- 學位論文
探討腺苷對人類慢性骨髓癌細胞K562的抗癌機制
Investigating anti-tumoral activity of adenine on human chronic myelogenous leukemia cell K-562
摘要
近年來逐漸重視從天然物萃取出有效成分，尋找對抗癌症或延緩癌症的方法。毛竹水萃物的成分之一: 腺苷(adenine)已被證實為單磷酸腺苷-活化蛋白質激酶(AMPK)的活化劑。 AMPK是細胞代謝的主要調控因子，過去許多的研究中指出， AMPK會影響細胞內許多訊息傳遞路徑並參與多項生理機制的調控，透過活化AMPK的方式可以治療代謝以及發炎相關的疾病，也證實可以抑制癌細胞的生長。 因此，本論文進一步探討adenine對於人類慢性骨髓性白血病(Chronic myelogenous leukemia, CML) K562 細胞是否具有抗癌作用及其作用機轉。實驗結果顯示，使用adenine處理後 K562 細胞的存活率下降，形態發生改變。經由流式細胞儀的分析結果發現，在24小時後，隨著 adenine 的濃度增加，細胞週期停滯在 G2/M 期的比例也增加。48小時後觀察到 sub-G1 期也略微上升。接著透過西方墨點法分析，發現與細胞凋亡相關的蛋白表現量皆無顯著改變。此外，透過 Acidic vesicular organelle (AVO)染色發現此一autophagy marker在adenine處理後有增加的趨勢。推測 adenine 抑制人類慢性骨髓性血癌細胞株 K562 細胞的主要作用，可能是促使其細胞週期停滯與進入 autophagy 的程序。而這一連串的反應機制，確實是經由 AMPK 活化所導致。藉由使用 AMPK 的活性抑制劑 Compound C預處理後，原本因為 adenine 而增加表現的蛋白，都明顯的受到了抑制。綜合以上結果顯示， adenine 可促使人類慢性骨髓性白血病細胞生長受到抑制並且走向 autophagy ，期許其未來對於應用於白血病的治療和藥物研發具有潛在的可行性。
並列摘要
Plant-derived phytochemicals have been used as therapeutic agents for hundreds of years. Natural products from plants and other species have been proven to be a promising resource for mining potential anticancer drugs or compounds. Previous studies have indicated that AMP-activated protein kinase (AMPK) is a key player in maintaining energy homeostasis in response to metabolic stress and activation of AMPK suppresses cell proliferation of non-malignant cells and tumor cells. The aim of this study was to investigate effects of adenine, an active compound isolated from Phyllostachys Edulis leaf extract, on human chronic myelogenous leukemia cell line K562 and further elucidate the underlying mechanisms. Cell viability analysis showed that adenine dose-dependently reduced viability of K562 by using MTT assay. Morphological analysis showed that cell morphology of K562 cells treated with adenine was significantly altered. Flow cytometric analysis showed that adenine obviously induced G2/M phase arrest as well as slightly increased of sub-G1 after 48 hours. Further immunoblotting showed that expression of apoptosis-related proteins are insignificantly influenced. In addition, adenine increased the autophagy marker by using AVO staining. The involvement of AMPK activation in the adenine-induced cellular responses was also demonstrated by using AMPK inhibitor compound c. In conclusion, our findings indicate that viability suppressive effect of adenine on K562 cells may attribute to induction of G2/M arrest and autophagy via activation of AMPK. It suggests that adenine should be beneficial to chronic myelogenous leukemia treatment.