ABSTRACT
The tyrosine kinase system angiopoietin (Ang)/Tie interacts with vascular endothelial growth factor pathway and regulates vessel quiescence in adults as well as later steps of the angiogenic cascade related to vessel maturation. Since all Angs are able to bind to Tie-2 but none binds to Tie-1, the function of Tie-2 and its ligands have captured attention. However, emerging evidence indicates unique roles of the orphan receptor Tie-1 in angiogenesis under physiological and pathological conditions. It is required for maintaining vascular endothelial cell integrity and survival during murine embryo development and in adult and may be involved in modulating differentiation of hematopoietic cells in adult. Tie-1 exhibits poor tyrosine kinase activity and signals via forming heterodimers with Tie-2, inhibiting Tie-2 signaling mediated by Angs. This inhibition can be relieved by Tie-1 ectodomain cleavage mediated by tumor- and inflammatory-related factors, which causes destabilization of vessels and initiates vessel remodeling. Up-regulated Tie-1 expression has been found not only in some leukemia cells and tumor related endothelial cells but also in cytoplasm of carcinoma cells of a variety of human solid tumors, which is associated with tumor progression. In addition, it has pro-inflammatory functions in endothelial cells and is involved in some inflammatory diseases associated with angiogenesis. Recent research indicated that Tie-1 gene ablation exhibited significant effects on tumor blood- and lymph-angiogenesis and improved anti-Ang therapy, suggesting Tie-1 may be a potential target for tumor anti-angiogenesis treatment.
Subject(s)
Animals , Humans , Mice , Angiogenesis Inhibitors , Therapeutic Uses , Angiopoietins , Genetics , Metabolism , Embryo, Mammalian , Embryonic Development , Genetics , Endothelial Cells , Metabolism , Pathology , Gene Expression Regulation, Developmental , Gene Expression Regulation, Neoplastic , Neoplasms , Drug Therapy , Genetics , Metabolism , Pathology , Neovascularization, Pathologic , Drug Therapy , Genetics , Metabolism , Pathology , Protein Binding , Receptor, TIE-1 , Genetics , Metabolism , Receptor, TIE-2 , Genetics , Metabolism , Signal TransductionABSTRACT
<p><b>BACKGROUND</b>Hepatocellular carcinoma (HCC) is one of the deadliest cancers worldwide. In order to investigate the molecular biologic mechanism of HCC's development, we studied the expressions of SE-1, CD105 and CD31 in tumor endothelial cells (TECs) of HCC and in the serum of rats.</p><p><b>METHODS</b>We analyzed the expressions of SE-1, CD31 and CD105 in rat HCC tumor tissues using immunohistochemistry (IHC). Twenty HCC bearing rats and eighteen normal rats were examined for the expressions of SE-1, CD31 and CD105 antigens in serum by enzyme-linked immunosorbent assay (ELISA).</p><p><b>RESULTS</b>SE-1, CD31 and CD105 antigens were detected both in HCC tissue and in normal liver tissue with higher expressions of CD31 and CD105 in HCC while the SE-1 antigen expression was higher in normal liver. Similarly, serum CD31 and CD105 in rats with HCC were significantly increased compared with normal rats (t = 2.8628, P = 0.0086; t = 4.4922, P < 0.0001, respectively). In contrast, SE-1 antigen in HCC rat serum was significantly decreased compared with normal rats (t = 3.4983, P = 0.0011).</p><p><b>CONCLUSION</b>SE-1, CD31 and CD105 are closely related with liver tumor angiogenesis, which is similar to their performances in terms of their expressions in the serum.</p>
Subject(s)
Animals , Male , Rats , Antigens, CD , Blood , Carcinoma, Hepatocellular , Chemistry , Endothelial Cells , Chemistry , Allergy and Immunology , Enzyme-Linked Immunosorbent Assay , Immunohistochemistry , Liver Neoplasms, Experimental , Chemistry , Neovascularization, Pathologic , Blood , Platelet Endothelial Cell Adhesion Molecule-1 , Blood , Rats, Inbred BUFABSTRACT
<p><b>OBJECTIVE</b>To investigate the association of single nucleotide polymorphisms (SNPs) in matrix metalloproteinase-2 (MMP-2) and tissue inhibitor of metalloproteinase-2 (TIMP-2) with the risk of endometriosis and adenomyosis.</p><p><b>METHODS</b>Genotypes of MMP-2 and TIMP-2 were analyzed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method among 298 endometriosis patients, 180 adenomyosis patients and 324 matched control women.</p><p><b>RESULTS</b>No significant difference was found in allele frequencies and genotype distributions of MMP-2 -1306C/T polymorphism between endometriosis patients and control women (P> 0.05). However, there were significant differences in genotype and allele distributions of MMP-2 -1306C/T polymorphism between adenomyosis patients and control women (P< 0.05). Compared with CT+TT genotypes, CC genotype significantly increases the risk of adenomyosis, with an odds ratio of 1.83 (95% CI was 1.13-2.96). No significant difference was shown in allele frequencies and genotype distributions of the MMP-2 -735C/T polymorphism among the three groups (P>0.05). MMP-2 -1306C/T and -735C/T polymorphisms displayed linkage disequilibrium (D'=0.74). There was no significant difference in haplotype distributions of the two MMP-2 SNPs among the three groups ( P> 0.05). No significant difference was found in allele frequencies of TIMP-2 -418G/C polymorphism among the three groups (P> 0.05). However, the frequency of TIMP-2 CC genotype in endometriosis patients (0.7%) was significantly lower than that in the control women (3.7%) (P< 0.05).</p><p><b>CONCLUSION</b>The C allele of MMP-2 -1306C/T polymorphism did not modify the risk of developing endometriosis but significantly increase the risk of developing adenomyosis. The MMP-2 -735C/T and TIMP-2 -418G/C polymorphisms were not associated with the risk of developing endometriosis or adenomyosis.</p>