LB42708 is an orally active farnesyltransferase (FTase) inhibitor (IC50: 0.8/1.2/2.0 nM toward H/N/K-ras).

FTase (N-ras):1.2 nM, FTase (H-ras):0.8 nM, FTase (K-Ras):2.0 nM

在脂多糖的小鼠中, LB42708（12.5 mg/kg,i.p.）抑制NO、前列腺素E2、TNF-α及IL-1β的产生,并抑制CIA的进程.在Ras野生型和突变型的肿瘤中,LB42708（20 mg/kg/day,i.p.）对肿瘤生长及血管新生有抑制作用.

在H-ras和K-ras-改变的大鼠肠内壁细胞中,LB42708对生长和诱导凋亡有不可逆的抑制作用。在肿瘤相关的内皮细胞中,通过阻断Ras依赖的MAPK 和PI3K/Akt信号通路,LB42708对VEGF诱导的肿瘤血管新生产生抑制作用。在鼠巨噬细胞系RAW264.7细胞中,LB42708对脂多糖 + IFN-γ诱导的细胞内法尼化蛋白p21ras过程有明显抑制作用。在免疫激活的成骨细胞和巨噬细胞中,LB42708抑制一氧化氮合酶、环氧合酶-2、TNF-α及IL-1β、NO和PGE(2)的产生。通过抑制IKK活性,LB42708对NF-κB激活和iNOS启动子活性产生抑制作用。

Biochemical Assessment of PDGFRα Kinase Activity: Chinese hamster ovary (CHO) cells are transiently transfected with mutated or wild type PDGFRα constructs and treated with various concentrations of Crenolanib. Experiments involving recombinant DNA are performed using biosafety level 2 conditions in accordance with guidelines. Protein lysates from cell lines are prepared and subjected to immunoprecipitation using anti-PDGFRα antibodies followed by sequential immunoblotting for PDGFRα. Densitometry is performed to quantify drug effect using Photoshop software, with the level of phosphor- PDGFRα normalized to total protein. Densitometry and proliferation experimental results are analyzed using Calcusyn 2.1 software to mathematically determine the IC50 values. The Wilcoxon Rank Sum Test is used to compare the IC50 values of Crenolanib for a given mutation.

Cell growth is measured by MTT. Briefly, cells were seeded at 2 × 103 cells per well in 96-well culture plates in triplicate. After the addition of various concentrations of drugs, cells are incubated for 72 h. At the end of culture, the plates are washed twice with PBS, and cells are incubated with 200 μl of RPMI 1640 containing 10% FCS and 0.25 mg/ml of MTT at 37 °C for 3 h. The absorbance of each well is measured with Titer-Tech 96-well multiscanner at 570 nm. The viable cell number is proportional to the absorbance. (Only for Reference)