[Study on the high expression of brain-derived neurotrophic factor in multiple myeloma patients and its possible mechanism].

In order to investigate the expression of brain-derived neurotrophic factor (BDNF) and vascular endothelial growth factor (VEGF) in multiple myeloma patients and the in vitro and in vivo proangiogenic effects of BDNF, the plasma concentrations of BDNF and VEGF in MM patients and control group were determined by ELISA, the effect of BDNF on the in vitro proliferation of human umbilical vein endothelial cells (HUVEC) was examined by MTT assay; the effects of BDNF on HUVEC migration and tube formation were studied by modified Boyden chamber assay and tube formation assay, respectively. Matrigel plug assay and chorioallantoic membrane assay were used to evaluate the effect of BDNF on angiogenesis in vivo. The results demonstrated that the concentration of BDNF was (4.22 +/- 0.64) ng/ml and (2.03 +/- 0.38) ng/ml in MM group and control group, respectively, (P = 0.01). There was also a significant difference between VEGF levels of two groups [(79.35 +/- 13.25) pg/ml vs (34.41 +/- 1.78) pg/ml, P = 0.006]. The levels of BDNF and VEGF correlated significantly (r = 0.430, P = 0.025). BDNF stimulated the migration and tube formation in vitro significantly, although it had no effect on the proliferation of HUVEC. BDNF also stimulated angiogenesis both in matrigel plug of mouse model and in chick chorioallantoic membrane. It is concluded that the concentrations of BDNF and VEGF in MM patients' peripheral blood are at high level; BDNF can stimulate the angiogenesis markedly in vitro and in vivo. Therefore, BDNF may act as an important regulator in angiogenesis of MM.