GRP78-IN-3 (Compound 8) is a selective Grp78 (HSPA5) inhibitor with an IC50 of 0.59 μM. GRP78-IN-3 is 7-fold selective for HspA5 compared to HspA9 (IC50 of 4.3 μM) and >20-fold selective for HspA5 compared to HspA2 (IC50 of 13.9 μM).
GRP78-IN-3 (compound 8) is a potent small-molecule-competitive inhibitor of Hsp70 substrate binding. GRP78-IN-3 (0.1-100 μM) shows more potent inhibition efffects in a spheroid tumor model (U251 glioblastoma cells and H520 lung cancer cells)[1].
References:
[1]. Andrew J Ambrose, et al. Discovery and Development of a Selective Inhibitor of the ER Resident Chaperone Grp78. J Med Chem. 2022 Dec 14.