Showing papers in "American Journal of Translational Research in 2015"

Epithelial-mesenchymal transition in gastric cancer.

Abstract: Gastric cancer (GC) is one of the most common malignancies worldwide with poor prognosis for lack of early detection and effective treatment modalities. The significant influence of tumor microenvironment on malignant cells has been extensively investigated in this targeted-therapy era. Epithelial-mesenchymal transition (EMT) is a highly conserved and fundamental process that is critical for embryogenesis and some other pathophysiological processes, especially tumor genesis and progression. Aberrant gastric EMT activation could endow gastric epithelial cells with increased mesenchymal characteristics and less epithelial features, and promote cancer cell stemness, initiation, invasion, metastasis, and chemo-resistance with cellular adhesion molecules especially E-cadherin concomitantly repressed, which allows tumor cells to disseminate and spread throughout the body. Some pathogens, stress, and hypoxia could induce and aggravate GC via EMT, which is significantly correlated with prognosis. GC EMT is modulated by diverse micro-environmental, membrane, and intracellular cues, and could be triggered by various overexpressed transcription factors, which are downstream of several vital cross-talking signaling pathways including TGF-β, Wnt/β-catenin, Notch, etc. microRNAs also contribute significantly to GC EMT modulation. There are currently some agents which could suppress GC EMT, shedding light on novel anti-malignancy strategies. Investigating potential mechanisms modulating GC cell EMT and discovering novel EMT regulators will further elucidate GC biology, and may provide new biomarkers for early GC detection and potentially efficient targets for preventative and curative anti-GC intervention approaches to prevent local and distant invasions.

Potential mechanisms underlying the Runx2 induced osteogenesis of bone marrow mesenchymal stem cells.

Abstract: Bone marrow derived mesenchymal stem cells (BM-MSCs) belong a type of pluripotent stem cells and can be induced to differentiate into osteoblasts (OB). Runt-related transcription factor 2 (Runx2) is an osteogenesis specific transcription factor and plays an important role in osteogenesis of BM-MSCs. It can promote the expression of osteogenesis related genes, regulate cell cycle progression, improve bone microenvironment and affect functions of chondrocytes and osteoclasts, which have involvement of a large amount of signal molecules including TGF-β, BMP, Notch, Wnt, Hedgehog, FGF and microRNA. In this paper, we summarize the mechanisms underlying the Runx2 induced osteogenesis of BM-MSCs.

Diverse involvement of EZH2 in cancer epigenetics.

Abstract: EZH2 is the catalytic subunit of Polycomb Repressor Complex 2 (PRC2) which catalyzes methylation of histone H3 at lysine 27 (H3K27me) and mediates gene silencing of target genes via local chromatin reorganization. Numerous evidences show that EZH2 plays a critical role in cancer initiation, progression and metastasis, as well as in cancer stem cell biology. Indeed, EZH2 dysregulation alters gene expression programs in various cancer types. The molecular mechanisms responsible for EZH2 alteration appear to be diverse and depending on the type of cancer. Furthermore, accumulating evidences indicate that EZH2 could also act as a PRC2-independent transcriptional activator in cancer. In this review, we address the current understanding of the oncogenic role of EZH2, including the mechanisms of EZH2 dysregulation in cancer and progresses in therapeutic approaches targeting EZH2.

Plant-derived neuroprotective agents in Parkinson’s disease

Abstract: Parkinson's disease (PD) is one of the most common degenerative disorders of the central nervous system among the elderly. The disease is caused by the slow deterioration of the dopaminergic neurons in the substantia nigra. Treatment strategies to protect dopaminergic neurons from progressive damage have received much attention. However there is no effective treatment for PD. Traditional Chinese medicines have shown potential clinical efficacy in attenuating the progression of PD. Increasing evidence indicates that constituents of some Chinese herbs include resveratrol, curcumin, and ginsenoside can be neuroprotective. Since pathologic processes in PD including inflammation, oxidative stress, apoptosis, mitochondrial dysfunction, and genetic factors lead to neuronal degeneration, and these Chinese herbs can protect dopaminergic neurons from neuronal degeneration, in this article, we review the neuroprotective roles of these herbs and summarize their anti-inflammatory, antioxidant, and anti-apoptotic effects in PD. In addition, we discuss their possible mechanisms of action in in vivo and in vitro models of PD. Traditional Chinese medicinal herbs, with their low toxicity and side-effects, have become the potential therapeutic interventions for prevention and treatment of PD and other neurodegenerative diseases.

A non-invasive miRNA based assay to detect bladder cancer in cell-free urine.

Abstract: RNA from cell-free urine was analyzed in an attempt to identify a microRNA (miRNA) profile that could be used as a non-invasive diagnostic assay to detect the presence of urothelial carcinoma of the bladder (UCB) and provide a discriminatory signature for different stages of progression. In addition, the presence of specific miRNAs co-isolating with urinary extracellular vesicles/exosomes was investigated. RNA was isolated from cell-free urine of patients diagnosed with UCB (TaG1, T1G3, ≥T2, CIS) and control patients (healthy control and UCB patients with no evidence of disease). MiRNAs were profiled by qRT-PCR array on pooled samples within each group. Validation of the miRNAs was performed on individual samples using qRT-PCR. Extracellular vesicles were isolated via ultracentrifugation. 236 miRNAs were detected in at least one of the pooled samples. Seven of the miRNAs validated on individual samples had significantly higher levels in the cancer group. A panel of miRNAs discriminated between cancer and cancer-free patients with a sensitivity of 88% and specificity of 78%, (AUC=88.8%). We recorded a sensitivity of 80% for TaG1, 95% for T1G3, 90% for ≥T2 with specificity of 77% for healthy controls and 80% for no evidence of disease. Select miRNAs were detected in extracellular vesicles of UCB patients and healthy controls, albeit at different levels. Utilizing this non-invasive assay, we identified miRNA capable of detecting UCB and distinguishing different stages of progression, providing evidence that miRNA profiling in cell-free urine holds promise for the development of valuable clinical diagnostic tools.

MiRNA-155 mediates TAM resistance by modulating SOCS6-STAT3 signalling pathway in breast cancer.

Abstract: Breast cancer is the second leading cause of cancer induced death in women. Tamoxifen is an endocrine therapy which is administered to 70% of all breast cancer patients with estrogen receptor alpha (ERα) expression. Despite the initial response, most patients eventually acquire resistance to the drug. MicroRNAs (miRNAs) are a class of small non-coding RNAs which have the ability to post-transcriptionally regulate gene expression. Although the role of a few miRNAs has been described in tamoxifen resistance, little is known about how concerted actions of miRNAs targeting biological networks contribute to its resistance. In this study, we identified that miR-155 is frequently up-regulated in breast cancer with tamoxifen resistance. Ectopic expression of miR-155 induces cell survival and resistance to TAM, whereas inhibition of miR-155 causes cells to apoptosis and enhances TAM sensitivity. Further, we identified SOCS6 as a new direct target of miR-155. Sustained overexpression of miR-155 resulted in repression of SOCS6 protein and mRNA levels, and knockdown of miR-155 increased SOCS6 expression. Introduction of SOCS6 cDNA lacking the 3'-UTR abrogated miR-155-induced cell survival and chemoresistance. Finally, it was verified that SOCS6 or inhibition of STAT3 could inhibit miR-155 STAT3 activation and cell proliferation. In conclusion, our study reveals a molecular link between miR-155 and SOCS6-STAT3 and presents an evidence that miR-155 is a critical therapeutic target in breast cancer.

Linc-POU3F3 promotes cell proliferation in gastric cancer via increasing T-reg distribution.

Abstract: Long noncoding RNA (lncRNA) have been proved to participate in the oncogenesis or development of gastrointestinal tumors. In this study, we aimed to identify the function of lncRNAs in the differentiation of peripheral blood T cells especially the distribution of regulatory T cells (T-reg) in gastric cancer. The distribution of T-reg was detected by flow cytometry. Peripheral blood T-reg cells were significantly up-regulated in plasma samples of gastric cancer patients. LncRNA microarray detection indicated an aberrant expression profiling of lncRNAs in T-reg cells between gastric cancer patients and controls in which linc-POU3F3 was selected as a potential biomarker with the highest fold change value as well as the most stable expression level in each group. In addition, over-expression of linc-POU3F3 elevated Treg distribution in vitro and promoted tumor cell proliferation in the co-culture system. We further found that linc-POU3F3 could recruit TGF-beta which increased the phosphorylation of SMAD2/3. In conclusion, we found that linc-POU3F3 could promote the distribution of Tregs in peripheral blood T cell which caused an enhanced cell proliferation of gastric cancer cells by recruiting TGF-beta as well as activating TGF-beta signal pathway. This finding may provide a theoretical basis for the further exploration of lncRNAs function in immune cell cells of gastric cancer.

Cytokine networking of chondrocyte dedifferentiation in vitro and its implications for cell-based cartilage therapy

Abstract: Autologous chondrocyte implantation (ACI) is a golden treatment for large defects of the knee joint without osteoarthritis or other complications. Despite notable progresses, generation of a stable chondrocyte phenotype using progenitor cells remains a main obstacle for chondrocyte-based cartilage treatment. Monolayer chondrocyte expansion in vitro is accompanied by chondrocyte dedifferentiation, which produces a non-specific mechanically inferior extracellular matrix (ECM) unsuitable for ACI. In-depth understanding of the molecular events during chondrocyte dedifferentiation is required to maintain the capacity of in vitro expanded chondrocytes to produce hyaline cartilage-specific ECM. This review discusses key cytokines and signaling pathways involved in chondrocyte dedifferentiation from the standpoint of catabolism and anabolism. Some potential therapeutic strategies are also presented to counteract chondrocyte dedifferentiation for cell-based cartilage therapy.

Evading anti-angiogenic therapy: resistance to anti-angiogenic therapy in solid tumors.

Abstract: Vascular endothelial growth factor (VEGF) dependent tumor angiogenesis is an essential step for the initiation and promotion of tumor progression. The hypothesis that VEGF-driven tumor angiogenesis is necessary and sufficient for metastatic progression of the tumor, has been the major premise of the use of anti-VEGF therapy for decades. While the success of anti-VEGF therapy in solid tumors has led to the success of knowledge-based-therapies over the past several years, failures of this therapeutic approach due to the development of inherent/acquired resistance has led to the increased understanding of VEGF-independent angiogenesis. Today, tumor-angiogenesis is not a synonymous term to VEGF-dependent function. The extensive study of VEGF-independent angiogenesis has revealed several key factors responsible for this phenomenon including the role of myeloid cells, and the contribution of entirely new phenomenon like vascular mimicry. In this review, we will present the cellular and molecular factors related to the development of anti-angiogenic resistance following anti-VEGF therapy in different solid tumors.

Introduction to next generation of endothelial progenitor cell therapy: a promise in vascular medicine.

Abstract: The concept of Endothelial Progenitor Cells (EPCs) therapy for adult neovascularization has continuously received attention. They are believed to participate in endothelial repair and post natal angiogenesis due to their abilities in differentiating into endothelial cells and producing protective cytokines and growth factors. Abundant evidence supports the involvement of EPCs in capillary growth and in participating in the formation of collateral vessels, which lead to improved vascular perfusion and functional recovery in target tissue. Autologous EPC now is becoming a novel treatment option for therapeutic revascularization and vascular repair in ischemic diseases. However, various diseases such as diabetes, heart disease and ischemic diseases are related to EPC dysfunction and give rise to additional challenges of autologous EPC therapy. A novel strategy to enhance the number and function of EPCs is needed to be established to provide successful autologous EPCs therapy. Currently, clinical trials for the new generation of EPC therapy in treating peripheral ischemic diseases are underway. In this review we provide an overview and the limitations of current EPCs therapy with an introduction to the new strategies of next generation EPC therapy for more promising vascular and tissue regeneration therapy.

A critical role for HER3 in HER2-amplified and non-amplified breast cancers: function of a kinase-dead RTK

Abstract: ERBB3/HER3 is the most intriguing RTK by virtue of its ability to transduce multiple cytosolic signals for the proliferation and growth of tumor cells in spite of being a “kinase dead” receptor that binds to its true ligand, heregulin. Although other members of the HER3 family like EGFR and HER2 have long been recognized to be associated with breast tumorigenesis and studied because of their predictive and prognostic value, the significance of HER3 as an irrefutable component of HER family signalosome is a relatively new development. The recent understanding of signals originating from the oncogenic partnership of HER3 with HER2 in the context of HER2 amplification/overexpression showed the critical clinical value for the treatment of HER2+BC. The downstream signaling cascade (included but not limited to the PI3K signaling) associated with signals originating from HER2:HER3 dimers play a vital role in the tumorigenesis, drug-resistance and tumor progression of HER2+BC. The upregulation of HER3 activity provides an alternate “escape route” via which tumor cells bypass either the inhibition of the HER family RTKs or the inhibition of the downstream PI3K-AKT-mTOR signaling pathway. By understanding the signaling that provides this “escape route” for these tumor cells treated with a targeted therapy (HER2 inhibitors or inhibitors of downstream PI3K-AKT-mTOR signaling pathway), we are just beginning to appreciate the prognostic value of HER3 in breast cancer. In this review, we will discuss the relevance of HER3 signaling in the context of, (1) downstream oncogenic signals and (2) therapeutic options in HER2 amplified BC.

Mangiferin suppresses CIA by suppressing the expression of TNF-α, IL-6, IL-1β, and RANKL through inhibiting the activation of NF-κB and ERK1/2

Abstract: Rheumatoid arthritis is a systemic autoimmune disease characterized by chronic inflammation of synovial joints, ultimately leading to a progressive and irreversible joint destruction. Activation of nuclear factor-kappa B (NF-κB) promotes production of proinflammatory cytokines in various inflammatory diseases including rheumatoid arthritis. Mangiferin, 1,3,6,7-tetrahydroxyxanthone-C2-β-D-glucoside (C-glucosyl xanthone), is a naturally occurring polyphenol. Our previous results showed that mangiferin suppressed NF-κB activation. However, it is unclear, whether mangiferin can prevent rheumatoid arthritis through suppression of NF-κB activation and expression of various cytokines, such as tumor necrosis factor α (TNF-α) and interleukin-6 (IL-6), which play a critical role in the pathogenesis of rheumatoid arthritis. In the present study, we found that mangiferin suppressed the progression and incidence of CIA in DBA1/J mice. In CIA mice, mangiferin inhibited the mRNA expression of cytokine genes in thymus and spleen of CIA mie and led to decreased serum levels of IL-1β, IL-6, TNF-α, and receptor activator NF-κB ligand (RANKL) via inhibition of NF-κB and activation of extracellular signal-regulated kinase 1/2 (ERK1/2). In addition, mangiferin markedly inhibited not only developing but also clinically evident CIA. These findings suggest that mangiferin has potential clinical applications for the treatment of rheumatoid arthritis.

Isolation, primary culture, morphological and molecular characterization of circulating tumor cells in gynecological cancers.

Abstract: The focus of the study was to implement a new workflow for circulating tumor cells (CTCs) characterization that would allow the analysis of CTCs on a cytomorphological and molecular level in patients with diagnosed gynecological cancer. Our findings may be useful in future cancer patient management. The study introduces a size-based enrichment (MetaCell®) method for the separation of viable CTCs, followed by CTCs culturing in vitro and gene expression characterization. It is based on the observation of CTCs and DTCs (Disseminated Tumor Cells) in several case studies of ovarian, endometrial and cervical cancer by means of cytomorphology and gene expression profiling. The viability of the enriched CTCs was estimated using vital and lethal fluorescence nuclear staining. This type of staining may be predictive for the success rate of subsequent CTC growth in vitro. To identify CTCs in the enriched CTC fraction, cytomorphological evaluations based on vital fluorescence staining were followed by gene expression analysis of tumor-associated (TA) genes. Cytokeratin expression (KRT7, KRT19) was analyzed in combination with MUC1, MUC16, CD24, CD44 and ALDH1. Gene expression analysis has shown that short-term in vitro culture enhanced the differentiation process of the captured CTCs growing on a membrane. On the other hand, redundant white blood cells captured on the membrane were eliminated during a short-term culture. The most frequently elevated genes in ovarian cancer (serous type) are EPCAM, KRT19 and MUC1. It has been demonstrated that CTC presence revealed by cytomorphological evaluation may be usefully complemented by TA-gene expression analysis, to increase the sensitivity of the analysis.

miR-485-5p acts as a negative regulator in gastric cancer progression by targeting flotillin-1.

Abstract: MicroRNAs (miRNAs) play important roles in cancer progression including gastric cancer. miR-485-5p is reported as a potential suppressor in breast cancer, but its expression, cellular function and clinic features in gastric cancer is not known. In our study, we found that miR-485-5p expression was down-regulated in gastric cancer cell lines. miR-485-5p could inhibit gastric cancer cell growth in vitro and in vivo. We also found that miR-485-5p suppressed gastric cancer cell metastasis and sphere formation. It was confirmed flotillin-1 (Flot1) as a direct target of miR-485-5p, and up-regulation of miR-485-5p could decrease expression of Flot1 in gastric cancer cells. Further investigation showed that ectopic expression of Flot1 partially reversed the inhibition effect of enforced miR-485-5p expression on the malignant phenotypes of gastric cancer cells. The low expression of miR-485-5p in gastric cancer tissues was related to advanced clinical features and poorer prognosis. Our study suggested that miR-485-5p could be a potential prognostic marker and functions as a tumor suppressor in human gastric cancer by post-transcriptionally targeting Flot1.

miR-873 induces lung adenocarcinoma cell proliferation and migration by targeting SRCIN1

Abstract: microRNAs (miRNAs) are endogenously expressed, conserved and small noncoding RNA that regulate gene expression by the post-transcriptional level. In this study, we aim to examine the role of miR-873 in lung adenocarcinoma. We found that the expression of miR-873 was upregulated in four lung adenocarcinoma cell lines and tissues. In addition, the expression levels of SRCIN1 were inversely correlated with the expression levels of miR-873 in lung adenocarcinoma tissues. Furthermore, SRCIN1 was confirmed asthe direct target of miR-873 by luciferase reporter assay and Western blotting. Overexpression of miR-873 promoted the proliferation and migration of lung adenocarcinoma cells, while SRCIN1 upregulation inhibited their proliferation and migration. Restoration of SRCIN1 could significantly reverse the proliferation and migration promotion imposed by miR-873. In summary, this study reveals for the first time that miR-873 increase the lung adenocarcinoma cell proliferation and migration through directly inhibiting SRCIN1 expression.

Adipose-derived mesenchymal stem cells embedded in platelet-rich fibrin scaffolds promote angiogenesis, preserve heart function, and reduce left ventricular remodeling in rat acute myocardial infarction.

Abstract: Objective: This study tested the hypothesis that autologous adipose-derived mesenchymal stem cells (ADMSCs) embedded in platelet-rich fibrin (PRF) can significant promote myocardial regeneration and repair after acute myocardial infarction (AMI). Summary background: With avoiding the needle-related complications, PRF-embedded autologous ADMSCs graft provides a new effective stem cell-based therapeutic strategy for myocardial repair. Methods: Adult male Sprague-Dawley rats were equally divided (n = 8 per group) into group 1 (sham-operated), group 2 (AMI by ligating left coronary artery), group 3 (AMI+ PRF), and group 4 (AMI+PRF-embedded autologous ADMSCs). RPF with or without ADMSCs was patched on infarct area 1h after AMI induction. All animals were sacrificed on day 42 after echocardiography. Results: Left ventricular (LV) dimension and infarct/fibrotic areas were lowest in group 1, highest in group 2, in group 3 higher than in group 4, whereas LV performance and wall thickness exhibited a reversed pattern in all groups (all p < 0.001). Protein expressions of inflammatory (MMP-9, IL-1β), oxidative, apoptotic (Bax, cleaved PARP), fibrotic (Smad 3, TFG-β), hypertrophic (β-MHC), and heart failure (BNP) biomarkers displayed an identical pattern in infarct/fibrotic areas, whereas the protein expressions of anti-inflammatory (IL-10), anti-apoptotic (Bcl-2), anti-fibrotic (Smad1/5, BMP-2) biomarkers and α-MHC showed an opposite pattern (all p < 0.01). Angiogenic activities (c-Kit+, Sca-1+, CD31+, SDF-1α+, CXCR4+ cells; protein expressions of SDF-1α, CXCR4, VEGF) were highest in group 4 and lowest in group 1 (all p < 0.001). Conclusion: ADMSCs embedded in PRF offered significant benefit in preserving LV function and limiting LV remodeling after AMI.

Dystrophin-deficient large animal models: translational research and exon skipping

Abstract: Duchenne muscular dystrophy (DMD) is an X-linked recessive genetic disorder caused by mutations in the dystrophin gene. Affecting approximately 1 in 3,600-9337 boys, DMD patients exhibit progressive muscle degeneration leading to fatality as a result of heart or respiratory failure. Despite the severity and prevalence of the disease, there is no cure available. While murine models have been successfully used in illustrating the mechanisms of DMD, their utility in DMD research is limited due to their mild disease phenotypes such as lack of severe skeletal muscle and cardiac symptoms. To address the discrepancy between the severity of disease displayed by murine models and human DMD patients, dystrophin-deficient dog models with a splice site mutation in intron 6 were established. Examples of these are Golden Retriever muscular dystrophy and beagle-based Canine X-linked muscular dystrophy. These large animal models are widely employed in therapeutic DMD research due to their close resemblance to the severity of human patient symptoms. Recently, genetically tailored porcine models of DMD with deleted exon 52 were developed by our group and others, and can potentially act as a new large animal model. While therapeutic outcomes derived from these large animal models can be more reliably extrapolated to DMD patients, a comprehensive understanding of these models is still needed. This paper will discuss recent progress and future directions of DMD studies with large animal models such as canine and porcine models.

HOTAIR is a predictive and prognostic biomarker for patients with advanced gastric adenocarcinoma receiving fluorouracil and platinum combination chemotherapy.

Abstract: Accumulating evidence suggests that long non-coding RNA (lncRNA) HOTAIR participates in many types of cancer such as gastric cancer and may confer malignant phenotype to tumor cells. Fluorouracil and platinum combination chemotherapy is the first line therapy for gastric cancer. However, it is still unknown whether HOTAIR influences the outcome of cancer patients treated with chemotherapy. This study aimed to evaluate the association of HOTAIR expression with the prognosis of patients with advanced gastric adenocarcinoma (GA) receiving fluorouracil and platinum based chemotherapy. We examined the levels of HOTAIR in 168 GA samples using quantitative real-time PCR and analyzed its relationship with clinical features and prognosis of patients with advanced GA treated with fluorouracil and platinum based chemotherapy. Compared with paracancerous tissues, HOTAIR was significantly upregulated in GA tissues, especially in more advanced cases. High HOTAIR expression was an independent poor prognostic factor for patients with advanced GA. Further stratification analyses revealed that the association between HOTAIR expression and survival in patients with advanced GA remained significant in the subgroup of patients with TNM stages IIIA and IIIB, poorly differentiated, and smaller tumors. In conclusion, our results provide first evidence that HOTAIR may be served as a biomarker that predicts which patient with advanced GA will benefit from fluorouracil and platinum combination chemotherapy.

The altered autophagy mediated by TFEB in animal and cell models of amyotrophic lateral sclerosis.

Abstract: Autophagy is an intracellular degradation process that clears away aggregated proteins or aged and damaged organelles. Abnormalities in autophagy result in defects in clearance of these misfolded and aggregate proteins, which have been associated with neurodegenerative disorders. A key neuropathological hallmark of amyotrophic lateral sclerosis (ALS) that contributes to the progressive loss of motor neurons is abnormal protein aggregation of mutant Cu/Zn superoxide dismutase1 (SOD1). TFEB is a recently described gene that regulates autophagy. Several studies have reported that autophagy is altered in ALS, but little is known about the role and mechanisms of TFEB-mediated autophagy during the progression of ALS. In this study, altered expression of TFEB and Beclin-1 were detected in the spinal cords of ALS transgenic mice at different stages and in an NSC-34 cell model with the SOD1-G93A mutation using RT-PCR, western blot, and immunohistochemistry. The majority of cells positive for TFEB and Beclin-1 are β-tubulin III-labeled neurons, especially in the anterior horn of the gray matter. Overexpression of TFEB in NSC-34 cells with the SOD1-G93A mutation increased the mRNA and protein levels of Beclin-1, accompanied by increased levels of LC3-II protein. MTS assay revealed that TFEB overexpression increased proliferation and survival of NSC-34 cells with the SOD1-G93A mutation. Our findings suggest that TFEB promotes autophagy by enhancing the expression of Beclin-1. The altered autophagy mediated by TFEB is a key element in the pathogenesis of ALS, making TFEB a very promising target for the development of novel drugs and new gene therapeutics for ALS.

MiRNA-125b inhibits proliferation and migration by targeting SphK1 in bladder cancer.

Abstract: Background: MicroRNAs (miRNAs) are small, non-coding RNAs (18-25 nucleotides) that post-transcriptionally modulate gene expression by negatively regulating the stability or translational efficiency of their target mRNAs.The purpose of this study was to investigate the expression levels of miR-125b in human bladder cancer and its potential role in disease pathogenesis. Methods: The expression level of miR-125b was measured in 40 bladder cancer specimens and adjacent normal breast tissues by quantitative polymerase chain reaction (qPCR). MTT and colony formation assays, transwell, cell cycle assays were conducted to explore the potential function of miR-125b in human T24 bladder cancer cells. Luciferase reporter assays were performed to analyze the regulation of putative target of miR-125b. The effects of modulating miR-125b on endogenous levels of this target were subsequently confirmed via qRT-PCR and Western blot. Results: The expression of miR-125b in bladder cancer specimens was lower than adjacent normal tissues (P < 0.05). Overexpression of miR-125b inhibited cellular growth, suppressed cellular migration and caused an accumulation of cells in the G1 phase of the cell cycle, Luciferase assays revealed that miR-125b directly targeted the 3’UTR of SphK1. Overexpression of miR-125b led to the downregulation of SphK1 and protein level as assessed by qRT-PCR and Western blot. Targeted knockdown of SphK1 by siRNA significantly inhibited the proliferation of T24 bladder cancer cells. Conclusions: These findings suggest that miR-125b may act as a tumor suppressor gene in bladder cancer and that, in the future, targeting of this miRNA may provide a novel strategy for the diagnosis and treatment of patients with this lethal disease.

Influence of microRNA-related polymorphisms on clinical outcomes in coronary artery disease.

Abstract: Genetic variants in pre-microRNA (miRNA) genes or the 3'UTR of miRNA target genes could influence miRNA-mediated regulation of gene expression and thus contribute to the susceptibility and prognosis of human diseases. This study aimed to investigate the effect of 6 miRNA-related polymorphisms (miR-149 rs71428439, miR-146a rs2910164, miR-499 rs3746444, miR-423 rs6505162, miR-4513 rs2168518, and FABP2 rs11724758) on prognosis in 1004 patients with angiographic coronary artery disease (CAD). We found that miR-4513 rs2168518 was associated with blood pressure, triglycerides, total cholesterol, and fasting glucose levels, and risk of diabetes mellitus. miR-499 rs3746444 and miR-423 rs6505162 were associated with blood pressure and HDL levels, respectively. Both miR-4513 rs2168518 and miR-499 rs3746444 had significant impact on even-free survival. Furthermore, miR-4513 rs2168518 was associated with higher morality in CAD patients. In conclusion, miR-4513 rs2168518 and miR-499 rs3746444 might be potential biomarkers for the clinical prognosis of CAD.

DLAT subunit of the pyruvate dehydrogenase complex is upregulated in gastric cancer-implications in cancer therapy.

Abstract: An iTRAQ-based tandem mass spectrometry approach was employed to relatively quantify proteins in the membrane proteome of eleven gastric cancer cell lines relative to a denominator non-cancer gastric epithelial cell line HFE145. Of the 882 proteins detected, 57 proteins were found to be upregulated with > 1.3-fold change in at least 6 of the 11 cell lines. Bioinformatics analysis revealed that these proteins are significantly associated with cancer, cell growth and proliferation, death, survival and cell movement. The catalogue of membrane proteins presented that are potential regulators/effectors of gastric cancer progression has implications in cancer therapy. DLAT, a subunit of the pyruvate dehydrogenase complex, was selected as a candidate protein for further studies as its function in gastric cancer has yet to be established. SiRNA studies supported a role of DLAT in gastric cancer cell proliferation and carbohydrate metabolism, reprogramming of which is a hallmark of cancer. Our study contributes to recent interest and discussion in cancer energetics and related phenomena such as the Warburg and Reverse Warburg effects. Future mechanistic studies should lead to the elucidation of the mode of action of DLAT in human gastric cancer and establish DLAT as a viable drug target.

MicroRNA-205 functions as a tumor suppressor in colorectal cancer by targeting cAMP responsive element binding protein 1 (CREB1)

Abstract: Background: MicroRNAs (miRNA) have been documented playing critical roles in cancer progression. Aberrant expression of miR-205 has been reported in several types of cancer. However, the role and mechanism of miR-205 in colorectal cancer (CRC) remains unclear. Methods: In this study, the expression levels of miR-205 in CRC tissues and cell lines were detected by quantitative real-time PCR (qRT-PCR). MTT assay and transwell assays were applied to assess the effect of miR-205 on CRC cell proliferation, migration and invasion abilities in vitro. Furthermore, Dual-luciferase reporter assay was conducted to confirm the direct binding of miR-205 and target genes. Results: In the present study, we found that the expression level of miR-205 in CRC tissues and cell lines was significantly down-regulated. Functional assays showed that overexpression of miR-205 suppressed CRC cell proliferation, migration and invasion in vitro. In addition, cAMP responsive element binding protein 1 (CREB1) was identified as targets of miR-205. Silencing CREB1 had similar effects of miR-205 restoration on proliferation, migration and invasion in CRC cells. Conclusions: Our results demonstrated that miR-205 may act as a tumor suppressor by targeting the CREB1 gene and suppressing CRC cell proliferation, migration and invasion. Thus, miR-205 may represent a potential therapeutic target for CRC intervention.

MiR-133a suppresses the migration and invasion of esophageal cancer cells by targeting the EMT regulator SOX4.

Abstract: MicroRNAs (miRNAs) are small, non-coding RNAs which can function as oncogenes or tumor suppressor genes in human cancers In the present study, we demonstrated that the expression ofmiR-133a was dramatically decreased in examined esophageal squamous cell carcinoma (ESCC) cell lines and clinical ESCC tissue samples Additionally, miR-133a expression was inversely correlated with tumor progression in ESCCs We have found that over-expression of miR-133a significantly suppressed the proliferation, migration and invasion of ESCC cells in vitro miR-133a over-expression also significantly suppressed the aggressive phenotype of ESCC in vivo, suggesting that miR-133a may function as a novel tumor suppressor Further studies indicated that the EMT-related transcription factor Sox4 was a direct target gene of miR-133a, evidenced by the direct binding of miR-133a with the 3'UTR of Sox4 Notably, the EMT marker E-cadherin or vimentin, a downstream of Sox4, was also down-regulated or upregulated upon miR-133a treatment We have also shown that over-expressing or silencing Sox4 was able to elevate or inhibit the migration and invasion of ESCC cells, similar to the effect of miR-133a on the ESCC cells Moreover, knockdown of Sox4 reversed the enhanced migration and invasion mediated by anti-miR-133a These results demonstrate that miR-133a acts as a tumor suppressor in ESCC through targeting Sox4 and the EMT process miR-133a may serve as a potential target in the treatment of human esophageal cancer

Reversing the reduced level of endometrial GLUT4 expression in polycystic ovary syndrome: a mechanistic study of metformin action

Abstract: Conflicting results have been reported regarding whether or not insulin-regulated glucose transporter 4 (GLUT4) is expressed in human and rodent endometria. There is an inverse relationship between androgen levels and insulin-dependent glucose metabolism in women. Hyperandrogenemia, hyperinsulinemia, and insulin resistance are believed to contribute to endometrial abnormalities in women with polycystic ovary syndrome (PCOS). However, it has been unclear in previous studies if endometrial GLUT4 expression is regulated by androgen-dependent androgen receptors (ARs) and/or the insulin receptor/Akt/mTOR signaling network. In this study, we demonstrate that GLUT4 is expressed in normal endometrial cells (mainly in the epithelial cells) and is down-regulated under conditions of hyperandrogenemia in tissues from PCOS patients and in a 5α-dihydrotestosterone-induced PCOS-like rat model. Western blot analysis revealed reduced endometrial GLUT4 expression and increased AR expression in PCOS patients. However, the reduced GLUT4 level was not always associated with an increase in AR in PCOS patients when comparing non-hyperplasia with hyperplasia. Using a human tissue culture system, we investigated the molecular basis by which GLUT4 regulation in endometrial hyperplasia tissues is affected by metformin in PCOS patients. We show that specific endogenous organic cation transporter isoforms are regulated by metformin, and this suggests a direct effect of metformin on endometrial hyperplasia. Moreover, we demonstrate that metformin induces GLUT4 expression and inhibits AR expression and blocks insulin receptor/PI3K/Akt/mTOR signaling in the same hyperplasia human tissues. These findings indicate that changes in endometrial GLUT4 expression in PCOS patients involve the androgen-dependent alteration of AR expression and changes in the insulin receptor/PI3K/Akt/mTOR signaling network.

H19 derived microRNA-675 regulates cell proliferation and migration through CDK6 in glioma

Abstract: The long non-coding RNA (LncRNA) H19 is one of the most highly abundant and conserved transcripts involved in the mammalian development and tumorigenesis. H19 is expressed in both embryonic cells and tumor cells, but its physical and pathological functions still need to be further studied. Our results showed that microRNA-675, a microRNA in the first exon of H19, expressed in glioma. Over-expression of microRNA-675 in a range of glioma cell lines resulted in their immoderate proliferation and migration. In addition, H19 derived microRNA-675 was down-regulated in the glioma, and CDK6, a pivotal regulator in cell cycle, was a target of microRNA-675. The survival of glioma patients with low CDK6 expression significantly increased as compared to patients with high CDK6 expression. Moreover, the CDK6 expression was inversely correlated with microRNA-675 expression in the glioma. Our results suggest that H19 derived microRNA-675 may regulate giloma cell proliferation and migration through CDK6, and predict a poor prognosis of glioma patients.

Targeted next-generation sequencing of cancer genes identified frequent TP53 and ATRX mutations in leiomyosarcoma.

Abstract: Leiomyosarcoma is an aggressive soft tissue sarcoma with poor patient survival. The genetic changes of leiomyosarcoma remain to be discovered. In this study, we analyzed the genetic changes of 44 cancer-related genes by using next-generation sequencing in 54 leiomyosarcomas. We identified TP53 mutations in 19 of the 54 tumors (35%) and ATRX mutations in 9 of the 54 tumors (17%). The TP53-mutated leiomyosarcomas were limited to female patients (P = 0.006). All but 2 of the TP53-mutated leiomyosarcomas were located in the uterus (n = 11) or retroperitoneum (n = 6). The ATRX mutations were associated with poorly differentiated leiomyosarcomas (P = 0.028) and the presence of tumor necrosis (P = 0.015). Kaplan-Meier survival analysis showed that patients with ATRX-mutated leiomyosarcomas had worse overall survival than did patients with ATRX-wild-type leiomyosarcomas. All of the ATRX-mutated leiomyosarcomas showed the alternative lengthening of telomere phenotype. The ATRX mutations did not correlate with ATRX protein expression, as detected using immunohistochemistry. In conclusion, we identified loss of function of the p53 and ATRX pathways being the main mechanisms for leiomyosarcomas. The molecular mechanisms may provide new opportunities to treat these aggressive neoplasms.

TGF-β1 induces human aortic vascular smooth muscle cell phenotype switch through PI3K/AKT/ID2 signaling.

Abstract: The vascular smooth muscle cell (VSMC) phenotypic switch is considered to be the key pathophysiological change in various cardiovascular diseases, such as aortic dissection, atherosclerosis, and hypertension. The results in this study showed that TGF-β1 promotes the proliferation, migration and morphological changes of VSMC.TGF-β1 promoted the expressions of PI3K, P-PI3K, AKT, P-AKT, ID2, and OPN protein and suppressed the expressions of α-SMA and SM22α protein; the opposite results were observed for TGF-β1 inhibitor group, AKT inhibitor group and Combined inhibitors group. After the stimulation of TGF-β1 signaling, the mRNA levels of PI3K, AKT, ID2, and OPN were the highest, while the mRNA levels of α-SMA and SM22α were the lowest; the opposite results were found in the same groups above. These results suggested the PI3K/AKT/ID2 signaling pathway is involved in TGF-β1-mediated human aortic VSMC phenotypic switching, that is from a contractile to synthetic phenotype, and Combined inhibitors was more effective in inhibiting the phenotypic switch than a single inhibitor. The Combined inhibitors experiments may provide new avenues for the prevention and treatment of thoracic aortic dissection (TAD) that are based on the pathological effects of phenotypic switching.

Protective effects of icariin on cisplatin-induced acute renal injury in mice.

Abstract: Cisplatin chemotherapy often causes acute kidney injury in cancer patients. Icariin is a bioactive flavonoid, which has renal protection and anti-inflammation effects. This study investigated the mechanism underlying the attenuation of cisplatin-induced renal injury by icariin. BALB/c mice were treated with cisplatin (15 mg/kg) with or without treatment with icariin (30 or 60 mg/kg for 5 days). Renal function, histological changes, degree of oxidative stress and tubular apoptosis were examined. The effects of icariin on cisplatin-induced expression of renal TNF-α, NF-κB, cleaved caspase-3 and Bcl-2 family proteins were evaluated. Treatment of mice with cisplatin resulted in renal damage, showing an increase in blood urea nitrogen and creatinine levels, tubular damage, oxidative stress and apoptosis. These renal changes could be significantly improved by icariin treatment, especially in high dose of icariin group. Examination of molecules involving inflammation and apoptosis of the kidney revealed that treatment of icariin reduced expression of TNF-α, NF-κB, cleaved caspase-3, and Bax, increased the expression of BCL-2. These results indicate that icariin ameliorates the cisplatin-mediated nephrotoxicity via improving renal oxidant status, consequent NF-κB activation and inflammation cascade and apoptosis, and the following disturbed expression of apoptosis related proteins.

Loss of miR-532-5p in vitro promotes cell proliferation and metastasis by influencing CXCL2 expression in HCC.

Abstract: MicroRNAs (miRNAs) have been widely reported, which play important roles in cancer development. CXCL2 acts as an oncogene, however, its regulation by miRNAs is not clear in hepatocellular carcinoma (HCC). In our research, it is aimed to study the role of CXCL2 in HCC and the regulation of its expression by miRNAs. Firstly, we found that CXCL2 was up-regulated in the blood of patients with HCC and cell lines compared with the normal controls. CXCL2 could enhance HCC cell proliferation and metastasis. miR-532-5p was predicted as a regulatory miRNA of CXCL2 in HCC, and negatively associated with CXCL2 in HCC samples. It was also verified that miR-532-5p inhibited cell proliferation and metastasis of HCC cells by inhibition CXCL2. Collectively, our findings suggested that miR-532-5p may function as a tumor suppressor in HCC by targeting CXCL2.