M1233 Expression of Growth Factor Receptor and Potential Treatment in Cholangiocarcinoma (CC) Cell Lines

Abstract

Introduction: CC is a rare carcinoma of the biliary epithelium. Standard chemotherapy has little effect on CC. Growth factors and their receptors play an important role in tumor growth and metastasis. Neutralizing antibodies targeting growth factors and their receptors have been shown to be therapeutically effective. We therefore determined the expression of 7 growth factors in 4 human CC cell lines. The effect of monoclonal EGFR antibody on two human CC cell lines was tested. Methods: mRNA expression was studied for EGFR, VEGFR1, VEGFR2, VEGFR3, IGF1R, IGF2R and HGFR in the four human CC cell lines TFK-1, EGI-1, OZ and HuH28. Protein expression of these molecules was investigated by Western blot and immunohistochemistry. The effects of 0.1, 1.0, 10, 100 and 1000 mg/ml monoclonal anti-EGFR antibody (cetuximab, ErbituxO, Merck) were tested In Vitro in the two cell lines TFK-1 and EGI-1. Cell growth was analyzed by cell counting, cell metabolism by XTT assay and apoptosis by FACS. Results: mRNA and protein expression of all seven growth factor receptors was found in all four human CC cell lines by PCR, Western blot and immunohistochemistry. Cetuximab significantly inhibited cell growth of TFK-1 in a dose dependent manner (p < 0.05) but had no influence on EGI-1 cells. The metabolic activity of TFK-1 cells treated with cetuximab was increased dose dependently, however, decreased significantly over time. For EGI-1 cells metabolic activity remained largely unchanged. TFK-1 but not EGI-1 showed increased rates of apoptosis (p < 0.05). Results: Cetuximab has different major effects on cell growth, cell metabolism and apoptosis on human CC cell lines TFK-1 and EGI-1. Cetuximab inhibits TFK-1 cell growth and increased apoptosis. These effects are not related to the expression of growth factor receptors.