Objective: To investigate the anti-tumor activity of dihydroartemisinin in pancreatic cancer in vitro and in vivo.
Methods: For cultured cells, cell growth was determined by the MTT assay and apoptosis was evaluated by flow cytometry analysis stained with Annexin V-FITC/PI. The protein expression in BxPC-3 cells was analyzed by Western blot assay. BxPC-3 cells were injected subcutaneously into nude mice to establish pancreatic xenograft tumors and the tumor volume was monitored after exposure to dihydroartemisinin. Ki-67 staining and TUNEL assay were used to assess tumor cell proliferation and apoptosis in tumor tissue.
Results: After treatment by dihydroartemisinin in vitro, the proliferative inhibition rates of pancreatic cancer cells BxPC-3 and AsPC-1 reached up to (76.2 +/- 3.5)% and (79.5 +/- 2.9)%, and the apoptosis rates were up to (55.5 +/- 3.2)% and (40.0 +/- 3.5)%, the differences were significantly (P < 0.01) compared with control [(2.0 +/- 1.3)% and (0.9 +/- 0.4)%]. Dihydroartemisinin inhibited the growth of pancreatic xenograft tumors in nude mice. The proliferation index and apoptosis index were (49.1 +/- 3.9)% and (50.2 +/- 4.4)% respectively in dihydroartemisinin 50 mg/kg treatment group, compared to those of (72.1 +/- 3.3)% and (9.4 +/- 2.9)% in control, the differences were significantly (P < 0.01). Western blot assay indicated that dihydroartemisinin up-regulates expression of proliferation-associated protein p21(WAF1) and down-regulates expression of PCNA, increases expression of apoptosis-associated protein Bax and decreases expression of Bcl-2 and activates caspase-9 in BxPC-3 cells.
Conclusions: Dihydroartemisinin exerts anti-tumor activity in pancreatic cancer both in vitro and in vivo by proliferation inhibition and apoptosis induction. Dihydroartemisinin can be used as a potential anti-tumor drug in pancreatic cancer.