口腔鱗狀上皮細胞癌是全球常見的癌症之一，在台灣是男性癌症死亡原因的第四位，且發生率和死亡率有逐年升高的趨勢。嚼食檳榔被認為是造成口腔癌最重要的危險因素。文獻指出熱休克蛋白27（Heat shock protein 27，HSP27）在許多癌症組織有過度表現，但鮮少有研究探討HSP27在嚼食檳榔所引發之口腔鱗狀上皮細胞癌中扮演的角色。本研究收集48位有嚼食檳榔習慣的口腔鱗狀上皮細胞癌患者組織切片與10位無嚼食檳榔習慣的正常口腔上皮組織，以免疫組織化學染色法進行分析，並探討其表現強度與臨床特徵、組織分化及TNM stage的相關性。另培養正常口腔上皮細胞株（human oral keratinocytes，HOK）以西方點墨法探討檳榔鹼（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HSP27表現量相較於正常口腔上皮組織有較高的趨勢（p<0.05）。HSP27的表現強度與病患年齡、性別、TNM分類、臨床癌症期別並無相關性（p<0.05）。HOK細胞在加入arecoline作用後，HSP27表現量隨arecoline劑量與時間增加呈正相關（p< 0.05）。抗氧化劑N-acetyl-L-cysteine（NAC）、Epigallocatechin-3 gallate（EGCG）、HSP抑制劑quercetin、Cyclooxygenase-2（COX-2）抑制劑NS398、extracellular signal-regulated kinase（ERK）抑制劑PD98059、p38抑制劑SB203580可以抑制arecoline對HOK細胞誘發HSP27蛋白的表現（p<0.05）。由實驗結果顯示檳榔嚼塊誘發HSP27的表現可能是造成口腔鱗狀上皮細胞癌的致病機轉之一，且檳榔誘發HSP27的表現可能是經由ERK、p38的傳導路徑來調控。
Oral squamous cell carcinoma (OSCC) is the sixth most common cancers in the world. In Taiwan, OSCCs had been ranked as the fifth most prevalent cancer and the fourth leading cause of cancer deaths among men. Previous studies had shown that antioxidant proteins such as heat shock protein 27 (HSP27) was overexpressed in various cancers. Little is known about the role of HSP27 in the pathogenesis of areca quid chewing-associated OSCC. The aim of this study was to compare HSP27 expression in OSCCs and the normal oral tissues. In the present study, forty-eight OSCCs from areca quid chewers and ten normal oral tissue biopsy samples without areca quid chewing were analyzed by immunohistochemistry for HSP27. The normal human oral keratinocytes (HOKs) were challenged with arecoline, the major alkaloid of areca nut, by Western blot for HSP27. Furthermore, epigallocatechin-3 gallate (EGCG), cyclooxygenase-2 inhibitor NS398, glutathione precursor N-acetyl-L-cysteine (NAC), HSP inhibitor quercetin, extracellular signal-regulated protein kinase (ERK) inhibitor PD98059, and p38 inhibitor SB203580 were added to find the possible regulatory mechanisms. HSP 27 exhibited higher expression in OSCCs than normal specimens ( p<0.05). Arecoline was found to elevate HSP27 expression in a dose- and time-dependent manner (p<0.05). The additions of pharmacological agents were found to inhibit arecoline-induced HSP27 expression (p<0.05). HSP 27 expression is significantly elevated in areca quid chewing-associated OSCCs. Arecoline-induced HSP27 expression was downregulated by EGCG, NS398, NAC, quercetin, PD98059, and SB203580.
