Zhenshun Song

MiR-214 regulate gastric cancer cell proliferation, migration and invasion by targeting PTEN

BackgroundMicroRNAs are a class of small non-coding RNAs that play an important role in various human tumor initiation and progression by regulating gene expression negatively. The aim of this study was to investigate the effect of miR-214 on cell proliferation, migration and invasion, as well as the functional connection between miR-214 and PTEN in gastric cancer.MethodsmiR-214 and PTEN expression was determined in gastric cancer and matched normal tissues, and human gastric cancer cell lines by quantitative real-time PCR. The roles of miR-214 in cell proliferation, migration and invasion were analyzed with anti-miR-214 transfected cells. In addition, the regulation of PTEN by miR-214 was evaluated by Western blotting and luciferase reporter assays.ResultsmiR-214 was noted to be highly overexpressed in gastric cancer tissues and cell lines using qRT-PCR. The expression level of miR-214 is significantly associated with clinical progression and poor prognosis according to the analysis of the clinicopathologic data. We also found that the miR-214 levels are inversely correlated with PTEN in tumor tissues. And PTEN expression level is also associated with metastasis and invasion of gastric cancer. In addition, knockdown of miR-214 could significantly inhibit proliferation, migration and invasion of gastric cancer cells. Moreover, we demonstrate that PTEN is regulated negatively by miR-214 through a miR-214 binding site within the 3’-UTR of PTEN at the posttranscriptional level in gastric cancer cells.ConclusionsThese findings indicated that miR-214 regulated the proliferation, migration and invasion by targeting PTEN post-transcriptionally in gastric cancer. It may be a novel potential therapeutic agent for gastric cancer.

MicroRNA-106b in cancer-associated fibroblasts from gastric cancer promotes cell migration and invasion by targeting PTEN

It is well established that the interaction between cancer cells and microenvironment has a critical role in tumor development, but the roles of miRNAs in this interaction are rarely known. Here, we have shown that miR‐106b is up‐regulated in cancer associated fibroblasts compared with normal fibroblasts established from patients with gastric cancer, the expression level of miR‐106b is associated with poor prognosis of patients, and CAFs with down‐regulated miR‐106b could significantly inhibit gastric cancer cell migration and invasion by targeting PTEN. Taken together, these data suggest that miR‐106b might be a novel candidate target for the treatment of gastric cancer.

Comparison of different methods for the isolation of mesenchymal stem cells from umbilical cord matrix: Proliferation and multilineage differentiation as compared to mesenchymal stem cells from umbilical cord blood and bone marrow

We have identified the most appropriate method of isolating human umbilical cord matrix‐derived mesenchymal stem cells (UCM‐MSCs) and compared morphological, phenotypic, proliferative and differentiation characteristics of UCM‐MSCs with bone marrow‐derived MSCs (BM‐MSCs) and umbilical cord blood‐derived MSCs (UCB‐MSCs). Three explant culture methods and three enzymatic methods were compared with regards to time for primary culture, cell number, cell morphology, immune phenotype and differentiation potential. Morphological, phenotypic, proliferative and differentiation characteristics of UCM‐MSCs, BM‐MSCs and UCB‐MSCs were also compared. UCM‐MSCs isolated using the 10 mm size tissue explant method led to shorter primary culture time, higher numbers of isolated cells and higher proliferation rates compared with other isolation methods. Immune phenotype and multilineage differentiation capacity did not differ significantly among six groups. UCM‐MSCs had similar characteristics as BM‐MSCs and UCB‐MSCs, including fibroblastic morphology, typical immunophenotypic markers and multilineage differentiation capacity. In comparison with UCB‐MSCs and BM‐MSCs, UCM‐MSCs have higher proliferative capacity, higher rate of chondrogenic differentiation, and higher expression of CD 146. The results suggest that the 10 mm size tissue culture method is the optimal protocol for the isolation of UCM‐MSCs. Given the distinct advantages of UC, such as accessibility, painless acquisition and abundance of cells obtained, we propose that UC be considered an alternative to BM and UCB as a source of MSCs for cell therapy.

The role of tomato products and lycopene in the prevention of gastric cancer: a meta-analysis of epidemiologic studies.

BACKGROUND Gastric cancer is the second most common cause of death from cancer worldwide. Epidemiologic studies have examined the possible association between tomato products consumption and gastric cancer, but the relationship between tomato products and the risk of gastric cancer is controversial. We performed a meta-analysis of cohort and case-control studies to analyze this association. METHODS We systematically searched MEDLINE and EMBASE and contacted authors to identify potential studies published from January 1966 to June 2012. We pooled the relative risks from individual studies using a random-effects model and performed heterogeneity and publication bias analyses. RESULTS Twenty-one studies were eligible for our inclusion criteria, in a pooled analysis of all studies, consumption of large amounts of tomato products (in a comparison of the highest and lowest consumption groups) reduced the risk for gastric cancer (odds ratio, 0.73; 95% confidence interval, 0.60-0.90). The pooled OR of lycopene consumption and serum lycopene was 0.88 (95% CI=0.67-1.16) and 0.79 (95% CI=0.59-1.07), respectively. CONCLUSIONS Consumption of large amounts of tomato products is associated with a reduced risk of gastric cancer. However, because of potential confounding factors and exposure misclassification, further studies are required to establish these findings.

Low-pressure versus standard-pressure pneumoperitoneum for laparoscopic cholecystectomy: a systematic review and meta-analysis

BACKGROUND The feasibility and safety of low-pressure pneumoperitoneum in laparoscopic cholecystectomy remain unclear. METHODS A meta-analysis of randomized controlled trials comparing low-pressure with standard-pressure pneumoperitoneum was performed. RESULTS A total of 1,263 patients were included. Low-pressure pneumoperitoneum was associated with significantly decreased postoperative pain. The requirement for increased pressure was significantly greater in the low-pressure group (risk ratio = 6.16; P < .001). Operative time was similar, with only a slight statistical significance (weighted mean difference = 2.07; P < .001). Length of hospital stay was shorter in the low-pressure group (weighted mean difference = -.27; P = .01). No significant differences were found in surgical complications or conversion to open surgery. CONCLUSIONS Low-pressure pneumoperitoneum is feasible and safe and results in reduced postoperative pain and near-equal operative time compared with standard-pressure pneumoperitoneum. More studies are required to investigate the potential benefits of the reduced length of hospital stay.

Primary Closure and Rate of Bile Leak following Laparoscopic Common Bile Duct Exploration via Choledochotomy

Background: Choledocholithiasis is traditionally managed by endoscopic retrograde cholangiopancreatography or T-tube insertion following common bile duct exploration. This study examined the efficacy and safety of primary duct closure following laparoscopic common bile duct exploration (LCBDE) via choledochotomy. Methods: Between September 2011 and September 2013, 157 consecutive patients underwent LCBDE via choledochotomy. Results: Of 157 LCBDE procedures, 138 (87.9%) were successfully completed with primary closure of the choledochotomy. Eight patients (5.1%) underwent closure with T-tube drainage after choledochotomy and 11 patients (7.0%) were converted to open surgery. The biliary tree was free of stones at the end of surgery in 154 patients (98.1%). Postoperative bile leak occurred in 6 patients (3.8%). The median follow-up period was 18 (2-33) months, with no evidence of further bile duct stones or bile duct stricture in any patients. Univariable analysis revealed that successful duct clearance (p = 0.010) and diameter of the common bile duct (p < 0.001) were two significant risk factors for bile leak. Conclusions: Primary duct closure following LCBDE is effective and safe for the management of choledocholithiasis. The postoperative bile leak rate may be low in skilled laparoscopic surgeons with a careful selection of patients.

Intravenous hMSCs Ameliorate Acute Pancreatitis in Mice via Secretion of Tumor Necrosis Factor-α Stimulated Gene/Protein 6

The administration of mesenchymal stem cells/multipotent mesenchymal stromal cells (MSCs) to enhance tissue repair is currently undergoing clinical trials. Some studies, including our previous work, have also revealed the beneficial effect of MSCs in severe acute pancreatitis (SAP); however, their mechanisms or mode of action remain controversial. In this study, we demonstrated that intravenously (i.v.)-administered human MSCs (hMSCs) remarkably promoted recovery from experimental SAP without significant engraftment of hMSCs in the damaged pancreas. Interestingly, we found that i.v.-administered hMSCs with knockdown of TSG-6 expression lost most of their anti-inflammatory effects and thus could not significantly ameliorate SAP. As expected, the effects of hMSCs were also duplicated by i.v. infusion of recombinant TSG-6. Furthermore, our results showed that the increase of oxidative stress, activation of the NLRP3 inflammasome and NF-κB signaling in SAP was substantially inhibited following administration of hMSCs or TSG-6, which was dependent on the presence of CD-44 receptors in acinar cells. In conclusion, our study, for the first time, revealed that novel mechanisms are responsible for the immunomodulatory effect of i.v. hMSCs.

Braun enteroenterostomy during pancreaticoduodenectomy decreases postoperative delayed gastric emptying

BACKGROUND Modified digestive reconstruction during pancreaticoduodenectomy (PD) may affect the postoperative incidence of delayed gastric emptying (DGE). The purpose of this study is to investigate whether Braun enteroenterostomy following PD can reduce the incidence of DGE. METHODS Four hundred seven patients who received PD with child reconstruction from June 2000 to March 2013 were divided into 2 groups: 206 patients with Braun enteroenterostomy (Child-Braun group) and 201 patients without Braun enteroenterostomy (Child-non-Braun group). Clinical data were retrospectively extracted; univariate and multivariate analyses were performed to investigate the association between Braun enteroenterostomy and DGE. RESULTS DGE was less frequent in the Child-Braun group than in the Child-non-Braun group (6.7% vs. 26.87%, P < .001). The multivariate logistic regression analysis showed that Braun enteroenterostomy was the only significant independent factor associated with the reduced DGE after PD with Child reconstruction, with an odds ratio of 4.485 (95% confidence interval: 2.372 to 8.482, P < .001). CONCLUSION Braun enteroenterostomy reduces the incidence of postoperative DGE associated with PD.

Reciprocal and unidirectional scattering of parity-time symmetric structures

Parity-time symmetry is of great interest. The reciprocal and unidirectional features are intriguing besides the symmetry phase transition. Recently, the reciprocal transmission, unidirectional reflectionless and invisibility are intensively studied. Here, we show the reciprocal reflection/transmission in -symmetric system is closely related to the type of symmetry, that is, the axial (reflection) symmetry leads to reciprocal reflection (transmission). The results are further elucidated by studying the scattering of rhombic ring form coupled resonators with enclosed synthetic magnetic flux. The nonreciprocal phase shift induced by the magnetic flux and gain/loss break the parity and time-reversal symmetry but keep the parity-time symmetry. The reciprocal reflection (transmission) and unidirectional transmission (reflection) are found in the axial (reflection) -symmetric ring centre. The explorations of symmetry and asymmetry from symmetry may shed light on novel one-way optical devices and application of -symmetric metamaterials.

Bone marrow-derived mesenchymal stem cells (BMSCs) repair acute necrotized pancreatitis by secreting microRNA-9 to target the NF-κB1/p50 gene in rats

Acute pancreatitis (AP) is a common acute abdominal disease, 10–20% of which can evolve into severe AP (SAP) causing significant morbidity and mortality. Bone marrow-derived mesenchymal stem cells (BMSCs) have the potential of repairing SAP, but the detailed mechanism remains unknown. We demonstrate here that microRNA-9 (miR-9) modified BMSCs (pri-miR-9-BMSCs) can significantly reduce the pancreatic edema, infiltration, hemorrhage, necrosis, the release of amylase and lipase. Meanwhile, decreased local/systemic inflammatory response (TNF-α↓, IL-1β↓, IL-6↓, HMGB1↓, MPO↓, CD68↓, IL-4↑, IL-10↑, and TGF-β↑) and enhanced regeneration of damaged pancreas (Reg4↑, PTF1↑, and PDX1↑) are also promoted. But these effects diminish or disappear after antagonizing miR-9 (TuD). Besides, we find that miR-9 is negatively correlated with AP and miR-9 agomir which can mimic the effects of pri-miR-9-BMSCs and protect injured pancreas. Furthermore, we investigate that BMSCs deliver miR-9 to the injured pancreas or peripheral blood mononuclear cell (PBMC), which can target the NF-κB1/p50 gene and inhibit the NF-κB signaling pathway (p-P65↓, NF-κB1/p50↓, IκBα↑, IκBβ↑). Taken together, these results show that miR-9 is a key paracrine factor of BMSCs attenuating SAP targeting the NF-κB1/p50 gene and suppressing the NF-κB signaling pathway.