Co-transcriptional R-loops-mediated epigenetic regulation drives growth retardation and docetaxel chemosensitivity enhancement in advanced prostate cancer.

R-loops are prevalent three-stranded nucleic acid structures, comprising a DNA-RNA hybrid and a displaced single-stranded DNA, that frequently form during transcription and may be attributed to genomic stability and gene expression regulation. It was recently discovered that RNA modification contributes to maintain the stability of R-loops such as N6-methyladenosine (m6A). Yet, m6A-modified R-loops in regulating gene transcription remains poorly understood. Here, we demonstrated that insulin-like growth factor 2 mRNA-binding proteins (IGF2BPs) recognize R-loops in an m6A-dependent way. Consequently, IGF2BPs overexpression leads to increased overall R-loop levels, cell migration inhibition, and cell growth retardation in prostate cancer (PCa) via precluding the binding of DNA methyltransferase 1(DNMT1) to semaphorin 3 F (SEMA3F) promoters. Moreover, the K homology (KH) domains of IGF2BPs are required for their recognition of m6A-containing R-loops and are required for tumor suppressor functions. Overexpression of SEMA3F markedly enhanced docetaxel chemosensitivity in prostate cancer via regulating Hippo pathway. Our findings point to a distinct R-loop resolution pathway mediated by IGF2BPs, emphasizing the functional importance of IGF2BPs as epigenetic R-loop readers in transcriptional genetic regulation and cancer biology.The manuscript summarizes the new role of N6-methyladenosine in epigenetic regulation, we introduce the distinct R-loop resolution mediated by IGF2BP proteins in an m6A-dependent way, which probably lead to the growth retardation and docetaxel chemotherapy resistance in prostate cancer. Moreover, our findings first emphasized the functional importance of IGF2BPs as epigenetic R-loop readers in transcriptional genetic regulation and cancer biology. In addition, our research provides a novel RBM15/IGF2BPs/DNMT1 trans-omics regulation m6A axis, indicating the new crosstalk between RNA m6A methylation and DNA methylation in prostate cancer.

N6-methyladenosine-modified CircPSMA7 enhances bladder cancer malignancy through the miR-128-3p/MAPK1 axis.

Several studies have indicated that circular RNAs (circRNAs) play vital roles in the progression of various diseases, including bladder cancer (BCa). However, the underlying mechanisms by which circRNAs drive BCa malignancy remain unclear. In this study, we identified a novel circRNA, circPSMA7 (circbaseID:has_circ_0003456), showing increased expression in BCa cell lines and tissues, by integrating the reported information with circRNA-seq and qRT-PCR. We revealed that circPSMA7 is associated with a higher tumor grade and stage in BCa. M6A modification was identified in circPSMA7, and IGF2BP3 recognized this modification and stabilized circPSMA7, subsequently increasing the circPSMA7 expression. In vitro and in vivo experiments showed that circPSMA7 promoted BCa proliferation and metastasis by regulating the cell cycle and EMT processes. CircPSMA7 acted as a sponge for miR-128-3p, which showed antitumor effects in BCa cell lines, increasing the expression of MAPK1. The tumor proliferation and metastasis suppression induced by silencing circPSMA7 could be partly reversed by miR-128-3p inhibition. Thus, the METTL3/IGF2BP3/circPSMA7/miR-128-3p/MAPK1 axis plays a critical role in BCa progression. Furthermore, circPSMA7 may be a potential diagnostic biomarker and novel therapeutic target for patients with BCa.

FTO promotes clear cell renal cell carcinoma progression via upregulation of PDK1 through an m6A dependent pathway.

FTO, as an m6A mRNA demethylase, is involved in various cancers. However, the role of FTO in clear cell renal cell carcinoma (ccRCC) remains unclear. In the present study, we discovered FTO is upregulated in ccRCC. Functionally, knockdown of FTO significantly impairs the proliferation and migration ability of ccRCC cells. Mechanistically, our data suggest FTO promotes the proliferation and migration of ccRCC through preventing degradation of PDK1 mRNA induced by YTHDF2 in an m6A-dependent mechanism. Overall, our results identify the protumorigenic role of FTO through the m6A/YTHDF2/PDK1 pathway, which could be a promising therapeutic target for ccRCC.

SMAD3 and FTO are involved in miR-5581-3p-mediated inhibition of cell migration and proliferation in bladder cancer.

Previous research evidence suggests that microRNAs (miRNAs) play an indispensable role in onset and progression of bladder cancer (BCa). Here, we explored the functions and mechanisms of miR-5581-3p in BCa. miR-5581-3p, as a tumor suppressor in BCa, was detected at a lower expression level in BCa tissue and cells in contrast with the non-malignant bladder tissue and cells. Over-expression of miR-5581-3p remarkably dampened the migration and proliferation of BCa in vitro and in vivo. SMAD3 and FTO were identified as the direct targets of miR-5581-3p by online databases prediction and mRNA-seq, which were further verified. SMAD3 as a star molecule in modulating EMT progress of BCa had been formulated in former studies. Meanwhile, FTO proved as an N6-methyladenosine (m6A) demethylase in decreasing m6A modification was confirmed to regulate the migration and proliferation in BCa. In addition, we conducted rescue experiments and confirmed overexpressing miR-5581-3p partially rescued the effects of the overexpressing SMAD3 and FTO in BCa cells. In conclusion, our studies exhibit that miR-5581-3p is a novel tumor inhibitor of BCa.

Diverse Roles and Therapeutic Potentials of Circular RNAs in Urological Cancers.

Circular RNAs (circRNAs) are a novel class of noncoding RNAs, which are mainly formed as a loop structure at the exons caused by noncanonical splicing; they are much more stable than linear transcripts; recent reports have suggested that the dysregulation of circRNAs is associated with the occurrence and development of diseases, especially various human malignancies. Emerging evidence demonstrated that a large number of circRNAs play a vital role in a series of biological processes such as tumor cell proliferation, migration, drug resistance, and immune escape. Additionally, circRNAs were also reported to be potential prognostic and diagnostic biomarkers in cancers. In this work, we systematically summarize the biogenesis and characteristics of circRNAs, paying special attention to potential mechanisms and clinical applications of circRNAs in urological cancers, which may help develop potential therapy targets for urological cancers in the future.

circKDM4C enhances bladder cancer invasion and metastasis through miR-200bc-3p/ZEB1 axis.

Circular RNAs (circRNAs) play essential roles in human bladder cancer (BCa) development, however, unusual expression patterns and functional dysfunction of circRNAs in BCa have not been evaluated. In this study, we validated that circKDM4C (hsa_circ_0001839), derived from the KDM4C gene, is elevated in BCa cell lines as well as tissues. Functionally, overexpression of circKDM4C significantly enhances, and silencing of circKDM4C suppresses migration and invasion capabilities of BCa cells. Mechanistically, circKDM4C can directly interact with miR-200b-3p and miR-200c-3p as a miRNA sponge, which enhances the expression of ZEB1 and promotes mesenchymal phenotype. Conclusively, our findings indicate that circKDM4C may act as a pro-oncogenic factor in BCa invasion and metastasis via the circKDM4C/miR-200bc-3p/ZEB1 axis, which is a potential biomarker or therapeutic target for bladder cancer.

The Regulatory Role of RNA Metabolism Regulator TDP-43 in Human Cancer.

TAR-DNA-binding protein-43 (TDP-43) is a member of hnRNP family and acts as both RNA and DNA binding regulator, mediating RNA metabolism and transcription regulation in various diseases. Currently, emerging evidence gradually elucidates the crucial role of TDP-43 in human cancers like it is previously widely researched in neurodegeneration diseases. A series of RNA metabolism events, including mRNA alternative splicing, transport, stability, miRNA processing, and ncRNA regulation, are all confirmed to be closely involved in various carcinogenesis and tumor progressions, which are all partially regulated and interacted by TDP-43. Herein we conducted the first overall review about TDP-43 and cancers to systematically summarize the function and precise mechanism of TDP-43 in different human cancers. We hope it would provide basic knowledge and concepts for tumor target therapy and biomarker diagnosis in the future.

MicroRNA-501-3p inhibits the proliferation of kidney cancer cells by targeting WTAP.

BACKGROUND: Emerging evidence suggests that miR-501-3p plays an important role in the pathogenesis and progression of various carcinomas. However, its role and underlying mechanisms in renal cell carcinoma (RCC) remain to be elucidated. METHODS: Quantitative RT-PCR, western blot, and bioinformatics methods were used to evaluate the expression of miR-501-3p and Wilms' tumor 1-associating protein (WTAP) in RCC cell lines and clinical tissues. The effects of miR-501-3p on the proliferation of RCC cells were investigated using flow cytometric, colony formation, and CCK8 assays. The target gene of miR-501-3p was confirmed by western blotting, qRT-PCR, and dual-luciferase reporter assays. The levels of RNA methylation with N6-methyladenosine (m6 A) following miR-501-3p overexpression or knockdown of its target gene were quantified using a dot-blot assay. RESULTS: miR-501-3p expression was significantly downregulated in human RCC cell lines and tissues. In contrast, its overexpression markedly inhibited cancer cell proliferation in vitro by inducing G1 phase arrest. Moreover, WTAP was verified as a direct target gene of miR-501-3p. WTAP gene knockdown alone efficiently produced the same cancer-inhibiting effects as miR-501-3p overexpression, with the level of m6 A in RCC cells being decreased under both scenarios. The intermolecular interaction between miR-501-3p and WTAP was further substantiated by rescue experiments. CONCLUSION: RCC progression is regulated via the miR-501-3p/WTAP/CDK2 axis and is inhibited by the overexpression of miR-501-3p.

EGR2-mediated regulation of m6A reader IGF2BP proteins drive RCC tumorigenesis and metastasis via enhancing S1PR3 mRNA stabilization.

Emerging discoveries of dynamic and reversible N6-methyladenosine (m6A) modification on RNA in mammals have revealed the key roles of the modification in human tumorigenesis. As known m6A readers, insulin-like growth factor 2 mRNA-binding proteins (IGF2BPs) are upregulated in most cancers and mediates the enhancement of m6A-modified mRNAs stability. However, the mechanisms of IGF2BPs in renal cell cancer (RCC) still remain unclear. Bioinformatic analysis and RT-qPCR were performed to evaluate the expression of IGF2BPs and m6A writer Wilms tumor 1-associating protein (WTAP) in RCC samples and its correlation with patient prognosis. In vitro, in vivo biological assays were performed to investigate the functions of IGF2BPs and WTAP in RCC. Chromatin immunoprecipitation-qPCR (ChIP-qPCR) combined with bioinformatics analysis and following western blot assay, dual-luciferase reporter assays were performed to validate the regulatory relationships between transcription factor (TF) early growth response 2 (EGR2) and potential target genes IGF2BPs. RNA sequencing (RNA-seq), methylated RNA immunoprecipitation-qPCR (MERIP-qPCR), RIP-qPCR, m6A dot blot, and dual-luciferase reporter assays combined with bioinformatics analysis were employed to screen and validate the direct targets of IGF2BPs and WTAP. Here, we showed that early growth response 2 (EGR2) transcription factor could increase IGF2BPs expression in RCC. IGF2BPs in turn regulated sphingosine-1-phosphate receptor 3 (S1PR3) expression in an m6A-dependent manner by enhancing the stability of S1PR3 mRNA. They also promoted kidney tumorigenesis via PI3K/AKT pathway. Furthermore, IGF2BPs and WTAP upregulation predicted poor overall survival in RCC. Our studies showed that the EGR2/IGF2BPs regulatory axis and m6A-dependent regulation of S1PR3-driven RCC tumorigenesis, which enrich the m6A-modulated regulatory network in renal cell cancer. Together, our findings provide new evidence for the role of N6-methyladenosine modification in RCC.

miR-665 inhibits epithelial-to-mesenchymal transition in bladder cancer via the SMAD3/SNAIL axis.

Emerging research indicates that miRNAs can regulate cancer progression by influencing molecular pathways. Here, we studied miR-665, part of the DLK1-DIO3 miRNA cluster, which is downregulated by upstream methylation in bladder cancer. MiR-665 overexpression significantly downregulated the expression of SMAD3, phospho-SMAD3, and SNAIL, reversed epithelial-mesenchymal transition progression, and inhibited the migration of bladder cancer cells. To predict potential targets of miR-665, we used online databases and subsequently determined that miR-665 binds directly to the 3' untranslated region of SMAD3. Moreover, silencing of SMAD3 with small interfering RNAs phenocopied the effect of miR-665 overexpression, and overexpression of SMAD3 restored miR-665-overexpression-induced metastasis. This study revealed the role of the miR-665/SMAD3/SNAIL axis in bladder cancer, as well as the potential of miR-665 as a promising therapeutic target.

Upregulation of ARNTL2 is associated with poor survival and immune infiltration in clear cell renal cell carcinoma.

BACKGROUND: Aryl hydrocarbon receptor nuclear translocator like 2 (ARNTL2) is a member of the PAS superfamily. Previous studies explored the carcinogenic roles of transcription factor ARNTL2 in human malignancies. However, its roles in ccRCC have not been elucidated. This study sought to explore the roles of ARNTL2 in ccRCC and determine its correlations with tumor immunity. METHODS: The expression of ARNTL2 was analyzed using the GEO, TCGA and GTEx database, and verified in ccRCC tissue samples and cell lines by qRT-PCR and western blot analysis. Kaplan-Meier survival curve analysis, Cox regression analysis (including univariate and multivariate analysis) was utilized to evaluate the prognostic values of ARNTL2. Potential biological mechanisms of ARNTL2 were explored using GSEA method. Colony formation and wound healing assays were conducted to explore the oncogenic role of ARNTL2 in ccRCC. ssGSEA and xCell algorithm were used to explore the correlation between ARNTL2 expression and tumor immune microenvironment (TIME). RESULTS: ARNTL2 was significantly upregulated in ccRCC tissues and cell lines compared to normal kidney tissues and cell line. Enhanced expression of ARNTL2 was strongly linked to advanced clinical stage and unfavorable overall survival in ccRCC. ARNTL2 was determined as an independent prognostic marker through cox regression analysis. A prognostic nomogram was constructed to predict 1-, 3- and 5-year overall survival of ccRCC patients by integrating ARNTL2 expression with other clinicopathologic variables. GSEA analysis showed that focal adhesion, T cell receptor, cell cycle, and JAK-STAT signaling pathway were significantly enriched in high ARNTL2 samples. Silencing of ARNTL2 suppressed the colony formation ability and wound healing efficacy of ccRCC cell lines. xCell analysis showed that high expression level of ARNTL2 exhibited an immune infiltration status similar to CD8 + inflamed ccRCC subtype, which was characterized by high infiltration level of CD8 + T cell and high expression level of the immune escape biomarkers such as PD-L1, PD-L2, PD1 and CTLA4. CONCLUSION: ARNTL2 is an independent adverse predictor of ccRCC patient survival. High expression level of ARNTL2 is associated with immune infiltration, and may be a novel therapeutic target in ccRCC.

Comprehensive Analysis of Ferroptosis Regulators With Regard to PD-L1 and Immune Infiltration in Clear Cell Renal Cell Carcinoma.

Clear cell renal cell carcinoma (ccRCC) is one of the tumor types with sensitivity to ferroptosis, and immunotherapy has emerged as a standard pillar for metastatic ccRCC treatment, while it remains largely obscure whether ferroptosis influences the tumor immune microenvironment in ccRCC. Based on available data in The Cancer Genome Atlas, divergent expression profiles of ferroptosis regulators were noted in ccRCC and normal tissues, and we also found that the ferroptosis regulators correlated with the PD-L1 expression. Two independent subtypes were determined by consensus clustering analysis according to the expression level of ferroptosis regulators in ccRCC. Cluster 1 showed lower histological tumor stage and grade, more favorable prognosis, and higher PD-L1 expression compared to cluster 2. CIBERSORT analysis revealed that cluster 2 harbored higher infiltrated levels of CD8+ T cell, Tregs, and T follicular helper cell, while cluster 1 more correlated with the monocyte, M1 macrophage, and M2 macrophage. Gene set enrichment analysis indicated that the ERBB signaling and JAK_STAT signaling pathways were significantly enriched in cluster 1. We subsequently identified CARS as the potentially key immune infiltration-related ferroptosis regulator, whose high expression showed dismal prognosis and was positively correlated with PD-L1 expression in ccRCC. We also verified the upregulation of CARS in ccRCC tissues and cell lines via qRT-PCR method. Additionally, a pan-cancer analysis demonstrated that CARS closely related to the expression of immune checkpoint-related genes (especially PD-L1) and an unfavorable prognosis in diverse cancer types. In summary, our study suggested the crucial role of ferroptosis in immune infiltration of ccRCC, and CARS is a potentially novel prognostic biomarker and potential target for cancer immunotherapy.

Prognostic Value of Tumor-Associated Macrophages in Clear Cell Renal Cell Carcinoma: A Systematic Review and Meta-Analysis.

BACKGROUND: Tumor-associated macrophages (TAMs) are the major immune cells in tumor microenvironment. The prognostic significance of TAMs has been confirmed in various tumors. However, whether TAMs can be prognostic factors in clear cell renal cell carcinoma (ccRCC) is unclear. In this study, we aimed to clarify the prognostic value of TAMs in ccRCC. METHODS: We searched PubMed, Embase, and the Web of Science for relevant published studies before December 19, 2020. Evidence from enrolled studies were pooled and analyzed by a meta-analysis. Hazard ratios (HRs) and odd ratios (ORs) with 95% confidence intervals (CIs) were computed to evaluate the pooled results. RESULTS: Both of high CD68+ TAMs and M2-TAMs were risk factors for poor prognosis in ccRCC patients. The pooled HRs indicated that elevated CD68+ TAMs correlated with poor OS and PFS (HR: 3.97, 95% CI 1.39-11.39; HR: 5.73, 95% CI 2.36-13.90, respectively). For M2-TAMs, the pooled results showed ccRCC patients with high M2-TAMs suffered a worse OS and shorter PFS, with HR 1.32 (95% CI 1.16-1.50) and 1.40 (95% CI 1.14-1.72), respectively. Also, high density of TAMs was associated with advanced clinicopathological features in ccRCC. CONCLUSIONS: TAMs could be potential biomarkers for prognosis and novel targets for immunotherapy in ccRCC. Further researches are warranted to validate our results.

YTHDF2 mediates the mRNA degradation of the tumor suppressors to induce AKT phosphorylation in N6-methyladenosine-dependent way in prostate cancer.

BACKGROUND: N6-methyladenosine (m6A) is the most abundant modification in mRNA of humans. Emerging evidence has supported the fact that m6A is comprehensively involved in various diseases especially cancers. As a crucial reader, YTHDF2 usually mediates the degradation of m6A-modified mRNAs in m6A-dependent way. However, the function and mechanisms of m6A especially YTHDF2 in prostate cancer (PCa) still remain elusive. METHODS: To investigate the functions and mechanisms of YTHDF2 in PCa, in vitro, in vivo biofunctional assays and epigenetics experiments were performed. Endogenous expression silencing of YTHDF2 and METTL3 was established with lentivirus-based shRNA technique. Colony formation, flow cytometry and trans-well assays were performed for cell function identifications. Subcutaneous xenografts and metastatic mice models were combined with in vivo imaging system to investigate the phenotypes when knocking down YTHDF2 and METTL3. m6A RNA immunoprecipitation (MeRIP) sequencing, mRNA sequencing, RIP-RT-qPCR and bioinformatics analysis were mainly used to screen and validate the direct common targets of YTHDF2 and METTL3. In addition, TCGA database was also used to analyze the expression pattern of YTHDF2, METTL3 and the common target LHPP in PCa, and their correlation with clinical prognosis. RESULTS: The upregulated YTHDF2 and METTL3 in PCa predicted a worse overall survival rate. Knocking down YTHDF2 or METTL3 markedly inhibited the proliferation and migration of PCa in vivo and in vitro. LHPP and NKX3-1 were identified as the direct targets of both YTHDF2 and METTL3. YTHDF2 directly bound to the m6A modification sites of LHPP and NKX3-1 to mediate the mRNA degradation. Knock-down of YTHDF2 or METTL3 significantly induced the expression of LHPP and NKX3-1 at both mRNA and protein level with inhibited phosphorylated AKT. Overexpression of LHPP and NKX3-1 presented the consistent phenotypes and AKT phosphorylation inhibition with knock-down of YTHDF2 or METTL3. Phosphorylated AKT was consequently confirmed as the downstream of METTL3/YTHDF2/LHPP/NKX3-1 to induce tumor proliferation and migration. CONCLUSION: We propose a novel regulatory mechanism in which YTHDF2 mediates the mRNA degradation of the tumor suppressors LHPP and NKX3-1 in m6A-dependent way to regulate AKT phosphorylation-induced tumor progression in prostate cancer. We hope our findings may provide new concepts of PCa biology.

Roles of N6 -methyladenosine (m6 A) RNA modifications in urological cancers.

Epigenetics has long been a hot topic in the field of scientific research. The scope of epigenetics usually includes chromatin remodelling, DNA methylation, histone modifications, non-coding RNAs and RNA modifications. In recent years, RNA modifications have emerged as important regulators in a variety of physiological processes and in disease progression, especially in human cancers. Among the various RNA modifications, m6 A is the most common. The function of m6 A modifications is mainly regulated by 3 types of proteins: m6 A methyltransferases (writers), m6 A demethylases (erasers) and m6 A-binding proteins (readers). In this review, we focus on RNA m6 A modification and its relationship with urological cancers, particularly focusing on its roles and potential clinical applications.

METTL3/YTHDF2 m6 A axis promotes tumorigenesis by degrading SETD7 and KLF4 mRNAs in bladder cancer.

N6-Methyladenosine (m6 A) modification, the most prevalent modification of eukaryotic messenger RNA (mRNA), is involved in the progression of various tumours. However, the specific role of m6 A in bladder cancer (BCa) is still poorly understood. In this study, we demonstrated the tumour-promoting function and specific regulatory mechanism of m6 A axis, consisting of the core 'writer' protein METTL3 and the major reader protein YTHDF2. Depletion of METTL3 impaired cancer proliferation and cancer metastasis in vitro and in vivo. Through transcriptome sequencing, m6 A methylated RNA immunoprecipitation (MeRIP) and RIP, we determined that the METTL3/YTHDF2 m6 A axis directly degraded the mRNAs of the tumour suppressors SETD7 and KLF4, contributing to the progression of BCa. In addition, overexpression of SETD7 and KLF4 revealed a phenotype consistent with that induced by depletion of the m6 A axis. Thus, our findings on the METTL3/YTHDF2/SETD7/KLF4 m6 A axis provide the insight into the underlying mechanism of carcinogenesis and highlight potential therapeutic targets for BCa.

CCND1, NOP14 and DNMT3B are involved in miR-502-5p-mediated inhibition of cell migration and proliferation in bladder cancer.

OBJECTIVES: Downregulation of miR-502-5p has emerged as a critical factor in tumour progression in several cancers. Herein, we elucidated the role of miR-502-5p in bladder cancer. MATERIALS AND METHODS: RT-qPCR was performed to examine the expression of miR-502-5p in bladder cancer. And DNA methylation analysis showed that epigenetic mechanisms may contribute to the downregulation of miR-502-5p. Then, wound-healing assay, transwell assay, colony formation assay, CCK8 assay and flow cytometry analysis were applied to evaluate the function of miR-502-5p in bladder cancer cell lines. Western blot was conducted to measure the protein levels of related genes. Furthermore, dual-luciferase reporter assay, in vivo tumorigenesis assay and immunohistochemical staining were also conducted as needed. RESULTS: MiR-502-5p is frequently downregulated in BCa. Meanwhile, hypermethylation of CpG islands contributes to the downregulation of miR-502-5p. Functionally, overexpression of miR-502-5p inhibited cell proliferation and migration in vitro and repressed tumour growth in vivo. CCND1, DNMT3B and NOP14 were identified as direct targets of miR-502-5p. Interestingly, DNMT3B and miR-502-5p established a positive feedback loop in the regulation of bladder cancer. In addition, rescue experiments further validated the direct molecular interaction between miR-502-5p and its targets. CONCLUSIONS: Our study proposed and demonstrated that the miR-502-5p-mediated regulatory network is critical in bladder cancer; this network may be useful in the development of more effective therapies against bladder cancer.

Lower circulating adiponectin is associated with higher risk of renal cell carcinoma: A meta-analysis.

BACKGROUND: Changes in circulating adiponectin have been related to the risks of various cancers. However, the association between circulating adiponectin and the risk of renal cell carcinoma has not been fully determined. A meta-analysis was performed to evaluate the relationship between circulating adiponectin and renal cell carcinoma risk. METHODS: Observational studies that evaluated the association between circulating adiponectin and renal cell carcinoma risk were identified via a systematic search of PubMed and Embase databases. The difference between circulating adiponectin in renal cell carcinoma cases and healthy controls, and the multivariable adjusted association between circulating adiponectin and renal cell carcinoma risk were evaluated. A random effects model was used if significant heterogeneity existed; otherwise a fixed effects model was applied. RESULTS: Eight case-control studies with 2624 renal cell carcinoma cases and 2904 healthy controls were included. Pooled results showed that circulating adiponectin was significantly lower in renal cell carcinoma cases than in healthy controls (mean difference = -1.08 ug/mL; 95% confidence interval (CI) -1.62, -0.54; P < 0.001). Higher circulating adiponectin was independently associated with a significantly lowered risk of renal cell carcinoma (adjusted odds ratio for 1 SD increment of adiponectin = 0.78; 95% CI: 0.63, 0.96; P = 0.02). Subgroup analyses according to characteristics including study design, ethnics of participants, blood samples, numbers of participants, mean ages of participants, and study quality showed consistent results. CONCLUSIONS: Lower circulating adiponectin is associated with increased risk of renal cell carcinoma. The potential pathophysiological mechanisms underlying the role of circulating adiponectin in the pathogenesis of renal cell carcinoma deserve further investigation.

Dysregulation of ncRNAs located at the DLK1­DIO3 imprinted domain: involvement in urological cancers.

Genomic imprinting has been found to be involved in human physical development and several diseases. The DLK1-DIO3 imprinted domain is located on human chromosome 14 and contains paternally expressed protein-coding genes (DLK1, RTL1, DIO3) and numerous maternally expressed ncRNA genes (MEG3, MEG8, antisense RTL1, miRNAs, piRNAs, and snoRNAs). Emerging evidence has implicated that dysregulation of the DLK1-DIO3 imprinted domain especially the imprinted ncRNAs is critical for tumor progressions. Multiple miRNAs and lncRNAs have been investigated in urological cancers, of which several are transcribed from this domain. In this review, we present current data about the associated miRNAs, lncRNAs, and piRNAs and the regulation of differentially methylated regions methylation status in the progression of urological cancers and preliminarily propose certain concepts about the potential regulatory networks involved in DLK1-DIO3 imprinted domain.

Dual regulatory role of CCNA2 in modulating CDK6 and MET-mediated cell-cycle pathway and EMT progression is blocked by miR-381-3p in bladder cancer.

Emerging evidence has elucidated that microRNAs (miRNAs) transcribed from miRNA cluster at DLK-DIO3 imprinted domain are involved in various cancers. However, as one member of this cluster, the underlying mechanisms and functions of miR-381-3p in bladder cancer (BCa) still remains elusive. Here we demonstrate that the hypermethylated status of upstream maternally expressed gene 3 divergent methylation region reduces the expression of miR-381-3p in BCa by bisulfite-sequencing PCR. In vitro and in vivo experiments indicate that overexpression of miR-381-3p significantly inhibits cell proliferation via inducing G1 phase arrest and migration via down-regulating MET and CCNA2 induced EMT progression. CDK6/CCNA2/MET are all identified as the direct targets of miR-381-3p by bioinformatics analysis and dual-luciferase reporter assay. Furthermore, inhibition of CCNA2 mediated by miR-381-3p as the crucial biregulator not only participates in the proliferation regulation with CDK6 in cell cycle but also modulates the EMT progression via ROCK/AKT/ß-catenin/SNAIL pathway, which establishes an EMT circuit combined with miR-381-3p/MET/AKT/GSK-3ß/SNAIL pathway, and SNAIL is the last confocal target to induce EMT progression. To conclude, we propose 2 novel regulatory circuits mediated by miR-381-3p in BCa, which may assist in the development of more effective therapies against BCa in the future.-Li, J., Ying, Y., Xie, H., Jin, K., Yan, H., Wang, S., Xu, M., Xu, X., Wang, X., Yang, K., Zheng, X., Xie, L. Dual regulatory role of CCNA2 in modulating CDK6 and MET-mediated cell-cycle pathway and EMT progression is blocked by miR-381-3p in bladder cancer.