Inhibited Lung Cancer Cell Proliferation Research Articles

MicroRNA-3666 inhibits lung cancer cell proliferation, migration, and invasiveness by targeting BPTF.

A previous study by our group indicted that overexpression of bromodomain PHD-finger transcription factor (BPTF) occurs in lung adenocarcinoma, and is closely associated with advanced clinical stage, higher numbers of metastatic lymph nodes, the occurrence of distant metastasis, low histological grade, and poor prognosis. Down-regulation of BPTF inhibited lung adenocarcinoma cell proliferation and promoted lung adenocarcinoma cell apoptosis. The purpose of this study is to identify valuable microRNAs (miRNAs) that target BPTF to modulate lung adenocarcinoma cell proliferation. In our results, we found that miR-3666 was notably reduced in lung adenocarcinoma tissues and cell lines. Using an miR-3666 mimic, we discovered that cell proliferation, migration, and invasiveness were suppressed by miR-3666 overexpression, but these were all enhanced when the expression of miR-3666 was reduced. Moreover, bioinformatics analysis using the TargetScan database and miRanda software suggested a putative target site in BPTF 3'-UTR. Furthermore, using a luciferase reporter assay, we verified that miR-3666 directly targets the 3'-UTR of BPTF. Using Western blot we discovered that overexpression of miR-3666 negatively regulates the protein expression of BPTF. Finally, we identified that the PI3K-AKT and epilthelial-mesenchymal transition (EMT) signaling pathways were inhibited by miR-3666 overexpression in lung cancer cells. In conclusion, our data indicate that miR-3666 could play an essential role in cell proliferation, migration, and invasiveness by targeting BPTF and partly inhibiting the PI3K-AKT and EMT signaling pathways in human lung cancers.

The red wine component ellagic acid induces autophagy and exhibits anti-lung cancer activity invitro and invivo.

Red wine consists of a large amount of compounds such as resveratrol, which exhibits chemopreventive and therapeutic effects against several types of cancers by targeting cancer driver molecules. In this study, we tested the anti‐lung cancer activity of 11 red wine components and reported that a natural polyphenol compound ellagic acid (EA) inhibited lung cancer cell proliferation at an efficacy approximately equal to that of resveratrol. EA markedly increased the expression of the autophagosomal marker LC3‐II as well as inactivation of the mechanistic target of rapamycin signalling pathway. EA elevated autophagy‐associated cell death by down‐regulating the expression of cancerous inhibitor of protein phosphatase 2A (CIP2A), and CIP2A overexpression attenuated EA‐induced autophagy of lung cancer cells. Treating tumour‐bearing mice with EA resulted in significant inhibition of tumour growth with suppression of CIP2A levels and increased autophagy. In addition, EA potentiated the inhibitory effects of the natural compound celastrol on lung cancer cells in vitro and in vivo by enhancing autophagy and down‐regulating CIP2A. These findings indicate that EA may be a promising chemotherapeutic agent for lung cancer, and that the combination of EA and celastrol may have applicability for the treatment of this disease.

Hyperoside and let-7a-5p synergistically inhibits lung cancer cell proliferation via inducing G1/S phase arrest

Lung cancer remains one of the most aggressive human malignancies with a low survival rate. Hyperoside (quercetin-3-O-β-d-galactopyranoside) is a flavonol glycoside with an anti-cancer activity. The microRNA-let-7 was widely regarded as a tumor suppressor in human tumors. Here, we investigated the role of hyperoside and let-7a-5p on the lung cancer cell proliferation, cell cycle and apoptosis in A549 cells in vitro. Our results showed that hyperoside could inhibit the proliferation of A549 cells through inducing apoptosis and G1/S phase arrest. Let-7a-5p could inhibit the proliferation of A549 cells via inhibiting the process of G1/S phase. Additionally, hyperoside and let-7a-5p had a synergetic effect on suppressing the proliferation of A549 cells; microRNA-let-7a-5p directly regulated the expression of CCND1 in A549 cells. Our study illustrated that hyperoside and microRNA-let7a-5p might provide a synergistic effect on anti-cancer, which may provide a new idea for lung cancer treatment.

CircRNA hsa_circ_100395 regulates miR-1228/TCF21 pathway to inhibit lung cancer progression

ABSTRACTCircular RNA (circRNA) is shown to participate in various tumors, including lung cancer. Although a few circRNAs involved in lung cancer are reported, whether circRNA negatively regulates lung cancer development remains elusive. In this study, we showed hsa_circ_100395 expression was decreased in lung cancer tissues. Besides, hsa_circ_100395 level was inversely correlated with TNM stage and metastases in lung cancer and low hsa_circ_100395 expression in patients predicted poor prognosis. Overexpression of hsa_circ_100395 dramatically inhibited lung cancer cell proliferation, arrested cell-cycle progression and reduced cell migration and invasion in vitro. Xenograft experiments showed that hsa_circ_100395 overexpression delayed tumor growth in vivo. Mechanistically, we showed hsa_circ_100395 serves as a sponge for miR-1228 targeting TCF21 in lung cancer. Rescue assays indicated that hsa_circ_100395 regulates lung cancer cell proliferation, migration and invasion through modulating miR-1228/TCF21 pathway. Altogether, our study reveals a novel regulatory loop that hsa_circ_100395/miR-1228/TCF21 axis modulates lung cancer development.Abbreviations: circRNA: circular RNA; miRNA: microRNA; RNA-FISH: RNA fluorescence in situy bridization; qRT-PCR: Reverse transcription and quantitative real-time PCR.

Effects of cyclin G1 gene silencing on proliferation and apoptosis of lung cancer A549 cells

Objective Knockdown the Cyclin G1 in the A549 cell of lung cancer, to explore its effects on the proliferation and apoptosis of the A549 cell. Methods Cyclin G1 siRNA was transfected into A549 cells by using liposome transfection method, the expression levels of Cyclin G1 mRNA were detected by reverse transcriptase-polymerase chain reaction (RT-PCR), and the expression levels of β-catenin, c-Myc and Cyclin G1 proteins in A549 cells were detected by Western blotting technique. Thiazole blue methyl thiazol tetrazolium (MTT) method was used to detect the proliferation of A549 cells after 48 h transfection, and the flow cytometry detected changes in cell cycle and apoptosis rate. Results The absorbance value (A) and the expression levels of Cyclin G1 mRNA and β-catenin, c-Myc and Cyclin G1 proteins in A549 of the interference group were significantly lower than those of the control group (t=14.250, P=0.000, t=10.739, P=0.000). Compared with the control group, the proportion of cells of interference group after 48 h transfection in G0/G1 phaseand apoptosis ratesignificantly increased, proportion of cells in S phaseand G2/M phase significantly decreased, and the differences were statistically significant (t=5.074, P=0.007; t=4.634, P=0.010; t=3.099, P=0.000). Conclusion Knockdown Cyclin G1 gene can inhibit lung cancer cell proliferation and induce its apoptosis, the mechanism may be related to block the cell cycle in G0/G1 phase and cut β-catenin, c-Myc proteins in Wnt signaling pathways. Key words: Lung cancer; Cyclin G1; Cell proliferation; Cell apoptosis

MiR-23b suppresses lung carcinoma cell proliferation through CCNG1.

Lung carcinoma with high incidence rate could be divided into four subtypes, including small cell carcinoma, squamous cell carcinoma, adenocarcinoma and large cell carcinoma. miR-23b has been reported to have a low expression and play major roles in abundant tumors, however there is little research in lung carcinoma and hence the purpose of this study was to explore the impact of miR-23b in lung carcinoma. The RNA level of miR-23b and cyclin G1 (CCNG1) was measured by reverse transcription quantitative PCR. Luciferase activity reporter assay was used to verify that CCNG1 is a target of miR-23b. MTT and Transwell assays were utilized to test the functional studies of miR-23b in lung cancer cells. In lung carcinoma and lung cancer cells miR-23b expression is low compared with that in paracancerous tissues and normal lung cells. Low miR-23b expression inhibited lung cancer cell proliferation measured by MTT assay. We applied luciferase reporter to determine whether CCNG1 is a target of miR-23b and there was a negative correlation between them. Moreover, interference with CCNG1 reduced the cell proliferation ability, which partially reversed function of miR-23b. miR-23b inhibited cell proliferation of lung cancer by directly targeting CCNG1. It is suggested that miR-23b/CCNG1 axis may present a new target for the treatment of lung cancer.

Long noncoding RNA LINC00961 inhibits cell proliferation and induces cell apoptosis in human non-small cell lung cancer.

Long noncoding RNAs (LncRNAs) have been identified in multiple human cancer types, including lung cancer. An increasing number of studies have indicated that lncRNAs can function as important gene regulators. However, the biological mechanism of LINC00961 in lung cancerremains poorly understood. In our current study, we recognized lncRNA LINC00961, and we observed that it was significantly reduced in human non-small cell lung cancer (NSCLC) tissues. LINC00961 was elevated by infecting LV-LINC00961, while decreased by LV-shLINC00961 in H226 and A549 cells. Furthermore, it was shown that LINC00961 overexpression greatly inhibited lung cancer cell proliferation, whereas downregulated LINC00961 induced cell proliferation. In addition, further experiments showed that restoration of LINC00961 could dramatically increase apoptotic ratios of NSCLC H226 and A549 cells, and knockdown of LINC00961 exhibited an opposite effect. Moreover, Western blot analysis showed that upregulation of LINC00961 repressed proliferating cell nuclear antigen expression and increased Bax expression, indicating that it acts as an important pro-apoptosis gene. Conversely, inhibition of LINC00961 induced proliferating cell nuclear antigen expression and restrained Bax protein levels. Taking these together, LINC00961 might play a tumor suppressive role in NSCLC progression, and it could serve as a novel prognostic biomarker in NSCLC diagnosis and treatment.

Matrine inhibits the proliferation and migration of lung cancer cells through regulation of the protein kinase B/glycogen synthase kinase-3β signaling pathways.

Lung cancer is the leading cause of cancer-related mortality worldwide. Despite recent advances in treatment, lung cancer remains an incurable disease. Matrine, an active compound isolated from Sophora flavescens, has been demonstrated to inhibit proliferation and induce apoptosis of tumor cells. However, the protective effects and molecular mechanisms of matrine in lung cancer remain elusive. In the present study, the lung cancer cells H1299 and A549 were used to investigate how matrine affects the proliferation, migration and apoptosis of lung cancer cells in vitro. It was demonstrated that matrine is able to significantly suppress the proliferation and colony formation of lung cancer cells in vitro. Using cell apoptosis analysis, wound-healing and Transwell assays, it was demonstrated that matrine induced cellular apoptosis and inhibited the migration of lung cancer cells. Further experiments revealed that matrine significantly suppressed the phosphorylation of protein kinase B (Akt) and glycogen synthase kinase-3β (GSK-3β). The present results suggested that matrine inhibits lung cancer cell proliferation, and induces cell apoptosis by suppressing the Akt/GSK-3β signaling pathway, which demonstrated that matrine may have therapeutic potential for lung cancer.

The lncRNA MIR4435-2HG promotes lung cancer progression by activating β-catenin signalling.

Recently, emerging evidence has suggested that long noncoding RNAs (lncRNAs) have crucial roles in cancer progression. Here, we demonstrated that the lncRNA MIR4435-2HG was highly expressed in lung cancer tissues and correlated with histological grades and lymph node metastasis. Phenotypic analysis indicated that MIR4435-2HG knockdown inhibited lung cancer cell proliferation and invasion in vitro and in vivo. Notably, MIR4435-2HG knockdown suppressed the EMT (epithelial-mesenchymal transition) process and cancer stem cell traits of lung cancer cells. Mechanistically, MIR4435-2HG knockdown decreased the transactivation of β-catenin. MIR4435-2HG interacted with β-catenin and thus prevented its degradation by the proteasome system. Our findings highlight the important roles and mechanisms of MIR4435-2HG in lung cancer progression. High expression of lncRNA MIR4435-2HG correlates with lung cancer progression MIR4435-2HG promotes lung cancer cells proliferation and invasion MIR4435-2HG knockdown suppresses the EMT process and cancer stem cell traits MIR4435-2HG knockdown inhibits the β-catenin signalling.

Downregulation of occludin affects the proliferation, apoptosis and metastatic properties of human lung carcinoma.

Lung cancer is the most frequent and deadliest cancer in the world, especially in China. However, the molecular mechanisms involved in lung cancer remain unclear. Occludin (OCLN), one of the first identified tight junction proteins, has been revealed to be a necessary integral protein for tight junction structure and function. In the present study, we investigated the role of occludin in lung tumorigenesis. We found that occludin protein expression was highly increased in human lung cancer patient samples. Western blotting results also revealed that occludin expression was different in several lung cancer cell lines, with the highest level in SPC‑A1 cells. Moreover, occludin knockdown inhibited lung cancer cell proliferation invitro and invivo. In addition, occludin knockdown promoted the apoptosis of lung cancer cell lines and reduced the invasion ability. Mechanistically, the activity of key growth pathway AKT/PI3K was compromised after occludin knockdown. Expression of apoptosis‑related proteins, BAX, caspase‑3, caspase‑9 and AIF, but not Bcl‑2, were upregulated after silencing of occludin. Collectively, our findings for the first time identify the role of occludin as a tumor promoter and a pro‑metastatic factor in lung cancer, demonstrating that occludin is a potential prognostic biomarker and therapeutic target in lung cancer.

Poly‐(pentaerythritol adipate)‐co‐(poly ethylene glycol) Elastomers for the Sustained Release of Paclitaxel

ABSTRACTOver the past 10 years poly‐(polyol alkanoate)s elastomers have intensively been investigated due to their extraordinary potential for soft tissue engineering applications. In this work, a family of novel hyperbranched elastomers based on pentaerythritol and adipic acid, modified with PEG of 200 and 400 Da, is synthesized. The polymers are obtained by a simple 2 steps thermal process that avoids the use of toxic catalysts. Noteworthy, elastomers properties can be finely tuned by adjusting the molar ratio of monomers and curing conditions. The elastomers, which are fully characterized by standard methods, show excellent results in the in vitro controlled release of Paclitaxel. Cell culture assays indicate that all materials are able to inhibit lung cancer cell proliferation and that the release of Paclitaxel reduce cancer cell viability, indicating that the elastomers prepared hereby are good candidates for their use as eluting systems in long term cancer treatment. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018, 56, 1199–1209

Regulatory roles of OASL in lung cancer cell sensitivity to Actinidia chinensis Planch root extract (acRoots).

Lung cancer is one of the most common malignancies worldwide. Actinidia chinensis Planch root extract (acRoots) was found to have the capacity of the anti-tumor, although the molecular mechanisms remain unclear. The present study aims to investigate the molecular mechanisms by which lung cancer cells sense to inhibitory effects of acRoots with a special focus on immune-associated gene profiles. We firstly provide a preclinical evidence that acRoots can significantly inhibit lung cancer cell proliferation and apoptosis via the PI3K-OASL signal pathway. The heterogeneous alterations of immune-associated gene profiles of lung cancer cell types were measured after treatment with various doses of acRoots. The OASL gene was identified as the key regulator in molecular networks of acRoots-treated lung cancer cells and validated. The OASL gene plays an important role in the regulation of lung cancer cell sensitivity to acRoots, which modulated by the PI3K signal pathway. Thus, our data indicate that OASL can be one of the decisive regulators to maintain lung cancer cell susceptibility to acRoots and may be associated with the development of drug resistance. The regulation of OASL can be an alternative strategy to improve drug efficacy during cancer therapies.

Wild-type IDH2 promotes the Warburg effect and tumor growth through HIF1α in lung cancer.

Hotspot mutations of isocitrate dehydrogenase 1 and 2 (IDH1/2) have been studied in several cancers. However, the function of wild-type IDH2 in lung cancer and the mechanism of its contribution to growth of cancer cells remain unknown. Here, we explored the role and mechanism of wild-type IDH2 in promoting growth of lung cancer.Methods: Information regarding genomic and clinical application focusing on IDH2 in cancer was examined in several databases of more than 1,000 tumor samples. IDH2 expression was assessed by immunohistochemistry in tissues from lung cancer patients. The biological functions of IDH2 were evaluated by using cell-based assays and in vivo xenograft mouse models.Results: Here we reported that wild-type IDH2 is up-regulated and is an indicator of poor survival in lung cancer and several other cancers. Targeting IDH2 with shRNA resulted in decreased HIF1α expression, leading to the attenuation of lung cancer cell proliferation and tumor growth. Treatment of lung cancer cells with AGI-6780 (a small molecule inhibitor of IDH2), PX-478 (an inhibitor of HIF1α) or incubation with octyl-α-KG inhibited lung cancer cell proliferation.Conclusion: IDH2 promotes the Warburg effect and lung cancer cell growth, which is mediated through HIF1α activation followed by decreased α-KG. Therefore, IDH2 could possibly serve as a novel therapeutic target for lung cancer.

P1.03-019 Sophoridine Inhibits Lung Cancer Cell Proliferation through Activating Hippo Signaling and P53 Pathway

P1.03-019 Sophoridine Inhibits Lung Cancer Cell Proliferation through Activating Hippo Signaling and P53 Pathway

The component formula of Salvia miltiorrhiza and Panax ginseng induces apoptosis and inhibits cell invasion and migration through targeting PTEN in lung cancer cells.

Lung cancer still remains the leading cause of cancer-related death worldwide. It is an urgent need for development of novel therapeutic agents to improve current treatment of this disease. Here we investigate whether the effective component formula of traditional Chinese Medicine could serve as new potential therapeutic drugs to treat lung cancer. We optimize the most effective component formula of Salvia miltiorrhiza and Panax Ginseng (FMG), which is composed of Salvianolic acid A, 20(S)-Ginsenoside and Ginseng polysaccharide. We discovered that FMG selectively inhibited lung cancer cell proliferation and induced apoptosis but had no any cytotoxic effects on normal lung epithelial BEAS-2B cells. Moreover, FMG inhibited lung cancer cell migration and invasion. Mechanistically, we found that FMG significantly promoted p-PTEN expression and subsequently inhibited PI3K/AKT signaling pathway. The phosphatase activity of PTEN protein was increased after FMG bound to PTEN protein, indicating that PTEN is one of the FMG targeted proteins. In addition, FMG regulated expression of some marker proteins relevant to cell apoptosis, migration and invasion. Collectively, these results provide mechanistic insight into the anti-NSCLC of FMG by enhancing the phosphatase activity of PTEN, and suggest that FMG could be as a potential option for lung cancer treatment.

MiR-33a inhibits cell proliferation and invasion by targeting CAND1 in lung cancer.

Lung cancer continues to be one of the top five causes of cancer-related mortality. This study aims to identify down- and upregulated miRNAs and mRNA which can be used as potential biomarkers and/or therapeutic targets for lung cancer. Integrated analysis of differential expression profiles of miRNA and mRNA in lung cancer was performed by searching Gene Expression Omnibus datasets. Based on miRNA expression profiles, direct mRNA targets of miRNAs with experimental support were identified through miRTarBase. The levels of representative miRNAs and mRNAs were confirmed through qualitative real-time reverse transcriptase polymerase chain reaction (qRT-PCR). The miR-33a was decreased in non-small cell lung cancer (NSCLC) tissues compared with the para-carcinoma tissues, whereas its target mRNA of cullin-associated NEDD8-dissociated protein 1 (CAND1) was increased in NSCLC tissues. Further research has shown that miR-33a can inhibit lung cancer cell proliferation, cell cycle progression, and migration by targeting CAND1. Moreover, the CAND1 knockout lung cancer cells showed similar results as cells transfected with miR-33a mimic. These results suggested that the data mining based on online databases was an effective method in finding novel target in cancer research, and the miR-33a and CAND1 played an important role in lung cancer proliferation and cell migration.

A polymorphism in miR-1262 regulatory region confers the risk of lung cancer in Chinese population.

It has been proposed that the majority of disease-associated loci identified by genome-wide association studies (GWAS) are enriched in non-coding regions, such as the promoter, enhancer or non-coding RNA genes. Thus, we performed a two-stage case-control study to systematically evaluate the association of genetic variants in miRNA regulatory regions (promoter and enhancer) with lung cancer risk in 7,763 subjects (discovery stage: 2,331 cases and 3,077 controls; validation stage: 1,065 cases and 1,290 controls). As a result, we identified that rs12740674 (C > T) in miR-1262 enhancer was significantly associated with the increased risk of lung cancer (additive model in discovery stage: adjusted OR = 1.31, 95%CI = 1.13-1.53, p = 3.846 × 10-4 in Nanjing GWAS; adjusted OR = 1.20, 95%CI = 1.00-1.44, p = 0.041 in Beijing GWAS; validation stage: adjusted OR = 1.20, 95%CI = 1.03-1.41, p = 0.024). In meta-analysis, the p value for the association between rs12740674 and lung cancer risk reached 6.204 × 10-6 (adjusted OR = 1.24, 95%CI = 1.13-1.36). Using 3DSNP database, The Cancer Genome Atlas (TCGA) data and functional assays, we observed that the risk T allele of rs12740674 reduced the expression level of miR-1262 in lung tissue through chromosomal looping, and overexpression of miR-1262 inhibited lung cancer cell proliferation probably through targeting the expression levels of ULK1 and RAB3D. Our findings confirmed the important role that genetic variants of noncoding sequence play in lung cancer susceptibility and indicated that rs12740674 in miR-1262 may be biologically relevant to lung carcinogenesis.

IRX4204 in combination with erlotinib to target distinct pathways in lung cancer cells.

e14095 Background: IRX4204 is a Retinoid X Receptor (RXR) specific agonist (rexinoid). IRX4204 has high potency as a RXR agonist with low binding affinity to Retinoic Acid Receptors (RARs), PPAR, FXR or LXR. Our prior work with the less specific rexinoid bexarotene and erlotinib showed clinical activity in patients with lung cancer cases that harbored KRAS mutations. IRX4204 inhibits lung cancer cell proliferation and can chemoprevent carcinogen-induced lung cancers in mice. We sought to explore the underlying mechanisms engaged by the combination of IRX4204 and erlotinib. Materials and Methods: Human (H1703 and HOP62) and murine (ED1 and LKR13) lung cancer cell lines were treated with IRX4204, erlotinib, IRX4204 plus erlotinib, or vehicle. Reverse phase protein array (RPPA) and mRNA microarray analyses were performed to analyze comprehensively for differentially expressed growth regulatory proteins. Results: Combination of IRX4204 and erlotinib suppressed proliferation of both KRAS mutant (HOP62 and LKR13) and wild-type (H1703 and ED1) lung cancer cell lines. Additive effect was observed as compared to IRX4204 or erlotinib treatment alone. Combining IRX4204 with erlotinib markedly increased inhibition of specific therapeutic targets including Src, phosphorylated Akt and ribosomal S6 proteins. At the mRNA level, Ingenuity Pathway Analysis of species significantly increased or decreased by the combination treatment revealed multiple pathways related to oncogenic signaling. Specifically, we found in H1703 cell line regulation of Granzyme A and AMPK signaling and in HOP62 cell line inhibition of angiogenesis was implicated by altering TSP1 expression. Notably, in ED1 cell line PPARα/RXRα activation, PTEN signaling, PI3K/AKT signaling, TGF-β signaling, and AMPK signaling were each associated with effects of IRX4204 combined with erlotinib. Conclusions: Taken together, these data highlight specific mechanisms and candidate pharmacodynamic biomarkers of response to the combination of this rexinoid and EGFR-TKI in lung cancer. Based on these findings, a clinical trial (NCT02991651) with IRX4204 in combination with erlotinib is underway to treat patients with chemotherapy-refractory non-small cell lung cancer.

MiR-138 suppresses the proliferation, metastasis and autophagy of non-small cell lung cancer by targeting Sirt1.

The present study determined the role and mechanism of miR-138 in non-small cell lung cancer (NSCLC). In total, 45 freshly resected clinical NSCLC tissues were collected. The expression of miR-138 in tissues and cell lines were determined by real-time quantitative PCR. miR-138 mimics were transfected into A549 and Calu-3 cells in vitro, and then the effects of miR-138 on lung cancer cell proliferation, cell cycle, invasion and metastasis were investigated by CCK-8 assay, Transwell and flow cytometry, respectively. The protein expression of the potential target gene Sirt1 in lung cancer cells were determined by western blot analysis. Dual-Luciferase reporter assay was performed to further confirm whether Sirt1 was the target gene of miR-138. The expression of miR-138 was significantly lower in lung cancer tissues and was negatively correlated to the differentiation degree and lymph node metastasis of lung cancer. In vitro experiment results showed that miR-138 inhibited lung cancer cell proliferation, invasion and migration. It was verified that miR-138 could downregulate Sirt1 protein expression, inhibit epithelial-mesenchymal transition (EMT), decrease the activity of AMPK signaling pathway and elevate mTOR phosphorylation level. Dual-Luciferase reporter assay demonstrated that miR-138 could directly regulate Sirt1. Downregulation of Sirt1 alone can also cause the same molecular and biological function changes. Western blot analysis and confocal microscopy results indicated that overexpression of miR-138 or interference of Sirt1 expression could inhibit lung cancer cell autophagy activity possibly through AMPK-mTOR signaling pathway. miR-138 plays a tumor suppressor function in lung cancer. It may inhibit the proliferation, invasion and migration of lung cancer through downregulation of Sirt1 expression and activation of cell autophagy. The downregulation of miR-138 is closely related to the development of lung cancer.

Insulin-like growth factor binding protein-4 inhibits cell growth, migration and invasion, and downregulates COX-2 expression in A549 lung cancer cells.

Insulin-like growth factor binding protein 4 (IGFBP-4) and cyclooxygenase2 (COX-2) are associated with tumor inflammatory microenvironment which is involved in the progression of tumor. However, it is unclear that the roles of IGFBP-4 in lung cancer and the effects of IGFBP-4 on COX-2 expression. In this study, we showed that IGFBP-4 could decrease COX-2 production in lung cancer A549 cells. IGFBP-4 expression was significantly lower but COX-2 expression was higher in lung cancer tissues compared to matched adjacent normal tissues. In addition, IGFBP-4 could inhibit lung cancer cell proliferation, migration and invasion, and suppress the phosphorylation of PI3 K/AKT, ERK, and CREB. These results indicate that IGFBP-4 has potent antitumor effects in non-small cell lung cancer cells.