RESUMEN
Graphene, a two-dimensional carbon sheet with single-atom thickness, shows immense promise in several nanoscientific and nanotechnological applications, including in sensors, catalysis, and biomedicine. Although several studies have shown the cytotoxicity of graphene oxide in different cell types, there are no comprehensive studies on human embryonic kidney (HEK293) cells that include transcriptomic analysis and an in vitro investigation into the mechanisms of cytotoxicity following exposure to graphene oxide. Therefore, we exposed HEK293 cells to different concentrations of graphene oxide for 24 h and performed several cellular assays. Cell viability and proliferation assays revealed a significant dose-dependent cytotoxic effect on HEK293 cells. Cytotoxicity assays showed increased lactate dehydrogenase (LDH) leakage and reactive oxygen species (ROS) generation, and decreased levels of reduced glutathione (GSH) and increased level of oxidized glutathione indicative of oxidative stress. This detailed mechanistic approach showed that graphene oxide exposure elicits significant decreases in mitochondrial membrane potential and ATP synthesis, as well as in DNA damage and caspase 3 activity. Furthermore, our RNA-Seq analysis revealed that HEK293 cells exposed to graphene oxide significantly altered the expression of genes involved in multiple apoptosis-related biological pathways. Moreover, graphene oxide exposure perturbed the expression of key transcription factors, promoting these apoptosis-related pathways by regulating their downstream genes. Our analysis provides mechanistic insights into how exposure to graphene oxide induces changes in cellular responses and massive cell death in HEK293 cells. To our knowledge, this is the first study describing a combination of cellular responses and transcriptome in HEK293 cells exposed to graphene oxide nanoparticles, providing a foundation for understanding the molecular mechanisms of graphene oxide-induced cytotoxicity and for the development of new therapeutic strategies.
RESUMEN
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.
