Chetomin

Chetomin, an active component of Chaetomium globosum, is a heat shock protein 90/hypoxia-inducible factor 1 alpha (Hsp90/HIF1α) pathway inhibitor. Chetomin is a potent, nontoxic non-small cell lung cancer cancer stem cells (NSCLC CSC)-targeting molecule^[1]. IC50 & Target: Hsp90/HIF1α^[1] In Vitro: Chetomin (0~10 μM; 24 hours; H460 and H1299 cells) shows progressively lower expression of several survival-promoting proteins promoted by Hsp90/HIF1α activity, including insulin-like growth factor 1 (IGF1 R), epidermal growth factor receptor (EGFR), Src, mitogen-activated protein kinase kinase 1/2 (MEK1/2), activation of protein kinase B (Akt), and mammalian target of rapamycin (mTOR) ^[1].
Chetomin (0~10 μM; 24 hours; H1299 cells) elicits cell cycle arrest in susceptible and chemoresistant NSCLC cell lines^[1].
. Chetomin (1 µM; 3 days; H460 and H1299 cells) pretreatment abolishes their sphere-forming capacity. Chetomin inhibits sphere-forming by NSCLC CSCs within a nanomolar range, and proliferation of susceptible and chemoresistant NSCLC non-CSCs within a micromolar range. Chetomin (24 h) decreases HIF-response element activity in H460 and H1299 monolayer cultures. Chetomin (0~10 μM) specifically inhibits the Hsp90-HIF1α binding interaction in HIF1α's N-terminus ^[1]. In Vivo: Chetomin (0~100 mg/kg; p.o.) inhibits lung tumorigenesis in NSCLC mouse models^[1].
. Chetomin markedly decreases tumor formation in several murine models of NSCLC^[1].