Kinase experiment:

IRE1α oligomerization assay is set up using the nuclease reaction buffer, 2 μM recombinant hIRE1α, 2 mM ADP, and 60 μM of 3,6-DMAD. All reactions are performed in 20 μL with 10% DMSO to account for vehicle and incubated for 15 min at 30 ℃ to allow for oligomerization. The optical density of the sample is measured at 500 nm using a NanoDrop 2000[1].

Cell experiment:

2×104 cells per well are plated into 96-well plates and treatment started 0-12 hours after plating. RPMI 8226 and MM1.R human MM cells are treated with 0-6 μM 3,6-DMAD. After 24 hours of treatment, XTT reagent (ATCC) is added to the wells then cells are incubated for 2 hours and absorbance measured at both 475 nM and 660 nM using a BioTek Synergy H1 plate reader.[1].

Animal experiment:

Rats[1]5×106RPMI 8226 cells are implanted subcutaneously into the flanks of 4-6 weeks’ old NOD Scid mice. Drug treatment started when the sizes of the tumors reach 150 mm3. Four tumor-bearing mice per group are treated with 10 mg/kg 3,6-DMAD or vehicle (saline) intraperitoneally once every 2 days. Tumor volume is measured[1].

3,6-DMAD hydrochloride is a inhibitor of the IRE1α-XBP1 pathway of the unfolded protein response.

3,6-DMAD inhibits both IRE1α oligomerization and in vitro endoribonuclease (RNase) activity[1].

Following three intraperitoneal administrations of 3,6-DMAD at a dose of 10 mg/kg every 12 hours, 3,6-DMAD significantly inhibits in vivo XBP1-luciferase activity assessed 3.5 days after the initial treatment. 3,6-DMAD-treatment significantly inhibits tumor xenograft growth[1].

[1]. Jiang D, et al. Acridine Derivatives as Inhibitors of the IRE1α-XBP1 Pathway Are Cytotoxic to Human Multiple Myeloma. Mol Cancer Ther. 2016 Sep;15(9):2055-65.