The p70S6K Specific Inhibitor PF-4708671 Impedes Non-Small Cell Lung Cancer Growth

Background

As a serine/threonine protein kinase, p70S6K plays an important role in tumor cells. Evidence has revealed overexpression of p70S6K and phosphorylated p70S6K (p-p70S6K) in various tumor tissues, with these proteins identified as independent prognostic markers in non-small cell lung cancer (NSCLC). In this study, we explored the role of the p70S6K specific inhibitor PF-4708671 in NSCLC.

Methods

Three NSCLC cell lines (A549, SK-MES-1, and NCI-H460) were treated with PF-4708671 at five different concentrations, including 0.1μM, 0.3μM, 1μM, 3μM and 10μM, and protein levels were determined by Western-blot. Then, PF-4708671’s effects were assessed both in vitro (cell proliferation, apoptosis, cell cycle distribution, and invasion) and in vivo.

Results

The expression levels of p-p70S6K and the downstream effector S6 were significantly reduced by PF-4708671. Diametrically opposite, the downstream protein levels of BAD, Caspase3 and ERK had increased after treatment with PF-4708671. In addition, PF-4708671 drastically inhibited cell proliferation and invasion ability in A549, SK-MES-1 and NCI-H460 cells in vitro, causing cell cycle arrest in G0-G1 phase. Limited effects of PF-4708671 were observed on apoptosis in the three NSCLC cell lines assessed. Importantly, PF-4708671 could inhibit tumorigenesis in nude mice in vivo.

Conclusion

These findings demonstrated that the p70S6K specific inhibitor PF-4708671 has inhibitory effects on NSCLC tumorigenesis in vitro and in vivo. Therefore, P70S6K should be considered a new potential therapeutic target, and PF-470867 may be used as targeted drug for cancer treatment.     

LukS-PV induces cell cycle arrest and apoptosis through p38/ERK MAPK signaling pathway in NSCLC cells

Non-small-cell lung cancer (NSCLC) accounts for nearly 85% of lung cancer cases. LukS-PV, one of the two components of Panton-Valentine leucocidin (PVL), is produced by Staphylococcus aureus. The present study showed that LukS-PV can induce apoptosis in human acute myeloid leukemia (AML) lines (THP-1 and HL-60). However, the role of LukS-PV in NSCLC is unclear. In this study, we treated NSCLC cell lines A549 and H460 and a normal lung cell line, 16HBE, with LukS-PV and investigated the biological roles of LukS-PV in NSCLC. Cells were treated with varying concentrations of LukS-PV and cell viability was evaluated by CCK8 and EdU assay. Flow cytometry was used to detect cell apoptosis and analyze the cell cycle, and the expression of apoptosis and cell cycle-associated proteins and genes were identified by western blotting analysis and qRT-polymerase chain reaction, respectively. We found that LukS-PV inhibited the proliferation of NSCLC cells but had little cytotoxicity in normal lung cells. LukS-PV induced NSCLC cell apoptosis and increased the BAX/BCL-2 ratio, triggering S-phase arrest in A549 and H460 cells while increasing P21 expression and decreasing CDK2, cyclin D1, and cyclin A2 expression. We also observed increased P-p38 and P-ERK in NSCLC cells treated with LukS-PV. Treatment of NSCLC with LukS-PV combined with p38 and ERK inhibitors reversed the pro-apoptotic and pro-cell cycle arrest effects of LukS-PV. Overall, these findings indicate that LukS-PV has anti-tumor effects in NSCLC and may contribute to the development of anti-cancer agents.     

Breviscapine suppresses the growth of non-small cell lung cancer by enhancing microRNA-7 expression

Breviscapine (BVP) has previously been shown to inhibit the proliferation of hepatocellular carcinoma cells. However, little is known about the effects of BVP on non-small cell lung cancer (NSCLC) growth. Here, we aimed to study the effects of BVP on human NSCLC growth. We employed A549, NCL-H460 and A549 cells transfected with microRNA-7 (miR-7) mimic and inhibitor to investigate the effect of BVP on cell proliferation, apoptosis and apoptosis-associated molecules. The results showed that BVP significantly reduced the growth of A549 and NCL-H460 cells in a concentration-dependent and time-dependent manner, accompanied by a significant elevation of apoptosis. Additionally, the present study also confirmed that BVP-treated A549 cells showed increased levels of Bax and microRNA-7 (miR-7) and a decreased level of Bcl-2. The up-regulation of miR-7 enhanced the BVP sensitivity of NSCLC cells by suppressing cell proliferation and promoting cell apoptosis, while the inhibition of miR-7 reversed the anti-proliferative pro-apoptotic effects of BVP. Pre-treatment with miR-7 mimics enhanced the BVP-mediated down-regulation of Bax/Bcl-2 in NSCLC cells, while pre-treatment with the miR-7 inhibitor blocked the BVP-mediated down-regulation of Bax/Bcl. Taken together, these results confirm that BVP effectively inhibits NSCLC proliferation and that miR-7, as a novel target, is likely involved in BVP-induced growth suppression and the apoptosis of NSCLC cells.     

Baicalein inhibits cell growth and increases cisplatin sensitivity of A549 and H460 cells via miR‐424‐3p and targeting PTEN/PI3K/Akt pathway

Lung cancer is the leading cause of death in individuals with malignant disease. Non‐small‐cell lung cancer (NSCLC) is the most common type of lung cancer, and chemotherapy drugs such as cisplatin are the most widely used treatment for this disease. Baicalein is a purified flavonoid compound that has been reported to inhibit cancer cell growth and metastasis and increase sensitization to chemotherapeutic drugs via different pathways. Therefore, we assessed the effects of baicalein on the proliferation, apoptosis and cisplatin sensitivity in the NSCLC A549 and H460 cell lines and determined the pathways through which baicalein exerts its effects. Baicalein was slightly toxic to normal human bronchial NHBE cells but inhibited growth, induced apoptosis and increased cisplatin sensitivity in A549 and H460 cells. Baicalein down‐regulated miR‐424‐3p, up‐regulated PTEN expression and down‐regulated expression of PI3K and p‐Akt in A549 and H460 cells. Dual‐luciferase reporter assay demonstrated that PTEN is a target gene of miR‐424‐3p, and overexpression of miR‐424‐3p or silencing of PTEN partially attenuated the effects of baicalein on A549 and H460 cells. Taken together, we concluded that baicalein inhibits cell growth and increases cisplatin sensitivity to A549 and H460 cells via down‐regulation of miR‐424‐3p and targeting the PTEN/PI3K/Akt pathway.     

miR-497-5p inhibits tumor cell growth and invasion by targeting SOX5 in non–small-cell lung cancer

MicroRNAs plays an important role in the ccurrence and development of non–small-cell lung cancer (NSCLC). miR-497-5p has been reported to function as a tumor suppressor in various cancers. However, the role of miR-497-5p in NSCLC remains poorly understood. In this study, we aimed to investigate the biological role and potential molecular mechanism of miR-497-5p in NSCLC. Our results showed that the messenger RNA (mRNA) expression level of miR-497-5p was notably downregulated in human NSCLC tissues and cell lines. miR-497-5p overexpression remarkably inhibited NSCLC cell proliferation and increased cell apoptosis in A549 and H460 cells, whereas inhibition of miR-497-5p had an opposite effect. The ability of cell migration and invasion was inhibited by miR-497-5p overexpression but was increased by miR-497-5p inhibition. Moreover, our findings indicated that SOX5 was a direct target of miR-497-5p. The protein and mRNA expression levels of SOX5 in A549 cells were remarkably inhibited by miR-497-5p overexpression but was upregulated by miR-497-5p inhibition. Furthermore, SOX5 overexpression notably reversed the effect of miR-497-5p mimic on NSCLC cell proliferation, cell apoptosis, cell migration, and invasion. Taken together, these results indicated that miR-497-5p overexpression inhibited NSCLC cell proliferation, migration and invasion, and induced cell apoptosis through inhibiting SOX5 gene expression. It was conceivable that miR-497-5p might serve as a potential molecular target for NSCLC treatment.     

Knockdown of LncRNAZFAS1 suppresses cell proliferation and metastasis in non-small cell lung cancer

ABSTRACT

To evaluate the effects of LncRNAZFAS1 on cell proliferation and tumor metastasis in non-small cell lung cancer (NSCLC), we detected the expression level of LncRNAZFAS1 in NSCLC-related tissues and cells. qRT-PCR results revealed that LncRNAZFAS1 in tumor tissues was significantly higher than that in normal lung tissue, especially significantly up-regulated in stage III / IV and in metastatic NSCLC tissues. LncRNAZFAS1 expression was dramatically up-regulated in 4 NSCLC-related cells (A549, SPC-A1, SK-MES-1, and NCI-H1299), with having the highest expression level in A549 cells. Furthermore, we implemented a knockdown of LncRNAZFAS1 in A549 cells, and the results of CCK8 and Transwell assays suggested that knockdown of LncRNAZFAS1 significantly inhibited NSCLC cell proliferation and metastasis. Next, we constructed a tumor xenograft model to evaluate the effect of LncRNAZFAS1 on the NSCLC cell proliferation in vivo. The results indicated that knockdown of LncRNAZFAS1 dramatically inhibited A549 cells proliferation and repressed tumor growth. Additionally, knockdown of LncRNAZFAS1 drastically weakened the expressions of MMP2, MMP9 and Bcl-2 proteins, whereas noticeably strengthened the expression of BAX protein. Our results altogether suggest that knockdown of LncRNAZFAS1 has a negative effect on the proliferation and metastasis of NSCLC cell, which implying LncRNAZFAS1 is a potential unfavorable biomarker in patients with NSCLC.     

Aspirin boosts the synergistic effect of EGFR/p53 inhibitors on lung cancer cells by regulating AKT/mTOR and p53 pathways

The regimen of afatinib and vinorelbine has been used to treat breast or lung cancer cells with some limitations. Aspirin alone or in combination with other agents has shown unique efficacy in the treatment of cancer. We designed a preclinical study to investigate whether the triple therapy of aspirin, afatinib, and vinorelbine could synergistically inhibit the growth of p53 wild-type nonsmall cell lung cancer (NSCLC) cells. Three NSCLC cells A549, H460, and H1975 were selected to study the effect of triple therapy on cell proliferation and apoptosis. Compared to single agents, triple therapy synergistically inhibited the proliferation of lung cancer cells with combination index <1. Meanwhile, the therapeutic index of triple therapy was superior to that of single agents, indicating a balance between efficacy and safety in the combination of three agents. Mechanistic studies showed that triple therapy significantly induced apoptosis by decreasing mitochondrial membrane potential, increasing reactive oxygen species, and regulating mitochondria-related proteins. Moreover, epidermal growth factor receptor (EGFR) downstream signaling proteins including JNK, AKT, and mTOR were dramatically suppressed and p53 was substantially increased after NSCLC cells were exposed to the triple therapy. We provided evidence that the triple therapy of aspirin, afatinib and vinorelbine synergistically inhibited lung cancer cell growth through inactivation of the EGFR/AKT/mTOR pathway and accumulation of p53, providing a new treatment strategy for patients with p53 wild-type NSCLC.     

Id 基因在多种肺癌细胞中的表达及意义

目的：研究Id基因在肺癌和永生化支气管上皮细胞中的表达,探讨其在肺癌细胞中表达的意义。方法：利用半定量RT—PCR和Western blot方法检测多种肺癌和永生化支气管上皮细胞中Id1—Id4 mRNA和Id1—Id4蛋白的表达。结果：A549、NCI—H460、NCI—H446、SK—MES—1、Anip973中Id1-Id3 mRNA均高表达,Id1相对表达较强;而AGZY和MP-184中未表达Id1-Id3 mRNA;腺癌细胞均表达了Id4 mRNA,而NCI-H446、SK—MES—1未表达Id4mRNA。A549,NCA—H460,NCA—H446,SK—MES—1,Anip973中Id1,Id2,Id3蛋白均高表达,A549,NCA—H446,Anip973中Id2的表达高于NCA—H460,SK—MES—1;A549,NCA—H460,Anip973有出的高表达,NCI—H446,SK—MES—1无Id4的表达,Id1-Id4在AGZY和MP-184中均耒表达。结论：4种Id基因均作为癌基因在肺癌的发生发展中发挥作用,Id1,Id2,Id3与肺癌细胞的恶性程度以及增殖和转移密切相关,Id4可做为肺腺癌的检测标志物。     

MicroRNA-192 targeting retinoblastoma 1 inhibits cell proliferation and induces cell apoptosis in lung cancer cells

microRNAs play an important roles in cell growth, differentiation, proliferation and apoptosis. They can function either as tumor suppressors or oncogenes. We found that the overexpression of miR-192 inhibited cell proliferation in A549, H460 and 95D cells, and inhibited tumorigenesis in a nude mouse model. Both caspase-7 and the PARP protein were activated by the overexpression of miR-192, thus suggesting that miR-192 induces cell apoptosis through the caspase pathway. Further studies showed that retinoblastoma 1 (RB1) is a direct target of miR-192. Over-expression of miR-192 decreased RB1 mRNA and protein levels and repressed RB1-3'-UTR reporter activity. Knockdown of RB1 using siRNA resulted in a similar cell morphology as that observed for overexpression of miR-192. Additionally, RB1-siRNA treatment inhibited cell proliferation and induced cell apoptosis in lung cancer cells. Analysis of miRNA expression in clinical samples showed that miR-192 is significantly downregulated in lung cancer tissues compared to adjacent non-cancerous lung tissues. In conclusion, our results demonstrate that miR-192 is a tumor suppressor that can target the RB1 gene to inhibit cell proliferation and induce cell apoptosis in lung cancer cells. Furthermore, miR-192 was expressed at low levels in lung cancer samples, indicating that it might be a promising therapeutic target for lung cancer treatment.     

Cyr61, a member of CCN family, is a tumor suppressor in non-small cell lung cancer

Cysteine-rich protein 61 (Cyr61) is a member of a family of growth factor-inducible immediate-early genes. It regulates cell adhesion, migration, proliferation, and differentiation and is involved in tumor growth. In our experiments, the role of Cyr61 in non-small cell lung cancer (NSCLC) was examined. Expression of Cyr61 mRNA was decreased markedly in four of five human lung tumor samples compared with their normal matched lung samples. NSCLC cell lines NCI-H520 and H460, which have no endogenous Cyr61, formed 60-90% fewer colonies after being transfected with a Cyr61 cDNA expression vector than cells transfected with the same amount of empty vector. After stable transfection of a Cyr61 cDNA expression vector, proliferation of both H520-Cyr61 and H460-Cyr61 sublines decreased remarkably compared with the cells stably transfected with empty vector. The addition of antibody against Cyr61 partially rescued the growth suppression of both H520-Cyr61 and H460-Cyr61 cells. Cell cycle analysis revealed that both H520-Cyr61 and H460-Cyr61 cells developed G(1) arrest, prominently up-regulated expression of p53 and p21(WAF1), and had decreased activity of cyclin-dependent kinase 2. The increase of pocket protein pRB2/p130 was also detected in these cells. Notably, both of the Cyr61-stably transfected lung cancer cell lines developed smaller tumors than those formed by the wild-type cells in nude mice. Taken together, we conclude that Cyr61 may play a role as a tumor suppressor in NSCLC.     

Grape proanthocyanidins induce apoptosis by loss of mitochondrial membrane potential of human non-small cell lung cancer cells in vitro and in vivo

Lung cancer remains the leading cause of cancer-related deaths worldwide, and non-small cell lung cancer (NSCLC) represents approximately 80% of total lung cancer cases. The use of non-toxic dietary phytochemicals can be considered as a chemotherapeutic strategy for the management of the NSCLC. Here, we report that grape seed proanthocyanidins (GSPs) induce apoptosis of NSCLC cells, A549 and H1299, in vitro which is mediated through increased expression of pro-apoptotic protein Bax, decreased expression of anti-apoptotic proteins Bcl2 and Bcl-xl, disruption of mitochondrial membrane potential, and activation of caspases 9, 3 and poly (ADP-ribose) polymerase (PARP). Pre-treatment of A549 and H1299 cells with the caspase-3 inhibitor (z-DEVD-fmk) significantly blocked the GSPs-induced apoptosis of these cells confirmed that GSPs-induced apoptosis is mediated through activation of caspases-3. Treatments of A549 and H1299 cells with GSPs resulted in an increase in G1 arrest. G0/G1 phase of the cell cycle is known to be controlled by cyclin dependent kinases (Cdk), cyclin-dependent kinase inhibitors (Cdki) and cyclins. Our western blot analyses showed that GSPs-induced G1 cell cycle arrest was mediated through the increased expression of Cdki proteins (Cip1/p21 and Kip1/p27), and a simultaneous decrease in the levels of Cdk2, Cdk4, Cdk6 and cyclins. Further, administration of 50, 100 or 200 mg GSPs/kg body weight of mice by oral gavage (5 d/week) markedly inhibited the growth of s.c. A549 and H1299 lung tumor xenografts in athymic nude mice, which was associated with the induction of apoptotic cell death, increased expression of Bax, reduced expression of anti-apoptotic proteins and activation of caspase-3 in tumor xenograft cells. Based on the data obtained in animal study, human equivalent dose of GSPs was calculated, which seems affordable and attainable. Together, these results suggest that GSPs may represent a potential therapeutic agent for the non-small cell lung cancer.     

MicroRNA‐198 inhibition of HGF/c‐MET signaling pathway overcomes resistance to radiotherapy and induces apoptosis in human non–small‐cell lung cancer

Non–small‐cell lung cancer (NSCLC) is the most common cause of death from cancer worldwide. MicroRNAs (miRNAs) are a group of important regulators in NSCLC, including miR‐198. However, the underlying molecular mechanisms of miR‐198 involvement in intrinsic resistance to radiotherapy in NSCLC remain to be elucidated. In this study, to investigate the clinical significance of miR‐198 in NSCLC in relation to the response to radiotherapy, we determined the expression patterns of miR‐198 between responders and nonresponders after 2 months of radiotherapy and found that decreased expressions of miR‐198 were associated with radiotherapy resistance. In addition, we altered the endogenous miR‐198 using mimics or inhibitors to examine the effects of miR‐198 on 4‐Gy–irradiated A549 and SPCA‐1 cells in vitro. Upregulating miR‐198 was shown to inhibit cell proliferation, migration, and invasion and induce apoptosis. MiR‐198 inhibition produced a reciprocal result. PHA665752, a selective small‐molecule c‐Met inhibitor, potently inhibited hepatocyte growth factor (HGF)‐stimulated and constitutive c‐Met phosphorylation and rescued 4‐Gy–irradiated A549 and SPCA‐1 cells from miR‐198 inhibition. Most importantly, we established tumor xenografts of 4‐Gy–irradiated A549 and SPCA‐1 cells in nude mice and found that miR‐198 could suppress tumor formation. Hence, our data delineates the molecular pathway by which miR‐198 inhibits NSCLC cellular proliferation and induces apoptosis following radiotherapy, providing a novel target aimed at improving the radiotherapeutic response in NSCLC.     

Long non‐coding RNA H19 is responsible for the progression of lung adenocarcinoma by mediating methylation‐dependent repression of CDH1 promoter

Lung adenocarcinoma is a common histologic type of lung cancer with a high death rate globally. Increasing evidence shows that long non‐coding RNA H19 (lncRNA H19) and CDH1 methylation are involved in multiple tumours. Here, we tried to investigate whether lncRNA H19 or CDH1 methylation could affect the development of lung adenocarcinoma. First, lung adenocarcinoma tissues were collected to detect CDH1 methylation. Then, the regulatory mechanisms of lncRNA H19 were detected mainly in concert with the treatment of overexpression of lncRNA H19, siRNA against lncRNA H19, overexpression of CDH1 and demethylating agent A‐5az in lung adenocarcinoma A549 cell. The expression of lncRNA H19 and epithelial‐mesenchymal transition (EMT)‐related factors as well as cell proliferation, sphere‐forming ability, apoptosis, migration and invasion were detected. Finally, we observed xenograft tumour in nude mice so as to ascertain tumorigenicity of lung adenocarcinoma cells. LncRNA H19 and methylation of CDH1 were highly expressed in lung adenocarcinoma tissues. A549 cells with silencing of lncRNA H19, overexpression of CDH1 or reduced CDH1 methylation by demethylating agent 5‐Az had suppressed cell proliferation, sphere‐forming ability, apoptosis, migration and invasion, in addition to inhibited EMT process. Silencing lncRNA H19 could reduce methylation level of CDH1. In vivo, A549 cells with silencing lncRNA H19, overexpression of CDH1 or reduced CDH1 methylation exhibited low tumorigenicity, reflected by the smaller tumour size and lighter tumour weight. Taken together, this study demonstrates that silencing of lncRNA H19 inhibits EMT and proliferation while promoting apoptosis of lung adenocarcinoma cells by inhibiting methylation of CDH1 promoter.     

RNA interferences targeting the Fanconi anemia/BRCA pathway upstream genes reverse cisplatin resistance in drug-resistant lung cancer cells

Background

Cisplatin is one of the most commonly used chemotherapy agent for lung cancer. The therapeutic efficacy of cisplatin is limited by the development of resistance.In this study, we test the effect of RNA interference (RNAi) targeting Fanconi anemia (FA)/BRCA pathway upstream genes on the sensitivity of cisplatin-sensitive (A549 and SK-MES-1) and -resistant (A549/DDP) lung cancer cells to cisplatin.

Result

Using small interfering RNA (siRNA), knockdown of FANCF, FANCL, or FANCD2 inhibited function of the FA/BRCA pathway in A549, A549/DDP and SK-MES-1 cells, and potentiated sensitivity of the three cells to cisplatin. The extent of proliferation inhibition induced by cisplatin after knockdown of FANCF and/or FANCL in A549/DDP cells was significantly greater than in A549 and SK-MES-1 cells, suggesting that depletion of FANCF and/or FANCL can reverse resistance of cisplatin-resistant lung cancer cells to cisplatin. Furthermore, knockdown of FANCL resulted in higher cisplatin sensitivity and dramatically elevated apoptosis rates compared with knockdown of FANCF in A549/DDP cells, indicating that FANCL play an important role in the repair of cisplatin-induced DNA damage.

Conclusion

Knockdown of FANCF, FANCL, or FANCD2 by RNAi could synergize the effect of cisplatin on suppressing cell proliferation in cisplatin-resistant lung cancer cells through inhibition of FA/BRCA pathway.     

Cyclin D1 regulates lung cancer invasion and metastasis

Cyclin D1, as a regulatory factor in cell cycle, is highly expressed in many tumors, such as lung cancer, breast cancer and thyroid cancer. The aim of the present study was to study the role of Cyclin D1 in invasion and metastasis of lung cancer cells. Lung adenocarcinoma cell line A549 and squamous cell line SK-MES-1 were selected as the objects, because A549 expresses Cyclin D1 highly, and SK-MES-1 expresses lowly. Nude mice were injected with A549 or SK-MES-1 via tail vein, and were sacrificed after 4 weeks for cancer tissue isolation. The harvested cancer cells were reinjected into another nude mouse. After one more time of such seeding, highly metastatic lung cancer model was established. After A549 and SK-MES-1 were transfected with Cyclin D1 RNAi and expression vector respectively, transwell migration assay was used to analyze transferring capacity of lung cancer cells. Western blot was used to detect Cyclin D1 and WNT/TCF pathway proteins expressions in parental cell lines and cancer tissue from metastasis model animals. The results showed that, along with the increase of seeding times, lung cancer cells from model animals, no matter A549 or SK-MES-1, exhibited augmented metastasis activity and up-regulated Cyclin D1 expression. The transferring capacity was weakened significantly in A549 cells where the Cyclin D1 was interfered by RNAi, and it was enhanced significantly in SK-MES-1 cells which were transfected with the expression vector of Cyclin D1. The expressions of WNT/TCF pathway proteins, including β-catenin, lymphoid enhancer-binding factor (LEF) and T cell factor (TCF), increased significantly in highly metastatic model animals. The parental cell lines showed lower expressions of WNT/TCF pathway proteins compared with cancer tissue from metastasis model animals. These results suggest that Cyclin D1 is closely related with the invasion and metastasis of lung cancer cells, and the WNT/TCF signal pathway may promote the expression of Cyclin D1.     

Low-grade neuroinflammation due to chronic sleep deprivation results in anxiety and learning and memory impairments

Non-small-cell lung cancer (NSCLC) is still the main threat of cancer-associated death. Current treatment of NSCLC has limited effectiveness, and unfortunately, the prognosis of NSCLC remains poor. Therefore, a novel strategy for cancer therapy is urgently needed. Stem cell therapy has significant potential for cancer treatment. Mesenchymal stem cells (MSCs) with capacity for self-renewal and differentiation into various cells types exhibit the feature of homing to tumor site and immunosuppression, have been explored as a new treatment for various cancers. Studies revealed that the broad repertoire of trophic factors secreted by MSCs extensively involved in the interplay between MSCs and tumor cells. In this study, we confirmed that MSCs do have the paracrine effect on proliferation and migration of NSCLC cells (A549, NCI-H460, and SK-MES-1). Co-culture system and conditioned medium experiments results showed that soluble factors secreted by MSCs inhibited the proliferation of NSCLC cells in vitro. The scratch assay showed that conditioned medium of MSCs could suppress the migration of NSCLC cells in vitro. Western blot results showed that the expression of proteins relevant to cell proliferation, anti-apoptosis, and migration was remarkably decreased via MAPK/eIF4E signaling pathway. We speculated that soluble factors secreted by MSCs might be responsible for inhibitory mechanism of NSCLC cells. By Human Gene Expression Microarray Assay and recombinant Vascular Endothelial Growth Factor 165 (VEGF165) neutralizing experiment, we verified that VEGF might be responsible for the down-regulation of proteins related to cell proliferation, anti-apoptosis, and migration by suppressing translation initiation factor eIF4E via MAPK signaling pathway. Taken together, our study demonstrated that a possible trophic factor secreted by MSCs could manipulate translation initiation of NSCLC cells via MAPK signaling pathway, and significantly affect the fate of tumor cells, which will be a new strategy for cancer therapy.     

Inhibition of Proliferation of Non-small Cell Lung Cancer Cells by a bFGF Antagonist Peptide

Non-small cell lung cancer (NSCLC) is a leading cause of cancer-related mortality worldwide. Basic fibroblast growth factor (bFGF) is up-regulated in NSCLC patients and plays an important role in tumor growth. In this paper, we attempt to evaluate the therapeutic potential of bFGF binding peptide (named as P7) using as a potent bFGF antagonist via exploration of its anti-proliferation effect on NSCLC cells. Our experiments showed that P7 peptide inhibited bFGF-stimulated proliferation of NSCLC cell lines including A549, H1299, and H460. The inhibitory mechanism of P7 involved cell cycle arrest at the G0/G1phase caused by suppression of cyclin D1, blockage of the activation of Erk1/2, P38, Akt, and inhibition of bFGF internalization. Strategies using bFGF antagonist peptides with potent anti-proliferation property may have therapeutic potential in NSCLC.     

香菇C91-3菌丝发酵蛋白对H22肿瘤细胞体内外抗肿瘤机制的初探

目的探讨香菇C91-3菌丝发酵蛋白(LFP91-3)对H22肿瘤细胞抑瘤作用及相关机制。方法应用不同剂量LFP91-3(50、100和150μg)对H22荷瘤小鼠腹水瘤模型和腋下实体瘤进行治疗,观察其生存期和体内抑瘤作用;并用MTT法(LFP91-3浓度5、10、15μg/mL)和流式细胞仪对经LFP作用的H22肿瘤细胞进行观察和检测。结果香菇C91-3菌丝发酵提取蛋白(LFP91-3)能延长H22荷瘤小鼠的生存期,对体外培养的H22有直接杀伤作用,抑瘤率出现对浓度和时间的依赖性。LFP91-3能将H22肿瘤细胞株细胞周期阻滞到S期并诱导出细胞凋亡。结论 LFP91-3在体内、外对H22肿瘤细胞有较好的抑瘤作用,主要是诱导其调亡。