Selvakumaran Muthu, Pisarcik Debra A, Bao Rudi, Yeung Anthony T, Hamilton Thomas C
Ovarian Cancer Program, Medical Oncology, Fox Chase Cancer Center, Philadelphia, Pennsylvania 19111, USA.
Cancer Res. 2003 Mar 15;63(6):1311-6.
Ovarian cancer is the leading cause of death among women from gynecological malignancies inthe United States. Resistance to the chemotherapeutic agent cisplatin isa major limitation for the successful treatment of ovarian cancer. In an effort to overcome the cisplatin resistance problem in ovarian cancer treatment, we have sought to enhance cisplatin cytotoxicity by perturbing the nucleotide excision repair (NER) pathway. The NER pathway is responsible for repairing cisplatin bound to DNA. Expression of one of the NER components, ERCC1, is correlated with cisplatin drug resistance. Hence, we targeted ERCC1 by antisense RNA methodologies, and we show that we could sensitize a relatively sensitive A2780 cell line and also the highly resistant OVCAR10 cell line to cisplatin by expressing antisense ERCC1 RNA in them as measured with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assays. The A2780 cell lines expressing antisense ERCC1 had 1.9-8.1-fold enhancements in cisplatin sensitivity. The OVCAR10 antisense ERCC1 cell lines had IC(50) values ranging from 2.28 microM to 2.7 microM cisplatin as compared with 9.52 micro M for control OVCAR10 cells. The OVCAR10 antisense ERCC1 cells also show reduced DNA-damage repair capacity as assessed by host cell reactivation. Furthermore, immunocompromised mice transplanted with the antisense cell lines survived longer than the mice bearing control cells after response to cisplatin treatment. These data suggest that it is possible to substantially enhance the cisplatin cytotoxicity by disturbing the NER pathway in cisplatin-resistant cell lines and to enhance the survival capacity of mice in an ovarian cancer xenograft model.
在美国，卵巢癌是女性妇科恶性肿瘤死亡的主要原因。对化疗药物顺铂产生耐药性是卵巢癌成功治疗的一个主要限制因素。为了克服卵巢癌治疗中顺铂耐药性问题，我们试图通过干扰核苷酸切除修复（NER）途径来增强顺铂的细胞毒性。NER途径负责修复与DNA结合的顺铂。NER组分之一ERCC1的表达与顺铂耐药性相关。因此，我们采用反义RNA方法靶向ERCC1，并且我们表明，通过在相对敏感的A2780细胞系以及高度耐药的OVCAR10细胞系中表达反义ERCC1 RNA，用3-（4,5-二甲基噻唑-2-基）-2,5-二苯基四氮唑溴盐试验测定，我们可以使它们对顺铂敏感。表达反义ERCC1的A2780细胞系对顺铂的敏感性提高了1.9至8.1倍。与对照OVCAR10细胞的9.52μM相比，OVCAR10反义ERCC1细胞系的半数抑制浓度（IC50）值范围为2.28μM至2.7μM顺铂。通过宿主细胞再激活评估，OVCAR10反义ERCC1细胞也显示出DNA损伤修复能力降低。此外，移植了反义细胞系的免疫受损小鼠在接受顺铂治疗后比携带对照细胞的小鼠存活时间更长。这些数据表明，通过干扰顺铂耐药细胞系中的NER途径来大幅增强顺铂的细胞毒性以及在卵巢癌异种移植模型中提高小鼠的存活能力是可能的。
