title: Increased expression of matrix metalloproteinases-21 and -26 and TIMP-4 in pancreatic adenocarcinoma.
abstract: Pancreatic adenocarcinoma is known for early aggressive local invasion, high metastatic potential, and a low 5-year survival rate. Matrix metalloproteinases (MMPs) play important roles in tumor growth and invasion. Earlier studies on pancreatic cancer have found increased expression of certain MMPs to correlate with poorer prognosis, short survival time or presence of metastases. We studied the expression of MMP-21, -26, and tissue inhibitor of matrix metalloproteinases (TIMP)-4 in 50 tissue samples, including 25 adenocarcinomas, seven other malignant pancreatic tumors, and 18 control samples of non-neoplastic pancreatic tissue with immunohistochemistry. The regulation of MMP-21, -26, and TIMP-4 mRNAs by cytokines was studied with RT-PCR in pancreatic cancer cell lines PANC-1, BxPC-3, and AsPC-1. MMP-21, -26, and TIMP-4 were detected in cancer cells in 64, 40, and 60% of tumors, respectively. MMP-21 expressed in well-differentiated cancer cells and occasional fibroblasts, like TIMP-4, tended to diminish in intensity from grade I to grade III tumors. Patients with metastatic lymph nodes had increased expression of MMP-26 in actual tumor samples. All cultured cancer cell lines expressed MMP-21 basally at low levels, and presence of the protein was confirmed immunohistochemically in cultured cells. MMP-21 expression was induced by epidermal growth factor (EGF) in PANC-1 cells. MMP-26 was neither expressed basally nor induced by tumor necrosis factor alpha, transforming growth factor beta-1 (TGFbeta1), EGF, or interferon gamma. Basal TIMP-4 expression was lowest in the poorly differentiated cancer cell line PANC-1 compared to better-differentiated BxPC-3 and AsPC-1 cells. TIMP-4 expression was induced by TGFbeta1 in PANC-1 cells and by EGF in BxPC-3 cells. Our findings suggest that MMP-21 is not a marker of invasiveness, but rather of differentiation, in pancreatic cancer and it may be upregulated by EGF. The putative role of MMP-26 as a marker of metastases warrants further studies. Unlike other TIMPs, TIMP-4 was not upregulated in relation to aggressiveness of pancreatic cancer.
authors.affiliation: Department of Dermatology, Helsinki University Central Hospital and Biomedicum Helsinki, University of Helsinki, Helsinki, Finland.
authors.forename: Ville
authors.initials: V
authors.lastname: Bister
authors.forename: Tiina
authors.initials: T
authors.lastname: Skoog
authors.forename: Susanna
authors.initials: S
authors.lastname: Virolainen
authors.forename: Tuula
authors.initials: T
authors.lastname: Kiviluoto
authors.forename: Pauli
authors.initials: P
authors.lastname: Puolakkainen
authors.forename: Ulpu
authors.initials: U
authors.lastname: Saarialho-Kere
mesh_terms: D000230:Adenocarcinoma / Q000378:metabolism* / Q000473:pathology; D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000032:analysis*; D045744:Cell Line, Tumor; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D020782:Matrix Metalloproteinases / Q000096:biosynthesis*; D053505:Matrix Metalloproteinases, Secreted / Q000096:biosynthesis*; D008875:Middle Aged; D009362:Neoplasm Metastasis / Q000503:physiopathology; D010190:Pancreatic Neoplasms / Q000378:metabolism* / Q000473:pathology; D012333:RNA, Messenger / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D019714:Tissue Inhibitor of Metalloproteinases / Q000096:biosynthesis*; D000097792:Tissue Inhibitor of Metalloproteinase-4
chemical_list: D014408:Biomarkers, Tumor; D020782:Matrix Metalloproteinases; D053505:Matrix Metalloproteinases, Secreted; D012333:RNA, Messenger; D019714:Tissue Inhibitor of Metalloproteinases; D000097792:Tissue Inhibitor of Metalloproteinase-4; C471969:MMP21 protein, human