Center for Translational Research in Biomedical Sciences, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung 833, Taiwan.
Am J Pathol. 2013 Feb;182(2):516-28. doi: 10.1016/j.ajpath.2012.10.023. Epub 2012 Dec 3.
The functions of Rap-1A in oral carcinogenesis are largely unexplored. In this study, we examined the expression of Rap-1A at different malignant stages of oral cavity squamous cell carcinoma (OCSCC). Semiquantitative RT-PCR, quantitative RT-PCR, and Western blotting were used to evaluate Rap-1A mRNA and protein expressions, respectively, in paired OCSCC patient specimens. To determine the possible correlation between Rap-1A expression and various clinical characteristics, 256 samples from patients with OCSCC were evaluated by immunohistochemical staining. Strong Rap-1A expression was a significant prognostic marker and predictor of aggressive OCSCC. The overall and disease-specific 5-year survival rates were significantly correlated with strong expression of Rap-1A (P < 0.001). Functionally, overexpressed Rap-1A could promote oral cancer cell migration and invasion by Transwell chambers and wound healing assay. Conversely, the suppression of Rap-1A expression using Rap-1A-mediated siRNA was sufficient to decrease cell motility. Furthermore, our data also illustrated that Aurora-A could not only induce mRNA and protein expressions of Rap-1A for enhancing cancer cell motility but also co-localize and form a complex with Rap-1A in the oral cancer cell line. Finally, immunohistochemical staining, indirect immunofluorescence, and Western blotting analysis of human aggressive OCSCC specimens revealed a significantly positive correlation between Rap-1A and Aurora-A expression. Taken together, our results suggest that the Aurora-A/Rap-1A pathway is associated with survival, tumor progression, and metastasis of OCSCC patients.
Rap-1A 在口腔癌发生中的功能在很大程度上尚未被探索。在这项研究中，我们研究了 Rap-1A 在口腔鳞状细胞癌（OCSCC）不同恶性阶段的表达。使用半定量 RT-PCR、定量 RT-PCR 和 Western blot 分别评估配对 OCSCC 患者标本中的 Rap-1A mRNA 和蛋白表达。为了确定 Rap-1A 表达与各种临床特征之间的可能相关性，对 256 例 OCSCC 患者样本进行了免疫组织化学染色评估。强烈的 Rap-1A 表达是一个显著的预后标志物和侵袭性 OCSCC 的预测因子。总体和疾病特异性 5 年生存率与 Rap-1A 的强表达显著相关（P < 0.001）。功能上，过表达 Rap-1A 可以通过 Transwell 室和划痕愈合试验促进口腔癌细胞迁移和侵袭。相反，使用 Rap-1A 介导的 siRNA 抑制 Rap-1A 表达足以降低细胞迁移能力。此外，我们的数据还表明，Aurora-A 不仅可以诱导 Rap-1A 的 mRNA 和蛋白表达以增强癌细胞的迁移能力，而且还可以在口腔癌细胞系中与 Rap-1A 共定位并形成复合物。最后，对人类侵袭性 OCSCC 标本进行免疫组织化学染色、间接免疫荧光和 Western blot 分析显示，Rap-1A 和 Aurora-A 的表达之间存在显著的正相关。综上所述，我们的研究结果表明，Aurora-A/Rap-1A 通路与 OCSCC 患者的生存、肿瘤进展和转移有关。
