Aicar effect in early neuronal development

Modeling of cancer stem cells and the tumor microenvironment Via NT2/D1 cells to probe pathology and treatment for cancer and beyond

INTRODUCTION

Unique from the other tumor cells, tumorigenic cancer stem cells (CSCs) manifest as a subpopulation of cells within the tumor that exhibit genetic and phenotypic features and signaling processes, which escape traditional anti-oncogenic treatments, thereby triggering metastases and relapses of cancers. Critical to cancer biology is the crosstalk between CSCs and tumor microenvironment (TME), implicating a CSC-based cancer immunotherapy. Cognizant of CSCs' significant role in cancer pathology and treatment, finding a biological model that recapitulates CSCs and TME may allow a better understanding of tumor onset and progression for testing CSC-based therapies. In this review paper, we examined the CSC and TME characteristics of the human embryonal carcinoma NTERA-2 clonal cell line called NTERA-2 cl.D1 or NT2/D1 cells and discussed their potential utility for research and development of treatments for cancer and central nervous system (CNS) disorders.

METHODS

To probe our hypotheses that NT2/D1 cells display CSC and TME properties key to tumor development, which can serve as a screening platform to test cancer and CNS therapeutics, we conducted a literature review over a 10-year period (2014-2024), focusing on PUBMED and Science Direct published articles on cellular models of cancer, with emphasis on milestone research discoveries on NT2/D1 cells relevant to CSCs and TME. We categorized the studies under pre-clinical and clinical investigations in supporting the existence of CSC and TME features in NT2/D1 cells and providing a laboratory-to-clinic translational basis for cancer and CNS therapeutics.

CONCLUSIONS

NT2/D1 cells stand as a feasible biological model that recapitulates the crosstalk of CSCs and TME, which may critically contribute to our understanding of cancer and CNS biology and therapeutics. Designing therapeutics against CSCs' distinct self-renewal and differentiation capacities within the TME opens new avenues for treating cancers and CNS disorders.

Integrative Analyses of Transcriptomes to Explore Common Molecular Effects of Antipsychotic Drugs

There is little understanding of the underlying molecular mechanism(s) involved in the clinical efficacy of antipsychotics for schizophrenia. This study integrated schizophrenia-associated transcriptional perturbations with antipsychotic-induced gene expression profiles to detect potentially relevant therapeutic targets shared by multiple antipsychotics. Human neuronal-like cells (NT2-N) were treated for 24 h with one of the following antipsychotic drugs: amisulpride, aripiprazole, clozapine, risperidone, or vehicle controls. Drug-induced gene expression patterns were compared to schizophrenia-associated transcriptional data in post-mortem brain tissues. Genes regulated by each of four antipsychotic drugs in the reverse direction to schizophrenia were identified as potential therapeutic-relevant genes. A total of 886 genes were reversely expressed between at least one drug treatment (versus vehicle) and schizophrenia (versus healthy control), in which 218 genes were commonly regulated by all four antipsychotic drugs. The most enriched biological pathways include Wnt signaling and action potential regulation. The protein-protein interaction (PPI) networks found two main clusters having schizophrenia expression quantitative trait loci (eQTL) genes such as PDCD10, ANK2, and AKT3, suggesting further investigation on these genes as potential novel treatment targets.

HGprt deficiency disrupts dopaminergic circuit development in a genetic mouse model of Lesch–Nyhan disease

In Lesch–Nyhan disease (LND), deficiency of the purine salvage enzyme hypoxanthine guanine phosphoribosyl transferase (HGprt) leads to a characteristic neurobehavioral phenotype dominated by dystonia, cognitive deficits and incapacitating self-injurious behavior. It has been known for decades that LND is associated with dysfunction of midbrain dopamine neurons, without overt structural brain abnormalities. Emerging post mortem and in vitro evidence supports the hypothesis that the dopaminergic dysfunction in LND is of developmental origin, but specific pathogenic mechanisms have not been revealed. In the current study, HGprt deficiency causes specific neurodevelopmental abnormalities in mice during embryogenesis, particularly affecting proliferation and migration of developing midbrain dopamine (mDA) neurons. In mutant embryos at E14.5, proliferation was increased, accompanied by a decrease in cell cycle exit and the distribution and orientation of dividing cells suggested a premature deviation from their migratory route. An abnormally structured radial glia-like scaffold supporting this mDA neuronal migration might lie at the basis of these abnormalities. Consequently, these abnormalities were associated with an increase in area occupied by TH⁺ cells and an abnormal mDA subpopulation organization at E18.5. Finally, dopaminergic innervation was disorganized in prefrontal and decreased in HGprt deficient primary motor and somatosensory cortices. These data provide direct in vivo evidence for a neurodevelopmental nature of the brain disorder in LND. Future studies should not only focus the specific molecular mechanisms underlying the reported neurodevelopmental abnormalities, but also on optimal timing of therapeutic interventions to rescue the DA neuron defects, which may also be relevant for other neurodevelopmental disorders.

Physiological levels of folic acid reveal purine alterations in Lesch-Nyhan disease

Lesch-Nyhan disease (LND), caused by a deficient salvage purine pathway, is characterized by severe neurological manifestations and uric acid overproduction. However, uric acid is not responsible for brain dysfunction, and it has been suggested that purine nucleotide depletion, or accumulation of other toxic purine intermediates, could be more relevant. Here we show that purine alterations in LND fibroblasts depend on the level of folic acid in the culture media. Thus, physiological levels of folic acid induce accumulation of 5-aminoimidazole-4-carboxamide riboside 5'-monophosphate (ZMP), an intermediary of de novo purine biosynthetic pathway, and depletion of ATP. Additionally, Z-nucleotide derivatives (AICAr, AICA) are detected at high levels in the urine of patients with LND and its variants (hypoxanthine-guanine phosphoribosyltransferase [HGprt]-related neurological dysfunction and HGprt-related hyperuricemia), and the ratio of AICAr/AICA is significantly increased in patients with neurological problems (LND and HGprt-related neurological dysfunction). Moreover, AICAr is present in the cerebrospinal fluid of patients with LND, but not in control individuals. We hypothesize that purine alterations detected in LND fibroblasts may also occur in the brain of patients with LND.