【 Abstract 】 Objective Overexpressions of epidermal growth factor (EGF) and EGF receptor have been associated with progression and invasive phenotype of pancreatic cancer. However, the underlying molecular mechanism by which EGF worked in pancreatic cancer cells has not been completely understood. In this study, effect of EGF on the invasion and metastasis of pancreatic cancer cells and its regulatory mechanism were investigated. Methods The effects of EGF on the proliferation, adhesion and invasion of pancreatic cancer cells were detected by WST-1 proliferation assay, adhesion assay and invasive assay, respectively. The activity and expression of MMP-2 and MMP-9 were examined by zymography, Western blot and RT-PCR, respectively. The activity of NF- κ B was examined by EMSA. Results EGF could significantly promote the invasiveness of pancreatic cancer cells but did not affect cell proliferation or adhesion. The expressions of NF- κ B and MMP-9 were significantly increased by EGF, but EGF did not affect the activity and expression of MMP-2. Furthermore, EGF stimulated the NF- κ B binding activity. Pretreatment with NF- κ B inhibitors, pyrrolidine dithiocarbamate (PDTC), could significantly inhibit the activity of NF- κ B induced by EGF. Meanwhile, the EGF-induced expression and activity of MMP-9, as well as cell invasiveness were also inhibited by NF- κ B inhibitor. Conclusion EGF could increase the expression and promote the invasiveness of MMP-9 via the activation of NF- κ B in pancreatic cancer cells, which implies that NF- κ B inhibitant, such as PDTC, may diminish the invasiveness of pancreatic cancer cells.
【Abstract】ObjectiveTo evaluate the relationships between the transporters BSEP， MRP2， MDR3 and cholesterol calculus formation. MethodsTwenty hepatic tissue specimens were taken from consented patients with cholesterol calculus during intraoperative liver biopsy, of which ten were taken from patients without cholesterol calculus. RNA of liver tissue from all the samples was extracted and ultraviolet spectrophotometry was used to measure the content and purity of it. The mRNA and protein expressions of BSEP, MRP2 and MDR3 were determined by reverse transcriptionpolymerase chain reaction (RTPCR) and Western blot analysis, respectively. ResultsRTPCR showed that the mRNA expressions of BSEP, MRP2 and MDR3 in liver were significantly lower in patients with cholesterol calculus （0.47±0.18, 1.12±0.39 and 1.02±0.24） than those in the liver of patients without calculus （0.90±0.42, 2.48±0.89 and 1.94±0.80）,P＜0.01. And Western blot also showed the protein expressions of these transporters were significantly lower in patients with cholesterol calculus （90.16±18.82, 45.43±22.77 and 61.08±14.77） than those in the liver of patients without calculus (186.17±4.34, 160.47±30.19 and 100.84±15.44). ConclusionThe decreased expression of BSEP, MRP2 and MDR3 may correlate with the formation of cholesterol calculus.