Gemcitabine combined with gum mastic causes potent growth inhibition and apoptosis of pancreatic cancer cells

Aim: To investigate the antiproliferative and apoptotic effects of gemcitabine combined with gum mastic and the underlying mechanisms in human pancreatic cancer cell lines. Methods: Cell proliferation and apoptosis were examined using the methyl thiazolyl tetrazolium (MTT) assay and propidium iodine staining, respectively. The expression of Bcl-2, Bax, NF-kappa B p65 subunit, and I kappa B alpha protein was measured using Western blotting. Results: Gemcitabine 0.01-100 mu g/mL inhibited cell proliferation and induced apoptosis in both pancreatic cancer BxPC-3 and COLO 357 cells. Gum mastic 40 mu g/mL significantly potentiated the antiproliferative and apoptotic effects of gemcitabine 10 mu g/mL after 72-h treatment. When cells were treated with gemcitabine in combination with gum mastic, the I kappa B alpha level was increased, whereas NF-kappa B activation was blocked; the expression of Bax protein was substantially increased, but Bcl-2 protein was down-regulated. Conclusion: Gemcitabine combined with gum mastic causes potent apoptosis in pancreatic cancer cells. The combination may be an effective therapeutic strategy for pancreatic cancer.