Comprehensive DNA Methylation Analysis of Human Neuroblastoma Cells Treated With Haloperidol and Risperidone

Accumulating evidence suggests that the epigenetic alterations induced by antipsychotics contribute to the therapeutic efficacy. However, global and site-specific epigenetic changes by antipsychotics and those shared by different classes of antipsychotics remain poorly understood. We conducted a comprehensive DNA methylation analysis of human neuroblastoma cells cultured with antipsychotics. The cells were cultured with low and high concentrations of haloperidol or risperidone for 8 days. DNA methylation assay was performed with the Illumina HumanMethylation450 BeadChip. We found that both haloperidol and risperidone tended to cause hypermethylation changes and showed similar DNA methylation changes closely related to neuronal functions. A total of 294 differentially methylated probes (DMPs), including 197 hypermethylated and 97 hypomethylated DMPs, were identified with both haloperidol and risperidone treatment. Gene ontology analysis of the hypermethylated probe-associated genes showed enrichment of genes related to the regulation of neurotransmitter receptor activity and lipoprotein lipase activity. Pathway analysis identified that among the DMP-associated genes, SHANK1 and SHANK2 were the major genes in the neuropsychiatric disorder-related pathways. Our data would be valuable for understanding the mechanisms of action of antipsychotics from an epigenetic viewpoint.

Investigation of the Effects of Zinc Oxide Nanoparticles on Membrane Damage of Human Neuroblastoma Cell Lineage (SH-SY5Y) and Change of Tau Protein Structure by Spectroscopic Methods

The use of nanoparticles in biological applications and cancer treatment has increased dramatically in the recent decade. Metal oxides of nanoparticles are among the most significant nanoparticles. Due to its suitable physical and chemical properties, zinc oxide is utilized in various fields, especially biomedicine and cancer treatment. This has raised a great deal of concern about the effects of nanoparticles on the body's biomolecules. The current study was set out to investigate zinc oxide nanoparticle's effects on neuroblastoma cells and their interaction with Tau protein. MTT and LDH tests were performed according to the instructions to evaluate the toxicity of zinc oxide nanoparticles on human neuroblastoma cells. Afterward, UV spectroscopy, CD spectroscopy, and fluorescence spectroscopy were performed according to the guidelines to investigate the interaction of zinc oxide nanoparticles with Tau protein. The results of the MTT assay showed a decrease in the survival rate of human neuroblastoma cells in a dose-dependent manner. The results of the Lactate dehydrogenase evaluation indicated an increase in LDH enzyme leakage from human neuroblastoma cells. Furthermore, zinc oxide nanoparticles form complexes with Tau-P through spontaneous and electrostatic interactions. The interaction of zinc oxide nanoparticles with Tau-P caused the accumulation of this protein and showed a significant change in the Tau-P structure. CD spectroscopy results showed that zinc oxide nanoparticles changed the α-helix and β-sheet structure of the Tau protein. Besides, the results of the Stern-Volmer equation revealed that the type of interaction of zinc nanoparticles with Tau-P is static quenching interaction. In summary, these results demonstrated the safety aspect of zinc oxide nanoparticles in proteins and natural cells and their biological applications, which emphasizes further investigation on zinc oxide nanoparticles usage. Zinc oxide nanoparticles can manipulate the structure of Tau-P that can lead to Alzheimer's disease. Consequently, more studies on the use of zinc oxide nanoparticles are required.

Analysis of Asymmetric Cell Division Using Human Neuroblastoma Cell Lines as a Model System

Neuroblastoma is one of the most common childhood solid tumors and develops from neural stem cells that normally comprise the embryonic structure termed the neural crest. Human neuroblastoma cell lines have special properties as they exhibit cell growth and are induced to become mature neurons by drugs such as retinoid. Therefore, we examined asymmetric cell division (ACD) using human neuroblastoma cells as an ACD model, and confirmed that ACD in human cancer cells is evolutionally conserved. Furthermore, we demonstrated that MYCN is involved in cell division fate. We introduce the brief history of ACD study using neuroblastoma cell lines and discuss why human neuroblastoma cells are an ideal model system for clarifying the mechanism of ACD.

Methylmercury Induced Apoptosis of Human Neuroblastoma Cells Through the ROS Mediated Caspase and PARP/AIF Dependent Pathways

Methylmercury (MeHg) is an environmental neurotoxic substance, which can be absorbed by the human body through the digestive tract, and easily cross the blood-brain barrier, causing irreversible damage to the human central nervous system. Reactive oxygen species (ROS) are involved in various ways of intracellular physiological or pathological processes including neuronal apoptosis. The current studies attempted to explore the role of ROS-mediated PARP/AIF apoptosis signal in the process of MeHg inducing human neuroblastoma cells (SH-SY5Y) death. Here, the present studies found that SH-SY5Y cells underwent apoptosis in response to MeHg, which was accompanied by increased the levels of ROS and calcium ion, and the activation of caspase cascades and poly ADP-ribose polymerase (PARP). The decrease in ROS levels significantly reduced the expression of these proteins and the rate of apoptosis. Inhibition of caspase pathway can reduce the rate of apoptosis, but can not prevent the occurrence of apoptosis. Furthermore, inhibition of PARP signaling can significantly reduce the apoptosis rate and the expression of caspase pathway related proteins. Collectively, these results indicated that ROS mediated activation of caspase pathway and PARP /AIF signaling pathway are involved in MeHg induced apoptosis, and there is a certain relationship between the two pathways.