Presence of active gelatinases in endometrial carcinoma and correlation of matrix metalloproteinase expression with increasing tumor grade and invasion

Abstract

BACKGROUND The actions of the extracellular‐matrix degrading enzymes, matrix metalloproteinases (MMPs), are implicated in tumorigenesis. The cellular localization of MMP‐2, MMP‐9, membrane type 1 (MT1)‐MMP, tissue inhibitors of metalloproteinases (TIMPs) 1‐3, and the presence of active gelatinases were investigated in endometrial carcinoma. METHODS Endometrial carcinomas were grouped according to histologic grade (Grades 1‐3), depth of myometrial invasion (0, < 50%, > 50%) and the presence of vascular/lymphatic invasion. Twenty‐nine endometrial carcinoma biopsies were investigated immunohistochemically to determine the tissue localization of MMP‐2 (gelatinase A), MMP‐9 (gelatinase B), MT1‐MMP, and TIMPs 1‐3. In situ hybridization was performed to localize MMP‐2 and MMP‐9 mRNA. The presence of active gelatinases was assessed using in situ zymography. RESULTS Epithelial tumor cells were the main site of MMP‐2, MMP‐9, and MT1‐MMP protein. Variable stromal cell localization was also observed, particularly in areas adjacent to tumor nests. Semiquantitative analysis revealed increases in MMP‐9 and MMP‐2 but not MT1‐MMP staining scores in tumor epithelial cells in the transition from histologic Grade 1 to Grades 2 and 3. Matrix metalloproteinase‐9 and MT1‐MMP staining scores in tumor cells were significantly associated with the presence of myometrial invasion and vascular/lymphatic invasion, while MMP‐2 did not correlate with these factors. In addition, MT1‐MMP was co‐localized with MMP‐2, supporting its role in the activation of proMMP‐2. Tumor cells from all histologic grades stained intensely for TIMP‐2 and TIMP‐3 proteins, while variable stromal staining was observed. In Grade 1 carcinomas TIMP‐1 was predominantly immunolocalized to the stromal compartment with variable tumor cell localization being observed in Grades 2 and 3 carcinomas. Matrix metalloproteinase‐9 and MMP‐2 mRNAs were predominantly observed in tumor epithelial cells as well as in the stroma to varying degrees. In situ zymography revealed active forms of gelatinases at the cellular surface and in association with tumor epithelial cells within endometrial carcinoma tissues. CONCLUSIONS These data suggest that increasing expression of MMPs and endometrial carcinoma progression are closely related. Active gelatinases are present in endometrial carcinoma, resulting in alterations to the microenvironment that promote tumor invasion and metastasis. Cancer 2002;94:1466–75. © 2002 American Cancer Society. DOI 10.1002/cncr.10355

Patterns of MMP-2 and MMP-9 expression in human cancer cell lines

“…Research on various cancers has localized gelatinases by in situ hybridization both in cancer cells themselves and in mesenchymal cells adjacent to the invading tumor front (15,24,25). In situ hybridization of breast cancer tissue, detected stromelyn-3 mRNA exclusively in stromal cells not cancer cells (26) and colon adenocarcinoma u-PA immunoreactivity and mRNA were found in the tumor stroma and not in the cancer cells (25).…”

“…MMP-2 and MMP-9 are cleaved by other MMPs or proteases to yield the activated forms of 68, 58 and 54 kDa for MMP-2, and 84 kDa for MMP-9. Increased expression of MMP-2 and MMP-9 is reported in many human tumors, including ovarian, breast and prostate tumors, and melanoma (13)(14)(15). Type IV collagen is a major structural protein for ECM and basement membrane.…”

Comparative effects of EGCG, green tea and a nutrient mixture on the patterns of MMP-2 and MMP-9 expression in cancer cell lines

“…Type IV collagenase matrix metalloproteinases (MMPs), in particular, MMP-2 and MMP-9, gelatinase A and B, respectively, have been found to promote invasion and metastasis of malignant tumors (4,5). Elevated levels of MMP-2 and MMP-9 are often correlated with malignancies of liver (6,7), brain (8), breast (9), prostate (10), cervical (11), ovarian (12) and other cancers. Degradation of the ECM by MMPs and the increased expression of MMPs associated with tumor growth, angiogenesis and metastasis point to MMPs as an attractive target for cancer treatment.…”

Matrix metalloproteinases 2 and 9 (gelatinases A and B) expression in malignant mesothelioma and benign pleura

“…Reports using semiquantitative gelatin zymography have correlated MMP-2 and/or MMP-9 activity with survival and disease progression in several solid tumour types (Brown et al,1993b;Tokuraku et al, 1995;Ikebe et al, 1999;Papathoma et al, 2000;Lengyel et al, 2001;Di Nezza et al, 2002;Waas et al, 2002). The use of SDS in the buffers activates latent gelatinase isoforms, which enables assessment of both the latent (pro) and active bands of enzymatic activity.…”