| Abstract: | 口腔鱗狀上皮細胞癌(oral squamous cell carcinoma，簡稱OSCC)是最常見的口腔癌，在台灣地區嚼食檳榔被認為是造成口腔癌的主要原因之一。文獻指出，熱休克蛋白47 (Heat shock protein 47，簡稱HSP47)在許多癌症組織中有過度表達，但鮮少有文獻探討HSP47的表現與嚼食檳榔嚼塊所造成口腔鱗狀上皮細胞癌中所扮演的角色。本研究利用免疫組織化學染色法(Immunohistochemistry，簡稱IHC)觀察正常口腔上皮組織與嚼食檳榔引發口腔鱗狀上皮細胞癌的組織切片中HSP47之表現，並探討其HSP47表現強弱與TNM stage、臨床特徵及細胞分化之相關性。藉由西方點墨法(Western blotting)探討培養口腔上皮細胞珠OC2細胞在加入檳榔鹼(arecoline)引發口腔鱗狀上皮細胞癌可能的致病機轉。實驗結果發現在口腔鱗狀上皮細胞癌的組織中HSP47表現量明顯高於正常口腔上皮組織(p<0.05)。HSP47表現量與年齡、性別、T分類、階段及分化並無相關性(p>0.05)，而較高的HSP47表現量較不易有淋巴結轉移之情形(p=0.015)。OC2細胞在加入arecoline刺激後HSP47表現量隨劑量與時間之增加而增加(p<0.05)。抗氧化劑N-acetyl-L-cysteine (NAC)可抑制HSP47的表現(p<0.05)；此外，extracellular signal-regulated kinase (ERK) 抑制劑PD98059、phosphatidylinositol 3-kinase (PI3K)抑制劑LY294002、cyclooxygenase-2 (COX-2)抑制劑NS-398、tyrosine kinases 抑制劑Herbimycine A，能抑制arecoline誘發HSP47的表現量(p<0.05)。由實驗結果顯示檳榔嚼塊誘發HSP47的表現可能是造成口腔鱗狀上皮細胞癌的致病機轉之一，且arecoline誘發HSP47蛋白表現可能是經由ERK、PI3K、COX-2及tyrosine kinase的傳導路徑來調控。
Oral squamous cell carcinoma (OSCC) is the most common form of oral cancer, which chewing areca quid is one of the main cause oral cancer. Previous studies had shown that antioxidant proteins such as heat shock protein 47 (HSP47) was overexpressed in various cancers. Little is known about the role of heat shock protein in the pathogenesis of areca quid chewing-associated OSCC. In the present study, thirty-two OSCC specimens and ten normal oral tissue biopsy samples without areca quid chewing were analyzed by immunohistochemistry. The oral epithelial cell line OC2 cells were challenged with arecoline, a major areca nut alkaloid, by using Western blot analysis. Furthermore, glutathione precursor N-acetyl-L-cysteine (NAC), extracellular signal-regulated protein kinase (ERK) inhibitor PD98059, phosphatidylinositol 3-kinase (PI3K) inhibitor LY294002, cyclooxygenase-2 inhibitor NS-398, and tyrosine kinase inhibitor herbimycin A were added to find the possible regulatory mechanisms.HSP47 expression was significantly higher in OSCC specimens than normal epithelium (p<0.05). No significant difference in HSP47 expression was observed with respect to age, sex, T category, stage, and differentiation (p>0.05). The lower HSP47 expression was associated with lymph node metastasis (p=0.015). Arecoline was found to elevate HSP47 expression in a dose- and time-dependent manner (p<0.05). The addition of NAC, PD98059, LY294002, NS398, and herbimycin A markedly inhibited the arecoline-induced HSP47 expression (p<0.05). Our findings demonstrated that HSP47 expression is significantly upregulated in areca quid chewing-associated OSCCs. HSP47 could be used clinically as a marker for lymph node metastasis of oral carcinogenesis. In addition, arecoline-induced HSP47 expression was downregulated by NAC, PD98059, LY294002, NS-398, and Herbimycin A. |
