Expression of matrix metalloproteinase-2 and-9 and tissue inhibitor of metalloproteinase-1 and-2 in intraductal and nonintraductal growth type of cholangiocarcinoma

BACKGROUND: The intraductal growth (IG) type of cholangiocarcinoma has a better prognosis than the mass forming (MF) and periductal infiltrating (PI) types. Matrix metalloproteinase (MMP)-2 and MMP-9, regulated by tissue inhibitor of metalloproteinases (TIMP)-2 and TIMP-1, respectively, play important roles in the degradation of the basement membrane during tumor invasion. Alteration in MMPs and TIMPs may regulate the gross morphology of cholangiocarcinoma. METHODS: MMP-2 and MMP-9 were analyzed in 35 cholangiocarcinomas and 4 normal livers with fresh tissue using zymography and real-time reverse transcription-polymerase chain reaction (RT-PCR), and expressions of MMP-2, MMP-9, TIMP-1, and TIMP-2 were evaluated in 76 cholangiocarcinomas by immunohistochemistry. RESULTS: Activity of MMP-2 and its active form were detected in 80% and 57% of cholangiocarcinomas respectively. The total MMP-2, active 62 kDa MMP-2, and MMP-2 mRNA increased 5.4 and 8.2 times, 4.4 and :10.9 times, and 2.9 and 5.8 times in the MF and PI types, respectively, compared to the IG type. The majority of MMP-9 was in the proform and active 82 kDa MMP-9 was detected in 9% of cholangiocarcinomas. MMP-9 revealed no significant difference in relation to the gross types. The balanced expressions of MMP-2/TIMP-2 and MMP-9/TIMP-1 were significantly decreased in the MF and PI types, compared to the IG type. In the normal and nonneoplastic livers, the expressions of MMP-2 and MMP-9 were very low without active forms. CONCLUSIONS: The activities of MMP-2 and loss of balanced expressions of MMP-2/TIMP-2 and MMP-9/TIMP-1 are suggested as playing important roles in invasive growth related to the gross type of cholangiocarcinoma.