Multicenter Validation of Enhancer of Zeste Homolog 2 Expression as an Independent Prognostic Marker in Localized Clear Cell Renal Cell Carcinoma

Understanding Factors that Influence Prognosis and Response to Therapy in Clear Cell Renal Cell Carcinoma

In this review, we highlight and contextualize emerging morphologic prognostic and predictive factors in renal cell carcinoma. We focus on clear cell renal cell carcinoma (ccRCC), the most common histologic subtype. Our understanding of the molecular characterization of ccRCC has dramatically improved in the last decade. Herein, we highlight how these discoveries have laid the foundation for new approaches to prognosis and therapeutic decision-making for patients with ccRCC. We explore the clinical relevance of common mutations, established gene expression signatures, intratumoral heterogeneity, sarcomatoid/rhabdoid morphology and PD-L1 expression, and discuss their impact on predicting response to therapy.

The miR-302/367 cluster: Aging, inflammation, and cancer

MicroRNAs (miRNAs) are a class of noncoding RNAs that occupy a significant role in biological processes as important regulators of intracellular homeostasis. First, we will discuss the biological genesis and functions of the miR-302/367 cluster, including miR-302a, miR-302b, miR-302c, miR-302d, and miR-367, as well as their roles in physiologically healthy tissues. The second section of this study reviews the progress of the miR-302/367 cluster in the treatment of cancer, inflammation, and diseases associated with aging. This cluster's aberrant expression in cells and/or tissues exhibits similar or different effects in various diseases through molecular mechanisms such as proliferation, apoptosis, cycling, drug resistance, and invasion. This article also discusses the upstream and downstream regulatory networks of miR-302/367 clusters and their related mechanisms. Particularly because studies on the upstream regulatory molecules of miR-302/367 clusters, which include age-related macular degeneration, myocardial infarction, and cancer, have become more prevalent in recent years. MiR-302/367 cluster can be an important therapeutic target and the use of miRNAs in combination with other molecular markers may improve diagnostic or therapeutic capabilities, providing unique insights and a more dynamic view of various diseases. It is noted that miRNAs can be an important bio-diagnostic target and offer a promising method for illness diagnosis, prevention, and treatment.

RCC1 functions as a tumor facilitator in clear cell renal cell carcinoma by dysregulating cell cycle, apoptosis, and EZH2 stability

BACKGROUND

RCC1 functions as a pivotal guanine nucleotide exchange factor and was reported to be involved in mitosis, the assembly of the nuclear envelope, nucleocytoplasmic transport in cell physiological processes. Recent studies reported that RCC1 could regulate immunological pathways and promote the growth of some malignant solid tumors. However, the prognostic value and exact function of RCC1 remain unknown in patients with clear cell renal cell carcinoma (cRCC).

METHODS

The UALCAN and KM plotter portals were used to analyze the expression profile and related tumor prognosis of RCC1 in ccRCC using data from TCGA. The expression profile of RCC1 was also confirmed in clinical samples using qRT-PCR, western blotting, and immunohistochemistry. The role of RCC1 on ccRCC cells in vitro was confirmed by a series of functional assays. Animal experiments were performed to verify the suppressive effect of RCC1 knockdown on tumor growth in vivo. The correlation of RCC1 expression with that of EZH2 was explored in clinical samples using IHC. The interaction between RCC1 and EZH2 was further verified using a CO-IP assay and a protein stability assay.

RESULTS

RCC1 was upregulated in ccRCC tissues compared with normal tissues in TCGA dataset and paired clinical samples. RCC1 promoted ccRCC progression by accelerating the cell cycle and suppressing apoptosis. In addition, RCC1 could bind EZH2 and regulate its expression at the posttranscriptional level. RCC1 and EZH2 expression showed a strong correlation in clinical samples. Further investigation proved that RCC1 regulated EZH2 protein stability through the ubiquitin-proteasome pathway.

CONCLUSIONS

RCC1 could be a potential therapeutic target in ccRCC. The RCC1/EZH2 axis takes part in the development of ccRCC.

The LMR-SSIGN-MAPS model predicts disease-free survival in patients with localized clear cell renal cell carcinoma

Introduction

Prediction models are increasingly being used to predict outcomes after surgery, and such a model would be a precious tool for patients with clear cell renal cell carcinoma (ccRCC) after surgery.

Aim

To develop a comprehensive model for predicting disease-free survival (DFS) in patients with localized ccRCC.

Material and methods

In a retrospective analysis of 612 patients, least absolute shrinkage and selection operator (LASSO) Cox regression analysis was performed to identify significant predictors, and then risk factors were used to construct a prognostic model. Harrell's concordance index (C-index) was used to assess the accuracy of the model.

Results

The lymphocyte-to-monocyte ratio (LMR), Mayo Clinic stage, size, grade, necrosis score (SSIGN), and Mayo adhesive probability score (MAPS) were the significant risk factors screened by LASSO Cox regression and reconfirmed by multivariate Cox regression analysis in 44 variables. Then a model was constructed by combining the LMR, SSIGN, and MAPS. The C-index of the LMR-SSIGN-MAPS model was greater than the SSIGN score alone. Kaplan-Meier survival analysis demonstrated a significant association between higher LMR-SSIGN-MAPS score and poorer DFS.

Conclusions

The LMR-SSIGN-MAPS model, which consists of preoperative inflammation biomarkers, a perinephric adipose tissue image-based scoring system, and pathological features, showed the strengths of easy-to-use and high predictability and might also be used as a promising prognosis model in predicting DFS for patients with localized ccRCC.

The role of histone methylation in renal cell cancer: an update

Renal cell carcinoma accounts for 2-3% of all cancers. It is difficult to diagnose early. Recently, genome-wide studies have identified that histone methylation was one of the functional classes that is most frequently dysregulated in renal cell cancer. Mutation or mis-regulation of histone methylation, methyltransferases, demethylases are associated with gene expression and tumor progression in renal cell cancer. Herein, we summarize histone methylations, demethylases and their alterations and mechanisms in renal cell cancer.

Combining expression of RNF43 and infiltration level of CD163+ tumor associated macrophage predicts prognosis of clear cell renal cell carcinoma

Searching for reliable indicators for evaluating prognosis diagnosed with clear cell renal cell carcinoma (ccRCC) is crucial for improving clinical therapies. However, current researches have looked mainly at the prognostic value of a single intratumoral indicator, neglecting tumor-infiltrating immune cells (TIICs) in the microenvironment. This study examined whether the integration of Ring finger protein 43 (RNF43) expression and CD163⁺ tumor-associated macrophage (TAM) infiltration in combination with clinical indexes forecast ccRCC patient outcome with relatively high accuracy. Firstly, the expression of RNF43 and CD163 were detected with immunohistochemistry. Totally, 346 ccRCC patients were random separated evenly into training and validation datasets to make further analyses. We found that RNF43 expression was negatively correlated with infiltration level of CD163⁺ TAM in ccRCC, which was closely associated with the TNM stage and outcome of these patients. The multiple regression analysis demonstrated that RNF43, CD163, and TNM stage could function as independent risk factors in overall survival (OS) and progression-free survival (PFS) prediction of ccRCC. Furthermore, a better postoperative prognosis index for ccRCC patients was obtained by combining RNF43 and CD163⁺ TAMs, which assessed with time-dependent C-index analyses and a nomogram. Consequently, combining RNF43 and CD163⁺ TAMs along with TNM stage acquired robust accuracy in forecasting outcome of patients with ccRCC. In conclusion, combining intratumoral RNF43 expression, CD163⁺ TAM infiltration, and TNM stage could significantly enhance the veracity in forecasting postoperative outcomes.

Machine learning-based prognosis signature for survival prediction of patients with clear cell renal cell carcinoma

The sole clinicopathological characteristic is not enough for the prediction of survival of patients with clear cell renal cell carcinoma (ccRCC). However, the survival prediction model constructed by machine learning technology for patients with ccRCC using clinicopathological features is rarely reported yet. In this study, a total of 5878 patients diagnosed as ccRCC from four independent patient cohorts were recruited. The least absolute shrinkage and selection operator analysis was implemented to identify optimal clinicopathological characteristics and calculate each coefficient to construct the prognosis model. In addition, weighted gene co-expression network and gene enrichment analysis associated with risk score were also carried out. Three clinicopathologic features were selected for the construction of the prognosis risk score model as the prognostic factors of ccRCC, including tumor size, tumor grade, and tumor stage. In the CPTAC (Clinical Proteomic Tumor Analysis Consortium) cohort, the General cohort, the SEER (Surveillance, Epidemiology, and End Results) cohort, and the Huashan cohort, patients with high-risk score had worse clinical outcomes than patients with low-risk score (hazard ratio 5.15, 4.64, 3.96, and 5.15, respectively). Further functional enrichment analysis demonstrated that our machine learning-based risk score was significantly connected with some cell proliferation-related pathways, consisting of DNA repair, cell division, and cell cycle. In summary, we developed and validated a machine learning-based prognosis prediction model, which might contribute to clinical decision-making for patients with ccRCC.

Intratumoral Resolution of Driver Gene Mutation Heterogeneity in Renal Cancer Using Deep Learning

Intratumoral heterogeneity arising from tumor evolution poses significant challenges biologically and clinically. Dissecting this complexity may benefit from deep learning (DL) algorithms, which can infer molecular features from ubiquitous hematoxylin and eosin (H&E)-stained tissue sections. Although DL algorithms have been developed to predict some driver mutations from H&E images, the ability of these DL algorithms to resolve intratumoral mutation heterogeneity at subclonal spatial resolution is unexplored. Here, we apply DL to a paradigm of intratumoral heterogeneity, clear cell renal cell carcinoma (ccRCC), the most common type of kidney cancer. Matched IHC and H&E images were leveraged to develop DL models for predicting intratumoral genetic heterogeneity of the three most frequently mutated ccRCC genes, BAP1, PBRM1, and SETD2. DL models were generated on a large cohort (N = 1,282) and tested on several independent cohorts, including a TCGA cohort (N = 363 patients) and two tissue microarray (TMA) cohorts (N = 118 and 365 patients). These models were also expanded to a patient-derived xenograft (PDX) TMA, affording analysis of homotopic and heterotopic interactions of tumor and stroma. The status of all three genes could be inferred by DL, with BAP1 showing the highest sensitivity and performance within and across tissue samples (AUC = 0.87-0.89 on holdout). BAP1 results were validated on independent human (AUC = 0.77-0.84) and PDX (AUC = 0.80) cohorts. Finally, BAP1 predictions correlated with clinical outputs such as disease-specific survival. Overall, these data show that DL models can resolve intratumoral heterogeneity in cancer with potential diagnostic, prognostic, and biological implications.

SIGNIFICANCE

This work demonstrates the potential for deep learning analysis of histopathologic images to serve as a fast, low-cost method to assess genetic intratumoral heterogeneity. See related commentary by Song et al., p. 2672.

LncRNA-MIAT promotes thyroid cancer progression and function as ceRNA to target EZH2 by sponging miR-150-5p

While long noncoding RNAs (lncRNAs) have been reported to play an important role in human cancer types, they remain poorly understood in papillary thyroid carcinoma (PTC). The aim of this study was to use genome-wide expression profiling to identify lncRNAs acting as competing endogenous RNAs (ceRNAs) in PTC. We constructed a ceRNA network based on our lncRNA microarray data and validated the correlation between myocardial infarction-associated transcript lncRNA (MIAT), miRNA-150-5p, and EZH2 in vitro and in vivo. We found 15 lncRNAs, 28 miRNAs, and hundreds of mRNAs involved in this ceRNA network. Splendid positive correlations were found between the MIAT and EZH2 expression in types of cancer in TCGA data. Besides, significant differences in MIAT/EZH2 expression were found among various clinicopathological features. Gain- and loss-of-function experiments revealed that MIAT inhibited cell proliferation and migration in vitro. Moreover, EZH2 was identified as a direct downstream target of miR-150-5p in PTC cells. Restoration of EZH2 expression partially abolished the biological effects of miR-150-5p. Furthermore, overexpression of MIAT was inversely correlated with miR-150-5p expression. Knockdown of MIAT produced significant behavioral alter maybe partly due to the function of the MIAT-150-5p-EZH2 network. Our findings suggest MIAT may inhibit EZH2 expression and promote PTC cell invasion via the miR-150/EZH2 pathway. Therefore, MIAT may serve as a valuable prognostic biomarker and therapeutic target for PTC.

LncRNA-MIAT promotes thyroid cancer progression and function as ceRNA to target EZH2 by sponging miR-150-5p

While long noncoding RNAs (lncRNAs) have been reported to play an important role in human cancer types, they remain poorly understood in papillary thyroid carcinoma (PTC). The aim of this study was to use genome-wide expression profiling to identify lncRNAs acting as competing endogenous RNAs (ceRNAs) in PTC. We constructed a ceRNA network based on our lncRNA microarray data and validated the correlation between myocardial infarction-associated transcript lncRNA (MIAT), miRNA-150-5p, and EZH2 in vitro and in vivo. We found 15 lncRNAs, 28 miRNAs, and hundreds of mRNAs involved in this ceRNA network. Splendid positive correlations were found between the MIAT and EZH2 expression in types of cancer in TCGA data. Besides, significant differences in MIAT/EZH2 expression were found among various clinicopathological features. Gain- and loss-of-function experiments revealed that MIAT inhibited cell proliferation and migration in vitro. Moreover, EZH2 was identified as a direct downstream target of miR-150-5p in PTC cells. Restoration of EZH2 expression partially abolished the biological effects of miR-150-5p. Furthermore, overexpression of MIAT was inversely correlated with miR-150-5p expression. Knockdown of MIAT produced significant behavioral alter maybe partly due to the function of the MIAT-150-5p-EZH2 network. Our findings suggest MIAT may inhibit EZH2 expression and promote PTC cell invasion via the miR-150/EZH2 pathway. Therefore, MIAT may serve as a valuable prognostic biomarker and therapeutic target for PTC.

Integrating HECW1 expression into the clinical indicators exhibits high accuracy in assessing the prognosis of patients with clear cell renal cell carcinoma

BACKGROUND

Although many intratumoral biomarkers have been reported to predict clear cell renal cell carcinoma (ccRCC) patient prognosis, combining intratumoral and clinical indicators could predict ccRCC prognosis more accurately than any of these markers alone. This study mainly examined the prognostic value of HECT, C2 and WW domain-containing E3 ubiquitin protein ligase 1 (HECW1) expression in ccRCC patients in combination with established clinical indicators.

METHODS

The expression level of HECW1 was screened out by data-independent acquisition mass spectrometry (DIA-MS) and analyzed in ccRCC patients from the The Cancer Genome Atlas (TCGA) database and our cohort. A total of 300 ccRCC patients were stochastically divided into a training cohort and a validation cohort, and real-time PCR, immunohistochemistry (IHC) and statistical analyses were employed to examine the prognostic value of HECW1 in ccRCC patients.

RESULTS

The expression level of HECW1 usually decreased in human ccRCC specimens relative to control specimens in TCGA (p < 0.001). DIA-MS, Real-time PCR, and IHC analyses also showed that the majority of ccRCCs harbored decreased HECW1 expression compared with that in normal adjacent tissues (p < 0.001). Additionally, HECW1 expression was reduced in ccRCC cell lines compared with the normal renal cell line HK-2 (p < 0.001). Moreover, lower HECW1 expression was found in ccRCC patients with a higher tumor node metastasis (TNM) stage, bone metastasis, or first-line targeted drug resistance (p < 0.001). Low HECW1 expression indicated higher TNM stage, SSIGN (Stage, Size, Grade, and Necrosis) score and WHO/ISUP grade and poor prognosis in ccRCC patients (p < 0.05). Even after multivariable adjustment, HECW1, TNM stage, and SSIGN score served as independent risk factors. The c-index analysis showed that integrating intratumoral HECW1 expression into TNM stage or SSIGN score resulted in a higher c-index value than these indicators alone for predicting ccRCC patient prognosis.

CONCLUSION

HECW1 is a novel prognostic biomarker and therapeutic target in ccRCC, and integrating intratumoral HECW1 expression with established clinical indicators yields higher accuracy in assessing the postoperative prognosis of ccRCC patients.

ZMYND8 preferentially binds phosphorylated EZH2 to promote a PRC2-dependent to -independent function switch in hypoxia-inducible factor-activated cancer

Both gene repressor (Polycomb-dependent) and activator (Polycomb-independent) functions of the Polycomb protein enhancer of zeste homolog 2 (EZH2) are implicated in cancer progression. EZH2 protein can be phosphorylated at various residues, such as threonine 487 (T487), by CDK1 kinase, and such phosphorylation acts as a Polycomb repressive complex 2 (PRC2) suppression "code" to mediate the gene repressor-to-activator switch of EZH2 functions. Here we demonstrate that the histone reader protein ZMYND8 is overexpressed in human clear cell renal cell carcinoma (ccRCC). ZMYND8 binds to EZH2, and their interaction is largely enhanced by CDK1 phosphorylation of EZH2 at T487. ZMYND8 depletion not only enhances Polycomb-dependent function of EZH2 in hypoxia-exposed breast cancer cells or von Hippel-Lindau (VHL)-deficient ccRCC cells, but also suppresses the FOXM1 transcription program. We further show that ZMYND8 is required for EZH2-FOXM1 interaction and is important for FOXM1-dependent matrix metalloproteinase (MMP) gene expression and EZH2-mediated migration and invasion of VHL-deficient ccRCC cells. Our results identify a previously uncharacterized role of the chromatin reader ZMYND8 in recognizing the PRC2-inhibitory phosphorylation "code" essential for the Polycomb-dependent to -independent switch of EZH2 functions. They also reveal an oncogenic pathway driving cell migration and invasion in hypoxia-inducible factor-activated (hypoxia or VHL-deficient) cancer.

Review of Prognostic Expression Markers for Clear Cell Renal Cell Carcinoma

Context: The number of prognostic markers for clear cell renal cell carcinoma (ccRCC) has been increasing regularly over the last 15 years, without being integrated and compared.

Objective: Our goal was to perform a review of prognostic markers for ccRCC to lay the ground for their use in the clinics.

Evidence Acquisition: PubMed database was searched to identify RNA and protein markers whose expression level was reported as associated with survival of ccRCC patients. Relevant studies were selected through cross-reading by two readers.

Evidence Synthesis: We selected 249 studies reporting an association with prognostic of either single markers or multiple-marker models. Altogether, these studies were based on a total of 341 distinct markers and 13 multiple-marker models. Twenty percent of these markers were involved in four biological pathways altered in ccRCC: cell cycle, angiogenesis, hypoxia, and immune response. The main genes (VHL, PBRM1, BAP1, and SETD2) involved in ccRCC carcinogenesis are not the most relevant for assessing survival.

Conclusion: Among single markers, the most validated markers were KI67, BIRC5, TP53, CXCR4, and CA9. Of the multiple-marker models, the most famous model, ClearCode34, has been highly validated on several independent datasets, but its clinical utility has not yet been investigated.

Patient Summary: Over the years, the prognosis studies have evolved from single markers to multiple-marker models. Our review highlights the highly validated prognostic markers and multiple-marker models and discusses their clinical utility for better therapeutic care.

Combining UBR5 and CD163+ tumor-associated macrophages better predicts prognosis of clear cell renal cell carcinoma patients

PURPOSE

Identification of reliable postoperative indicators for accurately evaluating prognosis of clear cell renal cell carcinoma (ccRCC) patients remains an important clinical issue. This study determined the prognostic value of UBR5 expression in ccRCC patients by combining with CD163⁺ tumor-associated macrophages (TAMs) and the established clinical parameters.

METHODS

The expression of UBR5 was analyzed in ccRCC patients from TCGA databases. A total of 310 ccRCC patients were randomly divided into the training and validation cohorts at a 3:2 or 1:1 ratio, and immunohistochemistry (IHC) and statistical analyses were performed to examine the prognostic value of UBR5 and CD163⁺ TAMs.

RESULTS

UBR5 expression was commonly downregulated in human ccRCC specimens, which was associated with TNM stage, SSIGN, WHO/ISUP Grading and poor prognosis of ccRCC patients. In addition, UBR5 expression was negatively correlated with CD163 expression (a TAM marker) in ccRCC tissues, and combining expressions of UBR5 and CD163 better predicted worse overall survival and progression-free survival of ccRCC patients. Even after multivariable adjustment, UBR5, CD163, TNM stage and SSIGN appeared to be independent risk factors. By time-dependent c-index analysis, the integration of intratumoral UBR5 and CD163 achieved higher c-index value than UBR5, CD163, TNM stage or SSIGN alone in predicting ccRCC patients' prognosis. Moreover, the incorporation of both UBR5 and CD163 into the clinical indicators TNM stage or SSIGN exhibited highest c-index value.

CONCLUSIONS

Integrating intratumoral UBR5 and CD163⁺ TAMs with the current clinical parameters achieves better accuracy in predicting ccRCC patients' postoperative prognosis.

Histone Methyltransferase EZH2: A Potential Therapeutic Target for Kidney Diseases

Enhancer of zeste homolog 2 (EZH2) is a histone-lysine N-methyltransferase enzyme that catalyzes the addition of methyl groups to histone H3 at lysine 27, leading to gene silencing. Mutation or over-expression of EZH2 has been linked to many cancers including renal carcinoma. Recent studies have shown that EZH2 expression and activity are also increased in several animal models of kidney injury, such as acute kidney injury (AKI), renal fibrosis, diabetic nephropathy, lupus nephritis (LN), and renal transplantation rejection. The pharmacological and/or genetic inhibition of EZH2 can alleviate AKI, renal fibrosis, and LN, but potentiate podocyte injury in animal models, suggesting that the functional role of EZH2 varies with renal cell type and disease model. In this article, we summarize the role of EZH2 in the pathology of renal injury and relevant mechanisms and highlight EZH2 as a potential therapeutic target for kidney diseases.

Potential of enhancer of zeste homolog 2 inhibitors for the treatment of SWI/SNF mutant cancers and tumor microenvironment modulation

Enhancer of zeste homolog 2 (EZH2), a catalytic component of polycomb repressive complex 2 (PRC2), is commonly overexpressed or mutated in many cancer types, both of hematological and solid nature. Till now, plenty of EZH2 small molecule inhibitors have been developed and some of them have already been tested in clinical trials. Most of these inhibitors, however, are effective only in limited cases in the context of EZH2 gain-of-function mutated tumors such as lymphomas. Other cancer types with aberrant EZH2 expression and function require alternative approaches for successful treatment. One possibility is to exploit synthetic lethal strategy, which is based on the phenomenon that concurrent loss of two genes is detrimental but the deletion of either of them leaves cell viable. In the context of EZH2/PRC2, the most promising synthetic lethal target seems to be SWItch/Sucrose Non-Fermentable chromatin remodeling complex (SWI/SNF), which is known to counteract PRC2 functions. SWI/SNF is heavily involved in carcinogenesis and its subunits have been found mutated in approximately 20% of tumors of different kinds. In the current review, we summarize the existing knowledge of synthetic lethal relationships between EZH2/PRC2 and components of the SWI/SNF complex and discuss in detail the potential application of existing EZH2 inhibitors in cancer patients harboring mutations in SWI/SNF proteins. We also highlight recent discoveries of EZH2 involvement in tumor microenvironment regulation and consequences for future therapies. Although clinical studies are limited, the fundamental research might help to understand which patients are most likely to benefit from therapies using EZH2 inhibitors.

Potential biomarkers and risk assessment models to enhance the tumor-node-metastasis (TNM) staging classification of urologic cancers

INTRODUCTION

The anatomic-based TNM classification is considered the benchmark in cancer staging and has been regularly updated since its inception. In the current era of precision medicine, the added intention for future TNM modifications is to heighten its impact in the more 'personalized' level of cancer care. In urologic cancers, this goal may be achieved by incorporating 'non-anatomic' factors into TNM, such as biomarkers (e.g. gene alterations, molecular subtypes, genomic classifiers) and risk assessment models (e.g. nomogram, look-up table), while maintaining the anatomic extent as the foundation of staging. These different prognosticators can be combined and integrated, may serve as substratifiers for T, N, or M categories, and perhaps, incorporated as elements in TNM stage groupings to enhance their prognostic capability in urologic cancers.

AREAS COVERED

This review highlights candidate biomarkers and risk assessment models that can be explored to potentially improve TNM prognostication of bladder, prostate, kidney, and testicular cancers.

EXPERT OPINION

Recent advances in molecular analysis have increased the understanding of the genomic, transcriptomic, and epigenetic features for biomarker use in prognostication of urologic cancers, which together with the available risk assessment models, may complement and overcome the limitations of the traditional TNM staging.

Genomic profiling in renal cell carcinoma

The treatment landscape of metastatic renal cell carcinoma (RCC) has been revolutionized over the past two decades, bringing forth an era in which more than a dozen therapeutic agents are now available to treat patients. As a consequence, personalized care has become a critical part of developing effective treatment guidelines and improving patient outcomes. One of the most important emerging aspects of precision medicine in cancer is matching patients and treatments based on the genomic characteristics of an individual and their tumour. Despite the lack of a single genomic predictor of treatment response or prognostication feature in RCC, emerging research suggests that the identification of such markers remains promising. Mutations in VHL and alterations in its downstream pathways are the mainstay of RCC development and progression. However, the predictive value of VHL mutations has been questioned. Further research has examined mutations in genes involved in chromosome remodelling (for example, PBRM1, BAP1 and SETD2), DNA methylation and DNA damage repair, all of which have been associated with clinical outcomes. Here, we provide a comprehensive overview of genomic evidence in the context of RCC and its potential predictive and prognostic value.

High level of EZH2 expression is linked to high density of CD8-positive T-lymphocytes and an aggressive phenotype in renal cell carcinoma

Purpose

Enhancer of zeste homolog 2 (EZH2), the catalytic part of the Polycomb repressive complex 2 (PRC2), has a prognostic role in renal cell carcinoma (RCC) and was recently shown to modulate the immune response by reducing tumor cell immunogenicity.

Methods

To investigate whether the prognostic role of EZH2 might be driven by a modified immune environment, more than 1800 RCCs were analyzed in a tissue microarray for EZH2 expression and CD8 positive lymphocytes were quantitated by automated digital imaging.

Results

EZH2 positivity was found in 75.2% of 1603 interpretable tumors. In clear cell RCC, high EZH2 expression was significantly linked to high ISUP, Furmann, and Thoenes grade (p < 0.0001 each), advanced stage (p < 0.0001), nodal (p = 0.0190) and distant metastasis (p < 0.0001) as well as shortened overall (p < 0.0027) and recurrence free survival (p < 0.0001). The density of CD8+ cells varied from 0 to 5048 cells/mm² (Median 120 cells/mm²). A high CD8+ count was significantly associated with high ISUP, Fuhrmann, and Thoenes grade (p < 0.0001 each), advanced tumor stage (p = 0.0041), distant metastasis (p = 0.0026) as well as reduced overall survival (p = 0.0373) and recurrence free survival (p = 0.0450). The density of CD8+ cells continuously increased with raising EZH2 levels (p < 0.0001).

Conclusion

Our data support a striking prognostic role of both EZH2 expression and the density of CD8+ cells in RCC. The tight relationship of EZH2 expression and CD8+ cell counts in RCC is consistent with models suggesting that EZH2 overexpression can be caused by high lymphocyte content in certain tumor types. Such a mechanism could explain the unique finding of high lymphocyte counts driving poor prognosis in RCC patients.

EZH2 negatively regulates PD-L1 expression in hepatocellular carcinoma

Background

Accumulating studies suggest that targeting epigenetic modifications could improve the efficacy of tumor immunotherapy; however, the mechanisms underlying this phenomenon remain largely unknown. Here, we investigated the ability of the epigenetic modifier, enhancer of zeste 2 polycomb repressive complex 2 subunit (EZH2), to regulate the expression of immune checkpoint inhibitor, programmed death-1 ligand 1 (PD-L1) in hepatocellular carcinoma (HCC).

Methods

Immunohistochemistry and multiplex immunofluorescence staining were performed to analyze the expression and correlation of EZH2 and PD-L1 in HCC tissues. Immunoblotting, quantitative real-time PCR, flow cytometry, chromatin immunoprecipitation, and dual-luciferase reporter gene assays were performed to evaluate the regulatory roles of EZH2 on PD-L1 expression.

Results

In vitro cell experiments revealed that EZH2 negatively regulated the PD-L1 expression of hepatoma cell lines in IFNγ-dependent manner. Mechanistic studies demonstrated that EZH2 could suppress PD-L1 expression by upregulating the H3K27me3 levels on the promoters of CD274 (encoding PD-L1) and interferon regulatory factor 1 (IRF1), an essential transcription factor for PD-L1 expression, without affecting the activation of the IFNγ-signal transducer and activator of transcription 1 (STAT1) pathway. Clinical samples from HCC patients with immune-activated microenvironments showed negative correlations between EZH2 and PD-L1 expression in hepatoma cells. Multivariate Cox analysis demonstrated that the combination of EZH2 and PD-L1 was an independent prognostic factor for both OS and RFS for patients with HCC.

Conclusions

The epigenetic modificator EZH2 can suppress the expression of immune checkpoint inhibitor PD-L1 by directly upregulating the promoter H3K27me3 levels of CD274 and IRF1 in hepatoma cells, and might serve as a potential therapeutic target for combination of immunotherapy for immune-activated HCC.

Ubiquitous expressed transcript promotes tumorigenesis by acting as a positive modulator of the polycomb repressive complex 2 in clear cell renal cell carcinoma

BACKGROUND

The ubiquitous expressed transcript (UXT) plays a key role in various tumors by regulating transcriptional activity of multiple transcription factors, including androgen receptor (AR). However, the role of UXT in clear cell renal cell carcinoma (ccRCC) is still unknown.

METHODS

Yeast two-hybrid screening, GST pull-down and co-immunoprecipitation assays were performed to detect the interacting protein of UXT. Chromatin immunoprecipitation (ChIP) was performed to investigate the levels of histone H3 lysine 27 trimethylation at the HOXA9 promoters. CCK-8 assays, colony formation assays and Transwell assays were performed to detect the proliferation, colony formation, migration and invasion of renal cancer cells. Quantitative PCR analysis was performed to detect the expressions of UXT in human ccRCC samples.

RESULTS

The enhancer of zeste homolog 2 (EZH2) is a novel UXT interacting protein and UXT interacts with EZH2 in the nucleus. In addition, UXT interacts with the polycomb repressive complex 2 (PRC2) through directly binding to EZH2 and suppressor of zeste 12 homolog (SUZ12), but not to embryonic ectoderm development (EED). Moreover, the UXT activates EZH2 histone methyltransferase activity by facilitating EZH2 binding with SUZ12. We further provided striking evidences that knockdown of UXT inhibits proliferation, colony formation, migration and invasion of renal cancer cells, in an EZH2-dependent manner. Importantly, the upregulation of UXT expression was observed in clinical ccRCC samples, and the high expression level of UXT was associated with advanced stage, distant metastasis and poor overall survival in patients with ccRCC.

CONCLUSION

The UXT is a novel regulator of the PRC2 and acts as a renal cancer oncogene that affects the progression and survival of ccRCC patients.

3-deazaneplanocin A protects against cisplatin-induced renal tubular cell apoptosis and acute kidney injury by restoration of E-cadherin expression

3-deazaneplanocin A (3-DZNeP) has been used as an inhibitor of enhancer of zeste homolog 2 (EZH2). Here, we explore the role and underlying mechanisms action of 3-DZNeP in abrogating cisplatin nephrotoxicity. Exposure of cultured mouse renal proximal tubular epithelial cells (mTECs) to cisplatin resulted in dose and time-dependent cleavage of caspase-3, decrease of cell viability, and increase of histone H3 lysine 27 trimethylation (H3K27me3), whereas expression levels of EZH2, a major methyltransferase of H3K27me3, were not affected. Treatment with 3-DZNeP significantly inhibited cisplatin-induced activation of caspase-3, apoptosis, loss of cell viability but did not alter levels of EZH2 and H3K27me3 in cultured mTECs. 3-DZNeP treatment did not affect activation of extracellular signal-regulated kinase (ERK) 1/2, p38 or c-Jun N-terminal kinases (JNK) 1/2, which contribute to renal epithelial cell death, but caused dose-dependent restoration of E-cadherin in mTECs exposed to cisplatin. Silencing of E-cadherin expression by siRNA abolished the cytoprotective effects of 3-DZNeP. In contrast, 3-DZNeP treatment potentiated the cytotoxic effect of cisplatin in H1299, a non-small cell lung cancer cell line that expresses lower E-cadherin levels. Finally, administration of 3-DZNeP attenuated renal dysfunction, morphological damage, and renal tubular cell death, which was accompanied by E-cadherin preservation, in a mouse model of cisplatin nephrotoxicity. Overall, these data indicate that 3-DZNeP suppresses cisplatin-induced tubular epithelial cell apoptosis and acute kidney injury via an E-cadherin-dependent mechanism, and suggest that combined application of 3-DZNeP with cisplatin would be a novel chemotherapeutic strategy that enhances the anti-tumor effect of cisplatin and reduces its nephrotoxicity.

Functional Long Noncoding RNAs (lncRNAs) in Clear Cell Kidney Carcinoma Revealed by Reconstruction and Comprehensive Analysis of the lncRNA-miRNA-mRNA Regulatory Network

BACKGROUND A variety of treatment strategies have been developed for clear cell kidney carcinoma (KIRC); however, there is still a need for effective therapeutic targets and prognostic molecular biomarkers. Given that long noncoding RNAs (lncRNAs) has been emerging as an important regulator in tumorigenesis, we explored potential functional lncRNAs in KIRC by comprehensively analyzing the lncRNA-miRNA-mRNA regulatory network with bioinformatics processing tools. MATERIAL AND METHODS RNA-seq/miRNA-seq data of KIRC in The Cancer Genome Atlas (TCGA) were obtained and analyzed. The "edgeR" package in R software was used to identify differentially expressed lncRNAs (DElncRNAs, differentially expressed long noncoding RNAs), miRNAs (DEmiRNAs, differentially expressed micro RNAs), and mRNAs (DEmRNAs, differentially expressed messenger RNAs) in KIRC and normal samples. A global triple network was conducted based on the competing endogenous RNA (ceRNA) theory, and survival analysis was conducted by "survival" package in R software. RESULTS A total of 4246 DElncRNAs, 179 DEmiRNAs, and 5758 DEmRNAs were identified, among which a subset of them (321 lncRNAs, 26 miRNAs, and 1068 mRNAs) were found to constitute a global ceRNA network in KIRC. Four lncRNAs (ENTPD3-AS1, FGD5-AS1, LIFR-AS1, and UBAC2-AS1) were revealed to be potential therapeutic targets as well as prognostic biomarkers of KIRC by our extensive functional analysis. CONCLUSIONS We reported here the identification of functional lncRNAs in KIRC via a TCGA data-based bioinformatics analysis. We believe that this study might contribute to improving the comprehension of the lncRNA-mediated ceRNA regulatory mechanisms in the tumorigenesis of KIRC. Meanwhile, our results suggested that 4 lncRNAs might act as potential therapeutic targets or candidate prognostic biomarkers in KIRC.

Prognostication in Kidney Cancer: Recent Advances and Future Directions

The most common type of cancer originating in the kidney is renal cell carcinoma (RCC). In both localized and advanced RCC, a number of clinical, pathologic, and molecular factors have been identified as having prognostic significance. In localized disease, risk stratification has traditionally involved the anatomic extent of disease, and several integrated scoring systems have been developed to help predict outcomes after definitive local therapy. In metastatic RCC, integrated prognostic models have also been established. These are used to stratify patients in contemporary clinical trials and to guide risk-directed treatment selection in clinical practice. Although many prognostic factors are common to both localized and advanced disease, there are some important distinctions. In both of these types of disease, the prognostic role of specific molecular and genomic alterations is an area of active investigation. In this review, we highlight the current staging systems and prognostic factors in localized and metastatic RCC. We also explore future directions in this area, including the expanding role of molecular biomarkers and their integration into the traditional prognostic models.

Chromosome 3p Loss-Orchestrated VHL, HIF, and Epigenetic Deregulation in Clear Cell Renal Cell Carcinoma

Clear cell renal cell carcinoma (ccRCC) is the most common renal cell carcinoma subtype, and metastatic ccRCC is associated with 5-year survival rates of 10% to 20%. Genetically, ccRCC originates from sequential losses of multiple tumor suppressor genes. Remarkably, chromosome 3p loss occurs in more than 90% of sporadic ccRCCs. This results in concurrent one-copy loss of four tumor suppressor genes that are also mutated individually at high frequency in ccRCC (ie, VHL, 80%; PBRM1, 29% to 46%; BAP1, 6% to 19%; and SETD2, 8% to 30%). Pathogenically, 3p loss probably represents the first genetic event that occurs in sporadic ccRCC and the second genetic event in VHL-mutated hereditary ccRCC. VHL constitutes the substrate recognition module of the VCB-Cul2 E3 ligase that degrades HIF1/2α, whereas PBRM1, BAP1, and SETD2 are epigenetic modulators that regulate gene transcription. Because 3p loss and VHL inactivation are nearly universal truncal events in ccRCC, the resulting HIF1/2 signaling overdrive and accompanied tumor hypervascularization probably underlie the therapeutic benefits observed with vascular endothelial growth factor receptor inhibitors, including sorafenib, sunitinib, pazopanib, axitinib, bevacizumab, cabozantinib, and lenvatinib. Furthermore, recent marked advances in ccRCC genomics, transcriptomics, proteomics, metabolomics, molecular mechanisms, mouse models, prognostic and predictive biomarkers, and clinical trials have rendered invaluable translational insights concerning precision kidney cancer therapeutics. With an armamentarium encompassing 13 drugs that exploit seven unique therapeutic mechanisms (ie, cytokines, vascular endothelial growth factor receptor, mTORC1, cMET/AXL, fibroblast growth factor receptor, programmed cell death-1 and programmed death-ligand 1, and cytotoxic T-cell lymphocyte associated-4) to treat metastatic renal cell carcinoma, one of the imminent clinical questions concerning care of patients with metastatic ccRCC is how a personalized treatment strategy, through rationally combining and sequencing different therapeutic modalities, can be formulated to offer the best clinical outcome for individual patients. Here, we attempt to integrate recent discoveries of immediate translational impacts and discuss future translational challenges and opportunities.

Prognostic Value of a Long Non-coding RNA Signature in Localized Clear Cell Renal Cell Carcinoma

BACKGROUND

Long non-coding RNAs (lncRNAs) can be used as prognostic biomarkers in many types of cancer.

OBJECTIVE

We sought to establish an lncRNA signature to improve postoperative risk stratification for patients with localized clear cell renal cell carcinoma (ccRCC).

DESIGN, SETTING, AND PARTICIPANTS

Based on the RNA-seq data of 444 stage I-III ccRCC tumours from The Cancer Genome Atlas project, we built a four-lncRNA-based classifier using the least absolute shrinkage and selection operation (LASSO) Cox regression model in 222 randomly selected samples (training set) and validated the classifier in the remaining 222 samples (internal validation set). We confirmed this classifier in an external validation set of 88 patients with stage I-III ccRCC from a Japan cohort and using quantitative reverse transcription polymerase chain reaction (RT-PCR) in another three independent sets that included 1869 patients from China with stage I-III ccRCC.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Univariable and multivariable Cox regression, Harrell's concordance index (c-index), and time-dependent receiver operating characteristic curves were used to evaluate the association of the classifier with overall survival, disease-specific survival, and disease-free survival.

RESULTS AND LIMITATIONS

Using the LASSO Cox regression model, we built a classifier named RCClnc4 based on four lncRNAs: ENSG00000255774, ENSG00000248323, ENSG00000260911, and ENSG00000231666. In the RNA-seq and RT-PCR data sets, the RCClnc4 signature significantly stratified patients into high-risk versus low-risk groups in terms of clinical outcome across and within subpopulations and remained as an independent prognostic factor in multivariate analyses (hazard ratio range, 1.34 [95% confidence interval {CI}: 1.03-1.75; p=0.028] to 1.89 [95% CI, 1.55-2.31; p<0.001]) after adjusting for clinical and pathologic factors. The RCClnc4 signature achieved a higher accuracy (mean c-index, 0.72) than clinical staging systems such as TNM (mean c-index, 0.62) and the stage, size, grade, and necrosis (SSIGN) score (mean c-index, 0.64), currently reported prognostic signatures and biomarkers for the estimation of survival. When integrated with clinical characteristics, the composite clinical and lncRNA signature showed improved prognostic accuracy in all data sets (TNM + RCClnc4 mean c-index, 0.75; SSIGN + RCClnc4 score mean c-index, 0.75). The RCClnc4 classifier was able to identify a clinically significant number of both high-risk stage I and low-risk stage II-III patients.

CONCLUSIONS

The RCClnc4 classifier is a promising and potential prognostic tool in predicting the survival of patients with stage I-III ccRCC. Combining the lncRNA classifier with clinical and pathological parameters allows for accurate risk assessment in guiding clinical management.

PATIENT SUMMARY

The RCClnc4 classifier could facilitate patient management and treatment decisions.

Quelle place pour les traitements médicaux avant et après chirurgie es stades localisés ?

La place des traitements médicaux adjuvants dans les stades localisés du cancer du rein reste en France du domaine de la recherche clinique en 2017. Seul l’essai S-TRAC évaluant un an de sunitinib versus placebo a montré une augmentation significative de la survie sans maladie de 5,6 à 6,8 ans (HR = 0,76 ; p = 0,03) contrairement aux deux essais publiés de phase III, ASSURE (sunitinib ou sorafénib versus placebo un an) et PROTECT (pazopanib versus placebo un an). De nombreux essais d’immunothérapie avec les inhibiteurs des points de contrôle de la réponse immunitaire sont en cours. Les inhibiteurs de tyrosine-kinase ont démontré une efficacité en néoadjuvant en termes de réponse tumorale (de 18 à 28 %) sans toxicité surajoutée lors de la chirurgie et permettant le plus souvent une épargne néphronique. Néanmoins, cette stratégie versus une néphrectomie partielle d’emblée dans une équipe entraînée n’a pas été démontrée.

Low expression of WW domain-containing oxidoreductase associates with hepatocellular carcinoma aggressiveness and recurrence after curative resection

WW domain‐containing oxidoreductase (WWOX), which has a protein‐interaction domain and is regarded to be a tumor suppressor, has been known to play an important role in anti‐angiogenesis and cancer progression. This study aimed to investigate prognostic values of WWOX expression in hepatocellular carcinoma (HCC) patients after hepatectomy. Additionally, we intended to formulate a valuable prognostic nomogram for HCCs. 182 HCC patients who underwent hepatectomy from January 2009 to January 2010 were enrolled in our study. qRT‐PCR, Western blot, and immunohistochemistry on tissue microarrays were then used to determine the expression levels of WWOX. An evaluation of the role of WWOX expression levels in the prognosis and outcome of patients was established. A decrease in the expression of WWOX was found when compared to adjacent tumor‐free tissues, which led to worse overall survival (OS) and recurrence‐free survival (RFS) and, therefore, was considered as an independent negative factor in the prognosis of HCC. Two nomograms, comprising WWOX, alpha‐fetoprotein (AFP), tumor size, and γ‐glutamyltransferase (γ‐GT), were constructed to obtain superior discriminatory abilities than conventional staging systems in terms of C‐index and clinical net benefit on decision curve analysis (DCA) for OS and RFS. Our data suggest that WWOX expression is strongly related to HCC post‐resection aggressiveness and recurrence. Additional advanced and accurate predictive model through the incorporation of WWOX into nomogram could help predict OS or RFS for HCC patients.

Multi-institutional evaluation of the prognostic significance of EZH2 expression in high-grade upper tract urothelial carcinoma

PURPOSE

Enhancer of zeste homolog 2 is a methyltransferase encoded by the EZH2 gene, whose role in upper tract urothelial carcinoma (UTUC) is poorly understood. We sought to evaluate the prognostic value of EZH2 expression in UTUC.

METHODS

We reviewed a multi-institutional cohort of patients who underwent radical nephroureterectomy for high-grade UTUC from 1990 to 2008. Immunohistochemistry for EZH2 was performed on tissue microarrays. Percentage of staining was evaluated, and the discriminative value of EZH2 was tested, with EZH2 positivity defined as>20% staining present. Clinicopathologic characteristics and oncologic outcomes (recurrence-free (RFS), cancer-specific (CSS), and overall survival (OS)) were compared, stratified by EZH2 positivity. The prognostic role of EZH2 was assessed using Kaplan-Meier, univariate (UVA), and multivariate (MVA) Cox regression analyses. Significance was defined for P<0.05.

RESULTS

A total of 376 patients were included for analysis, with median follow-up 36.0 months. Overall, 78 (20.7%) were EZH2-positive. EZH2 expression was more often associated with ureteral location, lymphovascular invasion, sessile architecture, necrosis, and concomitant carcinoma in situ. On UVA, increased EZH2 expression was a significant predictor for inferior RFS (HR 1.63, P = 0.033), CSS (HR 2.03, P = 0.003), and OS (HR 2.11, P<0.001). On MVA EZH2 remained a significant predictor of worse CSS (HR 1.99 [95% CI: 1.21-3.27], P = 0.007) and OS (HR 1.54 [95% CI: 1.06-2.24], P = 0.024), while significance was lost for RFS.

CONCLUSION

Increased EZH2 expression is associated with adverse pathologic features and inferior oncologic outcomes in patients with high-grade UTUC. The role of EZH2 biology in UTUC pathogenesis remains to be further elucidated.

Adjuvant therapy for advanced renal cell carcinoma

INTRODUCTION

Locally advanced, non-metastatic renal cell carcinoma (RCC) is conventionally managed with surgery. However, patients are at a high risk of RCC recurrence and have poor survival outcomes. An effective adjuvant systemic treatment is needed to improve on these outcomes. Targeted molecular and immune-based therapies have been investigated, or are under investigation, but their role in this setting remains unclear. Areas covered: A comprehensive search of PubMed and ClinicalTrials.gov was performed for relevant literature. The following topics pertinent to adjuvant therapy in RCC were evaluated: strategies for patient selection, cytokine-based immunotherapy, vaccine therapy, VEGF and non-VEGF targeted molecular agents, and immune checkpoint inhibitors. Expert commentary: Strong evidence for the incorporation of adjuvant therapy in high-risk RCC is lacking. Multiple targeted molecular therapies have been examined with only one approved for use. Genetic and molecular-based prognostic models are needed to determine who may benefit from adjuvant therapy. Developing adjuvant therapy strategies in the future depends on the results of important ongoing trials with immunotherapy and targeted agents.

Adjuvant Antiangiogenic Agents in Post-nephrectomy Renal Cell Carcinoma: A Systematic Review and Meta-analysis

Context

The role of antiangiogenic agents in advanced renal cell carcinoma (RCC) is well established. However, it is still not clear whether this benefit can be extrapolated to the adjuvant setting.

Objective

To determine the efficacy and safety of antiangiogenic agents in patients with RCC and a high risk of relapse after nephrectomy.

Evidence acquisition

We searched PubMed, Embase, and the Cochrane Central Register of Controlled Trials for randomized controlled trials (RCTs) evaluating the use of any oral antiangiogenic agent compared to placebo in post-nephrectomy RCC patients. Prespecified data elements were extracted from each trial. Outcomes of interest included overall survival (OS) and disease-free survival (DFS). The overall effect was pooled using the DerSimonian and Laird random-effects models.

Evidence synthesis

Three RCTs comparing antiangiogenics to placebo among 3693 patients met our inclusion criteria and were used in meta-analyses. Overall, antiangiogenics did not improve DFS (hazard ratio [HR] 0.92, 95% confidence interval [CI] 0.78-1.07) or OS (HR 0.99, 95% CI 0.79-1.25). These results persisted when restricting the analysis to patients with clear cell carcinoma and patients with highest risk of relapse. Similarly, sunitinib did not show any improvement in the entire cohort for either DFS (HR 0.89, 95% CI 0.67-1.19) or OS (HR 1.11, 95% CI 0.90-1.37).

Conclusions

In this meta-analysis, antiangiogenics did not improve OS and DFS over placebo in high-risk RCC after nephrectomy. Further studies are needed to identify the patient population that might derive a benefit from antiangiogenics in the adjuvant setting.

Patient summary

In this article, we found that there is currently insufficient evidence to support the use of oral antiangiogenics in nonmetastatic renal cell carcinoma after nephrectomy. In addition, the use of oral antiangiogenics was associated with a 2.7-fold higher rate of significant side effects compared to placebo.