IL-6 induces neuroendocrine dedifferentiation and cell proliferation in non-small cell lung cancer cells

Interleukin-6 (IL-6) has been identified as an important growth regulator of lung cancer cells. Elevation of serum levels of IL-6 has been found in a subpopulation of lung cancer patients, but rarely in patients with benign lung diseases. Approximately 15% of non-small cell lung cancer (NSCLC) tumors exhibit neuroendocrine (NE) properties (NSCLC-NE) and have been suggested to have the biological characteristics similar to small cell lung cancer (SCLC) with early metastasis and initial responsiveness to chemotherapy. We recently showed that IL-6 promotes cell proliferation and downregulates the expression of neuron-specific enolase (NSE, one of the major NE markers) in NSCLC-NE cells. In this study, we show that IL-6 stimulates a transient increase of tyrosine phosphorylation of STAT3 in a dose-dependent fashion. Inhibition of STAT3 signaling pathway by either AG-490 (JAK2-specific inhibitor) or overexpression of STAT3Y705F (a dominant-negative STAT3) reverses NSE expression in IL-6- treated NSCLC-NE cells. In addition, IL-6 induces phosphorylation and activation of p38 MAPK. SB-203580, a p38 MAPK-specific inhibitor, inhibits IL-6-induced p38 MAPK phosphorylating activity and suppresses IL-6-stimulated cell proliferation. Together, our results indicate that STAT3 signaling pathway is involved in IL-6-induced NE differentiation and that p38 MAPK is associated with IL-6-stimulated growth regulation in NSCLC-NE cells. These data suggest that both kinase pathways play critical roles in the pathogenesis of NSCLC-NE malignancies, providing new molecular targets for future therapeutic approaches.     

Multipathways for transdifferentiation of human prostate cancer cells into neuroendocrine-like phenotype

The neuroendocrine (NE) cell is a minor cell population in normal human prostate glands. The number of NE cells is increased in advanced hormone-refractory prostate carcinomas (PCA). The mechanism of increased NE cell population in these advanced tumors is poorly understood. We examined molecular mechanisms which may be involved in the regulation of the transdifferentiation process of human PCA cells leading to a NE phenotype. We compared PCA cell lines LNCaP and PC-3 in the following medium conditions: steroid-reduced (SR), interleukin-6 (IL-6)-supplemented, or dibutyrate cAMP (db-cAMP)-supplemented. We found that androgen-responsive C-33 LNCaP cells responded to all treatments, having a neuronal-like morphology. In contrast, C-81 LNCaP cells, having a decreased androgen responsiveness, had a less pronounced effect although followed a similar trend. Androgen-unresponsive PC-3 cells showed little change in their morphology. Grown in the SR condition, the level of neuron-specific enolase (NSE), a marker of neuronal cells, was upregulated in C-33 LNCaP cells, while to a lesser degree in the presence of IL-6. In the presence of db-cAMP, the NSE level in C-33 cells was decreased, lower than that in control cells. An opposite effect was observed for C-81 LNCaP cells. Nevertheless, the NSE level was only elevated in db-cAMP-treated PC-3 cells, but no change was found in PC-3 cells grown in the SR- or IL-6-supplemented medium. Thus, a similar gross phenotypic change may correlate with differential molecular expressions. We also analyzed the expression of protein tyrosine phosphatase alpha (RPTPalpha) since it plays a critical role in normal neuronal differentiation and signaling. Our results showed that the expression of RPTPalpha correlates with the NE phenotypic change of LNCaP cells in the SR condition. In summary, our data clearly show that the molecular process by which cultured human prostate cancer cells undergo a transdifferentiation process to a NE cell-like phenotype is accompanied by differential expressions of different markers, and a gross NE cell-like phenotype can occur by exposing PCA cells to different pharmacological agents.     

Inhibitory effect of Disulfiram/copper complex on non-small cell lung cancer cells

Non-small cell lung cancer (NSCLC) is the most common cause of cancer-related death in both men and women worldwide. Recently, Disulfiram has been reported to be able to inhibit glioblastoma, prostate, or breast cancer cell proliferation. In this study, the synergistic effect of Disulfiram and copper on NSCLC cell growth was investigated. Inhibition of cancer cell proliferation was detected by 1-(4,5-Dimethylthiazol-2-yl)-3,5-diphenylformazan (MTT) assay and cell cycle analysis. Liquid colony formation and tumor spheroid formation assays were used to evaluate their effect on cancer cell clonogenicity. Real-time PCR was performed to test the mRNA level of cancer stem cell related genes. We found that Disulfiram or copper alone did not potently inhibit NSCLC cell proliferation in vitro. However, the presence of copper significantly enhanced inhibitory effect of Disulfiram on NSCLC cell growth, indicating a synergistic effect between Disulfiram and copper. Cell cycle analysis showed that Disulfiram/copper complex caused NSCLC cell cycle arrest in G2/M phase. Furthermore, Disulfiram/copper significantly increased the sensitivity of cisplatin in NSCLC cells tested by MTT assay. Liquid colony formation assay revealed that copper dramatically increased the inhibitory effect of Disulfiram on NSCLC cell colony forming ability. Disulfiram combined with copper significantly attenuated NSCLC cell spheroid formation and recuded the mRNA expression of lung cancer stem cell related genes. Our data suggest that Disulfiram/copper complex alone or combined with other chemotherapy is a potential therapeutic strategy for NSCLC patients.     

Interaction between epidermal growth factor receptor and interleukin-6 receptor in NSCLC progression

Even though the interaction between epithelial growth factor receptor (EGFR) and interleukin-6 receptor (IL-6R) has been found in many tumors, there is a lack of relevant in-depth study of lung cancer. The following study investigates the interaction of EGFR and IL-6R in lung cancer. In the current study, EGFR, IL-6, and glycoprotein 130 (GP130) were highly expressed in non–small cell lung cancer (NSCLC) tissue samples and were associated with clinicopathological features and poor prognosis of patients with NSCLC. Furthermore, the effect of EGF and IL-6 on biological behavior of lung cancer cells (cell proliferation, invasion, cycle, and apoptosis) and the expression of EGFR, GP130, p-protein kinase B (p-AKT), and p-p44/42 mitogen-activated protein kinase (p-p44/42 MAPK) was significantly stronger compared with other treatment groups (all P < 0.05). These results suggest that EGFR and IL-6R have synergistic effects on NSCLC progression. This could help to solve the problem of EGFR inhibitors in the treatment of lung cancer resistance and improve the efficacy of current treatment for lung cancer through a combination of EGFR and IL-6R signaling pathways.     

C1QTNF6 regulates cell proliferation and apoptosis of NSCLC in vitro and in vivo

Objectives: Lung cancer has been reported as the leading cause of cancer-associated deaths in humans, and its incidence continues to increase in the world. A growing number of studies have shown that dysregulated genes are associated with the occurrence and poor prognosis of a variety of tumors, including non-small cell lung cancer (NSCLC). C1q/tumor necrosis factor-related protein 6 (C1QTNF6), a member of the C1q/tumor necrosis factor-related protein (CTRP) family, has been revealed to play a role in carcinogenesis and cancer progression. Nevertheless, the effects and mechanisms of C1QTNF6 in NSCLC remain unrevealed. Materials and methods: MTT (3-(4,5)-dimethylthiahiazo(-z-y1)-3,5-di-phenytetrazoliumromide) and colony formation, flow cytometric and transwell assays were performed to explore the cell function. Real-time PCR (RT-PCR) and Western blot were used to analyze the mRNA and protein expression. Results: In the present study, we found that C1QTNF6 significantly promoted the proliferation of SPCA1 and A549 cells by MTT and colony formation assays. In addition, down-regulation of C1QTNF6 weakened the tumor growth in vivo. Besides, C1QTNF6 remarkably reduced apoptosis by flow cytometric analysis and TUNEL assay. Furthermore, the capability of migration and invasion was obviously enhanced on C1QTNF6 overexpression. Conclusion: Overall, our results demonstrated that inhibition of C1QTNF6 attenuated cell proliferation, migration, invasion and promoted apoptosis in vitro and in vivo of NSCLC. Based on the above results, our study provided us with a new and key perspective in understanding and treating NSCLC.     

miR-221 通过作用DVL2 影响前列腺癌细胞系的侵袭功能*

目的:评价miR-221在前列腺癌细胞系中表达的变化对其神经内分泌样转化及其侵袭功能的影响。方法:以Northern blot检测LNCaP,LNCaP-AI两种前列腺癌细胞系中7种microRNA的表达变化;细胞转染法检测在雄激素剥夺环境中LNCaP和LNCaP-AI细胞系中miR-221的作用;CCK-8法检测细胞在不同阶段的生长增殖水平;Transwell法检测转染细胞的侵袭能力;qRT-PCR和Western blot检测转染的细胞中神经元特异性烯醇化酶(NSE)及dishevelled-2(DVL2)表达的变化。结果:与雄激素依赖性前列腺癌(ADPC)的细胞系LNCaP相比,miR-221在雄激素非依赖性前列腺癌(AIPC)的细胞系LNCaP-AI中明显高表达。通过转染使miR-221在LNCaP细胞系中高表达可促进细胞的NSE表达,加速其神经内分泌样分化。而在LNCaP-AI细胞系中下调miR-221水平则会升高靶基因DVL2的表达水平,并增强LNCaP-AI细胞的迁移和侵袭能力。结论:该实验证实在AIPC和ADPC细胞系中miR-221存在表达差异。miR-221可促进前列腺癌细胞的神经内分泌样转化,这可能是导致前列腺癌雄激素非依赖转化的重要原因。MiR-221可通过作用DVL2调节晚期前列腺癌细胞的转移和侵袭。     

Effects of Cinobufagin on the Proliferation,Migration, and Invasion of H1299 Lung Cancer Cells

Cinobufagin (CB), with its steroidal nucleus structure, is one of the major, biologically active components of Chan Su. Recent studies have shown that CB exerts inhibitory effects against numerous cancer cells. However, the effects of CB regarding the metastasis of non-small cell lung cancer (NSCLC) and the involved mechanisms need to be further studied. The purpose of the present study aimed to report the inhibitory function of CB against proliferation and metastasis of H1299 cells. CB inhibited proliferation of H1299 lung cancer cells with an IC₅₀ value of 0.035±0.008 μM according to the results of MTT assays. Antiproliferative activity was also observed in colony forming cell assays. In addition, 5-ethynyl-2’-deoxyuridine (EdU) retention assays revealed that CB significantly inhibited the rate of DNA synthesis in H1299 cells. Moreover, results of the scratch wound healing assays and transwell migration assays displayed that CB exhibited significant inhibition against migration and invasion of H1299 cells. Furthermore, CB could concentration-dependently reduce the expression of integrin α2, β-catenin, FAK, Src, c-Myc, and STAT3 in H1299 cells. These western blotting results indicated that CB might target integrin α2, β-catenin, FAK and Src to suppress invasion and migration of NSCLC, which was consistent with the network pharmacology analysis results. Collectively, findings of the current study suggest that CB possesses promising activity against NSCLC growth and metastasis.     

Involvement of TRPC Channels in Lung Cancer Cell Differentiation and the Correlation Analysis in Human Non-Small Cell Lung Cancer

The canonical transient receptor potential (TRPC) channels are Ca²⁺-permeable cationic channels controlling the Ca²⁺ influx evoked by G protein-coupled receptor activation and/or by Ca²⁺ store depletion. Here we investigate the involvement of TRPCs in the cell differentiation of lung cancer. The expression of TRPCs and the correlation to cancer differentiation grade in non-small cell lung cancer (NSCLC) were analyzed by real-time PCR and immunostaining using tissue microarrays from 28 patient lung cancer samples. The association of TRPCs with cell differentiation was also investigated in the lung cancer cell line A549 by PCR and Western blotting. The channel activity was monitored by Ca²⁺ imaging and patch recording after treatment with all-trans-retinoic acid (ATRA). The expression of TRPC1, 3, 4 and 6 was correlated to the differentiation grade of NSCLC in patients, but there was no correlation to age, sex, smoking history and lung cancer cell type. ATRA upregulated TRPC3, TRPC4 and TRPC6 expression and enhanced Ca²⁺ influx in A549 cells, however, ATRA showed no direct effect on TRPC channels. Inhibition of TRPC channels by pore-blocking antibodies decreased the cell mitosis, which was counteracted by chronic treatment with ATRA. Blockade of TRPC channels inhibited A549 cell proliferation, while overexpression of TRPCs increased the proliferation. We conclude that TRPC expression correlates to lung cancer differentiation. TRPCs mediate the pharmacological effect of ATRA and play important roles in regulating lung cancer cell differentiation and proliferation, which gives a new understanding of lung cancer biology and potential anti-cancer therapy.     

mir-615-5p 通过靶向调节癌基因TRAF4抑制非小细胞肺癌细胞的增殖

已知mir-615-5p可抑制癌细胞的增殖,然而其具体分子机制尚不明确。本研究证明,mir-615-5p通过负调节癌基因TRAF4,从而抑制NSCLC细胞的增殖。运用实时定量PCR检测NSCLC患者癌组织和癌旁正常组织、正常人肺支气管上皮细胞系HBE和3种人源NSCLC细胞系中mir-615-5p的表达,发现与正常的组织和细胞相比,mir-615-5p在NSCLC癌组织和癌细胞中表达水平显著降低;运用Western印迹检测HBE细胞和NSCLC细胞系中TRAF4蛋白的表达,发现TRAF4在NSCLC细胞中表达显著升高;MTT和CCK 8分析结果显示,转染mir-615-5p mimic 可显著降低NSCLC细胞的增殖能力;生物学信息分析和萤光素酶报告基因检测结果显示,mir-615-5p可靶定结合TRAF4 mRNA,并下调TRAF4蛋白的水平;pcDNA-TRAF4转染后细胞增殖检测结果显示,过表达TRAF4能够消除mir-615-5p引起的细胞增殖抑制作用。综上所述,mir-615-5p通过靶定结合癌基因TRAF4的mRNA,下调TRAF4蛋白的水平,从而抑制NSCLC细胞的增殖。     

Cooperative regulation of non-small cell lung carcinoma by nicotinic and beta-adrenergic receptors: a novel target for intervention

Lung cancer is the leading cause of cancer death; 80-85% of lung cancer cases are non-small cell lung cancer (NSCLC). Smoking is a documented risk factor for the development of this cancer. Although nicotine does not have the ability to initiate carcinogenic events, recent studies have implicated nicotine in growth stimulation of NSCLC. Using three NSCLC cell lines (NCI-H322, NCI-H441 and NCI-H1299), we identified the cooperation of nicotinic acetylcholine receptors (nAChRs) and β-adrenergic receptors (β-ARs) as principal regulators of these effects. Proliferation was measured by thymidine incorporation and MTT assays, and Western blots were used to monitor the upregulation of the nAChRs and activation of signaling molecules. Noradrenaline and GABA were measured by immunoassays. Nicotine-treated NSCLC cells showed significant induction of the α7nAChR and α4nAChR, along with significant inductions of p-CREB and p-ERK1/2 accompanied by increases in the stress neurotransmitter noradrenaline, which in turn led to the observed increase in DNA synthesis and cell proliferation. Effects on cell proliferation and signaling proteins were reversed by the α7nAChR antagonist α-BTX or the β-blocker propranolol. Nicotine treatment also down-regulated expression of the GABA synthesizing enzyme GAD 65 and the level of endogenous GABA, while treatment of NSCLC cells with GABA inhibited cell proliferation. Interestingly, GABA acts by reducing β-adrenergic activated cAMP signaling. Our findings suggest that nicotine-induced activation of this autocrine noradrenaline-initiated signaling cascade and concomitant deficiency in inhibitory GABA, similar to modulation of these neurotransmitters in the nicotine-addicted brain, may contribute to the development of NSCLC in smokers. Our data suggest that exposure to nicotine either by tobacco smoke or nicotine supplements facilitates growth and progression of NSCLC and that pharmacological intervention by β blocker may lower the risk for NSCLC development among smokers and could be used to enhance the clinical outcome of standard cancer therapy.     

Reticulocalbin 1 is required for proliferation and migration of non-small cell lung cancer cells regulated by osteoblast-conditioned medium

Reticulocalbin1 (RCN1) is implicated in tumorigenesis and tumour progression. However, whether RCN1-mediated bone metastasis of non-small cell lung cancer (NSCLC) cells was elusive. Here, we assessed the effect of osteoblast-conditioned medium (CM) on proliferation and migration of NSCLC cell line, NCI-H1299 and NCI-H460 cells, and identified the soluble mediators in CMs from osteoblasts and NSCLC cells using MTT, Clonogenicity, Transwell, wound healing, RT-PCR, and Western blotting assays, and LC-MS/MS analysis, respectively. Furthermore, the role of RCN1 was investigated in NSCLC cells cultured with or without osteoblast-CM. Tumour growth and bone resorption were measured in a nude mouse model bearing NCI-H1299 cells transduced with shRNA/RCN1 vector using in vivo imaging technique and micro-CT. The results showed that RCN1 with a higher abundance in osteoblast-CM, which was present in extracellular vesicles (EVs), enhanced RCN1 expression in NSCLC cells. Osteoblast-CM partially offset the inhibitory effect of RCN1 depletion on proliferation and migration of NSCLC cells. RCN1 depletion-induced endoplasmic reticulum (ER) stress caused by increasing GRP78, CHOP, IRE1α, p-IRE1α, p-PERK and p-JNK, which was positively regulated by self-induced autophagy, contributed to suppression of proliferation and migration in NCI-H1299 cells. Therefore, osteoblasts produced RCN1 to transfer into NSCLC cells partially through EVs, facilitating proliferation and migration of NSCLC cells via blocking ER stress. RCN1 could be required for proliferation and migration of NSCLC cells regulated by osteoblast-CM.     

Interaction of estrogen receptor β5 and interleukin 6 receptor in the progression of non–small cell lung cancer

Numerous studies have shown that the estrogen receptor beta (ERβ) and interleukin 6 receptor (IL-6R) had interaction in many tumors, including lung cancer. Previous studies found that ERβ5 exhibits a different biological function compared with the other subtypes of ERβ. Therefore, this study mainly explores the interaction between ERβ5 and IL-6R in the progression of lung cancer. We found that the expression of ERβ5, IL-6 and glycoprotein 130 (GP130) were significantly increased (P < 0.001) and the 5-year survival rate with the co-expression of ERβ5 and GP130 is significantly lower (P = 0.0315) in non-small cell lung cancer (NSCLC) patients. The cell proliferation, invasion, and cell cycle were markedly increased, and the cell apoptotic was markedly inhibited with the concurrent action of ERβ5 and IL-6 in A549 cells (P < 0.05). In addition, the expression of ERβ5, GP130, p-AKT, and p-44/42 MAPK was also significantly increased in A549 cells (P < 0.05). These results indicate that ERβ5 and GP130 can synergistically promote the progression of NSCLC and maybe combined as an independent prognostic factor in patients. In addition, these results also provide a theoretical basis for the combined targeting therapy of ERβ5 and GP130 in NSCLC.     

miR-204通过抑制OGT的表达调控非小细胞肺癌细胞的增殖和迁移

目的:探究miR-204和O-连接N-乙酰氨基葡萄糖转移酶(O link N-acetylglucosamine transferase,OGT)对非小细胞肺癌(Non-small cell lung cancer,NSCLC)细胞增殖和转移的影响,并深入分析其可能机制。方法:采用Oncomine及KM-Ploter数据库分析OGT在肺癌组织中的表达及与肺癌患者预后的关系;采用慢病毒转染人非小细胞肺癌A549及永生化人肺支气管上皮细胞BEAS-2B,分别构建OGT稳定下调和过表达的细胞系,利用CCK-8、平板克隆和裸鼠皮下成瘤实验检测细胞增殖的情况,划痕实验、Transwell实验和裸鼠尾静脉注射肺转移模型检测细胞转移的情况。利用数据库分析可能参与OGT调控的microRNA,并用双荧光素酶报告基因验证。利用TCGA数据库分析miR-204在肺癌中的表达情况,并在30例肺癌组织及其对应癌旁组织中分析miR-204与OGT之间的相关性。结果:OGT在肺癌组织中呈高表达,且与患者的不良预后相关(HR=1.22,P 0.01);OGT的表达上调肺癌细胞的增殖和转移;miR-204可以负向调控OGT的表达,且miR-204在肺癌组织中表达水平显著低于癌旁组织,在肺癌组织中miR-204的水平与OGT的表达水平呈负相关(R~2=-0.4729,P 0.01)。结论:在非小细胞肺癌中,miR-204的降低通过上调OGT的表达促进肺癌的增殖和转移。     

Lack of squamous cell lung carcinoma in vitro chemosensitivity to various drug regimens in the adenosine triphosphate cell viability chemosensitivity assay.

A pilot study on squamous cell lung carcinoma (LC) chemosensitivity in adenosine triphosphate cell viability chemosensitivity assay (ATP-CVA) was performed. Besides the histological investigation, a modified ATP-CVA was used for the analysis of cancer cell chemosensitivity to four drug regimens, including topotecan, a promising agent for non-small-cell lung cancer (NSCLC) chemotherapy. Results of in vitro chemosensitivity testing showed chemoresistance or only weak response in the predominant amount of tumors.     

Production of CCL20 from lung cancer cells induces the cell migration and proliferation through PI3K pathway

Tumour inflammatory microenvironment is considered to play a role in the sensitivity of tumour cells to therapies and prognosis of patients with lung cancer. The expression of CCL20, one of the critical chemoattractants responsible for inflammation cells recruitment, has been shown overexpressed in variety of tumours. This study aimed at investigating potential mechanisms of CCL20 function and production in human non‐small cell lung cancer (NSCLC). Expression of CCL20 gene and protein in lung tissues of patients with NSCLC and NSCLC cells (A549) were determined. The interleukin (IL)‐1β‐induced signal pathways in A549 and the effect of CCL20‐induced A549 cell migration and proliferation were determined using migration assays and cell‐alive monitoring system. Mechanisms of signal pathways involved in the migration of CCL20 were also studied. We initially found that NSCLC tumour tissues markedly overexpressed CCL20 in comparison with normal lung samples. In addition, IL‐1β could directly promote CCL20 production in lung cancer cells, which was inhibited by extracellular signal‐regulated kinase (ERK)1/2 inhibitor, p38 mitogen‐activated protein kinase (p38 MARP) inhibitor or PI3K inhibitors. CCL20 promoted lung cancer cells migration and proliferation in an autocrine manner via activation of ERK1/2‐MAPK and PI3K pathways. Our data indicated that IL‐1β could stimulate CCL20 production from lung cancer cells through the activation of MAPKs and PI3K signal pathways, and the auto‐secretion of CCL20 could promote lung cancer cell migration and proliferation through the activation of ERK and PI3K signal pathways. Our results may provide a novel evidence that CCL20 could be a new therapeutic target for lung cancer.