Comparative study of the immunohistochemical expression of metalloproteinases 2, 7 and 9 between clearly invasive carcinomas and “in situ” trophoblast invasion

Abstract

Matrix metalloproteinases (MMPs) are endopeptidases considered to participate in the transient invasive property of trophoblastic cells during embryo implantation and placentation. The same molecules play an important role in the invasive and metastatic potential of cancer cells. The aim of this study was to compare the immunohistochemical expression of MMP2, 7and 9between clearly invasive carcinomas and "in situ" trophoblast invasion in an effort to illuminate their distinct roles in uncontrolled and controlled invasion. <br />We performed an immunohistochemical analysis of 45 clearly invasive carcinomas of various organs (colorectal, gastric, breast, pulmonary, renal) and 40 first trimester gestation specimens (before the 9th week of gestation). The markers expression was evaluated semiquantitavely, seperately in cancer parenchymal and gestational trophoblastic cells as well as cancer stromal and decidual cells, according to apercentage scale (0 %, 50% of cells) and according to staining intensity (0, +, ++, +++). <br />MMP9 was expressed more often in the malignant parenchymal as well as in the malignant stromal component of carcinomas than in the trophoblastic (p=0, 0118) and decidual (p=0,017) component of gestations respectively. Although all carcinomas and almost all gestation specimens stained for MMP2 and MMP7, the immunostaining for both molecules was statistically more extensive and intense in trophoblasts and decidual cells by comparison to cancerous elements.<br />In conclusion, although there seems to be adirect link between cancer invasion and MMP9 immunohistochemical expression, the role of MMP2 and MMP7 appears to be more complicated underlining the complexity of the mechanisms involved in cancer spreading.