Background and Aims: Topoisomerase I (TOP1) partici-pates the repair of DNA double-strand breaks (DSBs) upon radiation therapy (RT). RNF144A mediates ubiquitination of catalytic subunit of DNA protein kinase (DNA-PKcs...Background and Aims: Topoisomerase I (TOP1) partici-pates the repair of DNA double-strand breaks (DSBs) upon radiation therapy (RT). RNF144A mediates ubiquitination of catalytic subunit of DNA protein kinase (DNA-PKcs), a critical factor in DSB repair. This study aimed to investigate the natural killer (NK) cell-mediated radiosensitization with TOP1 inhibition and the mechanism by DNA-PKcs/RNF144A. Methods: In vitro synergism with TOP1i or cocultured NK cells and RT were evaluated in human hepatocellular car-cinoma (HCC) cell lines (Huh7/PLC5) by clonogenic surviv-als. Orthotopic xenografts were treated with Lipotecan and/or RT. Protein expression was analyzed by western blotting, immunoprecipitation, subcellular fractionation, and confocal microscopy. Results: Lipotecan/RT had a superior synergis-tic effect to RT on HCC cells. Combined RT/Lipotecan reduced the xenograft size by 7-fold than RT (p<0.05). Lipotecan caused more radiation-induced DNA damage and DNA-PKcs signaling. The expression of major histocompatibility com-plex class I-related chain A and B (MICA/B) on tumor cells is associated with the sensitivity to NK cell-mediated lysis. Cocultured NK and HCC cells with Lipotecan radiosensitized HCC cells/tissues with the expression of MICA/B. RNF144A increased more in Huh7 cells with combined RT/TOP1i, and reduced the prosurvival function of DNA-PKcs. The effect was reversed by inhibiting the ubiquitin/proteasome system. In comparison, RNF144A decreased through nuclear transloca-tion with the cumulated DNA-PKcs and radio-resistance of PLC5 cells. Conclusions: TOP1i reinforces NK cell-activated anti-HCC effect of RT through RNF144A mediated DNA-PKcs ubiquitination. RNF144A provides a reason for differentiating radiosensitization effect between HCC cells.展开更多
目的:探讨环指蛋白144B(ring finger protein 144B,RNF144B)在胃癌组织中的表达水平及其与胃癌患者临床预后的关系。方法:回顾性分析2013年1月-2014年1月在兰州大学第二医院确诊并行根治性手术治疗的胃癌患者的临床资料;我们的研究一共...目的:探讨环指蛋白144B(ring finger protein 144B,RNF144B)在胃癌组织中的表达水平及其与胃癌患者临床预后的关系。方法:回顾性分析2013年1月-2014年1月在兰州大学第二医院确诊并行根治性手术治疗的胃癌患者的临床资料;我们的研究一共纳入了105名患者,记录患者的TNM分期、肿瘤大小、分化水平、癌胚抗原(carcino-embryonic antigen,CEA)等指标并记录患者的总体生存时间(overall survival,OS);利用免疫组织化学染色(immunohistochemistry,IHC)检测RNF144B在胃癌及癌旁组织中的表达,并分析其与患者一般临床病理特征的联系;应用Cox回归模型评估患者术后总体生存时间的影响因素;使用Kaplan-Meier Plotter数据库对RNF144B进行生存相关性分析,随后利用临床数据进行验证。结果:RNF144B在胃癌组织中显著高表达(P=0.0039),RNF144B高表达组的患者CEA水平、Ki67阳性率、临床病理分期、T分期均显著高于低表达组,而分化程度差于低表达组(P<0.05);多因素分析显示RNF144B高表达、肿瘤分化程度低、临床病理分期高均是影响胃癌患者术后总体生存时间的独立因素(P<0.05);Kaplan-Meier法分析得RNF144B高表达组术后5年生存率(6.06%)低于低表达组(29.69%)(P<0.01)。结论:RNF144B在胃癌中高表达并标志着更差的临床预后。展开更多
基金National Taiwan University Hospi-tal(NTUH 106-M3649,107-M4030,108-M4213,109-M4767 and 110-M5149)the Ministry of Science and Technology of Taiwan(MOST 106-2314-B-002-063-,107-2314-B-002-097-and 108-2314-B-002-046-).
文摘Background and Aims: Topoisomerase I (TOP1) partici-pates the repair of DNA double-strand breaks (DSBs) upon radiation therapy (RT). RNF144A mediates ubiquitination of catalytic subunit of DNA protein kinase (DNA-PKcs), a critical factor in DSB repair. This study aimed to investigate the natural killer (NK) cell-mediated radiosensitization with TOP1 inhibition and the mechanism by DNA-PKcs/RNF144A. Methods: In vitro synergism with TOP1i or cocultured NK cells and RT were evaluated in human hepatocellular car-cinoma (HCC) cell lines (Huh7/PLC5) by clonogenic surviv-als. Orthotopic xenografts were treated with Lipotecan and/or RT. Protein expression was analyzed by western blotting, immunoprecipitation, subcellular fractionation, and confocal microscopy. Results: Lipotecan/RT had a superior synergis-tic effect to RT on HCC cells. Combined RT/Lipotecan reduced the xenograft size by 7-fold than RT (p<0.05). Lipotecan caused more radiation-induced DNA damage and DNA-PKcs signaling. The expression of major histocompatibility com-plex class I-related chain A and B (MICA/B) on tumor cells is associated with the sensitivity to NK cell-mediated lysis. Cocultured NK and HCC cells with Lipotecan radiosensitized HCC cells/tissues with the expression of MICA/B. RNF144A increased more in Huh7 cells with combined RT/TOP1i, and reduced the prosurvival function of DNA-PKcs. The effect was reversed by inhibiting the ubiquitin/proteasome system. In comparison, RNF144A decreased through nuclear transloca-tion with the cumulated DNA-PKcs and radio-resistance of PLC5 cells. Conclusions: TOP1i reinforces NK cell-activated anti-HCC effect of RT through RNF144A mediated DNA-PKcs ubiquitination. RNF144A provides a reason for differentiating radiosensitization effect between HCC cells.
