Long non-coding RNA PlncRNA-1 promotes cell proliferation and hepatic metastasis in colorectal cancer.

Emerging evidence has identified that long non-coding RNAs (lncRNAs) may play an important role in the pathogenesis of many cancer types, including colorectal cancer (CRC). However, the role of PlncRNA-1 in CRC remains unclear. The aim of our present study was to investigate the potential functions of PlncRNA-1 in CRC and to identify the underlying mechanisms of action. We demonstrated that up-regulated PlncRNA-1 in CRC tissues and cells promoted cell proliferation by accelerating cell cycle process and inhibiting cell apoptosis in vitro, enhanced tumor growth and matastasis in vivo and was associated with cell migration and invasion, EMT process of CRC cells. In addition, PlncRNA-1 was a target of miR-204 and enhanced the expression of an endogenous miR-204 target, MMP9 in CRC cells. Furthermore, we found that PlncRNA-1 activates Wnt/ß-catenin pathway through the miR-204 in CRC cells. These results suggest that the PlncRNA-1/miR-204/ Wnt/ß-catenin regulatory network may shed light on tumorigenesis in CRC.

[In vitro analysis and in vivo tracing of BrdU-labeled rat bone marrow mesenchymal stem cells].

OBJECTIVES: To investigate the optimal condition of bromodeoxyuridine (BrdU) labeling for bone marrow mesenchymal stem cells (BMSCs) in vitro and the feasibility of in vivo tracing of BrdU-labeling BMSCs. METHODS: BMSCs were isolated from Wistar rats and were in vitro routinely cultured. The third passage BMSCs was used for identification of special surface antigens by immunohistochemical methods. The purified BMSCs were incubated with BrdU at different concentrations for different incubating time to investigate optimal BrdU concentration and incubating time for cell labeling. The cell labeling index of BrdU was calculated with immunohistochemical analysis. BMSCs labeled BrdU were injected into damaged gastric mucosa of rats by micro injector. The colonization of BMSCs labeled BrdU in gastric mucosa was viewed. RESULTS: After purification and proliferation, the primary cultured BMSCs were uniformly long spindle-shapped form and formed cell colony, which showed the characteristics of stem cell. Immunocytochemistry showed BMSCs were positive for CD44 and CD90, while negative for CD14, CD45. The labeling rate of BrdU increased with the labeling time lasting and reached its height at 48 h. After incubating 48 and 72 hours, the labeling rate of BrdU with a concentration of 10 micromol/L was higher than that of BrdU with a concentration of 5 micromol/L (P < 0.05) and similar with that of BrdU with a concentration of 15 micromol/L (P > 0.05). In addition, the BrdU labeling could be detected after five consecutive passages and the labeling time could keep 21 d. The pathological observation demonstrated that BrdU-labeled BMSCs could colonize the damaged gastric mucosa with normal morphologic characteristics during observation period. CONCLUSION: BrdU labeling might be a feasible method for dynamic observation of the migration, growth and differentiation of migrating BMSCs in colonizing sites.

Glutathione S-transferase T1 (GSTT1) gene polymorphism and gastric cancer susceptibility: a meta-analysis of epidemiologic studies.

PURPOSE: Studies investigating the association between genetic polymorphism of glutathione S-transferase T1 (GSTT1) and gastric cancer risk have reported conflicting results. Therefore, we conducted this meta-analysis to provide more precise evidence. METHODS: We searched the databases Medline, PubMed, Embase, and China National Knowledge Infrastructure up to July 30, 2009. Thirty-six studies with 4,357 gastric cancer cases and 9,796 controls were selected. Odds ratio (OR) and 95% confidence intervals (CI) were calculated based on fixed- and random-effects models. RESULTS: The combined results based on all studies showed there was a significant link between GSTT1 null genotype and gastric cancer risk (OR = 1.14, 95%CI = 1.01-1.28). In subgroup analysis stratified on the basis of ethnic group, we also observed positive association between GSTT1 polymorphism and gastric cancer risk among Caucasians (non-Europeans + non-Americans), but not among East Asians. When stratifying by control source, the overall ORs for population- and hospital-based studies were 1.09 (95%CI = 0.94-1.28) and 1.17 (95%CI = 1.03-1.34), respectively. Subjects with both GSTM1 and GSTT1 negative genotypes had increased gastric cancer risk compared with those who had nonnull genotypes of both GST genes. Subgroup analyses for Helicobacter pylori infection and smoking habit did not reveal any significant association between GSTT1 polymorphism and gastric cancer development. CONCLUSIONS: This meta-analysis suggests that GSTT1 gene polymorphism may be not associated with increased gastric cancer risk among Europeans, Americans, and East Asians. More large-scale studies based on the same racial group are needed.

Aspirin use and the risk of gastric cancer: a meta-analysis.

PURPOSE: Studies investigating the association between aspirin use and gastric cancer risk have reported conflicting results. The objective of this study was to quantitatively summarize the evidence for such a relationship. RESULTS: Two investigators independently searched the Medline, PubMed, Embase, and Academic Search Premier (EBSCO) databases. Fourteen studies with a total number of 5,640 gastric cancer cases were identified. Most of the study populations were Caucasian. The combined results based on all studies showed there was no statistically significant difference between aspirin use and gastric cancer risk (odds ratio (OR) = 0.80, 95% confidence intervals (CI) = 0.54-1.19). When stratifying by study designs and gender, results were similar except for cohort and randomized controlled trial (RCT) studies (OR = 0.72, 95% CI = 0.62-0.84). When stratifying by location and Helicobacter pylori (H. pylori) infection, we observed there were lower risks in noncardia gastric cancer (OR = 0.62, 95% CI = 0.55-0.69) and H. pylori-infected individuals (OR = 0.62, 95% CI = 0.42-0.90) for aspirin users. Among Caucasians, there were lower risks for noncardia gastric cancer (OR = 0.73, 95% CI = 0.62-0.87) and H. pylori-infected individuals (OR = 0.62, 95% CI = 0.42-0.90) also. CONCLUSIONS: This meta-analysis indicated that regular use of aspirin may be associated with reduced risk of noncardia gastric cancer, especially among Caucasians; for H. pylori-infected subjects the result was similar.

[Expression of glucose transporter 1 in human breast carcinoma and its clinical significance].

OBJECTIVE: To investigate the expression of glucose transporter 1 (Glut1) in human breast cancer and its relationship to proliferating cell nuclear antigen (PCNA) protein, other tumor biomarkers and clinical pathologic factors. METHODS: Imunohistochemical staining (SP) was applied to measure the expression of Glut1 and PCNA in 20 cases of human breast fibroadenoma, 20 cases of usual hyperplasia and 80 cases of breast carcinoma. RESULTS: Glut1 was not found expressing in breast fibroadenoma and hyperplastic lesions. In contrast, the total positive rate of Glut1 in breast carcinoma was 58.8% (47/80); that in the ductal carcinoma in situ (DCIS) was 45.0% (9/20), that in the well-differentiated invasive carcinoma was 50.0% (15/30) and that in the poorly differentiated was 76.7% (23/30). The total positive rate of PCNA in breast carcinoma was 75% (60/80), that in DCIS was 65% (13/20) and that in invasive carcinoma was 78.3% (47/60). There was a positive correlation between Glut1 and PCNA level (r = 0.742, P (< 0.01). CONCLUSION: The overexpression of Glut1 play important roles in carcinogenesis and progression of breast carcinoma and closely correlate with cell proliferation of breast carcinoma, may suggest different therapeutic approaches or the need for closer follow-up, and be wished to become a new target for treatment of breast carcinoma.

[Effects of the different culture and isolation methods on the growth, proliferation and biology characteristics of rat bone marrow mesenchymal stem cells].

OBJECTIVE: To explore a suitable method for isolation, purification and multiplication of bone marrow mesenchymal stem cells (BMSCs). METHODS: Density gradient centrifugation and adherence separation methods were applied for isolation of BMSCs from Wistar rats. The cells were cultured and proliferated in culture medium containing calf serum (CS), fetal bovine serum (FBS), free of serum or different volume fraction of FBS. The characteristic and the morphology of BMSCs were observed under inverted microscope every day. The growth curves were draw and the surface antigen of BMSCs were detected by immunocytochemistry technique. The microstructure was observed by transmission electron microscope (TEM). RESULTS: The pure primary cells can be procured by density gradient centrifugation. But the primary cells cultured by adherence separation methods demonstrated higher cytoactive, more rapid proliferation, earlier colony confluence and shorter time for passage than that cultured by density gradient centrifugation method. The cells by adherence separation methods were essentially purified at passage 4. Both CS and FBS can promote the growth and proliferation of BMSCs, but the colony forming efficacy of cells (46.50%) cultured in medium containing 0.12 volume fraction FBS was the highest. The cells surface markers CD44, CD90 were positive and CD14, CD45 were negative. BMSCs were observed by TEM and possessed the characteristic of stem cells. Conclusion BMSCs with high quality and activity can be obtained with adherence separation by suitable method and culture conditions. L-DMEM medium containing 0.12 volume fraction FBS showed more profitable for the growth and proliferation of BMSCs.

Parenchymal-sparing versus extended hepatectomy for colorectal liver metastases: A systematic review and meta-analysis.

AIMS: To assess the safety and efficacy of parenchymal-sparing hepatectomy (PSH) as a treatment of colorectal liver metastases (CLM). METHODS: A comprehensive medical literature search was performed. Perioperative and long-term survival outcomes were pooled. Subgroup analysis and meta-regression analysis were performed to identify potential sources of heterogeneity. RESULTS: A total of 18 studies comprising 7081 CLM patients were eligible for this study. The PSH was performed on 3974 (56.1%) patients. We found that the OS (overall survival; hazard ratio [HR] = 1.01, 95% confidence interval [CI]: 0.94-1.08) and RFS (recurrence-free survival; HR = 1.00, 95% CI: 0.94-1.07) were comparable between non-PSH and PSH group. The perioperative outcomes were better in PSH than in non-PSH group. Non-PSH group was significantly associated with longer operative time (standard mean difference [SMD] = 1.17, 95% CI: 0.33-2.00), increased estimated blood loss (SMD = 1.36, 95% CI: 0.64-2.07), higher intraoperative transfusion rate (risk ratio [RR] = 2.27, 95% CI: 1.60-3.23), and more postoperative complications (RR = 1.39, 95% CI: 1.16-1.66). Meta-regression analyses revealed that no variable influenced the association between surgical types and the survival outcomes. CONCLUSIONS: This study shows that PSH is associated with better perioperative outcomes without compromising oncological outcomes. Given the increasing incidence of hepatic parenchyma, the PSH treatment offers a greater opportunity of repeat resection for intrahepatic recurrent tumors. It should be considered as an effective surgical approach for CLM.

Overweight, obesity and gastric cancer risk: results from a meta-analysis of cohort studies.

The relationship between excess body weight and gastric cancer risk has not been well studied to date. We therefore carried out a systematic review and meta-analysis of published cohort studies to evaluate the association between excess body weight and gastric cancer risk. An electronic search of the MEDLINE, PubMed, EMBASE and Academic Search Premier (EBSCO) databases, which contain articles published from 1950 onwards, was conducted in order to select studies for this meta-analysis. Ten studies with a total number of 9492 gastric cancer cases and a studied population of 3,097,794 were identified. Overall, excess body weight [body mass index (BMI)25] was associated with an increased risk of gastric cancer [odds ratio (OR)=1.22; 95% confidence intervals (CIs)=1.06-1.41]. Specifically, a stratified analysis showed that excess body weight was associated with an increased risk of cardia gastric cancer [overweight and obese (BMI 25), OR=1.55, 95% CIs=1.31-1.84] and gastric cancer among non-Asians (overweight and obese, OR=1.24, 95% CIs=1.14-1.36); however, the stratified analysis also showed that there was no statistically significant link between excess body weight and gastric cancer in the following subgroups: males (overweight and obese, OR=1.22, 95% CIs=0.96-1.55), females (overweight and obese, OR=1.13, 95% CIs=0.65-1.94), non-cardia gastric cancer (overweight and obese, OR=1.18, 95% CIs=0.96-1.45) and Asians (overweight and obese, OR=1.17, 95% CIs=0.88-1.56). The combined results of this meta-analysis, however, do indicate that overweight and obesity are associated with an increased risk of gastric cancer. The strength of the association also increases with increasing BMI.