目的 探究替莫唑胺對(duì)膠質(zhì)瘤細(xì)胞U251凋亡的影響及其作用機(jī)制。方法 40、80、120 μmol/L替莫唑胺培養(yǎng)U251細(xì)胞系48 h，觀察形態(tài)變化，流式細(xì)胞術(shù)檢測(cè)細(xì)胞凋亡率，實(shí)時(shí)熒光定量PCR（qRT-PCR）法檢測(cè)caspase 3表達(dá)，用caspase 3試劑盒檢測(cè)caspase 3的活性，蛋白免疫印跡（Western blotting）法檢測(cè)熱休克蛋白90（HSP90）、p-HSP90、絲氨酸蘇氨酸蛋白激酶（AKT）和p-AKT表達(dá)。結(jié)果 替莫唑胺80、120μmol/L組細(xì)胞數(shù)目減少，細(xì)胞核體積明顯縮小，染色質(zhì)固縮。替莫唑胺80、120 μmol/L組細(xì)胞凋亡率、caspase 3的表達(dá)水平和活性明顯高于對(duì)照組，p-HSP90、p-AKT的表達(dá)水平明顯低于對(duì)照組（P<0.05），呈劑量相關(guān)性。結(jié)論 替莫唑胺能夠促進(jìn)膠質(zhì)瘤細(xì)胞U251凋亡，可能是通過抑制HSP90和AKT表達(dá)來實(shí)現(xiàn)的。

Objective To explore the influence of temozolomide on apoptosis of glioma cell line U251 and study its mechanisms. Methods U251 cell line were treated with 40, 80, and 120 μmol/L temozolomide for 48 h. Morphological changes were observed, and apoptosis rate was detected by flow cytometry. Caspase 3 expression was detected by using real-time quantitative PCR (qRT-PCR) method, and the activity of caspase 3 was tested by using caspase 3 Kit. HSP90, p-HSP90, AKT and p-AKT expressions were detected by Western blotting method. Results The number of cells decreased in 80 and 120 μmol/L temozolomide groups, and nucleus size decreased significantly, and chromatin contracted. The apoptosis rate and expression levels and activities of caspase 3 in 80 and 120 μmol/L temozolomide groups were significantly higher than those in the control group, but P-HSP90 and p-AKT expression levels were significantly lower than those in the control group (P < 0.05), and were in a dose manner. Conclusion Temozolomide can promote the apoptosis of glioma cell line U251, and it may be achieved by inhibiting the expression of HSP90 and AKT.