ObjectiveTo explore the key genes influencing diacylglycerol metabolism in neuroblastoma （NB）， clarify the expression and clinical significance of diacylglycerol acyltransferase 2 （DGAT2） in NB， and provide a theoretical basis for the diagnosis and targeted therapy of NB. MethodsNB transcriptome data were obtained from GEO （GSE49710） and TCGA （TARGET-NBL） databases. Differentially expressed genes （DEGs） commonly upregulated in MYCN-amplified groups were screened， and the key gene DGAT2 was identified by intersecting the screened DEGs with the diacylglycerol metabolism-related gene set followed by prognostic analysis and comparison. The expression of DGAT2 was analyzed via the R2 database. The potential impact of DGAT2 on the immune microenvironment was explored by combining the single-cell dataset GSE137804. Immunohistochemistry （IHC） was used to detect the expression level of DGAT2 and its correlation with MYCN expression in 55 clinical NB tissues and mouse xenograft tumor tissues. ResultsA total of 907 DEGs commonly upregulated in the MYCN-amplified groups were screened， among which three DEGs were highly expressed in the diacylglycerol metabolism-related gene set （P＜0.05）. After comparison， DGAT2 was found to have the most significant impact on prognosis （HR=1.4， 95% CI：1.2，1.7； P=5.41×10^-7）. Survival analysis showed that patients with high DGAT2 expression had a significantly shorter overall survival. Single-cell analysis revealed that high expression of DGAT2 led to an immunosuppressive microenvironment in NB. IHC results showed that the expression of DGAT2 in NB tissues was significantly positively correlated with MYCN expression in the tumor tissue microarrays of clinical NB patients and the tissues of mouse ectopic xenograft tumors （r_s=0.369 4，P＜0.01）. ConclusionsDGAT2 is highly expressed in MYCN-amplified NB， and may independently predict poor prognosis in NB patients. It is expected to become a diagnostic marker for NB and a potential therapeutic target for MYCN-amplified NB.

Objective To study the effects of eliminating free radical and increasing antioxidative capacity of glutathione peroxidase 1(GPX1) on PC12 cells. MethodsGPX1 recombinant plasmid and Plncxplasmid were transfected into PC12 cells and PC12 cells highly-expressing GPX1 stably were sieved by G418 solution. PC12 ceils were treated with different concentrations of amyloid β-protein (Aβ25-35) for 48 h, to decide the optimal concentration of Aβ25-35 and construct ideal cell model. GPX1/pLNCX/PC12 group, pLNCX/ PC12 group and PC12 group were treated with optimal concentration of Aβ25-35 ,respectively for 48 h, and their absorbance (A) value by MTT conversion was compared among three groups.ResultsCell clone highly expressing GPX1 stably were obtained by G418 selection. The increment of cell inhibition ratio was 24.7 ％ after 20 μmol/L Aβ25-35 treatment for 48 h, compared with control group (P＜0.01). Thus the optimization concentration of Aβ25-35 was 20 μmol/L. After treatment with 20 μmol/L for 48 h, the A value was significantly higher in GPX1/pLNCX/PC12 group than in pLNCX/ PC12 group and in PC12 cells group(0.53±0. 02 vs. 0.44±0.02;0.53±0.02 vs. 0.39±0.07, P＜0.01). Conclusions Transfection of GPX1 recombinant plasmid may protect cell against injury from free radical and reverse the decrease of PC12 cell survival rate impaired by Aβ25-35.

Gene Expression Profiling ; Humans ; Macrophages ; metabolism ; MicroRNAs ; genetics ; metabolism ; Mycobacterium tuberculosis ; genetics ; metabolism