AZD2171 shows potent antitumor activity against gastric cancer over-expressing fibroblast growth factor receptor 2/keratinocyte growth factor receptor.
OBJECTIVE
AZD2171 is an oral, highly potent, and selective vascular endothelial growth factor signaling inhibitor that inhibits all vascular endothelial growth factor receptor tyrosine kinases. The purpose of this study was to investigate the activity of AZD2171 in gastric cancer.


METHODS
We examined the antitumor effect of AZD2171 on the eight gastric cancer cell lines in vitro and in vivo.


RESULTS
AZD2171 directly inhibited the growth of two gastric cancer cell lines (KATO-III and OCUM2M), with an IC(50) of 0.15 and 0.37 micromol/L, respectively, more potently than the epidermal growth factor receptor tyrosine kinase inhibitor gefitinib. Reverse transcription-PCR experiments and immunoblotting revealed that sensitive cell lines dominantly expressed COOH terminus-truncated fibroblast growth factor receptor 2 (FGFR2) splicing variants that were constitutively phosphorylated and spontaneously dimerized. AZD2171 completely inhibited the phosphorylation of FGFR2 and downstream signaling proteins (FRS2, AKT, and mitogen-activated protein kinase) in sensitive cell lines at a 10-fold lower concentration (0.1 micromol/L) than in the other cell lines. An in vitro kinase assay showed that AZD2171 inhibited kinase activity of immunoprecipitated FGFR2 with submicromolar K(i) values ( approximately 0.05 micromol/L). Finally, we assessed the antitumor activity of AZD2171 in human gastric tumor xenograft models in mice. Oral administration of AZD2171 (1.5 or 6 mg/kg/d) significantly and dose-dependently inhibited tumor growth in mice bearing KATO-III and OCUM2M tumor xenografts.


CONCLUSIONS
AZD2171 exerted potent antitumor activity against gastric cancer xenografts overexpressing FGFR2. The results of these preclinical studies indicate that AZD2171 may provide clinical benefit in patients with certain types of gastric cancer.
Takeda
Masayuki
M
Shien Lab, National Cancer Center Hospital, Tsukiji, Chuo-ku, Tokyo, Japan.
Arao
Tokuzo
T
Yokote
Hideyuki
H
Komatsu
Teruo
T
Yanagihara
Kazuyoshi
K
Sasaki
Hiroki
H
Yamada
Yasuhide
Y
Tamura
Tomohide
T
Fukuoka
Kazuya
K
Kimura
Hiroshi
H
Saijo
Nagahiro
N
Nishio
Kazuto
K
D000284:Administration, Oral; D000818:Animals; D000970:Antineoplastic Agents / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use*; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D019281:Dimerization; D000077156:Gefitinib; D006801:Humans; D051379:Mice; D008815:Mice, Inbred Strains; D011799:Quinazolines / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use*; D034741:RNA, Small Interfering / Q000494:pharmacology; D051497:Receptor, Fibroblast Growth Factor, Type 2 / Q000032:analysis / Q000037:antagonists & inhibitors* / Q000378:metabolism; D013274:Stomach Neoplasms / Q000188:drug therapy* / Q000201:enzymology; D015854:Up-Regulation / Q000187:drug effects; D023041:Xenograft Model Antitumor Assays; D007211:Indoles
D000970:Antineoplastic Agents; D000077156:Gefitinib; D011799:Quinazolines; D034741:RNA, Small Interfering; D051497:Receptor, Fibroblast Growth Factor, Type 2; C065104:keratinocyte growth factor receptor; C500926:cediranib; D007211:Indoles