MicroRNAs in Non-small Cell Lung Cancer: Current Status and Future Therapeutic Promises

HDAC inhibitor ITF2357 reduces resistance of mutant-KRAS non-small cell lung cancer to pemetrexed through a HDAC2/miR-130a-3p-dependent mechanism

BACKGROUND

Histone deacetylases (HDAC) contribute to oncogenic program, pointing to their inhibitors as a potential strategy against cancers. We, thus, studied the mechanism of HDAC inhibitor ITF2357 in resistance of mutant (mut)-KRAS non-small cell lung cancer (NSCLC) to pemetrexed (Pem).

METHODS

We first determined the expression of NSCLC tumorigenesis-related HDAC2 and Rad51 in NSCLC tissues and cells. Next, we illustrated the effect of ITF2357 on the Pem resistance in wild type-KARS NSCLC cell line H1299, mut-KARS NSCLC cell line A549 and Pem-resistant mut-KARS cell line A549R in vitro and in xenografts of nude mice in vivo.

RESULTS

Expression of HDAC2 and Rad51 was upregulated in NSCLC tissues and cells. Accordingly, it was revealed that ITF2357 downregulated HDAC2 expression to diminish the resistance of H1299, A549 and A549R cells to Pem. HDAC2 bound to miR-130a-3p to upregulate its target gene Rad51. The in vitro findings were reproduced in vivo, where ITF2357 inhibited the HDAC2/miR-130a-3p/Rad51 axis to reduce the resistance of mut-KRAS NSCLC to Pem.

CONCLUSION

Taken together, HDAC inhibitor ITF2357 restores miR-130a-3p expression by inhibiting HDAC2, thereby repressing Rad51 and ultimately diminishing resistance of mut-KRAS NSCLC to Pem. Our findings suggested HDAC inhibitor ITF2357 as a promising adjuvant strategy to enhance the sensitivity of mut-KRAS NSCLC to Pem.

GEMIN6 Overexpression Correlates with the Low Immune Cell Infiltration and Poor Prognosis in Lung Adenocarcinoma

Background. Gem nuclear organelle-associated protein 6 (GEMIN6) is a component of the GEMINS protein family involved in the survival of motor neuron (SMN) complex. SMN interfered with snRNP assembly and mRNA processing resulting in tumorigenesis. We performed this study to explore the association between GEMIN6 and lung adenocarcinoma (LUAD). Methods. We used The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases to collect transcriptomic expression data of LUAD patients and analyze the difference in GEMIN6 expression between normal and tumor tissues of LUAD. qRT-PCR analysis was also performed to detect the expression of GEMIN6 in normal and LUAD cells. The expression of GEMIN6 on the LUAD patient survival outcome was estimated by the Kaplan–Meier curves and Cox analyses. In addition, the Metascape online tool and single-sample GSEA were employed to find out the underlying biological mechanisms of GEMIN6. Furthermore, the correlations of GEMIN6 expression with immune cell infiltration in LUAD were analyzed by ssGSEA and Spearman correlation analysis. Results. Compared with the normal tissues and cells, the expression of GEMIN6 was significantly higher in LUAD tissues and cells; the high expression GEMIN6 was also found in the advanced pathologic stage and advanced N and T stages of LUAD. GEMIN6 high expression was significantly associated with inferior overall survival. The heat map revealed the top 20 coexpressed genes with GEMIN6, including SF3B6, CPSF3, and PSMB3. Functional enrichment analysis demonstrated that enrichment genes are associated with the cell cycle, mRNA processing, and energy metabolism. Additionally, GEMIN6 was negatively related to the immune cell infiltration in LUAD. Conclusions. This study demonstrated that GEMIN6 was involved in the tumorigenesis and progression of LUAD. GEMIN6 could be an important molecular marker of poor prognosis and a therapeutic target of LUAD.

The expression of miRNA-216b is negatively correlated with 18F-FDG uptake in non-small cell lung cancer

Background

This study aimed to investigate the correlation between miRNA-216b expression in patients with non-small cell lung cancer (NSCLC) and ¹⁸F-fluorodeoxyglucose (FDG) uptake by PET/CT and to explore the clinical application value of 18F-FDG PET/CT in miRNA-216b based on therapy for NSCLC.

Methods

Eighty patients with NSCLC and 40 healthy subjects were enrolled in our study. The SUVmax of the lesion area by PET/CT imaging was calculated. SUVmax represented the highest concentration of 18F-FDG in the lesion. The expression of miRNA-216b in the plasma and fiber bronchoscopic puncture of NSCLC patients was detected by RT qPCR. Then Pearson correlation analysis was used to analyze the correlation between miRNA-216b expression and 18F-FDG uptake in patients with different types of NSCLC.

Results

Compared with healthy subjects, SUVmax of early adenocarcinoma and advanced adenocarcinoma were increased. Compared with healthy subjects, SUVmax of early squamous and advanced squamous were increased. And the SUVmax content of advanced adenocarcinoma and squamous cell carcinoma was higher than that of early adenocarcinoma and squamous cell carcinoma. Compared with healthy subjects, the expression of miRNA-216b in the plasma of patients with early and advanced adenocarcinoma was reduced, and the expression of miRNA-216b in the plasma of patients with early and advanced squamous cell carcinoma was reduced. Compared with adjacent tissues, the expression of miRNA-216b in early adenocarcinoma tissues and advanced adenocarcinoma tissues was reduced, and the expression in early squamous cell carcinoma and advanced squamous cell carcinoma was reduced. Pearson correlation analysis showed a negative correlation between SUVmax and miRNA-216b (plasma and tissue) in patients with four types of NSCLC.

Conclusion

miRNA-216b expression was negatively correlated with ¹⁸F-FDG uptake in NSCLC. miRNA-216b could be used for the classification and staging of non-small cell lung cancer. ¹⁸F-FDG PET/CT may be used to evaluate the therapeutic response in application of miRNA-216b-based cancer treatment.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12957-021-02376-2.

Effects of miR-132-3p on progress and epithelial mesenchymal transition of non-small cell lung cancer via regulating KLF7

Background

MicroRNAs (miRNAs) often appear as oncogenes or tumor suppressor genes. The aim of this research was to examine miR-132-3p and Kruppel-like factor 7 (KLF7) effects in the development of non-small cell lung cancer (NSCLC).

Methods

We used quantitative reverse transcription polymerase chain reaction (qRT-PCR) to determine miR-132-3p expression in tissue specimens and 6 cells (A549, H1650, H292, H1299, H1944, BEAS-2b). Luciferase report forecasted the targeting relationship between miR-132-3p and KLF7. The expression of KLF7 and interstitial protein was determined by western blot. Proliferation test and Transwell assay were adopted for examining cell development. The Cell Counting Kit-8 (CCK-8) colorimetric method was used to observe the effects of miR-132-3p and KLF7 on the proliferation, metastasis, and invasion of NSCLC tumor cells. In order to determine whether the metastasis of NSCLC tumor cells was epithelial-mesenchymal transition (EMT)-mediated, supplementary experiments with E-cadherin and vimentin were performed.

Results

An increased expression of miR-132-3p was detected in NSCLC. Its mimic promoted the proliferation of tumor cells. As an immediate site of miR-132-3p, KLF7 was reversely adjusted via miR-132-3p and restrained the development of tumor cells in NSCLC, the effects of which were attenuated via KLF7 over-expression. Besides, the presence of EMT-related diversions was confirmed in NSCLC.

Conclusions

By targeting KLF7, miR-132-3p was capable of promoting the proceeding of NSCLC tumor cells. We discovered miR-132-3p/KLF7 route may exhibit curative target for NSCLC.

miR-101-3p sensitizes non-small cell lung cancer cells to irradiation

Recent studies have revealed that microRNAs regulate radiosensitivity of non-small cell lung cancer (NSCLC). The aim of this study was to investigate whether miR-101-3p is correlated with radiosensitivity of NSCLC. According to our results, miR-101-3p was downregulated in NSCLC tissues and cell lines. Moreover, miR-101-3p was decreased in A549 cells’ response to irradiation in a dose-dependent manner. Upregulation of miR-101-3p decreased survival fraction and colony formation rate and increased irradiation-induced apoptosis in irradiation-resistant cells, while miR-101-3p depletion had the opposite effects in irradiation-sensitive cells. Furthermore, mechanistic target of rapamycin (mTOR) is a target gene of miR-101-3p. The expressions of mTOR, p-mTOR, and p-S6 were curbed by overexpression of miR-101-3p in A549R cells, which was enhanced by repression of miR-101-3p in A549 cells. Intriguingly, elevation in mTOR abated miR-101-3p upregulation-induced increase in irradiation sensitivity in irradiation-resistant cell line. In contrast, rapamycin undermined miR-101-3p inhibitor-mediated reduction of irradiation sensitivity in irradiation-sensitive cell line. Besides, miR-101-3p overexpression enhanced the efficacy of radiation in an NSCLC xenograft mouse model. In conclusion, miR-101-3p sensitized A549 cells to irradiation via inhibition of mTOR-signaling pathway.

MicroRNA‑103 modulates tumor progression by targeting KLF7 in non‑small cell lung cancer

Numerous studies have identified that microRNAs (miRs) play a crucial role in the tumorigenesis of non-small cell lung cancer (NSCLC). However, to the best of our knowledge, the physiological function of miR-103 in NSCLC is not fully understood. Experiments in the present study revealed that miR-103 expression was increased in NSCLC cell lines. In addition, a series of methods, including MTT, colony formation, 5-ethynyl-2′-deoxyuridine, Transwell, wound healing, flow cytometric, reverse transcription-quantitative PCR and western blot assays, were performed, which revealed that overexpression of miR-103 enhanced cell growth, migration, invasion and epithelial-mesenchymal transition (EMT), and suppressed apoptosis of A549 and H1299 cells. Additionally, a dual-luciferase reporter assay indicated that miR-103 directly targets the 3′-untranslated region of Kruppel-like factor 7 (KLF7), and KLF7 expression was negatively regulated by miR-103 expression. Furthermore, the present findings demonstrated that miR-103 promoted EMT via regulating the Wnt/β-catenin signaling pathway in NSCLC. Collectively, the current results demonstrated that miR-103 serves a tumorigenesis role in NSCLC development by targeting KLF7, at least partly via the Wnt/β-catenin signaling pathway. Consequently, these findings indicated that miR-103/KLF7/Wnt/β-catenin may provide a novel insight into underlying biomarkers for improving the diagnosis and treatment of NSCLC.

MicroRNA-147b suppresses the proliferation and invasion of non-small-cell lung cancer cells through downregulation of Wnt/β-catenin signalling via targeting of RPS15A

Deregulation of microRNAs (miRNAs) leads to malignant growth and aggressive invasion during cancer occurrence and progression. miR-147b has emerged as one of the cancer-related miRNAs that are dysregulated in multiple cancers. Yet, the relevance of miR-147b in non-small-cell lung cancer (NSCLC) remains unclear. In the present study, we aimed to report the biological function and signalling pathways mediated by miR-147b in NSCLC. Our results demonstrate that miR-147b expression is significantly downregulated in NSCLC tissues and cell lines. Overexpression of miR-147b decreased the proliferative ability, colony-forming capability, and invasive potential of NSCLC cells. Notably, our study identified ribosomal protein S15A (RPS15A), an oncogene in NSCLC, as a target gene of miR-147b. Our results showed that miR-147b negatively modulates RPS15A expression in NSCLC cells. An inverse correlation between miR-147b and RPS15A was evidenced in NSCLC specimens. Moreover, miR-147b overexpression downregulated the activation of Wnt/β-catenin signalling via targeting of RPS15A. Overexpression of RPS15A partially reversed the miR-147b-mediated antitumour effect in NSCLC cells. Collectively, these findings reveal that miR-147b restricts the proliferation and invasion of NSCLC cells by inhibiting RPS15A-induced Wnt/β-catenin signalling and suggest that the miR-147b/RPS15A/Wnt/β-catenin axis is an important regulatory mechanism for malignant progression of NSCLC.

MicroRNA‑629 inhibition suppresses the viability and invasion of non‑small cell lung cancer cells by directly targeting RUNX3

Dysregulated microRNAs (miRNAs/miRs) directly modulate the biological functions of non‑small cell lung cancer (NSCLC) cells and contribute to the initiation and progression of NSCLC; however, the specific roles and underlying mechanisms of the dysregulated miRNAs in NSCLC require further investigation. The present study reported that miRNA‑629‑5p (miR‑629) was upregulated in NSCLC tissues and cell lines. High miR‑629 expression levels were significantly associated with tumour size, clinical stage and lymph node metastasis in patients with NSCLC. Functional experiments indicated that miR‑629 inhibition suppressed the viability and invasion NSCLC cells in vitro. Furthermore, bioinformatics prediction, luciferase reporter assay, reverse transcription‑quantitative polymerase chain reaction and western blot analysis demonstrated that runt‑related transcription factor 3 (RUNX3) was a direct target gene of miR‑629 in NSCLC. Restoration of RUNX3 expression suppressed the effects of miR‑629 inhibition in NSCLC cells. Rescue experiments revealed that RUNX3 knockdown partially abrogated the effects of miR‑629 inhibition on NSCLC cells. In summary, miR‑629 directly targeted RUNX3 to inhibit the progression of NSCLC, suggesting that this miRNA may be considered as a diagnostic and therapeutic target for patients with NSCLC.

FBXL3 is regulated by miRNA-4735-3p and suppresses cell proliferation and migration in non-small cell lung cancer

Non-small cell lung cancer (NSCLC) is the most common type of primary lung cancer and regarded as cancer killer. The aim of this study was to discover the detailed function and molecular mechanism of F-box and leucine rich repeat protein 3 (FBXL3) in NSCLC. In this study, the expression level of FBXL3 in NSCLC tissues and cell lines was firstly examined and identified. Moreover, the relationship between FBXL3 and the overall survival rate of NSCLC patients was analyzed by Kaplan-Meier survival curve. Functionally, MTT, colony formation assay and transwell assays were performed to determine the role of FBXL3 in regulating NSCLC cell proliferation, migration and invasion. The proliferation and migration were suppressed by overexpression of FBXL3, indicating the potential tumor suppressive role of FBXL3 in NSCLC. In addition, the dual-luciferase reporter and RNA pull-down assays revealed that miR-4735-3p was a novel upstream modulator of FBXL3. Further study showed that miR-4735-3p was upregulated in NSCLC tissues and cell lines. Finally, rescue assays and function assays revealed that miR-4735-3p exerted oncogenic function in NSCLC, and this function can be attenuated by FBXL3. Taken together, FBXL3 was regulated by miR-4735-3p and suppressed cell proliferation and invasion in non-small cell lung cancer.

Nucleic Acid-Based Therapeutics for Pulmonary Diseases

Nucleic acid-based therapeutics present huge potential in the treatment of pulmonary diseases ranging from lung cancer to asthma and chronic pulmonary diseases, which are often fatal and widely prevalent. The susceptibility of nucleic acids to degradation and the complex structure of lungs retard the effective pulmonary delivery of nucleic acid drug. To overcome these barriers, different strategies have been exploited to increase the delivery efficiency using chemically synthesized nucleic acids, vector encapsulation, proper formulation, and administration route. However, several limitations regarding off-target effects and immune stimulation of nucleic acid drugs hamper their translation into the clinical practice. Therefore, their successful clinical application will ultimately rely on well-developed carriers and methods to ensure safety and efficacy. In this review, we provide a comprehensive overview of the nucleic acid application for pulmonary diseases, covering action mechanism of the nucleic acid drugs, the novel delivery systems, and the current formulation for the administration to lungs. The latest advances of nucleic acid drugs under clinical evaluation to treat pulmonary disorders will also be detailed.

MicroRNA-598 inhibits the proliferation and invasion of non-small cell lung cancer cells by directly targeting ZEB2

An increasing number of studies have observed that microRNAs (miRNAs) are abnormally expressed in non-small cell lung cancer (NSCLC), and that their aberrant expression links with the progression and development of NSCLC. Therefore, it is necessary to full elucidate the specific roles of miRNAs in NSCLC, as this may facilitate the identification of novel therapeutic targets. In the present study, it was observed that miRNA-598 (miR-598) expression was significantly downregulated in NSCLC tissues and cell lines. Decreased miR-598 was negatively correlated with TNM stage and lymph node metastasis in NSCLC patients. In addition, ectopic expression of miR-598 reduced NSCLC cell proliferation and invasion in vitro. The zinc finger E-box-binding homeobox 2 (ZEB2) was validated as a direct target of miR-598 in NSCLC cells. ZEB2 was upregulated in NSCLC tissues and the upregulation of ZEB2 was inversely correlated with the miR-598 level. The results revealed that restored ZEB2 expression abrogated the inhibitory effects of miR-598 overexpression in NSCLC cells. In conclusion, the results of the present study revealed that miR-598 may inhibit the progression of NSCLC by directly targeting ZEB2, which suggests that this miRNA may be identified as a potential novel prognostic biomarker and therapeutic target for patients with NSCLC.

MicroRNA-1179 suppresses cell growth and invasion by targeting sperm-associated antigen 5-mediated Akt signaling in human non-small cell lung cancer

Accumulating evidence has identified microRNA-1179 (miR-1179) as a novel cancer-related miRNA that is dysregulated in multiple cancers and plays an important role in regulating cancer development and progression. However, little is known about the role of miR-1179 in non-small cell lung cancer (NSCLC). Thus, in the present study, we aimed to investigate the potential biological function and regulatory mechanism of miR-1179 in NSCLC. The results showed that decreased expression of miR-1179 expression was frequently detected in primary NSCLC tissues and cell lines. Overexpression of miR-1179 suppressed the growth and invasion of NSCLC cells in vitro while its inhibition promoted the opposite effect. Sperm-associated antigen 5 (SPAG5) was an identified as a target gene of miR-1179. Moreover, SPAG5 expression was increased in NSCLC cells and showed an inverse correlation with miR-1179 in NSCLC specimens. SPAG5 knockdown inhibited the growth and invasion of NSCLC cells, results that simulated a similar effect to miR-1179 overexpression. Mechanistic investigations showed that miR-1179 overexpression or SPAG5 knockdown significantly downregulated the activation of Akt signaling. Additionally, SPAG5 overexpression partially reversed the antitumor effect of miR-1179. Overall, our results demonstrated that miR-1179 inhibited the growth and invasion of NSCLC cells by targeting SPAG5 and inhibiting Akt, findings that highlight the importance of the miR-1179/SPAG5/Akt axis in the progression of NSCCL.

A meta-analytic review of the association between two common SNPs in miRNAs and lung cancer susceptibility

Background

MicroRNAs (miRNAs) are involved in many biological processes, including tumor suppression. Multiple studies have shown an association between the miRNA-196a2 rs11614913 and miRNA-146a rs2910164 polymorphisms and cancer risk. However, the implications of the reported data are debatable and inconclusive.

Materials and methods

Relevant articles were retrieved from the PubMed, EMBASE, China National Knowledge Infrastructure, and WanFang databases from January 1, 2007, to April 30, 2017. Studies were assessed based on designated inclusion and exclusion criteria, and data were manually extracted from relevant studies by two investigators. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to explore the association between two single-nucleotide polymorphisms (SNPs) in miRNAs and lung cancer susceptibility.

Results

Nine eligible articles were included, consisting of 3,101 cancer cases and 3,234 controls for miRNA-196a2 rs11614913, and 3,483 cases and 3,578 controls for miRNA-146a rs2910164. For studies evaluating miRNA-196a2 rs11614913, significant associations with lung cancer risk were discovered. Overall, the pooled analysis showed that miRNA-196a2 rs11614913 was associated with a decreased cancer risk (CC vs TT: OR = 1.25, 95% CI: 1.09–1.44; CT vs TT: OR = 1.26, 95% CI: 1.03–1.53). For miRNA-146a rs2910164, only the CC genotype was found to be associated with high lung cancer risk (OR = 1.30, 95% CI: 1.13–1.49). Subgroup analyses based on ethnicity, source of control group, and country indicated that there were strong associations between miRNA-146a rs2910164 and cancer risk.

Conclusion

The results indicated that lung cancer risk was significantly associated with miRNA-196a2 rs11614913 and miRNA-146a rs2910164. These two common SNPs in miRNAs may be potential biomarkers of lung cancer.

MicroRNA-216b regulated proliferation and invasion of non-small cell lung cancer by targeting SOX9

Micro (mi)RNAs are small, evolutionarily conserved and endogenous noncoding RNA molecules between 19 and 24 nucleotides in length. The potential roles of miRNAs in the carcinogenesis and progression of non-small cell lung cancer (NSCLC) have been studied previously. In the present study, it was revealed that miRNA-216b (miR-216b) expression was lower in NSCLC tissue and cell lines compared with that in adjacent healthy lung tissue samples and the normal bronchial epithelial 16HBE cell line, respectively. The ectopic expression of miR-216b inhibited the proliferation and invasion of NSCLC cells in vitro. SRY-Box 9 (SOX9) was identified as a direct target of miR-216b in NSCLC. In addition, SOX9 small interfering RNA was able to mimic the effects of miR-216b overexpression on cell proliferation and invasion in NSCLC. Therefore, the data reported in the present study demonstrate that miR-216b is an important tumor suppressor in NSCLC. These data may contribute to the understanding of the molecular mechanism underlying the carcinogenesis and progression of NSCLC, and provide novel therapies for patients with NSCLC.

MicroRNA-454 inhibits non‑small cell lung cancer cells growth and metastasis via targeting signal transducer and activator of transcription-3

Lung cancer is one of the most common type of cancers and the leading cause of cancer‑related mortality worldwide. Non-small cell lung cancer (NSCLC) accounts for >80% of lung cancer cases. Emerging studies have suggested that microRNAs are dysregulated in NSCLC and serve important roles in NSCLC initiation and development. However, to the best of our knowledge, the expression, roles and molecular mechanism of microRNA‑454 (miR‑454) have not been investigated in NSCLC. In the present study, miR‑454 was demonstrated to be significantly downregulated in NSCLC tissues and cell lines, as assessed by western blot analysis and reverse transcription‑quantitative polymerase chain reaction. Reduced miR‑454 expression was significantly correlated with aggressive clinicopathological features in NSCLC. In addition, upregulation of miR‑454 suppressed proliferation, migration and invasion NSCLC cells, as assessed by Cell Counting Kit‑8 and in vitro migration and invasion assays, respectively. Furthermore, bioinformatics analysis identified STAT3 as a direct target gene of miR‑454, and STAT3 knockdown was demonstrated to simulate the effects of miR‑454 overexpression in NSCLC. In conclusion, the present study provided convincing evidence that miR‑454 is downregulated in NSCLC, and regulates growth and metastasis by directly targeting STAT3, which suggests that miR‑454 may be an efficient therapeutic target for NSCLC.

miR-103 Functions as a Tumor Suppressor by Directly Targeting Programmed Cell Death 10 in NSCLC

Non-small cell lung cancer (NSCLC) accounts for about 85% of all lung cancer cases. Absence of miR-103 has recently been identified to be associated with metastatic capacity of primary lung tumors. However, the exact role of miR-103 in NSCLC and the molecular mechanism are unclear. In the present study, we showed that miR-103 expression was reduced in NSCLC tissues and cells. miR-103 expression was negatively correlated with tumor size and stage. The overall survival was longer in patients with higher miR-103 level than in those with lower miR-103 expression. miR-103 inhibited cell proliferation in A549 cells, decreased tumor weight and volume, and prolonged survival of tumor-implanted nude mice. miR-103 increased apoptotic cell death in A549 cells. Furthermore, miR-103 decreased the invasion and migration abilities in A549 cells, as evidenced by Transwell and wound healing results. Downregulation of miR-103 significantly reduced the level of programmed cell death 10 (PDCD10). We found a significant decrease in the relative luciferase activity of the reporter gene in A549 cells cotransfected with the miR-103 mimic and pGL3-PDCD10 WT 3′-UTR, but not pGL3-PDCD10 mut 3′-UTR. We showed that overexpression of PDCD10 significantly inhibited miR-103-induced inhibition of cell proliferation, increased apoptosis, and decreased invasion and migration in A549 cells. Moreover, we found that PDCD10 expression was increased in NSCLC tissues and cells. PDCD10 expression was positively correlated with tumor size and stage. Overexpression of PDCD10 increased cell proliferation and inhibited apoptosis in A549 cells. The data demonstrated that dysregulation of the miR-103/PDCD10 signal may be a novel therapeutic target for the treatment of NSCLC.

WITHDRAWN: MicroRNA-505 modulates cancer proliferation and migration in human non-small cell lung cancer through inverse regulation of FZD4

This article has been withdrawn at the request of the Editor-in-Chief. Following peer-review and acceptance of the above referenced paper for publication in Lung Cancer, the Editor-in-Chief was contacted by the Editor-in-Chief of the journal, Gene Therapy, with information that the manuscript had simultaneously been submitted to both Lung Cancer and Gene Therapy. A referee selected to review the manuscript for Gene Therapy was also contacted by the Editor-in-Chief of the journal, Respiratory Research, with a request to review the same manuscript for that journal. The three journals ascertained that the manuscript had been simultaneously submitted to all three journals. In addition, as part of their investigation of potential simultaneous submission, the Editors of Lung Cancer compared the manuscript submitted to Gene Therapy with that accepted for publication in Lung Cancer, and this has raised concerns related to the data presented in the paper. The paper accepted for publication in Lung Cancer examines A549 and H810 cells. The paper submitted to Gene Therapy examines A549 and H510A cells. However, the data presented in both papers, including the figures, are identical. The Editors of Lung Cancer have asked the authors for an explanation, but the corresponding author has not responded. The Publisher apologizes for any inconvenience this may cause. The full Elsevier Policy on Article Withdrawal can be found at https://www.elsevier.com/about/our-business/policies/article-withdrawal.

MiR-199a-5p suppresses tumorigenesis by targeting clathrin heavy chain in hepatocellular carcinoma

The deregulation of microRNA (miRNA) is frequently associated with a variety of cancers, including hepatocellular carcinoma (HCC). In this study, we investigated the expression and possible role of miR-199a-5p in HCC. The expression of miR-199a-5p was measured by quantitative RT-PCR in HCC. The effect of miR-199a-5p was evaluated by cell viability and colony formation assays in HCC cell lines and tumor cell growth assay in xenograft nude mice. Quantitative real time PCR results showed that miR-199a-5p was down-regulated in 77.9 % (67/86) of HCC tissues compared with adjacent nontumor tissues. MiR-199a-5p mimic reduced cell viability and colony formation by induction of cell arrest in HCC cell lines and inhibited tumor cell growth in xenograft nude mice, but miR-199a-5p inhibitor increased cell viability and colony formation in HCC cell lines and tumor cell growth in xenograft nude mice. Furthermore, CLTC was defined as a potential direct target of miR-199a-5p by MiRanda and TargetScan predictions. The dual-luciferase reporter gene assay results showed that CLTC was a direct target of miR-199a-5p. The use of miR-199a-5p mimic or inhibitor could decrease or increase CLTC protein levels in HCC cell lines. We conclude that the frequently down-regulated miR-199a-5p can regulate CLTC and might function as a tumor suppressor in HCC. Therefore, miR-199a-5p may serve as a useful therapeutic agent for miRNA-based HCC therapy.

Polymorphisms in GEMIN4 and AGO1 Genes Are Associated with the Risk of Lung Cancer: A Case-Control Study in Chinese Female Non-Smokers

MicroRNA biosynthesis genes can affect the regulatory effect of global microRNAs to target mRNA and hence influence the genesis and development of human cancer. Here, we selected five single nucleotide polymorphisms (SNPs) (rs7813, rs2740349, rs2291778, rs910924, rs595961) in two key microRNA biosynthesis genes (GEMIN4 and AGO1) and systematically evaluated the association between these SNPs, the gene-environment interaction and lung cancer risk. To control the impact of cigarette smoking on lung cancer, we recruited Chinese female non-smokers for the study. The total number of lung cancer cases and cancer-free controls were 473 and 395 in the case-control study. Four SNPs showed statistically significant associations with lung cancer risk. After Bonferroni correction, rs7813 and rs595961 were evidently still associated with lung cancer risk. In the stratified analysis, our results revealed that all five SNPs were associated with the risk of lung adenocarcinoma; after Bonferroni correction, significant association was maintained for rs7813, rs910924 and rs595961. Haplotype analysis showed GEMIN4 haplotype C-A-G-T was a protective haplotype for lung cancer. In the combined unfavorable genotype analysis, with the increasing number of unfavorable genotypes, a progressively increased gene-dose effect was observed in lung adenocarcinoma. We also found that individuals exposed to cooking oil fumes showed a relatively high risk of lung cancer, but no interactions were found between cooking oil fume exposure or passive smoking exposure with these SNPs, either on an additive scale or a multiplicative scale. Overall, this is the first study showing that rs7813 and rs595961 could be meaningful as genetic markers for lung cancer risk.

Clinical Utility of Liquid Diagnostic Platforms in Non-Small Cell Lung Cancer

: A firmer understanding of the genomic landscape of lung cancer has recently led to targeted, therapeutic advances in non-small cell lung cancer. Historically, the reference standard for the diagnosis and genetic interrogation for advanced-stage patients has been tissue acquisition via computed tomography-guided core or fine needle aspiration biopsy. However, this process can frequently put the patient at risk and remains complicated by sample availability and tumor heterogeneity. In addition, the time required to complete the diagnostic assays can negatively affect clinical care. Technological advances in recent years have led to the development of blood-based diagnostics or "liquid biopsies" with great potential to quickly diagnose and genotype lung cancer using a minimally invasive technique. Recent studies have suggested that molecular alterations identified in cell-free DNA (cfDNA) or circulating tumor DNA can serve as an accurate molecular proxy of tumor biology and reliably predict the response to tyrosine kinase therapy. In addition, several trials have demonstrated the high accuracy of microRNA (miRNA) platforms in discerning cancerous versus benign nodules in high-risk, screened patients. Despite the promise of these platforms, issues remain, including varying sensitivities and specificities between competing platforms and a lack of standardization of techniques and downstream processing. In the present report, the clinical applications of liquid biopsy technologies, including circulating tumor cells, proteomics, miRNA, and cfDNA for NSCLC, are reviewed and insight is provided into the diagnostic and therapeutic implications and challenges of these platforms.

IMPLICATIONS FOR PRACTICE

Although tumor biopsies remain the reference standard for the diagnosis and genotyping of non-small cell lung cancer, they remain fraught with logistical complexities that can delay treatment decisions and affect clinical care. Liquid diagnostic platforms, including cell-free DNA, proteomic signatures, RNA (mRNA and microRNA), and circulating tumor cells, have the potential to overcome many of these barriers, including rapid and accurate identification of de novo and resistant genetic alterations, real-time monitoring of treatment responses, prognosis of outcomes, and identification of minimal residual disease. The present report provides insights into new liquid diagnostic platforms in non-small cell lung cancer and discusses the promise and challenges of their current and future clinical use.

MiR-99a regulates ROS-mediated invasion and migration of lung adenocarcinoma cells by targeting NOX4

miR-99a is frequently downregulated in various types of human malignancies including lung adenocarcinoma. Recent studies have reported that miR-99a regulates cell growth and cell cycle progression by targeting mTOR, AKT1 and FGFR3. However, the underlying mechanisms involved in the modulation of invasion and migration by miR-99a remain elusive. In this study, we analyzed the relationship between the expression of miR-99a and clinical stage or metastasis in 90 matched lung adenocarcinoma and adjacent non-tumor lung tissues. Downregulation of miR-99a was significantly associated with advanced stage and tumor metastasis in lung adenocarcinoma patients, and it was found to be a poor prognostic factor in lung adenocarcinoma. Furthermore, functional experiments found that overexpression of miR-99a inhibited the proliferation, migration and invasion of lung adenocarcinoma A549 and Calu3 cells in vitro. We then identified NOX4 as a target gene of miR-99a and NOX4 mediated the inhibition of invasion and migration of lung adenocarcinoma cells by miR-99a. By targeting NOX4-mediated ROS production, miR-99a regulated the invasion and migration of lung adenocarcinoma cells. Moreover, overexpression of miR-99a significantly inhibited tumor growth in vivo. Immunohistochemical staining analysis of the mouse tumor tissues revealed that NOX4 levels were downregulated in the miR-99a treatment group, confirming the in vitro data of NOX4 as a direct target gene of miR-99a. Taken together, these data indicate for the first time that miR-99a directly regulates the invasion and migration in lung adenocarcinoma by targeting NOX4 and that overexpression of miR-99a may become a therapeutic strategy for lung adenocarcinoma.

miRNA-204 suppresses human non-small cell lung cancer by targeting ATF2

MicroRNAs (miRNAs) play a critical role in cancer development and progression. Deregulated expression of miR-204 has been reported in several cancers, but the mechanism through which miR-204 modulates human non-small cell lung cancer (NSCLC) is largely unknown. In this study, we investigate the expression and functional role of miR-204 in human NSCLC tissues and cell lines. RNA isolation, qRT-PCR, MTT, colony formation assay, cell cycle assay, cell apoptosis assay, cell migration assay, and Western blot were performed. Statistical analysis was performed using SPSS 18.0 software and statistical significance was accepted at p value <0.05. miR-204 level was significantly reduced in NSCLC tissues as compared to that of non-neoplastic tissues. Transient over-expression of miR-204 by transfecting with miR-204 mimics suppressed NSCLC cell proliferation, migration, and induced apoptosis and G1 arrest, whereas inhibition of miR-204 showed the converse effects. Additionally, activating transcription factor 2 (ATF2), an important transcription factor, was demonstrated as a potential target gene of miR-204. Subsequent investigations found a negative correlation between miR-204 level and ATF2 expression in NSCLC tissue samples. Moreover, we observed that miR-204 expression inversely affected endogenous ATF2 expression at both mRNA and protein levels in vitro. Taken together, miR-204 may act as a tumor suppressor by directly targeting ATF2 in NSCLC.

miR-1290 is a potential prognostic biomarker in non-small cell lung cancer

BACKGROUND

miR-1290 is a newly discovered microRNA (miRNA), and its role in non-small cell lung cancer (NSCLC) remains unknown. This study aimed to evaluate the expression levels of miR-1290 in NSCLC tissues and serum, and explore its associations with clinicopathological characteristics and prognosis of NSCLC patients.

METHODS

A total of 33 pairs of tissues and 73 serum samples were obtained from NSCLC patients and expression levels of miR-1290 were detected by specific TaqMan qRT-PCR. The relationship between miR-1290 expression levels in NSCLC tissues and serum and clinicopathological characteristics was estimated respectively. The correlation between serum miR-1290 expression levels and overall survival of NSCLC patients was performed by Kaplan-Meier analysis and Cox proportional hazards model.

RESULTS

We determined that miR-1290 expression levels were increased significantly in NSCLC tissues compared with non-tumor adjacent normal tissues, and higher miR-1290 expression levels were positively correlated with high tumor stage (P=0.004) and positive lymph node metastasis (P=0.013). Compared with benign lung disease and healthy controls, serum levels of NSCLC patients exhibited higher expression of miR-1290. Furthermore, the up-regulation of serum miR-1290 more frequently occurred in NSCLC patients with high TNM stage, positive lymph node metastasis (P=0.022 and P=0.024, respectively). Kaplan-Meier analysis demonstrated that high serum miR-1290 expression levels predicted poor survival (P=0.022). Cox proportional hazards risk analysis indicated that miR-1290 was an independent prognostic factor for NSCLC.

CONCLUSIONS

Our study suggests that miR-1290 is overexpressed in NSCLC, and serum miR-1290 may be used as a potential prognostic biomarker for NSCLC.

Non-invasive approaches to monitor EGFR-TKI treatment in non-small-cell lung cancer

Tyrosine kinase inhibitors of epidermal growth factor receptor (EGFR-TKIs) are standard treatments for advanced non-small-cell lung cancer (NSCLC) patients harboring activating epidermal growth factor receptor (EGFR) mutations. Nowadays, tumor tissues acquired by surgery or biopsy are the routine materials for EGFR mutation analysis. However, the accessibility of tumor tissues is not always satisfactory in advanced NSCLC. Moreover, a high proportion of NSCLC patients will eventually develop resistance to EGFR-TKIs. Invasive procedures, such as surgery or biopsy, are impractical to be performed repeatedly to assess the evolution of EGFR-TKI resistance. Thus, exploring some convenient and less invasive techniques to monitor EGFR-TKI treatment is urgently needed. Circulating cell-free tumor DNA (ctDNA) has a high degree of specificity to detect EGFR mutations in NSCLC. Besides, ctDNA is capable of monitoring the disease progression during EGFR-TKI treatment. Certain serum microRNAs that correlate with EGFR signaling pathway, such as miR-21 and miR-10b, have been demonstrated to be helpful in evaluating the efficiency of EGFR-TKI therapeutics. A commercialized serum-based proteomic test, named VeriStrat test, has shown an outstanding ability to predict the clinical outcome of NSCLC patients receiving EGFR-TKIs. Analysis of EGFR mutations in circulating tumor cells (CTCs) is feasible, and CTCs represent a promising material to predict EGFR-TKI-treatment efficacy and resistance. These evidences suggested that non-invasive techniques based on serum or plasma samples had a great potential for monitoring EGFR-TKI treatment in NSCLC. In this review, we summarized these non-invasive approaches and considered their possible applications in EGFR-TKI-treatment monitoring.

miR-330-3p controls cell proliferation by targeting early growth response 2 in non-small-cell lung cancer

Non-small-cell lung cancer (NSCLC) is one of the most common lung cancers, and microRNAs (miRNAs) have been reported to play essential roles in NSCLC. Recent studies have indicated that miR-330-3p expression is up-regulated in NSCLC samples and in tissues of NSCLC brain metastasis. In this study, up-regulation of miR-330-3p expression was confirmed in NSCLC and 20 NSCLC patient samples. Furthermore, miR-330-3p was over-expressed in NSCLC cell lines A549 and H23, and the promotive function of miR-330-3p was investigated in regulating NSCLC cell proliferation and cell cycle distribution. To identify potential target genes of miR-330-3p in NSCLC, the miRNA target prediction databases were used. Luciferase activity assay and real-time RT-PCR analysis confirmed that miR-330-3p is negatively correlated with the expression of early growth response 2 (EGR2). Moreover, it was also found that EGR2 mRNA contains two potential binding sites for miR-330-3p. Knock-down of EGR2 with siRNA was demonstrated to have a similar effect as the over-expression of miR-330-3p in NSCLC cell lines. Taken together, our results show that EGR2 is a target of miR-330-3p.

Emerging role of MicroRNAs and long noncoding RNAs in respiratory disease

The advent of techniques such as microarrays and high-throughput sequencing has revolutionized our ability to examine messenger RNA (mRNA) expression within the respiratory system. Importantly, these approaches have also uncovered the widespread expression of "noncoding RNAs," including microRNAs and long noncoding RNAs, which impact biologic responses through the regulation of mRNA transcription and/or translation. To date, most studies of the role of noncoding RNAs have focused on microRNAs, which regulate mRNA translation via the RNA interference pathway. These studies have shown changes in microRNA expression in cells and tissues derived from patients with asthma, pulmonary fibrosis, cystic fibrosis, COPD, and non-small cell lung cancer. Although the evidence is currently limited, we review the work that has been carried out in cell and animal models that has identified the function and mechanism of action of a small number of these microRNAs in disease etiology. In addition to microRNAs, we assess the emerging evidence that long noncoding RNAs regulate respiratory phenotype. Because these investigations into long noncoding RNAs were performed almost exclusively in non-small cell lung cancer, future work will need to extend these into other respiratory diseases and to analyze how microRNAs and long noncoding RNAs interact to regulate mRNA expression. From a clinical perspective, the targeting of noncoding RNAs as a novel therapeutic approach will require a deeper understanding of their function and mechanism of action. However, in the short term, changes in miRNA and long noncoding RNA expression are likely to be of use as biomarkers for disease stratification and/or assessment of drug action.

MicroRNA-146a rs2910164 polymorphism is associated with susceptibility to non-small cell lung cancer in the Chinese population

The aim of the present study was to investigate the association of single nucleotide polymorphisms (SNP) of the microRNA-146a (miR-146a) genes with the risk of nonsmall cell lung cancer (NSCLC). The genotyping of miR-146a rs2910164 polymorphism was detected by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The results showed that CC genotype and C allele distribution in the NSCLC patient were significantly higher than that of the controls (P=0.03 and 0.03, respectively). No significant differences were found between the two subgroups when stratified by clinical characteristics including age, sexual, smoke status, histological type, lymph node metastasis and clinical stage. In addition, the expression of miR-146a was detected by the Taqman real-time PCR. It demonstrated that the miR-146a expression was significantly decreased in NSCLC patients compared with that of nonmalignant lung tissues (P=0.01). In addition, the miR-146a expression of CC genotypes subgroup was significantly decreased than of GC/GG genotype subgroup in tumor tissues (P=0.0022). It confirmed that the SNP rs2910164 could functionally affect the miR-146a expression levels. In conclusion, it showed that the rs2910164 polymorphism of miR-146a is associated with the risk of NSCLC in the Chinese population.

Selective TRAIL-induced cytotoxicity to lung cancer cells mediated by miRNA response elements

Lung cancer is among the most common cancers, and the current therapeutic strategies are still inefficient in most cases. Tumour necrosis factor-related apoptosis-inducing ligand (TRAIL) is a promising biological agent for cancer treatment because of its potent pro-apoptotic effect on cancer cells. However, TRAIL also induces apoptosis in normal cells and therefore may cause toxicity to normal tissues if clinically applied. To address this issue, we inserted microRNA response elements (MREs) of miR-133a, miR-137 and miR-449a, which are all underexpressed in lung cancer cells, into an adenoviral vector to regulate TRAIL expression. This MRE-regulated vector (Ad-TRAIL-MRE) was able to express TRAIL in a lung-cancer-specific fashion. No TRAIL expression was detected in normal cells. Consistently, Ad-TRAIL-MRE exerted cytotoxicity to lung cancer cells, rather than normal cells, perhaps via inducing selective apoptosis. The selective TRAIL-mediated growth-inhibiting effect was further confirmed in a tumour xenograft model. Also, Ad-TRAIL-MRE only resulted in very low hepatotoxicity when applied. Collectively, we generated a novel TRAIL-expressing adenoviral vector that was regulated by MREs. This strategy permits TRAIL expression in a lung-cancer-specific manner and is worth further studying for clinical trials.

MicroRNA-215 is a potential prognostic marker for cervical cancer

Recently, microRNAs (miRNAs) have been shown to be involved in multiple biological pathways that can influence tumor progression and metastasis and they can serve as prognostic biomarkers in many cancers. The present study examined the prognostic significance of miR-215 in cervical cancer. The paraffin-embedded paired cervical scrape samples and tumor tissue samples from 302 patients with stage II cervical cancer were detected for the expression of miR-215 by using qRT-PCR. A miR-215-based classifier was established by using the Cox regression model. The prognostic and predictive accuracy of this classifier was determined in both the internal testing group of 138 patients, and the external independent group of 280 patients. Moreover, cervical cancer HeLa cells overexpressing miR-215 (HeLa-miR-215) were constructed and subcutaneously injected into the nude mice to examine the effect of miR-215 on tumor growth and metastasis in vivo. The results showed that the expression level of miR-215 was significantly higher in cervical cancer tissues than in paired normal tissues (P<0.0001). When patients were classified into high- and low-risk cancer progression groups according to miR-215 level, the 5-year disease-free survival in high- and low-risk groups were 43% (95% CI: 32.1-51.6) and 67% (95% CI: 48.6-77.3) (hazard ratio [HR] 2.02, 95% CI: 1.16-3.52; P=0.013) respectively. Moreover, the expression level of miR-215 was negatively associated with survival rate in patients at TNM stage T3 (HR: 3.317; 95% CI: 1.18-5.14, P=0.017) and TNM stage T4 (HR: 3.48; 95% CI: 1.49-4.45, P=0.008). Tumor volume in nude mice injected with HeLa-miR-215 cells was significantly larger than that in mice injected with control HeLa cells. It was concluded that the expression level of miR-215 is associated with cervical tumor progression and worse survival rate, suggesting that it may serve as a potential prognostic marker to identify patients at higher risk of recurrence.