TRANSCRIPTIONAL REGULATION OF UROKINASE PLASMINOGEN ACTIVATOR GENE IN METASTATIS

恶性肿瘤原发部位肿瘤细胞转移的原因 对大多数癌症患者的死亡负责。这一过程 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，血管内，通过 血管生成、外渗与肿瘤新病灶的建立 远离原发肿瘤。这些步骤可能涉及 几种受多种调控的蛋白水解酶的作用 在交代过程中暂时的水平。通过它的能力 激活纤溶酶原为纤溶酶，uPA是参与其中的酶 变形过程。我们使用的是人类骨肉瘤模型，包括 显示出不同的形成肿瘤和转移能力的细胞系 在裸鼠体内。编码uPA的基因在每个基因中都是单拷贝 这些细胞系。经Northern印迹杂交，非致瘤性 亲本细胞株HOS低水平表达uPA mRNA，而其两个 转化后的派生词AD110和KRIB大约表达5-10倍 同样多的uPA基因。使用CAT分析的初步启动子分析表明 UPA的5‘侧翼区域含有负调控 在HOS细胞中活跃的元素。同样的地区似乎也带来了积极的影响 在AD110和KRIB细胞中的启动子活性。隔离程序 用于分析的核运行的核已经被优化，并且核运行 目前正在进行检测。

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.