Laminin-332 and its Receptors in Carcinoma Progression

描述(申请人提供)：皮肤浸润性鳞状细胞癌在美国是一个严重的问题，每年有超过100万例病例。随着发病率的上升，手术和放射治疗是唯一可行的治疗选择，因此迫切需要开发更具体的分子药物来对抗这种疾病。为此，这项建议试图从功能上描述真皮-表皮交界处的重要成分，以确定基底膜蛋白如何作为皮肤鳞状细胞癌侵袭和发展的重要驱动力。层粘连蛋白-332是表皮基底膜的重要组成部分，是表皮肿瘤发生所必需的，我们已经通过使用人体皮肤鳞状细胞癌活体模型证明了这一点。最近的数据表明，层粘连蛋白-332‘S的蛋白水解性修饰、其与III型胶原的结合以及与a6？4整合素的相互作用在鳞状细胞癌的发生发展中起着重要作用，但目前尚缺乏一个整合了所有这些特征的层粘连蛋白-332在鳞状细胞癌中作用的统一模型。除了6？4整合素外，其他几种细胞表面受体与层粘连蛋白-332相互作用，包括Syndecan-1、c-Met和EGFR，这些受体也可能参与鳞癌发生过程中层粘连蛋白-332衍生的信号转导。这些分子如何协同激活SCC中的促肿瘤信号通路仍有待充分阐明，这也是本研究的重点。首先，我们计划研究层粘连蛋白-332的各个结构域通过基因缺失和抗体抑制在这一过程中的作用。我们还将阐明4整合素中包含的特定残基所贡献的促肿瘤信号。其次，我们将研究4整合素相关分子的作用，以了解它们如何与层粘连蛋白-332和4整合素一起协调增殖、细胞侵袭、层粘连蛋白-332沉积、金属蛋白酶活性和其他对癌症进展至关重要的功能。最后，基于初步数据显示在不破坏正常皮肤凝聚力的情况下特异性抑制鳞状细胞癌的发生，使用抗层粘连蛋白-332的G45结构域的抗体，我们计划开发和测试一组抗层粘连蛋白-332结构域的抗体以及III型胶原NC1抗体。在这些研究中，我们将从功能上表征这些抗体如何作用于鳞状细胞癌的肿瘤发生，以及正常皮肤。我们还将确定联合抗体疗法是否能产生协同抑癌作用。在拟议的资助期结束时，我们希望回答关于细胞外基质在皮肤鳞状细胞癌发生中的作用的基本问题，并了解有潜力开发新的和特定的皮肤鳞状细胞癌治疗方法的新信息。公共卫生相关性：皮肤鳞状细胞癌(SCC)是人类第二常见的癌症，但缺乏有效和特异的分子治疗方法。这项建议侧重于了解真皮-表皮基底膜蛋白laminin-332和a6？4整合素在促进鳞癌进展和侵袭中所起的关键作用。这项建议还寻求开发新的和特定的分子疗法，在不破坏正常皮肤组织的情况下抑制鳞癌中层粘连蛋白-332及其相关分子的功能。

DESCRIPTION (provided by applicant): Invasive squamous cell carcinoma of the skin is a significant problem in the U.S. with over one million cases annually. With a rising incidence and with surgery and radiation therapy as the only feasible treatment options, the need for development of more specific molecular agents to combat this disease is great. Towards this end, this proposal seeks to functionally characterize important components of the dermal-epidermal junction to determine how basement membrane proteins act as a significant driving force for invasion and progression of cutaneous squamous cell carcinoma. Laminin-332 is an essential component of the epidermal basement membrane, and is required for epidermal tumorigenesis as we have shown through use of an in vivo model of human cutaneous SCC. Recent data suggest that laminin-332's proteolytic modifications, its binding to collagen VII and its interaction with a6¿4 integrin each play important roles in SCC tumorigenesis, however a unified model of laminin-332 function in SCC which incorporates all of these features is lacking. In addition to a6¿4 integrin, several other cell surface receptors interact with laminin-332, including syndecan-1, c-Met and EGFR, and these receptors may also participate in laminin-332 derived signaling during SCC tumorigenesis. How these molecules coordinate together to activate pro-tumorigenic signaling pathways in SCC remains to be fully elucidated and is the focus of this proposal. First we plan to study the contributions of individual domains of laminin-332 to this process by both genetic deletion and antibody inhibition. We will also elucidate the pro-tumorigenic signaling contributed by specific residues contained in ¿4 integrin. Second, we will examine the role of ¿4 integrin associated molecules to understand how they, with laminin-332 and ¿4 integrin, coordinate proliferation, cellular invasion, laminin-332 deposition, metalloproteinase activity and other functions essential for carcinoma progression. Finally, based on preliminary data showing specific inhibition of SCC tumorigenesis without disruption of normal skin cohesion, using an antibody against the G45 domain of laminin-332, we plan to develop and test a panel of antibodies against other laminin-332 domains as well as a collagen VII NC1 antibody. In these studies, we will functionally characterize how these antibodies act on SCC tumorigenesis, as well as normal skin. We will also determine whether combination antibody therapy can produce synergistic carcinoma inhibition. At the end of the proposed funding period, we hope to have answered fundamental questions about the role of the extracellular matrix in SCC tumorigenesis and to learn new information which has the potential for the development of novel and specific therapies for cutaneous SCC. PUBLIC HEALTH RELEVANCE: Squamous cell carcinoma (SCC) of the skin is the second most common human cancer, but effective and specific molecular therapies for this disease are lacking. This proposal focuses on understanding the critical role that the dermal-epidermal basement membrane proteins laminin-332 and a6¿4 integrin play in facilitating SCC progression and invasion. This proposal also seeks to develop novel and specific molecular therapies to inhibit the function of laminin-332 and associated molecules in SCC without disrupting normal skin tissue.