| 摘要: | 口腔癌在台灣地區是竄升最快的癌症，近十五年來行政院衛生署統計數據顯示由癌症死因的第十位上升到第六位。
PA-42 是從中草藥植物苦蘵中所萃取出來的抗癌活性成份；而苦蘵以往有文獻報導能對血癌、肺癌、直腸癌、子宮頸癌、肺癌和肝癌細胞產生細胞毒性的作用。截至目前為止的研究，我們率先研究 PA-42 對於人類口腔癌細胞株 HSC-3 是否有生長抑制的能力及其機轉，本篇研究目的為探討 PA-42 對於調控人類口腔癌 HSC-3 細胞增生、細胞週期及細胞凋亡，來評估是否有化學保護抗癌作用的能力。
實驗結果中發現， PA-42 有效抑制口腔癌 HSC-3 細胞生長。而低劑量 1.6 μg/ml PA-42 促使細胞DNA受損後，誘導細胞產生 G2/M 期停滯，影響 p53 、 Wee1 蛋白表現增加及降低 Cdc2 、 Cyclin B1 等相關蛋白表現； PA-42 導致 HSC-3 細胞鈣離子釋放及粒線體膜電位下降； PA-42 促使 AIF 、 Bax 及 Bcl-2 從粒線體釋放出來，並且會造成 caspase-3 裂解以及 DNA 的斷裂，最後導致細胞凋亡；同時， PA-42 也增加 HSC-3 細胞中的 Fas 蛋白表現量。由上述結果可知， PA-42 是透過內在路徑 (粒線體路徑) 、外在路徑 (死亡接受器路徑) 兩種方式導致細胞凋亡。
在我們的研究結果中亦指出，藉由細胞傷口轉移及細胞侵襲試驗證實 PA-42 可抑制細胞轉移及侵襲，同時抑制 α-smooth muscle actin、 MMP-3、MMP-9 及 GRB2 蛋白表現，但增加 E-cadherin 的表現；並在共軛焦顯微鏡下觀察到 PA-42 將細胞骨架由間質型轉成上皮型。 由上述結果得知 PA-42 可抑制細胞的轉移侵襲。
綜合上述結果， PA-42 誘導人類口腔癌HSC-3細胞細胞凋亡與抑制細胞轉移，開拓未來人類口腔癌化學保護新藥物治療及預防的指標。
The oral cancer is the most incident cancer, with the place rate rising fast from 10th forward 6th most common cause of cancer death in past fifteen years in Taiwan.
PA-42 is an anticancer active compound and isolated from a Chinese medicine herb, physalis angulata. Physalis angulata has been reported to exhibit anti-tumor effect in several human cancers such as leukemia, lung, colon, cervix, hepatoma and melanomas cancers. In our preliminary studies, we first investigated the influence of PA-42 in human oral squamous carcinoma cancer (OSCC) cell lines HSC-3. We evaluate the chemopreventive role of cancer of PA-42 in vitro by studying the regulation of proliferation, cell cycle, and apoptosis with dose- and time- dependent manner by MTT assay, flow cytometry, nuclear DAPI stain assay, comet assay, and DNA fragmentation assay.
In the results, the data shown that PA-42 has exhibited effective cells growth inhibition in HSC-3 cells. Low dose of PA-42 induced DNA damage and then led to undergo G2/M phase arrest, with an increase in p53 and wee1 and a decrease in cdc2 and Cyclin A/B1 and protein. PA-42 induced the Ca2+ production release and a decrease in the mitochondrial membrane potential in HSC-3 cells. PA-42 induced apoptosis by releasing AIF、Bax and Bcl-2 from mitochondria, and cleavage caspase-3 and then caused DNA fragmentation. PA-42 also increased the expression of Fas in HSC-3 cells. The conclusion of the results is that PA-42 induced apoptosis through both the intrinsic and extrinsic pathways in HSC-3 cells.
In our study, PA-42 has revealed that the migration and invasion of HSC-3 cells was suppressed by wound healing assay, transwell migration assay, and matrigel invasion assay. PA-42 has also suppressed MMP-3 and GRB2 expressions with western blot and reversed cytoskeleton from mesenchymal-like to epithelial-like with confocal image in HSC-3 cells. The conclusion of the results is that PA-42 suppressed metastasis in HSC-3 cells.
These results indicate that PA-42 induced apoptosis and suppressed metastasis in HSC-3 cells. PA-42 is a novel candidate agent for the chemoprevention of human oral squamous cancer in the future. |
