143 research outputs found

    KillerFLIP: A Novel Lytic Peptide Specifically Inducing Cancer Cell Death

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    One of the objectives in the development of effective cancer therapy is induction of tumor-selective cell death. Toward this end, we have identified a small peptide that, when introduced into cells via a TAT cell-delivery system, shows a remarkably potent cytoxicity in a variety of cancer cell lines and inhibits tumor growth in vivo, whereas sparing normal cells and tissues. This fusion peptide was named killer FLIP as its sequence was derived from the C-terminal domain of c-FLIP, an anti-apoptotic protein. Using structure activity analysis, we determined the minimal bioactive core of killerFLIP, namely killerFLIP-E. Structural analysis of cells using electron microscopy demonstrated that killerFLIP-E triggers cell death accompanied by rapid (within minutes) plasma membrane permeabilization. Studies of the structure of the active core of killer FLIP (-E) indicated that it possesses amphiphilic properties and self-assembles into micellar structures in aqueous solution. The biochemical properties of killerFLIP are comparable to those of cationic lytic peptides, which participate in defense against pathogens and have also demonstrated anticancer properties. We show that the pro-cell death effects of killer FLIP are independent of its sequence similarity with c-FLIP L as killer FLIP-induced cell death was largely apoptosis and necroptosis independent. A killer FLIP-E variant containing a scrambled c-FLIP L motif indeed induced similar cell death, suggesting the importance of the c-FLIP L residues but not of their sequence. Thus, we report the discovery of a promising synthetic peptide with novel anticancer activity in vitro and in vivo.

    A multidisciplinary approach to the seismotectonics of the Lunigiana and Garfagnana extensional basins (Northern Tuscany, Italy)

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    New geological and morpho-structural surveys are integrated with seismological and seismic reflection data in order to define the active and potentially seismogenic sources of the Lunigiana and Garfagnana extensional basins (Tuscany, Northern Italy). The seismogenic role of the E-W-striking transfer fault between the Lunigiana and Garfagnana basins, located at the northern termination of the Apuane metamorphic core, and its possible association with a number of historical earthquakes are also discussed

    Cannibalism of Live Lymphocytes by Human Metastatic but Not Primary Melanoma Cells

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    The phenomenon of cell cannibalism, which generally refers to the engulfment of cells within other cells, was described in malignant tumors, but its biological significance is still largely unknown. In the present study, we investigated the occurrence, the in vivo relevance, and the underlying mechanisms of cannibalism in human melanoma. As first evidence, we observed that tumor cannibalism was clearly detectable in vivo in metastatic lesions of melanoma and often involved T cells, which could be found in a degraded state within tumor cells. Then, in vitro experiments confirmed that cannibalism of T cells was a property of metastatic melanoma cells but not of primary melanoma cells. In particular, morphologic analyses, including time-lapse cinematography and electron microscopy, revealed a sequence of events, in which metastatic melanoma cells were able to engulf and digest live autologous melanoma-specific CD8+ T cells. Importantly, this cannibalistic activity significantly increased metastatic melanoma cell survival, particularly under starvation condition, supporting the evidence that tumor cells may use the eating of live lymphocytes as a way to ‘‘feed’’ in condition of low nutrient supply. The mechanism underlying cannibalism involved a complex framework, including lysosomal protease cathepsin B activity, caveolae formation, and ezrin cytoskeleton integrity and function. In conclusion, our study shows that human metastatic melanoma cells may eat live T cells, which are instead programmed to kill them, suggesting a novel mechanism of tumor immune escape. Moreover, our data suggest that cannibalism may represent a sort of ‘‘feeding’’ activity aimed at sustaining survival and progression of malignant tumor cells in an unfavorable microenvironment. (Cancer Res 2006; 66(7): 3629-38

    Prognostic Relevance of Neutrophil to Lymphocyte Ratio (NLR) in Luminal Breast Cancer: A Retrospective Analysis in the Neoadjuvant Setting

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    The neutrophil to lymphocyte ratio (NLR) is a promising predictive and prognostic factor in breast cancer. We investigated its ability to predict disease-free survival (DFS) and overall survival (OS) in patients with luminal A- or luminal B-HER2-negative breast cancer who received neoadjuvant chemotherapy (NACT). Pre-treatment complete blood cell counts from 168 consecutive patients with luminal breast cancer were evaluated to assess NLR. The study population was stratified into NLRlow or NLRhigh according to a cut-off value established by receiving operator curve (ROC) analysis. Data on additional pre- and post-treatment clinical-pathological characteristics were also collected. Kaplan-Meier curves, log-rank tests, and Cox proportional hazards models were used for statistical analyses. Patients with pre-treatment NLRlow showed a significantly shorter DFS (HR: 6.97, 95% CI: 1.65-10.55, p = 0.002) and OS (HR: 7.79, 95% CI: 1.25-15.07, p = 0.021) compared to those with NLRhigh. Non-ductal histology, luminal B subtype, and post-treatment Ki67 ≥ 14% were also associated with worse DFS (p = 0.016, p = 0.002, and p = 0.001, respectively). In a multivariate analysis, luminal B subtype, post-treatment Ki67 ≥ 14%, and NLRlow remained independent prognostic factors for DFS, while only post-treatment Ki67 ≥ 14% and NLRlow affected OS. The present study provides evidence that pre-treatment NLRlow helps identify women at higher risk of recurrence and death among patients affected by luminal breast cancer treated with NACT

    Neoadjuvant immune-checkpoint blockade in triple-negative breast cancer: current evidence and literature-based meta-analysis of randomized trials

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    Chemotherapy based on the sequential use of anthracyclines and taxanes has long represented the most efficacious approach in the management of early-stage, triple-negative breast cancer, whose aggressive behavior is widely renowned. This standard chemotherapy backbone was subsequently enriched by the use of carboplatin, based on its association with increased pathologic complete response and efficacy in the metastatic setting. Following the results from the IMpassion130 trial, the recent approval of the immunotherapic agent atezolizumab in combination with chemotherapy as first-line treatment for programmed-death ligand 1-positive, unresectable locally advanced, or metastatic triple-negative breast cancer increasingly fueled the flourishing of trials of immune-checkpoint inhibitors in the early setting. In this work, we review the most recent inherent literature in light of key methodological issues and provide a quantitative summary of the results from phase II–III randomized trials of immunotherapic agents combined with chemotherapy in the setting of interest. Hints regarding future directions are also discussed
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