Bcl-2 expression correlates positively with serum basic fibroblast growth factor (bFGF) and negatively with cellular vascular endothelial growth factor (VEGF) in patients with chronic lymphocytic leukaemia

A large proportion of B-chronic lymphocytic leukaemia (B-CLL) cells express the anti-apoptotic protein Bcl-2. Basic fibroblast growth factor (bFGF) ha s been shown to upregulate the expression of Bcl-2 in B-CLL cell lines. Vas cular endothelial growth factor (VEGF) has been shown to enhance the surviv al of endothelial cells by upregulating the expression of Bcl-2. Ih the pre sent study, eve measured serum and cellular levels of bFGF and VEGF in 85 p atients with CLL using a commercial quantitative sandwich enzyme immunoassa y technique. Levels of Bcl-2 were also assayed concomitantly using Western blot analysis. The mean serum level of bFGF was 53.4 pg/ml (range 0-589) and that of VEGF 459.2 pg/ml (range 33-1793). The mean cellular level of bFGF was 158.3 pg/2 x 10(5) cells (range 0.8-841) and VEGF 42.4 pg/2 x 10(5) cells (range 0-24 4). A high correlation was found between serum and cellular bFGF levels (P < 0.001) but not between the corresponding VEGF levels, Twenty-nine of 69 p atients (42%) evaluated for Bcl-2 level, expressed it. The Bcl-2 level was positively correlated with the serum bFGF level (P = 0.007). However, surpr isingly there was a negative correlation between Bcl-2 expression and intra cellular VEGF level (P = 0.003). A positive correlation was also found betw een serum bFGF and disease follow-up time and log white blood cell count. T hese findings indicate that in CLL there is a correlation between angiogene sis-related factors and apoptosis-related protein expression, and elevated bFGF levels may account for the elevated Bcl-2 levels.