Individualized DNA based therapy of bladder cancer

膀胱癌是包括德国和近东国家在内的世界范围内最重要的癌症之一。它具有很大的生物学异质性和临床异质性。可用的治疗方法包括经尿道和根治性手术以及化疗，但由于浅表乳头状肿瘤的复发和浸润性癌症的全身扩散，这些方法的疗效受到限制。因此，分子标记物对于预测预后和改善治疗方式是必要的。理想情况下，他们可以帮助选择个性化的治疗方法。因此，本项目的目标是开发预测膀胱移行细胞癌预后的分子标记物，并针对每种肿瘤的特点开发基于DNA的基因疗法。H19和IGF2基因在膀胱移行细胞癌特定亚群中的异位表达是表观遗传和遗传机制共同作用的结果。H19的调控序列已经被成功地用于靶向培养中的TCC细胞、在几个异位和原位动物模型中、甚至在乳头状癌患者中靶向表达有毒蛋白白喉毒素A(DT-A)。在本项目中，将扩大用于此目的的调控序列的保留范围，以涵盖更大比例的TCC。使用IGF2调控序列的构建体和1GF2表达的研究将继续进行。新的肿瘤特异性启动子将通过对显示TCC中DNA低甲基化和异位表达的基因的研究而产生。这项研究还应该为TCC分类提供改进的基于甲基化的分析方法，其潜力将在不同人群的患者中进行探索。子项目旨在通过使用另一种治疗性蛋白质胞苷脱氨酶，以及通过DT-A与肿瘤坏死因子α的可能协同作用，扩大基于DNA的TCC治疗的疗效。

Bladder carcinoma (TCC) is one of the most important cancers worldwide, including Germany and Near East countries. It is characterized by great biological and clinical heterogeneity. Available therapies include transurethral and radical surgery and chemotherapy, which are limited in efficacy by recurrences of superficial papillary tumors and systemic spread of invasive cancers. Therefore, molecular markers are needed for predicting prognosis and for improved therapeutic modalities. Ideally, they could help to select individualized therapies. The goals of the present project are accordingly the development of molecular markers for TCC prognosis and of a DNA-based gene therapy tailored to the properties of each tumor. Ectopic expression of the H19 and IGF2 genes in specific subsets of TCC is caused by epigenetic and genetic mechanisms. Regulatory sequences from H19 have already been used to successfully target expression of a toxic protein, diphtheria toxin A (DT-A), to TCC cells in culture, in several heterotopic and orthotopic animal models, and even in patients with papillary cancer. In the present project, the repertoire of regulatory sequences for this purpose will be expanded to cover a larger proportion of TCC. Investigation of constructs using IGF2 regulatory sequences and of 1GF2 expression will be continued. New tumor-specific promoters will be derived from an investigation of genes displaying DNA hypomethylation and ectopic expression in TCC. This investigation should also provide improved methylation-based assays for TCC classification, whose potential will be explored in patients from the different populations. Subprojects aim at amplifying the efficacy of DNA-based TCC therapy by using another therapeutic protein, cytidine deaminase, and through a possible synergism of DT-A with tumor necrosis factor alpha.