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  • 1
    Publication Date: 2011-10-21
    Description: Angiogenesis is critical during tumour initiation and malignant progression. Different strategies aimed at blocking vascular endothelial growth factor (VEGF) and its receptors have been developed to inhibit angiogenesis in cancer patients. It has become increasingly clear that in addition to its effect on angiogenesis, other mechanisms including a direct effect of VEGF on tumour cells may account for the efficiency of VEGF-blockade therapies. Cancer stem cells (CSCs) have been described in various cancers including squamous tumours of the skin. Here we use a mouse model of skin tumours to investigate the impact of the vascular niche and VEGF signalling on controlling the stemness (the ability to self renew and differentiate) of squamous skin tumours during the early stages of tumour progression. We show that CSCs of skin papillomas are localized in a perivascular niche, in the immediate vicinity of endothelial cells. Furthermore, blocking VEGFR2 caused tumour regression not only by decreasing the microvascular density, but also by reducing CSC pool size and impairing CSC renewal properties. Conditional deletion of Vegfa in tumour epithelial cells caused tumours to regress, whereas VEGF overexpression by tumour epithelial cells accelerated tumour growth. In addition to its well-known effect on angiogenesis, VEGF affected skin tumour growth by promoting cancer stemness and symmetric CSC division, leading to CSC expansion. Moreover, deletion of neuropilin-1 (Nrp1), a VEGF co-receptor expressed in cutaneous CSCs, blocked VEGF's ability to promote cancer stemness and renewal. Our results identify a dual role for tumour-cell-derived VEGF in promoting cancer stemness: by stimulating angiogenesis in a paracrine manner, VEGF creates a perivascular niche for CSCs, and by directly affecting CSCs through Nrp1 in an autocrine loop, VEGF stimulates cancer stemness and renewal. Finally, deletion of Nrp1 in normal epidermis prevents skin tumour initiation. These results may have important implications for the prevention and treatment of skin cancers.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Beck, Benjamin -- Driessens, Gregory -- Goossens, Steven -- Youssef, Khalil Kass -- Kuchnio, Anna -- Caauwe, Amelie -- Sotiropoulou, Panagiota A -- Loges, Sonja -- Lapouge, Gaelle -- Candi, Aurelie -- Mascre, Guilhem -- Drogat, Benjamin -- Dekoninck, Sophie -- Haigh, Jody J -- Carmeliet, Peter -- Blanpain, Cedric -- England -- Nature. 2011 Oct 19;478(7369):399-403. doi: 10.1038/nature10525.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉IRIBHM, Universite Libre de Bruxelles, 808 route de Lennik, 1070 Brussels, Belgium.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/22012397" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Carcinoma, Squamous Cell/*blood supply/*pathology ; Cell Differentiation ; Cell Proliferation ; Cells, Cultured ; Disease Models, Animal ; Epithelial Cells/cytology ; Gene Deletion ; Gene Expression Regulation, Neoplastic ; Mice ; Neoplastic Stem Cells ; Neuropilin-1/genetics/*metabolism ; *Signal Transduction ; Skin Neoplasms/*blood supply/*pathology ; Vascular Endothelial Growth Factor A/genetics/*metabolism
    Print ISSN: 0028-0836
    Electronic ISSN: 1476-4687
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
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  • 2
    Publication Date: 2014-06-10
    Description: Cancer stem cells (CSCs) have been reported in various cancers, including in skin squamous-cell carcinoma (SCC). The molecular mechanisms regulating tumour initiation and stemness are still poorly characterized. Here we find that Sox2, a transcription factor expressed in various types of embryonic and adult stem cells, was the most upregulated transcription factor in the CSCs of squamous skin tumours in mice. SOX2 is absent in normal epidermis but begins to be expressed in the vast majority of mouse and human pre-neoplastic skin tumours, and continues to be expressed in a heterogeneous manner in invasive mouse and human SCCs. In contrast to other SCCs, in which SOX2 is frequently genetically amplified, the expression of SOX2 in mouse and human skin SCCs is transcriptionally regulated. Conditional deletion of Sox2 in the mouse epidermis markedly decreases skin tumour formation after chemical-induced carcinogenesis. Using green fluorescent protein (GFP) as a reporter of Sox2 transcriptional expression (SOX2-GFP knock-in mice), we showed that SOX2-expressing cells in invasive SCC are greatly enriched in tumour-propagating cells, which further increase upon serial transplantations. Lineage ablation of SOX2-expressing cells within primary benign and malignant SCCs leads to tumour regression, consistent with the critical role of SOX2-expressing cells in tumour maintenance. Conditional Sox2 deletion in pre-existing skin papilloma and SCC leads to tumour regression and decreases the ability of cancer cells to be propagated upon transplantation into immunodeficient mice, supporting the essential role of SOX2 in regulating CSC functions. Transcriptional profiling of SOX2-GFP-expressing CSCs and of tumour epithelial cells upon Sox2 deletion uncovered a gene network regulated by SOX2 in primary tumour cells in vivo. Chromatin immunoprecipitation identified several direct SOX2 target genes controlling tumour stemness, survival, proliferation, adhesion, invasion and paraneoplastic syndrome. We demonstrate that SOX2, by marking and regulating the functions of skin tumour-initiating cells and CSCs, establishes a continuum between tumour initiation and progression in primary skin tumours.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Boumahdi, Soufiane -- Driessens, Gregory -- Lapouge, Gaelle -- Rorive, Sandrine -- Nassar, Dany -- Le Mercier, Marie -- Delatte, Benjamin -- Caauwe, Amelie -- Lenglez, Sandrine -- Nkusi, Erwin -- Brohee, Sylvain -- Salmon, Isabelle -- Dubois, Christine -- del Marmol, Veronique -- Fuks, Francois -- Beck, Benjamin -- Blanpain, Cedric -- England -- Nature. 2014 Jul 10;511(7508):246-50. doi: 10.1038/nature13305. Epub 2014 Jun 8.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Universite Libre de Bruxelles, IRIBHM, Brussels B-1070, Belgium. ; 1] Universite Libre de Bruxelles, IRIBHM, Brussels B-1070, Belgium [2]. ; 1] Department of Pathology, Erasme Hospital, Universite Libre de Bruxelles, Brussels B-1070, Belgium [2] DIAPATH-Center for Microscopy and Molecular Imaging (CMMI), Gosselies B-6041, Belgium. ; Department of Pathology, Erasme Hospital, Universite Libre de Bruxelles, Brussels B-1070, Belgium. ; Laboratory of Cancer Epigenetics, Universite Libre de Bruxelles, Brussels B-1070, Belgium. ; Machine Learning Group, Computer Science Department, Faculte des Sciences, Universite Libre de Bruxelles, Brussels B-1050, Belgium. ; Department of Dermatology, Erasme Hospital, Universite Libre de Bruxelles, Brussels B-1070, Belgium. ; 1] Universite Libre de Bruxelles, IRIBHM, Brussels B-1070, Belgium [2] WELBIO, Universite Libre de Bruxelles, Brussels B-1070, Belgium.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/24909994" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; *Carcinoma, Squamous Cell/genetics/pathology ; Cell Adhesion/genetics ; Cell Proliferation ; Cell Transformation, Neoplastic/*genetics/metabolism ; Disease Models, Animal ; Gene Deletion ; Gene Expression Profiling ; Gene Expression Regulation, Neoplastic ; Gene Knockdown Techniques ; Gene Regulatory Networks/genetics ; Mice ; Mice, Inbred Strains ; Neoplastic Stem Cells/*metabolism ; SOXB1 Transcription Factors/genetics/*metabolism ; *Skin Neoplasms/genetics/pathology
    Print ISSN: 0028-0836
    Electronic ISSN: 1476-4687
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
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  • 3
    Publication Date: 2012-08-03
    Description: Recent studies using the isolation of a subpopulation of tumour cells followed by their transplantation into immunodeficient mice provide evidence that certain tumours, including squamous skin tumours, contain cells with high clonogenic potential that have been referred to as cancer stem cells (CSCs). Until now, CSC properties have only been investigated by transplantation assays, and their existence in unperturbed tumour growth is unproven. Here we make use of clonal analysis of squamous skin tumours using genetic lineage tracing to unravel the mode of tumour growth in vivo in its native environment. To this end, we used a genetic labelling strategy that allows individual tumour cells to be marked and traced over time at different stages of tumour progression. Surprisingly, we found that the majority of labelled tumour cells in benign papilloma have only limited proliferative potential, whereas a fraction has the capacity to persist long term, giving rise to progeny that occupy a significant part of the tumour. As well as confirming the presence of two distinct proliferative cell compartments within the papilloma, mirroring the composition, hierarchy and fate behaviour of normal tissue, quantitative analysis of clonal fate data indicates that the more persistent population has stem-cell-like characteristics and cycles twice per day, whereas the second represents a slower cycling transient population that gives rise to terminally differentiated tumour cells. Such behaviour is shown to be consistent with double-labelling experiments and detailed clonal fate characteristics. By contrast, measurements of clone size and proliferative potential in invasive squamous cell carcinoma show a different pattern of behaviour, consistent with geometric expansion of a single CSC population with limited potential for terminal differentiation. This study presents the first experimental evidence for the existence of CSCs during unperturbed solid tumour growth.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Driessens, Gregory -- Beck, Benjamin -- Caauwe, Amelie -- Simons, Benjamin D -- Blanpain, Cedric -- 079249/Wellcome Trust/United Kingdom -- 092096/Wellcome Trust/United Kingdom -- England -- Nature. 2012 Aug 23;488(7412):527-30. doi: 10.1038/nature11344.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Universite Libre de Bruxelles, IRIBHM, Brussels B-1070, Belgium.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/22854777" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Carcinoma, Squamous Cell/genetics/pathology ; Cell Count ; Cell Differentiation ; *Cell Lineage ; Cell Proliferation ; *Cell Tracking ; Clone Cells/metabolism/pathology ; Disease Models, Animal ; Humans ; Mice ; Models, Biological ; Neoplastic Stem Cells/metabolism/pathology ; Skin Neoplasms/genetics/*pathology ; Stochastic Processes ; Tumor Microenvironment
    Print ISSN: 0028-0836
    Electronic ISSN: 1476-4687
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
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  • 4
    Publication Date: 2018-12-04
    Description: Tumors use indoleamine 2,3-dioxygenase-1 (IDO1) as a major mechanism to induce an immunosuppressive microenvironment. IDO1 expression is upregulated in many cancers and considered to be a resistance mechanism to immune checkpoint therapies. IDO1 is induced in response to inflammatory stimuli such as IFN and promotes immune tolerance by depleting tryptophan and producing tryptophan catabolites, including kynurenine, in the tumor microenvironment. This leads to effector T-cell anergy and enhanced T reg function through upregulation of FoxP3. As a nexus for the induction of key immunosuppressive mechanisms, IDO1 represents an important immunotherapeutic target in oncology. Here, we report the identification and characterization of the novel selective, orally bioavailable IDO1 inhibitor EOS200271/PF-06840003. It reversed IDO1-induced T-cell anergy in vitro . In mice carrying syngeneic tumor grafts, PF-06840003 reduced intratumoral kynurenine levels by over 80% and inhibited tumor growth both in monotherapy and, with an increased efficacy, in combination with antibodies blocking the immune checkpoint ligand PD-L1. We demonstrate that anti–PD-L1 therapy results in increased IDO1 metabolic activity thereby providing additional mechanistic rationale for combining PD-(L)1 blockade with IDO1 inhibition in cancer immunotherapies. Supported by these preclinical data and favorable predicted human pharmacokinetic properties of PF-06840003, a phase I open-label, multicenter clinical study (NCT02764151) has been initiated.
    Print ISSN: 1535-7163
    Electronic ISSN: 1538-8514
    Topics: Medicine
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