Viral Vectors in Tumors: Effects of Taxol and Radiation

描述(由申请人提供)： 肿瘤细胞在有限的空间内的增殖使血管塌陷，从而限制了治疗剂在肿瘤中的渗透和均匀分布。我们最近的数据还表明，在有限的空间内生长的肿瘤球体可以上调透明质酸的表达，透明质酸是一种间质基质(IM)分子，阻碍间质液体的运动和分子扩散。紫杉醇诱导的细胞凋亡减轻了受限空间的影响，从而改善了通过肿瘤IM的血管灌流和液体流动。相反，放射减少了通过肿瘤IM的液体流动。因此，这项研究的目标将是确定：1)紫杉醇和辐射对间质运输和IM分子产生的影响，2)检验在有限空间中生长上调肿瘤细胞糖胺聚糖表达并减少扩散运输的假设，以及3)确定由细胞凋亡引起的空隙是否产生有利于病毒快速和更均匀地渗透的间质途径。光漂白后的荧光恢复和水力传导性的测量将检验紫杉醇增强肿瘤间质运输的假设。转运数据将与IM基质分子和细胞凋亡的水平有关。在有限的空间中生长对透明质酸表达的影响将在 在体外通过增加胶原蛋白或琼脂糖凝胶浓度来生长肿瘤球体。为了验证细胞凋亡增强病毒粒子在肿瘤中的分布体积和基因转染率的假设，将用紫杉醇和caspase-8可诱导启动子导入细胞中诱导细胞凋亡。多光子激光扫描显微镜将被用来测量病毒载体在肿瘤中的分布体积，并确定由细胞凋亡引起的空隙是否形成相互连接的间质路径，从而增强病毒颗粒的运动。透明质酸合成酶2的正义结构将检验这一假说，即透明质酸参与细胞凋亡后空隙的重塑和阻塞，从而减少间质运输和病毒载体的移动。紫杉醇诱导的细胞凋亡(空隙形成)增强基因治疗抗肿瘤效果的假设将得到验证。这一结果将为如何最好地结合病毒载体和细胞毒剂提供洞察力。

DESCRIPTION (provided by applicant): The proliferation of neoplastic cells in a confined space collapses blood vessels thus restricting the penetration and uniform distribution of therapeutic agents in tumors. Our recent data also shows that growth of tumor spheroids in a confined space can upregulate the expression of hyaluronan an interstitial matrix (IM) molecule that hinders interstitial fluid movement and molecular diffusion. The induction of apoptosis by taxol alleviates the confined space effects, thus improving vascular perfusion and fluid flow through the tumor IM. In contrast, radiation reduces fluid flow through the tumor IM. Thus the objectives of the proposed study will be to determine: 1) the effects of taxol and radiation on interstitial transport, and on the production of IM molecules, 2) test the hypothesis that growth in a confined space upregulates the expression of glycosaminoglycans by tumor cells and reduces diffusive transport and 3) determine if the void spaces induced by apoptosis produce interstitial pathways that favor a rapid and more uniform penetration of viruses. Fluorescence recovery after photobleaching and measurements of hydraulic conductivity will test the hypothesis that taxol enhances interstitial transport in tumors. The transport data will be related to the levels of IM matrix molecules and apoptosis. The effects of growth in a confined space on the expression of hyaluronan will be tested in vitro by growing tumor spheroids in increasing concentrations of collagen or agarose gels. To test the hypothesis that apoptosis enhances the distribution volume of viral particles and gene transfection in tumors, apoptosis will be induced with taxol and in cells transfected with a caspase-8 inducible promoter. Multiphoton laser-scanning microscopy will be used to measure in tumors the distribution volume of viral vectors and determine if the void spaces induced by apoptosis form interconnected interstitial pathways that enhance the movement of viral particles. Sense constructs of hyaluronan synthase 2 will test the hypothesis that hyaluronan participates in the remodeling and obstruction of the void spaces following apoptotic death, thus reducing interstitial transport and the movement of viral vectors. The hypothesis that taxol-induced apoptosis (void space formation) enhances the antitumor efficacy of gene therapy will be tested. The results will provide insight on how to best combine viral vectors and cytotoxic agents.