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Advances in understanding lung cancer biology and tumor markers aid clinicians in managing the disease. Cancer-associated antigen (CA)125 has garnered increasing attention in lung cancer research and may benefit the treatment and follow-up of this type of cancer. In Thai lung cancer patients, knowledge regarding ethnic differences in cancer cell biology is largely absent. We generated lung cancer cells from the pleural effusion fluids of a Thai patient and designated these as P1 cells. P1 cells were assessed for growth rate, response to chemotherapy, and the presence of tumor markers, in particular CA125 expression. Results of immunofluorescence indicated that P1 cells exhibited strong expression levels of CA125, comparable to that of established H460 lung cancer cells. Furthermore, P1 cells were analyzed for the expression of additional markers. Results revealed that H460 cells exhibited strong immunofluorescent signals from cytokeratin-19 fragments (CYFRA 21-1) and squamous cell carcinoma antigen (SCCA) while P1 presented only CYFRA 21-1 signals. We also found evidence of relative cisplatin resistance in P1 compared to the susceptibility level of established lung cancer cells. Thus, the results and methodology described in this study may aid the development of lung cancer diagnostic and therapeutic approaches and, in particular, advance understanding of ethnic differences.

Cisplatin-induced nephrotoxicity has been accepted as an important obstacle for efficient cisplatin-based chemotherapy. Silymarin from seeds of milk thistle [Silybum marianum L. (Asteraceae)] has been shown to possess various potential pharmacological properties; however, whether or not this agent selectively protects renal cells from cisplatin-induced cell death with no interfering effect on cancer cells is not clear.Potential of silymarin in protection of cisplatin-induced renal cell death without compromising effect on anticancer activity of cisplatin was demonstrated in this study.Cisplatin-induced cell death was evaluated in human proximal tubular HK-2, lung carcinoma H460, and melanoma G361 cells using MTT, Hoechst 33342, and propidium iodide assays.Cisplatin induced both apoptosis and necrosis in HK-2 cells and caused a decrease in cell viability by ~40% and 60% at the doses of 25 and 100 µM, respectively. Pretreatment with 25-200 µM of silymarin significantly protected against cisplatin-induced cell death in a dose-dependent manner. In contrast, pretreatment of silymarin (25-100 µM) caused no significant change on cisplatin-induced cell death in H460 cells but significantly potentiated cisplatin-induced apoptosis in G361 cells.These findings reveal the selectivity of silymarin in protection of renal cells from cisplatin-induced cell death and could be beneficial for the development of this considerately safe compound as a renoprotective agent.

Although cisplatin is one of the most efficient chemotherapeutic agents for the treatment of solid tumors, frequently observed nephrotoxicity has limited its use in several patients. Materials and methods: The protective effect of Glycine max (GM) and Chrysanthemum indicum (CM) extracts on cisplatin-induced apoptosis in human proximal tubular HK-2 cells was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), Hoechst 33342, and propidium iodide assays. Reactive oxygen species (ROS) were determined by flow cytometry with 2,7-dichlorofluorescein diacetate (DCFH2-DA). Results: Cisplatin-induced renal cell toxicity through the induction of hydrogen peroxide (H2O2•−) and hydroxyl radical (OH). CM extract protected cisplatin-induced apoptosis by its anti-oxidant activity against H2O2 and OH•−, while GM extract scavenged only H2O2. Furthermore, GM and CM extracts protect renal cells without significant interfering effect on cisplatin toxicity in lung cancer H460 and melanoma G361 cells. Conclusion: GM and CM extracts exhibited a promising protective effect on cisplatin-induced nephrotoxicity which could benefit the development for nephroprotective approaches.

Ethnopharmacological relevance Barakol, an anxiolytic agent isolated from Senna siamea leaves which has been traditionally used for producing natural sleep, has been described as toxic to patients. Aim of the study The aim of current study was to investigate the molecular mechanism of barakol-induced toxicity in mouse embryonal carcinoma P19 cell model. Materials and methods XTT assay was used to determine cell viability in P19 cells treated with barakol. Apoptotic cells were detected by Hoechst 33342 staining. Intracellular reactive oxygen species (ROS) generation was analyzed by flow cytometry using a fluorescent dye, DCFH-DA. Detection of apoptotic protein expression in P19 cells was performed by Western blot analysis. Caspase-9 activity was measured using a fluorescent immunosorbent enzyme assay kit. Results Treatment with barakol decreased cell viability in a concentration- and time-dependent manner with an IC50 value of 1.5 mM in 24-h treated cells. A Hoechst 33342 assay revealed that barakol cytotoxicity was due to a significant increase in the number of apoptotic cells. Different scavengers to characterize ROS were utilized and revealed that hydroxyl radicals played a major role in ROS-induced apoptosis in barakol-treated cells. Western blot analysis demonstrated that barakol-induced apoptosis was mediated by the increase in expression ratio of Bax/Bcl-2. Furthermore, increase in caspase-9 activity after exposure to barakol for 24 h was also observed. Pretreatment of cells with N-acetyl- l -cysteine (NAC) attenuated intracellular ROS generation, the Bax/Bcl-2 protein expression, and apoptosis. Conclusions The mechanism of barakol-mediated toxicity in P19 cells is mainly associated with the ROS generation, followed by the imbalance of the Bax/Bcl-2 ratio, and caspase-9 activation leading to apoptotic cell death. Pretreatment of cells with NAC could antagonize the toxicity produced by barakol.

Renieramycin M, has been shown to exhibit promising anticancer activity against some cancer cell lines; however, the underlying mechanism remains unknown.Renieramycin M was isolated from the blue sponge Xestospongia sp. Anticancer and antimetastatic activities of renieramycin M were investigated in human non-small cell lung cancer cells.Renieramycin M treatment caused p53 activation, which subsequently down-regulated anti-apoptotic MCL-1 and BCL-2 proteins, while the level of pro-apoptotic BAX protein was not altered. The subtoxic concentrations of renieramycin M significantly decreased invasion and migration abilities of cancer cells. In addition, this compound showed a strong inhibitory effect on anchorage-independent growth of the cells.These results reveal that renieramycin M induced lung cancer cells apoptosis through p53-dependent pathway and the compound may inhibit progression and metastasis of lung cancer cells.

Anoikis or detachment-induced apoptosis plays an essential role in the regulation of cancer cell metastasis. Caveolin-1 (Cav-1) is a key protein involved in tumor metastasis, but its role in anoikis and its regulation during cell detachment are unclear. We report here that Cav-1 plays a key role as a negative regulator of anoikis through a reactive oxygen species (ROS)-dependent mechanism in human lung carcinoma H460 cells. During cell detachment, Cav-1 is downregulated, whereas ROS generation is upregulated. Hydrogen peroxide and hydroxyl radical are two key ROS produced by cells during detachment. Treatment of the cells with hydrogen peroxide scavengers, catalase and N-acetylcysteine, promoted Cav-1 downregulation and anoikis during cell detachment, indicating that produced hydrogen peroxide plays a primary role in preventing anoikis by stabilizing Cav-1 protein. Catalase and N-acetylcysteine promoted ubiquitination and proteasomal degradation of Cav-1, which is a major pathway of its downregulation during cell anoikis. Furthermore, addition of hydrogen peroxide exogenously to the cells inhibited Cav-1 downregulation by preventing the formation of Cav-1-ubiquitin complex, supporting the inhibitory role of endogenous hydrogen peroxide in Cav-1 degradation during cell detachment. Together, these results indicate a novel role of hydrogen peroxide as an endogenous suppressor of cell anoikis through its stabilizing effect on Cav-1.

Anoikis, an apoptosis triggered by loss of cell anchorage, has been shown to be a principal mechanism of inhibition of tumor metastasis. Recently, anti-apoptotic Bcl-2 and Cav-1 proteins have been demonstrated to be highly associated with tumor metastasis and apoptosis resistance. Curcumin, a major active component of turmeric, Curcuma longa, has been shown to inhibit neoplastic evolution and tumor progression; however, the underlying mechanisms are unclear. In this study, we investigated the effect of curcumin on cell anoikis as a possible mechanism of anti-tumorigenic action of curcumin, and evaluated the potential role of Bcl-2 and Cav-1 in this process. Our results showed that ectopic expression of either Bcl-2 or Cav-1 induced anoikis resistance of lung carcinoma H460 cells. Curcumin downregulated Bcl-2 protein during anoikis and sensitized the cells to detachment-induced apoptosis, whereas it had no significant effect on Cav-1 protein expression. Bcl-2 down-regulation as well as anoikis enhancement by curcumin were inhibited by superoxide anion scavenger, Mn(III)tetrakis(4-benzoic acid) porphyrin chloride, but were unaffected by other ROS scavengers including catalase and deferoxamine, suggesting that superoxide anion is a key player in the downregulation of Bcl-2 by curcumin. Furthermore, we provided evidence that curcumin decreased Bcl-2 level through ubiquitin-proteasomal degradation which sensitized cells to detachment-induced apoptosis. These findings indicate a novel pathway for curcumin regulation of Bcl-2 and provide a key mechanism of anoikis regulation that may be exploited for metastatic cancer treatment.

Anoikis, a detachment-induced apoptosis, is a principal mechanism of inhibition of tumor cell metastasis. Tumor cells can acquire anoikis resistance which is frequently observed in metastatic lung cancer. This phenomenon becomes an important obstacle of efficient cancer therapy. Recently, signaling mediators such as caveolin-1 (Cav-1) and nitric oxide (NO) have garnered attention in metastasis research; however, their role and the underlying mechanisms of metastasis regulation are largely unknown. Using human lung carcinoma H460 cells, we show that NO impairs the apoptotic function of the cells after detachment. The NO donors sodium nitroprusside and diethylenetriamine NONOate inhibit detachment-induced apoptosis, whereas the NO inhibitors aminoguanidine and 2-(4-carboxyphenyl) tetramethylimidazoline-1-oxyl-3-oxide promote this effect. Resistance to anoikis in H460 cells is mediated by Cav-1, which is significantly down-regulated after cell detachment through a non-transcriptional mechanism involving ubiquitin-proteasomal degradation. NO inhibits this down-regulation by interfering with Cav-1 ubiquitination through a process that involves protein S-nitrosylation, which prevents its proteasomal degradation and induction of anoikis by cell detachment. These findings indicate a novel pathway for NO regulation of Cav-1, which could be a key mechanism of anoikis resistance in tumor cells.

The purpose of this study was to investigate the sensitizing effect of curcumin on cisplatin-induced apoptosis in non-small cell lung cancer (NSCLC) H460 cells. Curcumin was shown to induce superoxide anion generation, down-regulate anti-apoptotic Bcl-2 protein, and subsequently sensitize cells to cisplatin-induced apoptosis. Co-treatment of the cells with curcumin and cisplatin resulted in increased apoptosis and reversal of Bcl-2-mediated cisplatin resistance. The mechanism by which curcumin down-regulates Bcl-2 and sensitizes cells to cisplatin-induced apoptosis involves proteasomal degradation of Bcl-2. These findings indicate a novel pathway for curcumin regulation of Bcl-2, which could benefit the development of a cisplatin sensitizing agent.

As part of an ongoing search for the novel pharmacological activities of Phyllanthus emblica, the present study has shown its type I collagen promoting and anti-collagenase effects on primary mouse fibroblast cells. At a concentration of 0.1 mg/ml, emblica extract significantly increased the type I pro-collagen level up to 1.65-fold, and 6.78-fold greater than that of an untreated control, determined by immunocytochemistry and Western blot analysis, respectively. Emblica extract caused an approximately 7.75-fold greater type I pro-collagen induction compared to the known herbal collagen enhancer asiaticoside at the same treatment concentration (0.1 mg/ml). Moreover, emblica extract inhibited collagenase activity in a dose-dependent manner. Maximal inhibition was observed (78.67 +/- 3.51%) at a concentration of 1 mg/ml. In summary, emblica extract has a promising pharmacological effect that benefits collagen synthesis and protects against its degradation and could be used as a natural anti-aging ingredient.

The aim of this study was to investigate a newly synthesized dextrin-zidovudine (AZT) conjugate designed as a sustained release prodrug of AZT for parenteral administration. AZT was first reacted with succinic anhydride to form a succinoylated AZT which was subsequently coupled with dextrin to yield the dextrin-AZT conjugate. The structure of the conjugate was characterized by FT-IR and (1)H-NMR spectroscopy. The drug content of the conjugate was 18.9 wt.%. The release in vitro of free AZT and succinoylated AZT was investigated in buffer solutions at pH 5.5 and 7.4 and in human plasma. AZT and succinoylated AZT release from the conjugate was 1.4% (pH 5.5), 41.7% (pH 7.4) and 78.4% in human plasma after 24 h. Release was complete in human plasma after 48 h. A pharmacokinetic study in rats following intravenous administration of the conjugate showed prolonged plasma levels of AZT compared to free AZT. The use of the conjugate extended the plasma half-life of AZT from 1.3 to 19.3 h and the mean residence time from 0.4 to 23.6 h. Furthermore, the conjugate provided a significant greater area under the plasma concentration-time curve and reduced the systemic clearance of AZT. This study suggested the potential of this novel dextrin-AZT conjugate as a new intravenous preparation of AZT.

Twenty bromotyrosine alkaloids, including a new compound, 13-oxosubereamolline D (5), were isolated from the Thai sponge Acanthodendrilla sp. Their structures were determined by analyses of 1D- and 2D-NMR, high-resolution mass, and circular dichroism data. The complete 1H and 13C NMR assignments of 5,7β-dichlorocavernicolin (19) and 5,7α-dichlorocavernicolin (20) are described herein for the first time. The acetylcholinesterase (AChE) inhibitory activity of all isolated compounds was evaluated. Only homoaerothionin (7) and fistularin 1 (10) exhibited inhibitory activity against human recombinant AChE ( hrAChE) with IC50s of 4.5 and 47.5 μM, respectively. The hrAChE inhibition kinetics of 7, the most potent alkaloid, showed increased K m and unchanged V max values, suggesting its competitive mode of inhibition. The spirocyclohexadienylisoxazole and the length of the alkyl diamine linkage were proposed as the crucial parts for its strong inhibitory activity. This finding indicates a therapeutic potential for 7 in acetylcholine-related diseases, most importantly Alzheimer's disease.

In the paper titled “Long-Term Nitric Oxide Exposure Enhances Lung Cancer Cell Migration,” the Acknowledgments is corrected as follows. This work was supported by grants from the Thailand Research Fund (P. Chanvorachote) and the 90th Anniversary of Chulalongkorn University Fund (Ratchadaphiseksomphot Endowment Fund). The authors would like to thank Mr. Krich Rajprasit for his assistance in proofreading.

Cisplatin is a potent cytotoxic agent commonly used for the treatment of solid tumors. However, tumor cell–acquired resistance to cisplatin-induced apoptosis is a major limitation for efficient therapy, as frequently observed in human lung cancer. Nitric oxide (NO) is a key regulator of apoptosis, but its role in cisplatin-induced cell death and the underlying mechanism are largely unknown. Previous studies indicate increased NO synthase activity and elevated NO production in lung carcinomas, which correlate with the incidence of chemotherapeutic resistance. Here, we show that NO impairs the apoptotic function of cells and increases their resistance to cisplatin-induced cell death in human lung carcinoma H-460 cells. The NO donors sodium nitroprusside and dipropylenetriamine NONOate were able to inhibit cisplatin-induced cell death, whereas the NO inhibitors aminoguanidine and 2-(4-carboxyphenyl)-4,4,5,5-tetra-methylimidazoline-1-oxyl-3-oxide had opposite effect. Cisplatin resistance in H-460 cells is mediated by Bcl-2, and NO up-regulates its expression by preventing the degradation of Bcl-2 via ubiquitin-proteasome pathway. Cisplatin-induced generation of reactive oxygen species causes dephosphorylation and degradation of Bcl-2. In contrast, generation of NO has no effect on Bcl-2 phosphorylation but induces S-nitrosylation of the protein, which inhibits its ubiquitination and subsequent proteasomal degradation. These findings indicate a novel pathway for NO regulation of Bcl-2, which provides a key mechanism for cisplatin resistance and its potential modulation for improved cancer chemotherapy. (Cancer Res 2006; 66(12): 6365-60)

Alteration of cancer cell toward mesenchymal phenotype has been shown to potentiate tumor aggressiveness by increasing cancer cell metastasis. Herein, we report the effect of triclosan, a widely used antibacterial agent found in many daily products, in enhancing the epithelial-to-mesenchymal transition (EMT) in aggressive anoikis resistant human H460 lung cancer cells. EMT has been long known to increase abilities of the cells to increase migration, invasion, and survival in circulating system. The present study reveals that treatment of the cancer cells with triclosan at the physiologically related concentrations significantly increased the colony number of the cancer cells assessed by tumor formation assay. Also, the mesenchymal-like morphology and decrease in cell-to-cell adhesion were observed in triclosan-treated cells. Importantly, western blot analysis revealed that triclosan-treated cells exhibited decreased E-cadherin, while the levels of EMT markers, namely N-cadherin, vimentin, snail and slug were found to be significantly up-regulated. Furthermore, EMT induced by triclosan treatment was accompanied by the activation of focal adhesion kinase/ATP dependent tyrosine kinase (FAK/Akt) and Ras-related C3 botulinum toxin substrate 1 (Rac1), which enhanced the ability of the cells to migrate and invade. In conclusion, we demonstrated for the first time that triclosan may potentiate cancer cells survival in detached condition and motility via the process of EMT. As mentioned capabilities are required for success in metastasis, the present study provides the novel toxicological information and encourages the awareness of triclosan use in cancer patients.

Bcl-2 is mainly thought to regulate cell apoptosis. However, little is known about its regulation associated with cell metastasis. Here, we demonstrate that Bcl-2 plays an important role in the cell spreading, adhesion and migration of non-small cell lung cancer cells. To study the role of Bcl-2, mutant cell lines exhibiting stably up-regulated and down-regulated Bcl-2 were generated using Bcl-2 plasmid and RNA interference. As compared to control H460 cells, Bcl-2 overexpressed cells exhibited significantly decreased cell spreading, adhesion and migration. Consistent with these results, the loss of Bcl-2 in Bcl-2 knockdown cells increased cell spreading, adhesion and migration. The morphology characteristics study has shown that Bcl-2 increased mesenchymal-epithelial transition phenotype whereas the loss of Bcl-2 increased epithelial-mesenchymal transition phenotype. The increase of fluorescent intensity of phalloidin staining in Bcl-2 overexpressed cells suggesting actin polymerization might be responsible in the supression of cell spreading, adhesion and migration. This result may explain why Bcl-2 has been suggested as a prognostic factor for survival in lung cancer patients. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 477. doi:1538-7445.AM2012-477

As part of an ongoing search for the novel pharmacological activities of Phyllanthus emblica, the present study has shown its type I collagen promoting and anti-collagenase effects on primary mouse fibroblast cells. At a concentration of 0.1 mg/ml, emblica extract significantly increased the type I pro-collagen level up to 1.65-fold, and 6.78-fold greater than that of an untreated control, determined by immunocytochemistry and Western blot analysis, respectively. Emblica extract caused an approximately 7.75-fold greater type I pro-collagen induction compared to the known herbal collagen enhancer asiaticoside at the same treatment concentration (0.1 mg/ml). Moreover, emblica extract inhibited collagenase activity in a dose-dependent manner. Maximal inhibition was observed (78.67 +/- 3.51%) at a concentration of 1 mg/ml. In summary, emblica extract has a promising pharmacological effect that benefits collagen synthesis and protects against its degradation and could be used as a natural anti-aging ingredient.

Background In order to gain insight into neuroprotective effects of ECa 233, a standardized extract of Centella asiatica, previously demonstrated in animal models of memory impairment induced by transient global ischemia or intracerebroventricular injection of β-amyloid, the effect of ECa 233 on neurite outgrowth of human IMR-32 neuroblastoma cell line was investigated. Methods Cells were seeded and incubated with various concentrations of ECa 233. Morphometric analysis was carried out by a measurement of the longest neurite growth of cells at 24 and 48 h. Contributing signaling pathways possibly involved were subsequently elucidated by western blot analysis. Results While ECa 233 had only limited effects on cell viability, it significantly enhanced neurite outgrowth of IMR-32 cells at the concentrations of 1–100 μg/ml. Western blot analysis revealed that ECa 233 significantly upregulated the level of activated ERK1/2 and Akt of the treated cells suggesting their involvement in the neuritogenic effect observed, which was subsequently verified by the finding that an addition of their respective inhibitors could reverse the effect of ECa 233 on these cells. Conclusions The present study clearly demonstrated neurite outgrowth promoting activity of ECa 233. ERK1/2 and Akt signaling pathways seemed to account for the neurotrophic effect observed. In conjunction with in vivo neuroprotective effect of ECa 233 previously reported, the results obtained support further development of ECa 233 for clinical use in neuronal injury or neurodegenerative diseases.