Induction of apoptosis associated with chromosomal DNA fragmentation and caspase-3 activation in leukemia L1210 cells by TiO2 nanoparticles

Titania-Graphene Oxide Nanocomposite-Based Philadelphia-Positive Leukemia Therapy

Philadelphia-positive (Ph+) leukemia is a type of blood cancer also known as acute lymphoblastic leukemia (ALL), affecting 20-30% of adults diagnosed worldwide and having an engraved prognosis as compared to other types of leukemia. The current treatment regimens mainly rely on tyrosine kinase inhibitors (TKIs) and bone marrow transplants. To date, several generations of TKIs have been developed due to associated resistance and frequent relapse, with cardiovascular system anomalies being the most devastating complication. Nanotechnology has the potential to address these limitations by the targeted drug delivery and controlled release of TKIs. This study focused on the titanium dioxide (TiO2) and graphene oxide (GO) nanocomposite employment to load nilotinib and ponatinib TKIs for therapy of Ph+ leukemia cell line (K562) and Ba/F3 cells engineered to express BCR-ABL oncogene. Meanwhile, after treatment, the oncogene expressing fibroblast cells (Rat-1 P185) were evaluated for their colony formation ability under 3D conditions. To validate the nanocomposite formation, the TiO2-GO nanocomposites were characterized by scanning electron microscope, DLS, XRD, FTIR, zeta potential, EDX, and element mapping. The TKI-loaded TiO2-GO was not inferior to the free drugs after evaluating their effects by a cell viability assay (XTT), apoptosis induction, and colony formation inhibition. The cell signaling pathways of the mammalian target of rapamycin (mTOR), signal transducers and activators of transcription 5 (STAT5), and extracellular signal-regulated kinase (Erk1/2) were also investigated by Western blot. These signaling pathways were significantly downregulated in the TKI-loaded TiO2-GO-treated groups. Based on the findings above, we can conclude that TiO2-GO exhibited excellent drug delivery potential that can be used for Ph+ leukemia therapy in the future, subject to further investigations.

Fe-N Co-Doped Titanium Dioxide Nanoparticles Induce Cell Death in Human Lung Fibroblasts in a p53-Independent Manner

The advancement of nanotechnology in the last decade has developed an abundance of novel and intriguing TiO₂-based nanomaterials that are widely used in many sectors, including industry (as a food additive and colorant in cosmetics, paints, plastics, and toothpaste) and biomedicine (photoelectrochemical biosensing, implant coatings, drug delivery, and new emerging antimicrobial agents). Therefore, the increased use of engineered nanomaterials in the industry has raised serious concern about human exposure and their unexpected cytotoxic effects. Since inhalation is considered the most relevant way of absorbing nanomaterials, different cell death mechanisms induced in MRC-5 lung fibroblasts, following the exposure to functionalized TiO₂ NPs, were investigated. Long-term exposure to TiO₂ nanoparticles co-doped with 1% of iron and nitrogen led to the alteration of p53 protein activity and the gene expression controlled by this suppressor (NF-kB and mdm2), DNA damage, cell cycle disruptions at the G2/M and S phases, and lysosomal membrane permeabilization and the subsequent release of cathepsin B, triggering the intrinsic pathway of apoptosis in a Bax- and p53-independent manner. Our results are of major significance, contributing to the understanding of the mechanisms underlying the interaction of these nanoparticles with in vitro biological systems, and also providing useful information for the development of new photocatalytic nanoparticles that are active in the visible spectrum, but with increased biocompatibility.

[Influence of oxidative/antioxidative biomarkers and inflammatory cytokines on rats after sub-acute orally administration of titanium dioxide nanoparticles]

OBJECTIVE

To evaluate the sub-acute oral effect of titanium dioxide (TiO₂) nanoparticles on the oxidation/antioxidation biomarkers and inflammatory cytokines in blood, liver, intestine, and colon in rats.

METHODS

Twenty four 4-week-old clean-grade Sprague Dawley (SD) rats were randomly devided into 4 groups by body weight (n=6, control, low, middle, and high), in which the rats were orally exposed to TiO₂ nanoparticles at doses of 0, 2, 10 and 50 mg/kg body weight/day for 28 consecutive days separately. Food intake, body weight and abnormal behaviors during the experiment were recorded. The rats were euthanized on the 29th day. The blood was collected via abdominal aortic method and centrifuged to collect the serum. Tissues from liver, intestine and colon were collected and homogenated. Then enzyme-linked immunosorbent assay (ELISA) and microwell plate methods were used to detect oxidation/antioxidation biomarkers including superoxide dismutase (SOD), glutathione (GSH), glutathione peroxidase (GSH-Px), total mercapto (T-SH), glutathione disulfide (GSSG), malomdialdehvde (MDA) and inflammatory cytokines including interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) in the serum, liver, intestine and colon in the rats.

RESULTS

Compared with the control group, no significant differences in body weight, food intake and organ coefficients were observed in all the three groups after TiO₂ gavage. No significant changes in GSH, GSH-Px, T-SH, and IL-6 were observed. Compared with the control group, significant increase of SOD activity in serum in high dose group, signi-ficant increase of GSSG concentration in intestine in middle and high dose group and significant increase of MDA concentration in liver in low and high dose group were observed. Compared with the control group, a significant increase of TNF-α in liver in middle and high dose group was observed.

CONCLUSION

TiO₂ nanoparticle can increase antioxidant enzymes activities in blood, increase oxidative biomarkers in liver and intestine, increase inflammatory cytokines in liver in rats after a 28-day sub-acute orally administration. Among blood, liver, intestine, and colon, liver is most sensitive to the toxicity induced by TiO₂ nanoparticles, followed by intestine, blood, and colon in sequence.

Titanium dioxide nanoparticles induced the apoptosis of RAW264.7 macrophages through miR-29b-3p/NFAT5 pathway

Titanium dioxide nanoparticles (TiO₂ NPs) are widely found in consumer and industrial products, contributing to their prevalent presence in our surroundings. In this study, several miRNAs in the immuno-related pathways were found to be dysregulated in RAW264.7 cells after 24-h exposure to TiO₂ NPs, including miR-29b-3p, which had not been previously found to be associated with the dysregulation of immunity after exposure to TiO₂ NPs. The KEGG pathway and GO enrichment analysis suggested that miR-29b-3p functioned both in the T and B cell receptor signaling pathways. The NFAT5 gene was predicted to regulate miR-29b-3p using the MiRDB online database. The expression of miR-29b-3p and NFAT5 was found to be inversely correlated using qRT-PCR and western blotting analysis. Dual-luciferase reporter gene assays demonstrated the precise regulatory relationship between miR-29b-3p and NFAT5. The upregulation of miR-29b-3p was found to reinforce the apoptosis of cells, while no changes were found in terms of the cell cycle or cell proliferation, using MTT, cell apoptosis, and cycle detection experiments. Our results demonstrate that miR-29b-3p is involved in the response of RAW264.7 cells to exposure to TiO₂, proving evidence for the further study of the toxicity and mechanisms of nano-TiO₂ exposure.

Melatonin Enhances Palladium-Nanoparticle-Induced Cytotoxicity and Apoptosis in Human Lung Epithelial Adenocarcinoma Cells A549 and H1229

Palladium nanoparticles (PdNPs) are increasingly being used in medical and biological applications due to their unique physical and chemical properties. Recent evidence suggests that these nanoparticles can act as both a pro-oxidant and as an antioxidant. Melatonin (MLT), which also shows pro- and antioxidant properties, can enhance the efficacy of chemotherapeutic agents when combined with anticancer drugs. Nevertheless, studies regarding the molecular mechanisms underlying the anticancer effects of PdNPs and MLT in cancer cells are still lacking. Therefore, we aimed to investigate the potential toxicological and molecular mechanisms of PdNPs, MLT, and the combination of PdNPs with MLT in A549 lung epithelial adenocarcinoma cells. We evaluated cell viability, cell proliferation, cytotoxicity, oxidative stress, mitochondrial dysfunction, and apoptosis in cells treated with different concentrations of PdNPs and MLT. PdNPs and MLT induced cytotoxicity, which was confirmed by leakage of lactate dehydrogenase, increased intracellular protease, and reduced membrane integrity. Oxidative stress increased the levels of reactive oxygen species (ROS), malondialdehyde (MDA), nitric oxide (NO), protein carbonyl content (PCC), lipid hydroperoxide (LHP), and 8-isoprostane. Combining PdNPs with MLT elevated the levels of mitochondrial dysfunction by decreasing mitochondrial membrane potential (MMP), ATP content, mitochondrial number, and expression levels of the main regulators of mitochondrial biogenesis. Additionally, PdNPs and MLT induced apoptosis and oxidative DNA damage due to accumulation of 4-hydroxynonenal (HNE), 8-oxo-2'-deoxyguanosine (8-OhdG), and 8-hydroxyguanosine (8-OHG). Finally, PdNPs and MLT increased mitochondrially mediated stress and apoptosis, which was confirmed by the increased expression levels of apoptotic genes. To our knowledge, this is the first study demonstrating the effects of combining PdNPs and MLT in human lung cancer cells. These findings provide valuable insights into the molecular mechanisms involved in PdNP- and MLT-induced toxicity, and it may be that this combination therapy could be a potential effective therapeutic approach. This combination effect provides information to support the clinical evaluation of PdNPs and MLT as a suitable agents for lung cancer treatment, and the combined effect provides therapeutic value, as non-toxic concentrations of PdNPs and MLT are more effective, better tolerated, and show less adverse effects. Finally, this study suggests that MLT could be used as a supplement in nano-mediated combination therapies used to treat lung cancer.

Cytotoxicity and Transcriptomic Analyses of Biogenic Palladium Nanoparticles in Human Ovarian Cancer Cells (SKOV3)

Ovarian cancer incidence continues to increase at an alarming rate. Although various therapeutic approaches exist for ovarian cancer, they have limitations, including undesired side effects. Therefore, nanoparticle (NP)-mediated therapy may be a viable, biocompatible, and suitable alternative. To the best of our knowledge, no comprehensive analysis has been undertaken on the cytotoxicity and cellular pathways involved in ovarian cancer cells, particularly SKOV3 cells. Here, we investigated the effect of palladium NPs (PdNPs) and the molecular mechanisms and cellular pathways involved in ovarian cancer. We assayed cell viability, proliferation, cytotoxicity, oxidative stress, DNA damage, and apoptosis and performed an RNA-Seq analysis. The results showed that PdNPs elicited concentration-dependent decreases in cell viability and proliferation and induced increasing cytotoxicity at increasing concentrations, as determined by leakage of lactate dehydrogenase, increased levels of reactive oxygen species and malondialdehyde, and decreased levels of antioxidants like glutathione and superoxide dismutase. Furthermore, our study revealed that PdNPs induce mitochondrial dysfunction by altering mitochondrial membrane potential, reducing adenosine triphosphate levels, inducing DNA damage, and activating caspase 3, all of which significantly induced apoptosis in SKOV3 cells following PdNPs treatment. Gene ontology (GO) term analysis of PdNPs-exposed SKOV3 cells showed various dysregulated pathways, particularly nucleosome assembly, telomere organization, and rDNA chromatin silencing. When genes downregulated by PdNPs were applied to GO term enrichment analysis, nucleosome assembly was the top-ranked biological pathway. We also provide evidence for an association between PdNPs exposure and multiple layers of epigenetic transcriptional control and establish a molecular basis for NP-mediated apoptosis. These findings provide a foundation, potential targets, and novel insights into the mechanism underlying toxicity and pathways in SKOV3 cells, and open new avenues to identify novel targets for ovarian cancer treatment.

Internalization of Titanium Dioxide Nanoparticles Is Cytotoxic for H9c2 Rat Cardiomyoblasts

Titanium dioxide nanoparticles (TiO₂ NPs) are widely used in industry and daily life. TiO₂ NPs can penetrate into the body, translocate from the lungs into the circulation and come into contact with cardiac cells. In this work, we evaluated the toxicity of TiO₂ NPs on H9c2 rat cardiomyoblasts. Internalization of TiO₂ NPs and their effect on cell proliferation, viability, oxidative stress and cell death were assessed, as well as cell cycle alterations. Cellular uptake of TiO₂ NPs reduced metabolic activity and cell proliferation and increased oxidative stress by 19-fold measured as H₂DCFDA oxidation. TiO₂ NPs disrupted the plasmatic membrane integrity and decreased the mitochondrial membrane potential. These cytotoxic effects were related with changes in the distribution of cell cycle phases resulting in necrotic death and autophagy. These findings suggest that TiO₂ NPs exposure represents a potential health risk, particularly in the development of cardiovascular diseases via oxidative stress and cell death.

Rough Titanium Oxide Coating Prepared by Micro-Arc Oxidation Causes Down-Regulation of hTERT Expression, Molecular Presentation, and Cytokine Secretion in Tumor Jurkat T Cells

The response of the human Jurkat T cell leukemia-derived cell line (Jurkat T cells) after 24 h of in vitro exposure to a titanium substrate (12 × 12 × 1 mm³) with a bilateral rough (R_a = 2.2–3.7 μm) titanium oxide coating (rTOC) applied using the micro-arc method in a 20% orthophosphoric acid solution was studied. A 1.5-fold down-regulation of hTERT mRNA expression and decreases in CD3, CD4, CD8, and CD95 presentation and IL-4 and TNFα secretion were observed. Jurkat T cell inactivation was not correlated with the generation of intracellular reactive oxygen species (ROS) and was not mediated by TiO₂ nanoparticles with a diameter of 14 ± 8 nm at doses of 1 mg/L or 10 mg/L. The inhibitory effect of the rTOC (R_a = 2.2–3.7 μm) on the survival of Jurkat T cells (Spearman’s coefficient r_s = −0.95; n = 9; p < 0.0001) was demonstrated by an increase in the necrotic cell count among the cell population. In turn, an elevation of the Ra index of the rTOC was accompanied by a linear increase (r = 0.6; p < 0.000001, n = 60) in the magnitude of the negative electrostatic potential of the titanium oxide surface. Thus, the roughness of the rTOC induces an electrostatic potential and decreases the viability of the immortalized Jurkat T cells through mechanisms unrelated to ROS generation. This may be useful for replacement surgery applications of rough TiO₂ implants in cancer patients.

Iron oxide magnetic nanoparticles combined with actein suppress non-small-cell lung cancer growth in a p53-dependent manner

Actein (AT) is a triterpene glycoside isolated from the rhizomes of Cimicifuga foetida that has been investigated for its antitumor effects. AT treatment leads to apoptosis in various cell types, including breast cancer cells, by regulating different signaling pathways. Iron oxide (Fe₃O₄) magnetic nanoparticles (MNPs) are nanomaterials with biocompatible activity and low toxicity. In the present study, the possible benefits of AT in combination with MNPs on non-small-cell lung cancer (NSCLC) were explored in in vitro and in vivo studies. AT-MNP treatment contributed to apoptosis in NSCLC cells, as evidenced by activation of the caspase 3-signaling pathway, which was accompanied by downregulation of the antiapoptotic proteins Bcl2 and BclXL, and upregulation of the proapoptotic signals Bax and Bad. The death receptors of TRAIL were also elevated following AT-MNP treatment in a p53-dependent manner. Furthermore, a mouse xenograft model in vivo revealed that AT-MNP treatment exhibited no toxicity and suppressed NSCLC growth compared to either AT or MNP monotherapies. In conclusion, this study suggests a novel therapy to induce apoptosis in suppressing NSCLC growth in a p53-dependent manner by combining AT with Fe₃O₄ MNPs.

ROS-Mediated Apoptosis and Genotoxicity Induced by Palladium Nanoparticles in Human Skin Malignant Melanoma Cells

The present work was designed to investigate the effect of palladium nanoparticles (PdNPs) on human skin malignant melanoma (A375) cells, for example, induction of apoptosis, cytotoxicity, and DNA damage. Diseases resulting from dermal exposure may have a significant impact on human health. There is a little study that has been reported on the toxic potential of PdNPs on A375. Cytotoxic potential of PdNPs (0, 5, 10, 20, and 40 μg/ml) was measured by tetrazolium bromide (MTT assay) and NRU assay in A375 cells. PdNPs elicited concentration and time-dependent cytotoxicity, and longer exposure period induced more cytotoxicity as measured by MTT and NRU assay. The molecular mechanisms of cytotoxicity through cell cycle arrest and apoptosis were investigated by AO (acridine orange)/EtBr (ethidium bromide) stain and flow cytometry. PdNPs not only inhibit proliferation of A375 cells in a dose- and time-dependent model but also induce apoptosis and cell cycle arrest at G2/M phase (before 12 h) and S phase (after 24 h). The induction of oxidative stress in A375 cells treated with above concentration PdNPs for 24 and 48 h increased ROS level; on the other hand, glutathione level was declined. Apoptosis and DNA damage was significantly increased after treatment of PdNPs. Considering all results, PdNPs showed cytotoxicity and genotoxic effect in A375 cells.

Luffa echinata Roxb. Induced Apoptosis in Human Colon Cancer Cell (SW-480) in the Caspase-dependent Manner and Through a Mitochondrial Apoptosis Pathway

BACKGROUND

Luffa echinata Roxb. (LER) (Cucurbitaceae) showed tremendous medicinal importance and are being used for the treatment of different ailments.

OBJECTIVE

In this study, the antiproliferative properties and cell death mechanism induced by the extract of the fruits of LER were investigated.

MATERIALS AND METHODS

MTT and LDH assay were used to test the antiproliferative and cytotoxicity of LER extract, respectively. The intracellular ROS were measured by a fluorometric assay. The expression of several apoptotic-related proteins in SW-480 cells treated by LER was evaluated by Western blot analysis.

RESULTS

The methanolic extract of LER fruits inhibited the proliferation of human colon cancer cells (SW-480) in both dose- and time-dependent manners. The LER-treated cells showed obvious characteristics of cell apoptosis, including cell shrinkage, destruction of the monolayer, and condensed chromatin. In addition, treatments of various concentrations of LER extracts caused the release of lactate dehydrogenase as a dose-dependent manner via stimulation of the intracellular metabolic system. LER induced apoptosis, DNA fragmentation, and cellular ROS accumulation in SW-480 cells. Treatment of LER on SW-480 cells promoted the expression of caspases, Bax, Bad, and p53 proteins and decreased the levels of Bcl-2 and Bcl-XL.

CONCLUSIONS

These results indicated that treatment with LER-induced cell death in mitochondrial apoptosis pathway by regulating pro-apoptotic proteins via the up regulation of the p53 protein. These findings highlight the potentials of LER in the treatment of human colon cancer.

SUMMARY

LER induced apoptosis, DNA fragmentation, and cellular ROS accumulation in SW-480 cells. Treatment of LER on SW-480 cells promoted the expression of caspases, Bax, Bad, and p53 proteins and decreased the levels of Bcl-2 and Bcl-XL.

Green Chemistry Approach for Synthesis of Effective Anticancer Palladium Nanoparticles

The purpose of this study was to design and synthesize Palladium nanoparticles (PdNPs) using an environmentally friendly approach and evaluate the in vitro efficacy of PdNPs in human ovarian cancer A2780 cells. Ultraviolet-Visible (UV-Vis) spectroscopy was used to monitor the conversion of Pd(II) ions to Pd(0)NPs. X-ray diffraction (XRD) revealed the crystallinity of the as-synthesized PdNPs and Fourier transform infrared spectroscopy (FTIR) further confirmed the role of the leaf extract of Evolvulus alsinoides as a reducing and stabilizing agent for the synthesis of PdNPs. Dynamic light scattering (DLS) and transmission electron microscopy (TEM) showed that the average size of the NPs was 5 nm. After a 24-h exposure to PdNPs, cell viability and light microscopy assays revealed the dose-dependent toxicity of the PdNPs. Furthermore, the dose-dependent cytotoxicity of the PdNPs was confirmed by lactate dehydrogenase (LDH), increased reactive oxygen species (ROS) generation, activation of PdNPs-induced autophagy, impairment of mitochondrial membrane potential (MMP), enhanced caspase-3 activity, and detection of TUNEL-positive cells. Our study demonstrates a single, simple, dependable and green approach for the synthesis of PdNPs using leaf extracts of Evolvulus alsinoides. Furthermore, the in vitro efficacy of PdNPs in human ovarian cancer cells suggests that it could be an effective therapeutic agent for cancer therapy.

Design of multifunctional FePt/GO nanocomposites for targeting, dual-modal imaging diagnostic and in situ therapeutic potential theranostic platform

In this work, highly monodispersed chemically disordered face centered cubic (fcc) FePt nanoparticles (NPs) were assembled on graphene oxide (GO) surface to form FePt/GO nanocomposites via a simple polyol protocol.