权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

MITOMYCIN C-DNA ADDUCTS IN TUMOR CELLS

肿瘤细胞中的丝裂霉素 C-DNA 加合物

基本信息

批准号：
2895677
负责人：
MARIA TOMASZ
金额：
$ 20.62万
依托单位：
HUNTER COLLEGE
依托单位国家：
美国
项目类别：
财政年份：
1997
资助国家：
美国
起止时间：
1997-09-17 至 2001-07-31
项目状态：
已结题

项目摘要

The long-term goal of the proposed studies is to elucidate critical cellular mechanisms involved int he antitumor activity of mitomycin C (MC), a natural product widely employed in clinical cancer chemotherapy, and to translate this information into the improved use of MC and its analogs against cancer. Four intracellular variables will be examined with regards to their effects on the cytotoxicity and DNA-adduct-forming ability of MC in tumor cells: (i) The nature of the enzymes that reductively activate MC; (ii) the glutathione level in the cell; (iii) low intracellular pH; and (iv) monofunctional (decarbamoyl mitomycin C) versus bifunctional mitomycin (MC) as the administered agent. All of the variables will be studies in the EMT66 mouse mammary tumor cell line. Complete MC-DNA adduct patterns formed in the cells will be determined using [3H]-labeled MC and analyzing the radiolableed adducts by HPLC, by a method developed previously in our laboratoy. Analogous analyses will be conducted in cell-free system using purified MC-activating enzymes and EMT6DNA, to evaluate intrinsic (cell-independent) effects of the above variables on DNA adduct patterns. The structures of unknown MC-DNA adducts will be determined. Cytotoxicity of MC to cells with enhanced levels of gluthathione as well as the cytotoxicity of the mitomycin metabolie 2, 7-diaminomitosene will be studied in conjunction with the DNA-adduct analyses. This work is expected to result I identifying in intact cells (i) critical MC-activating enzynes and modulation of their activity by cellular microenvironmental conditions and (ii) the relative cytotoxic importance of MC-DNA cross-links versus MC-monoadducts. The knowledge obtained should contribute to improving the use of the mitomycins in the treatment of cancer.

拟议研究的长期目标是阐明关键丝裂霉素C抗肿瘤作用的细胞机制 (MC)，一种广泛用于临床癌症的天然产物化疗，并将这些信息转化为更好的使用 MC及其类似物的抗癌作用。四个细胞内变量将检查其对细胞毒性的影响，肿瘤细胞中MC的DNA加合物形成能力：（i）还原激活MC的酶;（ii）细胞;（iii）低细胞内pH;和（iv）单功能（脱氨甲酰丝裂霉素C）与双功能丝裂霉素（MC）作为管理的代理人。所有变量都将在 EMT 66小鼠乳腺肿瘤细胞系。完全MC-DNA加合物将使用[3 H]-标记的MC测定细胞中形成的图案并通过HPLC分析放射性加合物，在我们的实验室里开发的。类似的分析将使用纯化的MC-活化酶在无细胞系统中进行和EMT 6DNA，以评估内源性（细胞非依赖性）的影响，上述变量对DNA加合物模式的影响。未知的结构将测定MC-DNA加合物。 MC对细胞的细胞毒性具有增强的谷胱甘肽水平以及丝裂霉素代谢产物2，7-二氨基丝裂霉素将在结合DNA加合物分析。这项工作预计将结果I在完整细胞中鉴定出（i）关键的MC-活化酶和通过细胞微环境条件调节它们的活性和（ii）MC-DNA交联的相对细胞毒性重要性相对于MC-单加合物。获得的知识应该有助于涉及改善丝裂霉素在癌症治疗中的应用。