Biomarker For ccRCC Research Articles

IGLL5 is correlated with tumor‐infiltrating immune cells in clear cell renal cell carcinoma

Renal cell carcinomas (RCCs) account for about 90% of renal tumors, and their major histological subtype is ccRCC (clear cell RCC). Increasing evidence has indicated that the tumor microenvironment plays a significant role in the occurrence and development of ccRCC. In this study, we used ESTIMATE and CIBERSORT computational methods to calculate the proportion of immune and stromal components and the rate of TICs (tumor‐infiltrating immune cells) in 539 ccRCC samples from The Cancer Genome Atlas database. By examining the intersection of the differentially expressed genes obtained by the protein–protein interaction network and Cox regression analysis, we identified only one overlapping gene: IGLL5 (immunoglobulin lambda‐like polypeptide 5). We report that IGLL5 expression is correlated with TICs. Furthermore, our immunoinfiltration analyses revealed that three types of TIC are positively correlated with IGLL5 expression. IGLL5 may have potential as a prognostic biomarker of ccRCC.

Identification of a Metastasis-Associated Gene Signature of Clear Cell Renal Cell Carcinoma.

Clear cell renal cell carcinoma (ccRCC) is one of the most frequent pathological subtypes of kidney cancer, accounting for ~70–75%, and the major cause of mortality is metastatic disease. The difference in gene expression profiles between primary ccRCC tumors and metastatic tumors has not been determined. Thus, we report integrated genomic and transcriptomic analysis for identifying differentially expressed genes (DEGs) between primary and metastatic ccRCC tumors to understand the molecular mechanisms underlying the development of metastases. The microarray datasets GSE105261 and GSE85258 were obtained from the Gene Expression Omnibus (GEO) database, and the R package limma was used for DEG analyses. In summary, the results described herein provide important molecular evidence that metastatic ccRCC tumors are different from primary tumors. Enrichment analysis indicated that the DEGs were mainly enriched in ECM–receptor interaction, platelet activation, protein digestion, absorption, focal adhesion, and the PI3K–Akt signaling pathway. Moreover, we found that DEGs associated with a higher level of tumor immune infiltrates and tumor mutation burden were more susceptible to poor prognosis of ccRCC. Specifically, our study indicates that seven core genes, namely the collagen family (COL1A2, COL1A1, COL6A3, and COL5A1), DCN, FBLN1, and POSTN, were significantly upregulated in metastatic tumors compared with those in primary tumors and, thus, potentially offer insight into novel therapeutic and early diagnostic biomarkers of ccRCC.

Development of a novel gene signature to predict prognosis and response to PD-1 blockade in clear cell renal cell carcinoma

ABSTRACT Clear cell renal cell carcinoma (ccRCC) is the most common kidney malignancy characterized by a poor prognosis. The treatment efficacy of immune checkpoint inhibitors (ICIs) also varies widely in advanced ccRCC. We aim to construct a robust gene signature to improve the prognostic discrimination and prediction of ICIs for ccRCC patients. In this study, adopting differentially expressed genes from seven ccRCC datasets in GEO (Gene Expression Omnibus), a novel signature (FOXM1&TOP2A) was constructed in TCGA (The Cancer Genome Atlas) database by LASSO and Cox regression. Survival and time-dependent ROC analysis revealed the strong predictive ability of our signature in discovery set, two online validation sets and one tissue microarray (TMA) from our institution. High-risk group based on the signature comprises more high-grade (G3&G4) and advanced pathologic stage (stageIII/IV) tumors and presents hyperactivation of cell cycle process according to the functional analysis. Meanwhile, high-risk tumors demonstrate an immunosuppressive phenotype with more infiltrations of regulatory T cells (Tregs), macrophages and high expressions of genes negatively regulating anti-tumor immunity. Low-risk tumors have an improved response to anti-PD-1 therapy and the predictive ability of our signature is better than other recognized biomarkers in ccRCC. A nomogram containing this signature showed a high predictive accuracy with AUCs of 0.90 and 0.84 at 3 and 5 years. Overall, this robust signature could predict prognosis, evaluate immune microenvironment and response to anti-PD-1 therapy in ccRCC, which is very promising in clinical promotion.

Identification and validation of the clinical roles of the VHL-related LncRNAs in clear cell renal cell carcinoma.

Accumulating evidence suggests that lncRNAs (long non-coding RNAs) function as oncogenes or tumor suppressor genes in ccRCC (clear cell renal cell carcinoma). Although VHL (Von Hippel-Lindau) gene inactivation is by far the most common carcinogenic driving event in ccRCC, the roles of VHL-related lncRNAs in ccRCC remain unknown. In this study, using RNA-seq and clinical data in TCGA-KIRC (the Cancer Genome Atlas-Kidney Renal Clear Cell Carcinoma), we identified VHL-related lncRNAs through WGCNA (Weighted Gene Co-expression Network Analysis), correlation analysis and catRAPID algorithm, and explored their clinical characteristics in ccRCC. Results showed that 10 lncRNAs (AC112220.2, AL391121.1, USP46-AS1, AL450326.1, MID1IP1-AS1, SUCLG2-AS1, RAP2C-AS1, FGD5-AS1, AC018647.2 and AC015922.2) were identified as VHL-related lncRNAs, and they were down-regulated in ccRCC tissues. Survival analysis results indicated that high expression groups of AC112220.2, AL391121.1, USP46-AS1, AL450326.1, SUCLG2-AS1, RAP2C-AS1, FGD5-AS1, AC018647.2 and AC015922.2 had significantly longer OS (Overall Survival) than their respective low expression groups. Meanwhile high AC112220.2, USP46-AS1, AL450326.1, SUCLG2-AS1, FGD5-AS1, AC018647.2 and AC015922.2 expression groups had remarkably longer DFS (Disease Free Survival) than their respective low expression groups. Besides, FGD5-AS1 and AL391121.1 expression were decreased in VHL mutant tissues compared with VHL non-mutant tissues. Moreover, high expression group of FGD5-AS1 had significantly longer OS and DFS than their respective low expression groups in VHL mutant ccRCC. In addition, we found that DNA hypermethylation may also play an important role in decreased FGD5-AS1 expression. Furthermore, we validated the expression of FGD5-AS1 in VHL mutant and non-mutant ccRCC tissues and cell lines. In conclusion, our results demonstrated that lncRNA FGD5-AS1 was significantly associated with VHL and can serve as a novel biomarker of ccRCC.

LINC01232 serves as a novel biomarker and promotes tumour progression by sponging miR-204-5p and upregulating RAB22A in clear cell renal cell carcinoma

Background Long non-coding RNAs (lncRNAs) are involved in the progression of various cancers, including clear cell renal cell carcinoma (ccRCC). This study aimed to investigate the expression and prognostic value of long intergenic non-protein coding RNA (LINC) 01232 in ccRCC and preliminary explore the molecular mechanism underlying the role of LINC01232 in ccRCC progression. Methods Tumour tissues and adjacent normal tissues of 122 patients with ccRCC were collected in this study. The levels of LINC01232, microRNA (miR)-204-5p and RAB22A were measured by quantitative real-time PCR. The proliferation, migration and invasion of ccRCC cells were detected by cell counting kit-8 assay and Transwell assay, respectively. The interaction among LINC01232, miR-204-5p and RAB22A was confirmed by bioinformatics analysis, dual-luciferase reporter assay and Pearson correlation analysis. The association of LINC01232 and miR-204-5p with ccRCC patient survival was verified by the Kaplan–Meier method and log-rank test. The prognostic value of LINC01232 in ccRCC was confirmed by Cox regression analysis. Results LINC01232 expression was increased in ccRCC tumour tissues and ccRCC cells and independently predicted the prognosis of ccRCC patients. In addition, LINC01232 silencing inhibited ccRCC cell proliferation, migration and invasion. Moreover, LINC01232 served as a sponge for miR-204-5p, and miR-204-5p reduction reversed the inhibitory effect of LINC01232 silencing on ccRCC cell function. Furthermore, LINC01232 could sponge miR-204-5p, causing the elevation of RAB22A in ccRCC, thereby promoting ccRCC cell function. Conclusion LINC01232 may be an independent prognostic biomarker in ccRCC and plays an oncogenic role in ccRCC progression by sponging miR-204-5p and upregulating RAB22A.

Diagnostic and prognostic value of ABC transporter family member ABCG1 gene in clear cell renal cell carcinoma

ABSTRACT As the most common histologic subtype of renal cancer, clear cell renal cell carcinoma (ccRCC) poses a serious threat to public health. However, there are no specific molecular-targeted drugs for ccRCC at present. Human ATP-binding cassette (ABC) transporter family plays an important role in homeostasis maintenance. This study aimed to evaluate the potential diagnostic value of ABC genes in ccRCC. A total of 952 samples of ccRCC patients (707) and controls (245) from three different datasets were included for analysis. Receiver operating characteristic analysis and t-test were used to analyze the differential expression of ABC genes in ccRCC patients and control samples at mRNA level during screening and validations. The Cancer Genome Atlas (TCGA-ccRCC) dataset was utilized to investigate the correlation between ABC genes expression and prognostic value in ccRCC. We then investigated the interactions between ABCG1 and proteins in the Comparative Toxicogenomics Database (CTD). Finally, we found that ATP-binding cassette transporter G member 1 (ABCG1) was over-expressed in ccRCC patients compared with healthy samples at mRNA level. Cox regression analysis and Kaplan–Meier analysis showed that ccRCC patients with high ABCG1 expression had better overall survival (OS) than those patients with low expression (hazard ratio (HR) = 0.662, p = 0.007). This study demonstrated that ABCG1 is a potential diagnostic and prognostic biomarker in ccRCC and discussed the molecular mechanisms underlying the relationship between ccRCC and ABCG1, which might provide guidance for better management and treatment of ccRCC in the future.

A Novel miRNA-Based Model Can Predict the Prognosis of Clear Cell Renal Cell Carcinoma.

Clear cell renal cell carcinoma (ccRCC) is one of the most prevalent renal malignant cancer, whose survival rate and quality of life of patients are still not satisfactory. Nevertheless, the TNM staging system currently used in clinical cannot make accurate survival predictions and precise treatment decisions for ccRCC patients. Therefore, there is an urgent need for more reliable biomarkers to identify high-risk subgroups of ccRCC patients to guide timely intervention and treatment. Recently, MiRNAs have been shown to be closely related to the procession of a variety of tumors, and they have high stability in various tissues, which makes them suggested to have the potential as a prognostic biomarker of ccRCC. In this study, by analyzing and processing the miRNAs expression profile of ccRCC patients from the TCGA database, we finally constructed an excellent miRNAs signature and verified it through a variety of methods. In order to build a more accurate and reliable clinical predictive model, we integrated the miRNAs signature with other prognostic-related clinical parameters to construct a nomogram. Functional enrichment analysis showed that miRNAs in the signature may regulate the genes involved in the Hippo signaling pathway, Tight junction, and Wnt signaling pathway to cause different prognoses of ccRCC patients, which may provide a reference for subsequent basic research and targeted therapy. To conclude, our study constructed a useful miRNAs signature, which allows the prognosis stratification for ccRCC patients and thereby guides the timely and effective interventions on high-risk patients. At the same time, this study also found the potential biological pathways involved in the procession of ccRCC.

Silencing of the chemokine CXC receptor 4 (CXCR4) hampers cancer progression and increases cisplatin (DDP)-sensitivity in clear cell renal cell carcinoma (ccRCC)

ABSTRACT Aberrant expression of the chemokine CXC receptor 4 (CXCR4) is closely associated with cancer progression and drug-resistance in multiple cancers, and we first investigated the role of CXCR4 in regulating cancer pathogenesis and cisplatin (DDP)-resistance in clear cell renal cell carcinoma (ccRCC) in the present study. Here, we identified that CXCR4 acted as an oncogene to promote cancer progression and genetically silencing of CXCR4 increased cisplatin (DDP)-sensitivity in ccRCC in vitro and in vivo. Functionally, analysis from the clinical and cellular data indicated that CXCR4 was significantly upregulated in ccRCC tissues and cells, compared to their normal counterparts. Next, the loss-of-function experiments validated that knock-down of CXCR4 suppressed cell proliferation, invasion, migration and epithelial-mesenchymal transition (EMT) in ccRCC cells, while CXCR4 overexpression had opposite effects on the above cellular functions. Consistently, the xenograft tumor-bearing mice models were established, and the results supported that knock-down of CXCR4 inhibited tumor growth and the expression levels of Ki67 protein in vivo. In addition, the ccRCC cells were exposed to DDP treatment, and we surprisingly found that upregulation of CXCR4 increased DDP-resistance in ccRCC cells, and conversely, CXCR4 ablation sensitized ccRCC cells to DDP stimulation. Taken together, we concluded that CXCR4 ablation hindered cancer progression and enhanced DDP-sensitivity in ccRCC, and the present study identified a novel therapeutic biomarker for ccRCC.

Overexpression of chemokine receptor lymphotactin receptor 1 has prognostic value in clear cell renal cell carcinoma.

BackgroundClear cell renal cell carcinoma (ccRCC) is an aggressive subtype of renal cell carcinoma. X‐C motif chemokine receptor 1 (XCR1) exerts important roles in tumor progression; however, its role in ccRCC is unclear.MethodsWe utilized publicly available data from The Cancer Genome Atlas (TCGA) to assess the role of XCR1 in ccRCC and validated the results in 36 samples from patients with ccRCC who underwent curative resection in Xinqiao Hospital Chongqing. XCR1 overexpression was identified in ccRCC, which was confirmed by qRT‐PCR assay and immunohistochemical staining of ccRCC samples.ResultsFor the TCGA and clinical data, Kaplan–Meier survival analysis revealed that higher XCR1 expression in ccRCC was related to longer overall survival. Cox regression analysis suggested that XCR1 is an independent risk factor for ccRCC. GSEA analysis suggested that XCR1 is associated with the JAK/STAT signaling pathway. XCR1 knockdown by small interfering RNA (siRNA) significantly increased ccRCC cell proliferation and migration, and decreased cell apoptosis.ConclusionWe found higher XCR1 expression in ccRCC compared with that in normal tissues is related to longer overall survival in patients with ccRCC. XCR1 knockdown significantly increased RCC cells proliferation and migration, and decreased apoptosis. XCR1 might be used as a prognostic biomarker in ccRCC in the future.

Circ_101341 Deteriorates the Progression of Clear Cell Renal Cell Carcinoma Through the miR- 411/EGLN3 Axis.

BackgroundClear cell renal cell carcinoma (ccRCC) is one of the main subtypes of renal cell carcinoma, with intense aggressiveness. The involvement of circular RNAs (circRNAs) in human cancers attracts much concern. The intention of this study was to investigate the expression of circ_101341 and explore its function in ccRCC.Materials and MethodsThe expression of circ_101341, miR-411 and Egl nine homolog 3 (EGLN3) was measured using quantitative real-time polymerase chain reaction (qRT-PCR). Cell proliferation was assessed by cell counting kit-8 (CCK-8) assay and colony formation assay. Cell migration and invasion were monitored by transwell assay. Xenograft model was established to explore the role of circ_101341 in vivo. The protein levels of E-cadherin (E-cad), N-cadherin (N-cad), matrix metalloprotein-9 (MMP9) and EGLN3 were detected by Western blot. Bioinformatic analysis was conducted using Circinteractome and starBase. The targeted relationship was verified using dual-luciferase reporter assay, RNA-binding protein immunoprecipitation (RIP) assay and RNA pull-down assay.ResultsThe expression of circ_101341 was elevated in ccRCC tissues and cells. Functionally, circ_101341 knockdown depleted proliferation, migration and invasion of ccRCC cells in vitro and restricted tumor growth in vivo. Circ_101341 directly targeted miR-411, and miR-411 inhibition revised the inhibitory effects of circ_101341 knockdown on proliferation, migration and invasion in ccRCC cells. Moreover, miR-411 directly bound to EGLN3, and EGLN3 overexpression also rescued the effects of circ_101341 knockdown.ConclusionCirc_101341 functioned as a tumor promoter to strengthen proliferation, migration and invasion by regulating EGLN3 via sponging miR-411, indicating that circ_101341 was a potential diagnostic and therapeutic biomarker of ccRCC.

The expression and prognostic value of RNA binding proteins in clear cell renal cell carcinoma.

BackgroundRNA binding proteins (RBPs) have previously been demonstrated to be involved in the initiation and development of human cancers. However, its role in clear cell renal cell carcinoma (ccRCC) is not yet clear. The study was intended to explore the diagnostic and prognostic value of RBPs in ccRCC via bioinformatics methods of public datasets.MethodsData download from the Cancer Genome Atlas (TCGA) database was used to identify differentially expressed RBPs between normal renal samples and cancerous samples. Then, we performed the gene ontology (GO) annotation and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses of differentially expressed genes (DEGs) using the ClusterProfiler package. Next, the protein-protein interaction (PPI) network was built by the online tool STRING database and Cytoscape software. The significant module and hub genes were screened by MCODE and Cytohubba plugin, respectively. Lastly, we performed a systematical analysis to investigate the diagnostic and prognostic value of candidate RBPs.ResultsA total of 133 DEGs, including 39 upregulated RBPs and 94 downregulated RBPs, were screened between ccRCC samples and noncancerous samples. From these data, eight candidate RBPs (RPS2, GAPDH, RPS20, EIF4A1, RPL18, RPL13, RPL18A, and RPS19) were identified.ConclusionsIn summary, we screened differentially expressed RBPs of ccRCC, which were enriched mainly in various biological processes and signaling pathways. Furthermore, we identified eight candidate RBPs, which could serve as potential biomarkers of ccRCC.

Characterization of the Prognostic Values of the CXCR1-7 in Clear Cell Renal Cell Carcinoma (ccRCC) Microenvironment.

Background: As cancer immunotherapy has become a hot research topic, the values of CXC chemokine receptors (CXCRs) in tumor microenvironment have been increasingly realized. More and more evidence showed that the aberrant expression of CXCRs is closely related to the prognosis of various cancers. However, prognostic values and the exact roles of different CXCRs in clear cell renal cell carcinoma (ccRCC) have not yet been elucidated.Methods: To further evaluate the potential of seven CXCRs as prognostic biomarkers for ccRCC, multiple online analysis tools, including ONCOMINE, UALCAN (TCGA dataset), Kaplan–Meier Plotter, MethSurv, cBioPortal, GEPIA, Metascape, and TIMER databases, were utilized in our research.Results: The mRNA expression of CXCR4/6/7 was significantly increased in ccRCC patients, and all CXCRs are remarkably related to tumor stage or grade of ccRCC. Higher levels of CXCR3/4/5/6 expression were correlated with worse overall survival (OS) in patients with ccRCC, while higher expression of CXCR2 was associated with better OS. 23.14% mutation rate (118/510) of CXCR1-7 was observed in ccRCC patients, and the genetic alterations in CXCRs were related to worse OS and progression-free survival in ccRCC patients. Additionally, 53 CpGs of CXCR1-7 showed significant prognostic values. For functional enrichment, our results showed that CXCRs and their similar genes may be involved in cancer-associated pathways, immune process, and angiogenesis, etc. Besides, CXCRs were significantly correlated with multiple immune cells (e.g., CD8+ T cell, CD4+ cell, and dendritic cell).Conclusion: This study explored the potential prognostic values and roles of the CXCRs in ccRCC microenvironment. Our results suggested that CXCR4 and CXCR6 could be the prognostic biomarkers for the patients with ccRCC.

CLDN10 associated with immune infiltration is a novel prognostic biomarker for clear cell renal cell carcinoma.

Aims: To identify the clinical roles ofCLDN10in clear cell renal cell carcinoma (ccRCC). Materials & methods: Using data from TCGA-KIRC, GEO DataSets and laboratory experiments to determine the prognostic and clinicopathological characteristics of CLDN10. Results: CLDN10 expression was remarkably reduced in ccRCC. Downregulated CLDN10 was related to metastasis and poor prognosis. Multivariate Cox analysis determined that elevated CLDN10 expression was independently correlated with longer OS and DFS. Moreover, CLDN10 expression was negatively associated with the methylation levels of cg10305311 and cg16275739. CLDN10 expression was alsoassociated with naive CD4 andmemory T-cell and dendritic cell infiltration. Conclusions: Immune-related CLDN10 is an independent prognostic biomarker of ccRCC. DNA hypermethylation plays an important role in decreased CLDN10 expression.

Combining epigenetic and clinicopathological variables improves specificity in prognostic prediction in clear cell renal cell carcinoma

BackgroundMetastasized clear cell renal cell carcinoma (ccRCC) is associated with a poor prognosis. Almost one-third of patients with non-metastatic tumors at diagnosis will later progress with metastatic disease. These patients need to be identified already at diagnosis, to undertake closer follow up and/or adjuvant treatment. Today, clinicopathological variables are used to risk classify patients, but molecular biomarkers are needed to improve risk classification to identify the high-risk patients which will benefit most from modern adjuvant therapies. Interestingly, DNA methylation profiling has emerged as a promising prognostic biomarker in ccRCC. This study aimed to derive a model for prediction of tumor progression after nephrectomy in non-metastatic ccRCC by combining DNA methylation profiling with clinicopathological variables.MethodsA novel cluster analysis approach (Directed Cluster Analysis) was used to identify molecular biomarkers from genome-wide methylation array data. These novel DNA methylation biomarkers, together with previously identified CpG-site biomarkers and clinicopathological variables, were used to derive predictive classifiers for tumor progression.ResultsThe “triple classifier” which included both novel and previously identified DNA methylation biomarkers together with clinicopathological variables predicted tumor progression more accurately than the currently used Mayo scoring system, by increasing the specificity from 50% in Mayo to 64% in our triple classifier at 85% fixed sensitivity. The cumulative incidence of progress (pCIP5yr) was 7.5% in low-risk vs 44.7% in high-risk in M0 patients classified by the triple classifier at diagnosis.ConclusionsThe triple classifier panel that combines clinicopathological variables with genome-wide methylation data has the potential to improve specificity in prognosis prediction for patients with non-metastatic ccRCC.

MiR-483-5p downregulation contributed to cell proliferation, metastasis, and inflammation of clear cell renal cell carcinoma.

Inflammation status are especially for tumor growth, and microRNAs (miRNAs) confirmed to participate in cancer occurrence and progression. However, the role of miR-483-5p and the relation with inflammation have not been elucidated in renal cell cancer (RCC). In this study, we intended to explore miR-483-5p expression and the relationship of inflammation status in clear cell renal cell cancer (ccRCC). Using microarray and qRT-PCR (Quantitative Real-time Polymerase Chain Reaction), we investigated the miR-483-5p expression in plasma and ccRCC cancer tissues. Then, we analyzed the correlation of miR-483-5p with clinicopathological parameters and inflammation status in ccRCC. Receiver operator characteristic (ROC) curves analysis was used to analyze the discrimination efficiency of miR-483-5p. in vitro experiments explored the biological role of miR-483-5p in renal cancer cells. miR-483-5p expression was upregulated in plasma of 5 patients with microarray and 12 patients with qRT-PCR in ccRCC at day 7 postoperatively. In addition, low expression of miR-483-5p was found in 58 ccRCC cancer tissues when compared with non-cancerous tissues. miR-483-5p could sufficiently discriminate ccRCC with the area under the curve (AUC) of 0.739 (P < .0001) from normal tissues. Higher expression of miR-483-5p was positively related to lower tumor stage and higher relative expression of miR-483-5p was inversely related to neutrophil-to-lymphocyte ratio (NLR) (P = .03) and lymphocyte-to-monocyte ratio (LMR) (P = .026). Overexpression of miR-483-5p lead to reverse epithelial-mesenchymal transition (EMT) process, restrain cell proliferation and metastasis of renal cancer cells. Our findings suggest that miR-483-5p expression is negatively correlation with inflammation status and may be a potential plasma biomarker for ccRCC.

Prognostic Value of YTHDF2 in Clear Cell Renal Cell Carcinoma.

m6A, the main form of mRNA modification, participates in regulating multiple normal and pathological biological events, especially in tumorigenesis. However, there is little known about the association of m6A-related genes with prognosis of clear cell renal cell cancer (ccRCC). Therefore, the prognostic value of m6A-related genes was investigated using Kaplan–Meier curves of overall survival (OS) with the log-rank test and Cox regression analysis. The differential expression of YTHDF2 mRNA in ccRCC and tumor-adjacent normal tissues and associated with clinicopathological characteristics was also analyzed. The alteration of cancer signaling pathways was screened by Gene Set Enrichment Analysis (GSEA). Univariate analysis showed that 15 m6A-related genes (including YTHDF2) were closely related to prognosis. Multivariate analysis further confirmed that YTHDF2 could serve as an independent prognostic factor for the OS of ccRCC patients (P < 0.001). Low-level expression of YTHDF2 had poor prognosis in ccRCC patients with lower tumor–node–metastasis (TNM) stage, age > 61, non-distant metastasis, non-lymph node metastasis, female gender, and higher histological grade (P < 0.05). Moreover, YTHDF2 expression in ccRCC tissues (N = 529) is significantly lower than that of tumor-adjacent normal tissues (N = 72, P = 0.0086). Furthermore, GSEA demonstrated that AKT/mTOR/GSK3 pathway, EIF4 pathway, CHREBP2 pathway, MET pathway, NFAT pathway, FAS pathway, EDG1 pathway, and CTCF pathway are altered in tumors with high YTHDF2 expression. Taken together, our results demonstrated that YTHDF2 (an m6A-related gene) could serve as a potential prognostic biomarker of ccRCC, and targeting epigenetic modification may be a novel therapeutic strategy for the treatment of ccRCC.

Identification of Key Genes of Prognostic Value in Clear Cell Renal Cell Carcinoma Microenvironment and a Risk Score Prognostic Model

Objective We aimed at identifying the key genes of prognostic value in clear cell renal cell carcinoma (ccRCC) microenvironment and construct a risk score prognostic model. Materials and Methods Immune and stromal scores were calculated using the ESTIMATE algorithm. A total of 539 ccRCC cases were divided into high- and low-score groups. The differentially expressed genes in immune and stromal cells for the prognosis of ccRCC were screened. The relationship between survival outcome and gene expression was evaluated using univariate and multivariate Cox proportional hazard regression analyses. A risk score prognostic model was constructed based on the immune/stromal scores. Results The median survival time of the low immune score group was longer than that of the high immune score group (p = 0.044). Ten tumor microenvironment-related genes were selected by screening, and a predictive model was established, based on which patients were divided into high- and low-risk groups with markedly different overall survival (p < 0.0001). Multivariate Cox analyses showed that the risk score prognostic model was independently associated with overall survival, with a hazard ratio of 1.0437 (confidence interval: 1.0237–1.0641, p < 0.0001). Conclusions Low immune scores were associated with extended survival time compared to high immune scores. The novel risk predictive model based on tumor microenvironment-related genes may be an independent prognostic biomarker in ccRCC.

Apolipoprotein C1 (APOC1): A Novel Diagnostic and Prognostic Biomarker for Clear Cell Renal Cell Carcinoma.

Background: Apolipoprotein C1 (APOC1) has been proved to play a critical role in gastric, breast, lung, and pancreatic cancer. However, the relationship between APOC1 and urinary tumors remains unclear. This study aimed to assess the diagnostic and prognostic value of APOC1 in urinary tumors.Methods: We performed a pan analysis of APOC1 mRNA expression in urinary cancer using the Gene Expression Profiling Interactive Analysis (GEPIA) database. To further investigate the prognostic value of APOC1 expression in urinary cancers, the Kaplan-Meier plotter database was used. Furthermore, we collected the tumor and adjacent normal samples of 32 ccRCC patients to perform qRT-PCR and western blotting assays. A total of 72 cases with ccRCC were analyzed using tissue microarrays (TMAs).Results: Our results based on Kaplan-Meier plotter database indicated that a high expression of APOC1 may lead to poor overall survival (OS, p = 0.0019) in patients with ccRCC. Furthermore, the cancer stages and tumor grade of ccRCC appeared to be strongly linked with APOC1 expression according to UALCAN database. Hence, we reached a preliminary conclusion that APOC1 may play a key role in the tumorigenesis and progression of ccRCC. Furthermore, the Kaplan-Meier survival curve analyses of 72 clinical patients indicated that high expression of APOC1 was associated with poor progression-free survival (PFS, p = 0.007) and OS (p = 0.022). In addition, univariate Cox regression analysis confirmed the significant relationship between APOC1 expression and survival (p = 0.038). The TMAs analysis in combination with the patients' clinicopathological features was also performed. The expression of APOC1 was found to be significantly correlated with the tumor size (p = 0.018) and histological grade (p = 0.016).Conclusions: In conclusion, the findings of our study suggest that APOC1 may serve as a novel diagnostic and prognostic biomarker for ccRCC. Further evidence on the mechanism of APOC1 promoting tumor progression may transform it to a new therapeutic target for the treatment of ccRCC.

SOX6 represses tumor growth of clear cell renal cell carcinoma by HMG domain-dependent regulation of Wnt/β-catenin signaling.

Sex-determining region Y box (SOXs) are expressed in various cells and control cell fate and differentiation in a multitude of physiologic processes. SOX6, a main representative of SOXs, is involved in the regulation of carcinogenesis in various human malignancies. However, the role of SOX6 in clear cell renal cell carcinoma (ccRCC) remains unclear. In this study, SOX6 expression in ccRCC and its clinical significance were investigated. In vitro and in vivo assays were used to explore the tumor-related function and the underlying molecular mechanism of SOX6 in ccRCC. We confirmed that SOX6 was frequently downregulated in ccRCC tissues and cell lines. Besides, downregulation of SOX6 was significantly associated with larger tumor sizes, advanced tumor stage, higher Fuhrman grades, and its expression could act as an independent prognostic factor for ccRCC (hazards ratio = 0.590, P = .026). Gain/loss-of-function experiments demonstrated that SOX6 could remarkably inhibit tumor cell growth and foci formation in vitro and xenograft tumorigenesis in vivo, respectively. Mechanistically, SOX6 could influence cell cycle by regulating the G1/the S phase transition and had an inhibitory effect on Wnt/β-catenin signaling as well as its target genes, c-Myc and cyclin D1. Interesting, the tumor-suppressive function of SOX6 was proved to be dependent on its specific high-mobility-group (HMG) domain. In general, our findings indicated that SOX6 was a novel tumor suppressor and prognostic biomarker in ccRCC. SOX6 could inhibit tumor growth by negatively regulating the Wnt/β-catenin signaling pathway in an HMG domain-dependent manner in ccRCC, which might provide a novel therapeutic approach for ccRCC.

High PRAS40 mRNA expression and its role in prognosis of clear cell renal cell carcinoma.

BackgroundClear cell renal cell carcinoma (ccRCC) is one of the most common type of kidney malignancy. The proline-rich Akt substrate of 40 kDa (PRAS40) plays an important role in tumor growth. The present study aimed to analysis the prognostic value of PRAS40 mRNA expression in ccRCC.MethodsWe analyzed the PRAS40 mRNA expression using the data from TCGA-KIRC cohort. A receiver operating characteristic (ROC) curve was performed to assessed the diagnostic value of PRAS40 mRNA expression in ccRCC. Chi-square test was used to analyzed the correlation between clinical characteristics and PRAS40 mRNA expression. Kaplan-Meier analysis and Cox analysis were performed to determine the prognostic value of PRAS40 mRNA expression in ccRCC. Gene set enrichment analysis (GSEA) was conducted using TCGA database.ResultsOur results revealed that PRAS40 mRNA expression was higher in ccRCC tissues than in normal tissues. PRAS40 presented a moderate diagnostic value in ccRCC. High PRAS40 mRNA expression was correlated with histological grade, clinical stage, T classification, distant metastasis and vital status of ccRCC. High PRAS40 mRNA expression was associated with poor overall survival. Furthermore, Multivariate analysis revealed that PRAS40 was an independent risk factor for ccRCC patients. Myc targets, DNA repair, oxidative phosphorylation, glycolysis, adipogenesis, p53 pathway, reactive oxygen species pathway, myogenesis were differentially enriched in the phenotype that positively correlated with PRAS40.ConclusionsIn conclusion, our results suggest that PRAS40 was a promising diagnostic and prognostic biomarker for ccRCC.