GENE THERAPY OF MALIGNANT MESOTHELIOMA USING E1 DELETED ADENOVIRUS

恶性间皮瘤（MM）是一种目前尚无有效治疗方法的肿瘤。我们进行了一项I期临床试验，以评估在劳斯肉瘤病毒（RSV）启动子驱动下，将含有单纯疱疹病毒胸苷激酶基因（HSVtk）的重组腺病毒（rAd）注入MM患者胸膜间隙的安全性和可行性，随后用抗病毒药物更昔洛韦（GCV）进行全身治疗14天。先前在MM动物模型中实施rAd.RSVtk -GCV方案可显著减少肿瘤负荷，延长生存期，并具有最小的全身毒性。该临床试验是一项剂量递增研究，旨在确定rAd.RSVtk的最大耐受胸膜内剂量。26名患者已经完成了剂量水平高达1 × 10 × 12斑块形成单位（pfu） Ad的治疗。RSVtk并发症最少。毒副反应包括病毒注射后的低烧、贫血、肝功能检查的短暂性升高和注射部位附近的皮肤水泡。对选择的基因递送后活检样本的评估显示tk基因通过DNA PCR、原位杂交和免疫组织化学以剂量依赖的方式转移的证据。载体给药后活检样本的免疫组化分析可见中性粒细胞为主的炎症反应。患者对腺病毒载体有明显的体液和细胞免疫反应。总之，Ad。RSVtk/GCV基因治疗在MM患者中是安全的，似乎有证据表明TK基因以剂量依赖的方式转移，重组腺病毒在进入胸膜腔时引起强烈的免疫反应。

Malignant mesothelioma (MM) is a neoplasm for which no effective therapy currently exists. We conducted a Phase I clinical trial to assess the safety and feasibility of intrapleural delivery of recombinant adenovirus (rAd) containing the Herpes Simplex Virus thymidine kinase gene (HSVtk) driven by the Rous Sarcoma Virus (RSV) promoter into the pleural space of patients with MM followed by systemic treatment with the antiviral drug ganciclovir (GCV) for 14 days. Prior implementation of the rAd.RSVtk -GCV protocol in animal models of MM resulted in significant reduction of tumor burden and prolongation of survival with minimal systemic toxicity. The clinical trial was a dose escalation study designed to determine the maximally-tolerated intrapleural dose of rAd.RSVtk. Twenty-six patients have completed treatment at dose levels up to l.0x10 12 plaque forming units (pfu) Ad.RSVtk with minimal complications. Toxicities seen include low-grade fever after viral instillation, anemia, transient elevation of liver function tests, and vesicular skin eruptions near the instillation site. Evaluation of selected post-gene delivery biopsy samples revealed eavidence of tk gene transfer via DNA PCR, in situ hybridization, and immunohistochemistry in a dose-dependent fashion. Neutrophil-predominant inflammatory responses were seen on IHC analysis of post-vector administration biopsy samples. Patients develop significant evidence of humoral and cellular immune responses against the adenoviral vector. In summary, Ad.RSVtk/GCV gene therapy is safe in MM paatients, there appears to be evidence of TK gene transfer in a dose-dependent fashion, and recombinant adenoviruses elicit strong immune responses when delivered into the pleural space.