Lung Carcinoma Cell Proliferation Research Articles

Targeted Disruption of PDCD2 Delays G1/S Transition in Lung Carcinoma by Inhibiting Cyclin D1 Transcription

We previously reported on high expression of define PDCD2 in human malignancies. Knockdown of PDCD2 reduced the proliferation of leukemia and lung carcinoma cells. However, the mechanism by which PDCD2 reduces tumor proliferation remains unclear. This study tested the hypothesis that lowered PDCD2 would delay the proliferation of A549 lung carcinoma cells. Entry of A549 cells into S-phase was significantly (p-value 0.05) delayed when PDCD2 was knockdown. This correlated with a significant downregulation of cyclin D1, and AKT phosphorylation. Inhibition of the PI3K/AKT signaling pathway by Ly294002 decreased levels of PDCD2. These findings are consistent with a role for PDCD2 to mediate the entry of A549 cells into the cell cycle. Resting A549 cells showed PDCD2 localizing in the nucleus and plasma membrane and became diffuse with cell division, suggesting that PDCD2 is mitogen-dependent and may be involved in the proper timing of cell cycle. These findings may represent a promising venue to develop PDCD2 in clinical applications.

Fusing WGCNA and Machine Learning for Immune-Related Gene Prognostic Index in Lung Adenocarcinoma: Precision Prognosis, Tumor Microenvironment Profiling, and Biomarker Discovery.

The objective is to create an IRGPI (Immune-related genes prognostic index), which could predict the survival and effectiveness of immune checkpoint inhibitor (ICI) treatment for lung adenocarcinoma (LUAD). By applying weighted gene co-expression network analysis (WGCNA), we ascertained 13 genes associated with immune functions. An IRGPI was constructed using four genes through multicox regression, and its validity was assessed in the GEO dataset. Next, we explored the immunological and molecular attributes and advantages of ICI treatment in subcategories delineated by IRGPI. The model genes were also validated by the random forest tree, and functional experiments were conducted to validate it. The IRGPI relied on the genes CD79A, IL11, CTLA-4, and CD27. Individuals categorized as low-risk exhibited significantly improved overall survival in comparison to those classified as high-risk. Extensive findings indicated that the low-risk category exhibited associations with immune pathways, significant infiltration of CD8 T cells, M1 macrophages, and CD4 T cells, a reduced rate of gene mutations, and improved sensitivity to ICI therapy. Conversely, the higher-risk group displayed metabolic signals, elevated frequencies of TP53, KRAS, and KEAP1 mutations, escalated levels of NK cells, M0, and M2 macrophage infiltration, and a diminished response to ICI therapy. Additionally, our study unveiled that the downregulation of IL11 effectively impedes the proliferation and migration of lung carcinoma cells, while also inducing cell cycle arrest. IRGPI is a biomarker with significant potential for predicting the effectiveness of ICI treatment in LUAD patients and is closely related to the microenvironment and clinicopathological characteristics.

Sensitivity of Lewis lung carcinoma cells to glycolysis and glutaminolysis inhibition

Awareness of the key role of metabolic reprogramming in tumor cell progression has promoted the exploration of approaches to inhibit glycolysis to develop novel antitumor therapy. Highly promising in clinical terms is sodium oxamate, an inhibitor of the enzyme lactate dehydrogenase, which is a critical regulator of glycolysis in tumor cells. Therefore, studying the mechanisms of sodium oxamate action is a relevant issue in modern oncology. The purpose of this work was to examine the impact of oxamate on the survival and proliferative activity of Lewis lung carcinoma (LLC) cells under glutamine deficiency. The conducted research has shown that LLC cells exhibit heterogeneity in their sensitivity to the cytostatic/cytotoxic effects of oxamate: approximately 65% of cells are sensitive to its cytostatic/cytotoxic action, while 35% are resistant. In sensitive cells, sodium oxamate exerts a significant cytotoxic effect by activating apoptosis and, probably, by inhibiting the rate of glucose consumption and lactate production by tumor cells. Glutamine deficiency in the nutrient medium significantly increases the cytotoxic effect of sodium oxamate. No significant stimulation of reactive oxygen species production by tumor cells was observed under the influence of oxamate. It was found that sodium oxamate is capable of inducing G2/M cell cycle arrest in LLC cells in the proliferation of Lewis lung carcinoma cells.

Midazolam impedes lung carcinoma cell proliferation and migration via EGFR/MEK/ERK signaling pathway.

Non-small-cell lung cancer (NSCLC) is a dominating type of lung cancer with high morbidity and mortality. Midazolam has been reported to promote cell apoptosis in NSCLC, but the molecular mechanism of midazolam remains to be further explored. In the current work, cell viability, proliferation, migration, and apoptosis rates of NSCLC cells treated with midazolam were measured using cell counting kit-8 assay, 5-ethynyl-2'-deoxyuridine (EdU) and colony formation assays, transwell, and flow cytometry assay, respectively, to evaluate the malignant behaviors. Western blot was applied to access EGFR/MEK/ERK pathway-related protein levels. The results demonstrated midazolam significantly declined the viability of NSCLC cells. Furthermore, midazolam restrained cell proliferation and migration and contributed to cell apoptosis in NSCLC. Midazolam exerted suppressive function to EGFR pathway during NSCLC development. Moreover, the activation of EGFR/MEK/ERK pathway abrogated the effects of midazolam on NSCLC cell proliferation, apoptosis, and migration. Taken together, midazolam exhibited anti-tumor effects hallmarked by EGFR pathway inhibition, providing a novel insight into the treatment of NSCLC.

Lamprey prohibitin 2 inhibits non-small cell lung carcinoma cell proliferation by down-regulating the expression and phosphorylation levels of cell cycle-associated proteins

Prohibitin 2 (PHB2) is an evolutionarily conserved and functionally diverse protein that plays an important role in multiple cellular functions, including cell proliferation, cell migration, and apoptosis, and is also known to participate in the process of tumorigenesis and development. In this study, the lamprey PHB2 (Lm-PHB2) gene was over-expressed in KRAS (kirsten rat sarcoma viral oncogene homolog)-mutated non-small cell lung carcinoma (NSCLC) cells to investigate its effect on cell proliferation. The effects of Lm-PHB2 protein on the proliferation of NSCLC cells were determined by treating cells with the purified recombinant Lm-PHB2 protein (rLm-PHB2) followed by cell counting kit (CCK) assays and flow cytometry. Analysis showed that rLm-PHB2 blocked cells in the G2 phase and inhibited the cell proliferation of A549, Calu-1, and NCI-H226 to various degrees. The effect on Calu-1 cells was the most obvious and was concentration- and time-dependent. Similarly, cells transfected with the pEGFP-N1-Lm-PHB2 plasmid also resulted in the suppression of proliferation in A549 cells and Calu-1 cells. Quantitative real-time polymerase chain reaction (qRT-PCR) showed that Lm-PHB2 inhibited cell proliferation by repressing the transcription of PLK1 (polo-like kinase 1), Wee1 (wee1 kinase), CCNB1 (cyclin B1), and CDC25C (cell division control protein 25C). According to western blot analysis, Lm-PHB2 not only down-regulated the expression of PLK1, Wee1, CCNB1, and CDC25C but also reduced the phosphorylation levels of CCNB1 and CDC25C, thus blocking Calu-1 cells in G2/M phase. Our findings demonstrate a function of lamprey PHB2 that may inhibit the proliferation of some NSCLC cells by down-regulating the expression and phosphorylation of cell cycle-associated proteins.

Pinostrobin suppresses the proliferation of lung carcinoma cells by abrogating the cell cycle progression through the inhibition of Notch signaling pathway

• Pinostrobin (PN) suppressed the growth and proliferation of lung cancer cells (A549). • PN induced apoptosis via intrinsic apoptosis pathway. • PN abrogated the cell cycle progression in A549 lung cancer cells. • PN downregulated notch signaling cascade in lung cancer. Pinostrobin (PN) is a dietary bioflavonoid naturally found in numerous medicinal plants. Even though the anticancer potential of flavonoids has been studied; however the molecular targets and the exact mechanism behind their apoptosis-inducing actions are not yet fully elucidated. The present study was aimed to investigate if PN could induce apoptosis in lung cancer A549 cells of human origin. PN reduced the proliferation of A549 cells in a dose-dependent manner. Induction of apoptosis was observed in PN-treated lung cancer cells as evident by DNA fragmentation and Annexin V positive cells. The PN induced reactive oxygen species (ROS) generation in A549 cells, leading to activation of key regulators of apoptosis such as Bax, Bad and Bcl2 as well as release of cytochrome c, and activation of the caspase cascade including caspase-9 and -3. Enhanced loss of Δψm, cytochrome c release and cleavage of caspase-3 & -9 strongly corroborated our findings. Furthermore, PN treatment of lung cancer cells arrested the cell cycle in G0/G1 phase, inhibited constitutive expression of Cyclin D1and CDK4 and induced the mRNA levels of p21 Cip1 . A dose-dependent decreased expression of Notch-1, Jagged-1 and Hes-1 were noted in PN treated A549 cells. These findings demonstrated that PN suppressed the growth of A549 cells via downregulating the Notch pathway. Thus, subsequent studies focusing on molecular mechanism of PN can pave path for anticancer drug design.

The targeted delivery of chitosan nanoparticles to treat indoxacarb: induced lung fibrosis in rats

BackgroundThis study evaluated the effects of chitosan nanoparticles (Ch-NPs) on indoxacarb (INDOX)-induced pulmonary fibrosis in in vivo and in vitro models. In in vivo studies, 40 male albino rats were randomly divided into four groups (10 rats/group): Group 1, normal control; Group 2, INDOX (600 mg/kg b.w.); Group 3, Ch-NPs (2 mg/kg b.w.); and Group 4, Ch-NPs + INDOX. Characterization of Ch-NPs was done measuring dynamic light scattering, zeta potential, Fourier-transform infrared spectroscopy, transmission electron microscopy, and antioxidant activity studies after various Ch-NPs treatments. From in vitro studies, the impact of Ch-NPs on A549 lung carcinoma cell proliferation was also examined.ResultsOur data indicated that INDOX provoked considerable lung damage as indicated by decreased antioxidant enzyme levels of superoxide dismutase and glutathione peroxidase, increased production of nitric oxide and malondialdehyde serum levels, elevated myeloperoxidase activity, increased hydroxyproline and cytokeratin-19 serum levels, and significantly upregulated matrix metallopeptidase-9 and microRNA-101 gene expression levels when compared with controls. Furthermore, histopathological and immunohistochemical investigations of cyclooxygenase-2 in the lung tissue revealed marked inflammation, severe fibrosis, and neutrophil infiltration. Critically, Ch-NPs treatment significantly reversed INDOX-induced changes in lung biochemical, histopathological, and immunohistochemical outcomes.ConclusionTherefore, Ch-NPs may function as potential therapeutic drugs for lung fibrosis owing to their antioxidant, anti-inflammatory, and antifibrotic activities with neutrophil infiltration.

Pomolic acid inhibits proliferation of human lung carcinoma cells via induction of apoptosis and suppression of cell migration and invasion

Purpose: To investigate the anti-proliferative effect of pomolic acid on lung cancer cells (A549), and theunderlying mechanism.Methods: The viability of pomolic acid-treated A549 cells was determined by MTT and colony formation assays. Cell colony formation was monitored with acridine orange/ethidium bromide (AO/EB) staining. Protein expressions of Bax and Bcl-2 were assayed by western blotting.Results: Pomolic acid suppressed the growth of A549 cells, with an half-maximal inhibitory concentration of (IC50) of 10 μM (p < 0.05). However, the IC50 of pomolic acid for normal BEAS-2B cells was 80 μM. Pomolic acid also decreased colony formation of A549 cells. At 20 μM, the percentage of A549 colonies decreased to 14 % of control. The dose-dependent cytotoxicity of pomolic acid against A549 cells was mediated via induction of apoptosis and oxidative stress. Pomolic acid treatment enhanced the expression of Bax and decreased the expression of Bcl-2 in A549 cells. Moreover, pomolic acid inhibited the migration and invasion in A549 cells in a dose-dependent manner (p < 0.05).Conclusion: These results indicate the potent anticancer effect of pomolic acid against human lung cancer cells. Thus, pomolic acid has promising potential as a lead molecule for the development of chemotherapy.

Cloning, Expression and Inhibitory Effects on Lewis Lung Carcinoma Cells of rAj-Tspin from Sea Cucumber (Apostichopus japonicus).

In recent years, sea cucumber has become a favorite healthcare food due to its characteristic prevention of cardiovascular diseases, suppression of tumors, as well as enhancement of immunity. In order to screen the anti-tumoral proteins or peptides from sea cucumber (Apostichopus japonicus), its cDNA library was analyzed, and a disintegrin-like and metalloproteinase with thrombospondin type 1 motif, member 13 (ADAMTS13)-like was found. ADAMTS13-like contains 10 thrombospondin 1 (TSP1) domains. Based on analysis of bioinformatics, the third TSP1 domain of this protein, which is further named Aj-Tspin, contains an arginine-glycine-aspartate (RGD) motif. Since our previous studies showed that the recombinant RGD-containing peptide from lampreys showed anti-tumoral activity, the third TSP1 domain of ADAMTS13-like was chosen to evaluate it’s effect on tumor proliferation and metastasis, despite the fact it shares almost no homologue with disintegrins from other species. After artificial synthesis, its cDNA sequence, Aj-Tspin, which is composed of 56 amino acids, was subcloned into a pET23b vector and expressed as a recombinant Aj-Tspin (rAj-Tspin) in a soluble form with a molecular weight of 6.976 kDa. Through affinity chromatography, rAj-Tspin was purified as a single protein. Both anti-proliferation and immunofluorescence assays showed that rAj-Tspin suppressed the proliferation of Lewis lung carcinoma (LLC) cells through apoptosis. Adhesion assay also displayed that rAj-Tspin inhibited the adhesion of LLC cells to ECM proteins, including fibronectin, laminin, vitronectin and collagen. Lastly, rAj-Tspin also suppressed the migration and invasion of LLC cells across the filter in transwells. Thus, the above indicates that rAj-Tspin might act as a potential anti-tumoral drug in the future and could also provide information on the nutritional value of sea cucumber.

CircZNF652 accelerates the proliferation and migration of primary lung carcinoma cells by downregulating miR-766

Purpose: To explore the biological functions and molecular mechanism of circZNF652 involvement in primary lung carcinoma.Methods: CircZNF652 levels in primary lung carcinoma cases and controls were determined using quantitative real-time polymerase chain reaction (qRT-PCR). Its prognostic value in primary lung carcinoma was examined by depicting it with Kaplan-Meier curves. The biological functions of circZNF652 in regulating proliferative and migratory capacities in A549 and SPC-A-1 cells were analyzed from the curves. Interaction between circZNF652 and its downstream gene, miR-766, wasassessed, and their co-regulation on primary lung carcinoma was determined by rescue experiments.Results: CircZNF652 was abnormally and significantly upregulated in primary lung carcinoma cases (p< 0.05), resulting in a poor prognosis. The knockdown effect of circZNF652 attenuated the proliferative and migratory capacities of A549 and SPC-A-1 cells, and downregulated epithelial-mesenchymal transition (EMT)-associated genes. CircZNF652 bound and negatively regulated miR-766, a keydownstream gene involved in circZNF652-induced aggravation of primary lung carcinoma.Conclusion: CircZNF652 serves as an oncogene, triggering the aggravation of primary lung carcinoma by negatively regulating miR-766. The results of this study may provide new insights into the treatment of lung carcinoma.

ZMYM3 May Promote Cell Proliferation in Small Cell Lung Carcinoma.

Zinc finger, myeloproliferative, and mental retardation-type containing 3 (ZMYM3) is a highly conserved protein among vertebrates. Although it promotes DNA repair and moderate histone acetylation, the other functions of ZMYM3 remain unclear. We herein examined the physiological functions of ZMYM3 in human lung cancer using a ZMYM3-knockdown small cell lung cancer (SCLC) cell line. ZMYM3-knockdown SCLC cells grew slowly and the Ki-67 labeling index was lower in ZMYM3-knockdown cells than in mock cells. The subcutaneous tumors that formed after xenotransplantation into immunodeficient mice were slightly smaller in the ZMYM3-knockdown group than in the mock group. Furthermore, public RNA-sequencing data analyses showed similar RNA profiles between ZMYM3 and some cell proliferation markers. These results indicate that ZMYM3 promotes cell proliferation in human lung carcinomas, particularly SCLC.

Metabolomics and integrated network pharmacology analysis reveal Tricin as the active anti-cancer component of Weijing decoction by suppression of PRKCA and sphingolipid signaling

Currently, conventional methods of treating non-small cell lung cancer (NSCLC) have many disadvantages. An alternative effective therapy with minimal adverse reactions is urgently needed. Weijing decoction (WJD), which is a classic ancient Chinese herbal prescription, has been used successfully to treat pulmonary system diseases containing lung cancer in the clinic. However, the key active component and target of Weijing decoction are still unexplored. Therefore, for the first time, our study aims to investigate the pharmacological treatment mechanism of Weijing decoction in treating NSCLC via an integrated model of network pharmacology, metabolomics and biological methods. Network pharmacology results conjectured that Tricin is a main bioactive component in this formula which targets PRKCA to suppress cancer cell growth. Metabolomics analysis demonstrated that sphingosine-1-phosphate, which is regulated by sphingosine kinase 1 and sphingosine kinase 2, is a differential metabolite in plasma between the WJD-treated group and the control group, participating in the sphingolipid signaling. In vitro experiments demonstrated that Tricin had vital effects on the proliferation, pro-apoptosis, migration and colony formation of Lewis lung carcinoma cells. Through a series of validation assays, Tricin inhibited the tumor growth mainly by suppressing PRKCA/SPHK/S1P signaling and antiapoptotic signaling. On the other hand, Weijing formula could inhibit the tumor growth and prolong the survival time. A high dosage of Tricin was much more potent in animal experiments. In conclusion, we confirmed that Weijing formula and its primary active compound Tricin are promising alternative treatments for NSCLC patients.

Effects of Sevoflurane on Lewis Lung Carcinoma Cell Proliferation In Vivo and In Vitro.

Background and objectives: There are several studies that sevoflurane could enhance proliferation of cancer cells, while others suggest no effect on clinical outcome. We conducted in vivo and in vitro experiments to investigate the effects of sevoflurane, a volatile anesthetic, on proliferation and outcomes of Lewis lung carcinoma (LLC) cells. Materials and Methods: A total of 37 mice were injected with LLC cells to compare the tumor size and survival of the sevoflurane exposed group (sevo group) and control group. The sevo group was exposed to 2% sevoflurane and 4 L/min of oxygen for 1 h per day 3 times per week, and the control group was exposed only to 4 L/min of oxygen. In vitro study, 12 plates incubated with LCC cells. 6 plates were exposed to 2% sevoflurane for 1 hr/day for 3 days and 6 plates were not exposed, and cell proliferation was compared after 3 days. Results: There were no significant differences in survival or tumor size between mice exposed to sevoflurane and control mice (survival: 29.06 ± 4.45 vs. 28.76 ± 3.75, p = 0.836; tumor size: 0.75 (0.41–1.02) vs. 0.49 (0.11–0.79), p = 0.153). However, in vitro study, the proliferation of LLC cells exposed to sevoflurane increased by 9.2% compared to the control group (p = 0.018). Conclusions: Sevoflurane (2 vol%) exposure could promote proliferation of LLC cells in vitro environment, but may not affect proliferation of LLC cells in vivo environment. These results suggest that in vitro studies on the effects of anesthetics on cancer may differ from those of in vivo or clinical studies.

Knockdown of miR-543 Inhibits the Proliferation and Migration of Small-Cell Lung Carcinoma Cells and Induces Apoptosis.

This article aims to explore the effects and possible mechanism of miR-543 on small-cell lung carcinoma (SCLC) cells. The respective levels of miR-543 in lung carcinoma tissues, para-cancerous tissues, human normal lung cells MRC-9, and SCLC cells were detected by RT-qPCR. The proliferation, apoptosis, and migration of SCLC cells were detected after the miR-543 level in SCLC cells was altered by miRNA mimics and inhibitors. The levels of apoptosis-related proteins and potential downstream targeted proteins of miR-543 were detected by western blots. The study revealed that KNTC1 was highly expressed in lung carcinoma tissues and SCLC cells (P < 0.01). It also showed that knockdown of miR-543 can inhibit the proliferation and migration of SCLC cells, induce apoptosis, and increase the level of apoptosis-related proteins. These changes were reversed by the addition of mimics that increased miR-543 levels. The level of miR-543 was positively correlated with the protein expression level of downstream MUC1, β-catenin, and CDC42 in SCLC cells, suggesting that miR-543 may play a role through them. Thus this study concludes that MiR-543 can affect the function of SCLC cells, which may play a crucial role in the presence and development of SCLC.

Long non‑coding RNA LINC00887 promotes progression of lung carcinoma by targeting the microRNA‑206/NRP1 axis

Long non-coding RNAs (lncRNAs) have been reported to participate in multiple biological processes, including tumorigenesis. In the current study, the function of a novel lncRNA LINC00887 was investigated in lung carcinoma. For this purpose, LINC00887 expression was assessed by reverse-transcription quantitative PCR. Cell viability was determined by the CCK-8 and EdU assays. Cell invasion, migration were assessed by the transwell and wound healing assays, respectively. A dual luciferase assay was used for analysis of the interaction between LINC00887 and miR-206, as well as the relationship of miR-206 with NRP1. A tumor xenograft study was performed to investigate the LINC00887-miR-206-NRP1 axis in vivo. The expression levels of LINC00887 were upregulated in lung carcinoma tissues and cells compared with adjacent tissues or normal cells (BEAS-2B). Knockdown LINC00887 significantly inhibited the proliferation, migration and invasion of lung carcinoma A549 and NCI-H460 cells. Furthermore, LINC00887 was identified as a competing endogenous RNA and to directly interact with miR-206. Mechanistically, miR-206 was demonstrated to regulate neuropilin-1 (NRP1) expression by targeting the NRP1 3′-untranslated region. The results of the present study suggested that the LINC00887-miR-206-NRP1 axis served a critical role in regulating lung carcinoma cell proliferation, migration and invasion. In addition, xenograft tumor model experiments revealed that silencing LINC00887 suppressed lung carcinoma tumor growth of in vivo. In summary, our results suggest that LINC00887 may serve an oncogenic role in lung carcinoma by targeting the miR-206/NRP1 axis, providing a potential therapeutic target for patients with lung carcinoma.

Design, synthesis, and evaluation of novel combretastatin A‐4 based chalcone derivatives as anticancer agents

AbstractA series of combretastatin A‐4 based chalcones (14a‐l) were designed, synthesized and these compounds examined for inhibitory effects on the proliferation of human lung (A549), breast (MCF‐7), melanoma (A375), and colon (HT‐29) carcinoma cells. Compounds 14b, 14c, 14e, 14h, and 14i (tri/dimethoxy, methyl, and mono/dinitro derivatives) have exhibited the most potent antiproliferative activity with IC50 &lt; 2 μM and the hexa methoxy derivative 14b, the most promising one, which displayed the potent inhibitory activities in MCF‐7 (IC50: 10 nM), A375 (IC50: 12 nM), and A549 (IC50: 65 nM) cell lines, and is 18 times more potent than the CA‐4. Compound 14b represents a new scaffold and the results provide insights into further development of anticancer agents.

Ticagrelor prevents tumor metastasis via inhibiting cell proliferation and promoting platelet apoptosis

Tumor cells can activate platelets, which in turn facilitate tumor cell survival and dissemination. Platelets inhibition or blocking platelet-tumor cell interactions has become a strategy to suppress tumor progression. In this study, we investigated the effect of ticagrelor, a new antiplatelet drug, on tumor cell proliferation and metastasis. Our results show that ticagrelor not only inhibits the proliferation, migration, and invasion of B16F10 and Lewis lung carcinoma cells but also induces platelet apoptosis. In addition, we find that apoptosis of the platelet cells is dose dependent. Further, the result of in-vivo experiments proved that ticagrelor treatment decreased the tumor metastasis. The results of this study demonstrate that ticagrelor may be a potential anti-tumor agent for tumor metastasis.

RP11‑284F21.9 promotes lung carcinoma proliferation and invasion via the regulation of miR‑627‑3p/CCAR1.

Lung carcinoma is a prominent cause of mortality among patients with cancer. Previous studies have reported the vital role of long non-coding RNAs (lncRNAs) in the malignant progression of lung cancer. lncRNA RP11-284F21.9 was originally identified to be expressed in lung carcinoma, but its specific function remains unknown. Therefore, the present study aimed to elucidate the role of lncRNA RP11-284F21.9 in lung carcinoma progression. The expression of RP11-284F21.9 in lung cell lines and tissues was measured using reverse transcription-quantitative PCR. The endogenous expression of RP11-284F21.9 was silenced using RNA interference, and cell viabilities were measured with a Cell Counting Kit-8 assay. The invasion and apoptosis of cells were determined via Transwell assays and flow cytometry, respectively. The protein expression levels were measured by western blotting. An increased expression of RP11-284F21.9 was identified in both lung carcinoma tissues and cells. Knockdown of RP11-284F21.9 in lung carcinoma cells inhibited cell proliferation and invasion, but promoted cell apoptosis. The present study identified the existence of a direct interaction between RP11-284F21.9 and microRNA (miRNA/miR)-627-3p. Mechanistically, it was demonstrated that RP11-284F21.9 promoted the proliferation and invasiveness of lung carcinoma cells, in part, via the regulation of miR-627-3p. Furthermore, cell division cycle and apoptosis regulator 1 (CCAR1) was identified as a target gene of miR-627-3p. The in vivo tumor growth assay also demonstrated that the knockdown of RP11-284F21.9 suppressed tumor growth, upregulated miR-627-3p and downregulated CCAR1 in the xenograft model of nude mice. Thus, the present findings indicated the tumor promoting functions of RP11-284F21.9 in the progression of lung carcinoma, and provided a novel lncRNA/miRNA axis as a target for the management of lung cancer.

Endogenous thrombopoietin promotes non-small-cell lung carcinoma cell proliferation and migration by regulating EGFR signalling.

Thrombopoietin (TPO) is a haematopoietic cytokine mainly produced by the liver and kidneys, which stimulates the production and maturation of megakaryocytes. In the past decade, numerous studies have investigated the effects of TPO outside the haematopoietic system; however, the role of TPO in the progression of solid cancer, particularly lung cancer, has not been well studied. Exogenous TPO does not affect non‐small‐cell lung cancer (NSCLC) cells as these cells show no or extremely low TPO receptor expression; therefore, in this study, we focused on endogenous TPO produced by NSCLC cells. Immunohistochemical analysis of 150 paired NSCLC and adjacent normal tissues indicated that TPO was highly expressed in NSCLC tissues and correlated with clinicopathological parameters including differentiation, P‐TNM stage, lymph node metastasis and tumour size. Suppressing endogenous TPO by small interfering RNA inhibited the proliferation and migration of NSCLC cells. Moreover, TPO interacted with the EGFR protein and delayed ligand‐induced EGFR degradation, thus enhancing EGFR signalling. Notably, overexpressing TPO in EGF‐stimulated NSCLC cells facilitated cell proliferation and migration, whereas no obvious changes were observed without EGF stimulation. Our results suggest that endogenous TPO promotes tumorigenicity of NSCLC via regulating EGFR signalling and thus could be a therapeutic target for treating NSCLC.

CircFOXM1 promotes proliferation of non-small cell lung carcinoma cells by acting as a ceRNA to upregulate FAM83D

BackgroundBiological role and clinical significance of circular RNAs (circRNAs) remain largely unknown. Herein, we aimed to investigate biological function, molecular mechanism, and clinical significance of a circular RNA FOXM1 (circFOXM1) in non-small cell lung cancer (NSCLC).MethodsExpression of circFOXM1 was measured in 48 paired samples of NSCLC by qRT-PCR. Functional roles of circFOXM1 on tumor cells were explored by in vitro and in vivo assays. Transcriptome sequencing was employed to screen the molecules involved in circFOXM1 regulatory network. RNA immunoprecipitation, luciferase analysis, RNA pull-down, and rescue assay were used to investigate potential mechanisms of circFOXM1.ResultsWe found that circFOXM1 was significantly upregulated in NSCLC tissues, and its upregulation was positively correlated with advanced clinical stage and poor prognosis of NSCLC patients. Gain or loss-of-function assay showed that circFOXM1 promoted cell proliferation and cell cycle progression. In vivo assays showed that silencing circFOXM1 inhibited xenograft tumor growth. Mechanically, transcriptome sequencing data indicated that silencing circFOXM1 led to the downregulation of cell cycle-related mRNAs. RNA pull-down and dual-luciferase reporter assay suggested that circFOXM1 could bind to miR-614, and FAM83D was an essential gene involved in the circFOXM1/miR-614 regulatory network.ConclusionscircFOXM1promotes NSCLC progression by interacting with miR-614 and thus inactivating the function of miR-614, which will further release the suppression of FAM83D. circFOXM1/miR-614/FAM83D regulatory network may serve as a potential therapeutic target for NSCLC patients.