A cell culture analysis of the expression of cathepsin D activity during myogenesis and tumor progression.

There is considerable evidence supporting the involvement of acidic lysosomal proteases in the catabolic processes associated with developmental programs. I examined levels of catD activity in cell and media fractions prepared from developmental and pathological cell culture model systems. In prefusion myoblasts, this activity eluted at 34 kDa, a molecular mass consistent with the fully processed double chain form of the protease. In fused myoblasts, a second peak of activity appeared consistent with the less processed, single chain form of catD. Unlike myogenesis, the progression of lowly metastatic MCF-7 breast cancer cells to highly metastatic, adriamycin-resistant ones was accompanied by a decrease in catD activity. (Abstract shortened by UMI.)Dept. of Biological Sciences. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis1998 .K44. Source: Masters Abstracts International, Volume: 39-02, page: 0439. Adviser: Michael Dufresne. Thesis (M.Sc.)--University of Windsor (Canada), 1998