Objective To investigate the differences of kinesin family member 4 (KIF4A) expression between hepatic carcinoma and adjacent tissue in patients with chronic hepatitis B virus (HBV) infection,and to understand the effect of HBV on the expression of KIF4A.Methods Reverse transcriptase-polymerase chain reaction and Western blot were used to measure the expression of KIF4A in hepatic carcinoma and adjacent tissues. HepG2 cells were co-transfected with KIF4A promoter containing the luciferase gene and HBV infectious clone pHBV1.3,and luciferase activity was measured.Expression of KIF4A in HepG2 cells was measured after tranfected with different doses of pHBV1.3.The student's t-test was used for statistic analysis.Results Expression of KIF4A was much higher in hepatic carcinoma than that in adjacent tissues.HBV enhanced KIF4 A gene promoter activity and the luciferase activities were increased as the concentration of pHBV1.3 increased ( 0,0.2,0.4,0.6 and0.8 μg/mL),which were (126.8± 13.4),(219.8±16.7),(387.6±21.5),(586.5 ± 228.9 ) and (657.6 ± 35.5 ) RUL/μg protein,respectively,while the luciferase activities were (123.6± 13.8),(131.8± 14.6),(129.7-13.5),(135.3± 13.4) and (127.1± 12.7) RUL/μg protein,respectively with different doses of control plasmids transfected,and statistical analysis showed significant difference between them (t=4.875,P=0.006).And HBV upregulated KIF4A mRNA and protein expressions in HepG2 cells in a concentration-dependent manner.Conclusion Expression of KIF4A is enhanced in hepatic carcinoma and HBV can upregulate KIF4A expression.

Using lipase segregation agar containing trioleoylglycerol, we obtained 18 lipase positive clones by screening from a metagenome library of dairy rumen microflora containing 15,360 clones. The average insert size of lipase positive clones was about 60 kb. Lipase enzyme activity analysis by p-NPP method indicated that Lipase6, Lipase7 and Lipase8 had higher lipolytic activities to substrates of p-nitrophenyl palmitate (C16), p-nitrophenyl alaurate (C12) and p-nitrophenyl palmitate (C16) respectively. The optimum pH of Lipase 6, Lipase 7 and Lipase 8 were 7.5. The halflife period of Lipase 8 with the value of 15 min in 70 degrees C decreased with the increase of temperature. In conclusion, the lipases screened in this study had different substrates specificity and good thermo stability, which laid a basis for large-scale industrial application.
Animals ; Bacteria ; genetics ; Cattle ; Cloning, Molecular ; Female ; Gene Library ; Lipase ; genetics ; metabolism ; Metagenome ; genetics ; Rumen ; microbiology ; Substrate Specificity ; Temperature