT) models of the same individual. We added observations on 3D surface scans from sample subsets of pelves (N=39) and skulls (=50) for comparability. We compared the scores and measurements obtained from the application of each method to the three sets of observations using Cohen's κ tests and relative technical error of measurement (rTEM). Results: 1) metric traits are more repeatable and consistent than nonmetric traits; b) virtual modalities compared better to each other than visual-tactile modalities and c) precise trait descriptions are more important than the modality. Discussion: Our data suggest that traditional sex estimation methods developed on dry bone (visual-tactile sensations) can be applied interchangeably to virtual specimens (visual-only sensation) without obtaining substantially different information. More than other factors, however, precise trait definition is pivotal for the interchangeability of analogous and virtual modalities

Neuroprotective potential of isothiocyanates in an in vitro model of neuroinflammation

Isothiocyanates (ITCs), present as glucosinolate precursors in cruciferous vegetables, have shown anti-inflammatory, antioxidant and anticarcinogenic activities. Here, we compared the effects of three different ITCs on ROS production and on the expression of matrix metalloproteinase (MMP)-2 and -9, which represent important pathogenetic factors of various neurological diseases. Primary cultures of rat astrocytes were activated by LPS and simultaneously treated with different doses of Allyl isothiocyanate (AITC), 2-Phenethyl isothiocyanate (PEITC) and 2-Sulforaphane (SFN). Results showed that SFN and PEITC were able to counteract ROS production induced by H2O2. The zymographic analysis of cell culture supernatants evidenced that PEITC and SFN were the most effective inhibitors of MMP-9, whereas, only SFN significantly inhibited MMP-2 activity. PCR analysis showed that all the ITCs used significantly inhibited both MMP-2 and MMP-9 expression. The investigation on the mitogen-activated protein kinase (MAPK) signaling pathway demonstrated that ITCs modulate MMP transcription by inhibition of extracellular-regulated protein kinase (ERK) activity. Results of this study suggest that ITCs could be promising nutraceutical agents for the prevention and complementary treatment of neurological diseases associated with MMP involvement

COX-2 targeting in cancer: a new beginning?

Cyclo-oxygenase-2 (COX-2), the inducible enzyme catalyzing the rate-limiting step in the conversion of arachidonic acid into eicosanoids, is overexpressed in a wide variety of malignancies and associates with poor prognostic features [1]. Consequently, selective COX-2 inhibitors have been explored as therapeutic or chemopreventive agents in different settings; however, initial enthusiasm was tempered by reports of substantial gastrointestinal toxicity as well as of increased cardiovascular risk, mostly coming from postmarketing use as anti-inflammatory drugs and Cancer Research Campaign (UK) chemoprevention trials and eventually resulting in the withdrawal of rofecoxib from the market [2]

Neuroprotective potential of isothiocyanates in an in vitro model of neuroinflammation

Isothiocyanates (ITCs), present as glucosinolate precursors in cruciferous vegetables, have shown anti-inflammatory, antioxidant and anticarcinogenic activities. Here, we compared the effects of three different ITCs on ROS production and on the expression of matrix metalloproteinase (MMP)-2 and -9, which represent important pathogenetic factors of various neurological diseases. Primary cultures of rat astrocytes were activated by LPS and simultaneously treated with different doses of Allyl isothiocyanate (AITC), 2-Phenethyl isothiocyanate (PEITC) and 2-Sulforaphane (SFN). Results showed that SFN and PEITC were able to counteract ROS production induced by H2O2. The zymographic analysis of cell culture supernatants evidenced that PEITC and SFN were the most effective inhibitors of MMP-9, whereas, only SFN significantly inhibited MMP-2 activity. PCR analysis showed that all the ITCs used significantly inhibited both MMP-2 and MMP-9 expression. The investigation on the mitogen-activated protein kinase (MAPK) signaling pathway demonstrated that ITCs modulate MMP transcription by inhibition of extracellular-regulated protein kinase (ERK) activity. Results of this study suggest that ITCs could be promising nutraceutical agents for the prevention and complementary treatment of neurological diseases associated with MMP involvement

Brachial plexus neuropathy as unusual onset of diffuse neurolymphomatosis

: We present a patient with a large B cell gastric lymphoma in total remission who, after 4 months, developed a fatal progressive peripheral neuropathy with an unusual early involvement of the right brachial plexus. No evidence of lymphoma was found at whole body computed tomography, magnetic resonance imaging of the head, cervical spine and right brachial plexus, bone marrow biopsy or repeated lumbar punctures. The diagnosis of neurolymphomatosis was made only at postmortem examination

E-learning course improves knowledge in tobacco dependence, electronic nicotine delivery systems and heat-not-burn products in Medical School students

Background: Adequate training in tobacco, nicotine dependence and treatment is lacking in Medical School education. With the rise in popularity of electronic alternatives to cigarettes, future physicians should also be provided with the more recent scientific evidence on these products during their undergraduate studies. We introduced an e-learning course for Medical School students and assessed its effec-tiveness of increasing knowledge on these topics. Methods: We developed 16 didactic modules divided in 3 courses: tobacco dependence (TDI), treating tobacco dependence (TDII) and electronic products and tobacco control (TDIII). The course was offered to 4th, 5th, and 6th year Medical School students in Italy. To assess learning outcomes, we examined the pre- to post- changes in knowledge scores associated with each course. Paired and independent samples t-tests were performed overall, and among smokers and non-smokers separately. Results: A total of 1318 students completed at least one of the courses; 21% were self-reported smokers. A significant increase in knowledge was observed at the end of TDI (pre-course: 52.1±15.9, post-course: 79.9±13.5, p<0.001), TDII (pre-course: 52.5±13.0, post-course: 66.5±12.0, p<0.001) and TDIII (pre-course: 52.2±15.3, post-course: 76.1±17.7, p<0.001). Smokers showed significantly lower improvements compared to non-smokers. Conclusions: The e-learning course was effective in increasing knowledge about tobacco dependence, treatments, and electronic ni-cotine products in advanced medical students. Given the fundamental role for healthcare practitioners in encouraging and assisting people in quitting smoking, e-learning may be a useful tool in providing up-to-date and standardized training in the area during Medical School

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

Therapeutic targeting of the MEK/MAPK signal transduction module in acute myeloid leukemia

: The mitogen-activated protein kinase (MAPK) pathway regulates growth and survival of many cell types, and its constitutive activation has been implicated in the pathogenesis of a variety of malignancies. In this study we demonstrate that small-molecule MEK inhibitors (PD98059 and PD184352) profoundly impair cell growth and survival of acute myeloid leukemia (AML) cell lines and primary samples with constitutive MAPK activation. These agents abrogate the clonogenicity of leukemic cells but have minimal effects on normal hematopoietic progenitors. MEK blockade also results in sensitization to spontaneous and drug-induced apoptosis. At a molecular level, these effects correlate with modulation of the expression of cyclin-dependent kinase inhibitors (p27(Kip1) and p21(Waf1/CIP1)) and antiapoptotic proteins of the inhibitor of apoptosis proteins (IAP) and Bcl-2 families. Interruption of constitutive MEK/MAPK signaling therefore represents a promising therapeutic strategy in AML

Identification and antimicrobial activity of most representative secondary metabolites from different plant species

Abstract Background The plant kingdom constitutes an enormous reservoir of bioactive molecules, generally used by plants to prevent or to protect themselves from pathogens' attacks. To date, several primary or secondary plant metabolites have been already proven to exert antibiotic activities; nonetheless, researchers are still continuing to lavish great efforts to identify and characterize new natural molecules one by one. Aiming at the replacement of synthetic chemical products, the bioactivity of plant extracts should be assessed case by case, and active substances should be tested as individuals to obtain accurate information on the real usefulness of plant metabolites. In this work major glycoalkaloids obtained from Solanum nigrum, glucosinolates from Armoracia rusticana, and cannabinoids from Cannabis sativa were identified. The antimicrobial activity of crude extracts and pure components against Gram+ (Bacillus cereus (A1I), Bacillus thuringiensis (B7I2), and Bacillus amyloliquefaciens (A5TI)) and Gram− bacteria (Pseudomonas orientalis (A14-1II), and Stenotrophomonas maltophilia (B9TIII)), employed as model organisms, was tested. Result Major glycoalkaloids, glucosinolates, and cannabinoids were identified in crude plants' extracts using high-resolution LC–ESI-FTICR/MS. From antimicrobial assays useful information towards a few of biological activities of crude extracts and individual components were obtained. Solanum nigrum extracts revealed inhibition activity on all bacteria tested as well as the main active glycoalkaloids, solamargine and solasonine, which were found to be active even when tested individually. At assayed concentrations, A. rusticana extract was active towards a few of the microorganisms tested, confirming that the activity of glucosinolates can be referred only partially to the mother molecules, while biological efficiency of such kind of compounds is mainly due to their enzymatic breaking off, where myrosinase converts them into isothiocyanates and/or thiocyanates. Hemp-type C. sativa extract showed antimicrobial activity only against Gram+ bacteria, but the main individual components tested showed always a limited bioactivity. Conclusion Promising results were obtained, but tests performed in vitro are only the first step of a wider investigation as required for an extensive application. Further research efforts are necessary to demonstrate the efficiency of natural substances in different target environments