Nucleoside Phosphonate Analogs and HPV Positive Cancers

西多福韦（CDV）是一种广谱抗病毒药物，对大多数双链DNA具有活性 病毒。许多DNA病毒被认为是病毒诱导的细胞凋亡的重要因素。 恶性肿瘤使用抗病毒药物治疗癌症的概念尚处于起步阶段，值得探索。该提案旨在评估新的、高活性的CDV类似物，其对DNA病毒的活性显著更高，同时具有降低的肾毒性，这是西多福韦利用的限制因素。我们已经合成并测试了CDV的烷氧基烷基类似物，其比未修饰的CDV至少有效10倍。我们的初步结果，在测试这样的代理人对人乳头状瘤阳性细胞系，Me-180和HeLa，表明细胞正在经历凋亡和S期阻滞。这种作用在宫颈癌细胞中比在正常HFF或PHK细胞中突出200-300倍。这可能是由于p53依赖性或p53非依赖性因素。在早期的结构-活性研究中，我们已经确定西多福韦的烷氧基乙基酯比烷氧基丙基CDV酯对宫颈癌细胞的抗增殖作用更强。此外，烷基链中一个双键的存在似乎增强了对宫颈癌细胞如Me-180和HeLa的抗增殖活性。OleyloxyethyI-CDV的活性比我们评价的第一种化合物HDP-CDV高15至80倍。我们计划继续结构-活性工作，评估新化合物的抗增殖作用及其对正常细胞和表达高危亚型的HPV DNA+细胞系中细胞周期的影响。将选择最具活性和选择性的化合物在植入肿瘤的无胸腺裸鼠中进行测试。将通过评价基因和蛋白质表达以及细胞周期效应来探索作用机制。我们相信，结构-活性和分子分析方法可能会取得成功，并可广泛适用于其他类型的癌症，其中HPV癌基因干扰p53和pRb的水平和功能。这一提议可能导致用于治疗宫颈癌和其他HPV相关癌症的新药物。

Cidofovir (CDV) is a broad spectrum antiviral with activity against most double-stranded DNA viruses. A number of DNA viruses have been implicated as essential factors in viral-induced malignancy. The concept of using antivirals for treating cancers is in its infancy and worth exploring. This proposal seeks to evaluate new, highly active analogs of CDV that are substantially more active against DNA viruses while having reduced nephrotoxicity, a limiting factor in the utilization of cidofovir. We have synthesized and tested alkyoxyalkyl analogs of CDV that were at least 10 fold more potent than unmodified CDV. Our preliminary results in testing such agents against the human papilloma positive cell lines, Me-180 and HeLa, demonstrated that the cells were undergoing apoptosis and S phase arrest. This effect was 200-300 times more prominent in cervical cancer cells than in normal HFF or PHK cells. This may be due to p53 dependent or p53 independent factors. In early structure-activity studies we have identified that alkoxyethyl esters of cidofovir are more more potent antiproliferatives to cervical cancer cells than are alkoxypropyl CDV esters. Furthermore, the presence of one double bond in the aikyl chain seems to enhance the antiproliferative activity against cervical cancer cells such as Me-180 and HeLa. OleyloxyethyI-CDV is 15 to 80 times more active than HDP-CDV, the first compound we evaluated. We plan to continue structure-activity work, assessing antiproliferative effects of the new compounds and their effect on the cell cycle in normal cells and a panel HPV DNA+ cell lines expressing high risk subtypes. The most active and selective compounds will be selected for testing in athymic nude mice implanted with tumors. The mechanism of action will be explored by evaluating gene and protein expression and cell cycle effects. We believe that the structure-activity and molecular analysis approach may yield success and could be broadly applicable to a other types of cancer where HPV oncogenes interfere with the levels and function of p53 and pRb. This proposal could lead to new agents for treatment of cervical cancer and other HPV-associated cancers.