Project description:The consensus molecular subtype (CMS) classification divides colorectal cancer (CRC) into four distinct subtypes based on RNA-expression profiles. The biological differences between CMSs are already present in CRC precursor lesions, but not all CMSs pose the same risk of malignant transformation. To fully understand the path to malignant transformation and to determine whether CMS is a fixed entity during progression, genomic and transcriptomic data from two regions of the same CRC lesion were compared: the precursor and carcinoma region. In total, 24 patients that underwent endoscopic removal of T1-2 CRC were included. Regions were subtyped for CMS and DNA mutation analysis was performed. Additionally, a set of 85 benign adenomas was CMS subtyped. This analysis revealed that almost all benign adenomas were classified as CMS3 (91.8%). In contrast, CMS2 was the most prevalent subtype in precursor regions (66.7%), followed by CMS3 (29.2%). CMS4 was absent in precursor lesions and originated at the carcinoma stage. Importantly, CMS switching occurred in a substantial number of cases and almost all (6 out of 7) CMS3 precursor regions showed a shift to a different subtype in the carcinoma part of the lesion, which in 4 cases was classified as CMS4. In conclusion, our data indicate that CMS3 is related to a more indolent type of precursor lesions that less likely progresses to CRC and when this occurs it often associates with a subtype change that includes the more aggressive mesenchymal CMS4. In contrast, an acquired CMS2 signature appeared to be rather fixed during early CRC development. Combined our data shows that subtype changes occur during progression and that CMS3 switching is related to changes in the genomic background through acquisition of a novel driver mutation (TP53) or selective expansion of a clone, but also occurred independent of such genetic changes.
Project description:The consensus molecular subtype (CMS) classification divides colorectal cancer (CRC) into four distinct subtypes based on RNA-expression profiles. The biological differences between CMSs are already present in CRC precursor lesions, but not all CMSs pose the same risk of malignant transformation. To fully understand the path to malignant transformation and to determine whether CMS is a fixed entity during progression, genomic and transcriptomic data from two regions of the same CRC lesion were compared: the precursor and carcinoma region. In total, 24 patients that underwent endoscopic removal of T1-2 CRC were included. Regions were subtyped for CMS and DNA mutation analysis was performed. Additionally, a set of 85 benign adenomas was CMS subtyped. This analysis revealed that almost all benign adenomas were classified as CMS3 (91.8%). In contrast, CMS2 was the most prevalent subtype in precursor regions (66.7%), followed by CMS3 (29.2%). CMS4 was absent in precursor lesions and originated at the carcinoma stage. Importantly, CMS switching occurred in a substantial number of cases and almost all (6 out of 7) CMS3 precursor regions showed a shift to a different subtype in the carcinoma part of the lesion, which in 4 cases was classified as CMS4. In conclusion, our data indicate that CMS3 is related to a more indolent type of precursor lesions that less likely progresses to CRC and when this occurs it often associates with a subtype change that includes the more aggressive mesenchymal CMS4. In contrast, an acquired CMS2 signature appeared to be rather fixed during early CRC development. Combined our data shows that subtype changes occur during progression and that CMS3 switching is related to changes in the genomic background through acquisition of a novel driver mutation (TP53) or selective expansion of a clone, but also occurred independent of such genetic changes.
Project description:Recently a consensus molecular subtype (CMS) classification of colorectal cancer (CRC) has been established that is based on the transcriptional rather than the genetic profile of an individual tumor and which may ultimately help to individualize CRC therapy. So far, however, the lack of appropriate animal models that faithfully recapitulate the different molecular subtypes impedes adequate preclinical testing of stratified therapeutic concepts. Here we demonstrate that constitutive AKT activation in intestinal epithelial cells markedly enhances colonic tumor invasion and metastasis in Trp53DIEC mice (Trp53ΔIECAktE17K) upon challenge with the carcinogen azoxymethane (AOM). Gene-expression profiling indicates that Trp53ΔIECAktE17K tumors closely resemble the human mesenchymal colorectal cancer subtype (CMS4), which is characterized by the poorest survival rate among the four consensus molecular subtypes of CRC. Trp53ΔIECAktE17K tumors are further characterized by a NOTCH pathway gene signature and a distinct cell autonomous upregulation of Notch3 in tumor epithelia while treatment of Trp53ΔIECAktE17K mice with a NOTCH3-inhibiting antibody reduces invasion and metastasis. Conversely, selective activation of NOTCH3 by overexpression of NOTCH3-IC in Akt wt tumor organoids strongly promotes development of metastasis in an orthotopic transplantation model. In CRC patients NOTCH3 expression correlates positively with tumor grading and the presence of lymph node as well as distant metastases and is specifically upregulated in CMS4 tumors. Therefore, we suggest NOTCH3 as a putative target for advanced CMS4 CRC 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).