Júlia Perera-Bel

Dr. Júlia Perera-Bel


Research Focus & Metrics

Academic Career Length

12Years (2015-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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9 October 2015 in The ISME Journal
Verified
Journal Article
Closed access
MPMassimo C Pernice
Massimo C Pernice
CGCaterina R Giner
Caterina R Giner
RLRamiro Logares
Ramiro Logares
JPJúlia Perera-Bel
Júlia Perera-Bel
SASilvia G. Acinas
Silvia G. Acinas
RMRamon Massana
Ramon Massana
In this work, we study the diversity of bathypelagic microbial eukaryotes (0.8–20 μm) in the global ocean. Seawater samples from 3000 to 4000 m depth from 27 stations in the Atlantic, Pacific and Indian Oceans were analyzed by pyrosequencing the V4 region of the 18S ribosomal DNA. The relative abundance of the most abundant operational taxonomic units agreed with the results of a parallel metagenomic analysis, suggesting limited PCR biases in the tag approach. Although rarefaction curves for single stations were seldom saturated, the global analysis of all sequences together suggested an adequate recovery of bathypelagic diversity. Community composition presented a large variability among samples, which was poorly explained by linear geographic distance. In fact, the similarity between communities was better explained by water mass composition (26% of the variability) and the ratio in cell abundance between prokaryotes and microbial eukaryotes (21%). Deep diversity appeared dominated by four taxonomic groups (Collodaria, Chrysophytes, Basidiomycota and MALV-II) appearing in different proportions in each sample. Novel diversity amounted to 1% of the pyrotags and was lower than expected. Our study represents an essential step in the investigation of bathypelagic microbial eukaryotes, indicating dominating taxonomic groups and suggesting idiosyncratic assemblages in distinct oceanic regions.

31 August 2020 in Cancer Research
Verified
Journal Article
Open access
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JBJoaquim Bellmunt
Joaquim Bellmunt
JKJaegil Kim
Jaegil Kim
BRBrendan Reardon
Brendan Reardon
JPJúlia Perera-Bel
Júlia Perera-Bel
AOAnna Orsola
Anna Orsola
DKDavid J. Kwiatkowski
David J. Kwiatkowski
High-grade T1 (HGT1) bladder cancer is the highest risk subtype of non–muscle-invasive bladder cancer with unpredictable outcome and poorly understood risk factors. Here, we examined the association of somatic mutation profiles with nonrecurrent disease (GO, good outcome), recurrence (R), or progression (PD) in a cohort of HGT1 patients. Exome sequencing was performed on 62 HGT1 and 15 matched normal tissue samples. Both tumor only (TO) and paired analyses were performed, focusing on 95 genes known to be mutated in bladder cancer. Somatic mutations, copy-number alterations, mutation load, and mutation signatures were studied. Thirty-three GO, 10 R, 18 PD, and 1 unknown outcome patients were analyzed. Tumor mutational burden (TMB) was similar to muscle-invasive disease and was highest in GO, intermediate in PD, and lowest in R patients (P = 0.017). DNA damage response gene mutations were associated with higher TMB (P < 0.0001) and GO (P = 0.003). ERCC2 and BRCA2 mutations were associated with GO. TP53, ATM, ARID1A, AHR, and SMARCB1 mutations were more frequent in PD. Focal copy-number gain in CCNE1 and CDKN2A deletion was enriched in PD or R (P = 0.047; P = 0.06). APOBEC (46%) and COSMIC5 (34%) signatures were most frequent. APOBEC-A and ERCC2 mutant tumors (COSMIC5) were associated with GO (P = 0.047; P = 0.0002). pT1b microstaging was associated with a genomic cluster (P = 0.05) with focal amplifications of E2F3/SOX4, PVRL4, CCNE1, and TP53 mutations. Findings were validated using external public datasets. These findings require confirmation but suggest that management of HGT1 bladder cancer may be improved via molecular characterization to predict outcome. Significance: Detailed genetic analyses of HGT1 bladder tumors identify features that correlate with outcome, e.g., high mutational burden, ERCC2 mutations, and high APOBEC-A/ERCC2 mutation signatures were associated with good outcome.

25 October 2018 in Glia
Verified
Journal Article
Closed access
PDF file
RBRaquel Blazquez
Raquel Blazquez
DWDarius Wlochowitz
Darius Wlochowitz
AWAlexander Wolff
Alexander Wolff
SSStefanie Seitz
Stefanie Seitz
AWAstrid Wachter
Astrid Wachter
TPTobias Pukrop
Tobias Pukrop

12 July 2024 in Science Advances
Verified
Journal Article
Open access
MCMarta E. Camarena
Marta E. Camarena
PTPatrick Theunissen
Patrick Theunissen
MRMarta Ruiz
Marta Ruiz
JRJorge Ruiz-Orera
Jorge Ruiz-Orera
BCBeatriz Calvo-Serra
Beatriz Calvo-Serra
MAM. Mar Albà
M. Mar Albà
The expression of tumor-specific antigens during cancer progression can trigger an immune response against the tumor. Here, we investigate if microproteins encoded by noncanonical open reading frames (ncORFs) are a relevant source of tumor-specific antigens. We analyze RNA sequencing data from 117 hepatocellular carcinoma (HCC) tumors and matched healthy tissue together with ribosome profiling and immunopeptidomics data. Combining human leukocyte antigen–epitope binding predictions and experimental validation experiments, we conclude that around 40% of the tumor-specific antigens in HCC are likely to be derived from ncORFs, including two peptides that can trigger an immune response in humanized mice. We identify a subset of 33 tumor-specific long noncoding RNAs expressing novel cancer antigens shared by more than 10% of the HCC samples analyzed, which, when combined, cover a large proportion of the patients. The results of the study open avenues for extending the range of anticancer vaccines.

20 February 2025 in Nature Communications
Verified
Journal Article
Open access
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LBLilian Marie Boll
Lilian Marie Boll
SOSergio Vázquez Montes de Oca
Sergio Vázquez Montes de Oca
MCMarta E. Camarena
Marta E. Camarena
RCRobert Castelo
Robert Castelo
JBJoaquim Bellmunt
Joaquim Bellmunt
MAM. Mar Albà
M. Mar Albà
Advanced bladder cancer patients show very variable responses to immune checkpoint inhibitors (ICIs) and effective strategies to predict response are still lacking. Here we integrate mutation and gene expression data from 707 advanced bladder cancer patients treated with anti-PD-1/anti-PD-L1 to build highly accurate predictive models. We find that, in addition to tumor mutational burden (TMB), enrichment in the APOBEC mutational signature, and the abundance of pro-inflammatory macrophages, are major factors associated with the response. Paradoxically, patients with high immune infiltration do not show an overall better response. We show that this can be explained by the activation of immune suppressive mechanisms in a large portion of these patients. In the case of non-immune-infiltrated cancer subtypes, we uncover specific variables likely to be involved in the response. Our findings provide information for advancing precision medicine in patients with advanced bladder cancer treated with immunotherapy.

15 March 2018 in Genome Medicine
Verified
Journal Article
Open access
PDF file
JPJúlia Perera-Bel
Júlia Perera-Bel
BHBarbara Hutter
Barbara Hutter
CHChristoph Heining
Christoph Heining
ABAnnalen Bleckmann
Annalen Bleckmann
MFMartina Fröhlich
Martina Fröhlich
Tim BeißbarthTim Beißbarth
Tim Beißbarth
A comprehensive understanding of cancer has been furthered with technological improvements and decreasing costs of next-generation sequencing (NGS). However, the complexity of interpreting genomic data is hindering the implementation of high-throughput technologies in the clinical context: increasing evidence on gene–drug interactions complicates the task of assigning clinical significance to genomic variants. Here we present a method that automatically matches patient-specific genomic alterations to treatment options. The method relies entirely on public knowledge of somatic variants with predictive evidence on drug response. The output report is aimed at supporting clinicians in the task of finding the clinical meaning of genomic variants. We applied the method to 1) The Cancer Genome Atlas (TCGA) and Genomics Evidence Neoplasia Information Exchange (GENIE) cohorts and 2) 11 patients from the NCT MASTER trial whose treatment discussions included information on their genomic profiles. Our reporting strategy showed a substantial number of patients with actionable variants in the analyses of TCGA and GENIE samples. Notably, it was able to reproduce experts’ treatment suggestions in a retrospective study of 11 patients from the NCT MASTER trial. Our results establish a proof of concept for comprehensive, evidence-based reports as a supporting tool for discussing treatment options in tumor boards. We believe that a standardized method to report actionable somatic variants will smooth the incorporation of NGS in the clinical context. We anticipate that tools like the one we present here will become essential in summarizing for clinicians the growing evidence in the field of precision medicine. The R code of the presented method is provided in Additional file 6 and available at https://github.com/jperera-bel/MTB-Report .