Human splicing factor SPF45 (RBM17) confers broad multidrug resistance to anticancer drugs when overexpressed -: a phenotype partially reversed by selective estrogen receptor modulators
Human splicing factor SPF45 (RBM17) confers broad multidrug resistance to anticancer drugs when overexpressed -: a phenotype partially reversed by selective estrogen receptor modulators
复制标题
DOI：
10.1158/0008-5472.can-03-3675
复制
发表时间：
2005-08-01
期刊：
影响因子：
11.2
通讯作者：
Dantzig, AH
中科院分区：
文献类型：
--
作者：
Perry, WL;Shepard, RL;Dantzig, AH
剪接因子SPF 45（RBM 17）在许多实体瘤中经常过表达，并且在HeLa细胞中的稳定表达赋予对多柔比星和长春新碱的抗性。在这项研究中，我们的特点是稳定的A2780卵巢癌细胞转染。在3天的细胞毒性试验中，人SPF 45过表达赋予对卡铂、长春瑞滨、多柔比星、依托泊苷、米托蒽醌和长春新碱3- 21倍的抗性。此外，在检测的最高药物浓度下观察到对吉西他滨和培美曲塞的耐药性。使用锤头状核酶敲低亲代A2780细胞中的SPF 45使A2780细胞对依托泊苷敏感，相对于无催化活性的核酶对照和未转染的细胞，其敏感性接近5倍，表明SPF 45在对某些药物的内在抗性中的作用。A2780-SPF 45细胞积累了与载体转染和亲本A2780细胞相似的多柔比星水平，表明耐药性不是由于药物积累的差异。努力确定小分子，可以阻止SPF 45介导的耐药性显示，选择性雌激素受体（ER）调节剂他莫昔芬和LY 117018（雷洛昔芬类似物）部分逆转SPF 45介导的耐药性A2780-SPF 45细胞中的米托蒽醌从21倍至8倍和5倍，分别，但没有显着影响载体对照细胞的米托蒽醌敏感性。定量PCR显示ER β在A2780转染子中表达，而ER α不表达。免疫共沉淀实验表明，SPF 45和ER β在体内物理相互作用。因此，A2780细胞中SPF 45介导的耐药性可能部分归因于SPF 45对ER β调节基因转录或选择性剪接的影响。
The splicing factor SPF45 (RBM17) is frequently overexpressed in many solid tumors, and stable expression in HeLa cells confers resistance to doxorubicin and vincristine. In this study, we characterized stable transfectants of A2780 ovarian carcinoma cells. In a 3-day cytotoxicity assay, human SPF45 overexpression conferred 3- to 21-fold resistance to carboplatin, vinorelbine, doxorubicin, etoposide, mitoxantrone, and vincristine. In addition, resistance to gemcitabine and pemetrexed was observed at the highest drug concentrations tested. Knockdown of SPF45 in parental A2780 cells using a hammerhead ribozyme sensitized A2780 cells to etoposide by similar to 5-fold relative to a catalytically inactive ribozyme control and untransfected cells, suggesting a role for SPF45 in intrinsic resistance to some drugs. A2780-SPF45 cells accumulated similar levels of doxorubicin as vector-transfected and parental A2780 cells, indicating that drug resistance is not due to differences in drug accumulation. Efforts to identify small molecules that could block SPF45-mediated drug resistance revealed that the selective estrogen receptor (ER) modulators tamoxifen and LY117018 (a raloxifene analogue) partially reversed SPF45-mediated drug resistance to mitoxantrone in A2780-SPF45 cells from 21-fold to 8- and 5-fold, respectively, but did not significantly affect the mitoxantrone sensitivity of vector control cells. Quantitative PCR showed that ER beta but not ER alpha was expressed in A2780 transfectants. Coimmunoprecipitation experiments suggest that SPF45 and ER beta physically interact in vivo. Thus, SPF45-mediated drug resistance in A2780 cells may result in part from effects of SPF45 on the transcription or alternate splicing of ER beta-regulated genes.