Quantitative analysis of vascular endothelial growth factor expression in chronic lymphocytic leukaemia

Vascular endothelial growth factor (VEGF) Flays a central role in solid tumour angiogenesis, although its expression has never been previously documented in circulating lymphoma or leukaemia cells. Here we have quantified mRNA encoding VEGF isoforms 121 and 165 in peripheral lymphocytes of 6/6 CLL patients using Northern blotting and quantitative reverse transcription-polymerase chain reaction (RT-PCR) techniques. No VEGF mRNA could be detected in control lymphocytes. VEGF expression in primary lymphoma cells was lower than in normoxic human colorectal carcinoma cells (LS174T), implying that VEGF expression within tumour cells must be regulated by a range of malignancy-associated factors.