| 摘要: | 目前肺癌在全球及台灣高居癌症發生率第一位。臨床化學治療上，病人有許多抗藥性及預後不佳之情形。現今雖有許多中草藥應用於癌症治療，但其機轉不明確。
桑黃(Phellinu linteus)為台灣，韓國，日本及其他亞洲國家常用的一種藥用菌菇。許多文獻指出桑黃具有很好的抗氧化及抗發炎之活性，其也常用來治療一些疾病，例：口腔潰瘍、腸胃疾病及癌症等。Hispolon是從桑黃(Phellinu linteus)中所分離出具活性的化合物，已有文獻指出其有抗腫瘤之活性。此研究將探討Hispolon在人類肺鱗狀細胞CH27細胞株所誘導細胞凋亡及細胞週期停滯之分子機轉。
在細胞存活率分析中，Hispolon可抑制CH27細胞生長且呈現劑量與時間依存性。Hispolon誘導CH27細胞凋亡可從DNA裂解，細胞核濃縮(DAPI染色)及Annexin-V/PI 雙染證實。Hispolon 誘導細胞凋亡可透過調節 Bcl-2 蛋白家族之表現，例如：Bax、Bcl-2及Bid，並伴隨增加Fas、Caspase-3, -8, -9 及 PARP 之蛋白表現。投予50 μg/ml Hispolon 於12小時、24小時及48小時經由流式細胞儀分析，可得知細胞週期停致於S期是藉由增加 p53 及減少 cdk 2, Cyclin A, cdc 2 and Cyclin B1的蛋白表現。
結果顯示，Hispolon抑制 CH27 細胞增生，其分子機轉是藉由：(1)導致肺癌細胞 CH27 停滯於S期，（2）藉由活化 Caspase 路徑，導致細胞凋亡。
Lung cancer is the leading cause of cancer deaths worldwide, and has been reported to be the leading cause of cancer death in Taiwan. It is more resistant to cytotoxic chemotherapy and causing the treatment of patients to fail. Several Chinese herbal medicines have used to treat cancers but the mechanisms are not clear.
Phellinus linteus (PL) has been used as a traditional medicinal mushroom in China, Korea, Japan and other Asian countries for the treatment of various diseases, including oral ulcer, gastroenteric disorder and various cancers.
Hispolon was an active compound isolated from Phellinu linteus that had been reported to exhibit antitumor effect. This study investigated how hispolon affect the lung cancer cell lines CH27 and also understand the related mechanisms. In the MTT assay, treatment of Hispolon inhibited the growth of CH27 in the dose- and time- dependent manner. Hispolon inducing CH27 cells apoptosis was confirmed by Annexin V/PI staining, DNA fragmentation assay and nuclear condensation (DAPI staining). Hispolon-induced apoptosis was involved in modulation of the expressions of Bcl-2 family proteins, such as Bax, Bcl-2 and Bid. There were also accompanied by increasing Fas, caspase-8 and cleavage of caspase-3, caspase-9, and PARP protein levels. Following 12 h, 24 h and 48 h exposure to 50 μg/ml Hispolon, flow cytometric analysis revealed an increase in the cell population in S-phase. During the S-phase arrest, Hispolon increased p53 level and decreased the protein levels of cdk2, Cyclin A, cdc2 and Cyclin B1.
These result suggested that Hispolon inhibited the proliferation of CH27 cells via S- phase arrest and induced CH27 cell apoptosis by caspase-dependent pathway.
Key words : Hispolon ; lung cancer ; cell cycle ; caspase ; apoptosis |
