ΔNp63α在基底细胞中表达的分子调控机制及其促宫颈鳞癌细胞分化的抗肿瘤作用研究

The major pathological type of cervical tumor is squamous cell carcinoma. Although there is a strong association between the oncoprotein E6, E7 produced by high-risk human papillomavirus (HR-HPV) and the development of cervical carcinoma, the exact molecular pathogenesis of this progress has not been clearly clarified. The basal cell in the squamous epithelial tissue has the ability of both proliferation and differentiation into keratinocyte and death; therefore, the abnormal differentiation of the basal cell will result in excessive cell proliferation and malignant cell transformation. We have found that ΔNp63α, specifically expressed in the basal cell, crucially regulates the differentiation of the basal cell; furthermore, the expression of ΔNp63α is decreased in cervical squamous cancer by HPV16 E6. We speculate that HR-HPV can promote tumor formation through disturbing cell differentiation by inhibition the expression of ΔNp63α. In this project, by using the recombinant organotypic culture system and keratinocyte differentiation induction model of the primary basal cell, we plan to elucidate the molecular mechanisms of the differentiation disturbance and malignant transformation of the basal cell after inhibition of the expression of ΔNp63α by HPV16 E6; we also plan to find out the anti- tumor effects by inducing differentiation, keratin and death of squamous cancer cell after restoration the expression of ΔNp63α. The aim of this project is to provide new ideas for effectively preventing and targeted therapy to cervical cancer.

子宫颈癌的病理类型以鳞癌为主，其发病机制与高危型人乳头瘤病毒（HR-HPV）表达的癌蛋白E6、E7密切相关，但其机制尚未完全阐释清楚。鳞状上皮组织的基底细胞兼备增殖及向鳞状细胞分化致角化死亡的潜能，因此其分化障碍将导致增殖异常、加速细胞癌变。 我们发现，ΔNp63α特异表达在基底细胞中并关键性调控其分化，但在子宫颈鳞癌组织中表达显著降低，并且ΔNp63α的表达被HPV16 E6显著抑制。推测HR-HPV通过抑制ΔNp63α的表达阻碍细胞的正常分化而促进肿瘤的形成。 本课题拟利用已经建立的原代基底细胞立体培养、分化诱导模型，研究和发现HPV16 E6抑制基底细胞中ΔNp63α的表达致其分化受阻、恶性转化的分子机制；探讨恢复ΔNp63α的表达促进鳞癌细胞的分化、角化死亡的抗肿瘤作用，为子宫颈癌的有效预警、针对性治疗提供新思路。

本课题通过生物信息学方法、报告基因实验阐明了ΔNp63α基因的转录调控分子机制：转录因子stat3激活ΔNp63α的启动子正性调控其转录水平，而过量表达的ΔNp63α反馈抑制stat3的磷酸化；同时转录因子ΔNp63α可以通过激活自身启动子而增强其转录水平表达。通过过表达及沉默ΔNp63α的稳定转染细胞株的mRNA\miRNA\LncRNA\ChIP-seq芯片分析，绘制了ΔNp63α在子宫颈鳞状上皮癌组织中的调控的靶基因图谱；目前已经确证了直接的转录调控途径包括：ΔNp63α-TWIST1-EMT抑制EMT信号转导途径、ΔNp63α-LIF-stat3抑制细胞增殖信号转导途径、ΔNp63α-TEAD1抑制细胞增殖信号转导途径等。间接调控的途径已经确证的是ΔNp63α抑制ENST00000447565的水平而促进LIF mRNA的降解。通过动物实验确证了恢复ΔNp63α表达诱导子宫颈鳞癌细胞分化、角化死亡而抑制肿瘤恶性生物学行为的影响及分子机制，为子宫颈鳞癌的防治提出新策略、新靶点。本课题的完成发表了SCI文章6篇；中文核心及统计源期刊文章17篇，待发表SCI 2篇。其他实验数据在进一步整理和完善、撰写文章过程中。培养硕士4名，联合培养博士2名、硕士8名。课题组延续省级申报课题2项。