1,721,064 research outputs found

    Involvement of autophagy in ovarian cancer: a working hypothesis

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    Abstract Autophagy is a lysosomal-driven catabolic process that contributes to preserve cell and tissue homeostases through the regular elimination of damaged, aged and redundant self-constituents. In normal cells, autophagy protects from DNA mutation and carcinogenesis by preventive elimination of pro-oxidative mitochondria and protein aggregates. Mutations in oncogenes and oncosuppressor genes dysregulate autophagy. Up-regulated autophagy may confer chemo- and radio-resistance to cancer cells, and also a pro-survival advantage in cancer cells experiencing oxygen and nutrient shortage. This fact is the rationale for using autophagy inhibitors along with anti-neoplastic therapies. Yet, aberrant hyper-induction of autophagy can lead to cell death, and this phenomenon could also be exploited for cancer therapy. The actual level of autophagy in the cancer cell is greatly affected by vascularization, inflammation, and stromal cell infiltration. In addition, small non-coding microRNAs have recently emerged as important epigenetic modulators of autophagy. The present review focuses on the potential involvement of macroautophagy, and on its genetic and epigenetic regulation, in ovarian cancer pathogenesis and progression.</p

    High serum levels of Transforming Growth Factor-beta1, Interleukin-10 and Vascular Endothelial Growth Factor in pancreatic adenocarcinoma patients

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    BACKGROUND: Pancreatic adenocarcinomas are among the most aggressive types of cancer with an extremely poor diagnosis. Since this type of cancer is not well amenable to chemo- and radiotherapy or immunotherapy, surgical resection remains the only feasible treatment to date. Transforming Growth Factor (TGF)-beta and Interleukin (IL)-10 are potent immunomodulators that have been shown to suppress several aspects of the immune response. Vascular Endothelial Growth Factor (VEGF) is a powerful angiogenic factor, recently thought to be involved in neoangiogenesis and metastasis spreading. Therefore the three cytokines may contribute, by different pathways, to immune escape and growth of tumor. This study was conducted to determine the possible significance of TGF-beta1, IL-10 and VEGF as markers for monitoring the clinical course of pancreatic adenocarcinoma patients. METHODS: Cytokine serum levels were measured in 30 pancreatic cancer patients and in 30 age and sex-matched healthy subjects. RESULTS: In comparison to serum concentrations in controls, TGF-beta1, IL-10 and VEGF levels were significantly elevated in all patients. Where the patients were divided by groups on the basis of the clinical stage of the disease, no differences were observed in TGF-beta1 levels among the groups. On the contrary, IL-10 and VEGF were more represented in stage IV patients than in stage II and III patients. In addition, the 14 patients who underwent surgical resection had postoperative cytokine serum levels markedly lower than those observed at diagnosis. CONCLUSIONS: Overall, the results suggest the importance of these markers in predicting the biological activity of the disease and suggest new targets for future rational therapies

    Integrins in T Cell Physiology

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    From the thymus to the peripheral lymph nodes, integrin-mediated interactions with neighbor cells and the extracellular matrix tune T cell behavior by organizing cytoskeletal remodeling and modulating receptor signaling. LFA-1 (αLβ2 integrin) and VLA-4 (α4β1 integrin) play a key role throughout the T cell lifecycle from thymocyte differentiation to lymphocyte extravasation and finally play a fundamental role in organizing immune synapse, providing an essential costimulatory signal for the T cell receptor. Apart from tuning T cell signaling, integrins also contribute to homing to specific target organs as exemplified by the importance of α4β7 in maintaining the gut immune system. However, apart from those well-characterized examples, the physiological significance of the other integrin dimers expressed by T cells is far less understood. Thus, integrin-mediated cell-to-cell and cell-to-matrix interactions during the T cell lifespan still represent an open field of research

    p27Kip1 is inactivated in human colorectal cancer by cytoplasmic localization associated with activation of Akt/PKB

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    p27Kip1 is a nuclear member of the Kip/Cip family of cyclin-dependent kinase inhibitors and is a negative cell cycle regulator that is thought to play a role in tumour suppression. Reduced levels of p27Kip1 are frequent in human cancers and these have been associated with poor prognosis. We have analysed p27Kip1 expression and intracellular localization in 70 human colorectal cancers by western blotting and immunohistochemistry and the results related to Akt expression and clinical pathological parameters. p27Kip1 protein expression, as evaluated by western blotting, was absent or reduced in about 63% of colorectal cancers compared with both peritumoral and normal tissue. Cytoplasmic p27Kip1 was detected, by immunohistochemical analysis, in 30% (21 of 70) of cases indicating that translocation of p27Kip1 protein into the cytoplasm may be responsible for p27Kip1 inactivation. The analysis of phosphorylated Akt by western blotting indicated that it was expressed in 38% (8 of 21) of tumours showing cytoplasmic p27Kip1. Patients whose cancer presented accumulation of cytoplasmic p27Kip1 showed poorer outcomes for cancer-related relapse and survival. These results suggest that cytoplasmic p27Kip1 localization, associated or not with Akt activation, may contribute to colorectal tumorigenesis and metastasis and it may be useful as a negative prognostic factor for the outcome of patients with colorectal cancer
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