Human Non-small Cell Lung Carcinoma Cell Research Articles

Silencing RNA-Mediated Knockdown of IFITM3 Enhances Senecavirus A Replication.

Senecavirus A (SVA) is a non-enveloped, positive sense, single-stranded RNA virus that causes vesicular diseases in pigs. Interferon-induced transmembrane 3 (IFITM3) is an interferon-stimulated gene (ISG) that exhibits broad antiviral activity. We investigated the role of IFITM3 in SVA replication. Both viral protein expression and supernatant virus titer were significantly increased when endogenous IFITM3 was knocked down by approximately 80% in human non-smallcell lung carcinoma cell line (NCI-H1299) compared to silencing RNA control. Interestingly, overexpression of exogenous IFITM3 in NCI-H1299 cells also significantly enhanced viral protein expression and virus titer compared to vector control, which was positively correlated with induction of autophagy mediated by IFITM3 overexpression. Overall, our results indicate an antiviral role of endogenous IFITM3 against SVA. The exact molecular mechanisms by which endogenous IFITM3 limits SVA replication remain to be determined in future studies.

Histone demethylase KDM6A coordinating with KMT2B regulates self-renewal and chemoresistance of non-small cell lung cancer stem cells

Background and aimsWnt signaling is essential for the maintenance of cancer stem cells (CSCs), but mutations in the β-catenin and APC genes are less common in non-small cell lung carcinoma (NSCLC). Thus, the mechanism underlying the constitutive activation of Wnt signaling in lung CSCs is still unknown. Materials and methodsGene set enrichment analysis and immunohistochemistry were performed to establish the correlation between KDM6A/KM2B and CSC stemness. Human NSCLC cell lines were genetically manipulated for functional studies. Sphere formation assay and stemness gene expression profiling were examined to investigate the role of KDM6A/KMT2B in lung CSCs. Tumor xenograft assay were used to identify the function of KDM6A/KMT2B on tumorigenicity and tumor recurrence in vivo. Western blot analysis, coimmunoprecipitation and chromatin immunoprecipitation were performed to understand KDM6A/KMT2B mediated epigenetic regulation of Histone 3 lysine 4 methylation (H3K4me) on Wnt signaling pathway. ResultsWe discovered that the expression of Histone demethylase KDM6A and methyltransferase KMT2B correlate with the stemness of CSCs in NSCLC. KDM6A coordinates with KMT2B to activate the Wnt/β-catenin signaling pathway by regulating the H3K4me3 level and promotes the tumorigenicity and maintenance of CSC stemness. Furthermore, KDM6A/ KMT2B overexpression promotes the CSC chemoresistance and tumor recurrence both in vitro and in vivo. Inhibition of KDM6A and KMT2B potently suppress tumor initiation and recurrence in xenografted animal models. ConclusionOur findings suggest that KDM6A and KMT2B mediate the constitutive activation of Wnt/β-catenin signaling in lung CSCs, potentially providing a therapeutic target for NSCLC.

COX7A1 enhances the sensitivity of human NSCLC cells to cystine deprivation-induced ferroptosis via regulating mitochondrial metabolism

COX7A1, a subunit of cytochrome c oxidase, holds an important position in the super-assembly which integrates into multi-unit heteromeric complexes peripherally in the mitochondrial electron transport chain (ETC). Recently, some studies indicated the significant potential of COX7A1 in cancer metabolism and therapy. However, the underlying metabolic process and therapy mechanism remain unclear. In this study, COX7A1-overexpressed cell line was established via lentivirus transduction. The relationship between COX7A1 and ferroptosis, a novel form of cell death driven by iron-dependent lipid peroxidation, was further analyzed in different human non-small-cell lung carcinoma (NSCLC) cells respectively. Our results showed that COX7A1 increased the sensitivity of NSCLC cells to the ferroptosis induced by cysteine deprivation via enhancing the tricarboxylic acid (TCA) cycle and the activity of complex IV in mitochondrial ETC. Meanwhile, COX7A1 suppressed mitochondrial dynamics as well as mitochondrial biogenesis and mitophagy through blocking autophagic flux. The autophagy activator, rapamycin, relieved the autophagic blockage and further strengthened the sensitivity to cysteine deprivation-induced ferroptosis of NSCLC cells in vitro and in vivo. Taken together, our data indicate the close association of COX7A1 with cysteine deprivation-induced ferroptosis, and provide a novel insight into the therapy mode against human NSCLC.

Pharmacological targeting of CBP/p300 drives a redox/autophagy axis leading to senescence-induced growth arrest in non-small cell lung cancer cells

p300/CBP histone acetyltransferases (HAT) are critical transcription coactivators involved in multiple cellular activities. They act at multiple levels in non-small cell lung carcinoma (NSCLC) and appear, therefore, as promising druggable targets. Herein, we investigated the biological effects of A-485, the first selective (potent) drug-like HAT catalytic inhibitor of p300/CBP, in human NSCLC cell lines. A-485 treatment specifically reduced p300/CBP-mediated histone acetylation marks and caused growth arrest of lung cancer cells via activation of the autophagic pathway. Indeed, A-485 growth-arrested cells displayed phenotypic markers of cell senescence and failed to form colonies. Notably, disruption of autophagy by genetic and pharmacological approaches triggered apoptotic cell death. Mechanistically, A-485-induced senescence occurred through the accumulation of reactive oxygen species (ROS), which in turn resulted in DNA damage and activation of the autophagic pathway. Interestingly, ROS scavengers were able to revert senescence phenotype and restore cell viability, suggesting that ROS production had a key role in upstream events leading to growth arrest commitment. Altogether, our data provide new insights into the biological effects of the A-485 and uncover the importance of the autophagic/apoptotic response to design a new combinatorial anticancer strategy.

Targeting the SREBP-1/Hsa-Mir-497/SCAP/FASN Oncometabolic Axis Inhibits the Cancer Stem-like and Chemoresistant Phenotype of Non-Small Cell Lung Carcinoma Cells.

Background: Lung cancer remains a leading cause of cancer-related death, with an annual global mortality rate of 18.4%. Despite advances in diagnostic and therapeutic technologies, non–small cell lung carcinoma (NSCLC) continues to be characterized by a poor prognosis. This may be associated with the enrichment of cancer stem cells (CSCs) and the development of chemoresistance—a double-edged challenge that continues to impede the improvement of long-term outcomes. Metabolic reprogramming is a new hallmark of cancer. Sterol regulatory element-binding proteins (SREBPs) play crucial regulatory roles in the synthesis and uptake of cholesterol, fatty acids, and phospholipids. Recent evidence has demonstrated that SREBP-1 is upregulated in several cancer types. However, its role in lung cancer remains unclear. Objective: This study investigated the role of SREBP-1 in NSCLC biology, progression, and therapeutic response and explored the therapeutic exploitability of SREBP-1 and SREBP-1-dependent oncometabolic signaling and miRNA epigenetic regulation. Methods: We analyzed SREBP-1 levels and biological functions in clinical samples and the human NSCLC cell lines H441 and A549 through shRNA-based knock down of SREBP function, cisplatin-resistant clone generation, immunohistochemical staining of clinical samples, and cell viability, sphere-formation, Western blot, and quantitative PCR assays. We conducted in-silico analysis of miRNA expression in NSCLC samples by using the Gene Expression Omnibus (GSE102286) database. Results: We demonstrated that SREBP-1 and SCAP are highly expressed in NSCLC and are positively correlated with the aggressive phenotypes of NSCLC cells. In addition, downregulation of the expression of tumor-suppressing hsa-miR-497-5p, which predictively targets SREBP-1, was observed. We also demonstrated that SREBP-1/SCAP/FASN lipogenic signaling plays a key role in CSCs-like and chemoresistant NSCLC phenotypes, especially because the fatostatin or shRNA targeting of SREBP-1 significantly suppressed the viability, cisplatin resistance, and cancer stemness of NSCLC cells and because treatment induced the expression of hsa-miR-497. Conclusion: Targeting the SREBP-1/hsa-miR-497 signaling axis is a potentially effective anticancer therapeutic strategy for NSCLC.

Spherical Invasion Assay: A Novel Method to Measure Invasion of Cancer Cells.

The invasion of tumor cells into the neighboring blood vessels and lymph nodes is a vital step for distant metastasis. Traditionally, the invasive activity of growth factors (or the anti-invasive activity of drugs) is measured with the Boyden chamber assay. However, this assay has a few disadvantages like poor physiological relevance of transwell inserts and an inability to control chemokine gradients. The Boyden chamber assay is one of the most prevalent methods to measure the invasion of cancer cells. It would be advantageous to develop another assay that could validate the results of the Boyden chamber assay. With this in mind, our laboratory developed the spherical invasion assay (SIA) to measure the pro-invasive activity of human cancer cells. The SIA also circumvents some of the drawbacks of the Boyden chamber assay. The present manuscript measures the anti-invasive activity of the Src kinase inhibitor PP2 in A549 human non-small cell lung carcinoma (NSCLC) cells using the SIA. The SIA protocol is comprised of two steps. In the first step, A549 human NSCLC cells (treated or not with PP2) were mixed with Matrigel and seeded in the middle of an eight-well chamber slide. After 24 h, a second layer of Matrigel was overlaid over the first layer. Over the course of the next 24 h, the A549 cells invade from the primary to the secondary Matrigel layers. Subsequently, the cells are visualized by phase-contrast microscopy and the images obtained are quantified using ImageJ to calculate the anti-invasive activity of PP2 in A549 cells. The results of the SIA correlate well with Boyden chamber assays. The SIA may be adapted for multiple experimental designs, such as drug screening (to combat invasion and metastasis), measuring the pro-invasive activity of growth factors, and elucidating the signaling pathways underlying the pro-invasive/anti-invasive activity of biological modifiers. Graphic abstract: Diagrammatic illustration of the spherical invasion assay ( Hurley et al., 2017 ) . A. The first layer is comprised of human cancer cells mixed in a 1:1 suspension with Phenol Red containing Matrigel (represented as LAYER 1 in the figure). After 24 h, the cancer cells grow and extend up to the boundary of this first layer. B. A second layer of 1:1 solution Phenol Red-free Matrigel, in Phenol Red-free RPMI (represented as LAYER 2 in the figure) is added on top of the first Matrigel spot. The cells are incubated for 24 h at 37°C. C. Over these 24 h, the cancer cells invade from the primary layer into the secondary Matrigel layer. The chamber slides are observed by phase-contrast microscopy. D. A representative photograph of the images obtained by the SIA is shown. The black arrow indicates the cancer cells invading into the second layer of Matrigel. The dotted line represents the interface between the two layers. The distance to which the cells have traveled (into the secondary Matrigel layer) is measured at ten sites (for each photograph) in a randomized double-blind fashion by three independent observers, using NIH ImageJ Version 1.47. This process is repeated for three separate photographic fields per sample.

Dual targeting of MEK and PI3K effectively controls the proliferation of human EGFR-TKI resistant non-small cell lung carcinoma cell lines with different genetic backgrounds

BackgroundMolecular targeted therapy for non-small cell lung carcinoma (NSCLC) is restricted due to resistance to epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs). This study evaluated the effects of dual targeting of MEK and PI3K in human EGFR-TKI resistant NSCLC cell lines.MethodsEGFR-TKI resistant NSCLC cell lines H1975, H460, and A549, with different mutation and amplification status in EGFR, K-RAS, PIK3CA, and MET genes, were treated with a MEK162 (MEK inhibitor) and BKM120 (PI3K inhibitor) combination or a BIBW2992 (EGFR inhibitor) and ARQ197 (MET inhibitor) combination and assayed for cell proliferation, apoptosis, and cell cycle distribution.ResultsDual targeting of MEK and PI3K efficiently inhibited the cell proliferation, induced apoptosis and the G0/G1 cell cycle, and decreased the phosphorylation of ERK1/2, AKT, S6, and 4E-BP1. H460 cells with K-RAS and PIK3CA mutation were most sensitive to MEK162 and BKM120 combinations. H1975 cells with EGFR and PIK3CA mutation and MET amplification were sensitive to BIBW2992 and ARQ197 combinations.ConclusionDual targeting regulated the proliferation of EGFR-TKI-resistant NSCLC cells, especially mutants in K-RAS and PIK3CA that are promising for EGFR-TKI-resistant NSCLC therapeutics.

The Anti-Non-Small Cell Lung Cancer Cell Activity by a mTOR Kinase Inhibitor PQR620.

In non-small-cell lung carcinoma (NSCLC), aberrant activation of mammalian target of rapamycin (mTOR) contributes to tumorigenesis and cancer progression. PQR620 is a novel and highly-potent mTOR kinase inhibitor. We here tested its potential activity in NSCLC cells. In primary human NSCLC cells and established cell lines (A549 and NCI-H1944), PQR620 inhibited cell growth, proliferation, and cell cycle progression, as well as cell migration and invasion, while inducing significant apoptosis activation. PQR620 disrupted assembles of mTOR complex 1 (mTOR-Raptor) and mTOR complex 2 (mTOR-Rictor-Sin1), and blocked Akt, S6K1, and S6 phosphorylations in NSCLC cells. Restoring Akt-mTOR activation by a constitutively-active Akt1 (S473D) only partially inhibited PQR620-induced cytotoxicity in NSCLC cells. PQR620 was yet cytotoxic in Akt1/2-silenced NSCLC cells, supporting the existence of Akt-mTOR-independent mechanisms. Indeed, PQR620 induced sphingosine kinase 1 (SphK1) inhibition, ceramide production and oxidative stress in primary NSCLC cells. In vivo studies demonstrated that daily oral administration of a single dose of PQR620 potently inhibited primary NSCLC xenograft growth in severe combined immune deficient mice. In PQR620-treated xenograft tissues, Akt-mTOR inactivation, apoptosis induction, SphK1 inhibition and oxidative stress were detected. In conclusion, PQR620 exerted potent anti-NSCLC cell activity via mTOR-dependent and -independent mechanisms.

NRF2 regulates the sensitivity of human NSCLC cells to cystine deprivation-induced ferroptosis via FOCAD-FAK signaling pathway

Transcription factor nuclear factor-erythroid 2-like 2 (NRF2) mainly regulates cellular antioxidant response, redox homeostasis and metabolic balance. Our previous study illustrated the translational significance of NRF2-mediated transcriptional repression, and the transcription of FOCAD gene might be negatively regulated by NRF2. However, the detailed mechanism and the related significance remain unclear. In this study, we mainly explored the effect of NRF2-FOCAD signaling pathway on ferroptosis regulation in human non-small-cell lung carcinoma (NSCLC) model. Our results confirmed the negative regulation relationship between NRF2 and FOCAD, which was dependent on NRF2-Replication Protein A1 (RPA1)-Antioxidant Response Elements (ARE) complex. In addition, FOCAD promoted the activity of focal adhesion kinase (FAK), which further enhanced the sensitivity of NSCLC cells to cysteine deprivation-induced ferroptosis via promoting the tricarboxylic acid (TCA) cycle and the activity of Complex I in mitochondrial electron transport chain (ETC). However, FOCAD didn't affect GPX4 inhibition-induced ferroptosis. Moreover, the treatment with the combination of NRF2 inhibitor (brusatol) and erastin showed better therapeutic action against NSCLC in vitro and in vivo than single treatment, and the improved therapeutic function partially depended on the activation of FOCAD-FAK signal. Taken together, our study indicates the close association of NRF2-FOCAD-FAK signaling pathway with cysteine deprivation-induced ferroptosis, and elucidates a novel insight into the ferroptosis-based therapeutic approach for the patients with NSCLC.

Tumor growth suppression using a combination of taxol-based therapy and GSK3 inhibition in non-small cell lung cancer.

Glycogen synthase kinase-3 (GSK3) is over-expressed and hyperactivated in non-small cell lung carcinoma (NSCLC) and plays a role in ensuring the correct alignment of chromosomes on the metaphase plate during mitosis through regulation of microtubule stability. This makes the enzyme an attractive target for cancer therapy. We examined the effects of a selective cell-permeant GSK3 inhibitor (CHIR99021), used alone or in combination with paclitaxel, using an in vitro cell growth assay, a quantitative chromosome alignment assay, and a tumor xenograft model. CHIR99021 inhibits the growth of human H1975 and H1299 NSCLC cell lines in a synergistic manner with paclitaxel. CHIR99021 and paclitaxel promoted a synergistic defect in chromosomal alignment when compared to each compound administered as monotherapy. Furthermore, we corroborated our in vitro findings in a mouse tumor xenograft model. Our results demonstrate that a GSK3 inhibitor and paclitaxel act synergistically to inhibit the growth of NSCLC cells in vitro and in vivo via a mechanism that may involve converging modes of action on microtubule spindle stability and thus chromosomal alignment during metaphase. Our findings provide novel support for the use of the GSK3 inhibitor, CHIR99021, alongside taxol-based chemotherapy in the treatment of human lung cancer.

Role of INSL4 Signaling in Sustaining the Growth and Viability of LKB1-Inactivated Lung Cancer.

The LKB1 tumor suppressor gene is commonly inactivated in non-small cell lung carcinomas (NSCLC), a major form of lung cancer. Targeted therapies for LKB1-inactivated lung cancer are currently unavailable. Identification of critical signaling components downstream of LKB1 inactivation has the potential to uncover rational therapeutic targets. Here we investigated the role of INSL4, a member of the insulin/IGF/relaxin superfamily, in LKB1-inactivated NSCLCs. INSL4 expression was analyzed using global transcriptome profiling, quantitative reverse transcription PCR, western blotting, enzyme-linked immunosorbent assay, and RNA in situ hybridization in human NSCLC cell lines and tumor specimens. INSL4 gene expression and clinical data from The Cancer Genome Atlas lung adenocarcinomas (n = 515) were analyzed using log-rank and Fisher exact tests. INSL4 functions were studied using short hairpin RNA (shRNA) knockdown, overexpression, transcriptome profiling, cell growth, and survival assays in vitro and in vivo. All statistical tests were two-sided. INSL4 was identified as a novel downstream target of LKB1 deficiency and its expression was induced through aberrant CRTC-CREB activation. INSL4 was highly induced in LKB1-deficient NSCLC cells (up to 543-fold) and 9 of 41 primary tumors, although undetectable in all normal tissues except the placenta. Lung adenocarcinomas from The Cancer Genome Atlas with high and low INSL4 expression (with the top 10th percentile as cutoff) showed statistically significant differences for advanced tumor stage (P < .001), lymph node metastasis (P = .001), and tumor size (P = .01). The INSL4-high group showed worse survival than the INSL4-low group (P < .001). Sustained INSL4 expression was required for the growth and viability of LKB1-inactivated NSCLC cells in vitro and in a mouse xenograft model (n = 5 mice per group). Expression profiling revealed INSL4 as a critical regulator of cell cycle, growth, and survival. LKB1 deficiency induces an autocrine INSL4 signaling that critically supports the growth and survival of lung cancer cells. Therefore, aberrant INSL4 signaling is a promising therapeutic target for LKB1-deficient lung cancers.

Development of a Fluorinated Analogue of Erlotinib for PET Imaging of EGFR Mutation\u2013Positive NSCLC

PurposePositron emission tomography (PET) using [11C]erlotinib identifies non-small cell lung carcinoma (NSCLC) tumors with activating mutations in the epidermal growth factor receptor (EGFRm). The short half-life of C-11, however, limits its clinical utility to centers with a nearby cyclotron. We therefore developed a F-18–labeled analogue of erlotinib for imaging EGFRm NSCLC.Procedures6-O-Fluoroethylerlotinib (6-O-FEE) was synthesized and its anti-proliferative activity was tested using human NSCLC cell lines. The F-18–labeled compound, 6-O-[18F]FEE, was obtained in a two-step synthesis, and PET acquisitions were carried out following its injection to NSCLC tumor–bearing mice.ResultsIn vitro, 6-O-FEE had maintained the selectivity and potency of erlotinib to EGFRm NSCLC. In vivo, 6-O-[18F]FEE accumulation in EGFRm tumors at 60 min after injection was 2- and 3.3-fold higher than in erlotinib-resistant or erlotinib-insensitive tumors, respectively.Conclusions6-O-[18F]FEE holds promise for imaging EGFRm NSCLC, warranting further investigation to fully explore its potential for stratifying NSCLC patients.

Baicalin, a Chinese Herbal Medicine, Inhibits the Proliferation and Migration of Human Non-Small Cell Lung Carcinoma (NSCLC) Cells, A549 and H1299, by Activating the SIRT1/AMPK Signaling Pathway.

BackgroundBaicalin is a flavonoid derived from Scutellaria baicalensis, used in Chinese herbal medicine. Activation of the sirtuin 1 gene (SIRT1) and adenosine monophosphate (AMP)-activated protein kinase gene (AMPK), the SIRT1/AMPK signaling pathway, is associated with human malignant tumors. The aim of this study was to investigate the effects of baicalin on the cell viability, apoptosis, proliferation, and migration of human non-small cell lung cancer (NSCLC) cells, A549 and H1299, in vitro.Material/MethodsHuman NSCLC cells, A549 and H1299, were treated with serial doses of baicalin. Small interfering RNA (siRNA) silencing of the SIRT1 and AMPK genes was performed using cell transfection. The MTT assay was used to determine cell viability, flow cytometry was used to measure cell apoptosis, wound healing and transwell assays were used to assess cell migration of A549 and H1299 cells. Western blotting was used to measure protein expression and phosphorylation levels in untreated A549 and H1299 cells, and cells treated with increasing doses of baicalin.ResultsBaicalin inhibited the viability, migration, and invasion of A549 and H1299 cells, and increased cell apoptosis in a dose-dependent manner. Baicalin activated the SIRT1/AMPK and mechanistic target of rapamycin (mTOR), and SIRT1/AMPK and matrix metalloproteinase (MMP) signaling in A549 and H1299 cells in a dose-dependent manner. siRNA silencing of SIRT1 and AMPK reduced the effects of baicalin on cell proliferation and migration.ConclusionsBaicalin, a flavonoid used in Chinese herbal medicine, inhibited the proliferation and migration of human NSCLC cells, A549 and H1299, by activating the SIRT1/AMPK signaling pathway.

TSPAN12 is overexpressed in NSCLC via p53 inhibition and promotes NSCLC cell growth in vitro and in vivo.

BackgroundTetraspanin 12 (TSPAN12), a member of the phylogenetically ancient tetraspanin family, is linked to impaired vascularization of the eye called familial exudative vitreoretinopathy, while the functional role of TSPAN12 in lung cancer has not been well characterized.ResultsIn our study, TSPAN12 is able to regulate the growth of non-small-cell lung carcinoma (NSCLC) cells both in vitro and in vivo. TSPAN12 mRNA level was significantly increased in human NSCLC samples compared with their corresponding paracancerous histologic normal tissues. In addition, TSPAN12 expression, which is frequently upregulated in NSCLC, is inversely correlated with p53 expression. Furthermore, the expression levels of TSPAN12 were also increased in three human NSCLC cell lines compared to human bronchial epithelial (16HBE) cells. Then, we studied the effects of TSPAN12 silencing by short hairpin ribonucleic acid on NSCLC cell growth in vitro and tumorigenesis in vivo, along with the effect on the p53 pathway. Knockdown of TSPAN12 in NSCLC cells inhibited cell proliferation and colony formation. In addition, knockdown of TSPAN12 increased apoptosis in NSCLC cells. Mechanistically, TSPAN12 could modulate the expression of p53, p21, and p27 in NSCLC cells. In a tumor xenograft model, TSPAN12 silencing inhibits the tumor growth of H1299 cells.ConclusionTaken together, our results reveal that TSPAN12 plays an important role in NSCLC and is a potential biomarker and a promising target in the treatment of NSCLC.

PGE2 mediates EGFR internalization and nuclear translocation via caveolin endocytosis promoting its transcriptional activity and proliferation in human NSCLC cells.

Prostaglandin E2 (PGE2) contributes to tumor progression by promoting cancer cell growth, invasion and by creating a favorable pro-tumor microenvironment. PGE2 has been reported to transactivate and internalize into the nucleus receptor tyrosine kinases such as Epidermal growth factor receptor (EGFR), thereby supporting tumor progression. Here we demonstrate that in non-small cell lung carcinoma (NSCLC) cells, PGE2 induces EGFR nuclear translocation via different dynamin-dependent endocytic pathways, promotes the formation of an EGFR-STAT3 complex, affects nuclear EGFR target gene expression and mediates tumor cell proliferation. Indeed, we find that PGE2 induces EGFR internalization and consequent nuclear import through Clathrin- and Caveolin-mediated endocytosis and through the interaction of EGFR with Importin β1. Within the nucleus, EGFR forms a complex with STAT3, an event blocked by ablation of Clathrin Heavy Chain or Caveolin-1. The combination of EGF and PGE2 prolongs nuclear EGFR transcriptional activity manifested by the upregulation of CCND1, PTGS2, MYC and NOS2 mRNA levels and potentiates nuclear EGFR-induced NSCLC cell proliferation. Additionally, NSCLC patients with high expression of a nuclear EGFR gene signature display shorter survival times than those with low expression, thus showing a putative correlation between nuclear EGFR and poor prognosis in NSCLC. Together, our findings indicate a complex mechanism underlying PGE2-induced EGF/EGFR signaling and transcriptional control, which plays a key role in cancer progression.

Tetrahydrocurcumin‑induced autophagy via suppression of PI3K/Akt/mTOR in non‑small cell lung carcinoma cells.

Lung carcinoma is the leading cause of mortality due to cancer worldwide. Autophagy has a significant role in the development and progression of non‑small cell lung carcinoma (NSCLC). A previous study has revealed that tetrahydrocurcumin (THC), a traditional Chinese medicine isolated from Curcumawenyujin (Chen & Ling, 1981), induces autophagy in human A549 NSCLC cells. The present study evaluated THC‑induced autophagy in A549 cells using various assays, including the Cell Counting Kit‑8, acridine orange staining, flow cytometry, reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR), and western blot analysis of the markers of autophagy. THC inhibited the growth and proliferation of A549 cells (P<0.05). Acridine orange staining and flow cytometry revealed that THC treatment significantly enhanced autophagic cell proliferation inhibition (P<0.05). The RT‑qPCR analysis revealed that THC treatment increased Beclin‑1 expression level and compared with the control group (P<0.05). The light chain 3 (LC3)‑II/LC3‑I ratio was reduced in THC‑treated cells when compared with the control group (P<0.05). Protein expression of various markers of autophagy, including p62, phosphorylated (p)‑mechanistic target of rapamycin (mTOR), phosphoinositide 3‑kinase (PI3K), p‑PI3K, protein kinase B (Akt), and p‑Akt was significantly reduced in THC‑treated cells (P<0.05). In conclusion, the present study revealed the underlying mechanisms associated with THC‑induced autophagy. A promising method of enhancing the therapeutic efficacy of THC against NSCLC cells may include inducing autophagy via inhibition of the PI3K/Akt/mTOR signaling pathway.

Effect of miR-21 on Apoptosis in Lung Cancer Cell Through Inhibiting the PI3K/ Akt/NF-κB Signaling Pathway in Vitro and in Vivo

Background/Aims: Lung cancer is one of the most common malignancies in the world. Apoptosis-stimulating protein of p53 (ASPP2), a tumorigenesis related protein, plays a critical role in the initiation and development of various types of cancers. However, the effect of ASPP2 on lung cancer remains unknown. The purpose of this study aims to investigate the mechanism of ASPP2 regulated by miR-21 in lung cancer in vitro and in vivo. Methods: In the study, migration and invasion assays, apoptosis assay, caspase activity assay, TUNEL staining, real time PCR and western blot were used to investigate the mechanism of ASPP2 regulated by miR-21 in lung cancer in vitro and in vivo. Results: We demonstrated that the miR-21 inhibitor induced apoptosis through inhibiting the PI3K/Akt/NF-κB signaling pathway in non-small cell lung carcinoma (NSCLC). Moreover, ASPP2 was directly targeted by miR-21 in NSCLC cells. Down-regulation of miR-21 suppressed cell migration and invasion, as well as the EMT signaling pathway in NSCLC cells. Furthermore, the miR-21 inhibitor induced cell apoptosis via the caspase dependent pathway in NSCLC cells. The miR-21 inhibitor enhanced caspase-3, 8, 9 activity in NSCLC cells. In addition, the caspase inhibitor significantly reduced the apoptosis induced by the miR-21 inhibitor in NSCLC cells. Conclusions: Our results revealed that the miR-21 inhibitor could induce apoptosis through inhibiting the PI3K/Akt/NF-κB signaling pathway in human NSCLC cells, and might serve as a therapeutic strategy to treat NSCLC.

CXCR4 Accelerates Osteoclastogenesis Induced by Non-Small Cell Lung Carcinoma Cells Through Self-Potentiation and VCAM1 Secretion

Background/Aims: Non-small cell lung carcinoma (NSCLC) metastasis to bone leads to skeletal-related events and a poor quality of life. Unravelling the mechanism of metastasis is crucial for improving survival. Previous work has implicated the role of CXCR4 in bone metastasis; however, the underlying mechanisms are unknown. Methods: The human bone metastasis tissue samples were obtained from lung cancer patients during surgery with consents. The patients were followed up and the overall survival curve was analysed. The expression of CXCR4, VCAM1, and ADAM17 was measured with real-time PCR, western blot and immunochemistry staining in human tissue or NSCLC cell lines. The effects of CXCR4, soluble VCAM1 and ADAM17 on NSCLC proliferation, migration and invasion were measured with CCK-8, monolayer scratch assay and transwell chamber, respectively. The amount of soluble VCAM1 in the conditioned medium was detected with ELISA. Tartrate-resistant acid phosphatasethe (TRAP) staining was performed to stain the multinucleated cells regarded as osteoclasts. Results: In this study, CXCR4 was found to be highly expressed in bone destruction area of metastatic NSCLC samples and related to poor survival in NSCLC patients with bone metastasis. CXCR4 potentiated NSCLC with enhanced proliferation and invasion abilities, while CXCR4 knockdown significantly suppressed the growth and invasion. Furthermore, CXCR4 promoted lung cancer-induced osteoclast differentiation with increased osteoclast formation. We also found that soluble VCAM1 (sVCAM1) secreted in NSCLC contributed to the osteoclastogenesis induced by CXCR4. The overexpression of CXCR4 increased sVCAM1, and the sVCAM1 secreted from CXCR4-overexpressing NSCLC cells recruited and arrested additional osteoclast progenitors to promote osteoclastogenesis. ADAM17 was confirmed to act as a downstream mediator of CXCR4. The chemical inhibition of ADAM17 with TAPI-2 decreased sVCAM1 secretion and the number of TRAP+ osteoclasts. Conclusion: Taken together, these results indicated that CXCR4 potentiated NSCLC and promoted osteoclastogenesis through sVCAM1, which was cleaved by ADAM17. These data support the pivotal role of the cross talk between CXCR4 and ADAM17-VCAM1 in NSCLC-induced bone metastasis.

MiR-768-3p is involved in the proliferation, invasion and migration of non-small cell lung carcinomas.

Altered microRNA expression has been found to be a common feature of several cancers, including lung carcinomas. However, the possible roles of miR-768-3p in the pathological changes of lung carcinomas are still unknown. The aim of the present study was to investigate the expression and possible effects of miR-768-3p in human non-small cell lung carcinomas (NSCLC). Eighty-three NSCLC patients attending the clinic of Kunming Hospital were invited to participate in the study. Their tumor samples were obtained for qRT-PCR analysis. Human NSCLC cell lines, A549 and HCC4006, were employed and transfected with either miR-768-3p mimics or miR-768-3p antagomir. Following transfection, the invitro and invivo proliferation, apoptosis fractions, migration and invasion of NSCLC cells were evaluated. The data revealed that: i)upregulated miR-768-3p in tumors were associated with the clinicopathological features of NSCLC patients; ii)inhibiting miR-768-3p function by miR-768-3p antagomir induced distinctly apoptosis and Fas/FasL expressional alteration of NSCLC cells; iii)miR-768-3p antagomir transduction also decreased the viability, migration and invasion, as well as MMP-2 and MMP-9 activities in A549 and HCC4006 cells; and iv)miR-768-3p antagomir transfection also inhibited the growth and proliferation of NSCLC xenografts in nude mice. The present results suggested that abnormal elevated miR-768-3p in NSCLC tumors and cell lines played important roles in NSCLC carcinogenic progression, and the targeting of miR-768-3p might be a potential therapeutic strategy for the treatment of NSCLC.

MiR-1254 suppresses HO-1 expression through seed region-dependent silencing and non-seed interaction with TFAP2A transcript to attenuate NSCLC growth.

MicroRNAs (miRNAs) are a class of small non-coding RNAs, which direct post-transcriptional gene silencing (PTGS) and function in a vast range of biological events including cancer development. Most miRNAs pair to the target sites through seed region near the 5’ end, leading to mRNA cleavage and/or translation repression. Here, we demonstrated a miRNA-induced dual regulation of heme oxygenase-1 (HO-1) via seed region and non-seed region, consequently inhibited tumor growth of NSCLC. We identified miR-1254 as a negative regulator inhibiting HO-1 translation by directly targeting HO-1 3’UTR via its seed region, and suppressing HO-1 transcription via non-seed region-dependent inhibition of transcriptional factor AP-2 alpha (TFAP2A), a transcriptional activator of HO-1. MiR-1254 induced cell apoptosis and cell cycle arrest in human non-small cell lung carcinoma (NSCLC) cells by inhibiting the expression of HO-1, consequently suppressed NSCLC cell growth. Consistently with the in vitro studies, mouse xenograft studies validated that miR-1254 suppressed NSCLC tumor growth in vivo. Moreover, we found that HO-1 expression was inversely correlated with miR-1254 level in human NSCLC tumor samples and cell lines. Overall, these findings identify the dual inhibition of HO-1 by miR-1254 as a novel functional mechanism of miRNA, which results in a more effective inhibition of oncogenic mRNA, and leads to a tumor suppressive effect.