Publications by authors named "Laura Romero-Perez"

Article Synopsis
  • Ewing sarcoma (EwS) is a rare type of cancer that affects bones and soft tissues, caused by changes in chromosomes that lead to special proteins altering gene activity.
  • Scientists believe that variations in a specific part of the genome (6p25.1) might influence how this cancer develops by affecting gene expression.
  • They found that people with EwS often have longer DNA sequences at this spot, which enhance the cancer-fighting protein RREB1, leading to increased cell growth and division linked to the disease.
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Chromosomal instability (CIN) is a hallmark of cancer. Yet, many childhood cancers, such as Ewing sarcoma (EwS), feature remarkably 'silent' genomes with minimal CIN. Here, we show in the EwS model how uncoupling of mitosis and cytokinesis via targeting protein regulator of cytokinesis 1 (PRC1) or its activating polo-like kinase 1 (PLK1) can be employed to induce fatal genomic instability and tumor regression.

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Sarcomas are malignant soft tissue and bone tumours affecting adults, adolescents and children. They represent a morphologically heterogeneous class of tumours and some entities lack defining histopathological features. Therefore, the diagnosis of sarcomas is burdened with a high inter-observer variability and misclassification rate.

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Different methods have been described for the preservation of biopsy or resection samples. In the routine pathology, the cheapest and most commonly used is fixation of samples in formalin and embedding in paraffin (FFPE samples). This method preserves tissue samples for a very long time and is suitable for several specialized techniques such as fluorescence in situ hybridization (FISH) and immunohistochemistry, the latter being the most frequent and often the only additional method used for establishment of final diagnosis.

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Western blot is an experimental method used to analyze protein expression. In Ewing sarcoma, as in many other diseases, Western blot provides information about the level of protein expression in different cell conditions, in comparison with other tissues or upon induced molecular changes. Based on the specific pattern of protein expression of the tissue, as well as on the characteristics of the protein of interest, the antibodies and protocol of Western blot may be modified according to different specifications.

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Ewing sarcoma (EwS) is an aggressive childhood cancer likely originating from mesenchymal stem cells or osteo-chondrogenic progenitors. It is characterized by fusion oncoproteins involving EWSR1 and variable members of the ETS-family of transcription factors (in 85% FLI1). EWSR1-FLI1 can induce target genes by using GGAA-microsatellites as enhancers.

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Soft tissue sarcomas (STSs) are heterogeneous cancers associated with poor prognosis due to high rates of local recurrence and metastasis. The programmed death receptor ligand 1 (PD-L1) is expressed in several cancers. PD-L1 interacts with its receptor, PD-1, on the surface of tumor-infiltrating lymphocytes (TILs), thereby attenuating anti-cancer immune response.

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Ewing sarcoma (EwS) is an aggressive cancer displaying an undifferentiated small-round-cell histomorphology that can be easily confused with a broad spectrum of differential diagnoses. Using comparative transcriptomics and immunohistochemistry (IHC), we previously identified BCL11B and GLG1 as potential specific auxiliary IHC markers for -positive EwS. Herein, we aimed at validating the specificity of both markers in a far larger and independent cohort of EwS (including -positive cases) and differential diagnoses.

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YAP1 and TAZ (WWTR1) oncoproteins are the final transducers of the Hippo tumor suppressor pathway. Deregulation of the pathway leads to YAP1/TAZ activation fostering tumorigenesis in multiple malignant tumor types, including sarcoma. However, oncogenic mutations within the core components of the Hippo pathway are uncommon.

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Purpose: Uterine neoplasms comprise a broad spectrum of lesions, some of which may pose a diagnostic challenge even to experienced pathologists. Recently, genome-wide DNA methylation-based classification of central nervous system tumors has been shown to increase diagnostic precision in clinical practice when combined with standard histopathology. In this study, we describe DNA methylation patterns of a diverse set of uterine neoplasms and test the applicability of array-based DNA methylation profiling.

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In prostate adenocarcinoma (PCa), distinction between indolent and aggressive disease is challenging. Around 50% of PCa are characterized by TMPRSS2-ERG (T2E)-fusion oncoproteins defining two molecular subtypes (T2E-positive/negative). However, current prognostic tests do not differ between both molecular subtypes, which might affect outcome prediction.

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Pediatric malignancies including Ewing sarcoma (EwS) feature a paucity of somatic alterations except for pathognomonic driver-mutations that cannot explain overt variations in clinical outcome. Here, we demonstrate in EwS how cooperation of dominant oncogenes and regulatory germline variants determine tumor growth, patient survival and drug response. Binding of the oncogenic EWSR1-FLI1 fusion transcription factor to a polymorphic enhancer-like DNA element controls expression of the transcription factor MYBL2 mediating these phenotypes.

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Background: Up to 30-40% of Ewing sarcoma (EwS) patients with non-metastatic disease develop local or metastatic relapse within a time span of 2-10 years. This is in part caused by the absence of prognostic biomarkers that can identify high-risk patients and thus assign them to risk-adapted monitoring and treatment regimens. Since cancer stemness has been associated with tumour relapse and poor patient outcomes, we investigated in the current study the prognostic potential SOX2 (sex determining region Y box 2) - a major transcription factor involved in development and stemness - which was previously described to contribute to the undifferentiated phenotype of EwS.

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Stromal Antigen 1 and 2 (STAG1/2) are key subunits of the cohesin complex that mediate sister chromatid cohesion, DNA repair, transcriptional regulation, and genome topology. Genetic alterations comprising any of the 11 cohesin-associated genes possibly occur in up to 26% of patients included in The Cancer Genome Atlas (TCGA) studies. STAG2 shows the highest number of putative driver truncating mutations.

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Purpose: Recent studies revealed divergent gene expression patterns in Ewing sarcoma (EwS) with canonical EWSR1-ETS gene fusions and undifferentiated round cell sarcomas (URCS) with EWSR1 rearrangements fused to the non-ETS gene NFATc2. Thus, the question arises whether the latter tumors really belong to EwS.

Methods: We collected five cases matching the group of URCS with EWSR1-NFATc2 fusion and performed DNA methylation and copy number profiling.

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Ewing sarcoma (EwS) is an aggressive cancer characterized by chromosomal translocations generating fusions of the EWSR1 gene with ETS transcription factors (in 85% FLI1). EWSR1-FLI1 induces gene expression via binding to enhancer-like GGAA-microsatellites, whose activity correlates with the number of consecutive GGAA-repeats. Herein we investigate the role of the secretory neuropeptide CALCB (calcitonin-related polypeptide β) in EwS, which signals via the CGRP (calcitonin gene-related peptide) receptor complex, containing RAMP1 (receptor activity modifying protein 1) as crucial part for receptor specificity.

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Most tumours have an aberrantly activated lipid metabolism that enables them to synthesize, elongate and desaturate fatty acids to support proliferation. However, only particular subsets of cancer cells are sensitive to approaches that target fatty acid metabolism and, in particular, fatty acid desaturation. This suggests that many cancer cells contain an unexplored plasticity in their fatty acid metabolism.

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Purpose: Endoglin (ENG; CD105) is a coreceptor of the TGFβ family that is highly expressed in proliferating endothelial cells. Often coopted by cancer cells, ENG can lead to neo-angiogenesis and vasculogenic mimicry in aggressive malignancies. It exists both as a transmembrane cell surface protein, where it primarily interacts with TGFβ, and as a soluble matricellular protein (sENG) when cleaved by matrix metalloproteinase 14 (MMP14).

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Soft-tissue sarcomas are rare, heterogeneous, and often aggressive mesenchymal cancers. Many of them are associated with poor outcome, partially because biomarkers that can identify high-risk patients are lacking. Studies on sarcomas are often limited by small sample-sizes rendering the identification of biomarkers difficult when focusing on individual cohorts.

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Next-generation sequencing (NGS) has overcome important limitations to the molecular diagnosis of Inherited Retinal Dystrophies (IRD) such as the high clinical and genetic heterogeneity and the overlapping phenotypes. The purpose of this study was the identification of the genetic defect in 32 Spanish families with different forms of IRD. With that aim, we implemented a custom NGS panel comprising 64 IRD-associated genes in our population, and three disease-associated intronic regions.

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Although TAZ, the final effector of the Hippo pathway that modulates epithelial to mesenchymal transition and stemness, has been implicated in the development of different types of cancer, its role in endometrial cancer has not yet been studied. Thus, we evaluated the expression of TAZ in different types of endometrial cancer by immunohistochemistry. TAZ expression was detected in 76% of undifferentiated endometrial carcinomas, 54% of endometrial carcinosarcomas, 46% of endometrial serous carcinomas, 36% of grade 3 endometrioid carcinomas, and 18% of grade 1-2 endometrioid carcinomas, with statistically significant differences.

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The Hippo signaling pathway, a conserved regulator of organ size, has emerged as an important regulatory pathway in cancer. The final transducer effectors of this pathway in mammals are the oncoproteins TAZ and YAP1, which are transcriptional coactivators of target genes involved in cell proliferation and survival. TAZ has been previously reported to play a role in tumorigenesis in breast cancer, but detailed analyses of the different breast cancer phenotypes have not been conducted thus far.

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