Development of a Novel Anti-HIF-1α Screening System Coupled with Biochemical and Biological Validation for Rapidly Selecting Potent Anti-Cancer Compounds

Breast cancer (BCa) is the most diagnosed cancer and the second leading cause of cancer death in the American women. Adaptation to the hypoxic environment seen in solid tumors is critical for tumor cell survival and growth. The activation of hypoxia inducible factor-1 alpha (HIF-1α), an important master transcriptional factor that is induced and stabilized by intratumoral hypoxia, stimulates a group of HIF-1α-regulated genes including vascular endothelial growth factor (VEGF), leading tumor cells towards malignant progression. Therefore, a promising therapeutic approach to cancer treatment is to target HIF-1α. The goal of this project was to develop and validate a screening system coupled with secondary screen/validation process that has the capability to screen large numbers of potential anti-cancer small-molecule compounds based on their anti-HIF-1α activities. Breast cancer MDA-231 cells were used as the model to select potent anti-HIF-1α compounds by their abilities to inhibit transactivation of a VEGF promoter fused to a luciferase reporter gene under hypoxia. Positive compounds were then validated by a series of assays that confirm compounds' anti-HIF-1α activities including measurement of HIF-1α downstream VEGF gene expression and angiogenic ability of BCa cells. Results of our pilot screening demonstrate that this prototype screening coupled with validation system can effectively select highly potent anti-HIF-1α agents from the compound library, suggesting that this prototype screen system has the potential to be developed into a high-throughput screen (HTS) coupled with automated validation process for the screening and identification of novel and effective anti-cancer drugs based on anti-HIF-1α mechanism.