ObjectiveTo systematically investigate the functional roles of the nucleotide metabolism-related gene ecto-5'-nucleotidase (NT5E) in lung adenocarcinoma (LUAD) and to provide potential molecular targets for precision diagnosis and targeted therapy. MethodsMulti-omics analyses were performed using transcriptomic data from The Cancer Genome Atlas (TCGA) and gene expression omnibus (GEO) to identify key prognostic genes and to construct a prognostic model. Tumor tissue specimens from patients with LUAD who underwent surgical resection at the Qingdao Central Hospital of University of Health and Rehabilitation Sciences between May and June 2023 were collected for prognostic gene validation, and tissue microarrays were constructed to evaluate protein expression. In vitro, the biological effects of NT5E on LUAD cells were validated by quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR), Western blotting, wound-healing, Transwell, EdU, cell-cycle, and apoptosis assays. ResultsA total of 10 paired tumor and adjacent non-tumor tissue samples were used for validation of key prognostic genes, including 4 male and 6 female patients, with a mean age of (58.00±13.06) years. In addition, tissue microarrays comprising 90 patients were analyzed, including 28 male and 62 female patients, with a mean age of (60.07±7.98) years. Bioinformatic screening identified NT5E as a representative prognostic gene that was significantly upregulated in LUAD tissues. Survival analyses demonstrated that high NT5E expression was associated with markedly poorer overall survival and served as an independent risk factor. qRT-PCR and tissue microarray-based immunohistochemistry further confirmed its elevated expression in tumor tissues. Functional experiments showed that NT5E knockdown significantly inhibited cell migration, invasion, and proliferation while promoting apoptosis, whereas NT5E overexpression exerted the opposite effects. ConclusionNT5E markedly promotes LUAD cell proliferation, migration, and invasion and suppresses apoptosis, indicating that NT5E acts as an oncogenic driver in LUAD and may serve as a promising prognostic biomarker and therapeutic target.
Objective
To investigate the effect of N-acetylcysteine (NAC) on the apoptosis during myocardial ischemia reperfusion injury in rats’ heart transplantation, and to explore the possible role of NAC in myocardial apoptosis.
Methods
Sixty healthy male Lewis rats (weighing, 200-220 g) were randomly divided into 3 groups, 20 rats each group (10 donors and 10 recipients). In control group, 1 mL normal saline was infused via inferior vena cava at 30 minutes before donor harvesting; in donor preconditioning group, NAC (300 mg/kg) was infused via inferior vena cava at 30 minutes before donor harvesting, but no treatment in recipients; and in recipient preconditioning group, NAC (300 mg/kg) was infused via inferior vena cava at 30 minutes before recipient transplantation, but no treatment in donors. Heart transplantation was established in each group. Blood was drawn at 6 and 24 hours after reperfusion for analysis of aspartate aminotransferase (AST), alanine aminotransferase (ALT), lactate dehydrogenase (LDH) as markers of graft injury; myocardial tissue was harvested to determine the superoxide dismutase (SOD) and lipid hydroperoxide (LPO) activity at 24 hours after reperfusion and to observe the histology and ultrastructural changes. Graft active Caspase-3 protein expression was measured by immunohistochemistry staining, and apoptosis index (AI) was calculated by TUNEL.
Results
The heart transplantation operation was successfully completed in all groups, and the rats survived to the end of the experiment. The serum levels of AST, ALT, and LDH in donor and recipient preconditioning groups were significantly lower than those in control group at 6 hours after reperfusion (P lt; 0.05); the levels of AST and ALT in donor preconditioning group and the levels of AST and LDH in recipient preconditioning group were significantly lower than those in control group at 24 hours (P lt; 0.05); and no significant difference was found between donor and recipient perconditioning groups (P gt; 0.05). The levels of AST, ALT, and LDH at 24 hours were significantly lower than those at 6 hours in each group (P lt; 0.05) except the level of ALT in recipient preconditioning group (P gt; 0.05). SOD activity and SOD/LPO in donor and recipient preconditioning groups were significantly higher than those in control group (P lt; 0.05), but no significant difference between donor and recipient preconditioning groups (P gt; 0.05); there was no significant difference in LPO activity among 3 groups (P gt; 0.05). Histological staining and transmission electron microscope showed that myocardial injury in recipient preconditioning group was obviously lighter than that in donor preconditioning group and control group. Active Caspase-3 in recipient pretreatment group was significantly higher than that in donor preconditioning group and control group (P lt; 0.05). AI of donor and recipient preconditioning groups was significantly lower than that of control group (P lt; 0.05), but no significant difference was found between donor and recipient preconditioning groups (P gt; 0.05).
Conclusion
NAC can relieve ischemia reperfusion injury in rats’ heart transplantation by improving myocardial SOD content, and reducing active Caspase-3 activity and AI, which has a protective effect on myocardial cell of donor heart.
