| 摘要: | 存在漆樹屬（Rhus）枝條中的雙查耳酮（bichalcone）是屬於黃酮素類（flavonoid）的一種，文獻報告指出雙查耳酮具有能抑制癌細胞生長的效應。我們以3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay篩選了由吳天賞教授實驗室所提供的十六種新合成含雙查耳酮結構之衍生物對二十五種不同類型的人類癌細胞株存活率的影響，最後選擇效果較佳的(2E,2?SE)-1,1?S-(5,5?S-(Piperazine-1,4-diylbis(methylene))bis(4-hydroxy-3-methoxy-5,1-phenylene))bis(3-phenylprop-2-en-1-one) (TSWU-CD4)來繼續研究探討其毒殺癌細胞之分子機轉。實驗結果發現，TSWU-CD4對人類舌鱗狀細胞癌CAL-27、咽部鱗狀細胞癌FaDu、膠質母細胞瘤GBM-8401、鼻咽癌細胞NPC-TW039等細胞株具有明顯的細胞毒殺作用，且此現象呈現劑量與時間的正相關性。並進一步的發現，以50% 抑制濃度（IC50）2.5~3.5 ?嵱 TSWU-CD4能誘導此四種人類癌細胞株之細胞週期停滯於S期，且會導致細胞凋亡（apoptosis）之變化包括DNA片斷化（DNA fragmentation）、caspase-3的活化、poly (ADP-ribose) polymerase的裂解及sub-G1的比例增加。TSWU-CD4誘導細胞週期停滯於S期可能是藉由活化caspase-3介導的p21waf1/Cip1裂解與影響cyclin B1及cyclin-dependent kinase 2的表現有關。除此之外，TSWU-CD4的作用也會使癌細胞內細胞自噬（autophagy）標幟蛋白質LC3-Ⅰ及內質網壓力（endoplasmic reticulum stress）調節蛋白質glucose-regulated protein 78 (GRP-78)表現量增加。然而，TSWU-CD4導致此四種人類癌細胞株細胞凋亡之確切分子機制仍待進一步探討。
Bichalcone is a flavonoid from the Rhus pyroides, has been shown to inhibit the growth of human cancer cell lines. By using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, we have detected the cytotoxicity of 16 novel newly synthesized bichalcone derivatives kindly provided by professor Tian-Shun Wu on 25 different types of human cancer cell lines. We choosed (2E,2?SE)-1,1?S-(5,5?S-(Piperazine-1,4-diylbis(methylene))bis(4-hydroxy-3-methoxy-5,1-phenylene))bis(3-phenylprop-2-en-1-one) (TSWU-CD4) which has the most cytotoxic effect to further study the molecular mechanism of its cytotoxicity in human cancer cell line. The results show that TSWU-CD4 has dose- and time-dependent effect of growth inhibition in human tongue squamous cell carcinoma CAL-27, human pharynx squamous cell carcinoma FaDu, human brain glioblastoma multiforme GBM-8401, and human nasopharyngeal carcinoma NPC-TW039 cell lines. The 50% inhibiting concentration values of TSWU-CD4 on those cells were 2.5 to 3.5 ????. TSWU-CD4 can induce apoptosis of human cancer cells, which was characterized by morphological changes, DNA fragmentation, caspase-3 activation, cleavage of poly (ADP-ribose) polymerase, and increase of sub-G1 population. The data also indicate that induction of S phase arrest by TSWU-CD4 in CAL-27, NPC-TW039, FaDu, and GBM-8401 cells may be able to modulate the expression of cyclin-B1, cdk-2, and caspase-3-mediated cleavage of p21waf1/Cip1. In addition, TSWU-CD4 can increase levels of autophagy maker protein LC3-Ⅰ and endoplasmic reticulum (ER) stress regulatory protein GRP-78. However, the definite molecular mechanism of TSWU-CD4 on apoptosis induction in human cancer cells still needs to be investigated further. |
