Development of BCAT inhibitors as potential drugs to combat pancreatic cancer

Introduction and background

The enzymes BCAT (cytosolic isoform BCAT1 and mitochondrial isoform BCAT2) are catalyzing the conversion of branched chain amino acids isoleucine, leucine and valine to their corresponding keto acids for further degradation. The products of this process are used as sources of energy and building blocks for new molecules in cells. Interestingly, BCAT enzymes has recently been implicated in several forms of cancers, including the severe pancreatic cancer, as these enzymes also support the rapid growing cancer cells in particular. There is an urgent need to identify new drugs to combat pancreatic cancer. Recently, we have screened, identified and partly characterized a set of inhibitors for both BCAT1 and BCAT2.

Aim of project

The aim of this project is to further develop our present BCAT1/2 inhibitors in search for new compounds with even higher potency than our current set of compounds. We will use enzymatic assays, cell based tests with exposure to cancer cells, as well as structural studies to improve inhibitory effects in both biochemical and cell assays.

Project plan and methods

The project will consist of the following tasks and methods

1. Express recombinant human BCAT isoforms using E. coli as host and purify the enzymes using chromatographic principles.
2. Determine inhibitory effects (IC50-values) and protein affinities (KD-values) for potential BCAT inhibitors. IC50-values will be determined using an enzymatic assay, and KD-values will be determined using various biophysical methods.
3. Test inhibitors in cell-based assays to determine toxicity and cancer cell specificity.
4. Determine 3D structures of BCAT-inhibitor complexes by protein crystallography and use the obtained 3D models to design even more potent inhibitors.   

Organisation / collaboration

The project is a collaboration between group leaders Bj?rn Dalhus and Lars Eide at the Department of Medical Biochemistry, University of Oslo and Oslo University Hospital (OUS). Our laboratory is located at Rikshospitalet, where we have access to relevant technologies to complete the project. Dalhus is an experienced structural biologist, with interest in drug design, and Eide is an expert in metabolism and mitochondrial biology. Hans-Petter Hersleth will serve as the internal supervisor at IBV and as a partner for the structural studies.