title: Analysis of anti-proliferative and chemosensitizing effects of sunitinib on human esophagogastric cancer cells: Synergistic interaction with vandetanib via inhibition of multi-receptor tyrosine kinase pathways.
abstract: The receptor tyrosine kinases (RTKs), epidermal growth factor receptor (EGFR) and vascular endothelial growth factor receptor 1-3 (VEGFR1-3), are frequently expressed in gastric cancer and are putative therapeutic targets in this disease. We have investigated the anti-proliferative and chemosensitizing properties of the multitargeted small-molecule RTK inhibitors sunitinib and vandetanib in a panel of 4 human gastric and esophageal cancer cell lines. In the 1st instance, the expression of potential targets of these small-molecule inhibitors was examined by reverse transcriptase-polymerase chain reaction, western blotting, and flow cytometry. EGFR mRNA and protein was detected in all cases, with VEGFR2 expression noted in all but 1 line. Both EGF and VEGF were shown to stimulate tumor cell growth, and both sunitinib and vandetanib were found to be associated with significant dose-dependent inhibition of proliferation and an enhancement of apoptosis, as determined by MTT and propidium iodide/Annexin V labeling assays, respectively. The addition of sunitinib to VEGF-stimulated NCI-N87 cells was associated with a reduction in MAPK phosphorylation (pMAPK) but not Akt phosphorylation (pAkt), whereas the addition of vandetanib was associated with reductions in both VEGF- and EGF-mediated VEGFR2 phosphorylation, pMAPK and pAkt. Co-administration of sunitinib significantly enhanced the sensitivity of MKN-45 cells to cisplatin and irinotecan. In addition, vandetanib synergistically enhanced the sunitinib-associated inhibition of gastric cancer cell growth. In conclusion, these preliminary data confirm the importance of EGFR and VEGFR signaling in gastric cancer and suggest that the simultaneous inhibition of RTK-pathways through sunitinib and vandetanib may provide therapeutic benefit in this disease.
authors.affiliation: First Department of Internal Medicine, Johannes Gutenberg University Hospital, Mainz, Germany.
authors.forename: Orestis
authors.initials: O
authors.lastname: Lyros
authors.forename: Annett
authors.initials: A
authors.lastname: Mueller
authors.forename: Florian
authors.initials: F
authors.lastname: Heidel
authors.forename: Carl C
authors.initials: CC
authors.lastname: Schimanski
authors.forename: Ines
authors.initials: I
authors.lastname: Gockel
authors.forename: Peter R
authors.initials: PR
authors.lastname: Galle
authors.forename: Hauke
authors.initials: H
authors.lastname: Lang
authors.forename: Markus
authors.initials: M
authors.lastname: Moehler
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects; D015153:Blotting, Western; D049109:Cell Proliferation / Q000187:drug effects*; D002478:Cells, Cultured; D004347:Drug Interactions; D004357:Drug Synergism; D004359:Drug Therapy, Combination; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D066246:ErbB Receptors / Q000235:genetics / Q000378:metabolism; D004938:Esophageal Neoplasms / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D005434:Flow Cytometry; D006801:Humans; D007211:Indoles / Q000494:pharmacology*; D010766:Phosphorylation / Q000187:drug effects; D010880:Piperidines / Q000494:pharmacology*; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D011758:Pyrroles / Q000494:pharmacology*; D011799:Quinazolines / Q000494:pharmacology*; D012333:RNA, Messenger / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction / Q000187:drug effects*; D013274:Stomach Neoplasms / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D000077210:Sunitinib; D014471:Umbilical Veins / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D040281:Vascular Endothelial Growth Factor Receptor-1 / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D040301:Vascular Endothelial Growth Factor Receptor-2 / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D040321:Vascular Endothelial Growth Factor Receptor-3 / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism
chemical_list: D000970:Antineoplastic Agents; D007211:Indoles; D010880:Piperidines; D047428:Protein Kinase Inhibitors; D011758:Pyrroles; D011799:Quinazolines; D012333:RNA, Messenger; C512478:EGFR protein, human; D066246:ErbB Receptors; D040281:Vascular Endothelial Growth Factor Receptor-1; D040301:Vascular Endothelial Growth Factor Receptor-2; D040321:Vascular Endothelial Growth Factor Receptor-3; D051057:Proto-Oncogene Proteins c-akt; D000077210:Sunitinib; C452423:vandetanib