Combination chemotherapy of nafamostat mesylate with gemcitabine for gallbladder cancer targeting nuclear factor-κB activation.

BACKGROUND

Gemcitabine is an effective chemotherapeutic agent for advanced gallbladder cancer. However, chemoresistance attributable to gemcitabine-induced nuclear factor-κB (NF-κB) activation has been reported. We previously reported that nafamostat mesylate inhibited NF-κB activation and induced apoptosis in pancreatic cancer. Therefore, we hypothesized that nafamostat mesylate inhibits gemcitabine-induced NF-κB activation and enhances apoptosis induced by gemcitabine in gallbladder cancer.

MATERIALS AND METHODS

In vitro, we assessed NF-κB activation of a gallbladder cancer cell line (NOZ) treated with nafamostat mesylate, gemcitabine, or a combination of both. In vivo, we established a xenograft gallbladder cancer model in mice by subcutaneous injection of NOZ cells. Five weeks after implantation, the animals were treated with nafamostat mesylate three times a week in the nafamostat mesylate group, with gemcitabine once a week in the gemcitabine group, or with a combination of nafamostat mesylate three times a week and gemcitabine once a week in the combination group, respectively. In the control group, only the vehicle of gemcitabine and nafamostat mesylate was injected at the same time course.

RESULTS

In the combination group, NF-κB activation was inhibited and apoptosis was enhanced compared with gemcitabine alone in vitro and vivo. Tumor growth in the combination group was significantly slower than that in the gemcitabine group (P < 0.001). At the end of the study, the tumor weight and volume in the combination group were significantly lower than those in the gemcitabine group (P = 0.039 and 0.028, respectively).

CONCLUSIONS

Combination chemotherapy of gemcitabine with nafamostat mesylate enhances the anti-tumor effect against xenograft gallbladder cancer model in mice.