ccRCC Tissues Research Articles

Semaphorin 6D as an independent predictor for better prognosis in clear cell renal cell carcinoma

IntroductionClear cell renal cell carcinoma (ccRCC) is the most common type of RCC and is associated with poor survival. However, the mechanisms underlying its development have not been thoroughly investigated. Semaphorin 6D (SEMA6D) is differentially expressed in various cancers, including lung adenocarcinoma and colorectal cancer. However, the role and mechanism of SEMA6D in ccRCC remain unexplored. Materials and methodsWe obtained 25 pairs of ccRCC tissue samples and 57 urine samples from patients with ccRCC and 52 urine samples from healthy volunteers. We performed RNA sequencing and compared the results with data from The Cancer Genome Atlas database to identify our gene of interest, SEMA6D. To verify the differential expression of SEMA6D, we used real-time quantitative polymerase chain reaction, immunohistochemistry, and enzyme-linked immunosorbent assay. Finally, we conducted in vitro proliferation, migration and invasion experiments. ResultsSEMA6D expression was significantly lower in ccRCC tissue compared to that in normal tissue. Comparative analysis of our results with data from online databases revealed that the expression level of SEMA6D in ccRCC tissue correlated with the clinical stage and pathological grade of ccRCC. Furthermore, higher SEMA6D expression was associated with improved quality of life of patients with ccRCC. In addition, the diagnostic value of SEMA6D was confirmed using data from two Gene Expression Omnibus ccRCC databases. The results showed that SEMA6D can be used as a predictor for ccRCC diagnosis, with an area under the curve of 0.9642. ConclusionSEMA6D may serve as a diagnostic and prognostic biomarker for ccRCC.

MicroRNA-4735-3p Facilitates Ferroptosis in Clear Cell Renal Cell Carcinoma by Targeting SLC40A1.

Objective Clear cell renal cell carcinoma (ccRCC) is the major histopathological subtype of renal cancer, and ferroptosis is implicated in the pathogenesis of ccRCC. The present study was aimed at investigating the role and underlying mechanisms of microRNA-4735-3p (miR-4735-3p) in ccRCC. Methods Human ccRCC cell lines were transfected with the miR-4735-3p mimic or inhibitor to manipulate the expression of miR-4735-3p. Cell proliferation, colony formation, cell migration, cell invasion, cell death, oxidative stress, lipid peroxidation, and iron metabolism were determined. To validate the necessity of solute carrier family 40 member 1 (SLC40A1), human ccRCC cell lines were overexpressed with SLC40A1 using adenoviral vectors. Results miR-4735-3p expression was reduced in human ccRCC tissues and cell lines but elevated upon ferroptotic stimulation. The miR-4735-3p mimic increased, while the miR-4735-3p inhibitor decreased oxidative stress, lipid peroxidation, iron overload, and ferroptosis of human ccRCC cell lines. Mechanistic studies identified SLC40A1 as a direct target of miR-4735-3p, and SLC40A1 overexpression significantly attenuated iron overload and ferroptosis in the miR-4735-3p mimic-treated human ccRCC cell lines. Conclusion miR-4735-3p facilitates ferroptosis and tumor suppression in ccRCC by targeting SLC40A1.

Overexpression of TP53INP2 Promotes Apoptosis in Clear Cell Renal Cell Cancer via Caspase-8/TRAF6 Signaling Pathway.

Clear cell renal cell cancer (ccRCC) is a tumor of high malignancy, which can escape apoptosis. The tumor protein p53-inducible nuclear protein 2 (TP53INP2), known as an autophagy protein, is the essential part for autophagosome formation and sensitizes cells to apoptosis. Our study is aimed at exploring the role of TP53INP2 in ccRCC. We have identified the autophagy-related genes (ARGs) of differential expression in ccRCC patients with the help of the TCGA database by bioinformatics analysis. Our assays of quantitative real-time polymerase chain reaction (qRT-PCR) and western blot were for the determination on the both levels of mRNA and protein. Overexpression of TP53INP2 on cellular proliferation, migration, and apoptosis of ccRCC was verified in the ways of performing CCK-8, wound scrape, transwell and flow cytometry assays in vitro, and a mice tumor model in vivo. Transmission electron microscopy was used to measure autophagy formation. The underlying mechanisms of TP53INP2 on ccRCC were determined via coimmunoprecipitation. TP53INP2 was found highly associated with an outcome of worse overall survival (OS) in Kaplan-Meier curves, and this parameter in ccRCC tissues was also lower than the normal tissues. Overexpression of TP53INP2 inhibited ccRCC cellular proliferation, migration, and invasion, as well as the tumor growth of mice. Those cells treated with autophagy inhibitor chloroquine (CQ) or TP53INP2 increased the apoptosis rate. TP53INP2 promoted autophagy formation and elevated the ratio of LC3 II/LC3 I. However, TP53INP2 did not significantly decrease the p-mTOR level. In addition, TP53INP2 activates the expressions of caspase-3, caspase-8, and PARP. Caspase-8 and TNF receptor associated factor 6 (TRAF6) were found to bind to each other in the presence of TP53INP2. TP53INP2 induces apoptosis in ccRCC cells through caspase-8/TRAF6 pathway, rather than the autophagy-dependent pathway.

A Novel Cuproptosis-Related Prognostic Gene Signature and Validation of Differential Expression in Clear Cell Renal Cell Carcinoma.

Clear cell renal cell carcinoma (ccRCC) is the most prevalent subtype of renal cell carcinoma, which is characterized by metabolic reprogramming. Cuproptosis, a novel form of cell death, is highly linked to mitochondrial metabolism and mediated by protein lipoylation. However, the clinical impacts of cuproptosis-related genes (CRGs) in ccRCC largely remain unclear. In the current study, we systematically evaluated the genetic alterations of cuproptosis-related genes in ccRCC. Our results revealed that CDKN2A, DLAT, DLD, FDX1, GLS, PDHA1 and PDHB exhibited differential expression between ccRCC and normal tissues (|log2(fold change)| > 2/3 and p < 0.05). Utilizing an iterative sure independence screening (SIS) method, we separately constructed the prognostic signature of CRGs for predicting the overall survival (OS) and progression-free survival (PFS) in ccRCC patients. The prognostic score of CRGs yielded an area under the curve (AUC) of 0.658 and 0.682 for the prediction of 5-year OS and PFS, respectively. In the Kaplan−Meier survival analysis of OS, a higher risk score of cuproptosis-related gene signature was significantly correlated with worse overall survival (HR = 2.72 (2.01–3.68), log-rank p = 1.76 × 10−7). Patients with a higher risk had a significantly shorter PFS (HR = 2.83 (2.08–3.85), log-rank p = 3.66 × 10−7). Two independent validation datasets (GSE40435 (N = 101), GSE53757 (N = 72)) were collected for meta-analysis, suggesting that CDKN2A (log2(fold change) = 1.46, 95%CI: 1.75–2.35) showed significantly higher expression in ccRCC tissues while DLAT (log2(fold change) = −0.54, 95%CI: −0.93–−0.15) and FDX1 (log2(fold change) = −1.01, 95%CI: −1.61–−0.42) were lowly expressed. The expression of CDKN2A and FDX1 in ccRCC was also significantly associated with immune infiltration levels and programmed cell death protein 1 (PD-1) expression (CDKN2A: r = 0.24, p = 2.14 × 10−8; FDX1: r = −0.17, p = 1.37 × 10−4). In conclusion, the cuproptosis-related gene signature could serve as a potential prognostic predictor for ccRCC patients and may offer novel insights into the cancer treatment.

Novel Diagnostic Value of Driver Gene Transcription Signatures to Characterise Clear Cell Renal Cell Carcinoma, ccRCC.

Routine molecular tumour diagnostics are augmented by DNA-based qualitative and quantitative molecular techniques detecting mutations of DNA. However, in the past decade, it has been unravelled that the phenotype of cancer, as it’s an extremely complex disease, cannot be fully described and explained by single or multiple genetic variants affecting only the coding regions of the genes. Moreover, studying the manifestation of these somatic mutations and the altered transcription programming—driven by genomic rearrangements, dysregulation of DNA methylation and epigenetic landscape—standing behind the tumorigenesis and detecting these changes could provide a more detailed characterisation of the tumour phenotype. Consequently, novel comparative cancer diagnostic pipelines, including DNA- and RNA-based approaches, are needed for a global assessment of cancer patients. Here we report, that by monitoring the expression patterns of key tumour driver genes by qPCR, the normal and the tumorous samples can be separated into distinct categories. Furthermore, we also prove that by examining the transcription signatures of frequently affected genes at 3p25, 3p21 and 9p21.3 genomic regions, the ccRCC (clear cell renal cell carcinoma) and non-tumorous kidney tissues can be distinguished based on the mRNA level of the selected genes. Our results open new diagnostics possibilities where the mRNA signatures of tumour drivers can supplement the DNA-based approaches providing a more precise diagnostics opportunity leading to determine more precise therapeutic protocols.

PD01-05 MIR-182-5P INHIBITS THE TUMORIGENESIS OF CLEAR CELL RENAL CELL CARCINOMA BY REPRESSING UBE2T

You have accessJournal of UrologyCME1 May 2022PD01-05 MIR-182-5P INHIBITS THE TUMORIGENESIS OF CLEAR CELL RENAL CELL CARCINOMA BY REPRESSING UBE2T Wu Yucai, Gong Yanqing, Li Xuesong, and Zhou Liqun Wu YucaiWu Yucai More articles by this author , Gong YanqingGong Yanqing More articles by this author , Li XuesongLi Xuesong More articles by this author , and Zhou LiqunZhou Liqun More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000002516.05AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Ubiquitin-conjugating enzyme E2T (UBE2T), a member of the E2 family, has been reported to be overexpressed in certain tumor types and to have an important role in the Fanconi anemia pathway. However, the role of UBE2T in clear cell renal cell carcinoma (ccRCC) has not been clarified. MicroRNAs (miRNAs) participate in tumorigenesis by binding to genes and proteins that regulate cell proliferation or cell apoptosis. The aim of this study was to determine the role of UBE2T and the relationship between miR-182-5p and UBE2T in ccRCC. METHODS: UBE2T expression levels were detected by real-time quantitative PCR (RT-qPCR) and western blot in ccRCC cell lines and tissues. Protein expression of UBE2T was assessed in a total of 93 ccRCC patients from Peking University First Hospital (PKU) by immunohistochemistry (IHC). The effects of UBE2T knockdown/overexpression on the proliferation, invasion and metastasis of ccRCC cells were assessed by MTS assays, wound healing assays, transwell invasion assays and flow cytometry. The effects of in vivo treatment were evaluated through xenograft experiments. The relationship between miR-182-5p and UBE2T was verified by dual luciferase reporter gene assay. RESULTS: UBE2T was highly expressed in ccRCC cells and tissues. High expression of UBE2T was positively correlated with advanced pathological stage, histological grade, maximum diameter and distant metastasis of the tumor. Multivariate analysis revealed that the UBE2T expression was an independent risk factor for overall survival (OS) and recurrence-free survival (RFS) in patients with ccRCC. Knockdown of UBE2T significantly suppressed proliferation, migration and invasion of RCC. Flow cytometry analysis showed that knocking down UBE2T could promote RCC cell cycle arrest at G2/M phase and increase cell apoptosis. A xenograft model also confirmed that suppression of UBE2T significantly delayed tumor formation and growth in vivo. In addition, miR-182-5p inhibited the expression of UBE2T protein through targeting UBE2T mRNA, and then inhibited the proliferation, migration and invasion of ccRCC. CONCLUSIONS: Our research reveals that miR-182-5p and UBE2T probably play a critical role in ccRCC progression, and they may be the potential therapeutic targets for ccRCC. Source of Funding: The present study was funded by the National Key R&D Program of China (grant no. 2019YFA09006001) and the National Natural Science Foundation of China (grant nos. 81772703 and 81972380) © 2022 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 207Issue Supplement 5May 2022Page: e31 Advertisement Copyright & Permissions© 2022 by American Urological Association Education and Research, Inc.MetricsAuthor Information Wu Yucai More articles by this author Gong Yanqing More articles by this author Li Xuesong More articles by this author Zhou Liqun More articles by this author Expand All Advertisement PDF DownloadLoading ...

PD43-11 METHYLATION HETEROGENEITY IN CCRCC OFFERS INSIGHTS INTO TUMORIGENESIS AND BIOMARKER DEVELOPMENT

You have accessJournal of UrologyCME1 May 2022PD43-11 METHYLATION HETEROGENEITY IN CCRCC OFFERS INSIGHTS INTO TUMORIGENESIS AND BIOMARKER DEVELOPMENT Sabrina Rossi, Victoria Dombrowe, Sara Pita, Christopher Smith, Grant Stewart, Roland Schwarz, and Charlie Massie Sabrina RossiSabrina Rossi More articles by this author , Victoria DombroweVictoria Dombrowe More articles by this author , Sara PitaSara Pita More articles by this author , Christopher SmithChristopher Smith More articles by this author , Grant StewartGrant Stewart More articles by this author , Roland SchwarzRoland Schwarz More articles by this author , and Charlie MassieCharlie Massie More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000002604.11AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Approximately 30% of patients with clear cell renal cell carcinoma (ccRCC) will develop a recurrence, however there are currently no validated prognostic biomarkers. This has been identified as a key research priority. Biomarker development has been hampered by significant genetic intra-tumoral heterogeneity (ITH), yet methylation ITH is largely uncharacterised. We therefore aim to evaluate methylation heterogeneity between patients, within patients and within individual tumour samples. METHODS: Multi-region samples were collected from fresh frozen nephrectomy specimens from individuals with ccRCC (Ethical approval: REC ID 03/018). Multiple tumour and normal samples were obtained from each patient (at least 5 samples per patient). Methylation analysis was performed using the Illumina EPIC-seq to obtain high-resolution sequence-level data. Matched samples were processed for copy-number alterations (whole exome sequencing) and gene expression (RNA-seq). An independent cohort of ccRCC tissue samples was sequenced for external validation. RESULTS: We sequenced 136 samples from 18 ccRCC patients, which consists of the largest multi-region methylation cohort to date. We observed extensive heterogeneity between patients, which dominated over within-patient heterogeneity. Although disordered methylation is believed to be a stochastic process, there were significant changes in methylation epipolymorphism between ccRCC and normal kidney at the promoter region of 47 known kidney cancer genes (including SLC16A3, MYC, WT1, KRT7 and KRT18). This finding was confirmed in an independent cohort of 71 ccRCC tumour and normal samples. Genes with significantly disordered methylation in tumour are more often associated with significant hypermethylation in ccRCC (87% genes hypermethylated) rather than hypomethylation, and are negatively correlated with gene expression, implying that methylation disorder may have a functional consequence. Several genes which have been implicated in ccRCC prognosis (including DKK2, SFRP1, CCND1, SERPINF1, SMAD3) demonstrated heterogeneous methylation patterns. CONCLUSIONS: Heterogeneous methylation between patients and within a sample may be a key determinant of the noted failure to validate prognostic genes in ccRCC. Disordered methylation and ITH may lead to inconsistent results amongst samples, which is exacerbated by different methylation platforms covering disparate CpGs within the promoter of genes. This key finding may help identify prognostic methylation markers in future. Source of Funding: Cancer Research UK © 2022 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 207Issue Supplement 5May 2022Page: e707 Advertisement Copyright & Permissions© 2022 by American Urological Association Education and Research, Inc.MetricsAuthor Information Sabrina Rossi More articles by this author Victoria Dombrowe More articles by this author Sara Pita More articles by this author Christopher Smith More articles by this author Grant Stewart More articles by this author Roland Schwarz More articles by this author Charlie Massie More articles by this author Expand All Advertisement PDF DownloadLoading ...

Guanylate-binding Protein 2 Expression Is Associated With Poor Survival and Malignancy in Clear-cell Renal Cell Carcinoma.

Clear-cell renal cell carcinoma (ccRCC) is a common recalcitrant cancer. However, little is known about biomarkers of ccRCC. In the present study, we investigated the role of guanylate-binding protein 2 (GBP2), an interferon-induced GTPase, in ccRCC and its potential as a biomarker of this disease. GBP2 expression was analyzed using the Gene Expression Omnibus, The Cancer Genome Atlas, and Human Protein Atlas databases. Univariate and multivariate Cox-regression analyses were used to investigate the prognostic value of GBP2 in ccRCC. In addition, quantitative real-time polymerase chain reactions, western blotting, and immunohistochemistry were performed to confirm the expression of GBP2 in tissues from patients with ccRCC who had undergone radical nephrectomy at the Department of Urology, the First Affiliated Hospital of Chongqing Medical University (Chongqing, P. R. China). Cell-function assays were performed to investigate the effect of GBP2 on Caki-1 human kidney-cancer cells. Bioinformatics and in vitro experiments showed that the expression of GBP2 was up-regulated in ccRCC tissues and cells and was positively correlated with the malignant clinicopathological parameters of the disease. Univariate and multivariate Cox-regression analyses showed that GBP2 expression was an independent risk factor for the prognosis of ccRCC. Cell-function assays showed that GBP2 expression promoted the proliferation, migration, and invasion of Caki-1 cells through the WNT/β-catenin signaling pathway. The present results indicate that GBP2 expression may serve as a prognostic biomarker for ccRCC.

Multi-Omics Analysis of the Prognosis and Biological Function for TRPV Channel Family in Clear Cell Renal Cell Carcinoma.

BackgroundThe transient receptor potential vanilloid (TRPV) channels family, TRPV1-6, has been identified to profoundly affect a wide spectrum of pathological processes in various cancers. However, the biological function and prognostic value of TRPVs in clear cell renal cell carcinoma (ccRCC) are still largely unknown.MethodsWe obtained the gene expression data and clinical information of 539 ccRCC patients from The Cancer Genome Atlas (TCGA) database. A series of databases were used for data processing and visualization, including GEPIA, GeneMANIA, MethSurv, GSCA, TIMER, and starBase databases.ResultsThe mRNA expression of TRPV2/3 was upregulated while the expression of TRPV5/6 was downregulated in ccRCC tumor tissues. TRPV family members in ccRCC were rarely mutated (nearly 7 frequencies). The ROC curve showed that TRPV2/5/6 had a high diagnostic ability in discriminating ccRCC from the control samples (AUC>0.9). Higher levels of TRPV3 expression were associated with poor prognosis of ccRCC patients, while higher expression of TRPV4 was associated with favorable prognosis. The expression of TRPV3 in normal and ccRCC tissues was validated by Immunohistochemistry, and its expression was remarkably related to high histologic grade and advanced stage. Besides, TRPV3 exhibit a reduction of DNA methylation level with tumor progression, and 12 CpGs of TRPV3 were associated with a significant prognosis. In addition, TRPV3 expression was significantly associated with the accumulation of several tumor-infiltrating immune cells, especially regulatory T cells. Furthermore, high levels of TRPV3 induced the expression of immune checkpoints such as LAG3, CTLA4, PDCD1, and TIGIT. Finally, we predicted a key SNHG3/AL513497.1-miR-10b-5p-TRPV3 axis linking to carcinogenesis and progression of ccRCC.ConclusionOur study may uncover TRPV channels–associated molecular mechanisms involved in the tumorigenesis and progression of ccRCC. TRPV family members might be diagnosed and prognostic markers and potential therapeutic targets for ccRCC patients.

Prediction of overall survival based upon a new ferroptosis-related gene signature in patients with clear cell renal cell carcinoma

BackgroundClear cell renal cell carcinoma (ccRCC) is the most common and lethal renal cell carcinoma (RCC) histological subtype. Ferroptosis is a newly discovered programmed cell death and serves an essential role in tumor occurrence and development. The purpose of this study is to analyze ferroptosis-related gene (FRG) expression profiles and to construct a multi-gene signature for predicting the prognosis of ccRCC patients.MethodsRNA-sequencing data and clinicopathological data of ccRCC patients were downloaded from The Cancer Genome Atlas (TCGA). Differentially expressed FRGs between ccRCC and normal tissues were identified using ‘limma’ package in R. GO and KEGG enrichment analyses were conducted to elucidate the biological functions and pathways of differentially expressed FRGs. Consensus clustering was used to investigate the relationship between the expression of FRGs and clinical phenotypes. Univariate and the least absolute shrinkage and selection operator (LASSO) Cox regression analysis were used to screen genes related to prognosis and construct the optimal signature. Then, a nomogram was established to predict individual survival probability by combining clinical features and prognostic signature.ResultsA total of 19 differentially expressed FRGs were identified. Consensus clustering identified two clusters of ccRCC patients with distinguished prognostic. Functional analysis revealed that metabolism-related pathways were enriched, especially lipid metabolism. A 7-gene ferroptosis-related prognostic signature was constructed to stratify the TCGA training cohort into high- and low-risk groups where the prognosis was significantly worse in the high-risk group. The signature was identified as an independent prognostic indicator for ccRCC. These findings were validated in the testing cohort, the entire cohort, and the International Cancer Genome Consortium (ICGC) cohort. We further demonstrated that the signature-based risk score was highly associated with the ccRCC progression. Further stratified survival analysis showed that the high-risk group had a significantly lower overall survival (OS) rate than those in the low-risk group. Moreover, we constructed a nomogram that had a strong ability to forecast the OS of the ccRCC patients.ConclusionsWe constructed a ferroptosis-related prognostic signature, which might provide a reliable prognosis assessment tool for the clinician to guide clinical decision-making and outcomes research.

Epigenetic activation of RBM15 promotes clear cell renal cell carcinoma growth, metastasis and macrophage infiltration by regulating the m6A modification of CXCL11

Clear cell renal cell carcinoma (ccRCC) is a common kidney malignancy that is characterized by poor prognosis. RNA-binding motif protein 15 (RBM15) has been identified as an oncogene in multiple tumors. Nevertheless, the function and mechanism of RBM15 in ccRCC are not clear. In this study, RBM15 was found to be upregulated in ccRCC cells and tissues. RBM15 enhanced the proliferation, clone formation, migration, invasion and epithelial-interstitial transition of ccRCC cells. Enhanced RBM15 was caused by the abundant histone 3 acetylation modification of the RBM15 promoter induced by EP300/CBP. RBM15 enhanced the stability of CXCL11 mRNA in an m6A-dependent manner. Moreover, RBM15 was found to promote macrophage infiltration and M2 polarization by promoting the secretion of CXCL11 in ccRCC cells in vitro and in vivo. Our findings highlight the function of RBM15 in ccRCC and reveal a novel identified EP300/CBP-RBM15-CXCL11 signaling axis, which promotes ccRCC progression and provides new insight into ccRCC therapy.

DLK2 Acts as a Potential Prognostic Biomarker for Clear Cell Renal Cell Carcinoma Based on Bioinformatics Analysis.

Clear cell renal cell carcinoma (ccRCC) is the most common RCC subtype with a high mortality. It has been reported that delta-like 1 homologue (DLK1) participates in the tumor microenvironmental remodeling of ccRCC, but the relationship between delta-like 2 homologue (DLK2, a DLK1 homologue) and ccRCC is still unclear. Thus, this study aims to investigate the role of DLK2 in the biological function and disease prognosis of ccRCC using bioinformatics analysis. The TNMplot database showed that DLK2 was upregulated in ccRCC tissues. From the UALCAN analysis, the overexpression of DLK2 was associated with advanced stage and high grade in ccRCC. Moreover, the Kaplan-Meier plotter (KM Plotter) database showed that DLK2 upregulation was associated with poor survival outcome in ccRCC. By the LinkedOmics analysis, DLK2 signaling may participated in the modulation of ccRCC extracellular matrix (ECM), cell metabolism, ribosome biogenesis, TGF-β signaling and Notch pathway. Besides, Tumor Immune Estimation Resource (TIMER) analysis showed that the macrophage and CD8+ T cell infiltrations were associated with good prognosis in ccRCC patients. Finally, DLK2 overexpression was associated with the reduced macrophage recruitments and the M1–M2 polarization of macrophage in ccRCC tissues. Together, DLK2 may acts as a novel biomarker, even therapeutic target in ccRCC. However, this study lacks experimental validation, and further studies are required to support this viewpoint.

Assessment of the prognostic value of SPOCK1 in clear cell renal cell carcinoma: a bioinformatics analysis.

BackgroundClear cell renal cell carcinoma (ccRCC) is one of the most common urological malignancies, and once metastasis occurs, it often has a poor prognosis and lacks effective treatment. Therefore, there is an urgent need to screen some new biomarkers and explore their molecular mechanisms to improve the early clinical diagnosis and targeted therapy of ccRCC. SPOCK1 (SPARC/osteonectin, CWCV and Kazal-like domains proteoglycan 1) is a conserved multi-domain proteoglycan that plays an important role in the development of multiple cancer types; however, its prognostic value in ccRCC has not been investigated. The study of the prognostic value of SPOCK1 in ccRCC is a good complement to the study of ccRCC biomarkers.MethodsDatabases of this study included Oncomine, Kaplan-Meier Plotter, GEPIA, GeneMANIA, cBioPortal, and TIMER. Student’s t-test was used to analyze the differences in SPOCK1 expression in ccRCC tissues compared with tumor-adjacent normal tissues. Kaplan-Meier curves for survival analysis were used to assess the correlation between the expression of SPOCK1 and the prognostic outcomes. Correlation module drew the expression scatterplots between SPOCK1 and immune cell infiltration in ccRCC, together with the Spearman’s rho value and estimated statistical significance.ResultsThe SPOCK1 mRNA expression was significantly higher in ccRCC tissues (mean expression ± SD: 920.2±195.2) than in normal tissues (mean expression ± SD: 358.4±29.1, P=0.008), and high SPOCK1 expression significantly and positively correlated with the pathological stage of ccRCC patients (F value =10.2, P<0.001). Higher expression of SPOCK1 was also associated with significantly shorter overall survival (OS) and disease-free survival (DFS) in ccRCC patients (GEPIA: P=0.046, P<0.001, respectively; Kaplan-Meier Plotter: P=0.002, P=0.0022, respectively). The function of SPOCK1 is mainly related to tumor development and extracellular matrix remodeling, and it may participate in the epithelial-mesenchymal transition process. SPOCK1 expression significantly and positively correlated with infiltration of several immune cells in ccRCC, including cancer-associated fibroblasts (CAFs) (Rho =0.333, P=2.16×10−13), tumor-associated macrophages (TAMs) (Rho =0.18, P=1.02×10−4), and tumor-associated neutrophils (TANs) (Rho =0.165, P=3.83×10−4). Conversely, there was a significant and negative correlation between SPOCK1 expression and infiltration of CD4+ T cells (Rho =−0.113, P=0.015).ConclusionsSPOCK1 may be a potential prognostic biomarker in ccRCC.

Dissection of PD-L1 promoter reveals differential transcriptional regulation of PD-L1 in VHL mutant clear cell renal cell carcinoma

AbstractProgrammed death-ligand 1 (PD-L1) is constitutively expressed by hypoxia-inducible factor 2α (HIF2α). It can be induced by interferon gamma (IFNγ) signaling in clear cell renal cell carcinoma (ccRCC). Clinical trials of metastatic ccRCCs have suggested that a canonical IFNγ signature is a better biomarker for therapeutic response to immune checkpoint inhibitors (ICIs) than PD-L1 expression levels in tumor cells. To understand the therapeutic response to ICIs according to PD-L1 expression levels, we analyzed transcriptional regulation of the PD-L1 promoter by HIF2α and IFNγ-inducible interferon regulatory factor-1 (IRF-1) in ccRCC cells. Here, we present two ccRCC cell models showing differential PD-L1 expression levels in response to IFNγ and hypoxia. Analysis of The Cancer Genome Atlas RNA-sequencing data revealed that PD-L1 expression correlated with JAK2 and STAT1 expression of the canonical IFNγ signature in ccRCC tissues. Upon IFNγ stimulation, PD-L1 was induced by sequential activation of JAK2/STAT1/IRF-1 signaling in both WT- and Mut- VHL ccRCC cells. IFNγ activated the IRF-1α site of the PD-L1 promoter. The IFNγ-mediated increase of PD-L1 expression in Mut-VHL cells was 4.8-fold greater than that in WT-VHL cells. Under normoxia condition, PD-L1 expression in Mut-VHL cells was significantly higher than that in WT-VHL cells due to high basal HIF2α expression. Under hypoxia condition, PD-L1 expression in WT-VHL cells was induced up to 1.8-fold through activation of hypoxia-response elements 2 and 3. In contrast, although PD-L1 in Mut-VHL cells was already highly expressed in the basal state through activation of hypoxia-response elements 2, 3, and 4, it was no longer induced by hypoxia. In conclusion, Mut-VHL ccRCC cells displayed higher PD-L1 expression due to high basal HIF2α expression and a stronger response to IFNγ stimulation than WT-VHL cells. The fact that HIF2α antagonists can potentially reduce PD-L1 expression levels should be considered in ICI combination therapy.Through analysis of the PD-L1 promoter, the authors describe two clear cell renal cell carcinoma (ccRCC) models that exhibit differential PD-L1 expression levels upon IFNγ and hypoxia stimulation. Mutant-VHL ccRCC cells display higher PD-L1 expression than wild-type-VHL ccRCC cells due to high basal HIF2α expression and a stronger response to IFNγ stimulation. Thus, mutant-VHL ccRCC cells are expected to respond well to immune checkpoint inhibitors.

Functional deficiency of succinate dehydrogenase promotes tumorigenesis and development of clear cell renal cell carcinoma through weakening of ferroptosis

ABSTRACT Clear cell renal cell carcinoma (ccRCC) is the most common subtype of renal carcinomas, with high mortality and poor prognoses worldwide. Succinate dehydrogenase (SDH) consists of four nuclear-encoded subunits and it is the only complex involved in both the tricarboxylic acid (TCA) cycle and oxidative phosphorylation (OXPHOS). Previous studies have shown decreased SDH activity in ccRCC. However, the role and underlying molecular mechanisms of SDH in ccRCC initiation and development remain unclear. In the present study, pan-cancer analysis of SDH gene expression was analyzed and the relationship between SDH gene expression and clinicopathological parameters was assessed using different databases. cBioPortal, UACLAN, and Tumor Immune Estimation Resource (TIMER) were subsequently utilized to analyze genetic alterations, methylation, and immune cell infiltration of SDH genes in ccRCC patients. We found SDHs were significantly downregulated in ccRCC tissues and correlated with ccRCC progression. Increased methylation and high SDH promoter mutation rates may be the cause of reduced expression of SDHs in ccRCC. Moreover, the interaction network showed that SDH genes were correlated with ferroptosis-related genes. We further demonstrated that SDH inhibition dampened oxidative phosphorylation, reduced ferroptotic events, and restored ferroptotic cell death, characterized by eliminated mitochondrial ROS levels, decreased cellular ROS and diminished peroxide accumulation. Collectively, this study provides new insights into the regulatory role of SDH in the carcinogenesis and progression of ccRCC, introducing a potential target for advanced antitumor therapy through ferroptosis.

GSDMs are potential therapeutic targets and prognostic biomarkers in clear cell renal cell carcinoma

GSDM family is a group of critical proteins that mediate pyroptosis and plays an important role in cell death and inflammation. However, their specific function in clear cell renal cell carcinoma (ccRCC, KIRC) have not been clarified comprehensively. In this study, we assessed the roles of the GSDM family in expression, prognostic value, functional enrichment analysis, genetic alterations, immune infiltration and DNA methylation in ccRCC patients by using different bioinformatics databases. We found that the expression levels of GADMA-E were significantly higher in ccRCC tissues compared with normal tissues, while the expression level of PJVK was decreased. Moreover, survival analysis indicated that upregulation of GSDME was related to poor overall survival (OS) and recurrence-free survival (RFS) of ccRCC patients. The main function of differentially expressed GSDM homologs was related to ion transport. We also found that the expression profiles of the GSDM family were highly correlated with infiltrating immune cells (i.e., CD8+ T cells, CD4+ T cells, B cells, macrophages, neutrophils and dendritic cells), and there were significant differences in the expression of GSDM family in different ccRCC immune subtypes. Furthermore, DNA methylation analysis indicated that the DNA methylation levels of GSDMA/B/D/E were decreased, while the DNA methylation level of PJVK was increased. In conclusion, this study provides integrated information about abnormal GSDM family members as potential biomarkers for the diagnosis and prognosis of ccRCC. Especially, GSDME was a potential clinical target and prognostic biomarkers for patients with ccRCC.

Single-cell RNA-sequencing analysis reveals MYH9 promotes renal cell carcinoma development and sunitinib resistance via AKT signaling pathway

Clear cell renal cell carcinoma (ccRCC) is a serious threat to human health worldwide, while its heterogeneity limits therapeutic success and leads to poor survival outcomes. Single-cell RNA-sequencing (scRNA-seq) is an important technology, which provides deep insights into the genetic characteristics of carcinoma. In this study, we profiled the gene expression of single cells from human ccRCC tissues and adjacent normal tissues using the scRNA-seq. We found that MYH9 was commonly upregulated in the ccRCC cell subgroup. Additionally, MYH9 was of highly expression in ccRCC tissues and predicted poor prognosis of ccRCC patients. MYH9 knockdown in ccRCC cells dampened their proliferative and metastatic potentials, whereas MYH9 overexpression enhanced these properties. In vivo, MYH9 also promoted ccRCC growth. Mechanistic studies showed that MYH9 played these vital roles through AKT signaling pathway. Furthermore, MYH9/AKT axis determined the responses of ccRCC cells to sunitinib treatment and might serve as a biomarker for sunitinib benefits in ccRCC patients. Thus, MYH9 might be a novel therapeutic target and prognostic predictor for ccRCC.

METTL14-mediated N6-methyladenosine modification of ITGB4 mRNA inhibits metastasis of clear cell renal cell carcinoma

BackgroundIntegrin β4 (ITGB4) participates in tumorigenesis and progression of several malignancies, but its role and related mechanisms in clear cell renal cell carcinoma (ccRCC) remain unclear.MethodsQuantitative real-time PCR (qRT-PCR), western blot and immunohistochemistry were used to detect mRNA and protein levels of relevant genes. Biological functions of ITGB4 and methyltransferase-like 14 (METTL14) were determined by in vitro and in vivo experiments. The levels of N6-methyladenosine (m6A) in ccRCC tissues and adjacent normal tissues were calculated via total RNA m6A quantification assay. The m6A modification of ITGB4 was demonstrated via m6A RNA immunoprecipitation (MeRIP), RIP and luciferase reporter assays.ResultsITGB4 was significantly overexpressed in ccRCC tissues and high level of ITGB4 predicted poor prognosis as well as metastasis. Functionally, ITGB4 stimulated ccRCC cell migration and invasion in vitro and metastasis in vivo with epithelial–mesenchymal transition (EMT) strengthened. Mechanically, the total levels of m6A were reduced in ccRCC tissues. METTL14, a favorable factor for ccRCC patients’ prognosis, facilitated m6A modification on ITGB4 3′UTR and subsequently accelerated ITGB4 mRNA degradation, leading to its declined expression. Furthermore, the METTL14-mediated inhibition of ITGB4 expression was dependent on the YTH domain family protein 2 (YTHDF2), which acted as an m6A reader to bind to ITGB4 mRNA and to promote its decay. In addition, we demonstrated that knockdown of METTL14 promoted ccRCC cell migration, invasiveness and metastasis as well as stimulating the EMT process and the PI3K/AKT signal by overexpressing ITGB4.ConclusionOur study reveals that METTL14 inhibits ITGB4 expression via m6A modification to attenuate metastasis and EMT of ccRCC cells, suggesting the METTL14/ITGB4 axis as a potential prognostic biomarker and therapeutic target for ccRCC.DsMVtdrTRB4TieaKUTmiEpVideo

DRAM1 plays a tumor suppressor role in clear cell renal cell carcinoma through modulating Akt signaling

BackgroundClear cell renal carcinoma (ccRCC) is one of the most common malignant tumors worldwide. DNA damage-regulated autophagy modulator1 (DRAM1) plays an important roles in apoptosis and tumor progression. However, the role of DRAM1 in ccRCC is still unknown. In our study, we aimed to investigate the effect of DRAM1 in the progression of ccRCC. MethodsThe expression and prognostic information of DRAM1 in ccRCC were obtained by immunohistochemistry staining and bioinformatics database. Cell proliferation, migration, invasion were detected by CCK-8 assay, wound-healing and transwell assays, and the cell apoptosis was examined by tunel assay and flow cytometry analysis. Western blot was used to detect the expression of DRAM1, Bax, Bcl2, Akt, p53,E-cadherin, N-cadherin of ccRCC cells. ResultsDecreased expression of DRAM1 was found in ccRCC tissues, which predicted a shorter survival rate in ccRCC patient. We confirmed that DRAM1 inhibited the proliferation, migration, invasion and epithelial mesenchymal transformation (EMT), while enhanced the apoptosis of ccRCC cells. In addition, the results of inhibition of Akt signaling were consistent with the above. We further proved that DRAM1 over-expression decreased the phosphorylation of Akt signaling, and overexpression of DRAM1 could reverse oncogenic function induced by the over-activating of Akt in ccRCC cells. Conclusionoverexpression of DRAM1 plays a tumor suppressive role in ccRCC through inactivation of Akt and highlights the potential role of DRAM1 as a prognostic biomarker in ccRCC.

Identification of Novel Prognostic Signatures for Clear Cell Renal Cell Carcinoma Based on ceRNA Network Construction and Immune Infiltration Analysis.

Objective Clear cell renal cell carcinoma (ccRCC) carries significant morbidity and mortality globally and is often resistant to conventional radiotherapy and chemotherapy. Immune checkpoint blockade (ICB) has received attention in ccRCC patients as a promising anticancer treatment. Furthermore, competitive endogenous RNA (ceRNA) networks are crucial for the occurrence and progression of various tumors. This study was aimed at identifying reliable prognostic signatures and exploring potential mechanisms between ceRNA regulation and immune cell infiltration in ccRCC patients. Methods and Results Gene expression profiling and clinical information of ccRCC samples were obtained from The Cancer Genome Atlas (TCGA) database. Through comprehensive bioinformatic analyses, differentially expressed mRNAs (DEmRNAs; n = 131), lncRNAs (DElncRNAs; n = 12), and miRNAs (DEmiRNAs; n = 25) were identified to establish ceRNA networks. The CIBERSORT algorithm was applied to calculate the proportion of 22 types of tumor-infiltrating immune cells (TIICs) in ccRCC tissues. Subsequently, univariate Cox, Lasso, and multivariate Cox regression analyses were employed to construct ceRNA-related and TIIC-related prognostic signatures. In addition, we explored the relationship between the crucial genes and TIICs via coexpression analysis, which revealed that the interactions between MALAT1, miR-1271-5p, KIAA1324, and follicular helper T cells might be closely correlated with the progression of ccRCC. Ultimately, we preliminarily validated that the potential MALAT1/miR-1271-5p/KIAA1324 axis was consistent with the ceRNA theory by qRT-PCR in the ccRCC cell lines. Conclusion On the basis of the ceRNA networks and TIICs, we constructed two prognostic signatures with excellent predictive value and explored possible molecular regulatory mechanisms, which might contribute to the improvement of prognosis and individualized treatment for ccRCC patients.