Progression and Metastasis of Oral Tongue Cancer

描述（由申请人提供）：口腔鳞状细胞癌（SCCOC）是全球第六大癌症死亡原因。然而，对SCCOC肿瘤进展的细胞和分子机制知之甚少。在之前的资助期内，我们证明获得抗气味剂是口腔上皮肿瘤进展的一个重要标志。结果表明，S100A7蛋白是一种低分子量（11.4 kDa）的Ca2+结合蛋白，属于S100多基因蛋白家族，在嗜酒病敏感和耐药细胞中存在差异表达。进一步分析表明，S100A7在侵袭前、分化良好的SCCOC中过表达。然而，随着浸润性癌的进展，S100A7的表达在肿瘤发生的晚期经常下调或减少。虽然很明显，S100A7蛋白对某些癌症的肿瘤发生至关重要，但鉴于其双相表达，尚不清楚S100A7在SCCOC中是否起“致癌”或“抑瘤”作用。我们的初步结果表明，尽管S100A7在癌前口腔病变中过表达，但S100A7至少部分通过其作为2-catenin降解的“新型”调节剂的作用，通过下调肿瘤生长、EMT、肿瘤侵袭/转移，在SCCOC进展中发挥重要的抑制作用。因此，本应用的中心假设是S100A7作为“肿瘤抑制因子”在SCCOC的发生和进展中发挥重要作用，通过抑制2-catenin、Twist和Snail抑制细胞增殖、运动、EMT和侵袭。这一假设将在4个特定目标中进行测试，我们期望完成这4个目标中概述的方法将有助于我们确定S100A7在SCCOC中作为肿瘤抑制因子的作用，并且这些信息将增强我们对SCCOC临床分期的能力，并确定潜在的新治疗靶点。

DESCRIPTION (provided by applicant): Squamous cell carcinoma of the oral cavity (SCCOC) is the sixth leading cause of cancer deaths worldwide. However, little is known about the cellular and molecular mechanisms of SCCOC tumor progression. In the prior funding period, we demonstrated that acquisition of anoikis-resistance is an important hallmark of oral epithelial tumor progression. Results of our cDNA microarray expression analysis of anoikis-resistant and - sensitive cells revealed that the S100A7 protein, a low-molecular-weight (11.4 kDa) Ca2+binding protein that belongs to S100 multigenic protein family, is differentially expressed in anoikis-sensitive and -resistant cells. Further analyses indicated that S100A7 is overexpressed in pre-invasive, well-differentiated SCCOC. However, with the progression to invasive carcinomas, S100A7 expression is often down-regulated or diminished in the late stages of tumorigenesis. While it is evident that S100A7 protein is critical to the tumorigenesis of certain cancers, it remains unclear whether S100A7 plays an "oncogenic" or "tumor suppressive" role in SCCOC given its biphasic expression. Our preliminary results show that despite its overexpression in premalignant oral lesions, S100A7 plays an important inhibitory role in SCCOC progression by down-regulating tumor growth, EMT, tumor invasion/metastasis at least in part through its role as a "novel" regulator of 2-catenin degradation. Thus, the central hypothesis of this application is that S100A7 plays an important role as a "tumor suppressor" in SCCOC development and progression, through its inhibition of cell proliferation, motility, EMT, and invasion by inhibition of 2-catenin, Twist, and Snail. This hypothesis will be tested in 4 specific aims, and it is our expectation that completion of the approaches outlined in these 4 aims will help us to define S100A7's role as a tumor suppressor in SCCOC and that this information will enhance our ability to clinically stage SCCOC and identify potential new targets for therapy.