Objective To investigate the mutation phenomenon of 20 autosomal STR loci in Henan Han population. Methods A total of 3011 parentage confirmed cases were collected to screen mutation events, ascertain the source of mutation, calculate mutation rate, analyze mutation rules and compare with the mutation condition of populations in different regions. Results 76 mutation events were observed in 19 STR loci, the average and accumulative mutation rate reached to 0.08% and 1.6629%, respectively. The ration of paternal versus maternal mutation was 8:1. Mutation rates of Penta E and D12S391 loci in Henan Han population were lower than the Han population of northern China(P<0.05); the mutation rate of CSF1PO locus were lower than Guangdong population and Yunan Han population(P<0.05); the mutation rates of D6S1043 and D12S391 loci were lower than Guangdong population(P<0.05). Conclusion STR mutation events were common in paternity testing. Region differences among mutation rate were significant.

Objective To identify the half-sibling relationship by comprehensive using three different methods. Methods STR genotype was performed on A, A's mother, B and B's mother by using PowerPlex21 kit, AGCU Expressmarker 21+1 kit, Microreader 23sp-B kit and AGCU X-19 STR kit respectively. Based on the results of STR genotype and X-STR, we determined half-sibling relationship by ITO, discriminant function analysis and IBS. Results HIS was between 1.36×102and 2.09×105in ITO which indicated that A and B had the same father. The IBS and discriminant function analysis also had the same conclusion. Conclusion Comprehensive using multiple methods can obtain reliable result to identify the half-sibling relationship from the same father.

Tissue inhibitor of metalloproteinases-2 (TIMP-2) inhibits tumor migration and invasion. Obtaining TIMP-2 protein is conducive to a comprehensive and in-depth study of its function and mechanism in tumorigenesis and development. We collected human TIMP-2 protein through prokaryotic expression in vitro. We expressed, purified and characterized human TIMP-2 protein. First, the human TIMP-2 gene was cloned from the cDNA obtained by reverse transcription of total RNA of human lung cancer A549 cells, and constructed to pET28a vector. The recombinant plasmid pET28a-TIMP-2 was transformed into Escherichia coli BL21(DE3) after restriction endonuclease digestion and sequencing analysis. The expression of TIMP-2 protein was induced by isopropyl-β-D-thiogalactoside (IPTG), and the expression conditions were optimized. After purification by nickel affinity column, the fusion protein His-TIMP-2 was identified by Western blotting method and its biological activity was detected by gelatin zymography. The fusion protein His-TIMP-2 existed in the form of inclusion body in E. coli. In a certain range, the concentration of IPTG had no significant effect on the expression amount of His-TIMP-2. But in this expression system, induction temperature and time were the key parameters, and the expression amount of His-TIMP-2 in E. coli increased with the increase of induction temperature. The purified and refolded fusion protein could effectively inhibit the activity of matrix metalloproteinases expressed by human lung cancer A549 cells. The acquisition of active fusion protein lays a foundation for further study of the function and mechanism of human TIMP-2, and is of great significance for tumor therapy.
Cloning, Molecular ; Escherichia coli/genetics* ; Humans ; Recombinant Fusion Proteins/genetics* ; Recombinant Proteins ; Tissue Inhibitor of Metalloproteinase-2/genetics*