MiR-1307-5p targeting TRAF3 upregulates the MAPK/NF-κB pathway and promotes lung adenocarcinoma proliferation

Abstract Background Non-small cell lung cancer (NSCLC) includes lung adenocarcinoma (LUAD) and lung squamous cell carcinoma (LUSC). MicroRNA (miRNA) plays an important role in the regulation of post-transcriptional gene expression in animals and plants, especially in lung adenocarcinoma. Methods MiR-1307-5p is an miRNA with significant differences screened by the second generation of high-throughput sequencing in the early stage of our research group. In the current study, a series of in vitro and in vivo experiments were carried out. MiR-1307-5p mimic, miR-1307-5p inhibitor, and NC were transfected into A549 and H1299 lung adenocarcinoma cells. The correlation between miR-1307-5p and clinicopathological features in pathological samples was analyzed using a lung adenocarcinoma tissue microarray, and miR-1307-5p expression was detected by qPCR. CCK-8, EdU, colony formation, scratch test, and Transwell assays were used to observe cell proliferation and migration. Double luciferase assay, western blot, qPCR, and immunohistochemistry were employed in confirming the target relationship between miR-1307-5p and TRAF3. Western blotting was used to analyze the relationship between miR-1307-5p and the NF-κB/MAPK pathway. Finally, the effect of miR-1307-5p on tumor growth was studied using a subcutaneous tumorigenesis model in nude mice. Results Increased miR-1307-5p expression was significantly related to decreased overall survival rate of lung adenocarcinoma patients, revealing miR-1307-5p as a potential oncogene in lung adenocarcinoma. MiR-1307-5p mimic significantly promoted while miR-1307-5p inhibitor reduced the growth and proliferation of A549 and H1299 cells. MiR-1307-5p overexpression significantly enhanced the migration ability while miR-1307-5p inhibition reduced the migration ability of A549 and H1299 cells. Target binding of miR-1307-5p to TRAF3 was confirmed by double luciferase assay, western blot, qPCR, and immunohistochemistry. miR-1307-5p caused degradation of TRAF3 mRNA and protein. MiR-1307-5p targeted TRAF3 and activated the NF-κB/MAPK pathway. TRAF3 colocalized with p65 and the localization of TRAF3 and p65 changed in each treatment group. Tumor volume of the lv-miR-1307-5p group was significantly larger than that of the lv-NC group, and that of the lv-miR-1307-5p-inhibitor group was significantly smaller than that of the lv-NC group. Conclusion In conclusion, miR-1307-5p targets TRAF3 and activates the NF-κB/MAPK pathway to promote proliferation in lung adenocarcinoma.

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Effect of bypass kinase pathways on acquired CDK4/6 inhibitor resistance.

Journal of Clinical Oncology ◽

10.1200/jco.2018.36.6_suppl.379 ◽

2018 ◽

Vol 36 (6_suppl) ◽

pp. 379-379

Author(s):

Renee De Leeuw ◽

Christopher McNair ◽

Matthew Joseph Schiewer ◽

Neermala Poudel Neupane ◽

Michael Augello ◽

...

Keyword(s):

Mapk Pathway ◽

Early Stage ◽

Mapk Signaling ◽

Cross Resistance ◽

Mek Inhibitors ◽

Mesenchymal Transition ◽

Inhibitor Resistance ◽

Tumor Types

379 Background: Cyclin Dependent Kinase-4/6 (CDK4/6) kinase inhibitors have shown clinical benefit in treatment of solid tumor types, including breast cancer. However, resistance is common, and the underpinning mechanisms of action are not well understood. Given the dependence of CDK4/6 inhibitors on retinoblastoma tumor suppressor (RB) function for activity, this class of agents may be particularly effective in tumor types for which RB loss is infrequent or occurs late in tumor progression. Methods: Here, models of acquired palbociclib resistance were generated in early stage, RB positive cancers, wherein it was shown acquired palbociclib resistance resulted in cross-resistance to other CDK4/6 inhibitors under clinical testing. Results: Cells showing acquired resistance exhibited aggressive in vitro and in vivo phenotypes without genetic loss of RB or RB pathway members, including enhanced proliferative capacity, migratory potential, and characteristics of epithelial to mesenchymal transition. Further analyses through integration of RNA sequencing and phospho-proteomics identified activation of the MAPK signaling pathway as a mediator of CDK4/6 inhibitor resistance, capable of bypassing CDK4/6 activity. However, this altered kinase dependence resulted in sensitization to MEK inhibitors, suggestive of new clinical opportunities in CDK4/6 resistant tumors. Conclusions: In sum, the studies herein not only identify activation of the MAPK pathway as capable of bypassing the CDK4/6 requirement and promoting aggressive tumor characteristics, but nominate MEK inhibitors as potential mechanisms to treat or prevent CDK4/6 inhibitor resistance.

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Enhancing the Therapeutic Efficacy of KRASG12C Inhibitors in Lung Adenocarcinoma Cell Models by Cotargeting the MAPK Pathway or HSP90

Journal of Oncology ◽

10.1155/2021/2721466 ◽

2021 ◽

Vol 2021 ◽

pp. 1-13

Author(s):

Ying Liu ◽

Lei Wu ◽

Hong Lu ◽

En Wu ◽

Jun Ni ◽

...

Keyword(s):

Drug Resistance ◽

Lung Adenocarcinoma ◽

Tyrosine Kinases ◽

Tumor Regression ◽

Mapk Pathway ◽

Transcriptional Profiling ◽

Multidrug Resistant ◽

Mitogen Activated Protein Kinase

Background. KRASG12C inhibitors have shown promising efficacy in early clinical trials, but drug resistance compromises their long-term benefits. Therefore, it is critical to understand the mechanisms of drug resistance and to design appropriate combinatory treatments to improve efficacy. Methods. To understand the comprehensive mechanisms of drug resistance, we treated lung cancer cells with KRASG12C inhibitors for different periods and performed transcriptional profiling and signaling analysis to identify critical factors and pathways that drive drug tolerance and resistance. We also evaluated several drug combinations in vitro and in vivo to identify potentially effective therapeutics. Results. We found that the feedback activation of multiple receptor tyrosine kinases (RTKs) may have cooperatively induced intrinsic and adaptive resistance to KRASG12C inhibitors. Notably, continuous KRAS inhibition induced a multidrug-resistant phenotype, implying that upfront combinatory treatment might be required to treat this group of patients. We also demonstrated that concurrently targeting multiple nodes in the RTK/RAS/RAF/MEK/ERK axis improved the efficacy of KRASG12C inhibitors, mainly by suppressing the reactivation of the mitogen-activated protein kinase (MAPK) pathway. Moreover, the combined use of HSP90 and KRASG12C inhibitors effectively induced tumor regression in lung adenocarcinoma models in vitro and in vivo. Conclusion. Together, our findings revealed mechanisms underlying KRASG12C inhibitors resistance and provided novel candidate combinatory strategies to improve their anticancer activity.

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Hypoxia-Related Gene FUT11 Promoted Pancreatic Cancer Progression Via Maintaining The Stabilization of PDK1

10.21203/rs.3.rs-152464/v2 ◽

2021 ◽

Author(s):

Wenpeng Cao ◽

Zhirui Zeng ◽

Runsang Pan ◽

Zhiwei He ◽

Hao Wu ◽

...

Keyword(s):

Pancreatic Cancer ◽

Cell Growth ◽

Western Blot ◽

Cancer Progression ◽

Pyruvate Dehydrogenase Kinase ◽

Cell Counting ◽

Luciferase Assay ◽

Migration And Invasion

Abstract Background: Hypoxia participated in the occurrence and development of pancreatic cancer (PC). However, genes associated with hypoxia respond and their regulated mechanism in PC cells were unclear. The current research was aimed to illuminate the role and hypoxia regulated mechanism of fucosyltransferase 11 (FUT11) in the progression of PC.Methods: After predicting FUT11 as a key hypoxia associated gene in PC using bioinformatics analysis. The expression of FUT11 in PC using quantitative real-time fluorescent PCR, western blot and immunohistochemistry. The effects of FUT11 on PC cells proliferation, migration and invasion under normoxia and hypoxia were detected using Cell Counting Kit 8, 5-ethynyl-2’-deoxyuridine assay, colony formation assay and transwell assay. Spleen capsule injected liver metastasis and subcutaneously injected model were performed to confirm the effects of FUT11 in vivo. Furthermore, western blot, luciferase assay and immunoprecipitation were performed to explore the regulated relationship among FUT11, hypoxia-inducible factor 1α (HIF1α) and pyruvate dehydrogenase kinase 1 (PDK1) in PC.Results: FUT11 was markedly increased of PC cells in hypoxia, up-regulated in the PC clinical tissues, and predicted a poor outcome. Inhibition of FUT11 reduced PC cell growth and mobility of PC cells under normoxia and hypoxia conditions in vitro, and growth and mobility in vivo. FUT11 bind with PDK1 and regulated the expression PDK1 under normoxia and hypoxia. FUT11 knockdown significantly increased the degradation rate of PDK1 under hypoxia, while treatment with MG132 can relieve the degradation of PDK1 induced by FUT11 knockdown. Overexpression of PDK1 in PC cells under hypoxia conditions reversed the suppressiv impacts of FUT11 knockdown on PC cell growth and mobility. In addition, HIF1α bound to the enhancer of FUT11 and increased its expression, as well as co-expressing with FUT11 in PC tissues. Furthermore, overexpress of FUT11 partially rescued the suppressiv effects of HIF1α knockdown on PC cell growth and mobility in hypoxia conditions.Conclusion: Our data further implicate that hypoxia-induced FUT11 in PC contributes to proliferation and metastasis by maintaining the stability of PDK1, and suggest FUT11 maybe a novel and effective target for treatment of pancreatic cancer.

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Elevated ANXA1 Expression Causes Glucocorticoid Resistance in Acute Lymphoblastic Leukemia Via Activating the Wnt/β-Catenin Signaling Pathway

Blood ◽

10.1182/blood-2019-130322 ◽

2019 ◽

Vol 134 (Supplement_1) ◽

pp. 5198-5198

Author(s):

Ping Liu ◽

Dan Ma ◽

Jishi Wang

Keyword(s):

Western Blot ◽

Cell Lines ◽

Conflicts Of Interest ◽

Expression Profiles ◽

Lymphoblastic Leukemia ◽

Luciferase Assay ◽

Protein Levels ◽

Leukemia Relapse

Background: Acute lymphoblastic leukaemia (ALL) is one of the most common clonal malignant diseases in children, and it stems from unchecked proliferation of lymphoid progenitor cells. Glucocorticoids (GCs) such as prednisolone and dexamethasone are used as a chemotherapeutic drug in the treatment of ALL. GC-induced cell mortality is first mediated by the activation of glucocorticoid receptor (GR), followed by its translocation into the nucleus to activate or inhibit gene transcription. However, up to ~20% patients with leukemia relapse and become resistant to GCs. Therefore, a better understanding the molecular basis of chemoresistance in ALL would provide novel therapeutic opportunities for patients. Methods: By analyzing the published mRNA expression profiles (GSE5280; GSE94302) obtained from NCBI (https://www.ncbi.nlm.nih.gov/geo/), we found that higher expression of ANXA1 was significantly associated with decreased overall survival of ALL patients. We also examined the expression of ANXA1 at mRNA and protein levels in a variety of ALL cell lines by using qRT-PCR and western blot analyses. The mRNA and protein expression of ANXA1 in ALL cell lines and patients were determined using Real-time PCR and Western blot respectively. Functional assays, such as CCK-8, FACS, and Tunel assay used to determine the oncogenic role of ANXA1 in ALL progression. Furthermore, western blotting and luciferase assay were used to determine the mechanism of ANXA1 promotes chemoresistance in ALL cells. Results: The expression of ANXA1 was markedly upregulated in ALL cell lines and patients, and high ANXA1 expression was associated with relapsed/refractory ALL patients. ANXA1 overexpression confers glucocorticoids (GCs) resistance on ALL cells; however, down-regulated of ANXA1 sensitized ALL cell lines to GC both in vitro and in vivo. Additionally, ANXA1 upregulated the levels of FPRs by promoting Wnt/β-catenin signalling. Conclusions: Our findings provided evidence that ANXA1 is a potential therapeutic target for patients with ALL. Targeting ANXA1 signaling may be a promising strategy to enhance GC response during ALL chemo-resistance. Disclosures No relevant conflicts of interest to declare.

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CircRNA_0000392 Promotes Colorectal Cancer Progression by Sponging miR-193a-5p

10.21203/rs.3.rs-59369/v1 ◽

2020 ◽

Author(s):

Hanchen Xu ◽

Yujing Liu ◽

Peiqiu Cheng ◽

Chunyan Wang ◽

Yang Liu ◽

...

Keyword(s):

Colorectal Cancer ◽

Expression Profile ◽

High Throughput ◽

Molecular Mechanisms ◽

High Throughput Sequencing ◽

Malignant Progression ◽

Luciferase Assay ◽

Circular Rnas

Abstract Background: Circular RNAs (circRNAs), an important member of the non-coding RNA family, have been revealed the role in the pathogenic progression of diseases in recent years, particularly in the malignant progression of cancer. With the application of high-throughput sequencing technology, a large number of circRNAs have been found in tumor tissues, and some circRNAs have demonstrated the role as oncogenic genes. In this study, we analyzed the circRNA expression profile in colorectal cancer (CRC) tissues and normal adjacent tissues by high-throughput sequencing, focusing on the circRNA_0000392, a circRNA with significantly increased expression in colorectal cancer tissues, and further investigating its function in the progression of colorectal cancer.Methods: The expression profile of circRNAs in 6 pairs of CRC tissues and normal adjacent tissues was analyzed by RNA-sequencing. We verified the differential circRNAs with expanded samples by qRT-PCR, focused on circRNA_0000392, and evaluated its associations with clinicopathological features. Then we knocked down circRNA_0000392 in CRC cells and evaluated the effect in vitro and in vivo by functional experiments. The dual luciferase assay and RNA pull-down were performed to further explore the downstream potential molecular mechanisms.Results: CircRNA_0000392 was significantly up-regulated in CRC compared with normal adjacent tissues and cell line. The expression level of circRNA_0000392 was positively correlated with the malignant progression of CRC. Functional studies revealed that reducing the expression of circRNA_0000392 could inhibit the proliferation and invasion of CRC both in vitro and in vivo. Mechanistically, circRNA_0000392 could act as a sponge of miR-193a-5p and regulate the expression of PIK3R3, then affect the activation of the AKT-mTOR pathway in CRC cells.Conclusions: The circRNA_0000392 has the function as an oncogene through miR-193a-5p/PIK3R3-Akt axis in CRC cells, implying that circRNA_0000392 is a potential therapeutic target for the treatment of colorectal cancer and a predictive marker for CRC patients.

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GRP75-upregulated HMGA1 Expression Promotes Stage I Lung Adenocarcinoma Progression by Activating the JNK/c-JUN Signaling Pathway

10.21203/rs.3.rs-92170/v1 ◽

2020 ◽

Author(s):

Guo-Bing Qiao ◽

Ren-Tao Wang ◽

Shu-Nan Wang ◽

Shaolin Tao ◽

Qun-You Tan ◽

...

Keyword(s):

Cell Growth ◽

Lung Adenocarcinoma ◽

Signaling Pathway ◽

Early Stage ◽

High Mobility ◽

Stage I ◽

Sequencing Analysis ◽

Hmga1 Expression

Abstract Background: Recurrence is a major challenge in early-stage lung adenocarcinoma (LUAD) treatment. However, the recurrence mechanism is still unclear, and no biomarkers can predict recurrence in early-stage LUAD. Here, we investigated the role and mechanism of high-mobility group AT-hook 1 (HMGA1) and glucose-regulated protein 75-kDa (GRP75) in stage I LUAD and evaluated their potential as biomarkers for predicting the recurrence and prognosis of stage I LUAD.Methods: A TCGA dataset was used to investigate the clinical significance of HMGA1 and GRP75 in early-stage LUAD. Western blotting and immunohistochemistry were used to measure protein expression levels. The biological functions of HMGA1 and GRP75 in LUAD were investigated both in vitro and in vivo through overexpression and knockdown experiments. The interaction and regulation between HMGA1 and GRP75 were evaluated with coimmunoprecipitation and ubiquitination assays. The downstream signaling pathway of the GRP75/HMGA1 axis was investigated by mRNA-sequencing analysis.Results: High expression of HMGA1 and GRP75 was associated with recurrence and a poor prognosis in stage I LUAD patients. In particular, HMGA1 had potential as an independent prognostic factor. Overexpression of GRP75 or HMGA1 promoted LUAD cell growth and metastasis, while silencing GRP75 or HMGA1 inhibited LUAD cell growth and metastasis. In vitro and clinical data showed that the expression level of GRP75 positively regulated HMGA1 in LUAD and that GRP75 played an HMGA1-dependent role. In addition, GRP75 prolonged the half-life of HMGA1 by inhibiting HMGA1 ubiquitination via direct binding to HMGA1. Finally, we demonstrated that the GRP75/HMGA1 axis played a role by activating JNK/c-JUN signaling in LUAD.Conclusions: The activation of GRP75/HMGA1/JNK/c-JUN signaling is an important mechanism that promotes the progression of stage I LUAD, and a high level of HMGA1 is a novel biomarker for predicting recurrence and prognosis in patients with stage I LUAD.

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Abstract 249: Mir-211 Regulates Bone Marrow Mesenchymal Stem Cells Migration Through Stat5a

Circulation Research ◽

10.1161/res.115.suppl_1.249 ◽

2014 ◽

Vol 115 (suppl_1) ◽

Author(s):

Xin Yang Hu ◽

Panpan Chen ◽

Yan Wu ◽

Wei Zhu ◽

Jian-an Wang

Keyword(s):

Stem Cells ◽

Mesenchymal Stem Cells ◽

Cardiac Function ◽

Western Blot ◽

Target Genes ◽

Luciferase Assay ◽

Rt Pcr ◽

Transwell Assay ◽

Migration Ability

Background: Efficacy of intravenous mesenchymal stem cells (MSCs) administration for myocardial infarction (MI) is limited by low cell migration to the damaged myocardium. Our previous study demostrated that migration ability of MSCs enhanced by hypoxia preconditioning (HPC). miRNA microarray displayed that miR-211 exhibited most significant change between HPC and normoxia cultured MSCs. The aim of this study is to study whether and how miR-211 regulate MSCs migration. Methods: In vitro, transwell assay were used to assess the migration ability of MSC moduated by miR-211 using overexpressing and knockdown lentivirus. The target gene of miR-211 predicted by Targetscan were verified by PCR, western blot and lucifurase assay. Chromatin immunoprecitation (ChiP) were used to explore the transcription factors that regulate the expression of miR-211. To evaluate the effect of miR-211 on MSCs migration in vivo, miR-211-mimic and miR-211-shRNA male MSCs were intravenously delivered 24h after MI, the engraft cells were detected by RT-PCR of SRY gene. Results: Quatitative RT-PCR showed that miR-211 expression of MSCs upregulated by HPC. MiR-211 mimic improved MSCs migration by 31.03% (p<0.05), however, knockdown miR-211 using shRNA attenuated MSCs migration ability significantly. Signal transducer and activator of transcription 5A (STAT5A) was predicted as one of miR-211 target genes, PCR and Western blot showed miR-211 overexpression dramatically decreased STAT5A expression, while miR-211 knockdown upregulated STAT5A. The luciferase assay showed the similar results. Transwell assay showed that STAT5A knockdown reverse the inhibition of MSCs migration induced by miR-211-shRNA. Intrestingly, ChiP assay showed that STAT5A can combine to the promoter of miR-211, which lead to the regulation of miR-211 transcription. In vivo data showed that MiR-211 overexpression enhanced MSCs homing to ischemic myocardium, and miR-211 overexprssing MSCs improved cardiac function 28days post-MI. However, miR-211 knockdown decreased MSCs homing and hampered cardiac function recovery. Conclusions: These results indicate that miR-211 has important role in regulating MSCs migration through targeting STAT5A, meanwhile STAT5A regulated miR-211 transcription.

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LncRNA ST7-AS1, by regulating miR-181b-5p/KPNA4 axis, promotes the malignancy of lung adenocarcinoma

Cancer Cell International ◽

10.1186/s12935-020-01652-7 ◽

2020 ◽

Vol 20 (1) ◽

Author(s):

Rong-Hang Hu ◽

Zi-Teng Zhang ◽

Hai-Xiang Wei ◽

Lu Ning ◽

Jiang-Shan Ai ◽

...

Keyword(s):

Lung Adenocarcinoma ◽

Noncoding Rna ◽

Molecular Mechanisms ◽

Epithelial Mesenchymal Transition ◽

Luciferase Assay ◽

Migration And Invasion ◽

Loss Of Function ◽

Mesenchymal Transition

Abstract Background Growing evidence suggests that suppressor of tumorigenicity 7 antisense RNA 1 (ST7-AS1) is an oncogenic long noncoding RNA (lncRNA). However, little is known on its clinical significance, biological functions, or molecular mechanisms in lung adenocarcinoma (LUAD). Methods The expression of ST7-AS1 and miR-181b-5p were examined by qRT-PCR. The correlations between ST7-AS1 level and different clinicopathological features were analysed. In vitro, LUAD cells were examined for cell viability, migration and invasion by MTT, wound healing and Transwell assay, respectively. Epithelial-mesenchymal transition (EMT) biomarkers were detected by Western blot. The regulations between ST7-AS1, miR-181b-5p, and KPNA4 were examined by luciferase assay, RNA immunoprecipitation, RNA pulldown. Both gain- and loss-of-function strategies were used to assess the importance of different signalling molecules in malignant phenotypes of LUAD cells. The in vivo effect was analysed using the xenograft and the experimental metastasis mouse models. Results ST7-AS1 was upregulated in LUAD tissues or cell lines, correlated with tumours of positive lymph node metastasis or higher TNM stages, and associated with shorter overall survival of LUAD patients. ST7-AS1 essentially maintained the viability, migration, invasion, and EMT of LUAD cells. The oncogenic activities of ST7-AS1 were accomplished by sponging miR-181b-5p and releasing the suppression of the latter on KPNA4. In LUAD tissues, ST7-AS1 level positively correlated with that of KPNA4 and negatively with miR-181b-5p level. In vivo, targeting ST7-AS1 significantly inhibited xenograft growth and metastasis. Conclusions ST7-AS1, by regulating miR-181b-5p/KPNA4 axis, promotes the malignancy of LUAD cells. Targeting ST7-AS1 and KPNA4 or up-regulating miR-181b-5p, therefore, may benefit the treatment of LUAD.

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Ral GTPases targeted by miR-215-5p promote lung cancer proliferation and migration

10.21203/rs.3.rs-35058/v1 ◽

2020 ◽

Author(s):

Hao Zhu ◽

Shufang Cui ◽

Gentao Fan ◽

Jing Zhang ◽

Xiaofeng Hua ◽

...

Keyword(s):

Lung Cancer ◽

Western Blot ◽

Luciferase Assay ◽

Rt Pcr ◽

Cancer Proliferation ◽

Ral Gtpases ◽

And Migration ◽

Proliferation And Migration

Abstract Background The Ras-like guanosine triphosphatases (Ral GTPases) belongs to the Ras superfamily of small GTPases. Ras mutations occur in more than one in three human tumors. However, treatments acting directly on Ras post-translational modifications were developed and have been manufactured for many years, although they have demonstrated poor clinical performance. Ral GTPases include RalA and RalB, seem to be a new potential pathway downstream of mutant Ras. Methods In this study, we examined protein and mRNA level of Ral GTPases in lung specimens from 12 lung cancer patients using Western Blot and RT-PCR. The effects of RalA and RalB on the proliferation and migration were examined by functional tests in vitro and in vivo. The binding site in miR-215-5p and RalA or RalB was predicted using bioinformatics software and proved by Western Blot, RT-PCR and luciferase assay. The effect of miR-215-5p on RalA and RalB were examined in cell lines and xenograft mice. Results Here, we reported that miR-215-5p was downregulated in human lung cancer tissues compared with noncancerous tissues, whereas the expression level of Ral GTPases was higher. We further verified that the negative regulation of Ral GTPases by miR-215-5p could inhibit the proliferation and migration of lung cancer in vitro and in vivo. Conclusion In this study, we reported that RalA and RalB promote lung cancer proliferation and migration. Moreover, we identified miR-215-5p as a tumor suppressor that targets Ral GTPases. Our results may offer therapeutic opportunities in lung cancer.

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Ezh2 Inhibitors Reverse Resistance to Gefitinib in Primary Egfr Wild-type Lung Cancer Cells

10.21203/rs.3.rs-33892/v1 ◽

2020 ◽

Author(s):

Hao Gong ◽

Yongwen Li ◽

Yin Yuan ◽

Weiting Li ◽

Hongbing Zhang ◽

...

Keyword(s):

Lung Cancer ◽

Lung Adenocarcinoma ◽

Cell Viability ◽

Lung Squamous Cell Carcinoma ◽

The Cancer Genome Atlas ◽

Egfr Mutations ◽

Wild Type ◽

Egfr Tkis

Abstract Background: Lung cancer is the leading cause of cancer-related death worldwide. Non–small-cell lung cancer (NSCLC) is the most common type of lung cancer. Traditional anticancer therapies involving epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors (EGFR-TKIs) have been proven beneficial in the treatment of patients with EGFR mutations. However, patients with EGFR wild-type NSCLC usually fail to respond to EGFR-TKIs. Enhancer of zeste homolog 2 (EZH2), a key molecule of the PRC2 complex, plays an important role in epigenetic regulation and is overexpressed in various tumors. EZH2 inhibitors sensitize various types of tumor cells to antitumor drugs. Therefore, this study aimed to investigate whether the EZH2 inhibitors GSK343 and DZNep, whencombined with gefitinib, can reverse EGFR-TKI resistance in EGFR wild-type NSCLC. Methods:EZH2 expression was evaluated using the RNA sequencing dataset of NSCLC patients (502 lung squamous cell carcinoma cases including 49 paracancerous lung tissues and 513 lung adenocarcinoma cases including 59 paracancerous lung tissues) from The Cancer Genome Atlas (TCGA). We simultaneously also verified EZH2 expressionin 40 NSCLC samples and their corresponding paracancerous lung tissues from our institution via quantitative PCR. The lung adenocarcinoma cell lines A549 and H1299 were treated with EZH2-specific small interfering RNA or EZH2 inhibitors and subjected to analyses of cell viability and apoptosis as well as of EGFR pathway protein expressions by western blotting. Results: EZH2 was upregulated in human NSCLC tissues and was correlated with poor prognosis in patients with lung adenocarcinoma based on data from both TCGA and our institution. Both EZH2 inhibitors sensitized A549 and H1299 cells to gefitinib and suppressed cell viability and proliferation in vitroby downregulating the phosphorylation of EGFR and AKT and inducing cell apoptosis. Co-administration of EZH2 inhibitors (GSK343 or DZNep) with gefitinib exerted stronger inhibitory effects on tumor activity, cell proliferation, and cell migration than single drug administration in vitro and in vivo.Conclusion: Co-administration of EZH2 inhibitors with EGFR-TKIs may be feasible for the treatment of EGFR wild-type NSCLC in patients who refuse traditional chemotherapy.

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