Expressions of Poly(ADP-ribose) Glycohydrolase(PARG) and Membrane Type 1 Matrix Metalloproteinase(MT1-MMP) in Colorectal Carcinoma

Objective：To investigate the significance of Poly（ADP-ribose） glycolhydrolase（PARG） and membrane type 1 matrix metalloproteinase（MT1-MMP） expressions in human colorectal carcinoma.Methods：Immunohistochemical staining for PARG and MT1-MMP was carried out on colorectal adenoma-carcinoma tissue microarrays containing normal colorectal mucosae,adenoma,adenoma with malignant transformation and adenocarcinoma（total 130 specimens）.The expressions of PARG and MT1-MMP in the GLTN [Gallotannin]-treated and GLTN-untreated lovo cells were detected by Western Blot.Results：PARG expression in adenocarcinoma（83.1%） and adenoma with malignant transformation（66.7%） was significantly higher than that in normal colorectal mucosa（10%） and adenoma（10.5%）.Expression of MT1-MMp in normal colorectal mucosa and adenoma was negative,while the expression in adenocarcinoma（80.3%） and adenoma with malignant transformation（72.2%） was high.The expressions of PARG and MT1-MMP in adenocarcinoma with metastasis and in late tumor stages were significantly higher than those in adenocarcinoma with no metastasis and in early tumor stages.Thus,PARG expression shows a positive correlation with the expression of MT1-MMP.The expressions of PARG and MT1-MMP in GLTN-treated lovo cells were weaker than that in GLTN-untreated lovo cells.Conclusion：The expression of PARG was probably related to the development of colorectal carcinoma.PARG may play an important role for the regulation of MT1-MMP expression in colorectal carcinoma.