| 摘要: | 摘要 YT-1一個新合成的抗癌化合物，我們利用人類血癌細胞（U937、HL-60、K562 cells）去測試YT-1對此三株血癌細胞株是否具有抗癌活性。結果顯示，YT-1對此三株血癌細胞株具有細胞毒殺性且IC50濃度於0.5~10 μM間。以IC50的濃度處理U937、HL-60、K562，24小時後，觀察其細胞型態，發現細胞內有凋亡小體的出現，核內的DNA呈梯度斷裂的模樣及細胞產生凋亡時特殊外在型態的改變。利用流式細胞儀分析經YT-1處理後之血癌細胞，顯示有sub-G1(代表Apoptotic cell)增加且細胞週期隨時間增加停滯於G2/M期。除此之外，利用西方墨點法觀察以YT-1處理之U937細胞，其蛋白質表現量的變化，發現Bcl-2表現量減少，Bax、Bak、Bid、cytochrome c蛋白質量增加，Caspase 3、8、9被活化且PARP被分解。 Caspase專一性抑制劑明顯的減少經YT-1處理之U937細胞內Caspase 的活性，並提升細胞之增值率。YT-1會使U937、HL-60、K562 cells之細胞週期抑制在G2/M期，為了探討細胞週期受抑制之機制，我們以西方墨點法分析Cyclin、CKI、CDK蛋白質表現的變化，發現YT-1處理之U937細胞，其Cyclin B、CDK1、p21表現量增加，以上結果顯示，YT-1抑制人血癌細胞的增值作用，與誘導細胞凋亡及抑制細胞週期進行有關聯性。; Abstract We studies the effect of YT-1, 2-phenyl-4-quinolone, a newly developed anti-cancer agent, on cell proliferation, cell cycle progression, and induction of apoptosis in human leukemia (U937, HL-60 and K562) cells. YT-1 was cytotoxic to human leukemia (U937, HL-60 and K562) cells, with IC50 values between 0.5~10 μM. Treatment with YT-1 resulted in a dose-dependent generation of apoptotic oligonucleosomes, typical DNA-laddering and apoptosis-specific morphological changes. Flow cytometric analysis further confirmed that YT-1-treated human leukemia (U937, HL-60 and K562) cells were hypodiploid, in terms of DNA content, and were arrested at the G2/M arrest. Furthermore, down-regulation of Bcl-2, Bid, up-regulation of Bax, Bak and cytochrome c, activation of caspase 3 , 8 , 9 and cleavage of PARP were detected by western blotting method in YT-1 treated U937 cells. Caspase inhibitors significantly reduced YT-1-induced caspase activity and cell death. In addition , YT-1 induced G2/M arrest in U937、HL-60 and K562 cells . Western blotting analysis of cyclins、CDKs and CKIs revealed that YT-1 induced Cyclin B、CDK1 and p21 proteins. This results indicated that the ability of YT-1 to inhibit cell proliferation may be mediated by the induction of apoptosis and cell arrest. |
