Characterization of a new trabectedin-resistant myxoid liposarcoma cell line that shows collateral sensitivity to methylating agents
Characterization of a new trabectedin-resistant myxoid liposarcoma cell line that shows collateral sensitivity to methylating agents
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DOI：
10.1002/ijc.26340
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发表时间：
2012-07-01
影响因子：
6.4
通讯作者：
D'Incalci, M.
中科院分区：
文献类型：
--
作者：
Uboldi, S.;Bernasconi, S.;D'Incalci, M.
粘液样脂肪肉瘤（MLS）以表达 FUS-CHOP 融合基因为特征，在临床上对 DNA 结合抗肿瘤剂曲贝替定非常敏感。然而，最终会出现耐药性，从而阻止疾病根除。为了研究耐药机制，开发了曲贝替定耐药细胞系 402-91/ET。对曲贝替定的耐药性与 MDR 相关蛋白的表达、曲贝替定的摄取/流出或 GSH 水平无关，亲代细胞和耐药细胞中的 GSH 水平相似。由于核苷酸切除修复缺陷，402-91/ET 细胞对紫外线过敏：XPG 互补降低了对紫外线的敏感性，但仅部分降低了对曲贝替定的敏感性。由于缺乏 O6-甲基鸟嘌呤-DNA-甲基转移酶 (MGMT) 活性，402-91/ET 细胞对替莫唑胺表现出附带敏感性，这与 MGMT 启动子的高甲基化有关。在 402-91 细胞中，染色质免疫沉淀 (ChIP) 分析显示，如前所述，FUS-CHOP 与 PTX3 和 FN1 基因启动子结合，并且曲贝替定导致 FUS-CHOP 从 DNA 分离。在此我们报告，相反，在 402-91/ET 细胞中，FUS-CHOP 不与这些启动子结合。两种细胞系之间涉及不同途径（包括信号转导、细胞凋亡和应激反应）的基因转录调节存在差异。 Trabectedin 在 402-91 细胞系中激活参与脂肪形成程序的基因转录，例如 c/EBPα 和 β，但在 402-91/ET 细胞系中则不然。 402-91/ET 对替莫唑胺的附带敏感性为研究甲基化药物在曲贝替定耐药的 MLS 患者中的潜在用途提供了依据。
Myxoid Liposarcomas (MLS), characterized by the expression of FUS-CHOP fusion gene are clinically very sensitive to the DNA binding antitumor agent, trabectedin. However, resistance eventually occurs, preventing disease eradication. To investigate the mechanisms of resistance, a trabectedin resistant cell line, 402-91/ET, was developed. The resistance to trabectedin was not related to the expression of MDR related proteins, uptake/efflux of trabectedin or GSH levels that were similar in parental and resistant cells. The 402-91/ET cells were hypersensitive to UV light because of a nucleotide excision repair defect: XPG complementation decreased sensitivity to UV rays, but only partially to trabectedin. 402-91/ET cells showed collateral sensitivity to temozolomide due to the lack of O6-methylguanine-DNA-methyltransferase (MGMT) activity, related to the hypermethylation of MGMT promoter. In 402-91 cells chromatin immunoprecipitation (ChIP) assays showed that FUS-CHOP was bound to the PTX3 and FN1 gene promoters, as previously described, and trabectedin caused FUS-CHOP detachment from DNA. Here we report that, in contrast, in 402-91/ET cells, FUS-CHOP was not bound to these promoters. Differences in the modulation of transcription of genes involved in different pathways including signal transduction, apoptosis and stress response between the two cell lines were found. Trabectedin activates the transcription of genes involved in the adipogenic-program such as c/EBPa and beta, in 402-91 but not in 402-91/ET cell lines. The collateral sensitivity of 402-91/ET to temozolomide provides the rationale to investigate the potential use of methylating agents in MLS patients resistant to trabectedin.