PLATELET-DERIVED ENDOTHELIAL-CELL GROWTH-FACTOR (THYMIDINE PHOSPHORYLASE) EXPRESSION IN LUNG-CANCER

Platelet-derived endothelial cell growth factor/thymidine phosphorylas e (PD-ECGF/TP) is an enzyme with angiogenic and cell motility properti es. Moreover, it is involved in the transformation of fluoropyrimidine s into active cytotoxic metabolites. In the present study, the express ion of PD-ECGF in normal lung and lung cancer was immunohistochemicall y evaluated using the P-GF.44C monoclonal antibody. Alveolar and tumou ral macrophages were invariably stained and were used as an internal c ontrol for assessment of the staining. Alveolar epithelium was always negative, whilst bronchiolar epithelium showed occasional positive rea ctivity. Normal lung and tumour endothelium was occasionally positive. Positive staining in more than 50 per cent of cells was observed in 2 3/71 squamous carcinomas (32 per cent), 16/38 (42 per cent) adenocarci nomas, and 2/6 (33 per cent) adenosquamous carcinomas, Differentiated areas and areas of squamous metaplasia were more strongly positive tha n other tumour areas. All 22 small cell carcinomas and one carcinoid t umour were negative. The present study provides a baseline for future studies in non-small cell lung cancer to correlate PD-ECGF expression with tumour vascularization, prognosis, and response to chemotherapy.