耐顺铂人肺腺癌细胞系A549^DDP耐药机理进一步探讨

应用递增浓度的方法建立了一株顺铂（ＣＤＤＰ）耐药细胞系Ａ５４９ＤＤＰ。用溴化乙啶荧光分光光度法测定细胞内Ｐｔ－ＤＮＡ链间交联物（ＩＣＬ）；用无焰原子吸收光谱法测定细胞浆内及细胞核内铂含量；用流式细胞法及荧光显微镜测定铂的外排速度。结果显示：耐药细胞Ａ５４９ＤＤＰ较亲代敏感细胞Ａ５４９对ＣＤＤＰ耐受性增加８．９倍，与亲代敏感细胞Ａ５４９相比，Ａ５４９ＤＤＰ胞浆内及核内ＣＤＤＰ积聚分别为亲代细胞的１６．９％与２４．３％，铂含量与ＣＤＤＰ浓度正相关；Ａ５４９ＤＤＰ外排ＣＤＤＰ的功能较Ａ５４９明显增强，ＩＣＬ形成量低８４．１％，而修复功能增强２倍。结果提示：Ａ５４９ＤＤＰ细胞内ＣＤＤＰ积聚减少和修复功能增强是ＣＤＤＰ的主要耐药机理。

Mechanison of Resistance of Human Cell Line A 549 DDP to Cisplatin

A resistant human lung adenocarcinoma cell line A 549 DDP was established by stepwise increasing content of cisplatin in the culture medium.The intracellular and intranuclear accumulation of cisplatin were measured by atomic absorption spectrometry. The interstrand cross linked DNA (ICL)was measured by ethidium bromide fluorescence assay. The removal of GS X was determined by FCM and fluorescence microscopy. The A 549 DDP cell line was 8.9 fold resistant to cisplatin than its parent cell line A 549 .The intracellular and intranuclear accumulation of cisplatin in the A 549 DDP cell line was 16.9 and 24.3 percent of A 549 cell line respectively. The repair rate in A 549 DDP cell line was 2 fold higher than that in A 549 . The resistant cell line A 549 DDP extruded CDDP more quickly than the sensitive cell line A 549 . The results mentioned above showed that decreased accumulation of CDDP may be a key mechanism in CDDP resistance,while the increased Pt DNA repair capacity may play a role in CDDP resistance.