Pharmacological or genetic inhibition of hypoxia signaling attenuates oncogenic RAS-induced cancer phenotypes.

Oncogenic Ras mutations are highly prevalent in hematopoietic malignancies. However, it is difficult to directly target oncogenic RAS proteins for therapeutic intervention. We have developed a Drosophila Acute Myeloid Leukemia (AML) model induced by human KRASG12V, which exhibits a dramatic increase in myeloid-like leukemia cells. We performed both genetic and drug screens using this model. The genetic screen identified 24 candidate genes able to attenuate the oncogenic RAS-induced phenotype, including two key hypoxia pathway genes HIF1A and ARNT (HIF1B). The drug screen revealed echinomycin, an inhibitor of HIF1A, could effectively attenuate the leukemia phenotype caused by KRASG12V. Furthermore, we showed that echinomycin treatment could effectively suppress oncogenic RAS-driven leukemia cell proliferation using both human leukemia cell lines and a mouse xenograft model. These data suggest that inhibiting the hypoxia pathway could be an effective treatment approach for oncogenic RAS-induced cancer phenotype, and that echinomycin is a promising targeted drug to attenuate oncogenic RAS-induced cancer phenotypes.