Executive Summary : | Triple negative breast cancer (TNBC) accounts to nearly 33% of the total breast cancer cases in India, which is twice that of USA. Therapeutic options for TNBC are limited due to lack of targeted therapy, resulting in increased fatalities. This shows the dire need of TNBC-focused drug discovery research. The long-term goal of this project is to identify a dual inhibitor targeting two pathways in TNBC. This proposal aims to achieve the first step of this goal which is to identify a potent and selective inhibitor of Mps1 and its potential synergistic combinations. Mps1 is a cell cycle protein which plays a prominent role during cell division. Several studies reported the role of Mps1 in TNBC and validated it as a target of interest. Herein, we propose to perform high-throughput virtual screening (HTVS) of several libraries to identify novel heterocyclic inhibitors. PIs screened ChemBridge library and have identified xx as one of the scaffolds of interest. Screening other libraries will identify more potential scaffolds (hits). Representative compounds from each scaffold will then be synthesized through conventional organic chemistry. Enzymatic inhibition of Mps1 will be tested for the representative compounds from each scaffold using Invitrogen enzyme assays. A small compound library of the active scaffold identified in enzymatic assays will be synthesized. These compounds will again be screened for enzymatic inhibition of Mps1 to understand the structure-activity relationships. PIs expect to discover low nanomolar inhibitors of Mps1. These inhibitors will be screened in TNBC cell lines for following assays: (1) MTT assay to measure the cell viability and growth inhibition (2) colony formation assay and (3) cell migration inhibition assay. Based on these enzymatic and cellular assays, novel Mps1 inhibitors with growth inhibition of TNBC cells will be identified. Further, the top 3 compounds will be screened in combination with inhibitors of other targets in TNBC cell lines. The compounds will be screened along with (1) an inhibitor of PARP-1 which is involved in DNA repair pathway, (2) an inhibitor of BRD4, which is overexpressed in several TNBCs, and (3) an inhibitor of PI3K/AKT pathway, to identify the synergistic combinations of Mps1 in TNBC. Successful completion of the synergistic studies will provide the platform to develop a dual agent through single-agent pharmacology, which will be the objective of a future proposal. |