北京大学学报（医学版）2018，Vol.50Issue(2)：318-325,8.DOI:10.3969/j.issn.1671-167X.2018.02.019
拓扑异构酶抑制剂通过ATM/ATR和NF-κB途径上调乳腺癌细胞MICA/B的表达
Topoisomerase inhibitor upregulates MICA/B expression in breast cancer cells through ATM/ATR and NF-κB pathway
摘要
Abstract
Objective:To investigate the effects of chemotherapeutic agents widely used in clinical practice on major histocompatibility complex class Ⅰ-related chain A and B (MICA/B) expression in breast cancer cells,and to explore the molecular mechanisms involved.Methods:We examined MICA/B mRNA and surface protein expressions in breast cancer cells treated with chemotherapeutic agents by real-time RT-PCR and flow cytometry respectively.The blocking effects of ataxia telangiectasia mutated and Rad3-related kinase (ATM/ATR) inhibitor caffeine and nuclear factor κB (NF-κB) inhibitor pynolidine dithiocarbamate (PDTC) on etoposide-upregulated MICA/B mRNA and surface protein expressions were investigated.Electrophoretic mobility shift assay (EMSA) was taken to investigate whether etoposide enhanced the binding of NF-κB to MICA/B gene promoter.Results:Three topoisomerase inhibitors etoposide,camptothecin and doxorubicine upregulated MICA and MICB mRNA expressions in breast cancer cell MCF-7.Comparing to no-drug-treated cells,MICA mRNA levels increased to (1.68 ±0.17),(2.54±0.25) and (3.42±0.15) fold,and levels of MICB mRNA increased to (1.82±0.24),(1.56 ± 0.05) and (5.84 ± 0.57) fold respectively in cancer cells treated by etoposide at the concentrations of 5,20 and 100 μmol/L (P ＜ 0.05).MICA and MICB mRNA levels also increased significantly when MCF-7 cells were incubated with camptothecin or doxorubicine at the specific concentrations (P ＜ 0.05).MICB mRNA expression also increased slightly in another breast cancer cell SK-BR-3 treated by topoisomerase Ⅱ inhibitors etoposide and camptothecin (P ＜ 0.05).Furthermore,etoposide and camptothecin upregulated MICA/B surface protein expression in MCF-7 cells (P ＜ 0.05),and the upregulation was found in both living and apoptotic cells.Our study showed that etoposide induced-MICA/B expression in MCF-7 was inhibited by caffeine at different concentrations.When cancer cells were treated by caffeine with 1,5 and 10 mmol/L,MICA mRNA levels decreased from (3.75 ± 0.25) to (0.89±0.05),(0.81 ±0.02) and (0.48 ±0.04) fold respectively (P ＜0.001),and MICB mRNA levels decreased from (6.85 ± 0.35) to (1.36 ± 0.13),(0.76 ± 0.06) and (0.56 ± 0.03) fold (P ＜0.05),while MICA/B protein levels decreased from (3.42 ± 0.05) to (1.32 ± 0.03),(1.21 ± 0.06)and (1.14 ± 0.03) fold (P ＜ 0.001),indicating that etoposide-induced MICA/B expression was inhibited by ATM/ATR inhibitor.Similarly,NF-κB inhibitor PDTC also inhibited MICA/B mRNA and protein expressions induced by etoposide significantly when MCF-7 cells were incubated with PDTC at the concentrations of 10,50 and 100 μmol/L (P ＜ 0.05),indicating that NF-κB was also involved in this process.EMSA showed that the binding of NF-κB to MICA/B promoter enhanced in MCF-7 cells after etoposide treatment.Conclusion:Topoisomerase inhibitor increased MICA/B mRNA and protein expressions in breast cancer cells,indicating that chemotherapeutic agents might increase the recognizing and killing ability of immunocytes to breast cancer cells.ATM/ATR and NF-κB pathways might be involved in it.关键词
拓扑异构酶抑制剂/MHC Ⅰ类链相关分子A/B/毛细血管扩张性共济失调突变蛋白/毛细血管扩张性共济失调Rad3相关激酶/NF-κB/乳腺肿瘤Key words
Topoisomerase inhibitors/MHC class Ⅰ-related chain A/B/Ataxia telangiectasia mutated proteins/Ataxia telangiectasia and Rad3-related kinase/NF-kappa B/Breast neoplasms分类
医药卫生引用本文复制引用
朱燕,石永进,赵玉亮,朱平..拓扑异构酶抑制剂通过ATM/ATR和NF-κB途径上调乳腺癌细胞MICA/B的表达[J].北京大学学报（医学版）,2018,50(2):318-325,8.基金项目
国家自然科学基金(81370612)和国家自然科学青年基金(81102211)资助 Supported by the National Natural Science Foundation of China (81370612) and the National Natural Science Yong Scholar Foundation of China (81102211) （81370612）
