Objective To examine the effects of the MEK inhibitor on human pancreatic cancer cells, and to explore the molecular mechanisms. Methods Human pancreatic cancer cell lines CFPANC1, PANC1 and MiaPaCa2 were treated with MEK inhibitor PD98059 or DMSO, the sensitivity was analyzed by an MTT assay, and cell cycle distribution was evaluated by flow cytometry( FCM), The transcriptional level and protein expression of tumor suppressor genes were detected by real-time RT-PCR and western blot respectively. DNA methyltransferase (Dnmt)1, 3a and 3b were also assayed by western blot, The methylation status of the promoter of the p16INK4A gene was assayed by methylation-specific PCR (MSP). Results PD98059 inhibited to various degrees the growth of three pancreatic cancer cell lines, accompanied by G0-G1 cell cycle arrest. PD98059 up-regulated the expression of p16INK4a, p21WAF1, p27KIP1 mRNA, demethylated the hypermethylation status of p16INK4a gene promoter, and decreased Dnmtl and Dnmt3b in CFPANC1 and PANC1 cell lines. PD98059 only increased the expression of p27KIP1, while the changes of p16INK4a, p21WAF1 and Dnmt were less marked in MiaPaCa2 cell line. Conclusions MEK inhibitor PD98059 down-regulate the activation of Dnmt and up-regulate tumor supress genes, along with the inhibition of cell proliferation and cell cycle progression.

Objective To study the therapeutic effects of EUS-guided biliary drainage (EUS-BD) using a nitinol fully covered self-expandable metal stents in patients with malignant obstructive jaundice after failed ERCP.Methods From January 2016 to January 2018,all patients with malignant obstructive jaundice who failed ERCP underwent EUS-guided biliary drainage using nitinol fully covered self-expandable metal stent at Affiliated Hangzhou First People' s Hospital,Zhejiang University School of Medicine.The operation success rate,liver functional recovery time,complication rate,length of hospital stay and survival time were observed.Results Of 36 patients who underwent EUS-guided biliary drainage,34 were successfully performed,with 19 through the stomach,and 15 through the duodenum.The operation success rate was 94.4％ (34/36).The liver functional recovery time of the 34 patients were 25.8 ±.6.5 days.One patient developed hemobilia and one cholangitis,both improved after conservative treatment.The total complication rate was 5.6％ (2/36).The hospital stay and survival time were 21.5 ± 4.7 days and 220.5 ± 54.8 days,respectively.Conclusion EUS-BD using nitinol fully covered self-expandable metal stents was a feasible and effective treatment in patients with malignant biliary obstruction after failed ERCP.

Objective To evaluate the efficacy of endoscopic ultrasound guided biliary drainage (EUS-BD) in patients with biliary obstruction and surgically altered anatomies.Methods We collected data from 33 patients with biliary obstruction and surgically altered anatomies from January 2016 to January 2018 in Zhejiang University School of Medicine Affiliated Hangzhou First People's Hospital who underwent EUS-guided biliary drainage after unsuccessful ERCP.The operation success rate,clinical success rate,complication rate,hospital stay were studied.Results Of 33 patients,31 were successfully operated and stented using endoscopic ultrasound puncture:14 patients through the stomach,17 patients through the duodenum;8 patients by the rendezvous approach.The operation success rate was 93.9％.Of the 33 patients,28 had a significant decrease in jaundice,with a clinical success rate of 84.9％.Complications consisted of 2 patients with bleeding and 1 patient with cholangitis.These patients improved after conservative treatment.The complications rate was 9.1％.The hospital stay was (12.4±5.7) d.Conclusion EUS-BD can be the first choice for patients with biliary obstruction and surgically altered anatomy after failed endoscopic retrograde cholangiograohv in centers with exoertise in EUS-BD procedures.