TRANSCRIPTIONAL REGULATION OF UROKINASE PLASMINOGEN ACTIVATOR GENE IN METASTATIS

肿瘤细胞从恶性肿瘤原发部位转移 导致癌症患者死亡的原因。 的过程 转移是复杂的，涉及几个步骤，包括侵袭和 细胞外基质的降解、内渗、转运 血管、外渗和新肿瘤病灶的建立 远离原发肿瘤。 这些步骤可能涉及 几种蛋白水解酶的作用，这些酶在几个 在代谢过程中暂时处于水平。 通过它的能力， 将纤溶酶原激活为纤溶酶，uPA是参与纤溶酶的酶之一。 metastic过程。 我们使用的是人骨肉瘤模型， 显示出不同的形成肿瘤和转移能力的细胞系 在无胸腺裸鼠中。 编码uPA的基因在每一个细胞中都是单拷贝的， 细胞系。 通过北方印迹杂交， 亲本细胞系HOS表达低水平的uPA mRNA，而其两个亲本细胞系HOS表达低水平的uPA mRNA。 转化的衍生物AD 110和KRIB表达约5-10倍， 同样多的uPA mRNA。 使用CAT测定的初步启动子分析表明， uPA的5'侧翼区含有一个负调控区， HOS细胞中的活性元素。 同一区域似乎赋予积极的 AD 110和KRIB细胞中的启动子活性。 隔离程序 用于核运行分析的核已被优化， 目前正在进行化验。

Metastasis of tumor cells from the primary site of a malignancy accounts for the majority of fatalities in cancer patients. The process of metastasis is complex and involves several steps including invasion and degradation of the extracellular matrix, intravasation, transit through the vasculature, extravasation, and establishment of new tumor foci distant from the primary tumor. These steps probably involve the actions of several proteolytic enzymes which are regulated at several levels temporally during the metastic process. Through its ability to activate plasminogen to plasmin, uPA is among the enzymes involved in the metastic process. We are using a human osteosarcoma model comprised of cell lines showing varying abilities to form tumors and metastasize in athymic nude mice. The gene encoding uPA is single copy in each of the cell lines. By Northern blot hybridization, the nontumorigenic parental cell line HOS expresses low levels of uPA mRNA while two of its transformed deriatives, AD110 and KRIB, express approximately 5-10 times as much uPA mRNA. Preliminary promoter analysis using CAT assay suggest that the 5' flanking region of uPA contains a negative regulatory element active in HOS cells. The same region appears to confer positive promoter activity in AD110 and KRIB cells. Procedures for isolating nuclei for nuclear run on assays have been optimized and nuclear run on assays are currently underway.