Dual epidermal growth factor receptor and vascular endothelial growth factor receptor inhibition with NVP-AEE788 for the treatment of aggressive follicular thyroid cancer.
OBJECTIVE
Patients with radioiodine-resistant follicular thyroid cancer (FTC) have a poor prognosis, if metastasized, with currently available treatment modalities. Epidermal growth factor (EGF) and vascular endothelial growth factor (VEGF) and their receptors (EGFR and VEGFR) have been reported to be overexpressed in FTC and have been implicated in FTC development. We hypothesized that inhibiting the phosphorylation of EGFR and VEGFR by treatment with NVP-AEE788 (AEE788), a novel dual specific EGFR and VEGFR inhibitor, either alone or in combination with paclitaxel, would inhibit the growth of FTC xenografts in an orthotopic nude mouse model.


METHODS
To confirm previous reports, EGF and EGFR expression and vascularity were analyzed in human samples of FTC, Hürthle cell carcinoma, and normal thyroid tissues. EGFR expression in four FTC cell lines was measured using Western blotting. The antitumor effect of AEE788 on FTC cells in vitro was evaluated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assays and Western blotting. The effect of AEE788, alone and in combination with paclitaxel, on FTC tumor growth in an orthotopic nude mouse model was also investigated. Immunohistochemical analysis of EGFR and VEGFR signaling status, cell proliferation, apoptosis, and microvessel density was done.


RESULTS
EGF, EGFR, and vascularity were increased in human thyroid tumor samples and EGFR was increased in FTC cells. AEE788 inhibited FTC cell growth in vitro and reduced the phosphorylation status of EGFR, VEGFR, and two downstream targets, AKT and mitogen-activated protein kinase, in FTC cells. AEE788 alone and, to a greater extent, AEE788 plus paclitaxel suppressed FTC tumor growth in the thyroids of nude mice.


CONCLUSIONS
Dual inhibition of EGFR and VEGFR by AEE788 could represent a novel approach to the treatment of radioiodine-resistant FTC.
Younes
Maher N
MN
Department of Head and Neck Surgery, The University of Texas M.D. Anderson Cancer Center, Houston, Texas 77030-4009, USA.
Yazici
Yasemin D
YD
Kim
Seungwon
S
Jasser
Samar A
SA
El-Naggar
Adel K
AK
Myers
Jeffrey N
JN
D018263:Adenocarcinoma, Follicular / Q000175:diagnosis / Q000188:drug therapy*; D000818:Animals; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000494:pharmacology / Q000627:therapeutic use; D015153:Blotting, Western; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D004195:Disease Models, Animal; D018450:Disease Progression; D066246:ErbB Receptors / Q000037:antagonists & inhibitors* / Q000378:metabolism; D006801:Humans; D008297:Male; D051379:Mice; D008819:Mice, Nude; D017239:Paclitaxel / Q000494:pharmacology / Q000627:therapeutic use; D010766:Phosphorylation / Q000187:drug effects; D011237:Predictive Value of Tests; D011379:Prognosis; D011687:Purines / Q000494:pharmacology* / Q000627:therapeutic use; D040262:Receptors, Vascular Endothelial Growth Factor / Q000037:antagonists & inhibitors* / Q000378:metabolism; D013329:Structure-Activity Relationship; D013964:Thyroid Neoplasms / Q000175:diagnosis / Q000188:drug therapy*; D023041:Xenograft Model Antitumor Assays
D011687:Purines; D066246:ErbB Receptors; D040262:Receptors, Vascular Endothelial Growth Factor; C489254:AEE 788; D017239:Paclitaxel