| 摘要: | 非小細胞肺癌在所有肺癌中大約佔 75％。儘管醫療的進步，但非小細胞肺癌在晚期的治癒效果仍然不佳。因此，尋找新的治療非小細胞肺癌的藥物是重要的研究課題。台灣欒樹屬無患子科，欒樹屬，為台灣原生種。 KOH-AL1 為木酚素類化合物，是由台灣欒樹的葉部所萃取而得。根據過去文獻， KOH-AL1 具有抗氧化，並且能抑制人類癌細胞株的生長。然而， KOH-AL1對人類非小細胞肺癌的機轉尚未被研究。本研究的目地為探討 KOH-AL1 對人類肺腺癌 A549 細胞生長存活之影響，並研究其作用機制。 實驗結果顯示， KOH-AL1 對於A549細胞具有抑制細胞生長的作用；流式細胞儀的分析結果顯示， KOH-AL1 處理後會使細胞週期停滯於 G2 / M 期。西方墨點分析法之結果，發現KOH-AL1處理可降低cyclin A和 CDC25C 及增加 p53、p27KIP 1、p21CIP/WAF 1 和cyclin B1的表現。另外，TUNEL染色法發現 KOH-AL1會誘發細胞凋亡。同時， KOH-AL1會增加 p53及磷酸化 p53ser15、磷酸化 DNA-PKCS、磷酸化 ATM、磷酸化 ERK、磷酸化 JNK與促凋亡蛋白分子 Bax及 Bak 蛋白的表現量。但會降低抗凋亡蛋白Mcl-1 、Bcl-2和磷酸化AKT的表現量。處理 KOH-AL1也會使cytochrome c 由粒線體的intermembrane space 釋放到細胞質，並增加caspase-2 、 -3 與 -9的活性，由此啟動與粒線體相關的細胞凋亡路徑，進而促使細胞凋亡。研究結果顯示， KOH-AL1可促使人類肺腺癌細胞 A549細胞 G2/M 期停滯，進而誘導細胞走向凋亡的途徑。本研究結果意味著KOH-AL1具有發展成為人類非小細胞肺癌治療藥物之潛力。
Non-small cell lung cancer (NSCLC) comprises over approximately 75% in all lung cancers. Despite development of medicine have rapid advances in pharmacology, the treatment of NSCLC patients remain extremely insufficient at terminal care. Therefore an effective therapy for treatment of patients with NSCLC is urgently needed. KOH-AL1, a natural lignan isolated from leaves of Koelreuteria henryi Dummer, has antioxidant, and anitproliferative activities. However, the effects of KOH-AL1 on NSCLC cells have not been studied. This study was aimed to examine the effects and underlying mechanisms of KOH-AL1 in regulating cell growth and survival in human lung adenocarcinoma A549 cells. Treatment of A549 cells with KOH-AL1 resulted in inhibiting cell proliferation and arresting cell cycle at G2/M phase. Data from immunoblot analysis showed that the protein levels of cyclin A and CDC25C were decreased, but p53, p27KIP 1, p21CIP/WAF 1 and cyclin B1 were increased that might contribute to KOH-AL1-induced cell cycle G2/M phase perturbation. In addition, KOH-AL1 also induced apoptosis in A549 cells which was characterized by TUNEL assay, the TUNEL positive cells were remarkably increased upon KOH-AL1 treatment. Moreover, exposure to KOH-AL1 could increase the levels of p53 and phosphorylated p53ser15, phosphorylated DNA-PKCS, phosphorylated ATM, phosphorylated ERK and phosphorylated JNK, as well as pro-apoptotic proteins including Bax and Bak. However, the levels of anti-apoptotic proteins such as Mcl-1, Bcl-2 and the phosphorylated AKTser473 were significantly decreased after incubation with KOH-AL1. Furthermore, KOH-AL1 treatment caused cytochrome c releasing from mitochondria to cytoplasm, activation of caspase-2, caspase-9 and caspase-3, preceding morphologic features of apoptosis. Taken together, KOH-AL1 was capable of eliciting cell cycle G2/M-phase arrest and inducing intrinsic apoptotic cell death in human lung adenocarcinoma A549 cells. This study provides a molecular basis for evaluation of the potential therapeutic use of KOH-AL1 in NSCLC treatment. |
