Comparison of gene expression profiles between paired primary and metastasis colorectal carcinoma
ABSTRACT: Paired tissues (normal colon, primary colorectal carcinoma, normal liver, liver metastasis of colorectal carcinoma) from 2 colorectal carcinoma patients in Taiwan were processed to generate total RNA, which was subsequently analyzed for gene expression using Affymetrix U133 plus 2.0 arrays. Overall design: Comparison of gene expression profiles between paired normal colon and primary colorectal carcinoma; between primary colorectal carcinoma and liver metastasis colorectal carcinoma
Project description:Paired tissues (normal colon, primary colorectal carcinoma, normal liver, liver metastasis of colorectal carcinoma) from 2 colorectal carcinoma patients in Taiwan were processed to generate total RNA, which was subsequently analyzed for gene expression using Affymetrix U133 plus 2.0 arrays. Comparison of gene expression profiles between paired normal colon and primary colorectal carcinoma; between primary colorectal carcinoma and liver metastasis colorectal carcinoma
Project description:Liver metastasis is one of the major causes of death in colorectal cancer (CRC) patients. To understand this process, we investigated whether the gene expression profiling of matched colorectal carcinomas and liver metastases could reveal key molecular events involved in tumor progression and metastasis. We performed experiments using a cDNA microarray containing 17,104 genes with the following tissue samples: paired tissues of 25 normal colorectal mucosa, 27 primary colorectal tumors, 13 normal liver and 27 liver metastasis, and 20 primary colorectal tumors without liver metastasis. To remove the effect of normal cell contamination, we selected 4,583 organ-specific genes with a false discovery rate (FDR) of 0.0067% by comparing normal colon and liver tissues using significant analysis of microarray, and these genes were excluded from further analysis. We then identified and validated 46 liver metastasis-specific genes with an accuracy of 83.3% by comparing the expression of paired primary colorectal tumors and liver metastases using prediction analysis of microarray. The 46 selected genes contained several known oncogenes and 2 ESTs. To confirm that the results correlated with the microarray expression patterns, we performed RT-PCR with WNT5A and carbonic anhydrase II. Additionally, we observed that 21 of the 46 genes were differentially expressed (FDR = 2.27%) in primary tumors with synchronous liver metastasis compared with primary tumors without liver metastasis. We scanned the human genome using a cDNA microarray and identified 46 genes that may play an important role in the progression of liver metastasis in CRC. Keywords: gene expression profiling using cDNA microarray We performed 17K cDNA microarray with the amplified RNAs from the following tissue samples: normal colorectal mucosa, primary colorectal tumors, normal liver and liver metastasis tumors, and primary colorectal tumors without liver metastasis. Organ-specific genes in normal colon and liver tissues were excluded from the pre-filtered genes, and then we discovered and validated liver metastasis-specific genes commonly up-regulated in the primary colorectal tumors and liver metastasis tumors. To confirm the microarray data, we performed a RT-PCR of two genes (WNT5A and carbonic anhydrase II) in the primary colorectal tumors with and without liver metastases.
Project description:Genome wide miRNA expression profiling was performed using Affymetric miRNA v. 3.0 Array on 48 samples which included paired FFPE colon tuomor and metastisized liver and paired normal colon, normal liver). The data set was divided into two categories and identified by tissue source and patient demographics: Tissue (Colon, Liver), Source (Colon Tumor Liver Met, Colon Normal, Liver Normal), Sex (Male, Female), Patient Pair. microRNAs (miRs) are frequently dysregulated in colorectal cancer (CRC) and subsets are correlated with advanced tumor stage and metastasis. Despite this, the development of prognostic biomarkers that predict metastatic potential remain limited. Our study was designed to identify, validate, and elucidate underlying biology imposed by a miR signature that defines and predicts metastatic disease. Genome-wide miR expression profiling was performed on fourteen patient-matched stage IV primary CRC tumors and corresponding liver metastases using microRNA array technology. Based on these results, this miR panel was then validated and evaluated in normal colon tissue (N = 5), early stage (I & II, N = 11) and late stage (Stage III & IV, N = 14) colorectal primary tumors via qRT-PCR. Overall design: General study design included biological replicates and controls. miRNA was isolated from paired FFPE colon tumor and metastasized liver tumor samples derived from the same patient. Controls were paired normal colon and liver samples from the same patients. There were 42 samples total including: 28 paired patient colon tumor (14) and liver metastases (14), 14 paired normal colon (7) and normal liver (7). Thus, biological replicates
Project description:Comparison of expression profiles of primary colorectal cancers with liver metastases of the same patient. Additionally, expression data of normal colon and liver tissue. Abstract of publication will be included upon publication Keywords: expression profiling, colorectal cancer, colon cancer, liver metastasis, normal colonic tissue, normal liver tissue RNA of 18 primary colorectal cancers, 18 matched liver metastases, 7 normal colon epithelium samples and 5 normal liver tissue samples hybridized on Human Sentrix-6 V2 (Illumina)
Project description:Comparison of expression profiles of primary colorectal cancers with liver metastases of the same patient. Additionally, expression data of normal colon and liver tissue. Abstract of publication will be included upon publication Keywords: expression profiling, colorectal cancer, colon cancer, liver metastasis, normal colonic tissue, normal liver tissue Overall design: RNA of 18 primary colorectal cancers, 18 matched liver metastases, 7 normal colon epithelium samples and 5 normal liver tissue samples hybridized on Human Sentrix-6 V2 (Illumina)
Project description:Gene expression profiles of various isolated normal and tumour cell types The goal was to identify genes differentially expressed in different cell types between normal and tumour tissues. To this end, different cell types (endothelial cells, macrophages and epithelial cells) were isolated from non-paired primary normal colon tissues and colorectal carcinomas and subsequently RNA was isolated. Endothelial cells and epithelial cells were isolated using facs-sorting, whereas macrophages were isolated by means of plastic adherence. For comparison RNA was also isolated from non-paired whole normal colon tissue and whole tumour colorectal carcinomas (so called “bulk”). RNA was processed and hybridized onto Agilent microarrays. Primary goal was to establish an endothelial cell genetic profile. For this we compared the gene expression of tumour endothelial cells (TECs) with normal endothelial cells (NECs). Overall design: The analysis consisted of 3 batches that were hybridized at 3 different time points. Besides colon tissues, but outside the scope of these analyses, also RNA of whole kidney or liver (metastasis) tissues and cell fractions were hybridized on these arrays. Some replicate samples within and between batches served as technical replicates and as reference within one batch. References for batch 2 were colon tumour bulk 94 and for batch 3 colon tumour bulk 121. Technical replicates were: colon adenocarcinoma 104 (n=2), colon tumour EC 109 (n=2), colon tumour EC 118 (n=2), colon tumour epithelial cells 124 (n=2), kidney normal EC 4 (n=2), kidney tumour EC 4 (n=2), kidney normal EC 5 (n=2), kidney normal EC 6 (n=2), colon normal EC 68 (n=2), kidney normal EC 7 (n=2), colon tumour EC 71 (n=2), liver metastasis 72 (n=2), colon tumour EC 80 (n=2), colon normal EC 81 (n=2), colon normal EC 82 (n=2), colon normal EC 89 (n=2), kidney tumour EC 8II (n=2), kidney normal EC 9 (n=2), colon tumour EC 94 (n=2), colon tumour bulk 99 (n=2), colon tumour EC 99 (n=2), colon tumour bulk 94 (n=3, reference batch 2), colon tumour bulk 121 (n=13, reference batch 3).
Project description:Comparison of genomic alterations of primary colorectal cancers with liver metastases of the same patient Keywords: array CGH, colorectal cancer, colon cancer, liver metastasis 21 primary colorectal cancers and 21 matched liver metastases hybridized against sex-matched control pools
Project description:We performed whole exome sequencing and copy number analysis for 15 triplets, each comprising normal colorectal tissue, primary colorectal carcinoma, and its synchronous matched liver metastasis. We analyzed the similarities and differences between primary colorectal carcinoma and matched liver metastases in regards to somatic mutations and somatic copy number alterationss (SCNAs). The genomic profiling demonstrated mutations in APC(73%), KRAS (33%), ARID1A and PIK3CA (6.7%) genes between primary colorectal and metastatic liver tumors. TP53 mutation was observed in 47% of the primary samples and 67% in liver metastatic samples. The grouped pairs, in hierarchical clustering showed similar SCNA patterns, in contrast to the ungrouped pairs. Many mutations (including those of known key cancer driver genes) were shared in the grouped pairs. The ungrouped pairs exhibited distinct mutation patterns with no shared mutations in key driver genes. Four ungrouped liver metastasis samples had mutations in DNA mismatch repair genes along with hypermutations and a substantial number of copy number of alterations. Genomically, colorectal and metastatic liver tumors were very similar. However, in a subgroup of patients, there were genetic variations in liver metastases in the loss of DNA mismatch repair genes. Copy number analysis of Affymetrix CytoScanHD arrays was performed for 15 primary colorectal carcinoma and 15 samples of their matched liver metastases. 15 normal samples prepared from each of the patient was used as the reference for the study. Nexus Copy number 6.1 software was used for somatic copy number alteration analysis.
Project description:Comparison of genomic alterations of primary colorectal cancers with liver metastases of the same patient Keywords: array CGH, colorectal cancer, colon cancer, liver metastasis Overall design: 21 primary colorectal cancers and 21 matched liver metastases hybridized against sex-matched control pools
Project description:Background: Liver metastasis is the major cause of death following a diagnosis of colorectal cancer (CRC) and is a major health burden. Most molecular studies of CRC have profiled primary tumor samples and not the metastasis samples. In this study, we compared the copy number profiles of matched primary and liver metastatic CRC to better understand how the genomic structure of primary CRC differs from the metastasis. This has important implications for whether it is justified to base therapeutic approaches solely on data from the primary tumour. Methods: Paired primary and metastatic tumours from 16 patients and their adjacent normal tissue samples were analyzed using Single-Nucleotide-Polymorphism (SNP) arrays to determine copy number alterations. Nine patients had a synchronous liver metastasis at the time of CRC diagnosis and 7 patients developed a liver metastasis metachronously. Genome-wide chromosomal copy number alterations were assessed, with particular attention to 189 genes known to be somatically altered in CRC and 25 genes that are clinically actionable in CRC. These data were analyzed with respect to the timing of primary and metastatic tissue resection and with exposure to chemotherapy. Results: The genomic divergence with the whole genome duplication correction applied the average percent copy number discordance across all pairs of samples was 22.02%. The pairs of tumour samples collected prior to treatment revealed a significantly higher copy number differences compared to previously treated liver metastasis samples (P=0.024). However, loss of heterozygosity (LOH) acquired in metastasis was significantly higher in previously treated liver metastasis samples compared to treatment naïve liver metastasis samples (P= 0.0064) and which included where KRAS mutation was present in the primary cancers but was not detectable in the metastatic sample following chemotherapy. With regard to 25 genes that are clinically actionable in CRC, amplification of the genes ERBB2, FGFR1, CDK8 or PIK3CA was observed in the metastatic tissue of 4 patients but not in the matched primary CRC. In these cases, knowledge of these metastatic specific alterations could have informed therapeutic decision making and may have improved patient outcome. Conclusion: Intra-patient genomic discrepancies observed between primary and metastatic tissue Overall design: Paired primary CRC and metastatic liver tumour DNA, and normal patient DNA was assayed with the Omni 2.5-8, V1.0 and V1.1 IlluminaBeadChips as per manufacturer’s instructions (Illumina). SNP arrays were scanned on an iScan (Illumina), data was processed using the Genotyping module (v.1.9.4) in GenomeStudio v.2011.1 (Illumina) to calculate B-allele frequencies (BAF) and logR ratios. GAP software was used to segment the SNP array data and determine the level of copy number which was classified into one of 5 categories: homozygous deletion (copy number: 0), loss (copy number:1), copy neutral LOH (copy number:2), gain (copy number: 3-5) and amplification (copy number: 6-8).