Proliferation Of A549 Lung Cancer Cells Research Articles

Green synthesis of gold nanoparticles via Moringa oleifera seed extract: antioxidant, antibacterial and anticarcinogenic activity on lung cancer

Plant-mediated biosynthesis of nanoparticles is a green method that allows synthesis in one-pot process. Synthesis of gold nanoparticles with plant extracts has gained interest in the field of biomedicine due to its variety of applications. This study presents the synthesis via green chemistry of gold nanoparticles (AuNPs) using the methanol extract of Moringa oleifera seeds. The AuNPs were synthesized at room temperature. UV–Vis spectroscopy confirmed the formation of AuNPs by identifying the surface plasmon resonance located at 546 nm. TEM analysis shows spherical nanoparticles. FTIR analysis demonstrated the presence of specific bioactive molecules responsible for the Au3+ ion reduction process. The antioxidant activity of the nanoparticles was evaluated on the stabilization of the DPPH radical (1,1-diphenyl-2-picrylhydrazyl, 2,2-diphenyl-1-(2,4,6-trinitrophenyl) hydrazyl). The antimicrobial activity analysis was developed by broth microdilution method at different concentrations against Escherichia coli and Staphylococcus aureus. Minimum inhibitory concentration were 400 µg/mL and 200 µg/mL, respectively. A549 lung cancer cell proliferation was measured according to the MTT protocol, indicating a dose-dependent response and a IC50 of 163.9 ± 13.27 µg/mL. The AuNPs synthesized using M. oleifera seeds showed promise as active materials for antimicrobial or anticancer products.

Melatonin protects mice from 5-FU hepatotoxicity and improves 5-FU antitumor effects by an apoptotic pathway dependent on cell cycle arrest in A549 human lung cancer cells

Abstract Objectives This study determined if melatonin (MLT) can be used with 5-fluorouracil (5-FU), an anticancer drug as adjuvants to reduce A549 lung cancer cell proliferation and sensitise those cells to 5-FU at lower doses while protecting mice from hepatotoxicity. Methods In vitro, MTT assays assessed cell proliferation, and Annexin-V flow cytometry measured A549 cell apoptosis. RT-qPCR measured apoptotic markers tumour suppressor gene P53, KI-67, Bax, Bcl-2, and caspase3; and immunoblotting evaluated cell cycle parameters P21, CDK2, and cyclin E. ELISA biochemical analysis examined liver function, reactive oxygen species (ROS) and antioxidant assays, and inflammatory markers, in vivo. Masson’s trichome, haematoxylin, and eosin stains examined histopathological changes and fibrosis under a microscope. Key findings MLT combined with 5-FU elevated chemo-sensitization by decreasing A549 cell proliferation, lowering the IC50, increasing P21, P53, and Bax, decreasing Bcl-2, Ki-67, CDK2, and cyclin E, and inducing apoptosis and cell cycle arrest at G0/G1. After 5-FU [intraperitoneal (IP)]/MLT (oral) co-administration in vivo, all parameters improved and reversed. Liver enzymes (aspartate aminotransferase and alanine transaminase), bilirubin, albumin, total protein, albumin/globulin ratio, ROS, 4-HNE, H2O2, and pro-inflammatory cytokines; IL-6, IL-1β, and TNFα declined while antioxidant enzymes like SOD, CAT, GSH, and GPx, and IL-10 (anti-inflammatory) increased in combined MLT/5-FU treated groups compared with untreated and 5-FU alone treated groups. Histopathology confirmed these results. Conclusions MLT protected A549 cells from 5-FU-induced hepatotoxicity and enhanced 5-FU’s antitumor effect in vitro. These results support MLT/5-FU’s benefits, suggesting a more effective lung cancer treatment with fewer hepatotoxicity side effects. That could provide a novel therapeutic strategy for lung cancer.

AIF-1, a potential biomarker of aggressive tumor behavior in patients with non-small cell lung cancer.

Allogeneic inflammatory factor-1 (AIF-1) overexpression has been reported to be associated with tumorigenesis and tumor metastasis. This study aimed to investigate the role of AIF-1 in the development and progression of non-small cell lung cancer (NSCLC). AIF-1, IL-6, and VEGF expressions in human NSCLC tissue were examined by immunofluorescence staining. Bioinformatics analyses were performed to identify AIF-1-related molecules and pathways in NSCLC. Human lung cancer A549 cell proliferation was assessed by CCK-8 assay, and cell migration was evaluated with wound-healing assay. IL-6 and VEGF secretions in A549 cell culture supernatants were quantified using the Elecsys IL-6 immunoassay kit and Vascular Endothelial Growth Factor Assay Kit. RT-PCR and western blot were performed to quantify the expressions of AIF-1, IL-6, and VEGF mRNAs and proteins involved in p38-MAPK and JAK/STAT3 signaling such as p-p38 and p-STAT3. The effects of AIF-1 on A549 cell proliferation and the expressions of IL-6 and VEGF were assessed using SB203580 and ruxolitinib. The results showed that AIF-1 expression was higher in human NSCLC tissue than that in paracancer tissue. High AIF-1 expression was associated with metastasis, higher TNM stage, and poorer survival. Bioinformatics connected AIF-1 to JAK/STAT signaling in NSCLC. AIF-1 increased A549 cell proliferation, migration, IL-6 secretion and, VEGF secretion, and these effects were attenuated by inhibition of p38-MAPK or JAK/STAT3 signaling. In conclusion, AIF-1 may promote aggressive NSCLC behavior via activation of p38-MAPK and JAK/STAT signaling.

Chemical and Biological Evidence of the Efficacy of Shengxian Decoction for Treating Human Lung Adenocarcinoma

Shengxian Decoction (SXT) is a traditional Chinese medicine prescription comprising several anti-cancer medicinal herbs. However, the anti-cancer effect of SXT has rarely been reported. Herein, we explored the therapeutic potential of SXT for the treatment of lung adenocarcinoma (LUAD). High-performance liquid chromatography analysis of crude SXT extract revealed the abundance of mangiferin, an established anti-cancer compound. The serum pharmacological evaluation revealed that serum SXT suppressed A549 lung cancer cell proliferation in vitro. The tumor-inhibitory activity of SXT was confirmed in vivo via tumor formation assays in nude mice. We applied biochemical, histopathological and imaging approaches to investigate the cellular targets of SXT. The results indicated that the treatment with SXT induced tumor necrosis, and downregulated hypoxia-inducible factor 1 alpha in the serum. In vivo biosafety assessment of SXT revealed low levels of toxicity in mouse models. Our study provides the first scientific evidence that SXT effectively represses cancer cell growth and, thus, may serve as a safe anti-cancer agent for LUAD treatment.

Mechanism regulating the inhibition of lung cancer A549 cell proliferation and structural analysis of the polysaccharide Lycium barbarum

The water-soluble polysaccharide LBP-1 was isolated and characterized from Lycium barbarum L. LBP-1 was mainly composed of arabinose, galactose, glucose, xylose, mannose at a molar ratio of 37.53: 28.08: 14.72: 7.83: 4.50, respectively. Based on nuclear magnetic resonance (NMR) and methylation analysis, the backbone of LBP-1 was speculated in the α-L-Ara(1→[5-α-L-Ara(1 → 3)-β-D-Galp-(1→]n→4)-α-D-Galp-(1[→5-α-L-Ara (1]n [→6)-β-D-Galp-(1 → 4)-β-D-Galp-(1→]n, and the side chains of LBP-1 were in the α-L-Ara(1 → 3)-β-D-Galp-(1 → 6 position. These results showed that LBP-1 inhibited the growth of cancer A549 cells through cell cycle arrest and apoptosis, with an IC50 value of 42.5 μg/mL. In addition, LBP-1 altered the expression of Cyclin D1, Cyclin D3, and CDK 2, thus blocking the cell cycle in G0/G1 phase, reducing cell migration, and regulating the PI3K/Akt/mTOR signaling pathway to induce apoptosis.

Structural analysis of a glucoglucuronan derived from laminarin and the mechanisms of its anti-lung cancer activity

Laminarin (LA), a storage glucan, was purified from the brown alga Sargassum thunbergii. After specific oxidation using the stable nitroxyl radical, 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO), together with NaBr and NaClO, glucoglucuronan (LAO) was obtained. Compositional analysis of LAO showed a molar ratio of glucuronic acid (GlcA) to glucose (Glc) of 12.7: 1. Nuclear magnetic resonance (NMR) and mass spectroscopy (MS) showed LAO to have a backbone of (1 → 3)-linked β-D-GlcpA interspersed with (1 → 3, 1 → 6)-linked β-D-Glcp, that was terminated with β-D-GlcpA. LAO inhibited human lung cancer A549 cell proliferation in vitro. IC50 values at 12 h and 24 h were 2.70 mg/mL and 2.85 mg/mL, respectively. Western blotting showed that TSC2 was up-regulated at an LAO concentration of 3.80 mg/mL. FAK, PI3K, P-AKT and mTOR were down-regulated, indicating LAO inhibited cancer cell proliferation through the FAK/PI3K/AKT/mTOR pathway. Surface plasmon resonance (SPR) studies revealed that LAO showed an IC50 of 0.07 mg/mL inhibiting the binding of heparin to fibroblast growth factor 1 (FGF1) LAO inhibition of heparin binding to FGF2 fluctuated between 15% and 28%, suggesting that LAO inhibits A549 cell proliferation by selectively interacting with FGF1.

Structural characterization and anti-lung cancer activity of a sulfated glucurono-xylo-rhamnan from Enteromorpha prolifera

A sulfated glucurono-xylo-rhamnan (EP-3-H) was purified from a green alga, Enteromorpha prolifera. EP-3-H and its oligomers were characterized by high performance liquid chromatography, mass spectrometry and one and two-dimensional nuclear magnetic resource spectroscopy. The structural analysis showed EP-3-H has a backbone of glucurono-xylo-rhamnan, branches with glucuronic acid and sulfated at C3 of rhamnose and/or C2 of xylose. The inhibition of EP-3-H on human lung cancer A549 cell proliferation in vitro and its therapeutic effects in BALB/c-nu mice in vivo were determined to evaluate the anti-lung cancer activity of EP-3-H. The tumor inhibition level was 59 %, suggesting that EP-3-H might be a good candidate for the treatment of lung cancer. Surface plasmon resonance (SPR) studies revealed the IC50 on the binding of fibroblast growth factors, (FGF1 and FGF2), to heparin were 0.85 and 1.47 mg/mL, respectively. These results suggest that EP-3-H inhibits cancer proliferation by interacting with these growth factors.

MicroRNA-425-5p Inhibits Lung Cancer Cell Growth in Vitro and in Vivo by Downregulating TFIIB-Related Factor 2.

Lung cancer is the most common cancer type with increasingly high incidence. MicroRNAs provide the potential biomarkers for lung cancer treatment. Thus, we aimed to investigate the function of microRNA-425-5p in lung cancer development and the underlying mechanisms. MicroRNA-425-5p overexpression inhibited A549 lung cancer cell proliferation in vitro and in vivo. On the other hand, microRNA-425-5p inhibition increased A549 proliferation. Mechanistically, the underlying mechanism by which microRNA-425-5p inhibits lung cancer cell growth was mediated through its ability in targeting and downregulating the TFIIB-related factor 2. Our results for the first time identified microRNA-425-5p as a tumor suppressor in lung cancer. Thus, microRNA-425-5p may serve as a potential therapeutic target for lung cancer.

Seseli petraeum M. Bieb. (Apiaceae) Significantly Inhibited Cellular Growth of A549 Lung Cancer Cells through G0/G1 Cell Cycle Arrest.

Seseli L. is an important genus of the Apiaceae family, with a large number of aromatic species. It is used in traditional medicine extensively, but there is quite limited information on their phytochemicals and biological activities. Seseli petraeum M. Bieb. grows in Northern Anatolia, and there are no phytochemical studies on this species. In the present study, we aimed to investigate the effect of the extracts of S. petraeum on A549 lung cancer cell proliferation. For this purpose, the antiproliferative effect was determined via MTT assay, and the extracts obtained from the root of S. petraeum showed a significant inhibitory effect on cell proliferation. The hexane extract of the root exhibited potent inhibition on A549 cancer cell growth at the 24th hour with 3.432 mg/mL IC50 value. The results also showed that the hexane extract had displayed cytotoxic effect through an arrest at the G0/G1 phase of the cell cycle and induced apoptosis as well as DNA damage of A549 cells. Consequently, this study demonstrated the antiproliferative potential of the extracts from S. petraeum, especially hexane extract from the roots. Further studies are required to identify the mechanisms underlying these effects.

MiR‑338‑3p inhibits A549 lung cancer cell proliferation and invasion by targeting AKT and β‑catenin signaling pathways.

The aim of the present study was to explore the underlying mechanism of microRNA-338-3p (miR-338-3p) in lung cancer cell (A549) invasion and proliferation. A microarray assay showed that miR-338-3p upregulated 216 and downregulated 147 genes in A549 cells, and the differentially expressed genes were enriched for several signaling pathways, including AKT and β-catenin signaling pathways. Western blotting results showed that phosphorylated (p)-AKT at Ser473 and at Thr308 and p-β-catenin at Ser552 were downregulated. Inhibiting AKT signaling pathway decreased β-catenin signaling pathway. Overexpression of β-catenin promoted the invasion of A549 cells. In addition, miR-338-3p showed inhibitory effect on the primary tumor developed from KrasG12D mice. Together, the data of the present study support that miR-338-3p inhibits lung cancer cell invasion and proliferation by downregulating AKT/β-catenin signaling pathway. The present findings supported the potential use of miR-338-3p in the treatment of lung cancer.

Diprophylline inhibits non-small cell lung cancer A549 cell proliferation and migration, and promotes apoptosis, by downregulating PI3K signaling pathway.

Diprophylline (DPL) is identified as a methylxanthine (MX) derivative. A number of MX derivatives are reported to have anti-tumor effects. However, it is not clear whether DPL has a therapeutic effect on non-small cell lung cancer (NSCLC). The aim of the present study was to investigate the effects of DPL on NSCLC and to elucidate the potential underlying mechanism. A Cell Counting Kit-8 assay was used to evaluate the potential effect of DPL on A549 cell proliferation. Transwell invasion and migration assays were performed to assess the effect of DPL on A549 cell migration and invasion. Furthermore, the percentage of apoptotic cells was detected by flow cytometric analysis, and proteins associated with apoptosis, including apoptosis regulator Bcl-2, apoptosis regulator BAX and active caspase-3, were examined by western blotting. Finally, the expression levels of molecules relevant to phosphoinositide 3-kinase (PI3K) signaling were detected by western blot analysis. The present study demonstrated that DPL may significantly inhibit A549 cell proliferation, migration and invasion. Furthermore, treatment with DPL may significantly induce A549 cell apoptosis. Finally, the protein expression levels associated with the PI3K signaling pathway were significantly inhibited in A549 cells following treatment with DPL. In conclusion, DPL may inhibit the proliferation and migration of NSCLC by inactivating the PI3K signaling pathway, and DPL is a promising novel therapeutic drug for NSCLC.

Effects of cyclin G1 gene silencing on proliferation and apoptosis of lung cancer A549 cells

Objective Knockdown the Cyclin G1 in the A549 cell of lung cancer, to explore its effects on the proliferation and apoptosis of the A549 cell. Methods Cyclin G1 siRNA was transfected into A549 cells by using liposome transfection method, the expression levels of Cyclin G1 mRNA were detected by reverse transcriptase-polymerase chain reaction (RT-PCR), and the expression levels of β-catenin, c-Myc and Cyclin G1 proteins in A549 cells were detected by Western blotting technique. Thiazole blue methyl thiazol tetrazolium (MTT) method was used to detect the proliferation of A549 cells after 48 h transfection, and the flow cytometry detected changes in cell cycle and apoptosis rate. Results The absorbance value (A) and the expression levels of Cyclin G1 mRNA and β-catenin, c-Myc and Cyclin G1 proteins in A549 of the interference group were significantly lower than those of the control group (t=14.250, P=0.000, t=10.739, P=0.000). Compared with the control group, the proportion of cells of interference group after 48 h transfection in G0/G1 phaseand apoptosis ratesignificantly increased, proportion of cells in S phaseand G2/M phase significantly decreased, and the differences were statistically significant (t=5.074, P=0.007; t=4.634, P=0.010; t=3.099, P=0.000). Conclusion Knockdown Cyclin G1 gene can inhibit lung cancer cell proliferation and induce its apoptosis, the mechanism may be related to block the cell cycle in G0/G1 phase and cut β-catenin, c-Myc proteins in Wnt signaling pathways. Key words: Lung cancer; Cyclin G1; Cell proliferation; Cell apoptosis

Abstract 1082: MerTK promotes resistance to irreversible EGFR TKIs by activation of the PI3K-AKT pathway in NSCLCs expressing wild-type EGFR

Abstract Lung cancer is the leading cause of cancer-related death with poor survival rates worldwide. Non-small cell lung cancer (NSCLC) accounts for 85% of all lung cancers and 60% of these have overexpression of wild-type EGFR (wtEGFR), which portends a poor prognosis. In addition, in a recent clinical trial 6 of 12 lung cancer patients whose tumors acquired a resistance-conferring T790M EGFR mutation during treatment with an EGFR TKI reverted to wtEGFR after treatment with Rociletinib/CO-1686, an irreversible EGFR TKI that is selective for the T790M mutant. These data suggest that targeting wtEGFR may improve treatment outcomes; however, to date single agents that target wtEGFR have not been effective in large scale clinical trials and new ways to target wtEGFR in this context are needed. Our laboratory previously identified the MerTK receptor tyrosine kinase as a potential therapeutic target in NSCLC and developed MRX-2843 as a novel MerTK-selective small molecule tyrosine kinase inhibitor with favorable properties for clinical translation. Irrespective of driver oncogene status, treatment with a MerTK inhibitor yields potent anti-tumor effects in NSCLC cell culture models and blocks tumor growth in xenografts of the MerTK-dependent wtEGFR-expressing A549 cell line. In an attempt to more potently block A549 lung cancer cell proliferation, we screened a library of 378 kinase inhibitors that are in various stages of development and identified synergy between MRX-2843 and multiple irreversible EGFR TKIs, including CO-1686 and Osimertinib/AZD-9291. Further, we found that wtEGFR and MerTK were frequently co-expressed and co-immunoprecipitated with each other in NSCLC cancer cell lysates. Synergistic inhibition of cell expansion was observed in a spectrum of NSCLC cell lines with wtEGFR expression treated with the combination therapy, including H1299 (NRAS mutation), H157 (KRAS mutation), H3122 (ALK fusion), and Colo699 (FGFR1 overexpression). On a mechanistic level, combined treatment with 1μM CO-1686 and 100 nM MRX-2843 dramatically inhibited phosphorylation of both MerTK and EGFR and downstream signaling through the PI3K-AKT and MAPK-ERK pathways, while treatment with equivalent doses of either single agent did not efficiently inhibit MerTK, EGFR or downstream signaling. Additionally, CO-1686 mediated synergistic inhibition of A549 expansion in combination with a PI3K or AKT inhibitor, suggesting a role for PI3K-AKT activation downstream of MerTK contributing to the resistance of wtEGFR NSCLCs to irreversible EGFR TKIs. Taken together, our data provide rationale for a novel strategy for treatment of NSCLC with wtEGFR overexpression by combining MRX-2843 and an irreversible EGFR inhibitor. Citation Format: Dan Yan, Xiaodong Wang, Stephen V. Frye, Shelton H. Earp, Deborah DeRyckere, Douglas K. Graham. MerTK promotes resistance to irreversible EGFR TKIs by activation of the PI3K-AKT pathway in NSCLCs expressing wild-type EGFR [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 1082. doi:10.1158/1538-7445.AM2017-1082

Effect of bevacizumab on proliferation and invasion of human lung cancer A549 cells

To study the effect and mechanism of bevacizumab on proliferation and invasion of human lung cancer A549 cells. A549 cells were treated with bevacizumab. Proliferation and invasion of the bevacizumab-treated A549 cells were detected using cell counting kit CCK-8 and Transwell assay, respectively. The expression of the mRNA and protein of MMP-2, MMP-9 and c-Met were detected by real-time PCR and Western blotting, respectively. Proliferation activity was inhibited at the concentration of 10 µg/ml and promoted at the concentration of 100 µg/ml bevacizumab. Bevacizumab in the concentration of 50 µg/ml had a stronger inhibitory effect on the invasion of A549 cells (16 406.19 ± 5 674.23 penetrated cells) than that of control group (36 108.68 6 263.83, P<0.05). The real-time PCR showed that bevacizumab had a stronger inhibitory effect on the expression of MMP-2 and MMP-9 mRNA at the concentration of 50 µg/ml and on the expression c-Met mRNA at the concentration of 10 µg/ml bevacizumabin the A549 cells. However bevacizumab at the concentration of 100 µg/ml showed a promoting effect on the expression of MMP-2, MMP-9 and c-Met mRNA (1.82 ± 0.31, 1.60 ± 0.25, 2.63 ± 0.48), significantly higher than that of the control group (1.00 ± 0.19, 1.00 ± 0.23, 1.00 ± 0.22, P<0.05). The expression of MMP-2, MMP-9 and c-Met mRNA and protein was inhibited by 10 µg/ml bevacizumab in a time-dependent manner. The Western blot assay showed that bevacizumab had a bi-directional effect on the expression of MMP-2 and c-Met proteins in the A549 cells: a promoting effect at 100 µg/ml and inhibitory effect on the expression of MMP-2 at 50 µg/ml bevacizumab, and inhibitory effect on the expression of c-Met protein at 10 µg/ml bevacizumab. Our findings indicate that in a certain range of concentrations, bevacizumab has prominent inhibitory effect on the proliferation and invasion of A549 cells. However,over the concentration of 100 µg/ml, bevacizumab shows a weakening anti-invasion effect, even has a promoting effect on cell proliferation. This phenomenon may be related to the inhibiting effect on the expression of MMP-2 and c-Met proteins in a non-concentration-dependent manner by bevacizumab.

Cyclin-dependent kinase 5 regulates the proliferation, motility and invasiveness of lung cancer cells through its effects on cytoskeletal remodeling

Determining the molecular phenotype is a key to understanding and predicting the metastatic potential and the prognosis for patients with lung cancer. Our previous study demonstrated that increased expression of cyclin‑dependent kinase 5 (CDK5) in patients with non‑small cell lung cancer (NSCLC) is associated with a poorer prognosis. The present study aimed to further investigate the underlying mechanism of CDK5 in vitro and in vivo using the A549 human NSCLC cell line. A 3‑(4,5‑dimethylthiazol‑2‑yl)‑2,5‑diphenyltetrazolium bromide assay was used to quantify the proliferation of the A549 cells; migration assay and invasiveness assays were performed using Transwell chambers and wound healing assays were used to assess cell motility, which was assessed by measuring the movement of cells. Inhibition of CDK5 by roscovitine and small interfering (si)RNA was used to investigate the mechanism of CDK5 in the process of A549 lung cancer cell proliferation, migration and invasion. The results demonstrated that functional inhibition of CDK5 using roscovitine and siRNA markedly suppressed the proliferation of A549 cells and resulted in a reduced tumor mass in vivo. In addition, the hinhibition of CDK5 reduced the migration and invasiveness of the A549 cells in vitro and in vivo. Notably, CDK5 inhibition also impaired tumor cell cytoskeletal remodeling and led to loss of cell polarity, which may partially explain the reduction of A549 cell mobility and invasiveness. The results of the present study revealed that CDK5 may be important in the regulation of migration and invasiveness in NSCLC through its effects on cytoskeletal remodeling.

Influence of propofol on proliferation and apoptosis of human lung cancer A549 cells

Objective To investigate the influence of propofol on lung cancer cell proliferation and apoptosis in vitro. Methods MTT assay was used to detect the inhibition effect of propofol on the growth of A549. Flow cytometry was applied to detect the impact of propofol on apoptosis of A549 cells. Western blotting was used to determine the effect of propofol on aquaporin 1(AQP1) protein expression in A549 cells, and the migration ability of A549 cells was investigated by Transwell chamber. Results MTT assay and flow cytometry showed that the rate of inhibition and apoptosis in the experiment group after propofol acting on A549 were(52.8±5.2)%,(61.2±5.9)%, (69.4±6.1)%;(42.8±4.1)%,(59.8±11.2)%,(71.4±13.4)%, respectively. The expression of AQP1 protein was 0.87±0.12、0.54±0.07、0.31±0.04;and the migration ability of A549 cells was 1.35±8.98、51.78±7.58、40.35±5.12. Conclusion Propofol can significantly inhibit the proliferation, apoptosis and migration ability of human lung cancer A549 cells, which may be associated with the down- regulation of AQP1 protein. Key words: Propofol; Lung cancer; Apoptosis; Aquaporin 1

Effects of 17-AAG on the proliferation and apoptosis of human lung cancer A549 and H446 cells

To observe the effect of 17-(allylamino)-17-demethoxygeldanamycin (17-AAG) on the apoptosis of human lung cancer cell lines A549 and H446, and to investigate the potential mechanisms. Proliferation inhibition and apoptosis assays, and the cell cycles were detected by MTT and flow cytometry respectively. Western blot was used to determine the expression level of proteins such as Hsp90, Hsp70, AKt, Her-2, Bcl-2 and Bax. After treated with 17-AAG, the proliferation of both A549 and H446 cells was inhibited significantly in a dose-dependent manner; as the concentration of 17-AAG was from 50 to 500 nmol/L, the IC₅₀ values to A549 and H446 cell lines were (222 ± 13) nmol/L and (189 ± 7) nmol/L respectively at 48 h. Cell cycle assays showed that 17-AAG was able to arrest cell cycles of A549 and H446 cell lines at the G₂/M phase. Apoptosis assay showed that 17-AAG was capable of inducing apoptosis in A549 and H446 cell lines. After treated with 17-AAG for 48 h, there were significant differences between the 400 nmol/L groups(46.3% for A549 cell line and 56.9% for H446 cell line) and the control group (11.9% for A549 cell line and 6.9% for H446 cell line, P < 0.01). Western blot results showed that the relative proteins of the Hsp90 signal pathway in both A549 and H446 cell lines underwent similar changes after 17-AAG treatment: Akt and Her-2 decreased significantly while the expression of Hsp70 increased. Meanwhile, the expression of Bcl-2 decreased but that of Bax increased, indicating that 17-AAG was able to promote apoptosis mode in A549 and H446 cells. 17-AAG can regulate the expression level of apoptosis-related proteins such as Bax and Bcl-2 by Hsp90 signaling pathway in A549 and H446 cells, and ultimately inhibit cell proliferation and induce apoptosis.

MicroRNA-490-3P targets CDK1 and inhibits ovarian epithelial carcinoma tumorigenesis and progression

The expression of microRNA-490-3P has been reported to regulate hepatocellular carcinoma cell proliferation, migration and invasion, and its overexpression significantly inhibits A549 lung cancer cell proliferation. Here, we demonstrated for the first time that miR-490 mRNA expression was significantly lower in ovarian carcinoma and borderline tumors compared to benign tumors, and lower in metastatic ovarian carcinoma (omentum) than primary ovarian carcinoma, and was negatively associated with differentiation and International Federation of Gynecology and Obstetrics (FIGO) staging. MiR-490-3P overexpression promoted G1/S or G2/M arrest and apoptosis; reduced cell proliferation, migration and invasion; reduced CDK1, Bcl-xL, MMP2/9, CCND1, SMARCD1 mRNA or protein expression; and induced P53 expression. Dual-luciferase reporter assay indicated miR-490-3P directly targeted CDK1. In vivo studies showed that miR-490-3P transfection suppressed tumor development and CDK1, Bcl-xL, MMP2/9 expression while inducing P53 expression. These findings indicate that miR-490-3P may target CDK1 and inhibit ovarian epithelial carcinoma tumorigenesis and progression.

Exogenous p53 upregulated modulator of apoptosis (PUMA) decreases growth of lung cancer A549 cells.

To investigate the influence of exogenous p53 upregulated modulator of apoptosis (PUMA) expression on cell proliferation and apoptosis in human non-small cell lung cancer A549 cells and transplanted tumor cell growth in nude mice. A549 cells were divided into the following groups: control, non- carrier (NC), PUMA (transfected with pCEP4- (HA) 2-PUMA plasmid), DDP (10 μg/mL cisplatin treatment) and PUMA+DDP (transfected with pCEP4-(HA)2-PUMA plasmid and 10 μg/mL cisplatin treatment). The MTT method was used to detect the cell survival rate. Cell apoptosis rates were measured by flow cytometry, and PUMA, Bax and Bcl-2 protein expression levels were measured by Western blotting. Compared to the control group, the PUMA, DDP and PUMA+DDP groups all had significantly decreased A549 cell proliferation (p<0.01), with the largest reduction in the PUMA+DDP group. Conversely, the apoptosis rates of the three groups were significantly increased (P<0.01), and the PUMA and DDP treatments were synergistic. Moreover, Bax protein levels significantly increased (p<0.01), while Bcl-2 protein levels significantly decreased (p<0.01). Finally, both the volume and the weights of transplanted tumors were significantly reduced (p<0.01), and the inhibition ratio of the PUMA+DDP group was significantly higher than in the single DDP or PUMA groups. Exogenous PUMA effectively inhibited lung cancer A549 cell proliferation and transplanted tumor growth by increasing Bax protein levels and reducing Bcl-2 protein levels.

Effect of daphnoretin on the proliferation and apoptosis of A549 lung cancer cells in vitro.

Daphnoretin is an active constituent of Wikstroemia indica C.A. Mey., which is widely distributed in the northwest and southwest regions of China. Previous studies have shown that daphnoretin has anticancer effects on leukemia, osteosarcoma and uterine cervix cancer cells. However, the effect of daphnoretin on human lung cancer cells has yet to be elucidated. In the present study, daphnoretin was observed to inhibit A549 lung cancer cell proliferation in a concentration- and time-dependent manner. Fluorescent microscopy and flow cytometric analysis showed that daphnoretin induced A549 cell apoptosis in a concentration-dependent manner. Western blot analysis also revealed that daphnoretin induced apoptosis through the regulation of the B-cell lymphoma-2 gene family in A549 cells. These findings indicate that daphnoretin may have potential as a therapeutic agent for the management of lung cancer.