PO.ET06.03 · 实验与分子治疗
拓展TXNRD抑制剂治疗三阴性乳腺癌的治疗潜力
Expanding the therapeutic potential of TXNRD inhibitors for triple-negative breast cancer
作者与单位 Authors & Affiliations
摘要 Abstract
中文摘要
三阴性乳腺癌（TNBC）在所有乳腺癌亚型中5年生存率最低，对于许多患者而言，标准治疗仅限于多药化疗方案。因此，有必要探索更佳的治疗靶点和策略。我们此前证明，硫氧还蛋白还原酶1（TXNRD1）和硫氧还蛋白还原酶2（TXNRD2）水平升高与TNBC较低的无复发生存期和总生存期相关，两者均为TNBC的相关靶点。我们开发了新型非共价TXNRD抑制剂（TXNRD(i)s），通过荧光生化分析和TXNRD相关基因的qPCR证明，其在TNBC模型中成功抑制TXNRD1和TXNRD2。此外，这些TXNRD(i)s在体外和体内TNBC模型中对侵袭性表型显示出多效性抗癌活性。TXNRD(i)s处理可降低TNBC模型中的2D细胞活力、乳腺球形成、胶原侵袭和原发异种移植瘤生长。机制上，我们鉴定出由TXNRD(i)s引起的核糖核苷酸还原酶（RNR）功能障碍。鉴于RNR提供dNTP——DNA合成和修复的构建单元——这引出了TXNRD(i)s诱导DNA损伤和复制应激的假说。此外，这一效应被聚（ADP-核糖）聚合酶（PARP）抑制所加剧，在BRCA野生型TNBC细胞系中产生协同效应。使用COMET和复制叉停滞（fork stall）分析、显微镜和Western blot，我们得出结论：存在TXNRD(i)s诱导的复制应激和DNA损伤的证据，并通过对模型细胞系可诱导性敲低TXNRD1和TXNRD2的遗传学方法，验证了抑制剂作用于靶点。将TXNRD(i)s与奥拉帕利（Olaparib）联合使用，我们在BRCA野生型TNBC模型中观察到两种抑制剂的协同效应。我们的TXNRD(i)s与PARP抑制剂在BRCA野生型TNBC细胞系中所显示的协同作用，既拓展了我们TXNRD(i)s的治疗潜力，也为PARP抑制剂适应症的扩展开辟了可能性。
查看英文原文 English abstract
Triple negative breast cancer (TNBC) has the lowest 5-year survival of all breast cancersubtypes, and for many patients the standard of care is limited to a multiagent chemotherapyregimen. Therefore, there is a need to explore improved therapeutic targets and strategies. We havepreviously demonstrated that elevated levels of both thioredoxin reductase 1 (TXNRD1) andthioredoxin reductase 2 (TXNRD2) correlates with lower recurrence-free and overall survival inTNBC and are both relevant targets for TNBC.We have developed new non-covalent TXNRD inhibitors (TXNRD(i)s) that successfullyinhibit TXNRD1 and TXNRD2 in TNBC models as demonstrated through fluorescent biochemicalassays and qPCR of TXNRD related genes. Additionally, these TXNRD(i)s show pleiotropic anti-cancer activity against aggressive phenotypes in both in vitro and in vivo TNBC models. Treatmentwith TXNRD(i)s reduces 2D viability, mammosphere formation, collagen invasion, and primaryxenograft growth in TNBC models.Mechanistically, we have identified ribonucleotide reductase (RNR) dysfunction causedby our TXNRD(i)s. Given that RNR provides dNTPs, the building block for both DNA synthesisand repair, this led to the hypothesis that TXNRD(i)s induce DNA damage and replicative stress.Furthermore, this is aggravated by poly (ADP-ribose) polymerase (PARP) inhibition, leading toa synergistic effect in BRCA wild-type TNBC cell lines. Using COMET and fork stall assays,microscopy, and western blotting, we concluded there is evidence of replicative stress and DNAdamage induced by our TXNRD(i)s and validated the inhibitors are acting on target by using agenetic approach with inducible TXNRD1 and TXNRD2 knockdowns of our model cell line.Using our TXNRD(i)s in combination with Olaparib, we observed synergistic effects with the twoinhibitors in BRCA wild-type TNBC models. The synergy shown between our TXNRD(i)s andPARP inhibitors in BRCA wild-type TNBC cell lines expands the therapeutic potential of ourTXNRD(i)s as well as opening the possibility to an expansion of PARP inhibitors.
利益披露 Disclosure
B. Flowers, None..
I. Lloshi, None..
V. Petukhova, None.