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Cell-cell interactions in control of tissue homeostasis, tumor development and parasitic infection / Request for a Laser Capture Microdissection Apparatus

English title Cell-cell interactions in control of tissue homeostasis, tumor development and parasitic infection / Request for a Laser Capture Microdissection Apparatus
Applicant Dotto Gian-Paolo
Number 121329
Funding scheme R'EQUIP
Research institution Centre Integratif de Genomique Faculté de Biologie et Médecine Université de Lausanne
Institution of higher education University of Lausanne - LA
Main discipline Dermatology
Start/End 01.10.2008 - 31.01.2010
Approved amount 203'095.00
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Keywords (8)

cancer; melanoma; skin UVB response; leishmania; parasite infection; Laser; Capture; Microdissection

Lay Summary (English)

Lead
Lay summary
Melanoma incidence is constantly increasing and prognosis remains poor if very early and complete removal of a primary lesion is not achieved. Emerging evidences indicate the importance of cross-regulation existing between melanocytes and surrounding cell populations under homeostatic and perturbed and/or neoplastic conditions. A major effort is ongoing to understand melanoma carcinogenesis by performing wide-scale gene expression analysis of cancer and surrounding cells. When applying microgenomics to explore the molecular process of melanoma development, it is essential that cells are not damaged during microdissection. Laser Capture Microdissection (LCM) offers a unique solution for minimal interference in cell integrity and immediate analysis of in vivo specimens, even in minute amounts. The state-of-the-art LCM apparatus that we have purchased with the support of this FNS grant, offers simultaneous LCM and fluorescence detection. These features will enable us to collect adjacent populations of different cells in subsequent steps, without damage of the surrounding tissue, for further biochemical analysis.
Direct link to Lay Summary Last update: 21.02.2013

Responsible applicant and co-applicants

Associated projects

Number Title Start Funding scheme
102212 La calcineurine dans le contrôle de la croissance-différenciation 01.10.2003 Project funding (Div. I-III)

Abstract

Homotypic and heterotypic cell-cell interactions are key to control of normal tissue homeostasis and their alterations play a critical role in the onset and extension of neoplastic as well as infectious diseases. Laser Capture Microdissection (LCM) provides a unique tool to probe into the reciprocal influences of various cell types in an intact organ under normal and pathological conditions and in response to clues from the environment. Recent advances in LCM apparatuses allow to couple this technique with surface immuno-labeling of cells, for the capture of several small subpopulations of closely juxtaposed cells. As such, the availability of this system will enable us to develop entirely new research efforts and potentiate and expand significantly the scope of others that we have currently in progress. The present application is based on two research proposals on: (I) Impact of UV light on melanoma development; (II) Role of neutrophils and B cells in the immune response to the protozoan parasite Leishmania major. The goals of these various efforts are summarized here below :I) Impact of UV light on melanoma developmentIt has been shown that UV light induces transient structural changes on benign nevi (moles) rendering them microscopically similar to melanoma in situ : one week after UV-irradiation, melanocytes appear spindle-shaped with a hyperchromatic nucleus and migrate from the basal layer towards the surface of epidermis (pagetoid spread) ; cells then return the their initial status after two or three weeks. In this particular situation, the cross-talk between melanocytes and surrounding skin cells of other type is dramatically altered. Our goal is to establish a molecular basis for these alterations by defining a cell-specific gene expression signature for the UV-mediated mimicry on benign melanocytic lesions that can contribute to melanoma conversion. Global mRNA analysis of the various cellular compartments, obtained by LCM, will be used to address the following specific aims: 1) We will test the hypothesis that melanocytes in benign nevi expresses genes with a specific intracellular regulatory function that are altered in response to UVB and contribute to melanoma development.2) We will test the hypothesis that other cells surrounding benign nevi, specifically keratinocytes and fibroblasts, express genes for diffusible factors that are altered in the response to UVB and that control, through a paracrine mechanism, the behavior of melanocytes, and their malignant behavior.II) Role of neutrophils and B cells in the immune response to Leishmania majorLeishmania major is a sandfly-transmitted protozoan parasite residing and replicating in phagocytes. Infection of humans or animals with L. major leads to a disease that is self-healing or chronic depending on the parasite strain and the genetic background of the host. The main goal of this study is to understand the role of neutrophils in the organization of an efficient immune response following infection with L. major, with potential therapeutics applications in Leishmania and also other types of infections. More specifically, we are interested to compare neutrophils in mice susceptible or resistant to infection. Global mRNA analysis of the various cellular compartments, obtained by LCM, will be used to address the following specific aims: 1) We will test the hypothesis that neutrophils from mice resistant or susceptible to infection with L. major secrete distinct chemokine pattern contributing to distinct cellular recruitment and activation at the site of infection resulting in the shaping of a protective (CD4+ Th1) or resistant (CD4+ Th2) immune response.2) We will test the hypothesis that other cells surrounding neutrophils, specifically dendritic cells, express genes that are influenced by the presence of neutrophils, comparing cells obtained from resistant and susceptible mice depleted or not of neutrophils.
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