Background &Aims: Connective tissue growth factor (CTGF)has been shown to be implicated in tumor development and progression. The aim of this study was to investigate the role of CTGF in progression of colorectal ...Background &Aims: Connective tissue growth factor (CTGF)has been shown to be implicated in tumor development and progression. The aim of this study was to investigate the role of CTGF in progression of colorectal cancer (CRC). Methods: Immunohistochemical staining of specimens from 119 patients with CRC was performed. Liposome-mediated transfection was used to introduce a CTGF expression vector into CRC cell lines. Transfectants were tested in invasive ability and experimental hepatic metastasis in BALB/c mice. Furthermore, a FOPflash/TOPflash reporter assay was performed to investigate CTGF on the β-catenin/T-cell factor signaling pathway. Results: Patients with stage II and stage III CRC whose tumors displayed high CTGFexpression had a significantly higher overall survival and a disease-free advantage over patients with CRC with low CTGF expression. Alterations in the CTGF level in CRC cell lines modulated their invasive ability with an inverse correlation. In addition, a reduction in the CTGF level of CT26 cells after stable transfection with antisense CTGF resulted in increased liver metastasis in BALB/c mice. The activity of the β-catenin/T-cell factor signaling pathway and its downstream effector gene matrix metalloproteinase 7 in these CTGF-transfected cells was strongly attenuated. Blockage of matrix metalloproteinase 7 with its neutralizing antibodies inhibited increased invasiveness in antisense CTGF-transfected CT26 cells. Conclusions: Our results implicate CTGF as a key regulator of CRC invasion and metastasis, and it appears to be a useful and better prognosis factor for patients with stage II and stage III CRC.展开更多
Background: Early events in the progression of 90%of sporadic colorectal cancers depend on constitutive activation of Wnt signalling. Recent data also indicate a close association between the Hedgehog (Hh) and Wnt pat...Background: Early events in the progression of 90%of sporadic colorectal cancers depend on constitutive activation of Wnt signalling. Recent data also indicate a close association between the Hedgehog (Hh) and Wnt pathways in colonic epithelial cell differentiation. Aims: To investigate whether expression of Gli1, a transactivator of Hh signalling, can suppress Wnt signalling and inhibit proliferation of human colorectal cancer cells. Methods: Gli1 and nuclear β-catenin expression were examined in a series of 40 human colorectal cancers by immunohistochemistry. We quantified Gli1 and nuclear β-catenin staining as markers of Hh and Wnt pathway activation, respectively. Two human colon cancer cell lines, SW480 and HCT116, with mutations in APC and β-catenin, respectively, were used. The effects of Gli1 overexpression on Wnt transcriptional activity, β-catenin subcellular distribution, and proliferation in these cells were analysed. Results: Nuclear accumulation of β-catenin and the Gli1 staining level were inversely associated in the 40 human colorectal cancers. Wnt transcriptional activity was reduced in Gli1 transfected cells. These effects were observed even in Gli1 transfected cells cotransfected with mutated β-catenin. Furthermore, nuclear accumulation of β-catenin was diminished compared with that in empty vector transfected cells, and downregulated transcription of c-Myc was observed in Gli1 transfected cells. Proliferation of Gli1 transfected cells was also significantly suppressed compared with that in empty vector transfected cells. Conclusions: Our data suggest that Gli1 plays an inhibitory role in the development of colorectal cancer involving Wnt signalling, even in cases with the stabilising mutation of β-catenin.展开更多
文摘Background &Aims: Connective tissue growth factor (CTGF)has been shown to be implicated in tumor development and progression. The aim of this study was to investigate the role of CTGF in progression of colorectal cancer (CRC). Methods: Immunohistochemical staining of specimens from 119 patients with CRC was performed. Liposome-mediated transfection was used to introduce a CTGF expression vector into CRC cell lines. Transfectants were tested in invasive ability and experimental hepatic metastasis in BALB/c mice. Furthermore, a FOPflash/TOPflash reporter assay was performed to investigate CTGF on the β-catenin/T-cell factor signaling pathway. Results: Patients with stage II and stage III CRC whose tumors displayed high CTGFexpression had a significantly higher overall survival and a disease-free advantage over patients with CRC with low CTGF expression. Alterations in the CTGF level in CRC cell lines modulated their invasive ability with an inverse correlation. In addition, a reduction in the CTGF level of CT26 cells after stable transfection with antisense CTGF resulted in increased liver metastasis in BALB/c mice. The activity of the β-catenin/T-cell factor signaling pathway and its downstream effector gene matrix metalloproteinase 7 in these CTGF-transfected cells was strongly attenuated. Blockage of matrix metalloproteinase 7 with its neutralizing antibodies inhibited increased invasiveness in antisense CTGF-transfected CT26 cells. Conclusions: Our results implicate CTGF as a key regulator of CRC invasion and metastasis, and it appears to be a useful and better prognosis factor for patients with stage II and stage III CRC.
文摘Background: Early events in the progression of 90%of sporadic colorectal cancers depend on constitutive activation of Wnt signalling. Recent data also indicate a close association between the Hedgehog (Hh) and Wnt pathways in colonic epithelial cell differentiation. Aims: To investigate whether expression of Gli1, a transactivator of Hh signalling, can suppress Wnt signalling and inhibit proliferation of human colorectal cancer cells. Methods: Gli1 and nuclear β-catenin expression were examined in a series of 40 human colorectal cancers by immunohistochemistry. We quantified Gli1 and nuclear β-catenin staining as markers of Hh and Wnt pathway activation, respectively. Two human colon cancer cell lines, SW480 and HCT116, with mutations in APC and β-catenin, respectively, were used. The effects of Gli1 overexpression on Wnt transcriptional activity, β-catenin subcellular distribution, and proliferation in these cells were analysed. Results: Nuclear accumulation of β-catenin and the Gli1 staining level were inversely associated in the 40 human colorectal cancers. Wnt transcriptional activity was reduced in Gli1 transfected cells. These effects were observed even in Gli1 transfected cells cotransfected with mutated β-catenin. Furthermore, nuclear accumulation of β-catenin was diminished compared with that in empty vector transfected cells, and downregulated transcription of c-Myc was observed in Gli1 transfected cells. Proliferation of Gli1 transfected cells was also significantly suppressed compared with that in empty vector transfected cells. Conclusions: Our data suggest that Gli1 plays an inhibitory role in the development of colorectal cancer involving Wnt signalling, even in cases with the stabilising mutation of β-catenin.
