The modifier subunit of glutamate cysteine ligase relates to cisplatin resistance in human small cell lung cancer xenografts in vivo

Glutamate cysteine ligase (GCL) plays an important role in the intracellular detoxification of cisplatin (CDDP). GCL is composed of a modifier or light chain subunit (GCLM) and a catalytic or heavy chain subunit (GCLC). Previously, we showed that the GCL subunits enhanced CDDP-resistance in non-small cell lung cancer (NSCLC) xenografts. In small cell lung cancer (SCLC), it is unclear whether the GCL subunits are essential to CDDP-resistance. We examined the gene expression of GCLM and GCLC in four human SCLC xenografts with the real-time polymerase chain reaction (PCR). An in vivo drug sensitivity test with CDDP was performed on the SCLC xenografts. CDDP-resistance was examined as the growth ratio of the relative volume of the treated xenografts to the controls (T/C%). The expression level of GCLM gene in SCLC was significantly lower than that in NSCLC (p=0.0026, Welch's t-test). One of four SCLC xenografts showed 62% of T/C and this was evaluated as CDDP-resistance, while the other three xenografts were sensitive to CDDP in vivo (Mann-Whitney U-test, p<0.01, one-sided). The expression level of the GCLM gene was significantly correlated to T/C% (Fisher's test, p=0.0289, correlations = 0.975), while the GCLC gene expression level was not associated with T/C%. These results suggest that the overexpression of GCLM is correlated with CDDP-resistance in SCLC xenografts in vivo.     

The modifier subunit of glutamate cysteine ligase (GCLM) is a molecular target for amelioration of cisplatin resistance in lung cancer

It is unclear whether a subunit of glutamate cysteine ligase [a modifier subunit (GCLM) and a catalytic subunit (GCLC)] is an effective target for ameliorating cisplatin (CDDP)-resistance. We inhibited each subunit of GCL mRNA using a specific ribozyme (M-Rz and C-Rz) in the pulmonary adenocarcinoma cell line A549. GCL activity was suppressed by the ribozyme. CDDP-resistance was more effectively ameliorated when GCLM rather than GCLC was inhibited. GCLM is a potentially more effective pharmacologic target for ameliorating CDDP-resistance in non-small cell lung cancer than GCLC.     

Expression of copper-transporting P-type adenosine triphosphatase (ATP7B) correlates with cisplatin resistance in human non-small cell lung cancer xenografts

Copper-transporting P-type adenosine triphosphatase (ATP7B) is reportedly associated with platinum drug resistance in various solid carcinomas. However, the impact of ATP7B on platinum drug resistance in non-small cell lung cancer (NSCLC) remains unknown. We investigated ATP7B expression in nine human NSCLC xenografts using real-time polymerase chain reaction (PCR) and immunohistochemistry, and examined the relationship between the expression level of ATP7B and in vivo cisplatin (CDDP) sensitivity. ATP7B mRNA expression was significantly correlated with in vivo cisplatin sensitivity [coefficient of determination (R(2))=0.949, p=0.005]. ATP7B protein was detected in the nine xenografts. The ATP7B protein expression level was comparable to that of ATP7B mRNA. ATP7B mRNA and protein expression levels in the CDDP-resistant xenografts were significantly higher than those in the CDDP-sensitive xenografts (p=0.0389 and p=0.0357, respectively, Mann-Whitney U test). These results suggest that ATP7B is a CDDP-resistance marker in human NSCLC xenografts in vivo.     

非小细胞肺癌顺铂耐药相关基因生物信息学研究

目的：通过分析非小细胞肺癌顺铂敏感株及耐药株的基因芯片表达数据,筛选差异基因及关键通路,构建蛋白相互作用网络,探讨关键集群功能。方法:从GEO数据库获得基因芯片表达数据,利用GEO2R工具筛选差异基因,通过STRING数据库和Cytoscape软件构建蛋白相互作用网络,经DAVID富集得到相关特征基因与信号通路信息。结果：通过芯片分析共获得481个差异表达基因,相比于敏感细胞株,顺铂获得性耐药细胞株中有418个上调基因和63个下调基因。差异基因功能主要富集在piRNA代谢、DNA甲基化修饰、细胞有丝分裂及细胞周期进程等信号通路。蛋白复合物预测得到主要功能集群6个,分别与细胞趋化性、细胞角化性、piRNA代谢过程、细胞因子受体相互作用、细胞因子分泌调节及染色质沉默相关生物进程相关。结论:本研究利用生物信息学方法,发现顺铂耐药细胞株特征基因及信号通路,其中SAA1、KRT5、TDRD9、BCL2A1、CSF1R和HIST1H1A等显著上调基因及其功能集团可能是非小细胞肺癌顺铂耐药的潜在分子机制,为临床精准治疗提供新的理论依据。     

Augmentation of cytotoxicity of chemotherapy by human alpha-interferons in human non-small cell lung cancer xenografts

Three human non-small lung cancer xenograft lines were used to study the activity of combinations of cytotoxic drugs with human alpha-interferons (IFNs). Statistically significant potentiation of cis-platinum (CDDP) and cyclophosphamide (CY) given weekly in a low dose was seen when human lymphoblastoid interferon (IFN-alpha nl) (2 X 10(5) mu/mouse/day) was administered simultaneously. The median tumor doubling times for CDDP in the three tumors (35, 22, and 29 days) increased to 52, 51, and 41 days when IFN-alpha nl was added. A similar though less marked effect was seen with CY (median doubling time increased from 21.5, 19.5, and 27 days to 32, 27, and 35 days with the addition of IFN-alpha nl). IFN-alpha nl alone at this dosage was shown to have some cytotoxic activity. Similar potentiation of CDDP and ifosfamide was seen in two tumors when human recombinant alpha-2 interferon was added at a lower dose (2 X 10(4) mu/mouse/day). Median doubling times for CDDP increased from 17 and 14 days to 27 and 18.5 days with the addition of human recombinant alpha-2 interferon, whereas for ifosfamide they increased from 11.5 and 14 days to 15 and 16 days. Human recombinant alpha-2 interferon in this dose had no effect as a single agent.     

非小细胞肺癌组织ERCC1表达与顺铂化疗耐药关系的研究

目的:探讨非小细胞肺癌(NSCLC)组织中ERCC1表达水平与顺铂(DDP)化疗耐药的相关性。方法:应用免疫组化SP法检测82例NSCLC组织中ERCC1的表达并分析其与DDP化疗耐药的关系。结果:ERCC1表达水平与NSCLC患者年龄、性别、临床分期及组织学类型无关,P>0.05。ERCC1阴性表达组的化疗有效率为53.5%(23/43),而ERCC1阳性表达组的化疗有效率为17.9%(7/39),两组比较差异有统计学意义,χ2=4.76,P=0.04。结论:ERCC1在NSCLC组织中的表达水平与DDP化疗耐药有关。     

Role of metallothionein1h in cisplatin resistance of non-small cell lung cancer cells

Objective  

Despite platinum-based adjuvant chemotherapy has improved greatly patients’ outcomes, drug resistance poses a major impediment to the successful use of such an effective agent. Metallothioneins(MTs) are known to play putative roles in cancer cell proliferation, apoptosis, differentiation, drug resistance and prognosis. The present studiy was to investigte the role of metallethioein1H(MT1H) in cisplatin resistance of human non-small cell lung cancer(NSCLC) cell lines in vitro or its possible molecular mechanisms.     

非小细胞肺癌顺铂化疗耐药相关微RNA的筛选及鉴定

 目的　探讨肿瘤细胞微RNA（miRNA）对化疗药物敏感性的作用。方法　通过miRNA芯片技术检测顺铂（DDP）耐药细胞株A549／DDP与非耐药细胞株A549的miRNA表达的差异,利用荧光定量聚合酶链反应（PCR）技术验证相应miRNA的表达情况,通过在细胞株中抑制或过表达目标miRNA,研究其对细胞化疗药物敏感性的影响。结果　A549／DDP细胞对DDP的耐药为A549细胞的18倍。A549／DDP细胞与A549细胞存在51个表达水平差异在4倍以上的miRNA,其中24个表达上调,27个表达下调。PCR进一步证实miR-376c、miR-31、miR-29a、miR-221在A549／DDP细胞中显著上调,miR-196a、miR-20a、miR-20b、miR-17、miR-451在A549／DDP细胞中显著下调。在提高A549／DDP细胞中miR-17的表达后,细胞对DDP的敏感度增加了11.7 %,提高miR-451的表达或者抑制miR-29a的表达后,对DDP的敏感度分别下降了15.5 %、12.9 %,抑制miR-376c、miR-31、miR-221或过表达miR-196a、miR-20a、miR-20b均不影响A549／DDP细胞对DDP的敏感度。结论　非小细胞肺癌DDP耐药细胞与非耐药细胞的miRNA表达谱有差异,miRNA参与肺癌化疗耐药,miR-17具有逆转非小细胞肺癌DDP耐药的潜力。     

MicroRNA signatures of TRAIL resistance in human non-small cell lung cancer

To define novel pathways that regulate susceptibility to tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) in non-small cell lung cancer (NSCLC), we have performed genome-wide expression profiling of microRNAs (miRs). We show that in TRAIL-resistant NSCLC cells, levels of different miRs are increased, and in particular, miR-221 and -222. We demonstrate that these miRs impair TRAIL-dependent apoptosis by inhibiting the expression of key functional proteins. Indeed, transfection with anti-miR-221 and -222 rendered CALU-1-resistant cells sensitive to TRAIL. Conversely, H460-sensitive cells treated with -221 and -222 pre-miRs become resistant to TRAIL. miR-221 and -222 target the 3'-UTR of Kit and p27(kip1) mRNAs, but interfere with TRAIL signaling mainly through p27(kip1). In conclusion, we show that high expression levels of miR-221 and -222 are needed to maintain the TRAIL-resistant phenotype, thus making these miRs as promising therapeutic targets or diagnostic tool for TRAIL resistance in NSCLC.     

Reversal of cisplatin resistance with amphotericin B in a non-small cell lung cancer cell line.

The potentiation of anticancer agents by non-anticancer drugs is one of the possible strategies for overcoming cellular resistance to chemotherapy. In order to overcome cis-diamminedichloroplatinum(II) (CDDP) resistance, we evaluated the sensitizing effect on CDDP-induced cytotoxicity of various non-anticancer agents which might alter membrane transport, by means of a colorimetric [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] (MTT) assay. Drugs which have previously been demonstrated to modify multidrug resistance did not show a sensitizing effect to cisplatin. Only amphotericin B (AmB) selectively conquered CDDP resistance in the CDDP-resistant cell line. A drug accumulation study done by the atomic absorption method demonstrated that the accumulation of CDDP in the resistant cell line recovered to the level of the parental cell line after treatment with AmB. Thus, AmB might overcome CDDP resistance by increasing the accumulation of CDDP.     

The role of glutathione in resistance to cisplatin in a human small cell lung cancer cell line

The role of glutathione (GSH) in resistance to cisplatin (CDDP) was studied in a human small cell lung carcinoma cell line (GLC4) and a CDDP-resistant subline (GLC4-CDDP). In addition to studying the steady state of GSH, the kinetics of this defence system were also studied via the monitoring of the GSH status of the cells under continuous pressure of CDDP. GLC4-CDDP maintained its elevated GSH level whereas GLC4 (under pressure of CDDP) quickly synthesised GSH to about twice its initial level, corresponding with 80% of the GSH level of GLC4-CDDP. D,L-buthionine-S,R-sulphoximine (BSO) was used to analyse the role of GSH in resistance to CDDP. Pretreatment with BSO (48 h, 50 microM, GSH not detectable) increased the CDDP-induced cytotoxicity 2.8-fold in GLC4-CDDP and 1.7-fold in GLC4. In GLC4 no changes in the amount of platinum (Pt) bound to DNA could be observed after GSH depletion. Changes in formation of interstrand cross-links or the main Pt-containing intrastrand cross-link in digested DNA, the Pt-GG adduct, were also not observed. In GSH depleted GLC4-CDDP cells, an increase in the amount of Pt bound to DNA and in the Pt-GG adduct was observed. Pretreatment with BSO substantially reduced the repair of Pt bound to DNA in both cell lines. We conclude that an increased GSH level and GSH synthesis capacity were demonstrated in CDDP resistant cells. The observations after BSO treatment suggest two roles for GSH in CDDP resistance, namely that of a cytosolic elimination resulting in less DNA platination and a nuclear effect on the formation and repair of DNA platinum adducts.     

TIP30逆转人非小细胞肺癌吉非替尼耐药的实验研究

  目的  本实验旨在研究TIP30能否逆转非小细胞肺癌（non-small cell lung cancer,NSCLC）的吉非替尼耐药,并探讨其可能的机制。  方法  慢病毒LV-TIP30转染NSCLC吉非替尼耐药株PC9/GR上调TIP30,以PC9/GR、PC9/GR-LVTIP30和PC9/GR-LVNC为研究对象,分别加或不加5 μmol/L吉非替尼处理共6组细胞。CCK8检测细胞增殖抑制率,划痕修复实验、Transwell实验检测细胞迁移侵袭能力,免疫印迹实验检测p-AKT、p-ERK、p-MEK以及核内EGFR蛋白表达水平。  结果  非吉非替尼处理组中,PC9/GR-LVTIP30细胞的增殖、迁移和侵袭能力与PC9/GR细胞相比均受到明显的抑制（P < 0.05）,吉非替尼处理组中PC9/GR-LVTIP30细胞较PC9/GR细胞抑制作用更明显（P < 0.05）;过表达TIP30后,蛋白p-MEK、p-ERK、p-AKT表达水平降低,核内EGFR表达水平较PC9/GR降低,差异均具有统计学意义（P < 0.05）。  结论  上调TIP30能够逆转人非小细胞肺癌PC9/GR细胞对吉非替尼的耐药性,其发挥作用的机制可能是通过抑制EGFR核内化,进而抑制下游信号通路相关蛋白p-AKT、p-ERK、p-MEK激活发挥作用。      

Aberrant p53 staining does not predict cisplatin resistance in locally advanced non-small cell lung cancer

Cisplatin based chemotherapies have increased the survival in nonsmall cell lung cancer. A mechanism for identifying tumors resistant to cisplatin would be useful in avoiding unnecessary toxicity of platinum regimens. Mutation of p53 has been shown to induce chemotherapy resistance in vitro. We hypothesized that tumors staining for p53 would be resistant to cisplatin. In Cancer and Leukemia Group B protocol 8935, patients with stage IIIA (N2 node positive) nonsmall cell lung cancer received chemotherapy followed by surgery, then post-operative chemotherapy and/or radiation. All patients underwent pre-treatment staging mediastinoscopy. Twenty-five out of forty-nine pre-treatment mediastinal lymph node specimens stained positively for p53. Positive staining did not correlate with response to chemotherapy or survival. It did predict a slightly higher complete or partial resection rate compared to negative staining (76 vs. 45%) (p = 0.042). A trend toward longer median survivals was seen in patients with positive p53 staining. This study does not support the ability of p53 staining to predict chemotherapy resistance.     

非小细胞肺癌放疗抵抗研究进展

放射治疗是非小细胞肺癌的重要治疗手段之一,而肿瘤放疗抵抗限制了放疗的疗效。提高放疗疗效仍是目前非小细胞肺癌患者治疗中亟待解决的重要难题之一。研究PI3K/AKT/mTOR信号通路、肿瘤干细胞、微小RNA、HGF/c-Met、常规分割放疗等在非小细胞肺癌放疗抵抗中的作用机制,对提高非小细胞肺癌患者的生存率及改善非小细胞肺癌患者的预后具有重要意义。     

紫杉醇联合顺铂与紫杉醇单药治疗非小细胞肺癌的疗效比较

目的:观察紫杉醇联合顺铂与紫杉醇单药治疗非小细胞肺癌(NSCLC)的疗效及不良反应.方法:采用前瞻性随机对照研究方法,对49例非小细胞肺癌初治患者进行随机分组.TAX组22例采用TAX单药治疗方案,TAX 175mg/m2,第1天,每4周重复;TP组27例,DDP 30mg/m2,第1-3天,TAX 75mg/m2,第1天,每4周重复.结果:TP组与TAX组总有效率分别为48.1%与43.3%(P=0.716);疾病控制率分别为88.8%和86.7%(P=0.799).TP组白细胞下降比TAX组稍低,在不良反应方面TP组比TAX组略有改善.结论:DDP联合TAX是治疗NSCLC的有效方案.可取得与TAX相似的有效率.在某些不良反应方面显示出一定优势.     

NP与GP方案治疗晚期非小细胞肺癌的临床对照研究

目的：评价吉西他滨联合顺铂方案与诺维本联合顺铂方案治疗晚期非小细胞肺癌的疗效及毒副反应。方法：经病理组织学或细胞学证实的64例晚期非小细胞肺癌患者,随机分为两组。A组32例,以诺维本（NVB）25mg/m^2,第1、8天溶于生理盐水100ml中快速静滴。顺铂80mg/m^2静滴,第1天;B组32例,以吉西他滨（GEM）1200mg/m^2静滴,第1、8天,DDP用法同A组。两方案均每3周重复,2周期以上评价疗效。结果：A、B两组的有效率分别为46.8%（15/32）和53.1%（17/32）;B组Ⅲ-Ⅳ度血小板减少高于A组,但Ⅲ-Ⅳ度白细胞减少及过敏明显低于A组。结论：A,B两组疗效、MST和1年生存率无明显差异（P〉0.05）;TTP有显著性差异（P〈0.05）。     

CXCL4对非小细胞肺癌H460细胞顺铂耐药性的影响及其机制探讨

目的:探讨血小板因子4（CXCL4）对人非小细胞肺癌H460细胞顺铂耐药性的影响及其作用机制。方法:体外诱导法建立顺铂耐药的非小细胞肺癌细胞株H460/DDP,并鉴定其生物学特性。采用CCK-8法分别检测H460及H460/DDP对顺铂的耐药性。qRT-PCR及Western Blot检测亲本细胞株H460及顺铂耐药株H460/DDP中CXCL4的mRNA及蛋白表达水平。通过CCK-8法检测过表达或者敲低CXCL4后亲本细胞株H460或顺铂耐药株H460/DDP对顺铂的敏感性。最后利用Western Blot及qRT-PCR法探讨CXCL4抵抗非小细胞肺癌化疗敏感性的调控机制。结果:成功构建了非小细胞肺癌顺铂耐药株H460/DDP（H460/DDP IC50=55.005 μg/ml）,CCK-8结果提示顺铂耐药株H460/DDP与亲本细胞株H460细胞的增殖速度没有明显差异（P＞0.05）;顺铂耐药株H460/DDP中,CXCL4 mRNA及蛋白水平均显著增高（P＜0.000 1）;在亲本细胞株H460中稳定过表达CXCL4能显著降低其对顺铂的敏感性（P＜0.000 1）,而于顺铂耐药株H460/DDP中敲低CXCL4能显著增加H460/DDP对顺铂的敏感性（P＜0.000 1）;Western Blot及qRT-PCR结果显示,CXCL4能激活Wnt/β-catenin 信号通路,促进下游基因MYC、CyclinD1、MMP-7、CDK4的表达。结论:CXCL4通过调控Wnt/β-catenin 信号通路促进非小细胞肺癌对顺铂的耐药性。