Testicular Germ Cell Tumors Acquire Cisplatin Resistance by Rebalancing the Usage of DNA Repair Pathways.
Testicular Germ Cell Tumors Acquire Cisplatin Resistance by Rebalancing the Usage of DNA Repair Pathways.
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DOI：
10.3390/cancers13040787
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发表时间：
2021-02-13
期刊：
影响因子：
5.2
通讯作者：
Barchi M
中科院分区：
文献类型：
--
作者：
Caggiano C;Cavallo F;Giannattasio T;Cappelletti G;Rossi P;Grimaldi P;Feldman DR;Jasin M;Barchi M
生殖细胞肿瘤由于其对顺铂化疗的独特敏感性而成为可治愈实体瘤的模型。患者通常为青壮年，尽管治愈率很高，但约有20%的患者未达到缓解或复发，其中50%的患者死于疾病。他们对治疗产生耐药性的机制在很大程度上尚不清楚。通过使用睾丸生殖细胞肿瘤（TGCT）细胞系作为模型，我们研究了顺铂获得性耐药的机制。我们证明了耐药性是通过 DNA 修复途径选择的精细调节而发生的。也就是说，在耐药细胞中，TP53 结合蛋白 1 (53BP1) 和 DNA 依赖性蛋白激酶 (DNA-PKcs) 表达的减少抑制了非同源末端连接对双链断裂的修复。然而，顺铂引起的损伤可以通过同源重组有效修复。此外，我们证明聚（ADP-核糖）聚合酶（PARP）与顺铂联合的药理学抑制对顺铂耐药细胞具有相加/协同作用，这代表了在挽救治疗中引入PARP抑制剂的概念证明。尽管生殖细胞肿瘤（GCT）对基于顺铂的化疗有很高的反应率，但仍有一部分患者对治疗没有反应，并且预后明显较差。耐药性背后的生物学机制仍然未知。在这项研究中，通过使用两种在长期接触药物后获得顺铂耐药性的 TGCT 细胞系，我们鉴定了一些关键蛋白和获得性耐药机制。我们发现顺铂耐药细胞系具有非同源末端连接（NHEJ）较少的表型。这与顺铂治疗后 TP53 结合蛋白 1 (53BP1) 和 DNA 依赖性蛋白激酶 (DNA-PKcs) 蛋白的基础表达减少以及 53BP1 病灶形成减少相关。与这些观察结果一致，53BP1 蛋白表达的调节改变了细胞系对顺铂的耐药性，而 DNA-PKcs 活性的抑制则拮抗了顺铂的细胞毒性。 NHEJ 的抑制伴随着同源重组修复途径 DNA 双链断裂 (DSB) 修复功能的增强。因此，顺铂耐药细胞对 PARP 抑制剂 (PARPi) 单一疗法的耐药性更强。此外，当PARPi与顺铂联合给药时，它发挥了相加/协同作用，并减少了细胞毒性的顺铂剂量。这些结果表明顺铂难治性患者的治疗可能受益于低剂量顺铂联合PARPi的治疗。
Germ cell tumors are a model of curable solid tumors due to their unique sensitivity to cisplatin-based chemotherapy. Patients are typically young adults, and despite high cure rate, about 20% of them do not achieve remission or relapse, and 50% of them succumb to the disease. The mechanisms behind their resistance to therapy are largely unknown. By using Testicular Germ Cell Tumor (TGCT) cell lines as a model, we investigated the mechanism of acquired resistance to cisplatin. We demonstrated that resistance occurred by a fine modulation of the DNA repair pathway choice. Namely, in resistant cells, repair of double-strand breaks by non-homologous end joining was dampened by the reduced expression of TP53-binding protein 1 (53BP1) and DNA-dependent protein kinase (DNA-PKcs). However, cisplatin-induced damage was repaired efficiently by homologous recombination. Additionally, we demonstrate that pharmacological inhibition of poly (ADP-ribose) polymerase (PARP) combined with cisplatin had an additive/synergistic effect on cisplatin-resistant cells, which represents the proof of concept for introducing PARP inhibitors in salvage therapy. Despite germ cell tumors (GCTs) responding to cisplatin-based chemotherapy at a high rate, a subset of patients does not respond to treatment and have significantly worse prognosis. The biological mechanisms underlying the resistance remain unknown. In this study, by using two TGCT cell lines that have acquired cisplatin resistance after chronic exposure to the drug, we identified some key proteins and mechanisms of acquired resistance. We show that cisplatin-resistant cell lines had a non-homologous end-joining (NHEJ)-less phenotype. This correlated with a reduced basal expression of TP53-binding protein 1 (53BP1) and DNA-dependent protein kinase (DNA-PKcs) proteins and reduced formation of 53BP1 foci after cisplatin treatment. Consistent with these observations, modulation of 53BP1 protein expression altered the cell line’s resistance to cisplatin, and inhibition of DNA-PKcs activity antagonized cisplatin cytotoxicity. Dampening of NHEJ was accompanied by a functional increase in the repair of DNA double-strand breaks (DSBs) by the homologous recombination repair pathway. As a result, cisplatin-resistant cells were more resistant to PARP inhibitor (PARPi) monotherapy. Moreover, when PARPi was given in combination with cisplatin, it exerted an additive/synergistic effect, and reduced the cisplatin dose for cytotoxicity. These results suggest that treatment of cisplatin-refractory patients may benefit from low-dose cisplatin therapy combined with PARPi.
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影响因子：
6.2
作者：
Ghazarian AA;Kelly SP;Altekruse SF;Rosenberg PS;McGlynn KA
通讯作者：
McGlynn KA
由 53BP1-RIF1 和 BRCA1-CtIP 组成的细胞周期依赖性调节回路控制 DNA 修复途径的选择。
影响因子：
16
作者：
Escribano-Diaz, Cristina;Orthwein, Alexandre;Durocher, Daniel
通讯作者：
Durocher, Daniel
影响因子：
0.7
作者：
Cavallo, Francesca;Feldman, Darren R.;Barchi, Marco
通讯作者：
Barchi, Marco
影响因子：
16
作者：
Bunting, Samuel F.;Callen, Elsa;Kozak, Marina L.;Kim, Jung Min;Wong, Nancy;Lopez-Contreras, Andres J.;Ludwig, Thomas;Baer, Richard;Faryabi, Robert B.;Malhowski, Amy;Chen, Hua-Tang;Fernandez-Capetillo, Oscar;D'Andrea, Alan;Nussenzweig, Andre
通讯作者：
Nussenzweig, Andre
影响因子：
37.3
作者：
Koul, Sanjay;Houldsworth, Jane;Murty, Vundavalli V
通讯作者：
Murty, Vundavalli V