Exosomes derived from colon cancer cells and plasma of colon cancer patients promote migration of SW480 cells through Akt/mTOR pathway.

OBJECTIVE: To investigate the effect of exosomes derived from colon cancer (CC) cells and plasma of CC patients on migration of SW480 cells. METHODS: The exosomes derived from culture medium of human colon epithelial cell line NCM460 and CC cell line SW620 were isolated by ultracentrifugation. The exosomes derived from plasma of CC patients and healthy controls were isolated by size exclusion chromatography (SEC). The particle size and morphology of exosomes were identified by nanoparticle tracking analysis (NTA) and transmission electron microscopy (TEM) respectively, and exosomal markers were detected by Western blotting. The uptake of fluorescent DiI labeled exosomes by SW480 cells was observed by confocal microscopy. Transwell assay was used to detect the effect of exosomes on the migration of SW480 cells. The expression level of associated proteins in signaling pathway were analyzed by Western blotting. Rapamycin, an inhibitor of mTOR, was used to study the role of mTOR signaling pathway on exosomes mediated migration of SW480 cells. RESULTS: The results of NTA and TEM showed that the particle size of the isolated exosomes was about 120 nm, which were small vesicles with membrane structure. The expressions of exosomal markers Alix, TSG101 and CD63 could be detected. The exosomes were evidenced by a red fluorescent signal inside the cytoplasm of SW480 recipient cells, and could promote the migration of SW480 cells, which is associated with Akt/mTOR signaling pathway. Compared with the control group, plasma exosomes derived from CC patients could significantly promote the migration of SW480 cells. Inhibition the activity of mTOR signaling could attenuate the migration of SW480 cells. CONCLUSIONS: Exosomes derived from CC cells and plasma of CC patients could promote the migration of SW480 cells, which is associated with Akt/mTOR signaling pathway.

Efficacy of single- versus split-dose polyethylene glycol electrolyte solution for morning colonoscopy: A randomized controlled study.

BACKGROUND: Split-dose (SPD) regimen has been proved more effective than a single-dose (SID) regimen for various drug preparations; however, limited data have focused on morning colonoscopy. We implemented this study to compare the bowel cleanliness and tolerability of a same-day SID versus SPD 2 L polyethylene glycol electrolyte solution (PEG) for morning colonoscopy. METHODS: Patients undergoing morning colonoscopy were randomized into two groups, SID or SPD. In the SID group, patients had to complete 2 L PEG between 4 and 6 am on the day of colonoscopy. In the SPD group, patients had to complete 1 L PEG between 8 and 9 pm on the day before followed by another 1 L PEG between 5 and 6 am on the day of colonoscopy. Colonoscopy was performed between 8 and 12 am under anesthesia. Investigators and endoscopists were blinded to the allocation. The primary end point was the effectiveness of bowel cleansing according to the Boston Bowel Preparation Scale (BBPS). The secondary outcomes were polyp detection rate, compliance, tolerability, and patient satisfaction. RESULTS: Overall, there were 147 and 148 patients in the SID and SPD group, respectively. The SPD group had a better quality of bowel preparation than the SID group with a total BBPS score of 7.25 ± 1.53 versus 6.71 ± 1.65 (P = 0.005). No difference in the polyp detection rate was noted, although more polyps were detected in the SPD group. More patients felt acceptable with the bowel preparation regimen in the SPD group compared to the SID group (76% vs. 65%, P = 0.03). The adverse events were more commonly observed in the SID group, presented as nausea and vomiting. CONCLUSION: For morning colonoscopy, split-dose 2 L PEG is superior to single-dose 2 L PEG by improved bowel preparation, better tolerability, and patient satisfaction.

Human chorionic gonadotropin promotes cell proliferation through the activation of c-Met in gastric cancer cells.

Hormones and their receptors affect the development process of gastric cancer. Previous studies have revealed that human chorionic gonadotropin (hCG) is expressed in gastric cancer tissue. However, the mechanism by which hCG exerts its effects on gastric cancer cells had not been reported. In the present study, the expression of hCG and its receptor was detected in gastric cancer tissues and para-carcinoma tissues of 62 patients with gastric carcinoma. Following the treatment of gastric cancer cells SGC-7901 with hCG, a cell counting kit-8 assay, flow cytometry, a colony formation assay and a xenograft tumor model in nude mice were used to detect the effect of hCG on cell proliferation; and the expression of c-Met was determined by western blot analysis. The expression of hCG and its receptor were significantly higher in gastric cancer tissues compared with that of the matched para-carcinoma tissue (P<0.01). Proliferation of SGC-7901 cells treated with hCG was significant higher and the number of cells at the G2/M phase of the cell cycle increased compared with the control cells. Hepatocyte growth factor transmembrane protein receptor expression was increased in hCG-treated cells compared with the control cells, which relies on the protein kinase A signaling pathway. The present study revealed the potential function of hCG in the development of gastric cancer, suggesting that hCG may be a molecular marker and potential drug target in gastric cancer.

Performance Evaluation of Protein Chip Assay for Rapid Diagnosis of Hepatitis C Virus Infection in Injection Drug Abusers.

BACKGROUND: We evaluated the performance of a protein chip assay for the detection of antibodies to hepatitis C virus (HCV) peptides among injection drug abusers (IDAs) by comparing the assay with existing methods, including enzyme-linked immunosorbent assay (ELISA), reverse transcription-polymerase chain reaction (RT-PCR), and recombinant immunoblot assay (RIBA). METHODS: Seventy serum samples collected from IDAs were analyzed by protein chip assay. ELISA, RT-PCR, and RIBA assay were used to validate the results. RESULTS: The protein chips could detect different peptides' antibodies against HCV-C, HCV-NS3, HCV-NS4, HCV-NS5, and HCV-mix antigen; no cross reactivity between antigens was observed. Results of the protein-chip assay were compared with those of ELISA. Any inconsistency in results was validated by both RT-PCR and RIBA. Concordance between the results of the protein-chip assay and ELISA was 96.3% for positive samples and 100% for negative samples. The protein chip had a higher specificity than ELISA, a higher sensitivity than RTPCR, and similar specificity and sensitivity as compared to RIBA. The limit of detection of HCV antibodies in the protein chip assay was examined and calculated by incubation of model array with different dilutions. The protein chip assay required smaller amounts of both samples and reagents; it detected serum antibody in sample quantity as low as 3 ng/mL and at antibody dilution as low as 1:1000; its cost was low as well. The positive rates in the antiC, anti-NS3, anti-NS4, and anti-NS5 groups were significantly associated with levels of HCV RNA and the viral load. The HCV RNA and protein chip positive rate in the injection equipment-sharing group was higher than that in the non-injection equipment-sharing group. CONCLUSIONS: The protein chip assay is a faster and simpler approach to simultaneously screen for all HCV peptide antibodies accurately and to provide a rapid diagnosis of HCV infection in IDAs. The dominant positive HCV peptide antibodies were significantly associated with HCV RNA load, especially in the injection equipment-sharing group.

High-definition i-Scan colonoscopy is superior in the detection of diminutive polyps compared with high-definition white light colonoscopy: a prospective randomized-controlled trial.

INTRODUCTION: Recognition of flat and small neoplastic lesions by colonoscopy is still challenging. High-definition (HD) i-Scan colonoscopy is a promising technique to maximize the sensitivity of colonoscopy; however, whether i-Scan can increase the detection rate of polyps is still unclear. The aim of this study was to prospectively compare HD i-Scan colonoscopy with HD colonoscopy for the detection rate of polyps in routine practice. MATERIALS AND METHODS: A total of 449 patients who underwent total colonoscopy for the first time were randomized in a 1 : 1 ratio to undergo HD+i-Scan colonoscopy or HD colonoscopy. Detected colorectal polyps were judged according to type, location, and size. The primary endpoint was the detection rate and the total number of polyps. RESULTS: The number of polyps identified in the HD+i-Scan group was significantly higher than that in the HD group (P=0.041), and this difference was more obvious for diminutive polyps (P=0.035). The number of patients with at least one polyp was not significantly different between the two groups irrespective of the size or the location. Overall, 268 polyps were removed, 130 in the HD+i-Scan group and 138 in the HD group. Among these, three high-grade intraepithelial neoplasia were found in diminutive polyps. CONCLUSION: HD+i-Scan colonoscopy is superior to HD colonoscopy in detecting diminutive polyps on the basis of this prospective randomized-controlled trial.

Endoscopic ultrasonography in preoperative staging of gastric cancer: determination of tumor invasion depth, nodal involvement and surgical resectability.

AIM: Current study was aimed to evaluate the usefulness of EUS in TNM staging of gastric cancer by comparing EUS preoperative staging with pathological findings, and the preliminary exploration of possible reasons for overstaging and understaging phenomenon was especially intended. METHODS: A total of 35 patients with histologically confirmed gastric adenocarcinoma were referred to EUS and staged preoperatively by using the TNM system. The preoperative endosonographic results were compared with the histopathological staging. RESULTS: The overall accuracy of EUS for determination of the T stage was 80.0 %, and for T1, T2, T3, and T4 was 100 %, 71.4 %, 87.5 % and 72.7 %, respectively. For N stage, EUS had the accuracy of 68.6 %, with sensitivity and specificity of 66.7 % and 73.7 %, respectively. Resectability was predicted with sensitivity and specificity of 87.5 % and 100 %, respectively. CONCLUSION: EUS is an accurate staging modality in most cases, with a few exceptions of overstaging and understaging. Patients with gastric cancers can benefit from preoperative EUS staging for establishing individualized therapy. However, EUS criteria to differentiate benign from malignant nodes still need to be further defined by future studies.