Regulators of Epithelial Tumor Progression

描述（由申请人提供）： 上皮组织中的肿瘤进展（>90%的人类恶性肿瘤的部位）涉及肿瘤-基质界面处的相互作用。在从原位瘤形成到浸润性癌的进展过程中，该界面是上皮基底膜（BM）。皮肤鳞状细胞癌（SCC），作为美国第二大常见癌症，对我们的退伍军人患者来说是一个毁灭性的负担，并且是上皮恶性肿瘤的原型。该建议将描述肿瘤-间质相互作用在体内早期SCC肿瘤进展中的作用，以及在人类肿瘤形成的新器官型模型中的作用。 没有局部侵袭，上皮肿瘤不能转移，然而在早期肿瘤发生期间控制BM处的肿瘤-间质相互作用的蛋白质是不确定的。流行的癌症进展模型不包括完整BM上的结构上忠实的人类组织内的人类细胞，因此可能提供误导性结果。在前一个周期中，我们开发了一种诱导型表皮癌的人皮肤异种移植模型，并将其用于鉴定人类组织肿瘤进展中以整合素为中心的基因网络的破坏。与此一致，主要表皮整联蛋白亚基21和24的表达在自发性患者SCC中是异常的。证实了21在早期人类肿瘤进展中的适度功能作用，然而，其他整合素在这种情况下的作用尚未表征。我们推测，21与其他主要的表皮2整合素亚基，24，在人类上皮细胞，使肿瘤侵袭合作。因此，目的I被设计为表征BM整合素在人皮肤组织中的表皮肿瘤进展中的潜在合作作用。 人体组织肿瘤进展的体外器官型模型由于其速度、成本和与体外药物抑制剂一起使用的易处理性以及其从定义的元素重建肿瘤微环境的潜力而成为体内模型的有吸引力的补充。在上一个资助周期中，我们改进了一种器官型模型，该模型结合了可诱导的肿瘤性正常人上皮细胞、具有BM的完整基质和基质细胞，以生成皮肤、食管、宫颈和口咽组织的此类模型。正常间质成纤维细胞增强肿瘤向深部浸润的进展，这与它们潜在分泌一系列整合素配体（包括纤连蛋白、胶原蛋白和层粘连蛋白）一致。因为它可以从定义的细胞群中产生，而不会潜在地混淆异种移植模型中观察到的小鼠宿主细胞的浸润，所以器官型瘤形成模型能够直接评估与加速肿瘤进展有关的基质细胞群，包括癌症相关成纤维细胞（CAF）。目的II旨在使用不同的人组织平台研究上述目的I中的潜在协同整联蛋白作用，并开始定义CAF相对于正常成纤维细胞在肿瘤进展中的功能影响。 该提案旨在表征BM中肿瘤-基质相互作用的介质，作为未来癌症预防和治疗策略的基础。

DESCRIPTION (provided by applicant): Tumor progression in epithelial tissues, the sites of >90% of human malignancies, involves interactions at the tumor-stroma interface. During progression from in situ neoplasia to invasive cancer, this interface is the epithelial basement membrane (BM). Cutaneous squamous cell carcinoma (SCC), as the second most common cancer in the U.S., is a devastating burden on our veteran patients, and serves as a prototype epithelial malignancy. This proposal will characterize the role of tumor-stroma interactions in early SCC tumor progression in vivo and in a new organotypic model of human neoplasia. Without local invasion, epithelial neoplasms fail to metastasize, yet the proteins controlling tumor- stroma interactions at the BM during early tumorigenesis are undefined. Prevalent cancer progression models don't include human cells within architecturally faithful human tissue on an intact BM, and thus can provide misleading results. During the prior cycle, we developed a human skin xenograft model of inducible epidermal cancer and used it to identify disruption of an integrin-centered gene network in human tissue tumor progression. Consistent with this, expression of the major epidermal integrin subunits, 21 and 24 is abnormal in spontaneous patient SCCs. A modest functional role for 21 in early human tumor progression was confirmed, however, the role of other integrins in this setting is uncharacterized. We postulate that 21 acts cooperatively with the other major epidermal 2 integrin subunit, 24, in human epithelia to enable neoplastic invasion. Aim I is thus designed to characterize a potentially cooperative role of BM integrins in epidermal tumor progression in human skin tissue in vivo. In vitro organotypic models of human tissue tumor progression are attractive complements to in vivo models by virtue of their speed, cost, and tractability to use with in vitro drug inhibitors as well as their potential to recreate the tumor microenvironment from defined elements. During the last funding cycle, we refined an organotypic model incorporating inducibly neoplastic normal human epithelial cells, intact stroma with BM, and stromal cells to generate such models for skin, esophageal, cervical and oropharyngeal tissues. Normal stromal fibroblasts enhanced tumor progression to deep invasion, consistent with their potential secretion of an array of integrin ligands, including fibronectin, collagens, and laminins. Because it can be generated from defined cell populations without potentially confounding infiltration by mouse host cells seen in xenograft models, organotypic neoplasia models enable direct assessment of stromal cell populations implicated in accelerating tumor progression, including cancer-associated fibroblasts (CAFs). Aim II is designed to study both the potentially cooperative integrins roles in Aim I above using a distinct human tissue platform and to begin to define the functional impact of CAFs versus normal fibroblasts in tumor progression. This proposal aims to characterize mediators of tumor-stroma interactions at the BM as a foundation for future strategies for cancer prevention and treatment.