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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

B-AgNPs and F-AgNPs induces caspase-3 activity in MDA-MB-231 cells.Notes: MDA-MB-231 cells were treated with AgNPs and F-AgNPs with or without caspase-3 inhibitor Ac-DEVD-CHO for 24 hours. The concentration of p-nitroanilide released from the substrate was calculated from the absorbance at 405 nm. The results are expressed as the mean ± standard deviation of three independent experiments. The 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; Con, control; F-AgNPs, fungus- derived AgNPs.
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f11-ijn-10-4203: B-AgNPs and F-AgNPs induces caspase-3 activity in MDA-MB-231 cells.Notes: MDA-MB-231 cells were treated with AgNPs and F-AgNPs with or without caspase-3 inhibitor Ac-DEVD-CHO for 24 hours. The concentration of p-nitroanilide released from the substrate was calculated from the absorbance at 405 nm. The results are expressed as the mean ± standard deviation of three independent experiments. The 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; Con, control; F-AgNPs, fungus- derived AgNPs.

Mentions: Caspases are potent cysteine proteases whose functions are tightly linked to their structural makeup, and their induction in the apoptotic pathway is known to play a vital role in both the initiation and execution of apoptosis. It was reported that caspase-3 is essential for cellular DNA fragmentation.65,92,93 ROS is known to stimulate the intrinsic pathway of apoptosis, and it causes impairment of outer mitochondrial membrane permeability, followed by the release of cytochrome c, and procaspases-2, -3, and -9. We measured the expression level of procaspase-3 in both B-AgNP- and F-AgNP-treated cells, and the results showed significantly lower expression in AgNPs-treated cells than in untreated cells (Figure 10). Similarly, Xi et al observed a gradual decrease in caspase-3 expression in human histocytic lymphoma U937 cells treated with nanoparticle realgar powders (NRP), which indicates that caspase-3 plays an important role in nanoparticle-induced apoptosis.94 In order to show the link between decreased level of procaspase-3 and increased level of caspase-3, we measured the level of caspase-3 activation using the peptide substrate, Ac-DEVD-pNA. The cells treated with B-AgNPs and F-AgNPs significantly increased caspase-3 level compared with untreated cells (Figure 11). The results suggest that the increased level of caspase-3 activation in AgNP-treated cells could contribute to cell death through apoptosis.9,10 These results concluded that both AgNPs could induce apoptosis in breast cancer cells in a caspase-3-dependent manner.9,10


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)

B-AgNPs and F-AgNPs induces caspase-3 activity in MDA-MB-231 cells.Notes: MDA-MB-231 cells were treated with AgNPs and F-AgNPs with or without caspase-3 inhibitor Ac-DEVD-CHO for 24 hours. The concentration of p-nitroanilide released from the substrate was calculated from the absorbance at 405 nm. The results are expressed as the mean ± standard deviation of three independent experiments. The 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; Con, control; F-AgNPs, fungus- derived AgNPs.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4494182&req=5

f11-ijn-10-4203: B-AgNPs and F-AgNPs induces caspase-3 activity in MDA-MB-231 cells.Notes: MDA-MB-231 cells were treated with AgNPs and F-AgNPs with or without caspase-3 inhibitor Ac-DEVD-CHO for 24 hours. The concentration of p-nitroanilide released from the substrate was calculated from the absorbance at 405 nm. The results are expressed as the mean ± standard deviation of three independent experiments. The 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; Con, control; F-AgNPs, fungus- derived AgNPs.
Mentions: Caspases are potent cysteine proteases whose functions are tightly linked to their structural makeup, and their induction in the apoptotic pathway is known to play a vital role in both the initiation and execution of apoptosis. It was reported that caspase-3 is essential for cellular DNA fragmentation.65,92,93 ROS is known to stimulate the intrinsic pathway of apoptosis, and it causes impairment of outer mitochondrial membrane permeability, followed by the release of cytochrome c, and procaspases-2, -3, and -9. We measured the expression level of procaspase-3 in both B-AgNP- and F-AgNP-treated cells, and the results showed significantly lower expression in AgNPs-treated cells than in untreated cells (Figure 10). Similarly, Xi et al observed a gradual decrease in caspase-3 expression in human histocytic lymphoma U937 cells treated with nanoparticle realgar powders (NRP), which indicates that caspase-3 plays an important role in nanoparticle-induced apoptosis.94 In order to show the link between decreased level of procaspase-3 and increased level of caspase-3, we measured the level of caspase-3 activation using the peptide substrate, Ac-DEVD-pNA. The cells treated with B-AgNPs and F-AgNPs significantly increased caspase-3 level compared with untreated cells (Figure 11). The results suggest that the increased level of caspase-3 activation in AgNP-treated cells could contribute to cell death through apoptosis.9,10 These results concluded that both AgNPs could induce apoptosis in breast cancer cells in a caspase-3-dependent manner.9,10

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