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Morrissey E.R.,University of Cambridge | Vermeulen L.,Center for Experimental Molecular Medicine
EMBO Journal | Year: 2014

How mutations lead to tumor formation is a central question in cancer research. Although cellular changes that follow the occurrence of common mutations are well characterized, much less is known about their effects on the population level. Now, two recent studies reveal in what way oncogenic aberrations alter stem cell dynamics to provide cells with an evolutionary advantage over their neighbors (Amoyel et al,; Baker et al,). A new study on clonal tracing in human tissue validates the concept of neutral competition, earlier revealed by genetic manipulation in various model organisms. © 2014 The Authors.

Vermeulen L.,Center for Experimental Molecular Medicine | Meijer G.A.,VU University Amsterdam
Nature Reviews Gastroenterology and Hepatology | Year: 2015

Colorectal cancer (CRC) is considered a heterogeneous disease, both regarding pathogenesis and clinical behaviour. Four decades ago, the adenoma-carcinoma pathway was presented as the main pathway towards CRC, a conclusion that was largely based on evidence from observational morphological studies. This concept was later substantiated at the genomic level. Over the past decade, evidence has been generated for alternative routes in which CRC might develop, in particular the serrated neoplasia pathway. Providing indisputable evidence for the neoplastic potential of serrated polyps has been difficult. Reasons include the absence of reliable longitudinal observations on individual serrated lesions that progress to cancer, a shortage of available animal models for serrated lesions and challenging culture conditions when generating organoids of serrated lesions for in vitro studies. However, a growing body of circumstantial evidence has been accumulated, which indicates that ≥ 15% of CRCs might arise through the serrated neoplasia pathway. An even larger amount of post-colonoscopy colorectal carcinomas (carcinomas occurring within the surveillance interval after a complete colonoscopy) have been suggested to originate from serrated polyps. The aim of this Review is to assess the current status of the serrated neoplasia pathway in CRC and highlight clinical implications. © 2015 Macmillan Publishers Limited.

Kemper K.,Center for Experimental Molecular Medicine
Oncotarget | Year: 2010

Tumor initiating or cancer stem cells (CSCs) are suggested to be responsible for tumor initiation and growth. Moreover, therapy resistance and minimal residual disease are thought to result from selective resistance of CSCs. Isolation of CSCs from colon carcinomas can be accomplished by selection of a subpopulation of tumor cells based on expression of one or multiple cell surface markers associated with cancer stemness, like CD133, CD44, CD24, CD29, CD166 and Lgr5. Identification of colon CSCs will lead to a better rational for new therapies that aim to target this fraction specifically. In this review, we analyze known markers used for selection of colon CSCs and their potential function in CSC biology. Moreover, we discuss potential targeting strategies for eradicating CSCs specifically in order to develop more effective therapeutic strategies as well as to address more fundamental questions like the actual role of CSCs in tumor growth.

Sottoriva A.,University of Cambridge | Vermeulen L.,Center for Experimental Molecular Medicine | Tavare S.,University of Cambridge
PLoS Computational Biology | Year: 2011

The cancer stem cell (CSC) concept is a highly debated topic in cancer research. While experimental evidence in favor of the cancer stem cell theory is apparently abundant, the results are often criticized as being difficult to interpret. An important reason for this is that most experimental data that support this model rely on transplantation studies. In this study we use a novel cellular Potts model to elucidate the dynamics of established malignancies that are driven by a small subset of CSCs. Our results demonstrate that epigenetic mutations that occur during mitosis display highly altered dynamics in CSC-driven malignancies compared to a classical, non-hierarchical model of growth. In particular, the heterogeneity observed in CSC-driven tumors is considerably higher. We speculate that this feature could be used in combination with epigenetic (methylation) sequencing studies of human malignancies to prove or refute the CSC hypothesis in established tumors without the need for transplantation. Moreover our tumor growth simulations indicate that CSC-driven tumors display evolutionary features that can be considered beneficial during tumor progression. Besides an increased heterogeneity they also exhibit properties that allow the escape of clones from local fitness peaks. This leads to more aggressive phenotypes in the long run and makes the neoplasm more adaptable to stringent selective forces such as cancer treatment. Indeed when therapy is applied the clone landscape of the regrown tumor is more aggressive with respect to the primary tumor, whereas the classical model demonstrated similar patterns before and after therapy. Understanding these often counter-intuitive fundamental properties of (non-)hierarchically organized malignancies is a crucial step in validating the CSC concept as well as providing insight into the therapeutical consequences of this model. © 2011 Sottoriva et al.

Sottoriva A.,University of Cambridge | Sloot P.M.A.,University of Amsterdam | Medema J.P.,Center for Experimental Molecular Medicine | Vermeulen L.,Center for Experimental Molecular Medicine
Cell Cycle | Year: 2010

The finding that only a sub-fraction of tumor cells, so called Cancer Stem Cells (CSC), is endowed with the capacity to initiate new tumors has important consequences for fundamental as well as clinical cancer research. Previously we established by computational modeling techniques that CSC driven tumor growth instigates infiltrative behavior, and perhaps most interesting, stimulates tumor cell heterogeneity. An important question that remains is to what extend CSC functions are intrinsically regulated or whether this capacity is orchestrated by the microenvironment, i.e., a putative CSC niche. Here we investigate how extrinsic regulation of CSC properties affects the characteristics of malignancies. We find that highly invasive growth in tumors dependent on a small subset of cells is not restricted to CSC-driven tumors, but is also observed in tumors where the CSC capacity of tumor cells is completely defined by the microenvironment. Importantly, also the high level of heterogeneity that was observed for CSC-driven tumors is preserved and partially even increased in malignancies with a microenvironmentally orchestrated CSC population. This indicates that invasive growth and high heterogeneity are fundamental properties of tumors fueled by a small population of tumor cells. © 2010 Landes Bioscience.

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