Expression of c-Met and its role in development and progression of colorectal cancer

Objective To investigate expression of c-Met,the protein tyrosine kinase receptor for hepatocyte growth factor/scatter(HGF) in colorectal cancer,its relationship with micro-vessel density(MVD),and its role in progression and metastasis of colorectal cancer.Methods C-Met expression was detected at the protein level by immunohistochemistry and at the mRNA level by semi-quantitative reverse transcriptase-polymerase chain reaction in colorectal adenocarcinomas(80 cases),colorectal adenoma(60 cases) and normal mucosa(40 cases).MVD expression marked with CD 105 was determined and calculated by immunohistochemistry.Correlation of C-Met and MVD expressions and their association with clinicopathological features and outcome were analyzed.Results C-Met-positive rate was 71.3%(57/80) in colorectal cancer,31.7%(19/60) in colorectal adenoma and 17.5%(7/40) in normal mucosa.C-Met expression in colon cancer was significantly higher than that in colorectal adenoma and normal mucosa(P0.01).C-Metand MVD expressions were associated with lymph node metastasis,tumor differentiation and Dukes stage(P0.05).c-Met expression was correlated with MVD(r=0.034 6,P0.05).MVD in the c-Met(+) group was higher than that in the c-Met(-) group(P0.01).Also,a significant increase in c-Met and MVD was detected in colorectal cancer with liver metastasis compared with primary colorectal cancer(P0.01).Conclusions c-Met may play an important role in progression and metastasis of colorectal cancer.Moreover,combined evaluation of c-Met and MVD expressions might be a useful indicator for liver metastasis in patients with colorectal cancer.