Chatterjee S, Cheng M F, Berger S J, Berger N A
Department of Medicine, Case Western Reserve University School of Medicine, Cleveland, Ohio 44106-4937.
Cancer Res. 1994 Aug 15;54(16):4405-11.
Cell lines deficient in poly(ADP-ribose) synthesis due to enzyme deficiency (ADPRT54 and ADPRT351) or substrate deficiency (N2, N3, and N4) are resistant to topoisomerase II-directed agents, including etoposide (VP-16), N-[4-(9-acridinylamino)-3-methoxyphenyl]methanesulfonamide, and Adriamycin, relative to the effect of these agents on parental V79 Chinese hamster cells. Resistance is stable in the ADPRT54 and ADPRT351 cell lines, whereas resistance in the N2, N3, and N4 cell lines occurs when the cells are grown in nicotinamide-deficient medium to produce a state of NAD deficiency. However, sensitivity to VP-16 reverts to normal when cellular NAD levels return to control levels during growth in nicotinamide-containing complete medium. Poly(ADP-ribose) polymerase-deficient cell lines show constitutively increased levels of a protein at M(r) 78,000 on Coomassie blue-stained, sodium dodecyl sulfate-polyacrylamide gels that was subsequently confirmed with monoclonal antibodies to be M(r) 78,000 glucose-regulated stress protein (GRP78). Similarly, N2, N3, and N4 cells show induction of GRP78 under nicotinamide-deficient conditions. Induction of GRP78 is associated with elevated levels of GRP78 mRNA and appears to be regulated at the transcriptional level. When N3 cells with deficiency of poly(ADP-ribose) synthesis due to NAD deficiency are shifted to complete, nicotinamide-containing medium, they restore their NAD content, undergo a decrease in GRP78 levels, and regain sensitivity to VP-16. When V79 cells are shifted to nicotinamide-deficient medium they undergo a reduction in NAD content, followed by a progressive elevation in GRP78 levels, and they subsequently become increasingly resistant to VP-16. These studies demonstrate a clear association between deficiency of the NAD-poly(ADP-ribose) synthesis system, induction of GRP78 synthesis, and resistance to VP-16.
由于酶缺乏（ADPRT54和ADPRT351）或底物缺乏（N2、N3和N4）而导致聚（ADP - 核糖）合成缺陷的细胞系，相对于这些药物对亲本V79中国仓鼠细胞的作用，对拓扑异构酶II导向的药物具有抗性，这些药物包括依托泊苷（VP - 16）、N - [4 - （9 - 吖啶基氨基） - 3 - 甲氧基苯基]甲磺酰胺和阿霉素。ADPRT54和ADPRT351细胞系中的抗性是稳定的，而N2、N3和N4细胞系中的抗性是当细胞在缺乏烟酰胺的培养基中生长以产生NAD缺乏状态时出现的。然而，当细胞在含烟酰胺的完全培养基中生长期间细胞内NAD水平恢复到对照水平时，对VP - 16的敏感性恢复正常。聚（ADP - 核糖）聚合酶缺陷的细胞系在考马斯亮蓝染色的十二烷基硫酸钠 - 聚丙烯酰胺凝胶上显示M（r）78,000处的一种蛋白质水平持续增加，随后用单克隆抗体证实该蛋白质为M（r）78,000葡萄糖调节应激蛋白（GRP78）。同样，N2、N3和N4细胞在烟酰胺缺乏条件下显示GRP78的诱导。GRP78的诱导与GRP78 mRNA水平升高相关，并且似乎在转录水平受到调节。当由于NAD缺乏而导致聚（ADP - 核糖）合成缺陷的N3细胞转移到含烟酰胺的完全培养基中时，它们恢复其NAD含量，GRP78水平降低，并重新获得对VP - 16的敏感性。当V79细胞转移到缺乏烟酰胺的培养基中时，它们的NAD含量降低，随后GRP78水平逐渐升高，并且它们随后对VP - 16的抗性越来越强。这些研究表明NAD - 聚（ADP - 核糖）合成系统的缺陷、GRP78合成的诱导与对VP - 16的抗性之间存在明显关联。
