| Experiment ID | EXP00095 |
| Reference | Title: Human colon cancer profiles show differential microRNA expression depending onmismatch repair status and are characteristic of undifferentiated proliferativestates. Author: Sarver AL, French AJ, Borralho PM, Thayanithy V, Oberg AL, Silverstein KA,Morlan BW, Riska SM, Boardman LA, Cunningham JM, Subramanian S, Wang L, Smyrk TC,Rodrigues CM, Thibodeau SN, Steer CJ. Journal: BMC Cancer. 2009 Nov 18;9:401. doi: 10.1186/1471-2407-9-401. Abstract: BACKGROUND: Colon cancer arises from the accumulation of multiple genetic andepigenetic alterations to normal colonic tissue. microRNAs (miRNAs) are small,non-coding regulatory RNAs that post-transcriptionally regulate gene expression. Differential miRNA expression in cancer versus normal tissue is a common eventand may be pivotal for tumor onset and progression.METHODS: To identify miRNAs that are differentially expressed in tumors and tumorsubtypes, we carried out highly sensitive expression profiling of 735 miRNAs onsamples obtained from a statistically powerful set of tumors (n = 80) and normal colon tissue (n = 28) and validated a subset of this data by qRT-PCR.RESULTS: Tumor specimens showed highly significant and large fold changedifferential expression of the levels of 39 miRNAs including miR-135b, miR-96,miR-182, miR-183, miR-1, and miR-133a, relative to normal colon tissue.Significant differences were also seen in 6 miRNAs including miR-31 and miR-592, in the direct comparison of tumors that were deficient or proficient for mismatchrepair. Examination of the genomic regions containing differentially expressedmiRNAs revealed that they were also differentially methylated in colon cancer at a far greater rate than would be expected by chance. A network of interactionsbetween these miRNAs and genes associated with colon cancer provided evidence forthe role of these miRNAs as oncogenes by attenuation of tumor suppressor genes.CONCLUSION: Colon tumors show differential expression of miRNAs depending onmismatch repair status. miRNA expression in colon tumors has an epigeneticcomponent and altered expression that may reflect a reversion to regulatoryprograms characteristic of undifferentiated proliferative developmental states. PMID: 19922656 |
| Expressiion Profile | Description: Genome-wide analysis of miRNA levels in colon cancer Organism: Homo sapiens GEO ID: GSE18392 Platform: GPL8178 Number of samples: 145 |
| Design and Sample | Cancer Type: colon cancer Cancer SubType: N/D Cell Line: N/D Experimental Design: high grade vs low grade Case Sample: colon tumour TNM stage 4 Control Sample: colon tumour TNM stage 2 Num of Case: 15 Num of Control: 44 Quantification Software: Limma Num of miRNAs: 486 |
| Identification | Num of Up: 30 Num of Down: 56 |