Platelet-derived growth factor receptors and ligands are up-regulated in paediatric fibromatoses

Aims: Platelet-derived growth factors (PDGF) and their receptors (PDGFR) play an essential role in pathways involved in the regulation of cell proliferation, growth and function. Overexpression of PDGF/R is reported in a wide range of solid tumours. The aim was to determine levels of PDGF/R expression in paediatric fibromatoses and myofibromatosis. Methods and results: Quantitative real-time polymerase chain reaction was used to examine the expression level of alpha and beta isoforms of PDGF/R in 17 fibromatoses, four myofibromatoses and three dermatofibrosarcoma protuberans (DFSP) in children. Fifteen of 17 (88%) fibromatoses and all myofibromatoses and DFSPs demonstrated increased expression of PDGF alpha and beta compared with a panel of normal tissues. In terms of the cognate receptors, 13/17 (76%) fibromatoses demonstrated increased expression for PDGFR alpha and R beta, whereas 3/4 myofibromatoses demonstrated increased expression of PDGFR alpha and all four had increased PDGFR beta expression. All DFSPs were associated with increased expression of both PDGFR alpha and PDGFR beta compared with normal control tissues. Conclusions: Increased expression of PDGF/R alpha beta may play an important role in the mechanism of growth of these paediatric fibromatous lesions and warrants further investigation, since novel therapeutic interventions could potentially be developed in the light of the expression patterns.