AEE788, a dual tyrosine kinase receptor inhibitor, induces endothelial cell apoptosis in human cutaneous squamous cell carcinoma xenografts in nude mice.
OBJECTIVE
We investigated whether concomitant blockade of the epidermal growth factor receptor (EGFR) and vascular endothelial growth factor receptor (VEGFR) signaling pathways by AEE788, a dual inhibitor of EGFR and VEGFR tyrosine kinases, would inhibit the growth of cutaneous squamous cell carcinoma (SCC) cells and human cutaneous cancer xenografts in nude mice.


METHODS
We examined the effects of AEE788 on the phosphorylation of EGFR and VEGFR-2 in cutaneous SCC cells expressing EGFR and VEGFR-2 and cutaneous SCC cell growth and apoptosis. We assessed the in vivo antitumor effects of AEE788 in a xenograft model in nude mice. AEE788 (50 mg/kg) was given orally thrice weekly to mice that had been s.c. injected with Colo16 tumor cells. Mechanisms of in vivo AEE788 activity were determined by immunohistochemical analysis.


RESULTS
Treatment of cutaneous SCC cells with AEE788 led to dose-dependent inhibition of EGFR and VEGFR-2 phosphorylation, growth inhibition, and induction of apoptosis. In mice treated with AEE788, tumor growth was inhibited by 54% at 21 days after the start of treatment compared with control mice (P < 0.01). Immunohistochemical analysis revealed that AEE788 inhibited phosphorylation of EGFR and VEGFR and induced apoptosis of tumor cells and tumor-associated endothelial cells.


CONCLUSIONS
In addition to inhibiting cutaneous cancer cell growth by blocking EGFR and VEGFR signaling pathways in vitro, AEE788 inhibited in vivo tumor growth by inducing tumor and endothelial cell apoptosis.
Park
Young Wook
YW
Department of Head and Neck Surgery, University of Texas M.D. Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, TX 77030, USA.
Younes
Maher N
MN
Jasser
Samar A
SA
Yigitbasi
Orhan G
OG
Zhou
Ge
G
Bucana
Corazon D
CD
Bekele
Benjamin N
BN
Myers
Jeffrey N
JN
D000284:Administration, Oral; D000818:Animals; D017209:Apoptosis; D002294:Carcinoma, Squamous Cell / Q000473:pathology*; D049109:Cell Proliferation; D042783:Endothelial Cells; D066246:ErbB Receptors / Q000037:antagonists & inhibitors; D006801:Humans; D051379:Mice; D008819:Mice, Nude; D011687:Purines / Q000008:administration & dosage / Q000494:pharmacology*; D040262:Receptors, Vascular Endothelial Growth Factor / Q000037:antagonists & inhibitors; D015398:Signal Transduction; D012878:Skin Neoplasms / Q000473:pathology*; D014183:Transplantation, Heterologous
D011687:Purines; D066246:ErbB Receptors; D040262:Receptors, Vascular Endothelial Growth Factor; C489254:AEE 788