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MicroRNAs are small non-coding regulatory molecules exerting pleiotropic action in different biological processes such as proliferation, differentiation, apoptosis, migration and metastasis. Deregulation of miRNA expression has been observed in various cancers, and accumulating data suggest that miRNAs can display an oncogenic, antioncogenic or an ambiguous behavior in relationship to tumor environment. In a previous research we showed that the synthetic cannabinoid WIN55,212-2 is able to reduce the migratory activity of osteosarcoma MG63 cells analyzed by means of wound healing assay. So we undertook a study to evaluate the biochemical mechanism through which WIN plays this action. To this purpose we evaluated the levels of miR-29b1, a member of miR-29 family which has been shown to impact critical steps in the migratory and metastatic cascade, such as EMT, apoptosis and angiogenesis. RT-PCR experiments showed that in MG63 cells 5 M WIN increased the level of miR-29b1 of about 700-fold. This effect was accompanied by the reduction in its putative targets MMP-2, PDGF-B and N-MYC, thus indicating that the miRNA is functionally active. Moreover, cells stably overexpressing miR-29b1 did not close the wound after 48 h, mimicking the effect of WIN in untransfected control cells. Notably, ERα(+) MCF-7 and triple negative MDA-MB-231 cells, two different breast cancer models, treated with the cannabinoid migrated into the scratched area significantly faster than the respective control cells. In these cells WIN also increased the level of miR-29b1 targets. Therefore, differently from osteosarcoma cells, these preliminary observations seem to indicate that WIN promotes migration ability in breast cancer cells. The reasons for this diverse behaviour could rely on miR-29b1, whose expression can change in different cell types or show temporal differences dictated by cell physiology and tumor microenvironment impact. Studies are in progress to shed light on the molecular mechanisms underlying this different response.

Caspase-8 (casp-8) is well known as an initiator caspase involved in cell death signalling, although its activity in many cancer cell types seems to work under non-apoptotic conditions. Moreover, in several types of cancer, casp-8 is only rarely mutated and often its expression is very elevated. Since cancer cell growth also depends on evasion of apoptosis, the upregulation of casp-8 in tumours may suggest one or more non-apoptotic roles (1). Here we report our recent studies carried out in MDA-MB-231 cells, derived from clinically aggressive forms of Triple-Negative Breast Cancer, where we have assessed the non-canonical roles of casp-8. Firstly, we evaluated casp-8 mRNA and protein levels in MDA-MB-231 cells, demonstrating that they were upregulated with respect to HMEC (normal Human Mammalian Epithelial Cells). Thereafter, to assess the role of casp-8, we silenced it by small interfering-RNA. Interestingly casp-8-knockdown, strongly decreased MDA-MB-231 cell growth by delaying G0/G1- to S-phase transition and increasing p21, p27 and hypophosphorylated/active form of pRb levels. No effects were evidenced on cell viability. To assess the metastatic capacity of MDA-MB-231 cells, the gene expression profiles of the relative markers after casp-8 knockdown were also measured. Surprisingly the expression of a number of genes and/or proteins such as VEGFA, C-MYC, CTNNB1, HMGA2, CXCR4, KLF4, VERSICAN V1 and MMP2 potently increased accompanied by migratory and metastatic capacities of cells, as shown by wound healing and matrigel assays. We suggest that among these genes, KLF4, a transcriptional factor with a dual role (activator and repressor), and responsible for p21 and p27 induction, could play critical roles (2). Casp-8 through KLF4 down-regulation, could manage the expression of critical proliferative and migratory/invasive genes. We suggest that these unusual roles played by casp-8 in MDA-MB-231 cells, should be better explored, in order to identify it as a molecular therapeutic target. References 1. Stupack DG. Caspase-8 as a Therapeutic Target in Cancer. Cancer Lett 332:133–140, 2013. 2. Tiwari N et al. Klf4 Is a Transcriptional Regulator of Genes Critical for EMT, Including Jnk1 (Mapk8). PLoS One 8, 2013.

Lifestyle factors are responsible for a considerable portion of cancer incidence worldwide, but credible estimates from the World Health Organization and the International Agency for Research on Cancer (IARC) suggest that the fraction of cancers attributable to toxic environmental exposures is between 7% and 19%. To explore the hypothesis that low-dose exposures to mixtures of chemicals in the environment may be combining to contribute to environmental carcinogenesis, we reviewed 11 hallmark phenotypes of cancer, multiple priority target sites for disruption in each area and prototypical chemical disruptors for all targets, this included dose-response characterizations, evidence of low-dose effects and cross-hallmark effects for all targets and chemicals. In total, 85 examples of chemicals were reviewed for actions on key pathways/ mechanisms related to carcinogenesis. Only 15% (13/85) were found to have evidence of a dose-response threshold, whereas 59% (50/85) exerted low-dose effects. No dose-response information was found for the remaining 26% (22/85). Our analysis suggests that the cumulative effects of individual (non-carcinogenic) chemicals acting on different pathways, and a variety of related systems, organs, tissues and cells could plausibly conspire to produce carcinogenic synergies. Additional basic research on carcinogenesis and research focused on low-dose effects of chemical mixtures needs to be rigorously pursued before the merits of this hypothesis can be further advanced. However, the structure of the World Health Organization International Programme on Chemical Safety 'Mode of Action' framework should be revisited as it has inherent weaknesses that are not fully aligned with our current understanding of cancer biology. © The Author 2015.

Two cDNA clones named P9* and P1* of 794 and 631 bp, respectively, were isolated from a Λ ZAP cDNA expression library using Parietaria judaica (Pj) pollen-specific IgE antibodi

The aim of this study was to determine the frequencies of ACE (I/D), AGT (M235T), AT1R (A1166C) and MTHFR (C677T) polymorphisms in a well-defined (in regards to health and nutritional status and lifestyle) population of young, healthy, exercise-trained subjects (no. 100) from the Campania region of Southern Italy. We also investigated whether there was any correlation between these polymorphisms and biochemical, hematological and hemostatic parameters in this "low-risk" population. Gene polymorphisms were analyzed with the polymerase chain reaction and restriction enzyme analysis. Allele frequencies of the genotypes examined were in Hardy-Weinberg equilibrium and agree with those reported in the Italian population. No associations were found between ACE, AGT, AT1R gene polymorphisms and anthropometric, clinical and laboratory parameters. However, the MTHFR (C677T) polymorphism was significantly associated with lower hemoglobin plasma levels in TT vs. CC + CT females (p < 0.016). This report is the first to describe the frequencies of RAS and MTHFR gene polymorphisms in young, exercise-trained volunteers from Campania and to identify an association between the MTHFR gene polymorphisms and lower hemoglobin plasma levels in young healthy females.

Goodson, William H. et al., © The Author 2015. Lifestyle factors are responsible for a considerable portion of cancer incidence worldwide, but credible estimates from the World Health Organization and the International Agency for Research on Cancer (IARC) suggest that the fraction of cancers attributable to toxic environmental exposures is between 7% and 19%. To explore the hypothesis that low-dose exposures to mixtures of chemicals in the environment may be combining to contribute to environmental carcinogenesis, we reviewed 11 hallmark phenotypes of cancer, multiple priority target sites for disruption in each area and prototypical chemical disruptors for all targets, this included dose-response characterizations, evidence of low-dose effects and cross-hallmark effects for all targets and chemicals. In total, 85 examples of chemicals were reviewed for actions on key pathways/ mechanisms related to carcinogenesis. Only 15% (13/85) were found to have evidence of a dose-response threshold, whereas 59% (50/85) exerted low-dose effects. No dose-response information was found for the remaining 26% (22/85). Our analysis suggests that the cumulative effects of individual (non-carcinogenic) chemicals acting on different pathways, and a variety of related systems, organs, tissues and cells could plausibly conspire to produce carcinogenic synergies. Additional basic research on carcinogenesis and research focused on low-dose effects of chemical mixtures needs to be rigorously pursued before the merits of this hypothesis can be further advanced. However, the structure of the World Health Organization International Programme on Chemical Safety 'Mode of Action' framework should be revisited as it has inherent weaknesses that are not fully aligned with our current understanding of cancer biology., We gratefully acknowledge the support of the National Institute of Health-National Institute of Environmental Health Sciences (NIEHS) conference grant travel support (R13ES023276); Glenn Rice, Office of Research and Development, United States Environmental Protection Agency, Cincinnati, OH, USA also deserves thanks for his thoughtful feedback and inputs on the manuscript; William H.Goodson III was supported by the California Breast Cancer Research Program, Clarence Heller Foundation and California Pacific Medical Center Foundation; Abdul M.Ali would like to acknowledge the financial support of the University of Sultan Zainal Abidin, Malaysia; Ahmed Lasfar was supported by an award from the Rutgers Cancer Institute of New Jersey; Ann-Karin Olsen and Gunnar Brunborg were supported by the Research Council of Norway (RCN) through its Centres of Excellence funding scheme (223268/F50), Amancio Carnero’s lab was supported by grants from the Spanish Ministry of Economy and Competitivity, ISCIII (Fis: PI12/00137, RTICC: RD12/0036/0028) co-funded by FEDER from Regional Development European Funds (European Union), Consejeria de Ciencia e Innovacion (CTS-1848) and Consejeria de Salud of the Junta de Andalucia (PI-0306-2012); Matilde E. Lleonart was supported by a trienal project grant PI12/01104 and by project CP03/00101 for personal support. Amaya Azqueta would like to thank the Ministerio de Educacion y Ciencia (‘Juande la Cierva’ programme, 2009) of the Spanish Government for personal support; Amedeo Amedei was supported by the Italian Ministry of University and Research (2009FZZ4XM_002), and the University of Florence (ex60%2012); Andrew R.Collins was supported by the University of Oslo; Annamaria Colacci was supported by the Emilia-Romagna Region - Project ‘Supersite’ in Italy; Carolyn Baglole was supported by a salary award from the Fonds de recherche du Quebec-Sante (FRQ-S); Chiara Mondello’s laboratory is supported by Fondazione Cariplo in Milan, Italy (grant n. 2011-0370); Christian C.Naus holds a Canada Research Chair; Clement Yedjou was supported by a grant from the National Institutes of Health (NIH-NIMHD grant no. G12MD007581); Daniel C.Koch is supported by the Burroughs Wellcome Fund Postdoctoral Enrichment Award and the Tumor Biology Training grant: NIH T32CA09151; Dean W. Felsher would like to acknowledge the support of United States Department of Health and Human Services, NIH grants (R01 CA170378 PQ22, R01 CA184384, U54 CA149145, U54 CA151459, P50 CA114747 and R21 CA169964); Emilio Rojas would like to thank CONACyT support 152473, Ezio Laconi was supported by AIRC (Italian Association for Cancer Research, grant no. IG 14640) and by the Sardinian Regional Government (RAS); Eun-Yi Moon was supported by grants from the Public Problem-Solving Program (NRF-015M3C8A6A06014500) and Nuclear R&D Program (#2013M2B2A9A03051296 and 2010-0018545) through the National Research Foundation of Korea (NRF) and funded by the Ministry of Education, Science and Technology (MEST) in Korea; Fahd Al-Mulla was supported by the Kuwait Foundation for the Advancement of Sciences (2011-1302-06); Ferdinando Chiaradonna is supported by SysBioNet, a grant for the Italian Roadmap of European Strategy Forum on Research Infrastructures (ESFRI) and by AIRC (Associazione Italiana Ricerca sul Cancro; IG 15364); Francis L.Martin acknowledges funding from Rosemere Cancer Foundation; he also thanks Lancashire Teaching Hospitals NHS trust and the patients who have facilitated the studies he has undertaken over the course of the last 10 years; Gary S.Goldberg would like to acknowledge the support of the New Jersey Health Foundation; Gloria M.Calaf was supported by Fondo Nacional de Ciencia y Tecnología (FONDECYT), Ministerio de Educación de Chile (MINEDUC), Universidad de Tarapacá (UTA); Gudrun Koppen was supported by the Flemish Institute for Technological Research (VITO), Belgium; Hemad Yasaei was supported from a triennial project grant (Strategic Award) from the National Centre for the Replacement, Refinement and Reduction (NC3Rs) of animals in research (NC.K500045.1 and G0800697); Hiroshi Kondoh was supported in part by grants from the Ministry of Education, Culture, Sports, Science, and Technology of Japan, Japan Science and Technology Agency and by JST, CREST; Hsue-Yin Hsu was supported by the Ministry of Science and Technology of Taiwan (NSC93-2314-B-320-006 and NSC94-2314-B-320-002); Hyun Ho Park was supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF) of the Ministry of Education, Science and Technology (2012R1A2A2A01010870) and a grant from the Korea Healthcare Technology R&D project, Ministry of Health and Welfare, Republic of Korea (HI13C1449); Igor Koturbash is supported by the UAMS/NIH Clinical and Translational Science Award (UL1TR000039 and KL2TR000063) and the Arkansas Biosciences Institute, the major research component of the Arkansas Tobacco Settlement Proceeds Act of 2000; Jan Vondráček acknowledges funding from the Czech Science Foundation (13-07711S); Jesse Roman thanks the NIH for their support (CA116812), John Pierce Wise Sr. and Sandra S.Wise were supported by National Institute of Environmental Health Sciences (ES016893 to J.P.W.) and the Maine Center for Toxicology and Environmental Health; Jonathan Whitfield acknowledges support from the FERO Foundation in Barcelona, Spain; Joseph Christopher is funded by Cancer Research UK and the International Journal of Experimental Pathology; Julia Kravchenko is supported by a philanthropic donation by Fred and Alice Stanback; Jun Sun is supported by a Swim Across America Cancer Research Award; Karine A.Cohen-Solal is supported by a research scholar grant from the American Cancer Society (116683-RSG-09-087-01-TBE); Laetitia Gonzalez received a postdoctoral fellowship from the Fund for Scientific Research–Flanders (FWO-Vlaanderen) and support by an InterUniversity Attraction Pole grant (IAP-P7-07); Laura Soucek is supported by grant #CP10/00656 from the Miguel Servet Research Contract Program and acknowledges support from the FERO Foundation in Barcelona, Spain; Liang-Tzung Lin was supported by funding from the Taipei Medical University (TMU101-AE3-Y19); Linda Gulliver is supported by a Genesis Oncology Trust (NZ) Professional Development Grant, and the Faculty of Medicine, University of Otago, Dunedin, New Zealand; Louis Vermeulen is supported by a Fellowship of the Dutch Cancer Society (KWF, UVA2011-4969) and a grant from the AICR (14–1164); Mahara Valverde would like to thank CONACyT support 153781; Masoud H. Manjili was supported by the office of the Assistant Secretary of Defense for Health Affairs (USA) through the Breast Cancer Research Program under Award No. W81XWH-14-1-0087 Neetu Singh was supported by grant #SR/FT/LS-063/2008 from the Department of Science and Technology, Government of India; Nicole Kleinstreuer is supported by NIEHS contracts (N01-ES 35504 and HHSN27320140003C); P.K. Krishnakumar is supported by the Funding (No. T.K. 11-0629) of King Abdulaziz City for Science and Technology, Riyadh, Saudi Arabia; Paola A.Marignani is supported by the Dalhousie Medical Research Foundation, The Beatrice Hunter Cancer Institute and CIHR and the Nova Scotia Lung Association; Paul Dent is the holder of the Universal Inc.Chair in Signal Transduction Research and is supported with funds from PHS grants from the NIH (R01-CA141704, R01-CA150214, R01-DK52825 and R01-CA61774); Petr Heneberg was supported by the Charles University in Prague projects UNCE 204015 and PRVOUK P31/2012, and by the Czech Science Foundation projects P301/12/1686 and 15-03834Y; Po Sing Leung was supported by the Health and Medical Research Fund of Food and Health Bureau, Hong Kong Special Administrative Region, Ref. No: 10110021; Qiang Cheng was supported in part by grant NSF IIS-1218712; R. Brooks Robey is supported by the United States Department of Veterans Affairs; Rabindra Roy was supported by United States Public Health Service Grants (RO1 CA92306, RO1 CA92306-S1 and RO1 CA113447); Rafaela Andrade-Vieira is supported by the Beatrice Hunter Cancer Research Institute and the Nova Scotia Health Research Foundation, Renza Vento was partially funded by European Regional Development Fund, European Territorial Cooperation 2007–13 (CCI 2007 CB 163 PO 037, OP Italia-Malta 2007–13) and grants from the Italian Ministry of Education, University and Research (MIUR) ex-60%, 2007; Riccardo Di Fiore was a recipient of fellowship granted by European Regional Development Fund, European Territorial Cooperation 2007–2013 (CCI 2007 CB 163 PO 037, OP Italia-Malta 2007–2013); Rita Dornetshuber-Fleiss was supported by the Austrian Science Fund (FWF, project number T 451-B18) and the Johanna Mahlke, geb.-Obermann-Stiftung; Roberta Palorini is supported by a SysBioNet fellowship; Roslida Abd Hamid is supported by the Ministry of Education, Malaysia-Exploratory Research Grant Scheme-Project no: ERGS/1-2013/5527165; Sabine A.S.Langie is the beneficiary of a postdoctoral grant from the AXA Research Fund and the Cefic-LRI Innovative Science Award 2013; Sakina Eltom is supported by NIH grant SC1CA153326; Samira A.Brooks was supported by National Research Service Award (T32 ES007126) from the National Institute of Environmental Health Sciences and the HHMI Translational Medicine Fellowship; Sandra Ryeom was supported by The Garrett B. Smith Foundation and the TedDriven Foundation; Thierry Massfelder was supported by the Institut National de la Santé et de la Recherche Médicale INSERM and Université de Strasbourg; Thomas Sanderson is supported by the Canadian Institutes of Health Research (CIHR; MOP-115019), the Natural Sciences and Engineering Council of Canada (NSERC; 313313) and the California Breast Cancer Research Program (CBCRP; 17UB-8703); Tiziana Guarnieri is supported by a grant from Fundamental Oriented Research (RFO) to the Alma Mater Studiorum University of Bologna, Bologna, Italy and thanks the Fondazione Cassa di Risparmio di Bologna and the Fondazione Banca del Monte di Bologna e Ravenna for supporting the Center for Applied Biomedical Research, S.Orsola-Malpighi University Hospital, Bologna, Italy; W.Kimryn Rathmell is supported by the V Foundation for Cancer Research and the American Cancer Society; William K.Decker was supported in part by grant RP110545 from the Cancer Prevention Research Institute of Texas; William H.Bisson was supported with funding from the NIH P30 ES000210; Yon Rojanasakul was supported with NIH grant R01-ES022968; Zhenbang Chen is supported by NIH grants (MD004038, CA163069 and MD007593); Zhiwei Hu is grateful for the grant support from an institutional start-up fund from The Ohio State University College of Medicine and The OSU James Comprehensive Cancer Center (OSUCCC) and a Seed Award from the OSUCCC Translational Therapeutics Program.

A novel cancer stem-like cell line (3AB-OS), expressing a number of pluripotent stem cell markers, was irreversibly selected from human osteosarcoma MG-63 cells by long-term treatment (100 days) with 3-aminobenzamide (3AB). 3AB-OS cells are a heterogeneous and stable cell population composed by three types of fibroblastoid cells, spindle-shaped, polygonal-shaped, and rounded-shaped. With respect to MG-63 cells, 3AB-OS cells are extremely smaller, possess a much greater capacity to form spheres, a stronger self-renewal ability and much higher levels of cell cycle markers which account for G1-S/G2-M phases progression. Differently from MG-63 cells, 3AB-OS cells can be reseeded unlimitedly without losing their proliferative potential. They show an ATP-binding cassette transporter ABCG2-dependent phenotype with high drug efflux capacity, and a strong positivity for CD133, marker for pluripotent stem cells, which are almost unmeasurable in MG-63 cells. 3AB-OS cells are much less committed to osteogenic and adipogenic differentiation than MG-63 cells and highly express genes required for maintaining stem cell state (Oct3/4, hTERT, nucleostemin, Nanog) and for inhibiting apoptosis (HIF-1alpha, FLIP-L, Bcl-2, XIAP, IAPs, and survivin). 3AB-OS may be a novel tumor cell line useful for investigating the mechanisms by which stem cells enrichment may be induced in a tumor cell line. The identification of a subpopulation of cancer stem cells that drives tumorigenesis and chemoresistance in osteosarcoma may lead to prognosis and optimal therapy determination. Expression patterns of stem cell markers, especially CD133 and ABCG2, may indicate the undifferentiated state of osteosarcoma tumors, and may correlate with unfavorable prognosis in the clinical setting.

Background Acute myocardial infarction (AMI) in young women represent an extreme phenotype associated with a higher mortality compared with similarly aged men. Prothrombotic gene variants could play a role as risk factors for AMI at young age. Methods We studied Factor V Leiden, FII G20210A, MTHFR C677T and beta-fibrinogen -455G>A variants by real-time PCR in 955 young AMI (362 females) and in 698 AMI (245 females) patients. The data were compared to those obtained in 909 unrelated subjects (458 females) from the general population of the same geographical area (southern Italy). Results In young AMI females, the allelic frequency of either FV Leiden and of FII G20210A was significantly higher versus the general population (O.R.: 3.67 for FV Leiden and O.R.: 3.84 for FII G20210A; p Discussion and conclusion Our data confirm that young AMI in females is a peculiar phenotype with specific risk factors as the increased plasma procoagulant activity of FV and FII. On the contrary, the homozygous state for the 677T MTHFR variant may cause increased levels of homocysteine and/or an altered folate status and thus an increased risk for AMI, particularly in males. The knowledge of such risk factors (that may be easily identified by molecular analysis) may help to improve prevention strategies for acute coronary diseases in specific risk-group subjects.

The present study shows that nuclear factor erythroid 2-related factor 2 (NRF2) and miR-29b-1-5p are two opposite forces which could regulate the fate of MDA-MB-231 cells, the most studied triple-negative breast cancer (TNBC) cell line. We show that NRF2 activation stimulates cell growth and markedly reduces reactive oxygen species (ROS) generation, whereas miR-29b-1-5p overexpression increases ROS generation and reduces cell proliferation. Moreover, NRF2 downregulates miR-29b-1-5p expression, whereas miR-29b-1-5p overexpression decreases p-AKT and p-NRF2. Furthermore, miR-29b-1-5p overexpression induces both inhibition of DNA N-methyltransferases (DNMT1, DNMT3A, and DNMT3B) expression and re-expression of HIN1, RASSF1A and CCND2. Conversely, NRF2 activation induces opposite effects. We also show that parthenolide, a naturally occurring small molecule, induces the expression of miR-29b-1-5p which could suppress NRF2 activation via AKT inhibition. Overall, this study uncovers a novel NRF2/miR-29b-1-5p/AKT regulatory loop that can regulate the fate (life/death) of MDA-MB-231 cells and suggests this loop as therapeutic target for TNBC.

Triple-negative breast cancer (TNBC) is a form of BC characterized by highaggressiveness and therapy resistance probably determined by cancer stem cells. MCL1 is an antiapoptotic Bcl-2 family member that could limit the efficacy of anticancer agents as recombinant human tumor necrosis factor related apoptosis-inducing ligand (rh-TRAIL). Here, we investigated MCL1 expression in TNBC tissues and cells. We found MCL1 differentially expressed (upregulated or downregulated) in TNBC tissues. Furthermore, in comparison to the human mammary epithelial cells, we found that MDA-MB-231 cells show similar messenger RNA levels but higher MCL1 protein levels, whereas it resulted downregulated in MDA-MB-436 and BT-20 cells. We evaluated the effects of rh-TRAIL and A-1210477, a selective MCL1 inhibitor, on cell viability and growth of MDA-MB-231 cells. We demonstrated that the drug combination reduced the cell growth and activated the apoptotic pathway. Similar effects were observed on three-dimensional cultures and tertiary mammospheres of MDA-MB-231 cells. In MDA-MB-231 cells, after MCL1 silencing, rh-TRAIL confined the cell population in the sub-G0/G1 phase and induced a drop in the mitochondrial transmembrane potential. To understand themolecular mechanism by which the loss of MCL1 function sensitizes the MDA-MB-231 cells to rh-TRAIL, we analyzed by real-time reverse transcription polymerase chain reaction, the expression of genes related to apoptosis, stemness, cell cycle, and those involved in epigenetic regulation. Interestingly, among the upregulated genes through MCL1 silencing or inhibition, there was TNFRSF10A (DR4). Moreover, MCL1 inhibition increased DR4 protein levels and its cell surface expression. Finally, we demonstrated MCL1-DR4 interaction and dissociation of this complex after A-1210477 treatment. Overall, our findings highlight the potential MCL1-roles in MDA-MB-231 cells and suggest that MCL1 targeting could be an effective strategy to overcome TNBC's rh-TRAIL resistance.

The Bcl-2 family, which plays important roles in controlling cancer development, is divided into antiapoptotic and proapoptotic members. The change in the balance between these members governs the life and death of the cells. Mcl-1 is an antiapoptotic member of this family and its distribution in normal and cancerous tissues strongly differs from that of Bcl-2. In human cancers, where upregulation of antiapoptotic proteins is common, Mcl-1 expression is regulated independent of Bcl-2 and its inhibition promotes senescence, a major barrier to tumorigenesis. Cancer chemotherapy determines various kinds of responses, such as senescence and autophagy; however, the ideal response to chemotherapy is apoptosis. Mcl-1 is a potent oncogene that is regulated at the transcriptional, posttranscriptional, and posttranslational levels. Mcl-1 is a short-lived protein that, in the NH2 terminal region, contains sites for posttranslational regulation that can lead to proteasomal degradation. The USP9X Mcl-1 deubiquitinase regulates Mcl-1 and the levels of these two proteins are strongly correlated. Mcl-1 has three splicing variants (the antiapoptotic protein Mcl-1L and the proapoptotic proteins Mcl-1S and Mcl-1ES), each contributing toward apoptosis regulation. In cancers responsible for the most deaths in the world, the presence of Mcl-1 is associated with malignant cell growth and evasion of apoptosis. Mcl-1 is also one of the key regulators ofcancer stem cells’ self-renewal that contributes to tumor survival. A great number of indirect and selective Mcl-1 inhibitors have been produced and some of these have shown efficacy in several clinical trials. Thus, therapeutic manipulation of Mcl-1 can be a useful strategy to combat cancer.

As part of the Halifax Project, this review brings attention to the potential effects of environmental chemicals on important molecular and cellular regulators of the cancer hallmark of evading growth suppression. Specifically, we review the mechanisms by which cancer cells escape the growth-inhibitory signals of p53, retinoblastoma protein, transforming growth factor-beta, gap junctions and contact inhibition. We discuss the effects of selected environmental chemicals on these mechanisms of growth inhibition and cross-reference the effects of these chemicals in other classical cancer hallmarks.

MiR-29 family dysregulation occurs in various cancers including breast cancers. We investigated miR-29b-1 functional role in human triple negative breast cancer (TNBC) the most aggressive breast cancer subtype. We found that miR-29b-1-5p was downregulated in human TNBC tissues and cell lines. To assess whether miR- 29b-1-5p correlated with TNBC regenerative potential, we evaluated cancer stem cell enrichment in our TNBC cell lines, and found that only MDA-MB-231 and BT-20 produced primary, secondary and tertiary mammospheres, which were progressively enriched in OCT4, NANOG and SOX2 stemness genes. MiR-29b-1-5p expression inversely correlated with mammosphere stemness potential, and miR-29b-1 ectopic overexpression decreased TNBC cell growth, self-renewal, migration, invasiveness and paclitaxel resistance repressing WNT/βcatenin and AKT signaling pathways and stemness regulators. We identified SPINDLIN1 (SPIN1) among predicted miR-29b- 1-5p targets. Consistently, SPIN1 was overexpressed in most TNBC tissues and cell lines and negatively correlated with miR-29b-1-5p. Target site inhibition showed that SPIN1 seems to be directly controlled by miR-29b-1-5p. Silencing SPIN1 mirrored the effects triggered by miR-29b-1 overexpression, whereas SPIN1 rescue by SPIN1miScript protector, determined the reversal of the molecular effects produced by the mimic-miR-29b-1-5p. Overall, we show that miR-29b-1 deregulation impacts on multiple oncogenic features of TNBC cells and their renewal potential, acting, at least partly, through SPIN1, and suggest that both these factors should be evaluated as new possible therapeutic targets against TNBC., This study was partially funded by the European Regional Development Fund, European Territorial Cooperation 2007-2013, CCI 2007 CB 163 PO 037, OP Italia-Malta 2007-2013; the Italian Ministry of Education, University and Research (MIUR) ex-60%, 2013; R. Di Fiore and R. Drago-Ferrante were recipients of fellowships granted by the European Regional Development Fund, European Territorial Cooperation 2007-2013, CCI 2007 CB 163 PO 037, OP Italia-Malta 2007-2013; D. Carlisi was a recipient of a fellowship granted by MIUR (contract no. 82, January 23, 2014)., peer-reviewed

Osteosarcoma is a highly metastatic tumor affecting adolescents, for which there is no second-line chemotherapy. As suggested for most tumors, its capability to overgrow is probably driven by cancer stem cells (CSCs), and finding new targets to kill CSCs may be critical for improving patient survival. TP53 is the most frequently mutated tumor suppressor gene in cancers and mutant p53 protein (mutp53) can acquire gain of function (GOF) strongly contributing to malignancy. Studies thus far have not shown p53-GOF in osteosarcoma. Here, we investigated TP53 gene status/role in 3AB-OS cells-a highly aggressive CSC line previously selected from human osteosarcoma MG63 cells-to evaluate its involvement in promoting proliferation, invasiveness, resistance to apoptosis and stemness. By RT-PCR, methylation-specific PCR, fluorescent in situ hybridization, DNA sequence, western blot and immunofluorescence analyses, we have shown that-in comparison with parental MG63 cells where TP53 gene is hypermethylated, rearranged and in single copy-in 3AB-OS cells, TP53 is unmethylated, rearranged and in multiple copies, and mutp53 (p53-R248W/P72R) is post-translationally modified and with nuclear localization. p53-R248W/P72R-knockdown by short-interfering RNA reduced the growth and replication rate of 3AB-OS cells, markedly increasing cell cycle inhibitor levels and sensitized 3AB-OS cells to TRAIL-induced apoptosis by DR5 up-regulation; moreover, it strongly decreased the levels of stemness and invasiveness genes. We have also found that the ectopic expression of p53-R248W/P72R in MG63 cells promoted cancer stem-like features, as high proliferation rate, sphere formation, clonogenic growth, high migration and invasive ability; furthermore, it strongly increased the levels of stemness proteins. Overall, the findings suggest the involvement of p53-R248W/P72R at the origin of the aberrant characters of the 3AB-OS cells with the hypothesis that its GOF can be at the root of the dedifferentiation of MG63 cells into CSCs.

The sesquiterpene lactone parthenolide (PN) has recently attracted considerable attention because of its anti-microbial, anti-inflammatory and anticancer effects. However, the mechanism of its cytotoxic action on tumor cells remains scarcely defined. We recently provided evidence that the effect exerted by PN in MDA-MB-231 breast cancer cells was mediated by the production of reactive oxygen species (ROS). The present study shows that PN promoted the phosphorylation of EGF receptor (phospho-EGFR) at Tyr1173, an event which was observed already at 1 h of incubation with 25 µM PN and reached a peak at 8-16 h. This effect seemed to be a consequence of ROS production, because N-acetylcysteine (NAC), a powerful ROS scavenger, prevented the increment of phospho-EGFR levels. In addition fluorescence analyses performed using dihydroethidium demonstrated that PN stimulated the production of superoxide anion already at 2-3 h of incubation and the effect further increased prolonging the time of treatment, reaching a peak at 8-16 h. Superoxide anion production was markedly hampered by apocynin, a well known NADPH oxidase (NOX) inhibitor, suggesting that the effect was dependent on NOX activity. The finding that AG1478, an EGFR kinase inhibitor, substantially blocked both EGFR phosphorylation and superoxide anion production strongly suggested that phosphorylation of EGFR can be responsible for the activation of NOX with the consequent production of superoxide anion. Therefore, EGFR phosphorylation can exert a key role in the production of superoxide anion and ROS induced by PN in MDA-MB-231 cells.

The mechanism of the cytotoxic effect exerted by parthenolide on tumor cells is not clearly defined today. This article shows that parthenolide stimulates in human osteosarcoma MG63 and melanoma SK-MEL-28 cells a mechanism of cell death, which is not prevented by z-VAD-fmk and other caspase inhibitors. In particular treatment with parthenolide rapidly stimulated (1-2 h) reactive oxygen species (ROS) generation by inducing activation of extracellular signal-regulated kinase 1/2 (ERK 1/2) and NADPH oxidase. This event caused depletion of thiol groups and glutathione, NF-κB inhibition, c-Jun N-terminal kinase (JNK) activation, cell detachment from the matrix, and cellular shrinkage. The increase of ROS generation together with the mitochondrial accumulation of Ca(2+) also favored dissipation of Δψm, which seemed primarily determined by permeability transition pore opening, since Δψm loss was partially prevented by the inhibitor cyclosporin A. Staining with Hoechst 33342 revealed in most cells, at 3-5 h of treatment, chromatin condensation, and fragmentation, while only few cells were propidium iodide (PI)-positive. In addition, at this stage apoptosis inducing factor (AIF) translocated to the nucleus and co-localized with areas of condensed chromatin. Prolonging the treatment (5-15 h) ATP content declined while PI-positive cells strongly augmented, denouncing the increase of necrotic effects. All these effects were prevented by N-acetylcysteine, while caspase inhibitors were ineffective. We suggest that AIF exerts a crucial role in parthenolide action. In accordance, down-regulation of AIF markedly inhibited parthenolide effect on the production of cells with apoptotic or necrotic signs. Taken together our results demonstrate that parthenolide causes in the two cell lines a caspase-independent cell death, which is mediated by AIF.

Osteosarcoma (OS), an aggressive highly invasive and metastatic bone-malignancy, shows therapy resistance and recurrence, two features that likely depend on cancer stem cells (CSCs), which hold both self-renewing and malignant potential. So, effective anticancer therapies against OS should specifically target and destroy CSCs. We previously found that the let-7d microRNA was downregulated in the 3AB-OS-CSCs, derived from the human OS-MG63 cells. Here, we aimed to assess whether let-7d modulation affected tumorigenic and stemness properties of these OS-CSCs. We found that let-7d-overexpression reduced cell proliferation by decreasing CCND2 and E2F2 cell-cycle-activators and increasing p21 and p27 CDK-inhibitors. Let-7d also decreased sarcosphere-and-colony forming ability, two features associated with self-renewing, and it reduced the expression of stemness genes, including Oct3/4, Sox2, Nanog, Lin28B, and HMGA2. Moreover, let-7d induced mesenchymal-to-epithelial-transition, as shown by both N-Cadherin-E-cadherin-switch and decrease in vimentin. Surprisingly, such switch was accompanied by enhanced migratory/invasive capacities, with a strong increase in MMP9, CXCR4 and VersicanV1. Let-7d- overexpression also reduced cell sensitivity to apoptosis induced by both serum-starvation and various chemotherapy drugs, concomitant with decrease in caspase-3 and increase in BCL2 expression. Our data suggest that let-7d in 3AB-OS-CSCs could induce plastic-transitions from CSCs-to-non-CSCs and vice-versa. To our knowledge this is the first study to comprehensively examine the expression and functions of let-7d in OS-CSCs. By showing that let-7d has both tumor suppressor and oncogenic functions in this context, our findings suggest that, before prospecting new therapeutic strategies based on let-7d modulation, it is urgent to better define its multiple functions. J. Cell. Physiol. 231: 1832-1841, 2016. © 2015 Wiley Periodicals, Inc.

Triple-negative breast cancer (TNBC) is a clinically aggressive form of breast cancer that is unresponsive to endocrine agents or trastuzumab. TNBC accounts for ~10-20% of all breast cancer cases and represents the form with the poorest prognosis. Patients with TNBC are at higher risk of early recurrence, mainly in the lungs, brain and soft tissue, therefore, there is an urgent need for new therapies. The present study was carried out in MDA-MB-231 cells, where we assessed the role of caspase-8 (casp-8), a critical effector of death receptors, also involved in non‑apoptotic functions. Analysis of casp-8 mRNA and protein levels indicated that they were up-regulated with respect to the normal human mammalian epithelial cells. We demonstrated that silencing of casp-8 by small interfering-RNA, strongly decreased MDA-MB-231 cell growth by delaying G0/G1- to S-phase transition and increasing p21, p27 and hypo-phosphorylated/active form of pRb levels. Surprisingly, casp-8-knockdown, also potently increased both the migratory and metastatic capacity of MDA-MB‑231 cells, as shown by both wound healing and Matrigel assay, and by the expression of a number of related-genes and/or proteins such as VEGFA, C-MYC, CTNNB1, HMGA2, CXCR4, KLF4, VERSICAN V1 and MMP2. Among these, KLF4, a transcriptional factor with a dual role (activator and repressor), seemed to play critical roles. We suggest that in MDA-MB‑231 cells, the endogenous expression of casp-8 might keep the cells perpetually cycling through downregulation of KLF4, the subsequent lowering of p21 and p27, and the inactivation by hyperphosphorylation of pRb. Simultaneously, by lowering the expression of some migratory and invasive genes, casp-8 might restrain the metastatic ability of the cells. Overall, our findings showed that, in MDA-MB-231 cells, casp-8 might play some unusual roles which should be better explored, in order to understand whether it might be identified as a molecular therapeutic target.

Osteosarcoma is the second leading cause of cancer-related death for children and young adults. In this study, we have subcutaneously injected—with and without matrigel—athymic mice (Fox1nu/nu) with human osteosarcoma 3AB-OS pluripotent cancer stem cells (CSCs), which we previously isolated from human osteosarcoma MG63 cells. Engrafted 3AB-OS cells were highly tumorigenic and matrigel greatly accelerated both tumor engraftment and growth rate. 3AB-OS CSC xenografts lacked crucial regulators of beta-catenin levels (E-cadherin, APC, and GSK-3beta), and crucial factors to restrain proliferation, resulting therefore in a strong proliferation potential. During the first weeks of engraftment 3AB-OS-derived tumors expressed high levels of pAKT, beta1-integrin and pFAK, nuclear beta-catenin, c-Myc, cyclin D2, along with high levels of hyperphosphorylated-inactive pRb and anti-apoptotic proteins such as Bcl-2 and XIAP, and matrigel increased the expression of proliferative markers. Thereafter 3AB-OS tumor xenografts obtained with matrigel co-injection showed decreased proliferative potential and AKT levels, and undetectable hyperphosphorylated pRb, whereas beta1-integrin and pFAK levels still increased. Engrafted tumor cells also showed multilineage commitment with matrigel particularly favoring the mesenchymal lineage. Concomitantly, many blood vessels and muscle fibers appeared in the tumor mass. Our findings suggest that matrigel might regulate 3AB-OS cell behavior providing adequate cues for transducing proliferation and differentiation signals triggered by pAKT, beta1-integrin, and pFAK and addressed by pRb protein. Our results provide for the first time a mouse model that recapitulates in vivo crucial features of human osteosarcoma CSCs that could be used to test and predict the efficacy in vivo of novel therapeutic treatments.

BACKGROUND: The present study is the first effort in a comprehensive evaluation of the nutritive and biological properties of the meal from Rapa Catozza Napoletana (RCN) (Brassica rapa L. var. rapa) cultivar seeds as a new and alternative source of proteins. RESULTS: RCN seed meal revealed a good protein content (382.0 g kg−1) compared with conventional Brassica defatted meals. Total glucosinolates (6.0 g kg−1) were comparable to or even lower than those reported for other yellow- and brown-seeded cultivars. Low levels of both sinapine and phytic acid (10.0 and 10.0 g kg−1 respectively) suggest a minor influence of these compounds on meal mineral availability. The meal revealed quite a high polyphenolic content (13.0 g kg−1) composed of flavonol and hydroxycinnamic derivatives. With regard to meal biological properties, a higher radical-scavenging potential than reducing capacity and a broad antimicrobial spectrum, mainly against food-borne pathogens, were detected. CONCLUSION: RCN seed meal could be highly regarded as a component of human nutrition and animal feed for its good protein content, desirable amino acid profile and low antinutrient concentration. Results for the sample indicated appreciable antiradical activity and good properties for meal stability. Copyright © 2011 Society of Chemical Industry