Chevalones H–M: Six New α-Pyrone Meroterpenoids from the Gorgonian Coral-Derived Fungus Aspergillus hiratsukae SCSIO 7S2001

Six new α-pyrone meroterpenoid chevalones H–M (1–6), together with six known compounds (7–12), were isolated from the gorgonian coral-derived fungus Aspergillus hiratsukae SCSIO 7S2001 collected from Mischief Reef in the South China Sea. Their structures, including absolute configurations, were elucidated on the basis of spectroscopic analysis and X-ray diffraction data. Compounds 1–5 and 7 showed different degrees of antibacterial activity with MIC values of 6.25–100 μg/mL. Compound 8 exhibited potent cytotoxicity against SF-268, MCF-7, and A549 cell lines with IC50 values of 12.75, 9.29, and 20.11 μM, respectively.

RNAseq reveals extensive metabolic disruptions in the sensitive SF-295 cell line treated with schweinfurthins

The schweinfurthin family of natural compounds exhibit a unique and potent differential cytotoxicity against a number of cancer cell lines and may reduce tumor growth in vivo. In some cell lines, such as SF-295 glioma cells, schweinfurthins elicit cytotoxicity at nanomolar concentrations. However, other cell lines, like A549 lung cancer cells, are resistant to schweinfurthin treatment up to micromolar concentrations. At this time, the precise mechanism of action and target for these compounds is unknown. Here, we employ RNA sequencing of cells treated with 50 nM schweinfurthin analog TTI-3066 for 6 and 24 h to elucidate potential mechanisms and pathways which may contribute to schweinfurthin sensitivity and resistance. The data was analyzed via an interaction model to observe differential behaviors between sensitive SF-295 and resistant A549 cell lines. We show that metabolic and stress-response pathways were differentially regulated in the sensitive SF-295 cell line as compared with the resistant A549 cell line. In contrast, A549 cell had significant alterations in response genes involved in translation and protein metabolism. Overall, there was a significant interaction effect for translational proteins, RNA metabolism, protein metabolism, and metabolic genes. Members of the Hedgehog pathway were differentially regulated in the resistant A549 cell line at both early and late time points, suggesting a potential mechanism of resistance. Indeed, when cotreated with the Smoothened inhibitor cyclopamine, A549 cells became more sensitive to schweinfurthin treatment. This study therefore identifies a key interplay with the Hedgehog pathway that modulates sensitivity to the schweinfurthin class of compounds.

Neutrophil Extracellular Traps Facilitate A549 Cell Invasion and Migration in a Macrophage-Maintained Inflammatory Microenvironment

Introduction. The biological functions of neutrophil extracellular traps (NETs) in tumorigenesis have drawn an increasing amount of attention. This study explored the relationship between NETs and the inflammatory microenvironment in lung cancer cell invasion and metastasis. Methods. NETs were quantified using myeloperoxidase (MPO–DNA) and immunofluorescence staining. Cytokine levels were measured using ELISA kits. THP-1 and A549 cells were used for in vitro experiments. Transwell and Matrigel assays were used to assess the invasion and migration abilities of the cells. Results. Neutrophil infiltration and NET formation were observed in the lung cancer tissues. Compared with healthy controls, the level of MPO–DNA complexes in lung cancer patients increased remarkably and was positively correlated with peripheral blood neutrophil counts, smoking status, and poor prognosis. Increased circulating NET levels were also positively correlated with the levels of inflammatory cytokines, including IL-1β, IL-6, IL-18, and TNF-α. Neutrophils isolated from patients with lung cancer are more prone to NET release. NETs can promote the invasion and migration ability of THP-1 and A549 cell in coculture systems, while pretreatment with NET inhibitors can effectively reduce NET-induced invasion and metastasis. The ability of NETs to promote invasion and metastasis is partly dependent on macrophages. Conclusion. Taken together, our study demonstrated that NETs facilitate A549 cell invasion and migration in a macrophage-maintained inflammatory microenvironment.

Proteasome Inhibitor Immunotherapy for the Epithelial to Mesenchymal Transition: Assessing the A549 Lung Cancer Cell Microenvironment and the Role of M1, M2a and M2c ‘Hydrocortisone-Polarised’ Macrophages

Lung cancer is a leading cause of cancer-related deaths, primarily as a result of metastases. In this metastasis, the epithelial-to-mesenchymal transition (EMT) is essential. Interaction with the cancer cell microenvironment is primarily dependent on M1- and M2-polarized macrophage. In this study, we revealed the EMT-associated activity of M1, M2a and M2c macrophages in A549 lung cancer cells. We established a co-culture model of A549 lung cancer cells utilizing THP-1-derived M1/M2 polarised macrophages to explore the involvement of macrophages in the immune response, apoptosis, and EMT in lung cancer. Although multiple polarising agents are routinely used for M1 and M2 conversion, we assessed a new possible polarising agent, hydrocortisone. M1 increased A549 cell sensitivity to proteasome inhibitors and decreased A549 cell viability by inducing apoptosis. EMT was induced in the presence of M2c macrophages in A549 cells by the levels of vimentin, fibronectin, E-cadherin, NF-kB, CCL-17. We also revealed the antiproliferative effects of bortezomib and ixazomib on A549 cells in both 2D and 3D cultures. Our findings could help develop an immunotherapeutic strategy by shedding light on a previously undiscovered part of the EMT pathway. Furthermore, additional investigation may reveal that polarising tumour-associated macrophages to M1 and eliminating the M2a or particularly the M2c subtype are effective anti-cancer strategies.

Evaluation Of Antioxidant, Antidiabetic, Anti-Inflammatory And Anticancer Activities Of Delonix Regia Flower Extracts

Non-communicable diseases like diabetes and cancer are the major cause of death worldwide. Various drugs are used for the treatment of these diseases. However, they cause lots of side effects. There is a need for alternate drugs with fewer side effects. Medicinal plants serve as a good source for alternate form of treatment. Therefore, in this study, ethanolic and aqueous extracts of D. regia flowers were evaluated for their antioxidant, antidiabetic, anti-inflammatory and cytotoxic activity to justify its use as a medicinal plant. Total phenol and flavonoid content of the extracts were measured. GC-MS analysis of the extracts were done to investigate the presence of various bioactive compounds. Antioxidant activity was assessed by radical scavenging and reduction assays. Antidiabetic activity was assessed by the ability of extracts to inhibit enzyme alpha amylase. Anti-inflammatory activity was evaluated by membrane stabilization activity. Anticancer activity against MCF-7 and A549 cell lines were measured by the MTT assay.The ethanolic extract contained more phenols (282.940.80 mgGAE/g) and flavonoids (140.912.27 mgQE/g). GC-MS analysis showed the presence of compounds belonging to fatty acids, alkanes, phenols and organic alcohols. The aqueous extract showed strong superoxide radical scavenging activity with a low IC50 of 39.35±0.74 µg/mL. The ethanolic extract showed higher ferric reducing power with an IC50 of 59.65±0.28µg/mL. Ethanolic extract was more potent in inhibiting alpha amylase with a low IC50 value of 47.14±0.6 µg/mL. Ethanolic extract also showed maximum inhibition of 88.86±0.1% against heat induced lysis of cell membrane. Both extracts affected the proliferation of MCF-7 and A549 cell lines at 160 µg/mL. The results of the present study support the use of D. regia flower as a potential source of bioactive phytochemicals and can be used as a plant-based antioxidant, antidiabetic, anti-inflammatory and anticancer agent.

Mir-204 Regulates LPS-Induced A549 Cell Damage by Targeting FOXK2

Objective. To assess whether miR-204 and HA affect A549 cell injury induced by lipopolysaccharide. Material and Methods. A549 cells were treated with hirsutanol A, and cell damage was induced by LPS followed by analysis of cell proliferation by CCK-8, cell apoptosis by flow cytometry, apoptosis-related protein expression by western blot, downstream target of miR-20 by dual-luciferase reporter gene, and inflammatory factors by ELISA and PCR. Results. LPS can significantly inhibit the viability of A549 cells, induce cell apoptosis, and promote the release of IL-6, IL-1β, and TNF-α, while HA pretreatment can target FOXK2 by upregulating miR-204 levels, thereby alleviating apoptosis and promoting cell viability and at the same time inhibiting the release of inflammatory factors by inhibiting the activation of NF-κB. Conclusions. miR-204 participates in the protection of HA acute lung injury by targeting FOXK2.

Evaluation of the Anticancer Potential of Crude, Irradiated Cerastes cerastes Snake Venom and Propolis Ethanolic Extract & Related Biological Alterations

We aimed to evaluate the anticancer potential of crude venom (CV), γ irradiated Certastes cerastes venom (IRRV), and propolis ethanolic extract (PEE). IRRV showed a higher toxicity than CV, while CV-PEE showed higher toxicity than IRRV and CV against lung [A549] and prostate [PC3] cancer cells. Toxicity to [A549] and [PC3] cells was concentration and cell type dependent. In comparison to controls, apoptotic genes showed a significant upregulation of P53 and Casp-3 and a downregulation of Bcl-2. Also, induced elevated DNA accumulation in the [S] phase post PC3 cell treatment with IRRV and CV, as well as a significant DNA accumulation at G2/M phase after IRRV treatment of A549 cells. In contrast, PC3 cells showed a negligible cellular DNA accumulation after PEE treatment. Glutathione reductase [GR] was reduced in case of PC3 and A549 cell treated with IRRV, CV, and PEE compared with its values in untreated cell control. The Malondialdehyde [MDA] values in both cells recorded a significant elevation post IRRV treatment compared to the rest of the treatment regimen and untreated cell control. Similarly, IRRV and CV-PEE mix showed obviously higher reactive oxygen species [ROS] values than PC3 and A549 cell treatments with CV and PEE.

Potential Role of GST-π in Lung Cancer Stem Cell Cisplatin Resistance

Background. Cancer stem cells (CSCs) are responsible for tumorigenesis, chemoresistance, and metastasis. Chemoresistance is a major challenge in the management of lung cancer. Glutathione-sulphur-transferase-π (GST-π) plays an important role in the origin and development of various types of cancer by regulating the cellular redox balance. Recent investigations have demonstrated that GST-π is associated with the chemoresistance of lung CSCs (LCSCs). However, the mechanism of GST-π in lung cancer, particularly in LCSCs, remains unclear. The present study is aimed at exploring the potential role of GST-π in stemness and cisplatin (DDP) resistance of LCSCs. Materials and methods. In the present study, lung cancer cell spheres were established using the A549 cell line, which according to our previous research, was confirmed to exhibit characteristics of stem cells. Next, GST-π protein expression, apoptosis percentage, and intracellular reactive oxygen species (ROS) concentration in A549 adherent cells and A549 cell spheres were analyzed by western blotting and flow cytometry, respectively. Finally, DDP resistance, ROS concentration, and GST-π expression in LCSCs were analyzed following the interference with GST-π using DL-buthionine-(S,R)-sulphoximine and N-acetylcysteine. Results. The results revealed that GST-π was highly expressed in A549 cell spheres compared with A549 adherent cells and was associated with a decreased intracellular ROS concentration (both P < 0.05 ). Regulating GST-π protein expression could alter DDP resistance of LCSCs by influencing ROS. Conclusion. These results suggested that GST-π may be important for LCSC drug resistance by downregulating ROS levels. These findings may contribute to the development of new adjuvant therapeutic strategies for lung cancer.

Metformin promotes apoptosis of A549 cells via regulation of p-AMPK protein expression, bax/bcl-2 ratio and ROS levels

Purpose: To investigate the influence of metformin on apoptosis of pulmonary carcinoma cells (A549), and the associated mode of action.Methods: Pulmonary carcinoma cells in logarithmic growth phase were treated with graded concentrations of metformin, and the anti-proliferative and apoptotic effects of the drug were measured using MTT assay and flow cytometry, respectively. The levels of reactive oxygen species (ROS) in A549 cell suspension were determined with 2, 7- dihydrodichlorofluorescein diacetate (DCFH-DA) assay. The expression levels of phosphorylated AMP-activated protein kinase (p-AMPK), mammalian target of rapamycin (mTOR), and bax/bcl-2 ratio were measured using Western blotting and real-time fluorescence quantitative polymerase chain reaction (qRT-PCR).Results: Metformin significantly promoted A549 cell apoptosis, but suppressed its proliferative potential in a dose- and time-based fashion. The levels of ROS, superoxide anion and MDA in A549 cells were significantly and dose-dependently increased by metformin (p < 0.05). Moreover, metformin markedly upregulated the mRNA and protein expressions of p-AMPK as well as bax/bcl-2 ratio, but had no impact on the expression level of mTOR (p < 0.05).Conclusion: Metformin promotes apoptosis in A549 cells via regulation of p-AMPK protein expression, bax/bcl-2 ratio, and ROS levels, and hence may play a role in lung cancer therapy.