Inhibiting ERp29 expression enhances radiosensitivity in human nasopharyngeal carcinoma cell lines

ERp29 is an endoplasmic reticulum (ER) stress-inducible protein. It was found that ERp29 was highly expressed in several cancers and associated with resistance to oxidative and radiation stress, which may serve as a novel target for nasopharyngeal carcinoma (NPC) anticancer approach. In this study, we used immunohistochemistry to detect ERp29 expression in radioresistant and radiosensitive NPC tissues. As a result, ERp29 was up-regulated in radioresistant NPC tissues compared to radiosensitive NPC tissues. We also found that ERp29 knockdown attenuated radioresistance of NPC CNE-1 cells and ERp29 overexpression enhanced radioresistance of NPC CNE-2 cells. When exposed to radiation, ERp29 knockdown CNE-1 cells increased radiation-induced cell apoptosis and ERp29 overexpression CNE-2 cells reduced radiation-induced cell apoptosis. Further, we demonstrated that ERp29 up-regulated the expression of Hsp27. In conclusion, our study supports ERp29 could potentiate resistance to radiation in NPC cells, targeting of ERp29 is a rational strategy in treating radioresistant NPC.     

抑制Polo样激酶1对鼻咽癌细胞辐射敏感性的影响

目的:探索抑制Polo样激酶1(Polo-like kinase 1,PLK1)对鼻咽癌(nasopharyngeal carcinoma,NPC)细胞CNE-1和CNE-2辐射敏感性的影响.方法:分别运用siRNA和小分子抑制剂BI2536抑制CNE-1和CNE-2细胞内PLK1的表达或磷酸化,通过MTT法检测抑制PLK1对NPC细胞增殖能力的影响,流式细胞技术检测对细胞周期和凋亡的影响,细胞免疫荧光检测对辐射后DNA损伤位点的影响,克隆形成实验及曲线拟合计算对辐射后细胞放射生物参数和放射增敏比(sensitizationenhancement ratio,SER)的影响.结果:与对照组相比,抑制PLK1可以明显抑制NPC细胞增殖,并诱导细胞发生G2-M期阻滞和有丝分裂灾难.抑制NPC细胞PLK1联合射线辐射后,NPC细胞克隆形成能力下降(CNE-1:P ＜0.05;CNE-2:P ＜0.05),且随着BI2536浓度的增大克隆形成能力下降更加明显(CNE-1:P ＜0.05;CNE-2:P ＜0.05);细胞生存分数明显降低(均P＜0.05);核中γ-H2AX位点数目明显增加(P＜0.05);细胞凋亡率显著升高(均P＜0.05);siR-PLK1转染CNE-1和CNE-2后SER分别为1.1988和1.3198,BI2536处理CNE-1和CNE-2后SER分别为1.5508和1.2028.结论:抑制PLK1可以抑制NPC细胞增殖,诱导发生细胞周期阻滞和有丝分裂灾难,并能显著提高NPC细胞辐射敏感性.     

PNCK对鼻咽癌细胞增殖和凋亡作用的研究

目的 研究妊娠上调的非泛素性钙调蛋白激酶(Pregnancy-upregulated nonubiquitous calmodulin kinase,PNCK)在鼻咽癌组织中的表达以及对鼻咽癌细胞增殖和凋亡的作用。方法 采用免疫组织化学方法检测鼻咽癌癌组织和正常组织中PNCK表达水平。构建慢病毒载体干扰PNCK基因表达,并采用Real time PCR和免疫印迹结果证实,采用MTT方法、流式细胞术、Caspase3和Caspase7活性检测鼻咽癌肿瘤细胞增殖和凋亡的变化。结果 免疫组织化学结果显示PNCK蛋白在鼻咽癌癌组织中呈特异性高表达。Real time PCR和免疫印迹结果证实慢病毒成功干扰鼻咽癌CNE-2Z细胞中PNCK表达(PNCK基因在mRNA和蛋白水平表达受到显著抑制)。MTT检测结果显示抑制PNCK表达抑制CNE-2Z细胞增殖。此外,干扰PNCK表达引起CNE-2Z细胞Caspase3和Caspase7活性上升,流式细胞术表明干扰PNCK基因表达可以促进CNE-2Z细胞凋亡。结论 干扰PNCK基因表达抑制鼻咽癌细胞增殖并诱导肿瘤细胞凋亡,可能是治疗鼻咽癌的潜在靶点。     

Downregulation of lncRNA ANRIL inhibits proliferation,induces apoptosis,and enhances radiosensitivity in nasopharyngeal carcinoma cells through regulating miR-125a

Increasing evidence demonstrated that long non-coding RNA ANRIL serves as a fatal oncogene in many cancers, including nasopharyngeal carcinoma (NPC). However, little is known whether ANRIL regulated NPC cell radioresistance. Quantitative real-time PCR (qRT-PCR) was performed to examine the expression of lncRNA ANRIL and miR-125a in NPC tissues and cell lines. MTT assay was conducted to measure the cell viability of CNE2 and HONE1 cells. The apoptotic rate of CNE2 and HONE1 cells was determined by flow cytometry analysis. Colony survival was determined by clonogenic assay. Luciferase reporter assay was performed to verity the direct target of miR-125a. LncRNA ANRIL was evidently elevated in NPC tissues and cell lines. ANRIL inhibition suppressed proliferation, induced apoptosis, and enhanced radiosensitivity in NPC. Moreover, ANRIL could negatively modulate miR-125a expression. Furethermore, ANRIL upregulation reserved the inhibited proliferation, induced apoptosis, and enhanced radiosensitivity triggered by miR-125a overexpression. The expression of lncRNA ANRIL was upregulated in NPC tissues and cells. Moreover, knockdown of ANRIL repressed proliferation, promoted apoptosis, and improved radiosensitivity in NPC via functioning as a miR-125a sponge.     

Identification of genes involved in radioresistance of nasopharyngeal carcinoma by integrating gene ontology and protein-protein interaction networks

Radioresistance remains one of the important factors in relapse and metastasis of nasopharyngeal carcinoma. Thus, it is imperative to identify genes involved in radioresistance and explore the underlying biological processes in the development of radioresistance. In this study, we used cDNA microarrays to select differential genes between radioresistant CNE-2R and parental CNE-2 cell lines. One hundred and eighty-three significantly differentially expressed genes (p<0.05) were identified, of which 138 genes were upregulated and 45 genes were downregulated in CNE-2R. We further employed publicly available bioinformatics related software, such as GOEAST and STRING to examine the relationship among differentially expressed genes. The results show that these genes were involved in type I interferon-mediated signaling pathway biological processes; the nodes tended to have high connectivity with the EGFR pathway, IFN-related pathways, NF-κB. The node STAT1 has high connectivity with other nodes in the protein-protein interaction (PPI) networks. Finally, the reliability of microarray data was validated for selected genes by semi-quantitative RT-PCR and Western blotting. The results were consistent with the microarray data. Our study suggests that microarrays combined with gene ontology and protein interaction networks have great value in the identification of genes of radioresistance in nasopharyngeal carcinoma; genes involved in several biological processes and protein interaction networks may be relevant to NPC radioresistance; in particular, the verified genes CCL5, STAT1-α, STAT2 and GSTP1 may become potential biomarkers for predicting NPC response to radiotherapy.     

顺铂对人鼻咽癌CNE-2Z细胞端粒酶活性和细胞周期及凋亡的影响

目的研究顺铂对人鼻咽癌CNE-2Z细胞端粒酶活性、细胞周期及凋亡的影响,以探讨顺铂诱导CNE-2Z细胞凋亡与端粒酶活性水平的关系以及顺铂诱导鼻咽癌细胞凋亡的可能机制。方法分别以不同的药物浓度作用于体外培养的CNE-2Z细胞不同的时间,用TRAP-ELISA的方法定量检测CNE-2Z细胞在顺铂处理前后的端粒酶活性水平,同步进行细胞形态观察,流式细胞仪分析细胞周期的改变并检测凋亡。结果CNE-2Z细胞端粒酶呈阳性。用不同浓度的顺铂不同的时间作用于CNE-2Z细胞,结果细胞周期被阻滞在G1期,出现细胞凋亡,下调端粒酶活性,且呈时间依赖性及剂量依赖性。结论化疗药物顺铂可能是通过改变细胞周期分布(G1期阻滞)并同时诱导细胞凋亡、下调其端粒酶活性而发挥抗癌作用的,故可将化疗前后细胞端粒酶活性的变化作为鼻咽癌化疗敏感性指标之一。     

Caspase-3在X线诱导的鼻咽癌细胞凋亡中的调控作用

目的探讨X线诱导后鼻咽癌CNE-2细胞凋亡存在形式以及Caspase-3酶活性、mRNA、蛋白的表达及相互之间的关系,拟阐明Caspase-3在X线诱导的鼻咽癌细胞凋亡中的调控及意义。方法用不同剂量X线照射鼻咽癌CNE-2细胞,于不同时间检测细胞形态学及早期细胞凋亡率变化,分别用比色法、Western blot 、RT-PCR检测Caspase-3酶活性、蛋白含量、mRNA,同时设立酶活性抑制剂AC-DEVD-CHO对照组,观察Caspase-3酶活性被阻抑后细胞凋亡及Caspase-3表达的变化。结果（1）X线照射后鼻咽癌CNE-2细胞呈典型的凋亡特征,且早期凋亡率与射线剂量、诱导时间成正比;（2） CNE-2凋亡细胞中Caspase-3酶活性明显增高,用AC-DEVD-CHO抑制Caspase-3活性后细胞的凋亡率减少,且凋亡形态学特征不明显。（3）凋亡细胞中Caspase-3 mRNA表达量未见明显升高,而蛋白在凋亡形成后则完全裂解为17kD的活性Caspase-3,在正常细胞为32kD的pro-Caspase-3。结论X线诱导后CNE-2细胞呈典型的凋亡改变。凋亡细胞中有明显的Caspase-3激活,其Caspase-3的活性增高并非源于其转录的提高,而可能是翻译后酶前体的活化。抑制鼻咽癌Caspase-3酶活性,凋亡的发生可被抑制或是延迟。     

AMIGO2通过激活PI3K/AKT/mTOR信号通路促进鼻咽癌细胞的增殖

目的：探讨Ig 样结构域 2 黏附分子（adhesion molecule with Ig like domain 2,AMIGO2）在鼻咽癌（nasopharyngeal carcinoma,NPC）细胞增殖中的作用及其机制。方法: 选用2017年9月至11月福建省肿瘤医院收集的10例NPC组织和10例正常鼻 咽黏膜上皮组织标本,以及NPC细胞系CNE-1、CNE-2、SUNE-1、 6-10B、 C666-1和人永生化鼻咽黏膜上皮细胞株NP69, 用qPCR法 检测NPC组织和细胞中AMIGO2 mRNA的表达。构建慢病毒载体干扰AMIGO2表达, 用qPCR法验证其干扰效率; 用CCK-8 法、克隆形成及流式细胞术检测干扰AMIGO2表达对NPC细胞增殖、克隆形成和凋亡的影响, 用 Western blotting 检测干扰 AMIGO2 表达对 NPC 细胞增殖及 PI3K/AKT/mTOR 信号通路相关标志蛋白表达的影响。结果: AMIGO2在NPC组织和 CNE-2和SUNE-1细胞中高表达（均P<0.01）。慢病毒AMIGO2感染后,CNE-2和SUNE-1细胞的AMIGO2干扰效率均达50%以 上。干扰AMIGO2表达,显著降低CNE-2和SUNE-1细胞增殖及克隆形成能力（均P<0.01）、明显提高细胞的凋亡率（均P<0.01）; 降低 SUNE-1 细胞中PI3K、AKT和mTOR磷酸化蛋白的表达水平 （均P<0.01）、下调survivin 和 PCNA 蛋白的表达水平（均P<0.01）。 结论：AMIGO2通过激活PI3K/AKT/mTOR信号通路促进NPC细胞增殖并抑制其凋亡,提示AMIGO2可能是NPC治疗的潜 在靶点。     

ApoG2, a novel inhibitor of antiapoptotic Bcl-2 family proteins, induces apoptosis and suppresses tumor growth in nasopharyngeal carcinoma xenografts

Nasopharyngeal carcinoma (NPC) is a common malignant tumor in South China. It has been reported that overexpression of antiapoptotic Bcl-2 family proteins in NPC has caused the lack of long-term efficacy of conventional therapies. Apogossypolone (ApoG2), a novel small-molecule inhibitor of antiapoptotic Bcl-2 family proteins, has been discovered as the optimized derivative of gossypol. In this study, we found that in NPC cells, ApoG2 totally blocked the antiapoptotic function of Bcl-2 family proteins without affecting the expression levels of these proteins. ApoG2 selectively inhibited proliferation of 3 NPC cell lines (C666-1, CNE-1 and CNE-2) that highly expressed the antiapoptotic Bcl-2 proteins. This inhibitory activity was associated with release of cytochrome c, activation of caspase-9 and caspase-3 and apoptosis of sensitive NPC cells. However, ApoG2 had no obvious inhibitory effect on NPC cell line HONE-1, which expressed antiapoptotic Bcl-2 and Bcl-xL at a low level. We further found that ApoG2 effectively suppressed tumor growth of NPC xenografts in nude mice and enhanced the antitumor effect of CDDP (cisplatin) on NPC cells in vitro and in vivo. Immunohistochemical results showed that the expression of CD31 decreased after ApoG2 treatment, which suggested inhibition of angiogenesis in NPC xenografts. Our findings strongly suggest that ApoG2 may serve as a novel inhibitor of Bcl-2 family proteins and, by targeting these proteins, may become a promising drug for the treatment of NPC.     

ShRNA-mediated silencing of the ubiquitin-specific protease 22 gene restrained cell progression and affected the Akt pathway in nasopharyngeal carcinoma

Ubiquitin-specific protease 22 (USP22) is closely related with poor prognosis of cancer patients. However, the role of USP22 expression in nasopharyngeal carcinoma (NPC) has not been determined. The main aim of this study was to determine the role of USP22 in the pathologic processes of NPC. Immunohistochemistry (IHC), western blot (WB), and real-time polymerase chain reaction (RT-PCR) were used to measure the expression of USP22 in cell lines and tissues of NPC in comparison with expression in non-cancerous cells and tissues. USP22-specific short hairpin RNA (shRNA) was used to knock down USP22 expression in the NPC cell line CNE-1 and CNE-2. Furthermore, the impact of USP22 in cellular proliferation, growth, and cell cycle were detected respectively. WB was used to determine the role of USP22 in the AKT/GSK-3/Cyclin signaling pathway. The expression levels of USP22 were remarkably higher in NPC cell lines and tissues. With cell counting and the MTS assay, cellular growth and proliferation progression of USP22 knockdown cell line was shown to be effectively restrained. The USP22 silencing both in CNE-1 and CNE-2 cells caused them to accumulate in the G0/G1 phase of the cell cycle. USP22 knockdown was also found to modulate the AKT/GSK-3/Cyclin pathway, resulting in downregulation of p-AKT, p-GSK-3β, and cyclinD1. This study suggests that USP22 plays a critical regulatory role in the pathologic processes of NPC, and that it may be a potential biological treatment target in the future.     

人鼻咽癌细胞株自发性凋亡与放射敏感性的研究

  目的   探讨鼻咽癌细胞自发性凋亡对放射敏感性的预测意义及自发性凋亡水平差异的分子学基础。   方法   克隆形成实验测定人鼻咽高分化鳞癌细胞株(CNE-1)、人鼻咽低分化鳞癌细胞株(CNE-2)接受Varian加速器单野照射(6 MV X线)的存活分数, 单击多靶和线性二次模型拟合辐射剂量存活曲线并求出放射生物学参数; 流式细胞术检测自然生长2、4、6、8d细胞凋亡情况; RT-PCR、Western blot检测凋亡相关基因Bcl-2、Bcl-xl、Bcl-w、Bax、Bad、Bid、Bak转录及蛋白表达水平。   结果   函数模型参数显示CNE-2较CNE-1具有更高的辐射敏感性; 相同培养天数下CNE-2早期及晚期凋亡率显著高于CNE-1(P < 0.05);CNE-2中Bcl-2、Bcl-xl、Bcl-w、Bax、Bad、Bid、Bak基因转录及蛋白表达水平均高于CNE-1(P < 0.05)。   结论   自发性凋亡可能成为放射敏感性的预测指标, 自发性凋亡水平差异可能与凋亡相关基因差异性表达有关。      

Neoplastic cell apoptosis in nude mice transplants with nasopharyngeal carcinoma cell lines

We know that tumor growth speed is criticallyinfluenced by the ratio of neoplastic cell proliferation andcell death, and there are two patterns of cell death, namely,necrosis and apoptosis. What is the proportion of necrosisand apoptosis seen in nude mice transplants ofnasopharyngeal carcinoma (NPC) cell lines, CNE-1 andCNE-2? Does the apoptosis play an important role inneoplastic cell death? If so, what is the pathway ofapoptosis developed in those transplants?MATERIALS AND METHODS…     

Preclinical evaluation of PI3K inhibitor BYL719 as a single agent and its synergism in combination with cisplatin or MEK inhibitor in nasopharyngeal carcinoma (NPC)

Nasopharyngeal carcinoma (NPC) is endemic to Southeast Asia and over 40% of NPC tissues harbor PIK3CA amplifications. This study aims to study the preclinical activity of a novel PI3K inhibitor, BYL719, in 6 NPC cell lines: C666-1, CNE-2, HK1, HK1-EBV, HONE-1 and HONE-1-LMP1. Over 70% of growth inhibition was attained when NPC cell lines were exposed to increasing concentrations of BYL719, with IC₅₀ values at the low micro-molar range. Two BYL719-sensitive cell lines that harbor PIK3CA mutations, CNE-2 and HONE-1, were selected for further analysis on the effect of BYL719 on cell cycle progression, apoptosis and PI3K signaling. BYL719 significantly reduced the phosphorylation of Akt, and the Akt-mTOR axis downstream effector S6 in these 2 cell lines, but a feedback activation of MAPK was observed at 72 hours post-treatment. BYL719 induced G₀/G₁ cell cycle arrest and apoptosis in both cell lines. In 3D cell culture models, the growth of NPC spheroids was significantly inhibited in a dose-depending manner. When BYL719 was combined with a MEK inhibitor (AZD6244) in a 3D cell culture system, strong synergism on NPC cell growth was observed with attenuation of MAPK activation. A synergistic inhibitory effect on growth was observed when BYL719 was combined with higher dose levels of cisplatin. These data suggest that BYL719 has preclinical activity in NPC cell lines especially in those which harbor PIK3CA mutation. Combination with a MEK inhibitor maybe a useful strategy that warrants further investigation.     

赫赛汀对HER-2/neu基因高表达鼻咽癌细胞株生长的影响

目的：探讨赫赛汀(Herceptin)对HER-2／neu基因高表达鼻咽癌细胞株生长的影响及机制。方法：分别采用MTT法、^3H-TdR细胞掺入法检测Herceptin对鼻咽癌细胞株CNE-22和CNE-2体外生长的影响;用流式细胞仪检测Herceptin对CNE-2Z细胞生长、细胞周期和凋亡的影响。结果：Herceptin可抑制CNE-2Z细胞的生长,引起细胞凋亡指数的增加。结论：Herceptin可抑制高表达HER-2／neu基因鼻咽癌细胞株的生长,并诱导细胞凋亡的发生。     

鼻咽癌放射抗拒相关microRNAs研究进展

鼻咽癌是一种起源于鼻咽部上皮组织的鳞状细胞恶性肿瘤,在东南亚和中国华南地区具有很高的发病率,目前放疗已成为鼻咽癌的首选治疗方式。放射抗拒是鼻咽癌放疗成功的主要障碍,寻找鼻咽癌放射抗拒相关的生物标志物,明确放射抗拒的产生机制,对治疗具有重大意义。MicroRNAs通过结合靶mRNA的3’UTR 从而诱导其翻译抑制或降解,调节蛋白的表达,参与放疗反应相关的所有重要的细胞过程如DNA损伤反应与修复、细胞凋亡、增殖以及血管生成的调节。近年来鼻咽癌放射抗拒相关microRNAs的研究成为热点,本文就microRNAs及其潜在的作用机制进行综述。     

The effects of combining ionizing radiation and adenoviral p53 therapy in nasopharyngeal carcinoma

PURPOSE: Nasopharyngeal carcinoma (NPC) is a malignant disease of the head/neck region, with a 5-year survival level of approximately 65%. To explore gene therapy as a novel approach which might improve outcome, we have shown previously that introduction of human recombinant wild-type p53 mediated by the adenoviral vector (Ad5CMV-p53) was cytotoxic in two human nasopharyngeal carcinoma (NPC) cell lines (CNE-1 and CNE-2Z). The current work was designed to determine whether this strategy, combined with ionizing radiation (XRT), was more effective than either treatment alone. METHODS AND MATERIALS: CNE-1, CNE-2Z, and a normal human nasopharyngeal fibroblast strain, KS1, were infected with 2- and 6-plaque-forming units (pfu)/cell of Ad5CMV-p53, respectively. These doses were isoeffective for beta-galactosidase activity in the CNE-1 and CNE-2Z cells. XRT was administered 24 h post-infection, and Western blot analyses were conducted for p53, p21WAF1/CIP1, bax, and bcl-2 2 days after XRT. Cell survival was assessed using a clonogenic assay. Presence of DNA ladders reflecting apoptosis was detected using DNA agarose gel electrophoresis, and cell cycle was analyzed using flow cytometry. RESULTS: The combination of Ad5CMV-p53 plus XRT (2, 4, and 6 Gy) resulted in an approximately 1-log greater level of cytotoxicity compared to that observed with XRT alone for both NPC cell lines. The two modalities appear to be interacting in a synergistic manner in cancer cells, but not in KS1 fibroblasts. XRT alone stimulated minimal p53 expression in control cells; Ad5CMV-p53 alone induced significant recombinant p53 expression, which was not further enhanced by the addition of XRT. Similar observations were made for p21WAF1/CIP1 expression. No changes were observed for bax or bcl-2 expression with any of these treatments. Apoptosis was induced following 4 Gy of XRT alone, but was observed after only 2 Gy when combined with Ad5CMV-p53. Cell cycle analysis indicated that Ad5CMV-p53 infection did not perturb the cell cycle beyond that observed with XRT alone. CONCLUSION: p53 gene therapy and XRT appears to interact in a synergistic manner; underscoring the significant potential of this novel strategy in the treatment of NPC.     

鼻咽癌细胞系CNE-2Z放射敏感性异质性与凋亡的关系

目的评估人鼻咽癌细胞系CNE-2Z放射敏感性异质性与凋亡敏感性的相关性。方法用流式细胞仪、荧光显微镜、电镜、Western-blot检测H5和S1凋亡能力的不同及凋亡相关蛋白表达的差异。结果H5、S1两种细胞的凋亡率均随着照射后时间的延长而增加,但H5比S1高且差异有显著性(P<0.05)。结论人鼻咽癌细胞系CNE-2Z放射敏感性的异质性,与细胞受射线照射后凋亡呈正相关,对射线敏感的亚细胞系凋亡率高。     

盐霉素增加鼻咽癌CNE-2细胞放疗敏感性的实验研究

目的:探讨盐霉素（Sal）对鼻咽癌CNE-2细胞的放疗增敏作用及其可能的机制。方法:CCK8测定不同浓度盐霉素、不同剂量放疗及联合应用对CNE-2细胞增殖的抑制作用;平板克隆实验观察盐霉素联合放疗后细胞的克隆形成率;Hoechst33258染色观察细胞凋亡;流式细胞术检测细胞凋亡率及细胞周期的变化情况。结果:CCK8结果显示,盐霉素和放疗对鼻咽癌CNE-2细胞的生长有显著的抑制作用,呈浓度和剂量依赖性,且联合组抑制作用强于单纯药物组或放疗组。平板克隆实验显示盐霉素联合放疗后能显著降低细胞的克隆形成率;Hoechst33258染色显示盐霉素联合放疗治疗后细胞凋亡现象更明显;细胞流式术检测显示联合组较单纯药物组或放疗组凋亡率增加,盐霉素对放疗具有增敏作用。药物组和放疗组均能使G2/M期细胞比例增加,两者联合效果更明显。结论:盐霉素能增加人鼻咽癌CNE-2细胞的放疗敏感性,其作用机制可能与周期阻滞及其凋亡诱导相关。