Activation of p53 in cervical carcinoma cells by small molecules
Activation of p53 in cervical carcinoma cells by small molecules
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DOI：
10.1073/pnas.97.15.8501
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发表时间：
2000-07-18
影响因子：
11.1
通讯作者：
Lane, DP
中科院分区：
文献类型：
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作者：
Hietanen, S;Lain, S;Lane, DP
在超过90%的宫颈癌和癌源性细胞系中，p53肿瘤抑制通路被人乳头瘤病毒（HPV）破坏。HPV E6蛋白促进p53的降解，从而抑制通常响应HPV E7癌基因表达而发生的p53的稳定和活化。通过阻断该途径恢复这些细胞中的p53功能应促进选择性治疗作用。在这里，我们表明，治疗与小分子核输出抑制剂，来普霉素B，放线菌素D导致转录活性p53的HeLa细胞，CaSki，SiHa细胞的细胞核中的积累。北方印迹分析显示，放线菌素D和来普霉素B均降低了HPV E6-E7 mRNA的量，而与药物联合治疗显示病毒mRNA几乎完全消失。联合治疗激活了p53依赖性转录，并观察到p21（WAF 1/CIP 1）和Hdm 2 mRNA的增加。联合处理导致细胞凋亡，如通过指示半胱天冬酶3活性的核碎裂和PARP裂解所证明的。通过表达显性负性p53蛋白，这些作用大大降低。目前的研究表明，小分子可以重新激活p53在宫颈癌细胞，这种重新激活与广泛的生物反应，包括诱导细胞的凋亡死亡。
In over 90% of cervical cancers and cancer-derived cell lines, the p53 tumor suppressor pathway is disrupted by human papillomavirus (HPV). The HPV E6 protein promotes the degradation of p53 and thus inhibits the stabilization and activation of p53 that would normally occur in response to HPV E7 oncogene expression. Restoration of p53 function in these cells by blocking this pathway should promote a selective therapeutic affect. Here we show that treatment with the small molecule nuclear export inhibitor, leptomycin B, and actinomycin D leads to the accumulation of transcriptionally active p53 in the nucleus of HeLa, CaSki, and SiHa cells. Northern blot analyses showed that both actinomycin D and leptomycin B reduced the amount of HPV E6-E7 mRNA whereas combined treatment with the drugs showed almost complete disappearance of the viral mRNA. The combined treatment activated p53-dependant transcription, and increases in both p21(WAF1/CIP1) and Hdm2 mRNA were seen. The combined treatment resulted in apoptotic death in the cells, as evidenced by nuclear fragmentation and PARP-cleavage indicative of caspase 3 activity. These effects were greatly reduced by expressing a dominant negative p53 protein. The present study shows that small molecules can reactivate p53 in cervical carcinoma cells, and this reactivation is associated with an extensive biological response, including the induction of the apoptotic death of the cells.