RESUMO
Inward rectifying potassium channels sensitive to ATP levels (KATP) have been the subject of investigation for several decades. Modulators of KATP channels are well-established treatments for metabolic as well as cardiovascular diseases. Experimental studies have also shown the potential of KATP modulation in neurodegenerative disorders. However, to date, data regarding the effects of KATP antagonists/agonists in experiments related to neurodegeneration remain inconsistent. The main source of confusion in evaluating available data seems to be the choice of experimental models. The present study aims to provide a comprehensive understanding of the effects of both opening and blocking KATP channels in two forms of SH-SY5Y cells. Our results offer valuable insights into the significance of metabolic differences between differentiated and non-differentiated SH-SY5Y cells, particularly in the context of glibenclamide and diazoxide effects under normal conditions and during the initiation of pathological events simulating Parkinson's disease in vitro. We emphasize the analysis of mitochondrial functions and changes in mitochondrial network morphology. The heightened protein expression of KATP channels identified in non-differentiated SH-SY5Y cells seems to be a platform for a more significant impact of KATP modulators in this cell type. The efficiency of rotenone treatment in inducing morphological changes in the mitochondrial network depends on the differentiation status of SH-SY5Y cells.
RESUMO
BACKGROUND: Brain tumors are a heterogeneous group of malignancies characterized by inter- and intratumoral heterogeneity. Among them, the most aggressive and, despite advances in medicine, still incurable remains glioblastoma. One of the reasons is the high recurrence rate of the disease and resistance to temozolomide, a golden standard in chemotherapy of brain tumors. Therefore, mapping the pathways responsible for tumorigenesis at the transcriptional level may help to determine the causes and aggressive behavior among different glial tumors. PATIENTS AND METHODS: Biopsies from patients with astrocytoma (N = 6), glioblastoma (N = 22), and meningioma (N = 14) were included in the sample set. A control group consisted of RNA isolated from healthy human brain (N = 3). The reverse-transcribed cDNAs were analyzed using the Human Cancer PathwayFinder™ real-time PCR Array in a 96-well format. The expression of 84 genes belonging to 9 signaling pathways (angiogenesis, apoptosis, cell cycle and senescence, DNA damage and repair, epithelial-to-mesenchymal transition, hypoxia, overall metabolism, and telomere dynamics) was determined for each sample. RESULTS: By determining the relative expression of selected genes, we characterized the transcriptomic profile of individual brain malignancies in the context of signaling pathways involved in tumorigenesis. We observed deregulation in 50, 52.4 and 53.6% % of the genes in glioblastomas, meningiomas and astrocytomas, respectively. The most pronounced changes with statistical significance compared to control were observed in the genes associated with epithelial-to-mesenchymal transition (CDH2, FOXC2, GSC, SNAI2, and SOX10), cellular senescence (BMI1, ETS2, MAP2K1, and SOD1), DNA repair (DDB2, ERCC3, GADD45G, and LIG4), and dynamic of telomeres (TEP1, TERF2IP, TNKS, and TNKS2). CONCLUSION: Based on the obtained data, we can conclude that individual diagnoses differ in transcriptomic profile. An individual molecular approach is therefore necessary in order to provide comprehensive and targeted therapy on multiple metabolic pathways in the diagnosis of brain tumors.
