GCBRGCN: Integration of ceRNA and RGCN to Identify Gastric Cancer Biomarkers

Gastric cancer (GC) is a prevalent malignancy, and the discovery of biomarkers plays a crucial role in the diagnosis and prognosis of GC. However, current strategies for identifying GC biomarkers often focus on a single ribonucleic acid (RNA) class, neglecting the potential for multiple RNA types to collectively serve as biomarkers with improved predictive capabilities. To bridge this gap, our study introduces the GC biomarker relation graph convolution neural network (GCBRGCN) model which integrates the competing endogenous RNA (ceRNA) network with GC clinical informations and whole transcriptomics data, leveraging the relational graph convolutional network (RGCN) to predict GC biomarkers. It demonstrates exceptional performance, surpassing traditional machine learning and graph neural network algorithms with an area under the curve (AUC) of 0.8172 in the task of predicting GC biomarkers. Our study identified three unreported potential novel GC biomarkers: CCNG1, CYP1B1, and CITED2. Moreover, FOXC1 and LINC00324 were characterized as biomarkers with significance in both prognosis and diagnosis. Our work offers a novel framework for GC biomarker identification, highlighting the critical role of multiple types RNA interaction in oncological research.

Role of miR‑181a‑5p in cancer (Review)

MicroRNAs (miRNAs) are non‑coding RNAs (ncRNAs) that can post‑transcriptionally suppress targeted genes. Dysregulated miRNAs are associated with a variety of diseases. MiR‑181a‑5p is a conserved miRNA with the ability to regulate pathological processes, such as angiogenesis, inflammatory response and obesity. Numerous studies have demonstrated that miR‑181a‑5p exerts regulatory influence on cancer development and progression, acting as an oncomiR or tumor inhibitor in various cancer types by impacting multiple hallmarks of tumor. Generally, miR‑181a‑5p binds to target RNA sequences with partial complementarity, resulting in suppression of the targeted genes of miR‑181a‑5p. However, the precise role of miR‑181a‑5p in cancer remains incompletely understood. The present review aims to provide a comprehensive summary of recent research on miR‑181a‑5p, focusing on its involvement in different types of cancer and its potential as a diagnostic and prognostic biomarker, as well as its function in chemoresistance.

Loss of cancer-associated fibroblast-derived exosomal DACT3-AS1 promotes malignant transformation and ferroptosis-mediated oxaliplatin resistance in gastric cancer

AIMS

Long non-coding RNAs (lncRNAs), as one of the components of exosomes derived from cancer-associated fibroblasts (CAFs), exhibit a crucial role in the pathogenesis and chemoresistance of gastric cancer (GC). Herein, we investigated the role and mechanism of a novel lncRNA disheveled binding antagonist of beta catenin3 antisense1 (DACT3-AS1) and its involvement in GC.

METHODS

DACT3-AS1 was identified by RNA-sequencing and verified by quantitative reverse transcription polymerase chain reaction (qRT-PCR). The functional role of DACT3-AS1 in GC was evaluated using in vitro and in vivo experiments including Transwell assay, 5-Ethynyl-2'-deoxyuridine (EdU) assay, immunoblotting, and xenograft tumor mouse model. Dual-luciferase reporter assay was performed to assess the association between genes.

RESULTS

DACT3-AS1 was downregulated and involved in poor prognosis of patients with GC. The results from both in vitro and in vivo experiments showed that DACT3-AS1 suppressed cell proliferation, migration, and invasion through targeting miR-181a-5p/sirtuin 1 (SIRT1) axis. Additionally, DACT3-AS1 was transmitted from CAFs to GC cells mainly via exosomes. Exosomal DACT3-AS1 alleviated xenograft tumor growth. DACT3-AS1 conferred sensitivity of cancer cells to oxaliplatin through SIRT1-mediated ferroptosis both in vitro and in vivo.

CONCLUSIONS

CAFs-derived exosomal DACT3-AS1 is a suppressive regulator in malignant transformation and oxaliplatin resistance. DACT3-AS1 could be used for diagnosis and treatment of GC.

LNCAROD promotes the proliferation and migration of gastric cancer: a bioinformatics analysis and experimental validation

Gastric cancer (GC) is a heterogeneous disease at the molecular and clinical levels. The diffuse subtype is associated with more aggressive behavior and poor prognosis than the intestinal subtype. Epithelial-to-mesenchymal transition (EMT) may be involved in the diffuse mesenchymal phenotype. Long non-coding RNA (lncRNA) deregulation plays a vital role in GC development and progression. Here, we aimed to comprehensively disclose lncRNAs associated with GC diffuse/mesenchymal type. RNA-sequencing expression profiles of patients with stomach adenocarcinoma and the corresponding clinical data were downloaded from The Cancer Genome Atlas database. Differentially expressed lncRNAs related to tumor samples and diffuse subtype were identified. The lncRNA activating regulator of DKK1 (LNCAROD) was experimentally studied. Furthermore, a lncRNA-miRNA-mRNA network was constructed to identify potential biological functions of LNCAROD. LNCAROD expression was detected by reverse transcription-quantitative polymerase chain reaction in GC cell lines. LNCAROD expression was silenced using the small interference RNA strategy. Cell proliferation and migration were evaluated using colony formation assay, scratch wound healing, and Transwell migration assays. LNCAROD was significantly upregulated in some GC cells. The knocking down of LNCAROD significantly reduced cell proliferation and migration. LNCAROD-miR-181-PROX1 axis was introduced as a potential regulatory mechanism by which LNCAROD may exert its functions in cells. Our findings highlight that LNCAROD is involved in cell proliferation and migration in GC and supports its implicit role in regulating EMT. It may serve as a potential diagnostic and therapeutic target in GC. In addition, LNCAROD may function through the possible regulatory axis in GC development.

Identification of common molecular signatures of SARS-CoV-2 infection and its influence on acute kidney injury and chronic kidney disease

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the main cause of COVID-19, causing hundreds of millions of confirmed cases and more than 18.2 million deaths worldwide. Acute kidney injury (AKI) is a common complication of COVID-19 that leads to an increase in mortality, especially in intensive care unit (ICU) settings, and chronic kidney disease (CKD) is a high risk factor for COVID-19 and its related mortality. However, the underlying molecular mechanisms among AKI, CKD, and COVID-19 are unclear. Therefore, transcriptome analysis was performed to examine common pathways and molecular biomarkers for AKI, CKD, and COVID-19 in an attempt to understand the association of SARS-CoV-2 infection with AKI and CKD. Three RNA-seq datasets (GSE147507, GSE1563, and GSE66494) from the GEO database were used to detect differentially expressed genes (DEGs) for COVID-19 with AKI and CKD to search for shared pathways and candidate targets. A total of 17 common DEGs were confirmed, and their biological functions and signaling pathways were characterized by enrichment analysis. MAPK signaling, the structural pathway of interleukin 1 (IL-1), and the Toll-like receptor pathway appear to be involved in the occurrence of these diseases. Hub genes identified from the protein-protein interaction (PPI) network, including DUSP6, BHLHE40, RASGRP1, and TAB2, are potential therapeutic targets in COVID-19 with AKI and CKD. Common genes and pathways may play pathogenic roles in these three diseases mainly through the activation of immune inflammation. Networks of transcription factor (TF)-gene, miRNA-gene, and gene-disease interactions from the datasets were also constructed, and key gene regulators influencing the progression of these three diseases were further identified among the DEGs. Moreover, new drug targets were predicted based on these common DEGs, and molecular docking and molecular dynamics (MD) simulations were performed. Finally, a diagnostic model of COVID-19 was established based on these common DEGs. Taken together, the molecular and signaling pathways identified in this study may be related to the mechanisms by which SARS-CoV-2 infection affects renal function. These findings are significant for the effective treatment of COVID-19 in patients with kidney diseases.

Can mild cognitive impairment and Alzheimer's disease be diagnosed by monitoring a miRNA triad in the blood?

Objectively diagnosing age‐related cognitive impairment (ACI), mild cognitive impairment (MCI), and early‐stage Alzheimer's disease (AD) is a difficult task, as most cognitive impairment is clinically established via questionnaires, history, and physical examinations. A recent study has suggested that monitoring a miRNA triad, miR‐181a‐5p, miR‐146a‐5p, and miR‐148a‐3p can identify ACI and its progression to MCI and AD (Islam et al., EMBO Mol Med. 13: e14997, 2021). This commentary deliberates findings from this article, such as elevated levels of the miRNA triad in the brain impairing neural plasticity and cognitive function, the efficiency of measuring the miRNA triad in the circulating blood diagnosing MCI and AD, and the promise for improving cognitive function in MCI and AD by inhibiting this miRNA triad. Additional studies required prior to employing this miRNA triad in clinical practice are also discussed.

MicroRNAs as potential indicators of the development and progression of uterine leiomyoma

Recent studies demonstrated a significant role of several microRNAs (miRs) in the development of leiomyoma. Here, we investigated miR expression profiles using microarray and found a significantly higher expression of miRs in leiomyoma than in adjacent myometrium. We also confirmed the upregulation of five selected miRs including miR-181a-5p, 127-3p, 28-3p, 30b-5p and let-7c-5p in cellular proliferation, extracellular matrix turnover, and angiogenesis by RT-qPCR. Interestingly, the miRs showed a higher expression in cases of large leiomyoma or in patients with a history of transfusion due to anemia. We then analyzed the expression of the miR target molecules including Transforming Growth Factor Beta Receptor 2 (TGFBR2) and Insulin-like Growth Factor 2 mRNA Binding Protein 1 (IGF2BP1) via immunohistochemistry. TGFBR2 and IGF2BP1 were positively stained in 81% and 62.5% of leiomyoma tissues but not in adjacent myometrium. Both were more frequently positive in patients with ≥ 6 cm leiomyoma and mass effect. The mean expression levels of miR-181a-5p, 127-3p, 28-3p, 30b-5p and let-7c-5p were higher in cases with TGFBR2 and IGF2BP1 positive leiomyoma. We observed several miRs were overexpressed in leiomyoma tissues, and these results provide insight into the role of miRs in the development and progression of leiomyoma and underscore the need to validate their utility as diagnostic or therapeutic targets.

Identification of hub Genes in the Pathogenesis of Ischemic Stroke Based on Bioinformatics Analysis

Objective

The present study aimed to identify the function of ischemic stroke (IS) patients’ peripheral blood and its role in IS, explore the pathogenesis, and provide direction for clinical research progress by comprehensive bioinformatics analysis.

Methods

Two datasets, including GSE58294 and GSE22255, were downloaded from Gene Expression Omnibus database. GEO2R was utilized to obtain differentially expressed genes (DEGs). Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis of DEGs were performed using the database annotation, visualization and integrated discovery database. The protein-protein interaction (PPI) network of DEGs was constructed by search tool of searching interactive gene and visualized by Cytoscape software, and then the Hub gene was identified by degree analysis. The microRNA (miRNA) and miRNA target genes closely related to the onset of stroke were obtained through the miRNA gene regulatory network.

Results

In total, 36 DEGs, containing 27 up-regulated and nine down-regulated DEGs, were identified. GO functional analysis showed that these DEGs were involved in regulation of apoptotic process, cytoplasm, protein binding and other biological processes. KEGG enrichment analysis showed that these DEGs mediated signaling pathways, including HTLV-I infection and microRNAs in cancer. The results of PPI network and cytohubba showed that there was a relationship between DEGs, and five hub genes related to stroke were obtained : SOCS3, KRAS, PTGS2, EGR1, and DUSP1. Combined with the visualization of DEG-miRNAs, hsa-mir-16-5p, hsa-mir-181a-5p and hsa-mir-124-3p were predicted to be the key miRNAs in stroke, and three miRNAs were related to hub gene.

Conclusion

Thirty-six DEGs, five Hub genes, and three miRNA were obtained from bioinformatics analysis of IS microarray data, which might provide potential targets for diagnosis and treatment of IS.

Effects of lncRNA ANRIL-knockdown on the proliferation, apoptosis and cell cycle of gastric cancer cells

Gastric cancer is one of the most common types of malignant tumor of the gastrointestinal tract worldwide. Cisplatin (DDP) is a commonly used chemotherapeutic drug in the clinic; however, the resistance of gastric cancer cells to DDP limits its efficacy. In the present study, drug-resistant gastric cancer cell lines were constructed using the stepwise continuous selection method, and the relative expression levels of long non-coding RNA (lncRNA) CDKN2B antisense RNA 1 (ANRIL) and microRNA (miR)-181a-5p were detected using reverse transcription-quantitative PCR. The knockdown of lncRNA ANRIL and miR-181a-5p expression was performed by transfection with shRNA-ANRIL and an miR-181a-5p inhibitor, respectively. Cellular proliferation and sensitivity to DDP were assessed using Cell Counting Kit-8 analysis. Cell apoptosis and cell cycle distribution were assessed using flow cytometry and western blotting. The binding relationships between ANRIL, miR-181a-5p and cyclin G1 (CCNG1) were verified using a dual luciferase reporter assay. The results revealed that the expression levels of miR-181a-5p were downregulated in all drug-resistant cell lines. ANRIL-knockdown inhibited cellular proliferation, and promoted apoptosis and cell cycle arrest; however, following the knockdown of miR-181a-5p, the inhibition of cell cycle arrest was alleviated. Notably, miR-181a-5p, ANRIL and CCNG1 were found to have targeting relationships. In conclusion, the findings of the present study suggested that knocking down the expression of ANRIL inhibited cellular proliferation, and promoted apoptosis and cell cycle arrest. Furthermore, its downstream target, miR-181a-5p, inhibited the proliferation of drug-resistant cells and enhanced their sensitivity to DDP.

MiR-181 Family Modulates Osteopontin in Glioblastoma Multiforme

Simple Summary

MicroRNAs can silence a broad set of target genes that may benefit heterogeneous tumors like glioblastoma. We have previously shown that osteopontin has an oncogenic role and may have immune modulatory effects on macrophages. In the current study, we used miRNAs to target osteopontin in tumor cells and modulate immune cells to elicit an antitumor effect. Intravenous delivery of miR-181a to immune competent mice bearing intracranial glioblastoma demonstrated a 22% increase in median survival duration relative to that of control mice. The overexpression of miR-181a in tumor cells led to decreased OPN production and proliferation and increased apoptosis in vitro, and increased survival duration of the mice when compared to its controls. miR-181a controls osteopontin expression in tumor cells by regulating their proliferation and apoptosis.

Abstract

MiRNAs can silence a wide range of genes, which may be an advantage for targeting heterogenous tumors like glioblastoma. Osteopontin (OPN) plays both an oncogenic role in a variety of cancers and can immune modulate macrophages. We conducted a genome wide profiling and bioinformatic analysis to identify miR-181a/b/c/d as potential miRNAs that target OPN. Luciferase assays confirmed the binding potential of miRNAs to OPN. Expression levels of miR-181a/b/c/d and OPN were evaluated by using quantitative real-time PCR and enzyme-linked immunosorbent assay in mouse and human glioblastomas and macrophages that showed these miRNAs were downregulated in Glioblastoma associated CD11b+ cells compared to their matched blood CD14b+ cells. miRNA mimicking and overexpression using lentiviruses showed that MiR-181a overexpression in glioblastoma cells led to decreased OPN production and proliferation and increased apoptosis in vitro. MiR-181a treatment of immune competent mice bearing intracranial glioblastoma demonstrated a 22% increase in median survival duration relative to that of control mice.

Increased expression of plasma hsa-miR-181a in male patients with heroin addiction use disorder

BACKGROUND

Drug addiction is an uncontrolled, chronic, and recurrent encephalopathy that presently lacks specific and characteristic biomarkers for diagnosis and treatment. As regulators of gene expression, microRNAs (miRNAs) are increasingly used for diagnostic and prognostic purposes in various disease states. Previous studies indicated that miRNAs play important roles in the development and progression of drug addictions, including addiction to methamphetamine, cocaine, alcohol, and heroin.

METHODS

We identified significant miRNAs using the microarray method and then validated the hsa-miR-181a expression levels in 53 heroin addiction patients and 49 normal controls using quantitative real-time reverse transcription-polymerase chain reaction (qRT-PCR). Finally, the potential associations between transcriptional levels in heroin addiction patients and their clinicopathological features were analyzed.

RESULTS

A total of 2006 miRNAs were differentially expressed between heroin addiction patients and normal controls. The top 10 up-regulated miRNAs in patients were hsa-miR-21a, hsa-miR-181a, hsa-miR-4459, hsa-miR-4430, hsa-miR-4306, hsa-miR-22-3P, hsa-miR-486-5P, hsa-miR-371b-5P, hsa-miR-92a-3P, and hsa-miR-5001-5P. The top 10 down-regulated miRNAs in patients were hsa-miR-3195, hsa-miR-4767, hsa-miR-3135b, hsa-miR-6087, hsa-miR-1181, hsa-miR-4785, hsa-miR-718, hsa-miR-3141, hsa-miR-652-5P, and hsa-miR-6126. The expression level of hsa-miR-181a in heroin addiction patients was significantly increased compared with that in normal controls (P < .001). The area under the receiver operating characteristic curve of hsa-miR-181a was 0.783, the sensitivity was 0.867, and the specificity was 0.551.

CONCLUSIONS

The increased expression of hsa-miR-181a in the plasma of heroin patients may be a consequence of the pathological process of heroin abuse. This study highlights the potential of hsa-miR-181a as a novel biomarker for the diagnosis of heroin addiction.

Expression patterns of seven key genes, including β-catenin, Notch1, GATA6, CDX2, miR-34a, miR-181a and miR-93 in gastric cancer

Gastric cancer (GC) is one of the most prevalent cancers and a major cause of cancer related mortality worldwide. Incidence of GC is affected by various factors, including genetic and environmental factors. Despite extensive research has been done for molecular characterization of GC, it remains largely unknown. Therefore, further studies specially conducted among various ethnicities in different geographic locations, are required to know the precise molecular mechanisms leading to tumorigenesis and progression of GC. The expression patterns of seven candidate genes, including β-catenin, Notch1, GATA6, CDX2, miR-34a, miR-181a, and miR-93 were determined in 24 paired GC tissues and corresponding non-cancerous tissues by quantitative Real-Time PCR. The association between the expression of these genes and clinicopathologic factors were also investigated. Our results demonstrated that overall mRNA levels of GATA6 were significantly decreased in the tumor samples in comparison with the non-cancerous tissues (median fold change (FC) = 0.3143; P = 0.0003). Overall miR-93 levels were significantly increased in the tumor samples relative to the non-cancerous gastric tissues (FC = 2.441; P = 0.0002). β-catenin mRNA expression showed a strong positive correlation with miR-34a (r = 0.5784; P = 0.0031), and miR-181a (r = 0.5652; P = 0.004) expression. miR-34a and miR-181a expression showed a significant positive correlation (r = 0.4862; P = 0.016). Moreover, lower expression of Notch1 was related to distant metastasis in GC patients with a borderline statistical significance (p = 0.0549). These data may advance our understanding of the molecular biology that drives GC as well as provide potential targets for defining novel therapeutic strategies for GC treatment.

FBXL3 is regulated by miRNA-4735-3p and suppresses cell proliferation and migration in non-small cell lung cancer

Non-small cell lung cancer (NSCLC) is the most common type of primary lung cancer and regarded as cancer killer. The aim of this study was to discover the detailed function and molecular mechanism of F-box and leucine rich repeat protein 3 (FBXL3) in NSCLC. In this study, the expression level of FBXL3 in NSCLC tissues and cell lines was firstly examined and identified. Moreover, the relationship between FBXL3 and the overall survival rate of NSCLC patients was analyzed by Kaplan-Meier survival curve. Functionally, MTT, colony formation assay and transwell assays were performed to determine the role of FBXL3 in regulating NSCLC cell proliferation, migration and invasion. The proliferation and migration were suppressed by overexpression of FBXL3, indicating the potential tumor suppressive role of FBXL3 in NSCLC. In addition, the dual-luciferase reporter and RNA pull-down assays revealed that miR-4735-3p was a novel upstream modulator of FBXL3. Further study showed that miR-4735-3p was upregulated in NSCLC tissues and cell lines. Finally, rescue assays and function assays revealed that miR-4735-3p exerted oncogenic function in NSCLC, and this function can be attenuated by FBXL3. Taken together, FBXL3 was regulated by miR-4735-3p and suppressed cell proliferation and invasion in non-small cell lung cancer.

A panel of seven-miRNA signature in plasma as potential biomarker for colorectal cancer diagnosis

Colorectal cancer (CRC) has been one of the most commonly diagnosed cancers in global. The differential expression profiles of microRNAs (miRNAs) in CRC plasma of patients have the potential to serve as a diagnostic biomarker. We conducted a four-stage study to identify the potential plasma miRNAs for CRC detection. In the initial screening phase, Exiqon panel (miRCURY-Ready-to-Use-PCR-Human-panel-I + II-V1.M) including 3 CRC pools and 1 normal controls (NCs) pool were applied to acquire miRNA profiles. In the training stage (30 CRC VS. 30 NCs) and testing stage (79 CRC VS. 76 NCs), quantitative real-time polymerase chain reaction (qRT-PCR) was utilized to conduct candidate miRNA profiles. Then the identified miRNAs were verified in external validation stage (30 CRC VS. 26 NCs). Expression levels of identified miRNAs were assessed in tissue samples (24 pairs) and plasma exosomes (18 CRC VS. 18 NCs). Receiver operating characteristic (ROC) curves were constructed to evaluate the diagnostic accuracy. Seven miRNAs (miR-103a-3p, miR-127-3p, miR-151a-5p, miR-17-5p, miR-181a-5p, miR-18a-5p and miR-18b-5p) were significantly overexpressed in CRC compared with NCs. Area under the ROC curve of the seven-miRNA signature was 0.762, 0.824 and 0.895 for the training, testing and the external validation stages, respectively. Additionally, miR-103a-3p, miR-127-3p, miR-17-5p and miR-18a-5p were discovered significantly up-regulated in CRC tissues; while miR-17-5p, miR-181a-5p, miR-18a-5p and miR-18b-5p were significantly elevated in CRC plasma exosomes. In conclusion, we established a seven-miRNA signature in the peripheral plasma for CRC detection.

The Role of MicroRNA-181a in Myocardial Fibrosis Following Myocardial Infarction in a Rat Model

Background

The role of miR-181a in the development of cardiac disease and in particular, myocardial fibrosis following myocardial infarction (MI) remains unknown. The aim of this study was to explore the role of miR-181a in myocardial fibrosis in a rat model of MI and the expression of TGF-β receptor III (TβRIII).

Material/Methods

Forty adult male Wistar rats were randomly divided into an MI model group (n=30) and a control group with (n=10). The rat MI model involved ligating the left anterior descending (LAD) coronary artery in the model group; the control group was treated with a sham operation. Cardiac function was assessed using cardiac ultrasound. Myocardial fibroblasts were extracted from the rat hearts and transfected with a miR-mimic or miR-inhibitor, and cell growth was measured using an MTT assay. The level of miR-181a expression was detected using quantitative reverse transcription polymerase chain reaction (qRT-PCR) and Western blots.

Results

miR-181a expression was significantly increased during the progression of MI (P<0.05). Over-expression of miR-181a was associated with increased deposition of extracellular matrix (ECM) components, collagen I and fibronectin. This effect was reversed with the use of a miR-181a inhibitor (P<0.05). Upregulation of miR-181a suppressed the expression of TGF-β receptor III (TβRIII) by binding with 3′-UTR.

Conclusions

In this rat model of MI, the findings were that miR-181a had a role in the progression of myocardial fibrosis. The findings require further studies to determine whether miR-181a might provide a novel therapeutic target to limit myocardial fibrosis following MI.

miR-181a-5p Promotes Proliferation and Invasion and Inhibits Apoptosis of Cervical Cancer Cells via Regulating Inositol Polyphosphate-5-Phosphatase A (INPP5A)

Expression of miR-181a-5p associates with the proliferation and progression of cancer cells via its targets. This study was designed to investigate the effect of miR-181a-5p and its target inositol polyphosphate-5-phosphatase A (INPP5A) on the progression of cervical cancers. Upregulation of miR-181a-5p was revealed in the cervical cancer cell lines HeLa and SiHa in comparison with a normal cervical epithelium cell line End1/E6E7 (p < 0.001). The inhibition and upregulation of miR-181a-5p in cervical cancer cell lines significantly reduced or increased cell proliferation and invasion capacity, accompanied with enhanced or reduced apoptosis (p < 0.05). Moreover, INPP5A overexpression significantly inhibited cell proliferation and invasion capacity and enhanced cell apoptosis. The target relationship of miR-181a-5p to INPP5A was demonstrated by both the results of the Dual-Luciferase Reporter Assay and the fact that the miR-181a-5p mimic attenuated INPP5A's effect on cell proliferation, invasion, and apoptosis. To sum up, the overexpression of miR-181a-5p enhanced cell proliferation and invasion and inhibited apoptosis of cervical cancer cells by negatively targeting INPP5A. Therefore, inhibition of miR-181a-5p might benefit the inhibition of cervical cancer cell invasion.

MiR-129-5p functions as a tumor suppressor in gastric cancer progression through targeting ADAM9

MicroRNAs (miRNAs) are identified as key regulators in cancer initiation, progression and metastasis including gastric cancer (GC). The aim of the study is to explore clinical significance and potential mechanism of miR-129-5p in GC development. In the study, our results found that miR-129-5p expression was significantly downregulated in GC tissues, compared with adjacent normal tissues using qRT-PCR analyses. Furthermore, lower miR-129-5p expression closely associated with tumor size and lymph node invasion and poor prognosis of GC patients. Using CCK8 assay, cell colony formation, transwell invasion assay, we demonstrated that miR-129-5p overexpression reduced cell proliferation, cell colony formation and cell invasion capacity in MKN45 (higher miR-129-5p expression) and SGC-7901 (lower miR-129-5p expression). However, downregulation of miR-129-5p had reverse effects on cell proliferation and invasion. Targeting association analysis, dual luciferase assay, qRT-PCR and western blot analysis results verified that miR-129-5p could target the 3'UTR of ADAM9 mRNA and regulated its protein expression. Furthermore, we confirmed that miR-129-5p suppressed cell proliferation and invasion ability through regulating ADAM9. In vivo, upregulation of miR-129-5p also inhibited tumor growth. Therefore, these results indicated that miR-129-5p functioned as a tumor suppressor in GC and may be a potential target of GC treatment.

Identification of four plasma microRNAs as potential biomarkers in the diagnosis of male lung squamous cell carcinoma patients in China

Dysregulated microRNAs (miRNAs) in the plasma of patients with lung squamous cell carcinoma (LSCC) might serve as biomarkers for LSCC diagnosis. The expression of miRNAs was performed using quantitative reverse transcription-polymerase chain reaction (qRT-PCR) on the basis of Exiqon panels in the initial screening phase including three male LSCC pool samples and one normal control (NC) pool sample (per 10 samples were pooled as one pool sample). After the training (32 LSCC vs. 31 NCs), the testing (55 LSCC vs. 55 NCs), and the external validation (15 LSCC vs. 15 NCs) stages via qRT-PCR, a four-miRNA signature (miR-181a-5p, miR-21-5p, miR-106a-5p, and miR-93-5p) was identified for LSCC detection. Areas under the receiver operating characteristic (ROC) curve (AUC) of the four-miRNA panel for the training, the testing, and the external validation phases were 0.795, 0.827, and 0.914, respectively. Then, the four miRNAs were explored in LSCC tissue samples (23 LSCC vs. 23 NCs), and their expression was significantly up-regulated. However, none of the four miRNAs found significantly up-regulated in plasma exosomes expect miR-93-5p with borderline significance (16 LSCC vs. 16 NCs). In summary, our study established a four-miRNA peripheral plasma signature, which contributed to diagnosing male LSCC patients in China to a certain degree.

microRNA‑181a‑5p functions as an oncogene in renal cell carcinoma

Renal cell carcinoma (RCC) is one of the most common urinary tumors. Previous studies have demonstrated that microRNA (miR)‑181a‑5p has an important role in numerous types of cancer. However, the function of miR‑181a‑5p in RCC remains unknown. In the present study, the expression levels of miR‑181a‑5p in RCC tissues and cell lines were investigated using reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR) analysis. The results of the RT‑qPCR analyses suggested that the expression of miR‑181a‑5p was upregulated in RCC tissues and cells lines compared with adjacent normal renal tissues and normal renal cell lines. Furthermore, the effect of miR‑181a‑5p on cell proliferation, migration, invasion and apoptosis was investigated in the present study. Overexpression of miR‑181a‑5p was revealed to suppress the apoptosis of 786‑O and ACHN cells, in addition to enhancing the proliferation, migration and invasion abilities of 786‑O and ACHN cells in vitro, thus suggesting that miR‑181a‑5p may function as an oncogene in RCC. However, further studies are required to investigate the underlying mechanism of miR‑181a‑5p and its potential role as a biomarker for early detection and prognosis, in addition to as a therapeutic target in RCC.

MiR-133b inhibits proliferation and invasion of gastric cancer cells by up-regulating FBN1 expression

We aimed to investigate the influence of miR-133b/fibrillin 1 (FBN1) on proliferation and invasion of human gastric cancer (GC) cells. Carcinomatous and adjacent tissues of 43 GC patients, normal gastric mucosa cell line GES-1 and GC cell lines including AGS, HGC-27, KATO III, NCI-N87, SGC-7901, MKN-45 and MGC-803 were collected. Then, the expressions of miR-133b and FBN1 were detected by qRT-PCR. The dual luciferase reporter gene assay was conducted to determine the targeting relationship between miR-133b and FBN1.The protein expression levels of FBN1, β-catenin, Cyclin D1, C-myc and MMP-7 were detected by Western Blot. Furthermore, the cell viability, proliferation, migration and invasion ability were measured by CCK-8, colony formation assay, wound healing assay and Transwell assay, respectively. MiR-133b was down-regulated in GC tissues and cells compared with adjacent tissues and normal cells. Conversely, FBN1 was up-regulated in GC tissues and cells in contrast with adjacent tissues and normal cells. MGC-803 and MKN-45 cell lines were chosen to conduct the following assays. The luciferase reporter assay proved that miR-133b directly targeted FBN1. The overexpression of miR-133b and silence of FBN1 could inhibit the cell proliferative, migratory and invasive abilities of GC cells, while the influence of down-regulated miR-133b expression and up-regulated FBN1 expression were quite the contrary. Compared with NC group, in the miR-133b mimics group, the expression of β-catenin, N-cadherin and Wnt1 of Wnt/β-catenin signal pathway increased, while the expressions of E-cadherin decreased. MiR-133b inhibits the proliferative, migratory and invasive abilities of GC cells by increasing FBN1 expression.

Gene Expression Analysis of the Effect of Ischemic Infarction in Whole Blood

Given the abundance of stroke patients and deaths from stroke worldwide, many studies concerning the aftermath of stroke are being carried out. To reveal the precise effect of ischemic infarction, we conducted a comprehensive gene expression analysis. Alongside a middle cerebral artery occlusion (MCAO) Sprague–Dawley rat model, we used a group undergoing sham surgery for comparison, which was the same as MCAO surgery but without blood vessel occlusion. Subsequently, infarction of the brains of MCAO-treated rats occurred, but did not occur in the sham-treated rats. Using whole blood, we carried out DNA microarray analysis, revealing the gene expression alterations caused by stroke. Downregulation of immune pathways and cluster of differentiation (CD) molecules indicated immunodepression. By conducting miRNA microarray analysis, we extracted seven miRNAs as significantly regulated: miR-107-5p, miR-383-5p, miR-24-1-5p, mir-191b, miR-196b-5p, and miR-3552 were upregulated, and mir-194-1 was downregulated. Among these seven miRNAs, three had one target mRNA each that was extracted as differentially expressed, and the expression levels of all pairs were inversely correlated. This indicates the occurrence of miRNA–mRNA regulatory systems in blood: between miR-107-5p and H2A histone family member Z (H2afz), miR-196b-5p and protein tyrosine phosphatase receptor type C (Ptprc), and miR-3552 and serine/arginine-rich splicing factor 2 (Srsf2). Moreover, six miRNAs had matching human miRNAs with similar sequences, which are potential human stroke biomarkers.

miR-181a decelerates proliferation in cutaneous squamous cell carcinoma by targeting the proto-oncogene KRAS

Cutaneous squamous cell carcinoma (SCC) is the second most common human skin cancer with a rapidly increasing incidence among the Caucasian population. Among the many regulators, responsible for cancer progression and growth, microRNAs (miRNA) are generally accepted as key players by now. In our current study we found that microRNA-181a (miR-181a) shows low abundance in SCC compared to normal epidermal skin. In vitro, miRNA downregulation in normal primary keratinocytes induced increased proliferation, while in vivo miR-181a downregulation in HaCaT normal keratinocytes showed tumor-like growth increase up to 50%. Inversely, upregulation of these miRNAs in cancer cells lead to reduced cellular proliferation and induction of apoptosis in vitro. An in vivo therapeutic model with induced miR-181a expression in SCC13 cancer cells reduced tumor formation in mice by 80%. Modulation of miR-181a levels showed an inverse correlation with the proto-oncogene KRAS both on mRNA and protein level by direct interaction. Knockdown of KRAS mimicked the anti-proliferative effects of miR-181a overexpression in patient-derived SCC cells and abolished the enhanced viability of HaCaT cells following miR-181a knockdown. Furthermore, phospho-ERK levels correlated with KRAS levels, suggesting that the observed effects were mediated via the MAPK signaling pathway. miR-181a seemed regulated during keratinocyte differentiation probably in order to amplify the tumor suppressive character of differentiation. Taken together, miR-181a plays a crucial tumor suppressive role in SCC by targeting KRAS and could be a promising candidate for a miRNA based therapy.

miR-181a involves in the hippocampus-dependent memory formation via targeting PRKAA1

Post-transcriptional gene regulation by microRNAs (miRNAs) is involved in memory formation. However, the roles of individual miRNAs in these processes remain largely unknown. In this study, we want to clarify the role of miR-181a in hippocampus-dependent memory formation. A transient increase in miR-181a expression was observed after conditioned fear conditioning (CFC) and object location task (OLT) training. Selective overexpression or inhibition of miR-181a in the dorsal hippocampus (DH) via the injection of a miR-181a agomir or antagomir enhanced or impaired the CFC- and OLT-dependent memory formation, respectively. Using bioinformatics and luciferase assays, we identified PRKAA1 as a potential target gene of miR-181a. After CFC or OLT training, the expression and activity of PRKAA1 decreased as miR-181a expression increased and was effectively blocked by the miR-181a antagomir. Moreover, microinjection of the PRKAA1 agonist AICAR or inhibitor compound C in the DH reversed the roles of the miR-181a agomir or antagomir in CFC- and OLT-dependent memory formation. In conclusion, this work provides novel evidence describing the role and mechanism of miR-181a in hippocampus-dependent memory formation, which sheds light on the potential regulation of cognition and future treatments for cognitive disorders.

MEG2 is regulated by miR-181a-5p and functions as a tumour suppressor gene to suppress the proliferation and migration of gastric cancer cells

BACKGROUND

Protein-tyrosine phosphatase MEG2 (MEG2) is a classic tyrosine-specific protein tyrosine phosphatase (PTP). It has been reported that MEG2 participates in the carcinogenesis of the breast and liver. However, functions of MEG2 in gastric cancer remain poorly understood.

METHODS

We examined the expression of MEG2 protein by western blotting and that of miR-181a-5p by qRT-PCR. We used bioinformatic analyses to search for miRNAs that potentially target MEG2. We performed a luciferase reporter assay to investigate the interaction between miR-181a-5p and MEG2. In addition, we assessed the effects of MEG2 and miR-181a-5p on gastric cancer cells in vitro and in vivo.

RESULTS

We found that MEG2 is downregulated in human gastric cancer and that miR-181a-5p is predicted to be a potential regulator of MEG2. We also observed that expression of MEG2 is reversely correlated with that of miR-181a-5p in gastric cancer. Moreover, we observed that MEG2 regulation by miR-181a-5p significantly suppresses the proliferation and migration of gastric cancer cells in vitro and decelerates tumour growth in vivo.

CONCLUSIONS

Our results revealed that MEG2 is a tumour suppressor gene and negatively regulated by miR-181a-5p in gastric cancer.

MicroRNA-34 dysregulation in gastric cancer and gastric cancer stem cell

Gastric cancer is a major cause of cancer mortality worldwide, with a low survival rate for patients with advanced forms of the disease. Over the recent decades, the investigation of the pathophysiological mechanisms of tumourigenesis has opened promising avenues to understand some of the complexities of cancer treatment. However, tumour regeneration and metastasis impose great difficulty for gastric cancer cure. In recent years, cancer stem cells - a small subset of tumour cells in many cancers - have become a major focus of cancer research. Cancer stem cells are capable of self-renewal and are known to be responsible for tumour initiation, metastasis, therapy resistance and cancer recurrence. Recent studies have revealed the key role of microRNAs - small noncoding RNAs regulating gene expression - in these processes. MicroRNAs play crucial roles in the regulation of a wide range of biological processes in a post-transcriptional manner, though their expression is dysregulated in most malignancies, including gastric cancer. In this article, we review the consequences of aberrant expression of microRNA-34 in cancer and cancer stem cells, with a specific focus on the miR-34 dysregulation in gastric cancer and gastric cancer stem cells. We address the critical effects of the aberrant expression of miR-34 and its target genes in maintaining cancer stem cell properties. Information collection and discussion about the advancements in gastric cancer stem cells and microRNAs can be useful for providing novel insights into patient treatment.

Epigenetic modulation associated with carcinogenesis and prognosis of human gastric cancer

Gastric cancer (GC) is a leading cause of cancer-related death, particularly in Asia. Epidemiological and other clinical studies have identified an association between a number of risk factors, including Helicobacter pylori, and GC. A number of studies have also examined genetic changes associated with the development and progression of GC. When considering the clinical significance of the expression of a specific gene, its epigenetic modulation should be considered. Epigenetic modulation appears to be a primary driver of changes in gastric tissue that promotes carcinogenesis and progression of GC and other neoplasms. The role of epigenetic modulation in GC carcinogenesis and progression has been widely studied in recent years. In the present review, recent results of epigenetic modulation associated with GC and their effects on clinical outcome are examined, with particular respect to DNA methylation, histone modulation and non-coding RNA. A number of studies indicate that epigenetic changes in the expression of specific genes critically affect their clinical significance and further study may reveal epigenetic changes as the basis for targeted molecular therapy or novel biomarkers that predict GC prognosis or extension of this often fatal disease.

miR-181a modulates proliferation, migration and autophagy in AGS gastric cancer cells and downregulates MTMR3

MicroRNAs (miRs) have emerged as crucial regulators of tumorigenesis by regulating post-transcriptional gene expression. miR-181a was previously demonstrated to be overexpressed in human gastric cancer tissues and cell lines, whereas MTMR3 was underexpressed. The MTMR3 gene was identified as a direct target of miR-181a. However, its functional role in gastric cancer remains to be established. In the present study, miR-181a was demonstrated to inhibit MTMR3 expression in AGS cells. Ectopic expression of miR-181a mimics or introduction of MTMR3 small interfering RNA resulted in an increase in cell proliferation, colony formation, migration, invasion, as well as suppression of apoptosis. Further investigation in the present study indicated that overexpression of miR-181a, or depletion of MTMR3, attenuated starvation-induced autophagy in AGS cells. In addition, inhibition of endogenous miR-181a led to stimulation of autophagic activity. Collectively, these data suggest that miR-181a is a novel regulator of gastric cancer progression and autophagy, and miR-181a modulation may be a potential strategy for the development of miRNA-based therapeutics for gastric cancer.

miR-181a-5p promotes the progression of gastric cancer via RASSF6-mediated MAPK signalling activation

We previously discovered that Ras association domain family member 6 (RASSF6) was downregulated and predicted poor prognosis in GC patients. However, the mechanisms of the down regulation of RASSF6 in GC remained unclear. Increasing evidence indicates that dysregulation of microRNAs promotes the progression of cancer through the repression of tumour suppressors. Here, we identified miR-181a-5p as a novel regulator of RASSF6 in GC. Functionally, ectopic expression or silencing of miR-181a-5p, respectively, promoted or inhibited GC cell proliferation, colony formation and cell cycle transition, as well as enhanced or prevented the invasion, metastasis of GC cells and epithelial to mesenchymal transition of GC cells in vitro and in vivo. Molecularly, miR-181a-5p functioned as an onco-miRNA by activating the RASSF6-regulated MAKP pathway. Overexpression or silencing of RASSF6 could partially reverse the effects of the overexpression or repression of miR-181a-5p on GC progress caused by activation of the MAKP pathway in vitro and in vivo. Clinically, high miR-181a-5p expression predicted poor survival in GC patients, especially combined with low RASSF6 expression. Collectively, we identified miR-181a-5p as an onco-miRNA, which acts by directly repressing RASSF6 in GC.

Grouping miRNAs of similar functions via weighted information content of gene ontology

Background

Regulation mechanisms between miRNAs and genes are complicated. To accomplish a biological function, a miRNA may regulate multiple target genes, and similarly a target gene may be regulated by multiple miRNAs. Wet-lab knowledge of co-regulating miRNAs is limited. This work introduces a computational method to group miRNAs of similar functions to identify co-regulating miRNAsfrom a similarity matrix of miRNAs.

Results

We define a novel information content of gene ontology (GO) to measure similarity between two sets of GO graphs corresponding to the two sets of target genes of two miRNAs. This between-graph similarity is then transferred as a functional similarity between the two miRNAs. Our definition of the information content is based on the size of a GO term’s descendants, but adjusted by a weight derived from its depth level and the GO relationships at its path to the root node or to the most informative common ancestor (MICA). Further, a self-tuning technique and the eigenvalues of the normalized Laplacian matrix are applied to determine the optimal parameters for the spectral clustering of the similarity matrix of the miRNAs.

Conclusions

Experimental results demonstrate that our method has better clustering performance than the existing edge-based, node-based or hybrid methods. Our method has also demonstrated a novel usefulness for the function annotation of new miRNAs, as reported in the detailed case studies.

NanoStringDiff: a novel statistical method for differential expression analysis based on NanoString nCounter data

The advanced medium-throughput NanoString nCounter technology has been increasingly used for mRNA or miRNA differential expression (DE) studies due to its advantages including direct measurement of molecule expression levels without amplification, digital readout and superior applicability to formalin fixed paraffin embedded samples. However, the analysis of nCounter data is hampered because most methods developed are based on t-tests, which do not fit the count data generated by the NanoString nCounter system. Furthermore, data normalization procedures of current methods are either not suitable for counts or not specific for NanoString nCounter data. We develop a novel DE detection method based on NanoString nCounter data. The method, named NanoStringDiff, considers a generalized linear model of the negative binomial family to characterize count data and allows for multifactor design. Data normalization is incorporated in the model framework through data normalization parameters, which are estimated from positive controls, negative controls and housekeeping genes embedded in the nCounter system. We propose an empirical Bayes shrinkage approach to estimate the dispersion parameter in the model and a likelihood ratio test to identify differentially expressed genes. Simulations and real data analysis demonstrate that the proposed method performs better than existing methods.

Clinical observation on recombinant human endostatin combined with chemotherapy for advanced gastrointestinal cancer

OBJECTIVE

To explore the clinical efficacy and toxic and side effects of recombinant human endostatin (rh- endostatin/endostar) combined with chemotherapy in the treatment of advanced gastric cancer.

MATERIALS AND METHODS

A total of 70 patients with advanced gastrointestinal adenocarcioma confirmed by histopathology and/or cytological examination were divided into group A (37 patients) and group B (33 patients). Patients in group A were given intravenous drip of 15 mg endostar added into 500 mL normal saline, once every other day until the cessation of chemotherapy or patients' maximal tolerance to chemotherapy. Patients in group B received chemotherapy alone. Two groups selected the same chemotherapy regimens. FOLFIRI scheme: 90-min intravenous drip of 180 mg/m2 irinotecan, intravenous drip of 200 mg/m2 calcium folinate (CF) and 400 mg/m2 5-fluorouracil (5-Fu) on d1, and continuous intravenous pumping of 2 400 mg/m2 5-Fu for 46 h. FOLFOX4 scheme: intravenous injection of 85 mg/m2 oxaliplatin (L-OHP), 200 mg/m2 calcium folinate (CF) and 400 mg/m2 5-FU on d1 for 2 h, and then continuous intravenous pumping of 2 400 mg/m2 5-Fu for 46 h. XELOX scheme: oral administration of 1 500 mg/m2 xeloda (or tegafur 50~60 mg) in twice during d1~14 and intravenous drip of 135 mg/m2 L-OHP on d1 for 2 h. The modified FOLFOX scheme: intravenous injection of 135 mg/m2 L-OHP on d1 for 2 h, 200 mg/m2 CF and 1.0 g tegafur during d1~5. Whereas, control Group B received chemotherapy regimens which were same as Group A, but no addition of endostar. Before chemotherapy, patients were given intravenous injection of 8 mg ondansetron, intramuscular injection of 10 mg metoclopramide and 20 mg diphenhydramine for prevention of vomiting, protection of liver and stomach as well as symptomatic supportive treatment. One cycle was 21 d, 4~6 cycles in total. The efficacy was evaluated every 2 cycles.

RESULTS

32 patients in Group A could be evaluated, and the response rate (RR) and disease control rate (DCR) were 59.38% and 78.13%, respectively. 31 patients in Groups could be evaluated, and the RR and DCR were 32.26% and 54.84%, respectively. The differences between 2 groups were significant. The toxic effects include myelosuppression, gastrointestinal reaction, fatigue, cardiotoxicity and peripheral neurotoxicity.

CONCLUSIONS

Preliminary observations show that endostar (once every other day) combined with chemotherapy is effective in the treatment of advanced gastrointestinal cancer, with low toxic effects, good tolerance, deserving further study.

MiR-323-5p acts as a tumor suppressor by targeting the insulin-like growth factor 1 receptor in human glioma cells

BACKGROUND

MicroRNAs, small noncoding RNA molecules, can regulate mammalian cell growth, apoptosis and differentiation by controlling the expression of target genes. The aim of this study was to investigate the function of miR-323-5p in the glioma cell line, U251.

MATERIALS AND METHODS

After over-expression of miR-323- 5p using miR-323-5p mimics, cell growth, apoptosis and migration were tested by MTT, flow cytometry and cell wound healing assay, respectively. We also assessed the influence of miR-323-5p on the mRNA expression of IGF- 1R by quantitative real-time reverse transcriptase PCR (qRT-PCR), and on the protein levels by Western blot analysi. In addition, dual-luciferase reporter assays were performed to determine the target site of miR-323-5p to IGF-1R 3'UTR.

RESULTS

Our findings showed that over-expression of miR-323-5p could promote apoptosis of U251 and inhibit the proliferation and migration of the glioma cells.

CONCLUSIONS

This study demonstrated that increased expression of miR-323-5p might be related to glioma progression, which indicates a potential role of miR-323-5p for clinical therapy.

miR-124 inhibits growth and invasion of gastric cancer by targeting ROCK1

MicroRNAs (miRNAs) act as critical regulators of genes involved in many biological processes. Aberrant alteration of miRNAs have been found in many cancers, including gastric cancer (GC), but the molecular mechanisms are not well understood. Herein, we investigated the role of miR-124 in GC. We found that its expression was significantly reduced in both GC tissue samples and cell lines. Forced expression of miR-124 suppressed GC cell proliferation, migration, and invasion. Furthermore, the Rho-associated protein kinase (ROCK1) was identified as a direct target of miR-124 in GC cells. Finally, silencing of ROCK1 showed similar effects as miR-124 overexpression, while supplementation of ROCK1 remarkably restored the cell growth and invasion inhibited by miR-124. Together, our data demonstrate that miR-124 acts as a tumor suppressor by targeting ROCK1, and posit miR-124 as a novel strategy for GC treatment.

Anti-proliferation effects and molecular mechanisms of action of tetramethypyrazine on human SGC-7901 gastric carcinoma cells

AIM

To investigate the effects of tetramethypyrazine (TMP) on proliferation and apoptosis of the human gastric carcinoma cell line 7901 and its possible mechanism of action.

METHODS

The viability of TMP-treated 7901 cells was measured with a 3-(4, 5-dimethyl-thiazol-2-yl)-2,5-diphenyltetrazolium bromide assay (MTT) and cell apoptosis was analyzed by flow cytometry. The distribution of cells in different phases of cell cycle after exposure of TMPs was analyzed with flow cytometry. To investigate the molecular mechanisms of TMP-mediated apoptosis, the expression of NF-xBp65, cyclinD1 and p16 in SGC-7901 cells was analyzed by reverse transcription- polymerase chain reaction (RT-PCR) and western blotting.

RESULTS

TMP inhibited the proliferation of human gastric carcinoma cell line 7901 in dose and time dependent manners. Cell growth was suppressed by TMP at different concentrations (0.25, 0.5, 1.0, 2.0 mg/ml), the inhibition rate is 0.46%, 4.36%, 14.8%, 76.1% (48h) and 15.5%, 18.5%, 41.2%, 89.8% (72h) respectively. When the concentration of TMPs was 2.0mg/ml, G1-phase arrest in the SGC-7901 cells was significant based on the data for cell cycle distribution. RT-PCR demonstrated that NF-xBp65 and cyclin D1 mRNA expression was significantly down-regulated in 7901 cells treated with 2.0 mg/ml TMP for 72h (p<0.05), while the p16 mRNA level was up-regulated (p<0.05). The protein expression of NF-xBp65 and cyclin D1 decreased gradually with the increase in TMP concentration, compared with control cells (p<0.05), while expression of protein p16 was up-regulated (p<0.01).

CONCLUSION

TMP exhibits significant anti-proliferative and pro-apoptotic effects on the human gastric carcinoma cell line SGC-7901. NF-xBp65, cyclinD1 and p16 may also play important roles in the regulation mechanisms.

Differential microRNA expression profiles in HCT116 colorectal cancer cell lines located in the lung and colon

Colorectal cancer (CRC) is one of the most common types of cancer worldwide. The majority of mortalities caused by colorectal cancer are due to metastatic disease. As numerous CRC patients experience metastasis to the liver or lung and fail to respond to curative therapies, intensive research efforts have sought to identify the molecular changes or regulatory mechanisms underlying CRC metastasis. In the present study, a stable CRC cell line, HCT16, overexpressing firefly luciferase was constructed and an in vivo metastasis model was established via intravenous injection of this cell line. Using an imaging system, tumor tissue located in the lung and colon was separated and cells were prepared. The microRNA (miRNA) expression profiles of these lung homing or colon homing cells were assessed and compared. A total of 38 differentially expressed miRNAs were selected and confirmed our previous results; several of these have been reported to be involved in the regulation of cancer progression. However, the remaining miRNAs require further investigation. The present profiling may be the first step toward delineating the differential expression of miRNAs in the CRC cells located in the colon and the lung, enabling the elucidation of the regulation associated with miRNAs in colorectal lung metastases. These miRNAs require further validation and functional analysis to evaluate whether they are important in the pathogenesis of colorectal lung metastases or are adopted as markers to predict colorectal metastasis.

CXCL12-CXCR4 promotes proliferation and invasion of pancreatic cancer cells

OBJECTIVE

CXCL12 exerts a wide variety of chemotactic effects on cells. Evidence indicates that CXCL12, in conjunction with its receptor, CXCR4, promotes invasion and metastasis of tumor cells. Our objective was to explore whether the CXCL12-CXCR4 biological axis might influence biological behavior of pancreatic cancer cells.

METHODS

Miapaca-2 human pancreatic cancer cells were cultured under three different conditions: normal medium (control), medium + recombinant CXCL12 (CXCL12 group), or medium + CXCR4-inhibitor AMD3100 (AMD3100 group). RT-PCR was applied to detect mRNA expression levels of CXCL12, CXCR4, matrix metalloproteinase 2 (MMP-2), MMP-9, and human urokinase plasminogen activator (uPA). Additionally, cell proliferation and invasion were performed using CCK-8 colorimetry and transwell invasion assays, respectively.

RESULTS

CXCL12 was not expressed in Miapaca-2 cells, but CXCR4 was detected, indicating that these cells are capable of receiving signals from CXCL12. Expression of extracellular matrix-degrading enzymes MMP-2, MMP- 9, and uPA was upregulated in cells exposed to exogenous CXCL12 (P<0.05). Additionally, both proliferation and invasion of pancreatic cancer cells were enhanced in the presence of exogenous CXCL12, but AMD3100 intervention effectively inhibited these processes (P<0.05).

CONCLUSIONS

The CXCL12-CXCR4 biological axis plays an important role in promoting proliferation and invasion of pancreatic cancer cells.

Clinical application of endoscopic inguinal lymph node resection after lipolysis and liposuction for vulvar cancer

AIM

To examine lymph nodes obtained after lipolysis and liposuction of subcutaneous fat of the inguinal region of female vulvar cancer patients to explore the feasibility of clinical application.

METHODS

The field of operation was on the basis of the range of the conventional resection of inguinal lymph nodes. We injected lipolysis liquid fanwise, started liposuction after 15-20 minutes; then the subcutaneous fatty tissue was sucked out clearly by suction tube. We selected the first puncture holes located on 2-3 cm part below anterior superior spine, the others respectively being located 3cm and 6cm below the first for puncturing into the skin, imbedding a trocar to intorduce CO2 gas and the specular body, and excise the lymph nodes by ultrasonic scalpel. The surgical field chamber was set with negative pressure drainage and was pressured with a soft saline bag after surgery.

RESULTS

A lacuna emerged from subcutaneous of the inguinal region after lipolysis and liposuction, with a wide fascia easily exposed at the bottom where lymph nodes could be readily excised. The number of lymph nodes of ten patients excised within the inguinal region on each side was 4-18. The excised average number of lymph nodes was 11 when we had mature technology.

CONCLUSION

Most of adipose tissue was removed after lipolysis and liposuction of subcutaneous tissue of inguinal region, so that the included lymph nodes were exposed and easy to excise by endoscope. This surgery avoided the large incision of regular surgery of inguinal region, the results indicating that this approach is feasible and safe for used as an alternative technology.

Comparison of efficacy and toxicity of first line chemotherapy with or without epirubicin for patients with advanced stage soft tissue sarcoma

PURPOSE

To compare the safety and efficacy of first-line chemotherapy regimen with or without doxorubicin in treating patients with advanced soft tissue sarcoma (STS).

PATIENTS AND METHODS

We retrospectively analyzed a cohort of 56 patients histologically confirmed with STS who were treated at Jiangsu Cancer Hospital and Research Institute from July 2011 to June 2012.The basic element of first line chemotherapy contained epirubicin in group B and lacked epirubicin in group A. Response was assessed using RECIST criteria. The Kaplan-Meier method was used to estimate progress free survival (PFS).

RESULTS

According to RECIST criteria , patients in group treated by chemotherapy without epirubicin, the objective response (OR) ratio was 6.5 % (CR0%+PR6.5%). Disease control rate (DCR=CR+PR+SD) was 25.8% with a median follow-up of 14.6 months, including 2 patients achieving a partial response (PR 6.5%) and a stable response (SD 19.4%) in 6. In group B with epirubicin based regimens, no patient had complete response, PR (28 %) was observed in 7 and SD (24 %) in 6. DCR was observed in 13 patients (52%). By Fisher's exact test, the DCR difference between the two groups was statistically significant (p=0.046). In group A, median PFS was 3.0 months (95%CI:2.1-3.8), compared with 4.0 months (95% CI:3.03- 4.97) in group B (p=0.0397 by log-rank test). Epirubicin based chemotherapy and ECOG performance status 0-1 were identified as favorable factors for progression in our cohort of patients. Differences of nonhematologic and hematologic toxicities were not statistically significant between the two groups, and the addition of epirobicin was not associated with cardiac toxicity (p=0.446).

CONCLUSION

Our study demonstrates that epirubicin-based chemotherapy is effective and well tolerated, and is superior to chemotherapy without epirubicin regarding efficacy. Therefore it is recommended that epirubicin-based chemotherapy should be considered as first line for patients with advanced STS.

Ursolic acid promotes apoptosis of SGC-7901 gastric cancer cells through ROCK/PTEN mediated mitochondrial translocation of cofilin-1

Ursolic acid, extracted from the traditional Chinese medicine bearberry, can induce apoptosis of gastric cancer cells. However, its pro-apoptotic mechanism still needs further investigation. More and more evidence demonstrates that mitochondrial translocation of cofilin-1 appears necessary for the regulation of apoptosis. Here, we report that ursolic acid (UA) potently induces the apoptosis of gastric cancer SGC-7901 cells. Further mechanistic studies revealed that the ROCK1/PTEN signaling pathway plays a critical role in UA-mediated mitochondrial translocation of cofilin-1 and apoptosis. These findings imply that induction of apoptosis by ursolic acid stems primarily from the activation of ROCK1 and PTEN, resulting in the translocation of cofilin-1 from cytoplasm to mitochondria, release of cytochrome c, activation of caspase-3 and caspase-9, and finally inducing apoptosis of gastric cancer SGC-7901 cells.

Association of miR-193b down-regulation and miR-196a up-regulation with clinicopathological features and prognosis in gastric cancer

Dysregulated expression of microRNAs (miRNAs) has been shown to be closely associated with tumor development, progression, and carcinogenesis. However, their clinical implications for gastric cancer remain elusive. To investigate the hypothesis that genome-wide alternations of miRNAs differentiate gastric cancer tissues from those matched adjacent non-tumor tissues (ANTTs), miRNA arrays were employed to examine miRNA expression profiles for the 5-pair discovery stage, and the quantitative real-time polymerase chain reaction (qRT- PCR) was applied to validate candidate miRNAs for 48-pair validation stage. Furthermore, the relationship between altered miRNA and clinicopathological features and prognosis of gastric cancer was explored. Among a total of 1,146 miRNAs analyzed, 16 miRNAs were found to be significantly different expressed in tissues from gastric cancer compared to ANTTs (p<0.05). qRT-PCR further confirmed the variation in expression of miR-193b and miR-196a in the validation stage. Down-expression of miR-193b was significantly correlated with Lauren type, differentiation, UICC stage, invasion, and metastasis of gastric cancer (p<0.05), while over-expression of miR-196a was significantly associated with poor differentiation (p=0.022). Moreover, binary logistic regression analysis demonstrated that the UICC stage was a significant risk factor for down-expression of miR-193b (adjusted OR=8.69; 95%CI=1.06-56.91; p=0.043). Additionally, Kaplan-Meier survival curves indicated that patients with a high fold-change of down-regulated miR-193b had a significantly shorter survival time (n=19; median survival=29 months) compared to patients with a low fold-change of down-regulated miR-193b (n=29; median survival=54 months) (p=0.001). Overall survival time of patients with a low fold-change of up-regulated miR- 196a (n=27; median survival=52 months) was significantly longer than that of patients with a high fold-change of up-regulated miR-196a (n=21; median survival=46 months) (p=0.003). Hence, miR-193b and miR-196a may be applied as novel and promising prognostic markers in gastric cancer.

Differentially expressed wound healing-related microRNAs in the human diabetic cornea

MicroRNAs are powerful gene expression regulators, but their corneal repertoire and potential changes in corneal diseases remain unknown. Our purpose was to identify miRNAs altered in the human diabetic cornea by microarray analysis, and to examine their effects on wound healing in cultured telomerase-immortalized human corneal epithelial cells (HCEC) in vitro. Total RNA was extracted from age-matched human autopsy normal (n=6) and diabetic (n=6) central corneas, Flash Tag end-labeled, and hybridized to Affymetrix® GeneChip® miRNA Arrays. Select miRNAs associated with diabetic cornea were validated by quantitative RT-PCR (Q-PCR) and by in situ hybridization (ISH) in independent samples. HCEC were transfected with human pre-miR™miRNA precursors (h-miR) or their inhibitors (antagomirs) using Lipofectamine 2000. Confluent transfected cultures were scratch-wounded with P200 pipette tip. Wound closure was monitored by digital photography. Expression of signaling proteins was detected by immunostaining and Western blot. Using microarrays, 29 miRNAs were identified as differentially expressed in diabetic samples. Two miRNA candidates showing the highest fold increased in expression in the diabetic cornea were confirmed by Q-PCR and further characterized. HCEC transfection with h-miR-146a or h-miR-424 significantly retarded wound closure, but their respective antagomirs significantly enhanced wound healing vs. controls. Cells treated with h-miR-146a or h-miR-424 had decreased p-p38 and p-EGFR staining, but these increased over control levels close to the wound edge upon antagomir treatment. In conclusion, several miRNAs with increased expression in human diabetic central corneas were found. Two such miRNAs inhibited cultured corneal epithelial cell wound healing. Dysregulation of miRNA expression in human diabetic cornea may be an important mediator of abnormal wound healing.

Risk assessment on anastomotic leakage after rectal cancer surgery: an analysis of 753 patients

PURPOSE

To investigate the risk factors for anastomotic leakage (AL) after anterior resection for rectal cancer with a double stapling technique.

PATIENTS AND METHODS

Between January 2004 and December 2011, 753 consecutive patients in Jiangsu Cancer Hospital and Research Institute diagnosed with rectal cancer and undergoing anterior resection with a double stapling technique were recruited. All patients experienced a total mesorectal excision (TME) operation. Additionally, decrease of postoperative tumor supplied group of factors (TSGF), which have not been reported before, was proposed as a new indicator for AL. Univariate and multivariate analysis were performed to determine risk factors for AL.

RESULTS

AL was detected in 57 (7.6%) of 753 patients with rectal cancer. The diagnosis of anastomotic leakage was confirmed between the 6th and 12th postoperative day (POD; mean 8th POD). After univariate analysis and multivariate analysis, age (p<0.001), gender (p=0.002), level of anastomosis (p <0.001), preoperative body mass index (BMI) (p = 0.001) and reduction of TSGF in 5th POD was less than 10 μ/ml (p <0.001) were selected as 5 independent risk factors for AL. It was also indicated that a temporary defunctioning transverse ileostomy (p = 0.04) would decrease the occurrence of AL.

CONCLUSION

AL after anterior resection for rectal carcinoma is related to elderly status, low level site of the tumor (below the peritoneal reflection), being male, preoperative BMI and the decrease of TSGF in 5th POD is less than 10 m/ml. Preventive ileostomy is advisable after TME for low rectal tumors to prevent AL.

Acidic pelvic drainage as a predictive factor for anastomotic leakage after surgery for patients with rectal cancer

PURPOSE

To demonstrate the value of sequential determinations of pelvic drainage in the identification of increased risk of anastomotic leakage (AL) after anterior resection for rectal cancer with a double stapling technique.

PATIENTS AND METHODS

Between January 2004 and December 2011, data for the daily postoperative pH of pelvic drainage fluid in 753 consecutive patients with rectal cancer who initially underwent anterior resection with a double stapling technique were reviewed. All patients experienced a total mesorectal excision. Patients with anastomotic leakage (Group AL, n=57) were compared to patients without leakage (Group nAL, n=696). Patients with perioperatively abdominopelvic implants that were likely to affect pH value (determined at 25 °) other than leakage were excluded. Mean postoperative values were compared.

RESULTS

Anastomotic leakage was noted in 57 (7.6%) of 753 patients with rectal cancer. The diagnosis of anastomotic leakage was made between the 6th and 12th postoperative day (POD; mean 8th POD). There was no significance of the daily average values of pH on POD1 and 2 in group AL while a significantly sharp declining mean pH value reached its diagnostic point of AL (p<0.001) on POD3. A cut-off value of 6.978 on the 3rd POD maximized the sensitivity (98.7.0%) and specificity (94.7%) in assessing the risk of leakage.

CONCLUSION

According to these results, an early and persistent declining of pH value of pelvic drainage fluid after rectal surgery with anastomosis, is a marker of AL. A cut-off value of 6.798 on POD3 maximizes sensitivity and specificity.

Role of MYH polymorphisms in sporadic colorectal cancer in China: a case-control, population-based study

PURPOSE

Biallelic germline variants of the 8-hydroxyguanine (8-OG) repair gene MYH have been associated with colorectal neoplasms that display somatic G:C?T:A transversions. However, the effect of single germline variants has not been widely studied, prompting the present investigation of monoallelic MYH variants and susceptibility to sporadic colorectal cancer (CRC) in a Chinese population.

PATIENTS AND METHODS

Between January 2006 and December 2012, 400 cases of sporadic CRC and 600 age- and sex-matched normal blood donors were screened randomly for 7 potentially pathogenic germline MYH exons using genetic testing technology. Variants of heterozygosity at the MYH locus were assessed in both sporadic cancer patients and healthy controls. Univariate and multivariate analyses were performed to determine risk factors for cancer onset.

RESULTS

Five monoallelic single nucleotide polymorphisms (SNPs) were identified in the 7 exon regions of MYH, which were detected in 75 (18.75%) of 400 CRC patients as well as 42 (7%) of 600 normal controls. The region of exon 1 proved to be a linked polymorphic region for the first time, a triple linked variant including exon 1-316 G?A, exon 1-292 G?A and intron 1+11 C?T, being identified in 13 CRC patients and 2 normal blood donors. A variant of base replacement, intron 10-2 A?G, was identified in the exon 10 region in 21 cases and 7 controls, while a similar type of variant in the exon 13 region, intron 13+12 C?T, was identified in 8 cases and 6 controls. Not the only but a newly missense variant in the present study, p. V463E (Exon 14+74 T?A), was identified in exon 14 in 6 patients and 1 normal control. In exon 16, nt. 1678-80 del GTT with loss of heterozygosity (LOH) was identified in 27 CRC cases and 26 controls. There was no Y165C in exon 7 or G382D in exon 14, the hot- spot variants which have been reported most frequently in Caucasian studies. After univariate analysis and multivariate analysis, the linked variant in exon 1 region (p=0.002), intron 10-2 A?G (p=0.004) and p. V463E (p=0.036) in the MYH gene were selected as 3 independent risk factors for CRC.

CONCLUSIONS

According to these results, the linked variant in Exon 1 region, Intron 10-2 A?G of base replacement and p. V463E of missense variant, the 3 heterozygosity variants of MYH gene in a Chinese population, may relate to the susceptibility to sporadic CRC. Lack of the hot-spot variants of Caucasians in the present study may due to the ethnic difference in MYH gene.