Skin cancers are the most commonly diagnosed cancers. Understanding what are the factors contributing to skin tumour development can be instrumental to identify preventive therapies. The myeloid differentiation primary response gene (MyD)88, the downstream adaptor protein of most Toll-like receptors (TLR), has been shown to be involved in several mouse tumourigenesis models. We show here that TLR4, but not TLR2 or TLR9, is upstream of MyD88 in skin tumourigenesis. TLR4 triggering is not dependent on lipopolysaccharide associated to skin-colonizing bacteria, but on the high mobility group box-1 protein (HMGB1), an endogenous ligand of TLR4. HMGB1 is released by necrotic keratinocytes and is required for the recruitment of inflammatory cells and for the initiation of inflammation. The expression of TLR4 on both bone marrow-derived and radioresistant cells is necessary for carcinogenesis. Consistently, a human tissue microarray analysis showed that melanoma and colon cancer display an over-expression of TLR4 and its downstream adaptor protein MyD88 within tumours. Together, our results suggest that the initial release of HMGB1 triggers a TLR4-dependent inflammatory response that leads to tumour development.
TLR4-mediated skin carcinogenesis is dependent on immune and radioresistant cells / D. Mittal, F. Saccheri, E. Vénéreau, T. Pusterla, M.E. Bianchi, M. Rescigno. - In: EMBO JOURNAL. - ISSN 0261-4189. - 29:13(2010 Jul 07), pp. 2242-2252.
|Titolo:||TLR4-mediated skin carcinogenesis is dependent on immune and radioresistant cells|
MITTAL, DEEPAK (Primo)
SACCHERI, FABIANA MARIA SEBASTIANA (Secondo)
RESCIGNO, MARIA (Corresponding)
|Parole Chiave:||HMGB1; inflammation; skin; TLR4; tumourigenesis; animals; bone marrow cells; carcinogens; carcinoma; cells, cultured; HMGB1 protein; humans; keratinocytes; mice; mice, inbred C57bl; myeloid differentiation factor 88; radiation; skin; skin neoplasms; tissue array analysis; toll-like receptor 2; toll-like receptor 4; toll-like receptor 9; molecular biology; biochemistry, genetics and molecular biology (all); immunology and microbiology (all); neuroscience (all)|
|Settore Scientifico Disciplinare:||Settore MED/04 - Patologia Generale|
|Data di pubblicazione:||7-lug-2010|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.1038/emboj.2010.94|
|Appare nelle tipologie:||01 - Articolo su periodico|