REGULATED EXPRESSION OF TENASCIN AND AVB6 IN ORAL CANCER

鳞状细胞癌（SCC）约占口腔癌的96%或全部。 癌的 SCC具有局部侵袭性的趋势， 广泛转移;五年生存率低于50%。 肿瘤 侵袭和转移是一个复杂的过程， 肿瘤细胞与细胞外基质（ECM）之间的相互作用。 基质成分如层粘连蛋白和纤连蛋白已被研究 广泛讨论它们在肿瘤进展中的作用。 其他ECM 组件也发挥作用。 特别是，我们和其他人观察到， 生腱蛋白-C（TN-C）表达在口腔癌中上调。 在这 我们计划研究TN-C的表达及其与细胞凋亡的关系。 受体α v β 6在口腔SCC进展过程中受到调节。 TN-C是 一种大的寡聚糖蛋白，在 发育并参与形态发生运动，组织形成， 和组织修复。 TN-C包含多个结构域，既有粘附性又有抗粘附性。 粘附剂，与细胞、纤连蛋白和其他ECM分子相互作用。 有不同的同种型的分子，这是由于替代 mRNA剪接。 TN-C的一种受体是α v β 6。 一些证据表明 α v整联蛋白亚家族对于肿瘤生长，侵袭， 和转移。 首先，最近的研究表明， α v β 3抑制肿瘤血管生成。 第二，alphavbeta 3已经被证明 在垂直侵袭性黑色素瘤中表达上调。 第三，α v β 6是 最近发现在口腔鳞状细胞癌中新表达，而在正常口腔鳞状细胞癌中不表达 口腔粘膜 我们假设TN-C和α v β 6在肿瘤的进展中起作用。 口腔癌作为肿瘤细胞运动的共刺激调节剂， 入侵或基因表达。 本建议的具体目标是：（1） 为了评估腱生蛋白-C及其受体α v β 6的表达， 侵袭性口腔SCC的潜在标志物。 (2)以确定是否 alphavbeta 6表达的改变将改变侵袭性 口腔SCC细胞的行为。 (3)评估肿瘤的不同阶段 侵袭，使用动物模型，用于TN-C的差异表达， alphavbeta6. 这些研究应该丰富我们对如何减少- 良好表征的基质蛋白如腱生蛋白-C和α v β 6 口腔癌的发生发展 能够识别 这些口腔鳞状细胞癌肿瘤可能是最具侵袭性的，将有助于选择 最合适的治疗方式，并可能改善目前严峻的 这些肿瘤患者的预后。

Squamous cell carcinoma (SCC) accounts for approximately 96% or all oral cancers. SCC has a tendency to be locally invasive as well as to metastasize widely; the five-year survival rates are less than 50%. Tumor invasion and metastasis is a complex process involving multiple interactions between tumor cells and the extracellular matrix (ECM). Matrix components such as laminin and fibronectin have been studied extensively regarding their roles in tumor progression. However, other ECM components also play a role. In particular, we and others have observed that tenascin-C (TN-C) expression is upregulated in oral cancer. In this project we propose to investigate how the expression of TN-C and its receptor, alpha vbeta6, are regulated during oral SCC progression. TN-C is a large oligomeric glycoprotein that is transiently expressed during development and is involved in morphogenetic movements, tissue patterning, and tissue repair. TN-C contains multiple domains, both adhesive and anti- adhesive, that interact with cells, fibronectin, and other ECM molecules. There are different isoforms of the molecule, which result from alternative mRNA splicing. One receptor for TN-C is alphavbeta6. Several lines of evidence suggest that the alphav integrin subfamily is important for tumor growth, invasion, and metastasis. First, recent work has demonstrated that antagonists to alphavbeta3 inhibit tumor angiogenesis. Second, alphavbeta3 has been shown to be upregulated in vertically invasive melanoma. Third, alphavbeta6 was recently found to be neo-expressed in oral SCC, while absent from normal oral mucosa. We hypothesize that TN-C and alphavbeta6 play a role in the progression of oral cancer by acting as co-stimulatory modulators of tumor cell motility, invasion, or gene expression. The specific aims of this proposal are; (1) To assess the expression of tenascin-C and its receptor, alphavbeta6, as potential markers for invasive oral SCC. (2) To determine whether alterations in the expression of alphavbeta6 will modify the invasive behavior of oral SCC cells. (3) To evaluate different stages of tumor invasion, using an animal model, for differential expression of TN-C and alphavbeta6. These studies should enrich our understanding of how less- well-characterized matrix proteins like tenascin-C and the alphavbeta6 receptor contribute to oral cancer progression. Being able to identify those oral SCC tumors likely to be most invasive will help in selecting the most appropriate treatment modality and may improve the currently grim prognosis of patients with these tumors.