Mechanisms of homeostasis and invasive cell migration in skin tumorigenesis

描述(申请人提供)：这项提案的长期目标是了解促进生长和限制生长的信号如何相互作用以平衡彼此，以及它们的放松如何导致肿瘤的发展，肿瘤通常会变成恶性的、转移性的癌症。我的初步数据显示，皮肤上皮细胞中转化生长因子-β受体II(T(3RII))功能的丧失会导致自发性肛门和生殖器鳞状细胞癌(SCCs)，并与活性H-RAS协同作用形成转移性SCCs。粘着斑激酶(FAK)介导的整合素信号在这些癌症和培养的角质形成细胞中过度活跃，提示TfiRII缺失和FAK激活之间存在直接联系。事实上，FAK已被报道为上皮性肿瘤和肿瘤细胞系中最常见的过度激活的非受体酪氨酸激酶，但其功能和分子靶点在很大程度上尚不清楚。这一建议检验的中心假设是，FAK在TpRII缺陷皮肤上皮细胞的发育中发挥核心作用。这一假说将通过以下实验得到验证：1)评估WT、JftRII和FAK单条件突变小鼠和TJ3RII/FAK双条件突变小鼠自发肛门和生殖器发育或化学诱导皮肤SCC的可能性，并调查其潜在的细胞和病理变化；3)研究TpRII缺失和FAK活性增加如何促进皮肤癌变、恶性进展和侵袭性转移性角质形成细胞迁移；2)确定角质形成细胞中TfSRI功能缺失促进FAK激活的分子机制。这些实验数据将促进我们对TPRII和FAK介导的整合素信号在正常发育和疾病中的分子功能的理解，识别促进生长的RAS和整合素信号与生长限制的转化生长因子-β信号相互作用的分子机制，不仅控制细胞增殖，而且控制细胞生存、细胞骨架动力学和侵袭性细胞迁移，并确定即使在FAK功能缺失的情况下癌症形成的新的分子途径。总之，这项建议将加强我们对癌症发生的分子和细胞理解，并将揭示潜在的治疗靶点。

DESCRIPTION (provided by applicant): The long term goal of this proposal is to understand how growth promoting and restricting signals interact to balance one another and how their deregulation leads to the development of neoplastic tumors which often turn into malignant, metastatic carcinomas. My preliminary data revealed that loss of TGF-p receptor II (T(3RII) function in the skin epithelium produces spontaneous anal and genital squamous cell carcinomas (SCCs) and cooperates with active H-Ras to form metastatic SCCs. Focal adhesion kinase (FAK) mediated integrin signaling is hyperactive in these carcinomas and cultured keratinocytes suggesting a direct link between TfiRII loss and FAK activation. Indeed, FAK has been reported to be the most commonly hyper- activated non receptor tyrosine kinase in epithelial tumors and tumor cell lines, yet its functions and molecular targets are largely unknown. The central hypothesis tested by this proposal is that FAK plays a central role in the development of SCCs in TpRII deficient skin epithelium. This hypothesis will be tested experimentally by: 1) assessing the probabilities to develop spontaneous anal and genital, or chemically induced SCCs in skin of WT, JftRII and FAK single and TJ3RII/FAK double conditional mutant mice and investigating the underlying cellular and pathological alterations; 3) investigate how loss of TpRII and increased FAK activity promote skin carcinogenesis, malignant progression, and invasive metastatic keratinocyte migration; and 2) identification of molecular mechanisms by which loss of TfSRIlfunction in keratinocytes promotes FAK activation. Data generated from the proposed experiments will advance our understanding of the molecular functions of TPRII and FAK mediated integrin signaling in normal development and disease, identify the molecular mechanisms by which growth promoting Ras and Integrin signaling interact with growth restricting TGF-P signaling to control not only proliferation, but also cell survival, cytoskeletal dynamics and invasive cell migration, and identify novel molecular pathways by which carcinomas form even in the absence of FAK function. Together, this proposal will strengthen our molecular and cellular understanding of carcinogenesis and will reveal potential therapeutic targets.