Human Non-small Cell Lung Carcinoma Cell Lines Research Articles

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.

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.

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.

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.

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.

Evaluation of 99mTc-HYNIC-MPG as a novel SPECT radiotracer to detect EGFR-activating mutations in NSCLC.

Tyrosine kinase inhibitors (EGFR-TKIs) targeting the epidermal growth factor receptor (EGFR) have been used in non-small cell lung carcinoma (NSCLC) for years with promising results, in particular in patients with activating mutations in the EGFR kinase domain (exon 19 E746-A750 deletion or exon 21 L858R point mutation). However, despite their great success in the clinic, a significant number of patients do not respond to EGFR-TKIs, such as those carrying the L858R/T790M mutation or EGFR wild type. Thus, detecting the EGFR mutation status before EGFR-TKIs therapy is essential to ensure its efficacy. In this study, we report a novel SPECT tracer 99mTc-HYNIC-MPG that binds specifically to activating mutant EGFR and which could therefore be used to noninvasively select patients sensitive to EGFR-TKIs. We evaluated the capacity of 99mTc-HYNIC-MPG in detecting EGFR-activating mutations both in vitro and in vivo using four human NSCLC cell lines (PC9, H1975, H358 and H520). 99mTc-HYNIC-MPG had significantly higher accumulation in PC9 tumor cells when compared to H1975, H358 and H520 tumors cells, which may be due to the activating mutations (exon 19 deletion) in EGFR tyrosine kinase domain in PC9 cells. Thus, 99mTc-HYNIC-MPG SPECT imaging may be used to identify NSCLC tumors with a potential high response rate to EGFR-TKIs.

Reversal of the Apoptotic Resistance of Non-Small-Cell Lung Carcinoma towards TRAIL by Natural Product Toosendanin

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) selectively triggers cancer cell death via its association with death receptors on the cell membrane, but exerts negligible side effects on normal cells. However, some non-small-cell lung carcinoma (NSCLC) patients exhibited resistance to TRAIL treatment in clinical trials, and the mechanism varies. In this study, we described for the first time that toosendanin (TSN), a triterpenoid derivative used in Chinese medicine for pain management, could significantly sensitize human primary NSCLC cells or NSCLC cell lines to TRAIL-mediated apoptosis both in vitro and in vivo, while showing low toxicity against human primary cells or tissues. The underlying apoptotic mechanisms involved upregulation of death receptor 5 (DR5) and CCAAT/enhancer binding protein homologous protein, which is related to the endoplasmic reticulum stress response, and is further associated with reactive oxygen species generation and Ca2+ accumulation. Surprisingly, TSN also induced autophagy in NSCLC cells, which recruited membrane DR5, and subsequently antagonized the apoptosis-sensitizing effect of TSN. Taken together, TSN can be used to sensitize tumors and the combination of TRAIL and TSN may represent a useful strategy for NSCLC therapy; moreover, autophagy serves as an important drug resistance mechanism for TSN.

Serine-arginine protein kinase 1 promotes a cancer stem cell-like phenotype through activation of Wnt/β-catenin signalling in NSCLC.

Cancer stem cells (CSCs) are commonly associated with cancer recurrence and metastasis that occurs in up to 30-55% of non-small-cell lung carcinoma (NSCLC) patients. Herein, we showed that serine-arginine protein kinase 1 (SRPK1) was highly expressed at both the mRNA and the protein levels in human NCSLC. SRPK1 was associated with the clinical features of human NSCLC, including clinical stage (p < 0.001) and T (p = 0.001), N (p = 0.007), and M (p = 0.001) classifications. Ectopic overexpression of SRPK1 promoted the acquisition of a stem cell-like phenotype in human NSCLC cell lines cultured in vitro. Overexpression of SRPK1 increased sphere formation and the proportion of side-population cells that exclude Hoechst dye. Conversely, SRPK1 silencing reduced the number of spheres and the proportion of side-population cells. Mouse studies indicated that SRPK1 promoted NSCLC cell line tumour growth and SRPK1 overexpression reduced the number of tumour cells required to initiate tumourigenesis in vivo. Mechanistically, gene set enrichment analysis showed that Wnt/β-catenin signalling correlated with SRPK1 mRNA levels and this signalling pathway was hyperactivated by ectopic SRPK1 expression in NSCLC cell lines. Immunofluorescence demonstrated that SRPK1 enhanced β-catenin accumulation in the nuclei of NSCLC cell lines, and inhibition of β-catenin signalling abrogated the SRPK1-induced stem cell-like phenotype. Together, our findings suggest that SRPK1 promotes a stem cell-like phenotype in NSCLC via Wnt/β-catenin signalling. Moreover, SRPK1 may represent a novel target for human NSCLC diagnosis and therapy. Copyright © 2016 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

RalGPS2 Is Essential for Survival and Cell Cycle Progression of Lung Cancer Cells Independently of Its Established Substrates Ral GTPases.

The human genome contains six genes coding for proteins validated in vitro as specific activators of the small GTPases “Ras-related protein Ral-A” and “Ras-related protein Ral-B”, generically named Ral-guanine nucleotide exchange factors (RalGEF). Ral proteins are important contributors to Ras oncogenic signaling, and RAS oncogenes are important in human Non-Small Cell Lung Carcinoma (NSCLC). Therefore in this work, RalGEF contribution to oncogenic and non-oncogenic features of human NSCLC cell lines, as anchorage-dependent and independent growth, cell survival, and proliferation, was investigated. Among all human RalGEF, silencing of RGL1 and RALGPS1 had no detectable effect. However, silencing of either RGL2, RGL3, RALGDS or, to a larger extent, RALGPS2 inhibited cell population growth in anchorage dependent and independent conditions (up to 90 and 80%, respectively). RALGPS2 silencing also caused an increase in the number of apoptotic cells, up to 45% of the cell population in transformed bronchial BZR cells. In H1299 and A549, two NSCLC cell lines, RALGPS2 silencing caused an arrest of cells in the G0/G1-phase of cell cycle. Furthermore, it was associated with the modulation of important cell cycle regulators: the E3 Ubiquitin Protein Ligase S-phase kinase-associated protein 2 (Skp2) was strongly down-regulated (both at mRNA and protein levels), and its targets, the cell cycle inhibitors p27 and p21, were up-regulated. These molecular effects were not mimicked by silencing RALA, RALB, or both. However, RALB silencing caused a modest inhibition of cell cycle progression, which in H1299 cells was associated with Cyclin D1 regulation. In conclusion, RALGPS2 is implicated in the control of cell cycle progression and survival in the in vitro growth of NSCLC cell lines. This function is largely independent of Ral GTPases and associated with modulation of Skp2, p27 and p21 cell cycle regulators.

In vitro Basis for Cell Line‐Dependent Interaction between Sorafenib and Dasatinib in Human Non‐Small Cell Lung Carcinoma Cell Lines

BackgroundRecent clinical trials have demonstrated a better‐than‐average therapeutic outcome of the multi‐kinase inhibitor sorafenib in patients with chemorefractory non‐small cell lung carcinomas (NSCLCs) as well as the inevitable treatment failure due to the reduced tumor sensitivity to sorafenib over time. In search of strategies to overcome the acquired sorafenib resistance, we evaluated the feasibility of combining sorafenib with dasatinib for the treatment of NSCLCs with different sensitivity to sorafenib.MethodsThe sorafenib and dasatinib combination was evaluated in A549, H358 and H1915 human NSCLC cell lines. The effect of sorafenib and dasatinib alone and in combination on tumor cell growth was determined by the MTT assay using fixed molar concentration ratio design, inhibitory sigmoid Emax model and combination index (CI) theorem. Western blot analysis of changes in targeted signaling pathways were performed to assess sorafenib and dasatinib interactions.ResultsCombination of sorafenib with dasatinib inhibited the in vitro growth of A549, H358 and H1915 cells in an additive or synergistic fashion based on the CI values as defined by Chou and Talalay (mean CI = 0.99, 1.04 and 0.28 for A549, H358 and H1915, respectively). The improved in‐vitro sorafenib cytotoxicity by the combination in those NSCLC cells was associated with the increased inhibition of the AKT/GSK3 and MEK/ERK/p90RSK pathways.ConclusionsSorafenib and dasatinib exhibited increased cytotoxicity in NSCLC cell lines when used in combination. Given that the H1915 cell line was originally developed from a brain metastasis from a primary lung carcinoma, future studies are warranted for further assessment of the beneficial therapeutic effect of sorafenib and dasatinib combination in an in vivo orthotopic model of lung cancer metastasis to brain.Support or Funding InformationThis work is supported by the University of South Florida College of Pharmacy start‐up fund and Internal Seed Grant (2012–2013) to Q.Z.

Abstract 131: ALK oncogene regulates epithelial-mesenchymal transition (EMT) in ALK-rearranged non-small cell lung carcinoma through repression of the epithelial splicing regulatory proteins 1 and 2 (ESRP1 and ESRP2)

Abstract A subset of Non-Small Cell Lung Carcinoma (NSCLC) carries chromosomal rearrangements involving the Anaplastic Lymphoma Kinase (ALK) gene. More frequently ALK is juxtaposed to the echinoderm microtubule-associated protein-like 4 (EML4) gene on chromosome 2 and generates a constitutively active EML4-ALK fusion protein that triggers downstream oncogenic signals leading to increased cell proliferation and survival. The majority of ALK-rearranged NSCLC presents a peculiar histology characterized by a solid signet-ring cell and a mucinous cribriform pattern that is frequently associated with a metastatic phenotype. As the signet ring phenotype and metastasis are associated with epithelial-mesenchymal transition (EMT), a cellular reprogramming often activated in cancer cells during invasion and metastasis, we investigated whether ALK induces EMT in NSCLC. We performed RNA sequencing analysis on human ALK-rearranged NSCLC cell lines treated with ALK inhibitors or where EML4-ALK was knocked-down by shRNA. We found that EML-ALK regulated several genes related to EMT. In particular, the epithelial splicing regulatory proteins 1 and 2 (ESRP1 and ESRP2), key regulators of a splicing switch during EMT, were repressed in ALK-rearranged NSCLC cells and their repression was dependent on ALK activity. In keeping with these observations, H2228 and DFCI032 cells displayed a mesenchymal phenotype with almost complete suppression of the epithelial marker, E-cadherin, and a strong expression of the mesenchymal markers, vimentin and N-cadherin. In H2228 and DFCI032 cells, both E-cadherin suppression and vimentin up-regulation were dependent upon EML-ALK kinase activity because treatment with ALK inhibitors (TAE684 and crizotinib) or ALK knock-down reverted the phenotype of H2228 and DFCI032 from mesenchymal to epithelial and decreased their invasive potential. We excluded the involvement in EMT of ALK-rearranged NSCLC of other RTKs, such as EGFR or MET, because their inhibition did not have any effect on E-cadherin and vimentin expression. In ALK-rearranged NSCLC, the regulation of E-cadherin suppression was mainly transcriptional whereas vimentin regulation was post-transcriptional for both cell lines. Overexpression of ESRP1 led to up-regulation of E-cadherin, whereas ESRP1 knock-down impaired the reversion to an epithelial phenotype associated to inhibition of ALK activity. In conclusion, we showed that oncogenic ALK regulates EMT in NSCLC through ESRP repression. These findings could have implications for the biology of ALK-rearranged NSCLC in terms of metastatic potential and resistance to therapy. Citation Format: Claudia Voena, Lydia Varesio, Liye Zhang, Matteo Menotti, Teresa Poggio, Filomena Di Giacomo, Elena Panizza, Cristina Mastini, Mara Compagno, Stefano Monti, Roberto Chiarle. ALK oncogene regulates epithelial-mesenchymal transition (EMT) in ALK-rearranged non-small cell lung carcinoma through repression of the epithelial splicing regulatory proteins 1 and 2 (ESRP1 and ESRP2). [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 131. doi:10.1158/1538-7445.AM2015-131

The human NANOS3 gene contributes to lung tumour invasion by inducing epithelial-mesenchymal transition.

We have explored the role of the human NANOS3 gene in lung tumour progression. We show that NANOS3 is over-expressed by invasive lung cancer cells and is a prognostic marker for non-small cell lung carcinomas (NSCLCs). NANOS3 gene expression is restricted in testis and brain and is regulated by epigenetic events. It is up-regulated in cultured cells undergoing epithelial - mesenchymal transition (EMT). NANOS3 over-expression in human NSCLC cell lines enhances their invasiveness by up-regulating EMT, whereas its silencing induces mesenchymal - epithelial transition. NANOS3 represses E-cadherin at the transcriptional level and up-regulates vimentin post-transcriptionally. Also, we show that NANOS3 binds mRNAs encoding vimentin and regulates the length of their poly(A) tail. Finally, NANOS3 can also protect vimentin mRNA from microRNA-mediated repression. We thus demonstrate a role for NANOS3 in the acquisition of invasiveness by human lung tumour cells and propose a new mechanism of post-transcriptional regulation of EMT.

IL-27 inhibits epithelial-mesenchymal transition and angiogenic factor production in a STAT1-dominant pathway in human non-small cell lung cancer

BackgroundInterleukin-27 signaling is mediated by the JAK-STAT pathway via activation of STAT1 and STAT3, which have tumor suppressive and oncogenic activities, respectively. Epithelial–mesenchymal transition (EMT) and angiogenesis are key processes in carcinogenesis. Although IL-27 has been shown to have potent anti-tumor activity in various cancer models, the role of IL-27 in EMT and angiogenesis is poorly understood. In this study, we investigated the role of IL-27 in regulating EMT and angiogenesis through modulation of the STAT pathways in human non-small cell lung carcinoma (NSCLC) cells.MethodsSTAT activation following IL-27 exposure was measured in human NSCLC cell lines. Expression of epithelial (E-cadherin, γ-catenin) and mesenchymal (N-cadherin, vimentin) markers were assessed by Western blot analysis. Production of pro-angiogenic factors (VEGF, IL-8/CXCL8, CXCL5) were examined by ELISA. Cell motility was examined by an in vitro scratch and transwell migration assays. Selective inhibitors of STAT1 (STAT1 siRNAs) and STAT3 (Stattic) were used to determine whether both STAT1 and STAT3 are required for IL-27 mediated inhibition of EMT and secretion of angiogenic factors.ResultsOur results demonstrate that IL-27 stimulation in NSCLC resulted in 1) STAT1 and STAT3 activation in a JAK-dependent manner, 2) development of epithelial phenotypes, including a decrease in the expression of a transcriptional repressor for E-cadherin (SNAIL), and mesenchymal marker (vimentin) with a reciprocal increase in the expression of epithelial markers, 3) inhibition of cell migration, and 4) reduced production of pro-angiogenic factors. STAT1 inhibition in IL-27–treated cells reversed the IL-27 effect with resultant increased expression of Snail, vimentin and the pro-angiogenic factors. The inhibition of STAT3 activation had no effect on the development of the epithelial phenotype.ConclusionIL-27 induces mesenchymal to epithelial transition and inhibits the production of pro-angiogenic factors in a STAT1–dominant pathway. These findings highlight the importance of STAT1 in repressing lung carcinogenesis and describe a new anti-tumor mechanism of IL-27.

Abstract 1979: Tripartite motif 14 (TRIM14) is a putative tumor suppressor gene in non-small-cell lung cancer.

Abstract Background: Non-small-cell lung carcinoma (NSCLC) accounts for 85% of all malignant lung tumors. Our group previously identified Tripartite Motif 14 (TRIM14) as a component of a prognostic multigene expression signature for NSCLC patients. TRIM14 belongs to a conserved family of Tripartite Motif-encoding genes that are involved in a broad range of biological processes, such as transcriptional regulation, cell proliferation, and apoptosis. However, TRIM14 itself is poorly understood, especially in the context of cancer progression. Here we investigate the biological function of TRIM14 in NSCLC. Methods: The expression of TRIM14 was modified in human NSCLC cell lines (NCI-H1395, NCI-H1650 and NCI-H157) by lentivirus-mediated overexpression and short-hairpin RNA-mediated silencing. Effects were assessed by examining in vitro cell proliferation and anchorage-independent growth, and in vivo tumorigenicity in mice. Results: In vitro studies show that TRIM14 overexpression in NSCLC cells suppresses proliferation and anchorage-independent growth, whereas knock-down of TRIM14 expression promotes cell proliferation and colony formation. In vivo studies demonstrate that knock-down of TRIM14 expression significantly increases tumor growth in immunodeficient mice. Conclusion: This is the first study to suggest that TRIM14 may function as a tumor suppressor gene in lung cancer, affecting cell proliferation and anchorage-independent growth in vitro and tumor growth in mice. (Supported by Canadian Cancer Society Research Institute grant #020527) Citation Format: Josephine Hai, Ming-Sound Tsao. Tripartite motif 14 (TRIM14) is a putative tumor suppressor gene in non-small-cell lung cancer. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 1979. doi:10.1158/1538-7445.AM2013-1979

Abstract 2054: GP88 (Progranulin) is a therapeutic and prognostic target for Non-Small Cell Lung Carcinoma.

Abstract Annually, about 220,000 patients are diagnosed with lung cancer in the US and 150,000 die of the disease. Advanced and recent therapeutic development in NSCLC addresses targets found in small percentages of patients, thereby emphasizing the need for continued discoveries of additional targets of lung cancer, in order to develop of novel therapies and diagnosis. We have investigated the role of the autocrine growth and survival factor GP88 (Progranulin) on the biology of Non-Small Cell Lung Carcinoma (NSCLC). Previously, GP88 had been shown to play a critical role in the proliferation and survival of breast cancer. Pathological studies with 600 cases of estrogen receptor positive invasive ductal carcinoma in correlation with clinical outcome data have also shown that GP88 tissue expression was associated with a 4-fold increased risk of recurrence and a 2.5-fold increase in mortality whereas inhibition of GP88 action by a neutralizing antibody resulted in inhibition of tumor formation of breast adenocarcinoma in vivo. In the present study, we examined the role of GP88 in NSCLC. Examination of GP88 protein expression by immunohistochemistry was carried out with formalin fixed paraffin embedded sections of lung cancer cases. Results showed that both human adenocarcinoma and squamous carcinoma stained positive for GP88 whereas normal lung tissues were negative. Pathological studies of tissue GP88 expression by IHC in 85 stage 1 and 2 NSCLC tumors in correlation with clinical outcomes demonstrated that high GP88 expression was associated with a 4-fold increase in the risk of recurrence (p=0.0004) indicating that GP88 is a prognostic factor for NSCLC. Based on these observations, expression and action of GP88 in NSCLC were examined using two representative human NSCLC cell lines A549 and H1299. Inhibition of GP88 expression by GP88 SiRNA resulted in an inhibition of cell migration and proliferation of these cells. Similarly, neutralization of GP88 action by treating the cells with AG1, an anti-human GP88 neutralizing monoclonal antibody expressed in recombinant form also inhibited cell proliferation and migration. Based on these results, studies were carried out to examine the effect of AG1 antibody on NSCLC tumor formation in nude mice. Preclinical studies show that AG1 treatment inhibits tumor formation by 30-50% when used as a single agent or in combination therapy with chemotherapeutic drugs used in the standard of care in NSCLC. These data to be presented here point out that GP88 is a novel therapeutic and prognostic target and provide new opportunities for targeted therapy with companion diagnostic for NSCLC. Citation Format: Ginette Serrero, Guanjun Xia, Jianping Dong, Binbin Yue, Amanda Schech, Douglas Hawkins, David Reisman, Pablo Bejarano, Jun Hayashi. GP88 (Progranulin) is a therapeutic and prognostic target for Non-Small Cell Lung Carcinoma. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 2054. doi:10.1158/1538-7445.AM2013-2054