bFGF和VEGF在急性白血病中的表达及对HL-60细胞生长的影响

Expression of bFGF and VEGF in Acute Leukemia and Its Effects on HL-60 Cell Growth

为了研究急性白血病患者血清及细胞株培养上清中碱性成纤维细胞生长因子 (bFGF)、血管内皮细胞生长因子 (VEGF)的表达水平 ,并初步探讨白血病患者VEGF水平的评价方法以及VEGF特异性反义寡脱氧核苷酸(ASODN)的抗血管生成作用 ,用夹心ELISA法测定患者血清、细胞株 (HL 6 0、U937、NB4、JM和K5 6 2 )培养上清中bFGF和VEGF浓度 ,比较其差异 ,将VEGF血清浓度测定值 (pg ml)、血清浓度测定值经外周血血小板计数标化后标化值VEGF PLT(pg 10 6 )分别作为比较指示 ;HL 6 0细胞经不同浓度VEGFASODN作用后 ,利用噻唑蓝、ELISA法分别测定靶细胞的生长状态及其VEGF分泌水平。结果发现 :①急性白血病患者血清bFGF阳性率 (37.5 % )高于健康对照者 (10 % ) (P <0 .0 1) ,在 5株白血病细胞株中 ,NB4 、U937和K5 6 2细胞上清中检测到了bFGF表达 ;②急性白血病患者及健康者血清VEGF测定值差异无统计学差异 ,但二者标化值测相差显著 (P <0 .0 5 ) ;除U937外 ,其余 4株细胞株培养上清中均有VEGF表达 ;③HL 6 0细胞经 0 .5 ,1及 5 μmol LVEGFASODN作用 2 4小时后 ,其存活率与对照组相比明显降低 (P <0 .0 5 ) ;经 1,5 ,2 0 μmol LVEGFASODN作用 2 4小时后 ,HL 6 0细胞培养上清中VEGF浓度均明显低于对照 (P <0 .0 5 )。结论 :

The study was to investigate the expression levels of basic fibroblast growth factor (bFGF) and vascular endothelial growth factor (VEGF) in the serum of patients with acute leukemia and supernatants of leukemia cell lines as well as effects of VEGF-specific antisense oligodeoxynucleotides(ASODN)on the growth of HL-60 cells. Meanwhile the methods to evaluate the VEGF level in the serum of patients with acute leukemia were explored. The levels of bFGF and VEGF in the serum from 32 patients with acute leukemia and 10 healthy subjects and in the supernatants of 5 various human leukemia cell lines were quantified by means of the enzyme-linked immunosorbent assay (ELISA) and were compared. VEGF levels were evaluated not only without standardization but also after standardized by platelet and finally expressed as VEGF/PLT (pg/106). After with different concentrations of VEGF ASODN, HL-60 cell viability was examined with MTT assay and VEGF levels in supernatants were measured with ELISA, respectively. The results showed that bFGF was detected (3 pg/ml) in 14 out of 32 serum samples from patients with acute leukemia, and the positive (37.5%) was significantly higher than that in healthy controls (10%) (P<0.01). 3 out of 5 supernanant samples obtained from leukemia cell lines demonstrated positive for bFGF as well. There is no difference of the serum VEGF levels between leukemia patients and healthy controls, but the serum VEGF levels in the serum from leukemia patients were significantly higher than those in healthy controls(P<0.05)after standardization.4 out of 5 luekemia cell(U937 excluded) were found to expresse VEGF in the supernanant. After exposure of HL-60 cells to VEGF ASODN at a concentration of 0.5, 1 and 5 μmol/L for 24 hours, the cell viability gradually droped down to lower levels (P<0.05 vs controls). After treatment of HL-60 cells with VEGF ASODN at a concentration of 1,5 and 20 μmol/L for 24 hours, the VEGF levels in supernatants of target cells decreased (P<0.05 vs controls). The patients with acute leukemia represented the higher levels of serum bFGF and VEGF than controls. Most of leukemia cell lines expressed bFGF and VEGF at different levels. It is concluded that bFGF and VEGF both have effects on regulations of angiogenesis in acute leukemia, but VEGF plays a pivotal role. VEGF-specific ASODN may have a role in them VEGF expression downregulated. Different results may be obtained in the evaluation of VEGF levels in the serum of patients with acute leukemia if different calculation metheds are used. The methods reported can measure leukemia associated VEGF more accurately.