The Role of Platelet-Derived Growth Factor on Tumour Vascular Function and Morphology In Vivo Assessed by Susceptibility Magnetic Resonance Imaging
Robinson S, Ludwig C, Paulsson J, Griffiths J, Ostman A
St. George's, University of London
Platelet-derived growth factor (PDGF) contributes to numerous processes in tumour progression, including recruitment of pericytes and angiogenesis. Intrinsic-susceptibility MRI, sensitive to changes in endogenous deoxyhaemoglobin, was used to investigate the effects of PDGF on tumour vascular maturation and function in vivo. The transverse relaxation rate R2* of PDGF expressing B16 and control B16 melanomas was quantified during air, hypercapnia and hyperoxia challenge. Hypercapnia induced a negligible reduction in tumour R2*, whereas hyperoxia significantly reduced R2* of both tumour types, this reduction being significantly greater in the PDGF expressing tumours, consistent with increased pericyte coverage increasing blood vessel function in vivo.