NRAGE影响人食管癌细胞放射抗性的作用及其机制研究

背景与目的：食管癌是全球威胁人类生命和健康的常见恶性肿瘤之一，中国每年食管癌发病人数占全球发病总人数的一半以上，以食管鳞癌最为常见。放疗是食管癌三大治疗手段之一，而放射抗性是导致其治疗失败的主要原因。神经营养因子受体相互作用MAGE类药物（neurotrophin receptor-interacting MAGE homolog，NRAGE）在放射抗性细胞株TE13R120中表达量明显高于亲本TE13细胞，且NRAGE亚细胞定位变化可能参与食管癌细胞放射抗性的形成。通过基因转染构建NRAGE稳定表达的食管癌细胞系，以进一步明确NRAGE基因与食管鳞癌细胞放射抗性的关系，分析该基因影响放射抗性的具体机制。方法：通过基因转染构建NRAGE稳定表达的食管癌细胞系。采用细胞克隆形成实验检测细胞放射敏感性，采用流式细胞术检测细胞周期及凋亡；细胞划痕、Transwell侵袭实验检测细胞迁移、侵袭能力，采用实时荧光定量聚合酶链反应（real-time fluorescence quantitive polymerase chain reaction，RTFQ-PCR）和蛋白质印迹法（Western blot）检测细胞中β-catenin表达情况。组间差异采用t检验或方差分析。结果：实验分为转染过表达组（Eca109/NRAGE组）和空白对照组（Eca109组）。Eca109/NRAGE细胞中NRAGE的表达量明显高于Eca109（t=29.65，P<0.05）。照射后Eca109/NRAGE细胞的放射抗性显著高于Eca109。流式细胞术检测结果显示，Eca109/NRAGE细胞中对射线抵抗性最强的S期细胞比例增加，对射线最敏感的G ₂ /M期减少。Eca109/NRAGE细胞凋亡率较Eca109细胞降低（t=3.268，P<0.05）。Eca109/NRAGE细胞迁移和侵袭能力均高于Eca109。RTFQ-PCR和Western blot检测结果显示，β-catenin的mRNA表达及蛋白水平在Eca109/NRAGE细胞中明显高于Eca109（t=15.87，P<0.05）。结论：NRAGE参与Eca109细胞放射抗性的形成，改变细胞的细胞周期分布和凋亡情况，影响细胞迁移及侵袭能力并可能影响食管癌细胞的放射敏感性，该作用可能与激活Wnt/β-catenin信号转导通路有关。     

鼻咽癌细胞辐射抗拒的比较蛋白质组学分析

目的 通过分离并鉴定具有不同辐射抗拒的人鼻咽癌细胞株CNE-2R与CNE-2的差异表达蛋白,探讨与鼻咽癌细胞辐射抗拒相关的分子机制.方法 分别提取鼻咽癌辐射抗拒细胞株CNE-2R及其亲本细胞株CNE-2的总蛋白,采用双向凝胶电泳分离,经软件分析识别差异表达蛋白点,应用基质辅助激光解析电离飞行时间串联质谱技术(MALDI-TOF-MS)鉴定差异蛋白质.结果 两种不同辐射敏感性的鼻咽癌细胞株CNE-2R和CNE-2中,共筛选出差异表达明显的蛋白质点有32个,其中11个蛋白质被鉴定成功,在CNE-2R中上调的蛋白有3个,下调的蛋白有8个.结论 不同辐射敏感性的鼻咽癌细胞的差异表达蛋白,主要涉及调节凋亡、DNA损伤与修复、细胞周期调控、RNA转录、细胞信号转导、细胞骨架组成及辐射应激反应等多个方面.     

miR-193a-3p在食管癌细胞放射抵抗作用的初步研究

目的 探讨miR-193a-3p在食管鳞癌放射耐受性机制中的作用。方法 通过6 MV X射线对4个食管癌细胞系进行照射,采用MTT法检测出相对敏感系及耐受系细胞;茎环引物实时定量PCR法检测miR-193a-3p、miR-155、miR-22-3p在2个细胞中的表达,miR-193a-3p作为表达差异较为明显的microRNA被挑选进行下一步研究。分别合成并转染miR-193a-3p的mimic (3PM)或 antagomiR (3PA)序列及小干扰RNA (si-LOXL4)以提高或抑制其在细胞中的表达水平,MTT法和流式细胞分析术检测miR-193a-3p及其下游基因LOXL4对于放射敏感性的影响。结果 筛选出相对放射敏感细胞系(KYSE510)及耐受细胞系(KYSE410);miR-193a-3p在两系细胞中的表达水平差异显著高于miR-155、miR-22-3p (1.00:21.13);KYSE510细胞中转染mimic提高其表达后,与对照组相比,其放射敏感性降低,细胞凋亡比例显著下降11.10%(P<0.05),而KYSE410细胞中转染antagomiR后,其敏感性增加(P<0.05)。作为miR-193a-3p的下游基因,LOXL4的表达抑制也受到miR-193a-3p的调控,转染si-LOXL4降低其表达,与对照组相比放射敏感性也降低,细胞凋亡比例下降7.07%(P<0.05)。结论 miR-193a-3p可能通过调控基因LOXL4促进食管癌细胞放射耐受性。     

MTDH促进头颈鳞癌细胞放疗抵抗的实验研究

目的探讨星形胶质细胞上调基因1（astrocyte elevated gene 1,AEG 1,又称MTDH）对头颈部鳞状细胞癌（简称头颈鳞癌）放疗抵抗的影响。方法Western blotting检测放射线照射后头颈鳞癌细胞MTDH蛋白表达的改变。通过脂质体转染的MTDH cDNA和慢病毒介导的MTDH shRNA,分别在不同头颈鳞癌细胞中过表达和抑制MTDH,平板集落形成实验检测头颈鳞癌细胞放疗抵抗能力的改变,细胞免疫荧光染色检测DNA双链损伤指标γH2AX的表达。结果MTDH在头颈鳞癌细胞中的表达随着放射性照射剂量的增加和时间的延长逐渐升高。在CNE 2细胞中过表达MTDH,其体外集落形成能力增强;相反,在Tu686细胞中抑制MTDH的表达,其体外集落形成能力减弱。同时,细胞免疫荧光显示Tu686细胞在MTDH抑制后,其DNA双链损伤指标γH2AX的表达增加,表明DNA双链损伤修复过程受阻。结论MTDH能促进头颈鳞癌细胞放疗抵抗的形成,与其对DNA双链损伤修复的调控作用相关。     

Derris scandens Benth extract potentiates radioresistance of Hep-2 laryngeal cancer cells

The use of herbal products as radiosensitizers is a promising approach to increase the efficacy of radiotherapy. However, adverse effects related to the use of herbal medicine on radiotherapy are not well characterized. The present study concerns the impact of Derris scandens Benth extract on the radiosensitivity of Hep-2 laryngeal cancer cells. Pretreatment with D. scandens extract prior to gamma irradiation significantly increased clonogenic survival and decreased the proportion of radiation-induced abnormal nuclei of Hep-2 cells. Furthermore, the extract was found to enhance radiation-induced G2/M phase arrest, induce Akt activation, and increase motility of Hep-2 cells. The study thus indicated that D. scandens extract potentiates radioresistance of Hep-2 cells, further demonstrating the importance of cellular background for the adverse effect of D. scandens extract on radiation response in a laryngeal cancer cell line.     

miR-206 enhances nasopharyngeal carcinoma radiosensitivity by targeting IGF1

Radioresistance remains a major problem in nasopharyngeal carcinoma (NPC) treatment. However, the underlying molecular mechanisms of NPC radioresistance remain poorly understood. The present study aimed to investigate the potential role and mechanism of miR-206 in NPC radioresistance. We observed that miR-206 was down-regulated in radioresistant NPC cells. Furthermore, restoration of miR-206 in CNE2-IR cells suppressed enhanced radiosensitivity of NPC cells. In contrast, inhibition of miR-206 in CNE2 cells reduced the radiosensitivity. We also found that miR-206 directly targeted IGF1 and inhibited the PI3K/AKT pathway. Our data demonstrate that miR-206 sensitizes NPC cell to irradiation by targeting IGF1, highlighting the therapeutic potential of miR-206 in NPC radiosensitization.     

新型单羰基姜黄素衍生物B06对不同辐射抗拒鼻咽癌细胞的抑制作用

目的研究姜黄素及其单羰基结构衍生物B06对不同辐射抗拒鼻咽癌细胞株CNE-2与CNE-2R的作用。方法以MTr法检测姜黄素和B06对细胞增殖的影响。以流式细胞仪检测姜黄素和B06对细胞凋亡的影响,以Western-blot检测姜黄素和B06对ERS通路相关蛋白的影响。结果姜黄素对CNE-2和CNE-2R的IC50分别为8．35灿M和6．84μM,B06对CNE-2和CNE-2R的IC50分别为1．09μM和0．74μM。B06能激活CNE-2R细胞ERS通路中关键蛋白CHOP、XBP-1、ATF-4的表达,而姜黄素则不能激活其表达。结论新型单羰基姜黄素衍生物B06能更显著地抑制辐射抗拒鼻咽癌细胞的增殖,该作用机制很可能是通过ERS通路发挥,提示B06具有抑制辐射抗拒鼻咽癌细胞的潜在价值。     

miR-183 promotes radioresistance of lung adenocarcinoma H1299 cells via epithelial-mesenchymal transition

Lung adenocarcinomas are usually sensitive to radiation therapy, but some develop resistance. Radiation resistance can lead to poor patient prognosis. Studies have shown that lung adenocarcinoma cells (H1299 cells) can develop radioresistance through epithelial-mesenchymal transition (EMT), and this process is regulated by miRNAs. However, it is unclear which miRNAs are involved in the process of EMT. In our present study, we found that miR-183 expression was increased in a radioresistant lung adenocarcinoma cell line (H1299R cells). We then explored the regulatory mechanism of miR-183 and found that it may be involved in the regulation of zinc finger E-box-binding homeobox 1 (ZEB1) expression and mediate EMT in lung adenocarcinoma cells. qPCR results showed that miR-183, ZEB1, and vimentin were highly expressed in H1299R cells, whereas no difference was observed in E-cadherin expression. Western blot results showed that ZEB1 and vimentin were highly expressed in H1299R cells, while E-cadherin expression was decreased. When miR-183 expression was inhibited in H1299R cells, radiation resistance, proliferation, and cell migration were decreased. The expression of ZEB1 and vimentin in H1299R cells was decreased, while the expression of E-cadherin was increased. Moreover, miR-183 overexpression in H1299 cells enhanced radiation resistance, proliferative capacity, and cell migration ability. The expression of ZEB1 and vimentin in H1299 cells was increased, while that of E-cadherin was decreased. In conclusion, miR-183 may promote EMT and radioresistance in H1299 cells, and targeting the miR-183-ZEB1 signaling pathway may be a promising approach for lung cancer treatment.