{"title":"散发性早发性直肠腺癌基因表达分析。","authors":"V Nfonsam, W Xu, J Koblinski, J Jandova","doi":"","DOIUrl":null,"url":null,"abstract":"<p><strong>Background: </strong>Overall declines in incidence of rectal cancer (RC) in patients older than 50 years have been mostly attributed to improvement in treatment modalities and introduction of age-based screening. Recent studies, however, have shown a rise in the incidence of RC in patients younger than 50 years. The etiology of early-onset (EO) RC is not well understood. The aim of this study is to elucidate the molecular features of (EO) RC and show its uniqueness compared to late-onset (LO) disease.</p><p><strong>Methods: </strong>Two cohorts of patients with sporadic RC were identified. Tumors and matching non-involved tissues from six (EO) RC patients (< 50 years) and six (LO) RC patients (>65 years) were obtained from Pathology archives. Deparaffinized tissues were macro-dissected from FFPE sections, RNA isolated and used for expression profiling of 770 cancer related genes representing 13 canonical pathways. Statistical analysis was performed using the Gene Expression R-script module within the nCounter software v2.6. A gene was considered to be above background if the average count for the target gene was greater than the average counts for the eight negative control genes and if the P value of the t-test was less than 0.05.</p><p><strong>Results: </strong>When we compared rectal tumors to non-involved rectal tissues, changes in expression levels of 171 genes were statistically significant in early-onset group and 151 genes in late-onset group. Further comparative gene expression analysis between early- and late-onset rectal tumors normalized to their matching non-involved tissues revealed that changes in expression of 65 genes were unique to early-onset rectal tumors with 16 genes being up- and 49 genes down-regulated using the cutoff criteria of expression levels difference >2 fold and p-value <0.01. At the pathway level, MAPK signaling was the most deregulated pathway in early-onset rectal tumors compared to PI3K-AKT signaling pathway being the most deregulated in late-onset rectal tumors.</p><p><strong>Conclusions: </strong>Results of this study suggest that sporadic early-onset rectal cancer is characterized by distinct molecular events compared to late-onset disease.</p>","PeriodicalId":91867,"journal":{"name":"Gastrointestinal cancer : research & therapy","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5321608/pdf/nihms812213.pdf","citationCount":"0","resultStr":"{\"title\":\"Gene Expression Analysis of Sporadic Early-Onset Rectal Adenocarcinoma.\",\"authors\":\"V Nfonsam, W Xu, J Koblinski, J Jandova\",\"doi\":\"\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p><strong>Background: </strong>Overall declines in incidence of rectal cancer (RC) in patients older than 50 years have been mostly attributed to improvement in treatment modalities and introduction of age-based screening. Recent studies, however, have shown a rise in the incidence of RC in patients younger than 50 years. The etiology of early-onset (EO) RC is not well understood. The aim of this study is to elucidate the molecular features of (EO) RC and show its uniqueness compared to late-onset (LO) disease.</p><p><strong>Methods: </strong>Two cohorts of patients with sporadic RC were identified. Tumors and matching non-involved tissues from six (EO) RC patients (< 50 years) and six (LO) RC patients (>65 years) were obtained from Pathology archives. Deparaffinized tissues were macro-dissected from FFPE sections, RNA isolated and used for expression profiling of 770 cancer related genes representing 13 canonical pathways. Statistical analysis was performed using the Gene Expression R-script module within the nCounter software v2.6. A gene was considered to be above background if the average count for the target gene was greater than the average counts for the eight negative control genes and if the P value of the t-test was less than 0.05.</p><p><strong>Results: </strong>When we compared rectal tumors to non-involved rectal tissues, changes in expression levels of 171 genes were statistically significant in early-onset group and 151 genes in late-onset group. Further comparative gene expression analysis between early- and late-onset rectal tumors normalized to their matching non-involved tissues revealed that changes in expression of 65 genes were unique to early-onset rectal tumors with 16 genes being up- and 49 genes down-regulated using the cutoff criteria of expression levels difference >2 fold and p-value <0.01. At the pathway level, MAPK signaling was the most deregulated pathway in early-onset rectal tumors compared to PI3K-AKT signaling pathway being the most deregulated in late-onset rectal tumors.</p><p><strong>Conclusions: </strong>Results of this study suggest that sporadic early-onset rectal cancer is characterized by distinct molecular events compared to late-onset disease.</p>\",\"PeriodicalId\":91867,\"journal\":{\"name\":\"Gastrointestinal cancer : research & therapy\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":0.0000,\"publicationDate\":\"2016-01-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5321608/pdf/nihms812213.pdf\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Gastrointestinal cancer : research & therapy\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"2016/8/3 0:00:00\",\"PubModel\":\"Epub\",\"JCR\":\"\",\"JCRName\":\"\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Gastrointestinal cancer : research & therapy","FirstCategoryId":"1085","ListUrlMain":"","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2016/8/3 0:00:00","PubModel":"Epub","JCR":"","JCRName":"","Score":null,"Total":0}
Gene Expression Analysis of Sporadic Early-Onset Rectal Adenocarcinoma.
Background: Overall declines in incidence of rectal cancer (RC) in patients older than 50 years have been mostly attributed to improvement in treatment modalities and introduction of age-based screening. Recent studies, however, have shown a rise in the incidence of RC in patients younger than 50 years. The etiology of early-onset (EO) RC is not well understood. The aim of this study is to elucidate the molecular features of (EO) RC and show its uniqueness compared to late-onset (LO) disease.
Methods: Two cohorts of patients with sporadic RC were identified. Tumors and matching non-involved tissues from six (EO) RC patients (< 50 years) and six (LO) RC patients (>65 years) were obtained from Pathology archives. Deparaffinized tissues were macro-dissected from FFPE sections, RNA isolated and used for expression profiling of 770 cancer related genes representing 13 canonical pathways. Statistical analysis was performed using the Gene Expression R-script module within the nCounter software v2.6. A gene was considered to be above background if the average count for the target gene was greater than the average counts for the eight negative control genes and if the P value of the t-test was less than 0.05.
Results: When we compared rectal tumors to non-involved rectal tissues, changes in expression levels of 171 genes were statistically significant in early-onset group and 151 genes in late-onset group. Further comparative gene expression analysis between early- and late-onset rectal tumors normalized to their matching non-involved tissues revealed that changes in expression of 65 genes were unique to early-onset rectal tumors with 16 genes being up- and 49 genes down-regulated using the cutoff criteria of expression levels difference >2 fold and p-value <0.01. At the pathway level, MAPK signaling was the most deregulated pathway in early-onset rectal tumors compared to PI3K-AKT signaling pathway being the most deregulated in late-onset rectal tumors.
Conclusions: Results of this study suggest that sporadic early-onset rectal cancer is characterized by distinct molecular events compared to late-onset disease.