RESUMO
To evaluate possible roles of matrix metalloproteinase (MMP)-1, -2, tissue inhibitor of metalloproteinase (TIMP)-1, -2 and membrane-type-1 matrix metalloproteinase (MT1-MMP) in invasion of human gliomas, expressions of these proteins were investigated in ten cases of human glioma and two meningioma tissues and eight human glioma cell lines. In gelatin zymography, MMP-2 activities of glioblastomas were higher than astrocytomas. The activated form of MMP-2 was seen in five of six cases of glioblastomas, but not in astrocytomas. MMP-9 activity was detected in all cases of malignant astrocytomas but the reactivity of MMP-9 was weaker than that of MMP-2. MT1-MMP mRNA expression in glioblastomas was higher than that in astrocytomas. Five cases of glioblastomas with activated form of MMP-2 had MT1-MMP expressions. In vitro, human glioma cell lines with high expression of MT1-MMP also showed high MMP-2 activity. TIMP-1 transcripts were constitutively present in almost all glioma tissues and cell lines, whereas TIMP-2 mRNA were weak especially in malignant gliomas. Imbalance of TIMP-2/MMP-2 was observed using immunoprecipitation analysis in a glioma cell line. High expression of MMP-2 and MT1-MMP is possibly involved in invasiveness of malignant glioma.
Assuntos
Humanos , Animais , Northern Blotting/métodos , Encéfalo/patologia , Neoplasias Encefálicas/patologia , Neoplasias Encefálicas/enzimologia , Ativação Enzimática , Metaloproteinase 2 da Matriz/metabolismo , Metaloproteinase 2 da Matriz/genética , Metaloproteinase 9 da Matriz/metabolismo , Regulação Enzimológica da Expressão Gênica , Glioma/patologia , Glioma/enzimologia , Metaloendopeptidases/genética , Papio , Inibidor Tecidual de Metaloproteinase-2/genética , Inibidor Tecidual de Metaloproteinase-1/genética , Células Tumorais CultivadasRESUMO
To evaluate possible roles of matrix metalloproteinase (MMP)-1, -2, tissue inhibitor of metalloproteinase (TIMP)-1, -2 and membrane-type-1 matrix metalloproteinase (MT1-MMP) in invasion of human gliomas, expressions of these proteins were investigated in ten cases of human glioma and two meningioma tissues and eight human glioma cell lines. In gelatin zymography, MMP-2 activities of glioblastomas were higher than astrocytomas. The activated form of MMP-2 was seen in five of six cases of glioblastomas, but not in astrocytomas. MMP-9 activity was detected in all cases of malignant astrocytomas but the reactivity of MMP-9 was weaker than that of MMP-2. MT1-MMP mRNA expression in glioblastomas was higher than that in astrocytomas. Five cases of glioblastomas with activated form of MMP-2 had MT1-MMP expressions. In vitro, human glioma cell lines with high expression of MT1-MMP also showed high MMP-2 activity. TIMP-1 transcripts were constitutively present in almost all glioma tissues and cell lines, whereas TIMP-2 mRNA were weak especially in malignant gliomas. Imbalance of TIMP-2/MMP-2 was observed using immunoprecipitation analysis in a glioma cell line. High expression of MMP-2 and MT1-MMP is possibly involved in invasiveness of malignant glioma.
Assuntos
Humanos , Animais , Northern Blotting/métodos , Encéfalo/patologia , Neoplasias Encefálicas/patologia , Neoplasias Encefálicas/enzimologia , Ativação Enzimática , Metaloproteinase 2 da Matriz/metabolismo , Metaloproteinase 2 da Matriz/genética , Metaloproteinase 9 da Matriz/metabolismo , Regulação Enzimológica da Expressão Gênica , Glioma/patologia , Glioma/enzimologia , Metaloendopeptidases/genética , Papio , Inibidor Tecidual de Metaloproteinase-2/genética , Inibidor Tecidual de Metaloproteinase-1/genética , Células Tumorais CultivadasRESUMO
PURPOSE: Angiostatin, a 38 kDa internal fragment of plasminogen, is a potent inhibitor of angiogenesis. It blocks neovascularization and growth of primary and metastatic tumors in mice. To produce recombinant angiostatin protem comprising kringle 1-4 of plasminogen, we cloned the angiostatin cDNA from human liver tissue mRNA and expressed it in E. coli. MATERIALS AND METHODS: We cloned angiostatin cDNA from human liver tissue mRNA using reverse transcriptase polymerase chain reaction (RT-PCR) method. Cloned cDNA was ligated to pET22b (+) expression vector, transformed into E. coli stram BL21 (DE3) and expressed by IPTG induction. Recombinant human angiostatin protein was purified from the inclusion bodies of lysated bacterial pellet with 8 M urea solubilization, refolding, single step Lysine-Sepharose 4B affinity chromatography and 0.2 M E-aminocarproic acid elution. The anti-angiogenic activity of purified recombinant angiostatin was assayed with endothelial cell proliferation assay and chorioallantoic membrane assay (CAM). RESULTS: The identification of cloned angiostatin cDNA was confirmed by Southern hybridization and Pst I restriction enzyme digestion pattern. Angiostatin cDNA was expressed in E. coli, refolded in vitro and purified by Lysine Sepharose 4B affinity chromatography. The molecular weight of purified recombinant angiostatin was about 55 kDa on the SDS-PAGE. It inhibited the proliferation of bovine capillary endothelial (BCE) cells in vitro with a half-maximal inhibition concentration (ED50) of approximately 500 ng/mL. It also suppressed neovasculrization on the CAM assay. CONCLUSION: These results demonstrated that recombinant human angiostatin has similar function and biological activity compared with human angiostatin which is purified from porcine elastase digested human plasminogen fragment.