雌二醇增加拓扑异构酶 IIβ介导的 DNA 链断裂，从而引发 Xp11.2 易位性肾细胞癌。

Estradiol increases risk of topoisomerase IIβ-mediated DNA strand breaks to initiate Xp11.2 translocation renal cell carcinoma.

机构信息

Department of Urology, Affiliated Drum Tower Hospital, Medical School of Nanjing University, Nanjing, Jiangsu, China.

Department of Urology, Nanjing First Hospital, Nanjing Medical University, Nanjing, Jiangsu, China.

出版信息

Cell Commun Signal. 2021 Nov 16;19(1):114. doi: 10.1186/s12964-021-00790-3.

DOI:10.1186/s12964-021-00790-3

PMID:34784933

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC8594210/

Abstract

BACKGROUND

Xp11.2 translocation renal cell carcinoma (tRCC) is defined by translocation of the transcription factor E3 (TFE3) gene located on chromosome Xp11.2. Due to the high incidence in women, 17β-estradiol (E2) may be a factor influencing TFE3 breaks, and the topoisomerase II (TOP2) poison is considered one of the important risk factors in mediating DNA breaks. In this study, we investigated the potential pathogenesis of Xp11.2 tRCC using the renal epithelial cell line HK-2.

METHODS

Immunofluorescence assay was performed to analyze DNA breaks by quantifying phosphorylation of H2AX (γH2AX), and the micronuclei (MN) assay was designed for monitoring chromosome breaks. The chromatin immunoprecipitation (CHIP) was used to detect whether proteins bound to specific DNA site, and the co-immunoprecipitation (Co-IP) was used to confirm whether proteins bound to other proteins. In some experiments, siRNA and shRNA were transfected to knockdown target genes.

RESULTS

Our results demonstrated that DNA double-strand breaks were mediated by TOP2β in HK-2 cells, and this process could be amplified through estrogen receptor α (ERα)-dependent pathway induced by E2. After performing translocation site analysis using target region sequencing data in two Xp11.2 tRCC cell lines and ten Xp11.2 tRCC patients, we confirmed that TOP2β and ERα could both bind to TFE3 translocation sites directly to mediate DNA breaks in a E2-dependent manner. However, TOP2β and ERα were not observed to have direct interaction, indicating that their collaborative may be implemented in other ways. Besides, TFE3 was found to be upregulated through NRF1 with increasing E2 concentration, which could increase the risk of TFE3 breaks.

CONCLUSION

Our results indicate that E2 amplifies TOP2β-mediated TFE3 breaks by ERα-dependent pathway, and E2 upregulates TFE3 by NRF1 to increase the risk of TFE3 breaks. This suggests that E2 is an important pathogenic factor for Xp11.2 tRCC pathogenesis. Video Abstract.

摘要

背景

Xp11.2 易位性肾细胞癌（tRCC）的定义是转录因子 E3（TFE3）基因位于 Xp11.2 染色体上的易位。由于女性发病率较高，17β-雌二醇（E2）可能是影响 TFE3 断裂的一个因素，拓扑异构酶 II（TOP2）毒物被认为是介导 DNA 断裂的重要危险因素之一。在这项研究中，我们使用肾上皮细胞系 HK-2 研究了 Xp11.2 tRCC 的潜在发病机制。

方法

通过定量检测 H2AX（γH2AX）的磷酸化来进行免疫荧光分析以检测 DNA 断裂，设计微核（MN）测定法监测染色体断裂。使用染色质免疫沉淀（CHIP）检测是否有蛋白结合到特定的 DNA 位点，并用共免疫沉淀（Co-IP）来确认是否有蛋白结合到其他蛋白上。在一些实验中，转染 siRNA 和 shRNA 以敲低靶基因。

结果

我们的结果表明，TOP2β 在 HK-2 细胞中介导了 DNA 双链断裂，并且这个过程可以通过雌激素受体 α（ERα）依赖性途径放大，该途径由 E2 诱导。在对两个 Xp11.2 tRCC 细胞系和十个 Xp11.2 tRCC 患者的靶区测序数据进行易位位点分析后，我们证实 TOP2β 和 ERα 都可以直接结合到 TFE3 易位位点，以依赖 E2 的方式介导 DNA 断裂。然而，没有观察到 TOP2β 和 ERα 之间有直接相互作用，这表明它们的协作可能以其他方式实施。此外，随着 E2 浓度的增加，NRF1 发现 TFE3 上调，这可能增加 TFE3 断裂的风险。