Expression of growth factor receptors and targeting of EGFR in cholangiocarcinoma cell lines.
BACKGROUND
Cholangiocarcinoma (CC) is a malignant neoplasm of the bile ducts or the gallbladder. Targeting of growth factor receptors showed therapeutic potential in palliative settings for many solid tumors. The aim of this study was to determine the expression of seven growth factor receptors in CC cell lines and to assess the effect of blocking the EGFR receptor in vitro.


METHODS
Expression of EGFR (epithelial growth factor receptor), HGFR (hepatocyte growth factor receptor) IGF1R (insulin-like growth factor 1 receptor), IGF2R (insulin-like growth factor 2 receptor) and VEGFR1-3 (vascular endothelial growth factor receptor 1-3) were examined in four human CC cell lines (EGI-1, HuH28, OZ and TFK-1). The effect of the anti-EGFR-antibody cetuximab on cell growth and apoptosis was studied and cell lines were examined for KRAS mutations.


RESULTS
EGFR, HGFR and IGFR1 were present in all four cell lines tested. IGFR2 expression was confirmed in EGI-1 and TFK-1. No growth-inhibitory effect was found in EGI-1 cells after incubation with cetuximab. Cetuximab dose-dependently inhibited growth in TFK-1. Increased apoptosis was only seen in TFK-1 cells at the highest cetuximab dose tested (1 mg/ml), with no dose-response-relationship at lower concentrations. In EGI-1 a heterozygous KRAS mutation was found in codon 12 (c.35G>A; p.G12D). HuH28, OZ and TFK-1 lacked KRAS mutation.


CONCLUSIONS
CC cell lines express a pattern of different growth receptors in vitro. Growth factor inhibitor treatment could be affected from the KRAS genotype in CC. The expression of EGFR itself does not allow prognoses on growth inhibition by cetuximab.
Xu
Ling
L
Department of Internal Medicine I, University of Regensburg, 93042 Regensburg, Germany.
Hausmann
Martin
M
Dietmaier
Wolfgang
W
Kellermeier
Silvia
S
Pesch
Theresa
T
Stieber-Gunckel
Manuela
M
Lippert
Elisabeth
E
Klebl
Frank
F
Rogler
Gerhard
G
D000911:Antibodies, Monoclonal / Q000494:pharmacology; D061067:Antibodies, Monoclonal, Humanized; D000970:Antineoplastic Agents / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects; D001650:Bile Duct Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D001653:Bile Ducts, Intrahepatic / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D000068818:Cetuximab; D018281:Cholangiocarcinoma / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D004305:Dose-Response Relationship, Drug; D066246:ErbB Receptors / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D009154:Mutation; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D011518:Proto-Oncogene Proteins / Q000235:genetics; D019859:Proto-Oncogene Proteins c-met / Q000378:metabolism; D016283:Proto-Oncogene Proteins p21(ras); D012333:RNA, Messenger / Q000378:metabolism; D017978:Receptors, Growth Factor / Q000378:metabolism; D017451:Receptors, Somatomedin / Q000378:metabolism; D040262:Receptors, Vascular Endothelial Growth Factor / Q000378:metabolism; D013997:Time Factors; D018631:ras Proteins / Q000235:genetics
D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D000970:Antineoplastic Agents; C117307:KRAS protein, human; D047428:Protein Kinase Inhibitors; D011518:Proto-Oncogene Proteins; D012333:RNA, Messenger; D017978:Receptors, Growth Factor; D017451:Receptors, Somatomedin; C512478:EGFR protein, human; D066246:ErbB Receptors; C491743:MET protein, human; D019859:Proto-Oncogene Proteins c-met; D040262:Receptors, Vascular Endothelial Growth Factor; D016283:Proto-Oncogene Proteins p21(ras); D018631:ras Proteins; D000068818:Cetuximab