Objective To investigate the 5-lipoxygenase(5-LOX)expression in human pancreatic cancer cells and the inhibitory effect on growth of SW1990 by selective 5-LOX inhibitor zileuton in vitro.Methods The 5-LOX expression in pancreatic cancer cell was defected by immunocytochemistry and RT-PCR form May 10,2003 to May 25,2004.MTT and flow cytometry with AnnexinⅤ-FITC and propidium iodide(PI)staining and acridine orange(AO)staining were used to observe the effect of zileuton on the growth of SW1990cell line.Results The 5-LOX mRNA and protein expression was detectable in pancreatic cancer cell line by mmunohistochemistry and RT-PCR technique respectively.Zileuton could inhibit the growth of SW1990 cell line in a time-and dose-dependent manner.Conclusion Zileuton might inhibit the growth of SW1990 cell line in a time-and dose-dependent manner.

Objective To investigate the suppression effects of Tripotolide (TL) on the pancreatic cancer xenograft models and angiogenesis. Methods The growth suppression effect of TL on SW1990 was determined using cell count kit (CCK-8), apoptotic cells induced by TL were examined by morphology and terminal deoxynucleotidyl transferase-mediated nick end labeling (TUNEL) assay. The inhibitory effects of TL on the growth of tumor xenografts and tumor microvascular density (MVD) were investigated. ResultsTL inhibited the growth and proliferation of SW1990 cells in a concentration-dependent and time-dependent manner. The inhibition ratios of cells treated at 160 mg/ml TL for 24 h was 50. 6%, the apoptotic rate increased from 9.6% in the control group to 45.1% (P <0.01 ). The inhibition rate of cancer xenograft growth was 89.9% when TL was intratumorally injected at the dose of 0.5 mg/kg. The expression of VEGF in tumor tissue decreased while MVD also decreased from 36.25±8.64 to 9.87±3.34 (P <0.01 ). ConclusionsTL induced prominent growth inhibition and apoptosis in human pancreatic cancer cell lines. TL.can attenuate the growth of pancreatic caner xenografts through its effect on antiangiogenesis.