Properties Of Lung Cancer Cells Research Articles

Clinical prognostic significance of xeroderma pigmentosum group C and IFN‑γ in non‑small cell lung cancer.

Lung cancer is the most common cancer in the world due to its high incidence and recurrence. Genetic instability is one of the main factors leading to its occurrence, development and poor prognosis. Decreased xeroderma pigmentosum group C (XPC) expression notably enhances the stem cell properties of lung cancer cells and increases their proliferation and migration. Additionally, patients with lung cancer and low XPC expression had a poor prognosis. The purpose of the present study was to analyze the effect of XPC and IFN-γ on the clinical prognosis of patients with non-small cell lung cancer (NSCLC). Lung adenocarcinoma specimens were collected from a total of 140 patients with NSCLC. Additionally, from these 140 patients, 48 paracarcinoma tissue specimens were also collected, which were later used to construct tissue microarrays. The expression of XPC and IFN-γ in cancer tissues and in paraneoplastic tissues was detected using immunohistochemistry. The prognosis and overall survival of patients were determined through telephone follow-up. The results showed a positive correlation between expression of XPC and IFN-γ in NSCLC. Additionally, high expression of both markers was associated with a favorable prognosis in patients with NSCLC. The aforementioned findings suggest that the expression of XPC and IFN-γ has prognostic value in clinical practice and is expected to become a marker for clinical application.

Penta-O-Galloyl-β-D-Glucose in Pistacia integerrima Targets AMPK-ULK1 and ERK/STAT3 Signaling Axes to Induce ROS-Independent Autophagic Cell Death in Human Lung Cancer Cells.

Natural molecules have promising perspectives as adjuvants to chemotherapies against cancer. Pistacia chinensis subsp. Integerrima (hereafter, Pistacia integerrima) traditionally known for medicinal values in respiratory disorders was tested for anti-lung cancer properties. The extract prepared from Pistacia integerrima (PI) selectively impaired the viability of lung cancer cells, A549 and NCI-H460, compared to non-cancer cells. At non-lethal concentrations, PI mitigated colony-forming, spheroid formations and metastatic properties of lung cancer cells. As a step toward identifying the phytomolecule that is imparting the anti-lung cancer properties in PI, we subjected the extract to extensive characterization through UPLC/QToF-MS and further validated the findings with UHPLC. The gallotannin, penta-O-galloyl-β-D-glucose (PGG), among others, was identified through UPLC/QToF-MS. PGG exhibits potential chemopreventive effects against various cancer types. However, a defined mechanism of action of PGG in restricting lung cancer progression is still unexplored. Bioactivity-guided column fractionations enabled the determination of PGG as the major phytochemical that governed PI-mediated AMPK-ULK1-dependent autophagy and apoptosis, albeit independent of intracellular ROS activation. Interestingly, the autophagy flux when inhibited restored the cell viability even in the presence of PI. The study further delineated that PI and PGG activated ERK and inhibited STAT3 to trigger apoptosis through caspase-3 and PARP 1 pathways. Collectively, the finding demonstrates that plant extract, PGG, in the PI extract effectively combats lung cancer progression through autophagic cell death by altering ERK/AMPK-ULK1/STAT3 signaling axes. The study proposes PGG as a potential AMPK activator and STAT3 inhibitor that can be exploited further in developing adjuvant chemotherapeutics against lung cancer.

Activation of MYO1G by lncRNA MNX1-AS1 Drives the Progression in Lung Cancer.

Lung cancer represents the most prevalent cancer worldwide and causes the death of many patients. Cancer stem cells (CSCs), a subpopulation of cancer cells, have the capacities of self-renewal, unlimited proliferation, and multiple differentiation potential. The purpose of this study was to explore the potential role of long noncoding RNA (lncRNA) MNX1-AS1 on maintaining the stemness of CSC in lung cancer. CSCs were firstly sorted by flow cytometry. After the determination of the target of the present study using Gene Expression Omnibus dataset, MNX1-AS1was found to be highly expressed in lung cancer tissues and cells. Deletion of MNX1-AS1 inhibited proliferation, migration, invasion and sphere-forming abilities of CSC. Furthermore, subcellular fractionation, fluorescence in situ hybridization, RNA immunoprecipitation, and dual-luciferase experiments demonstrated that MNX1-AS1 recruited the transcription factor POU domain class 2 transcription factor 2 (POU2F2) to the nucleus and activated the myosin IG (MYO1G) expression. MYO1G overexpression partially reversed the si-MNX1-AS1-decreased stemness of CSCs. Finally, MNX1-AS1 suppression significantly repressed the growth of xenografts in vivo. Our study highlights the importance of the MNX1-AS1/POU2F2/MYO1G axis in stem cell-like properties of lung cancer cells.

TGF-β/Akt/Smad signaling regulates ionizing radiation-induced epithelial-mesenchymal transition in acquired radioresistant lung cancer cells

ObjectiveTo define the properties of lung cancer cells that resisted conventionally fractionated radiation exposure. MethodsAcquired radioresistant lung cancer cell line A549 was constructed by X-ray irradiation with a clinical conventional fraction dose of 2 ​Gy daily during 30 fractions. Cell morphology, molecular markers, migration capacity and invasion potential were evaluated by the microscope, Western blot, immunofluorescence, wound healing test and transwell chamber assay, respectively. ResultsRadioresistant A549 ​cells shifted from an epithelial to a mesenchymal morphology, termed as epithelial-mesenchymal transition (EMT), and was accompanied by decreased expressions of epithelial markers (F ​= ​4.568, P ​< ​0.05) and increased expression of mesenchymal markers (F ​= ​4.270, P ​< ​0.05), greater migratory and invasive capabilities (t ​= ​6.386, 5.644, P ​< ​0.05). The expression of TGF-β, and phosphorylated levels of Akt and Smad3 were also enhanced (F ​= ​6.496, 4.685, 3.370, P ​< ​0.05). Furthermore, the EMT phenotype induced by radiation could be reversed through inhibition of TGF-β, Akt or Smad3, indicating a functional relationship between them. ConclusionsEMT mediates acquired radioresistance of lung cancer cells induced by IR with clinical parameters, and the crosstalk mode of TGF-β/Akt/Smad signaling plays a critical regulatory role in this process.

Human bone marrow mesenchymal stem cell-derived exosomes containing microRNA-425 promote migration, invasion and lung metastasis by down-regulating CPEB1.

ObjectiveBone marrow mesenchymal stem cell-derived exosomes (BMSC-Exos) could mediate the malignancy of tumor cells by transmitting targeted cargo. Therein, this study intends to explore the function of BMSC-Exos transmitting microRNA-425 (miR-425)/cytoplasmic polyadenylation binding protein 1 (CPEB1) in lung cancer growth.MethodsmiR-425 and CPEB1 levels in cancer tissues and cells were measured. BMSCs and their exosomes were collected and identified. After intervention with BMSC-Exos, miR-425 or CPEB1, invasion and migration of A549 and NCI-H1299 cells in vitro, and lung metastasis of A549 cells in vivo were observed. The relationship between miR-425 and CPEB1 was verified.ResultsmiR-425 was highly expressed while CPEB1 was lowly expressed in lung cancer tissues of patients. CPEB1 was the direct target of miR-425. Down-regulating miR-425 or up-regulating CPEB1 decreased cell invasion and migration ability of A549 and NCI-H1299 cells, as well as decreased the number of lung metastasis lesions in vivo. After co-culture with BMSC-Exos, A549 and NCI-H1299 cells showed promoted migration and invasion in vitro and A549 cells demonstrated increased lung metastasis in vivo. Down-regulated miR-425 or up-regulated CPEB1 reversed the promotion of BMSC-Exos on lung cancer cell invasion, migration and lung metastasis.ConclusionBMSC-Exos could deliver miR-425 to inhibit CPEB1 expression in lung cancer cells, thereby promoting the malignant biological properties of lung cancer cells and their metastasis in vivo.

Knockdown of pancreatic adenocarcinoma upregulated factor (PAUF) suppresses proliferation, migration, invasion, and cancer stem cell properties in lung cancer cells

&#x0D; &#x0D; &#x0D; &#x0D; Purpose: To investigate the role of pancreatic adenocarcinoma up-regulated factor (PAUF) in lung cancer.&#x0D; Method: Proliferation of lung cancer cell lines (A549 and H1299) was determined using MTS and Edu staining assays. Wound healing and transwell assays were performed to evaluate cell migration and invasion abilities. Lung cancer stem cell (CSC) marker expressions, including CD133, CD44, ALDH1, SOX2, and Oct4, were determined by western blot assay.&#x0D; Results: Knockdown of PAUF significantly inhibited A459 and H1299 cell proliferation (p &lt; 0.01). The wound healing and transwell assay results indicated that depletion of PAUF markedly suppressed H1299 and A549 cell migration and invasion, compared with the control cells (p &lt; 0.01). Knockdown of PAUF reduced distinct CSC marker expression, suggesting inhibition of CSC phenotypes, and reduced phosphorylated focal adhesion kinase (FAK), phosphorylated Src, and phosphorylated extracellular signal-regulated kinase (ERK), but not total FAK, Src, and ERK. These results suggested that knockdown of PAUF deactivated the FAK/Src/ERK signal pathway.&#x0D; Conclusion: Knockdown of PAUF inhibits lung cancer cell proliferation, migration, invasion, and CSC properties via deactivation of FAK/Src/ERK signal pathway. These results may provide a novel strategy for the development of lung cancer therapeutics.&#x0D; &#x0D; &#x0D; &#x0D;

GNAQ knockdown promotes bone metastasis through epithelial-mesenchymal transition in lung cancer cells.

AimsBone metastasis ultimately occurs due to a complex multistep process, during which the interactions between cancer cells and bone microenvironment play important roles. Prior to colonization of the bone, cancer cells must succeed through a series of steps that will allow them to gain migratory and invasive properties; epithelial-to-mesenchymal transition (EMT) is known to be integral here. The aim of this study was to determine the effects of G protein subunit alpha Q (GNAQ) on the mechanisms underlying bone metastasis through EMT pathway.MethodsA total of 80 tissue samples from patients who were surgically treated during January 2012 to December 2014 were used in the present study. Comparative gene analysis revealed that the GNAQ was more frequently altered in metastatic bone lesions than in primary tumour sites in lung cancer patients. We investigated the effects of GNAQ on cell proliferation, migration, EMT, and stem cell transformation using lung cancer cells with GNAQ-knockdown. A xenograft mouse model tested the effect of GNAQ using micro-CT analyses and histological analyses.ResultsGNAQ-knockdown showed down-regulation of tumour growth through mitogen-activated protein kinase (MAPK) signalling in lung cancer cells, but not increased apoptosis. We found that GNAQ-knockdown induced EMT and promoted invasiveness. GNAQ-knockdown cells injected into the bone marrow of murine tibia induced tumour growth and bone-to-lung metastasis, whereas it did not in control mice. Moreover, the knockdown of GNAQ enhanced cancer stem cell-like properties in lung cancer cells, which resulted in the development of resistance to chemotherapy.ConclusionThe present study reveals that the GNAQ-knockdown induced cancer stem cell-like properties.Cite this article: Bone Joint Res 2021;10(5):310–320.

Tumor promoting effects of exosomal microRNA-210 derived from lung cancer cells on lung cancer through the RUNX3/PI3K/AKT signaling pathway axis.

Exosomes are involved in a range of processes in lung cancer such as cell proliferation, metastasis, and angiogenesis. Tumor-derived exosomes participate in the formation and progression of lung cancer by delivering functional biomolecules, including microRNAs (miRNA). The purpose of the present study was to determine the role of lung cancer cell-derived exosomal miR-210 in the proliferation and invasion of lung cancer cells and its underlying mechanism. Initially, exosomes were isolated from A549 cells and characterized by transmission electron microscopy and assessment of exosomal marker expression. RT-qPCR determined that miR-210 expression was elevated in exosomes as well as lung cancer cells. As reflected by dual-luciferase reporter assay, miR-210 negatively regulated RUNX3 expression. Following loss- and gain- function assay, it was found that miR-210 inhibition suppressed biological properties of A549 and H460 cells, which could be reversed by the silencing of RUNX3. miR-210 elevation induced the p-PI3K/PI3K and p-AKT/AKT levels, suggesting the activation of PI3K/AKT signaling pathway. Collectively, exosomal miR-210 targeted and negatively regulated RUNX3 expression to promote malignant properties of lung cancer cells by potentiating PI3K/AKT signaling pathway.

Inhibition of lysine acetyltransferases impairs tumor angiogenesis acting on both endothelial and tumor cells

BackgroundUnderstanding the signalling pathways involved in angiogenesis, and developing anti-angiogenic drugs are one of the major focuses on cancer research. Herein, we assessed the effect of CPTH6, a lysine acetyltransferase inhibitor and anti-tumoral compound, on angiogenesis-related properties of both endothelial and cancer cells.MethodsThe in vitro effect of CPTH6 on protein acetylation and anti-angiogenic properties on endothelial and lung cancer cells was evaluated via wound healing, trans-well invasion and migration, tube formation, immunoblotting and immunofluorescence. Matrigel plug assay, zebrafish embryo and mouse xenograft models were used to evaluate in vivo anti-angiogenic effect of CPTH6.ResultsCPTH6 impaired in vitro endothelial angiogenesis-related functions, and decreased the in vivo vascularization both in mice xenografts and zebrafish embryos. Mechanistically, CPTH6 reduced α-tubulin acetylation and induced accumulation of acetylated microtubules in the perinuclear region of endothelial cells. Interestingly, CPTH6 also affected the angiogenesis-related properties of lung cancer cells, and conditioned media derived from CPTH6-treated lung cancer cells impaired endothelial cells morphogenesis. CPTH6 also modulated the VEGF/VEGFR2 pathway, and reshaped cytoskeletal organization of lung cancer cells. Finally, anti-migratory effect of CPTH6, dependent on α-tubulin acetylation, was also demonstrated by genetic approaches in lung cancer cells.ConclusionOverall, this study indicates that α-tubulin acetylation could play a role in the anti-angiogenic effect of CPTH6 and, more in general, it adds information to the role of histone acetyltransferases in tumor angiogenesis, and proposes the inhibition of these enzymes as an antiangiogenic therapy of cancer.

Oct4 promotes M2 macrophage polarization through upregulation of macrophage colony-stimulating factor in lung cancer

BackgroundExpression of Oct4 maintains cancer stem cell (CSC)-like properties in lung cancer cells and is correlated with poor prognosis of lung adenocarcinoma. M2-type tumor-associated macrophages (TAMs) promote cancer cell migration and metastasis. Tumor microenvironments promote monocyte differentiation into M2 TAMs via a complex cytokine-based connection. We explored the role of Oct4 in cytokine secretion in lung cancer and its impact on M2 TAM polarization.MethodsMonocytes co-cultured with the conditioned medium from Oct4-overexpressing lung cancer cells were used to investigate M2 TAM differentiation. The inflammatory factors in the conditioned medium of Oct4-overexpressing A549 cells were examined using human inflammation antibody arrays. The correlations of Oct4, macrophage colony-stimulating factor (M-CSF), and M2 TAMs were validated in lung cancer cells, syngeneic mouse lung tumor models, and clinical samples of non-small cell lung cancer (NSCLC).ResultsOct4-overexpressing A549 cells expressed elevated levels of M-CSF, which contributed to increased M2 macrophages and enhanced tumor migration. Overexpression of Oct4 enhanced tumor growth and reduced the survival of lung tumor-bearing mice, which was correlated with increased number of M2 macrophages in lung cancer. Notably, NSCLC patients with high expression levels of Oct4, M-CSF, and M2 TAMs had the poorest recurrence-free survival. A positive correlation between Oct4, M-CSF, and M2 TAMs was observed in the tumor tissue of NSCLC patient. Treatment with all-trans retinoic acid exerted anti-tumor effects and reduced M2 TAMs in tumor-bearing mice.ConclusionsOur results indicate that Oct4 expressed by lung cancer cells promotes M2 macrophage polarization through upregulation of M-CSF secretion, leading to cancer growth and metastasis. Our findings also implicate that the Oct4/M-CSF axis in M2 macrophage polarization may be potential therapeutic targets for lung cancer.

OPN promotes the aggressiveness of non-small-cell lung cancer cells through the activation of the RON tyrosine kinase

Osteopontin (OPN) is identified as a diagnostic and prognostic biomarker of tumor progression and metastasis. In non-small-cell lung cancer (NSCLC), the functions of OPN have not been well characterized. The current study sought to investigate the clinical implications of OPN expression in NSCLC and the role of OPN in the aggressiveness of the lung cancer cells. Using a proteomics approach, we identified that phospho-RON (p-RON) was one of the most remarkably up-regulated proteins in OPN-overexpressing cells. The levels of OPN and RON transcripts were unveiled as independent prognostic indicators of survival in NSCLC (p = 0.001). Higher levels of OPN, RON and p-RON proteins were observed in tumor tissues. Knock down of the OPN gene suppressed the migration and invasion abilities of the A549 lung cancer cells which endogenously expresses OPN. While ectopic expression of OPN in the SK-MES-1 lung cancer cells increased levels of cellular invasion and migration. In addition, these changes were accompanied by a phosphorylated activation of RON. Small-molecule inhibition of RON or siRNA silencing of RON significantly reduced OPN-induced migration and invasion of lung cancer cells and had an inhibitory effect on the OPN-mediated cell epithelial-mesenchymal transition. Our study suggests that in NSCLC, the aberrant expression of OPN can be considered as an independent survival indicator and is associated with disease progression. OPN plays a crucial role in promoting migration and invasion properties of lung cancer cells through its phosphorylation activation of the RON signaling pathway, implying its potential as a therapeutic target in the treatment of NSCLC.

Zunyimycin C inhibits the proliferation of lung cancer cells by inducing apoptosis through an AKT-related mechanism

Zunyimycin C is a novel halogenated type II polyketide derived from the fermentation product of the Streptomyces species with notable antibiotic activity. However, it is still unclear whether zunyimycin C could inhibit the activity of cancer cells. In this study, human lung adenocarcinoma cell line A549, the large-cell lung cancer cell line NCI-H460 and the non-small-cell lung cancer cell line NCI-H1299 were employed to determine the in vitro anticancer properties of zunyimycin C and underlying molecular mechanisms. The cellular viability and proliferative properties of lung cancer cells were investigated using the Cell Counting Kit-8 and colony formation assay, respectively. The mRNA expression of apoptotic genes related to lung cancer was studied using reverse-transcription polymerase chain reaction. The apoptotic ratio was measured through flow cytometry. The protein expression was visualized via western blotting using specific antibodies. Zunyimycin C could inhibit cell proliferation and induce apoptosis in a dose-dependent manner. The expression levels of apoptosis-related proteins (i.e., BAX, cleaved-caspase-3, and cleaved-caspase-9) were increased compared with the control group. However, the levels of Bcl-2 and phosphorylated AKT were decreased by administration by zunyimycin C. Collectively, these results implied that zunyimycin C could inhibit cell proliferation and induce apoptosis via AKT phosphorylation.

Evaluation Method of Mechanical Properties of Living NSCLC Cells Based on Nano-indentation

Background:In AFM study of cell mechanical properties, the apparent elastic modulus of a cell is affected by many factors, especially the AFM tip geometry, indentation site of the cell, the application of the mathematical model and testing conditions.Background:In AFM study of cell mechanical properties, the apparent elastic modulus of a cell is affected by many factors, especially the AFM tip geometry, indentation site of the cell, the application of the mathematical model and testing conditions.Methods:In this study, indentation experiments of living cells under different conditions were performed aiming to build an accurate evaluation system of mechanical properties of lung cancer cells based on AFM. Comparisons of the effects of spherical and pyramid AFM tips, Hertz model of semiinfinite and finite thickness, cell nuclear and cytoplasmic indentation regions on the cell apparent elastic modulus were accomplished.Methods:In this study, indentation experiments of living cells under different conditions were performed aiming to build an accurate evaluation system of mechanical properties of lung cancer cells based on AFM. Comparisons of the effects of spherical and pyramid AFM tips, Hertz model of semiinfinite and finite thickness, cell nuclear and cytoplasmic indentation regions on the cell apparent elastic modulus were accomplished.Results:Compared with the calculated results by spherical tip, the elastic modulus distribution of non-small lung cancer cells (NSCLC) by pyramid tip was observed to be similar while the absolute values increased obviously, which were more than twice the numerical values by the spherical tip (p&lt;0.05). The apparent elastic modulus values were the overvalued cause of the underestimation of the contact region in pyramidal tip measurement. Two different indentations over nucleus or lamellipodium of NCI-H520 cell and NCI-H1299 cell were analyzed. Consequently, the exact elastic modulus over the nucleus area can be calculated accurately using the semi-infinite Hertz model while the finite thickness Hertz model should be used for elasticity assessment of cell lamellipodium with a small thickness.Results:Compared with the calculated results by spherical tip, the elastic modulus distribution of non-small lung cancer cells (NSCLC) by pyramid tip was observed to be similar while the absolute values increased obviously, which were more than twice the numerical values by the spherical tip (p&lt;0.05). The apparent elastic modulus values were the overvalued cause of the underestimation of the contact region in pyramidal tip measurement. Two different indentations over nucleus or lamellipodium of NCI-H520 cell and NCI-H1299 cell were analyzed. Consequently, the exact elastic modulus over the nucleus area can be calculated accurately using the semi-infinite Hertz model while the finite thickness Hertz model should be used for elasticity assessment of cell lamellipodium with a small thickness.Conclusion:This evaluation system provides technological support for accurate evaluation of viscoelastic properties of living cancer cells.Conclusion:This evaluation system provides technological support for accurate evaluation of viscoelastic properties of living cancer cells.

Overexpression of Aiolos promotes epithelial-mesenchymal transition and cancer stem cell-like properties in lung cancer cells

Aiolos/Ikaros family zinc finger 3 (IKZF3), a member of the Ikaros family of lymphocyte maturation-driving transcription factors, is highly expressed in hematopoietic malignancies. However, its role in epithelial-mesenchymal transition (EMT) and cancer stem cell (CSC)-like properties in lung cancer remains unknown. Human lung cancer cell lines H1299 with overexpressing Aiolos (H1299-Aiolos) and A549 with overexpressing Aiolos (A549-Aiolos) were generated by stable transfection. Cell migration and invasion assays were done to demonstrate their invasion and migration ability. Sphere formation assay was used to determine their tumor-initiating capability. Aiolos overexpression induced EMT and increased migration/invasiveness in H1299 and A549 cells. Aiolos overexpression also increased metastatic ability in vivo. Aiolos overexpression upregulated the expression of Twist and matrix metalloproteinase 16 (MMP16). By using knockdown of Twist or an inhibitor of phosphatidylinositol (PI) 3-kinase, EMT, migration/invasiveness ability, and MMP16 expression were reversed in H1299-Aiolos and A549-Aiolos cells. Overexpression of Aiolos upregulated the CSC-like properties in lung cancer cells, and were also reversed by an inhibitor of PI 3-kinase. For lung cancer cells, Aiolos overexpression promotes EMT and CSC-like properties through upregulating the PI 3-kinase/Akt pathway. The information is helpful for developing therapeutic strategies targeting Aiolos expression for lung cancer treatment.

Distinct mechanisms by which two forms of miR-140 suppress the malignant properties of lung cancer cells.

In this study we attempted to determine the molecular mechanisms underlying the two mature products of pre-miR-140 (3p and 5p) in malignant properties of lung cancer cells. The differential expression of the two forms of miR-140 in both NSCLC tissues and cell lines was determined by quantitative real-time PCR (qRT-PCR). The effects of the miR-140 mimics on the malignant properties of lung cancer cells were evaluated using invasion assay, adhesion assay, tubule formation assay and metabolite profiling. Biotin-miRNA pulldown and transcriptome profiling by RNA-seq were utilized to distinguish their mRNA targets of the miR-140 strands. Their downstream signalling pathways were unveiled using a high-throughput antibody array. Although both strands of the miR-140 are downregulated in the NSCLC, miR-140-3p is more predominant compared to miR-140-5p in lung cancer cell lines. Both miR-140 mimics suppress the invasion of lung cancer cells and the inhibitory effect of the miR-140 on adhesion is cell-dependent. Tumor conditioned media from A549 cells after treatment with miR-140-3p mimic reduce the tubule formation ability of the endothelial cells. Metabolite profiling indicates the alteration of glycine in both lung cancer cells following treatment with miR-140 mimics. The data from the RNA-sequencing and antibody array indicate that two miR-140 strands present different targeting and signalling profiles despite the existence of mutual targets such as IGF1R and FOS. In conclusion, two forms of miR-140 both suppress the malignant properties of lung cancer cells but through distinct and multiple mechanisms.

Abstract 5906: EGFR and SOX2 crosstalk determines EGFR-TKI

Abstract Activating mutations in the epidermal growth factor receptor (EGFR), while initiating lung tumorigenesis, render tumors susceptible to EGFR-tyrosine kinase inhibitors (TKIs). SOX2 functions as a cell fate determination factor in lung progenitor cells. However, how SOX2 expression affects TKI treatment and tumor invasion in lung cancer is obscure. Here we report that EGFR mutations crosstalk with SOX2 to maintain cell proliferation and barrier properties in lung cancer cells, some of which generate heterogeneity by switching off SOX2 expression, thus promoting TKI resistance and invasiveness. Downregulation of SOX2 expression by shRNA against SOX2 or TGF-beta treatment induced epithelial-to-mesenchymal transition (EMT) and endowed cell resistant to TKIs. TKI treatment selected EGFR-mutated lung cancer cells harboring low SOX2 expression with the EMT signature. TKI naïve EGFR-mutated lung cancer cells harboring low SOX2 expression exhibits intrinsic TKI resistance. Conversely, enhancing endogenous SOX2 expression reverses EMT and increases sensitivity to TKIs. Immunohistochemistry analysis revealed that low SOX2 expression predicts a poor survival in patients harboring EGFR mutations. Taken together, our findings show how cancer plasticity elicited by SOX2 expression and TKI selection generates distinct oncogenic properties and TKI sensitivity, providing critical insights into tumor progression in EGFR-mutated lung cancer. Citation Format: An-Chun Lee, Chia-Cherng Yu, Yuan-Hung Wang, Yu-Ting Chou. EGFR and SOX2 crosstalk determines EGFR-TKI [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 5906.

Grape seed procyanidin extract against lung cancer: the role of microrna-106b, bioavailability, and bioactivity.

MiR-106b is an oncomir and a potential target for anti-cancer therapy. We hypothesize that grape seed procyanidin extract (GSE) exerts antineoplastic effects on lung cancer through modulations of miR-106b and its downstream target. We found that GSE significantly down-regulated miR-106b in a variety of lung neoplastic cells and increased cyclin-dependent kinase inhibitor 1A (CDKN1A) mRNA and protein (p21) levels. Transfection of miR-106b mimics reversed the up-regulations of CDKN1A mRNA and p21, abrogated the GSE induced anti-proliferative and anti-invasive properties in lung cancer cells. Oral gavage of leucoselect phytosome (LP), a standardized GSE to athymic nude mice down-regulated MIR106B mRNA and miR-106b expressions, and increased CDKN1A mRNA expression in tumor xenografts, correlating to significant reduction of tumor growth. To assess bioavailability, GSE and metabolites in plasma levels, between 60–90 minutes after gavage of LP were measured by LC/MS at treatment week 4 and 8. A novel bioactivity assay was also developed using lung homogenates from treated mice co-cultured with human lung cancer cells. LP-treated mouse lung homogenates significantly reduced proliferations of various lung cancer cells. Our findings reveal novel antineoplastic mechanisms by GSE, further define the pharmacokinetics and pharmacodynamics of LP, and support the continued investigation of LP against lung cancer.

Bone marrow-derived fibrocytes promote stem cell-like properties of lung cancer cells

Cancer stem cells (CSCs) represent a minor population that have clonal tumor initiation and self-renewal capacity and are responsible for tumor initiation, metastasis, and therapeutic resistance. CSCs reside in niches, which are composed of diverse types of stromal cells and extracellular matrix components. These stromal cells regulate CSC-like properties by providing secreted factors or by physical contact. Fibrocytes are differentiated from bone marrow-derived CD14+ monocytes and have features of both macrophages and fibroblasts. Accumulating evidence has suggested that stromal fibrocytes might promote cancer progression. However, the role of fibrocytes in the CSC niches has not been revealed. We herein report that human fibrocytes enhanced the CSC-like properties of lung cancer cells through secreted factors, including osteopontin, CC-chemokine ligand 18, and plasminogen activator inhibitor-1. The PIK3K/AKT pathway was critical for fibrocytes to mediate the CSC-like functions of lung cancer cells. In human lung cancer specimens, the number of tumor-infiltrated fibrocytes was correlated with high expression of CSC-associated protein in cancer cells. These results suggest that fibrocytes may be a novel cell population that regulates the CSC-like properties of lung cancer cells in the CSC niches.

MicroRNA-128-3p-mediated depletion of Drosha promotes lung cancer cell migration.

Alteration in microRNAs (miRNAs) expression is a frequent finding in human cancers. In particular, widespread miRNAs down-regulation is a hallmark of malignant transformation. In the present report, we showed that the miR-128-3p, which is up-regulated in lung cancer tissues, has Drosha and Dicer, two key enzymes of miRNAs processing, as the main modulation targets leading to the widespread down-regulation of miRNA expression. We observed that the miRNAs downregulation induced by miR-128-3p contributed to the tumorigenic properties of lung cancer cells. In particular, miR-128-3p-mediated miRNAs down-regulation contributed to aberrant SNAIL and ZEB1 expression thereby promoting the epithelial-to-mesenchymal transition (EMT) program. Drosha also resulted to be implicated in the control of migratory phenotype as its expression counteracted miR-128-3p functional effects. Our study provides mechanistic insights into the function of miR-128-3p as a key regulator of the malignant phenotype of lung cancer cells. This also enforces the remarkable impact of Drosha and Dicer alteration in cancer, and in particular it highlights a role for Drosha in non-small-cell lung cancer cells migration.

Osteopontin production by TM4SF4 signaling drives a positive feedback autocrine loop with the STAT3 pathway to maintain cancer stem cell-like properties in lung cancer cells.

Transmembrane 4 L6 family proteins have been known to promote cancer. In this study, we demonstrated that transmembrane 4 L6 family member 4 (TM4SF4), which is induced by γ-radiation in non-small cell lung cancer (NSCLC) cells, is involved in epithelial-to-mesenchymal transition (EMT) and cancer stem cell (CSC) properties of NSCLC through the regulation of osteopontin (OPN). Forced TM4SF4 overexpression in A549 cells increased the secretion of OPN, which activates CD44 or integrin signaling and thus maintains EMT-associated CSC-like properties. OPN, known as a downstream target of β-catenin/T-cell factor 4 (TCF-4), was induced by up-regulated β-catenin via TM4SF4-driven phosphorylation of glycogen synthase kinase 3b (GSK3β). TCF4 complexed to promoter regions of OPN in TM4SF4-overexpressing A549 cells was also confirmed by chromatin immunoprecipitation. Knockout of either β-catenin or TCF4-suppressed OPN expression, demonstrating that both factors are essential for OPN expression in NSCLC cells. OPN secreted by TM4SF4/GSK3β/β-catenin signaling activated the JAK2/STAT3 or FAK/STAT3 pathway, which also up-regulates OPN expression in an autocrine manner and consequently maintains the self-renewal and metastatic capacity of cancer cells. Neutralizing antibody to OPN blocked the autocrine activation of OPN expression, consequently weakened the metastatic and self-renewal capacity of cancer cells. Collectively, our findings indicate that TM4SF4-triggered OPN expression is involved in the persistent reinforcement of EMT or cancer stemness by creating a positive feedback autocrine loop with JAK2/STAT3 or FAK/STAT3 pathways.