Exome sequencing identifies frequent mutation of the SWI/SNF complex gene PBRM1 in renal carcinoma

Deciphering the interplay between SETD2 mediated H3K36me3 and RNA N6-methyladenosine in clear cell renal cell carcinoma (ccRCC)

RNA N6-methyladenosine (m6A) plays diverse roles in RNA metabolism and its deregulation contributes to tumor initiation and progression. Clear cell renal cell carcinoma (ccRCC) is characterized by near ubiquitous loss of VHL followed by mutations in epigenetic regulators PBRM1, SETD2, and BAP1. Mutations in SETD2, a histone H3 lysine 36 trimethylase (H3K36me3), are associated with reduced survival, greater metastatic propensity, and metabolic reprogramming. While m6A and H3K36me3 deregulation are separately implicated in renal tumorigenesis, H3K36me3 may participate directly in m6A targeting, but the m6A-H3K36me3 interplay has not been investigated in the context of ccRCC. Using RCC-relevant SETD2 isogenic knockout and rescue cell line models, we demonstrate a dynamic redistribution of m6A in the SETD2 depleted transcriptome, with a subset of transcripts involved in metabolic reprogramming demonstrating SETD2 dependent m6A and expression level changes. Using a panel of six histone modifications we show that m6A redistributes to regions enriched in gained active enhancers upon SETD2 inactivation. Finally, we demonstrate a reversal of transcriptomic programs involved in SETD2 loss mediated metabolic reprogramming, and reduced cell viability through pharmacologic inhibition or genetic ablation of m6A writer METTL3 specific to SETD2 deficient cells. Thus, targeting m6A may represent a novel therapeutic vulnerability in SETD2 mutant ccRCC.

Prediction tools for assessing functional impacts of gene mutations in Clear Cell Renal Cell Carcinoma: A comparative study

Renal cell carcinoma (RCC) is a well-known malignancy characterized by specific gene mutations that elevate its occurrence. It can be categorized into clear cell RCC (ccRCC), papillary RCC, and chromophobe RCC, which account for approximately 85 % of all primary RCC cases. The mutations typically involve single-nucleotide variants (SNVs) that lead to amino acid substitutions, which influence various biological functions, including gene expression. Therefore, predicting the functional consequences of RCC-related single-nucleotide polymorphisms (SNPs), including substitutions, insertions, deletions, and duplications, is crucial for the effective clinical management of RCC. In recent years, the accessibility and popularity of tools for predicting SNP functional variations have grown, especially in research concerning the potential risks associated with key gene mutations in cancer. Accordingly, this study focused on commonly mutated genes in ccRCC, namely VHL, BAP1, PBRM1, and SETD2. Public data from sources such as The Cancer Genome Atlas and the National Center for Biotechnology Information were used to identify 61 gene mutation positions. Nine nonsynonymous mutation prediction tools were used for analysis, namely SIFT, Polyphen-2, Mutation Assessor, Fathmm, MutPred, CHASM, Revel, Provean, and SNP&GO. The tools were evaluated by their statistical performance, prediction distribution, and receiver operating characteristic curves. The three tools with the highest accuracy for predicting the functional consequences of mutations in the four frequently mutated genes associated with ccRCC were SIFT (accuracy of 0.75), Provean (0.7), and Polyphen-2 (0.69). These findings offer valuable insights into predicting ccRCC-related gene mutation effects, but further research and validation are essential to support their clinical applications.

Disclosing the development and focus of sequencing and omics studies in kidney neoplasm research

BACKGROUND

Kidney cancer is a worldwide prevalent urological malignancy and the leading cause of death. Sequencing and omics studies play a crucial role in unraveling its molecular mechanisms and diagnostic, prognostic, and therapeutic relevance. This study aims to offer a comprehensive review of the evolving trends and hotspots of sequencing and omics studies in kidney neoplasms.

METHODS

We conducted the retrieval of scientific publications on sequencing and omics studies in kidney neoplasms from the Web of Science Core Collection (WoSCC) on July 3, 2023. The R-based bibliometrix package, VOSviewer, and CiteSpace were utilized to conduct the holistic bibliometric analysis to obtain objective and data-driven results. A comprehensive consultation of papers was then proceeded for an in-depth review.

RESULTS

Our investigation yielded a dataset containing 1260 records from 509 sources, with 43,404 references, from 1960 to 2023. Publication and citation frequencies have been consistently growing. In country analysis, China and the USA led the research, displaying substantial collaboration. Notable contributors like TEH BT, SAUTER G, and FUTREAL PA shaped this research landscape. Key journals such as PLoS One, Cancer Research, and New England Journal of Medicine actively participated in and significantly influenced this field. Distinguished publications and references were also revealed, along with their historical citation and co-citation relationships. A panel of keywords, including RCC, biomarker, and multi-omics data were identified and clustered.

CONCLUSION

We obtained a profound understanding of the developing trends and hotspots of research investigating sequencing and omics studies in kidney neoplasms. Specifically, we have highlighted three hotspots: "explore molecular mechanisms of RCC pathogenesis, progression, and metastasis", "identify molecular biomarkers of RCC for diagnosis, prognosis, and therapeutics", "investigate tumor heterogeneity and tailor personalized therapeutic strategies for RCC". Hopefully, our study will serve as a valuable reference for scientific researchers and clinical practitioners.

Multiomics in Renal Cell Carcinoma: Current Landscape and Future Directions for Precision Medicine

PURPOSE OF REVIEW

Renal cell carcinoma (RCC) is a prevalent and increasingly diagnosed malignancy associated with high mortality and recurrence rates. Traditional diagnostic and therapeutic approaches have limitations due to the disease's molecular heterogeneity. This review aims to explore how the integration of omics sciences-genomics, transcriptomics, proteomics, and metabolomics-can enhance the diagnosis, prognosis, and treatment of RCC.

RECENT FINDINGS

Genomic analyses have uncovered critical mutations, including VHL, PBRM1, and BAP1, which support improved risk stratification and the development of targeted therapies. Transcriptomic and spatial transcriptomic studies have provided deeper insights into RCC heterogeneity and tumor microenvironment dynamics. Proteomic investigations have revealed potential biomarkers, while metabolomic approaches have highlighted RCC-specific metabolic shifts. Despite these advancements, several challenges persist, including intratumoral heterogeneity, difficulties in multi-omics data integration, and the limited clinical validation of biomarkers. Omics-driven approaches hold significant promise for advancing precision medicine in RCC. These technologies can facilitate earlier diagnosis, guide individualized therapies, and enhance prognostic evaluations. Future research must focus on validating multi-omic biomarkers and leveraging artificial intelligence to manage complex datasets, thereby supporting more informed clinical decision-making and personalized treatment strategies.

Genomic profiling of urological malignancies using tissue-based next generation sequencing

Advances in understanding genomic drivers of human malignancies have evolved from morphologic evaluations to in-depth DNA and RNA analyses and gene expression profiling. In urologic malignancies, these molecular diagnostics are integral to patient management, aiding pathological diagnosis, providing prognostic and predictive relevance, and identifying therapeutic options for advanced diseases. For instance, renal cell carcinoma frequently harbors alterations in VHL, PBRM1, and BAP1, influencing therapeutic responses, while urothelial carcinoma is characterized by FGFR3 mutations and TERT promoter alterations, which have implications for targeted therapy. Prostate cancer commonly involves TMPRSS2-ERG fusions and BRCA2 mutations, affecting treatment strategies, and penile squamous cell carcinoma follows distinct HPV-dependent and HPV-independent pathways, with mutations in TP53 and CDKN2A genes. These advances in molecular pathology have deepened our understanding of these complex diseases and facilitated the introduction of novel targeted therapies. While these advances promise improved diagnosis, prognosis, and treatment options, many questions remain regarding the variable patient responses within the same histologic types. Addressing these will enable optimal management strategies and the development of personalized treatments targeting specific molecular alterations to improve patient outcomes.

Discovery of Novel, Potent, and Orally Bioavailable SMARCA2 Proteolysis-Targeting Chimeras with Synergistic Antitumor Activity in Combination with Kirsten Rat Sarcoma Viral Oncogene Homologue G12C Inhibitors

Cancer genomic studies have identified frequent mutations in subunits of the SWI/SNF chromatin remodeling complex, including SMARCA4 in nonsmall cell lung cancer with a frequency of up to 33% in advanced-stage disease, making it the most frequently mutated complex. We and others have identified SMARCA2 to be synthetic lethal to SMARCA4, indicating that SMARCA2 is a high-value therapeutic target. Here, we disclose the discovery and characterization of potent, selective, and orally bioavailable cereblon-based SMARCA2 PROTACs. Biochemically, we showed that YDR1 and YD54 are potent SMARCA2 degraders. Further, we showed the antitumor growth inhibitory activity of YDR1 and YD54 in SMARCA4 mutant xenografts. Finally, we show that YDR1 and YD54 synergize with the KRAS G12C inhibitor sotorasib to inhibit the growth of SMARCA4 and KRAS G12C comutant lung cancer cells. These findings provide evidence for the utility of single agent or combination regimens containing SMARCA2 PROTACs as synthetic lethal therapeutics against SMARCA4 mutant cancers.

Liquid Biopsy as a New Tool for Diagnosis and Monitoring in Renal Cell Carcinoma

Renal cell carcinoma (RCC) presents a significant diagnostic challenge, particularly in small renal masses. The search for non-invasive screening methods and biomarkers has directed research toward liquid biopsy, which focuses on microRNAs (miRNAs), exosomes, and circulating tumor cells (CTCs). miRNAs are small non-coding RNA molecules that show considerable dysregulation in RCC, and they have potential for both diagnostic and prognostic applications. Research has highlighted their utility on biofluids, such as plasma, serum, and urine, in detecting RCC and characterizing its subtypes. Promising miRNA signatures have been associated with overall survival, suggesting their potential importance in the management of RCC. Exosomes, which carry a variety of molecular components, including miRNAs, are emerging as valuable biomarkers, whereas CTCs, released from primary tumors into the bloodstream, provide critical information on cancer progression. However, translation of these findings into clinical practice requires additional validation and standardization through large-scale studies and robust evidence. Although there are currently no approved diagnostic tests for RCC, the future potential of liquid biopsy in monitoring, treatment decision-making, and outcome prediction in patients with this disease is significant. This review examined and discussed recent developments in liquid biopsy for RCC, assessing both the strengths and limitations of these approaches for managing this disease.

Molecular landscape of clear cell renal cell carcinoma: targeting the Wnt/β-catenin signaling pathway

Clear cell renal cell carcinoma (ccRCC) is the most common subtype of renal cell carcinoma and is characterized by a complex molecular landscape driven by genetic and epigenetic alternations. Among the crucial signaling pathways implicated in ccRCC, the Wnt/β-catenin pathway plays a significant role in tumor progression and prognosis. This review delves into the molecular basis of ccRCC, highlighting the genetic and epigenetic modifications that contribute to its pathogenesis. We explore the significance of the Wnt/β-catenin pathway, focusing on its role in disease development, particularly the nuclear transport of β-catenin and its activation and downstream effects. Furthermore, we examine the role of antagonist genes in regulating this pathway within the context of ccRCC, providing insights into potential therapeutic targets. Dysregulation of this pathway, which is characterized by abnormal activation and nuclear translocation of β-catenin, plays a significant role in promoting tumor growth and metastasis. We explore the intricate molecular aspects of ccRCC, with a particular emphasis on this topic, underscoring the role of the pathway and emphasizing the importance and relevance of antagonist genes. Understanding the intricate interplay between these molecular mechanisms is crucial for developing innovative strategies to improve ccRCC treatment and patient outcomes.

Prevailing challenges in personalized treatment for metastatic renal cell carcinoma: a narrative review

INTRODUCTION

The management of metastatic renal cell carcinoma (mRCC) has advanced with recent therapies, yet optimizing treatment remains challenging due to disease heterogeneity and the growing number of options. Integrating systemic and local treatments requires a multidisciplinary approach to improve outcomes.

AREA COVERED

This review summarizes recent developments in treatment for mRCC. Upfront immuno-oncology (IO)-based combinations have improved survival, though concerns about overtreatment and toxicity persist. While the role of cytoreductive nephrectomy (CN) has declined to some extent, it may still benefit well-selected patients. Metastasis-directed therapies, including metastasectomy and stereotactic radiotherapy, provide prognostic value, particularly for oligometastatic lesions or brain metastases. Comprehensive genomic profiling (CGP) holds promise for personalized treatment but is currently limited by the lack of actionable mutations and predictive biomarkers.

EXPERT OPINION

A personalized, multimodal approach is essential for optimizing mRCC management. Careful patient selection is key to balancing the benefits of treatment with the risks of toxicity. While CN and metastasis-directed therapies remain useful in select cases, advancing individualized care requires the development of validated biomarkers and broader application of CGP.

Prognostic impact and landscape of cellular CXCR5 chemokine receptor expression in clear-cell renal cell carcinoma

CXCR5 is a chemokine receptor that promotes B cell follicular formation and antibody production. Indeed, CXCR5 has been found to be expressed in a variety of cancers; however, the role of CXCR5 expression in clear-cell renal cell carcinoma (ccRCC) remains unclear. We aimed to determine the impact of cellular CXCR5 expression on cancer outcomes, the PD-1/PD-L1 axis, and genetic states in patients with ccRCC. First, multiplex immunofluorescence staining for CXCR5, CD4, CD8, and AE1/AE3, along with automated single-cell counting, was performed to assess cellular CXCR5 expression in ccRCC and its association with prognosis. Second, the tumour microenvironment (TME) was analysed, with a focus on the relationship between the PD-1/PD-L1 axis and CXCR5 expression. Finally, an integrated analysis of CXCR5 expression and genomic mutation information was conducted to reveal the genetic background underlying CXCR5 expression. A total of 105 ccRCC patients were included. Among the 696,964 cells analysed, the distribution of CXCR5-expressing cells was as follows: 30% CXCR5+CD4+ cells, 9% CXCR5+CD8+ cells, and 26% CXCR5+AE1/AE3+ cells. Survival analysis revealed that tumours with low-CXCR5+CD8+ cells had a poor prognosis; TME analysis revealed a relationship between low-CXCR5+CD8+ status and a highly suppressive PD-L1-positive immune environment. Genomic analysis revealed a correlation between low-CXCR5+CD8+ status and high rates of alterations in chromatin remodelling genes, including PBRM1. This study highlights the significance of CXCR5+CD8+ cells in ccRCC, demonstrating their clinical implications and revealing the immunogenomic landscape underlying CXCR5 expression.

Nanosize Non-Viral Gene Therapy Reverses Senescence Reprograming Driven by PBRM1 Deficiency to Suppress iCCA Progression

Polybromo-1 (PBRM1) serves as a crucial regulator of gene transcription in various tumors, including intrahepatic cholangiocarcinoma (iCCA). However, the exact role of PBRM1 in iCCA and the mechanism by which it regulates downstream target genes remain unclear. This research has revealed that PBRM1 is significantly downregulated in iCCA tissues, and this reduced expression is linked to aggressive clinicopathological features and a poor prognosis. Furthermore, it is demonstrated that PBRM1 can impede iCCA progression, and a gene therapy nanomedicine is developed to treat iCCA in vivo by modulating PBRM1 expression. The heightened expression of PBRM1 induces by the nanomedicine substantially inhibited tumor growth in iCCA. Conversely, the decrease in PBRM1 results in the abnormal activation of the ERK1/2 signaling pathway, a reduction in p16, p53/p21, and cellular senescence, thereby promoting iCCA advancement. Treatment with U0126, an ERK1/2 inhibitor, effectively halted iCCA progression by regulating the PBRM1-ERK1/2-cellular senescence pathway. These findings underscore the significant role of PBRM1 in controlling iCCA progression and predicting prognosis. Targeting the PBRM1-ERK1/2-cellular senescence pathway with U0126 shows promise for clinical applications in treating iCCA.

Clear cell renal carcinoma essentially requires CDKL3 for oncogenesis

Clear cell renal cell carcinoma (ccRCC) is the predominant human renal cancer with surging incidence and fatality lately. Hyperactivation of hypoxia-inducible factor (HIF) and mammalian target of rapamycin (mTOR) signaling are the common signatures in ccRCC. Herein, we employed spontaneous ccRCC model to demonstrate the indispensability of an underappreciated Ser/Thr kinase, CDKL3, in the initiation and progression of ccRCC. Ablation of CDKL3 does not affect normal kidney, but abrogates Akt-mTOR hyperactivity and thoroughly prevents the formation and growth of the HIF-agitated ccRCC in vivo. Remarkable clinical correlations also supported the oncogenic role of CDKL3. Mechanism-wise, cytosolic CDKL3 unexpectedly behaves as the adaptor to physically potentiate mTORC2-dependent Akt activation without functioning through kinase activity. And mTORC2 can phosphorylate and stabilize CDKL3 to form a positive feedback loop to sustain the cancer-favored Akt-mTOR overactivation. Together, we revealed the pathological importance and molecular mechanism of CDKL3-mediated Akt-mTOR axis in ccRCC initiation and progression.

CDC20-Mediated Selective Autophagy Degradation of PBRM1 Affects Immunotherapy for Renal Cell Carcinoma

Polybromo 1 (PBRM1) inactivating mutations are associated with clinical benefit from immune checkpoint inhibitor treatments in clear cell renal cell carcinoma (ccRCC). However, whether targeting PBRM1 has the potential to enhance immunotherapy efficacy in patients with wild-type PBRM1 and the upstream pathways that regulate PBRM1 protein stability remain unclear. Here, it is demonstrated that PBRM1 knockdown induced M1 macrophage polarization and infiltration, which enhanced the efficacy of anti-PD-1 immunotherapy in RCC. Meanwhile, CDC20 catalyzes K27 ubiquitination of PBRM1 and promotes its degradation via p62-mediated selective autophagy. A bicyclic peptide (PB1-p62) is designed and constructed to target PBRM1 and p62, thereby promoting the degradation of PBRM1. As a result, the efficacy of anti-PD-1 immunotherapy is enhanced, leading to improved overall survival rates in syngeneic mouse tumor models. Overall, this finding suggest the clinical application of PB1-p62 and provide a novel approach for enhancing the effectiveness of immunotherapy in RCC patients with wild-type PBRM1.

Kidney cancer: From tumor biology to innovative therapeutics

Renal cell carcinoma (RCC) constitutes the most frequent kidney cancer of the adult population and one of the most lethal malignant tumors worldwide. RCC often presents without early symptoms, leading to late diagnosis. Prognosis varies widely based on the stage of cancer at diagnosis. In the early-stage, localized RCC has a relatively good prognosis, while advanced or metastatic RCC has a poor outcome. Obesity, smoking, genetic mutations and family history are all considered risk factors for RCC, while inherited disorders, such as Tuberous Sclerosis and von Hippel-Lindau syndrome, are causally associated with RCC development. Genetic screening, deep sequencing analysis, quantitative proteomics and immunostaining analysis on RCC tissues, biological fluids and blood samples have been employed to identify novel biomarkers, predisposing factors and therapeutic targets for RCC with important clinical implications for patient treatment. Combined approaches of gene-targeting strategies coupled to a deep functional analysis of cancer cell biology, both in vitro and in appropriate animal models of RCC, significantly contributed to identify and characterize relevant pathogenic mechanisms underlying development and progression of RCC. These studies provided also important cues for the generation of novel target-specific therapeutics that selectively restore deranged cancer cell signalling and dysfunctional immune checkpoints, positively impacting on the survival rate of treated RCC patients. In this review, we will describe the recent discoveries concerning the most relevant pathogenic mechanisms of RCC and will highlight novel therapeutic strategies that interrupt oncogenic pathways and restore immune defences in RCC patients.

USP7 facilitates deubiquitination of LRRC42 in colorectal cancer to accelerate tumorigenesis and augment Wnt/β-catenin signaling

Colorectal cancer is a prevalent malignancy with an increasing incidence worldwide. Leucine-rich repeat-containing protein 42 (LRRC42) is known to be dysregulated in tumor tissues, yet its role in colorectal cancer remains largely unexplored. Herein, the function of LRRC42 in colorectal cancer was investigated using clinical samples, cellular experiments, animal models, and multiple omics techniques. The results demonstrated that LRRC42 was highly expressed in colorectal cancer tissues and was associated with poor clinical outcomes. Silencing LRRC42 suppressed cell proliferation, induced G0/G1 phase arrest, and promoted apoptosis by reducing Bcl2 expression while elevating the expression of Bax, cleaved PARP and cleaved caspase 3. Conversely, LRRC42 overexpression exhibited the opposite effects. Consistent findings were observed in vivo. Additionally, ubiquitin specific peptidase 7 was identified as a potential LRRC42-interacting protein through immunoprecipitation-mass spectrometry, with ubiquitin specific peptidase 7 stabilizing LRRC42 expression by promoting its deubiquitination. Notably, LRRC42 overexpression partially reversed the effects of ubiquitin specific peptidase 7 silencing on tumor cell proliferation and apoptosis. mRNA sequencing analysis revealed that differentially expressed genes in LRRC42 overexpressing cells were linked to Wnt signaling pathway, suggesting that LRRC42 overexpression may activate this pathway. Furthermore, LRRC42 was proved to elevate the levels of ki67, cyclin D1 and WNT3, while reducing the level of p-β-catenin. These findings suggest that LRRC42 perhaps serve as a potential oncogenic factor in colorectal cancer, regulated by ubiquitin specific peptidase 7 and capable of activating Wnt/β-catenin signaling pathway.

Enhancer reprogramming underlies therapeutic utility of a SMARCA2 degrader in SMARCA4 mutant cancer

Genomic studies have identified frequent mutations in subunits of the SWI/SNF (switch/sucrose non-fermenting) chromatin remodeling complex including SMARCA4 and ARID1A in non-small cell lung cancer (NSCLC). Genetic evidence indicates that the paralog SMARCA2 is synthetic lethal to SMARCA4 suggesting SMARCA2 is a valuable therapeutic target. However, the discovery of selective inhibitors of SMARCA2 has been challenging. Here, we utilized structure-activity relationship (SAR) studies to develop YD23, a potent and selective proteolysis targeting chimera (PROTAC) targeting SMARCA2. Mechanistically, we show that SMARCA2 degradation induces reprogramming of the enhancer landscape in SMARCA4-mutant cells with loss of chromatin accessibility at enhancers of genes involved in cell proliferation. Furthermore, we identified YAP/TEADas key partners to SMARCA2 in driving growth of SMARCA4-mutant cells. Finally, we show that YD23 has potent tumor growth inhibitory activity in SMARCA4-mutant xenografts. These findings provide the mechanistic basis for development of SMARCA2 degraders as synthetic lethal therapeutics against SMARCA4-mutant lung cancers.

ARID2 Deficiency Enhances Tumor Progression via ERBB3 Signaling in TFE3-Rearranged Renal Cell Carcinoma

TFE3-rearranged Renal Cell Carcinoma (TFE3-RCC) is an aggressive subtype of RCC characterized by Xp11.2 rearrangement, leading to TFE3 fusion proteins with oncogenic potential. Despite advances in understanding its molecular biology, effective therapies for advanced cases remain elusive. This study investigates the role of ARID2, a component of the SWI/SNF chromatin remodeling complex, in TFE3-RCC. Through a series of in vitro and in vivo experiments, we confirmed that ARID2 acts as a tumor suppressor in TFE3-RCC. ARID2 knockout (KO) enhanced TFE3-RCC cell migration, proliferation, and tumor growth. Transcriptomic analysis revealed ERBB3 as a key target gene regulated by both PRCC-TFE3 and ARID2. Chromatin immunoprecipitation (ChIP) assays demonstrated that PRCC-TFE3 directly binds to and upregulates ERBB3 expression, with ARID2 KO further enhancing this effect. TFE3-RCC ARID2 KO cells exhibited significant gene expression enrichment in MAPK and ERBB3 signaling pathways. These cells also showed increased activation of ERBB3, EGFR, and selective activation of SRC and MAPK. TFE3-RCC ARID2 KO cells demonstrated heightened sensitivity to the ERBB3 inhibitor AZD8931 compared to their wild-type counterparts, exhibiting significantly reduced migration and proliferation rates. These findings suggest that the PRCC-TFE3-ARID2-ERBB3 axis plays a critical role in TFE3-RCC pathogenesis and highlights the potential of targeting ERBB3 in ARID2-deficient TFE3-RCC as a therapeutic strategy. This study provides new insights into the molecular mechanisms of TFE3-RCC and suggests avenues for precision treatment of this aggressive cancer.

Evaluation of PD-L1 expression in PBRM1-altered clear cell renal cell carcinoma

PURPOSE

Clear cell renal cell carcinoma (ccRCC) often harbors Polybromo 1 (PBRM1) alterations. These alterations are associated with immune checkpoint blockade response in ccRCC, particularly antiprogrammed cell death 1 (PD1)/programmed cell death ligand 1 (PD-L1)-targeted therapy. However, the association between PBRM1 alterations and PD-L1 expression in ccRCC remains unclear.

MATERIALS AND METHODS

We analyzed alterations in PBRM1 and PD-L1 expression using immunohistochemistry (IHC) targeting PBRM1 and PD-L1 (22C3) in tissues collected from patients with localized ccRCC (Cohort 1) and advanced ccRCC (Cohort 2). Additionally, next-generation sequencing (NGS) was conducted on Cohort 2 patients to analyze PBRM1 alterations.

RESULTS

Cohort 1 comprised 526 patients, of whom 139 (26.4%) exhibited PD-L1 positivity and 205 (38.9%) exhibited loss of PBRM1 expression in IHC. PD-L1 expression was positively associated with the loss of PBRM1 expression (P < 0.001) in localized ccRCC. Kaplan-Meier analysis indicated that PBRM1 expression loss and PD-L1 expression positively correlated with tumor recurrence (P < 0.001 and P = 0.003, respectively). Cohort 2 comprised 59 patients with advanced ccRCC, of whom 33 (56.9%) exhibited PBRM1 genetic alterations. PBRM1 IHC exhibited a sensitivity of 84.48% and specificity of 87.5% compared to NGS results. We did not find a significant association between PBRM1 mutation and PD-L1 expression, in contrast to the findings in Cohort 1. However, we frequently observed that PBRM1 mutation and PD-L1 expression occur concurrently, with 60% of PBRM1-altered ccRCC cases being PD-L1 positive.

CONCLUSION

Although our study did not establish a correlation between PBRM1 mutations and PD-L1 expression, it demonstrated that the occurrence of PBRM1-altered ccRCC with PD-L1 expression is not uncommon. Therefore, the presence of PBRM1 alterations may challenge the use of PD-L1 IHC as a predictive marker for PD-L1 blockade in ccRCC.

Prognostic Impact and Genomic Backgrounds of Renal Parenchymal Infiltration or Micronodular Spread in Nonmetastatic Clear Cell Renal Cell Carcinoma

A subset of clear cell renal cell carcinomas (ccRCCs) exhibits various growth patterns that infiltrate the normal renal parenchyma; however, our understanding of its association with cancer aggressiveness is incomplete. Here, we show that the morphology of the tumor interface with normal renal parenchyma is robustly associated with cancer recurrence after surgery, even when compared with the TNM staging system or the World Health Organization/International Society of Urological Pathology (WHO/ISUP) nuclear grade in nonmetastatic ccRCC. Hematoxylin and eosin-stained slides of whole tissue sections from surgical specimens were analyzed using a cohort of 331 patients with nonmetastatic ccRCC treated with radical nephrectomy. The patients were classified into 10 subgroups based on our classification algorithms for assessing the tumor interface with normal renal parenchyma. Among the 10 subgroups, 4 subgroups consisting of 40 patients (12%) were identified to have aggressive forms of nonmetastatic ccRCC associated with poor prognosis and unified as renal parenchymal infiltration or micronodular spread (RPI/MNS) phenotypes. Multivariable analyses showed that RPI/MNS phenotypes were robustly associated with shorter disease-free survival, independently of existing pathological factors including the TNM staging system and WHO/ISUP nuclear grade. The hazard ratio was highest for RPI/MNS (4.62), followed by WHO/ISUP grades 3 to 4 (2.11) and ≥pT3a stage (2.05). In addition, we conducted genomic analyses using next-generation sequencing of infiltrative lesions in 18 patients with RPI/MNS and tumor lesions in 33 patients without RPI/MNS. Results showed that alterations in SETD2 and TSC1 might be associated with RPI/MNS phenotypes, whereas alterations in PBRM1 might be associated with non-RPI/MNS phenotypes. These data suggest that RPI/MNS may be associated with aggressive genomic backgrounds of ccRCC, although more comprehensive analyses with a larger sample size are required. Future studies may further elucidate the clinical implications of RPI/MNS, particularly for deciding the indication of adjuvant treatment after nephrectomy.

ATF4/NUPR1 axis promotes cancer cell survival and mediates immunosuppression in clear cell renal cell carcinoma

Cancer cells encounter unavoidable stress during tumor growth. The stress-induced transcription factor, activating transcription factor 4 (ATF4), has been reported to upregulate various adaptive genes involved in salvage pathways to alleviate stress and promote tumor progression. However, this effect is unknown in clear cell renal cell carcinoma (ccRCC). In this study, we found that ATF4 expression was remarkably upregulated in tumor tissues and associated with poor ccRCC outcomes. ATF4 depletion significantly impaired ccRCC cell proliferation, migration, and invasion in vitro and in vivo by inhibiting the AKT/mTOR and epithelial-mesenchymal transition (EMT)-related signaling pathway. RNA sequencing and functional studies identified nuclear protein 1 (NUPR1) as a key downstream target of ATF4 for repressing ferroptosis and promoting ccRCC cell survival. In addition, targeting ATF4 or pharmacological inhibition using NUPR1 inhibitor ZZW115 promoted antitumor immunity in syngeneic graft mouse models, represented by increased infiltration of CD4+ and CD8+ T cells. Furthermore, ZZW115 could improve the response to the PD-1 immune checkpoint blockade. The results demonstrate that the ATF4/NUPR1 signaling axis promotes ccRCC survival and facilitates tumor-mediated immunosuppression, providing a set of potential targets and prognostic indicators for ccRCC patients.

ARID1A-BAF coordinates ZIC2 genomic occupancy for epithelial-to-mesenchymal transition in cranial neural crest specification

The BAF chromatin remodeler regulates lineage commitment including cranial neural crest cell (CNCC) specification. Variants in BAF subunits cause Coffin-Siris syndrome (CSS), a congenital disorder characterized by coarse craniofacial features and intellectual disability. Approximately 50% of individuals with CSS harbor variants in one of the mutually exclusive BAF subunits, ARID1A/ARID1B. While Arid1a deletion in mouse neural crest causes severe craniofacial phenotypes, little is known about the role of ARID1A in CNCC specification. Using CSS-patient-derived ARID1A+/- induced pluripotent stem cells to model CNCC specification, we discovered that ARID1A-haploinsufficiency impairs epithelial-to-mesenchymal transition (EMT), a process necessary for CNCC delamination and migration from the neural tube. Furthermore, wild-type ARID1A-BAF regulates enhancers associated with EMT genes. ARID1A-BAF binding at these enhancers is impaired in heterozygotes while binding at promoters is unaffected. At the sequence level, these EMT enhancers contain binding motifs for ZIC2, and ZIC2 binding at these sites is ARID1A-dependent. When excluded from EMT enhancers, ZIC2 relocates to neuronal enhancers, triggering aberrant neuronal gene activation. In mice, deletion of Zic2 impairs NCC delamination, while ZIC2 overexpression in chick embryos at post-migratory neural crest stages elicits ectopic delamination from the neural tube. These findings reveal an essential ARID1A-ZIC2 axis essential for EMT and CNCC delamination.

Association of circulating tumor DNA with patient prognosis in surgically resected renal cell carcinoma

BACKGROUND

Despite complete resection, 20%-50% of patients with localized renal cell carcinoma (RCC) experience recurrence within 5 years. Accurate assessment of prognosis in high-risk patients would aid in improving outcomes. Here we evaluate the use of circulating tumor DNA (ctDNA) in RCC using banked samples and clinical data from a single institution.

METHODS

The cohort consisted of 45 RCC patients (≥pT1b) who underwent complete resection. The presence of ctDNA in plasma was determined using a personalized, tumor-informed ctDNA assay (Signatera RUO, Natera, Inc.). Relationships with outcomes and other relevant clinical variables were assessed. The median follow-up was 62 months.

RESULTS

Plasma ctDNA was detected in 18 out of 36 patients (50%) pre-operatively and was associated with increased tumor size (mean 9.3 cm vs. 7.0 cm, P < .05) and high Fuhrman grade (60% grades III-IV vs 27% grade II, P = .07). The presence of ctDNA, either pre-operatively or at any time post-operatively, was associated with inferior relapse-free survival (HR = 2.70, P = .046; HR = 3.23, P = .003, respectively). Among patients who were ctDNA positive at any time point, the sensitivity of relapse prediction was 84% with a PPV of 90%. Of note, ctDNA positivity at a post-surgical time point revealed a PPV of 100% and NPV of 64%. The lack of ctDNA detection at both time points yielded an NPV of 80%.

CONCLUSIONS

Detection of plasma ctDNA using a personalized assay is prognostic of recurrence in patients with resected RCC. Herein, we describe a successful approach for its application and identify potential limitations to be addressed in future studies.

Opening and changing: mammalian SWI/SNF complexes in organ development and carcinogenesis

The switch/sucrose non-fermentable (SWI/SNF) subfamily are evolutionarily conserved, ATP-dependent chromatin-remodelling complexes that alter nucleosome position and regulate a spectrum of nuclear processes, including gene expression, DNA replication, DNA damage repair, genome stability and tumour suppression. These complexes, through their ATP-dependent chromatin remodelling, contribute to the dynamic regulation of genetic information and the maintenance of cellular processes essential for normal cellular function and overall genomic integrity. Mutations in SWI/SNF subunits are detected in 25% of human malignancies, indicating that efficient functioning of this complex is required to prevent tumourigenesis in diverse tissues. During development, SWI/SNF subunits help establish and maintain gene expression patterns essential for proper cellular identity and function, including maintenance of lineage-specific enhancers. Moreover, specific molecular signatures associated with SWI/SNF mutations, including disruption of SWI/SNF activity at enhancers, evasion of G0 cell cycle arrest, induction of cellular plasticity through pro-oncogene activation and Polycomb group (PcG) complex antagonism, are linked to the initiation and progression of carcinogenesis. Here, we review the molecular insights into the aetiology of human malignancies driven by disruption of the SWI/SNF complex and correlate these mechanisms to their developmental functions. Finally, we discuss the therapeutic potential of targeting SWI/SNF subunits in cancer.

Therapeutic modulation of ROCK overcomes metabolic adaptation of cancer cells to OXPHOS inhibition and drives synergistic anti-tumor activity

Genomic studies have identified frequent mutations in subunits of the SWI/SNF chromatin remodeling complex including SMARCA4 and ARID1A in non-small cell lung cancer. Previously, we and others have identified that SMARCA4-mutant lung cancers are highly dependent on oxidative phosphorylation (OXPHOS). Despite initial excitements, therapeutics targeting metabolic pathways such as OXPHOS have largely been disappointing due to rapid adaptation of cancer cells to inhibition of single metabolic enzymes or pathways, suggesting novel combination strategies to overcome adaptive responses are urgently needed. Here, we performed a functional genomics screen using CRISPR-Cas9 library targeting genes with available FDA approved therapeutics and identified ROCK1/2 as a top hit that sensitizes cancer cells to OXPHOS inhibition. We validate these results by orthogonal genetic and pharmacologic approaches by demonstrating that KD025 (Belumosudil), an FDA approved ROCK inhibitor, has highly synergistic anti-cancer activity in vitro and in vivo in combination with OXPHOS inhibition. Mechanistically, we showed that this combination induced a rapid, profound energetic stress and cell cycle arrest that was in part due to ROCK inhibition-mediated suppression of the adaptive increase in glycolysis normally seen by OXPHOS inhibition. Furthermore, we applied global phosphoproteomics and kinase-motif enrichment analysis to uncover a dynamic regulatory kinome upon combination of OXPHOS and ROCK inhibition. Importantly, we found converging phosphorylation-dependent regulatory cross-talk by AMPK and ROCK kinases on key RHO GTPase signaling/ROCK-dependent substrates such as PPP1R12A, NUMA1 and PKMYT1 that are known regulators of cell cycle progression. Taken together, our study identified ROCK kinases as critical mediators of metabolic adaptation of cancer cells to OXPHOS inhibition and provides a strong rationale for pursuing ROCK inhibitors as novel combination partners to OXPHOS inhibitors in cancer treatment.

Chromatin remodellers as therapeutic targets

Large-scale cancer genome sequencing studies have revealed that chromatin regulators are frequently mutated in cancer. In particular, more than 20% of cancers harbour mutations in genes that encode subunits of SWI/SNF (BAF) chromatin remodelling complexes. Additional links of SWI/SNF complexes to disease have emerged with the findings that some oncogenes drive transformation by co-opting SWI/SNF function and that germline mutations in select SWI/SNF subunits are the basis of several neurodevelopmental disorders. Other chromatin remodellers, including members of the ISWI, CHD and INO80/SWR complexes, have also been linked to cancer and developmental disorders. Consequently, therapeutic manipulation of SWI/SNF and other remodelling complexes has become of great interest, and drugs that target SWI/SNF subunits have entered clinical trials. Genome-wide perturbation screens in cancer cell lines with SWI/SNF mutations have identified additional synthetic lethal targets and led to further compounds in clinical trials, including one that has progressed to FDA approval. Here, we review the progress in understanding the structure and function of SWI/SNF and other chromatin remodelling complexes, mechanisms by which SWI/SNF mutations cause cancer and neurological diseases, vulnerabilities that arise because of these mutations and efforts to target SWI/SNF complexes and synthetic lethal targets for therapeutic benefit.

Discovery of Novel, Potent and Orally Bioavailable SMARCA2 PROTACs with Synergistic Anti-tumor Activity in Combination with KRAS G12C Inhibitors

Cancer genomic studies have identified frequent mutations in subunits of the SWI/SNF chromatin remodeling complex including SMARCA4 in non-small cell lung cancer with a frequency of up to 33% in advanced stage disease, making it the most frequently mutated complex in lung cancer. We and others have identified SMARCA2 to be synthetic lethal to SMARCA4, indicating SMARCA2 is a high value therapeutic target. Here, we disclose the discovery and characterization of potent, selective and orally bioavailable Cereblon-based SMARCA2 PROTACs. Biochemically, YDR1 and YD54 are potent SMARCA2 degraders with an average DC 50 of 7.7nM and 3.5nM respectively in SMARCA4 mutant lung cancer cells. Phenotypically, both YDR1 and YD54 selectively inhibited growth of SMARCA4 mutant cancer cells. Further, we showed anti-tumor growth inhibitory activity of YDR1 and YD54 in SMARCA4 mutant xenograft models of lung cancer. Finally, we show that YDR1 and YD54 synergize with the KRAS G12C inhibitor sotorasib to inhibit growth of SMARCA4 and KRAS G12C co-mutant lung cancer cells. These findings provide additional evidence for the utility of single agent or combination regimens containing SMARCA2 PROTACs as synthetic lethal therapeutics against SMARCA4 mutant cancers.

The influence of sex hormones on renal cell carcinoma

Kidney cancer is a common malignancy that constitutes around 5% of all cancer cases. Males are twice as likely to acquire renal cell carcinoma (RCC) compared to females and experience a higher rate of mortality. These disparities indicate that sex hormone (SH)-dependent pathways may have an impact on the aetiology and pathophysiology of RCC. Examination of SH involvement in conventional signalling pathways, as well as genetics and genomics, especially the involvement of ribonucleic acid, reveal further insights into sex-related differences. An understanding of SHs and their influence on kidney cancer is essential to offer patients individualized medicine that would better meet their needs in terms of prevention, diagnosis and treatment. This review presents the understanding of sex-related differences in the clinical manifestation of kidney cancer patients and the underlying biological processes.

Clinical protocol phase II study of tumor infiltrating lymphocytes in advanced tumors with alterations in the SWI/SNF complex: the TILTS study

The SWI/SNF complex is a chromatin remodeling complex comprised by several proteins such as SMARCA4 or SMARCB1. Mutations in its components can lead to the development of aggressive rhabdoid tumors such as epithelioid sarcoma, malignant rhabdoid tumor or small cell carcinoma of the ovary hypercalcemic type, among others. These malignancies tend to affect young patients and their prognosis is poor given the lack of effective treatments. Characteristically, these tumors are highly infiltrated by TILs, suggesting that some lymphocytes are recognizing tumor antigens. The use of those TILs as a therapeutic strategy is a promising approach worth exploring. Here, we report the clinical protocol of the TILTS study, a Phase II clinical trial assessing personalized adoptive cell therapy with TILs in patients affected by these tumor types.Clinical Trial Registration: 2023-504632-17-00 (www.clinicaltrialsregister.eu) (ClinicalTrials.gov).

Preclinical evidence in the assembly of mammalian SWI/SNF complexes: Epigenetic insights and clinical perspectives in human lung disease therapy

The SWI/SNF complex, also known as the BRG1/BRM-associated factor (BAF) complex, represents a critical regulator of chromatin remodeling mechanisms in mammals. It is alternatively referred to as mSWI/SNF and has been suggested to be imbalanced in human disease compared with human health. Three types of BAF assemblies associated with it have been described, including (1) canonical BAF (cBAF), (2) polybromo-associated BAF (PBAF), and (3) non-canonical BAF (ncBAF) complexes. Each of these BAF assemblies plays a role, either functional or dysfunctional, in governing gene expression patterns, cellular processes, epigenetic mechanisms, and biological processes. Recent evidence increasingly links the dysregulation of mSWI/SNF complexes to various human non-malignant lung chronic disorders and lung malignant diseases. This review aims to provide a comprehensive general state-of-the-art and a profound examination of the current understanding of mSWI/SNF assembly processes, as well as the structural and functional organization of mSWI/SNF complexes and their subunits. In addition, it explores their intricate functional connections with potentially dysregulated transcription factors, placing particular emphasis on molecular and cellular pathogenic processes in lung diseases. These processes are reflected in human epigenome aberrations that impact clinical and therapeutic levels, suggesting novel perspectives on the diagnosis and molecular therapies for human respiratory diseases.

Expanded detection and impact of BAP1 alterations in cancer

Aberrant expression of the BAP1 tumor suppressor gene is a prominent risk factor for several tumor types and is important in tumor evolution and progression. Here we performed integrated multi-omic analyses using data from The Cancer Genome Atlas (TCGA) for 33 cancer types and over 10,000 individuals to identify alterations leading to BAP1 disruption. We combined existing variant calls and new calls derived from a de novo local realignment pipeline across multiple independent variant callers, increasing somatic variant detection by 41% from 182 to 257, including 11 indels ≥40bp. The expanded detection of mutations highlights the power of new tools to uncover longer indels and impactful mutations. We developed an expression-based BAP1 activity score and identified a transcriptional profile associated with BAP1 disruption in cancer. BAP1 has been proposed to play a critical role in controlling tumor plasticity and normal cell fate. Leveraging human and mouse liver datasets, BAP1 loss in normal cells resulted in lower BAP1 activity scores and lower scores were associated with a less-differentiated phenotype in embryonic cells. Together, our expanded BAP1 mutant samples revealed a transcriptional signature in cancer cells, supporting BAP1's influences on cellular plasticity and cell identity maintenance.

TNFSF9 Is Associated with Favorable Tumor Immune Microenvironment in Patients with Renal Cell Carcinoma Who Are Treated with the Combination Therapy of Nivolumab and Ipilimumab

Combination therapy of nivolumab and ipilimumab (NIVO + IPI) for metastatic renal cell carcinoma (mRCC) has shown efficacy, but approximately 20% of patients experience disease progression in the early stages of treatment. No useful biomarkers have been reported to date. Therefore, it is desirable to identify biomarkers to predict treatment responses in advance. We examined the tumor microenvironment (TME)-related gene expression in mRCC patients treated with NIVO + IPI, between the response and non-response groups, using tumor tissues, before administering NIVO + IPI. In TME-related genes, TNFSF9 expression was identified as a candidate for the predictive biomarker. Its expression discriminated between the response and non-response groups with 88.89% sensitivity and 87.50% specificity (AUC = 0.9444). We further analyzed the roles of TNFSF9 in TME using bioinformatics from The Cancer Genome Atlas (TCGA) cohort. An adaptive immune response was activated in the TNFSF9-high-expression tumors. Indeed, T follicular helper cells, plasma B cells, and tumor-infiltrating CD8+ T cells were increased in the tumors, which indicates the promotion of humoral immunity due to enhanced T-B interactions. However, as the number of regulatory T cells (Treg) increased in the tumors, the percentage of dysfunctional T cells also increased. This suggests that not only PD-1 but also CTLA-4 inhibition may have suppressed Treg activation and improved the therapeutic effect in the TNFSF9 high-expression tumors. Therefore, TNFSF9 may predict the therapeutic efficacy of NIVO + IPI for mRCC and allow more appropriate patient selection.

Development of prognostic signatures and risk index related to lipid metabolism in ccRCC

Background

Clear cell renal cell carcinoma (ccRCC) is a metabolic disorder characterized by abnormal lipid accumulation in the cytoplasm. Lipid metabolism-related genes may have important clinical significance for prognosis prediction and individualized treatment.

Methods

We collected bulk and single-cell transcriptomic data of ccRCC and normal samples to identify key lipid metabolism-related prognostic signatures. qPCR was used to confirm the expression of signatures in cancer cell lines. Based on the identified signatures, we developed a lipid metabolism risk score (LMRS) as a risk index. We explored the potential application value of prognostic signatures and LMRS in precise treatment from multiple perspectives.

Results

Through comprehensive analysis, we identified five lipid metabolism-related prognostic signatures (ACADM, ACAT1, ECHS1, HPGD, DGKZ). We developed a risk index LMRS, which was significantly associated with poor prognosis in patients. There was a significant correlation between LMRS and the infiltration levels of multiple immune cells. Patients with high LMRS may be more likely to respond to immunotherapy. The different LMRS groups were suitable for different anticancer drug treatment regimens.

Conclusion

Prognostic signatures and LMRS we developed may be applied to the risk assessment of ccRCC patients, which may have potential guiding significance in the diagnosis and precise treatment of ccRCC patients.

A Rare Case of Synchronous Fumarate Hydratase-Deficient Renal Cell Carcinoma and Clear Cell Renal Cell Carcinoma With Fumarate Hydratase and von Hippel-Lindau Gene Mutations: A Clinicopathologic and Molecular Study

Fumarate hydratase-deficient renal cell carcinoma (FH-deficient RCC) is a rare and aggressive tumor characterized by pathogenic alterations in the fumarate hydratase (FH) gene. Clear cell renal cell carcinoma (clear cell RCC) is a common renal cell carcinoma (RCC) associated with von Hippel-Lindau (VHL) gene variations. Here, we reported a case of bilateral RCCs. A 60-year-old man was admitted to hospital with a 3.6 cm × 3.3 cm mass in the right kidney and a 2.8 cm × 2.3 cm nodule in the left kidney. Pathologically, the right tumor showed a nested growth pattern of cells with clear cytoplasm and was FH positive and 2-succinylcysteine (2SC) negative. The left tumor demonstrated a high-grade papillary pattern and was FH negative and 2SC positive. Whole-exome sequencing and Sanger sequencing identified a germline FH c.563A > T mutation in both the tumors and an additional somatic VHL c.479_480insA mutation in the right tumor, confirming the diagnosis of clear cell RCC and FH-deficient RCC in the right and left kidneys, respectively. We reported a rare case of synchronous bilateral clear cell RCC (right) and FH-deficient RCC (left) likely driven by somatic VHL mutation and germline FH mutation, respectively.

Context-specific functions of chromatin remodellers in development and disease

Chromatin remodellers were once thought to be highly redundant and nonspecific in their actions. However, recent human genetic studies demonstrate remarkable biological specificity and dosage sensitivity of the thirty-two adenosine triphosphate (ATP)-dependent chromatin remodellers encoded in the human genome. Mutations in remodellers produce many human developmental disorders and cancers, motivating efforts to investigate their distinct functions in biologically relevant settings. Exquisitely specific biological functions seem to be an emergent property in mammals, and in many cases are based on the combinatorial assembly of subunits and the generation of stable, composite surfaces. Critical interactions between remodelling complex subunits, the nucleosome and other transcriptional regulators are now being defined from structural and biochemical studies. In addition, in vivo analyses of remodellers at relevant genetic loci have provided minute-by-minute insights into their dynamics. These studies are proposing new models for the determinants of remodeller localization and function on chromatin.

A latent variable model for evaluating mutual exclusivity and co-occurrence between driver mutations in cancer

A key challenge in cancer genomics is understanding the functional relationships and dependencies between combinations of somatic mutations that drive cancer development. Such driver mutations frequently exhibit patterns of mutual exclusivity or co-occurrence across tumors, and many methods have been developed to identify such dependency patterns from bulk DNA sequencing data of a cohort of patients. However, while mutual exclusivity and co-occurrence are described as properties of driver mutations, existing methods do not explicitly disentangle functional, driver mutations from neutral, passenger mutations. In particular, nearly all existing methods evaluate mutual exclusivity or co-occurrence at the gene level, marking a gene as mutated if any mutation - driver or passenger - is present. Since some genes have a large number of passenger mutations, existing methods either restrict their analyses to a small subset of suspected driver genes - limiting their ability to identify novel dependencies - or make spurious inferences of mutual exclusivity and co-occurrence involving genes with many passenger mutations. We introduce DIALECT, an algorithm to identify dependencies between pairs of driver mutations from somatic mutation counts. We derive a latent variable mixture model for drivers and passengers that combines existing probabilistic models of passenger mutation rates with a latent variable describing the unknown status of a mutation as a driver or passenger. We use an expectation maximization (EM) algorithm to estimate the parameters of our model, including the rates of mutually exclusivity and co-occurrence between drivers. We demonstrate that DIALECT more accurately infers mutual exclusivity and co-occurrence between driver mutations compared to existing methods on both simulated mutation data and somatic mutation data from 5 cancer types in The Cancer Genome Atlas (TCGA).

Fast and accurate variant identification tool for sequencing-based studies

BACKGROUND

Accurate identification of genetic variants, such as point mutations and insertions/deletions (indels), is crucial for various genetic studies into epidemic tracking, population genetics, and disease diagnosis. Genetic studies into microbiomes often require processing numerous sequencing datasets, necessitating variant identifiers with high speed, accuracy, and robustness.

RESULTS

We present QuickVariants, a bioinformatics tool that effectively summarizes variant information from read alignments and identifies variants. When tested on diverse bacterial sequencing data, QuickVariants demonstrates a ninefold higher median speed than bcftools, a widely used variant identifier, with higher accuracy in identifying both point mutations and indels. This accuracy extends to variant identification in virus samples, including SARS-CoV-2, particularly with significantly fewer false negative indels than bcftools. The high accuracy of QuickVariants is further demonstrated by its detection of a greater number of Omicron-specific indels (5 versus 0) and point mutations (61 versus 48-54) than bcftools in sewage metagenomes predominated by Omicron variants. Much of the reduced accuracy of bcftools was attributable to its misinterpretation of indels, often producing false negative indels and false positive point mutations at the same locations.

CONCLUSIONS

We introduce QuickVariants, a fast, accurate, and robust bioinformatics tool designed for identifying genetic variants for microbial studies. QuickVariants is available at https://github.com/caozhichongchong/QuickVariants .

Dual-loss of PBRM1 and RAD51 identifies hyper-sensitive subset patients to immunotherapy in clear cell renal cell carcinoma

BACKGROUND

Homologous recombination deficiency (HRD), though largely uncharacterized in clear cell renal cell carcinoma (ccRCC), was found associated with RAD51 loss of expression. PBRM1 is the second most common mutated genes in ccRCC. Here, we introduce a HRD function-based PBRM1-RAD51 ccRCC classification endowed with diverse immune checkpoint blockade (ICB) responses.

METHODS

Totally 1542 patients from four independent cohorts were enrolled, including our localized Zhongshan hospital (ZSHS) cohort and Zhongshan hospital metastatic RCC (ZSHS-mRCC) cohort, The Cancer Genome Atlas (TCGA) cohort and CheckMate cohort. The genomic profile and immune microenvironment were depicted by genomic, transcriptome data and immunohistochemistry.

RESULTS

We observed that PBRM1-loss ccRCC harbored enriched HRD-associated mutational signature 3 and loss of RAD51. Dual-loss of PBRM1 and RAD51 identified patients hyper-sensitive to immunotherapy. This dual-loss subtype was featured by M1 macrophage infiltration. Dual-loss was, albeit homologous recombination defective, with high chromosomal stability.

CONCLUSIONS

PBRM1 and RAD51 dual-loss ccRCC indicates superior responses to immunotherapy. Dual-loss ccRCC harbors an immune-desert microenvironment but enriched with M1 macrophages. Dual-loss ccRCC is susceptible to defective homologous recombination but possesses high chromosomal stability.

Chromatin Remodelers Are Regulators of the Tumor Immune Microenvironment

Immune checkpoint inhibitors show remarkable responses in a wide range of cancers, yet patients develop adaptive resistance. This necessitates the identification of alternate therapies that synergize with immunotherapies. Epigenetic modifiers are potent mediators of tumor-intrinsic mechanisms and have been shown to regulate immune response genes, making them prime targets for therapeutic combinations with immune checkpoint inhibitors. Some success has been observed in early clinical studies that combined immunotherapy with agents targeting DNA methylation and histone modification; however, less is known about chromatin remodeler-targeted therapies. Here, we provide a discussion on the regulation of tumor immunogenicity by the chromatin remodeling SWI/SNF complex through multiple mechanisms associated with immunotherapy response that broadly include IFN signaling, DNA damage, mismatch repair, regulation of oncogenic programs, and polycomb-repressive complex antagonism. Context-dependent targeting of SWI/SNF subunits can elicit opportunities for synthetic lethality and reduce T-cell exhaustion. In summary, alongside the significance of SWI/SNF subunits in predicting immunotherapy outcomes, their ability to modulate the tumor immune landscape offers opportunities for therapeutic intervention.

Cancer-associated polybromo-1 bromodomain 4 missense variants variably impact bromodomain ligand binding and cell growth suppression

The polybromo, brahma-related gene 1-associated factors (PBAF) chromatin remodeling complex subunit polybromo-1 (PBRM1) contains six bromodomains that recognize and bind acetylated lysine residues on histone tails and other nuclear proteins. PBRM1 bromodomains thus provide a link between epigenetic posttranslational modifications and PBAF modulation of chromatin accessibility and transcription. As a putative tumor suppressor in several cancers, PBRM1 protein expression is often abrogated by truncations and deletions. However, ∼33% of PBRM1 mutations in cancer are missense and cluster within its bromodomains. Such mutations may generate full-length PBRM1 variant proteins with undetermined structural and functional characteristics. Here, we employed computational, biophysical, and cellular assays to interrogate the effects of PBRM1 bromodomain missense variants on bromodomain stability and function. Since mutations in the fourth bromodomain of PBRM1 (PBRM1-BD4) comprise nearly 20% of all cancer-associated PBRM1 missense mutations, we focused our analysis on PBRM1-BD4 missense protein variants. Selecting 16 potentially deleterious PBRM1-BD4 missense protein variants for further study based on high residue mutational frequency and/or conservation, we show that cancer-associated PBRM1-BD4 missense variants exhibit varied bromodomain stability and ability to bind acetylated histones. Our results demonstrate the effectiveness of identifying the unique impacts of individual PBRM1-BD4 missense variants on protein structure and function, based on affected residue location within the bromodomain. This knowledge provides a foundation for drawing correlations between specific cancer-associated PBRM1 missense variants and distinct alterations in PBRM1 function, informing future cancer personalized medicine approaches.

Established and emerging biomarkers of immunotherapy in renal cell carcinoma

Immunotherapies, such as immune checkpoint inhibitors, have heralded impressive progress for patient care in renal cell carcinoma (RCC). Despite this success, some patients' disease fails to respond, and other patients experience significant side effects. Thus, development of biomarkers is needed to ensure that patients can be selected to maximize benefit from immunotherapies. Improving clinicians' ability to predict which patients will respond to immunotherapy and which are most at risk of adverse events - namely through clinical biomarkers - is indispensable for patient safety and therapeutic efficacy. Accordingly, an evolving suite of therapeutic biomarkers continues to be investigated. This review discusses biomarkers for immunotherapy in RCC, highlighting current practices and emerging innovations, aiming to contribute to improved outcomes for patients with RCC.

Radiogenomic analysis based on lipid metabolism-related subset for non-invasive prediction for prognosis of renal clear cell carcinoma

PURPOSE

Multiple lipid metabolism pathways alterations are associated with clear cell renal cell carcinoma (ccRCC) development and aggressiveness. In this study, we aim to develop a novel radiogenomics signature based on lipid metabolism-related genes (LMRGs) that may accurately predict ccRCC patients' survival.

MATERIALS AND METHODS

First, 327 ccRCC were used to screen survival-related LMRGs and construct a gene signature based on The Cancer Genome Atlas (TCGA) database. Then, 182 ccRCC were analyzed to establish radiogenomics signature linking LMRGs signature to radiomic features in The Cancer Imaging Archive (TCIA) database included enhanced CT images and transcriptome sequencing data. Lastly, we validated the prognostic power of the identified radiogenomics signature using these patients of TCIA and the Third Xiangya Hospital.

RESULTS

We identified the LMRGs signature, consisting of 13 genes, which could efficiently discriminate between low-risk and high-risk patients and serve as an independent and reliable predictor of overall survival (OS). Radiogenomics signature, comprised of 9 radiomic features, was created and could accurately predict the expression level of LMRGs signature (low- or high-risk) for patients. The predictive performance of this radiogenomics signature was demonstrated through AUC values of 0.75 and 0.74 for the training and validation sets (at a ratio of 7:3), respectively. Radiogenomics signature was proven to be an independent risk factor for OS by multivariable analysis (HR = 4.98, 95 % CI:1.72-14.43, P = 0.003).

CONCLUSIONS

The LMRGs radiogenomics signature could serve as a novel prognostic predictor.

Translational Aspects of Epithelioid Sarcoma: Current Consensus

Epithelioid sarcoma (EpS) is an ultra-rare malignant soft-tissue cancer mostly affecting adolescents and young adults. EpS often exhibits an unfavorable clinical course with fatal outcome in ∼50% of cases despite aggressive multimodal therapies combining surgery, chemotherapy, and irradiation. EpS is traditionally classified in a more common, less aggressive distal (classic) type and a rarer aggressive proximal type. Both subtypes are characterized by a loss of nuclear INI1 expression, most often following homozygous deletion of its encoding gene, SMARCB1-a core subunit of the SWI/SNF chromatin remodeling complex. In 2020, the EZH2 inhibitor tazemetostat was the first targeted therapy approved for EpS, raising new hopes. Still, the vast majority of patients did not benefit from this drug or relapsed rapidly. Further, other recent therapeutic modalities, including immunotherapy, are only effective in a fraction of patients. Thus, novel strategies, specifically targeted to EpS, are urgently needed. To accelerate translational research on EpS and eventually boost the discovery and development of new diagnostic tools and therapeutic options, a vibrant translational research community has formed in past years and held two international EpS digital expert meetings in 2021 and 2023. This review summarizes our current understanding of EpS from the translational research perspective and points to innovative research directions to address the most pressing questions in the field, as defined by expert consensus and patient advocacy groups.

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 Killer's Web: Interconnection between Inflammation, Epigenetics and Nutrition in Cancer

Inflammation is a key contributor to both the initiation and progression of tumors, and it can be triggered by genetic instability within tumors, as well as by lifestyle and dietary factors. The inflammatory response plays a critical role in the genetic and epigenetic reprogramming of tumor cells, as well as in the cells that comprise the tumor microenvironment. Cells in the microenvironment acquire a phenotype that promotes immune evasion, progression, and metastasis. We will review the mechanisms and pathways involved in the interaction between tumors, inflammation, and nutrition, the limitations of current therapies, and discuss potential future therapeutic approaches.

Research progress of SWI/SNF complex in breast cancer

In the past decade, numerous epigenetic mechanisms have been discovered to be associated with cancer. The mammalian SWI/SNF complex is an ATP-dependent chromatin remodeling complex whose mutations are associated with various malignancies including breast cancer. As the SWI/SNF complex has become one of the most commonly mutated complexes in cancer, targeting epigenetic mutations acquired during breast cancer progress is a potential means of improving clinical efficacy in treatment strategies. This article reviews the composition of the SWI/SNF complex, its main roles and research progress in breast cancer, and links these findings to the latest discoveries in cancer epigenomics to discuss the potential mechanisms and therapeutic potential of SWI/SNF in breast cancer.

ARID1A loss is associated with increased NRF2 signaling in human head and neck squamous cell carcinomas

Prior to the next generation sequencing and characterization of the tumor genome landscape, mutations in the SWI/SNF chromatin remodeling complex and the KEAP1-NRF2 signaling pathway were underappreciated. While these two classes of mutations appeared to independently contribute to tumor development, recent reports have demonstrated a mechanistic link between these two regulatory mechanisms in specific cancer types and cell models. In this work, we expand upon these data by exploring the relationship between mutations in BAF and PBAF subunits of the SWI/SNF complex and activation of NRF2 signal transduction across many cancer types. ARID1A/B mutations were strongly associated with NRF2 transcriptional activity in head and neck squamous carcinomas (HNSC). Many additional tumor types showed significant association between NRF2 signaling and mutation of specific components of the SWI/SNF complex. Different effects of BAF and PBAF mutations on the polarity of NRF2 signaling were observed. Overall, our results support a context-dependent functional link between SWI/SNF and NRF2 mutations across human cancers and implicate ARID1A inactivation in HPV-negative HNSC in promoting tumor progression and survival through activation of the KEAP1-NRF2 signaling pathway. The tumor-specific effects of these mutations open a new area of study for how mutations in the KEAP1-NRF2 pathway and the SWI/SNF complex contribute to cancer.

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.

Multi-omics integration identifies cell-state-specific repression by PBRM1-PIAS1 cooperation

PBRM1 is frequently mutated in cancers of epithelial origin. How PBRM1 regulates normal epithelial homeostasis, prior to cancer initiation, remains unclear. Here, we show that PBRM1's gene regulatory roles differ drastically between cell states, leveraging human skin epithelium (epidermis) as a research platform. In progenitors, PBRM1 predominantly functions to repress terminal differentiation to sustain progenitors' regenerative potential; in the differentiation state, however, PBRM1 switches toward an activator. Between these two cell states, PBRM1 retains its genomic binding but associates with differential interacting proteins. Our targeted screen identified the E3 SUMO ligase PIAS1 as a key interactor. PIAS1 co-localizes with PBRM1 on chromatin to directly repress differentiation genes in progenitors, and PIAS1's chromatin binding drastically diminishes in differentiation. Furthermore, SUMOylation contributes to PBRM1's repressive function in progenitor maintenance. Thus, our findings highlight PBRM1's cell-state-specific regulatory roles influenced by its protein interactome despite its stable chromatin binding.