TRANSFORMING GROWTH FACTOR-B EXPRESSION IN MELANOMA DEVELOPMENT AND PROGRESSION

本申请的目的是确定肿瘤相关的 转化生长因子-β在恶性肿瘤发展中的作用 黑素瘤 该小组先前的工作表明，TGF-β是 原发性和恶性肿瘤持续表达 尽管TGF-β抑制黑色素瘤的生长， 体外 基于这些观察，假设TGF-β 在体内发挥对黑素瘤发展至关重要的作用， 因此超过了体外观察到的生长抑制作用。 相关 TGF-β的作用包括改变粘附分子的表达， 黑色素瘤细胞的蛋白水解酶， 肿瘤生长和转移扩散，以及对 肿瘤细胞 来自其他肿瘤系统的间接证据表明 TGF-β对所有这些现象的重要贡献。 的 提出的实验代表了一种直接的方法来确定哪一个 黑色素瘤衍生的TGF-β的这些潜在作用对于 黑色素瘤发展。 黑色素瘤细胞系来源于不同的进展阶段， 明确的致瘤性、转移能力、免疫原性和TGF-β 通过上调或抑制TGF-β的产生来实现 使用有义、反义和负显性表达载体， 选择的细胞系，然后深入分析肿瘤生长， 转移行为 对裸鼠致瘤性的影响通过 在非致瘤性人原代黑素瘤细胞中过表达TGF-β WM 1650。 通过抑制TGF-β 1的表达来分析对转移行为的影响。 高转移性人类1205-LU细胞中的β产生。 影响 免疫原性通过下调TGF-β产生来检测， 非免疫原性小鼠K1735黑色素瘤细胞变体和随后的 测定同基因免疫活性小鼠的免疫原性。 在 体外研究将集中于TGF-β对粘附的依赖性作用， 迁移和调节粘附分子和蛋白水解酶， 黑色素瘤细胞;免疫学研究将集中在TGF-β的影响 不同的淋巴细胞亚群。 这些研究的长期目标是确定黑色素瘤- 衍生的TGF-β提供了合适的治疗靶点。

The goal of this application is to define the role of tumor-associated transforming growth factor (TGF)-beta in the development of malignant melanoma. Previous work by this group demonstrated that TGF-beta is constitutively and persistently expressed by primary and malignant melanomas in vitro and in situ although TGF-beta inhibits melanoma growth in vitro. Based on these observations it is hypothesized that TGF-beta exerts effects in vivo that are essential to melanoma development and, thus, outweigh the growth-inhibitory effects observed in vitro. Relevant effects of TGF-beta include altered expression of adhesion molecules and proteolytic enzymes by melanoma cells, recruitment of host cells for local tumor growth and metastatic spread, and suppression of immune responses to tumor cells. Indirect evidence from other tumor systems suggests significant contributions of TGF-beta to all of these phenomena. The proposed experiments represent a direct approach to determine which of these potential effects of melanoma-derived TGF-beta are essential to melanoma development. Melanoma cell lines derived from distinct stages of progression and with defined tumorigenicity, metastatic capacity, immunogenicity, and TGF-beta effects is achieved by upregulation or suppression of TGF-beta production using sense, antisense, and negative dominant expression vectors in selected cell lines followed by in depth analysis of tumor growth and metastatic behavior. Effects on tumorigenicity in nude mice are studied by overexpressing TGF-beta in the non-tumorigenic human primary melanoma cell WM 1650. Effects on metastatic behavior are analyzed by suppressing TGF- beta production in the highly metastatic human 1205-LU cells. Effects on immunogenicity are examined by downmodulation of TGF-beta production in non-immunogenic mouse K1735 melanoma cell variants and the subsequent determination of immunogenicity in syngeneic, immunocompetent mice. In vitro studies will focus on TGF-beta dependent effects on adhesion, migration, and modulation of adhesion molecules and proteolytic enzymes in melanoma cells; immunological studies will focus on the effects of TGF-beta on different lymphocyte subsets. The long-term goal of these studies is to determine whether melanoma- derived TGF-beta provides a suitable therapeutic target.