Evaluating the immunoproteasome as a potential therapeutic target in cisplatin-resistant small cell and non-small cell lung cancer

We evaluated the expression of proteasome subunits to assess whether the proteasome could be a therapeutic target in cisplatin-resistant lung cancer cells. Cisplatin-resistant (CR) variants were established from three non-small cell lung cancer (NSCLC) cell lines (A549, H1299, and H1975) and two small cell lung cancer (SCLC) cell lines (SBC3 and SBC5). The expression of proteasome subunits, the sensitivity to immunoproteasome inhibitors, and 20S proteasomal proteolytic activity were examined in the CR variants of the lung cancer cell lines. All five CR cell lines highly expressed one or both of the immunoproteasome subunit genes, PSMB8 and PSMB9, while no clear trend was observed in the expression of constitutive proteasome subunits. The CR cells expressed significantly higher levels of PSMB8 and PSMB9 proteins, as well. The CR variants of the H1299 and SBC3 cell lines were more sensitive to immunoproteasome inhibitors, and had significantly more proteasomal proteolytic activity than their parental counterparts. The immunoproteasome may be an effective therapeutic target in a subset of CR lung cancers. Proteasomal proteolytic activity may be a predictive marker for the efficacy of immunoproteasome inhibitors in cisplatin-resistant SCLC and NSCLC.     

Proteasome inhibition improves fractionated radiation treatment against non-small cell lung cancer: an antioxidant connection

Non-small cell lung cancer frequently presents as a locally advanced disease. In this setting, radiation has a prominent role in cancer therapy. However, tumor adaptation to oxidative stress may lessen the efficacy of radiation therapy. Recent studies demonstrate that proteasome inhibitors increase the efficacy of radiation against a range of tumors. Although proteasome inhibition impacts on NF-kappaB translocation, the precise mechanism through which proteasome inhibitors induce tumor cell death and promote radiation efficacy remains unclear. The purpose of this study is to evaluate the potential of the proteasome inhibitor, MG-132, to improve the efficacy of radiation therapy and to determine whether its effect is linked to the suppression of the antioxidant enzyme, manganese superoxide dismutase (MnSOD). Human NSCLC (A549) cells were utilized both in vivo and in vitro to evaluate proteasome inhibition on radiation response. In vivo, mice that received combined treatments of 2.5 microg/g body weight MG-132 and 30 Gy demonstrated a delay in tumor regrowth in comparison to the 30 Gy control group. In vitro, clonegenic survival assays confirmed a dose-dependent enhancement of radiation sensitivity in combination with MG-132 and a significant interaction between the two. The levels of IkappaB-alpha, a NF-kappaB target gene and also an inhibitor of NF-kappaB nuclear translocation, decreased in a time-dependent manner following administration of MG-132 confirming the inhibition of the 26S proteasome. The MnSOD protein level was increased consistent with lower levels of IkappaB-alpha, confirming a NF-kappaB-mediated effect. Cells treated with radiation demonstrated an induction of MnSOD; however, the administration of MG-132 suppressed this induction These results support the hypothesis that proteasome inhibitors such as MG-132 can increase the efficacy of radiation therapy, in part, by suppression of cytoprotective NF-kappaB-mediated MnSOD expression.     

MKP1 repression is required for the chemosensitizing effects of NF-κB and PI3K inhibitors to cisplatin in non-small cell lung cancer

Treatment of non-small cell lung cancer (NSCLC) with cisplatin has a level of antitumor activity still modest. We have shown previously that MKP1/DUSP1 inhibits cisplatin-induced apoptosis in NSCLC cells and is overexpressed in tumors from most patients with stage I–II NSCLC. Here, using different NSCLC cell lines we found that MKP1 and NF-κB are differentially expressed. We studied whether targeting MKP1, NF-κB or both affects cisplatin-induced cell death. MKP1 is expressed in H460 and H727 cells. H727 and H1299 cells showed constitutive phosphorylation of Akt and increased NF-κB activity than did H460 cells. H460-MKP1-siRNA-expressing cells (but not H727-MKP1-siRNA or H1299-MKP1-siRNA cells) exhibit a marked increase in cisplatin response compared with parental cells. Treatment with the PI3K inhibitor LY294002 or the NF-κB inhibitor BAY11-7082 enhanced cisplatin antitumor activity in parental H1299 cells but only weakly affected responses of H727 and H460 cells. MKP1-siRNA expression enhanced the chemosensitization effect of LY294002 and BAY11-7082 on H727 and H460 cells. Additionally, NSCLC cell lines with higher NF-κB-constitutive activation were the most sensitive to PS-341 (Bortezomib), a non-specific NF-κB inhibitor. This finding suggests the proteasome as a suitable strategy in treating NSCLC tumors with high constitutive NF-κB activity. Altogether, these results showed that either an activated PI3K/Akt/NF-κB pathway and/or high MKP1 was linked to reduced sensitivity to cisplatin in NSCLC cells. Inhibition of NF-κB or PI3K potently enhanced cisplatin cytotoxicity in cells with endogenous or genetically induced low MKP1 levels. These findings support the potential improvement in cisplatin responses by co-targeting NF-κB or Akt and MKP1.     

E-钙黏蛋白在人非小细胞肺癌细胞多西他赛耐药中的作用

目的:探讨非小细胞肺癌(non-small cell lung cancer,NSCLC)A549、H1299、H358、H441多西他赛（docetaxel，DTX）耐药细胞株与上皮间质转化（epithelial-mesenchymal transition,EMT）的关系，并初步研究逆转E-cadherin的表达对NSCLC细胞多西他赛耐药性的影响。方法:应用Real-time PCR 和Western blot 方法检测上皮间质转化相关标志物E-cadherin、Vimentin、N-cadherin、Snail在亲本细胞和多西他赛耐药细胞之间的表达差异；应用慢病毒载体介导构建稳定表达E-cadherin的NSCLC多西他赛耐药细胞；MTS法检测NSCLC细胞多西他赛耐药特性。结果:与A549、H1299、H358、H441四株亲本细胞相比，多西他赛耐药细胞（A549DTX，H1299DTX，H358DTX，H441DTX）形态呈长梭形，呈上皮间质转化（EMT）样改变。多西他赛耐药细胞中E-cadherin表达下调，Vimentin、N-cadherin、Snail表达上调。成功构建了过表达E-cadherin的NSCLC多西他赛耐药细胞。过表达E-cadherin细胞株细胞形态与空载对照细胞株以及亲本耐药细胞株相比呈间质上皮转化(MET)样改变。MTS结果显示四种不同E-cadherin过表达的NSCLC多西他赛耐药细胞对多西他赛的敏感性均强于其亲本耐药细胞和空载对照细胞。结论:NSCLC多西他赛耐药细胞发生EMT样改变，上调E-cadherin能增加NSCLC多西他赛耐药细胞对多西他赛的敏感性。     

西妥昔单抗对非小细胞肺癌细胞的体外抑制作用

背景与目的 目前抗EGFR单抗--西妥昔单抗在肺癌的临床运用越来越广泛.本研究旨在探讨西 妥昔单抗对人肺癌细胞株(A549、H460、H1299、SPC-A-1)的体外作用.方法 我们选用浓度递增的西妥昔单抗 (1 nmol/mL-625 nmol/mL)作用于A549、SPC-A-1、H460、H1229四株细胞株,采用CCK8测定各组细胞增殖抑制情 况,选择A549、SPC-A-1细胞株用PI标记应后用流式细胞技术观察细胞凋亡情况,并采用免疫蛋白印迹法检测药物 处理后A549细胞EGFR信号转导通路关键酶的表达.结果 西妥昔单抗对A549、H460、H1299、SPC-A-1细胞的作用 均呈时间和浓度依赖性,作用后细胞的凋亡现象明显,同时细胞增殖均不同程度受到抑制;通过Western blot检测发 现p-AKT、p-EGFR、p-MAPK蛋白表达量较对照组明显下降.结论 西妥昔单抗在体外对肺癌细胞的增殖具有一定的 抑制作用,其作用可能与进一步下调了活化的EGFR信号转导通路关键酶的表达有关.     

Acquisition of an enhanced aggressive phenotype in human lung cancer cells selected by suboptimal doses of cisplatin following cell deattachment and reattachment

Chemotherapy is one major approach for treating non-small cell lung carcinoma (NSCLC). However, the progression-free survival rate depends on whether there is tumor metastasis after drug treatment. The biological behavior for its characteristics remains to be clarified. Here, we treated A549 and H1299 NSCLC cell lines with cisplatin, doxorubicin and gemcitabine at the IC(50) dose. Most attached cells were surviving cells (A549-A and H1299-A), whereas only a small portion of detached cells survived and reattached to tissue culture plates (A549-R and H1299-R) for further growth. Using cisplatin, a series of H1299 sublines (H1299-R2～H1299-R5) were also generated by the same selection procedure. Drug treatment increased the migratory ability of A549-R and H1299-R cells. A serial selection could enhance the invasiveness of cells. Cisplatin treatment inhibited the adhesion ability of H1299-R cells compared with their H1299 and H1299-A counterparts. H1299-R cells exhibited increased drug resistance to cisplatin and increased expression of ABCG2, CD133 and CD44. Compared with mice subcutaneously injected with H1299 cells, mice subcutaneously injected with H1299-R cells showed an increase in the number of metastatic lung nodules. We conclude that H1299-R cells selected by suboptimal doses of cisplatin following detachment from and reattachment to the tissue culture plate acquire an enhanced malignant phenotype. Therefore, they provide a more faithful lung cancer model associated with biological aggressiveness for studying clinically recurrent cancers after chemotherapy.     

miR-601靶向调控MMP-17抑制非小细胞肺癌的迁移和侵袭CSCD

目的探讨miR-601对非小细胞肺癌(NSCLC)迁移和侵袭能力的影响并探讨其可能的作用机制。方法RT-qPCR检测NSCLC组织中miR-601的表达,并分析表达水平与癌细胞侵袭和淋巴结转移的相关性。将miR-601 mimics瞬时转染A549细胞或H1299细胞,Transwell实验检测其对两种细胞迁移和侵袭能力的影响。生物信息学预测miR-601相关靶基因,采用双荧光素酶实验进行靶基因验证。检测miR-601的靶基因对A549细胞或H1299细胞迁移及侵袭能力的影响。结果miR-601在NSCLC组织中表达明显降低(P<0.001),且降低水平与癌细胞的浸润(P<0.007)及淋巴结转移(P<0.011)密切相关。瞬时转染miR-601 mimics能明显抑制A549细胞或H1299细胞的迁移及侵袭能力。生物信息学及荧光素酶报告实验提示MMP-17是miR-601的靶基因。MMP-17能促进A549细胞或H1299细胞的迁移和侵袭,但其促进迁移侵袭的能力可被miR-601抑制。结论miR-601通过靶向调控MMP-17而抑制非小细胞肺癌的迁移和侵袭。     

ITGAV在非小细胞肺癌中的表达及其与放射抵抗的关系

目的 探讨ITGAV的表达与NSCLC细胞放射敏感度的关系。方法 使用生物信息学方法分析ITGAV在NSCLC组织中的表达水平及其与NSCLC患者预后的相关性。克隆形成实验验证放射抵抗细胞与亲本细胞的放射敏感度差异，Western blot检测ITGAV的表达。Western blot、qRT-PCR验证si-ITGAV转染效率，选用最佳ITGAV干扰序列转染A549R、H1299R细胞。克隆形成实验、流式细胞术检测ITGAV干扰后对细胞克隆形成、凋亡和周期情况的影响。结果 ITGAV在非小细胞肺癌组织中表达水平明显高于正常组织（P<0.05），且其高表达与患者不良预后有关。ITGAV干扰组细胞在4、6、8 Gy射线照射克隆形成能力与阴性对照组相比显著降低（均P<0.05）。经6 Gy照射后，ITGAV干扰组细胞的凋亡率增加（PH1299R<0.0001, PA549R=0.0002），G2/M期细胞比例明显高于阴性对照组（PH1299R<0.0001, PA549R=0.0007）。结论 干扰ITGAV表达可以增加非小细胞肺癌放射敏感度。     

The proteasomal and apoptotic phenotype determine bortezomib sensitivity of non-small cell lung cancer cells

Bortezomib is a novel anti-cancer agent which has shown promising activity in non-small lung cancer (NSCLC) patients. However, only a subset of patients respond to this treatment. We show that NSCLC cell lines are differentially sensitive to bortezomib, IC₅₀ values ranging from 5 to 83 nM. The apoptosis-inducing potential of bortezomib in NSCLC cells was found to be dependent not only on the apoptotic phenotype but also on the proteasomal phenotype of individual cell lines. Upon effective proteasome inhibition, H460 cells were more susceptible to apoptosis induction by bortezomib than SW1573 cells, indicating a different apoptotic phenotype. However, exposure to a low dose of bortezomib did only result in SW1573 cells, and not in H460 cells, in inhibition of proteasome activity and subsequent apoptosis. This suggests a different proteasomal phenotype as well. Additionally, overexpression of anti-apoptotic protein Bcl-2 in H460 cells did not affect the proteasomal phenotype of H460 cells but did result in decreased bortezomib-induced apoptosis. In conclusion, successful proteasome-inhibitor based treatment strategies in NSCLC face the challenge of having to overcome apoptosis resistance as well as proteasomal resistance of individual lung cancer cells. Further studies in NSCLC are warranted to elucidate underlying mechanisms.     

不同非小细胞肺癌细胞株中DNA-PKcs的表达及其与放射敏感性的关系

背景与目的：DNA依赖蛋白激酶催化亚基（DNA—dependent protein kinase catalytic subunit,DNA—PKcs）在电离辐射引起的DNA双链断裂的修复过程中起着关键作用,可影响组织细胞对放射治疗的敏感性。本研究通过检测DNA—PKcs在不同组织学类型非小细胞肺癌（non-small cell lung cancer,NSCLC）细胞中的表达情况,探讨其与放射敏感性的关系。方法：Western blot及DNA—PK活性分析法检测NSCLC细胞株A549、H1299、L78、PGCL3和H460中DNA—PKcs的含量与活性。成克隆实验分别测定各细胞株照射后的剂量一存活曲线,并分析放射敏感性与DNA—PKcs的关系。结果：成克隆实验结果显示：不同NSCLC细胞株的放射敏感性不同,A549细胞2Gy剂量照射下的存活分数（survival fraction at 2Gy,SF2）为0．74,H1299细胞为0．25,H460细胞为0．21,PGCL3细胞为0．48．L78细胞为0．58。Western blot显示各NSCLC细胞株中DNA-PKcs的表达有差异．A549细胞的DNA—PKcs表达水平为3．26±0．98,L78细胞为0．51±0．07,H1299细胞为0．51±0．11,H460细胞为0．86±0．23,PGCL3细胞为2．60±0．76。A549细胞的DNA—PKcs活性为8．30±1．03,H1299细胞为2．45±0．52,H460细胞为0．11±0．02。PGCL3细胞为4．13±0．87．L78细胞为0．42±0．07。在腺癌及大细胞癌中SF2与DNA—PKcs含量（P〈0．05,r=0．95）及活性（P=0．03,r=0．98）呈线性相关。结论：在腺癌及大细胞癌中．DNA-PKcs是判断细胞放射敏感性的重要因素。     

Sensitivity of proteasome to its inhibitors increases during cAMP-induced differentiation of neuroblastoma cells in culture and causes decreased viability

Inhibition of proteasome activity is associated with a reduction in proliferation and apoptosis in cancer cells, depending upon the extent of inhibition. We have reported that a minimal inhibition of proteasome activity prevented adenosine 3'5'-cyclic monophosphate (cAMP)-induced differentiation and caused apoptosis in murine neuroblastoma (NB) cells in culture. In order to establish whether an elevated cAMP level increases the sensitivity of proteasome to its inhibitors, MG-132 and lactacystin (proteasome inhibitors) were added concomitantly with a stimulator of adenylate cyclase (prostaglandin A1) and an inhibitor of cyclic nucleotide phosphodiesterase (RO20-1724). Results showed that concentrations of MG-132 that did not reduce or that minimally inhibited proteasome activity also did not affect the proliferation of undifferentiated NB cells. However, these concentrations of MG-132 in the presence of an elevated cAMP level markedly inhibited proteasome activity and caused extensive cell death. Similar results were obtained with lactacystin. In normal murine fibroblasts, cAMP-induced reduction in proliferation was not affected by any concentration of MG-132 used in this study. These results suggest that proteasome exhibits increased sensitivity to its inhibitors following an elevation of cAMP level in NB cells, but not in normal fibroblasts, and that this may account for the enhanced cell death in NB cells. Thus, the strategy of using low doses of a proteasome inhibitor in combination with a cAMP-stimulating agent may be useful in pre-clinical and clinical studies on NB tumor because of the selectivity of the effect on cancer cells.     

Proteasome inhibitors potentiate leukemic cell apoptosis induced by the cyclin-dependent kinase inhibitor flavopiridol through a SAPK/JNK- and NF-kappaB-dependent process

Interactions between proteasome and cyclin-dependent kinase inhibitors have been examined in human leukemia cells in relation to induction of apoptosis. Simultaneous exposure (24 h) of U937 myelomonocytic leukemia cells to 100 nM flavopiridol and 300 nM MG-132 resulted in a marked increase in mitochondrial injury (cytochrome c, Smac/DIABLO release, loss of deltaPsi(m)), caspase activation, and synergistic induction of cell death, accompanied by a marked decrease in clonogenic potential. Similar effects were observed with other proteasome inhibitors (e.g., Bortezomib (VELCADE trade mark bortezomib or injection), lactacystin, LLnL) and cyclin-dependent kinase inhibitors (e.g., roscovitine), as well as other leukemia cell types (e.g., HL-60, Jurkat, Raji). In U937 cells, synergistic interactions between MG-132 and flavopiridol were associated with multiple perturbations in expression/activation of signaling- and survival-related proteins, including downregulation of XIAP and Mcl-1, activation of JNK and p34(cdc2), and diminished expression of p21(CIP1). The lethal effects of MG-132/flavopiridol were not reduced in leukemic cells ectopically expressing Bcl-2, but were partially attenuated in cells ectopically expressing dominant-negative caspase-8 or CrmA. Flavopiridol/proteasome inhibitor-mediated lethality was also significantly diminished by agents and siRNA blocking JNK activation. Lastly, coadministration of MG-132 with flavopiridol resulted in diminished DNA binding of NF-kappaB. Notably, pharmacologic interruption of the NF-kappaB pathway (e.g., by BAY 11-7082, PDTC, or SN-50) or molecular dysregulation of NF-kappaB (i.e., in cells ectopically expressing an IkappaBalpha super-repressor) mimicked the actions of proteasome inhibitors in promoting flavopiridol-induced mitochondrial injury, JNK activation, and apoptosis. Together, these findings indicate that proteasome inhibitors strikingly lower the apoptotic threshold of leukemic cells exposed to pharmacologic CDK inhibitors, and suggest that interruption of the NF-kappaB cytoprotective pathway and JNK activation both play key roles in this phenomenon. They also raise the possibility that combining proteasome and CDK inhibitors could represent a novel antileukemic strategy.     

Loss of expression of the differentially expressed in adenocarcinoma of the lung (DAL-1) protein is associated with metastasis of non-small cell lung carcinoma cells

The differentially expressed in adenocarcinoma of the lung-1 (DAL-1) protein is a member of the membrane-associated cytoskeleton protein 4.1 family. This protein was previously found to be downregulated or lost in more than half of primary non-small cell lung cancers (NSCLC). In this study, the relationship between DAL-1 expression and NSCLC metastasis was examined. DAL-1 mRNA and protein levels were measured in NSCLC cell lines and in tumor cells isolated from the pleural fluid of NSCLC patients clinically diagnosed with distant metastases to the bone or brain. The results revealed that DAL-1 expression was observed in two (GLC-82 and NCI-H460) out of seven metastatic NSCLC cell lines examined. DAL-1 expression was not observed in the cells isolated from the pleural fluid in nine out of ten patients. Overexpression of DAL-1 in A549 cells, a cell line lacking endogenous DAL-1, inhibited cell migration and invasion by approximately 38 and 48?%, respectively. In contrast, DAL-1 knockdown in NCI-H460 cells enhanced the migration and invasion potential of this cell line 4.6- and 3-fold, respectively. Furthermore, DAL-1 promoter methylation was observed in six of nine pleural fluid NSCLC cell isolates and in two cell lines (A549 and H1299), as evidenced by a lack of endogenous DAL-1. Demethylation in A549 cells successfully restored DAL-1 mRNA and protein expression levels, resulting in a parallel remarkable inhibition of migration and invasion. These results indicated that DAL-1 was pivotal in triggering NSCLC migration and invasion and that loss of DAL-1 expression was due to the epigenetic methylation.     

miR-492对非小细胞肺癌细胞迁移及侵袭能力的影响

目的:探讨miR-492对非小细胞肺癌（non-small cell lung cancer,NSCLC）细胞迁移和侵袭能力的影响,并探讨其可能的作用机制。方法:RT-qPCR检测NSCLC组织及细胞株（Calu-1、A549、H1650和H1299）中miR-492的表达。A549细胞瞬时转染miR-492 mimics或miR-492 inhibitors,并通过划痕实验及Transwell实验检测细胞的迁移及侵袭能力。双荧光素酶实验证实miR-492调控的靶基因。结果:NSCLC组织及细胞株中miR-492表达明显升高。将miR-492 mimics转染A549细胞后,细胞的迁移和侵袭能力明显增强。将miR-492 inhibitors转染A549细胞后,细胞的迁移和侵袭能力明显减弱。PTPN9是miR-492的直接靶基因。结论:miR-492可能通过调节靶基因PTPN9,从而促进NSCLC细胞的迁移和侵袭。     

Bik/NBK accumulation correlates with apoptosis-induction by bortezomib (PS-341, Velcade) and other proteasome inhibitors

Proteasome inhibitors have emerged as promising anticancer therapeutic agents. Bortezomib (PS-341), a specific proteasome inhibitor, exhibits antitumor activity against a wide range of malignancies and has been approved by the US Food and Drug Administration for the treatment of relapsed or refractory multiple myeloma. However, the molecular mechanisms of bortezomib-mediated apoptosis remain unclear. To characterize the mechanisms of apoptosis induction by proteasome inhibitors, we examined levels of Bcl-2 protein family members (Bik/NBK, Bax, Bak, Bcl-2, and Bcl-XL), release of cytochrome c, and activation of caspase-9 and -3 in human colon cancer cell lines DLD1, LOVO, SW620, and HCT116; human lung cancer cell line H1299; and human ovarian cancer cell line SKOV3 after they were treated with bortezomib. The result showed that bortezomib induced rapid accumulation of Bik/NBK but not other Bcl-2 family members in all six cell lines. Bortezomib-mediated Bik/NBK accumulation and apoptosis were also observed in human embryonic kidney cells 293 and normal human bronchial epithelial cells. Moreover, dramatic Bik/NBK accumulation and apoptosis induction were observed when cells were treated with proteasome inhibitor MG132 and calpain inhibitor I (ALLN). Furthermore, no detectable changes in IkappaBalpha levels or in NFkappaB functionality were found after treatment with bortezomib. Finally, Bik/NBK accumulation was caused by stabilization of the protein from degradation and was associated with bortezomib cytotoxicity and apoptosis induction. Pretreatment of DLD1 cells with Bik/NBK siRNA reduced bortezomib-mediated Bik/NBK accumulation and cell death. Our results suggested that Bik/NBK is one of the mediators of proteasome inhibitor-induced apoptosis.     

miR-93 通过靶向EphA4 激活ERK通路促进非小细胞肺癌细胞的增殖和迁移

目的：探讨miR-93/Eph受体A4（EphA4）分子轴通过细胞外调节蛋白激酶（extracellular regulated protein kinases,ERK）通路对非小细胞肺癌（non-small cell lung cancer,NSCLC）H460 和H1299 细胞增殖和迁移的影响。方法：用qPCR 检测H460 和H1299 细胞中miR-93 表达水平。分别在H460 细胞中转染miR-93 模拟物（mimics）和EphA4 过表达质粒、在H1299 细胞中转染miR-93 抑制剂（inhibitor）后,用MTT、Transwell 实验检测miR-93 对转染细胞增殖和迁移的影响。用双荧光素酶报告基因实验验证miR-93 与EphA4 之间的靶向调控关系。用Western blotting检测细胞中增殖细胞核抗原（proliferating cell nuclear antigen,PCNA）、EphA4、ERK和p-ERK 蛋白的表达水平,用MTT、Transwell 实验检测同时过表达miR-93 和EphA4 对H460 细胞增殖和迁移的影响。结果：miR-93 在H1299 细胞中表达水平高于H460 细胞（P<0.01）。过表达miR-93 促进H460 细胞增殖和迁移（均P<0.01）,敲低miR-93 抑制H1299 细胞增殖和迁移（均P<0.01）。双荧光素酶报告基因实验证实miR-93靶向调控EphA4,过表达miR-93明显下调H460细胞中EphA4 mRNA和蛋白表达水平（均P<0.05）,过表达miR-93 通过靶向EphA4 并激活ERK通路促进H460 细胞的增殖和迁移（均P<0.01）。结论：miR-93 促进NSCLC细胞增殖和迁移,其机制可能与靶向调控EphA4 并激活ERK通路有关。