Silver nanoparticles induce a non-immunogenic tumor cell death.

Immunogenic cell death (ICD) is a form of cell death characterized by the release of danger signals required to trigger an adaptive immune response against tumor-associated antigens. Silver nanoparticles (AgNP) display anti-proliferative and cytotoxic effects in tumor cells, but it has not been previously studied whether AgNP act as an ICD inductor. The present study evaluated the in vitro release of calreticulin as a damage-associated molecular pattern (DAMP) associated with the cytotoxicity of AgNP and their in vivo anti-cancer effects. In vitro, mouse CT26 colon carcinoma and MCA205 fibrosarcoma cells were exposed to AgNP and then cell proliferation, adhesion, and release of calreticulin were determined. The results indicated there were time- and concentration-related anti-proliferative effects of AgNP in both the CT26 and MCA205 lines. Concurrently, changes in cell adhesion were detected mainly in the CT26 cells. Regarding DAMP detection, a significant increase in calreticulin was observed only in CT26 cells treated with doxorubicin and AgNP; however, no differences were found in the MCA205 cells. In vivo, the survival and growth of subcutaneous tumors were monitored after vaccination of mice with cell debris from tumor cells treated with AgNP or after intra-tumoral administration of AgNP to established tumors. Consequently, anti-tumoral prophylactic immunization with AgNP-dead cells failed to protect mice from tumor re-challenge; intra-tumor injection of AgNP did not induce a significant effect. In conclusion, there was a noticeable anti-tumoral effect of AgNP in vitro in both CT26 and MCA205 cell lines, accompanied by the release of calreticulin in CT26 cells. In vivo, immunization with cell debris derived from AgNP-treated tumor cells failed to induce a protective immune response in the cancer model mice. Clearly, further research is needed to determine if one could combine AgNP with other ICD inducers to improve the anti-tumor effect of these nanoparticles in vivo.

Food Consumption and Metabolic Risks in Young University Students.

The purpose of this study was to analyze the association between components of the diet, metabolic risks, and the serum concentrations of adiponectin and interleukin-6 (IL-6). With prior informed consent, an analytical cross-sectional study was carried out with 72 students in their first year of university. The subjects had a mean age of 19.2 ± 1.0 years and body mass index of 23.38 ± 4.2, and they were mainly women (80.6%). Sociodemographic, anthropometric, and dietary data and metabolic risk factors were evaluated, and biochemical parameters and adipocytokines were also considered. The data were analyzed using means, ranges, and correlations, as well as principal components. In general, the protein, fat, and sodium intake were higher than the international dietary recommendations, and deficiencies in vitamins B5 and E, potassium, phosphorus, selenium, and zinc were observed. The most frequently observed metabolic risks were insulin resistance and hypoalphalipoproteinemia. IL-6 was positively correlated with lipid and protein intake. Adiponectin showed a positive correlation with high-density lipoprotein and a negative correlation with insulin, weight, and waist, while the adiponectin pattern was similar to that of vitamins E and A, which decreased with increasing intake of calories, macronutrients, and sodium. In general, a hypercaloric diet that was high in protein, fat, and sodium and deficient in vitamins, mainly fat-soluble, was associated with a lower concentration of adiponectin and a higher concentration of IL-6, which favor the presence of metabolic risks, including insulin resistance. Intervention studies are required to evaluate the dietary intake of metabolic markers in young people without comorbidities, which will lay the foundation for implementing prevention strategies.

Toxicity of silver nanoparticles in mouse bone marrow-derived dendritic cells: Implications for phenotype.

Silver nanoparticles (AgNP) are one of the most studied nanoparticles due to their anti-bacterial, -fungal, -viral, -parasitic, and -inflammatory properties. This raises the need to evaluate the toxicity and biological effects of AgNP in the immune system in order to develop new safer biomedical products. In this study, an AgNP formulation currently approved for veterinary applications was applied to mouse bone marrow-derived dendritic cells (BMDC), considered important antigen-presenting cells of the immune system, to evaluate cytotoxicity, genotoxicity, and any significant influence on expression of cellular markers associated with BMDC phenotype and maturation status. The results showed that after 12 h of AgNP exposure, a significant decrease in BMDC viability occurred at the highest concentration tested (1.0 µg AgNP/ml) and at lower doses, the cells maintained membrane integrity and metabolic activity. DNA damage was not significant with any AgNP level aside from the 1.0 µg AgNP/ml level. Regarding phenotype, no differences in expression of CD40 (co-stimulatory molecule highly present in mature BMDC) or in CD273 (a marker for inhibitory T-cell response) were observed. The current results showed that the toxicity of this AgNP formulation was dose-related. The findings also suggest BMDC could maintain structural conservation of co-stimulatory/co-inhibitory surface molecules after 12 h of exposure to this AgNP. This work represents the first step in identifying the toxic effects of this AgNP formulation on dendritic cells.

Adhesion, proliferation, and apoptosis in different molecular portraits of breast cancer treated with silver nanoparticles and its pathway-network analysis.

BACKGROUND: Silver nanoparticles (AgNPs) have attracted considerable attention due to the variety of their applications in medicine and other sciences. AgNPs have been used in vitro for treatment of various diseases, such as hepatitis B and herpes simplex infections as well as colon, cervical, and lung cancers. In this study, we assessed the effect on proliferation, adhesion, and apoptosis in breast cancer cell lines of different molecular profiles (MCF7, HCC1954, and HCC70) exposed to AgNPs (2-9 nm). METHODS: Breast cancer cell lines were incubated in vitro; MTT assay was used to assess proliferation. Adhesion was determined by real-time analysis with the xCELLingence system. Propidium iodide and fluorescein isothiocyanate-Annexin V assay were used to measure apoptosis. The transcriptome was assessed by gene expression microarray and Probabilistic Graphical Model (PGM) analyses. RESULTS: The results showed a decreased adhesion in breast cancer cell lines and the control exposed to AgNPs was noted in 24 hours (p≤0.05). We observed a significant reduction in the proliferation of MCF7 and HCC70, but not in HCC1954. Apoptotic activity was seen in all cell lines exposed to AgNPs, with an apoptosis percentage of more than 60% in cancer cell lines and less than 60% in the control. PGM analysis confirmed, to some extent, the effects of AgNPs primarily on adhesion by changes in the extracellular matrix. CONCLUSION: Exposure to AgNPs causes an antiproliferative, apoptotic, and anti-adhesive effect in breast cancer cell lines cultured in vitro. More research is needed to evaluate the potential use of AgNPs to treat different molecular profiles of breast cancer in humans.

Toxicity of silver nanoparticles in biological systems: Does the complexity of biological systems matter?

Currently, nanomaterials are more frequently in our daily life, specifically in biomedicine, electronics, food, textiles and catalysis just to name a few. Although nanomaterials provide many benefits, recently their toxicity profiles have begun to be explored. In this work, the toxic effects of silver nanoparticles (35nm-average diameter and Polyvinyl-Pyrrolidone-coated) on biological systems of different levels of complexity was assessed in a comprehensive and comparatively way, through a variety of viability and toxicological assays. The studied organisms included viruses, bacteria, microalgae, fungi, animal and human cells (including cancer cell lines). It was found that biological systems of different taxonomical groups are inhibited at concentrations of silver nanoparticles within the same order of magnitude. Thus, the toxicity of nanomaterials on biological/living systems, constrained by their complexity, e.g. taxonomic groups, resulted contrary to the expected. The fact that cells and virus are inhibited with a concentration of silver nanoparticles within the same order of magnitude could be explained considering that silver nanoparticles affects very primitive cellular mechanisms by interacting with fundamental structures for cells and virus alike.

Effect of the ADIPOQ Gene -11391G/A Polymorphism Is Modulated by Lifestyle Factors in Mexican Subjects.

BACKGROUND/AIMS: Single nucleotide polymorphisms (SNPs) in the ADIPOQ gene could explain the adiponectin level. However, the knowledge about the influence of genetic and lifestyle factors is not sufficient. The aim was to analyze whether the effect of the -11391G/A SNP in the ADIPOQ gene is modulated by lifestyle factors in Mexican subjects. METHODS: A cross-sectional study was performed in which 394 participants were analyzed. Genetic, anthropometric, biochemical, dietary, clinical and physical activity parameters were measured. Statistical analysis was performed with SPSSv19 software. RESULTS: The distribution of the -11391G/A SNP genotypes was 55.6 and 44.4% for GG and AG, respectively. The adiponectin level was modulated by the -11391G/A SNP in response to the body mass index (BMI); A allele carriers showed a higher adiponectin level compared to G homozygous carriers but only in the minor BMI tertile group (p=0.032). Adiponectin level variability was explained by gender [(r)=1.5, 95% CI 1.1-1.9, p=0.000], insulin resistance [(r)=-1.2, 95% CI -0.8 to -1.6, p=0.000], physical activity [(r)=0.6, 95% CI 0.2-0.9, p=0.002] and monounsaturated fat intake [(r)=0.5, 95% CI 0.38-1.0, p=0.047]. CONCLUSIONS: The adiponectin level was modulated by the interaction between BMI and -11391G/A SNP; this suggests that the lifestyle rather than genetic factors modulates serum adiponectin.

Effect of Ala54Thr polymorphism of FABP2 on anthropometric and biochemical variables in response to a moderate-fat diet.

OBJECTIVE: To analyze the effect of the fatty acid-binding protein (FABP2) gene Ala54Thr polymorphism on anthropometric and biochemical variables in response to a moderate-fat diet in overweight or obese subjects. METHODS: One hundred nine subjects with a body mass index ≥ 25 kg/m(2) were studied. Participants underwent a dietary intervention that consisted of 30% fat (saturated fat <7% of total calories), 15% protein, and 55% carbohydrates. The FABP2 genotypes were analyzed by polymerase chain reaction-restriction fragment length polymorphism. Anthropometric and biochemical data were measured at baseline, 1 mo, and 2 mo of nutritional intervention. RESULTS: The mean age was 38.6 ± 11.3 y and the mean body mass index 32.7 ± 6.1 kg/m(2), with 20 men (18%) and 89 women (82%). Fifty-three patients (48.6%) had genotype Ala54Ala (wild-type group) and 56 patients had genotype Ala54Thr/Thr54Thr (51.4%, mutant group). At baseline, no significant difference was found between the FABP2 genotypes groups, except for the carbohydrate intake and resting metabolic rate, which were higher in the Ala54Thr/Thr54Thr group (P < 0.05). At 2 mo, participants had lost 6.8% of their initial weight. The Ala54Thr/Thr54Thr group compared with the Ala54Ala group showed significant decreases in the parameters of weight (-7.5 versus -4.2 kg), body mass index (-2.1 versus -1.2 kg/m(2)), waist circumference (-7.6 versus -5.2 cm), waist-to-hip ratio (-0.04 versus -0.02), and C-reactive protein (-1.4 versus -0.76 mg/L), respectively (P < 0.05). After the resting metabolic rate was adjusted, the decreases in waist circumference, waist-to-hip ratio, and C-reactive protein remained significant between the two groups. CONCLUSIONS: This study showed that the Thr54 allele carriers responded better to a moderate-fat diet.