Dexamethasone Suppresses IL-33-exacerbated Malignant Phenotype of U87MG Glioblastoma Cells via NF-κB and MAPK Signaling Pathways.

BACKGROUND: Interleukin (IL)-33 is highly expressed in glioblastoma (GBM) and promotes tumor progression. Targeting IL-33 may be an effective strategy for the treatment of GBM. Dexamethasone (DEX) is a controversial drug routinely used clinically in GBM therapy. Whether DEX has an effect on IL-33 is unknown. This study aimed to investigate the effect of DEX on IL-33 and the molecular mechanisms involved. METHODS: U87MG cells were induced by tumor necrosis factor (TNF)-α to express IL-33 and then treated with DEX. The mRNA levels of IL-33, NF-κB p65, ERK1/2, and p38 were determined by real-time quantitative PCR. The expression of IL-33, IkBα (a specific inhibitor of NF-κB) and MKP-1 (a negative regulator of MAPK), as well as the phosphorylation of NF-κB, ERK1/2 and p38 MAPK, were detected by Western blotting. The secretion of IL-33 was measured by ELISA. The proliferation, migration and invasion of U87MG cells were detected by CCK8 and transwell assays, respectively. RESULTS: DEX significantly reduced TNF-α-induced production of IL-33 in U87MG cells, which was dependent on inhibiting the activation of the NF-κB, ERK1/2 and p38 MAPK signaling pathways, and was accompanied by the increased expression of IkBα but not MKP-1. Furthermore, the proliferation, migration and invasion of U87MG cells exacerbated by IL-33 were suppressed by DEX. CONCLUSION: DEX inhibited the production and tumor-promoting function of IL-33. Whether DEX can benefit GBM patients remains controversial. Our results suggest that GBM patients with high IL-33 expression may benefit from DEX treatment and deserve further investigation.

Association between miR-365 polymorphism and ischemic stroke in a Chinese population.

Background: Ischemic stroke (IS) represents a major cause of morbidity and mortality across the globe. The aberrant expression of miR-365 has been found to be implicated in a wide array of human diseases, including atherosclerosis and cancer. Studies on single-nucleotide polymorphisms (SNPs) in miRNA genes can help gain insight into the susceptibility to the condition. This study aimed to examine the relationship between miR-365 SNPs and the risk of IS. Methods: The study recruited 215 IS patients and 220 controls. The SNPscans genotyping was employed to genotype three polymorphic loci (rs121224, rs30230, and rs178553) of miR-365. The relative expression of miR-365 in peripheral blood mononuclear cells of the patients and controls was determined by using real-time quantitative PCR. Results: The miR-365 rs30230 polymorphism exhibited a significant association with the risk of developing IS (TC vs. CC: adjusted OR = 0.55, 95% CI: 0.33-0.92, P = 0.022; TT vs. CC: adjusted OR = 0.34, 95% CI: 0.14-0.85, P = 0.021; TC +TT vs. CC: adjusted OR = 0.51, 95% CI: 0.31-0.83, P = 0.007; T vs. C: adjusted OR = 0.57, 95% CI: 0.39-0.83, P = 0.004). Haplotype analysis revealed that the C-T-G haplotype was associated with a decreased risk of IS (OR = 0.68, 95% CI: 0.46-1.00, P = 0.047). Furthermore, miR-365 expression was significantly higher in IS patients than in controls (P < 0.001). Interestingly, patients with rs30230 TC or TT genotypes had lower miR-365 levels compared to their counterparts with CC genotypes (P < 0.001). Conclusions: The miR-365 rs30230 polymorphism might bear an association with IS susceptibility in the Chinese population, and the rs30230 TC/TT genotype might be a protective factor against IS.