A multidimensional network approach reveals microRNAs as determinants of the mesenchymal colorectal cancer subtype
Colorectal cancer (CRC) is a heterogeneous disease posing a challenge for accurate classification and treatment of this malignancy. There is no common genetic molecular feature that would allow for the identification of patients at risk for developing recurrences and thus selecting patients who would benefit from more stringent therapies still poses a major clinical challenge. Recently, an international multicenter consortium (CRC Subtyping Consortium) was established aiming at the classification of CRC patients in biologically homogeneous CRC subtypes. Four consensus molecular subtypes (CMSs) were identified, of which the mesenchymal CMS4 presented with worse prognosis signifying the impor…
The AC133 epitope, but not the CD133 protein, is lost upon cancer stem cell differentiation.
Abstract Colon cancer stem cells (CSC) can be identified with AC133, an antibody that detects an epitope on CD133. However, recent evidence suggests that expression of CD133 is not restricted to CSCs, but is also expressed on differentiated tumor cells. Intriguingly, we observed that detection of the AC133 epitope on the cell surface decreased upon differentiation of CSC in a manner that correlated with loss of clonogenicity. However, this event did not coincide with a change in CD133 promoter activity, mRNA, splice variant, protein expression, or even cell surface expression of CD133. In contrast, we noted that with CSC differentiation, a change occured in CD133 glycosylation. Thus, AC133 …
AKT3 Expression in Mesenchymal Colorectal Cancer Cells Drives Growth and Is Associated with Epithelial-Mesenchymal Transition
Simple Summary Colorectal cancer can be subdivided into four distinct subtypes that are characterised by different clinical features and responses to therapies currently used in the clinic to treat this disease. One of those subtypes, called CMS4, is associated with a worse prognosis and poor response to therapies compared to other subtypes. We therefore set out to explore what proteins are differentially expressed and used in CMS4 to find potential new targets for therapy. We found that protein AKT3 is highly expressed in CMS4, and that active AKT3 inhibits a protein that stalls growth of cancer cells (p27KIP1). We can target AKT3 with inhibitors which leads to strongly reduced growth of c…
Wnt activity defines colon cancer stem cells and is regulated by the microenvironment.
Despite the presence of mutations in APC or beta-catenin, which are believed to activate the Wnt signalling cascade constitutively, most colorectal cancers show cellular heterogeneity when beta-catenin localization is analysed, indicating a more complex regulation of Wnt signalling. We explored this heterogeneity with a Wnt reporter construct and observed that high Wnt activity functionally designates the colon cancer stem cell (CSC) population. In adenocarcinomas, high activity of the Wnt pathway is observed preferentially in tumour cells located close to stromal myofibroblasts, indicating that Wnt activity and cancer stemness may be regulated by extrinsic cues. In agreement with this noti…
Additional file 1 of Subtype-specific kinase dependency regulates growth and metastasis of poor-prognosis mesenchymal colorectal cancer
Additional file 1: Supplementary Fig. S1. Validation of PAK2 as an essential kinase for CMS4 cell lines. A, PAK1–3 mRNA expression levels in a panel of 28 CRC cell lines, also including those used for the drop-out screen, as determined by quantitative PCR. Of note: diamond for PAK3 located on x-axis indicates no mRNA could be detected in this sample. B, C, 2Log mRNA expression levels of PAK4–6 in CRC cell lines (B) and tumors (C), determined by microarray or RNA sequencing. D, Western blot for PAK1 protein expression in HT55 & SW948 (CMS2) and HuTu-80 & MDST8 (CMS4). 2,2,2-Trichloroethanol (2,2,2TCE) signal (excerpt taken around 60 kDa region) indicates amount of protein loaded per …
Subtype-specific kinase dependency regulates growth and metastasis of poor-prognosis mesenchymal colorectal cancer
Abstract Background Colorectal cancer (CRC) can be divided into four consensus molecular subtypes (CMS), each with distinct biological features. CMS4 is associated with epithelial-mesenchymal transition and stromal infiltration (Guinney et al., Nat Med 21:1350–6, 2015; Linnekamp et al., Cell Death Differ 25:616–33, 2018), whereas clinically it is characterized by lower responses to adjuvant therapy, higher incidence of metastatic spreading and hence dismal prognosis (Buikhuisen et al., Oncogenesis 9:66, 2020). Methods To understand the biology of the mesenchymal subtype and unveil specific vulnerabilities, a large CRISPR-Cas9 drop-out screen was performed on 14 subtyped CRC cell lines to un…
Additional file 10 of Subtype-specific kinase dependency regulates growth and metastasis of poor-prognosis mesenchymal colorectal cancer
Additional file 10. Full Western blot membrane images represented in the manuscript.
Colon Cancer Stem Cells Dictate Tumor Growth and Resist Cell Death by Production of Interleukin-4
A novel paradigm in tumor biology suggests that cancer growth is driven by stem-like cells within a tumor. Here, we describe the identification and characterization of such cells from colon carcinomas using the stem cell marker CD133 that accounts around 2% of the cells in human colon cancer. The CD133(+) cells grow in vitro as undifferentiated tumor spheroids, and they are both necessary and sufficient to initiate tumor growth in immunodeficient mice. Xenografts resemble the original human tumor maintaining the rare subpopulation of tumorigenic CD133(+) cells. Further analysis revealed that the CD133(+) cells produce and utilize IL-4 to protect themselves from apoptosis. Consistently, trea…
Cancer stem cells – old concepts, new insights
Cancer has long been viewed as an exclusively genetic disorder. The model of carcinogenesis, postulated by Nowell and Vogelstein, describes the formation of a tumor by the sequential accumulation of mutations in oncogenes and tumor suppressor genes. In this model, tumors are thought to consist of a heterogeneous population of cells that continue to acquire new mutations, resulting in a highly dynamic process, with clones that out compete others due to increased proliferative or survival capacity. However, novel insights in cancer stem cell research suggest another layer of complexity in the process of malignant transformation and preservation. It has been reported that only a small fraction…
Stem cell functionality is microenvironmentally defined during tumour expansion and therapy response in colon cancer
Solid malignancies have been speculated to depend on cancer stem cells (CSCs) for expansion and relapse after therapy. Here we report on quantitative analyses of lineage tracing data from primary colon cancer xenograft tissue to assess CSC functionality in a human solid malignancy. The temporally obtained clone size distribution data support a model in which stem cell function in established cancers is not intrinsically, but is entirely spatiotemporally orchestrated. Functional stem cells that drive tumour expansion predominantly reside at the tumour edge, close to cancer-associated fibroblasts. Hence, stem cell properties change in time depending on the cell location. Furthermore, although…
Consensus molecular subtypes of colorectal cancer are recapitulated in in vitro and in vivo models
Colorectal cancer (CRC) is a highly heterogeneous disease both from a molecular and clinical perspective. Several distinct molecular entities, such as microsatellite instability (MSI), have been defined that make up biologically distinct subgroups with their own clinical course. Recent data indicated that CRC can be best segregated into four groups called consensus molecular subtypes (CMS1-4), each of which has a unique biology and gene expression pattern. In order to develop improved, subtype-specific therapies and to gain insight into the molecular wiring and origin of these subtypes, reliable models are needed. This study was designed to determine the heterogeneity and identify the prese…
Single-cell cloning of colon cancer stem cells reveals a multi-lineage differentiation capacity.
Colon carcinoma is one of the leading causes of death from cancer and is characterized by a heterogenic pool of cells with distinct differentiation patterns. Recently, it was reported that a population of undifferentiated cells from a primary tumor, so-called cancer stem cells (CSC), can reconstitute the original tumor on xenotransplantation. Here, we show that spheroid cultures of these colon CSCs contain expression of CD133, CD166, CD44, CD29, CD24, Lgr5, and nuclear β-catenin, which have all been suggested to mark the (cancer) stem cell population. More importantly, by using these spheroid cultures or freshly isolated tumor cells from multiple colon carcinomas, we now provide compelling…
Assessing the carcinogenic potential of low-dose exposures to chemical mixtures in the environment: the challenge ahead
Goodson, William H. et al.
Additional file 8 of Subtype-specific kinase dependency regulates growth and metastasis of poor-prognosis mesenchymal colorectal cancer
Additional file 8: Table S1. Raw normalized sgRNA counts per sample per cell line of the CRISPR-Cas9 drop-out screen performed.
Additional file 9 of Subtype-specific kinase dependency regulates growth and metastasis of poor-prognosis mesenchymal colorectal cancer
Additional file 9: Table S2. Results from analysis of CRISPR-Cas9 drop-out screen representing the fold change within each replicate of sgRNA counts between t1 and t0.