人乳头瘤病毒16型E2蛋白对Daxx调控细胞凋亡的影响

Human papillomavirus type 16(HPV16) is closely associated with the occurrence and development of more than 50% cervical cancer. Death domain associate protein (Daxx) locating in nuclear PML-NBs is necessary for its inducing apoptosis. Our preliminary studies showed that HPV16 E2 protein co-located and interacted with Daxx, and that Daxx translocated from nucleus into nuclear membrane, cytoplasm or cell membrane in the development of cervical cancer with high-risk HPV positive. Therefore, we hypothesized that HPV16 E2 could cause Daxx location and other changes, and affect the regulating apoptosis induced by Daxx, so it is beneficial for resulting in the occurrence and development of cervical cancer. Based on the location, expression, gene sequence or other changes of Daxx in the occurrence and development of cervical cancer with HPV16 positive, this study will study the effects of HPV16 E2 on these changes, and will make sure the regulation of Daxx for cell cycle, proliferation and apoptosis with the expression of E2 or not and the influence of E2 on the expression of Daxx and Fas and their interaction by use of cell biology and molecular biology technology. This study helps us to know the effects of HPV16 E2 protein on Daxx regulating apoptosis, and to demonstrate the role of Daxx in the occurrence and development of cervical cancer, and provides the scientific experimental basis for certifying Daxx as a potential target protein in the intervention of cervical cancer associated with HPV16 infection.

人乳头瘤病毒16型(HPV16)与50％以上宫颈癌的发生密切关联。死亡结构域相关蛋白(Daxx)定位于PML-NBs是其诱导细胞凋亡的必要条件。我们前期研究发现，HPV16 E2蛋白与Daxx相互作用并存在共定位；在高危型HPV阳性宫颈癌进程中，Daxx从胞核内逐渐转位到核膜、胞浆及胞膜，因而推测HPV16 E2能引起Daxx定位或其它变化，势必影响Daxx对细胞凋亡的调控，从而有利于宫颈癌的发生。本项目拟通过细胞生物学和分子生物学等技术检测Daxx在HPV16阳性宫颈病变细胞内表达、定位及基因突变等并研究HPV16 E2对它们的影响，确定E2表达/缺失时Daxx对细胞周期、细胞增殖和凋亡的调控作用及其对Daxx和Fas相互作用的影响。本项目能明确E2对Daxx调控细胞凋亡的影响，证实Daxx在宫颈癌发生与发展中发挥某种作用，为揭示Daxx是HPV16所致宫颈癌的潜在干预靶蛋白提供科学依据。

Daxx是一种具有转录调控作用的多功能核蛋白，它参与HPV早期基因表达，且其定位的PML-NBs是HPV复制的一个集中点，因此PML-NBs很可能是HPV感染的始发位点。人乳头瘤病毒16型(HPV16)与50％以上宫颈癌的发生密切关联。本项目研究发现，从HPV16阳性的宫颈上皮内瘤变组织到宫颈癌组织，Daxx有从胞核逐渐转位到核膜、胞浆及胞膜的趋势；然而其表达水平略有增高且依然存在与PML以及ATRX的相互作用；在转染了HPV16 E2的C33A细胞中，虽然部分Daxx依然定位于PML核体，但同样也存在Daxx与HPV16 E2共定位并存在相互作用且Daxx有核转位现象；同时确定了E2高表达能负向调节Daxx对细胞凋亡的调控作用。本项目明确了HPV16 E2在Daxx调控细胞凋亡中的作用，证实了Daxx在宫颈癌发生与发展中发挥一定作用，为揭示Daxx是HPV16所致宫颈癌的潜在干预靶蛋白提供实验基础。