Overexpression of c-Met and of the transducers PI3K, FAK and JAK in breast carcinomas correlates with shorter survival and neoangiogenesis

Abstract

c-Met is responsible for cell motility and tumour spreading. c-Met expression and signal transducers reflecting c-Met functionality were investigated in breast carcinomas, in correlation with patient outcome and tumour vasculature. Tissue microarrays of 930 breast carcinomas were constructed, categorised according to patients' follow-up (4- to 10-year follow-up; median, 6.5 years). Standardised immunocytochemical procedures were performed using anti-c-Met, -PI3K, -FAK, -JAK, and -CD146, -FYN and an automated autostainer (Ventana). High-throughput densitometry measuring the extent of immunoprecipitates was assessed by image analysis (SAMBA). c-Met overexpression correlated with poor survival along with PI3K and FAK reflecting c-Met functionality and CD146 and FYN expression in endothelial cells. Automated quantification of immunocytochemical precipitates using image analysis was shown to provide an objective means of measuring cellular proteins that are potentially relevant for current practice in pathological diagnosis and for specific therapy combining inhibitors of both c-Met and downstream transducer pathways, and of tumour angiogenesis.