Interleukin-24-mediated antitumor effects against human glioblastoma via upregulation of P38 MAPK and endogenous TRAIL-induced apoptosis and LC3-II activation-dependent autophagy.

BACKGROUND: Melanoma differentiation-associated gene 7 (Mda-7) encodes IL-24, which can induce apoptosis in cancer cells. A novel gene therapy approach to treat deadly brain tumors, recombinant mda-7 adenovirus (Ad/mda-7) efficiently kills glioma cells. In this study, we investigated the factors affecting cell survival and apoptosis and autophagy mechanisms that destroy glioma cells by Ad/IL-24. METHODS: Human glioblastoma U87 cell line was exposed to a multiplicity of infections of Ad/IL-24. Antitumor activities of Ad/IL-24 were assessed by cell proliferation (MTT) and lactate dehydrogenase (LDH) release analysis. Using flow cytometry, cell cycle arrest and apoptosis were investigated. Using the ELISA method, the tumor necrosis factor (TNF-α) level was determined as an apoptosis-promoting factor and Survivin level as an anti-apoptotic factor. The expression levels of TNF-related apoptosis inducing ligand(TRAIL) and P38 MAPK genes were assessed by the Reverse transcription-quantitative polymerase chain reaction(RT­qPCR) method. The expression levels of caspase-3 and protein light chain 3-II (LC3-II) proteins were analyzed by flow cytometry as intervening factors in the processes of apoptosis and autophagy in the cell death signaling pathway, respectively. RESULTS: The present findings demonstrated that transduction of IL-24 inhibited cell proliferation and induced cell cycle arrest and cell apoptosis in glioblastoma. Compared with cells of the control groups, Ad/IL24-infected U87 cells exhibited significantly increased elevated caspase-3, and TNF-α levels, while the survivin expression was decreased. TRAIL was shown to be upregulated in tumor cells after Ad/IL-24 infection and studies of the apoptotic cascade regulators indicate that Ad/IL-24 could further enhance the activation of apoptosis through the TNF family of death receptors. In the current study, we demonstrate that P38 MAPK is significantly activated by IL-24 expression. In addition, the overexpression of mda-7/IL-24 in GBM cells induced autophagy, which was triggered by the upregulation of LC3-II. CONCLUSIONS: Our study demonstrates the antitumor effect of IL-24 on glioblastoma and may be a promising therapeutic approach for GBM cancer gene therapy.

Carotenoid pigment of Halophilic archaeon Haloarcula sp. A15 induces apoptosis of breast cancer cells.

The halophilic microorganisms living in extreme environments contain high concentrations of carotenoids with notable medical abilities. The purpose of this study was to evaluate the anticancer effect of carotenoids extracted from native Iranian halophilic microorganisms with the ability to inhibit breast cancer cell line. To begin the study, 40 halophilic strains were cultured, and 8 strains capable of producing pigmented colonies were chosen from those cultured strains. In the next step, from among 8 strains using MTT assay, 1 capable of reducing cell viability of the breast cancer MCF-7 cell line was chosen as a selective strain. The principal carotenoid was characterized using UV-visible, FT-IR spectroscopic, and LC-MASS analyses. Using real time PCR technique, the expression of genes specific for apoptosis, in the presence or absence of carotenoid, was examined. Among all strains, carotenoid extracted from strain A15 had the most potent cytotoxic effect on breast cancer cell line (IC50 = 0.0645 mg/mL). 16S rRNA gene analysis showed that strain A15 had similarity with Haloarcula hispanica for about 99.5%. According to the analysis results, it could be estimated that the principal carotenoid extracted form Haloarcula sp. A15 was similar to bacterioruberin. Both early and late apoptosis were increased significantly about 10% and 39%, respectively, due to upregulation of CASP3, CASP8, BAX genes expression in MCF-7 cell line. In contrast, the expression of genes MKI67, SOX2 were significantly downregulated in treated MCF-7 cell line. The results of this study showed that Halophilic archaeon strain could be a good candidate for the production of high added-value bacterioruberin due to its possible anticancer properties.

Correlation between Legionella pneumophila serogroups isolated from patients with ventilator-associated pneumonia and water resources: a study of four hospitals in Tehran, Iran.

Legionella pneumophila (L. pneumophila) is one of the main pathogens, causing pneumonia and respiratory tract infections, especially in patients with ventilator-associated pneumonia (VAP). This study aimed to approve the hypothesis that the serogroup distribution of L. pneumophila isolates from patients is correlated with Legionella strains in the environment. A total of 280 bronchoalveolar lavage (BAL) samples from VAP patients admitted to the intensive care unit (ICU) as well as 116 water samples from different sources in four hospitals in Tehran, Iran, were evaluated for the presence of L. pneumophila infection by culture, nested polymerase chain reaction (PCR), real-time PCR, and sequencing for genetic diversity. The molecular and culture methods found 24 (8.6%) and 5 (1.8%) samples to be positive for L. pneumophila in VAP patients, while they found 23 (19.8%) and 8 (6.9%) positive samples in water resources, respectively. The sequencing results indicated that all positive clinical samples and 14 (60.8%) environmental samples were belonged to L. pneumophila serogroup 1. Smoking, age, length of ICU stay, and duration of ventilator use had strong relationship with L. pneumophila infectivity. In conclusion, this is the first report from Iran to determine minor differences in the serogroup distribution of environmental and clinical strains. However, further studies are needed to confirm this relationship in different regions of Iran.

Desertifilum sp. EAZ03 cell extract as a novel natural source for the biosynthesis of zinc oxide nanoparticles and antibacterial, anticancer and antibiofilm characteristics of synthesized zinc oxide nanoparticles.

AIMS: The use of cyanobacterial cell extracts for the synthesis of zinc oxide nanoparticles (ZnO NPs) seems to be superior to other methods of synthesis because of its a green, environmentally friendly and low-cost approach. In this study, the cell extract of a newly characterized cyanobacterial strain Desertifilum sp. EAZ03 was used for the biosynthesis of ZnO NPs. The antimicrobial, antibiofilm and anticancer activities of the biosynthesized ZnO NPs (hereinafter referred to as CED-ZnO NPs) were examined as well. METHODS AND RESULTS: UV-Vis spectroscopy analysis of CED-ZnO NPs showed an absorbance band at 364 nm, and powder X-ray diffraction analysis confirmed the purity of the synthesized nanoparticles. The analyses of scanning electron microscopy and transmission electron microscopy images revealed that CED-ZnO NPs were rod-shaped with a size of 88 nm. The study of the biological features of CED-ZnO NPs showed a significant antimicrobial potential against the bacterial strains tested. CED-ZnO NPs were able to impede the biofilm formation by Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa up to 80%, 89% and 85%, respectively. The nanoparticles also showed 69%, 70% and 62% degrading activity against S. aureus, E. coli and P. aeruginosa 1-day-old biofilms, respectively. The antibiofilm activity of the synthesized nanoparticles was investigated by confocal laser scanning microscopy. The MTT assay showed that CED-ZnO NPs, at a concentration of 100 µg/ml, had less cytotoxicity towards normal lung (MRC-5) cells, at the half, compared to cancerous lung alveolar epithelial (A549) cells. The minimum inhibitory concentration and minimum bactericidal concentration values of CED-ZnO NPs against E. coli, P. aeruginosa and S. aureus were 1500, 2000 and 32 µg/ml, and 2500, 3500 and 64 µg/ml, respectively. CONCLUSIONS: The multifunctional CED-ZnO NPs seem to be promising for possible applications in the therapeutic and pharmaceutical industries. SIGNIFICANCE AND IMPACT OF THE STUDY: This study proposes a new approach for the biosynthesis of zinc oxide nanoparticles using a newly characterized cyanobacterial strain Desertifilum sp. EAZ03. The considerable antimicrobial, antibiofilm and anticancer activities of the biosynthesized zinc oxide nanoparticles further emphasize the emerging role of microbial systems in the green synthesis of metal oxide nanoparticles.

Protective cellular and mucosal immune responses following nasal administration of a whole gamma-irradiated influenza A (subtype H1N1) vaccine adjuvanted with interleukin-28B in a mouse model.

The use of gamma-irradiated influenza A virus (γ-Flu), retains most of the viral structural antigens, represent a promising option for vaccine development. However, despite the high effectiveness of γ-Flu vaccines, the need to incorporate an adjuvant to improve vaccine-mediated protection seems inevitable. Here, we examined the protective efficacy of an intranasal gamma-irradiated HIN1 vaccine co-administered with a plasmid encoding mouse interleukin-28B (mIL-28B) as a novel adjuvant in BALB/c mice. Animals were immunized intranasally three times at one-week intervals with γ-Flu, alone or in combination with the mIL-28B adjuvant, followed by viral challenge with a high lethal dose (10 LD50) of A/PR/8/34 (H1N1) influenza virus. Virus-specific antibody, cellular and mucosal responses, and the balance of cytokines in the spleen IFN-γ, IL-12, and IL-4) and in lung homogenates (IL-6 and IL-10) were measured by ELISA. The lymphoproliferative activity of restimulated spleen cells was also determined by MTT assay. Furthermore, virus production in the lungs of infected mice was estimated using the Madin-Darby canine kidney (MDCK)/hemagglutination assay (HA). Our data showed that intranasal immunization with adjuvanted γ-Flu vaccine efficiently promoted humoral, cellular, and mucosal immune responses and efficiently decreased lung virus titers, all of which are associated with protection against challenge. This combination also reduced IL-6 and IL-10 levels in lung homogenates. The results suggest that IL-28B can enhance the ability of the vaccine to elicit virus-specific immune responses and could potentially be used as an effective adjuvant.

Inactivation methods for whole influenza vaccine production.

Despite tremendous efforts toward vaccination, influenza remains an ongoing global threat. The induction of strain-specific neutralizing antibody responses is a common phenomenon during vaccination with the current inactivated influenza vaccines, so the protective effect of these vaccines is mostly strain-specific. There is an essential need for the development of next-generation vaccines, with a broad range of immunogenicity against antigenically drifted or shifted influenza viruses. Here, we evaluate the potential of whole inactivated vaccines, based on chemical and physical methods, as well as new approaches to generate cross-protective immune responses. We also consider the mechanisms by which some of these vaccines may induce CD8+ T-cells cross-reactivity with different strains of influenza. In this review, we have focused on conventional and novel methods for production of whole inactivated influenza vaccine. As well as chemical modification, using formaldehyde or ß-propiolactone and physical manipulation by ultraviolet radiation or gamma-irradiation, novel approaches, including visible ultrashort pulsed laser, and low-energy electron irradiation are discussed. These two latter methods are considered to be attractive approaches to design more sophisticated vaccines, due to their ability to maintain most of the viral antigenic properties during inactivation and potential to produce cross-protective immunity. However, further studies are needed to validate them before they can replace traditional methods for vaccine manufacturing.

A bio-inspired strategy for the synthesis of zinc oxide nanoparticles (ZnO NPs) using the cell extract of cyanobacterium Nostoc sp. EA03: from biological function to toxicity evaluation.

Cyanobacteria, as one of the largest groups of phototrophic bacteria, have a high potential as an excellent source of fine chemicals and bioactive compounds, including lipid-like compounds, amino acid derivatives, proteins, and pigments. This study aimed to synthesize ZnO nanoparticles using the cell extract of the cyanobacterium Nostoc sp. EA03 (CEN-ZnO NPs) through a rapid and eco-friendly approach. The biosynthesized nanoparticles, CEN-ZnO NPs, were characterized by UV-Vis spectroscopy, X-ray diffraction (XRD), zeta potential measurement, differential scanning calorimetry (DSC)/thermogravimetric analysis (TGA), FTIR, SEM, TEM, and EDX spectroscopy. The UV-Vis spectrum showed an absorption peak at 370 nm. The star-shaped CEN-ZnO NPs, as observed in the TEM and SEM images, had an average diameter of 50-80 nm. MIC and MBC values for E. coli, P. aeruginosa and S. aureus, were determined to be, respectively, 2000, 2000, and 64 µg ml-1, and 2500, 2500 and 128 µg ml-1. Further analysis through confocal laser scanning microscopy (CLSM) provided the observable confirmation that the CEN-ZnO NPs stunted the bacterial growth, preventing the formation of exopolysaccharides. The AFM analysis of surface topography of bacterial biofilm samples treated with CEN-ZnO NPs showed a rugged topography in some parts of the biofilm surface, indicating the destruction of biofilms. In contrast, in the untreated control samples, the structured biofilms were flat and prominent. MTT assay indicated that CEN-ZnO NPs had less cytotoxicity on the MRC-5 lung fibroblast cells compared with the cancerous treated A549 cells. As the concentration of the CEN-ZnO NPs increased, the amount of ROS produced in the tested bacterial strains also increased. Analyzing the data obtained from flow cytometry showed that the higher concentrations of CEN-ZnO NPs lead to a reduction in the viability of P. aeruginosa PAO1, E. coli and S. aureus. The biosynthesized ZnO nanoparticles using Nostoc cell extracts exhibited different attributes, inspiring enough to be considered for further investigation.