184 research outputs found

    BET protein inhibition sensitizes glioblastoma cells to temozolomide treatment by attenuating MGMT expression

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    Bromodomain and extra-terminal tail (BET) proteins have been identified as potential epigenetic targets in cancer, including glioblastoma. These epigenetic modifiers link the histone code to gene transcription that can be disrupted with small molecule BET inhibitors (BETi). With the aim of developing rational combination treatments for glioblastoma, we analyzed BETi-induced differential gene expression in glioblastoma derived-spheres, and identified 6 distinct response patterns. To uncover emerging actionable vulnerabilities that can be targeted with a second drug, we extracted the 169 significantly disturbed DNA Damage Response genes and inspected their response pattern. The most prominent candidate with consistent downregulation, was the O-6-methylguanine-DNA methyltransferase (MGMT) gene, a known resistance factor for alkylating agent therapy in glioblastoma. BETi not only reduced MGMT expression in GBM cells, but also inhibited its induction, typically observed upon temozolomide treatment. To determine the potential clinical relevance, we evaluated the specificity of the effect on MGMT expression and MGMT mediated treatment resistance to temozolomide. BETi-mediated attenuation of MGMT expression was associated with reduction of BRD4- and Pol II-binding at the MGMT promoter. On the functional level, we demonstrated that ectopic expression of MGMT under an unrelated promoter was not affected by BETi, while under the same conditions, pharmacologic inhibition of MGMT restored the sensitivity to temozolomide, reflected in an increased level of Îł-H2AX, a proxy for DNA double-strand breaks. Importantly, expression of MSH6 and MSH2, which are required for sensitivity to unrepaired O6-methylguanine-lesions, was only briefly affected by BETi. Taken together, the addition of BET-inhibitors to the current standard of care, comprising temozolomide treatment, may sensitize the 50% of patients whose glioblastoma exert an unmethylated MGMT promoter

    Development of a video-assisted thoracoscopic lobectomy program in a single institution: Results before and after completion of the learning curve

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    BACKGROUND: The development of a video assisted thoracic surgery lobectomy (VATS-L) program provides a dedicated surgical team with a recognized learning curve (LC) of 50 procedures. We analyse the results of our program, comparing the LC with subsequent cases. METHODS: From June 2012 to March 2015, we performed n = 146 VATS major pulmonary resections: n = 50 (Group A: LC); n = 96 (Group B). Pre-operative mediastinal staging followed the National Comprehensive Cancer Network guidelines. All procedures were performed using a standard anterior approach to the hilum; lymphadenectomy followed the NCCN recommendations. During the LC, VATS-L indication was reserved to clinical stages I, therefore evaluated case by case. RESULTS: Mean operative time was 191 min (120-290) in Group A and 162 min (85-360) in Group B (p <0,01). Pathological T status was similar between two Groups. Lymphadenectomy included a mean of 5.8 stations in Group A and 6.6 in Group B resulting in: pN0 disease: Group A n = 44 (88 %), Group B n = 80 (83.4 %); pN1: Group A n = 3 (6 %), Group B n = 8 (8.3 %); pN2: Group A n = 3 (6 %), Group B n = 8 (8.3 %). Conversion rate was: 8 % in group A (n = 4 vascular injuries); 1.1 % in Group B (n = 1 hilar lymph node disease). We registered n = 6 (12 %) complications in Group A, n = 10 (10.6 %) in Group B. One case (1.1 %) of late post-operative mortality (90 days) was registered in Group B for liver failure. Mean hospital stay was 6.5 days in Group A and 5.9 days in Group B. CONCLUSIONS: We confirm the effectiveness of a VATS-L program with a learning curve of 50 cases performed by a dedicated surgical team. Besides the LC, conversion rate falls down, lymphadenectomy become more efficient, indications can be extended to upper stages

    BMP-2 Variants in Breast Epithelial to Mesenchymal Transition and Microcalcifications Origin

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    This study aims to investigate the possible different roles of the BMP-2 variants, cytoplasmic and nuclear variant, in both epithelial to mesenchymal transition and in microcalcifications origin in human breast cancers. To this end, the in situ expression of cytoplasmic and nuclear BMP-2 was associated with the expression of the main epithelial to mesenchymal transition biomarkers (e-cadherin and vimentin) and molecules involved in bone metabolisms (RUNX2, RANKL, SDF-1) by immunohistochemistry. In addition, the expression of cytoplasmic and nuclear BMP-2 was associated with the presence of microcalcifications. Our data showed a significant association among the number of cytoplasmic BMP-2-positive cells and the number of both vimentin (positive association) and e-cadherin (negative association) positive breast cells. Conversely, no associations were found concerning the nuclear BMP-2-positive breast cells. Surprisingly, the opposite result was obtained by analyzing the variants of BMP-2 and both the expression of RANKL and SDF-1 and the presence of microcalcifications. Specifically, the presence of microcalcifications was related to the expression of nuclear BMP-2 variant rather than the cytoplasmic one, as well as a strong association between the number of nuclear BMP-2 and the expression of the main breast osteoblast-like cells (BOLCs) biomarkers. To further corroborate these data, an in vitro experiment for demonstrating the co-expression of nBMP-2 and RANKL or vimentin or SDF-1 in breast cancer cells that acquire the capability to produce microcalcifications was developed. These investigations confirmed the association between the nBMP-2 expression and both RANKL and SDF-1. The data supports the idea that whilst cytoplasmic BMP-2 can be involved in epithelial to mesenchymal transition phenomenon, the nuclear variant is related to the essential mechanisms for the formation of breast microcalcifications. In conclusion, from these experimental and translational perspectives, the complexity of BMP-2 signaling will require a detailed understanding of the involvement of specific BMP-2 variants in breast cancers

    The REShiP Project: Renewable Energy for Ship Propulsion

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    In recent years the acknowledgement of the relations between the emissions of exhaust gas, in particular CO2, and their effects on climate and environment has grown to a wide level. Many countries and international organizations have begun to work to mitigate the problem and drive the society towards more sustainable sources of energy. Shipping is no exception and in 2018 the IMO – International Maritime Organization set the ambitious goal of reducing the CO2 emissions of the shipping industries of at least 50% within 2050, compared to the levels of 2008. This has introduced the need to research and develop new, sustainable energy sources and power systems for ships. The REShiP projects is aimed to identify a type of ship which would be suitable for an early adoption of a carbon free or carbon neutral fuel and a matching power generation system, tailored on specific routes. A small ferry powered by a hybrid combination of liquid hydrogen-fuelled fuel cells and Lithium-ion batteries has thus been identified. A mathematical model was developed to optimize the usage of fuel cell and batteries based on the ship operative profile. A multi objective optimization was implemented to minimize system performance degradation. To support the mathematical model a 7 kW PEMFC power generating unit was assembled and relevant data have been analysed. Following a regulatory framework research and in lack of comprehensive prescriptive rules, the design of the ferry and the prototype was done in accordance with the alternative design approach based on the risk assessment methodology, reaching a level of confidence appropriate to award an approval in principle

    VEGF-induced intracellular Ca2+ oscillations are down-regulated and do not stimulate angiogenesis in breast cancer-derived endothelial colony forming cells.

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    Endothelial colony forming cells (ECFCs) represent a population of truly endothelial precursors that promote the angiogenic switch in solid tumors, such as breast cancer (BC). The intracellular Ca2+ toolkit, which drives the pro-angiogenic response to VEGF, is remodelled in tumor-associated ECFCs such that they are seemingly insensitive to this growth factor. This feature could underlie the relative failure of anti-VEGF therapies in cancer patients. Herein, we investigated whether and how VEGF uses Ca2+ signalling to control angiogenesis in BC-derived ECFCs (BCECFCs). Although VEGFR-2 was normally expressed, VEGF failed to induce proliferation and in vitro tubulogenesis in BC-ECFCs. Likewise, VEGF did not trigger robust Ca2+ oscillations in these cells. Similar to normal cells, VEGF-induced intracellular Ca2+ oscillations were triggered by inositol-1,4,5-trisphosphate-dependent Ca2+ release from the endoplasmic reticulum (ER) and maintained by store-operated Ca2+ entry (SOCE). However, InsP3-dependent Ca2+ release was significantly lower in BC-ECFCs due to the down-regulation of ER Ca2+ levels, while there was no remarkable difference in the amplitude, pharmacological profile and molecular composition of SOCE. Thus, the attenuation of the pro-angiogenic Ca2+ response to VEGF was seemingly due to the reduction in ER Ca2+ concentration, which prevents VEGF from triggering robust intracellular Ca2+ oscillations. However, the pharmacological inhibition of SOCE prevented BC-ECFC proliferation and in vitro tubulogenesis. These findings demonstrate for the first time that BC-ECFCs are insensitive to VEGF, which might explain at cellular and molecular levels the failure of anti-VEGF therapies in BC patients, and hint at SOCE as a novel molecular target for this disease

    Roles of Tumor-Educated Platelets (TEPs) in the biology of Non-Small Cell Lung Cancer (NSCLC): A systematic review. “Re-discovering the neglected biosources of the liquid biopsy family”

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    Due to their interactions with the neoplasm, platelets undergo various proteomic and transcriptomic modifica&#x2;tions, resulting in the development of what is known as the “Tumor-Educated Platelets (TEPs) phenotype”. Consequently, in addition to their suitability for Liquid Biopsy (LB) applications, they play a pivotal role in the malignancy by communicating with Circulating Tumor Cells (CTCs), Tumor Microenvironment (TME), and the tumor itself through multiple mechanisms and at multiple levels, ultimately promoting the metastasis of cancer. Therefore, this Systematic Review of MEDLINE and the Cochrane Library present in-depth insights into these phenomena, with the aim of enhancing the understanding of the complex interplay between TEPs and Non-Small Cell Lung Cancer (NSCLC). This endeavor serves to provide context and drive medical research efforts, which are increasingly focused on developing novel diagnostic and therapeutic technologies that leverage the specific binding of these platelets to the disease

    PolΞ: emerging synthetic lethal partner in homologous recombination-deficient tumors

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    The most remarkable finding in synthetic lethality (SL) is the hypersensitivity to PARP inhibitors (PARPis) of the tumors harboring defects in genes involved in homologous repair (HR) such as BRCA1/2. Despite initial responsiveness to PARPi, the penetrance of the synthetic lethal interactions between BRCA1/2 genes and PARPi is incomplete. Thus, a significant proportion of HR-defective tumors experience intrinsic or acquired resistance, representing a key challenge of clinical research. An expanded concept of SL is opening new ways and includes novel forms of genetic interactions, investigating not only traditional SL of pairs genes but also SL between biological pathways that regulate the same essential survival cell function. In this context, recent research showed that HR and theta-mediated end-joining (TMEJ) pathways exhibit SL. DNA polymerase theta (Pol theta) is encoded by the POLQ gene and is a key component of the TMEJ, an essential backup pathway, intrinsically mutagenic, to repair resected double-strand breaks (DSBs) when the non-homologous end joining (NHEJ) and HR are impaired. Pol theta is broadly expressed in normal tissues, overexpressed in several cancers, and typically associated with poor outcomes and shorter relapse-free survival. Notably, HR-deficient tumor cells present the characteristic mutational signatures of the error-prone TMEJ pathway. According to this observation, the loss of HR proteins, such as BRCA1 or BRCA2, contributes to increasing the TMEJ-specific genomic profile, suggesting synthetic lethal interactions between loss of the POLQ and HR genes, and resulting in the emerging interest for Pol theta as a potential therapeutic target in BRCA1/2-associated tumors.This review summarizes the converging roles of the POLQ and HR genes in DNA DSB repair, the early-stage clinical trials using Pol theta inhibitor to treat HR-defective tumors and to overcome BRCA-reversion mutations responsible for therapeutic resistance, and the novel pleiotropic effects of Pol theta, paving the way for the development of unexplored synthetic lethality strategies
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