Despite rapid advances in
chemotherapy and surgical resection strategies,
pancreatic cancer remains the fourth leading cause of
cancer related deaths in the United States with a 5-year survival rate of less than 5%. Therefore, novel therapeutic agents for the prevention and treatment of
pancreatic cancer are urgently needed. The aim of this study was to investigate the effect of
pristimerin, a quinonemethide
triterpenoid compound isolated from Celastraceae and Hippocrateaceae, on inhibition of cell proliferation and induction of apoptosis in three
pancreatic cancer cells, BxPC-3, PANC-1 and AsPC-1, in both monotherapy and in combination with
gemcitabine. Treatment with
pristimerin decreased the cell proliferation of all three
pancreatic cancer cells in a dose- and time-dependent manner. Treatment of
pancreatic cancer cells with
pristimerin also resulted in G1-phase arrest which was strongly associated with a marked decrease in the level of
cyclins (D1 and E) and
cyclin-dependent kinases (cdk2, cdk4 and cdk6 ) with concomitant induction of WAF1/p21 and KIP1/p27.
Pristimerin treatment also resulted in apoptotic cell death, cleavage of
caspase-3, modulation in the expressions of Bcl-2 family
proteins, inhibition of the translocation and
DNA-binding activity of NF-κB. In addition,
pristimerin potentiated the growth inhibition and apoptosis inducing effects of
gemcitabine in all three
pancreatic cancer cells, at least in part, by inhibiting constitutive as well as
gemcitabine-induced activation of NF-κB in both its
DNA-binding activity and transcriptional activity. Taken together, these data provide the first evidence that
pristimerin has strong potential for development as a novel agent against
pancreatic cancer.