MOLECULAR ANALYSIS OF HEPATOMA CELL MIGRATION FACTOR

细胞运动是肿瘤细胞向周围侵袭的必要条件 组织并实现转移。 增强细胞增殖的可溶性因子 在这个过程中也涉及到了运动性。 我们发现了一种活动 在人成纤维细胞的条件培养基中， 肝癌细胞 这项建议的长远目标是 描述了这种新的因子，暂命名为“肝癌细胞 迁移因子（HMF）。 HMF可分散高分化肝癌的紧密堆积集落 细胞分裂成单个细胞，并促进细胞从细胞中迁移出来。 殖民地 分散的细胞广泛分布，并呈现出 成纤维细胞，去分化形态。 这些表型变化 用小于1 ng/ml的部分纯化的HMF诱导。 的 估计分子量（60 kDa），靶细胞的窄范围 对肝细胞/肝癌细胞和其他生物和 生化数据表明，HMF不同于其他运动因子 以及已知影响细胞形态和运动性的细胞因子。 所以我们 工作假设是HMF是一种新的精氨酸型分子， 调节肝细胞/肝癌细胞的迁移和分化 并可能与肝癌的体内侵袭和转移有关。 为了研究HMF的生物学作用，我们将1）纯化HMF并获得 其氨基酸序列; 2）HMF cDNA分子克隆和测序; 3） 免疫组化法观察HMF的组织分布 用特异性抗体探针染色;和4）表征 HMF对细胞分化、迁移和侵袭的生物学效应 通过使用外源性添加的HMF和通过基因 将HMF cDNA转移到细胞中。 这些研究将有助于我们 了解肿瘤侵袭和转移的分子机制 的肝癌在体内，并确定在这些过程中的作用HMF。

Cell locomotion is essential for tumor cells to invade into surrounding tissues and achieve metastasis. Soluble factors that enhance cellular motility have been implicated in the process. We have found an activity in conditioned media of human fibroblasts that stimulates the motility of hepatoma cells. The long-term objective of this proposal is to characterize this novel factor, tentatively termed "hepatoma cell migration factor" (HMF). HMF disperses tightly packed colonies of well-differentiated hepatoma cells into single cells and promotes the migration of the cells out of colonies. The dispersed cells spread extensively and assume a fibroblastic, dedifferentiated morphology. These phenotypical changes are induced with less than 1 ng/ml of partially purified HMF. The estimated molecular weight (60 kDa), the narrow range of target cell specificity toward hepatocytes/hepatoma cells, and other biological and biochemical data suggest that HMF is distinct from other motility factors and cytokines known to affect cell morphology and motility. Thus, our working hypothesis is that HMF is a novel cytokine-type molecule which regulates the migration and differentiation of hepatocytes/hepatoma cells and possibly the invasion and metastasis of hepatoma in vivo. To examine the biological roles of HMF, we will 1) purify HMF and obtain its amino acid sequences; 2) molecularly clone and sequence HMF cDNA; 3) investigate the tissue distribution of HMF by immunohistochemical staining with specific antibody probes; and 4) characterize the biological effects of HMF on the differentiation, migration and invasion of hepatocytes/hepatoma cells by using exogenously added HMF and by gene transfer of HMF cDNA into cells. These studies will contribute to our understanding of the molecular mechanisms of the invasion and metastasis of hepatoma in vivo and define a role for HMF in these processes.