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Comparative assessment of the apoptotic potential of silver nanoparticles synthesized by Bacillus tequilensis and Calocybe indica in MDA-MB-231 human breast cancer cells: targeting p53 for anticancer therapy.

Gurunathan S, Park JH, Han JW, Kim JH - Int J Nanomedicine (2015)

Bottom Line: This is especially true in the area of nanomedicine, due to physicochemical properties, such as mechanical, chemical, magnetic, optical, and electrical properties, compared with bulk materials.The first goal of this study was to produce silver nanoparticles (AgNPs) using two different biological resources as reducing agents, Bacillus tequilensis and Calocybe indica.Cells pretreated with pifithrin-alpha were protected from p53-mediated AgNPs-induced toxicity.

View Article: PubMed Central - PubMed

Affiliation: Department of Animal Biotechnology, Konkuk University, Seoul, Republic of Korea.

ABSTRACT

Background: Recently, the use of nanotechnology has been expanding very rapidly in diverse areas of research, such as consumer products, energy, materials, and medicine. This is especially true in the area of nanomedicine, due to physicochemical properties, such as mechanical, chemical, magnetic, optical, and electrical properties, compared with bulk materials. The first goal of this study was to produce silver nanoparticles (AgNPs) using two different biological resources as reducing agents, Bacillus tequilensis and Calocybe indica. The second goal was to investigate the apoptotic potential of the as-prepared AgNPs in breast cancer cells. The final goal was to investigate the role of p53 in the cellular response elicited by AgNPs.

Methods: The synthesis and characterization of AgNPs were assessed by various analytical techniques, including ultraviolet-visible (UV-vis) spectroscopy, X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, dynamic light scattering (DLS), and transmission electron microscopy (TEM). The apoptotic efficiency of AgNPs was confirmed using a series of assays, including cell viability, leakage of lactate dehydrogenase (LDH), production of reactive oxygen species (ROS), DNA fragmentation, mitochondrial membrane potential, and Western blot.

Results: The absorption spectrum of the yellow AgNPs showed the presence of nanoparticles. XRD and FTIR spectroscopy results confirmed the crystal structure and biomolecules involved in the synthesis of AgNPs. The AgNPs derived from bacteria and fungi showed distinguishable shapes, with an average size of 20 nm. Cell viability assays suggested a dose-dependent toxic effect of AgNPs, which was confirmed by leakage of LDH, activation of ROS, and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL)-positive cells in MDA-MB-231 breast cancer cells. Western blot analyses revealed that AgNPs induce cellular apoptosis via activation of p53, p-Erk1/2, and caspase-3 signaling, and downregulation of Bcl-2. Cells pretreated with pifithrin-alpha were protected from p53-mediated AgNPs-induced toxicity.

Conclusion: We have demonstrated a simple approach for the synthesis of AgNPs using the novel strains B. tequilensis and C. indica, as well as their mechanism of cell death in a p53-dependent manner in MDA-MB-231 human breast cancer cells. The present findings could provide insight for the future development of a suitable anticancer drug, which may lead to the development of novel nanotherapeutic molecules for the treatment of cancers.

No MeSH data available.


Related in: MedlinePlus

Effect of B-AgNPs and F-AgNPs on cell viability of MDA-MB-231 cells.Notes: Cells were treated with various concentrations of B-AgNPs (A) and F-AgNPs (B) for 24 hours, and cytotoxicity was determined by the MTT method. The results are expressed as the mean ± SD of three independent experiments, each of which contained three replicates. Treated groups showed statistically significant differences from the control group by the Student’s t-test (P<0.05).Abbreviations: B-AgNPs, bacterium-derived AgNPs; F-AgNPs, fungus-derived AgNPs; MTT, 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide; SD, standard deviation.
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f6-ijn-10-4203: Effect of B-AgNPs and F-AgNPs on cell viability of MDA-MB-231 cells.Notes: Cells were treated with various concentrations of B-AgNPs (A) and F-AgNPs (B) for 24 hours, and cytotoxicity was determined by the MTT method. The results are expressed as the mean ± SD of three independent experiments, each of which contained three replicates. Treated groups showed statistically significant differences from the control group by the Student’s t-test (P<0.05).Abbreviations: B-AgNPs, bacterium-derived AgNPs; F-AgNPs, fungus-derived AgNPs; MTT, 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide; SD, standard deviation.

Mentions: Taking the literature into account, we were interested in studying the cytotoxicity of B-AgNPs and F-AgNPs derived from bacterial culture supernatant and milky mushroom extract, respectively, as a reducing agent. Therefore, we were interested in investigating whether AgNPs derived from two different capping agents and whether different shapes of AgNPs could influence cell viability with remarkable effect. To examine the effect of B-AgNPs (mostly spherical) and F-AgNPs (multishaped), MDA-MB-231 human breast cancer cells were treated with various concentrations of AgNPs, and cell viability was measured. After 24 hours of treatment with different AgNP concentrations, the MDA-MB-231 cells showed a dose-dependent decrease in cell viability compared with that of the control group, and the differences between B-AgNP- and F-AgNP-treated cells and the control group were statistically significant (Figure 6A and B). Cell viability assays showed that MDA-MB-231 cells were significantly inhibited by F-AgNPs and, to a lesser extent, by B-AgNPs. The significant toxicity of F-AgNPs may be due to the overall surface charge and/or surface coating of AgNPs.61 Our studies are consistent with previous studies showing that AgNPs exposure can induce changes in cell shape, reduce cell viability, and increase lactate dehydrogenase (LDH) release, and finally, result in cell apoptosis and necrosis.8,20,64–67 Edetsberger et al demonstrated that AgNPs with a size of ≤20 nm could enter cells without significant endocytosis and were distributed within the cytoplasm.68 Jiang et al reported that cellular uptake of AgNPs of ≤20 nm was greater than that of AgNPs of >100 nm in human glioma U251 cells.69 Our results are consistent with those previously reported. For example, Park et al showed the effects of various sizes of AgNPs (20, 80, and 113 nm) using in vitro assays for cytotoxicity, inflammation, genotoxicity, and developmental toxicity, and finally concluded that AgNPs of 20 nm were more toxic than larger nanoparticles.19 Pal et al showed the first comparative study on the bactericidal properties of AgNPs of different shapes in E. coli.63 Dong et al reported that triangular nanoprisms with sharp edges and vertices possess very high antibacterial properties compared with spherical-shaped AgNPs.70 Taken together, our results demonstrate that AgNPs undergo a shape-dependent interaction with cancer cells.


Comparative assessment of the apoptotic potential of silver nanoparticles synthesized by Bacillus tequilensis and Calocybe indica in MDA-MB-231 human breast cancer cells: targeting p53 for anticancer therapy.

Gurunathan S, Park JH, Han JW, Kim JH - Int J Nanomedicine (2015)

Effect of B-AgNPs and F-AgNPs on cell viability of MDA-MB-231 cells.Notes: Cells were treated with various concentrations of B-AgNPs (A) and F-AgNPs (B) for 24 hours, and cytotoxicity was determined by the MTT method. The results are expressed as the mean ± SD of three independent experiments, each of which contained three replicates. Treated groups showed statistically significant differences from the control group by the Student’s t-test (P<0.05).Abbreviations: B-AgNPs, bacterium-derived AgNPs; F-AgNPs, fungus-derived AgNPs; MTT, 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide; SD, standard deviation.
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Related In: Results  -  Collection

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f6-ijn-10-4203: Effect of B-AgNPs and F-AgNPs on cell viability of MDA-MB-231 cells.Notes: Cells were treated with various concentrations of B-AgNPs (A) and F-AgNPs (B) for 24 hours, and cytotoxicity was determined by the MTT method. The results are expressed as the mean ± SD of three independent experiments, each of which contained three replicates. Treated groups showed statistically significant differences from the control group by the Student’s t-test (P<0.05).Abbreviations: B-AgNPs, bacterium-derived AgNPs; F-AgNPs, fungus-derived AgNPs; MTT, 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide; SD, standard deviation.
Mentions: Taking the literature into account, we were interested in studying the cytotoxicity of B-AgNPs and F-AgNPs derived from bacterial culture supernatant and milky mushroom extract, respectively, as a reducing agent. Therefore, we were interested in investigating whether AgNPs derived from two different capping agents and whether different shapes of AgNPs could influence cell viability with remarkable effect. To examine the effect of B-AgNPs (mostly spherical) and F-AgNPs (multishaped), MDA-MB-231 human breast cancer cells were treated with various concentrations of AgNPs, and cell viability was measured. After 24 hours of treatment with different AgNP concentrations, the MDA-MB-231 cells showed a dose-dependent decrease in cell viability compared with that of the control group, and the differences between B-AgNP- and F-AgNP-treated cells and the control group were statistically significant (Figure 6A and B). Cell viability assays showed that MDA-MB-231 cells were significantly inhibited by F-AgNPs and, to a lesser extent, by B-AgNPs. The significant toxicity of F-AgNPs may be due to the overall surface charge and/or surface coating of AgNPs.61 Our studies are consistent with previous studies showing that AgNPs exposure can induce changes in cell shape, reduce cell viability, and increase lactate dehydrogenase (LDH) release, and finally, result in cell apoptosis and necrosis.8,20,64–67 Edetsberger et al demonstrated that AgNPs with a size of ≤20 nm could enter cells without significant endocytosis and were distributed within the cytoplasm.68 Jiang et al reported that cellular uptake of AgNPs of ≤20 nm was greater than that of AgNPs of >100 nm in human glioma U251 cells.69 Our results are consistent with those previously reported. For example, Park et al showed the effects of various sizes of AgNPs (20, 80, and 113 nm) using in vitro assays for cytotoxicity, inflammation, genotoxicity, and developmental toxicity, and finally concluded that AgNPs of 20 nm were more toxic than larger nanoparticles.19 Pal et al showed the first comparative study on the bactericidal properties of AgNPs of different shapes in E. coli.63 Dong et al reported that triangular nanoprisms with sharp edges and vertices possess very high antibacterial properties compared with spherical-shaped AgNPs.70 Taken together, our results demonstrate that AgNPs undergo a shape-dependent interaction with cancer cells.

Bottom Line: This is especially true in the area of nanomedicine, due to physicochemical properties, such as mechanical, chemical, magnetic, optical, and electrical properties, compared with bulk materials.The first goal of this study was to produce silver nanoparticles (AgNPs) using two different biological resources as reducing agents, Bacillus tequilensis and Calocybe indica.Cells pretreated with pifithrin-alpha were protected from p53-mediated AgNPs-induced toxicity.

View Article: PubMed Central - PubMed

Affiliation: Department of Animal Biotechnology, Konkuk University, Seoul, Republic of Korea.

ABSTRACT

Background: Recently, the use of nanotechnology has been expanding very rapidly in diverse areas of research, such as consumer products, energy, materials, and medicine. This is especially true in the area of nanomedicine, due to physicochemical properties, such as mechanical, chemical, magnetic, optical, and electrical properties, compared with bulk materials. The first goal of this study was to produce silver nanoparticles (AgNPs) using two different biological resources as reducing agents, Bacillus tequilensis and Calocybe indica. The second goal was to investigate the apoptotic potential of the as-prepared AgNPs in breast cancer cells. The final goal was to investigate the role of p53 in the cellular response elicited by AgNPs.

Methods: The synthesis and characterization of AgNPs were assessed by various analytical techniques, including ultraviolet-visible (UV-vis) spectroscopy, X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, dynamic light scattering (DLS), and transmission electron microscopy (TEM). The apoptotic efficiency of AgNPs was confirmed using a series of assays, including cell viability, leakage of lactate dehydrogenase (LDH), production of reactive oxygen species (ROS), DNA fragmentation, mitochondrial membrane potential, and Western blot.

Results: The absorption spectrum of the yellow AgNPs showed the presence of nanoparticles. XRD and FTIR spectroscopy results confirmed the crystal structure and biomolecules involved in the synthesis of AgNPs. The AgNPs derived from bacteria and fungi showed distinguishable shapes, with an average size of 20 nm. Cell viability assays suggested a dose-dependent toxic effect of AgNPs, which was confirmed by leakage of LDH, activation of ROS, and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL)-positive cells in MDA-MB-231 breast cancer cells. Western blot analyses revealed that AgNPs induce cellular apoptosis via activation of p53, p-Erk1/2, and caspase-3 signaling, and downregulation of Bcl-2. Cells pretreated with pifithrin-alpha were protected from p53-mediated AgNPs-induced toxicity.

Conclusion: We have demonstrated a simple approach for the synthesis of AgNPs using the novel strains B. tequilensis and C. indica, as well as their mechanism of cell death in a p53-dependent manner in MDA-MB-231 human breast cancer cells. The present findings could provide insight for the future development of a suitable anticancer drug, which may lead to the development of novel nanotherapeutic molecules for the treatment of cancers.

No MeSH data available.


Related in: MedlinePlus