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

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

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。

In order to study the effects of β 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(5,10,100μmol/L)and the occurrence of proliferation was earlier at lower concentration of VC(5μmol/L). β carotene at 10～100μmol/L could inhibit the proliferation of HL 60 cell in a dose dependent manner. VC(5μmol/L)had no influence on the expression of c myc gene( P >0 05), but β carotene could up regulate the expression of c myc( P <0 05). Our observations suggested that the inhibitory effect of β 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.