Proliferation Of A549 Lung Cancer Cells Research Articles

Role of pseudolaric acid B in A549 lung cancer cell proliferation and apoptosis

Recently, traditional Chinese medicine has gained attention for its potential use as a chemotherapeutic agent. Pseudolaric acid B (PAB) is a diterpene acid isolated from Pseudolarixkaempferi and possesses antifungal, antimicrobial, antifertility and antiangiogenic properties. It was also reported that PAB may inhibit proliferation and induce apoptosis in various types of cancer. However, its effects on A549 lung cancer cells remain to be determined. The present study aimed to determine the potential roles of PAB in the proliferation and apoptosis of A549 cells. The results showed that PAB inhibited A549 cell proliferation in a time‑ and dose‑dependent manner. Fluorescence microscopy results showed that cells treated with 20µmol/l PAB for 24h exhibited karyorrhexis and apoptotic body formation. In addition, A549 cells were treated with 5, 10, 20, 40 or 80µmol/l PAB for 24h and apoptosis was analyzed using Annexin‑V/propidium iodide kit. The apoptosis rates were 8.95, 18.71, 24.66, 35.02 and 43.64%, respectively, in PAB‑treated cells and 0.80% in the control group. Furthermore, western blot analysis showed that PAB treatment upregulated the protein levels of Bax, Bad and downregulated Bcl‑2 and Bcl‑xl expression. In conclusion, PAB may serve as a potent chemotherapeutic agent against human lung cancer.

Curcumin Inhibits Human Non-small Cell Lung Cancer A549 Cell Proliferation Through Regulation of Bcl-2/Bax and Cytochrome C

We intended to study the mechanism of the inhibitory action of curcumin on human non-small cell lung cancer A549 cell. The cell growth was determined by CCK-8 assay, and the results indicated that curcumin inhibited the cell proliferation in a concentration dependent manner. And to further confirm the relative anti-cancer mechanism of curcumin, RT-PCR was carried out to analysis the expression of relative apoptotic proteins Bax, Bcl-2. We found that curcumin could up-regulate the expression of Bax but down-regulate the expression of Bcl-2 in A549 cells. In addition, curcumin affect the mitochondrial apoptosis pathway. These results suggested that curcumin inhibited cancer cell growth through the regulation of Bcl-2/Bax and affect the mitochondrial apoptosis pathway.

Japanese apricot extract attenuates nuclear factor-κB activation and proteasomal activity in A549 lung cancer cells

The present study investigated the mechanism of Japanese apricot extract (JAE) in inhibiting lung cancer cells proliferation. JAE inhibited A549 lung cancer cell proliferation at non-cytotoxic doses and suppressed nuclear factor-κB (NF-κB) activation induced by TNF-α at a dose of 1 mg/mL (p<0.05). Proteasome activities of A549 cells were blocked by JAE in a dose-dependent manner at concentrations of 0.67 and 1 mg/mL (p<0.05). These results indicate that JAE has anti-proliferative activity against A549 cells and suppresses NF-κB activation, partially due to inhibiting proteasome activity.

Tetrazolium Violet Induced Apoptosis and Cell Cycle Arrest in Human Lung Cancer A549 Cells

Tetrazolium violet is a tetrazolium salt and has been proposed as an antitumor agent. In this study, we reported for the first time that tetrazolium violet not only inhibited human lung cancer A549 cell proliferation but also induced apoptosis and blocked cell cycle progression in the G1 phase. The results showed that tetrazolium violet significantly decreased the viability of A549 cells at 5-15 μM. Tetrazolium violet -induced apoptosis in A549 cells was confirmed by H33258 staining assay. In A549, tetrazolium violet blocked the progression of the cell cycle at G1 phase by inducing p53 expression and further up-regulating p21/WAF1 expression. In addition, an enhancement in Fas/APO-1 and its two forms of ligands, membrane-bound Fas ligand (mFasL) and soluble Fas ligand (sFasL), as well as caspase, were responsible for the apoptotic effect induced by tetrazolium violet. The conclusion of this study is that tetrazolium violet induced p53 expression which caused cell cycle arrest and apoptosis. These findings suggest that tetrazolium violet has strong potential for development as an agent for treatment lung cancer.

Eurycomanone suppresses expression of lung cancer cell tumor markers, prohibitin, annexin 1 and endoplasmic reticulum protein 28

Bioactive compounds from the medicinal plant, Eurycoma longifolia Jack have been shown to promote anti-proliferative effects on various cancer cell lines. Here we examined the effects of purified eurycomanone, a quassinoid found in Eurycoma longifolia Jack extract, on the expression of selected genes of the A549 lung cancer cells. Eurycomanone inhibited A549 lung cancer cell proliferation in a dose-dependent manner at concentrations ranging from 5 to 20 μg/ml. The concentration that inhibited 50% of cell growth (GI 50) was 5.1 μg/ml. The anti-proliferative effects were not fully reversible following the removal of eurycomanone, in which 30% of cell inhibition still remained ( p < 0.0001, T-test). At 8 μg/ml (GI 70), eurycomanone suppressed anchorage-independent growth of A549 cells by >25% ( p < 0.05, T-test, n = 8) as determined using soft agar colony formation assay. Cisplatin, a chemotherapy drug used for the treatment of non small cell lung cancer on the other hand, inhibited A549 cells proliferation at concentrations ranging from 0.2 μg/ml to 15 μg/ml with a GI 50 of 0.58 μg/ml. The treatment with eurycomanone reduced the abundance expression of the lung cancer markers, heterogeneous nuclear ribonucleoprotein (hnRNP) A2/B1, p53 tumor suppressor protein and other cancer-associated genes including prohibitin (PHB), annexin 1 (ANX1) and endoplasmic reticulum protein 28 (ERp28) but not the house keeping genes. The mRNA expressions of all genes with the exception of PHB were significantly downregulated, 72 h after treatment ( p < 0.05, T-test, n = 9). These findings suggest that eurycomanone at viable therapeutic concentrations of 5–20 μg/ml exhibited significant anti-proliferative and anti-clonogenic cell growth effects on A549 lung cancer cells. The treatment also resulted in suppression of the lung cancer cell tumor markers and several known cancer cell growth-associated genes.

Effect of selected phytochemicals on cell proliferation in A549 lung cancer cells

Effects of quercetin 3-β-d-glucoside, resveratrol, and curcumin on A549 lung cancer cell proliferation and the mechanism of these phytochemicals in regulating apoptosis and cell cycle arrest were investigated. A549 cells were treated with quercetin 3-β-d-glucoside, resveratrol, or curcumin at 37°C for 96 hr and cell viability was measured with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Proteins related to apoptosis and cell cycle in A549 cells were quantified with Western blotting assay. Quercetin 3-β-d-glucoside, resveratrol, and curcumin inhibited A549 cell proliferation in a dose-dependent manner (p<0.05). Quercetin 3-β-Dglucoside significantly decrease the expression level of CDK4 at concentrations of 5 mM and above (p<0.05). Curcumin lowered expression level of Bcl-2, CDK4, and cyclin D1 at concentrations of 100, 50, and above, and 50 mM and above, respectively (p<0.05). These results suggest that phytochemicals, which can be found in a normal diet, inhibit lung cancer cell proliferation and regulate the expression of the proteins involved in apoptosis and cell cycle.

Effects of Feiyanning Decoction on gene expression of nuclear factor-κB activated by tumor necrosis factor-α in lung adenocarcinoma cell line

To study the effects of Feiyanning Decoction, a compound traditional Chinese herbal medicine, on gene expression of nuclear factor-kappaB (NF-kappaB) activated by tumor necrosis factor-alpha (TNF-alpha) in lung adenocarcinoma cell line (A549). A549 cells were incubated with rat serum containing Feiyanning at different concentrations for 24 and 48 h, respectively. Morphology of cells was observed by an inverted microscope after treatment with reagents. The cell proliferation was examined by 2-(2-methoxy-4-nitrophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium, monosodium salt (WST-8) assay. The expressions of NF-kappaB and inhibitor kappaBalpha (IkappaBalpha) were studied by Western blotting. NF-kappaB-dependent luciferase reporter (3 x kappaB-luc) was transfected for 24 h, and the cells were treated with the reagents for 24 h, and then the transcriptional activity of NF-kappaB promoter was detected by luciferase assay. TNF-alpha (1 microg/L) strongly induced the expression of NF-kappaB by approximately 1.76-fold compared with the control in the nuclei of A549 cells, and the induced NF-kappaB expression was significantly suppressed by addition of Feiyanning (P < 0.01). In addition, Feiyanning inhibited the transcriptional activity of the NF-kappaB promoter. However, we observed no significant changes in IkappaBalpha expression (P > 0.05). Feiyanning Decoction can markedly inhibit human lung cancer A549 cell proliferation, which may be partly due to inhibition of NF-kappaB activation induced by TNF-alpha. It is therefore expected to be a new strategy for treating lung cancer.

Cyclooxygenase inhibitors not inhibit resting lung cancer A549 cell proliferation

Cyclooxygenase (COX) inhibitors were regarded as anticarcinogenic agents for lung cancer at least partly via PGE 2; but these were based on cytokin stimulation experiment on A549 cell. In order to clarify whether COX inhibitors directly inhibit A549 cell, three COX inhibitors, NS398 (selective COX-2 inhibitor), SC560 (selective COX-1 inhibitor), and acetyl salicylic acid (ASA, non-selective COX inhibitor), were studied. NS398, and ASA, can inhibit PGE 2 generation via COX-2 inhibition. The viability of A549 cell was assayed by MTT. However, without cytokin stimulation, all the three inhibitors (NS398 0.2–20 μM; SC560 1.0–100 nM; ASA 0.01–1.0 mM) were not able to inhibit A549 cell proliferation, in the other way round, NS398 promoted cell growth. And arachidonic acid (AA) and lipopolysaccharide (LPS) did not disturb the property of its growth. These data suggested that without cytokin stimulation, COX and PGE 2 may not be the kernel molecules involved in A549 cell proliferation, and COX inhibitors could not inhibit A549 cell growth directly.

Apigenin Inhibits Expression of Vascular Endothelial Growth Factor and Angiogenesis in Human Lung Cancer Cells: Implication of Chemoprevention of Lung Cancer

Apigenin is a natural dietary flavonoid. It has recently been shown to have anticancer effects on prostate and ovarian cancer cells. However, the molecular basis of the effect of apigenin on cancer cells remains to be elucidated. In this study, we found that apigenin inhibited A549 lung cancer cell proliferation and vascular endothelial growth factor (VEGF) transcriptional activation in a dose-dependent manner. In an attempt to understand the mechanism of apigenin-inhibited VEGF expression, we found that apigenin inhibited VEGF transcriptional activation through the hypoxia-inducible factor 1 (HIF-1) binding site and specifically decreased HIF-1alpha but not HIF-1beta subunit expression in the cells. In our efforts to understand the signaling pathway that mediates VEGF transcriptional activation, we found that apigenin inhibited AKT and p70S6K1 activation. When testing the effect of apigenin in vivo, we found that apigenin significantly inhibited tumor growth in nude mice. Apigenin inhibited HIF-1alpha and VEGF expression in the tumor tissues, suggesting an inhibitory effect of apigenin on angiogenesis. To confirm this, we showed that apigenin inhibited angiogenesis in nude mice using the Matrigel assay. HIF-1alpha and VEGF are well known inducers of angiogenesis. Our data suggested that apigenin may inhibit human lung cancer angiogenesis by inhibiting HIF-1alpha and VEGF expression, thus providing a novel explanation for the anticancer action of apigenin.

Effect of selenite combined with chemotherapeutic agents on the proliferation of human carcinoma cell lines.

Selenite is frequently used in combination with cancer chemotherapeutic agents to reduce side effects. However, the cytoprotective activity of selenite may also reduce the efficacy of chemotherapeutic drugs on tumor cells. This study was designed to examine the effects of selenite combined with cytotoxic agents used in clinical protocols [e.g., doxorubicine, docetaxel, 5-fluorouracil (5-FU), methotrexate (MTX), mafosphamide, mitomycin C, gemcitabine, etoposide, cisplatin, irinotecan, and oxaliplatin] on the proliferation of various carcinoma cell types. The data demonstrated that selenite had no marked effects on the antiproliferative activity of docetaxel, doxorubicine, 5-FU, MTX, and mafosphamide in MDA-MB-231 breast cancer cells. Likewise, no consistent changes were observed in A549 lung cancer cell proliferation when selenite was combined with cisplatin, etoposide, gemcitabine, or mitomycin C. On the other hand, selenite potentiated the cytotoxicity of 5-FU, oxaliplatin, and irinotecan in HCT116 colon cancer cells by approx 1.1-fold, 2.7-fold, and 2.6-fold, respectively. In SW620 colon cancer cells, selenite induced a 1.5-fold and 4.3-fold increase of the antiproliferative activity of 5-FU and oxaliplatin, respectively. Whereas irinotecan showed no effects on SW620 cell growth, a combination with selenite resulted in 23% inhibition. Our results indicate that selenite did not reduce the antiproliferative activity of chemotherapeutic agents in vitro. In addition, selenite was able to increase the inhibitory activity of docetaxel in A549 lung cancer cells, and of 5-FU, oxaliplatin, and irinotecan in HCT116 and SW620 colon cancer cells implying selenite is potentially useful as an adjuvant chemotherapeutic agent.