Sirtuin 6 regulates macrophage polarization to alleviate sepsis-induced acute respiratory distress syndrome via dual mechanisms dependent on and independent of autophagy.

BACKGROUND AIMS: Sepsis-induced acute respiratory distress syndrome (ARDS) can be mediated by an imbalance in macrophage polarization; however, the underlying mechanisms remain poorly understood. This study aimed to investigate the modulatory role of sirtuin 6 (SIRT6) in macrophage polarization during sepsis-induced ARDS. METHODS: A mouse ARDS model was established using cecal ligation and puncture. Isolated alveolar macrophages (AMs) and lipopolysaccharide (LPS)-stimulated bone marrow-derived macrophages (BMDMs) were adopted as in vitro models. Macrophage polarization was evaluated by measuring M1 and M2 macrophage percentages via flow cytometry and expression of specific markers. The expression of microtubule-associated light chain protein 3I/II and beclin-1 was detected for assessing macrophage autophagy. Binding between specificity protein 1 (SP1) and the target gene promoter was evaluated using a chromatin immunoprecipitation assay. RNA expression was analyzed by quantitative reverse transcription polymerase chain reaction and western blotting. RESULTS: Treatment with the SIRT6 activator UBCS039 significantly alleviated lung injury in the mouse ARDS model and enhanced autophagy and M2 polarization in isolated AMs. M2 polarization and autophagy in LPS-challenged BMDMs were also effectively promoted by UBCS039 treatment or SIRT6 overexpression. An adenosine monophosphate-activated protein kinase inhibitor (Compound C) or autophagy inhibitor (3-methyladenine) partially abrogated M2 polarization mediated by SIRT6 overexpression upon LPS exposure. SIRT6 induced autophagy and M2 polarization of BMDMs partially via its deacetylase activity. SIRT6 inhibited mammalian target of rapamycin transcription by modulating SP1 to promote BMDM M2 polarization, which was independent of autophagy. CONCLUSIONS: SIRT6 promotes M2 polarization of macrophages to alleviate sepsis-induced ARDS in an autophagy-dependent and -independent manner.

Influence of heel design on lower extremity biomechanics and comfort perception in overground running.

The study investigated whether an alteration of the shoe heel curvature would influence lower extremity biomechanics and comfort perception in running. Twenty recreational habitual rearfoot strikers performed five running trials in running shoes with three different heel curvature designs (short-parallel, long-parallel and oblique curvatures). Synchronised force plate and motion capturing systems were used to collect three-dimensional lower extremity joint kinetics and kinematics, followed by subjective comfort perception on the 15 cm Visual Analogue Scale. The results showed that participants wearing oblique and long-parallel curvature shoes exhibited larger initial frontal shoe-ground angle (p= 0.003, p= 0.016) and ankle inversion angle (p= 0.008, p= 0.032) as well as higher maximum sagittal foot slap velocity (p= 0.041, p = 0.011) compared with a short-parallel curvature shoe. When wearing the short-parallel curvature shoe, participants had better rearfoot stability perception than the oblique curvature shoes (p = 0.028). These results suggest that the short parallel curvature shoes had better motion control and stability perception than the other two curvature conditions. However, the design of heel curvature seems to have minimal influence on the cushioning related variables in running.

Effect of shoe wearing time and midsole hardness on ground reaction forces, ankle stability and perceived comfort in basketball landing.

This study examined the effect of wearing time on comfort perception and landing biomechanics of basketball shoes with different midsole hardness. Fifteen basketball players performed drop landing and layup first step while wearing shoes of different wearing time (new, 2-, 4-, 6- and 8-week) and hardness (soft, medium and hard). Two-way ANOVA with repeated measures was performed on GRF, ankle kinematic and comfort perception variables. Increased wearing time was associated with poorer force attenuation and comfort perception during landing activities (p < 0.05). The new shoes had significantly smaller forefoot (2- and 4-week) and rearfoot peak GRF impacts (all time conditions) in drop landing and smaller rearfoot peak GRF impact (6- and 8-week) in layup; shoes with 4-week of wearing time had significantly better perceptions of forefoot cushioning, forefoot stability, rearfoot cushioning, rearfoot stability and overall comfort than the new shoes (p < 0.05). Compared with hard shoes, the soft shoes had better rearfoot cushioning but poorer forefoot cushioning (p < 0.05). Shoe hardness and wearing time would play an influential role in GRF and comfort perception, but not in ankle kinematics. Although shoe cushioning performance would decrease even after a short wearing period, the best comfort perception was found at 4-week wearing time.

[Accuracy of endorectal ultrasonography in preoperative staging of rectal cancer].

OBJECTIVE: To evaluate the accuracy of endorectal ultrasonography in preoperative staging of rectal carcinoma. METHODS: The 319 patients with rectal adenocarcinoma underwent endorectal ultrasonography evaluation from January 2007 to March 2010. There were 175 males and 144 females, and the age of patients were 22-82 year old (median 59 years). According their visiting time, 319 patients were divided into 3 groups (period A: January to December 2007; period B: January to December 2008; and period C: January 2009 to March 2010). All patients underwent endorectal ultrasonography, and the 3 doctors had finished evaluations with 272 cases (Doctor 1, 2, 3 had finished evaluations with 162, 64 and 46 cases respectively). The endorectal ultrasonography staging was compared with the pathology findings based on the surgical specimens in 319 patients who had surgery. RESULTS: Overall accuracy in assessing the level of rectal wall invasion was 67%. The accuracy of uT2 and uT3 were 43% and 81% respectively, and the difference was statistically significant (χ(2) = 30.54, P < 0.01), and the accuracy of uT4a was 59%, which was lower than uT3 (81%,χ(2) = 13.77, P < 0.01). Overall accuracy in assessing nodal involvement in the 311 patients treated with radical surgery was 66%. Staging accuracy tends to improve with experience, the accuracy with Doctor 1 in period C(staging accuracy of T and N were 84% and 81% respectively) were higher than period A(staging accuracy of T and N were 55% and 41% respectively) (χ(2) = 6.65 and 13.27, P < 0.01). CONCLUSIONS: Transrectal ultrasound for preoperative staging of rectal has higher accuracy with mastered ultrasound doctor.

Long Non-coding RNA FENDRR Modulates Autophagy Through Epigenetic Suppression of ATG7 via Binding PRC2 in Acute Pancreatitis.

Acute pancreatitis (AP) is an inflammatory, complicated pancreatic disease, carrying significant morbidity and mortality. However, the molecular and cellular mechanisms involved in AP pathogenesis remain to be elucidated. Here, we explore the role of FOXF1 adjacent non-coding developmental regulatory RNA (FENDRR) in AP progression. Caerulein with or without LPS- induced or taurolithocholic acid 3-sulfate (TLC-S)-induced AP mouse models and cell models were performed for the validation of FENDRR expression in vivo and in vitro, respectively. Histopathological examinations of pancreatic tissues were performed to evaluate the severity of AP. Transmission electron microscopy was utilized to visualize the autophagic vacuoles. siRNA specifically targeting FENDRR was further applied. Flow cytometry was employed to assess cell apoptosis. ELISA, immunoflureoscence, and western blotting analysis were also performed to determine the levels of inflammatory cytokines and autophagy activity. RNA immunoprecipitation (RIP) and chromatin immunoprecipitation (ChIP) assays were carried out to reveal the epigenetic regulation of FENDRR on ATG7. Additionally, silencing FENDRR was also verified in AP mouse models. Higher FENDRR and impaired autophagy were displayed in both AP mouse models and cell models. FENDRR knockdown dramatically attenuated caerulein- or TLC-S-induced AR42J cells apoptosis and autophagy suppression. Further mechanistic experiments implied that the action of FENDRR is moderately attributable to its repression of ATG7 via direct interaction with the epigenetic repressor PRC2. Moreover, the silencing of FENDRR significantly induced the promotion of ATG7, thus alleviating the development of AP in vivo. Our study highlights FENDRR as a novel target that may contribute to AP progression, suggesting a therapeutic target for AP treatment.

Naringin improves sepsis-induced intestinal injury by modulating macrophage polarization via PPARγ/miR-21 axis.

Naringin exhibited various pharmacological activities. However, its biological function and underlying mechanism in regulating macrophage polarization remain elusive. This study aimed to investigate the regulatory network between naringin and macrophage polarization in sepsis-induced intestinal injury. Cecal ligation and puncture (CLP) was used to establish the animal model of sepsis. Chromatin immunoprecipitation and a luciferase reporter assay were used to determine the interplay between peroxisome proliferator-activated receptor γ (PPARγ) and miR-21 promoter, as well as miR-21 and its target genes. Naringin enhanced the overall survival of septic mice and alleviated the CLP-induced inflammatory response and intestinal damage. This was accompanied by the increased expression of PPARγ in the intestines and the stimulation of ileal macrophages toward the M2 phenotype. Furthermore, in lipopolysaccharide-stimulated bone marrow-derived macrophages, naringin stimulated M2 polarization. Mechanistically, PPARγ inhibition attenuated the promotion of M2 polarization caused by naringin, and the naringin/PPARγ regulatory work was compromised by miR-21 inhibition. The present study suggested that naringin promoted M2 polarization via the PPARγ/miR-21 axis, thus relieving sepsis-induced intestinal injury. This study provides novel insights into the mechanism by which naringin alleviated sepsis-induced intestinal injury through regulation of macrophage polarization.

MiR-20b-5p modulates inflammation, apoptosis and angiogenesis in severe acute pancreatitis through autophagy by targeting AKT3.

BACKGROUND: Severe acute pancreatitis (SAP) is a common acute abdominal disease with high morbidity and mortality. However, the mechanism underlying SAP is still unclear. METHODS: Cerulean and LPS (Cer-LPS) was used to establish a rat model and an in vitro model of SAP. qRT-PCR, western blot and IHC were determined to analyse the expression of mRNA and proteins. IL-1ß, TNF-α and IL-6 levels were measured applying ELISA. H&E staining was determined to observe the pathological changes. Apoptosis was tested by AV-PI staining using flow cytometry. CCK8 assay was taken to detect cell viability. Cell migration was assessed by transwell assay. Tube formation assay was conducted to evaluate angiogenesis. Luciferase assay was used to detect relationship of miR-20b-5p and AKT3. RESULTS: MiR-20b-5p was lowly expressed in SAP models both in vivo and in vitro. Overexpression of miR-20b-5p restrained inflammation and apoptosis in Cer-LPS treated pancreatic acinar cells. Furthermore, miR-20b-5p promoted the angiogenesis of vascular endothelial cells, since the viability, migration and the capability of tube formation were increased by miR-20b-5p. Mechanically, miR-20b-5p directly targeted AKT3 to promote autophagy. Furthermore, miR-20b-5p could prevent the inflammation, apoptosis and enhance angiogenesis via enhancing autophagy, which was verified in vivo. CONCLUSION: This study demonstrated miR-20b-5p attenuates SAP through directly targeting AKT3 to regulate autophagy, subsequently inhibit inflammation and apoptosis, and promote angiogenesis. Our findings suggested a novel target of miR-20b-5p for the therapy of SAP.

miR-375 Inhibits Autophagy and Further Promotes Inflammation and Apoptosis of Acinar Cells by Targeting ATG7.

OBJECTIVES: MicroRNAs have been considered to be closely related with the development of severe acute pancreatitis (SAP), and microRNA-375 (miR-375) was believed to be a marker of SAP. We aim to investigate the role of miR-375 in regulating SP. METHODS: Cerulein and lipopolysaccharide were used to establish the models of SAP. AR42J cell line was chosen for study in vitro. Flow cytometry was applied for assessing apoptosis. The contents of inflammatory factors were detected with related enzyme-linked immunosorbent assay and quantitative real-time polymerase chain reaction assays. Hematoxylin and eosin staining was applied to observe the pathological changes of pancreatic tissues. Immunohistochemistry analysis was conducted for investigating the expression of light chain 3. RESULTS: The level of miR-375 in pancreatitis tissues and cell lines was upregulated. Overexpression of miR-375 promoted inflammation and the apoptosis of acinar cells through inhibiting autophagy. The binding site between miR-375 and ATG7 was identified, and miR-375 could directly regulate the ATG7. microRNA-375 suppressed autophagy and promoted inflammation and the apoptosis of acinar cells via targeting ATG7. CONCLUSIONS: We proved that miR-375 could inhibit autophagy and promote inflammation and the apoptosis of acinar cells through regulating ATG7. This study first proves that miR-375 modulates the development of SAP through targeting ATG7.

Cytochrome C Oxidase Assembly Factor 1 Homolog Predicts Poor Prognosis and Promotes Cell Proliferation in Colorectal Cancer by Regulating PI3K/AKT Signaling.

PURPOSE: Colorectal cancer (CRC) is one of the most common malignancies in the world. The prognosis of advanced CRC is still poor. The purpose of this study was to identify a gene expression profile associated with CRC that may contribute to the early diagnosis of CRC and improve patient prognosis. PATIENTS AND METHODS: Five pairs of CRC tissues and paracancerous tissues were used to identify causative genes using microarray assays. The prognostic value of Cytochrome C Oxidase Assembly Factor 1 Homolog (COA1) in CRC was assessed in 90 CRC patients. Loss-of-function assays, cell proliferation assays using Celigo and MTT, colony formation assays, a subcutaneous xenograft mouse model, and apoptosis assays were used to define the effects of downregulation of COA1 in CRC cells in vitro and in vivo. The underlying molecular mechanisms of COA1 in CRC were also investigated. RESULTS: The causative gene COA1 was identified through microarray analysis. COA1 expression in CRC was notably associated with pathologic differentiation, tumor size, and tumor depth. COA1 expression may act as an independent prognostic factor for overall survival of CRC. Knockdown of COA1 inhibited the proliferation of CRC cells in vitro and the tumorigenicity of CRC cells in vivo. Decreased COA1 expression induced apoptosis of CRC cells. Based on the microarray assay results comparing HCT116 cells transfected with lentivirus encoding anti-COA1 shRNA or negative control shRNA, ingenuity pathway analysis (IPA) revealed that the PI3K/AKT signaling pathway was significantly enriched. Moreover, CCND1, mTOR, AKT1, and MDM2 were identified as the downstream genes of COA1. CONCLUSION: These findings demonstrate that COA1 promotes CRC cell proliferation and inhibits apoptosis by regulating the PI3K/AKT signaling pathway. Our results implicate COA1 as a potential oncogene involved in tumor growth and progression of CRC.

The CD40 rs1883832 Polymorphism Affects Sepsis Susceptibility and sCD40L Levels.

Sepsis is a severe and progressive disease characterized by systemic inflammatory response syndrome (SIRS). CD40 serves as a vital link between immune response and inflammation. This study was designed to investigate the potential association between a functional single-nucleotide polymorphism (SNP) of CD40 (rs1883832) and susceptibility to sepsis. We first performed a case-control study to explore the relationship between the CD40 rs1883832 polymorphism and sepsis. CD40 mRNA expression and protein expression were determined by real-time PCR and western blotting, respectively, in peripheral blood mononuclear cells (PBMCs) from sepsis patients and healthy controls. The plasma sCD40L levels in the two groups were measured by ELISA. The results showed that the frequencies of the TT genotype and the CD40 rs1883832 T allele were significantly higher in sepsis patients than in healthy controls. Plasma sCD40L levels were also significantly increased in sepsis patients. In addition, TT genotype carriers among sepsis patients displayed the highest CD40 expression at both the mRNA and protein levels, accompanied by the highest plasma sCD40L concentrations. In conclusion, the CD40 rs1883832 T allele acts as a risk factor for increased susceptibility to sepsis and may be involved in the process of sepsis through regulation of CD40 expression and plasma sCD40L levels.

MicroRNA-22 suppresses the growth, migration and invasion of colorectal cancer cells through a Sp1 negative feedback loop.

MicroRNAs have recently emerged as regulators of many biological processes including cell proliferation, development and differentiation. This study identified that miR-22 was statistically decreased in colorectal cancer clinical specimens and highly metastatic cell lines. Moreover, low miR-22 expression was associated with tumor metastasis, advanced clinical stage and relapse. Consistent with clinical observations, miR-22 significantly suppressed the ability of colorectal cancer cells to growth and metastasize in vitro and in vivo. Sp1 was validated as a target of miR-22, and ectopic expression of Sp1 compromised the inhibitory effects of miR-22. In addition, Sp1 repressed miR-22 transcription by binding to the miR-22 promoter, hence forming a negative feedback loop. Further study has shown that miR-22 suppresses the activity of PTEN/AKT pathway by Sp1. Our present results implicate the newly indentified miR-22/Sp1/PTEN/AKT axis might represent a potential therapeutic target for colorectal cancer.

MiR-92a promotes stem cell-like properties by activating Wnt/ß-catenin signaling in colorectal cancer.

We previously reported the oncogenic function of miR-92a in colorectal cancer. This study identified that miR-92a was upregulated in chemoresistant colorectal cancer cells and tissues. Ectopic expression of miR-92a conferred resistance to 5-fluorouracil-induced apoptosis in vitro, while antagomiR-92a significantly enhanced chemosensitivity in vivo. Moreover, Overexpression of miR-92a promoted the tumor sphere formation and the expression of stem cell markers. MiR-92a overexpression also displayed higher tumourigenesis in vivo. Furthermore, we demonstrated that miR-92a upregulates the Wnt/ß-catenin signaling activity via directly targeting KLF4, GSK3ß and DKK3, which are multiple level negative regulators of the Wnt/ß-catenin signaling cascade. In addition, our results indicate IL-6/STAT3 pathway increases miR-92a expression by directly targeting its promoter, resulting in Wnt/ß-catenin signaling activation and consequent promotion of stem-like phenotypes of colorectal cancer cells. Our present results suggest the essential role of IL-6/STAT3/miR-92a/Wnt/ß-catenin pathway in regulating the stem cell-like traits of colorectal cancer cells and provide a potential target for colorectal cancer therapy.

Protective mechanism of Panax notoginseng saponins on rat hemorrhagic shock model in recovery stage.

To explore protective mechanism of Panax notoginseng saponins (PNS) on rat hemorrhagic shock model in recovery stage. 72 Wistar rats were selected and divided into control group, model group and PNS group with 24 rats in each group. 200 mg/kg PNS was injected intravenously at 60 min of hemorrhagic shock stage in PNS groups. Changes of endotoxin, MPO, IL-6, SOD, MDA and TNF α were observed at 30 and 120 min of recovery stage by ELISA; water content of lung and intestine was detected; HE staining was applied to observe morphological change of intestinal mucosa, kidney, liver and lung; western blot was used to detect intercellular adhesion molecule-1 (ICAM-1) level in lung tissue and intestine tissue. At 30 min and 120 min of recovery stage, MDA, MPO, endotoxin, TNF α and IL-6 levels significantly increased in model group compared with control group, however SOD level significantly decreased, the difference was statistically significant (P < 0.05); PNS dose-dependently decreased MDA, MPO, endotoxin, TNF α and IL-6 levels, and increased SOD level, which was statistically significant (P < 0.05); In results of water content detection, water content in lung tissue and intestine tissue was significantly higher than in control group, however, after being treated with PNS, the water content was significantly decreased; HE staining showed the morphologic change of lung tissue cells; Western blot showed that in lung tissue and intestine tissue, ICAM-1 level in model group was significantly higher than in control group, and it was lower in PNS group than in model group. PNS can increase SOD activity, decrease levels of MDA, endotoxin and MPO, decrease expression of TNF α and IL-6, and decrease water content in lung tissue and intestine tissue. Thus, PNS is protective to rat hemorrhagic shock model by anti oxidative stress and anti-inflammatory pathways, and ICAM-1 may play an important role in the mechanism.

Learning curve of endorectal ultrasonography in preoperative staging of rectal carcinoma.

Accurate preoperative staging of rectal carcinoma is essential for optimal treatment. This study was designed to evaluate the accuracy and learning curve of endorectal ultrasonography (ERUS) in the preoperative staging of rectal carcinoma. We retrospectively analyzed the records of patients with rectal carcinoma who underwent preoperative ERUS followed by curative surgery at the Shanxi Province Tumor Hospital between January, 2007 and March, 2010. The patients were divided into three groups, namely A, B and C, depending on whether the examination was performed between January and December, 2007, between January and December, 2008 or between January, 2009 and March, 2010, respectively. Five physicians with no prior experience in ERUS performed the examinations. We compared the ERUS staging with the pathological findings using the tumor-node-metastasis (TNM) classification. The accuracy of ERUS in T and N staging after each additional consecutive 20 patients was calculated for physicians D, E and F. A total of 319 patients underwent ERUS prior to surgery. There were 38 patients in group A, 135 in group B and 146 in group C. Two of the five physicians performed only 47 of the 319 examinations, whereas the remaining 272 patients were examined by physicians D (n=162), E (n=64) and F (n=46). The overall accuracy in assessing the extent of rectal wall invasion (T) was 67%, with 16% of the cases overstaged and 17% understaged and the accuracy in assessing nodal involvement (N) was 66%, with 11% of the cases overstaged and 23% understaged. The total T and N staging accuracy of physicians D, E and F was 75 and 72%; 59 and 59%; and 50 and 52%, respectively. For physicians D, E and F, the accuracy of T and N staging after each additional 20 patients was calculated and the curve of the accuracy reached a plateau after physician D completed 80 cases. Therefore, ERUS is a valuable tool for assessing the depth of tumor invasion and it appears that after ~80 cases a physician may be considered able to apply it efficiently.

High expression of ZEB1 correlates with liver metastasis and poor prognosis in colorectal cancer.

Zinc finger E-box binding homeobox 1 (ZEB1) has been shown to promote invasion and metastasis in several types of human cancer and to have a prognostic role in certain cancers. However, the clinical significance of ZEB1 in colorectal cancer (CRC) has not been sufficiently investigated. This study aimed to address this issue. In this study, we compared the expression of ZEB1 between CRC tissues and normal adjacent mucosa using quantitative real-time RT-PCR. The association of ZEB1 expression with clinicopathological characteristics was analyzed by appropriate statistical analyses. Kaplan-Meier analysis and Cox proportional hazards regression models were used to investigate the association of ZEB1 expression with survival of patients. The results showed that the relative expression levels of ZEB1 were significantly higher in CRC tissues compared to the normal adjacent mucosa and higher expression of ZEB1 correlated with liver metastasis. Kaplan-Meier analysis indicated that patients with high ZEB1 had a poor overall survival. Moreover, the multivariate analysis showed that high expression of ZEB1 was an independent predictor of overall survival. Our data indicate the potential of ZEB1 as a novel prognostic biomarker for CRC.

[Laparoscopic versus open intersphincteric resection for low rectal cancer: a clinical comparative study].

OBJECTIVE: To compare the clinical and oncological outcomes between laparoscopic and open intersphincteric resection in patients with low rectal cancer. METHODS: From January 2007 to January 2010, patients with low rectal cancer treated by laparoscopic or open intersphincteric resection were included in a retrospective comparative study. Patients were classified into laparoscopy group (n=27) and open group (n=41). The operative procedures, postoperative complications, anal function and clinicopathological data were compared. RESULTS: Compared to the open group, the laparoscopic group had longer operative time [(242.2±42.5) min vs. (199.1±44.3) min, P=0.000], less blood loss [(150.5±102.2) ml vs. (258.4±149.2) ml, P=0.002], faster recovery of bowel function [(2.9±1.1) d vs. (3.6±1.5) d, P=0.032] and resumption of regular diet [(6.6±1.2) d vs. [(7.5±1.7) d, P=0.012], and shorter postoperative hospital stay [(7.7±1.4) d vs. (9.1±2.4) d, P=0.006]. The postoperative complication rate between the laparoscopic and open groups was not significantly different [18.5% (5/27) vs. 19.5% (8/41), P=0.464]. Oncological parameters were comparable between the two groups including lymph node harvested [(14.1±4.1) vs. (16.4±6.8), P=0.113], distal resection margin [(1.4±0.7) cm vs. (1.6±0.8) cm, P=0.311], and circumferential margin [7.4% (2/27) vs. 2.4% (1/41), P=0.709]. Local recurrence rates in laparoscopic and open groups were 7.4% (2/27) and 2.4% (1/41), and distant metastasis rates were 0 and 4.9% (2/41) respectively, and the differences were not significant (both P>0.05). CONCLUSIONS: Laparoscopic intersphincteric resection possesses same efficacy of open intersphincteric resection with less blood loss, shorter recovery time and hospital stay, and similar oncological outcomes, and no increased postoperative morbidity and mortality.

Plasma miR-200c and miR-18a as potential biomarkers for the detection of colorectal carcinoma.

It has been demonstrated that there are abundant stable microRNAs (miRNAs) in plasma/serum, which can be detected and are potentially disease-specific. The aim of this study was to investigate whether plasma miR-200c and miR-18a can be used as biomarkers for the detection of colorectal carcinoma (CRC). This study was divided into three parts: i) confirmation of higher miR-200c and miR-18a levels in primary CRC tissues compared to normal colorectal tissues; ii) evaluation of plasma miR-200c and miR-18a expression by comparing 78 patients with 86 healthy volunteers and iii) comparison of miR-200c and miR-18a levels in paired pre-and post-operative plasma in cancer patients who underwent curative CRC resection. Results showed that the expression of miR-200c and miR-18a was significantly higher in CRC compared to normal tissues. The plasma levels of miR-200c and miR-18a were significantly higher in CRC patients compared to controls. miR-200c yielded an area under the receiver-operating characteristics (ROC) curve (AUC) of 0.749 and miR-18a yielded an AUC of 0.804 when distinguishing CRC patients from the controls. Combined ROC analyses using the two miRNAs revealed an elevated AUC of 0.839 with 84.6% sensitivity and 75.6% specificity in discriminating CRC. Plasma levels of miR-200c and miR-18a were significantly lower in post-operative compared to pre-operative samples. The results of this study suggest that plasma miR-200c and miR-18a are significantly elevated in the plasma of CRC patients and that they may serve as non-invasive molecular markers for CRC screening.

Upregulation of microRNA-155 promotes the migration and invasion of colorectal cancer cells through the regulation of claudin-1 expression.

Human microRNA-155 (miR-155) has been demonstrated to regulate a variety of cellular functions, including epithelial-to-mesenchymal transition (EMT) by targeting multiple messenger RNAs (mRNAs). However, its role in colorectal cancer (CRC) remains unelucidated. Therefore, the aim of the present study was to investigate the effects of miR-155 on CRC cells. The expression level of miR-155 was quantified by quantitative real-time reverse transcriptase-PCR (qRT-PCR) in primary CRC tissues and normal adjacent mucosa. MTT, migration and invasion assays were used to examine the proliferation, migration and invasion of SW480 cells transfected with miR­155. The expression of miR-155 was significantly upregulated in the CRC tissues and the high expression of miR-155 correlated with an advanced clinical stage, lymph node and distant metastases. The ectopic expression of miR-155 enhanced the migration and invasive ability of the SW480 cells and altered their morphological appearance; however, cell proliferation was not affected. E-cadherin expression levels decreased, while ZEB1 expression levels increased in the SW480 cells overexpressing miR-155. Furthermore, the overexpression of miR-155 upregulated claudin-1 expression. Thus, our data suggest that miR-155 plays an important role in promoting CRC cell migration and invasion, at least in part through the regulation of claudin-1 expression and controlling metastasis in CRC.