HeLa细胞中LRP16影响电离辐射诱导的NF-κB核转位

LRP16 Affects the NF-κB Induced Nuclear Translocation by Ionizing Radiation in HeLa Cells

前期研究显示抑制LRP16的表达可以明显增加肿瘤细胞对辐射诱导凋亡的敏感性,但具体机制尚不清楚.大量研究表明,NF-κB信号通路在肿瘤产生辐射抵抗中起着重要的作用.为研究LRP16影响肿瘤细胞对辐射敏感性的可能机制,首先通过免疫荧光技术检测电离辐射刺激后不同时间点NF-κB的核转位情况;然后分别过表达和抑制LRP16的表达,采用Western印迹方法检测NF-κB在核蛋白与浆蛋白中的表达情况、IκB-α总体蛋白水平及磷酸化水平.结果发现,电离辐射后1 h,可见NF-κB明显入核;过表达LRP16可以促进NF-κB入核、提高IκB-α的磷酸化水平、促进IκB-α的降解;反之,抑制LRP16的表达可以抑制NF-κB入核、降低IκB-α的磷酸化水平、阻碍IκB-α的降解.上述研究结果表明,在HeLa细胞中LRP16可以影响电离辐射诱导的NF-κB核转位,该研究为LRP16参与肿瘤细胞产生辐射抵抗现象提供一种可能的机制.

Our previous study showed that the inhibition of LRP16 sensitize cancer cells to cell apoptosis induced by ionizing radiation（IR）.However,the specific mechanism remains unknown.A lot of studies suggested that the NF-kappa B signaling pathway plays a very important role in radioresistance.To study the potential mechanism that how LRP16 affects the radiosensitivity of cancer cells,immunofluorescence technique was used for determining the nuclear translocation of NF-kappa B induced by IR at different time points.LRP16 was overexpressed or knock down in HeLa cells,and Western blot was performed on cell extracts to check the expression of NF-κB,the degradation and phosphorylation of IκB-α.The results suggested that NF-kappa B translocated into nucleus significantly at 1 hour point post-IR.Overexpression of LRP16 promoted the nuclear translocation of NF-kappa B,the degradation and phosphorylation of IκB-α.Otherwise,knockdown of LRP16 inhibited the nuclear translocation of NF-κB,the degradation and phosphorylation of IκB-α.These data demonstrated that LRP16 affected the nuclear translocation of NF-kappa B induced by IR.The study will provide a possible mechanism that how LRP16 is involved in radioresistance of cancer cells.