BE-43547A exerts hypoxia-selective inhibition on human pancreatic cancer cells through targeting eEF1A1 and disrupting its association with FoxO1.

Hypoxia is a key feature of the tumor microenvironment that leads to the failure of many chemotherapies and induces more aggressive and resistant cancer phenotypes. Up to date, there are very few compounds and treatments that can target hypoxia. BE-43547A from Streptomyces sp. was one of the most hypoxia-selective compounds against PANC-1, MCF-7, and K562 cell lines. In this study, we investigated the molecular mechanism underlying the hypoxia selectivity of BE-43547A in human pancreatic cancer cells. We showed that BE-43547A displayed hypoxia-selective cytotoxicity in five pancreatic cancer cells (PANC-1, Capan-2, MIA PaCa-2, AsPC-1, and PaTu8988T) with IC values under hypoxia considerably lower than those under normoxia. We demonstrated that BE-43547A is directly bound to eEF1A1 protein in PaTu8988T cells under hypoxia. Furthermore, we revealed that hypoxia significantly elevated the expression levels of HIF1α, FoxO1, and eEF1A1 in the five pancreatic cancer cells; eEF1A1 interacted with FoxO1 in the cytoplasm, which was disrupted by BE-43547A followed by the nuclear translocation of FoxO1 and ultimate inhibition of JAK/STAT3 signaling pathway under hypoxia. This study reveals that BE-43547A, targeting eEF1A1, disrupts its interaction with FoxO1 in human pancreatic cancer cells under hypoxia. This compound could serve as a potential hypoxia-selective therapy.