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:Identification of differentially expressed microRNAs in Colorectal Cancer Distant metastasis is the major determinant of patient outcome in colorectal cancer and microRNAs have emerged as an increasingly important class of molecules which can regulate several steps of the metastatic cascade. By systematically analysing the miR expression profiles of resected metastasis-, corresponding primary tumor- and normal tissues of colorectal cancer patients, we were able to delineate a miR-signature indicative of the metastatically critical microRNA landscape.
Project description:Identification of differentially expressed microRNAs in Colorectal Cancer Distant metastasis is the major determinant of patient outcome in colorectal cancer and microRNAs have emerged as an increasingly important class of molecules which can regulate several steps of the metastatic cascade. By systematically analysing the miR expression profiles of resected metastasis-, corresponding primary tumor- and normal tissues of colorectal cancer patients, we were able to delineate a miR-signature indicative of the metastatically critical microRNA landscape. 9 colorectal cancer patients were profiled comprising 5 patients with tissues from the primary tumor, normal mucosa, secondary metastasis and the background tissue in which the metastasis ocurred. In the remaining 4 patients, one of these four tissue entitities is missing. One patient had two synchronous primary tumors, one in the colon and the other in the rectum.
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.
Project description:Chromosomal instable colorectal cancer is marked by specific large chromosomal copy number aberrations. Recently, focal aberrations of 3Mb or smaller have been identified as a common phenomenon in cancer. Inherent to their limited size, these aberrations harbour one or few genes. The aim of this study is to identify recurrent focal chromosomal aberrations and their candidate driver genes in a well defined series of stage II colon cancers and assess their potential clinical relevance. High resolution DNA copy number profiles were obtained from 38 formalin fixed paraffin embedded colon cancer samples with matched normal mucosa as a reference using array comparative genomic hybridization. In total, 81 focal chromosomal aberrations were identified that harboured 177 genes. Statistical validation of focal aberrations and identification of candidate driver genes was performed by enrichment analysis and mapping copy number and mutation data of colorectal-, breast-, pancreatic cancer and glioblastomas to loci of focal aberrations in stage II colon cancer. This analysis demonstrated a significant overlap with previously identified focal amplifications in colorectal cancer, but not with cancers from other sites. In contrast, focal deletions seem less tumour type specific since they also show significant overlap with focal deletions of other sites. Focal deletions detected are significantly enriched for cancer genes and genes frequently mutated in colorectal cancer. The mRNA expression of these genes is significantly correlated with DNA copy number status, supporting the relevance of focal aberrations. Loss of 5q34 and gain of 13q22.1 were identified as independent prognostic factors of survival in this series of patients. In conclusion, focal chromosomal copy number aberrations in stage II colon cancer are enriched in cancer genes which contribute to and drive the process of colorectal cancer development. DNA copy number status of these genes correlate with mRNA expression and some are associated with clinical outcome. 38 Stage II colorectal cancer (CRC) tissue samples (FFPE) of which 19 were done on expression arrays. One sample (Stage II colorectal cancer tissue samples (FFPE) 26) was also done on the 135K NimbleGen array. Fresh frozen and FFPE of the same CRC stage I sample was done on 105K agilent. The fresh frozen was across array in silico set out against a pool of blood of 18 healthy females.
Project description:Chromosomal instable colorectal cancer is marked by specific large chromosomal copy number aberrations. Recently, focal aberrations of 3Mb or smaller have been identified as a common phenomenon in cancer. Inherent to their limited size, these aberrations harbour one or few genes. The aim of this study is to identify recurrent focal chromosomal aberrations and their candidate driver genes in a well defined series of stage II colon cancers and assess their potential clinical relevance. High resolution DNA copy number profiles were obtained from 38 formalin fixed paraffin embedded colon cancer samples with matched normal mucosa as a reference using array comparative genomic hybridization. In total, 81 focal chromosomal aberrations were identified that harboured 177 genes. Statistical validation of focal aberrations and identification of candidate driver genes was performed by enrichment analysis and mapping copy number and mutation data of colorectal-, breast-, pancreatic cancer and glioblastomas to loci of focal aberrations in stage II colon cancer. This analysis demonstrated a significant overlap with previously identified focal amplifications in colorectal cancer, but not with cancers from other sites. In contrast, focal deletions seem less tumour type specific since they also show significant overlap with focal deletions of other sites. Focal deletions detected are significantly enriched for cancer genes and genes frequently mutated in colorectal cancer. The mRNA expression of these genes is significantly correlated with DNA copy number status, supporting the relevance of focal aberrations. Loss of 5q34 and gain of 13q22.1 were identified as independent prognostic factors of survival in this series of patients. In conclusion, focal chromosomal copy number aberrations in stage II colon cancer are enriched in cancer genes which contribute to and drive the process of colorectal cancer development. DNA copy number status of these genes correlate with mRNA expression and some are associated with clinical outcome.
Project description:Background & Aims: The metastatic process is complex and remains a major obstacle in the management of colorectal cancer (CRC). To gain a better insight into the biologic events driving the metastatic process we investigated genomic aberrations in a large cohort of matched CRC primaries and distant metastases from various sites. Methods: In total, 62 primary colorectal cancers, 62 matched normal specimens, and 68 matched metastases (from liver, lung, ovary, omentum, and distant lymph nodes) were analyzed by high resolution array comparative genomic hybridization (array CGH) for DNA copy number changes. Findings were validated using a publicly available dataset consisting of 21 primary tumors and matched liver metastases. Fluorescence in situ hybridization (FISH) was used to confirm some of the DNA copy number changes observed. Results: Overall patterns of DNA copy number aberrations were highly similar between primary tumors and their metastases, confirming clonality. Additional copy number aberrations in metastasis are rare and rather than recurrent they were sporadic for individual patients. The only recurrent differences between primary tumors and their metastases were two chromosomal regions, 6q21 and 8q24.21 encompassing the MYC oncogene, that coamplified in three metastases of two patients (3.2%). FISH analysis confirmed the high level co-amplification in the metastasis, which were not detected in their primary tumors. Conclusions: Primary CRC and their metastases show highly similar patterns of DNA copy number changes, additional copy number aberrations in metastasis are rare and recurrences exceptional. These observations are consistent with the hypothesis that the metastatic potential is predestined early in the development of the primary tumor. In total, 62 primary colorectal cancers, 62 matched normal specimens, and 68 matched metastases (liver, lung, ovarian, omentum and distant lymph nodes) were analyzed by high resolution array comparative genomic hybridization (array CGH).
Project description:Colorectal cancer, a leading cause of cancer-related mortality due to distant metastases, is largely driven by activating mutations in the WNT and MAPK pathways. Understanding the mechanism underlying the various steps involved in the metastatic process is essential for developing effective treatments. Using serial in vivo orthotopic passaging, we developed an immunocompetent mouse model of metastatic colorectal cancer. We demonstrate that highly metastatic tumor cells exhibit chromosomal amplifications in MAPK pathway genes, leading to increased MAPK activity, which in turn suppresses WNT-associated transcriptional programs, including stem cell genes. Pharmacological inhibition of mutant KRASG12D led to a reduction in the MAPK-high/ WNT-low transcriptional state and effectively decreased metastatic dissemination both to the lung and liver. Analysis of CRC patient data revealed that the metastatic gene signature associated with the MAPK-high/ WNT-low state correlated with poorer survival outcomes. These findings underscore the plasticity of metastasis-initiating cells in CRC that arise due to the opposing roles of MAPK and WNT signaling, despite the apparent synergy of these pathways observed during colon tumorigenesis.
Project description:Chromosomal aberrations were studied both in a lung cancer cell line and colorectal cancer tumor samples. Results were verified by SKY karyotypes and by DNA ploidy analysis. The sensitivity of detecting chromosomal aberrations in tumor samples was evaluated by analyzing data from simulated mixtures of the lung cancer cell line H1395 and the normal cell line 1395BL from the same patient. Copy number analysis is presented on 12 colorectal cancer tumor samples and on in silico dilutions of a lung cancer cell line and its patient-matched blood cell line.
Project description:Chromosomal aberrations were studied both in a lung cancer cell line and colorectal cancer tumor samples. Results were verified by SKY karyotypes and by DNA ploidy analysis. The sensitivity of detecting chromosomal aberrations in tumor samples was evaluated by analyzing data from simulated mixtures of the lung cancer cell line H1395 and the normal cell line 1395BL from the same patient.