26 research outputs found

    Integrated analysis of mismatch repair system in malignant astrocytomas

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    This is an open-access article distributed under the terms of the Creative Commons Attribution License.-- et al.Malignant astrocytomas are the most aggressive primary brain tumors with a poor prognosis despite optimal treatment. Dysfunction of mismatch repair (MMR) system accelerates the accumulation of mutations throughout the genome causing uncontrolled cell growth. The aim of this study was to characterize the MMR system defects that could be involved in malignant astrocytoma pathogenesis. We analyzed protein expression and promoter methylation of MLH1, MSH2 and MSH6 as well as microsatellite instability (MSI) and MMR gene mutations in a set of 96 low- and high-grade astrocytomas. Forty-one astrocytomas failed to express at least one MMR protein. Loss of MSH2 expression was more frequent in low-grade astrocytomas. Loss of MLH1 expression was associated with MLH1 promoter hypermethylation and MLH1 -93G>A promoter polymorphism. However, MSI was not related with MMR protein expression and only 5% of tumors were MSI-High. Furthermore, the incidence of tumors carrying germline mutations in MMR genes was low and only one glioblastoma was associated with Lynch syndrome. Interestingly, survival analysis identified that tumors lacking MSH6 expression presented longer overall survival in high-grade astrocytoma patients treated only with radiotherapy while MSH6 expression did not modify the prognosis of those patients treated with both radiotherapy and chemotherapy. Our findings suggest that MMR system alterations are a frequent event in malignant astrocytomas and might help to define a subgroup of patients with different outcome.This work was supported by Fondo de Investigación Sanitaria (FIS PI 10/00219), Instituto de Estudios de Ciencias de la Salud de Castilla y León IECSCYL and Junta de Castilla y León y Fondo Social Europeo (Orden EDU/330/2008).Peer Reviewe

    Patterns of incidental perineural invasion and prognosis in cutaneous squamous cell carcinoma: A multicenter, retrospective cohort study

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    To the Editor: Perineural invasion (PNI) is rare and usually incidental in cutaneous squamous cell carcinoma (SCC), with an incidence of 2.5% to 14%.1 Incidental PNI is associated with poor prognosis in cutaneous SCC,2 and some evidence suggests its outcome differs, depending on the PNI pattern. We evaluated patterns of incidental PNI, using a multicenter retrospective cohort of 140 cutaneous SCCs with incidental PNI to determine the influence of nerve involvement on cutaneous SCC prognosis.Dr Canueto is partially supported ~ by grants PI18/000587 (Instituto de Salud Carlos III, cofinanced by Fondo Europeo de Desarrollo Regional) and GRS 1835/A/18 (Gerencia Regional de Salud de Castilla y Leon)

    Effect of mTORC1/mTORC2 inhibition on T cell function: potential role in graft-versus-host disease control

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    Producción CientíficaThe mechanistic target of rapamycin (mTOR) pathway is crucial for the activation and function of T cells, which play an essential role in the development of graft-versus-host disease (GvHD). Despite its partial ability to block mTOR pathway, the mTORC1 inhibitor rapamycin has shown encouraging results in the control of GvHD. Therefore, we considered that simultaneous targeting of both mTORC1 and mTORC2 complexes could exert a more potent inhibition of T cell activation and, thus, could have utility in GvHD control. To assess this assumption, we have used the dual mTORC1/mTORC2 inhibitors CC214-1 and CC214-2. In vitro studies confirmed the superior ability of CC214-1 versus rapamycin to block mTORC1 and mTORC2 activity and to reduce T cell proliferation. Both drugs induced a similar decrease in Th1/Th2 cytokine secretion, but CC214-1 was more efficient in inhibiting na€ıve T cell activation and the expression of Tcell activation markers. In addition, CC214-1 induced specific tolerance against alloantigens, while preserving anti-cytomegalovirus response. Finally, in a mouse model of GvHD, the administration of CC214-2 significantly improved mice survival and decreased GvHD-induced damages. In conclusion, the current study shows, for the first time, the immunosuppressive ability of CC214-1 on T lymphocytes and illustrates the role of CC214-2 in the allogeneic transplantation setting as a possible GvHD prophylaxis agent.Gerencia Regional de Salud de Castilla y León (Proyecto GRS 726/A13

    HCV-coinfection is related to an increased HIV-1 reservoir size in cART-treated HIV patients: a cross-sectional study

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    In HIV-1/HCV-coinfected patients, chronic HCV infection leads to an increased T-lymphocyte immune activation compared to HIV-monoinfected patients, thereby likely contributing to increase HIV-1 reservoir that is the major barrier for its eradication. Our objective was to evaluate the influence of HCV coinfection in HIV-1 viral reservoir size in resting (r) CD4+ T-cells (CD25-CD69-HLADR-). Multicenter cross-sectional study of 97 cART-treated HIV-1 patients, including 36 patients with HIV and HCV-chronic co-infection without anti-HCV treatment, 32 HIV patients with HCV spontaneous clearance and 29 HIV-monoinfected patients. rCD4+ T-cells were isolated and total DNA was extracted. HIV viral reservoir was measured by Alu-LTR qPCR. Differences between groups were calculated with a generalized linear model. Overall, 63.9% were men, median age of 41 years and Caucasian. Median CD4+ and CD8+ T-lymphocytes were 725 and 858 cells/mm 3 , respectively. CD4+ T nadir cells was 305 cells/mm 3 . Proviral HIV-1 DNA size was significantly increased in chronic HIV/HCV-coinfected compared to HIV-monoinfected patients (206.21 ± 47.38 vs. 87.34 ± 22.46, respectively; P = 0.009), as well as in spontaneously clarified HCV co-infected patients when compared to HIV-monoinfected individuals (136.20 ± 33.20; P = 0.009). HIV-1/HCV co-infected patients showed a larger HIV-1 reservoir size in comparison to HIV-monoinfected individuals. This increase could lead to a greater complexity in the elimination of HIV-1 reservoir in HIV-1/HCV-coinfected individuals, which should be considered in the current strategies for the elimination of HIV-1 reservoir.Financial support was provided by the Instituto de Salud Carlos III to VB (PI15CIII/00031), by the Spanish Ministry of Economy and Competitiveness to MC (SAF2016–78480-R) and The SPANISH AIDS Research Network RD16CIII/0002/0001, RD16CIII/0002/0002 and RD16/0025/0013 - ISCIII – FEDER. MRLP is supported by ISCIII - Subdirección General de Evaluacion and European Funding for Regional Development (FEDER) (PIE 13/00040 and RD12/0017/0017 RETIC de SIDA). C.P. is supported by the Portuguese Fundação para a Ciência e Tecnologia (FCT) (grant number SFRH/ BPD/77448/2011 is part of the EDCTP2 programme supported by the European Union). V.B., A.F.R. and N.R. are supported by the Miguel Servet programme from Fondo de Investigación Sanitaria (ISCIII) (grant number CP13/00098, CP14/CIII/00010 and CP14/00198, respectively)

    Targeting of PI3K/AKT/mTOR pathway to inhibit T cell activation and prevent graft-versus-host disease development

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    Producción CientíficaBackground: Graft-versus-host disease (GvHD) remains the major obstacle to successful allogeneic hematopoietic stem cell transplantation, despite of the immunosuppressive regimens administered to control T cell alloreactivity. PI3K/AKT/mTOR pathway is crucial in T cell activation and function and, therefore, represents an attractive therapeutic target to prevent GvHD development. Recently, numerous PI3K inhibitors have been developed for cancer therapy. However, few studies have explored their immunosuppressive effect. Methods: The effects of a selective PI3K inhibitor (BKM120) and a dual PI3K/mTOR inhibitor (BEZ235) on human T cell proliferation, expression of activation-related molecules, and phosphorylation of PI3K/AKT/mTOR pathway proteins were analyzed. Besides, the ability of BEZ235 to prevent GvHD development in mice was evaluated. Results: Simultaneous inhibition of PI3K and mTOR was efficient at lower concentrations than PI3K specific targeting. Importantly, BEZ235 prevented naïve T cell activation and induced tolerance of alloreactive T cells, while maintaining an adequate response against cytomegalovirus, more efficiently than BKM120. Finally, BEZ235 treatment significantly improved the survival and decreased the GvHD development in mice. Conclusions: These results support the use of PI3K inhibitors to control T cell responses and show the potential utility of the dual PI3K/mTOR inhibitor BEZ235 in GvHD prophylaxis.Asociación Española Contra el Cáncer (Proyecto AIOA110296BLAN).Gerencia Regional de Salud de Castilla y León (Proyecto GRS 726/A13

    Cutaneous intraneural perineurioma: a case report

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    Perineuriomas are benign neoplasms composed of perineurial cells. Classically, perineuriomas are divided into 2 distinct clinicopathologic entities, known as intraneural and extraneural perineuriomas. Intraneural perineuriomas, first described as interstitial hypertrophic neuritis, involve the major nerve trunks, causing motor or sensory deficits. Here, we report a case of a 42-year-old man presenting a lesion on the second finger of the right hand. The patient did not refer any previous trauma, tenderness, or sensorial nerve deficit. Histologic analysis showed a plexiform dermal lesion composed of enlarged nerve fascicles due to proliferation of spindle perineurial cells, arranged in onion-bulb-like structures. The proliferating cells showed positive membranous staining for epithelial membrane antigen and were negative for S100 protein, which highlighted residual Schwann cells. Fluorescence in situ hybridization studies revealed the loss of one signal for chromosome 22 probe in 15% of the spindle cells. In our report, we present the first case of cutaneous intraneural perineurioma, a benign tumor, which expands the morphological spectrum of cutaneous neural lesions.Peer Reviewe
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