Project description:Colorectal cancer can be divided into four consensus molecular subtypes, which might associate with distinct precursor lesions. The aim of this study was to determine the subtype affiliation of two types of colorectal adenomas: tubular adenomas (TAs) and sessile serrated adenomas (SSAs) and to determine the activity of TGFβ signaling and the role of this cytokine in subtype affiliation. Adenoma samples were collected in the Academic Medical Center (AMC), Amsterdam, The Netherlands. Tubular adenomas (TAs) were obtained from familial adenomatous polyposis (FAP) patients and sessile serrated adenomas (SSAs) were collected from serrated polyposis syndrome (SPS) patients.
Project description:Colorectal cancer can be divided into four consensus molecular subtypes, which might associate with distinct precursor lesions. The aim of this study was to determine the subtype affiliation of two types of colorectal adenomas: tubular adenomas (TAs) and sessile serrated adenomas (SSAs) and to determine the activity of TGFβ signaling and the role of this cytokine in subtype affiliation. Adenoma samples were collected in the Academic Medical Center (AMC), Amsterdam, The Netherlands. Tubular adenomas (TAs) were obtained from familial adenomatous polyposis (FAP) patients and sessile serrated adenomas (SSAs) were collected from serrated polyposis syndrome (SPS) patients. Gene expression was analyzed for 7 sessile serrated adenomas (SSA) and 9 tubular adenomas (TA).
Project description:Sessile serrated adenomas are now recognized as precursor lesions of a substantial subset of colorectal cancers arising via a so-called “serrated pathway”. However, their biological markers remain to be defined. The aim of our study was to identify differentially expressed genes in sessile serrated adenomas, hyperplastic polyps and tubular adenomas. Gene expression analysis demonstrated molecular differences between polyp types. Further studies using QRT-PCR on Cathepsin E demonstrated a significantly (p< 0.05) higher expression in sessile serrated adenomas as compared to both other polyp types. Trefoil Factor 1, showed the same trend of expression for sessile serrated adenomas as compared to hyperplastic polyps, and was significantly higher in both polyps compared to tubular adenomas. Immunohistochemistry for both proteins demonstrated strong cytoplasmic staining of abnormal crypts in all sessile serrated adenomas while staining in tubular adenomas and hyperplastic polyps was weak and focal. BRAF and KRAS mutation analysis were employed to further validate polyp discrimination. The findings demonstrated the positive association of the BRAF mutation, V600E, with sessile serrated adenomas and KRAS mutations with tubular adenomas (P<0.05). This study demonstrates CTSE and TFF1 over-expression in sessile serrated adenomas compared to both hyperplastic polyps and tubular adenomas. Keywords: colonic polyp tissue comparison, linear modelling, SSA
Project description:Traditional serrated adenomas (TSAs) are rare colorectal polyps characterized by unique histology features. Fusions in R-spondin genes have been found in TSAs, but it is not clear whether these are sufficient for TSA development. We established 2 patient-derived TSA organoid lines, and engineered chromosome rearrangements that involve R-spondin genes into human colonic organoids using CRISPR-Cas9. Consequently, we highlighted the similarity of the gene expression patterns between TSA organoids and engineered organoids.
Project description:The CpG island methylator phenotype is common in both BRAF mutant colorectal cancer and their precursors, the sessile serrated adenoma (SSA). SSAs acquire dysplasia immediate prior to progressing to invasive cancer. Here we examine the methylome of the remnant non-dysplastic portion of dysplastic sessile serrated adenomas to identify changes that occur immediately prior to the development of overt histological dysplasia.
Project description:Profiling project of a panel of tubular adenoma and serrated adenoma patient material collected in the Academic Medical Center (AMC) in Amsterdam, The Netherlands. The aim of the study was to compare the expression profiles of different types of colon cancer precursor lesions (tubular versus serrated adenomas) and determine their correspondence with a set of colon cancer patient-derived profiles that have distinct clinical outcomes. 6 serrated adenomas and 7 tubular adenomas are profiled in this study.
