α-Conotoxin recombinant protein ImI-AFP3 efficiently inhibits the growth and migration of lung cancer cells

α-Conotoxin ImI is a selective antagonist of alpha7 nicotinic acetylcholine receptor (α7 nAChR) that is involved in cancer development. Human alpha fetoprotein domain 3 (AFP3) is a prototype of anticancer agents. In an effort to design drugs for anticancer treatments, we fused the ImI peptide to AFP3 as a fusion protein for testing. The fusion protein (ImI-AFP3) was highly expressed in the insect Bac-to-Bac system. The purified fusion protein was found to have improved anticancer activity and synergized with the drug gefitinib to inhibit the growth and migration of A549 and NCI-H1299 lung cancer cells. Our data have demonstrated that the recombinant protein ImI-AFP3 is a promising candidate for drug development to suppress lung cancer cell growth, especially to suppress hepatoid adenocarcinoma of the lung (HAL) cell growth.

Comparative studies on the cytotoxic effects induced by iron oxide nanoparticles in cancerous and noncancerous human lung cells subjected to an alternating magnetic field

The cytotoxic effects of water-based ferrofluids composed of iron oxide nanoparticles, including magnetite (Fe3O4) and maghemite (γ-Fe2O3), ranging from 15 to 100 nm, were examined on various lung cancer cells including adenocarcinomic human alveolar basal epithelial cells (A549), nonsmall lung squamous cell carcinoma (H1703), small cell lung cancer cells (DMS 114), and normal bronchial epithelial cells (BEAS-2B). The cytotoxic effect was evaluated both with and without exposure to an alternating magnetic field (AMF). The studies revealed that neither AMF nor iron oxide nanoparticles when tested individually, produced cytotoxic effects on either cancerous or noncancerous cells. However, when applied together, they led to a significant decrease in cell viability and proliferative capacity due to the enhanced effects of magnetic fluid hyperthermia (MFH). The most pronounced effects were found for maghemite (<50 nm) when subjected to an AMF. Notably, A549 cells exhibited the highest resistance to the proposed hyperthermia treatment. BEAS-2B cells demonstrated susceptibility to magnetized iron oxide nanoparticles, similar to the response observed in lung cancer cells. The studies provide evidence that MFH is a promising strategy as a standalone treatment for different types of lung cancer cells. Nevertheless, to prevent any MFH-triggered adverse effects on normal lung cells, targeted magnetic ferrofluids should be designed.

Synergistic chemo-photothermal therapy using gold nanorods supported on thiol-functionalized mesoporous silica for lung cancer treatment

Cancer therapy necessitates the development of novel and effective treatment modalities to combat the complexity of this disease. In this project, we propose a synergistic approach by combining chemo-photothermal treatment using gold nanorods (AuNRs) supported on thiol-functionalized mesoporous silica, offering a promising solution for enhanced lung cancer therapy. To begin, mesoporous MCM-41 was synthesized using a surfactant-templated sol-gel method, chosen for its desirable porous structure, excellent biocompatibility, and non-toxic properties. Further, thiol-functionalized MCM-41 was achieved through a simple grafting process, enabling the subsequent synthesis of AuNRs supported on thiol-functionalized MCM-41 (AuNR@S-MCM-41) via a gold-thiol interaction. The nanocomposite was then loaded with the anticancer drug doxorubicin (DOX), resulting in AuNR@S-MCM-41-DOX. Remarkably, the nanocomposite exhibited pH/NIR dual-responsive drug release behaviors, facilitating targeted drug delivery. In addition, it demonstrated exceptional biocompatibility and efficient internalization into A549 lung cancer cells. Notably, the combined photothermal-chemo therapy by AuNR@S-MCM-41-DOX exhibited superior efficacy in killing cancer cells compared to single chemo- or photothermal therapies. This study showcases the potential of the AuNR@S-MCM-41-DOX nanocomposite as a promising candidate for combined chemo-photothermal therapy in lung cancer treatment. The innovative integration of gold nanorods, thiol-functionalized mesoporous silica, and pH/NIR dual-responsive drug release provides a comprehensive and effective therapeutic approach for improved outcomes in lung cancer therapy. Future advancements based on this strategy hold promise for addressing the challenges posed by cancer and transforming patient care.

Nanoporous gold microelectrode for electrochemical sensing of As(III) in cellular environment

The highly toxic arsenite (As(III)) could cause serious cytotoxicity on metabolism, resulting in several diseases. However, it is still a great challenge on the precise sensing of As(III) in complicated conditions, especially in cellular environment. In this work, a nanoporous gold microelectrode (NPG-μE) was fabricated by a simple electrochemical alloying/dealloying method and developed for the electroanalysis of As(III) in the lung cancer cellular (A549 cells) environment. The as-fabricated NPG-μE exhibited the excellent electrochemical performance towards As(III) detection at physiological pH (0.1 M PBS solution, pH 7.4) with a high sensitivity of 5.07 μA ppb-1 cm-2 and a low limit of detection of 0.25 ppb (S/N = 3). The large surface area derived from the nanoporous structure, and the well-dispersed active sites as well as the highly electro-catalytic activity of gold played a critical role on the improved electrochemical behaviors. Furthermore, the effect of the exposure time on electrochemical monitoring As(III) in A549 cellular environment was successfully investigated, revealing the fatal impact of As(III) on cell cycle. This work offered a great trial on investigating of the cytotoxicity of arsenite and their precise detection in complicated cellular environment.

Hibiscus-cisplatin combination treatment decreases liver toxicity in rats while increasing toxicity in lung cancer cells via oxidative stress- apoptosis pathway

Cisplatin (CIS) is a broad-spectrum anti-carcinogen that causes cytotoxic effects both in normal and cancer cells. The purpose of this study was to test whether Hibiscus sabdariffa (HS) extract can reduce CIS-induced hepatotoxicity in rodents and to assess its anticancer activity in vitro. Treatment with HS extract at daily doses of 500 mg/kg before and after a single dose of CIS (10 mg/kg) reduced hepatotoxicity in Wistar male albino rats. HS extract reduced activity of hepatic damage marker enzymes ( i.e. alanine and aspartate aminotransferases), necrosis, and apoptosis in liver tissues of CIS-treated rats. This hepatic protection was associated with reduced oxidative stress in liver tissues. The antioxidant effects of HS were manifested as a normalization of malondialdehyde levels and glutathione levels which were all raised after CIS-induction. In addition, HS treatment resulted in a decrease of catalase, and superoxide dismutase activity. The combined effects of CIS and HS were also studied in two human lung cancer cell lines (A549 and H460). Treatment with HS (20 μg /mL) enhanced the cytotoxic activity of CIS both in A549 and H460 cell lines. Interestingly, HS increased CIS-induced apoptosis and oxidative stress more clearly in A549 cells indicating that HS extract in combination with CIS could increase the efficacy of CIS in the treatment of cancer.

Silencing TAB182 inhibits cell EMT, migration and invasion by downregulating EGFR in A549 NSCLC cells

BACKGROUND

TAB182 is overexpressed in cancerous tissues and correlated with poor overall survival in lung cancer patients. Mechanistically, TAB182 participates in DNA damage repair and endows tumour cells with radio- and chemoresistance. However, its role in non-small cell lung cancer (NSCLC) remains unclear.

METHODS AND RESULTS

Cells with stable TAB182 knockdown (KD) were generated using A549 NSCLC cells, and we demonstrated that depleting TAB182 inhibits cell EMT, proliferation, colony formation, migration and invasion. Analysis of the TCGA database showed a positive correlation between TAB182 and EGFR, a well-established NSCLC oncoprotein. Then, we verified that silencing TAB182 decreases EGFR expression at both the mRNA and protein levels. Moreover, both TAB182 and EGFR were reported to restore ionizing radiation (IR)-triggered DNA damage. We validated that IR elevates the protein level of EGFR and that silencing TAB182 can alleviate IR-induced EGFR upregulation. Furthermore, overexpressing EGFR abrogates the inhibitory effects of TAB182 KD on EMT, migration, and invasion in A549 cells.

CONCLUSIONS

Our data demonstrated that EGFR expression is regulated by TAB182 and downregulation of TAB182 has a novel function to repress EMT, migration and invasion by decreasing EGFR, indicating TAB182 could regulate the malignant progression of NSCLC.

Exosomes derived from M1 macrophages inhibit the proliferation of the A549 and H1299 lung cancer cell lines via the miRNA-let-7b-5p-GNG5 axis

Background

Almost all cells are capable of secreting exosomes (Exos) for intercellular communication and regulation. Therefore, Exos can be used as a natural therapeutic platform to regulate genes or deliver drugs to treat diseases. M1 macrophages inhibit tumor growth by releasing pro-inflammatory factors. This study explored the applicability of M1 macrophage exosomes (M1-Exos) as gene carriers and the effects on GNG5 protein, and further examined whether macrophage repolarization could inhibit tumor activity.

Methods

M0 macrophages were polarized toward M1 using vitexin. Exos were obtained from M1 macrophages by ultra-centrifugation. The transwell non-contact co-culture system was used to co-culture M1 macrophages with HLF-α human lung epithelial cells or A549 or H1299 lung cancer cells. MTT, scratch, and transwell assays were used to detect the cell viability, migration, and invasion ability of cells in the four groups. Flow cytometry was used to detect the apoptosis rate of each group, and western blot (WB) analysis was performed to detect the change in the expression of proliferation- and apoptosis-related proteins. We screened the differentially expressed microRNAs using quantitative polymerase chain reaction technology. Luciferase reporter analysis was performed to explore the interaction between miRNA and protein. We used Xenografted A549 tumors in nude mice to study the effect of M1-Exos on tumor cell growth in vivo.

Results

The results showed that, under the M1 macrophage co-culture system, lung cancer cell viability, invasion, and migration ability decreased, and the number of apoptotic cells increased, will all indicators being statistically significant (P < 0.05). The expression levels of PCNA, KI67, and Bcl-2 decreased significantly, but that of Bax increased (P < 0.05). Exosomes can have the same effect on tumor cells as M1 macrophages. Exosomes can transport miR-let-7b-5p to tumor cells, and miR-let-7b-5p can inhibit tumor cell proliferation and promote tumor cell apoptosis by regulating the GNG5 protein level.

Conclusions

M1-Exos inhibit the proliferation, invasion, and metastasis of lung cancer cells through miRNA-let-7b-5p and GNG5 signaling pathways and inhibit the anti-apoptotic ability of lung cancer cells.

Undescribed isoquinolines from Zanthoxylum nitidum and their antiproliferative effects against human cancer cell lines

Eleven previously undescribed alkaloids, including three pairs of enantiomers nitidumalkaloids A-C, a pair of scalemic mixtures nitidumalkaloid D and three optically pure or achiral alkaloids, nitidumalkaloids E-G, along with 20 known alkaloids, were isolated from an ethanolic extract of the whole Zanthoxylum nitidum (Roxb.) DC plant. The chemical structures of the alkaloids were elucidated using a combination of comprehensive nuclear magnetic resonance (NMR) and high-resolution electro-spray ionization mass spectrometry (HR-ESI-MS) analyses. The configuration of the stereogenic centers of all undescribed compounds was precisely established based on single-crystal X-ray diffraction and electronic circular dichroism (ECD) calculations. Racemic mixtures of nitidumalkaloids A-D were purified, and their enantiomers were analyzed via chiral-phase high-performance liquid chromatography with electrochemical detection measurements (HPLC-ECD). Twelve compounds exhibited significant antiproliferative activities against a panel of cancer cell lines. Further studies were designed to investigate the underlying molecular mechanism of (1'S, 6R)-nitidumalkaloid B, which was the most active antiproliferative agent against human cancer A549 cells. G2/M cell cycle arrest, induction of apoptosis, and suppression of the Wnt/β-catenin signaling pathway were in part associated with the antiproliferative activity of (1'S, 6R)-nitidumalkaloid B. Moreover, (1'S, 6R)-nitidumalkaloid B inhibited cell migration by downregulating the epithelial-mesenchymal transition process in A549 cells. These data suggest that the antiproliferation activity of (1'S, 6R)-nitidumalkaloid B was correlated with the stereoselectivity of the stereoisomers, and (1'S, 6R)-nitidumalkaloid B was prioritized as a potential leading compound for the management of aggressive human non-small-cell lung cancer (NSCLC) from natural products.

Antineoplastic effects of erufosine on small cell and non-small cell lung cancer cells through induction of apoptosis and cell cycle arrest

BACKGROUND

Lung cancer (LC) is the most common types of cancer worldwide and is marked by high mortality rate. LC is classified into two major types due to their molecular and histological properties; non-small cell lung cancer (NSCLC) A549 and small cell lung cancer (SCLC). Currently, surgery, chemotherapy and radiation therapy are the most common treatment options of LC. However, the survival rate of LC is still very poor. Therefore, new treatment strategies are urgently needed. Erufosine (ErPC3) is a novel alkylphosphocholine and inhibits the translocation of Akt to the plasma membrane.

METHODS AND RESULTS

In the current study, the effects of ErPC3 in NSCLC cell line A549 and SCLC cell line DMS 114 in terms of cell viability, induction of apoptosis, cell cycle phase distribution, gene and protein expression levels, and migration capacity were investigated. 25 µM ErPC3 exhibited dose-dependent cytotoxicity against in both cancer cells. However, DMS 114 was more sensitive to ErPC3 than A549. Similarly, ErPC3 induced apoptotic cell ratio in DMS114 was significantly greater than A549. 25 µM ErPC3 caused the accumulation of both cell in G2/M phase. The levels of BCL-2 were downregulated and CASPASE 3-7 and BAX were upregulated while p-Akt levels were reduced in A549 and DMS 114 cells treated with 25 µM ErPC3. Besides, ErPC3 displayed anti-migratory effect on A549 and DMS 114.

CONCLUSION

These findings suggest that ErPC3 may be a promising novel therapeutic candidate for treatment of LC. ErPC3 treatment merits further investigation as potential agent against LC.

Ad-VT enhances the sensitivity of chemotherapy-resistant lung adenocarcinoma cells to gemcitabine and paclitaxel in vitro and in vivo

Background One of the main challenges in the clinical treatment of lung cancer is resistance to chemotherapeutic drugs. P-glycoprotein (P-gp)-mediated drug resistance is the main obstacle to successfully implementing microtubule-targeted tumor chemotherapy. Purpose In this study, we explored the effect of Ad-hTERTp-E1a-Apoptin (Ad-VT) on drug-resistant cell lines and the molecular mechanism by which Ad-VT combined with chemotherapy affects drug-resistant cells and parental cells. Methods In vitro, cell proliferation, colony formation, resistance index (RI), apoptosis and autophagy assays were performed. Protein expression was analyzed by Western blotting. Finally, a xenograft tumor model in nude mice was used to detect tumor growth and evaluate histological characteristics. Results Our results showed that Ad-VT had an obvious killing effect on A549, A549/GEM and A549/Paclitaxel cancer cells, and the sensitivity of drug-resistant cell lines to Ad-VT was significantly higher than that of parental A549 cells. Compared with A549 cells, A549/GEM and A549/Paclitaxel cells had higher autophagy levels and higher viral replication ability. Ad-VT decreased the levels of p-PI3k, p-Akt and p-mTOR and the expression of P-gp. In vivo, Ad-VT combined with chemotherapy can effectively inhibit the growth of chemotherapy-resistant tumors and prolong the survival of mice. Conclusions Thus, the combination of Ad-VT and chemotherapeutic drugs will be a promising strategy to overcome chemoresistance.

Chlorin e6 mediated photodynamic therapy triggers resistance through ATM-related DNA damage response in lung cancer cells

OBJECTIVE

Photodynamic therapy (PDT) has emerged as a promising strategy in the treatment of malignant tumors due to its high selectivity, non-toxicity, and non-invasiveness. However, PDT can also induce DNA damage and subsequent repair response, which may reduce the efficacy of PDT. In the present study, we sought to explore the effect of chlorin e6 (Ce6)-mediated PDT on DNA damage and DNA damage response (DDR) in lung cancer cells. In addition, the effect of PDT combined with ATM inhibitor on molecules of DDR and the possibility of improving the efficacy of PDT were further investigated.

MATERIALS AND METHODS

In the in vitro study, lewis cells were submitted to Ce6 treatment (2, 4, 8, 16, 32 μg/mL). To determine the concentration of Ce6, uptake and toxicity of Ce6 mediated PDT were detected using flow cytometry (FACS), Confocal microscopy, and CCK-8. In the subsequent research, 8 μg/mL of Ce6 was the treatment condition for inducing PDT. The different post-irradiation placement times were further grouped under this condition (2, 4, 6, 12 h). Cellular reactive oxygen species (ROS), damage of DNA were measured by DCFH-DA probe, comet assay respectively. Then the expression of p-ATM, p53, and γ-H2A.X proteins related to DNA damage response, was detected by WB. The efficacy of Ce6 induced PDT was also demonstrated by Annexin-V/PI staining as well as the expression of PCNA, cleaved-caspase-3. On this basis, ATM inhibitor was applied to treat lewis cells combined with Ce6 (2, 4 h) to investigate whether the efficacy of PDT induced by Ce6 can be improved after the ATM-related DDR was blocked. The cell viability, apoptosis, and expression of associated proteins were assayed.

RESULTS

At 2-4 h after PDT treatment, ROS was dramatically elevated in lewis cells, DNA double-strand breaks (DDSB) occurred, as well as up-regulation of DDR proteins γ-H2A.X, p-ATM, and p53. At the same time, lewis cells did not undergo significant apoptosis. After ATM inhibition, the DDR was significantly blocked within 2-4 hours after Ce6 induced PDT, along with a pronounced decrease in cell viability followed by a prominent increase of apoptosis.

CONCLUSION

Ce6-mediated PDT generates ROS in a short period time, thus inducing DNA damage, ATM-related DDR as well as promoting resistance of lung cancer cells to PDT. Combining ATM inhibitor with PDT could effectively inhibit the DDR induced by PDT, thereby enhancing the efficacy. This study reveals a new resistance mechanism of PDT and proposes an intervention strategy.

Antitumor activities of Aspiletrein A, a steroidal saponin from Aspidistra letreae, on non-small cell lung cancer cells

BACKGROUND

Lung cancer is one of the leading causes of death worldwide due to its strong proliferative and metastatic capabilities. The suppression of these aggressive behaviors is of interest in anticancer drug research and discovery. In recent years, many plants have been explored in order to discover new bioactive secondary metabolites to treat cancers or enhance treatment efficiency. Aspiletrein A (AA) is a steroidal saponin isolated from the whole endemic species Aspidistra letreae in Vietnam. Previously, elucidation of the structure of AA and screening of its cytotoxic activity against several cancer cell lines were reported. However, the antitumor activities and mechanisms of action have not yet been elucidated. In this study, we demonstrated the anti-proliferative, anti-migrative and anti-invasive effects of AA on H460, H23 and A549 human lung cancer cells.

METHODS

MTT, wound healing and Transwell invasion assays were used to evaluate the anti-proliferation, anti-migration and anti-invasion effects of AA, respectively. Moreover, the inhibitory effect of AA on the activity of protein kinase B (Akt), a central mediator of cancer properties, and apoptotic regulators in the Bcl-2 family proteins were investigated by Western blotting.

RESULTS

AA exhibits antimetastatic effects in human lung cancer cells through the inhibition of the pAkt/Akt signaling pathway, which in turn resulted in a significant inhibitory effect of AA on the migration and invasion of the examined lung cancer cells.

CONCLUSIONS

Aspiletrein A may be a potent inhibitor of protein kinase B (Akt). Hence, AA could be further explored as a potential antimetastatic lead compound.

Cytotoxicity of glucoevatromonoside alone and in combination with chemotherapy drugs and their effects on Na+,K+-ATPase and ion channels on lung cancer cells

Cardiac glycosides (CGs) are useful drugs to treat cardiac illnesses and have potent cytotoxic and anticancer effects in cultured cells and animal models. Their receptor is the Na⁺,K⁺ ATPase, but other plasma membrane proteins might bind CGs as well. Herein, we evaluated the short- and long-lasting cytotoxic effects of the natural cardenolide glucoevatromonoside (GEV) on non-small-cell lung cancer H460 cells. We also tested GEV effects on Na⁺,K⁺ -ATPase activity and membrane currents, alone or in combination with selected chemotherapy drugs. GEV reduced viability, migration, and invasion of H460 cells spheroids. It also induced cell cycle arrest and death and reduced the clonogenic survival and cumulative population doubling. GEV inhibited Na⁺,K⁺-ATPase activity on A549 and H460 cells and purified pig kidney cells membrane. However, it showed no activity on the human red blood cell plasma membrane. Additionally, GEV triggered a Cl-mediated conductance on H460 cells without affecting the transient voltage-gated sodium current. The administration of GEV in combination with the chemotherapeutic drugs paclitaxel (PAC), cisplatin (CIS), irinotecan (IRI), and etoposide (ETO) showed synergistic antiproliferative effects, especially when combined with GEV + CIS and GEV + PAC. Taken together, our results demonstrate that GEV is a potential drug for cancer therapy because it reduces lung cancer H460 cell viability, migration, and invasion. Our results also reveal a link between the Na⁺,K⁺-ATPase and Cl^- ion channels.

Purification and characterization of a novel white highly thermo stable laccase from a novel Bacillus sp. MSK-01 having potential to be used as anticancer agent

Laccases are multicoopper oxidases catalyzing the oxidation of phenolic as well as non-phenolic compounds. Laccases show typical blue color due to the presence of covalent Type 1 Cu-Cys bond which absorbs at 600 nm. However, recently some white laccases have also been identified which lacks typical spectra of blue laccases and do not show peak at 600 nm. In the present study, a novel white laccase was isolated from Bacillus sp. MSK-01. MSK laccase was purified and characterized in detail and the purified laccase was referred to MSKLAC. It has a molecular weight of 32 KDa. UV-visible spectrum of purified MSKLAC do not show characteristic peak at 600 nm and bend at 330 nm. The enzyme was repressed by conventional inhibitors of laccase like sodium azide, cysteine, dithiothreitol and β-mercaptoethanol. The laccase was highly thermo-stable enzyme having optimum temperature of 75 °C and could treasure more than 50% activity even at 100 °C. The optimum pH for ABTS and guaiacol was 4.5 and 8.0 respectively. MSKLAC was stable in the presence of most of the metal ions and surfactants. The effect of MSKLAC on lung cancer cell line was also assessed. It was observed that MSKLAC is inhibitory to lung cell cancer line. Thus, MSKLAC has potential to be used as an anti-proliferative agent to cancer cells.

Inhibition of lysine acetyltransferases impairs tumor angiogenesis acting on both endothelial and tumor cells

Background

Understanding the signalling pathways involved in angiogenesis, and developing anti-angiogenic drugs are one of the major focuses on cancer research. Herein, we assessed the effect of CPTH6, a lysine acetyltransferase inhibitor and anti-tumoral compound, on angiogenesis-related properties of both endothelial and cancer cells.

Methods

The in vitro effect of CPTH6 on protein acetylation and anti-angiogenic properties on endothelial and lung cancer cells was evaluated via wound healing, trans-well invasion and migration, tube formation, immunoblotting and immunofluorescence. Matrigel plug assay, zebrafish embryo and mouse xenograft models were used to evaluate in vivo anti-angiogenic effect of CPTH6.

Results

CPTH6 impaired in vitro endothelial angiogenesis-related functions, and decreased the in vivo vascularization both in mice xenografts and zebrafish embryos. Mechanistically, CPTH6 reduced α-tubulin acetylation and induced accumulation of acetylated microtubules in the perinuclear region of endothelial cells. Interestingly, CPTH6 also affected the angiogenesis-related properties of lung cancer cells, and conditioned media derived from CPTH6-treated lung cancer cells impaired endothelial cells morphogenesis. CPTH6 also modulated the VEGF/VEGFR2 pathway, and reshaped cytoskeletal organization of lung cancer cells. Finally, anti-migratory effect of CPTH6, dependent on α-tubulin acetylation, was also demonstrated by genetic approaches in lung cancer cells.

Conclusion

Overall, this study indicates that α-tubulin acetylation could play a role in the anti-angiogenic effect of CPTH6 and, more in general, it adds information to the role of histone acetyltransferases in tumor angiogenesis, and proposes the inhibition of these enzymes as an antiangiogenic therapy of cancer.

Exosomes carrying ALDOA and ALDH3A1 from irradiated lung cancer cells enhance migration and invasion of recipients by accelerating glycolysis

Lung cancer has been recognized as the leading cause of cancer-related death worldwide. Despite the improvements of treatment, the distant metastasis and recurrence of lung cancer caused by therapy resistance is the biggest challenge in clinical management. Extracellular vesicles named exosomes play crucial roles in intercellular communication as signaling mediators and are involved in tumor development. In this study, we isolated exosomes from irradiated lung cancer cells and co-cultured the exosomes with other lung cancer cells. It was found that cellular growth and motility of recipient cells were facilitated. High-throughput LC-MS/MS assay of exosomal proteins and Gene Ontology enrichment analyses indicated that the metabolic enzymes ALDOA and ALDH3A1 had potential contribution in exosome-enhanced motility of recipient cells, and clinical survival analysis demonstrated the close correlations between ALDOA or ALDH3A1 expression and poor prognosis of lung cancer patients. After co-culturing with exosomes derived from irradiated cancer cells, the expressions of these metabolic enzymes were elevated and the glycolytic activity was promoted in recipient cancer cells. In conclusion, our data suggested that exosomes from irradiated lung cancer cells regulated the motility of recipient cells by accelerating glycolytic process, where exosomal ALDOA and ALDH3A1 proteins were important signaling factors.

Biocompatible thiolate protected copper nanoclusters for an efficient imaging of lung cancer cells

We report, the one-pot synthesis of water-soluble and biocompatible 3-mercaptopropylsulfonate (MPS) protected novel copper nanoclusters (CuNCs). Interestingly, the TEM image of MPS protected CuNCs exhibits an ultrasmall nanoclusters of particle size <2-nm, similar to its Au and Ag analogue. The hydrophilic and biocompability property of thiolate protected CuNCs. i.e., MPS stabilized CuNCs and its luminescent nature gave rise to maximum quantum yield of 1.5%. Further, as achieved CuNCs was investigated for haemocompatibility, cell viability and fluorescent microscopic analysis with A549 lung cancer cell line. Haemolytic study was examined using human RBCs in the concentration range of 4 to 22 μg/mL for which 7.5% of haemolysis was obtained for an optimum concentration of 22 μg/mL of CuNCs. The cell viability analysis was carried out by MTT assay using A549 lung cancer cells for the minimum (10 μg/mL) and maximum (45 μg/mL) concentration of CuNCs which reports 93.1% and 38.2% cell viability respectively. The inverted light microscopic images from the control and CuNCs treated (20 μg/mL) cells exhibited an excellent biocompatibility with a normal morphology. Upon increasing the concentration of CuNCs upto 45 μg/mL, the cell viability trends to decrease and the cell morphology also denature gradually. Further, the bio-imaging application of CuNCs was analyzed with A549 lung cancer cells. The efficient imaging with CuNCs treated (20 μg/mL) A549 cells resulted in a green colour emission using FITC filter (460- 490 nm). Thereby the obtained results confirm the applicability of CuNCs for the biomedical and cancer diagnosis applications.

Effects of lysophosphatidic acid (LPA) receptor-2 (LPA2) and LPA3 on the regulation of chemoresistance to anticancer drug in lung cancer cells

Lysophosphatidic acid (LPA) mediates a variety of biological functions via the binding of G protein-coupled LPA receptors (LPA receptor-1 (LPA₁) to LPA₆). This study aimed to investigate the roles of LPA₂ and LPA₃ in the modulation of chemoresistance to anticancer drug in lung cancer A549 cells. In cell survival assay, cells were treated with cisplatin (CDDP) every 24 h for 2 days. The cell survival rate to CDDP of A549 cells was significantly elevated by an LPA₂ agonist, GRI-977143. To evaluate the roles of LPA₂-mediated signaling in cell survival during tumor progression, highly migratory (A549-R10) cells were generated from A549 cells. In the presence of GRI-977143, the cell survival rate to CDDP of A549-R10 cells were markedly higher than that of A549 cells, correlating with LPAR2 expression level. Moreover, to assess the effects of long-term anticancer drug treatment on cell survival, the long-term CDDP treated (A549-CDDP) cells were established from A549 cells. The cell survival rate to CDDP of A549-CDDP cells was elevated by GRI-977143. Since LPAR3 expression level was significantly higher in A549-CDDP cells than in A549 cells, we investigated the roles of LPA₃ in the cell survival to CDDP of A549 cells, using an LPA₃ agonist, 1-oleoyl-2-methyl-sn-glycero-3-phosphothionate ((2S)-OMPT). The cell survival rate to CDDP of A549 cells was significantly reduced by (2S)-OMPT treatment. In the presence of (2S)-OMPT, the cell survival rate to CDDP of A549 cells was elevated by LPA₃ knockdown. These results suggest that LPA signaling via LPA₂ and LPA₃ is involved in the regulation of chemoresistance in A549 cells treated with CDDP.

Impact of electronic cigarette heating coil resistance on the production of reactive carbonyls, reactive oxygen species and induction of cytotoxicity in human lung cancer cells in vitro

Electronic cigarette (e-cigarette; e-cig) use has grown exponentially in recent years despite their unknown health effects. E-cig aerosols are now known to contain hazardous chemical compounds, including carbonyls and reactive oxygen species (ROS), and these compounds are directly inhaled by consumers during e-cig use. Both carbonyls and ROS are formed when the liquid comes into contact with a heating element that is housed within an e-cig's atomizer. In the present study, the effect of coil resistance (1.5 Ω and 0.25 Ω coils, to obtain a total wattage of 8 ± 2 W and 40 ± 5 W, respectively) on the generation of carbonyls (formaldehyde, acetaldehyde, acrolein) and ROS was investigated. The effect of the aerosols generated by different coils on the viability of H1299 human lung carcinoma cells was also evaluated. Our results show a significant (p < 0.05) correlation between the low resistance coils and the generation of higher concentrations of the selected carbonyls and ROS in e-cig aerosols. Moreover, exposure to e-cig vapor reduced the viability of H1299 cells by up to 45.8%, and this effect was inversely related to coil resistance. Although further studies are needed to better elucidate the potential toxicity of e-cig emissions, our results suggest that these devices may expose users to hazardous compounds which, in turn, may promote chronic respiratory diseases.

Novel thiosemicarbazones induce high toxicity in estrogen-receptor-positive breast cancer cells (MCF7) and exacerbate cisplatin effectiveness in triple-negative breast (MDA-MB231) and lung adenocarcinoma (A549) cells

Cis-diamminedichloroplatinum(II) (CDDP), known as cisplatin, has been extensively used against breast cancer, which is the most frequent cancer among women, and lung cancer, the leading cancer that causes death worldwide. Novel compounds such as thiazole derivatives have exhibited antiproliferative activity, suggesting they could be useful against cancer treatment. Herein, we synthesized two novel thiosemicarbazones and an aldehyde to combine with CDDP to enhance efficacy against ER-positive breast MCF7 cancer cells, triple-negative/basal-B mammary carcinoma cells (MDA-MB231) and lung adenocarcinoma (A549) human cells. We synthesized 2,3,5,6-tetrafluoro-4-(2-mercaptoetanothiolyl)benzaldehyde (ALD), 5-[(2,3,5,6-tetrafluoro-4-(trifluoromethyl)phenyl)thio]-2-furaldehyde thiosemicarbazone (TSC1) and 5-[(4-(trifluoromethyl)phenyl)thio]-2-furaldehyde thiosemicarbazone (TSC2) and used them alone or in combination with subtoxic CDDP concentrations to evaluate cytotoxicity, cytoskeleton integrity and mitochondrial function. We found that none of the synthesized compounds improved CDDP activity against MCF7 cell cultures; however, TSC2 was effective in enhancing the cytotoxicity of CDDP against MDA-MB231 and A549 cancer cell cultures. We demonstrated that the cytotoxic effect is related to the TSC2 capacity to induce disruption in the cytoskeleton network and to decrease mitochondrial function.

New naphthalene derivatives induce human lung cancer A549 cell apoptosis via ROS-mediated MAPKs, Akt, and STAT3 signaling pathways

1,4-Naphthoquinone compounds are a class of organic compounds derived from naphthalene. They exert a wide variety of biological effects, but when used as anticancer drugs, have varying levels of side effects. In the present study, in order to reduce toxicity and improve the antitumor activity, we synthesized two novel 1,4-naphthoquinone derivatives, 2-(butane-1-sulfinyl)-1,4-naphthoquinone (BSQ) and 2-(octane-1-sulfinyl)-1,4-naphthoquinone (OSQ). We investigated the antitumor effects of BSQ and OSQ in human lung cancer cells and the underlying molecular mechanisms of these effects, focusing on the relationship between these compounds and reactive oxygen species (ROS) production. MTT assay and trypan blue exclusion assay results showed that BSQ and OSQ had significant cytotoxic effects in human lung cancer cells. Flow cytometry results indicated that the number of apoptotic cells and the intracellular ROS levels significantly increased after treatment with BSQ and OSQ. However, cell apoptosis was inhibited by pretreatment with the ROS scavenger N-acetyl-l-cysteine (NAC). Western blotting results showed that BSQ and OSQ increased the expression levels of p-p38 kinase and p-c-Jun N-terminal kinase (p-JNK), and decreased the expression levels of p-extracellular signal-regulated kinase (p-ERK), p-protein kinase B (p-Akt), and p-signal transducer and activator of transcription-3 (p-STAT3). These phenomena were blocked by mitogen-activated protein kinase (MAPK) inhibitors, Akt inhibitors and NAC. In conclusion, BSQ and OSQ induce human lung cancer A549 cell apoptosis by ROS-mediated MAPKs, Akt, and STAT3 signaling pathways. Therefore, BSQ and OSQ may be therapeutic potential agents for the treatment of human lung cancer.

Thrombin binding aptamer analogues containing inversion of polarity sites endowed with antiproliferative and anti-motility properties against Calu-6 cells

BACKGROUND

Although the thrombin binding aptamer (TBA) is endowed with both anticoagulant and antiproliferative properties, it is possible to reduce the first and enhance the second one by suitable chemical modifications.

METHODS

Two oligonucleotides (TBA353 and TBA535) based on the TBA sequence (GGTTGGTGTGGTTGG) and containing inversion of polarity sites have been investigated by CD, UV and electrophoretic techniques for their ability to form G-quadruplex structures. Furthermore, their anticoagulant (PT assay), antiproliferative (MTT assay) and anti-motility (wound healing assay) properties against Calu-6 cells have been tested and compared with TBA.

RESULTS

CD, UV and electrophoresis data indicate that both ODNs are able to form G-quadruplex structures. Particularly, results suggest that TBA535 adopts a G-quadruplex structure characterized by a loop arrangement different from that of TBA. Both TBA analogues drop the anticoagulant activity. However, TBA535 is endowed with a significant antiproliferative activity against lung cancer Calu-6 cells. Importantly, both TBA and TBA535 possess a remarkable anti-motility property against the same cell line.

CONCLUSIONS

Both TBA analogues TBA353 and TBA535 are able to form G-quadruplex structures with no anticoagulant activity. However only TBA535 is endowed with noteworthy antiproliferative and anti-motility properties against lung cancer Calu-6 cells.

GENERAL SIGNIFICANCE

The switching from the anticoagulant to antiproliferative property can be obtained also in TBA derivatives not adopting the "chair-like" G-quadruplex structure typical of TBA. Furthermore, results have highlighted an unprecedented anti-cell-motility property of TBA and TBA535 reinforcing the potential of these ODNs as anticancer drugs.

Resveratrol sensitizes lung cancer cell to TRAIL by p53 independent and suppression of Akt/NF-κB signaling

AIMS

TRAIL is a promising anticancer agent that has the potential to sensitize a wide variety of cancer or transformed cells by inducing apoptosis. However, resistance to TRAIL is a growing concern. Current manuscript aimed to employ combination treatment to investigate resveratrol induced TRAIL sensitization in NSCLC.

METHOD

A549 and HCC-15 cells were used in an experimental design. Cell viability was determined by morphological image, crystal violet staining and MTT assay. Apoptosis was evaluated by LDH assay, Annexin V and DAPI staining. Autophagy and apoptosis indicator protein were examined by western blotting. TEM and puncta assay was carried out to evaluate the autophagy. MTP and ROS activity was evaluated by JC-1 and H₂DCFDA staining.

FINDINGS

Resveratrol is a polyphenolic compound capable of activation of tumor suppressor p53 and its pro-apoptotic modulator PUMA. Herein, we showed the p53-independent apoptosis by decrease the expression of phosphorylated Akt-mediated suppression of NF-κB that is also substantiated with the downregulation of anti-apoptotic factors Bcl-2 and Bcl-xl in NSCLC, resulting in an attenuation of TRAIL resistance in combined treatment. Furthermore, apoptosis was induced in TRAIL-resistant lung cancer cells with a co-treatment of resveratrol and TRAIL assessed by the loss of MMP, ROS generations which resulting the translocation of cytochrome c from the mitochondria into the cytosol due to mitochondrial dysfunction. Moreover, autophagy flux was not affected by resveratrol-induced TRAIL-mediated apoptosis in NSCLC.

SIGNIFICANCE

Overall, targeting the NF-κB (p65) pathway via resveratrol attenuates TRAIL resistance and induces TRAIL-mediated apoptosis which could be the effective TRAIL-based cancer therapy regimen.

Modulation of serum albumin protein corona for exploring cellular behaviors of fattigation-platform nanoparticles

Albumin is the most abundant protein in blood, and is the most frequently identified protein in the protein corona of nanoparticles (NPs). Thus, albumin plays an important role in modulating NPs' physicochemical properties and bioavailability. In this study, the effect of bovine serum albumin (BSA) on gelatin-oleic nanoparticles' (GONs) physicochemical properties and cellular uptake were evaluated. Coumarin-6 was used as indicator to track the cellular uptake of GONs. The binding of BSA onto the GON surface increased the size, slightly reduced the negative net charge of the GON, and improved GON stability. The presence of BSA in cell culture media reduced the cellular uptake of BSA-uncoated GONs on human embryonic kidney cells 293 (HEK 293) and human adenocarcinoma alveolar basal epithelial cells (A549) in the media without FBS addition. Pre-coated BSA corona decreased cellular uptake of GONs in A549 cells in the media, with and without supplemented with 10% fetal bovine serum (FBS) but drastically increased cellular uptake on HEK 293 cells. BSA could be used to modulate protein corona as an endogenous ligand in NP design simply by mixing or incubating BSA with NPs before in vivo administration to inhibit or induce cellular uptake in specific cell types.

Antihypertensive drug-candesartan attenuates TRAIL resistance in human lung cancer via AMPK-mediated inhibition of autophagy flux

Angiotensin II type 1 receptor blockers (ARBs) are widely used as antihypertensive drugs. Candesartan is an ARB that has also been known for its anticancer effects but the exact molecular mechanism is remaining elusive. In this research, we showed for the first time that candesartan treatment significantly sensitized human lung adenocarcinoma cells to Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-mediated apoptosis by targeting TRAIL-DR5. TRAIL selectively kills cancer cells by binding to death receptors on the cell membrane, beyond the levels causing minimal toxicity in normal cells. However, some non-small-cell lung carcinoma (NSCLC) patients are resistant to TRAIL treatment in clinical trials due to inactivation of the death receptors during cytoprotective autophagy. The molecular mechanisms underlying candesartan-induced TRAIL-mediated apoptosis involved the downstream of AMPK phosphorylation resulting inhibition of autophagy flux, recruitment of death receptor 5 (DR5) and activation of apoptotic caspase cascade. Candesartan treatment also inhibits the expression of anti-apoptotic protein c-FLIP. Furthermore, blocking DR5 signaling using DR5 siRNA negatively regulated the apoptotic pathway and also induced autophagy flux, demonstrating the cytoprotective role of autophagy responsible for treatment resistance. This suggests that candesartan can be used to sensitize tumors to TRAIL treatment and may represent a useful strategy for human adenocarcinoma patients to overcome TRAIL resistance. Candesartan in combination with TRAIL also could be a novel therapeutic treatment for patients presenting both conditions of hypertension and lung cancer.

Glycosylated and non-glycosylated quantum dot-displayed peptides trafficked indiscriminately inside lung cancer cells but discriminately sorted in normal lung cells: An indispensable part in nanoparticle-based intracellular drug delivery

Difference in sub-cellular trafficking of glycosylated and naked peptides, between normal and lung cancer cells, was established. Normal lung tissue discriminately sorted glycosylated from non-glycosylated peptides by allowing golgi localization of the glycosylated peptides while restricting golgi entry of the naked peptides. This mechanism was surprisingly not observed in its cancer cell counterpart. Lung cancer cells tend to allow unrestricted localization of both glycosylated and naked peptides in the golgi apparatus. This newly discovered difference in sub-cellular trafficking between normal and lung cancer cells could potentially be used as an effective strategy in targeted intracellular delivery, especially targeting golgi-resident enzymes for possible treatment of diseases associated with glycans and glycoproteins, such as, congenital disease of glycosylation (CDG). This very important detail in intracellular trafficking inside normal and cancer cells is an indispensable part in nanoparticle-based intracellular drug delivery.

Dihydroartemisinin Sensitizes Human Lung Adenocarcinoma A549 Cells to Arsenic Trioxide via Apoptosis

Recent studies have shown that arsenic trioxide (ATO) is an effective anti-cancer drug for treatment of acute promyelocytic leukemia and other types of human cancer. However, we have found that lung cancer cells constantly develop a high level of resistance to ATO. In this study, we have explored a possibility of combination of dihydroartemisinin (DHA) and ATO treatments to reduce ATO resistance of lung cancer cells. We determined the combinatory effects of DHA and ATO on cytotoxicity of human lung adenocarcinoma (A549) cells. We showed that co-exposure to DHA and ATO of A549 cells synergistically increased the cytotoxicity and apoptotic cell death in the cells. We found that the synergistic effect of DHA and ATO in promoting apoptosis mainly resulted from increased cellular level of reactive oxygen species (ROS) and DNA damage. ATO alone only exerted moderate growth inhibitory effects on A549 cells. The results indicate that DHA can significantly sensitize ATO-induced cytotoxicity of A549 lung cancer cells through apoptosis mediated by ROS-induced DNA damage. Interestingly, we found that the combinatory treatment of DHA and ATO did not result in significant adverse effects in normal human bronchial epithelial (HBE) cells. Our results further provide evidence for the potential application of combinatory effects of DHA and ATO as a safe therapy for human lung cancer.

The extracellular vesicles secreted by lung cancer cells in radiation therapy promote endothelial cell angiogenesis by transferring miR-23a

Angiogenesis is an important factor contributing to the radioresistance of lung cancer. However, the associated mechanisms underlying radiotherapy-induced pro-angiogenesis are unclear. Here, we demonstrated that Extracellular vesicles (EVs) derived from cultured cells in vitro enhanced HUVEC proliferation and migration, and the enhancement effect became more obvious when HUVECs were treated with EV derived from A549 or H1299, two lung cancer cell lines. Additionally, the pro-angiogenesis effect induced by EV could be strengthened when the lung cancer cells were exposed to X-ray irradiation. Furthermore, we verified that the downregulation of PTEN plays a vital role in this process. By evaluating the changes in the levels of microRNAs(miRNAs) targeting PTEN in EV, we found that miR-23a was significantly upregulated and mediated a decrease in PTEN. A luciferase reporter gene transfer experiment demonstrated that PTEN was the direct target of miR-23a, and the kinetics of PTEN expression were opposite to those of miR-23a. Our results show that the miR-23a/PTEN pathway plays an important role in EV-induced angiogenesis. These findings implicate the miR-23a/PTEN axis as a novel therapeutic target for lung cancer radiotherapy.

Enterolactone alters FAK-Src signaling and suppresses migration and invasion of lung cancer cell lines

Background

Systemic toxicity of chemotherapeutic agents and the challenges associated with targeting metastatic tumors are limiting factors for current lung cancer therapeutic approaches. To address these issues, plant-derived bioactive components have been investigated for their anti-cancer properties because many of these agents are non-toxic to healthy tissues. Enterolactone (EL) is a flaxseed-derived mammalian lignan that has demonstrated anti-migratory properties for various cancers, but EL has not been investigated in the context of lung cancer, and its anticancer mechanisms are ill-defined. We hypothesized that EL could inhibit lung cancer cell motility by affecting the FAK-Src signaling pathway.

Methods

Non-toxic concentrations of EL were identified for A549 and H460 human lung cancer cells by conducting 3-(4, 5-Dimethylthiazol-2-yl)-2, 5-Dephenyltetrazolium Bromide (MTT) assays. The anti-migratory and anti-invasive potential of EL for lung cancer cell lines was determined by scratch wound healing and Matrigel® invasion assays. Changes in filamentous actin (F-actin) fiber density and length in EL-treated cells were determined using phalloidin-conjugated rhodamine dye and fluorescent microscopy. Vinculin expression in focal adhesions upon EL treatment was determined by immunocytochemistry. Gene and protein expression levels of FAK-Src signaling molecules in EL-treated lung cancer cells were determined using PCR arrays, qRT-PCR, and western blotting.

Results

Non-toxic concentrations of EL inhibited lung cancer cell migration and invasion in a concentration- and time-dependent manner. EL treatment reduced the density and number of F-actin fibers in lung cancer cell lines, and reduced the number and size of focal adhesions. EL decreased phosphorylation of FAK and its downstream targets, Src, paxillin, and decreased mRNA expression of cell motility-related genes, RhoA, Rac1, and Cdc42 in lung cancer cells.

Conclusions

Our data suggest that EL suppresses lung cancer cell motility and invasion by altering FAK activity and subsequent activation of downstream proteins needed for focal adhesion formation and cytoskeletal rearrangement. Therefore, administration of EL may serve as a safe and complementary approach for inhibiting lung tumor cell motility, invasion, and metastasis.

Electronic supplementary material

The online version of this article (doi:10.1186/s12906-016-1512-3) contains supplementary material, which is available to authorized users.

Cytotoxic activity of Androctonus australis hector venom and its toxic fractions on human lung cancer cell line

Background

Several studies have showed that animal venoms are a source of bioactive compounds that may inhibit the growth of cancer cells, which makes them useful agents for therapeutic applications. Recently, it was established that venom toxins from scorpions induced cytotoxic, antiproliferative and apoptogenic effects on cancer cells. Therefore, the present study aims to investigate the cytotoxic activity of Androctonus australis hector (Aah) scorpion venom and its toxic fractions (FtoxG-50 and F3) on NCI-H358 human lung cancer cells.

Methods

The cytotoxic and antiproliferative activities were estimated using MTT assay, lactate dehydrogenase release and clonogenic assays. Apoptosis was evaluated by Hoechst 33258 staining, DNA fragmentation assay and caspase-3 activity. Oxidative stress was analyzed by reactive oxygen species, nitric oxide, malondialdehyde and protein carbonyl levels along with assessment of antioxidant status. In addition, alteration of mitochondrial membrane potential was analyzed by JC1 fluorescent dye.

Results

The present findings showed that F3 fraction was more cytotoxic towards NCI-H358 lung cancer cells with an IC₅₀ of 27.05 ± 0.70 μg/mL than venom alone (396.60 ± 1.33 μg/mL) and its toxic fraction FtoxG-50 (45.86 ± 0.91 μg/mL). Nevertheless, F3 fraction was not cytotoxic at these concentrations on normal human lung fibroblast MRC-5 cells. Inhibition of NCI-H358 cell proliferation after F3 fraction exposure occurred mainly by apoptosis as evidenced by damaged nuclei, significant DNA fragmentation level and caspase-3 activation in a dose dependent manner. Moreover, F3 fraction enhanced oxidative and nitrosative stress biomarkers and dissipated mitochondrial membrane potential in lung cancer cells along with significant depletion in cellular enzymatic and non-enzymatic antioxidants. Further, the apoptosis induced by F3 fraction was markedly prevented by the antioxidant N-acetylcysteine (NAC) suggesting the potential mechanism of oxidative stress.

Conclusion

These findings suggest that F3 fraction could induce apoptosis in lung cancer cells through involvement of oxidative stress and mitochondrial dysfunction. Hence, these properties make F3 fraction a promising candidate for development of new anticancer agents.

Anticancer effect of SZC015 on lung cancer cells through ROS-dependent apoptosis and autophagy induction mechanisms in vitro

Oleanolic acid (OA) and its several derivatives possess various pharmacological activities, such as antitumor and anti-inflammation. In present study, anticancer effect of SZC015, an OA derivative, and its underlying mechanisms were investigated. We demonstrated that cell viability was significantly decreased in SZC015-treated lung cancer cells, but has less cytotoxicity in human bronchial epithelial cell line. Further investigation verified that apoptosis and autophagy induction and G₀/G₁ phase arrest were observed in SZC015-treated H322 cells. Mechanically, the level of Akt, p-Akt, p-IκBα, and total p65, the p-p65 in the cytoplasm and nucleus were suppressed by SZC015 in H322 cells, respectively. Inhibition of p65 nuclear translocation was also confirmed by immunofluorescence staining. In addition, co-treatment with chloroquine, an autophagy inhibitor, significantly inhibited SZC015-induced autophagy and enhanced SZC015-induced apoptotic cell death. Intracellular ROS was increased in a concentration-dependent manner, which could be prevented by N-Acetyl l-Cysteine, an ROS scavenger. Moreover, the level of Akt and procaspase-3 were increased, while the ratio of LC3 II/I was decreased. Taken together, our study demonstrates that the inhibitory effect of SZC015 against H322 cells is mediated by excessive ROS generation that could suppress Akt/NF-κB signaling pathway, which thereby leads to apoptotic and autophagic cell death.

Chemosensitizing effect of Paris Saponin I on Camptothecin and 10-hydroxycamptothecin in lung cancer cells via p38 MAPK, ERK, and Akt signaling pathways

Paris Saponin I (PSI), a steroidal sponins isolated from plant, has been exhibited antitumor and many other biological activities. In this study, we investigated the role and underlying mechanisms of PSI in the synergistic regulation of antitumor activity of Camptothecin (CPT) and 10-hydroxycamptothecin (HCPT) in four types of lung cancer cells. The inhibitory evaluation showed that PSI could significantly reduce the CPT/HCPT-mediated cell proliferation and enhance the sensitivities of H1299, H460 and H446 lung cancer cells to CPT/HCPT. Mechanism study indicated that PSI improved the CPT/HCPT induced apoptosis in lung cancer cells through mitochondria pathway including cytochrome C release and activation of caspase-9 and -3 cascades. Furthermore, PSI plus CPT/HCPT also increased the up-regulation of Bax and down-regulation of Bcl-2 and Bcl-XL in H460 and H446 cells. Moreover, PSI enhanced CPT/HCPT-mediated inhibition of p38 MAPK and activation of phosphorylation of p38 MAPK in H1299 cells, and suppression of Akt and ERK pathways activation in H460 cells as well as in H446 cells. Collectively, our results demonstrated that PSI functions as a chemosensitizer by enhancing apoptosis through influencing p38 MAPK, ERK, and Akt pathways in lung cancer cells, and the combination with CPT/HCPT might be a promising strategy for the development of new therapeutic agents.

The PDRG1 is an oncogene in lung cancer cells, promoting radioresistance via the ATM-P53 signaling pathway. Biomed Pharmacother. 2016;83:1471-1477. [PMID: 27610824 DOI: 10.1016/j.biopha.2016.08.034]

PDRG1, is short for P53 and DNA damage-regulated gene, which have been found over 10 years. Although severe studies have described the roles of PDRG1 separately in many kinds of tumors, how to act as an oncogene are unclear. To better verify the function of PDRG1 in lung cancer, both loss-function and gain-function of PDRG1 studies based on two human lung cancer lines were performed. Following the transfection of PDRG1, both A549 and 95-D cells showed significant changes in cell viability, the expression of some protein and apoptosis, which were all implied the PDRG1 is an oncogene. Another interesting finding is PDRG1 could promote radioresistance involved the ATM-p53 signaling pathway in lung cancer. If we combine radiotherapy with gene-targeted therapy together effectively, predominant effect may be acquired, which is a huge milestone in clinical cure about lung cancer.

Biotin-targeted Pluronic(®) P123/F127 mixed micelles delivering niclosamide: A repositioning strategy to treat drug-resistant lung cancer cells

With the aim to develop alternative therapeutic tools for the treatment of resistant cancers, here we propose targeted Pluronic(®) P123/F127 mixed micelles (PMM) delivering niclosamide (NCL) as a repositioning strategy to treat multidrug resistant non-small lung cancer cell lines. To build multifunctional PMM for targeting and imaging, Pluronic(®) F127 was conjugated with biotin, while Pluronic(®) P123 was fluorescently tagged with rhodamine B, in both cases at one of the two hydroxyl end groups. This design intended to avoid any interference of rhodamine B on biotin exposition on PMM surface, which is a key fundamental for cell trafficking studies. Biotin-decorated PMM were internalized more efficiently than non-targeted PMM in A549 lung cancer cells, while very low internalization was found in NHI3T3 normal fibroblasts. Biotin-decorated PMM entrapped NCL with good efficiency, displayed sustained drug release in protein-rich media and improved cytotoxicity in A549 cells as compared to free NCL (P<0.01). To go in depth into the actual therapeutic potential of NCL-loaded PMM, a cisplatin-resistant A549 lung cancer cell line (CPr-A549) was developed and its multidrug resistance tested against common chemotherapeutics. Free NCL was able to overcome chemoresistance showing cytotoxic effects in this cell line ascribable to nucleolar stress, which was associated to a significant increase of the ribosomal protein rpL3 and consequent up-regulation of p21. It is noteworthy that biotin-decorated PMM carrying NCL at low doses demonstrated a significantly higher cytotoxicity than free NCL in CPr-A549. These results point at NCL-based regimen with targeted PMM as a possible second-line chemotherapy for lung cancer showing cisplatin or multidrug resistance.

Quercetin metabolites inhibit MMP-2 expression in A549 lung cancer cells by PPAR-γ associated mechanisms

Our previous study demonstrated that quercetin-metabolite-enriched plasma (QP) but not quercetin itself upregulates peroxisome proliferator-activated receptor gamma (PPAR-γ) expression to induce G2/M arrest in A549 cells. In the present study, we incubated A549 cells with QP as well as quercetin-3-glucuronide (Q3G) and quercetin-3'-sulfate (Q3'S), two major metabolites of quercetin, to investigate the effects of quercetin metabolites on cell invasion and migration, the possible mechanisms and the role of PPAR-γ. We also compared the effects of QP with those of quercetin and troglitazone (TGZ), a PPAR-γ ligand. The results showed that QP significantly suppressed cell invasion and migration, as well as matrix metalloproteinases (MMPs)-2 activity and expression in a dose-dependent manner. The effects of 10% QP on those parameters were similar to those of 10μM quercetin and 20μM TGZ. However, QP and TGZ rather than quercetin itself increased the expressions of nm23-H1 and tissue inhibitor of metalloproteinase (TIMP-2). Furthermore, we demonstrated that Q3G and Q3'S also inhibited the protein expression of MMP-2. GW9662, a PPAR-γ antagonist, significantly diminished such an effect of Q3G and Q3'S. Silencing PPAR-γ expression in A549 cells also significantly diminished the suppression effect of Q3G and Q3'S on MMP-2 expression. Taken together, our study demonstrated that QP inhibited cell invasion and migration through nm23-H1/TIMP-2/MMP-2 associated mechanisms. The upregulation of PPAR-γ by quercetin metabolites such as Q3G and Q3'S could play an important role in the effects of QP.

cAMP signaling increases histone deacetylase 8 expression by inhibiting JNK-dependent degradation via autophagy and the proteasome system in H1299 lung cancer cells

This study aimed to investigate the roles of autophagy and the ubiquitin-proteasome system in the degradation of histone deacetylase 8 (HDAC8) and to clarify the mechanism by which cAMP signaling regulates this degradation. cAMP signaling was activated by treating H1299 non-small cell lung cancer cells with isoproterenol or forskolin/3-isobutyl-1-methylxanthine, and HDAC8 expression was assessed by western blot analysis. The inhibition of autophagy and ubiquitin-proteasome-dependent degradation increased HDAC8 expression. cAMP signaling inhibited JNK activation, which decreased the phosphorylation of Bcl-2, thereby reducing autophagy, and the phosphorylation of Itch, thereby reducing ubiquitination. These results suggest that the HDAC8 protein is degraded via autophagy and the ubiquitin-proteasome system and that cAMP signaling increases HDAC8 protein levels by reducing JNK-mediated autophagy and ubiquitin-proteasome-dependent degradation of the HDAC8 protein in H1299 lung cancer cells.

Antibacterial, antibiofilm and cytotoxic effects of Nigella sativa essential oil coated gold nanoparticles

This study reports the biological synthesis of gold nanoparticles using essential oil of Nigella sativa (NsEO-AuNPs). The synthesized NsEO-AuNPs were characterized by UV-visible spectra, X-ray diffraction (XRD), FTIR and Transmission electron microscopy (TEM). UV-vis spectra of NsEO-AuNPs showed strong absorption peak at 540 nm. The X-ray diffraction analysis revealed crystalline nature of nanoparticle with distinctive facets (111, 200, 220 and 311 planes) of NsEO-AuNPs. The FTIR spectra recorded peaks at 3388, 2842, 1685, 1607, 1391 and 1018 cm(-1). TEM studies showed the spherical shape of nanoparticles and the particle size ranges between 15.6 and 28.4 nm. The antibacterial activity of NsEO-AuNPs was greater against Gram positive Staphylococcus aureus MTCC 9542 (16 mm) than Gram negative Vibrio harveyi MTCC 7771 (5 mm) at the concentration of 10 μg ml(-1). NsEO-AuNPs effectively inhibited the biofilm formation of S. aureus and V. harveyi by decreasing the hydrophobicity index (78% and 46% respectively). The in-vitro anti-lung cancer activity confirmed by MTT assay on the cell line of A549 carcinoma cells showed IC50 values of bulk Au at 87.2 μg ml(-1), N. sativa essential oil at 64.15 μg ml(-1) and NsEO-AuNPs at 28.37 μg ml(-1). The IC50 value showed that NsEO-AuNPs was highly effective in inhibiting the A549 lung cancer cells compared to bulk Au and N. sativa essential oil.

Triptolide potentiates lung cancer cells to cisplatin-induced apoptosis by selectively inhibiting the NER activity

Background

Cisplatin and many other platinum-based compounds are important anticancer drugs that are used in treating many cancer types. The development of cisplatin-resistant cancer cells, however, quickly diminishes the effectiveness of these drugs and causes treatment failure. New strategies that reverse cancer cell drug resistance phenotype or sensitize cancer cells to these drugs, therefore, need to be explored in order to improve platinum drug-based cancer treatment. Triptolide is a bioactive ingredient isolated from Tripterygium wilfordii, a Chinese herbal medicine. Triptolide binds to the TFIIH basal transcription factor and is required for both transcription and nucleotide excision repair (NER), a DNA repair pathway involved in repairing DNA damage generated by the platinum-based anticancer drugs.

Methods

Caspase-3 activation and cell growth inhibition assays were used to determine the effect of triptolide on cisplatin-induced apoptosis and cell growth in lung cancer cells. Real time PCR, immunoblotting, and expression of reef coral red protein were used to determine a mechanism through which the presence of triptolide increased cisplatin-induced apoptosis of the lung cancer cells.

Results

Our caspase-3 activation studies demonstrated that the presence of low-levels of triptolide greatly increased the cisplatin-induced apoptosis of HTB182, A549, CRL5810, and CRL5922 lung cancer cells. The results of our cell growth inhibition studies revealed that the presence of low-levels triptolide itself had little effect on cell growth but greatly enhanced cisplatin-induced cell growth inhibition in both A549 and HTB182 cells. The results of our reef coral-red protein reporter expression studies indicated that the presence of low-levels triptolide did not affect expression of the reef coral-red protein from pDsRed2-C1 plasmid but greatly inhibited expression of the reef coral-red protein from cisplatin-damaged pDsRed2-C1 plasmid DNA in A549 cells. In addition, the results of our protein phosphorylation studies indicated that the presence of low-levels triptolide caused a decrease for cisplatin-induced CHK1 phosphorylation at Ser^317/345 but an increase for cisplatin-induced ATM phosphorylation at Ser¹⁹⁸¹ in both HTB182 and A549 cells.

Conclusion

The results of our studies suggest that the presence of low-levels of triptolide potentiates lung cancer cells to cisplatin treatment by selectively inhibiting NER activity, resulting in an increase in apoptosis of the lung cancer cells.

Sevoflurane suppresses hypoxia-induced growth and metastasis of lung cancer cells via inhibiting hypoxia-inducible factor-1α

PURPOSE

Hypoxia promotes the progression of lung cancer cells. Unfortunately, anesthetic technique might aggravate hypoxia of lung cancer cells. Sevoflurane is a commonly used anesthetic. Its effect on hypoxia-induced aggressiveness of lung cancer cells remains unknown. The aim of the study is to investigate the effects of sevoflurane on hypoxia-induced growth and metastasis of lung cancer cells. As hypoxia-inducible factor-1α (HIF-1α) plays a pivotal role in mediating the adaptation and tolerance of cancer cells under hypoxic microenvironment, the role of HIF-1α in the effect of sevoflurane on hypoxia-induced growth and metastasis has also been elucidated.

METHODS

A549 cells were treated with normoxia, hypoxia, co-treatment of sevoflurane and hypoxia, and dimethyloxaloylglycine (DMOG, a HIF-1α agonist) for 4 h, respectively. MTT assay and colony formation assay were used to evaluate cell growth. Transwell assay was performed to detect invasion and migration ability. The protein level of HIF-1α, X-linked inhibitor of apoptosis protein (XIAP), survivin, fascin, heparanase (HPA), and p38 MAPK were determined by Western blotting.

RESULTS

Hypoxia enhanced proliferation and metastatic potential of cells. Sevoflurane could suppress hypoxia-induced growth and metastasis ability of cells. Furthermore, HIF-1α, XIAP, survivin, fascin and HPA were down-regulated significantly by the co-treatment of sevoflurane and hypoxia as compared to hypoxia treatment. DMOG abolished the inhibiting effects of sevoflurane on hypoxia-induced growth and metastasis ability of cells. In addition, sevoflurane partly reversed the increase of p38 MAPK activity that was induced by hypoxia.

CONCLUSIONS

Sevoflurane could suppress hypoxia-induced growth and metastasis of lung cancer cells, which might be associated with modulating HIF-1α and its down-stream genes. Moreover, p38 MAPK signaling pathway was involved in the regulation of HIF-1α by sevoflurane.

The effect of caffeine on cisplatin-induced apoptosis of lung cancer cells

Background

Cisplatin is an important DNA-damaging anticancer drug that has been used to treat many cancer types. However, the effectiveness of cisplatin treatment diminishes quickly as cancer cells develop resistance to the drug, which eventually results in treatment failure. Caffeine is an ingredient contained in many food sources. Caffeine can inhibit activities of both ATM and ATR, two important protein kinases involved in DNA damage-induced cell cycle arrest and apoptosis. The effect of caffeine on cisplatin-based cancer treatment is not well known.

Methods

Caspase-3 activation and cell growth inhibition assays were used to determine the effect of caffeine on cisplatin-induced apoptosis and cell growth in lung cancer cells. Real time PCR, immunoblotting, and flow cytometry assays were used determine a mechanism through which the presence of caffeine increased cisplatin-induced apoptosis of the lung cancer cells.

Results

Our caspase-3 activation studies demonstrated that the presence of caffeine increased the cisplatin-induced apoptosis in both HTB182 and CRL5985 lung cancer cells. Our cell growth inhibition studies indicated that the presence of caffeine caused a more increase for cisplatin-induced cell growth inhibition. The results obtained from our real time PCR and western blot studies revealed that the presence of caffeine increased cisplatin-induced expression of the PUMA pro-apoptotic protein in these lung cancer cells. The results of our protein phosphorylation studies indicated that the presence of caffeine caused a decrease in CHK1 phosphorylation at Ser³¹⁷/Ser³⁴⁵ but an increase in ATM phosphorylation at Ser¹⁹⁸¹ in the lung cancer cells treated with cisplatin. In addition, our flow cytometry studies also revealed that the presence of caffeine caused an increase in G1 cell population but a decrease for cisplatin-induced cell cycle arrests at the S and the G2 checkpoints in HTB182 and CRL5985 cells respectively.

Conclusion

Our results suggest that the presence of caffeine increases the cisplatin-induced lung cancer cell killings by inhibiting ATR but inducing ATM activation, resulting in an increase in expression of PUMA protein and an increase in apoptosis.

5,3'-Dihydroxy-6,7,4'-trimethoxyflavanone exerts its anticancer and antiangiogenesis effects through regulation of the Akt/mTOR signaling pathway in human lung cancer cells

5,3'-Dihydroxy-6,7,4'-trimethoxyflavanone (DHTMF) is one of the constituents of Vitex rotundifolia, a medicinal herb that is used for the treatment of various disorders in China and Korea. In this study we evaluated the antitumor and antiangiogeneic activities of DHTMF. DHTMF significantly suppressed growth and induced apoptosis in lung carcinoma cells in a dose-dependent manner, as indicated by a decrease in Bcl-2 levels and increases in Bax and cleaved caspase-3 levels. In addition, DHTMF treatment significantly reduced the phosphorylation of Akt and mammalian target of rapamycin (mTOR), accompanied by reductions in the protein level of hypoxia-inducible factor (HIF-1α) and vascular endothelial growth factor (VEGF), which are key angiogenic molecules in H522 lung cancer cells. Furthermore DHTMF inhibited VEGF-induced angiogenesis, as indicated by reduced expression of CD34, tube formation and migration in human umbilical vein endothelial cells (HUVECs), as well as reduced neovascularization in an in vivo mouse Matrigel plug assay. DHTMF also inhibited phosphorylation of Akt, mTOR, and p70S6K in HUVECs and lung cancer cells. Taken together, our finding indicated that DHTMF inhibits Akt/mTOR signaling and reduces the expression of HIF-1 α and VEGF in tumor cells, which in turns inhibits endothelial cell-mediated angiogenesis. These results suggest that DHTMF inhibits angiogenesis as well as induces apoptosis via the Akt/mTOR pathway and might elicit pharmacological effects that are useful for treatment of lung cancer.

Effect of cigarette smoke condensate on gene promoter methylation in human lung cells

BACKGROUND

In lung cancer, an association between tobacco smoking and promoter DNA hypermethylation has been demonstrated for several genes. However, underlying mechanisms for promoter hypermethylation in tobacco-induced cancer are yet to be fully established.

METHODS

Promoter methylation was evaluated in control and cigarette smoke condensate (CSC) exposed human lung cells using the Methyl-Profiler DNA Methylation PCR System. PSAE cells were exposed to 0.3 or 1.0 μg/ml CSC for 72 hours and longer term for 14 and 30 days. NL-20 cells were exposed for 30 days to 10 or 100 μg/ml CSC.

RESULTS

Promoters of several genes, including hsa-let-7a-3, CHD1, CXCL12, PAX5, RASSF2, and TCF21, were highly methylated (>90%); hsa-let-7a-3 was affected in both cell lines and under all exposure conditions. Level of methylation tended to increase with CSC concentration and exposure duration (statistical differences were not determined). Percentage methylation of TCF21, which was >98% at exposures of 10 or 100 μg/ml CSC, was found to be reduced to 28% and 42%, respectively, in the presence of the dietary agent genistein.

CONCLUSIONS

Using array techniques, several tumor suppressor genes in human lung cells were identified that undergo promoter hypermethylation, providing further evidence of their potential involvement in tobacco smoke-induced lung carcinogenesis and their use as potential biomarkers of harm in tobacco smoke exposure. Results from the study also demonstrated the potential of a dietary agent to exert chemopreventive activity in human tissue against tobacco smoke related diseases through modulation of DNA methylation. Additional studies are needed to confirm these findings.

mTOR-dependent transcriptional repression of Pdcd4 tumor suppressor in lung cancer cells

Programmed cell death 4 (Pdcd4) tumor suppressor is frequently lost in tumors of various origins including lung cancer, and its loss contributes to tumor progression. However molecular mechanisms underlying Pdcd4 suppression in lung cancer cells remain largely unexplored. Here we investigated molecular mechanisms of Pdcd4 suppression in lung cancer cells. Besides enhanced mTOR-dependent proteasomal degradation of Pdcd4 protein, we found that Pdcd4 transcription is negatively regulated by mTOR signaling, and localized cis-acting element in Pdcd4 promoter responsible for this effect. In conclusion, we described a novel molecular mechanism of Pdcd4 suppression in cancer cells consisting from mTOR signaling-dependent transcriptional repression of Pdcd4.

DZNep, inhibitor of S-adenosylhomocysteine hydrolase, down-regulates expression of SETDB1 H3K9me3 HMTase in human lung cancer cells

3-Deazaneplanocin A (DZNep), an epigenetic anticancer drug, leads to the indirect suppression of S-adenosyl methionine-dependent cellular methylations by inhibiting S-adenosyl homocystein (AdoHcy) hydrolase. Although it is well known that DZNep targets the degradation of EZH2 protein, H3K27me3 HMTase, there are still uncertainties about the regulation of other types of HMTases during cell death. In this study, we describe that SETDB1 gene expression was regulated by DZNep treatment in human lung cancer cells. We confirm that DZNep induced growth inhibition and increased the dead cell population of lung cancer cells. DZNep treatment affected histone methylations, including H3K27me3 and H3K9me3, but not H3K4me3. Reduced levels of H3K27me3 and H3K9me3 were related with the decreased EZH2 and SETDB1 proteins. Real time PCR analysis showed that SETDB1 gene expression was decreased by DZNep treatment, but no effect was observed for EZH2 gene expression. We cloned the promoter region of SETDB1 and SUV39H1 genes, and performed luciferase assays. The promoter activity of SETDB1 gene was down regulated by DZNep treatment, whereas no effect on SUV39H1 promoter activity was observed. In conclusion, we suggest that DZNep regulates not only on H3K27me3 HMTase EZH2, but also H3K9 HMTase SETDB1 gene expression at the transcription level, implicating that the mechanism of action of DZNep targets multiple HMTases during the death of lung cancer cells.