Cell-free DNA analysis reveals POLR1D-mediated resistance to bevacizumab in colorectal cancer
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PROVIDER: EGAS00001003791 | EGA |
REPOSITORIES: EGA
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Project description:Bevacizumab is an approved anti-angiogenic drug for patients with metastasized colorectal cancer (mCRC) targeting VEGF. The survival benefit of anti-VEGF therapy in mCRC patients is limited to a few months and acquired resistance mechanisms are greatly unknown. Using plasma DNA, we studied the evolution of tumor genomes in a cohort of patients with mCRC (n=150) and observed a recurrent focal amplification (8.7% of cases) on chromosome 13q12.2. Analysis of TCGA data (n=619) suggested an association with later stages, which we confirmed by longitudinal plasma analyses. We defined the minimally amplified region and studied the mechanistic consequences of copy number gain of the involved genes. The amplification of one gene, POLR1D, impacted cell proliferation, resulting in upregulation of VEGFA, an important regulator of angiogenesis which has been implicated in the resistance to bevacizumab. In several patients, we observed the emergence of this 13q12.2 amplicon under bevacizumab treatment, which was invariably associated with evolution of therapy resistance. Hence, we describe a novel resistance mechanism against a widely applied treatment in mCRC patients which will impact clinical management .
| EGAD00001005761 | EGA
Project description:Bevacizumab represents anti-angiogenic effect in cancer patients by inhibiting vascular endothelial growth factor (VEGF). However, its use is still limited due to the resistance to the initial response. Such resistance could be regulated by various cell types and soluble factors, although the underlying mechanisms, especially cell-based mechanisms, remain incompletely understood. Here, we identified bone marrow-derived fibrocytes as a novel contributor for the acquired resistance to bevacizumab, defined as alpha-1 type I collagen-positive and CXCR4-positive cells. In mouse models of lung cancer and malignant pleural mesothelioma, fibrocytes mediated the resistance to bevacizumab as a main producer of fibroblast growth factor 2. Using clinical specimens of lung cancer that were surgically resected after bevacizumab treatment, we demonstrated that the number of fibrocytes was significantly increased in bevacizumab-treated tumor, and was correlated with the number of treatment cycles as well as CD31-positive vessels. Our results identify fibrocytes as a promising cell biomarker and a potential therapeutic target to overcome resistance to anti-VEGF therapy.
2015-12-03 | GSE59476 | GEO
Project description:KRAS mutation is a negative predictive factor for treatment with anti-epidermal growth factor receptor (EGFR) antibodies in metastatic colorectal cancer (mCRC). Novel predictive markers are required to further improve the selection of patients for this treatment. Here, we assessed the influence of modification of KRAS by gene copy number aberration (CNA) and microRNAs (miRNAs) in correlation to clinical outcome in mCRC patients treated with cetuximab in combination with chemotherapy and bevacizumab. Formalin-fixed paraffin-embedded primary tumour tissue was used from 34 mCRC patients in a phase III trial, who were selected based upon their good (n=17) or poor (n=17) progression-free survival (PFS) upon treatment with cetuximab in combination with capecitabine, oxaliplatin, and bevacizumab. Gene copy number at the KRAS locus was assessed using high resolution genome-wide array CGH and the expression levels of 17 miRNAs targeting KRAS were determined by real-time PCR. Good response was associated with 12p12.1 copy number loss, even in patients with a KRAS mutation, while copy number gain in wild-type KRAS patients was correlated with a poor response. In KRAS mutated tumours increased miR-200b and decreased miR-143 expression were associated with a good response. In wild-type KRAS patients, miRNA expression did not predict response in a multivariate model. Thus, assessment of KRAS CNA and miRNAs targeting KRAS might further optimize the selection of patients eligible for anti-EGFR therapy. Copy number detection was performed using NimbleScan and Nexus software Formalin-fixed paraffin-embedded primary tumour tissue was used from 34 metastisized colorectal cancer patients in a phase III trial (CKTO 2005-02; ClinTrials.gov NCT00208546) of the Dutch Colorectal Cancer Group (DCCG), who were selected based upon their good (n=17) or poor (n=17) progression-free survival (PFS) upon treatment with cetuximab in combination with capecitabine, oxaliplatin, and bevacizumab.
2012-01-01 | E-GEOD-32048 | biostudies-arrayexpress
Project description:Metastatic colorectal cancer (mCRC) is associated with multiple somatic copy number alterations (SCNAs). We analyzed SCNAs to estimate overall survival (OS) and progression free suvival (PFS) for mCRC patients treated with bevacizumab in combination with oxaliplatin or irinotecan.
2018-11-21 | GSE110785 | GEO
Project description:Microarrays were used to determine the efficacy of bevacizumab (a monoclonal antibody against the vascular endothelial growth factor and its receptors.) on endometrial cancer cells. Endometrial cancer is the most frequent gynecologic cancer in women. Long term outcomes for patients with advanced stage or recurrent disease are poor. Targeted molecular therapy against the vascular endothelial growth factor (VEGF) and its receptors constitute a new therapeutic option for these patients. The goal of our work was to assess the potential effectiveness of inhibition of VEGF/VEGFR signaling in a xenograft model of endometrial cancer using bevacizumab (Avastin, a humanized antibody against VEGFA). We also aimed to identify molecular markers of sensitivity or resistance to this agent. We show that bevacizumab retards tumor growth in athymic mice by inhibiting molecular components of signaling pathways that sustain cell survival and proliferation. We also demonstrate that resistance to bevacizumab may involve up-regulation of antiapoptotic genes and certain proto-oncogenes. Experiment Overall Design: Human xenografts produced from endometrial cell line, grown in athymic mice, were treated in vivo with bevacizumab.
2009-11-16 | E-GEOD-18195 | biostudies-arrayexpress
Project description:Bevacizumab induces glioblastoma resistance in two in vivo xenograft models. Two cell lines were developed with acquired resistance to bevacizumab. Gene expression difference were analyzed between treated and untreated tumors. Purpose: Antiangiogenic therapy reduces vascular permeability and delays progression but may ultimately promote an aggressive treatment-resistant phenotype. The aim of the present study was to identify mechanisms responsible for glioblastoma resistance to antiangiogenic therapy. Experimental Design: Glioma stem cell (GSC) NSC11 and U87 cell lines with acquired resistance to bevacizumab were developed from orthotopic xenografts in nude mice treated with bevacizumab. Genome-wide analyses were used to identify changes in tumor subtype and specific factors associated with resistance. Results: Mice with established parental NSC11 and U87 cells responded to bevacizumab, whereas glioma cell lines derived at the time of acquired resistance to anti-VEGF therapy were resistant to bevacizumab and did not have prolongation of survival compared to untreated controls. Gene expression profiling comparing anti-VEGF therapy-resistant cell lines to untreated controls demonstrated an increase in genes associated with a mesenchymal origin, cellular migration/invasion, and inflammation. Gene Set Enrichment Analysis (GSEA) demonstrated that bevacizumab-treated tumors showed a highly significant correlation to published mesenchymal gene signatures. Mice bearing resistant tumors showed significantly greater infiltration of myeloid cells in NSC11 and U87 resistant tumors. Invasion-related genes were also upregulated in both NSC11 and U87 resistant cells, which had higher invasion rates in vitro compared with their respective parental cell lines. Conclusions: Our studies identify multiple pro-inflammatory factors associated with resistance and identify a proneural-to-mesenchymal transition (PMT) in tumors resistant to antiangiogenic therapy. Glioma cell lines were injected into the caudate of nude mice and were allowed to grow untreated (samples labeled control) or were treated with 10 mg/kg IP twice weekly with bevacizumab (samples labeled Avastin). At the time of animal death, tumor tissue from the mouse was removed, and RNA was isolated and analyzed using gene expression. U87R and NSC11R represent cells resistant to bevacizumab (Avastin).
2013-07-01 | E-GEOD-45161 | biostudies-arrayexpress
Project description:The mechanisms by which tumors develop resistance to angiogenesis inhibitors, and the relative contributions of tumor cells and stroma to resistance, are not completely understood. We developed three human lung adenocarcinoma murine models of resistance to the VEGF inhibitor bevacizumab and, using species-specific profiling, separately investigated tumor cell and stromal molecules associated with resistance. Gene expression changes associated with acquired resistance occurred predominantly in stromal (mouse) and not tumor (human) cells. Components of the EGFR and FGFR2 pathways were significantly upregulated in stroma, but not in tumor cells. Increased activated EGFR was detected on pericytes of xenografts that acquired resistance and on endothelium of tumors with relative primary resistance. Acquired resistance was associated with a pattern of pericyte-covered, normalized revascularization, whereas tortuous, uncovered vessels were observed in relative primary resistance. Dual targeting of VEGF and EGFR pathways with bevacizumab and erlotinib, or the VEGFR/EGFR inhibitor vandetanib, reduced pericyte coverage and increased progression-free survival. These findings demonstrate that alterations in tumor stromal pathways, including EGFR and FGFR2, are associated with, and may contribute to VEGF inhibitor resistance and that targeting these pathways may improve therapeutic efficacy. Understanding stromal signaling may be critical for developing biomarkers for angiogenesis inhibitors and improving combination regimens. To identify changes in stromal and tumor gene expression associated with acquired resistance to anti-VEGF therapy, we performed RNA microarray analyses comparing H1975 control (vehicle-treated) and BV-resistant (bevacizumab-treated until progression) xenografts (n=3 biologic replicates per group of treatment) using Illumina mouse (WG-6 v2) and human (WG-6 v3)-specific expression arrays. Probes in these arrays have been designed to minimize cross-species reactivity and consistent with this essentially no cross reactivity was observed in experiments mixing human and mouse cell lines.Total RNA was extracted from snap-frozen tissues using the mirVanaTM miRNA Isolation Kit (Ambion, Austin, TX) according to manufacturer’s protocol. Biotin labeled cRNA samples for hybridization were prepared by using Illumina Total Prep RNA Amplification Kit (Ambion Inc., Austin, TX). One microgram of total RNA was used for the synthesis of cDNA and followed by an amplification and biotin labeling. Each of 1.5 μg of biotinylated cRNAs was hybridized to both mouseWG-6 v2 and human WG-6v3 Expression BeadChips (Illumina®, San Diego, CA) at the same time, for analysis of murine and human transcriptomes. Signals were developed by Amersham fluorolink streptavidin-Cy3 (GE Health care Bio-Sciences, Little Chalfont, UK). Gene expression data were collected by using Illumina bead Array Reader confocal scanner (BeadStation 500GXDW; Illumina Inc.). Data were analyzed using the BRB-ArrayTools Version 3.7.0 Beta platform developed by Dr. Richard Simon and the BRB-Array Tools development team. A log base 2 transformation was applied to the data set prior to data normalization. A median array was selected as the reference array for normalization and statistical significance was set using a p<0.01. Genes differentially expressed between groups were determined applying univariate t-test with estimation of the false discovery rate (FDR). Genes were determined using selection criteria of a p<0.005 and a fold-change ≥1.5.
2011-04-22 | E-GEOD-26644 | biostudies-arrayexpress
Project description:Bevacizumab induces glioblastoma resistance in two in vivo xenograft models. Two cell lines were developed with acquired resistance to bevacizumab. Gene expression difference were analyzed between treated and untreated tumors. Purpose: Antiangiogenic therapy reduces vascular permeability and delays progression but may ultimately promote an aggressive treatment-resistant phenotype. The aim of the present study was to identify mechanisms responsible for glioblastoma resistance to antiangiogenic therapy. Experimental Design: Glioma stem cell (GSC) NSC11 and U87 cell lines with acquired resistance to bevacizumab were developed from orthotopic xenografts in nude mice treated with bevacizumab. Genome-wide analyses were used to identify changes in tumor subtype and specific factors associated with resistance. Results: Mice with established parental NSC11 and U87 cells responded to bevacizumab, whereas glioma cell lines derived at the time of acquired resistance to anti-VEGF therapy were resistant to bevacizumab and did not have prolongation of survival compared to untreated controls. Gene expression profiling comparing anti-VEGF therapy-resistant cell lines to untreated controls demonstrated an increase in genes associated with a mesenchymal origin, cellular migration/invasion, and inflammation. Gene Set Enrichment Analysis (GSEA) demonstrated that bevacizumab-treated tumors showed a highly significant correlation to published mesenchymal gene signatures. Mice bearing resistant tumors showed significantly greater infiltration of myeloid cells in NSC11 and U87 resistant tumors. Invasion-related genes were also upregulated in both NSC11 and U87 resistant cells, which had higher invasion rates in vitro compared with their respective parental cell lines. Conclusions: Our studies identify multiple pro-inflammatory factors associated with resistance and identify a proneural-to-mesenchymal transition (PMT) in tumors resistant to antiangiogenic therapy.
2013-07-01 | GSE45161 | GEO
Project description:Background. Bevacizumab, an antibody neutralizing Vascular Endothelial Growth Factor (VEGF), is licensed for the management of patients with advanced colon cancer. However, tumor biomarkers identifying the molecular tumor subsets most amenable to angiogenesis modulation are lacking. Patients and Methods. We profiled expession of 24526 genes by means of whole genome 24K DASL (c-DNA-mediated, Annealing, Selection and Ligation) arrays, (Illumina, CA) in 16 bevacizumab-treated patients with advanced colon cancer (Test set). Genes with correlation to 8-month Progression-free status were studied by means of qPCR in two independent colon cancer cohorts: 49 patients treated with bevacizumab+chemotherapy (Bevacizumab qPCR set) and 72 patients treated with chemotherapy only (Control qPCR set). Endpoints were best tumor response before metastasectomy (ORR) and progression-free survival (PFS). Results. Five genes were significantly correlated to 8-month progression-free status in the Test set: overexpression of KLF12 and downregulation of AGR2, ALDH6A1, MCM5, TFF2. In the two independent datasets, irinotecan- or oxaliplatin-based chemotherapy was administered as first-line treatment and metastasectomies were subsequently applied in 8-14% of patients. No prognostically significant gene classifier encompassing all five genes could be validated in the Bevacizumab or Control qPCR sets. The complex gene expression profile of all-low tumor (ALDH6A1+TFF2+MCM5) was strongly associated with ORR in the Bevacizumab qPCR set (ORR 85.7%, p=0.007), but not in the Control set (ORR 36.4%, p=0.747). The Odds Ratio for response for the all-low tumor (ALDH6A1+TFF2+MCM5) profile versus any other ALDH6A1+TFF2+MCM5 profile was 15 (p=0.018) in the Bevacizumab qPCR set but only 0.72 (p=0.63) in the Control set. The tumor expression profile of (KLF12-high+TFF2-low) was significantly associated with PFS only in the Bevacizumab qPCR set: bevacizumab-treated patients with (KLF12-high + TFF2-low) tumors had superior PFS (median 14 months, 95% CI 2-21) compared to patients with any other (KLF12+TFF2) expression profile (median PFS 7 months, 95% CI 5-10, p=0.021). The Hazard Ratio for disease progression for (KLF12-high + TFF2-low) versus any other KLF12+TFF2 expression profile was 2.92 (p=0.03) in the Validation and 1.29 (p=0.39) in the Control set. Conclusions. Our <three-stage> hypothesis-generating study failed to validate the prognostic significance of a five-gene classifier in mCRC patients. Exploratory analyses suggest two gene signatures that are potentially associated with bevazicumab benefit in patients with advanced colon cancer. 18 tumor tissue samples were analysed, no replicates
2013-12-18 | E-GEOD-53127 | biostudies-arrayexpress
Project description:Microarrays were used to determine the efficacy of bevacizumab (a monoclonal antibody against the vascular endothelial growth factor and its receptors.) on endometrial cancer cells. Endometrial cancer is the most frequent gynecologic cancer in women. Long term outcomes for patients with advanced stage or recurrent disease are poor. Targeted molecular therapy against the vascular endothelial growth factor (VEGF) and its receptors constitute a new therapeutic option for these patients. The goal of our work was to assess the potential effectiveness of inhibition of VEGF/VEGFR signaling in a xenograft model of endometrial cancer using bevacizumab (Avastin, a humanized antibody against VEGFA). We also aimed to identify molecular markers of sensitivity or resistance to this agent. We show that bevacizumab retards tumor growth in athymic mice by inhibiting molecular components of signaling pathways that sustain cell survival and proliferation. We also demonstrate that resistance to bevacizumab may involve up-regulation of antiapoptotic genes and certain proto-oncogenes.
2009-09-22 | GSE18195 | GEO