Tyrosine Kinase Inhibitors. 10. Isomeric 4-[(3-Bromophenyl)amino]pyrido[d]- pyrimidines Are Potent ATP Binding Site Inhibitors of the Tyrosine Kinase Function of the Epidermal Growth Factor Receptor

Abstract

Following the discovery of the very high inhibitory ability of the 4-[(3-bromophenyl)amino]-quinazolines against the tyrosine kinase activity of the epidermal growth factor receptor (EGFR) (e.g., 3, IC50 0.029 nM), four series of related pyrido[d]pyrimidines bearing electron-donating groups at the 6- or 7-positions have been synthesized and evaluated. The compounds were prepared by nucleophilic substitution of the corresponding 6- and 7-fluoro analogues. While members of all series showed potent inhibitory activity against isolated EGFR, there were important differences between the different isomeric pyrido[d]pyrimidines and the parent quinazolines. Overall, the [3,4-d] and [4,3-d] series were the most potent, followed by the [3,2-d] compounds, with the [2,3-d] analogues being least active. Whereas in the parent quinazoline series the addition of steric bulk to a 6- or 7-NH2 substituent (i.e., NHMe and NMe2 groups) dramatically decreased potency, no such trend was discernable in the [3,2-d] series. Furthermore, in the 7-substituted pyrido[4,3-d]- and 6-substituted pyrido[3,4-d]pyrimidine series, and to a limited extent in the 7-substituted pyrido[2,3-d] series, such substitution increased potency dramatically, to the extent that the 7-(methylamino)pyrido[4,3-d]pyrimidine (5f) (IC50 0.13 nM) and 6-(methylamino)pyrido[3,4-d]pyrimidine (7f) (IC50 0.008 nM) constitute important new leads. Selected compounds were evaluated for their ability to inhibit EGFR autophosphorylation in A431 cells, and a positive quantitative correlation was found between this activity and inhibitory activity against the isolated enzyme.

Effect of combining anti-epidermal growth factor receptor antibody C225 and radiation on DU145 prostate cancer

“…1a, 2a and 3a). This is consistent with other reports (32,(36)(37)(38)(39). We also found that EGF treatments inhibited the DU145 prostate cell line in vitro (Figs.…”

Activation of c-Src by receptor tyrosine kinases in human colon cancer cells with high metastatic potential

“…To further understand the relationship between the EGFR and c-Src, the KM12 cell lines were pre-treated with a drug that speci®cally blocks EGFR activation (PD 158780) (Rewcastle et al, 1996) and then treated with 100 ng/ml EGF for 10 min prior to analysis of whole cell lysates by phosphotyrosine Western blots (Figure 7). EGF stimulation of untreated cells predictably enhanced autophosphorylation of protein bands consistent with EGFR (170 kDa) and c-Src (60 kDa) in the highly-metastatic cell lines (KM12 SM, KM12 L4A) but had no apparent e ect on c-Src in the poorly-metastatic cell line (KM12 C), mirroring previous experiments (see Figure 2a).…”

Involvement of lipoxygenase in lysophosphatidic acid-stimulated hydrogen peroxide release in human HaCaT keratinocytes

“…Previous studies have demonstrated the requirement of ROS for the mitogenic response [1,7,10,18]. To examine whether H # O # …”

“…To assess whether EGF receptor tyrosine kinase also mediates LPA-stimulated H # O # release, cells were treated with PD158780, a tyrosine kinase inhibitor specific for the EGF receptor [17][18][19], and LPA-or EGF-stimulated H # O # release was measured. As shown in Figure 3b, EGF stimulated H # O # release in HaCaT cells.…”

“…Importantly, we find that 5-lipoxygenase products 5-hydroperoxyeicosatetraenoic acid (5-HPETE) and leukotriene B % (LTB % ) are required for LPA-stimulated H # O # release in HaCaT cells. [17][18][19] was generously provided by Alan Kraker (Parke-Davis Pharmaceutical Research). Zileuton [20,21] was provided by Abbott Laboratories.…”