Project description:Approximately two decades ago, Vogelstein and Fearon proposed the adenoma-carcinoma sequence of sporadic CRC development and illustrated the accumulation of genetic alterations during the stepwise progression, thereby providing a guideline for clinical practice. Although the detection and excision of precancerous lesions could prevent colorectal cancer and reduce mortality, 6% of adenomas will ultimately develop into colorectal cancer. Thus, this genetic model for colorectal tumorigenesis may not completely reflect the complex essence of the disease and whether the mode of initiation of the events in the multistep progression affects the outcome of CRC is still unknown. In this study, mRNA and miRNA expression profiling was performed with human colorectal tissues, including normal mucosa, adenoma and adenocarcinoma. Then, an integrated approach was adopted to establish the regulatory interaction networks that were correlated with colorectal carcinogenesis. Finally, a 55-gene signature whose expression was down-regulated in precancerous lesions compared to normal tissue was identified as a potential early indicator of CRC survival. The results suggested that genes related to immunity and homeostasis played a critical role in protection against adenoma initiation and that the altered molecular events that influence colorectal cancer prognosis may be set in an early, precancerous stage. Four types of human colorectal tissues were selected by colonoscopic resection or colorectal surgery, including 12 normal mucosae, 21 low-grade adenomas (mild or moderate atypical hyperplasia), 30 high-grade adenomas (severe atypical hyperplasia or carcinoma in situ) and 25 adenocarcinomas. Gene expression profiling analysis of these samples was performed using Agilent 4x44K human whole genome gene expression microarray (G4112F).
Project description:Approximately two decades ago, Vogelstein and Fearon proposed the adenoma-carcinoma sequence of sporadic CRC development and illustrated the accumulation of genetic alterations during the stepwise progression, thereby providing a guideline for clinical practice. Although the detection and excision of precancerous lesions could prevent colorectal cancer and reduce mortality, 6% of adenomas will ultimately develop into colorectal cancer. Thus, this genetic model for colorectal tumorigenesis may not completely reflect the complex essence of the disease and whether the mode of initiation of the events in the multistep progression affects the outcome of CRC is still unknown. In this study, mRNA and miRNA expression profiling was performed with human colorectal tissues, including normal mucosa, adenoma and adenocarcinoma. Then, an integrated approach was adopted to establish the regulatory interaction networks that were correlated with colorectal carcinogenesis. Finally, a 55-gene signature whose expression was down-regulated in precancerous lesions compared to normal tissue was identified as a potential early indicator of CRC survival. The results suggested that genes related to immunity and homeostasis played a critical role in protection against adenoma initiation and that the altered molecular events that influence colorectal cancer prognosis may be set in an early, precancerous stage. Four types of human colorectal tissues were selected by colonoscopic resection or colorectal surgery, including 15 normal mucosae, 39 low-grade adenomas (mild or moderate atypical hyperplasia), 20 high-grade adenomas (severe atypical hyperplasia or carcinoma in situ) and 33 adenocarcinomas. MicroRNA expression profiling analysis of these samples was performed on Agilent 8Ã16K Human miRNA Microarray V3 (G4470C).
Project description:Colorectal cancer (CRC) is the third most common cancer worldwide. Colorectal polyps are recognised pre-cursors of CRC, however hyperplastic polyps lack malignant potential. The purpose of this study was to identify differences in gene expression between normal colonic mucosa, hyperplastic and adenomatous polyps from disease-free individuals. By comparing polyps believed to have malignant potential (adenomatous polyps) with hyperplastic polyps it is hoped that new insights into colorectal carcinogenesis can be achieved. 24 colonic samples comprising 8 normal colonic mucosa, 8 hyperplastic polyps and 8 adenomatous polyps.
Project description:Approximately two decades ago, Vogelstein and Fearon proposed the adenoma-carcinoma sequence of sporadic CRC development and illustrated the accumulation of genetic alterations during the stepwise progression, thereby providing a guideline for clinical practice. Although the detection and excision of precancerous lesions could prevent colorectal cancer and reduce mortality, 6% of adenomas will ultimately develop into colorectal cancer. Thus, this genetic model for colorectal tumorigenesis may not completely reflect the complex essence of the disease and whether the mode of initiation of the events in the multistep progression affects the outcome of CRC is still unknown. In this study, mRNA and miRNA expression profiling was performed with human colorectal tissues, including normal mucosa, adenoma and adenocarcinoma. Then, an integrated approach was adopted to establish the regulatory interaction networks that were correlated with colorectal carcinogenesis. Finally, a 55-gene signature whose expression was down-regulated in precancerous lesions compared to normal tissue was identified as a potential early indicator of CRC survival. The results suggested that genes related to immunity and homeostasis played a critical role in protection against adenoma initiation and that the altered molecular events that influence colorectal cancer prognosis may be set in an early, precancerous stage.
Project description:Approximately two decades ago, Vogelstein and Fearon proposed the adenoma-carcinoma sequence of sporadic CRC development and illustrated the accumulation of genetic alterations during the stepwise progression, thereby providing a guideline for clinical practice. Although the detection and excision of precancerous lesions could prevent colorectal cancer and reduce mortality, 6% of adenomas will ultimately develop into colorectal cancer. Thus, this genetic model for colorectal tumorigenesis may not completely reflect the complex essence of the disease and whether the mode of initiation of the events in the multistep progression affects the outcome of CRC is still unknown. In this study, mRNA and miRNA expression profiling was performed with human colorectal tissues, including normal mucosa, adenoma and adenocarcinoma. Then, an integrated approach was adopted to establish the regulatory interaction networks that were correlated with colorectal carcinogenesis. Finally, a 55-gene signature whose expression was down-regulated in precancerous lesions compared to normal tissue was identified as a potential early indicator of CRC survival. The results suggested that genes related to immunity and homeostasis played a critical role in protection against adenoma initiation and that the altered molecular events that influence colorectal cancer prognosis may be set in an early, precancerous stage.
Project description:Dysregulated miRNA in human colorectal cancer (CRC) were identified through comparison between 4 CRC tumors and their adjacent normal tissues by miRNA array. Histologically-confirmed CRC were included in this study. CRC tissues and paired adjacent normal tissues were obtained from the resected surgical specimens. The adjacent normal tissue is composed of normal colonic mucosa located at approximately 10 cm away from the cancer tissue. miRNA profiling of 754 human miRNAs was performed using TaqMan Human MiRNA Array Set v3.0. Quantitative real-time polymerase chain reaction (Q-PCR) was performed using Applied Biosystems 7900HT Real-Time PCR System (Applied Biosystems). Results were analyzed by the SDS RQ Manager 1.2 software (Applied Biosystems). 4 CRC tissues and 4 adjacent normal tissues were subjucted to qPCR based miRNA expression profiling. Equal amount of total RNA were used for analysis.
Project description:Colorectal cancer (CRC) tumorigenesis proceedes through well defined clinical stages assoicated with charateristic mutations. To get a better understanding of CRC progression at the transcriptional level, we performed transcriptome profiling on samples from normal colonic tissues, pre-malignant adenomas, carcinomas and metatases. We used Affymatrix microarry to get a broad view of gene expression during colorectal cancer progression and identified significantly differentially expressed genes between different stages
Project description:Dysregulated miRNA in human colorectal cancer (CRC) were identified through comparison between 4 CRC tumors and their adjacent normal tissues by miRNA array. Histologically-confirmed CRC were included in this study. CRC tissues and paired adjacent normal tissues were obtained from the resected surgical specimens. The adjacent normal tissue is composed of normal colonic mucosa located at approximately 10 cm away from the cancer tissue. miRNA profiling of 754 human miRNAs was performed using TaqMan Human MiRNA Array Set v3.0. Quantitative real-time polymerase chain reaction (Q-PCR) was performed using Applied Biosystems 7900HT Real-Time PCR System (Applied Biosystems). Results were analyzed by the SDS RQ Manager 1.2 software (Applied Biosystems).
Project description:To identify the regulatory mechanisms and signalling pathways involved in colorectal cancer (CRC) development, we compared the transcriptome of patient-derived tumor-initiating cells (TICs) with their normal stem cell counterparts of the same patient. This study demonstrates the relevance of AKT-signalling in colonic TIC proliferation and survival. Functional testing uncovered the selective AKT-inhibitor MK-2206 as a potential therapeutic for TIC-directed therapy in CRC. Gene expression profiling of tumor and normal tissues from 5 patients.
Project description:MicroRNAs (miRNA) are a class of small regulatory RNAs that mediate post-transcriptional silencing of specific target mRNAs. Data suggest the importance of miRNAs to cancer development and possibly to survival. Our overall hypothesis is that miRNA expression is unique to tumor molecular phenotype; that miRNA expression levels at time of diagnosis predicts survival; and that miRNA expression is associated with inflammation-related genetic and lifestyle factors key to colorectal cancer (CRC). This study takes a two pronged approach to addressing our hypotheses. While we propose to validate previously identified miRNAs that have been identified as associated with CRC (either by differential expression or from assessment of mutations), we will add to the field through discovery of new and important associations that may be unique to specific molecular phenotypes, to polyp to cancer progression, and to survival. We have analyzed the expression of 2006 human miRNAs using data derived from tumor and paired normal tissue at time of diagnosis from: 1975 people with incident colon cancer or rectal cancer and 290 polyps from colon and rectal cases (included in this study) who reported a prior polyp. MiRNA was obtained from dissected paraffin-embedded tissue and assessed using an Agilent microarray platform. We intend to extend our validation of previously identified mutated miRNAs and differentially expressed miRNAs to determine if these alterations are associated with specific tumor molecular phenotype (TP53, KRAS2, CIMP+, and for colon tumors MSI+), inflammation-related factors, clinical factors and survival. We will identify associations with miRNAs that are related to specific molecular phenotypes, with drivers in the carcinogenic process, and with clinical features and survival. These miRNAs will be validated using targeted Agilent Platform. Associations will be tested based on differential expression for both individual and groups of miRNAs using recent extensions of several statistical methods including ANOVA, logistic regression, and Cox proportional hazards models. Our sample size allows for both a training and validation component, and provides sufficient statistical power to meet the study goals. MiRNAs that are differentially expressed in polyps and in subsequent tumors will provide new insights into targets for screening and treatment as well as provide support that miRNAs function as the “driver” in the carcinogenic process. Testing of mutated miRNAs identified from sequencing in conjunction with tumor phenotype, clinical, and survival data will further validate the importance of these miRNAs, and provide insight as to which CRC molecular pathway the miRNAs function. Our rich dataset of lifestyle, genetic, clinical and prognosis, and tumor molecular phenotype on 1975 CRC and paired normal tissue allows us to examine factors that are associated with miRNA expression and mutation in a large sample of population-based cases in the most cost-efficient manner possible. The miRNAs identified in these analyses will elucidate pathways important in the etiology of CRC and will provide insight into potential targets for screening and treatment. MiRNAs are small, non-protein-coding RNA molecules that regulate gene expression either by post-transcriptionally suppressing mRNA translation or by mRNA degradation. We examine differentially expressed miRNAs in colorectal carcinomas, adenomas, and normal colonic mucosa. Data come from population-based studies of colorectal cancer conducted in Utah and the Kaiser Permanente Medical Care Program. A total of 1893 carcinoma/normal paired samples and 290 adenoma tissue samples were run on the Agilent Human miRNA Microarray V19.0 which contained 2006 miRNAs. We tested for significant differences in miRNA expression between paired carcinoma/adenoma/normal colonic tissue samples. Fewer than 600 miRNAs were expressed in >80% of people for colonic tissue; of these 86.5% were statistically differentially expressed between carcinoma and normal colonic mucosa using a False Discovery Rate of 0.05. Roughly half of these differentially expressed miRNAs showed a progression in levels of expression from normal to adenoma to carcinoma tissue. Other miRNAs appeared to be altered at the normal to adenoma stage, while others were only altered at the adenoma to carcinoma stage or only at the normal to carcinoma stage. Evaluation of the Agilent platform showed a high degree of repeatability (r=0.98) and reasonable agreement with the NanoString platform. Our data suggest that miRNAs are highly dysregulated in colorectal tissue among individuals with colorectal cancer; the pattern of disruption varies by miRNA as tissue progresses from normal to adenoma to carcinoma.