Lee Shiuan-Shinn, Tsai Chung-Hung, Ho Yung-Chuan, Chang Yu-Chao
Institute of Medicine, Chung Shan Medical University, Taichung, Taiwan.
Oral Oncol. 2008 Sep;44(9):884-90. doi: 10.1016/j.oraloncology.2007.11.004. Epub 2008 Jan 30.
Heat shock protein 70 (HSP70) is an important stress-induced protein. Areca quid chewing is a major risk factor of oral squamous cell carcinoma (OSCC). The aim of this study was to compare HSP70 expression in normal human oral epithelium and OSCC and further to explore the potential mechanisms that may lead to induce HSP70 expression. 41 OSCC and 10 normal epithelium specimens were examined by immunohistochemistry and analyzed by the clinico-pathological profiles. The oral epithelial cell line GNM cells were challenged with arecoline, a major areca nut alkaloid, by using Western blot analysis. Furthermore, glutathione precursor N-acetyl-l-cysteine (NAC), AP-1 inhibitor curcumin, extracellular signal-regulated protein kinase inhibitor PD98059, and protein kinase C inhibitor staurosporine were added to find the possible regulatory mechanisms. The results from immunohistochemistry demonstrated that HSP70 expression was significantly higher in OSCC specimens (p<0.05). No significant difference in HSP70 expression was observed with respect to age, sex, T category, and stage (p>0.05). The low HSP70 expression was associated with lymph node metastasis (p=0.005). The high HSP70 expression was found in poor differentiated tumor groups (p=0.036). Arecoline was found to elevate HSP70 expression in a dose- and time-dependent manner (p<0.05). The addition of NAC, curcumin, PD98059, and staurosporine markedly inhibited the arecoline-induced HSP70 expression (p<0.05). Taken together, HSP70 expression is significantly upregulated in areca quid chewing-associated OSCC. HSP70 could be used clinically as a marker for tumors possessing the potential for differentiation as well as lymph node metastasis. In addition, arecoline-induced HSP70 expression was downregulated by NAC, curcumin, PD98059, and staurosporine.
热休克蛋白70（HSP70）是一种重要的应激诱导蛋白。嚼槟榔是口腔鳞状细胞癌（OSCC）的主要危险因素。本研究的目的是比较HSP70在正常人口腔上皮和OSCC中的表达，并进一步探讨可能导致HSP70表达诱导的潜在机制。通过免疫组织化学检查41例OSCC和10例正常上皮标本，并根据临床病理特征进行分析。使用蛋白质印迹分析，用槟榔碱（一种主要的槟榔生物碱）刺激口腔上皮细胞系GNM细胞。此外，添加谷胱甘肽前体N-乙酰-L-半胱氨酸（NAC）、AP-1抑制剂姜黄素、细胞外信号调节蛋白激酶抑制剂PD98059和蛋白激酶C抑制剂星形孢菌素，以寻找可能的调节机制。免疫组织化学结果显示，HSP70在OSCC标本中的表达显著更高（p<0.05）。在年龄、性别、T分类和分期方面，HSP70表达未观察到显著差异（p>0.05）。低HSP70表达与淋巴结转移相关（p=0.005）。在低分化肿瘤组中发现高HSP70表达（p=0.036）。发现槟榔碱以剂量和时间依赖性方式升高HSP70表达（p<0.05）。添加NAC、姜黄素、PD98059和星形孢菌素显著抑制槟榔碱诱导的HSP70表达（p<0.05）。综上所述，HSP70表达在嚼槟榔相关的OSCC中显著上调。HSP70可在临床上用作具有分化潜能以及淋巴结转移潜能肿瘤的标志物。此外，NAC、姜黄素、PD98059和星形孢菌素下调了槟榔碱诱导的HSP70表达。
