Downregulation of TMPRSS4 Enhances Triple-Negative Breast Cancer Cell Radiosensitivity Through Cell Cycle and Cell Apoptosis Process Impairment.
Downregulation of TMPRSS4 Enhances Triple-Negative Breast Cancer Cell Radiosensitivity Through Cell Cycle and Cell Apoptosis Process Impairment.
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DOI：
10.31557/apjcp.2019.20.12.3679
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发表时间：
2019-12-01
期刊：
影响因子：
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通讯作者：
Zhou, Yunfeng
中科院分区：
文献类型：
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作者：
Assani, Ganiou;Segbo, Julien;Zhou, Yunfeng
背景：放射抗性仍然是癌症放射治疗的一个挑战。本研究旨在探讨TMPRSS4在三阴性乳腺癌（TNBC）细胞放射敏感性中的作用。 材料与方法：慢病毒载体转染MDA-MD-468三阴性乳腺癌细胞系后，通过克隆实验和CCK-8实验评估TMPRSS4下调对TNBC细胞放射敏感性的影响。 CCK-8 测定也用于进行细胞增殖分析。 Western blot检测细胞周期通路（cyclin D1）、细胞凋亡通路（Bax、Bcl2、Caspase3）、DNA损伤及DNA损伤修复（TRF2、Ku80、ˠH2AX）等相关蛋白的表达情况。流式细胞仪分析细胞周期和细胞凋亡。结果：MDA-MB-468细胞中TMPRSS4表达下调，增强MDA-MB-468细胞的放射敏感性。 TMPRSS4 沉默还改善了 IR 诱导的细胞增殖能力降低，并促进细胞停滞在与细胞周期蛋白 D1 表达抑制相关的 6 Gy IR 介导的 G2/M 期。此外，TMPRSS4 抑制增强了 6 Gy IR 诱导的 TNBC 细胞凋亡，随后分别过表达促凋亡蛋白和抗凋亡蛋白（Bax、Caspase3）和下调 Bcl2。另外，TMPRSS4 下调会增加 6 Gy IR 诱导的 DNA 损伤，并延迟 DNA 损伤修复，分别表现为 IR 后 1 小时和 10 小时 TRF2 下调以及 Ku80 和 ˠH2AX 表达永久增加。结论：TMPRSS4 下调增加三阴性乳腺癌细胞放射敏感性，可鼓励使用 TMPRSS4 抑制剂来提高 TNBC 放射抵抗患者的放疗效果。
BACKGROUND: Radioresistance remains a challenge for cancer radiotherapy. The present study aims to investigate the role of TMPRSS4 in triple negative breast cancer (TNBC) cell radiosensitivity.MATERIALS AND METHODS: After transfection of MDA-MD-468 triple negative breast cancer cells line by using the lentivirus vector, the effect of TMPRSS4 down-regulation on TNBC radiosensitivity was evaluated by using cloning assay and CCK-8 assay. The CCK-8 assay was also used for performing cell proliferation analysis. Western blot was carried out to detect the expression of certain proteins related to cell cycle pathways (cyclin D1), cell apoptosis pathways (Bax, Bcl2, and Caspase3), DNA damage and DNA damage repair (TRF2, Ku80 , ˠH2AX) . The cell cycle and cell apoptosis were also investigated using flow cytometer analysis.RESULTS: TMPRSS4 expression was down-regulated in MDA-MB-468 cells which enhanced MDA-MB-468 cells radiosensitivity. TMPRSS4 silencing also improved IR induced cell proliferation ability reduction and promoted cell arrested at G2/M phase mediated by 6 Gy IR associated with cyclin D1 expression inhibition. Moreover, TMPRSS4 inhibition enhanced TNBC apoptosis induced by 6 Gy IR following by over-expression of (Bax, Caspase3) and down-regulation of Bcl2 as the pro-apoptotic and anti-apoptotic proteins, respectively. Otherwise, TMPRSS4 down-regulation increases DNA damage induced by 6 Gy IR and delays DNA damage repair respectively illustrated by downregulation of TRF2 and permanent increase of Ku80 and ˠH2AX expression at 1 h and 10 h post-IR.CONCLUSION: Down-regulation of TMPRSS4 increases triple negative breast cancer cell radiosensitivity and the use of TMPRSS4 inhibitor can be encouraged for improving radiotherapy effectiveness in TNBC radioresistant patients.