• Asian Pacific Journal of Cancer Prevention
• /
• v.13 no.7
• /
• pp.3471-3476
• /
• 2012

Background and Objective: Histone deacetylase (HDAC) inhibitors represent a promising class of potential anticancer agents for treatment of human malignancies. In this study, we investigated the effect of trichostatin A (TSA), one such HDAC inhibitor, in combination with docetaxel (TXT), a cytotoxic chemotherapy agent or erlotinib, a novel molecular target therapy drug, on lung cancer A549 cells. Methods: A549 cells were treated with TXT, erlotinib alone or in combination with TSA, respectively. Cell viability, apoptosis, and cell cycle distribution were evaluated using MTT (3- (4, 5-dimethylthiazol-2-yl) -2, 5-diphenyltetrazolium bromide) assay, Hochst33258 staining and flow cytometry. Moreover, immunofluorescent staining and Western blot analysis were employed to examine alterations of ${\alpha}$-tubulin, heat shock protein 90 (hsp90), epidermal growth factor receptor (EGFR), and caspase-3 in response to the different exogenous stimuli. Results: Compared with single-agent treatment, co-treatment of A549 cells with TSA/TXT or TSA/erlotinib synergistically inhibited cell proliferation, induced apoptosis, and caused cell cycle delay at the $G_2/M$ transition. Treatment with TSA/TXT or TSA/erlotinib led to a significant increase of cleaved caspase-3 expression, also resulting in elevated acetylation of ${\alpha}$-tubulin or hsp90 and decreased expression of EGFR, which was negatively associated with the level of acetylated hsp90. Conclusions: Synergistic anti-tumor effects are observed between TXT or erlotinib and TSA on lung cancer cells. Such combinations may provide a more effective strategy for treating human lung cancer.

• Biotechnology and Bioprocess Engineering:BBE
• /
• v.9 no.5
• /
• pp.356-361
• /
• 2004

When SiHa cells were incubated for varying periods of time with extracts of PFF and PFM, the cytotoxicity of the ethanol extracts of PFF was higher than those of the other extracts. These results indicated that the extracts from fruiting bodies of p. ferulae contain antitumor Substances. When A549, SiHa and HeLa cells were incubated with different concentrations of PFF and PFM extracts, the ethanol extracts of PFF showed strong cytotoxicity against A549 tells at concentrations over $10{\mu}g/mL$ and against SiHa and HeLa cells at concentrations over $40{\mu}g/mL$. However, the differences in the cytotoxic effects of the hot water and ethanol extracts of PFM and the hot water extracts of PFF on all 3 cancer cells were not significant. Also, the PFF ethanol extracts induced synergistic effects on the TRAIL-induced apoptosis in A549 cells, which were strongly resistant to TRAIL. These results indicated that ethanol extracts of PFF were the most prominent antitumor agents toward lung cancer cells (A549).

• Asian Pacific Journal of Cancer Prevention
• /
• v.14 no.11
• /
• pp.6945-6948
• /
• 2013

Background: Diosgenin, a steroidal saponin from a therapeutic herb, fenugreek (Trigonellafoenum-graceum L.), has been recognized to have anticancer properties. Telomerase activity is not detected in typical healthy cells, while in cancer cell telomerase expression is reactivated, therefore providing a promising cancer therapeutic target. Materials and Methods: We studied the inhibitory effect of diosgenin on human telomerase reverse transcriptase gene (hTERT) expression which is critical for telomerase activity. MTT- assays and qRT-PCR analysis were conducted to assess cytotoxicity and hTERT gene expression inhibition effects, respectively. Results: MTT results showed that $IC_{50}$ values for 24, 48 and 72h after treatment were 47, 44 and $43{\mu}M$, respectively. Culturing cells with diosgenin treatment caused down-regulation of hTERT expression. Discussion: These results show that diosgenin inhibits telomerase activity by down-regulation of hTERT gene expression in the A549 lung cancer cell line.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
• /
• v.18 no.3
• /
• pp.37-43
• /
• 2005

This study was performed to determine the cytotoxic effect of methanol extract from Houttuynia Cordata and Glycine soja. The cell viability was determined by MTT method. Their cytotoxic activities against three cancer cell lines such as A549, MDA-MB-231 and SNU-C4 cell line were tested. Among them, The methanol extract of Houttuynia Cordata showed the strongest cytotoxic effect against SNU-C4 cells. These results suggest that the methanol extract of Houttuynia Cordata possessed a potential antitumorous agent. The free radical scavenging activity using DPPH method was the strongest of Houttuynia Cordata methanol extract and ethyl acetate fraction.

• Asian Pacific Journal of Cancer Prevention
• /
• v.15 no.20
• /
• pp.8631-8635
• /
• 2014

Glutathione S-transferase A1 (GSTA1) appears to be primarily involved in detoxification processes, but possible roles in lung cancer remain unclear. The objective of this study was to investigate the expression and function of GSTA1 in lung cancer cells. Real-time PCR and Western blotting were performed to assess expression in cancer cell lines and the normal lung cells, then verify the A549 cells line with stable overexpression. Localization of GSTA1 proteins was assessed by cytoimmunofluorescence. Three double-strand DNA oligoRNAs (SiRNAs) were synthesized prior to being transfected into A549 cells with Lipofectamine 2000, and then the most efficient SiRNA was selected. Expression of the GSTA1 gene in the transfected cells was determined by real-time PCR and Western blotting. The viability of the transfected cells were assessed by MTT. Results showed that the mRNA and protein expression of A549 cancer cells was higher than in MRC-5 normal cells. Cytoimmunofluorescence demonstrated GSTA1 localization in the cell cytoplasm and/or membranes. Transfection into A549 cells demonstrated that down-regulated expression could inhibit cell viability. Our data indicated that GSTA1 expression may be a target molecule in early diagnosis and treatment of lung cancer.

• Korean Journal of Food Science and Technology
• /
• v.36 no.6
• /
• pp.1001-1007
• /
• 2004

Chloroform layer from methanol extract of Corni fructus (Cornaceae) showed strong antiproliferation effect on human cancer cell lines by SRB assay. Anticarcinogenic-active compound was isolated and purified by silica gel column and thin layer chromatograpies, and identified as ursolic acid ($3{\beta}$-hydroxyrus-12-ene-28-oic acid, MW:456) by mass and IR spectrophotometries, and $^1H-and\;^{13}C-NMRs$. The compound inhibited proliferation of A549 (human lung cancer cell line) and MCF-7 (human breast cancer cell line) cells in dose-dependant manner when treated for 48 hr. Inhibition rates of both cells were over 40% and 90% compared with control cells at the $30\;{\mu}g/mL\;and\;100\;{\mu}g/mL$, respectively. Morphology of cells treated with the compound for 15 hr at $10\;{\mu}g/mL$ was distorted with shrinked cell mass, and cell number was lower than that of control cells. Cell cycle analysis showed sub-G1 phase arrest in both cell lines following 15 hr exposure to the compound; % of cell phase increased to 11.7 and 11.2% compared to the control of 4.0% and 2.1% in A549 and MCP-7 cells, respectively.

• Tuberculosis and Respiratory Diseases
• /
• v.66 no.3
• /
• pp.178-185
• /
• 2009

Background: Epigallocatechin-3-gallate (EGCG) is the major catechin in green tea, and has shown antiproliferative, antiangiogenic, antimetastatic and cell cycle pertubation activity in various tumor models. Hypoxia can be induced because angiogenesis is insufficient for highly proliferating cancer. Hypoxia-inducible factor-1$\alpha$ (HIF-1$\alpha$) and its downstream target, vascular endothelial growth factor (VEGF), are important for angiogenesis, tumor growth and metastasis. The aim of this study was to determine how hypoxia could cause changes in the cellular phenomena and microenvironment in a non-small cell culture system and to examine the effects of EGCG on a HIF-1$\alpha$ and VEGF in A549 cell line. Methods: A549 cells, a non-small cell lung cancer cell line, were cultured with DMEM and 10% fetal bovine serum. A decrease in oxygen tension was induced using a hypoxia microchamber and a $CO_2-N_2$ gas mixture. Gas analysis and a MTT assay were performed. The A549 cells were treated with EGCG (0, 12.5, 25, 50 ${\mu}mol/L$), and then examined by real-time-PCR analysis of HIF-1$\alpha$, VEGF, and $\beta$-actin mRNA. Results: Hypoxia reduced the proliferation of A549 cells from normoxic conditions. EGCG inhibited HIF-1$\alpha$ transcription in A549 cells in a dose-dependent manner. Compared to HIF-1$\alpha$, VEGF was not inhibited by EGCG. Conclusion: HIF-1$\alpha$ can be inhibited by EGCG. This suggests that targeting HIF-1$\alpha$ with a EGCG treatment may have therapeutic potential in non-small cell lung cancers.

• Asian Pacific Journal of Cancer Prevention
• /
• v.14 no.7
• /
• pp.4421-4426
• /
• 2013

Objective: The present study employed 5-aza-2'-deoxycytidine (5-Aza-CdR) to treat non-small cell lung cancer (NSCLC) cell line A549 to investigate the effects on proliferation and expression of the TFPI-2 gene. Methods: Proliferation was assessed by MTT assay after A549 cells were treated with 0, 1, 5, 10 ${\mu}mol/L$ 5-Aza-CdR, a specific demethylating agent, for 24, 48 and 72h. At the last time point cells were also analyzed by flow cytometry (FCM) to identify any change in their cell cycle profiles. Methylation-specific polymerase chain reaction (MSPCR), real time polymerase chain reaction(real-time PCR) and western blotting were carried out to determine TFPI-2 gene methylation status, mRNA expression and protein expression. Results: MTT assay showed that the growth of A549 cells which were treated with 5-Aza-CdR was significantly suppressed as compared with the control group (0 ${\mu}mol/L$ 5-Aza-CdR). After treatment with 0, 1, 5, 10 ${\mu}mol/L$ 5-Aza-CdR for 72h, FCM showed their proportion in G0/G1 was $69.7{\pm}0.99%$, $76.1{\pm}0.83%$, $83.8{\pm}0.35%$, $95.5{\pm}0.55%$ respectively (P<0.05), and the proportion in S was $29.8{\pm}0.43%$, $23.7{\pm}0.96%$, $15.7{\pm}0.75%$, $1.73{\pm}0.45%$, respectively (P<0.05), suggesting 5-Aza-CdR treatment induced G0/G1 phase arrest. MSPCR showed that hypermethylation in the promoter region of TFPI-2 gene was detected in control group (0 ${\mu}mol/L$ 5-Aza-CdR), and demethylation appeared after treatment with 1, 5, 10 ${\mu}mol/L$ 5-Aza-CdR for 72h. Real-time PCR showed that the expression levels of TFPI-2 gene mRNA were $1{\pm}0$, $1.49{\pm}0.14$, $1.86{\pm}0.09$ and $5.80{\pm}0.15$ (P<0.05) respectively. Western blotting analysis showed the relative expression levels of TFPI-2 protein were $0.12{\pm}0.01$, $0.23{\pm}0.02$, $0.31{\pm}0.02$, $0.62{\pm}0.03$ (P<0.05). TFPI-2 protein expression in A549 cells was gradually increased significantly with increase in the 5-Aza-CdR concentration. Conclusions: TFPI-2 gene promoter methylation results in the loss of TFPI-2 mRNA and protein expression in the non-small cell lung cancer cell line A549, and 5-Aza-CdR treatment could induce the demethylation of TFPI-2 gene promoter and restore TFPI-2 gene expression. These findings provide theoretic evidence for clinical treatment of advanced non-small cell lung cancer with the demethylation agent 5-Aza-CdR. TFPI-2 may be one molecular marker for effective treatment of advanced non-small cell lung cancer with 5-Aza-CdR.

• Tuberculosis and Respiratory Diseases
• /
• v.75 no.3
• /
• pp.95-103
• /
• 2013

Background: Small cell lung cancer (SCLC) transformation during epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) treatment in lung cancer has been suggested as one of possible resistance mechanisms. Methods: We evaluated whether SCLC transformation or neuroendocrine (NE) differentiation can be found in the cell line model. In addition, we also investigated its effect on responses to conventional chemotherapeutic drugs of the SCLC treatment. Results: Resistant cell lines to various kinds of EGFR-TKIs such as gefitinib, erlotinib, CL-387,785 and ZD6474 with A549, PC-9 and HCC827 lung adenocarcinoma cell lines were established. Among them, two resistant cell lines, A549/GR (resistant to gefitinib) and PC-9/ZDR (resistant to ZD6474) showed increased expressions of CD56 while increased synaptophysin, Rb, p16 and poly(ADP-ribose) polymerase were found only in A549/GR in western blotting, suggesting that NE differentiation occurred in A549/GR. A549/GR cells were more sensitive to etoposide and cisplatin, chemotherapeutic drugs for SCLC, compared to parental cells. Treatment with cAMP and IBMX induced synaptophysin and chromogranin A expression in A549 cells, which also made them more sensitive to etoposide and cisplatin than parental cells. Furthermore, we found a tissue sample from a patient which showed increased expressions of CD56 and synaptophysin after development of resistance to erlotinib. Conclusion: NE differentiation can occur during acquisition of resistance to EGFR-TKI, leading to increased chemosensitivity.

• Integrative Medicine Research
• /
• v.3 no.2
• /
• pp.67-73
• /
• 2014

Background: The transcription factor signal transducer and activator of transcription 3 (Stat3)is constitutively activated in many human cancers. It promotes tumor cell proliferation,inhibits apoptosis, induces angiogenesis and metastasis, and suppresses antitumor hostimmune responses. Therefore, Stat3 has emerged as a promising molecular target for cancertherapies. In this study, we evaluated the Stat3-suppressive activity of 38 herbal medicinestraditionally used in Korea.Methods: Medicinal herb extracts in 70% ethanol were screened for their ability to suppressStat3 in the A549 human lung cancer cell line. A Stat3-responsive reporter assay system wasused to detect intracellular Stat3 activity in extract-treated cells, and Western blot analyseswere performed to measure the expression profiles of Stat3-regulated proteins.Results: Fifty percent of the 38 extracts possessed at least mild Stat3-suppressive activities(i.e., activity less than 75% of the vehicle control). Ethanol extracts of Bupleurum falcatumL., Taraxacum officinale Weber, Solanum nigrum L., Ulmus macrocarpa Hance, Euonymus alatusSieb., Artemisia capillaris Thunb., and Saururus chinensis (Lour.) Baill inhibited up to 75% of thevehicle control Stat3 activity level. A549 cells treated with these extracts also had reducedBcl-xL, Survivin, c-Myc, and Mcl-1 expression.Conclusion: Many medicinal herbs traditionally used in Korea contain Stat3 activity-suppressing substances. Because of the therapeutic impact of Stat3 inhibition, these resultscould be useful when developing novel cancer therapeutics from medicinal herbs.