[Exosomes secreted from human umbilical cord mesenchymal stem cells promote pancreatic ductal adenocarcinoma growth by transferring miRNAs].

Objective: To observe the effects of exosomes derived from human umbilical cord mesenchymal stem cells on the proliferation and invasion of pancreatic cancer cells, and to analyze the contents of exosomes and explore the mechanisms affecting pancreatic cancer cells. Methods: Exosomes extracted from human umbilical cord mesenchymal stem cells were added to pancreatic cancer cells BxPC3, Panc-1 and mouse models of pancreatic cancer, respectively. The proliferative activity and invasion abilities of BxPC3 and Panc-1 cells were measured by cell counting kit-8 (CCK-8) and Transwell assays. The expressions of miRNAs in exosomes were detected by high-throughput sequencing. GO and KEGG were used to analyze the related functions and the main metabolic pathways of target genes with high expressions of miRNAs. Results: The results of CCK-8 cell proliferation assay showed that the absorbance of BxPC3 and Panc-1 cells in the hucMSCs-exo group was significantly higher than that in the control group [(4.68±0.09) vs. (3.68±0.01), P<0.05; (5.20±0.20) vs. (3.45±0.17), P<0.05]. Transwell test results showed that the number of invasion cells of BxPC3 and Panc-1 in hucMSCs-exo group was significantly higher than that in the control group (129.40±6.02) vs. (89.40±4.39), P<0.05; (134.40±7.02) vs. (97.00±6.08), P<0.05. In vivo experimental results showed that the tumor volume and weight in the exosomes derived from human umbilical cord mesenchymal stem cells (hucMSCs-exo) group were significantly greater than that in the control group [(884.57±59.70) mm(3) vs. (695.09±57.81) mm(3), P<0.05; (0.94±0.21) g vs. (0.60±0.13) g, P<0.05]. High-throughput sequencing results showed that miR-148a-3p, miR-100-5p, miR-143-3p, miR-21-5p and miR-92a-3p were highly expressed. GO and KEGG analysis showed that the target genes of these miRNAs were mainly involved in the regulation of glucosaldehylation, and the main metabolic pathways were ascorbic acid and aldehyde acid metabolism, which were closely related to the development of pancreatic cancer. Conclusion: Exosomes derived from human umbilical cord mesenchymal stem cells can promote the growth of pancreatic cancer cells and the mechanism is related to miRNAs that are highly expressed in exosomes.

[Clinical study of different surgical approaches in laparoscopic debridement for patients with infected pancreatic necrosis].

Objective: To examine the indications and effects of different surgical approaches in laparoscopic debridement for patients with infected pancreatic necrosis(IPN). Methods: The clinical data of 213 IPN patients treated by laparoscopic debridement at Department of General Surgery,Xuanwu Hospital, Capital Medical University from June 2012 to February 2019 were retrospectively analyzed.The therapeutic effects were summarized and analyzed according to different surgical approaches. There were 123 cases in retroperitoneal approach group, including 73 males and 50 females, aging of (51.3±12.4)years; 59 cases in omental sac approach group, including 32 males and 27 females, aging of (48.3±14.2)years; 23 cases in combined approach group, including 13 males and 10 females,aging of(54.3±19.7)years;8 cases in digestive tract approach group, including 5 males and 3 females, aging of(50.2±12.5)years. Results: The time from onset to operation in retro-peritoneal, omental sac, combined and digestive tract approach groups were (44.3±22.8), (47.3±24.3), (52.6±21.2), (51.2±30.1)days, respectively; the operation time was (52.3±26.4), (64.3±29.2), (82.8±24.7), (78.2±38.1) minutes respectively; the median bleeding volume was 18, 33, 42 and 30 ml, respectively; and the first time to eat after operation was (2.5±1.6),(3.8±1.8),(3.7±2.0),(8.4±3.9) days, respectively. The incidence of complications (Clavien-Dindo grade Ⅲ and above)was 10.6%(13/123),10.2% (6/59),17.4%(4/23),1/8 and the mortality was 4.9%(6/123),3.4%(2/59),4.3%(1/23)and 0,respectively.The overall mortality of all patients was 4.2%(9/213).The levels of inflammatory factors were significantly lower in all groups 7 days after operation than before,and no patients was converted to open surgery. Conclusion: Individualized selection of the optimal laparoscopic debridement approach of pancreatic necrosis plays an important role in improving the efficacy and prognosis of IPN patients.