Functional exploration of CCNE1 splicing forms as a possible link to bladder cancer susceptibility
Ontology highlight
ABSTRACT:
SUBMITTER: Kohaar I
PROVIDER: S-EPMC3439055 | biostudies-literature | 2011 Jan
REPOSITORIES: biostudies-literature
Similar Datasets
Project description:BackgroundAlternative splicing (AS)-related single nucleotide polymorphisms (SNPs) are associated with risk of cancers, but the potential mechanism has not been fully elucidated.MethodsTwo-stage case-control studies comprising 1630 cases and 2504 controls were conducted to investigate the association between the AS-SNPs and bladder cancer susceptibility. A series of assays were used to evaluate the functional effect of AS-SNPs on bladder cancer risk.ResultsWe observed that SNP rs558814 A>G located in lncRNA BCLET (Bladder Cancer Low-Expressed Transcript, ENSG00000245498) can decrease the risk of bladder cancer (odds ratio [OR] = 0.84, 95% confidence interval [CI] = 0.76-0.92, p = 3.26 × 10-4 ). Additionally, the G allele of rs558814 had transcriptional regulatory effects and facilitated the expression of BCLET transcripts, including BCLET-long and BCLET-short. We also found decreased BCLET expression in bladder cancer tissues and cells, and BCLET transcript upregulation substantially inhibited tumor growth of both bladder cancer cells and xenograft models. Mechanistically, BCLET recognized and regulated AS of MSANTD2 to participate in bladder carcinogenesis, preferentially promoting the production of MSANTD2-004.ConclusionsSNP rs558814 was associated with the expression of BCLET, which mainly increased the expression of MSANTD2-004 through AS of MSANTD2.
| S-EPMC10358201 | biostudies-literature
Project description:Background A single nucleotide polymorphism is identified at CCNE1 and RIP2. We evaluated the relationship between the CCNE1 or RIP2 and the risk, clinic stage and pathologic grade of bladder cancer. Methods Peripheral venous blood samples were obtained from 176 patients with bladder cancer and 210 controls with no cancers of any kinds. The diagnoses, pathological stage of bladder cancer were all determined according to the pathological reports of transurethral bladder cancer resection and radical cystectomy. The polymorphism was determined by polymerase chain reaction and sequencing methods. Results (I) The distribution of the CCNE1 and RIP 2 allele frequencies among control subjects was in Hardy-Weinberg equilibrium; (II) the frequency of CCNE1 (rs8102137) variant allele was significantly higher in the case subjects (40.91%) than in controls (30.95%) (P<0.05, OR=1.54, 95% CI 1.02–2.45). The frequency of CCNE1 (rs8102137) variant allele was significantly higher in the case subjects (72.73%) than in controls (62.38%) (P<0.05, OR=1.61, 95% CI, 1.04–2.48); (III) there was no association between the CCNE1 (rs8102137) and RIP2 (rs42490). Polymorphisms and Pathological grade and clinical stage of bladder cancer. Conclusions The CCNE1 (rs8102137) and RIP2 (rs42490) polymorphism have interaction in occurrence of bladder cancer process, no association with Pathological grade and clinical stage of bladder cancer.
| S-EPMC4842531 | biostudies-literature
Project description:Genome-wide association studies (GWAS) have been successful in the identification of the several urinary bladder cancer (UBC) susceptibility loci, pointing towards novel genes involved in tumor development. Despite that, functional characterization of the identified variants remains challenging, as they mostly map to poorly understood, non-coding regions. Recently, two of the UBC risk variants (PSCA and UGT1A) were confirmed to have functional consequences. They were shown to modify bladder cancer risk by influencing gene expression in an allele-specific manner. Although the role of the other UBC risk variants is unknown, it can be hypothesized-based on studies from different cancer types-that they influence cancer susceptibility by alterations in regulatory networks. The insight into UBC heritability gained through GWAS and further functional studies can impact on cancer prevention and screening, as well as on the development of new biomarkers and future personalized therapies.
| S-EPMC3709789 | biostudies-literature
Project description:BackgroundMetformin has been reported to function as the anti-tumor inhibiting the growth of different types of cancers, including bladder cancer. But there are few reports on the roles of Yap1, the key molecule of Hippo pathway, in the metformin induced inhibition of bladder cancer (BLCA). We are wondering if the inhibitory effect of metformin on bladder cancer is fulfilled via Yap1 and exploring the related mechanism.MethodsMTS and colony formation assays were used to explore the cellular viabilities and proliferation of BLCA cells challenged by metformin at different concentrations, in vitro. Flow Cytometry (FCM) was used to analyze the cell cycle and the cellular apoptosis of the BLCA cells. Western Blot was performed to detect the expressions of AMPKα, Yap1, CCND1, CCNE1/2 and CDK2/4/6 in the metformin-treated BLCA cell lines. RNAi method was used for the related genetic functional analysis. The relationships among Yap1, TEADs and CCNE1/2 were predicted and evaluated using bioinformatics, dual-luciferase reporter and co-immunoprecipitation (Co-IP) assays. For in vivo experiments, a xenograft model was used to investigate the effects of metformin on the proliferation of BLCA cells. And Immunohistochemistry (IHC) assay was performed to assess the expressions of CCNE1/2 and Yap1 proteins in the tumor tissues from the model.ResultsMetformin could inhibit the proliferation of the BLCA cells via inducing the G1 cell cycle arrest without apoptosis. And metformin upregulated the phosphorylated AMPKα and decreased the expressions of Yap1 and CCND1, CCNE1/2 and CDK4/6. AMPK inhibition by compound C (CC) restored the cell proliferation and the G1 cell cycle arrest induced by metformin, in vivo. Knockdown of YAP1 inhibited the proliferation of BLCA cells and caused the cell cycle arrest at G1 phase by decreasing the expressions of CCNE1/2 and other G1 phase related molecules, which has been restored by the Yap 5SA mutant. Bioinformatics analysis showed that trans-factor TEAD4 was highly expressed and positively associated with the expressions of CCNE1 and CCNE2 in BLCA and only TEAD4 was precipitated by Yap1 in the BLCA cells. Further studies demonstrated that Yap1 positively regulated both CCNE1 and CCNE2 expressions via forming complex with TEAD4. Furthermore, we observed that metformin inhibited the cell proliferation by decreasing the expressions of Yap1 and both CCNE1 and CCNE2 in xenograft model.ConclusionsThe results of our study reveal a new potential regulatory pathway in which metformin inhibits cell proliferation via AMPKα/Yap1/TEAD4/CCNE1/2 axis in BLCA cells, providing new insights into novel molecular therapeutic targets for BLCA.
| S-EPMC6712726 | biostudies-literature
Project description:BackgroundAnalysis of a microRNA (miRNA) expression signature of bladder cancer (BC) by deep-sequencing revealed that clustered miRNAs microRNA (miR)-451a, miR-144-3p, and miR-144-5p were significantly downregulated in BC tissues. We hypothesised that these miRNAs function as tumour suppressors in BC. The aim of this study was to investigate the functional roles of these miRNAs and their modulation of cancer networks in BC cells.MethodsThe functional studies of BC cells were performed using transfection of mature miRNAs. Genome-wide gene expression analysis, in silico analysis, and dual-luciferase reporter assays were applied to identify miRNA targets. The association between miR-144-5p levels and expression of the target genes was determined, and overall patient survival as a function of target gene expression was estimated by the Kaplan-Meier method.ResultsGain-of-function studies showed that miR-144-5p significantly inhibited cell proliferation by BC cells. Four cell cycle-related genes (CCNE1, CCNE2, CDC25A, and PKMYT1) were identified as direct targets of miR-144-5p. The patients with high CCNE1 or CCNE2 expression had lower overall survival probabilities than those with low expression (P=0.025 and P=0.032).ConclusionmiR-144-5p functions as tumour suppressor in BC cells. CCNE1 and CCNE2 were directly regulated by miR-144-5p and might be good prognostic markers for survival of BC patients.
| S-EPMC4506384 | biostudies-literature
Project description:Myotonic dystrophy type 2 (DM2) is a multisystemic disorder caused by a (CCTG)n repeat expansion in intron 1 of CNBP. Transcription of the repeats causes a toxic RNA gain of function involving their accumulation in ribonuclear foci. This leads to sequestration of splicing factors and alters pre-mRNA splicing in a range of downstream effector genes, which is thought to contribute to the diverse DM2 clinical features. Hyperlipidemia is frequent in DM2 patients, but the treatment is problematic because of an increased risk of statin-induced adverse reactions. Hypothesizing that shared pathways lead to the increased risk, we compared the skeletal muscle expression profiles of DM2 patients and controls with patients with hyperlipidemia on statin therapy. Neural precursor cell expressed, developmentally downregulated-4 (NEDD4), an ubiquitin ligase, was one of the dysregulated genes identified in DM2 patients and patients with statin-treated hyperlipidemia. In DM2 muscle, NEDD4 mRNA was abnormally spliced, leading to aberrant NEDD4 proteins. NEDD4 was down-regulated in persons taking statins, and simvastatin treatment of C2C12 cells suppressed NEDD4 transcription. Phosphatase and tensin homologue (PTEN), an established NEDD4 target, was increased and accumulated in highly atrophic DM2 muscle fibers. PTEN ubiquitination was reduced in DM2 myofibers, suggesting that the NEDD4-PTEN pathway is dysregulated in DM2 skeletal muscle. Thus, this pathway may contribute to the increased risk of statin-adverse reactions in patients with DM2.
| S-EPMC4116696 | biostudies-literature
Project description:We report here a genome-wide analysis of alternative splicing in 2 million human expressed sequence tags (ESTs), to identify splice forms that are up-regulated in tumors relative to normal tissues. We found strong evidence (P < 0.01) of cancer-specific splice variants in 316 human genes. In total, 78% of the cancer-specific splice forms we detected are confirmed by human-curated mRNA sequences, indicating that our results are not due to random mis-splicing in tumors; 73% of the genes showed the same cancer-specific splicing changes in tissue-matched tumor versus normal datasets, indicating that the vast majority of these changes are associated with tumorigenesis, not tissue specificity. We have confirmed our EST results in an independent set of experimental data provided by human-curated mRNAs (P-value 10(-5.7)). Moreover, the majority of the genes we detected have functions associated with cancer (P-value 0.0007), suggesting that their altered splicing may play a functional role in cancer. Analysis of the types of cancer-specific splicing shifts suggests that many of these shifts act by disrupting a tumor suppressor function. Sur prisingly, our data show that for a large number (190 in this study) of cancer-associated genes cloned originally from tumors, there exists a previously uncharacterized splice form of the gene that appears to be predominant in normal tissue.
| S-EPMC206480 | biostudies-literature
Project description:BackgroundUncontrolled proliferation is thought to be the most fundamental characteristic of cancer. Detailed knowledge of cancer cell proliferation mechanisms would not only benefit understanding of cancer progression, but may also provide new clues for developing novel therapeutic strategies.MethodsIn vitro function of MNX1 (Motor neuron and pancreas homeobox 1) in bladder cancer cell was evaluated using MTT assay, colony formation assay, and bromodeoxyuridine incorporation assay. Real-time PCR and western blotting were performed to detect MNX1 and CCNE1/2 expressions. In vivo tumor growth was conducted in BALB/c-nu mice.ResultsWe reported that MNX1 is responsible for sustaining bladder cancer cell proliferation. Abnormal MNX1 upregulation in bladder cancer cell lines and 167 human tissue specimens; high MNX1 expression levels correlated significantly with shorter 5-year overall and relapse-free survival in the bladder cancer patients. Furthermore, MNX1 overexpression accelerated bladder cancer cell proliferation and tumorigenicity both in vitro and in vivo, whereas MNX1 downregulation arrested it. In addition, MNX1 transcriptionally upregulated CCNE1 and CCNE2 by directly bounding to their promoters, which promoted G1-S transition in the bladder cancer cells.ConclusionThese findings reveal an oncogenic role and novel regulatory mechanism of MNX1 in bladder cancer progression and suggest that MNX1 is a potential prognostic biomarker and therapeutic target.
| S-EPMC6048799 | biostudies-literature
Project description:Bladder cancer is the most common malignancy of the urinary system. The incidence of bladder cancer of men is higher than that of women (approximately 4:1). Here, we summarize the bladder cancer-related risk factors, including environmental and genetic factors. In recent years, although the mortality rate induced by bladder cancer has been stable or decreased gradually, the public health effect may be pronounced. The well-established risk factors for bladder cancer are cigarette smoking and occupational exposure. Genetic factors also play important roles in the susceptibility to bladder cancer. A recent study demonstrated that hereditary non-polyposis colorectal cancer is associated with increased risk of bladder cancer. Since 2008, genome-wide association study (GWAS) has been used to identify the susceptibility loci for bladder cancer. Further gene-gene or gene-environment interaction studies need to be conducted to provide more information for the etiology of bladder cancer.
| S-EPMC3664723 | biostudies-literature
Project description:Protegrin-1 (PG-1) is an 18 residues long, cysteine-rich ?-sheet antimicrobial peptide (AMP). PG-1 induces strong cytotoxic activities on cell membrane and acts as a potent antibiotic agent. Earlier we reported that its cytotoxicity is mediated by its channel-forming ability. In this study, we have examined the amyloidogenic fibril formation properties of PG-1 in comparison with a well-defined amyloid, the amyloid-? (A?(1-42)) peptide. We have used atomic force microscopy (AFM) and thioflavin-T staining to investigate the kinetics of PG-1 fibrils growth and molecular dynamics simulations to elucidate the underlying mechanism. AFM images of PG-1 on a highly hydrophilic surface (mica) show fibrils with morphological similarities to A?(1-42) fibrils. Real-time AFM imaging of fibril growth suggests that PG-1 fibril growth follows a relatively fast kinetics compared to the A?(1-42) fibrils. The AFM results are in close agreement with results from thioflavin-T staining data. Furthermore, the results indicate that PG-1 forms fibrils in solution. Significantly, in contrast, we do not detect fibrillar structures of PG-1 on an anionic lipid bilayer 2-dioleoyl-sn-glycero-3-phospho-L-serine/1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoethanolamine; only small PG-1 oligomers can be observed. Molecular dynamics simulations are able to identify the presence of these small oligomers on the membrane bilayer. Thus, our current results show that cytotoxic AMP PG-1 is amyloidogenic and capable of forming fibrils. Overall, comparing ?-rich AMPs and amyloids such as A?, in addition to cytotoxicity and amyloidogenicity, they share a common structural motif, and are channel forming. These combined properties support a functional relationship between amyloidogenic peptides and ?-sheet-rich cytolytic AMPs, suggesting that amyloids channels may have an antimicrobial function.
| S-EPMC3072611 | biostudies-literature