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List of all SNVs found

List of primers used in Sanger sequencing and SNPs utilized to genotype the 84 normal adjacent and tumor samples.

List of recurrent mutated genes ranked by MutSig tool.

supplementary material legends (tables and figures)

Baseline characteristics of CRC patients (discovery dataset, Sanger validation dataset and TCGA datasets).

Supplementary Figures (1 to 15)

Mutations validated in Biomark platform (Fluidigm) and by Sanger Sequencing.

supplementary figures and table

Innate immune defense mechanisms play a pivotal role in antitumor responses. Recent evidence suggests that antiviral innate immunity is regulated not only by exogenous non–self-RNA but also by host-derived pseudogene RNAs. A growing body of evidence also indicates a biological role for pseudogenes as gene expression regulators or immune modulators. Here, we report an important role for BRCA1P1, the pseudogene of the BRCA1 tumor-suppressor gene, in regulating innate immune defense mechanisms in breast cancer cells. BRCA1P1 expresses a long-noncoding RNA (lncRNA) in breast cancer cells through divergent transcription. Expression of lncRNA-BRCA1P1 is increased in breast tumors compared with normal breast tissues. Depletion of BRCA1P1 induces an antiviral defense-like program, including the expression of antiviral genes in breast cancer cells. Furthermore, BRCA1P1-deficient cancer cells mimic virus-infected cells by stimulating cytokines and inducing cell apoptosis. Accordingly, depletion of BRCA1P1 increases host innate immune responses and restricts virus replication. In converse, overexpression of BRCA1P1 reduces cytokine expression in breast cancer cells. Mechanistically, lncRNA-BRCA1P1 is localized in the nucleus, binds to the NF-κB subunit RelA, and negatively regulates antiviral gene expression. Finally, in a xenograft mouse model of breast cancer, depletion of BRCA1P1 stimulates cytokine expression and local immunity, and suppresses tumor growth. Our results suggest an important role for BRCA1P1 in innate immune defense mechanisms and antitumor responses. This mechanism of antiviral immunity regulated by a host-derived pseudogene RNA may guide the development of novel therapies targeting immune responses in breast cancer.Significance:This study identifies a novel mechanism of innate immunity driven by a host pseudogene RNA that inhibits innate immune defense mechanisms and antitumor responses through regulation of antiviral gene expression.

List of recurrent mutations

List of statistically significant functions in which mutated genes are implicated.

Mutations found in AMER1 gene across different datasets

Innate immune defense mechanisms play a pivotal role in antitumor responses. Recent evidence suggests that antiviral innate immunity is regulated not only by exogenous non–self-RNA but also by host-derived pseudogene RNAs. A growing body of evidence also indicates a biological role for pseudogenes as gene expression regulators or immune modulators. Here, we report an important role for BRCA1P1, the pseudogene of the BRCA1 tumor-suppressor gene, in regulating innate immune defense mechanisms in breast cancer cells. BRCA1P1 expresses a long-noncoding RNA (lncRNA) in breast cancer cells through divergent transcription. Expression of lncRNA-BRCA1P1 is increased in breast tumors compared with normal breast tissues. Depletion of BRCA1P1 induces an antiviral defense-like program, including the expression of antiviral genes in breast cancer cells. Furthermore, BRCA1P1-deficient cancer cells mimic virus-infected cells by stimulating cytokines and inducing cell apoptosis. Accordingly, depletion of BRCA1P1 increases host innate immune responses and restricts virus replication. In converse, overexpression of BRCA1P1 reduces cytokine expression in breast cancer cells. Mechanistically, lncRNA-BRCA1P1 is localized in the nucleus, binds to the NF-κB subunit RelA, and negatively regulates antiviral gene expression. Finally, in a xenograft mouse model of breast cancer, depletion of BRCA1P1 stimulates cytokine expression and local immunity, and suppresses tumor growth. Our results suggest an important role for BRCA1P1 in innate immune defense mechanisms and antitumor responses. This mechanism of antiviral immunity regulated by a host-derived pseudogene RNA may guide the development of novel therapies targeting immune responses in breast cancer. Significance: This study identifies a novel mechanism of innate immunity driven by a host pseudogene RNA that inhibits innate immune defense mechanisms and antitumor responses through regulation of antiviral gene expression.

Aim: Gain insight about the role of DNA methylation in the malignant growth of colon cancer. Patients & methods: Methylation and gene expression from 90 adjacent-tumor paired tissues and 48 healthy tissues were analyzed. Tumor genes whose change in expression was explained by changes in methylation were identified using linear models adjusted for tumor stromal content. Results: No differences in methylation were found between adjacent and healthy tissues, but clear differences were found between adjacent and tumor samples. We identified hypermethylated CpG islands located in promoter regions that drive differential gene expression of transcription factors and their target genes. Conclusion: Changes in methylation of a few genes provoke important changes in gene expression, by expanding the signal through transcription activation/repression.

Funder: Spanish Ministry of Science, Innovation, and University. BFU2016-80570-R, Funder: Cancer Research UK (CRUK); doi: https://doi.org/10.13039/501100000289, Funder: Fundación Científica Asociación Española Contra el Cáncer (Scientific Foundation, Spanish Association Against Cancer); doi: https://doi.org/10.13039/501100002704, As the catalog of oncogenic driver mutations is expanding, it becomes clear that alterations in a given gene might have different functions and should not be lumped into one class. The transcription factor GATA3 is a paradigm of this. We investigated the functions of the most common GATA3 mutation (X308_Splice) and five additional mutations, which converge into a neoprotein that we called “neoGATA3,” associated with excellent prognosis in patients. Analysis of available molecular data from >3000 breast cancer patients revealed a dysregulation of the ER-dependent transcriptional response in tumors carrying neoGATA3-generating mutations. Mechanistic studies in vitro showed that neoGATA3 interferes with the transcriptional programs controlled by estrogen and progesterone receptors, without fully abrogating them. ChIP-Seq analysis indicated that ER binding is reduced in neoGATA3-expressing cells, especially at distal regions, suggesting that neoGATA3 interferes with the fine tuning of ER-dependent gene expression. This has opposite outputs in distinct hormonal context, having pro- or anti-proliferative effects, depending on the estrogen/progesterone ratio. Our data call for functional analyses of putative cancer drivers to guide clinical application.

Innate immune defense mechanisms play a pivotal role in anti-tumor responses. Recent evidence suggests that antiviral innate immunity is regulated not only by exogenous non-self-RNA but also by host-derived pseudogene RNAs. A growing body of evidence also indicates a biological role for pseudogenes as gene expression regulators or immune modulators. Here we report an important role for BRCA1P1, the pseudogene of the BRCA1 tumor suppressor gene, in regulating innate immune defense mechanisms in breast cancer cells. BRCA1P1 expresses a long-noncoding RNA (lncRNA) in breast cancer cells through divergent transcription. Expression of lncRNA BRCA1P1 is increased in breast tumors compared to normal breast tissues. Depletion of BRCA1P1 induces an antiviral defense-like program including the expression of antiviral genes in breast cancer cells. Furthermore, BRCA1P1-deficient cancer cells mimic virus-infected cells by stimulating cytokines and inducing cell apoptosis. Accordingly, depletion of BRCA1P1 increases host innate immune responses and restricts virus replication. In converse, overexpression of BRCA1P1 reduces cytokine expression in breast cancer cells. Mechanistically, lncRNA BRCA1P1 is localized in the nucleus, binds to the NF-κB subunit RelA, and negatively regulates antiviral gene expression. Lastly, in a xenograft mouse model of breast cancer, depletion of BRCA1P1 stimulates cytokine expression and local immunity, and suppresses tumor growth. Our results suggest an important role for BRCA1P1 in innate immune defense mechanisms and anti-tumor responses. This mechanism of antiviral immunity regulated by a host-derived pseudogene RNA may guide the development of novel therapies targeting immune responses in breast cancer.

As the catalogue of oncogenic driver mutations is expanding, it is becoming clear that alterations in a given gene should not be lumped into one single class, since they might have different functions. The transcription factorGATA3is a paradigm of this. Here, we address the functions of the most commonGATA3mutation (X308_Splice) which generates a neoprotein that we designate as neoGATA3, associated with good patient prognosis. Based on extensive analyses of molecular and clinical data from approximately 3000 breast cancer patients, supported by mechanistic studiesin vitro, we show that neoGATA3 interferes with the transcriptional programs controlled by estrogen and progesterone receptors, without fully abrogating them. This has opposite outputs in the pre- or post-menopausal hormonal context, having pro- or anti-proliferative effects, respectively. NeoGATA3 is an example of a context- and stage-dependent driver mutation. Our data call for functional analyses of putative cancer drivers to guide clinical application.

espanolObjetivo: determinar la incidencia y evolucion de la neuropatia periferica inducida por taxanos (NPIT) en pacientes con cancer de mama y valorar la influencia de la NPIT en la calidad de vida global (CV).Metodo: estudio descriptivo longitudinal prospectivo realizado en el Servicio de Oncologia del Hospital Clinic de Barcelona (julio 2015-abril 2016). Se incluyeron mujeres diagnosticadas de cancer de mama en su primera linea de tratamiento con quimioterapia (paclitaxel o docetaxel) en quienes se evaluo la neurotoxicidad y la calidad de vida mediante tres cuestionarios autoinformados validados al inicio, a las 6 y 12 semanas y un mes tras finalizar el tratamiento.Resultados: participaron 33 pacientes de las cuales el 84,4% habia desarrollado algun grado de NP al final del seguimiento. La neurotoxicidad empeoro de manera estadisticamente significativa con la acumulacion de dosis hasta el final del tratamiento y se mantuvo estable un mes tras la ultima administracion (p EnglishObjective: to determine the incidence and evolution of taxane-induced peripheral neuropathy (TIPN) in breast cancer patients, and to assess the influence of TIPN on overall quality of life (QoL). Method: a prospective longitudinal descriptive study conducted at the Oncology Unit of the Hospital Clinic de Barcelona (July, 2015- April, 2016). The study included women with diagnosis of breast cancer, on their first line of treatment with chemotherapy (paclitaxel or docetaxel); neurotoxicity and quality of life were evaluated through three self-reported questionnaires validated at baseline, at 6 and 12 weeks, and one month after completing treatment. Results: the study included 33 patients; 84.4% of them had developed some degree of PN at the end of follow-up. There was a statistically significant worsening in neurotoxicity with dose accumulation until the end of the treatment, and it remained stable one month after the last administration (p

Purpose: Somatic mutations occur at early stages of adenoma and accumulate throughout colorectal cancer progression. The aim of this study was to characterize the mutational landscape of stage II tumors and to search for novel recurrent mutations likely implicated in colorectal cancer tumorigenesis. Experimental Design: The exomic DNA of 42 stage II, microsatellite-stable colon tumors and their paired mucosae were sequenced. Other molecular data available in the discovery dataset [gene expression, methylation, and copy number variations (CNV)] were used to further characterize these tumors. Additional datasets comprising 553 colorectal cancer samples were used to validate the discovered mutations. Results: As a result, 4,886 somatic single-nucleotide variants (SNV) were found. Almost all SNVs were private changes, with few mutations shared by more than one tumor, thus revealing tumor-specific mutational landscapes. Nevertheless, these diverse mutations converged into common cellular pathways, such as cell cycle or apoptosis. Among this mutational heterogeneity, variants resulting in early stop codons in the AMER1 (also known as FAM123B or WTX) gene emerged as recurrent mutations in colorectal cancer. Losses of AMER1 by other mechanisms apart from mutations such as methylation and copy number aberrations were also found. Tumors lacking this tumor suppressor gene exhibited a mesenchymal phenotype characterized by inhibition of the canonical Wnt pathway. Conclusions: In silico and experimental validation in independent datasets confirmed the existence of functional mutations in AMER1 in approximately 10% of analyzed colorectal cancer tumors. Moreover, these tumors exhibited a characteristic phenotype. Clin Cancer Res; 21(20); 4709–18. ©2015 AACR.

SUMMARY Colorectal cancer (CRC) tumors are highly heterogeneous at a molecular level. Recent studies have proposed molecular classifications of intrinsic CRC molecular subtypes identified after applying unsupervised clustering methods to genome-wide data. Those subtypes, characterized by their distinct clinical and biological features, provide new insight about the complexity of CRC. A common finding shared by almost all analyses was the identification of microsatellite instable tumors as an independent cluster, which is associated to better prognosis. Clusters of tumors characterized by a high stromal component exhibited a poor outcome. Moreover, some of the clusters were associated with response to standard chemotherapy or targeted agents. Regarding biological functions underlying tumor subtypes, recurrent ones across different studies were WNT pathway activation, epithelial-to-mesenchymal transition or cancer stem cell-like phenotype. Now, the challenge is to translate these findings into a comprehensive CRC classification and characterization helpful for patients’ stratification and better clinical management.

In this study, we aim to identify the genes responsible for colorectal cancer risk behind the loci identified in genome-wide association studies (GWAS). These genes may be candidate targets for developing new strategies for prevention or therapy. We analyzed the association of genotypes for 26 GWAS single nucleotide polymorphisms (SNPs) with the expression of genes within a 2 Mb region (cis-eQTLs). Affymetrix Human Genome U219 expression arrays were used to assess gene expression in two series of samples, one of healthy colonic mucosa (n = 47) and other of normal mucosa adjacent to colon cancer (n = 97, total 144). Paired tumor tissues (n = 97) were also analyzed but did not provide additional findings. Partial Pearson correlation (r), adjusted for sample type, was used for the analysis. We have found Bonferroni-significant cis-eQTLs in three loci: rs3802842 in 11q23.1 associated to C11orf53, COLCA1 (C11orf92) and COLCA2 (C11orf93; r = 0.60); rs7136702 in 12q13.12 associated to DIP2B (r = 0.63) and rs5934683 in Xp22.3 associated to SHROOM2 and GPR143 (r = 0.47). For loci in chromosomes 11 and 12, we have found other SNPs in linkage disequilibrium that are more strongly associated with the expression of the identified genes and are better functional candidates: rs7130173 for 11q23.1 (r = 0.66) and rs61927768 for 12q13.12 (r = 0.86). These SNPs are located in DNA regions that may harbor enhancers or transcription factor binding sites. The analysis of trans-eQTLs has identified additional genes in these loci that may have common regulatory mechanisms as shown by the analysis of protein-protein interaction networks.

The genomic region encompassing the BRCA1 gene includes the BRCA1P1 pseudogene (BRCA1P1) within ~170kb at chromosome 17q21. The homology and proximity of BRCA1 and BRCA1P1 create a hot spot for recombination, resulting in a large genomic rearrangement found in some families with breast and ovarian cancers. While the significant role of BRCA1 in regulating the DNA damage response (DDR) is well defined, little is known about the biological properties of the BRCA1P1 pseudogene. To functionally annotate BRCA1P1, we conducted a CRISPR-Cas 9 knockout of the pseudogene, as well as knockdown of the expression using antisense oligonucleotides. Both knockout and knockdown of the pseudogene result in increases in apoptosis and sensitivity to DNA damaging drugs. Depletion of BRCA1P1 accumulates spontaneous DNA damage foci and leads to replication fork stalling. Mechanical studies reveal that the BRCA1P1 generates circular RNAs, which are retained in nuclei. Mass spectrometry followed by chromatin isolation by RNA purification (ChIRP) identifies a specific association of the circular RNAs with SERBP1 RNA-binding protein, which was confirmed by ChIRP-Western. Consequently, BRCA1P1 knockout decreased SERBP1 protein expression in the nuclei. Based on the previous report that SERBP1 binds to mRNAs of DDR proteins and controls their translation, we propose a mechanism of BRCA1P1-driven regulation of DDR protein expression through SERBP1. Our data indicate that the BRCA1P1 pseudogene plays a role in regulating replication fork progression and genomic instability in breast cancer cells through an interaction with SERBP1 RNA-binding protein. Citation Format: Yoo J. Han, Jing Zhang, Jennifer M. Mason, Toshio F. Yoshimatsu, Xinxin Du, Ian Hurley, Danny E. Kim, Aparna Anantharaman, Laia P. Brunet, Aleix Prat, John Kwon, Kannanganattu V. Prasanth, Olufunmilayo I. Olopade. Circular RNAs generated from the BRCA1 pseudogene regulates the DNA damage response through SERBP1 RNA-binding protein [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 1373.

Background: We propose that single-nucleotide polymorphisms (SNPs) in genes of the vascular endothelial growth factor pathway of angiogenesis will associate with survival in non-small-cell lung cancer (NSCLC) patients. Methods: Fifty-three SNPs in vascular endothelial growth factor-pathway genes were genotyped in 150 European stage I-III NSCLC patients and tested for associations with patient survival. Replication was performed in an independent cohort of 142 European stage I-III patients. Reporter gene assays were used to assess the effects of SNPs on transcriptional activity. Results: In the initial cohort, five SNPs associated (q < 0.05) with relapse-free survival (RFS). The minor alleles of intronic FLT1 SNPs, rs7996030 and rs9582036, associated with reduced RFS (hazard ratio [HR] = 1.67 [95% confidence interval, CI, 1.22-2.29] and HR = 1.51 [95% CI, 1.14-2.01], respectively) and reduced transcriptional activity. The minor alleles of intronic KRAS SNPs, rs12813551 and rs10505980, associated with increased RFS (HR = 0.64 [0.46-0.87] and HR = 0.64 [0.47-0.87], respectively), and the minor allelic variant of rs12813551 also reduced transcriptional activity. Lastly, the minor allele of the intronic KRAS SNP rs10842513 associated with reduced RFS (HR = 1.65 [95% CI, 1.16-2.37]). Analysis of the functional variants suggests they are located in transcriptional enhancer elements. The negative effect of rs9582036 on RFS was confirmed in the replication cohort (HR = 1.69 [0.99-2.89], p = 0.028), and the association was significant in pooled analysis of both cohorts (HR = 1.67 [1.21-2.30], p = 0.0001). Conclusions: The functional FLT1 variant rs9582036 is a prognostic determinant of recurrence in stage I-III NSCLC. Its predictive value should be tested in the adjuvant setting of stage I-III NSCLC.

Background Dysregulation of transcriptional programs leads to cell malfunctioning and can have an impact in cancer development. Our study aims to characterize global differences between transcriptional regulatory programs of normal and tumor cells of the colon. Methods Affymetrix Human Genome U219 expression arrays were used to assess gene expression in 100 samples of colon tumor and their paired adjacent normal mucosa. Transcriptional networks were reconstructed using ARACNe algorithm using 1,000 bootstrap replicates consolidated into a consensus network. Networks were compared regarding topology parameters and identified well-connected clusters. Functional enrichment was performed with SIGORA method. ENCODE ChIP-Seq data curated in the hmChIP database was used for in silico validation of the most prominent transcription factors. Results The normal network contained 1,177 transcription factors, 5,466 target genes and 61,226 transcriptional interactions. A large loss of transcriptional interactions in the tumor network was observed (11,585; 81% reduction), which also contained fewer transcription factors (621; 47% reduction) and target genes (2,190; 60% reduction) than the normal network. Gene silencing was not a main determinant of this loss of regulatory activity, since the average gene expression was essentially conserved. Also, 91 transcription factors increased their connectivity in the tumor network. These genes revealed a tumor-specific emergent transcriptional regulatory program with significant functional enrichment related to colorectal cancer pathway. In addition, the analysis of clusters again identified subnetworks in the tumors enriched for cancer related pathways (immune response, Wnt signaling, DNA replication, cell adherence, apoptosis, DNA repair, among others). Also multiple metabolism pathways show differential clustering between the tumor and normal network. Conclusions These findings will allow a better understanding of the transcriptional regulatory programs altered in colon cancer and could be an invaluable methodology to identify potential hubs with a relevant role in the field of cancer diagnosis, prognosis and therapy. Electronic supplementary material The online version of this article (doi:10.1186/1471-2407-14-708) contains supplementary material, which is available to authorized users.

e14613 Background: Aberration of normal genetic and epigenetic patterns occurs at early stages of colorectal cancer (CRC) and accumulates throughout cancer progression. To characterize pre-metastatic tumors, a series of stage II, microsatellite stable, colon tumors and their paired mucosa were profiled on RNA expression and DNA methylation microarrays ( www.colonomics.org ). Our aim is to define molecular subtypes based on recurrent gene mutations, methylation and expression profiles, and explore if these molecular subtypes are associated to patients’ prognosis. Methods: We have sequenced exomes (Illumina Genome Analyzer) of a subset of 42 COLONOMICS normal-tumor paired samples (21 good and 21 bad prognosis). Variants identified in normal tissue were used to filter SNPs. DNA methylation (Infinium Human Methylation 450k) and RNA expression (Affymetrix U219) data from those samples were used in this analysis. Correlation was used to assess the association between tumor mutations and differentially expressed/methylated genes. Significant genes were subsequently used to perform tumor clustering. Results: Exome analysis revealed a mean of 150 somatic mutations per sample. From these, 12 variants were recurrently mutated (KRAS, TP53, etc) in more than 3 tumors that were used to define tumor subtypes based on gene methylation/expression patterns. We obtained 12 profiles that clearly identified the cluster of mutated samples. For some profiles, the cluster only includes those tumors with the mutation. Interestingly, some clusters included the mutated samples and additional tumors showing the same phenotype despite not having the mutation. For each mutation, the overlapping between the differently methylated/expressed genes ranged from 14 to 200 common genes. When combining data from the three platforms two main CRC molecular subtypes emerge; each of which shows molecular heterogeneity but no association with prognosis. Conclusions: Mutational status is associated with gene methylation and expression patterns in CRC patients. Although none of these clusters was associated with prognosis, different groups of tumors could be related to distinctive pathways, which may reveal useful as therapeutic targets.

Angiogenesis is a host-mediated mechanism in disease pathophysiology. The vascular endothelial growth factor (VEGF) pathway is a major determinant of angiogenesis, and a comprehensive annotation of the functional variation in this pathway is essential to understand the genetic basis of angiogenesis-related diseases. We assessed the allelic heterogeneity of gene expression, population specificity of cis expression quantitative trait loci (eQTLs), and eQTL function in luciferase assays in CEU and Yoruba people of Ibadan, Nigeria (YRI) HapMap lymphoblastoid cell lines in 23 resequenced genes. Among 356 cis-eQTLs, 155 and 174 were unique to CEU and YRI, respectively, and 27 were shared between CEU and YRI. Two cis-eQTLs provided mechanistic evidence for two genome-wide association study findings. Five eQTLs were tested for function in luciferase assays and the effect of two KRAS variants was concordant with the eQTL effect. Two eQTLs found in each of PRKCE, PIK3C2A, and MAP2K6 could predict 44%, 37%, and 45% of the variance in gene expression, respectively. This is the first analysis focusing on the pattern of functional genetic variation of the VEGF pathway genes in CEU and YRI populations and providing mechanistic evidence for genetic association studies of diseases for which angiogenesis plays a pathophysiologic role. (C) 2013 Wiley Periodicals, Inc.