Objective To investigate the inhibitory effects of silencing expression ofEZH2 gene on the cell proliferation of human QBC939 cells and its mechanisms. Methods The targeting siRNA was designed and trans-fected into QBC939cells. The expressions of EZH2 mRNA and protein were detected by real-time qPCR and west-ern blotting,respectively. The ability of cellproliferationwas analyzed by MTT assay and plate clone formation assay. Cell apoptosis and cycle percentage weremeasured by flow cytometry. Cell senescence was assessed byβ-galactosi-dase dyeing.The expressions of H3K27me3,P14ARF,P16INK4a,P53,P21 and E2F1 proteinwere determined by West-ern blotting.Results Compared with the control group ,the expressions of mRNAand protein were significantly elevat-ed in experimental group. The ability of cellproliferation in the experiment group was significantly down regulated , which could also cause a rise of G1/S phase ,but not a marked variation of apoptosis rate. Silencing EZH2 would induce a obvious senescence phenotype in QBC939 cells. EZH2-siRNA transferredcould also down-regulate the expressions of H3K27me3 and E2F1 protein,while up-regulating the expressions of P14ARF,P16INK4a,P53 and P21 protein in QBC939 cells.Conclusions Silencing EZH2 could induce a significant inhibition on cell proliferation of QBC939 cells,the mechanism of which may be associated with the senescence pathway regulation.

Objective:To study the risk factors of surgical therapy in neonates with necrotizing enterocolitis (NEC).Methods:From January 2016 to July 2020, neonates with a confirmed diagnosis of NEC (Bell's Stage Ⅱ and above) admitted to our hospital were retrospectively enrolled. They were assigned into surgical group and conservative group according to whether surgeries were performed. The conditions during perinatal period, clinical characteristics and laboratory examinations at the onset of NEC were compared between the two groups. Multivariate Logistic regression analysis was used to determine the risk factors of surgical therapy.Results:A total of 177 neonates with NEC were identified, including 62 cases (35.0%) in the surgical group and 115 cases (65.0%) in the conservative group. Multivariate Logistic regression analysis showed that male gender ( OR=3.178,95% CI 1.457~6.929, P=0.004), comorbidity with shock ( OR=3.434, 95% CI 1.112~10.607, P=0.032), mechanical ventilation>7 d before NEC onset ( OR=3.663, 95% CI 1.098~12.223, P=0.035) and lymphocytes <2.0×10 9/L ( OR=4.121, 95% CI 1.801~9.430, P=0.001) at the onset of NEC were independent risk factors for surgical therapy. Conclusions:Male gender, comorbidity with shock, mechanical ventilation >7 d before NEC and lymphocytopenia at the onset are independent risk factors for surgical therapy in neonates with NEC (Stage Ⅱ and above).