FB23-2 is a potent and selective mRNA N6-methyladenosine (m6A) demethylase FTO inhibitor(IC50 : 2.6 μM).

FTO:2.6 μM (IC50)

FB23-2直接与FTO结合，选择性抑制FTO的m6A去甲基化酶活性。模拟FTO耗尽，FB23-2显著抑制人急性髓性白血病(AML)细胞系和原代AML细胞的增殖，并促进其分化/凋亡 in vitro[1]。

FB23-2在异种移植小鼠中显著抑制人类AML细胞系和原代细胞的进展[1]。

Quantitation of FB23 and FB23-2 in AML cells: NB4 and MONOMAC6 cells were treated with 10 μM FB23 or FB23-2 for 24 hr, respectively. Viable cells were distinguished with 0.1% trypan blue, counted and then harvested with PBS by several washings. Cells were diluted into 100 μl with 50% (v/v) water/methanol and followed by several shock freeze-thaw cycles. The supernatants were collected for analysis. The Ultimate 3000 system coupled with a TSQ Quantiva mass spectrometer was applied to determine the cellular concentration of compound FB23 and FB23-2. Analytes were separated on a XSELECT? HSS T3 column (100 mm × 3.0 mm, 2.5 μm). The mobile phases used for elution were (A) 0.1% (v/v) formic acid/water and (B) 0.1% (v/v) formic acid/acetonitrile. The mass spectrometer was operated in the negative MRM mode. Parent-to-product transitions were m/z 375.1→339.1, 375.1→298.1 for FB23, and m/z 390.3→318.0, 390.3→289.9 for FB23-2, respectively[1].

The NSGS mice were bred and subjected to the xeno-transplantation model. For the AML mouse model, 0.2 × 10^6 MONOMAC6 cells were directly transplanted into NSGS mice via tail vein. After 10 days, FB23-2 (2 mg/kg/day) and DMSO vehicle were intraperitoneally injected into the mice for a continuous 10 days. The mice were euthanized by CO2 inhalation if they exhibited classical AML symptoms including hunched posture, paralysis, and reduced body weight. Meanwhile, the PB, spleen, and liver samples were collected for further analysis[1].