Circular RNAs (circRNAs), a novel class of noncoding RNAs, have recently drawn lots of attention in the pathogenesis of human cancers. However, the role of circRNAs in cancer cells ...epithelial-mesenchymal transition (EMT) remains unclear. In this study, we aimed to identify novel circRNAs that regulate urothelial carcinoma of the bladder (UCB) cells' EMT and explored their regulatory mechanisms and clinical significance in UCBs.
We first screened circRNA expression profiles using a circRNA microarray in paired UCB and normal tissues, and then studied the clinical significance of an upregulated circRNA, circPRMT5, in a large cohort of patients with UCB. We further investigated the functions and underlying mechanisms of circPRMT5 in UCB cells' EMT. Moreover, we evaluated the regulation effect of circPRMT5 on miR-30c, and its target genes,
and
, in two independent cohorts from our institute and The Cancer Genome Atlas (TCGA).
We demonstrated that upregulated expression of circPRMT5 was positively associated with advanced clinical stage and worse survival in patients with UCB. We further revealed that circPRMT5 promoted UCB cell's EMT via sponging miR-30c. Clinical analysis from two independent UCB cohorts showed that the circPRMT5/miR-30c/SNAIL1/E-cadherin pathway was essential in supporting UCB progression. Importantly, we identified that circPRMT5 was upregulated in serum and urine exosomes from patients with UCB, and significantly correlated with tumor metastasis.
CircPRMT5 exerts critical roles in promoting UCB cells' EMT and/or aggressiveness and is a prognostic biomarker of the disease, suggesting that circPRMT5 may serve as an exploitable therapeutic target for patients with UCB.
Summary Background Current staging methods do not accurately predict the risk of disease recurrence and benefit of adjuvant chemotherapy for patients who have had surgery for stage II colon cancer. ...We postulated that expression patterns of multiple microRNAs (miRNAs) could, if combined into a single model, improve postoperative risk stratification and prediction of chemotherapy benefit for these patients. Method Using miRNA microarrays, we analysed 40 paired stage II colon cancer tumours and adjacent normal mucosa tissues, and identified 35 miRNAs that were differentially expressed between tumours and normal tissue. Using paraffin-embedded specimens from a further 138 patients with stage II colon cancer, we confirmed differential expression of these miRNAs using qRT-PCR. We then built a six-miRNA-based classifier using the LASSO Cox regression model, based on the association between the expression of every miRNA and the duration of individual patients' disease-free survival. We validated the prognostic and predictive accuracy of this classifier in both the internal testing group of 138 patients, and an external independent group of 460 patients. Findings Using the LASSO model, we built a classifier based on the six miRNAs: miR-21-5p, miR-20a-5p, miR-103a-3p, miR-106b-5p, miR-143-5p, and miR-215. Using this tool, we were able to classify patients between those at high risk of disease progression (high-risk group), and those at low risk of disease progression (low-risk group). Disease-free survival was significantly different between these groups in every set of patients. In the initial training group of patients, 5-year disease-free survival was 89% (95% CI 77·3–94·4) for the low-risk group, and 60% (46·3–71·0) for the high-risk group (hazard ratio HR 4·24, 95% CI 2·13–8·47; p<0·0001). In the internal testing set of patients, 5-year disease-free survival was 85% (95% CI 74·3–91·8) for the low-risk group, and 57% (42·8–68·5) for the high-risk group (HR 3·63, 1·86–7·01; p<0·0001), and in the independent validation set of patients, was 85% (79·6–89·0) for the low-risk group and 54% (46·4–61·1) for the high-risk group (HR 3·70, 2·56–5·35; p<0·0001). The six-miRNA-based classifier was an independent prognostic factor for, and had better prognostic value than, clinicopathological risk factors and mismatch repair status. In an ad-hoc analysis, the patients in the high-risk group were found to have a favourable response to adjuvant chemotherapy (HR 1·69, 1·17–2·45; p=0·0054). We developed two nomograms for clinical use that integrated the six-miRNA-based classifier and four clinicopathological risk factors to predict which patients might benefit from adjuvant chemotherapy after surgery for stage II colon cancer. Conclusion Our six-miRNA-based classifier is a reliable prognostic and predictive tool for disease recurrence in patients with stage II colon cancer, and might be able to predict which patients benefit from adjuvant chemotherapy. It might facilitate patient counselling and individualise management of patients with this disease. Funding Natural Science Foundation of China.
Although 5-methylcytosine (m
C) is a widespread modification in RNAs, its regulation and biological role in pathological conditions (such as cancer) remain unknown. Here, we provide the ...single-nucleotide resolution landscape of messenger RNA m
C modifications in human urothelial carcinoma of the bladder (UCB). We identify numerous oncogene RNAs with hypermethylated m
C sites causally linked to their upregulation in UCBs and further demonstrate YBX1 as an m
C 'reader' recognizing m
C-modified mRNAs through the indole ring of W65 in its cold-shock domain. YBX1 maintains the stability of its target mRNA by recruiting ELAVL1. Moreover, NSUN2 and YBX1 are demonstrated to drive UCB pathogenesis by targeting the m
C methylation site in the HDGF 3' untranslated region. Clinically, a high coexpression of NUSN2, YBX1 and HDGF predicts the poorest survival. Our findings reveal an unprecedented mechanism of RNA m
C-regulated oncogene activation, providing a potential therapeutic strategy for UCB.
Aberrant expression of transforming growth factor‐β1 (TGF‐β1) is associated with renal cell carcinoma (RCC) progression by inducing cancer metastasis. However, the downstream effector(s) in TGF‐β ...signaling pathway is not fully characterized. In the present study, the elevation of secreted protein acidic and rich in cysteine (SPARC) as a TGF‐β regulated gene in RCC was identified by applying differentially expressed gene analysis and microarray analysis, we further confirmed this result in several RCC cell lines. Clinically, the expression of these two genes is positively correlated in RCC patient specimens. Furthermore, elevated SPARC expression is found in all the subtypes of RCC and positively correlated with the RCC stage and grade. In contrast, SPARC expression is inversely correlated with overall and disease‐free survival of patients with RCC, suggesting SPARC as a potent prognostic marker of RCC patient survival. Knocking down SPARC significantly inhibits RCC cell invasion and metastasis both in vitro and in vivo. Similarly, in vitro cell invasion can be diminished by using a specific monoclonal antibody. Mechanistically, SPARC activates protein kinase B (AKT) pathway leading to elevated expression of matrix metalloproteinase‐2 that can facilitate RCC invasion. Altogether, our data support that SPARC is a critical role of TGF‐β signaling network underlying RCC progression and a potential therapeutic target as well as a prognostic marker.
Circular RNAs (circRNAs) have been indicated as potentially critical mediators in various types of tumor progression, generally acting as microRNA (miRNA) sponges to regulate downstream gene ...expression. However, the aberrant expression profile and dysfunction of circRNAs in human clear cell renal cell carcinoma (ccRCC) need to be further investigated. This study mined key prognostic circRNAs and elucidates the potential role and molecular mechanism of circRNAs in regulating the proliferation and metastasis of ccRCC.
circCHST15 (hsa_circ_0020303) was identified by mining two circRNA microarrays from the Gene Expression Omnibus database and comparing matched tumor versus adjacent normal epithelial tissue pairs or matched primary versus metastatic tumor tissue pairs. These results were validated by quantitative real-time polymerase chain reaction and agarose gel electrophoresis. We demonstrated the biological effect of circCHST15 in ccRCC both in vitro and in vivo. To test the interaction between circCHST15 and miRNAs, we conducted a number of experiments, including RNA pull down assay, dual-luciferase reporter assay and fluorescence in situ hybridization.
The expression of circCHST15 was higher in ccRCC tissues compared to healthy adjacent kidney tissue and higher in RCC cell lines compared to normal kidney cell lines. The level of circCHST15 was positively correlated with aggressive clinicopathological characteristics, and circCHST15 served as an independent prognostic indicator for overall survival and progression-free survival in patients with ccRCC after surgical resection. Our in vivo and in vitro data indicate that circCHST15 promotes the proliferation, migration, and invasion of ccRCC cells. Mechanistically, we found that circCHST15 directly interacts with miR-125a-5p and acts as a microRNA sponge to regulate EIF4EBP1 expression.
We found that sponging of miR-125a-5p to promote EIF4EBP1 expression is the underlying mechanism of hsa_circ_0020303-induced ccRCC progression. This prompts further investigation of circCHST15 as a potential prognostic biomarker and therapeutic target for ccRCC.
Microglia are highly motile cells that act as the main form of active immune defense in the central nervous system. Attracted by factors released from damaged cells, microglia are recruited towards ...the damaged or infected site, where they are involved in degenerative and regenerative responses and phagocytotic clearance of cell debris. ATP release from damaged neural tissues has been suggested to mediate the rapid extension of microglial process towards the site of injury. However, the mechanisms of the long-range migration of microglia remain to be clarified. Here, we found that lysosomes in microglia contain abundant ATP and exhibit Ca^2＋-dependent exocytosis in response to various stimuli. By establishing an efficient in vitro chemotaxis assay,
Clinically, most of human urothelial carcinoma of the bladder (UCB)-related deaths result from tumor metastasis, but the underlying molecular mechanisms are largely unknown. Recently, a growing ...number of tripartite motif (TRIM) family members have been suggested to be important regulators for tumorigenesis. However, the impact of most TRIM members on UCB pathogenesis is unclear. In this study, TRIM65 was first screened as an important oncogenic factor of UCB from the Cancer Genome Atlas (TCGA) database and was validated by a large cohort of clinical UCB tissues. By in vitro and in vivo experiments, we demonstrated that TRIM65 promotes UCB cell invasive and metastatic capacities. Notably, we showed that TRIM65 modulates cytoskeleton rearrangement and induces UCB cells epithelial-mesenchymal transition by the ubiquitination of ANXA2, ultimately leading to an enhanced invasiveness of UCB cells. Importantly, UCBs with high expression of TRIM65 and low expression of ANXA2 showed the poorest outcome. Collectively, our results suggest that the overexpression of TRIM65 has an essential oncogenic role via ubiquitination of ANXA2 in UCB pathogenesis, and that such could be used as a novel prognostic marker and/or therapeutic target for UCB.
•TRIM65 is overexpressed in UCBs and is an independent prognostic biomarker.•TRIM65 promotes UCB cell invasive and metastatic capacities.•TRIM65 modulates cytoskeleton rearrangement and induces UCB cell EMT.•TRIM65 promotes ANXA2 ubiquitination and degradation in UCB cells.•ANXA2 is responsible for TRIM65-induced UCB cell EMT, morphological alteration and invasiveness.
Sunitinib resistance is a major challenge in systemic therapy for renal cell carcinoma (RCC). The role of circular RNAs (circRNAs) in regulating sunitinib resistance of RCC is largely unknown. We ...established sunitinib-resistant RCC cell lines in vivo. Through RNA-sequencing, we identified circSNX6, whose expression is upregulated in sunitinib-resistant cells compared with their parental cells. High circSNX6 expression was correlated with sunitinib resistance and worse oncologic outcomes in a cohort of 81 RCC patients. In vitro and in vivo experiments confirmed that circSNX6 could promote sunitinib resistance in RCC. circSNX6 acts as a molecular “sponge” to relieve the suppressive effect of microRNA (miR)-1184 on its target gene, glycerophosphocholine phosphodiesterase 1 (GPCPD1), which increases intracellular lysophosphatidic acid (LPA) levels and, ultimately, promotes sunitinib resistance in RCC cells. Our findings demonstrated that the circSNX6/miR-1184/GPCPD1 axis had a critical role in regulation of intracellular LPA levels and sunitinib resistance in RCC; they also provide a novel prognostic indicator and promising therapeutic targets.
•circSNX6 is upregulated in sunitinib-resistant RCC cells.•The expression of circSNX6 is correlated with sunitinib resistance and poorer survival.•circSNX6 promotes sunitinib resistance of RCC cells in vitro and in vivo.•circSNX6 exerts its function via miR-1184/GPCPD1/intracellular LPA axis.•circSNX6 may be a promising therapeutic target and biomarker for sunitinib resistance.
Long noncoding RNAs (lncRNAs) have been reported to exert important roles in tumors, including clear cell renal cell carcinoma (ccRCC). PVT1 is an important oncogenic lncRNA which has critical ...effects on onset and development of various cancers, however, the underlying mechanism of PVT1 functioning in ccRCC remains largely unknown. VHL deficiency-induced HIF2α accumulation is one of the major factors for ccRCC. Here, we identified the potential molecular mechanism of PVT1 in promoting ccRCC development by stabilizing HIF2α. PVT1 was significantly upregulated in ccRCC tissues and high PVT1 expression was associated with poor prognosis of ccRCC patients. Both gain-of-function and loss-of function experiments revealed that PVT1 enhanced ccRCC cells proliferation, migration, and invasion and induced tumor angiogenesis in vitro and in vivo. Mechanistically, PVT1 interacted with HIF2α protein and enhanced its stability by protecting it from ubiquitination-dependent degradation, thereby exerting its biological significance. Meanwhile, HIF2α bound to the enhancer of PVT1 to transactivate its expression. Furthermore, HIF2α specific inhibitor could repress PVT1 expression and its oncogenic functions. Therefore, our study demonstrates that the PVT1/ HIF2α positive feedback loop involves in tumorigenesis and progression of ccRCC, which may be exploited for anticancer therapy.
Identification of high-risk localised renal cell carcinoma is key for the selection of patients for adjuvant treatment who are at truly higher risk of reccurrence. We developed a classifier based on ...single-nucleotide polymorphisms (SNPs) to improve the predictive accuracy for renal cell carcinoma recurrence and investigated whether intratumour heterogeneity affected the precision of the classifier.
In this retrospective analysis and multicentre validation study, we used paraffin-embedded specimens from the training set of 227 patients from Sun Yat-sen University (Guangzhou, Guangdong, China) with localised clear cell renal cell carcinoma to examine 44 potential recurrence-associated SNPs, which were identified by exploratory bioinformatics analyses of a genome-wide association study from The Cancer Genome Atlas (TCGA) Kidney Renal Clear Cell Carcinoma (KIRC) dataset (n=114, 906 600 SNPs). We developed a six-SNP-based classifier by use of LASSO Cox regression, based on the association between SNP status and patients' recurrence-free survival. Intratumour heterogeneity was investigated from two other regions within the same tumours in the training set. The six-SNP-based classifier was validated in the internal testing set (n=226), the independent validation set (Chinese multicentre study; 428 patients treated between Jan 1, 2004 and Dec 31, 2012, at three hospitals in China), and TCGA set (441 retrospectively identified patients who underwent resection between 1998 and 2010 for localised clear cell renal cell carcinoma in the USA). The main outcome was recurrence-free survival; the secondary outcome was overall survival.
Although intratumour heterogeneity was found in 48 (23%) of 206 cases in the internal testing set with complete SNP information, the predictive accuracy of the six-SNP-based classifier was similar in the three different regions of the training set (areas under the curve AUC at 5 years: 0·749 95% CI 0·660–0·826 in region 1, 0·734 0·651–0·814 in region 2, and 0·736 0·649–0·824 in region 3). The six-SNP-based classifier precisely predicted recurrence-free survival of patients in three validation sets (hazard ratio HR 5·32 95% CI 2·81–10·07 in the internal testing set, 5·39 3·38–8·59 in the independent validation set, and 4·62 2·48–8·61 in the TCGA set; all p<0·0001), independently of patient age or sex and tumour stage, grade, or necrosis. The classifier and the clinicopathological risk factors (tumour stage, grade, and necrosis) were combined to construct a nomogram, which had a predictive accuracy significantly higher than that of each variable alone (AUC at 5 years 0·811 95% CI 0·756–0·861).
Our six-SNP-based classifier could be a practical and reliable predictor that can complement the existing staging system for prediction of localised renal cell carcinoma recurrence after surgery, which might enable physicians to make more informed treatment decisions about adjuvant therapy. Intratumour heterogeneity does not seem to hamper the accuracy of the six-SNP-based classifier as a reliable predictor of recurrence. The classifier has the potential to guide treatment decisions for patients at differing risks of recurrence.
National Key Research and Development Program of China, National Natural Science Foundation of China, Guangdong Provincial Science and Technology Foundation of China, and Guangzhou Science and Technology Foundation of China.
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