Project description:In this study our aim was to document recurrent DNA copy number aberration associated breakpoints in primary tumors of colorectal cancer patients that ultimately received systemic treatment in the context of metastatic disease. Such data can be used to catalogue copy number aberration associated breakpoints and thereby affected genes. To this end, high quality arrayCGH data set of clinically well annotated colorectal cancer specimens was generated using FFPE tumor samples from patients from two phase III clinical trials, namely CAIRO and CAIRO2. arrayCGH data of colorectal cancers of patients from 2 clinical trials. 108 patients were treated with capecitabine first line, 110 patients were treated with capecitabine and irinotecan first line and 134 patients were treated with capecitabine, oxaliplatin and bevacizumab.
Project description:Despite advances in contemporary chemotherapeutic strategies, long term survival still remains elusive for patients with metastatic colorectal cancer. A better understanding of the molecular markers of drug sensitivity to match therapy with patient is needed to improve clinical outcomes. In this study, we used in vitro drug sensitivity data from the NCI-60 cell lines together with their Affymetrix microarray data to develop a gene expression signature to predict sensitivity to oxaliplatin. In order to validate our oxaliplatin sensitivity signature, Patient-Derived Colorectal Cancer Explants (PDCCEs) were developed in NOD-SCID mice from resected human colorectal tumors. Analysis of gene expression profiles found similarities between the PDCCEs and their parental human tumors, suggesting their utility to study drug sensitivity in vivo. The oxaliplatin sensitivity signature was then validated in vivo with response data from 14 PDCCEs treated with oxaliplatin and was found to have an accuracy of 92.9% (Sensitivity=87.5%; Specificity=100%). Our findings suggest that PDCCEs can be a novel source to study drug sensitivity in colorectal cancer. Furthermore, genomic-based analysis has the potential to be incorporated into future strategies to optimize individual therapy for patients with metastatic colorectal cancer. Fourty-two human tumors and murine explants of colorectal origin, both primary colon and of various metastatic sites, were processed for total RNA. The samples included RNA from 14 patient samples in addition to RNA from Patient-Derived Colorectal Cancer Explant (PDCCEs) generated from these 14 patient samples. The PDCCEs were processed as fresh frozen whole tumor in addition to formalin-fixed paraffin-embedded (FFPE) tumors.
Project description:Response to drug therapy in individual colorectal cancer (CRC) patients is associated with tumor biology. Here we describe the genomic landscape of tumor samples of a homogeneous well-annotated series of patients with metastatic CRC of two phase III clinical trials, CAIRO and CAIRO2. DNA copy number aberrations of 349 patients are determined. Within three treatment arms, 194 chromosomal sub-regions are associated with progression free survival PFS (uncorrected single-test p-values < 0.005). These sub-regions are filtered for effect on mRNA expression, using an independent data set from The Cancer Genome Atlas (TCGA) which returned 171 genes. Three chromosomal regions are associated with a significant difference in PFS between treatment arms with or without irinotecan. One of these regions, 6q16.1-q21, correlates in vitro with sensitivity to SN-38, the active metabolite of irinotecan. This genomic landscape of metastatic CRC reveals a number of DNA copy number aberrations associated with response to drug therapy. aCGH data of colorectal cancers of patients from 2 clinical trials (CAIRO, CAIRO2). 105 patients were treated with capecitabine first line (CAIRO arm A), 111 patients were treated with capecitabine and irinotecan first line (CAIRO arm B), and 133 patients were treated with capecitabine, oxaliplatin and bevacizumab (CAIRO2 arm A).
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.
Project description:To measure global gene expression in primary metastatic colorectal cancer patients who have undergone fluorouracil, leucovorin and oxaliplatin (FOLFOX) chemotherapy and screen valuable biomarkers to predict the effects of chemotherapy. Samples from primary metastatic colorectal cancer patients were collected. The effects of chemotherapy were evaluated.
Project description:Despite advances in contemporary chemotherapeutic strategies, long term survival still remains elusive for patients with metastatic colorectal cancer. A better understanding of the molecular markers of drug sensitivity to match therapy with patient is needed to improve clinical outcomes. In this study, we used in vitro drug sensitivity data from the NCI-60 cell lines together with their Affymetrix microarray data to develop a gene expression signature to predict sensitivity to oxaliplatin. In order to validate our oxaliplatin sensitivity signature, Patient-Derived Colorectal Cancer Explants (PDCCEs) were developed in NOD-SCID mice from resected human colorectal tumors. Analysis of gene expression profiles found similarities between the PDCCEs and their parental human tumors, suggesting their utility to study drug sensitivity in vivo. The oxaliplatin sensitivity signature was then validated in vivo with response data from 14 PDCCEs treated with oxaliplatin and was found to have an accuracy of 92.9% (Sensitivity=87.5%; Specificity=100%). Our findings suggest that PDCCEs can be a novel source to study drug sensitivity in colorectal cancer. Furthermore, genomic-based analysis has the potential to be incorporated into future strategies to optimize individual therapy for patients with metastatic colorectal cancer.
Project description:We report that previously described molecular subtypes of colorectal cancer are associated with the response to therapy in patients with metastatic disease. We also identified a patient population with high FOLFIRI sensitivity, as indicated by their 2.7-fold longer overall survival when treated with FOLFIRI, as first-line regimen, instead of FOLFOX. Our results demonstrate the interest of molecular classifications to develop tailored therapies for patients with metastatic colorectal cancer.
Project description:We report that previously described molecular subtypes of colorectal cancer are associated with the response to therapy in patients with metastatic disease. We also identified a patient population with high FOLFIRI sensitivity, as indicated by their 2.7-fold longer overall survival when treated with FOLFIRI, as first-line regimen, instead of FOLFOX. Our results demonstrate the interest of molecular classifications to develop tailored therapies for patients with metastatic colorectal cancer.
Project description:Using whole genome tumor gene expression profiling in patients treated for metastatic colorectal cancer, we attempted to define a signature able to discriminate between responders and non-responders to first-line chemotherapy.
Project description:Purpose: Irinotecan (SN38) and oxaliplatin are chemotherapeutic agents used in the treatment of colorectal cancer. However, the frequent development of resistance to these drugs represents a considerable challenge in the clinic. Alus as retrotransposons comprise 11% of the human genome. Genomic toxicity induced by carcinogens or drugs can reactivate Alus by altering DNA methylation. Whether or not reactivation of Alus occurs in SN38 and oxaliplatin resistance remains unknown. Methods: We applied reduced representation bisulfite sequencing (RRBS) to investigate the DNA methylome in SN38- or oxaliplatin-resistant colorectal cancer cell line models. Moreover, we extended the RRBS analysis to tumor tissue from 14 patients with colorectal cancer who either did or did not benefit from capecitabine + oxaliplatin treatment. For the clinical samples, we applied a concept of DNA methylation entropy to estimate the diversity of DNA methylation states of the identified resistance phenotype-associated methylation loci observed in the cell line models. Results: We identified different loci being characteristic for the different resistant cell lines. Interestingly, 53% of the identified loci were Alu sequences -- especially the Alu Y subfamily. Furthermore, we identified an enrichment of Alu Y sequences that likely results from increased integration of new copies of Alu Y sequence in the drug-resistant cell lines. In the clinical samples, SOX1 and other SOX gene family members were shown to display variable DNA methylation states in their gene regions. The Alu Y sequences showed remarkable variation in DNA methylation states across the clinical samples. Our findings imply a crucial role of Alu Y in colorectal cancer drug resistance. Our study underscores the complexity of colorectal cancer aggravated by mobility of Alu elements and stresses the importance of personalized strategies, using a systematic and dynamic view, for effective cancer therapy. Investigation of the representive methylome of well-established SN38 and Oxaliplatin resistant cell line models and 14 clinical colorectal metastatic samples that have developed resistance to XELOX to review the epigenetic mechnism of the drug resistance.