Non-CpG island promoter hypomethylation and miR-149 regulate the expression of SRPX2 in colorectal cancer

CircSEC24B activates autophagy and induces chemoresistance of colorectal cancer via OTUB1-mediated deubiquitination of SRPX2

Circular RNAs (circRNAs) are a type of regulatory RNA that feature covalently closed single-stranded loops. Evidence suggested that circRNAs play important roles in the progression and development of various cancers. However, the impact of circRNA on autophagy-mediated progression of colorectal cancer (CRC) remains unclear. The objective of this project was to investigate the influence of circSEC24B on autophagy and its underlying mechanisms in CRC. To validate the presence and circular structure of circSEC24B in CRC cells and tissues, PCR and Sanger sequencing techniques were employed. Drug resistance and invasive phenotype of CRC cells were evaluated using CCK8, transwell, and Edu assays. Gain- and loss-of-function experiments were conducted to assess the effects of circSEC24B and its protein partner on the growth, invasion, and metastasis of CRC cells in vitro and in vivo. Interactions between circSEC24B, OTUB1, and SRPX2 were analyzed through immunofluorescence, RNA-pulldown, and RIP assays. Mass spectrometry analysis was used to identify potential binding proteins of circRNA in CRC cells. Vectors were constructed to investigate the specific structural domain of the deubiquitinating enzyme OTUB1 that binds to circSEC24B. Results showed that circSEC24B expression was increased in CRC tissues and cell lines, and it enhanced CRC cell proliferation and autophagy levels. Mechanistically, circSEC24B promoted CRC cell proliferation by regulating the protein stability of SRPX2. Specifically, circSEC24B acted as a scaffold, facilitating the binding of OTUB1 to SRPX2 and thereby enhancing its protein stability. Additionally, evidence suggested that OTUB1 regulated SRPX2 expression through an acetylation-dependent mechanism. In conclusion, this study demonstrated that circSEC24B activated autophagy and induced chemoresistance in CRC by promoting the deubiquitination of SRPX2, mediated by the deubiquitinating enzyme OTUB1.

SRPX2 promotes cancer cell proliferation and migration of papillary thyroid cancer

Thyroid cancer is the endocrine tumor with the highest incidence at present. It originates from the thyroid follicular epithelium or follicular paraepithelial cells. There is an increasing incidence of thyroid cancer all over the world. We found that SRPX2 expression level was higher in papillary thyroid tumors than in normal thyroid tissues, and SRPX2 expression was closely related to tumor grade and clinical prognosis. Previous reports showed that SRPX2 could function by activating PI3K/AKT signaling pathway. In addition, in vitro experiments showed that SRPX2 promoted the proliferation and migration of papillary thyroid cancer (PTC). In conclusion, SRPX2 could promote the malignant development of PTC. This may be a potential treatment target for PTC.

The vascular gene Apold1 is dispensable for normal development but controls angiogenesis under pathological conditions

The molecular mechanisms of angiogenesis have been intensely studied, but many genes that control endothelial behavior and fate still need to be described. Here, we characterize the role of Apold1 (Apolipoprotein L domain containing 1) in angiogenesis in vivo and in vitro. Single-cell analyses reveal that - across tissues - the expression of Apold1 is restricted to the vasculature and that Apold1 expression in endothelial cells (ECs) is highly sensitive to environmental factors. Using Apold1-/- mice, we find that Apold1 is dispensable for development and does not affect postnatal retinal angiogenesis nor alters the vascular network in adult brain and muscle. However, when exposed to ischemic conditions following photothrombotic stroke as well as femoral artery ligation, Apold1-/- mice display dramatic impairments in recovery and revascularization. We also find that human tumor endothelial cells express strikingly higher levels of Apold1 and that Apold1 deletion in mice stunts the growth of subcutaneous B16 melanoma tumors, which have smaller and poorly perfused vessels. Mechanistically, Apold1 is activated in ECs upon growth factor stimulation as well as in hypoxia, and Apold1 intrinsically controls EC proliferation but not migration. Our data demonstrate that Apold1 is a key regulator of angiogenesis in pathological settings, whereas it does not affect developmental angiogenesis, thus making it a promising candidate for clinical investigation.

Epigenetic Alterations of Brain Non-Neuronal Cells in Major Mental Diseases

The tissue-specific expression and epigenetic dysregulation of many genes in cells derived from the postmortem brains of patients have been reported to provide a fundamental biological framework for major mental diseases such as autism, schizophrenia, bipolar disorder, and major depression. However, until recently, the impact of non-neuronal brain cells, which arises due to cell-type-specific alterations, has not been adequately scrutinized; this is because of the absence of techniques that directly evaluate their functionality. With the emergence of single-cell technologies, such as RNA sequencing (RNA-seq) and other novel techniques, various studies have now started to uncover the cell-type-specific expression and DNA methylation regulation of many genes (e.g., TREM2, MECP2, SLC1A2, TGFB2, NTRK2, S100B, KCNJ10, and HMGB1, and several complement genes such as C1q, C3, C3R, and C4) in the non-neuronal brain cells involved in the pathogenesis of mental diseases. Additionally, several lines of experimental evidence indicate that inflammation and inflammation-induced oxidative stress, as well as many insidious/latent infectious elements including the gut microbiome, alter the expression status and the epigenetic landscapes of brain non-neuronal cells. Here, we present supporting evidence highlighting the importance of the contribution of the brain's non-neuronal cells (in particular, microglia and different types of astrocytes) in the pathogenesis of mental diseases. Furthermore, we also address the potential impacts of the gut microbiome in the dysfunction of enteric and brain glia, as well as astrocytes, which, in turn, may affect neuronal functions in mental disorders. Finally, we present evidence that supports that microbiota transplantations from the affected individuals or mice provoke the corresponding disease-like behavior in the recipient mice, while specific bacterial species may have beneficial effects.

Apolipoprotein L Domain Containing 1 Inhibits Tissue Factor to Impede Thrombus Formation in a Rat Model of Deep Vein Thrombosis via Activating PI3K/Akt Pathway

BACKGROUND

Deep venous thrombosis (DVT) is one of the major health problems worldwide. Apolipoprotein L domain containing 1 (APOLD1) was reported to be downregulated in DVT. The present study intended to investigate whether APOLD1 affects thrombus formation in a rat model of DVT.

METHODS

The rat model of DVT was established by inferior vena cava (IVC) stenosis. At 6 hr, 12 hr, 24 hr, and 48 hr after IVC stenosis, the gross IVC with thrombus was dissected and observed. Then, the rats were preinjected with the lentiviral overexpression vector, APOLD1-LVs, 1 hr before IVC stenosis, to evaluate the influence of APOLD1 on thrombosis in rats. The serum levels of D-dimer and TAT as well as the content of TF in IVC tissues were detected by enzyme-linked immunosorbent assay (ELISA).

RESULTS

IVC stenosis resulted in thrombus formation in rats, increased serum levels of D-dimer and TAT, and decreased APOLD1 expression. APOLD1 overexpression inhibited in vivo thrombosis, reduced serum levels of D-dimer, and downregulated tissue factor (TF) activity and level. APOLD1 overexpression also increased p-PI3K and p-Akt protein levels.

CONCLUSIONS

APOLD1 suppresses thrombus formation in a rat model of DVT via downregulating TF expression by activating the PI3K/Akt pathway.

SRPX2 attenuated oxygen–glucose deprivation and reperfusion-induced injury in cardiomyocytes via alleviating endoplasmic reticulum stress-induced apoptosis through targeting PI3K/Akt/mTOR axis

Myocardial infraction (MI) is the leading cause of high morbidity and mortality worldwide. It was still urgently needed to find new and effective drugs for MI treatment by the use of myocardial ischemia/reperfusion (I/R) model. Sushi repeats contain the protein X-Linked 2 (SRPX2), which regulates a variety of important cell functions. However, its possible role in myocardial I/R and the progression of MI is still unclear. In this study, we investigated the role of SRPX2 in myocardial I/R. SRPX2 showed low expression in IR rats and H9C2 cells induced by oxygen–glucose deprivation/reperfusion (OGD/R). SRPX2 could increase OGD/R-induced H9C2 cell survival. In addition, SRPX2 suppressed the apoptosis of OGD/R-induced H9C2 cells. Furthermore, we found that SRPX2 could inhibit ER stress induced by OGD/R in H9C2 cells. Mechanically, we found that SRPX2 suppressed the PI3K/Akt/mTOR pathway, thus attenuating OGD/R -induced injury in H9C2 cells. Therefore, SRPX2 has the potential to serve as a target for MI treatment.

SRPX2 Promotes Tumor Proliferation and Migration via the FAK Pathway in Papillary Thyroid Carcinoma

Thyroid cancer is the most common form of endocrine cancer around the world, and among which papillary thyroid carcinoma (PTC) is the most ubiquitous pathological sub-kind. Sushi repeat-containing protein X-linked 2 (SRPX2) was reported to be an independent prognostic factor and significantly overexpressed in advanced PTC patients. However, the biological functions of SRPX2 remain ambiguous in PTC. Here, we explored SRPX2 expression profiles and functions in PTC, finding that SRPX2 expression was remarkably upregulated in PTC tissues and cell lines. Further colony formation, CCK-8, as well as transwell assay, suggested that SRPX2 silencing remarkably dampened PTC growth and migration. Mouse xenograft models were established to find that SRPX2 silence remarkably suppressed PTC proliferation and migration in vivo. Following mechanism studies revealed that SRPX2 realized its functions in the PTC process partially through activating the Focal adhesion kinase (FAK) phosphorylation. In conclusion, this study investigated the functions and mechanisms of the SRPX2/FAK pathway in PTC progression. SRPX2 could act as a prospective biologic signature and therapeutic target molecule for PTC.

RETRACTED ARTICLE: Down-regulation of lncRNA FEZF1-AS1 mediates regulatory T cell differentiation and further blocks immune escape in colon cancer

Statement of RetractionWe, the Editors and Publisher of the journal Expert Review of Molecular Diagnostics, have retracted the following article:Sen Hong, Zhenkun Yan, YuMei Song, MiaoMiao Bi & Shiquan Li. Down-regulation of lncRNA FEZF1-AS1 mediates regulatory T cell differentiation and further blocks immune escape in colon cancer. Expert Review of Molecular Diagnostics. 2021. DOI: 10.1080/14737159.2022.2012157Since publication, significant concerns have been raised about the integrity of the data and reported results in the article. When approached for an explanation, the authors did not provide their original data or any necessary supporting information. As verifying the validity of published work is core to the integrity of the scholarly record, we are therefore retracting the article. The corresponding author listed in this publication has been informed.We have been informed in our decision-making by our policy on publishing ethics and integrity and the COPE guidelines on retractions.The retracted article will remain online to maintain the scholarly record, but it will be digitally watermarked on each page as 'Retracted'.

Sushi-Repeat-Containing Protein X-Linked 2: A Potential Therapeutic Target for Inflammation and Cancer Therapy

Accumulating evidence has showed that sushi-repeat-containing protein X-linked 2 (SRPX2) is an abnormal expression in a variety of cancers and involved in cancer carcinogenesis, chemosensitivity, and prognosis, which mainly promote cancer cell metastasis, invasion, and migration by regulating the uPAR/integrins/FAK signaling pathway, epithelial-mesenchymal transition (EMT), angiogenesis, and glycosylation. Inflammation has been regarded as a key role in regulating cancer initiation, progression, EMT, and therapeutics. Furthermore, SRPX2 exhibited excellent antifibrosis effect via the TGFβR1/SMAD3/SRPX2/AP1/SMAD7 signaling pathway. Therefore, this review provides compelling evidence that SRPX2 might be a therapeutic target for inflammation and cancer-related inflammation for future cancer therapeutics.

Searching for New Molecular Targets for Oral Squamous Cell Carcinoma with a View to Clinical Implementation of Precision Medicine

Head and neck cancer, including oral squamous cell carcinoma (OSCC), is the eighth most common malignancy globally and is characterized by local invasiveness and high nodal metastatic potential. The OSCC incidence is also increasing, and the number of deaths is also rising steadily in Japan. The development of molecular markers to eradicate OSCC is an urgent issue for humankind. The increase in OSCC despite the declining smoking rate may be due to several viral infections through various sexual activities and the involvement of previously unfocused carcinogens, and genetic alterations in individual patients are considered to be more complicated. Given this situation, it is difficult to combat OSCC with conventional radiotherapy and chemotherapy using cell-killing anticancer drugs alone, and the development of precision medicine, which aims to provide tailor-made medicine based on the genetic background of each patient, is gaining attention. In this review article, the current status of the comprehensive search for driver genes and biomarkers in OSCC will be briefly described, and some of the candidates for novel markers of OSCC that were found will be outlined.

The Landscape of the Tumor Microenvironment in Skin Cutaneous Melanoma Reveals a Prognostic and Immunotherapeutically Relevant Gene Signature

The tumorigenesis of skin cutaneous melanoma (SKCM) remains unclear. The tumor microenvironment (TME) is well known to play a vital role in the onset and progression of SKCM. However, the dynamic mechanisms of immune regulation are insufficient. We conducted a comprehensive analysis of immune cell infiltration in the TME. Based on the differentially expressed genes (DEGs) in clusters grouped by immune infiltration status, a set of hub genes related to the clinical prognosis of SKCM and tumor immune infiltration was explored. Methods: We analyzed immune cell infiltration in two independent cohorts and assessed the relationship between the internal pattern of immune cell infiltration and SKCM characteristics, including clinicopathological features, potential biological pathways, and gene mutations. Genes related to the infiltration pattern of TME immune cells were determined. Furthermore, the unsupervised clustering method (k-means) was used to divide samples into three different categories according to TME, which were defined as TME cluster-A, -B, and -C. DEGs among three groups of samples were analyzed as signature genes. We further distinguished common DEGs between three groups of samples according to whether differences were significant and divided DEGs into the Signature gene-A group with significant differences and the Signature gene-B group with insignificant differences. The Signature gene-A gene set mainly had exon skipping in SKCM, while the Signature gene-B gene set had no obvious alternative splicing form. Subsequently, we analyzed genetic variations of the two signatures and constructed a competing endogenous RNA (ceRNA) regulatory network. LASSO Cox regression was used to determine the immune infiltration signature and risk score of SKCM. Finally, we obtained 13 hub genes and calculated the risk score based on the coefficient of each gene to explore the impact of the high- and low-risk scores on biologically related functions and prognosis of SKCM patients further. The correlation between the risk score and clinicopathological characteristics of SKCM patients indicated that a low-risk score was associated with TME cluster-A classification (p < 0.001) and metastatic SKCM (p < 0.001). Thirteen hub genes also showed different prognostic effects in pan-cancer. The results of univariate and multivariate Cox analyses revealed that risk score could be used as an independent risk factor for predicting the prognosis of SKCM patients. The nomogram that integrated clinicopathological characteristics and immune characteristics to predict survival probability was based on multivariate Cox regression. Finally, 13 hub genes that showed different prognostic effects in pan-cancers were obtained. According to immunohistochemistry staining results, Ube2L6, SRPX2, and IFIT2 were expressed at higher levels, while CLEC4E, END3, and KIR2DL4 were expressed at lower levels in 25 melanoma specimens. Conclusion: We performed a comprehensive assessment of the immune-associated TME. To elucidate the potential development of immune-genomic features in SKCM, we constructed an unprecedented set of immune characteristic genes (EDN3, CLEC4E, SRPX2, KIR2DL4, UBE2L6, and IFIT2) related to the immune landscape of TME. These genes are related to different prognoses and drug responses of SKCM. The immune gene signature constructed can be used as a robust prognostic biomarker of SKCM and a predictor of an immunotherapy effect.

Integrative analysis identifies an immune-relevant epigenetic signature for prognostication of non-G-CIMP glioblastomas

The clinical and molecular implications of DNA methylation alterations remain unclear among the majority of glioblastomas (GBMs) without glioma-CpGs island methylator phenotype (G-CIMP); integrative multi-level molecular profiling may provide useful information. Independent cohorts of non-G-CIMP GBMs or IDH wild type (wt) lower-grade gliomas (LGGs) from local and public databases with DNA methylation and gene expression microarray data were included for discovery and validation of a multimarker signature, combined using a RISK score model. Bioinformatic and in vitro functional analyses were employed for biological validation. Using a strict multistep selection approach, we identified eight CpGs, each of which was significantly correlated with overall survival (OS) of non-G-CIMP GBMs, independent of age, the O-6-methylguanine-DNA methyltransferase (MGMT) methylation status, treatments and other identified CpGs. An epigenetic RISK signature of the 8 CpGs was developed and validated to robustly and independently prognosticate prognosis in different cohorts of not only non-G-GIMP GBMs, but also IDHwt LGGs. It also showed good discriminating value in stratified cohorts by current clinical and molecular factors. Bioinformatic analysis revealed consistent correlation of the epigenetic signature to distinct immune-relevant transcriptional profiles of GBM bulks. Functional experiments showed that S100A2 appeared to be epigenetically regulated by one identified CpG and was associated with GBM cell proliferation, apoptosis, invasion, migration and immunosuppression. The prognostic 8-CpGs RISK score signature may be of promising value for refining current glioma risk classification, and its potential links to distinct immune phenotypes make it a promising biomarker candidate for predicting response to anti-glioma immunotherapy.

SRPX2 boosts pancreatic cancer chemoresistance by activating PI3K/AKT axis

Background and aim

This investigation was aimed at disclosing whether SRPX2 affected pancreatic cancer (PC) chemoresistance by regulating PI3K/Akt/mTOR signaling.

Methods

Totally 243 PC patients were recruited, and they were incorporated into partial remission (PR) group, stable disease (SD) group and progressive disease (PD) group in accordance with their chemotherapeutic response. PC cell lines (i.e. AsPC1, Capan2, VFPAC-1, HPAC, PANC-1, BxPC-3 and SW1990) and human pancreatic ductal epithelial cell lines (hTERT-HPNE) were also collected.

Results

PC patients of SD + PD group were associated with higher post-chemotherapeutic SRPX2 level than PR group, and their post-chemotherapeutic SRPX2 level was above the pretherapeutic SRPX2 level (P < 0.05). PR population showed lower SRPX2 level after chemotherapy than before chemotherapy (P < 0.05). Besides high serum SRPX2 level and SRPX2 level change before and after chemotherapy were independent predictors of poor PC prognosis. Additionally, si-SRPX2 enhanced chemosensitivity of PC cell lines, and expressions of p-PI3K, p-AKT and p-mTOR were suppressed by si-SRPX2 (P < 0.05). IGF-1 treatment could changeover the impact of si-SRPX2 on proliferation, migration, invasion and chemoresistance of PC cells (P < 0.05).

Conclusion

The SRPX2-PI3K/AKT/mTOR axis could play a role in modifying progression and chemoresistance of PC cells, which might help to improve PC prognosis.

MicroRNA-149: A review of its role in digestive system cancers

MicroRNAs (miRNAs) are a group of highly conserved, short (18-25 nucleotide long) non-coding RNAs which play important functional roles in cellular differentiation, biological development, pathogenesis and disease susceptibility and have been linked to both tumorigenesis and the malignant progression of various cancers. miRNAs primarily exert their function through the negative regulation of their target gene's transcription via the specific recognition of their 3' untranslated region. A single miRNA can regulate multiple target genes and most miRNAs are controlled by several factors. Recent studies have shown that microRNA-149 (miR-149) plays a pivotal role in the pathogenesis of digestive system cancers and may act as a potential diagnostic marker and therapeutic target. In this review, we summarize and discuss the most recent reports describing miR-149 in digestive system cancers, including its single nucleotide polymorphisms, expression levels, target genes, drug sensitivity and clinical significance.

Comparison of miRNA Expression Profiles between HIV-1 and HIV-2 Infected Monocyte-Derived Macrophages (MDMs) and Peripheral Blood Mononuclear Cells (PBMCs)

During the progression of HIV-1 infection, macrophage tropic HIV-1 that use the CCR5 co-receptor undergoes a change in co-receptor use to CXCR4 that is predominately T cell tropic. This change in co-receptor preference makes the virus able to infect T cells. HIV-2 is known to infect MDMs and T cells and is dual tropic. The aim of this study was to elucidate the differential expression profiles of host miRNAs and their role in cells infected with HIV-1/HIV-2. To achieve this goal, a comparative global miRNA expression profile was determined in human PBMCs and MDMs infected with HIV-1/HIV-2. Differentially expressed miRNAs were identified in HIV-1/HIV-2 infected PBMCs and MDMs using the next-generation sequencing (NGS) technique. A comparative global miRNA expression profile in infected MDMs and PBMCs with HIV-1 and HIV-2 identified differential expression of several host miRNAs. These differentially expressed miRNAs are likely to be involved in many signaling pathways, like the p53 signaling pathway, PI3K-Akt signaling pathways, MAPK signaling pathways, FoxO signaling pathway, and viral carcinogenesis. Thus, a comparative study of the differential expression of host miRNAs in MDMs and T cell in response to HIV-1 and HIV-2 infection will help us to identify unique biomarkers that can differentiate HIV-1 and HIV-2 infection.

A seven-gene signature model predicts overall survival in kidney renal clear cell carcinoma

Background

Kidney renal clear cell carcinoma (KIRC) is a potentially fatal urogenital disease. It is a major cause of renal cell carcinoma and is often associated with late diagnosis and poor treatment outcomes. More evidence is emerging that genetic models can be used to predict the prognosis of KIRC. This study aimed to develop a model for predicting the overall survival of KIRC patients.

Results

We identified 333 differentially expressed genes (DEGs) between KIRC and normal tissues from the Gene Expression Omnibus (GEO) database. We randomly divided 591 cases from The Cancer Genome Atlas (TCGA) into training and internal testing sets. In the training set, we used univariate Cox regression analysis to retrieve the survival-related DEGs and futher used multivariate Cox regression with the LASSO penalty to identify potential prognostic genes. A seven-gene signature was identified that included APOLD1, C9orf66, G6PC, PPP1R1A, CNN1G, TIMP1, and TUBB2B. The seven-gene signature was evaluated in the training set, internal testing set, and external validation using data from the ICGC database. The Kaplan-Meier analysis showed that the high risk group had a significantly shorter overall survival time than the low risk group in the training, testing, and ICGC datasets. ROC analysis showed that the model had a high performance with an AUC of 0.738 in the training set, 0.706 in the internal testing set, and 0.656 in the ICGC external validation set.

Conclusion

Our findings show that a seven-gene signature can serve as an independent biomarker for predicting prognosis in KIRC patients.

Combined serum miR-29c and miR-149 expression analysis as diagnostic genetic markers for colorectal cancer

Circulating miRNAs gathered much interest in cancer research as noninvasive biomarkers. The aim of this study was to analyze the expression of miR-29c and miR-149 among colorectal cancer (CRC) patients and to explore their diagnostic and prognostic potentials in relation to the clinical and pathological features. The expression levels of miR-29c and miR-149 were evaluated in the sera of 80 CRC patients, 80 colorectal adenoma (CRA) patients, and 80 healthy controls using quantitative real time polymerase chain reaction (PCR). Carcinoembryonic antigen serum levels were assayed using enzyme-linked immunosorbent assay. miR-29c and miR-149 were significantly downregulated among CRC patients compared with CRA and controls (miR-29c, 0.54 ± 0.19 vs. 0.86 ± 0.12, 0.99 ± 0.07, P < 0.001, respectively; miR-149, 0.46 ± 0.19 vs. 0.74 ± 0.012, 1.0 ± 0.22, P < 0.001, respectively). miR-29c and miR-149 significantly associated with advanced stages of CRC, tumor size, and lymphatic metastasis. By using receiver operating characteristic curve analysis, combined miR-29c and miR-149 revealed the highest diagnostic potential for CRA (area under the curve [AUC] = 0.967) from healthy controls as well as the diagnosis of CRC (AUC = 0.98) from CRA. Moreover, combined miRNAs revealed high diagnostic potential for the earlier stages of CRC compared with advanced stages (AUC = 0.96). In conclusion, combined serum miR-29c and miR-149 expression analysis established novel noninvasive biomarker for early CRC diagnosis.

Sushi Repeat Containing Protein X-linked 2 Is a Downstream Signal of LEM Domain Containing 1 and Acts as a Tumor-Promoting Factor in Oral Squamous Cell Carcinoma

Because oral squamous cell carcinomas (OSCCs) have a high potential for locoregional invasion and nodal metastasis, early detection and treatment are essential. A LAP2, emerin, MAN1 (LEM) domain containing 1 (LEMD1) is associated with local progression, clinical stage, nodal metastasis, poor prognosis, angiogenesis, and lymphangiogenesis in OSCC. Although LEMD is a cancer-testis antigen, the cancer-related signals related to LEMD1 remain unknown. In this study, we used a microarray analysis of OSCC cells to identify sushi repeat containing protein X-linked 2 (SRPX2) as a LEMD1-related downstream signal. LEMD1 expression was correlated with lymph node metastasis of OSCC according to the immunohistochemistry analysis. Furthermore, patients expressing SRPX2 had a significantly worse prognosis than those without SRPX2 expression. The concentration of SRPX2 in OSCC was positively correlated with the concentrations of LEMD1, urokinase plasminogen activator receptor (uPAR), and hepatocyte growth factor (HGF). In OSCC cells, SRPX2 secretion levels were elevated by interactions with uPAR and HGF. We also found that SRPX2 promotes endothelial cell proliferation and adhesion between endothelial cells and OSCC cells. These results suggest that SRPX2 might be a useful tumor marker for OSCC.

Long Non-Coding RNA PART1 Promotes Proliferation, Migration and Invasion of Hepatocellular Carcinoma Cells via miR-149-5p/MAP2K1 Axis

Background

Hepatocellular carcinoma (HCC) is the most common primary hepatic malignancy worldwide. Long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) have been identified as effective markers for the detection of multiple cancers. This study aimed to illuminate the mechanism of prostate androgen regulated transcript 1 (PART1) in HCC.

Materials and Methods

The levels of PART1, miR-149-5p and mitogen-activated protein kinase 1 (MAP2K1) mRNA were detected by quantitative real-time polymerase chain reaction (qRT-PCR) assay. Cell proliferation was assessed by Cell Counting Kit-8 (CCK-8) assay, and cell migration and invasion were evaluated by transwell assay. Dual-luciferase reporter assay was carried out to examine the relationship among PART1, miR-149-5p and MAP2K1. Western blot assay was conducted to measure the protein expression of MAP2K1.

Results

PART1 and MAP2K1 expression were greatly increased and miR-149-5p level was decreased in HCC tissues. Functional analysis revealed that the si-PART1 inhibited proliferation, migration and invasion of HCC cells. PART1 directly bound to miR-149-5p and miR-149-5p level was down-regulated by PART1. Moreover, restoration experiment demonstrated that the effect of PART1 knockdown on HCC cell progression could be partially rescued by miR-149-5p depletion. MiR-149-5p was predicted to target MAP2K1 and MAP2K1 expression was negatively modulated by miR-149-5p. Also, MAP2K1 rescued the inhibitory effects of miR-149-5p overexpression on proliferation, migration and invasion in HCC cells. Besides, the inhibition of miR-149-5p weakened the impact on MAP2K1 expression mediated by PART1 repression.

Conclusion

PART1 promoted proliferation, migration and invasion of HCC cells by regulating miR-149-5p/MAP2K1 axis.

Promoter Hypomethylation and Increased Expression of the Long Non-coding RNA LINC00152 Support Colorectal Carcinogenesis

Up-regulation of the long non-coding RNA LINC00152 can contribute to cancer development, proliferation and invasion, including colorectal cancer, however, its mechanism of action in colorectal carcinogenesis and progression is only insufficiently understood. In this work we correlated LINC00152 expression with promoter DNA methylation changes in colorectal tissues along the normal-adenoma-carcinoma sequence and studied the effects of LINC00152 silencing on the cell cycle regulation and on the whole transcriptome in colon carcinoma cells using cell and molecular biology techniques. LINC00152 was significantly up-regulated in adenoma and colorectal cancer (p < 0.001) compared to normal samples, which was confirmed by real-time PCR and in situ hybridization. LINC00152 promoter hypomethylation detected in colorectal cancer (p < 0.01) was strongly correlated with increased LINC00152 expression (r=-0.90). Silencing of LINC00152 significantly suppressed cell growth, induced apoptosis and decreased cyclin D1 expression (p < 0.05). Whole transcriptome analysis of LINC00152-silenced cells revealed significant down-regulation of oncogenic and metastasis promoting genes (e.g. YES proto-oncogene 1, PORCN porcupine O-acyltransferase), and up-regulation of tumour suppressor genes (e.g. DKK1 dickkopf WNT signalling pathway inhibitor 1, PERP p53 apoptosis effector) (adjusted p < 0.05). Pathway analysis confirmed the LINC00152-related activation of oncogenic molecular pathways including those driven by PI3K/Akt, Ras, WNT, TP53, Notch and ErbB. Our results suggest that promoter hypomethylation related overexpression of LINC00152 can contribute to the pathogenesis of colorectal cancer by facilitating cell progression through the up-regulation of several oncogenic and metastasis promoting pathway elements.

Global differences in the prevalence of the CpG island methylator phenotype of colorectal cancer

Background

CpG Island Methylator Phenotype (CIMP) is an epigenetic phenotype in CRC characterized by hypermethylation of CpG islands in promoter regions of tumor suppressor genes, leading to their transcriptional silencing and loss of function. While the prevalence of CRC differs across geographical regions, no studies have compared prevalence of CIMP-High phenotype across regions. The purpose of this project was to compare the prevalence of CIMP across geographical regions after adjusting for variations in methodologies to measure CIMP in a meta-analysis.

Methods

We searched PubMed, Medline, and Embase for articles focusing on CIMP published from 2000 to 2018. Two reviewers independently identified 111 articles to be included in final meta-analysis. We classified methods used to quantify CIMP into 4 categories: a) Classical (MINT marker) Panel group b) Weisenberg-Ogino (W-O) group c) Human Methylation Arrays group and d) Miscellaneous group. We compared the prevalence of CIMP across geographical regions after correcting for methodological variations using meta-regression techniques.

Results

The pooled prevalence of CIMP-High across all studies was 22% (95% confidence interval:21–24%; I² = 94.75%). Pooled prevalence of CIMP-H across Asia, Australia, Europe, North America and South America was 22, 21, 21, 27 and 25%, respectively. Meta-regression analysis identified no significant differences in the prevalence of CIMP-H across geographical regions after correction for methodological variations. In exploratory analysis, we observed variations in CIMP-H prevalence across countries.

Conclusion

Although no differences were found for CIMP-H prevalence across countries, further studies are needed to compare the influence of demographic, lifestyle and environmental factors in relation to the prevalence of CIMP across geographical regions.

Direct and sensitive detection of circulating miRNA in human serum by ligase-mediated amplification

MicroRNAs (miRNA) involve in regulating different physiological processes whose dysregulation is associated with a wide range of diseases including cancers, diabetes and cardiovascular problems. Herein, we report a direct, sensitive and highly selective detection assay for circulating microRNA (miRNA). This detection strategy employs magnetic nanoparticles as the reaction platform which can not only allow online pre-concentration and selective separation but also integrates ligation reaction with amplification to enhance the sensitivity of the detection assay. With the presence of the target miRNA, the locked nucleic acid (LNA)-modified molecular beacon (MB) opens up, exposing the binding sites at two ends. The 3'- and 5'-end of the MB responsible for the attachment onto the magnetic nanoparticles, and reporting probe for the attachment of the pair of amplification probes respectively. The ligase ligate RNA to DNA enhance the amplification efficiency. Upon labelled with intercalating fluorophores (YOYO-1) on the hybrids, the quantification of the target miRNA was determined by measuring the fluorescence intensity. A detection limit of 314 fM was achieved with trace amount of sample consumption (~20 μL). As a proof of concept, miRNA-149 was chosen as the target miRNA. This assay is capable of discriminating single-base and reliably quantifying circulating miRNA-149 in both healthy and cancer patient's serums. The result obtained was comparable with that of quantitative reverse transcription polymerase chain reaction (qRT-PCR), suggesting that this direct and sensitive assay can be served as a promising, non-invasive tool for early diagnosis of breast cancer and colorectal cancer.

DNA methylation of a non-CpG island promoter represses NQO1 expression in rat arsenic-transformed lung epithelial cells

NAD(P)H:quinone oxidoreductase 1 (NQO1), a phase II flavoenzyme that catalyzes reduction reactions to protect cells against electrophiles and oxidants, is involved in tumorigenesis. Altered methylation of the NQO1 gene has been observed and is speculated to result in aberrant NQO1 expression in rat cells undergoing chemical carcinogenesis, although this has not been proven experimentally. In this study, we first investigated the potential epigenetic mechanisms underlying the phenomenon of NQO1 differential expression in individual subclones of rat arsenic-transformed lung epithelial cells (TLECs). NQO1 expression of TLEC subclones with or without 5-aza-2'-deoxycytidine (5-Aza-CdR) treatment was assessed by reverse transcriptase-polymerase chain reaction (RT-PCR), western blot analysis, and real-time PCR. Methylation status of the NQO1 promoter in TLEC subclones was analyzed by bisulfite sequencing. Transcriptional activity of NQO1 promoter in vitro methylated was determined by luciferase assay using a CpG-free luciferase reporter driven by the NQO1 promoter region (-435 to +229). We found that non-CpG island (non-CpGI) within the NQO1 promoter was hyper- or hypo-methylated in TLEC subclones and corresponded to low and high gene expressions, respectively. Following the treatment with 5-Aza-CdR, transcription of the NQO1 gene in the hypermethylated subclones was restored, accompanied by demethylation of the NQO1 promoter. In vitro promoter methylation almost completely silenced reporter activity in TLECs. These results indicate that DNA methylation of the non-CpGI promoter contributes to epigenetic silencing of NQO1 in rat TLECs.

Regulation and functions of MicroRNA-149 in human cancers

MicroRNAs are small non-coding RNAs that play critical roles in the regulatory mechanisms involving cell differentiation, proliferation, apoptosis and tumorigenesis. Recent research efforts have been conducted to apply these discoveries into clinical functions, including the early diagnosis and therapeutic outcome of patients with cancer. Previous studies have shown that microRNA-149 (miR-149) is dysregulated in various human cancers and exerts its effects on tumorigenesis and tumour progression. In this review, we summarized the potential roles of miR-149 dysregulation and its target genes during tumorigenesis and clinical treatment of human cancers.

Sushi repeat-containing protein X-linked 2: A novel phylogenetically conserved hypothalamo-pituitary protein

Sushi repeat-containing protein X-linked 2 (SRPX2) is a novel protein associated with language development, synaptic plasticity, tissue remodeling, and angiogenesis. We investigated the expression and spatial localization of SRPX2 in normal mouse, rat, monkey, and human brain using in situ hybridization and immunohistochemistry. Antibody specificity was determined using in vitro siRNA based silencing of SRPX2. Cell type-specific expression was verified by double-labeling with oxytocin or vasopressin. Western blot was used to detect SRPX2 protein in rat and human plasma and cerebrospinal fluid. Unexpectedly, SRPX2 mRNA expression levels were strikingly higher in the hypothalamus as compared to the cortex. All SRPX2 immunoreactive (ir) neurons were localized in the hypothalamic paraventricular, periventricular, and supraoptic nuclei in mouse, rat, monkey, and human brain. SRPX2 colocalized with vasopressin or oxytocin in paraventricular and supraoptic neurons. Hypothalamic SRPX2-ir positive neurons gave origin to dense projections traveling ventrally and caudally toward the hypophysis. Intense axonal varicosities and terminal arborizations were identified in the rat and human neurohypophysis. SRPX2-ir cells were also found in the adenohypophysis. Light SRPX2-ir projections were observed in the dorsal and ventral raphe, locus coeruleus, and the nucleus of the solitary tract in mouse, rat and monkey. SRPX2 protein was also detected in plasma and CSF. Our data revealed intense phylogenetically conserved expression of SRPX2 protein in distinct hypothalamic nuclei and the hypophysis, suggesting its active role in the hypothalamo-pituitary axis. The presence of SRPX2 protein in the plasma and CSF suggests that some of its functions depend on secretion into body fluids.

DNA methylation directly downregulates human cathelicidin antimicrobial peptide gene (CAMP) promoter activity

LL-37, the active product of human cathelicidin antimicrobial peptide (CAMP) has a broad spectrum of antibacterial activity. LL-37 also has important physiological functions in immune regulation, angiogenesis and in modulating apoptosis. The roles of LL-37 in oral squamous cell carcinoma (OSCC) are still not clear. The correlation between DNA methylation and human CAMP expression is also unknown. Here human CAMP/LL-37 expression was assessed by immunohistochemistry in normal and OSCC tissues. The results indicated that low expression of CAMP/LL-37 correlated with histological differentiation and lymph node metastasis and also promoted tumor progression. A cell-specific methylation pattern in the promoter region of human CAMP was detected. Treatment with 5-aza-2'-deoxycytidine, a DNA demethylation reagent can increase human CAMP expression in epithelial cancer cells. The reporter assay showed that unmethylated human CAMP promoter activity was significantly higher than methylated promoter activity. Taken together, these results suggested that human CAMP/LL-37 might act as a tumor-suppressor in OSCC and DNA methylation might play roles during carcinogenesis via directly downregulating human CAMP promoter activity.

MicroRNA-33a downregulation is associated with tumorigenesis and poor prognosis in patients with hepatocellular carcinoma

In order to examine the prognostic significance of miR-33a in patients with hepatocellular carcinoma (HCC), total RNA was extracted from 149 HCC biopsies, 36 of which were paired with para-carcinoma tissues, and miR-33a expression was measured by reverse transcription-quantitative polymerase chain reaction. The results demonstrated that miR-33a expression was decreased in HCC biopsies compared with normal liver tissue samples. It was also demonstrated that miR-33a expression was significantly associated with tumor foci number. Furthermore, overall and progression-free survival time was decreased in patients expressing low miR-33a with multiple tumor foci. Taken together, the low expression of miR-33a may be a potential risk factor for HCC.

miR‑149‑5p promotes chemotherapeutic resistance in ovarian cancer via the inactivation of the Hippo signaling pathway

Chemotherapeutic resistance remains a critical clinical issue is responsible for treatment failure in patients with ovarian cancer. Evidence of the involvement of miRNAs in chemoresistance in ovarian cancer has been recently emerging. However, the underlying molecular links between chemoresistance and miRNAs remain largely unknown. In this study, we report that miR-149-5p expression is markedly elevated in chemoresistant ovarian cancer tissues compared with the chemosensitive ovarian cancer tissues. Furthermore, the silencing of miR-149-5p enhanced the chemosensitivity of ovarian cancer cells to cisplatin in vitro and in vivo. Conversely, the upregulation of miR-149-5p aggravated chemoresistance in ovarian cancer cells. Our results further revealed that miR-149-5p directly targeted the core kinase components of the Hippo signaling pathway, STE20-like kinase (MST)1 and protein salvador homolog 1 (SAV1), resulting in the inactivation of TEA domain (TEAD) transcription. On the whole, our findings reveal a novel mechanism of of action miR-149-5p in inducing chemotherapeutic resistance in ovarian cancer, indicating that miR-149-5p may serve as a chemotherapeutic response indicator and a potential therapeutic target in ovarian cancer.

microRNA-149 targets caspase-2 in glioma progression

Malignant gliomas are the most common form of intrinsic primary brain tumors worldwide. Alterations in microRNAs play a role in highly invasive malignant glioma, but detail mechanism still unknown. In this study, the role and mechanism of microRNA-149 (miR-149) in glioma are investigated. We show that miR-149 is expressed at substantially higher levels in glioma than in normal tissues. Stable overexpression of miR-149 augments potent prosurvival activity, as evidenced by promotion of cell viability, inhibition of apoptosis, and induced xenografted tumor growth in vivo. We further show that Caspase-2 is identified as a functional target of miR-149 and expression of caspase-2 is inversely associated with miR-149 in vitro. In addition, miR-149 promotes tumor survival in the U87-MG and A172 cell lines and it targets caspase-2 via inactivation of the p53 and p21 pathways. There results support a special role for miR-149 by targeting Caspase-2 to impact on p53 signaling pathway. We speculate that miR-149 has distinct biological functions in p53 wild type cells and p53 mutation cells, and the mechanisms involved remain to be explored in future. Our study suggests that targeting miR-149 may be a novel therapy strategy for treating p53 wild type glioma tumors in humans.

miR-149 in Human Cancer: A Systemic Review

MicroRNAs (miRNAs) are small noncoding RNAs that regulate post-transcriptional gene expression via binding to the 3'-untranslated region (3'-UTR) of targeted mRNAs. They are reported to play important roles in tumorigenesis and progression of various cancers. Among them, miR-149 was confirmed to be aberrantly regulated in various tumors. In this review, we provide a complex overview of miR-149, particularly summarize the critical roles of it in cancers and expect to lay the foundation for future works on this important microRNA.

Epigenetic alterations leading to TMPRSS4 promoter hypomethylation and protein overexpression predict poor prognosis in squamous lung cancer patients

Non-small cell lung cancer (NSCLC) is the leading cause of cancer-related death worldwide, which highlights the need of innovative therapeutic options. Although targeted therapies can be successfully used in a subset of patients with lung adenocarcinomas (ADC), they are not appropriate for patients with squamous cell carcinomas (SCC). In addition, there is an unmet need for the identification of prognostic biomarkers that can select patients at risk of relapse in early stages. Here, we have used several cohorts of NSCLC patients to analyze the prognostic value of both protein expression and DNA promoter methylation status of the prometastatic serine protease TMPRSS4. Moreover, expression and promoter methylation was evaluated in a panel of 46 lung cancer cell lines. We have demonstrated that a high TMPRSS4 expression is an independent prognostic factor in SCC. Similarly, aberrant hypomethylation in tumors, which correlates with high TMPRSS4 expression, is an independent prognostic predictor in SCC. The inverse correlation between expression and methylation status was also observed in cell lines. In vitro studies showed that treatment of cells lacking TMPRSS4 expression with a demethylating agent significantly increased TMPRSS4 levels. In conclusion, TMPRSS4 is a novel independent prognostic biomarker regulated by epigenetic changes in SCC and a potential therapeutic target in this tumor type, where targeted therapy is still underdeveloped.

miR-133b suppresses metastasis by targeting HOXA9 in human colorectal cancer

Functions and mechanisms of microRNA (miRNA) involved in colorectal cancer (CRC) metastasis are largely unknown. Here, a miRNA microarray analysis was performed in CRC primary tissues and metastatic hepatic tissues to disclose crucial miRNA involved in CRC metastasis. MiR-133b was decreased and negatively correlated with metastasis in CRC. Overexpression of miR-133b significantly suppressed metastasis of CRC in vitro and in vivo. HOXA9 was identified as a direct and functional target of miR-133b. In addition, HOXA9 was negatively correlated with miR-133b and promoted CRC malignant progress. Moreover, miR-133b decreased HOXA9 expression, and subsequently downregulated ZEB1 and upregulated E-cadherin expression. Intriguingly, lower miR-133b and higher HOXA9 expression significantly contributed to poorer outcomes in CRC patients. Multivariate analysis indicated that miR-133b was an independent and significant predictor of CRC patient overall survival. In conclusion, we newly determined that miR-133b targeted the HOXA9/ZEB1 pathway to promote tumor metastasis in CRC cells. This axis provided insights into the mechanism underlying miRNA regulation of CRC metastasis and a novel therapeutic target for CRC treatment.

The Effects of CpG Densities around Transcription Start Sites on Sex-Biased Gene Expression in Poecilia reticulata

As most genes are shared between females and males, DNA methylation is assumed to play a crucial role in sex-biased gene expression. DNA methylation exclusively occurs at CpG dinucleotides, and therefore, we would expect that CpG density around transcription start sites (TSSs) relate to sex-biased gene expression. Here we investigated the relationship between CpG densities around TSSs and the ratio of gene expression levels between sexes in the guppy (Poecilia reticulata), which displays remarkable sexual dimorphisms. We found that genes with sex-biased gene expression had different CpG densities downstream of TSSs compared with genes lacking sex-biased gene expression. Intriguingly, male-biased expression genes with intermediate CpG density downstream of TSSs exhibited greater differences in gene expression between sexes in the gonad and tail. Our findings suggested the possibility that CpGs around TSSs, especially in the downstream regions, play a crucial role in sex-biased gene expression through DNA methylation.

miR-149 represses metastasis of hepatocellular carcinoma by targeting actin-regulatory proteins PPM1F

microRNAs have been implicated in hepatocellular carcinoma (HCC) metastasis, which is predominant cause of high mortality in these patients. Although an increasing body of evidence indicates that miR-149 plays an important role in the growth and metastasis of multiple types of cancers, its role in the progression of HCC remains unknown. Here, we demonstrated that miR-149 was significantly down-regulated in HCC, which was correlated with distant metastasis and TNM stage with statistical significance. A survival analysis showed that decreased miR-149 expression was correlated with a poor prognosis of HCC as well. We found that over-expression of miR-149 suppressed migration and invasion of HCC cells in vitro. In addition, we identified PPM1F (protein phosphatase, Mg(2+)/Mn(2+)-dependent, 1F) as a direct target of miR-149 whose expression was negatively correlated with the expression of miR-149 in HCC tissues. The re-expression of PPM1F rescued the miR-149-mediated inhibition of cell migration and invasion. miR-149 regulated formation of stress fibers to inhibit migration, and re-expression of PPM1F reverted the miR-149-mediated loss of stress fibers. Moreover, we demonstrated that over-expression of miR-149 reduced pMLC2, a downstream effector of PPM1F, in MHCC-97H cells. In vivo studies confirm inhibition of HCC metastasis by miR-149. Taken together, our findings indicates that miR-149 is a potential prognostic biomarker of HCC and that the miR-149/PPM1F regulatory axis represents a novel therapeutic target for HCC treatment.

Tumor suppressor miR-149-5p is associated with cellular migration, proliferation and apoptosis in renal cell carcinoma

Several studies have recently explored the role of microRNAs (miRNAs, miRs) in the tumorigenesis of various types of cancer. miRNAs have been reported to be involved in numerous cell processes, including cell apoptosis, proliferation and migration, thus suggesting that miRNAs may have an important role in cancer progression. Downregulation of miR-149-5p has been detected in RCC tissues by microarray profiling; however, its expression and function in RCC has yet to be elucidated. In the present study, reverse transcription‑quantitative polymerase chain reaction was performed to detect the expression levels of miR‑149‑5p in RCC tissues and paired normal tissues. In order to determine whether miR-149-5p was able to regulate cell proliferation, apoptosis or migration, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, flow cytometric and wound healing assays were conducted. The results demonstrated that miR‑149‑5p was significantly downregulated in RCC tissues compared with in normal tissues (P<0.05). The restoration of miR-149-5p expression using synthetic mimics suppressed cell proliferation and migration, and promoted cell apoptosis. These results indicated that miR‑149‑5p may act as a tumor suppressor in RCC. The present study is the first, to the best of our knowledge, to identify miR‑149‑5p as a tumor suppressor in RCC. Future studies will be focused on the potential role of miR‑149‑5p as a biomarker for the early detection and prognostic prediction of RCC, and as a therapeutic target in RCC. In addition, further exploration regarding the pathways underlying the effects of miR‑149‑5p in RCC is required.

miR-149 controls non-alcoholic fatty liver by targeting FGF-21

Non‐alcoholic fatty liver disease (NAFLD), a lipid metabolism disorder characterized by the accumulation of intrahepatic fat, has emerged as a global public health problem. However, its underlying molecular mechanism remains unclear. We previously have found that miR‐149 was elevated in NAFLD induced by high‐fat diet mice model, whereas decreased by a 16‐week running programme. Here, we reported that miR‐149 was increased in HepG2 cells treated with long‐chain fatty acid (FFA). In addition, miR‐149 was able to promote lipogenesis in HepG2 cells in the absence of FFA treatment. Moreover, inhibition of miR‐149 was capable of inhibiting lipogenesis in HepG2 cells in the presence of FFA treatment. Meanwhile, fibroblast growth factor‐21 (FGF‐21) was identified as a target gene of miR‐149, which was demonstrated by the fact that miR‐149 could negatively regulate the protein expression level of FGF‐21, and FGF‐21 was also responsible for the effect of miR‐149 inhibitor in decreasing lipogenesis in HepG2 cells in the presence of FFA treatment. These data implicate that miR‐149 might be a novel therapeutic target for NAFLD.

MicroRNAs as growth regulators, their function and biomarker status in colorectal cancer

Gene expression is in part regulated by microRNAs (miRNAs). This review summarizes the current knowledge of miRNAs in colorectal cancer (CRC); their role as growth regulators, the mechanisms that regulate the miRNAs themselves and the potential of miRNAs as biomarkers. Although thousands of tissue samples and bodily fluids from CRC patients have been investigated for biomarker potential of miRNAs (>160 papers presented in a comprehensive tables), none single miRNA nor miRNA expression signatures are in clinical use for this disease. More than 500 miRNA-target pairs have been identified in CRC and we discuss how these regulatory nodes interconnect and affect signaling pathways in CRC progression.

Demethylation of the MafB promoter in a compromised β-cell model

Recent studies suggest that dedifferentiation of pancreatic β-cells is involved in compromised β-cell function in diabetes mellitus. We have previously shown that the promoter activity of MafB, which is expressed in α-cells of adult islets and immature β-cells in embryonic pancreas but not in mature β-cells in mice, is increased in compromised β-cells of diabetic model mice. Here, we investigated a rat β-cell line of INS1 cells with late-passage numbers, which showed extremely low expression of MafA and insulin, as an in vitro model of compromised β-cells. In these INS1 cells, the mRNA expression and the promoter activity of MafB were upregulated compared with the early-passage ('conventional') INS1 cells. Analysis of the MafB promoter in these late-passage INS1 cells revealed that specific CpG sites in the MafB promoter were partially demethylated. The reporter assay revealed that the unmethylated promoter activity of the 373 bp region containing these CpG sites was higher than the in vitro methylated promoter activity. These results suggest that the chronic culture of the rat β-cell line resulted in partial DNA demethylation of the MafB promoter, which may have a role in MafB promoter activation and possible dedifferentiation in our compromised β-cell model.

Increased urothelial cancer associated 1 is associated with tumor proliferation and metastasis and predicts poor prognosis in colorectal cancer

Long non-coding RNA, urothelial cancer associated 1 (UCA1), is reported to play a critical role in progression of carcinogenesis. In the present study, we identified differential expression of UCA1 in colorectal cancer (CRC) and paired peritumoral tissues using gene expression microarray analyses. qPCR analysis confirmed that UCA1 was upregulated in CRC (p<0.001) and the expression of UCA1 was statistically correlated with lymph node metastasis (P=0.040), distant metastasis (P=0.043) and tumor stage (P=0.010). Kaplan-Meier analysis indicated that patients with high UCA1 expression had a poor prognosis. Moreover, multivariate analysis identified UCA1 overexpression as an independent predictor for CRC. We also found that knockdown of UCA1 significantly suppressed cell proliferation and metastasis in CRC cells. Flow cytometry assays showed UCA1 silencing induced G0/G1 growth arrest and apoptosis of CRC cells. To further investigate the regulatory mechanisms of UCA1, we identified that Ets-2 bound to the UCA1 core promoter using luciferase assays. Collectively, our findings suggested that UCA1 might be an important prognostic indicator in CRC and may be a potential target for diagnosis and gene therapy.

Associations of Polymorphisms in mir-196a2, mir-146a and mir-149 with Colorectal Cancer Risk: A Meta-Analysis

MicroRNAs (miRNAs) are non-coding RNAs which act as tumor suppressors or oncogenes. And single nucleotide polymorphism (SNP) in miRNA regions is one type of genetic variations in human genome. Various studies have investigated the associations of miRNAs SNP and kinds of cancers. In this article, we searched eligible studies to explore the relationships between mir-196a2 /mir-146a /mir-149 polymorphisms and colorectal cancer (CRC). A literature search of PubMed, Web of Science and ScienceDirect was conducted to identify all relevant studies. Three genetic models with pooled ratio and 95% confidence interval were used to evaluate the associations. We found that mir-196a2 polymorphism was significantly associated with CRC in Asian group (additive model: OR = 1.197, 95%CI 1.084 ~ 1.32, P < 0.001; dominant model: OR = 1.247, 95%CI 1.065 ~ 1.46, P = 0.006; recessive model: OR = 1.298, 95%CI 1.101 ~ 1.531, P = 0.002). And no associations were observed between SNPs of mir-146a, mir-149 and CRC in three genetic models. We also found CRC risk was not associated with mir-146a and mir-149 polymorphisms in population subgroup analysis. The current meta-analysis suggests that mir-196a2 polymorphism is associated with CRC, especially in Asian group. While, no associations have been found between mir-146a /mir-149 polymorphisms and CRC.

Increased Sushi repeat-containing protein X-linked 2 is associated with progression of colorectal cancer

Sushi repeat-containing protein X-linked 2 (SRPX2) is a novel chondroitin sulfate proteoglycan overexpressed in gastrointestinal cancer. Its role in tumor biology remains unknown. The aim of this study was to investigate the expression of SRPX2 in colorectal cancer and its potential association with cancer progression. The expression of SRPX2 and its clinicopathological significance was evaluated using immunohistochemistry in a tissue microarray including 88 colon cancer and pairing normal tissues. The impact of SRPX2 on behavior of colorectal cancer cells and possible mechanism was explored using gene transfection and silencing. Strong staining of SRPX2 was noted in 71 (80.7 %) of 88 colon cancer specimen and 30 (34.1 %) of 88 adjacent normal tissues (P < 0.001). The expression of SRPX2 was significantly correlated with histological differentiation grade (P = 0.003), infiltration depth (P = 0.003), and clinical stage (P = 0.006). The expression of SRPX2 was significantly higher in HCT116 than in HT29 and SW480 cells. Suppression of endogenous SRPX2 expression by small interfering ribonucleic acid (siRNA) in HCT116 cells resulted in significant reduction in the ability of cell proliferation, adhesion, migration, and invasion. Up-regulation of endogenous SRPX2 in SW480 cells significantly promoted the migration and invasion of SW480 cells. In addition, inhibition of SRPX2 by siRNA led to notable down-regulation of β-catenin, matrix metalloproteinase (MMP)-2, and MMP-9. These findings indicate that overexpressed SRPX2 exerts an oncogenic role in colorectal cancer. SRPX2 may promote the invasion of colorectal cancer through MMP-2 and MMP-9 modulated by Wnt/β-catenin pathway.

Integrative analysis of differentially expressed microRNAs of pulmonary alveolar macrophages from piglets during H1N1 swine influenza A virus infection

H1N1 swine influenza A virus (H1N1 SwIV) is one key subtype of influenza viruses with pandemic potential. MicroRNAs (miRNAs) are endogenous small RNA molecules that regulate gene expression. MiRNAs relevant with H1N1 SwIV have rarely been reported. To understand the biological functions of miRNAs during H1N1 SwIV infection, this study profiled differentially expressed (DE) miRNAs in pulmonary alveolar macrophages from piglets during the H1N1 SwIV infection using a deep sequencing approach, which was validated by quantitative real-time PCR. Compared to control group, 70 and 16 DE miRNAs were respectively identified on post-infection day (PID) 4 and PID 7. 56 DE miRNAs were identified between PID 4 and PID 7. Our results suggest that most host miRNAs are down-regulated to defend the H1N1 SwIV infection during the acute phase of swine influenza whereas their expression levels gradually return to normal during the recovery phase to avoid the occurrence of too severe porcine lung damage. In addition, targets of DE miRNAs were also obtained, for which bioinformatics analyses were performed. Our results would be useful for investigating the functions and regulatory mechanisms of miRNAs in human influenza because pig serves as an excellent animal model to study the pathogenesis of human influenza.

Association of the miR-149 Rs2292832 polymorphism with papillary thyroid cancer risk and clinicopathologic characteristics in a Chinese population

(1) Background: The genetic predisposition to papillary thyroid cancer (PTC) is far from clearly elucidated. Rs2292832 is a genetic polymorphism that located in the precursor of mir-149 and has been studied in diverse cancers. Thus far, the role of rs2292832 in PTC tumorigenesis and progression was unclear; (2) Method: Rs2292832 was genotyped in 838 PTCs, 495 patients with thyroid benign tumors (BNs) and 1006 controls in a Chinese Han population. Clinicopathological data was collected and compared. The expression level of mature mir-149 was examined in 55 normal thyroid tissue samples; (3) Results: The CC genotype of rs2292832 was significantly associated with an increased risk of PTC compared with TT homozygote (OR = 1.60, 95% CI: 1.72–2.20, p = 0.003) and TT/TC combined genotype (OR = 1.54, 95% CI: 1.14–2.09, p = 0.005). Rs2292832 is an independent risk factor correlated with tumor invasion (p = 0.006) and higher T stage in PTC patients (p = 0.007), but uncorrelated with short-term disease persistence of PTC. PTC subjects carrying CC genotype have lower mir-149-5p expression than those with TC genotype (p = 0.002). Twelve predicted target genes have been identified by collaboratively using computational tools; (4) Conclusion: Rs2292832 was possibly involved in the susceptibility and local progression of PTC in Chinese patients, by altering the expression level of mir-149-5p and its target genes.