1,089 research outputs found

    Amplified and Homozygously Deleted Genes in Glioblastoma: Impact on Gene Expression Levels

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    This is an open-access article distributed under the terms of the Creative Commons Attribution License.-- et al.[Background]: Glioblastoma multiforme (GBM) displays multiple amplicons and homozygous deletions that involve relevant pathogenic genes and other genes whose role remains unknown. [Methodology]: Single-nucleotide polymorphism (SNP)-arrays were used to determine the frequency of recurrent amplicons and homozygous deletions in GBM (n = 46), and to evaluate the impact of copy number alterations (CNA) on mRNA levels of the genes involved. [Principal Findings]: Recurrent amplicons were detected for chromosomes 7 (50%), 12 (22%), 1 (11%), 4 (9%), 11 (4%), and 17 (4%), whereas homozygous deletions involved chromosomes 9p21 (52%) and 10q (22%). Most genes that displayed a high correlation between DNA CNA and mRNA levels were coded in the amplified chromosomes. For some amplicons the impact of DNA CNA on mRNA expression was restricted to a single gene (e.g., EGFR at 7p11.2), while for others it involved multiple genes (e.g., 11 and 5 genes at 12q14.1-q15 and 4q12, respectively). Despite homozygous del(9p21) and del(10q23.31) included multiple genes, association between these DNA CNA and RNA expression was restricted to the MTAP gene. [Conclusions]: Overall, our results showed a high frequency of amplicons and homozygous deletions in GBM with variable impact on the expression of the genes involved, and they contributed to the identification of other potentially relevant genes.This work was partially supported by Fundação para a Ciência e a Tecnologia, Portugal [FCT PIC/IC/83108/2007]; PhD fellowships from Fundação para a Ciência e a Tecnologia, Portugal [SFRH/BD/23086/2005, SFRH/BD/11820/2003]; Fundación Mutua Madrileña, Madrid, Spain [AP87692011]; and Instituto de Salud Carlos III, Ministerio de Ciencia e Innovación, Madrid, Spain [RTICC RD06/0020/0035].Peer Reviewe

    Biomarker analysis beyond angiogenesis: RAS/RAF mutation status, tumour sidedness, and second-line ramucirumab efficacy in patients with metastatic colorectal carcinoma from RAISE-a global phase III study

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    Carcinoma colorrectal; Ramucirumab; BRAFCarcinoma colorrectal; Ramucirumab; BRAFColorectal carcinoma; Ramucirumab; BRAFBackground Second-line treatment with ramucirumab+FOLFIRI improved overall survival (OS) versus placebo+FOLFIRI for patients with metastatic colorectal carcinoma (CRC) [hazard ratio (HR)=0.84, 95% CI 0.73–0.98, P = 0.022]. Post hoc analyses of RAISE patient data examined the association of RAS/RAF mutation status and the anatomical location of the primary CRC tumour (left versus right) with efficacy parameters. Patients and methods Patient tumour tissue was classified as BRAF mutant, KRAS/NRAS (RAS) mutant, or RAS/BRAF wild-type. Left-CRC was defined as the splenic flexure, descending and sigmoid colon, and rectum; right-CRC included transverse, ascending colon, and cecum. Results RAS/RAF mutation status was available for 85% of patients (912/1072) and primary tumour location was known for 94.4% of patients (1012/1072). A favourable and comparable ramucirumab treatment effect was observed for patients with RAS mutations (OS HR = 0.86, 95% CI 0.71–1.04) and patients with RAS/BRAF wild-type tumours (OS HR = 0.86, 95% CI 0.64–1.14). Among the 41 patients with BRAF-mutated tumours, the ramucirumab benefit was more notable (OS HR = 0.54, 95% CI 0.25–1.13), although, as with the other genetic sub-group analyses, differences were not statistically significant. Progression-free survival (PFS) data followed the same trend. Treatment-by-mutation status interaction tests (OS P = 0.523, PFS P = 0.655) indicated that the ramucirumab benefit was not statistically different among the mutation sub-groups, although the small sample size of the BRAF group limited the analysis. Addition of ramucirumab to FOLFIRI improved left-CRC median OS by 2.5 month over placebo (HR = 0.81, 95% CI 0.68–0.97); median OS for ramucirumab-treated patients with right-CRC was 1.1 month over placebo (HR = 0.97, 95% CI 0.75–1.26). The treatment-by-sub-group interaction was not statistically significant for tumour sidedness (P = 0.276). Conclusions In the RAISE study, the addition of ramucirumab to FOLFIRI improved patient outcomes, regardless of RAS/RAF mutation status, and tumour sidedness. Ramucirumab treatment provided a numerically substantial benefit in BRAF-mutated tumours, although the P-values were not statistically significant.This work was supported by Eli Lilly and Company. No grant number is applicable

    Testing the chemical tagging technique with open clusters

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    Context. Stars are born together from giant molecular clouds and, if we assume that the priors were chemically homogeneous and well-mixed, we expect them to share the same chemical composition. Most of the stellar aggregates are disrupted while orbiting the Galaxy and most of the dynamic information is lost, thus the only possibility of reconstructing the stellar formation history is to analyze the chemical abundances that we observe today. Aims. The chemical tagging technique aims to recover disrupted stellar clusters based merely on their chemical composition. We evaluate the viability of this technique to recover co-natal stars that are no longer gravitationally bound. Methods. Open clusters are co-natal aggregates that have managed to survive together. We compiled stellar spectra from 31 old and intermediate-age open clusters, homogeneously derived atmospheric parameters, and 17 abundance species, and applied machine learning algorithms to group the stars based on their chemical composition. This approach allows us to evaluate the viability and efficiency of the chemical tagging technique. Results. We found that stars at different evolutionary stages have distinct chemical patterns that may be due to NLTE effects, atomic diffusion, mixing, and biases. When separating stars into dwarfs and giants, we observed that a few open clusters show distinct chemical signatures while the majority show a high degree of overlap. This limits the recovery of co-natal aggregates by applying the chemical tagging technique. Nevertheless, there is room for improvement if more elements are included and models are improved.Comment: accepted for publication in Astronomy and Astrophysics. Corrected typo

    Association between inflammatory infiltrates and isolated monosomy 22/del(22q) in meningiomas

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    This is an open-access article distributed under the terms of the Creative Commons Attribution License.-- et al.Meningiomas contain highly variable levels of infiltrating tissue macrophages (TiMa) and other immune cells. In this study we investigated the potential association between the number and immunophenotype of inflammatory and other immune cells infiltrating the tumor as evaluated by multiparameter flow cytometry, and the clinico-biological, cytogenetic and gene expression profile (GEP) of 75 meningioma patients. Overall, our results showed a close association between the amount and cellular composition of the inflammatory and other immune cell infiltrates and the cytogenetic profile of the tumors. Notably, tumors with isolated monosomy 22/del(22q) showed greater numbers of TiMa, NK cells and (recently)-activated CD69+ lymphocytes versus meningiomas with diploid and complex karyotypes. In addition, in the former cytogenetic subgroup of meningiomas, tumor-infiltrating TiMa also showed a more activated and functionally mature phenotype, as reflected by a greater fraction of CD69+, CD63+, CD16+ and CD33+ cells. GEP at the mRNA level showed a unique GEP among meningiomas with an isolated monosomy 22/del(22q) versus all other cases, which consisted of increased expression of genes involved in inflammatory/immune response, associated with an M1 TiMa phenotype. Altogether, these results suggest that loss of expression of specific genes coded in chromosome 22 (e.g. MIF) is closely associated with an increased homing and potentially also anti-tumoral effect of TiMa, which could contribute to explain the better outcome of this specific good-prognosis cytogenetic subgroup of meningiomas.This work was partially supported by grants from the Fundação para a Ciência e Tecnologia (PIC/IC/83108/2007, FCT, Portugal), Fondo de Investigaciones Sanitarias (FIS/FEDER 06/0312 and RETICC RD06/0020/0035, Instituto de Salud Carlos III, Ministerio de Sanidad y Consumo, Madrid, Spain), Caja Burgos (Spain), and Fundación MMA (exp 75312010 and 87692011, Madrid, Spain). Patrícia Domingues is supported by grant (SFRH/BD/64799/2009) from FCT. Maria Dolores Tabernero is supported by IECSCYL (Soria, Spain).Peer Reviewe

    Genetic/molecular alterations of meningiomas and the signaling pathways targeted

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    This is an open-access article distributed under the terms of the Creative Commons Attribution License.-- et al.Meningiomas are usually considered to be benign central nervous system tumors; however, they show heterogenous clinical, histolopathological and cytogenetic features associated with a variable outcome. In recent years important advances have been achieved in the identification of the genetic/molecular alterations of meningiomas and the signaling pathways involved. Thus, monosomy 22, which is often associated with mutations of the NF2 gene, has emerged as the most frequent alteration of meningiomas; in addition, several other genes (e.g. AKT1, KLF4, TRAF7, SMO) and chromosomes have been found to be recurrently altered often in association with more complex karyotypes and involvement of multiple signaling pathways. Here we review the current knowledge about the most relevant genes involved and the signaling pathways targeted by such alterations. In addition, we summarize those proposals that have been made so far for classification and prognostic stratification of meningiomas based on their genetic/genomic features.This work was partially supported by grants from the Fundação para a Ciência e Tecnologia (PIC/IC/83108/2007, FCT, Portugal), Fondo de Investigaciones Sanitarias (RD12/0036/0048, Instituto de Salud Carlos III (ISCIII/FEDER), Ministerio de Sanidad y Consumo, Madrid, Spain), and Consejeria Sanidad Junta de Castilla y León, Gerencia Regional de Salud: GRS689/A/11, and Proyecto Intramural-IBSAL IB14-05. Patrícia Domingues is partially supported by a grant (SFRH/BD/64799/2009) from FCT. Maria Dolores Tabernero is supported by IECSCYL (Soria, Spain).Peer Reviewe

    Advances in the systemic treatment of therapeutic approaches in biliary tract cancer

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    Biliary tract cancer; Molecular testing; Next-generation sequencingCáncer del tracto biliar; Pruebas moleculares; Secuenciación de nueva generaciónCàncer del tracte biliar; Proves moleculars; Seqüenciació de nova generacióIntroduction Biliary tract cancers (BTCs) are a rare and heterogenous group with an increasing incidence and high mortality rate. The estimated new cases and deaths of BTC worldwide are increasing, but the incidence and mortality rates in South East Asia are the highest worldwide, representing a real public health problem in these regions. BTC has a poor prognosis with a median overall survival <12 months. Thus, an urgent unmet clinical need for BTC patients exists and must be addressed. Results The backbone treatment of these malignancies is chemotherapy in first- and second-line setting, but in the last decade a rich molecular landscape has been discovered, expanding conceivable treatment options. Some druggable molecular aberrations can be treated with new targeted therapies and have already demonstrated efficacy in patients with BTC, improving clinical outcomes, such as the FGFR2 or IDH1 inhibitors. Many other molecular alterations are being discovered and the treatment of BTC will change in the near future from our current clinical practice. Conclusions In this review we discuss the epidemiology, molecular characteristics, present treatment approaches, review the recent therapeutic advances, and explore future directions for patients with BTC. Due to the rich molecular landscape of BTC, molecular profiling should be carried out early. Ongoing research will bring new targeted treatments and immunotherapy in the near future

    Connexins in cancer: bridging the gap to the clinic

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    Gap junctions comprise arrays of intercellular channels formed by connexin proteins and provide for the direct communication between adjacent cells. This type of intercellular communication permits the coordination of cellular activities and plays key roles in the control of cell growth and differentiation and in the maintenance of tissue homoeostasis. After more than 50 years, deciphering the links among connexins, gap junctions and cancer, researchers are now beginning to translate this knowledge to the clinic. The emergence of new strategies for connexin targeting, combined with an improved understanding of the molecular bases underlying the dysregulation of connexins during cancer development, offers novel opportunities for clinical applications. However, different connexin isoforms have diverse channel-dependent and -independent functions that are tissue and stage specific. This can elicit both pro- and anti-tumorigenic effects that engender significant challenges in the path towards personalised medicine. Here, we review the current understanding of the role of connexins and gap junctions in cancer, with particular focus on the recent progress made in determining their prognostic and therapeutic potential
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