Objective:To investigate the effect of long non-coding RNA (LncRNA) LY6E-DT on temozolomide (TMZ) resistance in high grade glioma cells (HGG) cells and its mechanism.Methods:Bioinformatics screened the LncRNA correlated to the expression of O6-methylguanine-DNA methyltransferase (MGMT) in HGG tissue, and excavated potentially related microRNA (miRNA) . HGG cell U251 was cultured and randomly divided into control group, resistance group and interference group. Resistance group and interference group were treated with 0.2-16.0 μg·ml -1 TMZ gradient incremental induction, and isosmotic PBS was used to treat control group cells. Control group and resistance group were transfected with control vector, while the interference group was transfected with shRNA interference vector targeting LY6E-DT by lentivirus. The semi-inhibitory concentration (IC 50) of TMZ in each group was detected by CCK-8 experiment, the expression levels of LY6E-DT, miR-125a-5p and MGMT mRNA in each group were detected by real-time fluorescent quantitative PCR (RT-qPCR) , and the expression levels of MGMT protein were detected by Western blot. The effect of miR-125a-5p on MGMT and LY6E-DT was detected by luciferase reporter gene method. Results:LY6E-DT expression was positively correlated with MGMT (Pearson correlation coefficient = 0.32, P<0.001) , and it was found that LY6E-DT expression was significantly lower in HGG tissues, but it was not conducive to the prognosis of HGG patients; In the control group, resistance group and interference group, the expressions of LY6E-DT were 1.000±0.047, 3.704±0.402 and 0.743±0.064; the expressions of miR-125a-5p were 1.000±0.049, 0.351±0.031 and 0.934±0.050; the expressions of MGMT mRNA were 1.000±0.017, 5.205±0.462 and 3.183±0.667; the expressions of MGMT protein are 0.108±0.012, 0.891±0.063 and 0.375±0.038; TMZ IC 50 are 6.79±0.71, 30.52±3.69 and 15.64±2.25 μg·ml -1. Compared with the control group, LY6E-DT, MGMT and TMZ IC50 in the resistance group were significantly higher, while LY6E-DT expression in the interference group was significantly lower, MGMT and TMZ IC 50 were significantly higher ( P<0.05) ; Compared with the resistance group, the expression of LY6E-DT, MGMT mRNA and protein and TMZ IC 50 decreased significantly in the interference group ( P<0.05) . miR-125a-5p significantly inhibited luciferase expression of MGMT 3'UTR ( P<0.01) , while LY6E-DT significantly restored the expression level ( P<0.01) . Conclusion:LY6E-DT can promote MGMT expression and TMZ resistance in HGG cells, which is related to the inhibition of miR-125a-5p expression.

Objective:To explore the changes in serum advanced receptor for glycation end-products (sRAGE) and neuregulin-1 (NRG-1) in patients with different conditions of H-type hypertension combined with acute ischemic stroke (AIS) and their relationship with short-term prognosis.Methods:A total of 185 patients with H-type hypertension complicated with AIS admitted to the Linyi Central Hospital from January 2020 to December 2022 were selected and included in the AIS group. According to the National Institutes of Health Stroke Scale (NIHSS) score, there were 55 cases in the mild group (≤4 points), 86 cases in the moderate group (5-20 points), and 44 cases in the severe group (>20 points); According to the improved Rankin scale score, the patients were divided into a poor prognosis group (>2 points) and a good prognosis group (≤2 points). Another 100 healthy individuals who underwent physical examinations during the same period in our hospital were selected as the control group. Enzyme linked immunosorbent assay was used to detect serum sRAGE and NRG-1 levels in subjects. The correlation between serum sRAGE, NRG-1 levels and NIHSS score in patients with H-type hypertension complicated with AIS was analyzed through Spearman test. A multivariate logistic regression model was used to analyze the influencing factors of poor short-term prognosis in patients with H-type hypertension complicated with AIS. The receiver operating characteristic (ROC) curve analysis revealed the predictive value of serum sRAGE and NRG-1 levels for poor short-term prognosis in patients with H-type hypertension complicated with AIS.Results:The serum sRAGE level in the AIS group was higher than that in the control group, while the NRG-1 level was lower than that in the control group (all P<0.05). The serum sRAGE levels of patients in the mild, moderate, and severe groups increased sequentially, while the NRG-1 levels decreased sequentially (all P<0.05). Spearman correlation analysis showed that the NIHSS score was positively correlated with serum sRAGE levels ( rs=0.847, P<0.001) and negatively correlated with serum NRG1 levels ( rs=-0.810, P<0.001) in patients with H-type hypertension and AIS. After 90 days of follow-up, the incidence of poor prognosis in 185 patients with H-type hypertension and AIS was 37.84%(70/185). Multivariate logistic regression model analysis showed that increased age, diabetes, increased NIHSS score, increased homocysteine (Hcy) and increased sRAGE were independent risk factors for poor short-term prognosis of patients with type H hypertension combined with AIS, while increased NRG-1 was an independent protective factor (all P<0.05). ROC curve analysis showed that the combined detection of serum sRAGE and NRG-1 levels predicted a poor short-term prognosis in patients with H-type hypertension and AIS, with an area under the curve (AUC) of 0.876, which was higher than the predicted values of 0.795 and 0.791 for serum sRAGE and NRG-1 levels alone (all P<0.05). Conclusions:Elevated serum sRAGE levels and decreased NRG-1 levels are closely related to worsening of the condition and poor short-term prognosis in patients with H-type hypertension and AIS. The combined detection of serum sRAGE and NRG-1 levels has high predictive value for poor short-term prognosis in patients with H-type hypertension and AIS.