EFFICACY AND ANTITUMOR MECHANISMS OF EGFR ANTISENSE GENE THERAPY

EGFR反义基因治疗的疗效及抗肿瘤机制

• 批准号: 6480423
• 负责人: Jennifer Rubin Grandis
• 金额: $ 17.86万
• 依托单位: UNIVERSITY OF PITTSBURGH AT PITTSBURGH
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-08-01 至 2004-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6480423
• 关键词: antisense nucleic acid; apoptosis; carcinogenesis inhibitor; clinical research; clinical trial phase I; dosage; epidermal growth factor; gene therapy; growth factor receptors; human subject; human therapy evaluation; laboratory mouse; liposomes; neoplasm /cancer genetics; neoplasm /cancer transplantation; neoplastic growth; nonhuman therapy evaluation; oral pharyngeal neoplasm; protein isoforms; squamous cell carcinoma; transcription factor

We have demonstrated that EGFR up-regulation in OSCC is due to activated gene transcription and that down-modulation of EGFR results in decreased proliferation of OSCC but not normal cells. Further investigation in our laboratory revealed inhibition of tumor growth in vivo following intratumoral inoculation of an EGFR antisense expression construct based on the U6 small nuclear RNA promoter in complexed with DC-chol liposomes. This anti-tumor effect was accompanied by decreased EGFR protein expression in the tumors and increased apoptosis. Preliminary results suggest that EGFR signaling in OSCC involves constitutive activation of Stat3alpha-beta and that down-modulation of Stat3 using antisense oligonucleotides or dominant negative mutants result in inhibition of OSCC proliferation. The importance of this autocrine pathway is underscore by our finding that protein expression levels of EGFR in the primary OSCC tumor is a significant and independent predictor of decreased survival. Therefore, we propose to test the hypothesis that the loss of growth control in OSCC is mediated through acquisition of an EGFR autocrine signaling pathway, which can be targeted using an antisense gene therapy approach. In specific aim 1 we propose to characterize the effects of EGFR antisense therapy in OSCC in vitro and in murine xenograft models by determining: a) the association between EGFR expression levels and anti-tumor activity; and b) the dose, schedule, and time-dependent parameters for optimal effect. In specific aim 2 we propose to determine the mechanism of the anti-tumor effects of EGFR antisense gene therapy in vitro and in murine xenograft models by: a) characterizing the impact of treatment on expression and activation of specific STAT protein isoforms; and b) examination the consequences of therapy on apoptosis. In specific aim 3 we propose to determine in the phase I setting, the maximally tolerated dose (MTD) and biologic effects of intratumoral liposome-mediated EGFR antisense gene therapy in OSCC patients.

我们已经证明，表皮生长因子受体在口腔鳞状细胞癌中的上调是由于基因转录的激活，而下调表皮生长因子受体导致口腔鳞状细胞癌而不是正常细胞的增殖减少。我们实验室的进一步研究显示，肿瘤内接种基于U6小核RNA启动子与DC-chol脂质体复合的EGFR反义表达构建体后，体内肿瘤生长受到抑制。这种抗肿瘤作用伴随着肿瘤中EGFR蛋白表达的降低和细胞凋亡的增加。初步结果表明，表皮生长因子受体信号在口腔鳞状细胞癌涉及组成性激活的Stat 3 α-β和下调Stat 3使用反义寡核苷酸或显性负突变体的结果抑制口腔鳞状细胞癌增殖。我们的发现强调了这种自分泌途径的重要性，即原发性OSCC肿瘤中EGFR的蛋白表达水平是生存率降低的重要和独立的预测因子。因此，我们建议测试的假设，即在口腔鳞癌的生长控制的损失是通过收购介导的EGFR自分泌信号通路，这可以有针对性地使用反义基因治疗的方法。在具体目标1中，我们建议通过确定：a）EGFR表达水平与抗肿瘤活性之间的关系;和B）最佳效果的剂量、时间和时间依赖性参数，来表征EGFR反义治疗在体外OSCC和小鼠异种移植模型中的作用。在具体目标2中，我们建议通过以下方式确定EGFR反义基因治疗在体外和小鼠异种移植模型中的抗肿瘤作用机制：a）表征治疗对特定STAT蛋白亚型的表达和活化的影响;和B）检查治疗对细胞凋亡的影响。在具体目标3中，我们建议在I期设置中确定肿瘤内脂质体介导的EGFR反义基因治疗在OSCC患者中的最大耐受剂量（MTD）和生物学效应。