- 學位論文
靈芝萃取物T-612對非小細胞肺癌細胞株之抗癌活性研究
Studies on the Anticancer Activity of T-612 from Ganoderma in NSCLC Cell Lines
摘要
肺癌為全世界當前發生頻率最高且預後差的癌症，其高致死率使它近年來竄升為台灣癌症死亡原因的首位。絕大部分肺癌病患被診斷患病時多屬於晚期，此時病患已無法靠手術治癒，只能接受化學治療，或輔以放射線與標靶藥物治療；但臨床治療的困境是藥物常因其藥物毒性而使得投藥濃度受到相當大的侷限，且在治療後會產生抗藥性。因此為了能更有效的治療肺癌，發展新的治療藥物或是將現有之藥物輔以佐劑(adjuvant)以達到更好之治療效果為當前熱門的研究方向。靈芝是一種在亞洲國家被廣泛使用的傳統中藥，而其中的許多成分已有研究證實具有抗癌的功效。本研究主要目的是想探討靈芝萃取物T-612作用於肺腺癌細胞之抗癌效果。T-612之抗癌效果研究分為兩個方向：(1)作為肺癌治療藥物之佐劑。(2) 作為抗標靶藥物艾瑞莎之肺癌治療藥物。實驗結果顯示：(1) 在體外的實驗(in vitro)，將T-612與各種癌症化療常用藥物合併處理PC9細胞株，發現T-612與VP-16 (Topoisomerase II poison)合併使用能加強VP-16的抗癌活性(IC50=1.99 μM 降至0.51 μM)，且使細胞週期滯留在G2/M期的細胞顯著增加，最終造成細胞凋亡。同時也觀察到合併處理的實驗組可以促進活性氧化物(reactive oxygen species, ROS)的累積。將PC9細胞株接種於免疫缺陷小鼠皮下進行活體實驗(in vivo)發現，VP-16與T-612結合餵食比單獨使用VP-16更能有效抑制腫瘤生長。總和以上結果，本部分研究從體外細胞實驗與體內動物實驗皆證實了T-612具有潛力可以做為VP-16的佐劑。(2) 以T-612處理PC9及抗艾瑞莎之PC9IR肺癌細胞，觀察到T-612能夠抑制兩種細胞株的生長，且具有毒殺的效果 (PC9: IC50=8.1 μM ; PC9IR: IC50=4.4 μM, 72 h)。PC9IR細胞經過T-612處理後，我們發現細胞形態變圓且爬行能力(migration ability)降低；分析細胞內的變化情形，發現T-612會造成活性氧ROS堆積，且最終細胞走向細胞凋亡。
並列摘要
Lung cancer is one of the most common malignant diseases worldwide and it has become the leading cause of cancer-related mortality over the past years in Taiwan. Most lung carcinomas are diagnosed at an advanced stage, conferring a poor prognosis. If the tumor is aggressive, chemotherapy, radiotherapy and targeted therapy may be used in addition to or instead of surgery. But most of chemotherapeutic drugs are too toxic for human clinical use, and most patients who initially respond to targeted drugs will develop resistance. Therefore, providing an effective treatment for lung cancer is essential. Ganoderma (Lingzhi) as a well-known traditional Chinese herb has been used for medicinal purposes for centuries in Asia. There are many bioactive compounds have been reported as anticancer ingredients of the medical mushroom. We investigated the anti-cancer activities of T-612, a compound from Ganoderma tsugae Murr. (YK-01), to against the non-small cell lung cancer cells. The aim of our research is to develop T-612 as an (i) adjuvant for chemotherapeutic drugs and (ii) anticancer agent. (i) For T-612 as an adjuvant, T-612 was combined with other anticancer drugs. We found that T-612 enhanced anticancer activity of VP-16 through mitotic arrest and then induced apoptosis. In addition, we found that cyclin B1, Cdc25c and p21 expression level was modulated after combination treatment of VP-16 and T-612. ROS accumulation was also observed. Furthermore, the combination was also more effective than either single agent in inhibiting the growth of lung cancer xenografts in mice. (ii) Our data revealed that T-612 displayed growth inhibitory effects on both PC9 cells and Iressa-resistant PC9IR cells, Besides, T-612 could inhibit migration of PC9IR cells. The mechanism of T-612–induced cytotoxicity was through induction of reactive oxygen species (ROS) and led to apoptosis. These results suggest that T-612 is an effective adjuvant of VP-16 and potential anticancer agent.