BIBU 1361 dihydrochloride is a selective inhibitor of epidermal growth factor receptor (EGFR) kinase with an IC50 value of 0.038 ± 0.007 μM [1, 2].
The EGFR signaling pathway is associated with multiple intracellular signaling events that promote proliferation and survival. It plays a key role in the progression of glioblastoma multiforme (GBM) [2].
In glioma cells, EGFR signaling can induce the phosphorylation of Akt, Erk1/2 and STAT3. BIBU 1361 decreased levels of EGFR and subsequently decreased levels of p-EGFR. This effect was accompanied by the decrease in pAkt and the downstream target p-mTOR. P-S6 kinase and p-P70S6 kinase are two key targets of p-mTOR. Both of them are associated with cell proliferation. In glioma cells treated with BIBU 1361, P-S6 kinase and p-P70S6 kinase were also downregulated. E2F1 is a G1/S regulator. E2F1 is known to be interacted with by EGFR. The inhibition of Akt/mTOR signaling can affect cell cycle progression. In glioma cells, BIBU 1361 inhibited the expression of Akt/mTOR and decreased EGFR. In glioma cells, BIBU 1361 decreased the expression of cyclin E and E2F1, increased the level of p21, and increased cell number at the S and G2/M phase of the cell cycle [2].
The effect of BIBU 1361 in the animal body has not been found.
References:
[1]. Antczak C, Mahida JP, Bhinder B, et al. A High-Content Biosensor-Based Screen Identifies Cell-Permeable Activators and Inhibitors of EGFR Function Implications in Drug Discovery. Journal of biomolecular screening, 2012, 17(7): 885-899.
[2]. Ghildiyal R, Dixit D, Sen E. EGFR inhibitor BIBU induces apoptosis and defective autophagy in glioma cells. Molecular carcinogenesis, 2013, 52(12): 970-982.