Daxx对γ射线诱导HeLa细胞凋亡的影响

Effects of Daxx onγ-ray induced apoptosis of HeLa cells

研究过表达死亡结构域相关蛋白(Daxx)对经γ射线照射过的细胞凋亡的影响,探讨Daxx与辐射诱导细胞凋亡之间的关系及其机制。通过转染将宫颈癌HeLa细胞分为正常对照组、空质粒转染阴性组与Daxx转染组,利用生物细胞辐照仪经γ射线照射至不同剂量;Western blot检测细胞中Daxx的表达;MTT检测细胞的增殖情况;ELISA检测细胞中Caspase-8的相对活性;流式细胞术检测细胞凋亡情况。结果发现:随着照射剂量增加,细胞数量逐渐减少,且其中变形细胞越来越多;Daxx表达水平随着照射剂量增加而升高;Daxx转染的辐照细胞组的细胞增殖抑制率、A 405值以及细胞凋亡率均明显高于未辐照细胞组,差异均有统计学意义(p<0.01,p<0.05,p<0.05)。过表达Daxx能通过上调经γ射线照射细胞的Caspase-8活性,促进辐射诱导的细胞凋亡。

We studied the effects of overexpression of deathdomainassociated protein(Daxx)on cell apoptosis underγ-ray radiation.Further,we explored the relationship between Daxx and radiation-induced apoptosis and investigated the mechanism behind such apoptosis.Through transfection,cervicalcancer HeLa cells were divided into a control group,an empty plasmid-transfected negative group,and a Daxx-transfected group;the HeLa cells were irradiated with different doses ofγ-rays using a cell irradiator.The expression of Daxx protein in cells was detected by Western blot.Cell proliferation was detected by MTT.The relative activity of caspase-8 in cells was detected by ELISA whereas the cell apoptosis was detected by flow cytometry.The results showed that the total number of cells decreased with the increase in absorbed dose,whereas the number of deformed cells increased.Furthermore,the degree of Daxx expression increased with the increase in absorbed dose.Comparing the cells of the Daxx-transfected group with those of the unirradiated control group,we observed statistically significant increments(p<0.01,p<0.05,p<0.05)in the rate of inhibition against cell proliferation,the A 405 value,and rate of apoptosis.Hence,overexpression of Daxx promotes radiation-induced apoptosis by upregulating caspase-8 activity in theγ-ray irradiated cells.