Oncogenic functions of beta-human papillomavirus genomes and risk factors for cutaneous squamous cell carcinomas in human keratinocytes

乙型人乳头瘤病毒（HPV）被怀疑与疣状表皮发育不良（EV）患者和器官移植受者的皮肤鳞状细胞癌（cSCC）有关。目前，支持β - hpv基因组复制的生理相关组织培养系统允许分析病毒基因组的致瘤特性和cSCC发展的危险因素（如ev易感基因和紫外线照射对病毒复制周期的影响）尚未报道。我们的初步工作表明，β - hpv8、38和49在正常的人角质形成细胞（NHK）中复制，这是体内靶细胞。我们的分析还令人惊讶地揭示，当病毒E8^E2抑制因子失活（E8-）时，HPV49基因组仅使NHK永生化，这表明永生化在基因表达水平上受到限制。HPV49 e8基因组的永生化依赖于病毒E6和E7癌蛋白。该项目的目的是确定细胞E6和E7相互作用伙伴，如p53， MAML1 (master心智样蛋白1)，pRB和PTPN14（酪氨酸蛋白磷酸酶非受体14型），对角化细胞永生和β - hpv复制的贡献。此外，将测试ev易感基因TMC6（跨膜通道样蛋白6），TMC8（跨膜通道样蛋白8）和CIB1（钙和整合素结合蛋白1）是否作为角化细胞中β - hpv的限制因子。

Beta-human papillomaviruses (HPV) have been suspected to contribute to cutaneous squamous cell cancer (cSCC) in epidermodysplasia verruciformis (EV) patients and organ transplant recipients. Currently, physiologically relevant tissue culture systems that support beta-HPV genome replication allowing the analysis of oncogenic properties of viral genomes and the influence of risk factors for cSCC development such as EV-susceptibility genes and UV irradiation on the viral replication cycle have not been reported. Our preliminary work indicates that beta-HPV8, 38 and 49 replicate in normal human keratinocytes (NHK), the in vivo target cell. Our analyses also surprisingly reveal, that the HPV49 genome only immortalizes NHK, when the viral E8^E2 repressor is inactivated (E8-), indicating that immortalization is restricted at the level of gene expression. Immortalization of HPV49 E8-genomes is dependent on the viral E6 and E7 oncoproteins. Aim of the project is to determine the contributions of cellular E6 and E7 interaction partners, such as p53, MAML1 (Mastermind-like protein 1), pRB, and PTPN14 (Tyrosine-protein phosphatase non-receptor type 14), to keratinocyte immortalization and beta-HPV replication. Furthermore, it will be tested, if the EV-susceptibility genes TMC6 (Transmembrane channel-like protein 6), TMC8 (Transmembrane channel-like protein 8), and CIB1 (Calcium and integrin-binding protein 1) act as restriction factors for beta-HPV in keratinocytes.