PD168393 is an irreversible EGFR inhibitor (IC50: 0.70 nM), irreversibly alkylate Cys-773; inactive against PKC, FGFR, PDGFR, and insulin.

EGFR:0.70 nM

PD 168393 is docked into the ATP binding pocket of EGFR TK. PD168393 completely suppresses EGF-dependent receptor autophosphorylation in A431 cells during continuous exposure, with continous suppression even after 8 hr in compound-free medium. PD168393 inhibits heregulin-induced tyrosine phosphorylation in MDA-MB-453 cells with IC50 of 5.7 nM. PD168393 is inactive against insulin, PDGF and basic FGFR TKs as well as PKC. PD168393 inhibits EGF-mediated tyrosine phosphorylation in HS-27 human fibroblasts with IC50 of 1-6 nM but has little effect on FGF- or PDGF-mediated tyrosine phosphorylation. [1] PD168393 shows rapid and potent inhibition of Her2-induced tyrosine phosphorylation with IC50 of ~100 nM in 3T3-Her2 cells. D168393 also inhibits phosphorylation of PLCγ1/Stat1/Dok1/δ-catenin in 3T3-Her2 cells, except for Fyb. [2]

PD 168393 produces tumor growth inhibition of 115% in A431 human epidermoid carcinoma xenograft in nude mice, with 50% reduced phosphotyrosine content of EGFR. PD 168393 also shows a low plasma concentration. [1]

The effects of VU0364770 on rat mGlu1 and mGlu5 are assessed by using calcium mobilization and measuring the glutamate concentration-response relationship in the presence and absence of 10 μM VU0364770. Using a double-addition protocol, VU0364770 is added to the cells, followed 2.5 min later by a full concentration-response of glutamate. Shifts of the concentration-response relationship are used to assess potential potentiator (left shift of more than 2-fold) or antagonist (right shift of more than 2-fold or depression of the maximum response by at least 75%) activity of VU0364770. Compounds are further assessed for mGlu5 antagonist activity by performing a full concentration-response curve, starting at 30 μM and serially diluted it by using 1:3 dilutions, in the presence of an EC80 concentration of glutamate[1].