Ability Of Lung Cancer Cells Research Articles

Exogenous hydrogen sulfide donor NaHS alleviates nickel-induced epithelial-mesenchymal transition and the migration of A549cells by regulating TGF-β1/Smad2/Smad3 signaling.

Nickel compounds are known to be common environmental and occupational carcinogens which also promote the migration of lung cancer cells. However, the molecular mechanism yet remains to be clarified. Hydrogen sulfide (H2S) is involved in cancer biological processes. However, the exact effect and functionality of H2S on nickel, towards the promotion of the migration ability of lung cancer cells, remains to be unknown. In this study, we have found that the nickel chloride (NiCl2) treatment significantly downregulates the protein levels of endogenous H2S enzyme cystathionine β-synthase (CBS), cystathionine γ-lyase (CSE) and 3-Mercaptopyruvate sulfurtransferase (3-MST). A correlation between NiCl2-induced epithelial-mesenchymal transition (EMT) and the migration ability of lung cancer A549cells has been observed. Exogenous H2S donor, sodium hydrogen sulfide (NaHS) (100μmol/L), can reverse NiCl2-induced EMT as well as the migration ability of A549cells. NiCl2 treatment is able to upregulate the protein level of transforming growth factor-β1 (TGF-β1), p-Smad2, p-Smad3, p-JNK, p-ERK and p-P38 in a time-dependent fashion, indicating that both TGF-β1/Smad2/Smad3 and mitogen-activated protein kinase (MAPK) signaling cascades (a non-Smad pathway) may play essential roles in NiCl2-dependent EMT as well as cell migration of human lung cancer cells. Furthermore, exogenous NaHS alleviates the NiCl2-induced EMT and the migration ability of A549cells only by regulating TGF-β1/Smad2/Smad3, rather than the MAPK, signaling pathway. These results indicate that the exogenous administration of NaHS might be a potential therapeutic strategy against nickel-induced lung cancer progression.

Abstract A12: Inhibition of protease-activated receptor 4 (PAR4) suppresses C4a-induced invasion of lung cancer cells in vitro

Abstract It has been well established that chronic inflammation can cause neoplasm development and cancer cell dissemination. The complement system, an essential component of innate immunity, contains some of the most powerful proinflammatory molecules upon its activation. Recent studies have demonstrated that complement activation components, anaphylatoxins C3a and C5a, can regulate the fate of cancer cells through direct or regulatory effects on cancer cells or immune system. C4a (77 aa) is released from complement component C4 upon the activation of the classical and lectin pathways of the complement system. Our recent study provided the data that C4a acts as an untethered ligand for G protein-coupled receptors, protease activated receptor 1 (PAR1) and PAR4. It is still unclear whether C4a generates any effects on cancer cells through binding to its receptors. In our present study, we want to determine the effect of C4a on the invasive ability of lung cancer cells in vitro, which is supposed to be correlated with lung cancer cell metastasis in vivo. First, we checked the levels of C4a in the plasma from patients of different stages of lung cancer, and our results revealed that the plasma level of C4a from stage IV lung cancer patients is significantly higher than that from stage I lung cancer patients, suggesting C4a might be involved in the metastasis of late-stage lung cancer. In addition, our in silico analysis of data from lung adenocarcinoma and squamous cell carcinoma patients using Kalpan-Meier Plotter online database revealed a negative correlation between PAR4 expression and the overall survival and progression-free survival. Moreover, our in vitro transwell invasion experiments demonstrated that C4a could significantly enhance lung cancer cell invasion in a concentration-dependent fashion, and the blockade of PAR4 by its specific antagonist (ML354) significantly inhibited C4a-induced lung cancer cell invasion in vitro. Our data provide the direct evidence that complement activation fragment C4a induces lung cancer cell invasion through acting on its receptor PAR4, suggesting that targeting PAR4 as a therapeutic intervention might be beneficial for impeding cancer cell metastasis in late-stage lung cancer patients. Citation Format: Hongbin Wang, Lingxin Xiong, Zhibin Wang, Yuanyuan Wang, Ling Xu, Weidong Zhang. Inhibition of protease-activated receptor 4 (PAR4) suppresses C4a-induced invasion of lung cancer cells in vitro [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology and Immunotherapy; 2019 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2020;8(3 Suppl):Abstract nr A12.

DEK promotes the proliferation and invasion of lung cancers and indicates poor prognosis in lung adenocarcinomas.

DEK has been revealed to be overexpressed in many cancers and associated with cancer progression. The aim of the present study was to elucidate the role of DEK with a specific focus on its underlying mechanism in lung cancers. DEK expression in lung cancers and normal lung tissues and the correlations between DEK expression and clinicopathological parameters of lung cancers were investigated using the data from The Cancer Genome Atlas (TCGA). DEK expression was upregulated by DEK transfection or downregulated by DEK shRNA interference in A549 and H1299 cells. The effects of DEK on the Wnt signaling pathway and epithelial‑mesenchymal transition (EMT) were examined using western blotting. Proliferative and invasive abilities were observed in A549 and H1299 cells treated with DEK using an MTT assay, colony formation assay, and Transwell migration and invasion assays. The expression of DEK was higher in lung cancer tissues than that in normal lung tissues. DEK expression was positively correlated with the expression of epidermal growth factor receptor (EGFR) and KRAS in lung adenocarcinomas. High expression of DEK indicated poor prognosis in lung adenocarcinomas (P=0.018). Enhanced expression of DEK upregulated the levels of active‑β‑catenin and Wnt target genes, such as cyclin D1, c‑Myc and MMP7 and increased the proliferative and invasive abilities of lung cancer cells. Enhanced expression of DEK in A549 and H1299 cells also increased the levels of EGFR, KRAS, vimentin, Snail, and N‑cadherin, and decreased the level of E‑cadherin. The opposite results were obtained with knockdown of DEK expression. DEK was highly expressed in lung cancers and indicated poor prognosis in lung adenocarcinomas. DEK expression activated the Wnt signaling pathway and EMT process and promoted the proliferation and invasion of lung cancers.

Exosomal miR-106b serves as a novel marker for lung cancer and promotes cancer metastasis via targeting PTEN

As novel non-invasive tumor diagnostic biomarkers, exosomal bioactive miRNAs have received increasing attention. Herein, the aim of this study is to explore the clinical values and roles of exosomal miR106b in lung cancer. The exosomal miR-106b level was much higher in the serum of patients with lung cancer than that in healthy volunteers. Also, the exosomal miR-106b level in the lung cancer patient serum was associated with TNM stages and lymph node metastasis. Furthermore, exosomal miR-106b enhanced the migrated and invasive ability of lung cancer cells and increased the MMP-2 and MMP-9 expression. Mechanistically, exosomal miR-106b could target PTEN, and promote lung cancer cell migration and invasion. More importantly, PTEN overexpression reversed the effect of exosomal miR-106b on lung cancer cell migration and invasion. Taken together, these findings indicate that exosomal miR-106b may be a promising diagnostic biomarker and drug target for patients with lung cancer.

High Expression of TLR2 in the serum of patients with tuberculosis and lung cancer, and can promote the progression of lung cancer.

Purpose: The present paper investigated the expression of TLR2 in serum of patients with pulmonary tuberculosis and lung cancer, and verifiedthe effect of TLR2 on the biological characteristics of lung cancer cells. Methods: The common differentially expressed genes in tuberculosis and lung cancer samples were analyzed by edgeR. The intersection of genes was taken and the enrichment analysis and string interaction analysis were performed. The expression of TLR2, inflammatory factors IL6, IL17 and IL22 in serum of patients with pulmonary tuberculosis or lung cancer and lung cell were detected by ELISA. The mRNA and protein expression levels of TLR2, caspase-3, Bax and Bcl-2 were detected by qRT-PCR and Western blot. CCK-8, colony formation assay, transwell assay and flow cytometry were performed to detect the proliferation, invasion, migration and cells apoptosis of lung cancer cells. Results: Bioinformatics analysis found that high expression of TLR2 is a core regulator in lung cancer and tuberculosis. TLR2 and inflammatory factors IL6, IL17, IL22 are highly expressed in the serum of patients with tuberculosis and lung cancer by ELISA.TLR2 is also highly expressed in lung cancer cells. Silencing TLR2 inhibited the growth, invasion and migration ability of cells, and the expression of IL6, IL17 and IL22. It also promoted the expression of caspase-3 and Baxwith the decreased expression of Bcl-2. Conclusion: TLR2 and inflammatory factors IL6, IL17 and IL22 were highly expressed in the serum of patients with pulmonary tuberculosis and lung cancer. Silencing TLR2 could inhibit the growth, invasion and migration ability of lung cancer cells, and promote apoptosis.

RASSF10 Is a TGFβ-Target That Regulates ASPP2 and E-Cadherin Expression and Acts as Tumor Suppressor That Is Epigenetically Downregulated in Advanced Cancer.

The Ras Association Domain Family (RASSF) encodes members of tumor suppressor genes which are frequently inactivated in human cancers. Here, the function and the regulation of RASSF10, that contains a RA (Ras-association) and two coiled domains, was investigated. We utilized mass spectrometry and immuno-precipitation to identify interaction partners of RASSF10. Additionally, we analyzed the up- and downstream pathways of RASSF10 that are involved in its tumor suppressive function. We report that RASSF10 binds ASPP1 (Apoptosis-stimulating protein of p53) and ASPP2 through its coiled-coils. Induction of RASSF10 leads to increased protein levels of ASPP2 and acts negatively on cell cycle progression. Interestingly, we found that RASSF10 is a target of the EMT (epithelial mesenchymal transition) driver TGFβ (Transforming growth factor beta) and that negatively associated genes of RASSF10 are significantly over-represented in an EMT gene set collection. We observed a positive correlation of RASSF10 expression and E-cadherin that prevents EMT. Depletion of RASSF10 by CRISPR/Cas9 technology induces the ability of lung cancer cells to proliferate and to invade an extracellular matrix after TGFβ treatment. Additionally, knockdown of RASSF10 or ASPP2 induced constitutive phosphorylation of SMAD2 (Smad family member 2). Moreover, we found that epigenetic reduction of RASSF10 levels correlates with tumor progression and poor survival in human cancers. Our study indicates that RASSF10 acts a TGFβ target gene and negatively regulates cell growth and invasion through ASPP2. This data suggests that epigenetic loss of RASSF10 contributes to tumorigenesis by promoting EMT induced by TGFβ.

MiR-195 and miR-497 suppress tumorigenesis in lung cancer by inhibiting SMURF2-induced TGF-β receptor I ubiquitination.

SMURF2 is a member of the HECT family of E3 ubiquitin ligases that have important roles as a negative regulator of transforming growth factor‐β (TGF‐β) signaling through ubiquitin‐mediated degradation of TGF‐β receptor I. However, the regulatory mechanism of SMURF2 is largely unknown. In this study, we identified that micro(mi)R‐195 and miR‐497 putatively target SMURF2 using several target prediction databases. Both miR‐195 and miR‐497 bind to the 3′‐UTR of the SMURF2 mRNA and inhibit SMURF2 expression. Furthermore, miR‐195 and miR‐497 regulate SMURF2‐dependent TβRI ubiquitination and cause the activation of the TGF‐β signaling pathway in lung cancer cells. Upregulation of miR‐195 and miR‐497 significantly reduced cell viability and colony formation through the activation of TGF‐β signaling. Interestingly, miR‐195 and miR‐497 also reduced the invasion ability of lung cancer cells when cells were treated with TGF‐β1. Subsequent in vivo studies in xenograft nude mice model revealed that miR‐195 and miR‐497 repress tumor growth. These findings demonstrate that miR‐195 and miR‐497 act as a tumor suppressor by suppressing ubiquitination‐mediated degradation of TGF‐β receptors through SMURF2, and suggest that miR‐195 and miR‐497 are potential therapeutic targets for lung cancer.

LncRNA NEAT1/miR-1224/KLF3 contributes to cell proliferation, apoptosis and invasion in lung cancer.

The aim of this study was to detect the relationship between long-chain non-coding RNA (lncRNA) NEAT1 and microRNA-1224 (miR-1224) in lung cancer and to explore its underlying mechanism. The expression levels of lncRNA NEAT1 and miR-1224 in lung cancer tissues and cells were detected by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). The interaction between lncRNA NEAT1 with miR-1224, miR-1224, and KLF3 was detected by Dual-Luciferase Reporter Gene Assay. MTT 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide and flow cytometry were used to detect the changes in the proliferative and apoptosis abilities of lung cancer cells after silencing lncRNA NEAT1 or up-regulating miR-1224, respectively. Compared with adjacent normal tissues, lncRNA NEAT1 was significantly up-regulated, while miR-1224 was significantly down-regulated in lung cancer tissues. LncRNA NEAT1 could specifically bind to the 3'UTR of miR-1224 and regulate its expression. The inhibition of lncRNA NEAT1 remarkably reduced the proliferation and enhanced the apoptosis of lung cancer cells. However, the upregulation of the expression of miR-1224 level could significantly inhibit proliferation and promote the apoptosis rate of lung cancer cells. Furthermore, miR-1224 could downregulate KLF3 expression by directly binding to its 3'UTR. LncRNA NEAT1 can sponge the expression of miR-1224, thereby affecting the proliferation and apoptosis of lung cancer.

41P - LCSCAF1 maintains cancer stem-like traits by stabilizing c-Myc protein and promotes metastasis and recurrence in lung cancer

BackgroundAberrantly overexpressed lung cancer stem cell associated factor-X (LCSCAFX) has been implicated in non-small cell lung cancer (NSCLC) development. MethodsTo explore the effect of LCSCAFXon the lung cancer stem-like traitsin vitro and in vivo. ResultsWe reported that enforced expression of LCSCAFX promoted NSCLC cells invasion and metastasis, drug resistance and recurrencein vitro and in vivo, whereas depletion of LCSCAFX suppressed metastasis and relapse in NSCLC. Moreover, we found that LCSCAFX expression was elevated in lung cancer stem cells (LCSCs). Indeed, knockdown of LCSCAFX impaired lung cancer stem-like traits. Conversely, ectopic overexpression of LCSCAFX enhanced the self-renewal ability of lung cancer cells in vitro. In addition, elevated LCSCAFX robustly enhanced tumor initiating frequencies, as well as growth rates of NSCLC cells derived tumor xenografts in immunodeficient mice. Furthermore, mechanistic investigations established that LCSCAFX stabilized c-Myc protein by suppressing its ubiquitylation and proteasomal degradation, which is required for lung cancer stem-like properties maintenance. Consistently, immunohistochemical analysis of clinical lung tumor tissues showed that LCSCAFX was elevated in NSCLC tissues and high LCSCAFX expression serve as an independent prognostic marker in patients with NSCLC. Importantly, genetic depletion of LCSCAFX combined chemotherapy dramatically inhibited NSCLC progression in patient-derived xenograft (PDX) model. ConclusionsThese findings demonstrated a previously unappreciated role of LCSCAFX in the regulation of LCSCs, assigning LCSCAFX as a promising therapeutic target for lung cancer treatments. Legal entity responsible for the studyThe authors. FundingHas not received any funding. DisclosureAll authors have declared no conflicts of interest.

Curcumin suppresses cellular adhesion and migration of A549 lung cancer cells via a LIMK1/MLCK dependent mechanism

Cancer cell migration is a major cause of mortality in lung cancer patients. Despite intensive research regarding its efficacy in cancer treatment, the anti-metastatic properties of curcumin have been poorly investigated. Therefore, this work aims to explore the potential anti-migratory and anti-adhesive properties of curcumin on lung cancer cells. We also investigated the underlying molecular mode of action of curcumin. We performed scratch and adhesion assays to investigate the migratory and adhesive potentials of A549 cells. The cellular topological differences upon curcumin treatment were investigated using Scanning Electron Microscope. We also investigated the molecular mechanism triggered by curcumin using quantitative real-time PCR. Also, we performed an MTT toxicity assay to explore the toxic potential of curcumin on cancer cells. The student’s t-test was applied for evaluating the data significance using Microsoft Excel 2016. Our results showed that curcumin attenuates the migration and adhesion of A549 cancer cells at non-toxic concentrations. By coincidence, the scanning electron microscope study showed a decreased density of lamellipodia and filopodia upon curcumin treatment. Interestingly, we found that the expression levels of LIMK1 and MLCK genes were downregulated upon curcumin application. Taken together, curcumin inhibits the migration and adhesion abilities of lung cancer cells and could be used as a therapeutic agent against cancer cell migration. The underlying mechanism involves modulation of the expression levels of critical molecular targets including LIMK1 and MLCK proteins.

SOX9 dependent FOXA1 expression promotes tumorigenesis in lung carcinoma

The malignant proliferation is one of the major characteristic for tumor cells, however the mechanism of lung cancer cells uncontrollable proliferation is still confusing. This study investigated the mechanism of up-regulated FOXA1 in lung cancer and its tumorigenic function in lung cancer. FOXA1 showed an increasing expression pattern with the pathological progression in lung cancer, and SOX9 expression pattern is positively correlated with FOXA1. Furthermore, combined up-regulated FOXA1 and SOX9 usually resulted in a poor survival prognosis of patients with lung cancer. In addition, SOX9 was identified as a transcription factor of FOXA1 in lung cancer and involved in affecting the expression of FOXA1 targeted genes—Bcl2, CDKN1B, RPRM and NKX2. What's more, SOX9 can rescue the declining tumorigenic ability of lung cancer cells caused by FOXA1 silenced. This study indicates that SOX9 dependent FOXA1 expression promotes tumorigenic ability of lung cancer cells.

The influence of kinesin light chain-2 on the radiosensitivity of non-small cell lung cancer cells and the underlying mechanisms.

e14512 Background: Our previous study found upregulated kinesin light chain-2 (KLC2) in non-small cell lung cancer (NSCLC) cell lines and tissues, which is associated with a poor prognosis. KLC2 promotes the migration ability of lung cancer cells. However, the influence of KLC2 on radiosensitivity of NSCLC has not yet been reported. Methods: Sensitivity of lung cancer cells to radiation was analyzed by colony formation, γH2AX immunofluorescent staining assay and neutral comet assay in vitro and a xenograft tumor model in vivo. Gene set enrichment analysis (GSEA), qRT-PCR and western blot assay were performed to predict and validate the potential target genes of KLC2. Results: We found that down-regulation of KLC2 could significantly improve the radio-sensitivity of lung cancer cells, while the overexpression of KLC2 had the opposite effect. GSEA identified p53 signal pathway as differentially enriched with high KLC2 expression, which was validated by western blot assay. Using data from TCGA, we found a positive correlation between the mRNA level of KLC2 and that of HuR. The expression of KLC2 mRNA and protein in lung cancer cells was significantly reduced when downregulating HuR. Interestingly, the overexpression of KLC2 could also significantly decrease the expression of HuR. Conclusions: The above results indicated that HuR could upregulate the expression of KLC2, which might decrease the phosphorylation of p53 and thereby weakened the radio-sensitivity of NSCLC cells. KLC2 could also positively regulate the expression of HuR as a positive feedback. Support: 81572279, 2016J004, LC2016PY016, 2018CR033

Inhibition of proliferation and migration of melanoma cells by ketoconazole and Ganoderma immunomodulatory proteins.

Ketoconazole, an antifungal agent, has been used to inhibit hormone synthesis in types of prostate and breast cancer. Immunomodulatory proteins of Ganoderma microsporum (GMI) inhibit the tumor necrosis factor-α- and epidermal growth factor-induced metastatic ability of lung cancer cells. Cutaneous malignant melanoma is a highly invasive and metastatic skin cancer. However, to the best of our knowledge, there is limited understanding regarding the effects of ketoconazole and GMI on melanoma. The current study aimed to investigate the inhibitory effects of GMI combined with ketoconazole on melanoma survival and metastasis. The effects of GMI combined with ketoconazole on the viability, migration and protein expression of melanoma cells were determined by MTT assay, Boyden chamber assay and western blot analysis, respectively. The expression of monocyte chemoattractant protein-1 (MCP-1) was investigated by enzyme-linked immunoabsorbent assay. The present results indicate that ketoconazole enhances the GMI-induced decrease in proliferation and migration of A375.S2 melanoma cells in a concentration-dependent manner. Ketoconazole was identified to reduce the level of GMI-induced phosphorylated-adenosine monophosphate-activated protein kinase (p-AMPK)-α and autophagy; however, ketoconazole did not affect p-AMPK-β levels in A375.S2 cells. In addition, ketoconazole and dorsomorphin dihydrochloride, an AMPK inhibitor, were revealed to reduce MCP-1 secretion in A375.S2 cells. In summary, the present study revealed that ketoconazole enhances GMI-inhibited proliferation and migration of A375.S2 melanoma cancer cells, and inhibits the secretion of MCP-1.

The Root Bark of Morus alba L. Suppressed the Migration of Human Non-Small-Cell Lung Cancer Cells through Inhibition of Epithelial–Mesenchymal Transition Mediated by STAT3 and Src

The root bark of Morus alba L. (MA) has been traditionally used for the treatment of various lung diseases in Korea. Although recent research has demonstrated its anticancer effects in several cancer cells, it is still unclear whether MA inhibits the migratory ability of lung cancer cells. The present study investigated the effects of MA on the migration of lung cancer cells and explored the underlying mechanism. Results from a transwell assay and wound-healing assay demonstrated that methylene chloride extracts of MA (MEMA) suppressed the migration and invasion of H1299, H460, and A549 human non-small-cell lung cancer (NSCLC) cells in a concentration-dependent manner. Results from Western blot analyses showed that MEMA reduced the phosphorylation of STAT3 and Src. In addition, MEMA downregulated the expression of epithelial–mesenchymal transition (EMT) marker proteins including Slug, Snail, Vimentin, and N-cadherin, while upregulating the expression of Occludin—a tight-junction protein. The regulation of EMT markers and the decrease of migration by MEMA treatment were reversed once phospho-mimetic STAT3 (Y705D) or Src (Y527F) was transfected into H1299 cells. In conclusions, MEMA inhibited the migratory activity of human NSCLC cells through blocking Src/STAT3-mediated EMT.

The m6A demethylase FTO promotes the growth of lung cancer cells by regulating the m6A level of USP7 mRNA

Lung cancer is one of the leading causes of cancer-related death in developed countries. Despite decades of intensive efforts to comate this malignant disease, the prognosis of lung cancer remains unfavorable and is especially poor in advanced non-small cell lung cancer (NSCLC). However, whether and how the m6A demethylase FTO functions in lung cancer cells remain unknown. Here in the present study, we show that FTO plays an oncogenic role in human NSCLC. FTO mRNA and protein levels were overexpressed in human NSCLC tissues and cell lines, which was associated with the reduced m6A content. We next knocked down FTO expression in human lung cancer cell lines with lentivirus-mediated shRNAs and the cellular proliferation assay demonstrated that FTO loss-of-function reduced the proliferation rate of cancer cells. FTO knockdown also inhibited the colony formation ability of lung cancer cells. Importantly, our xenograft experiment showed that FTO knockdown reduced lung cancer cells growth in vivo. Mechanism analysis demonstrated that FTO decreased the m6A level and increased mRNA stability of ubiquitin-specific protease (USP7), which was relied on the demethylase activity of FTO. USP7 mRNA level was overexpressed in human lung cancer tissues and USP7 expression was positively correlated with FTO mRNA level. Genetic knockdown or pharmacological inhibition (P5091 or P22027) of USP7 reduced the proliferation rate of lung cancer cells and decreased the capacity of colony formation of lung cancer cells in vitro, whereas lung cancer cells growth inhibition by FTO knockdown is restored by overexertion of USP7. Collectively, our findings demonstrate that the m6A demethylase FTO promotes the growth of NSCLC cells by increasing the expression of USP7.

Aspirin ameliorates lung cancer by targeting the miR-98/WNT1 axis.

BackgroundAspirin, an anti‐inflammatory drug, has been widely investigated in the treatment of many cancer types, including colorectal, ovarian, breast, and prostate cancers. MicroRNAs (miRNAs) are the most well studied noncoding RNAs in cancers. In the current study, we were interested in defining the function of aspirin in lung cancer treatment and the related noncoding RNAs involved in this process.MethodsThe function of aspirin in lung cancer growth was evaluated by cell viability and colony formation assays. Screening of miRNAs affected by aspirin was performed through quantitative real‐time PCR. Prediction of miR‐98 targeting WNT1 was performed using online bioinformatics software and was further confirmed by luciferase reporter gene analysis. The levels of miR‐98 and WNT1 were tested through immunoblotting and quantitative real‐time PCR analysis in lung cancer cells under aspirin treatment.ResultsCell viability was sharply suppressed in lung cancer cells with an increasing dose of aspirin. Aspirin markedly weakened the malignant colony formation ability of lung cancer cells. One out of six tumor suppressor miRNAs could be obviously regulated by aspirin in lung cancer cells. The inhibition of miR‐98 on the luciferase activities of wild‐type 3' untranslated region vectors of WNT1 was clearly revealed in lung cancer cells. Meanwhile, the inhibitor of miR‐98 increased the luciferase activities of wild‐type 3' untranslated region vectors of WNT1. After treatment with aspirin the expression of miR‐98 was induced and then its target gene, WNT1, was depressed in the cells.ConclusionAspirin targets the miR‐98/WNT1 axis to ameliorate lung cancer development.

Ti0.8O2 Nanosheets Inhibit Lung Cancer Stem Cells by Inducing Production of Superoxide Anion.

Recent research into the cancer stem cell (CSC) concept has driven progress in the understanding of cancer biology and has revealed promising CSC-specific targets for drug discovery efforts. As malignancies of lung cancer have been shown to be strongly associated with activities of CSCs, we examined the effects of Ti0.8O2 nanosheets on these cells. Here we show that the nanosheets target lung CSCs but not normal primary dermal papilla (DP) stem cells. Whereas Ti0.8O2 caused a dramatic apoptosis along with a decrease in CSC phenotypes, in primary human DP cells such effects of nanosheets have been minimal. Nanosheets reduced the ability of lung cancer cells to generate three-dimensional tumor spheroids, lung CSC markers (CD133 and ALDH1A1), and CSC transcription factors (Nanog and Oct-4). Ti0.8O2 nanosheets reduced CSC signaling through mechanisms involving suppression of protein kinase B (AKT) and Notch-1 pathways. In addition, the nanosheets inhibited the migration and invasive activities of lung cancer cells and reduced epithelial-to-mesenchymal transition (EMT) markers as N-cadherin, vimentin, and Slug, as well as metastasis-related integrins (integrin-αv and integrin-β1). Importantly, we found that the selectivity of the Ti0.8O2 nanosheets in targeting cancer cells was mediated by induction of cellular superoxide anion in cancerous but not normal cells. Inhibition of nanosheet-induced superoxide anion restored the suppression of CSC and EMT in cancer cells. These findings demonstrate a promising distinctive effect of Ti0.8O2 nanosheets on lung CSC that may lead to opportunities to use such a nanomaterial in cancer therapy.

MiR-431 suppresses proliferation and metastasis of lung cancer via down-regulating DDX5.

We aimed to detect the role and function of microRNA-431 (miR-431) in lung cancer, and to investigate the underlying mechanism in regulating the development of lung cancer. Quantitative Real-time polymerase chain reaction (qRT-PCR) was utilized to measure the relative expression level of miR-431 in lung cancer tissues and cell lines. Cell counting kit-8 (CCK-8) and colony formation assays were employed to measure the proliferative ability of lung cancer cells. Meanwhile, transwell assay was recruited to detect the invasive and migratory abilities of lung cancer cells. Furthermore, dual-luciferase reporter gene assay was designed to verify the target gene of miR-431. Western blot assay was used to gauge the protein level of DDX5 (DEAD box polypeptide 5). MiR-431 expression was significantly lower in 122 lung cancer tissue samples or cell lines compared to the adjacent normal tissues or lung bronchial epithelial cell line, respectively. Over-expression of miR-431 significantly inhibited proliferation, invasion and migration of A549 cells. Down-regulation of miR-431 accelerated cell growth and metastasis of H1650 cells. DDX5 was proved to be a direct target for miR-431 in lung cancer. MiR-431 expression decreased in lung cancer tissues and cells. MiR-431 suppressed proliferation, invasion and migration of lung cancer cells via inhibiting the expression of DDX5. Our study might provide a novel target for the biological therapy of lung cancer.

TRPM7 overexpression enhances the cancer stem cell-like and metastatic phenotypes of lung cancer through modulation of the Hsp90\u03b1/uPA/MMP2 signaling pathway

BackgroundWaixenicin A, a bioactive extract of soft coral Sarcothelia edmondsoni, has been shown to be anti-neoplastic. However, its mechanisms of action remain unclear. Cancer stem cells (CSCs) and associated stemness factors are implicated in lung cancer. Here, we investigated the role of Waixenicin A on CSCs-like and metastatic lung cancer cells.MethodsWe demonstrated and compared TRPM7 expression in the non-tumor lung tissues or bronchial epithelial 16-HBE cell line. TRPM7 was aberrantly expressed in the cancer tissues and SPCA-1, NCI-H520, SK-MES-1, A549 and 95D cell lines.ResultsIncreased TRPM7 expression was associated with enhanced SOX2, KLF4, and CD133, Hsp90α, uPA, and MMP2 expression in lung cancer cells. TRPM7-silencing inhibited epithelial-to-mesenchymal transition (EMT), suppressed stemness markers and phenotypes, concomitantly suppressed Hsp90α/uPA/MMP2 axis. Coincidently, Waixenicin A treatment downregulated TRPM7 and oncogenic markers; Waixenicin A also attenuated the ability of lung cancer cells to form tumorspheres, in vitro. In validation, our clinicopathological analyses showed that a higher TRPM7 expression was positively correlated with the larger tumor size (p = 0.007), positive lymph node metastasis (p = 0.005) and disease grade (p = 0.003).ConclusionsThrough its ability to inhibit Hsp90α/uPA/MMP2 signaling and suppress TRPM7 expression, we showed that Waixenicin A is a potential anticancer therapeutic agent for treating malignant lung cancer.

Fusion with mesenchymal stem cells differentially affects tumorigenic and metastatic abilities of lung cancer cells.

Cell fusion plays a crucial role in cancer progression and leads to massive aberrant changes in chromosome and gene expression involved in tumor metastasis. Cancer cells can fuse with many cell types, including stromal cells, epithelial cells, macrophages, and endothelial cells. Mesenchymal stem cells (MSCs) have been reported to migrate and incorporate into tumor sites during cancer progression. However, the underlying mechanism of stem cell fusion in tumor metastasis has not been fully deciphered. In this research, we established a cell fusion model between lung cancer cells and MSCs in vitro. We found that the hybrid cells showed enhanced metastatic capacity with increased expression of MMP-2 and MMP-9, whereas the proliferation ability was inhibited and cell cycle was blocked in the G0 /G1 phase with elevated expression of p21, p27, and p53. Moreover, the hybrid cells lost epithelial morphology and exhibited an epithelial-mesenchymal transition (EMT) change with downregulation of E-cadherin and upregulation of N-cadherin, Vimentin, α-SMA and Fibronectin1. Meanwhile, the expressions of EMT transcription factors, including Snail1, Slug, Twist1, Zeb1, and Zeb2, were also increased in hybrid cells. More important, the fusion hybrids acquired stem cell-like properties, which exhibited increased expression stem cell transcription factors Oct4, Sox2, Nanog, Kif4 as well as Bmi1. Taken together, our results suggested that cell fusion between lung cancer cells and MSCs offered enhanced metastatic capacity and characteristics of cancer stem cell by undergoing EMT. This study will contribute to explaning the origin of lung cancer stem cells and to elucidate the role of cell fusion in cancer metastasis.