CHARACTERIZATION OF MONOCLONAL-ANTIBODIES AGAINST STROMELYSIN-3 AND THEIR USE TO EVALUATE STROMELYSIN-3 LEVELS IN BREAST-CARCINOMA BY SEMIQUANTITATIVE IMMUNOHISTOCHEMISTRY

Stromelysin-3 (ST3) is a matrix metalloproteinase which is expressed i n fibroblastic cells of most human invasive carcinomas and represents a potential new prognostic indicator. Expression of recombinant ST3 fo rms in Escherichia coli from cDNA constructs indicated that high level s of expression were achieved when the ST3 pro-domain was deleted. The putative mature form of ST3 thus produced and recovered from bacteria l inclusion bodies was used to prepare monoclonal antibodies (MAbs) ag ainst ST3 by immunization of BALB/C mice. Ten hybridomas producing MAb s against ST3 were obtained and analyzed for their ability to detect e ndogenous ST3 in breast cancer and in conditioned media from human fib roblasts. One of these MAbs (5ST-4A9) was found to be suitable for the routine detection of ST3 on breast cancer tissue sections, thus openi ng the possibility to evaluate ST3 prognostic value in breast cancer u sing semi-quantitative immunohistochemistry. (C) 1995 Wiley-Liss. Inc.