ABSTRACT
The aim of this study was to investigate the expression and clinical significance of cyclooxygenase 2 (COX-2) and vascular en-dothelial growth factor C (VEGF-C) in cholangiocarcinomas at differ-ent clinical and pathological stages. Eighty cholangiocarcinoma sam-ples of patients treated with surgery between January 2012 and January 2014 were collected. Immunohistochemistry was used to detect COX-2 and VEGF-C expression at different clinical and pathological stages. ELISA, real-time PCR, invasive chambers, and MTT assay were ap-plied in cultured cholangiocarcinoma cells treated with a COX-2 inhib-itor. Expression of COX-2 and VEGF-C correlated positively with the clinical TNM stage but did not correlate with the differentiation status. Inhibition of COX-2 activity reduced VEGF-C mRNA expression and secretion in cholangiocarcinoma cells and decreased their migration but not proliferation. Because of its ability to inhibit invasion, COX-2 could be a new target for treatment of cholangiocarcinoma.