AV-412 free base的生物活性 AV-412(MP-412) is a potent dual inhibitor of EGFR and ErbB2(IC50=19 nM) tyrosine kinases, including the mutant EGFR(L858R IC50=0.51 nM, T790M IC50=0.79 nM); inhibits autophosphorylation of EGFR and ErbB2 with IC(50) of 43 and 282 nM, respectively. IC50 value: 0.51 nM (EGFR L858R); 0.79 nM (EGFRT790M); 19 nM (ErbB2) [1] Target: EGFR; ErbB2; Mutant EGFR L858R/T790M in vitro: MP-412 (AV-412) is a potent dual inhibitor of EGFR and ErbB2 tyrosine kinases, including the mutant EGFR(L858R,T790M), which is clinically resistant to the EGFR-specific kinase inhibitors erlotinib and gefitinib. In an enzyme assay, MP-412 inhibited the EGFR variants and ErbB2 in the nanomolar range with over 100-fold selectivity compared with other kinases, apart from abl and flt-1, which were both moderately sensitive to the compound. In cells, MP-412 inhibited autophosphorylation of EGFR and ErbB2 with IC(50) of 43 and 282 nM, respectively. It also inhibited epidermal growth factor (EGF)-dependent cell proliferation with an IC(50) of 100 nM. Moreover, MP-412 abrogated EGFR signaling in the gefitinib-resistant H1975 cell line, which harbors a double mutation of L858R and T790M in EGFR [1]. MP-412 inhibited phosphorylation of EGFR and its downstream signaling in NCI-H1650 and NCI-H1975 cell lines, which harbor the E746-A750 deletion and L858R + T790M point mutations, respectively, in EGFR [2]. In MCF7 cells, MP-412 depleted not only ErbB2 but also estrogen receptor (ER)-α, and to some extent, affected Raf-1, while MP-412 activated Hsp70 expression. MP-412 increased immunocomplexing of Hsp70 with ErbB2 and ER-α, with simultaneous induction of ubiquitination of these client proteins. Furthermore, in combination with proteasome inhibitor, MP-412 resulted in the noticeable accumulation of ErbB2 and ER-α in the detergent insoluble fraction of cell lysates [3]. in vivo: In animal studies using cancer xenograft models, MP-412 (30 mg/kg) demonstrated complete inhibition of tumor growth of the A431 and BT-474 cell lines, which overexpress EGFR and ErbB2, respectively. MP-412 suppressed autophosphorylation of EGFR and ErbB2 at the dose corresponding to its antitumor efficacy. MP-412 showed a significant antitumor effect on the ErbB2-overexpressing breast cancer KPL-4 cell line, which is resistant to gefitinib [1]. MP-412 showed potent activity in KPL-4 and DU145 xenografts, in which lapatinib was ineffective. MP-412 also inhibited tumor models in which conventional chemotherapies were less effective [2].