β-胡萝卜素和VC对K562细胞c-myc基因表达的影响

Effects of β-carotene and Vitamin C on Expression of c-myc in Human Leukemic Cell

目的 研究 β-胡萝卜素和维生素C对白血病细胞中c-myc癌基因表达的影响。方法 体外培养白血病细胞株K5 6 2 ,分别添加不同浓度的β -胡萝卜素和VC ,培养 2 4h、4 8h、72h后 ,利用台盼蓝拒染法检测两种微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 VC(5、10、10 0 μmol/L)对K5 6 2细胞增殖具有显著的抑制作用 (P <0 0 5 ) ,而且低浓度的VC(5 μmol/L)对K5 6 2细胞的抑制作用出现较早。β -胡萝卜素 3个剂量组 (10、5 0、10 0 μmol/L)均可抑制K5 6 2细胞增殖 ,具有显著性差异 (P <0 0 5 )。VC(5 μmol/L)和β -胡萝卜素 (5 0 μmol/L)均能诱导K5 6 2细胞凋亡。VC(5 μmol/L)对K5 6 2细胞内c -myc的表达没有明显作用 (P >0 0 5 )。β -胡萝卜素 (5 0 μmol/L)对K5 6 2细胞内c -myc的表达有显著促进作用 (P <0 0 5 )。 结论 VC抑制K5 6 2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。

Objective To study the effect of β-carotene and vitamin C on the expression of c-myc oncogene in human leukemic cell.Methods Leukemic cell K562 was cultured in vitro for 24h,48h,72h by adding different concentration of β-carotene and vitamin.Meanwhile,trypan blue exclusion method and DNA gel electrophoresis and Northern blotting hybridization were used to detect the cell proliferation,the apoptosis and the expression of the c-myc gene.Results The proliferation of non-myelogenous leukemic cell line K562 was inhibited after exposed to Vit C(5?10?100μmol/L) and the effect occurred earlier at low concentration(5μmol/L) or high concentration(100μmol/L).β-carotene at concentrations(10-100μmol/L) could inhibit the proliferation of non-myelogenous leukemic cell line K562.The apoptosis of K562 cell were induced by Vit C(5μmol/L) and β-carotene(50μmol/L).Vit C(5μmol/L) could not influence the expression of c-myc gene( P >0 05),but β-carotene could up-regulating the expression of c-myc( P <0 05).Conclusion The inhibitory effect of β-carotene on the proliferation of leukemic cell was caused by the induction of apoptosis of K562 through up-regulating expression of c-myc gene,though the inhibitory effect of vitamin C on the proliferation of the cell was not related with expression of c-myc gene.