Table 2.

Inhibition by gefitinib of EGF-induced and basal phosphorylation of EGFR, Akt, and ERK1/2 in nine NSCLC and two epidermoid carcinoma cells

Cell LinesEGF-Induced (IC50, μm)aBasal Condition (IC50, μm)
P-EGFRP-AktP-ERK1/2P-EGFRP-AktP-ERK1/2

PC9

0.30 (1.0)

0.05 (1.0)

0.07 (1.0)

0.07 (1.0)

0.08 (1.0)

0.03 (1.0)
A5490.22 (0.7)0.06 (1.2)0.22 (3.1)0.25 (3.6)5< (63<)5< (167<)
H5220.30 (1.0)0.50 (10)0.40 (5.7)0.50 (7.1)5 (63)5< (167<)
H3220.43 (1.4)0.13 (2.0)5< (71<)0.35 (5.0)5< (63<)5< (167<)
H3580.40 (1.3)0.13 (2.0)0.75 (11)5 (71)5< (63<)0.1 (3.3)
EBC-10.80 (2.7)5< (100<)5< (71<)5 (71)10< (125<)10< (333<)
H1570.06 (0.2)0.07 (1.4)0.13 (1.9)0.7 (10)5 (63)5< (167<)
QG560.20 (0.7)0.90 (18)2.20 (31)0.3 (4.3)0.35 (4.4)5< (167<)
LK2ndb0.50 (10)0.08 (1.1)nd10< (125<)10< (333<)
A4310.04 (1.0)0.10 (1.0)0.04 (1.0)0.05 (1.0)0.5 (1.0)0.1 (1.0)
KB3-10.04 (1.0)0.12 (1.2)0.05 (1.3)0.13 (2.6)5 (10)5< (50<)
  • a IC50 values were obtained from 50% inhibitory doses of gefitinib on phosphorylation of EGFR, Akt, and ERK1/2 under EGF-stimulated or basal (10% serum) culture condition as presented in Fig. 2. The relative activity for IC50 of each cell line is presented in parentheses when normalized by the IC50 value in PC9 and A431, respectively.

  • b nd: not detected because of poor phosphorylation.