論文名稱:

口腔鱗狀細胞癌中離胺基氧化酶的表現和調控

 

The Expression and Regulation of Lysyl Oxidase in Oral Squamous Cell Carcinoma

研究生:

張淑杏  Shu-Shing Chang

 

(以作者名查詢陽明大學館藏系統)

 

(以作者名查詢全國圖書書目資訊網)

指導教授:

林姝君  Shu-Chun Lin

        學位類別:

碩士

        學校名稱:

國立陽明大學

系所名稱:

口腔生物研究所

            學號:

39117003

          學年度:

92

          語文別:

中文

          出版年:

93

關鍵字:

檳榔子水萃取物  areca nut extract (ANE)

 

離胺基氧化酶  lysyl oxidase (LOX)

 

口腔鱗狀細胞癌  oral squamous cell carcinoma (OSCC)

 

非癌配對組織  non-cancer matched tissue (NCMT)

全文說明:

電子全文

        論文頁數:

81

摘要:

  根據流行病學資料顯示,在台灣口腔癌於男性前十大癌症發生率中高居第四位,死亡率則為所有癌症之第七位,其原因與嚼食檳榔有密切關係。檳榔子水萃取物 (ANE) 為檳榔嚼塊之主要成分,且對於多種型態細胞具有細胞毒性以及基因毒性。目前對檳榔誘發口腔細胞轉型之基因調控機制瞭解不多。本實驗室先前利用刪減雜合術 (subtractive hybridization library) 篩選出口腔鱗狀細胞癌表現異常之基因,其中lysyl oxidase (LOX) 於口腔鱗狀細胞癌之表現大增。LOX是一個與銅離子依存的胺氧化酶,能夠在細胞外基質 (extracellular matrixECM),藉由氧化膠原蛋白和彈性蛋白上特殊的離胺酸殘基,使膠原蛋白和彈性蛋白交叉共價鍵結,並與腫瘤生成有關。但LOXLOX類似蛋白質近年亦發現具抑癌功能,且LOX基因家族在口腔癌生成之角色至今仍具爭議性。

 

  實驗首先就LOX基因在正常口腔角質上皮細胞 (normal human oral keratinocyte NHOK) 及不同口腔癌細胞株中mRNA的表現作比較,發現LOXLOXL3在不同口腔癌細胞株中的表現皆比正常口腔角質上皮細胞增加許多。在37組口腔鱗狀細胞癌與非癌配對組織中,探討LOX家族成員mRNA 表現之差異,結果LOXLOXL2LOXL3 mRNA 在口腔鱗狀細胞癌表現大於非癌配對組織,且LOXL3 mRNA表現上升與患者之較低存活率有關。以檳榔子水萃取物處理正常口腔角質上皮細胞和口腔鱗狀細胞癌細胞株OEC-M1,發現隨著劑量之升高,LOX mRNA表現也隨之提升,但非透過檳榔素 (檳榔主要成份之一) 之調控。此外,以RNAi技術建立刪減 (knock-down) LOX之穩定細胞株,方便以後對於LOX與細胞的外型、增生、細胞週期、貼附能力、藥劑的敏感度等進一步觀察。綜合以上本研究之發現, LOX及其家族基因在口腔癌所中扮演應屬促癌之角色。

   
 

  Epidemiological studies showed that the incidence of oral cancer is the 4th most common cancer in males and the 7th highest cause for cancer death in Taiwan. Areca nut extract (ANE), the main component of AQ, exerts cytotoxicity and genotoxicity to several types of cells. The pathogenetic mechanism for the transformation of oral keratinocyte is not clear today. Previous studies from our laboratory used the subtractive hybridization library technique to identify differentially expressed genes in oral squamous cell carcinoma (OSCC) and non-cancer matched tissue (NCMT). And identified several representative genes overexpressed in OSCC including lysyl oxidase (LOX). LOX is a copper-dependent amine oxidase that initiates the covalent cross-linking of collagen and elastin in extracellular matrix, and involved in tumorigenesis. However, LOX and LOX-related (LOXL) superfamily members have also been advocated as a tumor suppressor recently. In addition, the role of LOX in OSCC seemed controversial.

 

  First, this study examined the expression of LOX in normal human oral keratinocyte (NHOK) and OSCC cell lines. The result showed a significant increase of LOX and LOXL3 gene expression in different cancer cells comparing to NHOK. Comparsion between OSCC/NCMT pairs from 37 patients showed that LOX LOXL2 and LOXL3 mRNA expression were increased significantly in OSCC relative to NCMT, and the increase of LOXL3 mRNA expression correlated with lower survival rate of patients. In NHOK and an OSCC cell line, OEC-M1 treated with ANE, LOX mRNA expression was increased dose-dependently. But a major areca ingredient, arecoline did not cause such increase. LOX siRNA stable OSCC cells were established. This knock-down cells will be used to perceive the role of LOX in proliferation, invasion, mobility, anti-senescence, anti-apoptosis and

 

chemoresistance of OSCC cells in vitro. In conclusion, the findings in the present study substantiate that LOX gene families play an oncogenic role in OSCC.