Centennial Honors College
Western Illinois University
Undergraduate Research Day 2012
Poster Presentation
Cathepsin B Enzymatic Activity and Inhibition In Vitro and in MCF-7 Breast
Cancer Cells
Jennifer Tournear
Faculty Mentors: Lisa Wen and Jenq-Kuen Huang
Chemistry
Cathepsins are an enzyme family of lysosomal proteases. Lysosomal proteases travel
within the lysosomes of the cell and assist in the degradation of protein. The enzymes
are thought to be released into the cytosol of cells through lysosomal leakage. The
cathepsins have been widely studied and are associated with many human diseases
including cancer, osteoporosis, inflammatory airway diseases and acute pancreatitis.
The focus of this study is on cathepsin B and its activity in breast cancer cells. It is a
cysteine cathepsin endopeptidase and is an essential part of many biological
processes. It is when the proteolytic activity becomes unregulated that it is correlated
with human disease. This project observes the enzymatic activity of human cathepsin B
in vitro and in MCF-7 breast cancer cells. Inhibitors that have been previously
synthesized are also used in this project to determine the inhibition potency. The
results of an inhibition screening showed encouraging inhibition percentages and IC50
results of the top inhibitor were also promising. These results lead to an in progress
protocol of a determining the cathepsin B activity in the MCF-7 cells by tissue culturing,
inducing apoptosis, and implementing the Magic Red® protocol for the cathepsin B
assay. Studying the activity in MCF-7 breast cancer cells and the inhibition of, could be
a positive step in understanding cancer and the possibility of developing therapeutic
agents for such diseases.