Accessible Requires Authentication Published by De Gruyter November 13, 2012

Three-dimensional cultures modeling premalignant progression of human breast epithelial cells: role of cysteine cathepsins

Stefanie R. Mullins, Mansoureh Sameni, Galia Blum, Matthew Bogyo, Bonnie F. Sloane and Kamiar Moin
From the journal Biological Chemistry

Abstract

The expression of the cysteine protease cathepsin B is increased in early stages of human breast cancer. To assess the potential role of cathepsin B in premalignant progression of breast epithelial cells, we employed a 3D reconstituted basement membrane overlay culture model of MCF10A human breast epithelial cells and isogenic variants that replicate the in vivo phenotypes of hyperplasia (MCF10AneoT) and atypical hyperplasia (MCF10AT1). MCF10A cells developed into polarized acinar structures with central lumens. In contrast, MCF10AneoT and MCF10AT1 cells form larger structures in which the lumens are filled with cells. CA074Me, a cell-permeable inhibitor selective for the cysteine cathepsins B and L, reduced proliferation and increased apoptosis of MCF10A, MCF10AneoT and MCF10AT1 cells in 3D culture. We detected active cysteine cathepsins in the isogenic MCF10 variants in 3D culture with GB111, a cell-permeable activity-based probe, and established differential inhibition of cathepsin B in our 3D cultures. We conclude that cathepsin B promotes proliferation and premalignant progression of breast epithelial cells. These findings are consistent with studies by others showing that deletion of cathepsin B in the transgenic MMTV-PyMT mice, a murine model that is predisposed to development of mammary cancer, reduces malignant progression.


Corresponding author: Kamiar Moin, Barbara Ann Karmanos Cancer Institute, Wayne State University School of Medicine, Detroit, MI 48201, USA; and Department of Pharmacology, Wayne State University School of Medicine, Detroit, MI 48201, USA

Received: 2012-7-12
Accepted: 2012-10-4
Published Online: 2012-11-13
Published in Print: 2012-12-01

©2012 by Walter de Gruyter Berlin Boston