Liesheng Lu

Methionine Synthase A2756G Polymorphism and Risk of Colorectal Adenoma and Cancer: Evidence Based on 27 Studies

Methionine synthase (MTR), which plays a central role in maintaining adequate intracellular folate, methionine and normal homocysteine concentrations, was thought to be involved in the development of colorectal cancer (CRC) and colorectal adenoma (CRA) by affecting DNA methylation. However, studies on the association between MTR A2756G polymorphism and CRC/CRA remain conflicting. We conducted a meta-analysis of 27 studies, including 13465 cases and 20430 controls for CRC, and 4844 cases and 11743 controls for CRA. Potential sources of heterogeneity and publication bias were also systematically explored. Overall, the summary odds ratio of G variant for CRC was 1.03 (95% CI: 0.96–1.09) and 1.05 (95% CI: 0.99–1.12) for CRA. No significant results were observed in heterozygous and homozygous when compared with wild genotype for these polymorphisms. In the stratified analyses according to ethnicity, source of controls, sample size, sex, and tumor site, no evidence of any gene-disease association was obtained. Results from the meta-analysis of four studies on MTR stratified according to smoking and alcohol drinking status showed an increased CRC risk in heavy smokers (OR = 2.06, 95% CI: 1.32–3.20) and heavy drinkers (OR = 2.00, 95% CI: 1.28–3.09) for G allele carriers. This meta-analysis suggests that the MTR A2756G polymorphism is not associated with CRC/CRA susceptibility and that gene-environment interaction may exist.

Impact of Bariatric Surgery on Ghrelin and Obestatin Levels in Obesity or Type 2 Diabetes Mellitus Rat Model

We aimed to evaluate the therapeutic efficacy on weight control by different bariatric surgeries and investigate the ghrelin and obestatin changes after these surgeries in obesity and nonobese type 2 diabetes mellitus (T2DM) rats. Obese rats were randomly assigned to receive sleeve gastrectomy (SG, n = 8), minigastric bypass (MGBP, n = 8), roux-en-Y gastric bypass (RYGBP, n = 8), and sham operation (SO, n = 4). Another 4 rats served as control. Besides, Goto-Kakisaki (GK) rats were also randomly divided into similar groups except for total gastrectomy (TG, n = 8) group. The results showed that in obese rats, weigh loss in RYGBP group was similar to that in MGBP group but larger than that in SG group. Ghrelin significantly increased in RYGB group, but obestatin increased in MGBP group. Ghrelin/obestatin ratio significantly decreased in SG group. In GK rats, weight loss was most obvious in TG group. Postoperatively, ghrelin was significantly increased in MGBP and RYGB groups but decreased in TG group. Obestatin also showed an increase in MGBP and RYGB groups. Ghrelin/obestatin in TG group decreased significantly. In conclusion, RYGB and MGBP may be more suitable for obese rats, but TG may be the best strategy for T2DM rats to control weight with different mechanisms.

Incidence and risk factors for postsurgical gastroparesis syndrome after laparoscopic and open radical gastrectomy

BackgroundThe aim of this study was to investigate the differences and influencing factors for postsurgical gastroparesis syndrome incidence after laparoscopic and open radical gastrectomy.MethodsClinical data were collected for 563 patients who underwent open radical gastrectomy for gastric cancer and 72 cases receiving laparoscopic radical gastrectomy. We retrospectively analyzed the incidence of postsurgical gastroparesis syndrome, clinical features, course of disease, and risk factors of these two groups.ResultsThere was no statistical difference for the incident rate of postsurgical gastroparesis syndrome between laparoscopic and open radical gastrectomy (6.9% vs. 3.7%, P > 0.05). Preoperative outflow tract obstruction and Billroth II anastomosis were the two risk factors for postsurgical gastroparesis syndrome in the open radical gastrectomy group and the laparoscopic surgery for gastric cancer group. The same results were obtained from logistic regression statistical analysis. Age greater than 70 years was also one of the risk factors for postsurgical gastroparesis syndrome in the open radical gastrectomy group (P < 0.05).ConclusionsLaparoscopic radical gastrectomy for gastric cancer does not increase the incident rate of postsurgical gastroparesis syndrome.

UCA1 promotes cell proliferation and invasion of gastric cancer by targeting CREB1 sponging to miR-590-3p

Long noncoding RNAs (lncRNAs) have emerged as regulators in a variety of biological processes, including carcinogenesis in human cancer. UCA1 has been reported to be upregulated in gastric cancer (GC); however, the underlying functional roles of UCA1 in GC have not been established. In the current study, we showed that UCA1 is significantly higher in GC tissues and cells compared with adjacent normal tissues and a gastric epithelium cell line, respectively. Higher UCA1 expression was associated with lymph node metastasis, TNM stage, and poor overall survival (OS) in GC patients. In vitro functional studies confirmed that UCA1 promotes cell proliferation, colony formation ability, and cell invasion in GC cells. We demonstrated that knockdown of UCA1 inhibits tumor growth in vivo. The double luciferase reporter, RNA‐binding protein immunoprecipitation assay, and RNA pull down assay demonstrated that miR‐590‐3p serves as a target for UCA1. UCA1 promoted cell proliferation and invasion by negatively regulating miR‐590‐3p expression. Moreover, we demonstrated that CREB1 is a downstream target of miR‐590‐3p and UCA1 activates CREB1 expression by sponging to miR‐590‐3p. Thus, these results showed that UCA1 functions as an oncogene in GC and may be a target for treatment of GC.

Retraction Note to: siRNA-participated chemotherapy: an efficient and specific therapeutic against gastric cancer

Purpose This study aims to investigate the role of siRNA silencing fibroblast growth factor receptor (FGFR) expression in promoting chemotherapy effect of gastric cancer and to explore its mechanism.

Comparing the Effectiveness of Total Gastrectomy and Gastric Bypass on Glucose Metabolism in Diabetic Rats

BackgroundBariatric surgeries have been widely used in obesity associated type II diabetes. However, the mechanisms of surgical treatments for type II diabetes in non-obese patients remain controversial. Our study aims to compare the effectiveness of various bariatric surgeries in a non-obese diabetic rat model.MethodsGoto-Kakisaki (GK) rats were used to compare the outcome of total gastrectomy (TG), Roux-en-Y reconstruction after total gastrectomy (RYTG), and Roux-En-Y gastric bypass (RYGB). Body weight, food and water intake, and glucose level were monitored prior to and after surgery. Oral glucose tolerance tests (OGTT) were performed, and key metabolic hormones were measured at selected time points.ResultsDespite a significant reduction in body weight in TG and RYTG groups, their glucose metabolic rate was not improved. RYGB rats, with only moderate reduction in food intake and body weight, had significantly improved glucose metabolism. Insulin and ghrelin were significantly reduced in TG and RYTG groups, but remained unchanged in RYGB group.ConclusionsOur study demonstrated the effectiveness of RYGB surgery in treating type II diabetes in non-obese diabetic rats. These results suggest an important role of gastric system in regulating glucose homeostasis.

Long Noncoding RNA BCYRN1 Promotes the Proliferation of Colorectal Cancer Cells via Up-Regulating NPR3 Expression

Background/Aims: Long noncoding RNAs (lncRNAs) constitute a large proportion of noncoding transcripts that have recently emerged as a new class of important regulators in cancers. LncRNA BCYRN1, also known as BC200, has a potential function in tumorigenesis. However, the clinical significance of BCYRN1 and its effect on colorectal cancer (CRC) progression remains unclear. Methods: Quantitative reverse transcriptase PCR (qRT-PCR) was performed to investigate the expression of BCYRN1 in CRC tissues and cell lines. The biological function of BCYRN1 was also investigated through knockdown and overexpression of BCYRN1 in vitro. Microarray bioinformatics analysis was performed to analyze the putative targets of BCYRN1. Results: The results showed that BCYRN1 expression was significantly upregulated in 96 CRC tumor tissues compared with para-carcinoma control tissues. Additionally, BCYRN1 overexpression was associated with larger tumor size and advanced pathological stages in CRC patients. In vitro BCYRN1 knockdown significantly inhibited the proliferation and apoptosis of CRC cells. Furthermore, NPR3 was identified to be a target of BCYRN1 and was downregulated by BCYRN1 knockdown. Conclusion: Together, we provide the first evidence that BCYRN1 plays an oncogenic role in CRC cells. BCYRN1 may be a promising prognostic biomarker and a potential therapeutic target for CRC.

Laparoscopic gastrectomy for distal gastric cancer

This video presents a standard D2 laparoscopic-assisted gastrectomy for distal gastric cancer. The lymph node dissection of each station is performed as required in the standardized procedure of distal gastrectomy, followed by the Billroth II anastomosis through a small incision.