The early response to DNA damage can lead to activation of alternative splicing activity resulting in CD44 splice pattern changes
The early response to DNA damage can lead to activation of alternative splicing activity resulting in CD44 splice pattern changes
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DOI：
10.1158/0008-5472.can-07-0145
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发表时间：
2007-08-15
期刊：
影响因子：
11.2
通讯作者：
Duerksen-Hughes, Penelope J.
中科院分区：
文献类型：
--
作者：
Filippov, Valery;Filippova, Maria;Duerksen-Hughes, Penelope J.
人乳头瘤病毒16 E6癌基因的表达干扰了几个重要的细胞过程，包括对DNA损伤的p53依赖性反应。为了评估E6对DNA损伤早期反应的影响，我们通过比较全局表达谱分析，分析了丝裂霉素C诱导的基因毒性应激后表达E6的人U20 S细胞（U20 SE 64 b）以及表达p53的对照细胞（U20 SE 6AS）的基因表达。正如预期的那样，参与p53依赖性途径的基因在表达p53的细胞中被激活。然而，在U20 SE 64 b细胞中，发现了一组基本上不重叠的基因，包括SR家族的两个剪接因子。免疫印迹分析显示，在DNA损伤的早期反应期间，几种SR蛋白的表达增加，并伴随着选择性剪接活性的激活。通过用针对剪接因子SRp 55的小干扰RNA处理来破坏剪接活性导致DNA损伤后p53缺陷细胞的存活率增加。为了确定剪接活性的瞬时激活是由于E6介导的p53降解，还是由于E6的一些其他活性，我们比较了p53野生型和p53-/-等基因HCT 116细胞系的早期反应，发现剪接活性的增加仅在p53不存在的情况下观察到。最后，U20 SE 64 b和p53-/-细胞都显示出CD 44受体的剪接模式改变。总之，这些数据表明，缺乏p53的细胞可以在DNA损伤后激活选择性剪接。
Expression of the human papillomavirus 16 E6 oncogene interferes with several vital cellular processes, including the p53-dependent response to DNA damage. To assess the influence of E6 on the early response to DNA damage, we analyzed gene expression following mitomycin C-induced genotoxic stress in human E6-expressing U20S cells (U20SE64b) as well as in p53-expressing control cells (U20SE6AS) by comparative global expression profiling. As expected, genes involved in p53-dependent pathways were activated in p53-expressing cells. In the U20SE64b cells, however, a largely nonoverlapping group of genes was identified, including two splicing factors of the SR family. Immunoblot analysis revealed increased expression of several SR proteins during the early response to DNA damage, which was accompanied by activation of alternative splicing activity. Disruption of splicing activity by treatment with small interfering RNA directed against splicing factor SRp55 resulted in the increased viability of p53-deficient cells following DNA damage. To determine whether the transient activation of splicing activity was due to E6-mediated degradation of p53, or was due to some other activity of E6, we compared the early response of the p53 wild-type and p53-/- isogenic HCT116 cell lines, and found that the increase in splicing activity was observed only in the absence of p53. Finally, both the U20SE64b and the p53-/- cells showed altered splicing patterns for the CD44 receptor. Together, these data show that cells lacking p53 can activate alternative splicing following DNA damage.