NECROSIS AND APORTOSIS OF HUMAN PANCREATIC CANCER CELL LINES-FOR THE IMPROVEMENT OF ADJUVANT CHEMOTHERAPY FOR PANCREATIC CANCER

比较了50戈伊照射、足叶乙甙和叔丁基过氧化氢对人胰腺癌细胞凋亡和坏死的影响。在实验中使用人胰腺癌细胞系MIA paca 2和Panc-1以及人胆囊癌细胞系GB-d1。通过台盼蓝排除试验测定细胞死亡，分别对漂浮细胞和贴壁细胞进行细胞计数。在50戈伊照射后5天，来自三个细胞系的60%以上的细胞死亡，并且这些细胞明显地被加入1 μ M蛋白质合成抑制剂放线菌酮保护。巴氏染色显示3种不同细胞系均出现典型的凋亡核碎片和凋亡小体。电泳结果显示Panc-1和GB-d1的DNA呈梯状，而MIA paca 2的DNA呈涂片状。同样，在加入10 μ M依托泊苷后，在MIA paca 2上显示DNA涂片模式。流式细胞仪检测结果显示，50戈伊照射后24 h细胞完全停滞于G2-M期，足叶乙甙处理后细胞聚集于G2-M期，而叔丁基过氧化氢处理诱导的细胞坏死未观察到任何细胞周期延迟或停滞。结果表明，大剂量X射线照射后细胞的死亡可能是与常规坏死完全不同的凋亡。

Apoptosis and necrosis of human pancreatic cancer cell lines were comparatively investigated after 50 Gy irradiation, etoposide and tert-butylhydroperoxide. Human pancreatic cancer cell lines, MIA paca2 and Panc-1, and a human gall bladder cancer cell line, GB-d1 were used in the experiment. Cell deaths were determined by trypan blue exclusion test with cell number counting separately both on the floating cells and on the attached cells. Over 60% of the cells from three cell lines were dead 5 days after 50 Gy irradiation and those were clearly protected by the addition of 1 uM cycloheximide, a protein synthesis inhibitor. Typical apoptotic nuclear fragmentations and apoptotic bodies were also observed on 3 different cell lines by Papanicolaou staining. Electrophoresis revealed DNA ladder pattern on Panc-1 and GB-d1, however, DNA from MIA paca2 showed smear pattern. Again, DNA smear pattern was shown on MIA paca2 after the addition of 10 uM etoposide. With the flowcytometry, complete G2-M arrest 24 hr after 50 Gy irradiation and the accumulation to G2-M after the treatment of etoposide were shown while any cell cycle delay or arrest was not observed on necrosis induced by the treatment of tert-butylhydroperoxide. The results indicated that cell deaths after high dose X-ray irradiation may be apoptosis which is completely different from conventional necrosis.