Background and purpose: miR-21 is ovexpressed in various types of human cancers. This study was designed to investigate the effect of miR-21 knockdown on cell proliferation, migration and invasion of nasopharyngeal carcinoma (NPC) cell line CNE2. Methods: CNE2 was transfected with miR-21 inhibitor by LipofectamineTM2000. Meanwhile CNE2 was transfected with NC inhibitor as negative control. qRT-PCR was used to detect the miR-21 expression in these cells. The effects of miR-21 downregulation on cell proliferation, migration and invasion were evaluated by MTS, wound-healing Transwell and invasion assays. Results: miR-21 expression was remarkably downregulated in miR-21 inhibitor-transfected cells in concentration-dependent manner, indicating transfection with miR-21 inhibitor can effectively reduce expression level of miR-21 in CNE2 cells. Transfection of miR-21 inhibitor into CNE2 cells led to a signiifcant decrease in cell proliferation rate compared with control cells (P<0.05). miR-21 downregulation results in reduction of cell migration(P<0.05). Moreover, the cell invasion by Transwell invasion assay was reduced in miR-21-downregulated cells relative to control cells. Conclusion:miR-21 can promote cell proliferation, migration and invasion of NPC cells. And it maybe plays an important role in tumorigenesis and development of NPC.

Objective To explore the mechanism and therapeutic effects of wet dressing with 50％ magnesium sulfate ( MgSO4 ) as a part of comprehensive treatment for wound resulted from pit viper bites in children.Methods A total of 61 children with pit-viper-bitten wound enrolled from May 2009 through May 2011 were divided into two groups,namely the comprehensive treatment group (n =31 cases) and the conventional treatment group (n =30 eases). In the comprehensive treatment group,50％ magnesium sulfate wet dressing applied to the swelling parts of body in the early stage in addition to the conventional treatment and topically bandaged once a day keeping wet with spraying saline on the top of dressing.Before the treatment and on the 1st day,the 3rd day and the 5th day of treatment,the values of myocardial enzyme and the circumference of swelling parts were recorded,and the differences were analyzed by t- test.The differences in rate of wound healing in one week between two groups were analyzed by chi-square test.Results Before the treatment,there was no statistical difference in clinical features between the two groups with different modes of treatment for the viper-bitten children (P ＞ 0.05 ). During comprehensive treatment,the values of myocardial enzyme and the circumference of swelling parts decreased more markedly than those in conventional treatment group ( P ＜ 0.05 ).The rates of wound healing in one week of two groups were 80.5％ and 56.6％ respectively.Conclusions The comprehensive treatment with adjuvant of 50％ MgSO4 for the viper-bitten children can effectively reduce the tissue damage caused by venom,and the swelling as well,restoring function of body and shortening the time for wound healing and preventing complications.

ObjectiveTo investigate the effect and significance of cyclooxygenase-2 (COX-2) inhibitors on the expression of the Acsl gene family in the ileum of rats with nonalcoholic fatty liver disease (NAFLD). MethodsA total of 45 Sprague-Dawley rats were randomly divided into normal control group (15 rats given normal diet), NAFLD model group (15 rats given high-fat diet), and nimesulide group (15 rats given high-fat diet and nimesulide). All rats were sacrificed after 12 weeks of feeding, and then blood samples were collected from the inferior vena cava to measure total cholesterol (TC) and triglyceride (TG). HE staining and oil red O staining were performed for the liver to evaluate the degree of hepatic steatosis in each group, and quantitative real-time PCR was used to measure the mRNA expression of the Acsl family genes in the ileum. An analysis of variance was used for comparison of continuous data between multiple groups, and the least significant difference t-test was used for further comparison between two groups. ResultsCompared with the normal control group, the NAFLD model group had significant increases in serum TC and TG and marked hepatic steatosis (all P＜0.05); compared with the NAFLD model group, the nimesulide group had significant reductions in serum TC and TG and degree of hepatic steatosis (all P＜0.05). Compared with the normal control group, the NAFLD model group had a significant increase in the expression of COX-2 in the ileum (P＜0.05), and compared with the NAFLD model group, the nimesulide group had a significant reduction in the expression of COX-2 in the ileum (P＜005). Compared with the normal control group, the NAFLD model group had significant increases in the mRNA expression of Acsl3 and Acsl5 in the ileum (both P＜0.05), and compared with the NAFLD model group, the nimesulide group had significant reductions in the mRNA expression of Acsl3 and Acsl5 (both P＜0.05). ConclusionThe COX-2 inhibitor nimesulide can regulate the expression of the Acsl gene family in the ileum of rats with NAFLD, suggesting that COX-2 inhibitors may inhibit the progression of NAFLD through the Acsl gene.

ObjectiveTo obtain HSC-T6 cells with stable expression of Cas9 protein and HSC-T6-COX-2-/- cells with COX-2 gene defect by transfecting HSC-T6 cells with CRISPR/Cas9 lentiviral vector, and to provide a good method for further functional research and new strategies for the clinical treatment of liver fibrosis. MethodsThe COX-2 gene-specific sgRNAs (COX-2-sgRNA-1, COX-2-sgRNA-2, COX-2-sgRNA-3) were designed, synthesized, and connected to the GV371 vector, and the recombinant plasmid and the packaging plasmid were transfected into 293T cells to form lentivirus particles; the fluorescence method was used to measure virus titer. The most appropriate amount of the virus was calculated based on MOI. Lenti-Cas9-puro was transfected into HSC-T6 cells, and HSC-T6-Cas9 cells were screened out by puromycin; Lenti-COX-2-sgRNA-EGFP was transfected into HSC-T6-Cas9 cells to obtain HSC-T6-COX-2-/- cells. Cruiser enzyme digestion and Western blot were used to verify gene knockout at the gene and protein levels. An analysis of variance was used for comparison of continuous data between multiple groups, and the least significant difference t-test was used for further comparison between two groups. ResultsSequencing verified that the COX-2-sgRNA expression vector was constructed successfully. Recombinant expression plasmids and packaging plasmids were transfected into 293T cells to form lentivirus particles, and the fluorescence method showed a virus titer of ＞1×108. HSC-T6 cells with stable expression of Cas9 protein and HSC-T6-COX-2-/- cells with COX-2 gene defect were successfully constructed. The HSC-T6-Cas9 group had significantly higher relative mRNA expression of LV-Cas9-Puro than the CON group (541.93±105.76 vs 1.00±0.02, t=12.995, P＜0.01). Cruiser enzyme digestion and Western blot showed that the CRISPR/Cas9 lentivirus expression vectors played a role in the target, among which COX-2-sgRNA-2 knockout had the most significant effect, and this group had a significant reduction in the protein expression level of COX-2 compared with the CON group and the NC group (both P＜0.05), suggesting that COX-2-sgRNA was active. ConclusionA CRISPR/Cas9 lentivirus vector is successfully constructed for COX-2 target gene, and HSC-T6-COX-2-/- cells with stable COX-2 gene knockout are obtained.