Prognostic and Predictive Value of PBRM1 in Clear Cell Renal Cell Carcinoma

Downregulated expression of PBRM1 in sarcomatoid hepatocellular carcinoma

Sarcomatoid hepatocellular carcinoma (SHCC) is a rare and highly lethal subtype of HCC. The present study aimed to explore the unique markers of SHCC using whole gene expression analysis. Subsequently, gene expression analysis was performed using five sarcomatoid and seven carcinomatoid components of seven tissues from patients with SHCC. The results demonstrated a significant downregulation of polybromo 1 (PBRM1) gene expression in the sarcomatoid components. Immunohistochemical staining also indicated a decreased expression of PBRM1 in the sarcomatoid components. Moreover, gene ontology enrichment analysis revealed that most of the 336 differentially expressed genes between the sarcomatoid and carcinomatoid components were involved in functions associated with DNA replication and histone methylation, which was consistent with the loss of function of PBRM1 which encodes Switch/sucrose-non-fermentable chromatin remodeling complex protein. Therefore, the results of the present study suggested that PBRM1 may be a candidate biomarker for the evaluation of SHCC.

Identification of genomic drivers for the therapeutic response of Cabozantinib in patients with metastatic renal cell carcinoma

PURPOSE

Cabozantinib (CAB) as monotherapy or in combination with immune checkpoint inhibitors is used for systemic treatment of metastatic renal cell carcinoma (mRCC). However, little is known about predictors of treatment response to CAB. For this reason, known genomic drivers were examined to identify potential predictors of treatment response with CAB.

METHODS

Twenty mRCC patients receiving monotherapy (≥ first-line) with CAB were prospectively included. DNA was extracted from archived primary tumors or metastatic tissue. Targeted DNA sequencing was performed using a gene panel including 328 genes (QIAseq Targeted DNA V3 Panel, Qiagen). The variant evaluation was performed using Varsome. The endpoints were treatment-failure-free-survival (TFFS) to CAB.

RESULTS

26% of patients received systemic RCC treatment as the primary option. Six patients were treated with CAB in first-line (1L) and 12 patients in ≥ 2L. The median follow-up after initiation of systemic treatment was 26.7 months (mo). The PBRM1 (7 alleles), SETD2 (7 alleles), VHL (11 alleles), and CHEK2 (14 alleles) genes were most frequently altered. The median time to TFFS was 10.5 mo (95% confidence interval (CI) 6.2-14.7 mo). There was a longer treatment response to CAB in patients with alterations of the SETD2 gene (SETD2 alteration median TFFS not reached vs. no SETD2 alterations 8.4 mo (95% CI 5.2-11.6 mo); p = 0.024).

CONCLUSION

Pathogenic variant genes may indicate treatment response to systemic therapy in mRCC. Patients with alterations of the SETD2 gene show longer responses to CAB treatment.

PBRM1 loss is associated with increased sensitivity to MCL1 and CDK9 inhibition in clear cell renal cancer

MCL1 is a member of the BCL2 family of apoptosis regulators, which play a critical role in promoting cancer survival and drug resistance. We previously described PRT1419, a potent, MCL1 inhibitor with anti-tumor efficacy in various solid and hematologic malignancies. To identify novel biomarkers that predict sensitivity to MCL1 inhibition, we conducted a gene essentiality analysis using gene dependency data generated from CRISPR/Cas9 cell viability screens. We observed that clear cell renal cancer (ccRCC) cell lines with damaging PBRM1 mutations displayed a strong dependency on MCL1. PBRM1 (BAF180), is a chromatin-targeting subunit of mammalian pBAF complexes. PBRM1 is frequently altered in various cancers particularly ccRCC with ~40% of tumors harboring damaging PBRM1 alterations. We observed potent inhibition of tumor growth and induction of apoptosis by PRT1419 in various preclinical models of PBRM1-mutant ccRCC but not PBRM1-WT. Depletion of PBRM1 in PBRM1-WT ccRCC cell lines induced sensitivity to PRT1419. Mechanistically, PBRM1 depletion coincided with increased expression of pro-apoptotic factors, priming cells for caspase-mediated apoptosis following MCL1 inhibition. Increased MCL1 activity has been described as a resistance mechanism to Sunitinib and Everolimus, two approved agents for ccRCC. PRT1419 synergized with both agents to potently inhibit tumor growth in PBRM1-loss ccRCC. PRT2527, a potent CDK9 inhibitor which depletes MCL1, was similarly efficacious in monotherapy and in combination with Sunitinib in PBRM1-loss cells. Taken together, these findings suggest PBRM1 loss is associated with MCL1i sensitivity in ccRCC and provide rationale for the evaluation of PRT1419 and PRT2527 for the treatment for PBRM1-deficient ccRCC.

The incidence, pathogenesis, and management of non-clear cell renal cell carcinoma

Renal cell carcinoma (RCC) is the most common type of kidney cancer and is divided into two distinct subtypes, clear cell renal cell carcinoma (ccRCC) and non-clear cell renal cell carcinoma (nccRCC). Although many treatments exist for RCC, these are largely based on clinical trials performed in ccRCC and there are limited studies on the management of nccRCC. Non-clear cell RCC consists of multiple histological subtypes: papillary, chromophobe, translocation, medullary, collecting duct, unclassified, and other rare histologies. Due to variations in pathogenesis and therapeutic response, therapy should be tailored to specific variant histologies. For patients with localized nccRCC, surgical resection remains the gold standard. In the metastatic setting, the standard of care has yet to be clearly defined, and most guidelines recommend clinical trial participation. General therapeutic options include immunotherapy, either as monotherapy or in combination, targeted therapies such as vascular endothelial growth factor tyrosine kinase inhibitors and MET inhibitors, and chemotherapy in certain subtypes. Here we present a review of the incidence and pathogenesis of the various subtypes, as well as available clinical data to support therapeutic recommendations for these subtypes. We also highlight currently available clinical trials in nccRCC and future directions in investigating novel treatment modalities tailored to patients with variant histology.

Unveiling the immunogenomic landscape of cholangiocarcinoma: Identifying new prognostic markers and therapeutic targets based on CCL5 expression

BACKGROUND

Cholangiocarcinoma (CCA) stands as an aggressive malignancy of the biliary tract. The interplay between the tumor and immune system plays a pivotal role in disease progression and treatment outcomes. Hence, the present study aimed to extensively explore the immunogenomic landscape of CCA, with the objective of unveiling unique molecular and immunological signatures that could guide personalized therapeutic approaches.

METHODS

The study collected data from The Cancer Genome Atlas databases, performed gene set variation analysis for the chemokine ligand 5 (CCL5) high/low expression group, conducted principal component analysis, gene set enrichment analysis enrichment and mutation pattern analysis, generated a heatmap, and performed cox regression analysis.

RESULTS

The two discrete subpopulations were found to exhibit contrasting mutational and immunogenomic characteristics, emphasizing the heterogeneity of CCA. These subsets also showed pronounced discrepancies in the infiltration of immune cells, indicating diverse interactions with the tumor immune microenvironment. Furthermore, the dissimilarities in mutational patterns were observed within the two CCA subgroups, with PBRM1 and BAP1 emerging as the most frequently mutated genes. In addition, a prognostic framework was formulated and validated utilizing the expression profiles of COX16 and RSAD2 genes, effectively segregating patients into high-risk and low-risk cohorts. Furthermore, the connections between immune-related parameters and these risk groups were identified, underscoring the potential significance of the immune microenvironment in patient prognosis. In vitro experiments have shown that COX16 promotes the proliferation and metastasis of CCA cells, whereas RSAD2 inhibits it.

CONCLUSIONS

The present study provides an intricate depiction of the immunogenomic landscape of CCA based on CCL5 expression, thereby paving the way for novel immunotherapy strategies and prognostic assessment.

Expanded detection of BAP1 alterations in cancer and tumor type-specific expression score comparison

BAP1 is a tumor suppressor gene that was originally studied in uveal melanoma (UVM), kidney renal cell clear cell carcinoma (KIRC), and malignant mesothelioma (MESO). Early analyses focused on single-nucleotide variants, but other alteration types such as larger indels and gene-level copy number (CN) loss can also lead to loss of BAP1 expression. We performed integrated multi-omic analyses using data from The Cancer Genome Atlas (TCGA) for 33 cancer types and more than 10,000 individuals. We combined and manually reviewed existing variant calls and new calls derived from a de novo local realignment pipeline across multiple independent variant callers including indel callers, increasing detection of high-quality somatic variant calls by 30% from 91 to 130, including 7 indels ≥40bp. Including CN loss alterations, 1561 samples from 32 cancer types were BAP1-altered, with alterations being predominantly CN-driven. Differential expression and survival analyses revealed both shared and tissue-specific consequences associated with BAP1 alteration. Our findings broadly emphasize the improvements that are gained by using new computational approaches in large cancer-genome studies such as TCGA.

Genetic and Epigenetic Characteristics in Isolated Pancreatic Metastases of Clear-Cell Renal Cell Carcinoma

Isolated pancreatic metastases of renal cell carcinoma (IsPMRCC) are a rare manifestation of metastatic, clear-cell renal cell carcinoma (RCC) in which distant metastases occur exclusively in the pancreas. In addition to the main symptom of the isolated occurrence of pancreatic metastases, the entity surprises with additional clinical peculiarities: (a) the unusually long interval of about 9 years between the primary RCC and the onset of pancreatic metastases; (b) multiple pancreatic metastases occurring in 36% of cases; (c) favourable treatment outcomes with a 75% 5-year survival rate; and (d) volume and growth-rate dependent risk factors generally accepted to be relevant for overall survival in metastatic surgery are insignificant in isPMRCC. The genetic and epigenetic causes of exclusive pancreatic involvement have not yet been investigated and are currently unknown. Conversely, according to the few available data in the literature, the following genetic and epigenetic peculiarities can already be identified as the cause of the protracted course: 1. high genetic stability of the tumour cell clones in both the primary tumour and the pancreatic metastases; 2. a low frequency of copy number variants associated with aggressiveness, such as 9p, 14q and 4q loss; 3. in the chromatin-modifying genes, a decreased rate of PAB1 (3%) and an increased rate of PBRM1 (77%) defects are seen, a profile associated with a favourable course; 4. an increased incidence of KDM5C mutations, which, in common with increased PBRM1 alterations, is also associated with a favourable outcome; and 5. angiogenetic biomarkers are increased in tumour tissue, while inflammatory biomarkers are decreased, which explains the good response to TKI therapy and lack of sensitivity to IT.

Molecular differences in renal cell carcinoma between males and females

PURPOSE

The disparity in renal cell carcinoma (RCC) risk and treatment outcome between males and females is well documented, but the underlying molecular mechanisms remain poorly elucidated.

METHODS

We performed a narrative review synthesizing contemporary evidence on sex-specific molecular differences in healthy kidney tissue and RCC.

RESULTS

In healthy kidney tissue, gene expression differs significantly between males and females, including autosomal and sex-chromosome-linked genes. The differences are most prominent for sex-chromosome-linked genes and attributable to Escape from X chromosome-linked inactivation and Y chromosome loss. The frequency distribution of RCC histologies varies between the sexes, particularly for papillary, chromophobe, and translocation RCC. In clear-cell and papillary RCC, sex-specific gene expressions are pronounced, and some of these genes are amenable to pharmacotherapy. However, for many, the impact on tumorigenesis remains poorly understood. In clear-cell RCC, molecular subtypes and gene expression pathways have distinct sex-specific trends, which also apply to the expression of genes implicated in tumor progression.

CONCLUSION

Current evidence suggests meaningful genomic differences between male and female RCC, highlighting the need for sex-specific RCC research and personalized sex-specific treatment approaches.

JARID2 and EZH2, The Eminent Epigenetic Drivers In Human Cancer

Cancer has become a prominent cause of death, accounting for approximately 10 million death worldwide as per the World Health Organization reports 2020. Epigenetics deal with the alterations of heritable phenotypes, except for DNA alterations. Currently, we are trying to comprehend the role of utmost significant epigenetic genes involved in the burgeoning of human cancer. A sundry of studies reported the Enhancer of Zeste Homologue2 (EZH2) as a prime catalytic subunit of Polycomb Repressive Complex2, which is involved in several pivotal activities, including embryogenesis. In addition, EZH2 has detrimental effects leading to the onset and metastasis of several cancers. Jumonji AT Rich Interacting Domain2 (JARID2), an undebated crucial nuclear factor, has strong coordination with the PRC2 family. In this review, we discuss various epigenetic entities, primarily focusing on the possible role and mechanism of EZH2 and the significant contribution of JARID2 in human cancers.

Relationship between body composition and PBRM1 mutations in clear cell renal cell carcinoma: a propensity score matching analysis

OBJECTIVE

This study aimed to examine the relationship between body muscle and adipose tissue composition in clear cell renal cell carcinoma patients with PBRM1 gene mutation.

METHODS

Cancer Genome Atlas Kidney clear cell renal cell carcinoma and Clinical Proteomic Tumor Analysis Consortium clear cell renal cell carcinoma collections were retrieved from the Cancer Imaging Archive. A total of 291 clear cell renal cell carcinoma patients were included in the study retrospectively. Patients' characteristics were obtained from Cancer Imaging Archive. Body composition was assessed with abdominal computed tomography using the automated artificial intelligence software (AID-U™, iAID Inc., Seoul, Korea). Body composition parameters of the patients were calculated. To investigate the net effect of body composition, the propensity score matching procedure was applied over age, gender, and T-stage parameters.

RESULTS

 Of the patients, 184 were males and 107 were females. Mutations in the PBRM1 gene were detected in 77 of the patients. While there was no difference in adipose tissue areas between the PBRM1 mutation group and those without PBRM1 mutation, statistically significant differences were found in normal attenuated muscle area parameters.

CONCLUSION

 This study shows that there was no difference between adipose tissue areas in patients with PBMR1 mutation, but normal attenuated muscle area was found to be higher in PBRM1 patients.

PBRM1 bromodomains associate with RNA to facilitate chromatin association

PBRM1 is a subunit of the PBAF chromatin remodeling complex, which is mutated in 40-50% of clear cell renal cell carcinoma patients. It is thought to largely function as a chromatin binding subunit of the PBAF complex, but the molecular mechanism underlying this activity is not fully known. PBRM1 contains six tandem bromodomains which are known to cooperate in binding of nucleosomes acetylated at histone H3 lysine 14 (H3K14ac). Here, we demonstrate that the second and fourth bromodomains from PBRM1 also bind nucleic acids, selectively associating with double stranded RNA elements. Disruption of the RNA binding pocket is found to compromise PBRM1 chromatin binding and inhibit PBRM1-mediated cellular growth effects.

Significance of PBRM1 mutation in disease progress and drug selection in clear cell renal cell carcinoma

Clear cell renal cell carcinoma (ccRCC) is the predominant type of kidney cancer, and the mutation of PBRM1 (Polybromo 1) gene is a commonly observed genetic alteration. The high frequency of PBRM1 mutation in ccRCC suggests its potential use as a biomarker for personalized therapy. In this study, we aimed to investigate the significance of PBRM1 mutation in disease progression and drug sensitivity in ccRCC. Additionally, we analyzed the critical pathways and genes associated with PBRM1 mutation to understand its potential mechanisms. Our findings show that PBRM1 mutation was observed in 38% of ccRCC patients and correlated with advanced disease stages. We also identified selective inhibitors for ccRCC with PBRM1 mutation using online databases such as PD173074 and AGI-6780. Furthermore, we identified 1253 genes as differentially expressed genes (DEGs) that were significantly enriched in categories such as metabolic progression, cell proliferation, and development. Although PBRM1 mutation did not show an association with ccRCC prognosis, a lower PBRM1 expression level correlated with worsened prognosis. Our study provides insights into the association of PBRM1 mutation with disease progression in ccRCC and suggests potential gene and signaling pathways for personalized treatment in ccRCC with PBRM1 mutation.

Prognostic and predictive biomarkers for immunotherapy in advanced renal cell carcinoma

The therapeutic algorithm of renal cell carcinoma has been revolutionized by the approval of immunotherapy agents by regulatory agencies. However, objective and durable responses are still not observed in a large number of patients, and prognostic and predictive biomarkers for immunotherapy response are urgently needed. Prognostic models used in clinical practice are based on clinical and laboratory factors (such as hypercalcaemia, neutrophil count or Karnofsky Performance Status), but, with progress in molecular biology and genome sequencing techniques, new renal cell carcinoma molecular features that might improve disease course and outcomes prediction have been highlighted. An implementation of current models is needed to improve the accuracy of prognosis in the immuno-oncology era. Moreover, several potential biomarkers are currently under evaluation, but effective markers to select patients who might benefit from immunotherapy and to guide therapeutic strategies are still far from validation.

Development of genomic instability-associated long non-coding RNA signature: A prognostic risk model of clear cell renal cell carcinoma

Purpose

Renal clear cell carcinoma (ccRCC) is the most lethal of all pathological subtypes of renal cell carcinoma (RCC). Genomic instability was recently reported to be related to the occurrence and development of kidney cancer. The biological roles of long non-coding RNAs (lncRNAs) in tumorigenesis have been increasingly valued, and various lncRNAs were found to be oncogenes or cancer suppressors. Herein, we identified a novel genomic instability-associated lncRNA (GILncs) model for ccRCC patients to predict the overall survival (OS).

Methods

The Cancer Genome Atlas (TCGA) database was utilized to obtain full transcriptome data, somatic mutation profiles, and clinical characteristics. The differentially expressed lncRNAs between the genome-unstable-like group (GU) and the genome-stable-like group (GS) were defined as GILncs, with |logFC| > 1 and an adjusted p-value< 0.05 for a false discovery rate. All samples were allocated into GU-like or GS-like types based on the expression of GILncs observed using hierarchical cluster analyses. A genomic instability-associated lncRNA signature (GILncSig) was constructed using parameters of the included lncRNAs. Quantitative real-time PCR analysis was used to detect the in vitro expression of the included lncRNAs. Validation of the risk model was performed by the log-rank test, time-dependent receiver operating characteristic (ROC) curves analysis, and multivariate Cox regression analysis.

Results

Forty-six lncRNAs were identified as GILncs. LINC00460, AL139351.1, and AC156455.1 were employed for GILncSig calculation based on the results of Cox analysis. GILncSig was confirmed as an independent predictor for OS of ccRCC patients. Additionally, it presented a higher efficiency and accuracy than other RCC prognostic models reported before.

Conclusion

GILncSig score was qualified as a critical indicator, independent of other clinical factors, for prognostic prediction of ccRCC patients.

A Pan-Cancer Analysis of the Role of PBRM1 in Human Tumors

To understand common but distinctive systems to drive oncogenic stages in human tumors is critical for understanding disease programme and developing novel therapeutic strategies. PBRM1 is a critical gene in oncogenesis. We found that PBRM1 is upregulated in multiple cancer genes. Prognostic analyses indicated that higher PBRM1 showed better disease outcomes of head and neck squamous cell carcinoma (HNSC), KIRC, and UCEC, while poorer outcomes in KICH, skin cutaneous melanoma (SKCM), and esophageal carcinoma (ESCA). PBRM1 mutation was most frequent in renal cell carcinoma and showed better disease outcomes of pan-cancer. We also discovered that PBRM1 performance was associated with endothelial cell invasion status in COAD, HNSC, KIRC, LUAD, LUSC, OV, and PAAD, and cancer-related fibroblast invasion was observed in COAD, HNSC, KIRC, LUSC, MESO, OV, and PAAD. We also make the comparison of PBRM1's phosphorylation between normal and basic tumor systems as well as explore potential systems with distinctive functions in PBRM1-mediated oncogenesis. The analysis of pan-cancer offers us an outline of PBRM1's functions in various human cancers, which could promote a comprehensive understanding of PBRM1 in tumorigenesis.

Molecular characterization of renal cell carcinoma tumors from a phase III anti-angiogenic adjuvant therapy trial

Multigene assays can provide insight into key biological processes and prognostic information to guide development and selection of adjuvant cancer therapy. We report a comprehensive genomic and transcriptomic analysis of tumor samples from 171 patients at high risk for recurrent renal cell carcinoma post nephrectomy from the S-TRAC trial (NCT00375674). We identify gene expression signatures, including STRAC11 (derived from the sunitinib-treated population). The overlap in key elements captured in these gene expression signatures, which include genes representative of the tumor stroma microenvironment, regulatory T cell, and myeloid cells, suggests they are likely to be both prognostic and predictive of the anti-angiogenic effect in the adjuvant setting. These signatures also point to the identification of potential therapeutic targets for development in adjuvant renal cell carcinoma, such as MERTK and TDO2. Finally, our findings suggest that while anti-angiogenic adjuvant therapy might be important, it may not be sufficient to prevent recurrence and that other factors such as immune response and tumor environment may be of greater importance.

Based on the S-TRAC results, sunitinib is approved as adjuvant treatment for adult patients at high risk of recurrent RCC following nephrectomy. Here, the authors report the results of an integrated multi-omics tumor analysis of 171 patients from the trial and identify specific molecular subtypes as well as potential new targets.

Chromatin remodeling (SWI/SNF) complexes, cancer, and response to immunotherapy

Chromatin regulation involves four subfamilies composed of ATP-dependent multifunctional protein complexes that remodel the way DNA is packaged. The SWItch/Sucrose Non-Fermentable (SWI/SNF) chromatin remodeling complex subfamily mediates nucleosome reorganization and hence activation/repression of critical genes. The SWI/SNF complex is composed of the BRG-/BRM-associated factor and Polybromo-associated BAF complexes, which in turn have multiple subunits. Significantly, ~20% of malignancies harbor alterations in >1 of these subunits, making the genes encoding SWI/SNF family members among the most vulnerable to genomic aberrations in cancer. ARID1A is the largest subunit of the SWI/SNF complex and is altered in ~40%–50% of ovarian clear cell cancers and ~15%–30% of cholangiocarcinomas, in addition to a variety of other malignancies. Importantly, outcome was improved after immune checkpoint blockade (ICB) in patients with ARID1A-altered versuss wild-type tumors, and this result was independent of microsatellite instability or tumor mutational burden. Another subunit—PBRM1—is mutated in ~40% of clear cell renal cell carcinomas and ~12% of cholangiocarcinomas; there are contradictory reports regarding ICB responsiveness. Two other SWI/SNF subunits of interest are SMARCA4 and SMARCB1. SMARCA4 loss is the hallmark of small cell carcinoma of the ovary hypercalcemic type (and is found in a variety of other malignancies); SMARCA4 germline alterations lead to rhabdoid tumor predisposition syndrome-2; SMARCB1 germline alterations, rhabdoid tumor predisposition syndrome-1. Remarkable, although anecdotal, responses to ICB have been reported in both SMARCA4-aberrant and SMARCB1-aberrant advanced cancers. This review focuses on the role that SWI/SNF chromatin remodeling subunits play in carcinogenesis, the immune microenvironment, and in immunotherapy responsiveness.

Multiregional single-cell proteogenomic analysis of ccRCC reveals cytokine drivers of intratumor spatial heterogeneity

Intratumor heterogeneity (ITH) represents a major challenge for anticancer therapies. An integrated, multidimensional, multiregional approach dissecting ITH of the clear cell renal cell carcinoma (ccRCC) tumor microenvironment (TME) is employed at the single-cell level with mass cytometry (CyTOF), multiplex immunofluorescence (MxIF), and single-nucleus RNA sequencing (snRNA-seq) and at the bulk level with whole-exome sequencing (WES), RNA-seq, and methylation profiling. Multiregional analyses reveal unexpected conservation of immune composition within each individual patient, with profound differences among patients, presenting patient-specific tumor immune microenvironment signatures despite underlying genetic heterogeneity from clonal evolution. Spatial proteogenomic TME analysis using MxIF identifies 14 distinct cellular neighborhoods and, conversely, demonstrated architectural heterogeneity among different tumor regions. Tumor-expressed cytokines are identified as key determinants of the TME and correlate with clinical outcome. Overall, this work signifies that spatial ITH occurs in ccRCC, which may drive clinical heterogeneity and warrants further interrogation to improve patient outcomes.

The SWI/SNF chromatin remodeling factor DPF3 regulates metastasis of ccRCC by modulating TGF-β signaling

DPF3, a component of the SWI/SNF chromatin remodeling complex, has been associated with clear cell renal cell carcinoma (ccRCC) in a genome-wide association study. However, the functional role of DPF3 in ccRCC development and progression remains unknown. In this study, we demonstrate that DPF3a, the short isoform of DPF3, promotes kidney cancer cell migration both in vitro and in vivo, consistent with the clinical observation that DPF3a is significantly upregulated in ccRCC patients with metastases. Mechanistically, DPF3a specifically interacts with SNIP1, via which it forms a complex with SMAD4 and p300 histone acetyltransferase (HAT), the major transcriptional regulators of TGF-β signaling pathway. Moreover, the binding of DPF3a releases the repressive effect of SNIP1 on p300 HAT activity, leading to the increase in local histone acetylation and the activation of cell movement related genes. Overall, our findings reveal a metastasis-promoting function of DPF3, and further establish the link between SWI/SNF components and ccRCC.

The functional role of DPF3, a component of the SWI/SNF chromatin remodelling complex associated with clear cell renal cell carcinoma (ccRCC), remains unknown. Here, the authors characterise the mechanism by which DPF3 promotes metastasis via the activation of the TGF-β signalling pathway in ccRCC.

Identification and validation of an immune-related gene prognostic signature for clear cell renal carcinoma

Clear Cell Renal Carcinoma (ccRCC) accounts for nearly 80% of renal carcinoma cases, and immunotherapy plays an important role in ccRCC therapy. However, the responses to immunotherapy and overall survival for ccRCC patients are still hard to predict. Here, we constructed an immune-related predictive signature using 19 genes based on TCGA datasets. We also analyzed its relationships between disease prognosis, infiltrating immune cells, immune subtypes, mutation load, immune dysfunction, immune escape, etc. We found that our signature can distinguish immune characteristics and predict immunotherapeutic response for ccRCC patients with better prognostic prediction value than other immune scores. The expression levels of prognostic genes were determined by RT-qPCR assay. This signature may help to predict overall survival and guide the treatment for patients with ccRCC.

PBRM1 Deficiency Sensitizes Renal Cancer Cells to DNMT Inhibitor 5-Fluoro-2'-Deoxycytidine

PBRM1 is a tumor suppressor frequently mutated in clear cell renal cell carcinoma. However, no effective targeted therapies exist for ccRCC with PBRM1 loss. To identify novel therapeutic approaches to targeting PBRM1-deficient renal cancers, we employed a synthetic lethality compound screening in isogenic PBRM1+/+ and PBRM1-/- 786-O renal tumor cells and found that a DNMT inhibitor 5-Fluoro-2’-deoxycytidine (Fdcyd) selectively inhibit PBRM1-deficient tumor growth. RCC cells lacking PBRM1 show enhanced DNA damage response, which leads to sensitivity to DNA toxic drugs. Fdcyd treatment not only induces DNA damage, but also re-activated a pro-apoptotic factor XAF1 and further promotes the genotoxic stress-induced PBRM1-deficient cell death. This study shows a novel synthetic lethality interaction between PBRM1 loss and Fdcyd treatment and indicates that DNMT inhibitor represents a novel strategy for treating ccRCC with PBRM1 loss-of-function mutations.

Next-generation sequencing: unraveling genetic mechanisms that shape cancer immunotherapy efficacy

Immunity is governed by fundamental genetic processes. These processes shape the nature of immune cells and set the rules that dictate the myriad complex cellular interactions that power immune systems. Everything from the generation of T cell receptors and antibodies, control of epitope presentation, and recognition of pathogens by the immunoediting of cancer cells is, in large part, made possible by core genetic mechanisms and the cellular machinery that they encode. In the last decade, next-generation sequencing has been used to dissect the complexities of cancer immunity with potent effect. Sequencing of exomes and genomes has begun to reveal how the immune system recognizes “foreign” entities and distinguishes self from non-self, especially in the setting of cancer. High-throughput analyses of transcriptomes have revealed deep insights into how the tumor microenvironment affects immunotherapy efficacy. In this Review, we discuss how high-throughput sequencing has added to our understanding of how immune systems interact with cancer cells and how cancer immunotherapies work.

Development of a Phagocytosis-Dependent Gene Signature to Predict Prognosis and Response to Checkpoint Inhibition in Clear-Cell Renal Cell Carcinoma

Aim

The action of immune checkpoint inhibition (ICI) largely depends on antibody-dependent cellular phagocytosis (ADCP). We thus aim to develop ADCP-based ccRCC risk stratification as both prognostic and therapeutic markers of ICI.

Method

Genomic data from multiple public datasets (TCGA, etc.) were integrated. A cancer-intrinsic ADCP gene set for ccRCC tailored from a recent report was constructed based on the association with prognosis, immune infiltrates, and response to ICI. Therapeutic potential was profiled using genome-drug sensitivity datasets.

Results

ADCP genes were selected from a recent CRISPR/Cas9 screen report. Following a four-module panel based on clinical traits, we generated a six-gene signature (ARPC3, PHF19, FKBP11, MS4A14, KDELR3, and CD1C), which showed a strong correlation with advanced grade and stage and worsened prognosis, with a nomogram showing predictive efficacies of 0.911, 0.845, and 0.867 (AUC) at 1, 3, and 5 years, respectively. Signatures were further dichotomized, and groups with a higher risk score showed a positive correlation with tumor mutation burden, higher expressions of inhibitory checkpoint molecules, and increased antitumor immune infiltrates and were enriched for antitumor immune pathways. The high risk-score group showed better response to ICI and could benefit from TKIs of axitinib, tivozanib, or sorafenib, preferentially in combination, whereas sunitinib and pazopanib would better fit the low risk-score group.

Conclusion

Here we showed a six-gene ADCP signature that correlated with prognosis and immune modulation in ccRCC. The signature-based risk stratification was associated with response to both ICI and tyrosine kinase inhibition in ccRCC.

m6A Methylation Patterns and Tumor Microenvironment Infiltration Characterization in Clear-Cell Renal Cell Carcinoma

Increasing evidence suggests the essential regulation of RNA N6-methyladenosine (m6A) modification in carcinogenesis and immune response. Nevertheless, the potential impacts of these modifications on the tumor microenvironment (TME) immune cell infiltration characteristics in clear-cell renal cell carcinoma (ccRCC) remain unclear. Utilizing a consensus clustering algorithm, we determined three m6A modification patterns and identified three m6A-related gene clusters among 569 ccRCC samples, which were associated with different biological functions and clinical outcomes. Thereafter, the m6A score was constructed using m6A-associated signature genes to accurately exploit the m6A modification patterns within individual tumors. The m6A score was further demonstrated to be noticeably related to ccRCC prognosis. In addition, the m6A score was found to be strongly correlated with tumor mutational burden (TMB), microsatellite instability, immune infiltration, immune checkpoint expression, and immunotherapy response, which was also validated in the pan-cancer analyses. Our findings thoroughly elucidated that m6A modification contributes to tumor microenvironment immune-infiltrating characteristics and prognosis in ccRCC. Assessing the m6A modification patterns of individual patients with ccRCC will offer novel insights into TME infiltration and help develop more effective treatment strategies.

Radiogenomics in Clear Cell Renal Cell Carcinoma: A Review of the Current Status and Future Directions

Radiogenomics is a field of translational radiology that aims to associate a disease's radiologic phenotype with its underlying genotype, thus offering a novel class of non-invasive biomarkers with diagnostic, prognostic, and therapeutic potential. We herein review current radiogenomics literature in clear cell renal cell carcinoma (ccRCC), the most common renal malignancy. A literature review was performed by querying PubMed, Medline, Cochrane Library, Google Scholar, and Web of Science databases, identifying all relevant articles using the following search terms: "radiogenomics", "renal cell carcinoma", and "clear cell renal cell carcinoma". Articles included were limited to the English language and published between 2009-2021. Of 141 retrieved articles, 16 fit our inclusion criteria. Most studies used computed tomography (CT) images from open-source and institutional databases to extract radiomic features that were then modeled against common genomic mutations in ccRCC using a variety of machine learning algorithms. In more recent studies, we noted a shift towards the prediction of transcriptomic and/or epigenetic disease profiles, as well as downstream clinical outcomes. Radiogenomics offers a platform for the development of non-invasive biomarkers for ccRCC, with promising results in small-scale retrospective studies. However, more research is needed to identify and validate robust radiogenomic biomarkers before integration into clinical practice.

Use of immunotherapy in clinical management of genitourinary cancers - a review

Checkpoint inhibitors targeting PD-1/PD-L1 and CTLA-4 have revolutionized oncologic care delivery, including clinical management of genitourinary malignancies. Despite significant associated improvement in patient outcomes, molecular heterogeneity of tumors, variable tumor engagement with the immune response, and unique patient factors likely account for different clinical responses to immunotherapy agents. A search for predictive biomarkers of treatment response to checkpoint inhibitors is underway and several candidates, although imperfect, have been identified. Multiple checkpoint inhibitors have received approval as monotherapies or in combination with other agents in genitourinary cancers and clinical trial data continues to rapidly evolve. This review summarizes key published evidence involving use of checkpoint inhibitors in management of urothelial carcinoma, renal cell carcinoma, prostate adenocarcinoma, and penile squamous cell carcinoma. This review aims to help oncology practitioners develop an up-to-date, evidence-based approach to using these agents when managing patients with genitourinary cancers in clinical practice.

Biallelic inactivation of PBRM1 as a molecular driver in a rare pineoblastoma case: illustrative case

BACKGROUND

Pineoblastomas are a rare and aggressive pediatric neuroectodermal tumor subtype. Because of their rarity, pineoblastomas are still poorly understood, and there is little research delineating their molecular development and underlying genetic phenotype. Recent multiomic studies in pineoblastomas and pineal parenchymal tumors identified four clinically and biologically relevant consensus groups driven by signaling/processing pathways; however, molecular level alterations leading to these pathway changes are yet to be discovered, hence the importance of individually profiling every case of this rare tumor type.

OBSERVATIONS

The authors present the comprehensive somatic genomic profiling of a patient with pineoblastoma presenting with the loss of protein polybromo-1 (PBRM1) as a candidate genomic driver. Loss of PBRM1, a tumor suppressor, has been reported as a driver event in various cancer types, including renal cell carcinoma, bladder carcinoma, and meningiomas with papillary features.

LESSONS

This is the first report presenting biallelic loss of PBRM1 as a candidate molecular driver in relation to pineoblastoma.

The RBPJ/DAPK3/UBE3A signaling axis induces PBRM1 degradation to modulate the sensitivity of renal cell carcinoma to CDK4/6 inhibitors

Renal cell carcinoma (RCC) is a kind of malignant tumor originating from the renal tubular epithelium. Approximately 30% of patients with renal cancer are found to have metastasis when first diagnosed. Exploring other effective treatment methods in addition to surgery is an urgent need in the research field of renal cell carcinoma. Polybromo 1 (PBRM1) is the second most mutated gene in RCC, with a mutation rate of ~40%. Notably, the posttranscriptional modification of PBRM1 in RCC is unclear. In this study, we performed unbiased mass spectrometry of PBRM1 and identified ubiquitin-protein ligase E3A (UBE3A), an extensively studied E3 ligase that can bind with PBRM1 and regulate the stability of PBRM1 in renal cancer cells. We further found that RBPJ/DAPK3 modulated the E3 ligase activity of UBE3A by interfering with the PKA phosphorylation of UBE3A. Finally, we demonstrated that the RBPJ/DAPK3/UBE3A/PBRM1/p21 axis contributed to the sensitivity of renal cancer cells to CDK4/6 inhibitors. In addition, in combination with RBPJ inhibitors, CDK4/6 inhibitors showed synergistically enhanced effects on renal cancer cells. In summary, we not only revealed a novel RBPJ/DAPK3/UBE3A/PBRM1/p21 signaling axis but also identified a combination strategy for overcoming the resistance of renal cancer cells to CDK4/6 inhibitors.

Identification of CXCL10 as a Prognostic Biomarker for Clear Cell Renal Cell Carcinoma

Background

One of the widespread forms of kidney tumor is clear cell renal cell carcinoma (ccRCC), with poor prognosis and insensitivity to radio chemotherapy as there is limited capacity to understand the disease mechanism. This study aims at identifying potential biomarkers and the underlying processes of ccRCC using bioinformatics analysis.

Methods

Transcriptome data of relevant samples were downloaded from The Cancer Genome Atlas (TCGA) database. R software was used to screen differentially expressed genes (DEGs) using the “edgeR” package. Two types of analysis—Gene Ontology (GO) functional and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment—were accomplished by applying Database for Annotation, Visualization, and Integrated Discovery (DAVID) and Search Tool for the Retrieval of Interacting Genes database (STRING) online bioinformatics tools. A protein–protein interaction (PPI) network of the identified DEGs was constructed using Cytoscape software, and hub genes were subsequently selected via the Cytohubba plug-in. The selected genes were input into Oncomine for verification. Finally, selected hub genes were analyzed by doing survival analysis to notice the relationship between survival (OS) rate and the selected genes’ level of expression.

Results

There were 1,855 DEGs found connected to ccRCC, with 1,207 upregulated genes and 648 downregulated genes. G-protein-coupled receptor signaling pathway, integral component of membrane, calcium ion binding, and cytokine–cytokine receptor interaction were among the DEGs discovered. Oncomine confirmed the top six hub genes from the PPI network (C3, CXCR3, CXCL10, CCR5, CCL4, and CCL5). A high level of expression of CXCL10, one of these hub genes, was linked to a poor prognosis in individuals with ccRCC. The results of survival analysis showed that the expression level of CXCL10 was significantly correlated with the prognosis of ccRCC patients (p < 0.05).

Conclusions

From the analysis, the following results were drawn: CXCL10 might be a potential prognostic biomarker and novel therapeutic target for ccRCC.

First-line Immune Checkpoint Inhibitor Combinations in Metastatic Renal Cell Carcinoma: Where Are We Going, Where Have We Been?

The combination of targeted therapy and immunotherapy in the treatment of metastatic renal cell carcinoma (mRCC) has significantly improved outcomes for many patients. There are multiple FDA-approved regimens for the frontline setting based on numerous randomized Phase III trials. Despite these efforts, there remains a conundrum of identifying a biomarker-driven approach for these patients and it is unclear how to predict which patients are most likely to respond to these agents. This is due, in part, to an incomplete understanding of how these drug combinations work. The use of tyrosine kinase inhibitors that have multiple 'off-target' effects may lend themselves to the benefits observed when given in combination with immunotherapy. Further, targeting multiple clones within a patient's heterogenic tumor that are responsive to targeted therapy and others that are responsive to immunotherapy may also explain some level of improved response rates to the combination approaches compared to monotherapies. This review highlights the 5 FDA-approved regimens for mRCC in the frontline setting and offers insights into potential mechanisms for improved outcomes seen in these combination approaches.

Prognostic Factors for Localized Clear Cell Renal Cell Carcinoma and Their Application in Adjuvant Therapy

Simple Summary

Approximately one fifth of patients with newly diagnosed renal cell carcinoma (RCC) present with metastatic disease and over one third of the remaining patients with localized RCC will eventually have metastases spread to distant sites after complete resection of the primary tumor in the kidney. Usually, disease recurrence is observed within the first five years of follow-up, but late recurrences after five years are seen in up to 10% of patients. Despite novel biomarkers, simple histopathological factors, such as tumor size, tumor grade, and tumor extension into the blood vessels or beyond the kidney, are still valid features in predicting the risk of disease recurrence after surgery. The optimal set of prognostic factors remains unclear. The results from ongoing placebo-controlled adjuvant therapy trials may elucidate prognostic features that help to define high-risk patients for disease recurrence.

Abstract

Approximately 20% of patients with renal cell carcinoma (RCC) present with primarily metastatic disease and over 30% of patients with localized RCC will develop distant metastases later, after complete resection of the primary tumor. Accurate postoperative prognostic models are essential for designing personalized surveillance programs, as well as for designing adjuvant therapy and trials. Several clinical and histopathological prognostic factors have been identified and adopted into prognostic algorithms to assess the individual risk for disease recurrence after radical or partial nephrectomy. However, the prediction accuracy of current prognostic models has been studied in retrospective patient cohorts and the optimal set of prognostic features remains unclear. In addition to traditional histopathological prognostic factors, novel biomarkers, such as gene expression profiles and circulating tumor DNA, are extensively studied to supplement existing prognostic algorithms to improve their prediction accuracy. Here, we aim to give an overview of existing prognostic features and prediction models for localized postoperative clear cell RCC and discuss their role in the adjuvant therapy trials. The results of ongoing placebo-controlled adjuvant therapy trials may elucidate prognostic factors and biomarkers that help to define patients at high risk for disease recurrence.

Genomics of Clear-cell Renal Cell Carcinoma: A Systematic Review and Meta-analysis

CONTEXT

Although antiangiogenic treatments and immunotherapies have significantly improved the prognosis of metastatic renal cell carcinoma (RCC), many patients will develop resistance, leading to treatment failure. Genetic tumor heterogeneity is a major cause of this resistance.

OBJECTIVE

To perform a meta-analysis of genomic data for clear-cell RCC obtained from primary tumors and metastases to assess the prevalence of gene mutations and copy number alterations (CNAs).

EVIDENCE ACQUISITION

Articles were selected from Medline and Embase libraries using the search algorithm ("Kidney Neoplasms"[Mesh] OR "Renal Cell Carcinoma") AND ("Genomics"[Mesh] OR "Mutation") from January 1999 to February 2021. A critical review was conducted according to the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) statement. Ninety-three publications were selected for inclusion in this meta-analysis.

EVIDENCE SYNTHESIS

Our meta-analysis included a total 14 696 patients, 14 299 primary tumor samples, and 969 metastatic samples. We evaluated the overall and subgroup prevalence of gene mutations and CNAs, including comparisons between primary tumors and metastases. In particular, for metastases we observed that the mutation prevalence was significantly more marked for ten genes compared to primary tumors, with no or little heterogeneity across studies. The VHL mutation prevalence increased significantly from 64% in primary tumors to 75% in metastases (p < 0.001). There was a significant increase in CNA prevalence from primary tumors to metastases for chromosomes 1p36.11, 9p21.3, and 18 in terms of losses, and for chromosomes 1q21.3, 7q36.3, 8q, and 20q11.21 in terms of gains. CDKN2A, also called p16 and involved in cell-cycle progression, is located at the 9p21.3 locus and was lost in 76% of metastatic samples. ASXL1, located on 20p11.21 and amplified in 50% of metastatic RCCs compared to 21% of primary tumors (p < 0.001), is closely linked to BAP1 function.

CONCLUSIONS

Our results underline the added value of preferential biopsies on RCC metastases to fully explore the biology of metastatic disease for therapeutic purposes.

PATIENT SUMMARY

We reviewed the literature on genetic mutations in primary tumors and metastatic lesions in kidney cancer. Our pooled results for all the relevant studies show a higher level of mutations in metastases than in primary tumors. This highlights the importance of taking biopsies of metastases to analyze genetic mutations and potentially guide selection of the most suitable treatment strategy.

Microplastics in freshwater sediments: Analytical methods, temporal trends, and risk of associated organophosphate esters as exemplar plastics additives

It has been estimated that over 28 million tonnes of plastics end up in water bodies annually. These plastics degrade into microplastics (MPs), which along with microbeads and MPs from other sources such as wastewater treatment plants continue to threaten the aquatic system. At such small sizes, and corresponding larger surface areas per unit mass/volume, MPs exhibit enhanced capacity for absorbing and desorbing toxic chemicals/additives. Therefore, MPs can serve as vectors through which additives as well as other persistent, bio-accumulative, and toxic chemicals can enter the food chain. Additives are a significant component of most plastic products with some identified as hazardous to health and the environment. One group of additives that has continued to attract interest is organophosphate esters (OPEs), which are used both as flame retardants and plasticizers. Some of these OPEs are suspected carcinogens and endocrine disruptors and have been reported to exert serious toxic effects on freshwater biota. Separate studies on the presence and fate in the freshwater environment of these additives and MPs have emerged recently. However, no studies exist that examine the extent to which plastics additives such as OPEs in sediments are sorbed to MPs as opposed to the sediment itself. This has potentially important implications for the bioavailability of such additives and studies to examine this are recommended. This paper reviews critically the current state-of-knowledge on MPs in freshwater sediments, methods for their analysis, as well as their occurrence, temporal trends, and risks to the freshwater aquatic environment. Moreover, to facilitate the study of additives associated with MPs that have been extracted from sediments, we consider the possible effect of MP isolation methods on the determination of concentrations of associated additives like OPEs.

From Bench to Bedside: How the Tumor Microenvironment Is Impacting the Future of Immunotherapy for Renal Cell Carcinoma

Immunotherapy has revolutionized the treatment landscape for many cancer types. The treatment for renal cell carcinoma (RCC) has especially evolved in recent years, from cytokine-based immunotherapies to immune checkpoint inhibitors. Although clinical benefit from immunotherapy is limited to a subset of patients, many combination-based approaches have led to improved outcomes. The success of such approaches is a direct result of the tumor immunology knowledge accrued regarding the RCC microenvironment, which, while highly immunogenic, demonstrates many unique characteristics. Ongoing translational work has elucidated some of the mechanisms of response, as well as primary and secondary resistance, to immunotherapy. Here, we provide a comprehensive review of the RCC immunophenotype with a specific focus on how preclinical and clinical data are shaping the future of immunotherapy.

Comprehensive bioinformatics analyses of APOBECs family and identification of APOBEC3D as the unfavorable prognostic biomarker in clear cell renal cell carcinoma

Purpose: At present, how early screening for ccRCC is still a thorny issue for urologists. Probing the mechanisms underlying the development of ccRCC and finding relevant prognostic biomarkers remains crucial. Therefore, we systematically analyzed the APOBEC family in this study and identified APOBEC3D as a prognostic biomarker. Methods: In this study, based on the TCGA database, we systematically assessed the expression and prognosis of the APOBEC family and analyzed potential bioinformatic pathways. We then constructed nomograms to predict the prognosis of ccRCC patients better. Afterward, we further focused on APOBEC3D in our data on ccRCC specimens. The APOBEC3D should be extensively studied in ccRCC in the future. Results: The results showed that the APOBEC family showed the most significant changes in expression in ccRCC. The pathway enrichment analysis showed that APOBEC3 family members mainly regulated cytidine and cytosine-related processes. Subsequently, the Cox regression was used to construct prognostic signature, and validated in ICGC and GEO databases. Next, a nomogram was created integrating clinical parameters showing good predictive performance. Finally, we screened for APOBEC3D and found in our clinical sample that patients with high expression of APOBEC3D had a worse prognosis. Conclusion: Based on these results, APOBEC family members play important roles in the development of ccRCC, and APOBEC3D could serve as the biomarker for predicting patient prognosis.

SWI/SNF (BAF) complexes: From framework to a functional role in endothelial mechanotransduction

Endothelial cells (ECs) are constantly subjected to an array of mechanical cues, especially shear stress, due to their luminal placement in the blood vessels. Blood flow can regulate various aspects of endothelial biology and pathophysiology by regulating the endothelial processes at the transcriptomic, proteomic, miRNomic, metabolomics, and epigenomic levels. ECs sense, respond, and adapt to altered blood flow patterns and shear profiles by specialized mechanisms of mechanosensing and mechanotransduction, resulting in qualitative and quantitative differences in their gene expression. Chromatin-regulatory proteins can regulate transcriptional activation by modifying the organization of nucleosomes at promoters, enhancers, silencers, insulators, and locus control regions. Recent research efforts have illustrated that SWI/SNF (SWItch/Sucrose Non-Fermentable) or BRG1/BRM-associated factor (BAF) complex regulates DNA accessibility and chromatin structure. Since the discovery, the gene-regulatory mechanisms of the BAF complex associated with chromatin remodeling have been intensively studied to investigate its role in diverse disease phenotypes. Thus far, it is evident that (1) the SWI/SNF complex broadly regulates the activity of transcriptional enhancers to control lineage-specific differentiation and (2) mutations in the BAF complex proteins lead to developmental disorders and cancers. It is unclear if blood flow can modulate the activity of SWI/SNF complex to regulate EC differentiation and reprogramming. This review emphasizes the integrative role of SWI/SNF complex from a structural and functional standpoint with a special reference to cardiovascular diseases (CVDs). The review also highlights how regulation of this complex by blood flow can lead to the discovery of new therapeutic interventions for the treatment of endothelial dysfunction in vascular diseases.

Computational study of effective matrix metalloproteinase 9 (MMP9) targeting natural inhibitors

Object: The present study screened ideal lead natural compounds that could target and inhibit matrix metalloproteinase 9 (MMP9) protein from the ZINC database to develop drugs for clear cell renal cell carcinoma (CCRCC)-targeted treatment.

Methods: Discovery Studio 4.5 was used to compare and screen the ligands with the reference drug, solasodine, to identify ideal candidate compounds that could inhibit MMP9. The LibDock module was used to analyze compounds that could strongly bind to MMP9, and the top 20 compounds determined by the LibDock score were selected for further research. ADME and TOPKAT modules were used to choose the safe compounds from these 20 compounds. The selected compounds were analyzed using the CDOCKER module for molecular docking and feature mapping for pharmacophore prediction. The stability of these compound–MMP9 complexes was analyzed by molecular dynamic simulation. Cell counting kit-8, colony-forming, and scratch assays were used to analyze the anti-CCRCC effects of these ligands.

Results: Strong binding to MMP9 was exhibited by 6,762 ligands. Among the top 20 compounds, sappanol and sventenin exhibited nearly undefined blood–brain barrier level and lower aqueous solubility, carcinogenicity, and hepatotoxicity than the positive control drug, solasodine. Additionally, these compounds exhibited lower potential energies with MMP9, and the ligand–MMP9 complexes were stable in the natural environment. Furthermore, sappanol inhibited CCRCC cell migration and proliferation.

Conclusion: Sappanol and sventenin are safe and reliable compounds to target and inhibit MMP9. Sappanol can CCRCC cell migration and proliferation. These two compounds may give new thought to the targeted therapy for patients with CCRCC.

Comprehensive Genomic Landscape in Chinese Clear Cell Renal Cell Carcinoma Patients

Clear cell renal cell carcinoma (ccRCC) is the most common subtype of renal cell carcinoma (RCC). The genomic landscape in Chinese ccRCC needs to be elucidated. Herein, we investigated the molecular features of Chinese ccRCC patients. Genomic profiling of DNA was performed through next-generation sequencing (NGS) in Chinese patients with ccRCC between January 2017 and March 2020. Clinical information including age, gender, and tumor histology was collected. Immunohistochemistry (IHC) staining for PD-L1 expression was performed using PD-L1 IHC 22C3 pharmDx assay or Ventana PD-L1 SP263 assay. Data analyses were performed using R 3.6.1. A total of 880 Chinese ccRCC patients who have undergone NGS were included in this study. The most common somatic alterations were detected in VHL (59.7%), PBRM1 (18.0%), SETD2 (12.2%), BAP1 (10.2%), and TP53 (9.4%). Compared with The Cancer Genome Atlas (TCGA) database, a higher mutation frequency of VHL (59.7% vs. 50.0%, p < 0.001) and TP53 (9.4% vs. 3.5%, p < 0.001) and a lower mutation frequency of PBRM1 (18.0% vs. 31.0%, p < 0.001) were found in the Chinese cohort. Of the 460 patients who were evaluated for PD-L1 expression, 139 (30.2%) had positive PD-L1 expression. The median tumor mutational burden (TMB) value was 4.5 muts/Mb (range, 0–46.0). Five (0.7%) patients were identified as microsatellite instability-high (MSI-H). Furthermore, 52 (5.9%) patients were identified to carry pathogenic or likely pathogenic germline mutations in 22 cancer predisposition genes. This is the first large-scale comprehensive genomic analysis for Chinese ccRCC patients, and these results might provide a better understanding of molecular features in Chinese ccRCC patients, which can lead to an improvement in the personalized treatment for these patients.

Comparative Molecular Analysis of Primary Central Nervous System Lymphomas and Matched Vitreoretinal Lymphomas by Vitreous Liquid Biopsy

Primary Central Nervous System Lymphoma (PCNSL) is a lymphoid malignancy of the brain that occurs in ~1500 patients per year in the US. PCNSL can spread to the vitreous and retina, where it is known as vitreoretinal lymphoma (VRL). While confirmatory testing for diagnosis is dependent on invasive brain tissue or cerebrospinal fluid sampling, the ability to access the vitreous as a proximal biofluid for liquid biopsy to diagnose PCNSL is an attractive prospect given ease of access and minimization of risks and complications from other biopsy strategies. However, the extent to which VRL, previously considered genetically identical to PCNSL, resembles PCNSL in the same individual with respect to genetic alterations, diagnostic strategies, and precision-medicine based approaches has hitherto not been explored. Furthermore, the degree of intra-patient tumor genomic heterogeneity between the brain and vitreous sites has not been studied. In this work, we report on targeted DNA next-generation sequencing (NGS) of matched brain and vitreous samples in two patients who each harbored VRL and PCSNL. Our strategy showed enhanced sensitivity for molecular diagnosis confirmation over current clinically used vitreous liquid biopsy methods. We observed a clonal relationship between the eye and brain samples in both patients, which carried clonal CDKN2A deep deletions, a highly recurrent alteration in VRL patients, as well as MYD88 p.L265P activating mutation in one patient. Several subclonal alterations, however, in the genes SETD2, BRCA2, TERT, and broad chromosomal regions showed heterogeneity between the brain and the eyes, between the two eyes, and among different regions of the PCNSL brain lesion. Taken together, our data show that NGS of vitreous liquid biopsies in PCNSL patients with VRL highlights shared and distinct genetic alterations that suggest a common origin for these lymphomas, but with additional site-specific alterations. Liquid biopsy of VRL accurately replicates the findings for PCNSL truncal (tumor-initiating) genomic alterations; it can also nominate precision medicine interventions and shows intra-patient heterogeneity in subclonal alterations. To the best of our knowledge, this study represents the first interrogation of genetic underpinnings of PCNSL with matched VRL samples. Our findings support continued investigation into the utility of vitreous liquid biopsy in precision diagnosis and treatment of PCNSL/VRL.

Genomic analysis uncovers prognostic and immunogenic characteristics of ferroptosis for clear cell renal cell carcinoma

In this study, the characteristic patterns of ferroptosis in clear cell renal cell carcinoma (ccRCC) were systematically investigated with the interactions between ferroptosis and the tumor microenvironment (TME). On the mRNA expression profiles of 57 ferroptosis-related genes (FRGs), three ferroptosis patterns were constructed, with distinct prognosis and immune cell infiltrations (especially T cells and dendritic cells). The high ferroptosis scores were characterized by poorer prognosis, increased T cell infiltration, higher immune and stromal scores, elevated tumor mutation burden, and enhanced response to anti-CTLA4 immunotherapy. Meanwhile, the low ferroptosis scores were distinctly associated with enhanced tumor purity and amino acid and fatty acid metabolism pathways. Following validation, the ferroptosis score was an independent and effective prognostic factor. Collectively, ferroptosis could be involved in the diverse and complex TME. Evaluation of the ferroptosis patterns may heighten the comprehension about immune infiltrations in the TME, assisting oncologists to generate individualized immunotherapeutic strategies.

Mutational Analysis of PBRM1 and Significance of PBRM1 Mutation in Anti-PD-1 Immunotherapy of Clear Cell Renal Cell Carcinoma

Renal cell carcinoma is a common solid tumor. PBRM1 is one of the most mutation-prone genes in clear cell renal cell carcinoma (ccRCC) with the occurrence of mutation in 40% of ccRCC patients. Mutations in PBRM1 have been correlated with the efficacy of immunotherapy. However, the mutation types of PBRM1 are not well characterized. The effects of PBRM1 expression levels in the tumor microenvironment are not well studied. In addition, the mechanism and effect of anti-PD-1 immunotherapy in ccRCC tumor microenvironments are not well clarified. In this study, using bioinformatics methods we analyzed the alternation frequency and expression levels of PBRM1 in various tumors. Next, we experimentally validated their expression levels in ccRCC tissues from human and mouse models. We attempted to clarify the mechanisms of anti-PD-1 immunotherapy in ccRCC with various PBRM1 expression levels. Our results showed that deficiency of PBRM1 protein is correlated with CD4 T cell reduction in human and mouse ccRCC tissues. We also showed that anti-PD-1 Immunotherapy can increase the infiltration of T cells in both PBRM1 high and PBRM1 low tumors but to different degrees. Our study indicates that the reduction of CD4 cells in tumor tissues with low expression of PBRM1 may explain the compromised efficacy of anti-PD-1 immunotherapy in patients with PBRM1 mutated ccRCC. Our study sheds light on the potential of PBRM1 as a therapeutic target in ccRCC.

Down-regulation of BCL2L13 renders poor prognosis in clear cell and papillary renal cell carcinoma

Background

BCL2L13 belongs to the BCL2 super family, with its protein product exhibits capacity of apoptosis-mediating in diversified cell lines. Previous studies have shown that BCL2L13 has functional consequence in several tumor types, including ALL and GBM, however, its function in kidney cancer remains as yet unclearly.

Methods

Multiple web-based portals were employed to analyze the effect of BCL2L13 in kidney cancer using the data from TCGA database. Functional enrichment analysis and hubs of BCL2L13 co-expressed genes in clear cell renal cell carcinoma (ccRCC) and papillary renal cell carcinoma (pRCC) were carried out on Cytoscape. Evaluation of BCL2L13 protein level was accomplished through immunohistochemistry on paraffin embedded renal cancer tissue sections. Western blotting and flow cytometry were implemented to further analyze the pro-apoptotic function of BCL2L13 in ccRCC cell line 786-0.

Results

BCL2L13 expression is significantly decreased in ccRCC and pRCC patients, however, mutations and copy number alterations are rarely observed. The poor prognosis of ccRCC that derived from down-regulated BCL2L13 is independent of patients’ gender or tumor grade. Furthermore, BCL2L13 only weakly correlates with the genes that mutated in kidney cancer or the genes that associated with inherited kidney cancer predisposing syndrome, while actively correlates with SLC25A4. As a downstream effector of BCL2L13 in its pro-apoptotic pathway, SLC25A4 is found as one of the hub genes that involved in the physiological function of BCL2L13 in kidney cancer tissues.

Conclusions

Down-regulation of BCL2L13 renders poor prognosis in ccRCC and pRCC. This disadvantageous factor is independent of any well-known kidney cancer related genes, so BCL2L13 can be used as an effective indicator for prognostic evaluation of renal cell carcinoma.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-021-02039-y.

Characterization of Hypoxia-Related Molecular Subtypes in Clear Cell Renal Cell Carcinoma to Aid Immunotherapy and Targeted Therapy via Multi-Omics Analysis

Objective: Tumor hypoxia is a key factor in resistance to anti-cancer treatment. Herein, this study aimed to characterize hypoxia-related molecular subtypes and assess their correlations with immunotherapy and targeted therapy in clear cell renal cell carcinoma (ccRCC). Materials: We comprehensively analyzed copy number variation (CNV), somatic mutation, transcriptome expression profile and clinical information for ccRCC from TCGA and ICGC databases. Based on 98 prognosis-related hypoxia genes, samples were clustered using unsupervized non-negative matrix factorization (NMF) analysis. We characterized the differences between subtypes concerning prognosis, CNV, somatic mutations, pathways, immune cell infiltrations, stromal/immune scores, tumor purity, immune checkpoint inhibitors (ICI), response to immunotherapy and targeted therapy and CXC chemokines. Based on differentially expressed genes (DEGs) between subtypes, a prognostic signature was built by LASSO Cox regression analysis, followed by construction of a nomogram incorporating the signature and clinical features. Results: Two hypoxia-related molecular subtypes (C1 and C2) were constructed for ccRCC. Differential CNV, somatic mutations and pathways were found between subtypes. C2 exhibited poorer prognosis, higher immune/stromal scores, and lower tumor purity than C1. Furthermore, C2 had more sensitivity to immunotherapy and targeted therapy than C1. The levels of CXCL1/2/3/5/6/8 chemokines in C2 were distinctly higher than in C1. Consistently, DEGs between subtypes were significantly enriched in cytokine-cytokine receptor interaction and immune responses. This subtype-specific signature can independently predict patients' prognosis. Following verification, the nomogram could be utilized for personalized prediction of the survival probability. Conclusion: Our findings characterized two hypoxia-related molecular subtypes for ccRCC, which can assist in identifying high-risk patients with poor clinical outcomes and patients who can benefit from immunotherapy or targeted therapy.

A cytoskeletal function for PBRM1 reading methylated microtubules

Epigenetic effectors "read" marks "written" on chromatin to regulate function and fidelity of the genome. Here, we show that this coordinated read-write activity of the epigenetic machinery extends to the cytoskeleton, with PBRM1 in the PBAF chromatin remodeling complex reading microtubule methyl marks written by the SETD2 histone methyltransferase. PBRM1 binds SETD2 methyl marks via BAH domains, recruiting PBAF components to the mitotic spindle. This read-write activity was required for normal mitosis: Loss of SETD2 methylation or pathogenic BAH domain mutations disrupt PBRM1 microtubule binding and PBAF recruitment and cause genomic instability. These data reveal PBRM1 functions beyond chromatin remodeling with domains that allow it to integrate chromatin and cytoskeletal activity via its acetyl-binding BD and methyl-binding BAH domains, respectively. Conserved coordinated activity of the epigenetic machinery on the cytoskeleton opens a previously unknown window into how chromatin remodeler defects can drive disease via both epigenetic and cytoskeletal dysfunction.

Biomarkers in renal cell carcinoma: Towards a more selective immune checkpoint inhibition

•

Multiple prognostic markers are capable of predicting prognosis in mRCC.

•

Biomarkers capable of predicting immune treatment efficacy in mRCC are needed.

•

TIM-3 can have both a prognostic and predictive value.

•

Integrating biomarkers to the trials of combination therapies is essential.

Immune checkpoint inhibitors such as programmed death protein 1/programmed death-ligand 1 and cytotoxic T-lymphocyte–associated protein 4 inhibitors are already playing a central role in the treatment of metastatic renal cell carcinoma. However, they seem to be only effective in a subset of patients, with a high risk of innate and adaptive tumor resistance. Consequently, biomarkers capable of predicting immune treatment efficacy in advanced renal cancer are needed both in the clinical and the experimental setting. We hereby present a brief summary of evidence on the most studied biomarkers in metastatic renal cell carcinoma with a focus on the possible future place of T cell immunoglobulin and mucin domain-3 (TIM-3).

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

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

Comprehensive analyses of PBRM1 in multiple cancer types and its association with clinical response to immunotherapy and immune infiltrates

Background

The prognostic value of polybromo 1 (PBRM1) gene mutations in clear cell renal carcinoma (CCRCC) with anti-programmed death-ligand 1 (PD-L1) therapy remains controversial, and few studies have reported the impact of PBRM1 mutations in other cancer types.

Methods

The patient information was obtained from cBioPortal and the Tumor Immune Estimation Resource (TIMER) databases. Mann-Whitney U test were used for correlation analysis. For survival analyses, Kaplan-Meier survival curves were used and compared using the log-rank test. Cox’s regression model was used to perform univariable and multivariable analyses

Results

Our study, for the first time, performed comprehensive analyses of PBRM1 mutation frequency, PBRM1 expression, relationship of PBRM1 mutations with clinical benefit from immunotherapy, and PBRM1 expression with immune infiltrates in diverse cancer types. The results showed that the expression of PBRM1 was significantly lower in diverse cancer types compared with normal tissues. Based on multivariable analysis, PBRM1 mutations trended towards worse clinical outcomes from anti-PD-L1 in CCRCC, lung adenocarcinoma (LUAD), bladder urothelial carcinoma (BLCA), and skin cutaneous melanoma (SKCM), and a significant association was observed in LUAD and BLCA. PBRM1 mutations were associated with higher TMB in diverse cancer types and significant associations were observed in LUAD and BLCA. The expression of PBRM1 was found to positively correlate with immune infiltrates in diverse cancer types.

Conclusions

Our findings suggested caution in starting immunotherapy alone in PBRM1 mutant patients. Further studies are needed to improve treatment for PBRM1 mutant patients.

The Clinical Significance of DNA Damage Repair Signatures in Clear Cell Renal Cell Carcinoma

DNA damage repair plays an important role in cancer’s initiation and progression, and in therapeutic resistance. The prognostic potential of damage repair indicators was studied in the case of clear cell renal cell carcinoma (ccRCC). Gene expression profiles of the disease were downloaded from cancer genome databases and gene ontology was applied to the DNA repair-related genes. Twenty-six differentially expressed DNA repair genes were identified, and regression analysis was used to identify those with prognostic potential and to construct a risk model. The model accurately predicted patient outcomes and distinguished among patients with different expression levels of immune evasion genes. The data indicate that DNA repair genes can be valuable for predicting the progression of clear cell renal cell carcinoma and the clinical benefits of immunotherapy.