In-vitro and in-vivo inhibition of melanoma growth and metastasis by the drug combination of celecoxib and dacarbazine.

Celecoxib has been found to be effective in cancer prevention and treatment. Its combination with other chemotherapeutic agents was reported to produce synergistic/additive effects on various cancers. Dacarbazine (DTIC) is one of the most commonly used drugs in the treatment of metastatic melanoma. This investigation aimed to determine the in-vitro and in-vivo effects of the drug combination of celecoxib and DTIC on melanoma growth and metastasis. Melanoma cells B16-F10 and SK-MEL-28, and female C57BL/6 mice were used for the study. Our in-vitro data showed that significant synergistic effects were obtained when celecoxib was used together with various concentrations of DTIC. A study with B16-F10 cells using flow cytometry analysis showed that the drug combination induced significantly more apoptosis than each drug used individually. Our in-vivo results showed that the drug combination was much more effective than each drug used alone for the inhibition of both melanoma growth and metastasis in the B16-F10+C57BL/6 mouse models. For melanoma growth, the median survival rates for phosphate-buffered saline (PBS) (control), celecoxib (30 mg/kg), DTIC-1 (10 mg/kg), DTIC-2 (positive control, 50 mg/kg), and the drug combination (DTIC 10 mg/kg+celecoxib 30 mg/kg) were 6, 6.5, 7.5, 7.5, and 9 days, respectively. For melanoma metastasis, the average number of metastatic tumors in murine lungs was 53.7±10.7, 31.8±18.6, 21.2±21.7, 7.0±9.0, and 0.8±2.0 for PBS, DTIC-1, celecoxib, the drug combination, and DTIC-2. Our results warrant further investigation of the combination as an effective treatment for melanoma patients.