Cathepsin S（又稱CTSS 或CatS）在腫瘤之進程及轉移中扮演了相當重要的角色。此蛋白酵素在惡性腫瘤細胞中的表達量會大幅提升，並分泌至細胞外降解細胞外基質，進而幫助癌細胞轉移。此外，因腫瘤之高醣解作用，腫瘤微環境常為酸性環境，此酸性環境對於癌細胞之進程及轉移亦有相當大之重要影響。綜合以上，我決定利用先前研發合成之α-酮醯胺衍生化合物作為CTSS 抑制劑並探討此化合物在酸性環境下之抗癌效果。藉由將胰臟癌細胞暴露於酸性培養環境（pH 6.7），觀察到細胞內累積之LC3+自噬空泡增加及自噬作用（cell autophagy）標誌蛋白Atg12-Atg5 表達量上升，顯示了當癌細胞處於酸性環境時會藉由細胞自噬作用適應並存活於此環境。此外，雖然在酸性環境癌細胞之生長速率會大幅降低，但生存之癌細胞的Cathepsin S 表達量會明顯提升，若再施與癌細胞CTSS 抑制劑CCL-RJW-58，則會導致癌細胞走向死亡，推測此CTSS 抑制劑能作為抗癌之潛力藥物。根據此實驗結果顯示，此α-酮醯胺CTSS 抑制劑CCL-RJW-58 在酸性腫瘤環境下能達到更好的抗癌效果，提供了胰臟癌病患一個新的標靶治療方向。

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