N6-methyladenosine-induced hsa_circ_0011536 acts as a microRNA-576-5p sponge to promote ferroptosis of non-small cell lung cancer cells via transferrin receptor.

Radioresistance is considered as a main factor restricting efficacy of radiotherapy. However, the exact molecular mechanism of radioresistance has not been explained yet. In this study, to elucidate radioresistance mechanism in lung cancer, we compared radiation responses in two types of non-small cell lung cancer (NSCLC) cells with different radiosensitivity and identified key molecules conferring radioresistance. In radioresistant NSCLC cells, ionizing radiation (IR) led to casein kinase 2α (CK2α)- and PKC-mediated phosphorylation of rpS3 and TRAF2, respectively, which induced dissociation of rpS3-TRAF2 complex and NF-κB activation, resulting in significant up-regulation of prosurvival genes (cIAP1, cIAP2, and survivin). Also, dissociated phospho-rpS3 translocated into nucleus and bound with NF-κB complex (p65 and p50), contributing to p65 DNA binding property and specificity. However, in radiosensitive NSCLC cells, IR-mediated rpS3 phosphorylation was not detected due to the absence of CK2α overexpression. Consequently, IR-induced rpS3-TRAF2 complex dissociation, NF-κB activation, and prosurvival gene expression were not presented. Taken together, our findings revealed a novel radioresistance mechanism through functional orchestration of rpS3, TRAF2, and NF-κB in NSCLC cells. Moreover, we provided the first evidence for the function of rpS3 as a new TRAF2-binding protein and demonstrated that phosphorylation of both rpS3 and TRAF2 is a key control point of radioresistance in NSCLC cells. These results suggest that regulation of rpS3 and TRAF2 in combination with radiotherapy could have high pharmacological therapeutic potency for radioresistance of NSCLC.

To investigate the expression of S1 RNA binding domain 1 (SRBD1) in non-small cell lung cancer tissue and the effects of SRBD1 silencing on the biological behaviors of human non-small cell lung cancer cells, and to explore the molecular mechanism of SRBD1functions in human non-small cell lung cancer cells. Expressions of SRBD1 in human non-small cell lung cancer tissues and cell lines were examined by immunostaining and RT-PCR. shRNAs of SRBD1 were chemically synthesized and transfected into A549 and NCI-H1299 cells by lentivirus. Cell proliferation was assayed by cell counting, MTT and clone formation. Cell apoptosis was assayed by flow cytometry. Tumorigenicity was assessed by cell injection into BALB/c athymic nude mouse. Gene chip analysis was employed to explore genomic changes in A549 cells. Potential classical signaling pathways, upstream regulators and gene interaction networks were analyzed by Ingenuity Pathway Analysis, and verified by western blot analysis. SRBD1 was specifically expressed in human squamous cell carcinoma and highly expressed in lung cancer cell lines, NCI-H1299, A549 and NCI-H1975. SRBD1 directed-shRNA (shSRBD1) effectively reduced the expression of SRBD1 in A549 and NCI-H1299 cells. SRBD1 silencing inhibited cell proliferation, and promoted cell apoptosis in non-small cell lung cancer cells, and suppressed tumorigenesis in a nude mouse model. In addition, we found silencing of SRBD1 expression resulted in marked changes in gene expression in A549 cells. Besides, in shSRBD1 group, the protein levels of EPS 15, IGF1R, MYC, PYCR1 and HNRNPA0 were downregulated, and the expressions of several classical factors involved in the growth and apoptosis of cancer cells were also decreased. We found that SRBD1 were specifically expressed in non-small cell lung cancer tissue. Silencing of SRBD1 inhibits cell growth and promotes cell apoptosis in non-small cell lung cancer cells, and suppresses tumorigenesis in vivo, suggesting that SRBD1 may be a new diagnostic indicator and therapeutic target of non-small cell lung cancer.

Non‐small cell lung cancer (NSCLC) is the most common type of lung cancer. We aimed to investigate the role of LINC00184 in NSCLC. Migration, proliferation and invasion of NSCLC cells were analysed using the wound healing assay, cell counting kit‐8 assay and transwell assay, respectively. Apoptosis and cell cycle were assessed using flow cytometry. Online bioinformatics tools were utilized to predict downstream microRNAs (miRNA) or genes related to LINC00184 expression. The RNA pull‐down experiment and luciferase reporter assay were performed to verify the predictions thereof. LINC00184, miR‐524‐5p, and high mobility group 2 protein (HMGB2) expression levels in NSCLC tissues and cell lines were detected using quantitative real‐time polymerase chain reaction. An NSCLC mouse model was constructed for in vivo experiments. LINC00184 overexpression was observed in NSCLC tissues and cell lines and was found to be correlated with poor prognosis. LINC00184 knockdown inhibited cell proliferation, migration and invasion, induced cell cycle arrest and accelerated apoptosis in NSCLC cell lines. LINC00184 suppressed tumour growth and proliferation in NSCLC mouse models and directly targeted the miR‐524‐5p/HMGB2 axis. Moreover, the expression levels of LINC00184 and HMGB2 were negatively correlated with miR‐524‐5p expression, whereas LINC00184 expression was positively correlated with HMGB2 expression. LINC00184 affected the cell cycle, proliferation, apoptosis, migration and invasion in NSCLC via regulation of the miR‐524‐5p/HMGB2 axis.

The eukaryotic translation initiation factor 4A (eIF4A) family determines transcription efficiency by directly binding to precursor RNAs. One member, EIF4A3, modulates the expression of circRNAs. Circular RNA SCAP (circSCAP), a newly found circRNA, has been implicated in atherosclerosis. Yet, how circSCAP regulates cancer development and progression remains understudied. Here, we investigated the function of circSCAP and the molecular mechanism in the tumorigenesis and progression of non-small-cell lung cancer (NSCLC). CircSCAP was upregulated in both NSCLC tissues and cell lines and was mainly located in the cytoplasm. CircSCAP expression was promoted by EIF4A3, which was associated with poor prognosis in patients with NSCLC. CircSCAP sponged miR-7 to upregulate small mothers against decapentaplegic 2 (SMAD2). CircSCAP knockdown undermined cell proliferation, migration, and invasion abilities in NSCLC cell lines (SPCA1 and A549), which was rescued by either inhibiting miR-7 or overexpressing SMAD2. Moreover, circSCAP knockdown upregulated E-cadherin, while downregulating N-cadherin, Vimentin, and MMP9 in SPCA1 and A549 cells, which were abolished by either inhibiting miR-7 or overexpressing SMAD2. Additionally, miR-7 was markedly downregulated, whereas SMAD2 was significantly upregulated in NSCLC tissues. MiR-7 expression was inversely correlated with circSCAP and SMAD2 expression in NSCLC tissues. In conclusion, this study demonstrates that circSCAP is significantly upregulated in NSCLC cell lines and tissues and elucidates that circSCAP facilitates NSCLC progression by sponging miR-7 and upregulating SMAD2. The study provides a novel molecular target for early diagnosis and treatment of NSCLC.

Derlin-1 Is Overexpressed in Non-Small Cell Lung Cancer and Promotes Cancer Cell Invasion via EGFR-ERK–Mediated Up-Regulation of MMP-2 and MMP-9

Problem and aim The overexpression of MAP17 has been reported in various human carcinomas. However, its molecular mechanism in non-small cell lung cancer (NSCLC) has not been fully understood. Our study aimed to reveal the molecular mechanism of NSCLC that involved MAP17 and identify its target miRNA. Methods RT-qPCR and immunoblot assays were conducted to measure the expression of mRNA and protein in NSCLC tissues and cell lines. Meanwhile, the A549 cells (an NSCLC cell line) were randomly assigned to the MAP17 overexpression group, the MAP17 knockdown group and negative control group to study the roles of MAP17 in cell viability, cell proliferation, migration, invasion, and apoptosis by performing Trypan blue exclusion, MTT, colony formation, transwell, wound healing and flow-cytometric apoptosis assays. The luciferase reporter assay was conducted to confirm the target relationship between MAP17 and miR-27a-3p. Results The upregulation of MAP17 mRNA and protein was observed in NSCLC tissues and cell lines. In vitro, the positive roles of MAP17 on cell viability, migration, and invasion were confirmed in A549 cells. It was also found that MAP17 could inhibit cell apoptosis by suppressing the activation of the p38 pathway. This research eventually proved the target relationship between MAP17 and miR-27a-3p, and that miR-27a-3p reversed the effects of MAP17 in A549 cells by directly targeting MAP17. Conclusions MAP17 plays an oncogenic role in NSCLC by suppressing the activation of the p38 pathway. Apart from that, the miR-27a-3p can inhibit the expression of MAP17 to suppress the NSCLC progression.

Background Non-small-cell lung cancer (NSCLC) is one of the major diseases that threaten human health, and there is still no fundamental treatment method. Emerging evidences suggested that circRNAs might be an effective target to treatment NSCLC. However, the roles and detailed mechanisms of hsa_circ_0003176 in NSCLC still not clear. Methods hsa_circ_0003176 was identified from GSE101684 and GSE112214 datasets of Gene Expression Omnibus (GEO) database. The expression of hsa_circ_0003176 was detected by RT-qPCR in NSCLC tissues, paired adjacent nontumor tissues, and cell lines. RNA fluorescence in situ hybridization and nuclear and cytoplasmic RNA fractionation analysis was used to detect the subcellular localization of hsa_circ_0003176 in H1299 and A549 cells. Dual-luciferase reporter and RNA pull-down assay were used to confirm the regulatory of miR-182-5p to hsa_circ_0003176 and RBM5. The roles of hsa_circ_0003176 in NSCLC progression was evaluated both in vitro by CCK-8 assay, colony formation assay, wound-healing assay, and matrigel transwell assay and in vivo by the subcutaneous xenograft nude mouse experiment and lung metastasis nude mouse experiment. In addition, RNA pull down and luciferase reporter assays were carried out to investigate the interaction between hsa_circ_0003176 or RBM5 and miR-182-5p. Results Our results indicated that hsa_circ_0003176 showed typical characteristic of circRNAs, which was downregulated in both NSCLC tissues and cell lines. Functionally, overexpression of hsa_circ_0003176 suppressed the proliferation, migration, and invasion of NSCLC cells in vitro and inhibited NSCLC growth and metastasis in vivo. Furthermore, we found that hsa_circ_0003176 acts as sponge of miR-182-5p to regulate RBM5 expression. Further, in vitro rescue experiments demonstrated that hsa_circ_0003176 suppressed the proliferation, migration, and invasion of NSCLC cells by regulating miR-182-5p/RBM5 axis. Conclusion We demonstrated that hsa_circ_0003176 suppressed the NSCLC progression via regulating miR-182-5p/RBM5 axis. These data indicated that hsa_circ_0003176 might be a novel molecular target for NSCLC treatment.

Background: GGA3 has been reported to be related to cellular events such as cell survival, cell migration and cell apoptosis through different molecular mechanisms, which imply the potential role in tumorigenesis. However, the function of GGA3 in non-small cell lung cancer (NSCLC) is not clear. This research aims to reveal the effect of GGA3 on NSCLC proliferation and its underlying mechanisms. Methods: The mRNA expression of GGA3 and TrkA, and association between GGA3 and TrkA in NSCLC tissues were analyzed based on data from TCGA database. And the mRNA expression level of GGA3 in NSCLC cell lines was determined by qRT-PCR. Expression level of GGA3 in A549 cell was detected by qRT-PCR and western blot after transfected with pcDNA3.1-GGA3. Cell counting kit 8, transwell, and flow cytometry assays were performed to detect A549 cell proliferation, aggressiveness, and apoptosis. Western blot was applied to assess the protein expression during apoptosis and TrkA-AKT/ERK signaling pathway. Results: High expression of GGA3 was presented in NSCLC tissues and cell lines. In addition, overexpression of GGA3 could promote proliferation, invasion, and migration of A549 cell, but inhibit the apoptosis of A549 cell. After depletion of GGA3, the expression of anti-apoptotic protein Bcl-2 was increased, and the expression of pro-apoptotic protein Bax and Active Caspase 3 were reduced. Moreover, we found the expression of TrkA, p-AKT and p-ERK in pcDNA3.1-GGA3 group were obviously up-regulated in contrast with the sham group, which suggested that the induced effect of GGA3 on NSCLC cells might be performed via the TrkA-AKT/ERK signaling pathway. Conclusions: Taken together, overexpressed GGA3 in NSCLC could promote the A549 cells tumorigenesis partly through TrkA-AKT/ERK signaling pathway, supplying a theoretical basis for revealing the mechanism for NSCLC.

Non-small cell lung cancer (NSCLC) accounts for >80% of lung cancer cases and is the leading cause of cancer-associated mortality worldwide. Propofol is an anesthetic drug frequently used during tumor resection. It is also known to exert inhibitory effects on cancer. Although the role of propofol in NSCLC has been reported, its underlying mechanisms remain unknown. The present study aimed therefore to investigate the mechanisms of propofol action on NSCLC. Starbase V3.0 project was used to analyze the expression levels of microRNA-21-5p (miR-21-5p) and mitogen-activated protein kinase 10 (MAPK10) in NSCLC and adjacent normal tissues from patients with NSCLC and the association between miR-21-5p and MAPK10 expression level in NSCLC tissues. The correlation between MAPK10 expression and disease-free survival (DFS) in patients with NSCLC was analyzed using GEPIA software version 1.0. miR-21-5p and MAPK10 expression in tumor and adjacent normal tissues from patients with NSCLC was evaluated by reverse transcription-quantitative (RT-q) PCR and western blotting. Cell viability and apoptosis were assessed by using Cell Counting Kit-8 assay and flow cytometry, respectively. The interaction between miR-21-5p and MAPK10 was predicted by TargetScan/miRanda and verified by dual luciferase assay. The regulatory effect of propofol on miR-21-5p and MAPK10 expression in NSCLC cell lines was examined by RT-qPCR and western blotting. Starbase V3.0 project and the results of the present study indicated that tumor tissues presented a significantly lower MAPK10 level and a higher miR-21-5p level compared with the normal samples, and that miR-21-5p expression was negatively correlated with MAPK10 expression in the tumor tissues of patients with NSCLC. Furthermore, miR-21-5p targeted the 3′-untranslated region of MAPK10. In addition, compared with BEAS-2B cells, a higher miR-21-5p and a lower MAPK10 expression was observed in the NSCLC cell lines A549 and H1299, which was reversed by propofol. The overexpression of miR-21-5p abrogated the effects of propofol on A549 and H1299 cell viability and apoptosis by targeting MAPK10. Taken together, these findings demonstrated that propofol inhibited the viability and promoted the apoptosis of NSCLC cells by downregulating the miR-21-5p/MAPK10 axis.

PurposeRecent studies have identified important roles for long intergenic non-protein coding RNA 1426 (LINC01426) in glioma and clear cell renal cell carcinoma. The present study evaluated the expression profile of LINC01426 in non-small cell lung cancer (NSCLC) tissues and cell lines. Furthermore, the function of LINC01426 in NSCLC and the molecular mechanisms involved were extensively studied.MethodsThe abundance of LINC01426 in NSCLC tissues and cell lines was determined using quantitative reverse transcription–polymerase chain reaction. The cell counting kit-8 assay, flow cytometry, transwell experiments for migration and invasion, and xenograft tumor model were used to assess the function of LINC01426 in NSCLC cells. Mechanistic studies were performed using the luciferase reporter assay and RNA immunoprecipitation.ResultsSignificant LINC01426 upregulation was observed in NSCLC tissues and cell lines. Silencing LINC01426 inhibited proliferation, migration, and invasion of NSCLC cells and facilitated cell apoptosis in vitro. Furthermore, interference of LINC01426 restricted tumor growth of NSCLC cells in vivo. In addition, LINC01426 showed the ability to directly bind to microRNA-519d-5p (miR-519d-5p) and act as a molecular sponge for miR-519d-5p in NSCLC cells. Furthermore, the ETS proto-oncogene 1 (ETS1) was identified as a direct target of miR-519d-5p and LINC01426 could indirectly upregulate ETS1 expression by sponging miR-519d-5p. Moreover, the cancer-inhibiting activities of LINC01426 knockdown in NSCLC cells were partially offset by miR-519d-5p inhibition.ConclusionLINC01426 increases ETS1 expression by sequestering miR-519d-5p, thereby aggravating the malignant progression of NSCLC. The LINC01426/miR-519d-5p/ETS1 competing endogenous RNA pathway may provide a target for designing therapeutic agents for NSCLC treatment.

Lung cancer is a malignant tumor with extremely high morbidity and mortality. Recent studies have identified the vital role of LINC00511 (lncRNAs) in the development and progression of non-small cell lung cancer (NSCLC). In this research, we aim to explore the biological function of LINC00511 in the development and metastasis of NSCLC. LINC00511 expression in 57 paired NSCLC patients' tissues and matched normal tissues were detected by Real-time quantitative polymerase chain reaction (RT-qPCR). Cell proliferation assay, colony formation assay and transwell assay were conducted to observe the biological behavior changes of NSCLC cells through the influence of LINC00511. In addition, dual-luciferase reporter gene assay, RNA immunoprecipitation assay (RIP) and, chromatin immunoprecipitation (ChIP) were performed to discover the potential targets of LINC00511 in NSCLC cells. LINC00511 was highly expressed in NSCLC tissues and cell lines compared with controls. LINC00511 expression was positively correlated with tumor size, tumor stage, lymph node metastasis and distant metastasis, but negatively correlated with overall survival (OS) of NSCLC patients. Receiver Operating Characteristic (ROC) curves suggested that LINC00511 could be an effective indicator to distinguish NSCLC patients from normal people. Cell counting kit-8 (CCK-8), flow cytometry and transwell assay showed that knockdown of LINC00511 in A549 cells decreased viability, accelerated apoptosis and inhibited invasive and migratory abilities. Overexpression of LINC00511 in PC9 cells obtained the opposite biological effects. Chromatin fractionation predicted that LINC00511 was mainly distributed in the nucleus. RIP and ChIP assay showed that LINC00551 directly bound to lysine-specific demethylase 1 (LSD1) and enhancer of zeste homolog 2 (EZH2). It inhibited expressions of LATS2 and KLF2 by binding to their promoter regions. LINC00511 is upregulated in NSCLC tissues and cell lines. It is closely related to tumor size, tumor stage, lymph node metastasis and, distant metastasis of NSCLC patients. Knockdown of LINC00511 attenuates proliferative, migratory and invasive capacities, but induces apoptosis of NSCLC cells. LATS2 and KLF2 are target genes of LINC00511, which are regulated by LINC00511 through binding to EZH2 and LSD1, thus influencing the progression of NSCLC.

Mucosa-associated lymphoid tissue lymphoma translocation protein 1 (MALT1) inhibitors are effective in attenuating the progression of several types of cancer. However, their role in lung cancer requires further investigation. Therefore, the present study aimed to explore the effect of the MALT1 inhibitor, MI-2, on the behavior of non-small cell lung cancer (NSCLC) cells and to uncover their possible underlying mechanism of action. The mRNA and protein expression levels of MALT1 were detected in the human normal lung epithelial cell line BEAS-2B, and the NSCLC cell lines, NCI-H1299, NCI-H1650, HCC827, A549 and NCI-H23. Subsequently, NCI-H1650 and A549 cells were treated with MI-2. Additionally, NCI-H1650 and A549 cells were co-treated with anisomycin, a c-JUN N-terminal kinase (JNK) pathway activator, with or without MI-2. The results illustrated that the mRNA and protein expression levels of MALT1 were significantly increased in NCI-H1299, NCI-H1650, A549 and NCI-H23 cells compared with those in BEAS-2B cells. Treatment of NCI-H1650 and A549 cells with MI-2 for 72 h reduced the optical density value as determined using the Cell Counting Kit-8 assay. Consistently, the 5-ethynyl-2'-deoxyuridine assay also showed that proliferation was reduced in MI-2-treated NSCLC cells. In addition, MI-2 downregulated B-cell lymphoma 2 (BCL2), and enhanced BCL2-associated X-protein expression and apoptotic rate in NCI-H1650 and A549 cells. These findings indicated that MI-2 could inhibit NCI-H1650 and A549 cell proliferation and promote apoptosis. Furthermore, treatment of cells with MI-2 only attenuated the migration and invasion of NCI-H1650 cells. Notably, MI-2 decreased the expression levels of phosphorylated (p)-JNK and p-c-JUN in NCI-H1650 and A549 cells, thus suggesting that MI-2 could suppress the JNK/c-JUN signaling pathway. However, NSCLC cell co-treatment with anisomycin (JNK pathway activator) reversed the effect of MI-2 on the proliferation, apoptosis and activation of the JNK/c-JUN pathway in NCI-H1650 and A549 cells. In conclusion, the present study demonstrated that the MALT1 inhibitor, MI-2, could suppress NSCLC cell proliferation, migration and invasion, and induce apoptosis via inactivating the JNK/c-JUN pathway.

To uncover the role of microRNA-20a-5p (miRNA-20a-5p) in the progression of Non-small cell lung cancer (NSCLC) and the underlying mechanism. MiRNA-20a-5p level in NSCLC tissues and cell lines was determined by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). Its level in NSCLC patients with larger or smaller tumor size, and either with lymphatic metastasis or not was examined as well. Regulatory effects of miRNA-20a-5p on viability, cell cycle, and invasiveness of A549 and PC9 cells were assessed. The interaction between miRNA-20a-5p and KLF9 was explored by Dual-Luciferase Reporter Gene Assay and Spearman correlation test. At last, the role of miRNA-20a-5p/KLF9 axis in influencing the progression of NSCLC was determined. MiRNA-20a-5p was upregulated in NSCLC tissues and cell lines. Its level was much pronounced in NSCLC patients with larger tumor size or accompanied with lymphatic metastasis. Overexpression of miRNA-20a-5p in A549 cells enhanced viability, cell ratio in S phase, and invasiveness, while the knockdown of miRNA-20a-5p in PC9 cells achieved the opposite trends. KLF9 was confirmed to be the direct target of miRNA-20a-5p. There was a negative correlation between the expression levels of miRNA-20a-5p and KLF9 in NSCLC tissues. In addition, KLF9 overexpression could reverse the promotive effects of upregulated miRNA-20a-5p on the proliferation and invasiveness of A549 cells. On the contrary, the knockdown of KLF9 reversed the inhibitory effects of downregulated miRNA-20a-5p on cellular behaviors of PC9 cells. MiRNA-20a-5p stimulates NSCLC to proliferate and invade by targeting KLF9.

miR-409 Inhibits Human Non-Small-Cell Lung Cancer Progression by Directly Targeting SPIN1

Accumulating studies have suggested that microRNAs (miRs) play a significant role in lung cancer development and progression, especially in non-small cell lung cancer (NSCLC). The present study aimed to investigate the associations between miR-454-3p and NSCLC progression. qPCR assay was applied to examine the expression of miR-454-3p and transforming growth factor-β2 (TGFB2) in tissues and cell lines. CCK-8 and EdU assays were used to detect cell proliferation. Wound-healing and Transwell assays were conducted to assess cell migration and invasion. Western blotting assay was performed to explore the protein levels of epithelial-mesenchymal transition (EMT) markers. The interaction between miR-454-3p and TGFB2 was investigated with a luciferase reporter assay. miR-454-3p was downregulated in NSCLC tissues and NSCLC cell lines. miR-454-3p overexpression led to the suppression of proliferation, migration, and invasion in A549 and NCI-H1650 cells. In addition, the overexpression of miR-454-3p in A549 and NCI-H1650 cells significantly inhibited EMT. TGFB2 was revealed to be a direct target of miR-454-3p by using TargetScan database and luciferase reporter assay. TGFB2 was observed to be upregulated in NSCLC tissues and cell lines. Further mechanistic studies revealed that the inhibitory effects of miR-454-3p on NSCLC were reversed upon overexpression of TGFB2. These findings provided strong evidence that miR-454-3p suppressed NSCLC cell proliferation and metastasis by targeting TGFB2. The study suggests that targeting miR-454-3p could be a promising strategy for treating NSCLC.