The cyclooxygenase-2 inhibitor celecoxib attenuates hepatocellular carcinoma growth and c-Met expression in an orthotopic mouse model.

To demonstrate in vivo tumor growth inhibition, the liver cancer cell lines HepG2, BEL7402, and SMMC7721 were independently inoculated into the livers of 45 6-week-old nude mice. After 24 h, mice were randomly divided into celecoxib (intragastric celecoxib suspension, 300 mg/kg), negative control (equal volume intragastric saline), and positive control (intraperitoneal injection of 6 mg/kg doxorubicin) and treated once per day for 3 days. Body weights, tumor diameters, and tumor expressions of proliferating cell nuclear antigen (PCNA) and c-Met were determined at 23 days posttreatments. Significant increases in body weight were observed in celecoxib- or doxorubicin-treated mice compared to saline-treated animals and tumor growth was significantly attenuated, accompanied by downregulation of tumor PCNA expression (p < 0.01). Weight gain, attenuated tumor growth, and reduced PCNA expression were similar following celecoxib or doxorubicin treatment. Celecoxib also significantly reduced c-Met expression in HepG2- and BEL7402-induced tumors, but not SMMC7721-induced tumors (p < 0.05). In conclusion, celecoxib effectively suppressed the in vivo growth of liver cancer in an orthotopic tumor model. Celecoxib also inhibited tumor cell PCNA expression independent of changes in c-Met expression, with some variability between different implanted cell lines. This preclinical demonstration of celecoxib efficacy and safety provides a foundation for future clinical investigations involving use of this agent alone or as a component of chemotherapeutic regimens for treatment of HCC.