Screening of four signature genes for clinical testing through bioinformatics and in vitro methods in head and neck squamous cell carcinoma.

Head and neck squamous cell carcinoma (HNSC) is the 6th most common cancer around the globe; its underlying molecular mechanisms and accurate molecular markers are still lacking. In this study, we explored hub genes and their potential signaling pathways through which these genes participate in the development of HNSC. The GSE23036 gene microarray dataset was attained from the GEO (Gene Expression Omnibus) database. Hub genes were identified via the Cytohubba plug-in application of the Cytoscape. The Cancer Genome Atlas (TCGA) datasets and cell lines (HOK and FuDu) were used to evaluate expression variations in the hub genes. Moreover, promoter methylation, genetic alteration, gene enrichment, miRNA network, and immunocyte infiltration analysis were also performed to confirm the oncogenic role and biomarker potential of the hub genes in HNSC patients. Based on the hub gene analysis results, four hub genes, including KNTC1 (Kinetochore Associated 1), CEP55 (Centrosomal protein of 55 kDa), AURKA (Aurora A Kinase), and ECT2 (Epithelial Cell Transforming 2), with the highest degree scores were denoted as hub genes. All these four genes were significantly up-regulated in HNSC clinical samples and cell lines relative to their counterparts. Overexpression of KNTC1, CEP55, AURKA, and ECT2 was also associated with poor survival and various clinical parameters of the HNSC patients. Methylation analysis through targeted bisulfite sequencing of HOK and FuDu cell lines revealed that the overexpression of KNTC1, CEP55, AURKA, and ECT2 hub genes was due to their promoter hypomethylation. Moreover, higher expressions of KNTC1, CEP55, AURKA, and ECT2 were positively correlated with the abundance of the CD4+ T cells and macrophage while with the reduction of CD8+ T cells in HNSC samples. Finally, gene enrichment analysis showed that all hub genes are involved in "nucleoplasm, centrosome, mitotic spindle, and cytosol" pathways. In conclusion, the KNTC1, CEP55, AURKA, and ECT2 genes could be potential biomarkers for HNSC patients and provide a novel insight into the diagnosis and treatment of the disease.

The Influence of Prenatal Exposure to Methamphetamine on the Development of Dopaminergic Neurons in the Ventral Midbrain.

Methamphetamine, a highly addictive central nervous system (CNS) stimulant, is used worldwide as an anorexiant and attention enhancer. Methamphetamine use during pregnancy, even at therapeutic doses, may harm fetal development. Here, we examined whether exposure to methamphetamine affects the morphogenesis and diversity of ventral midbrain dopaminergic neurons (VMDNs). The effects of methamphetamine on morphogenesis, viability, the release of mediator chemicals (such as ATP), and the expression of genes involved in neurogenesis were evaluated using VMDNs isolated from the embryos of timed-mated mice on embryonic day 12.5. We demonstrated that methamphetamine (10 µM; equivalent to its therapeutic dose) did not affect the viability and morphogenesis of VMDNs, but it reduced the ATP release negligibly. It significantly downregulated Lmx1a, En1, Pitx3, Th, Chl1, Dat, and Drd1 but did not affect Nurr1 or Bdnf expression. Our results illustrate that methamphetamine could impair VMDN differentiation by altering the expression of important neurogenesis-related genes. Overall, this study suggests that methamphetamine use may impair VMDNs in the fetus if taken during pregnancy. Therefore, it is essential to exercise strict caution for its use in expectant mothers.

The Influence of Prenatal Exposure to Quetiapine Fumarate on the Development of Dopaminergic Neurons in the Ventral Midbrain of Mouse Embryos.

The effects of second-generation antipsychotics on prenatal neurodevelopment, apoptotic neurodegeneration, and postnatal developmental delays have been poorly investigated. Even at standard doses, the use of quetiapine fumarate (QEPF) in pregnant women might be detrimental to fetal development. We used primary mouse embryonic neurons to evaluate the disruption of morphogenesis and differentiation of ventral midbrain (VM) neurons after exposure to QEPF. The dopaminergic VM neurons were deliberately targeted due to their roles in cognition, motor activity, and behavior. The results revealed that exposure to QEPF during early brain development decreased the effects of the dopaminergic lineage-related genes Tyrosine hydroxylase(Th), Dopamine receptor D1 (Drd1), Dopamine transporter (Dat), LIM homeobox transcription factor 1 alfa (Lmx1a), and Cell adhesion molecule L1 (Chl1), and the senescent dopaminergic gene Pituitary homeobox 3 (Pitx3). In contrast, Brain derived neurotrophic factor (Bdnf) and Nuclear receptor-related 1 (Nurr1) expressions were significantly upregulated. Interestingly, QEPF had variable effects on the development of non-dopaminergic neurons in VM. An optimal dose of QEPF (10 µM) was found to insignificantly affect the viability of neurons isolated from the VM. It also instigated a non-significant reduction in adenosine triphosphate formation in these neuronal populations. Exposure to QEPF during the early stages of brain development could also hinder the formation of VM and their structural phenotypes. These findings could aid therapeutic decision-making when prescribing 2nd generation antipsychotics in pregnant populations.

Potential Therapeutic Target Protein Tyrosine Phosphatase-1B for Modulation of Insulin Resistance with Polyphenols and Its Quantitative Structure-Activity Relationship.

The increase in the number of cases of type 2 diabetes mellitus (T2DM) and the complications associated with the side effects of chemical/synthetic drugs have raised concerns about the safety of the drugs. Hence, there is an urgent need to explore and identify natural bioactive compounds as alternative drugs. Protein tyrosine phosphatase 1B (PTP1B) functions as a negative regulator and is therefore considered as one of the key protein targets modulating insulin signaling and insulin resistance. This article deals with the screening of a database of polyphenols against PTP1B activity for the identification of a potential inhibitor. The research plan had two clear objectives. Under first objective, we conducted a quantitative structure-activity relationship analysis of flavonoids with PTP1B that revealed the strongest correlation (R2 = 93.25%) between the number of aromatic bonds (naro) and inhibitory concentrations (IC50) of PTP1B. The second objective emphasized the binding potential of the selected polyphenols against the activity of PTP1B using molecular docking, molecular dynamic (MD) simulation and free energy estimation. Among all the polyphenols, silydianin, a flavonolignan, was identified as a lead compound that possesses drug-likeness properties, has a higher negative binding energy of -7.235 kcal/mol and a pKd value of 5.2. The free energy-based binding affinity (ΔG) was estimated to be -7.02 kcal/mol. MD simulation revealed the stability of interacting residues (Gly183, Arg221, Thr263 and Asp265). The results demonstrated that the identified polyphenol, silydianin, could act as a promising natural PTP1B inhibitor that can modulate the insulin resistance.

Central leptin and resistin combined elicit enhanced central effects on renal sympathetic nerve activity.

NEW FINDINGS: What is the central question of this study? Leptin and resistin act centrally to increase renal sympathetic nerve activity (RSNA). We investigated whether a combination of resistin and leptin could induce a greater response than either alone. We also used Fos protein to quantify the number of activated neurons in the brain. What is the main finding and its importance? A combination of leptin and resistin induced a greater increase in RSNA than either hormone alone. This was correlated with a greater number of activated neurons in the arcuate nucleus than with either hormone alone. Leptin and resistin act centrally to increase renal sympathetic nerve activity (RSNA). We investigated whether a combination of resistin and leptin could induce a greater response than either alone. Mean arterial pressure, heart rate and RSNA were recorded before and for 3 h after intracerebroventricular saline (control; n = 5), leptin (7 µg; n = 5), resistin (7 µg; n = 4) and leptin administered 15 min after resistin (n = 6). Leptin alone and resistin alone significantly increased RSNA (74 ± 17 and 50 ± 14%, respectively; P < 0.0001 compared with saline). When leptin and resistin were combined, there was a significantly greater increase in RSNA (163 ± 23%) compared with either hormone alone (P < 0.0001). Maximal responses of mean arterial pressure and heart rate were not significantly different between groups. We also used Fos protein to quantify the number of activated neurons in the brain. Compared with controls, there were significant increases in numbers of Fos-positive neurons in the arcuate and hypothalamic paraventricular nuclei when leptin or resistin was administered alone or when they were combined, and in the lamina terminalis when leptin and resistin were combined. Only in the arcuate nucleus was the increase significantly greater compared with either hormone alone. The findings show that a combination of leptin and resistin induces a greater RSNA increase and a greater number of activated neurons in the arcuate nucleus than with either hormone alone. Given that leptin makes an important contribution to the elevated RSNA observed in obese and overweight conditions, the increased concentrations of leptin and resistin may mean that the contribution of leptin to the elevated RSNA in those conditions is enhanced.