Signaling response to DNA damage in Dictyostelium

超出所提供的空间。化疗仍然是最常见的，往往是治疗人类癌症的唯一有效手段。不幸的是，肿瘤经常对许多最有效和最广泛使用的化疗药物产生耐药性，其中一个重要的例子是顺铂。顺铂耐药的分子机制尚不清楚，需要新的方法来理解这些机制。我们采取了一种基因发现的方法，在Dictyosteelium discoideum中使用插入诱变，以确定介导顺铂耐药的分子组分。我们已经确定了6个基因负责顺铂耐药。这些基因以前都没有与顺铂耐药相关。这些基因代表了减少顺铂耐药性发展的新靶点，因此提高了其治疗价值。选择其中两种基因产物，鞘氨醇-1-P裂解酶（其催化鞘氨醇-1-磷酸降解为磷酸乙醇胺和十六烷醛）和RegA磷酸二酯酶（其催化cAMP降解）进行详细研究，因为它们位于已知调节细胞增殖和细胞死亡方面的关键途径中。此外，我们有能力调节这些途径的基因，以及遗传研究顺铂细胞毒性和耐药性的基本机制。我们在该提议中提出了易于测试的假设，以1）确定我们的突变体中顺铂抗性的分子基础，2）确定由顺铂处理正常细胞引起的中心生化变化，以及3）预测含有S-I-P裂解酶和RegA基因的途径如何相互关联。这些假设将在Dictyosteoblastoma模型、人细胞和卵巢肿瘤中进行检验。这些研究将为耐药性提供重要的见解，并确定可以修改以增加顺铂疗效的其他细胞靶点。性能现场=

EXCEED THE SPACE PROVIDED. Chemotherapy remains the most common, and often the only effective means of treating human cancer. Unfortunately, tumors frequently develop resistance to many of the most effective and widely used chemotherapeutic agents - an important example of which is cisplatin. The molecular mechanism of developing resistance to cisplatin is not known, and new approaches, to understand the mechanisms are needed. We took a gene discovery approach, using insertional mutagenesis in Dictyostelium discoideum, to identify molecular components that mediate cisplatin resistance. We have identified 6 genes responsible for cisplatin resistance. None of these genes had previously been associated with cisplatin resistance. These genes represent novel targets for reducing the development of resistance to cisplatin, and therefore improving its therapeutic value. .Two of these, gene products, the sphingogsine-1-P lyase (which catalyzes the degradation of sphingosine-1- phosphate to phosphoethanolamine and hexadecanal) and RegA phosphodiesterase (which catalyzes the degradation of cAMP) have been chosen for detailed study because they lie in critical pathways that are known to regulate aspects of cell proliferation and cell death. Furthermore, we have the capability to modulate these pathways pharmacologically as well as genetically to investigate the basic mechanism of cisplatin cytotoxicity and resistance. We present in this proposal readily testable hypotheses to 1) determine the molecular basis of cisplatin resistance in our mutants, 2) determine central biochemical changes that result from cisplatin treatment of normal cells, and 3) predict how the pathways containing the S-l-P lyase and RegA genes are interrelated. These hypotheses will be tested in both the Dictyostelium model, human cells and ovarian tumors. These studies will provide significant insights into drug resistance and identify additional cellular targets which can be modified to increase the efficacy of cisplatin. PERFORMANCE SITE ========================================Section End===========================================