β-胡萝卜素和维生素C对白血病细胞c-myc基因表达的影响

为了研究β 胡萝卜素和维生素C(VC)对白血病细胞中c myc癌基因表达的影响 ,以探讨其抑制白血病细胞增殖的分子机理。分别添加不同浓度的 β 胡萝卜素和VC体外培养白血病细胞株HL 6 0 2 4、48、72h后 ,利用台盼蓝拒染法检测两种微量营养素对细胞增殖的抑制作用 ;同时取作用 2 4h的细胞利用Northern印迹杂交检测细胞中c myc基因的表达。结果发现 :VC(5、10、10 0 μmol L)对HL 6 0细胞增殖具有显著性抑制作用 (P <0 0 5 ) ,而且低浓度的VC(5 μmol L)对HL 6 0细胞的抑制作用出现较早。β 胡萝卜素三个剂量组 (10、5 0、10 0 μmol L)均可抑制HL 6 0细胞增殖 ,作用有显著性 (P <0 0 5 ) ,且呈剂量 效应关系。VC(5 μmol L)对HL 6 0细胞内c myc的表达没有显著性作用 (P >0 0 5 )。β 胡萝卜素 (5 0 μmol L)对HL 6 0细胞内c myc的表达有显著性促进作用 (P <0 0 5 )。提示VC抑制HL 6 0细胞增殖的效应与c myc的表达无关。β 胡萝卜素可能通过上调c myc基因的表达 ,进一步诱导白血病细胞凋亡 ,从而抑制白血病细胞增殖。

Effects of beta-carotene and vitamin C on the expression of c-myc in human leukemic cell]

In order to study the effects of beta-carotene and vitamin C(VC) on the expression of c-myc oncogene in human leukemic cell, myelogenous leukemic cell line HL-60 was cultured in vitro with standard methods. Trypan blue exclusion test and Northern blotting hybridization were used to detect the cell proliferation and the expression of c-myc gene. The results showed that the proliferation of HL-60 cell was inhibited after exposed to VC(5, 10, 100 mumol/L) and the occurrence of proliferation was earlier at lower concentration of VC(5 mumol/L). beta-carotene at 10-100 mumol/L could inhibit the proliferation of HL-60 cell in a dose dependent manner. VC(5 mumol/L) had no influence on the expression of c-myc gene(P > 0.05), but beta-carotene could up-regulate the expression of c-myc(P < 0.05). Our observations suggested that the inhibitory effect of beta-carotene on the proliferation of leukemic cells was caused by inducing apoptosis of HL-60 through up-regulating the expression of c-myc gene; however, the inhibitory effect of vitamin C on cell proliferation was not related to the expression of c-myc gene.