A chemical genomics screen highlights the essential role of mitochondria in HIF-1 regulation

作者:Lin Xiaoyu; David Caroline A; Donnelly Jennifer B; Michaelides Mike; Chandel Navdeep S; Huang Xiaoli; Warrior Usha; Weinberg Frank; Tormos Kathryn V; Fesik Stephen W; Shen Yu*
来源:Proceedings of the National Academy of Sciences, 2008, 105(1): 174-179.
DOI:10.1073/pnas.0706585104

摘要

Hypoxia-inducible factor-1 (HIF-1) plays an essential role in tumor development and progression by regulating genes that are vital for proliferation, glycolysis, angiogenesis, and metastasis. To identify strategies of targeting the HIF-1 pathway, we screened a siRNA library against the entire druggable genome and a small-molecule library consisting of 691,200 compounds using a HIF-1 reporter cell line. Although the siRNA library screen failed to reveal any druggable targets, the small-molecule library screen identified a class of alkyliminophenylacetate compounds that inhibit hypoxia-induced HIF-1 reporter activity at single-digit nanomolar concentrations. These compounds were found to inhibit hypoxia but not deferoxamine-induced HIF-1 alpha protein stabilization. Further analysis indicated that the alkyliminophenylacetate compounds likely inhibit the HIF-1 pathway through blocking the hypoxia-induced mitochondrial reactive oxygen species (ROS) production. Strikingly, all of the nonalkyliminophenylacetate HIF-1 inhibitors identified from the small-molecule library screen were also found to target mitochondria like the alkyliminophenylacetate compounds. The exclusive enrichment of mitochondria inhibitors from a library of >600,000 diverse compounds by using the HIF-1 reporter assay highlights the essential role of mitochondria in HIF-1 regulation. These results also suggest that targeting mitochondrial ROS production might be a highly effective way of blocking HIF-1 activity in tumors.