[Structure and function of insulin-like growth factor acid-labile subunits in mammalian homologues].

Insulin-like growth factors (IGFs) act as a critical signaling pathway in animals and play significant roles in body growth, development, and occurrence and progression of animal diseases. In the past, structural and functional studies of ligands, receptors and even specific binding proteins in the IGFs system have been extensively investigated. However, the functional study of insulin-like growth factor acid-labile subunit (IGFALS) mainly focused on the prolonging half-life of IGFs. Increasing number of studies indicated that mutations in the IGFALS DNA sequence and low expression level of IGFALS proteins can lead to growth and development retardation in animals. In this review, we summarize recent structural and functional studies of IGFALS in mammals, aiming to further identify detailed genetic mechanism of IGFALS.

[Study of the expression and function of Syk and VEGF-C in the development of non-small cell lung cancer].

OBJECTIVE: To explore the role of Syk and VEGF-C in the development of NSCLC. METHODS: Transfered these genes(eukaryotic expression vector pcDNA3.1-VEGF-C and pLNCX-syk)into A549 cells with the liposomes. Tested the expression of VEGF-C mRNA and Syk mRNA with RT-PCR.Investigated the cell invasion assay with transwell chamber in vitro. Analysis the expression of VEGF-C proteins in A549 cells and detect Syk and VEGF-C proteins of 81 NSCLC tissue samples with immunohistochemical staining. RESULTS: Higher expression of VEGF-C was revealed in VEGF-C-construct-transfected A549 cell than that in controls through RT-PCR (P < 0.05) and immunohistochemistry(P < 0.01).RT-PCR also revealed that Syk expression was higher in Syk-construct-transfected cells than in controls (P < 0.05). The cell invading experiments showed that there was more invaded cells in both transfected terms than in controls (P < 0.05). The expression of Syk protein in NSCLC tissue were significantly lower than that in the normal lung tissue (P < 0.05), while the expression of VEGF-C protein in NSCLC tissue were significantly higher than that in the normal lung tissue(P < 0.05). The expression of Syk and VEGF-C has a negative correlationship (r = -1.000, P = 0.019). CONCLUSION: The expression of Syk and VEGF-C has a negative correlationship in NSCLC tissue, VEGF-C-construct-transfected A549 cells are more aggressive than Syk-construct-transfected cells. And they may cooperated with each other in the development of NSCLC.

[Polymorphism of bovine TNF-a gene and its association with mastitis in Chinese Holstein cows].

Four hundred and seven Chinese Holstein cows were chosen and divided into 2 groups (healthy group (317), sub-clinical and clinical group (100)) to investigate variation in bovine Tumor necrosis factor-alpha (TNF-a) gene and analyze their associations with mastitis. By PCR-RFLP and CRS-RFLP analyses, three polymorphic sites were detected, with one G→A mutation at 39 bp in exon2 and one C→T mutation at 293 bp in exon4, and C→G mutation in 5´UTR. The three polymorphic sites were able to be cut by DraⅠ, AfaⅠ, and DdeⅠ restriction enzymes respectively, and the DraⅠlocus was Create Restriction Enzyme Cutting Site. Chi-square analysis suggested that the three polymorphic sites did not reach Hardy-Weinberg equilibrium (P<0.05). Least square linear model (LSM) analysis indicated that the DraⅠ, AfaⅠ, and DdeⅠloci of TNF-a gene were associated with somatic cell score (SCS) (P<0.05). Genotype AA in DraⅠlocus and BB in AfaⅠlocus showed significantly higher SCS (P<0.05) and genotype AB in DdeⅠlocus showed significantly lower SCS than AA and BB genotypes in the population tested (P<0.05). This suggested that genotypes BB in DraⅠloci, AA in AfaⅠloci, and AB in DdeⅠloci can be used as candidate markers for mastitis resistance selection in dairy cattle.