A Systematic Analysis on DNA Methylation and the Expression of Both mRNA and microRNA in Bladder Cancer

Background: DNA methylation aberration and microRNA (miRNA) deregulation have been observed in many types of cancers. A systematic study of methylome and transcriptome in bladder urothelial carcinoma has never been reported. Methodology/Principal Findings: The DNA methylation was profiled by modified methylation-specific digital karyotyping (MMSDK) and the expression of mRNAs and miRNAs was analyzed by digital gene expression (DGE) sequencing in tumors and matched normal adjacent tissues obtained from 9 bladder urothelial carcinoma patients. We found that a set of significantly enriched pathways disrupted in bladder urothelial carcinoma primarily related to "neurogenesis" and "cell differentiation" by integrated analysis of -omics data. Furthermore, we identified an intriguing collection of cancer-related genes that were deregulated at the levels of DNA methylation and mRNA expression, and we validated several of these genes (HIC1, SLIT2, RASAL1, and KRT17) by Bisulfite Sequencing PCR and Reverse Transcription qPCR in a panel of 33 bladder cancer samples. Conclusions/Significance: We characterized the profiles between methylome and transcriptome in bladder urothelial carcinoma, identified a set of significantly enriched key pathways, and screened four aberrantly methylated and expressed genes. Conclusively, our findings shed light on a new avenue for basic bladder cancer research

The regulatory role of nickel on H3K27 demethylase JMJD3 in kidney cancer cells

Nickel compounds are an important class of environmental pollutants and carcinogens. Chronic exposure to nickel compounds has been connected with increased risks of numerous cancers, including lung and kidney cancers. But the precise mechanism by which nickel compounds exert their carcinogenic properties is not completely understood. In this study, kidney cancer cells namely human embryonic kidney 293-containing SV40 large T-antigen (HEK293T) and 786-0 were incubated with various concentrations of nickel chloride for 24 h before analysing the expression of three histone H3K27 methylation-modifying enzymes and H3K27me3 using quantitative real-time polymerase chain reaction, Western blot and immunofluorescence analyses. Our results showed that incubation of nickel chloride upregulated the expression of H3K27me3 demethylase jumonji domain-containing protein 3 (JMJD3) in kidney cancer cells, which was accompanied by the reduction in the protein level of H3K27me3. Enhanced demethylation of H3K27me3 may represent a novel mechanism underlying the carcinogenicity of nickel compounds

Synthetic miRNA-Mowers Targeting miR-183-96-182 Cluster or miR-210 Inhibit Growth and Migration and Induce Apoptosis in Bladder Cancer Cells

Background: MicroRNAs (miRNAs) function as endogenous regulators of biological behaviors of human cancers. Several natural non-coding RNAs are reported to inhibit miRNAs by base-pairing interactions. These phenomena raise questions about the ability of artificial device to regulate miRNAs. The purpose of this study is to create synthetic devices that target a single miRNA or a miRNA cluster and to ascertain their therapeutic effects on the phenotypes of bladder cancer cells. Methodology/Principal Findings: Tandem bulged miRNA binding sites were inserted into the 39 untranslated region (UTR) of the SV-40 promoter-driven Renilla luciferase gene to construct two "miRNA-mowers" for suppression of miR-183-96-182 cluster or miR-210. A third device with tandem repeat sequences not complementary to any known miRNA was generated as an untargeted-control. In functional analyses, bladder cancer T24 and UM-UC-3 cells were transfected with each of the three devices, followed by assays for detection of their impacts. Luciferase assays indicated that the activities of the luciferase reporters in the miRNA-mowers were decreased to 30-50% of the untargeted-control. Using Real-Time qPCR, the expression levels of the target miRNAs were shown to be reduced 2-3-fold by the corresponding miRNA-mower. Cell growth, apoptosis, and migration were tested by MTT assay, flow cytometry assay, and in vitro scratch assay, respectively. Cell growth inhibition, increased apoptosis, and decreased motility were observed in miRNA-mowers-transfected bladder cancer cells. Conclusions/Significance: Not only a single target miRNA but also the whole members of a target miRNA cluster can be blocked using this modular design strategy. Anti-cancer effects are induced by the synthetic miRNA-mowers in the bladder cancer cell lines. miR-183/96/182 cluster and miR-210 are shown to play oncogenic roles in bladder cancer. A potentially useful synthetic biology platform for miRNA loss-of-function study and cancer treatment has been established in this work

The role of DRAM1 in mitophagy contributes to preeclampsia regulation in mice

Abstract Background: Preeclampsia (PE) is a pregnancy complication that is diagnosed by the new onset of hypertension and proteinuria. Although the pathogenesis of PE is still not fully understood, growing evidence indicates that oxidative stress and mitochondrial dysfunction may contribute to the progression of PE. Therefore, we aimed to determine the role of mitophagy in mitochondrial dysfunction and oxidative stress in PE. Moreover, we aimed to evaluate the role of DNA damage-regulated autophagy modulator 1 (DRAM1) in the development of PE. Results: In this study, we first constructed a mouse model of PE induced by Hif-1α and found a high level of oxidative stress, apoptosis and mitochondrial dysfunction in the placentas of PE mice. Additionally, the activity of mitophagy was decreased, and the level of DRAM1 was significantly decreased in the placentas of PE mice. To further explore the role of DRAM1 in mitophagy, DRAM1 was overexpressed in the placental tissues of PE mice. It was found that the overexpression of DRAM1 effectively improved the symptoms of PE mice and that blood lipid and urine protein levels were significantly reduced. Furthermore, DRAM1 overexpression also improved mitochondrial function and reduced oxidative stress in the placentas of PE mice. In addition, it improved mitochondrial fusion and fission and enhanced mitophagy.Conclusions: our results indicate a key role of DRAM1 in mitophagy in contributing to the regulation of PE. To our knowledge, this is the first study to confirm the role of DRAM1 in PE, and the study provides a new understanding of the pathophysiological mechanisms of PE.</jats:p

Effects of the synthetic miRNA-mowers on apoptosis of bladder cancer cells.

<p>T24 and UM-UC-3 cells were transfected with the devices in 6-well plates. Cell apoptosis was measured by the flow cytometry at 48 h post transfection. (A). Representative images of flow cytometry analysis in T24 cells. (B). Representative images of flow cytometry analysis in UM-UC-3 cells. (C). Cell apoptosis induction was observed in miRM-183/96/182-transfected bladder cancer T24 and UM-UC-3 cells using flow cytometry analysis. (D). Cell apoptosis induction was observed in miRM-210-transfected bladder cancer T24 and UM-UC-3 cells using flow cytometry analysis. We performed each experiment at least three times. Error bars, SD. ** P<0.01, compared with the untargeted-control.</p

Construction of the miRNA-mowers.

<p>We constructed miRNA-mowers by inserting multiple miRNA binding sites into the 3′ UTR of a Renilla luciferase gene. Each construct under control of a SV-40 promoter ended with a SV40 polyadenylation signal. An unregulated TK promoter-driven gene encoding firefly luciferase was used as a control. The black squares represented the linkers between the binding sites.</p

<b>Table1.</b> The inhibitory effects of endogenous miRNAs on the activities of the luciferase reporters in the miRNA-mowers.

<p>a The values are mean ± SD. Each experiment in the two cell lines was performed in triplicate for three independent times.</p