Loss of alleles of loci on the short arm of chromosome 3 in renal cell carcinoma

A Cerebellar Tumor-to-Tumor Metastasis in a Patient With Von Hippel-Lindau Disease

Tumor-to-tumor metastasis in the central nerve system is uncommon in our routine practice. Most reports include metastatic breast cancer into meningioma. Here we report a metastatic clear cell renal cell carcinoma (ccRCC) into a cerebellar hemangioblastoma in a patient with von Hippel-Lindau (VHL) disease. Imaging cannot distinguish metastatic ccRCC from primary cerebellar hemangioblastoma. Immuno-molecular studies are proven to be diagnostic. We also reviewed previously documented tumor-to-tumor metastasis of ccRCC to cerebellar hemangioblastoma in VHL disease. Lastly, we discussed potential mechanisms involved in the metastasis of ccRCC to hemangioblastoma in the cerebellum in patients with VHL.

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.

Aneuploidy and complex genomic rearrangements in cancer evolution

Mutational processes that alter large genomic regions occur frequently in developing tumors. They range from simple copy number gains and losses to the shattering and reassembly of entire chromosomes. These catastrophic events, such as chromothripsis, chromoplexy and the formation of extrachromosomal DNA, affect the expression of many genes and therefore have a substantial effect on the fitness of the cells in which they arise. In this review, we cover large genomic alterations, the mechanisms that cause them and their effect on tumor development and evolution.

SETD2 maintains nuclear lamina stability to safeguard the genome

Histone methyltransferases play essential roles in the organization and function of chromatin. They are also frequently mutated in human diseases including cancer1. One such often mutated methyltransferase, SETD2, associates co-transcriptionally with RNA polymerase II and catalyzes histone H3 lysine 36 trimethylation (H3K36me3) - a modification that contributes to gene transcription, splicing, and DNA repair2. While studies on SETD2 have largely focused on the consequences of its catalytic activity, the non-catalytic functions of SETD2 are largely unknown. Here we report a catalysis-independent function of SETD2 in maintaining nuclear lamina stability and genome integrity. We found that SETD2, via its intrinsically disordered N-terminus, associates with nuclear lamina proteins including lamin A/C, lamin B1, and emerin. Depletion of SETD2, or deletion of its N-terminus, resulted in widespread nuclear morphology abnormalities and genome stability defects that were reminiscent of a defective nuclear lamina. Mechanistically, the N-terminus of SETD2 facilitates the association of the mitotic kinase CDK1 with lamins, thereby promoting lamin phosphorylation and depolymerization required for nuclear envelope disassembly during mitosis. Taken together, our findings reveal an unanticipated link between the N-terminus of SETD2 and nuclear lamina organization that may underlie how SETD2 acts as a tumor suppressor.

PI3K/AKT/mTOR Dysregulation and Reprogramming Metabolic Pathways in Renal Cancer: Crosstalk with the VHL/HIF Axis

Renal cell carcinoma (RCC) represents 85-95% of kidney cancers and is the most frequent type of renal cancer in adult patients. It accounts for 3% of all cancer cases and is in 7th place among the most frequent histological types of cancer. Clear cell renal cell carcinoma (ccRCC), accounts for 75% of RCCs and has the most kidney cancer-related deaths. One-third of the patients with ccRCC develop metastases. Renal cancer presents cellular alterations in sugars, lipids, amino acids, and nucleic acid metabolism. RCC is characterized by several metabolic dysregulations including oxygen sensing (VHL/HIF pathway), glucose transporters (GLUT 1 and GLUT 4) energy sensing, and energy nutrient sensing cascade. Metabolic reprogramming represents an important characteristic of the cancer cells to survive in nutrient and oxygen-deprived environments, to proliferate and metastasize in different body sites. The phosphoinositide 3-kinase-AKT-mammalian target of the rapamycin (PI3K/AKT/mTOR) signaling pathway is usually dysregulated in various cancer types including renal cancer. This molecular pathway is frequently correlated with tumor growth and survival. The main aim of this review is to present renal cancer types, dysregulation of PI3K/AKT/mTOR signaling pathway members, crosstalk with VHL/HIF axis, and carbohydrates, lipids, and amino acid alterations.

Risk signature identification and NPRL2 affects sunitinib sensitivity in clear cell renal cell carcinoma

Tumor suppressor genes (TSGs) play a crucial role in tumorigenesis and drug resistance. We analyzed the subtypes of clear cell renal cell carcinoma (ccRCC) mediated by 8 genes contained in the 3p21.3 tumor suppressor gene cluster and their effects on TME cell infiltration based on the TCGA database. The risk score model was established by principal component analysis. The hub gene NPRL2 was selected by protein-protein interactions (PPI) analysis. The effect of NPRL2 on sunitinib sensitivity of ccRCC was verified by using CCK-8, colony formation assay, wound healing assay, transwell assay and xenograft tumor model. Changes in protein expression were detected by Western blotting. We found that 8 TSGs were all differentially expressed in ccRCC samples, which could divide ccRCC into two subtypes. The constructed risk score model could predict the prognosis and drug sensitivity of ccRCC patients, and was an independent prognostic factor for ccRCC. Over-expression of NPRL2 promoted apoptosis, inhibited EMT, decreased the phosphorylation of the PI3K/AKT/mTOR signaling pathway to inhibit its activity, and promoted the sensitivity of sunitinib to ccRCC cells. Collectively, our findings increased the understanding of TSGs in ccRCC, suggesting that NPRL2 as a TSG could enhance sunitinib sensitivity to ccRCC cells.

The expanding role of BAP1 in clear cell renal cell carcinoma

Mutations drive renal cell carcinoma biology and tumor growth. The BRCA1-associated protein-1 (BAP1) gene is frequently mutated in clear cell renal cell carcinoma (ccRCC) and has emerged as a prognostic and putative predictive biomarker. In this review, we discuss the role of BAP1 as a signature event of a subtype of ccRCC marked by aggressiveness, inflammation, and possibly a heightened response to immunotherapy.

Sunitinib resistance in renal cell carcinoma: From molecular mechanisms to predictive biomarkers

Currently, renal cell carcinoma (RCC) is the most prevalent type of kidney cancer. Targeted therapy has replaced radiation therapy and chemotherapy as the main treatment option for RCC due to the lack of significant efficacy with these conventional therapeutic regimens. Sunitinib, a drug used to treat gastrointestinal tumors and renal cell carcinoma, inhibits the tyrosine kinase activity of a number of receptor tyrosine kinases, including vascular endothelial growth factor receptor (VEGFR), platelet-derived growth factor receptor (PDGFR), c-Kit, rearranged during transfection (RET) and fms-related receptor tyrosine kinase 3 (Flt3). Although sunitinib has been shown to be efficacious in the treatment of patients with advanced RCC, a significant number of patients have primary resistance to sunitinib or acquired drug resistance within the 6-15 months of therapy. Thus, in order to develop more efficacious and long-lasting treatment strategies for patients with advanced RCC, it will be crucial to ascertain how to overcome sunitinib resistance that is produced by various drug resistance mechanisms. In this review, we discuss: 1) molecular mechanisms of sunitinib resistance; 2) strategies to overcome sunitinib resistance and 3) potential predictive biomarkers of sunitinib resistance.

Downstream Targets of VHL/HIF-α Signaling in Renal Clear Cell Carcinoma Progression: Mechanisms and Therapeutic Relevance

The clear cell variant of renal cell carcinoma (ccRCC) is the most common renal epithelial malignancy and responsible for most of the deaths from kidney cancer. Patients carrying inactivating mutations in the Von Hippel-Lindau (VHL) gene have an increased proclivity to develop several types of tumors including ccRCC. Normally, the Hypoxia Inducible Factor alpha (HIF-α) subunits of the HIF heterodimeric transcription factor complex are regulated by oxygen-dependent prolyl-hydroxylation, VHL-mediated ubiquitination and proteasomal degradation. Loss of pVHL function results in elevated levels of HIF-α due to increased stability, leading to RCC progression. While HIF-1α acts as a tumor suppressor, HIF-2α promotes oncogenic potential by driving tumor progression and metastasis through activation of hypoxia-sensitive signaling pathways and overexpression of HIF-2α target genes. One strategy to suppress ccRCC aggressiveness is directed at inhibition of HIF-2α and the associated molecular pathways leading to cell proliferation, angiogenesis, and metastasis. Indeed, clinical and pre-clinical data demonstrated the effectiveness of HIF-2α targeted therapy in attenuating ccRCC progression. This review focuses on the signaling pathways and the involved genes (cyclin D, c-Myc, VEGF-a, EGFR, TGF-α, GLUT-1) that confer oncogenic potential downstream of the VHL-HIF-2α signaling axis in ccRCC. Discussed as well are current treatment options (including receptor tyrosine kinase inhibitors such as sunitinib), the medical challenges (high prevalence of metastasis at the time of diagnosis, refractory nature of advanced disease to current treatment options), scientific challenges and future directions.

Characterization of Microscopic Multicellular Foci in Grossly Normal Renal Parenchyma of Von Hippel-Lindau Kidney

Background and Objectives: This study aims to describe the earliest renal lesions in patients with von Hippel-Lindau (VHL) disease, especially the multicellular microscopic pathologic events, to get information into the genesis of renal neoplasms in this condition. Materials and Methods: Multicellular events were identified, and 3dimensional reconstruction was performed in grossly normal kidney parenchyma from VHL disease patients by using H&E-stained slides previously prepared. Results: The lesions were measured and the volume of clusters was calculated. Immunohistochemistry was performed for downstream HIF-target protein carbonic anhydrase 9 (CAIX) as well as CD34 for assessment of angiogenesis. We divided lesions into four types according to lesion height/size. The number of lesions was markedly decreased from lesion 1 (smallest) to lesion 2, then from lesions 2 to 3, and again from lesion 3 to 4. Distribution was highly consistent in the four cases, and the same decrement pattern was seen in all blocks studied. The volumes of clusters were measured and divided into three categories according to their volume. The most frequent pathologic event in VHL kidneys was category 1 (smallest volume), then category 2, and then category 3. Conclusion: We demonstrate that tracking histologic and morphologic changes in 3 dimensions of multicellular microscopic pathologic events enabled us to confirm a protracted sequence of events from smaller to larger cellular amplification events in VHL kidney.

Derivative Chromosome 3 Loss from t(3;6)(q12;q14) Followed by Differential VHL Mutations Underlie Multifocal ccRCC

BACKGROUND/AIM

The Von Hippel-Lindau (VHL) gene encodes a protein (pVHL) that plays an important role in proteasome degradation of hypoxia inducible factor α (HIFα) through E3 activation. Accumulation of HIFα by loss of functional pVHL promotes tumorigenesis, thus, VHL has tumor suppressor gene capability in clear cell renal cell carcinoma (ccRCC). VHL is the most frequently mutated gene in ccRCC. The complete loss of VHL is mainly achieved by loss of chromosome 3p, which has a VHL coding region in combination with mutation or hypermethylation of the remaining copy of VHL. Given the risk of constitutional chromosome 3 translocation for RCC, it is important to detect the translocation and understand the mechanism underlying the development of multifocal ccRCC.

CASE REPORT

A 67-year-old female patient diagnosed with multifocal RCC underwent robot-assisted partial nephrectomy (RAPN) for three kidney tumors. A cancer gene panel test using next generation sequencing (NGS) detected differential VHL mutations (c.533T>G; p.L178R, c.465_466insTA; p.T157Ifs*3, c.343C>A; p.H115N), while VHL mutation was not detected in peripheral blood DNA. A tendency toward copy number loss of genes on der(3) was also detected in all tumors, but not in the germline one. A karyotype analysis revealed a germline translocation between 3 and 6, t(3;6)(q12;q14).

CONCLUSION

Chromosome 3 translocation and loss of derivative chromosome containing 3p and subsequent somatic differential VHL mutations in this case strongly support the previously proposed three-step model to explain the development of familial conventional ccRCC.

The 2022 World Health Organization Classification of Tumours of the Urinary System and Male Genital Organs-Part A: Renal, Penile, and Testicular Tumours

The fifth edition of the World Health Organization (WHO) classification of urogenital tumours (WHO "Blue Book"), published in 2022, contains significant revisions. This review summarises the most relevant changes for renal, penile, and testicular tumours. In keeping with other volumes in the fifth edition series, the WHO classification of urogenital tumours follows a hierarchical classification and lists tumours by site, category, family, and type. The section "essential and desirable diagnostic criteria" included in the WHO fifth edition represents morphologic diagnostic criteria, combined with immunohistochemistry and relevant molecular tests. The global introduction of massive parallel sequencing will result in a diagnostic shift from morphology to molecular analyses. Therefore, a molecular-driven renal tumour classification has been introduced, taking recent discoveries in renal tumour genomics into account. Such novel molecularly defined epithelial renal tumours include SMARCB1-deficient medullary renal cell carcinoma (RCC), TFEB-altered RCC, Alk-rearranged RCC, and ELOC-mutated RCC. Eosinophilic solid and cystic RCC is a novel morphologically defined RCC entity. The diverse morphologic patterns of penile squamous cell carcinomas are grouped as human papillomavirus (HPV) associated and HPV independent, and there is an attempt to simplify the morphologic classification. A new chapter with tumours of the scrotum has been introduced. The main nomenclature of testicular tumours is retained, including the use of the term "germ cell neoplasia in situ" (GCNIS) for the preneoplastic lesion of most germ cell tumours and division from those not derived from GCNIS. Nomenclature changes include replacement of the term "primitive neuroectodermal tumour" by "embryonic neuroectodermal tumour" to separate these tumours clearly from Ewing sarcoma. The term "carcinoid" has been changed to "neuroendocrine tumour", with most examples in the testis now classified as "prepubertal type testicular neuroendocrine tumour".

Current Systemic Treatments for the Hereditary Cancer Syndromes: Drug Development in Light of Genomic Defects

Advances in the genetic basis of different tumors have led to identification of tumor vulnerabilities that can be turn into targeted therapies. In this regard, PARP inhibitors cause synthetic lethality with tumors harboring BRCA1 or BRCA2 genetic alterations. On the other hand, tumors with microsatellite instability, either due to germline or sporadic alterations, are candidates for immune checkpoint inhibitors. Finally, patients with von Hippel-Lindau disease who carry a germline alteration in the VHL gene may benefit form belzutifan, a hypoxia-inducible factor 2 alpha inhibitor. Overall, research on the underlying pathological mechanisms of these tumors has provided new therapeutic opportunities that might be expanded to other sporadic tumors with similar biology.

Differential VHL mutation patterns in bilateral clear cell RCC distinguishes between independent primary tumors and contralateral metastatic disease

OBJECTIVE

To evaluate whether bilateral, multifocal clear cell renal cell carcinoma (ccRCC) patients can be differentiated by VHL mutation analysis into cases that represent either multiple independently arising primary tumors, or a single primary tumor which has spread ipsilaterally as well as to the contralateral kidney. The nature of kidney cancer multifocality outside of known hereditary syndromes is as yet poorly understood.

MATERIALS AND METHODS

DNA from multiple tumors per patient were evaluated for somatic VHL gene mutation and hypermethylation. A subset of tumors with shared VHL mutations were analyzed with targeted, next-generation sequencing assays.

RESULTS

This cohort contained 5 patients with multiple tumors that demonstrated a shared somatic VHL mutation consistent with metastatic spread including to the contralateral kidney. In several cases this was substantiated by additional shared somatic mutations in ccRCC-associated genes. In contrast, the remaining 14 patients with multiple tumors demonstrated unique, unshared VHL alterations in every analyzed tumor, consistent with independently arising kidney tumors. None of these latter patients showed any evidence of local spread or distant metastasis.

CONCLUSION

The spectrum of VHL alterations within evaluated bilateral, multifocal ccRCC tumors from a single patient can distinguish between multiple independent tumor growth and metastasis. This can be performed using currently available clinical genetic tests and will improve the accuracy of patient diagnosis and prognosis, as well as informing appropriate management.

Renal hypoxia-HIF-PHD-EPO signaling in transition metal nephrotoxicity: friend or foe?

The kidney is the main organ that senses changes in systemic oxygen tension, but it is also the key detoxification, transit and excretion site of transition metals (TMs). Pivotal to oxygen sensing are prolyl-hydroxylases (PHDs), which hydroxylate specific residues in hypoxia-inducible factors (HIFs), key transcription factors that orchestrate responses to hypoxia, such as induction of erythropoietin (EPO). The essential TM ion Fe is a key component and regulator of the hypoxia–PHD–HIF–EPO (HPHE) signaling axis, which governs erythropoiesis, angiogenesis, anaerobic metabolism, adaptation, survival and proliferation, and hence cell and body homeostasis. However, inadequate concentrations of essential TMs or entry of non-essential TMs in organisms cause toxicity and disrupt health. Non-essential TMs are toxic because they enter cells and displace essential TMs by ionic and molecular mimicry, e. g. in metalloproteins. Here, we review the molecular mechanisms of HPHE interactions with TMs (Fe, Co, Ni, Cd, Cr, and Pt) as well as their implications in renal physiology, pathophysiology and toxicology. Some TMs, such as Fe and Co, may activate renal HPHE signaling, which may be beneficial under some circumstances, for example, by mitigating renal injuries from other causes, but may also promote pathologies, such as renal cancer development and metastasis. Yet some other TMs appear to disrupt renal HPHE signaling, contributing to the complex picture of TM (nephro-)toxicity. Strikingly, despite a wealth of literature on the topic, current knowledge lacks a deeper molecular understanding of TM interaction with HPHE signaling, in particular in the kidney. This precludes rationale preventive and therapeutic approaches to TM nephrotoxicity, although recently activators of HPHE signaling have become available for therapy.

Mutation Profile Variability in the Primary Tumor and Multiple Pulmonary Metastases of Clear Cell Renal Cell Carcinoma. A Review of the Literature and Analysis of Four Metastatic Cases

(1) Background: There are limited data concerning inter-tumoral and inter-metastatic heterogeneity in clear cell renal cell carcinoma (CCRCC). The aim of our study was to review published data and to examine mutation profile variability in primary and multiple pulmonary metastases (PMs) in our cohort of four patients with metastatic CCRCC. (2) Methods: Four patients were enrolled in this study. The clinical characteristics, types of surgeries, histopathologic results, immunohistochemical and genetic evaluations of corresponding primary tumor and PMs, and follow-up data were recorded. (3) Results: In our series, the most commonly mutated genes were those in the canonically dysregulated VHL pathway, which were detected in both primary tumors and corresponding metastasis. There were genetic profile differences between primary and metastatic tumors, as well as among particular metastases in one patient. (4) Conclusions: CCRCC shows heterogeneity between the primary tumor and its metastasis. Such mutational changes may be responsible for suboptimal treatment outcomes in targeted therapy settings.

H3K36 trimethylation-mediated biological functions in cancer

Histone modification is an important form of epigenetic regulation. Thereinto, histone methylation is a critical determination of chromatin states, participating in multiple cellular processes. As a conserved histone methylation mark, histone 3 lysine 36 trimethylation (H3K36me3) can mediate multiple transcriptional-related events, such as the regulation of transcriptional activity, transcription elongation, pre-mRNA alternative splicing, and RNA m⁶A methylation. Additionally, H3K36me3 also contributes to DNA damage repair. Given the crucial function of H3K36me3 in genome regulation, the roles of H3K36me3 and its sole methyltransferase SETD2 in pathogenesis, especially malignancies, have been emphasized in many studies, and it is conceivable that disruption of histone methylation regulatory network composed of "writer", "eraser", "reader", and the mutation of H3K36me3 codes have the capacity of powerfully modulating cancer initiation and development. Here we review H3K36me3-mediated biological processes and summarize the latest findings regarding its role in cancers. We highlight the significance of epigenetic combination therapies in cancers.

Von Hippel-Lindau tumor suppressor pathways & corresponding therapeutics in kidney cancer

The identification and application of the Von Hippel-Lindau (VHL) gene is a seminal breakthrough in kidney cancer research. VHL and its protein pVHL are the root cause of most kidney cancers, and the cascading pathway below them is crucial for understanding hypoxia, in addition to the aforementioned tumorigenesis routes and treatments. We reviewed the history and functions of VHL/pVHL and Hypoxia-inducible factor (HIF), their well-known activities under low-oxygen environments as an E3 ubiquitin ligase and as a transcription factor, respectively, as well as their non-canonical functions revealed recently. Additionally, we discussed how their dysregulation promotes tumorigenesis: beginning with chromosome 3 p-arm (3p) loss/epigenetic methylation, followed by two-allele knockout, before the loss of complimentary tumor suppressor genes leads cells down predictable oncological paths. These different pathways can ultimately determine the grade, outcome, and severity of the deadliest genitourinary cancer. We finished by investigating current and proposed schemes to therapeutically treat clear cell renal cell carcinoma (ccRCC) by manipulating the hypoxic pathway utilizing Vascular Endothelial Growth Factor (VEGF) inhibitors, mammalian target of rapamycin complex 1 (mTORC1) inhibitors, small molecule HIF inhibitors, immune checkpoint blockade therapy, and synthetic lethality.

LRRK2 is a candidate prognostic biomarker for clear cell renal cell carcinoma

Background

Clear cell renal cell carcinoma (ccRCC), derived from renal tubular epithelial cells, is the most common malignant tumor of the kidney. The study of key genes related to the pathogenesis of ccRCC has become important for gene target therapy.

Methods

Bioinformatics analysis of The Cancer Genome Atlas (TCGA), the NCBI Gene Expression Omnibus (GEO) database, USUC Xena database, cBioPortal for Cancer Genomics, and MethSurv were performed to examine the aberrant genetic pattern and prognostic significance of leucine-rich repeat kinase 2 (LRRK2) expression and its relationship to clinical parameters. Immunohistochemistry and Western blot were performed to verify LRRK2 expression. The regulation of ccRCC tumor cell lines proliferation by LRRK2 was examined by CCK8 assay.

Results

Bioinformatics analysis showed that LRRK2 expression was up-regulated and largely correlated with DNA methylation in ccRCC. The up-regulation of LRRK2 was confirmed in ccRCC tissue immunohistochemically and by protein analysis. The level of expression was related to gender, pathological grade, stage, and metastatic status of ccRCC patients. Meanwhile, Kaplan–Meier analysis showed that high expression of LRRK2 correlates to a better prognosis; knockdown of LRRK2 expression attenuated the proliferation ability of ccRCC tumor cell lines; protein–protein interaction network analysis showed that LRRK2 interacts with HIF1A and EGFR.

Conclusion

We found that LRRK2 may play an important role in the tumorigenesis and progression of ccRCC. Our findings provided a potential predictor and therapeutic target in ccRCC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-021-02047-y.

Improved cancer biomarkers identification using network-constrained infinite latent feature selection

Identifying biomarkers that are associated with different types of cancer is an important goal in the field of bioinformatics. Different researcher groups have analyzed the expression profiles of many genes and found some certain genetic patterns that can promote the improvement of targeted therapies, but the significance of some genes is still ambiguous. More reliable and effective biomarkers identification methods are then needed to detect candidate cancer-related genes. In this paper, we proposed a novel method that combines the infinite latent feature selection (ILFS) method with the functional interaction (FIs) network to rank the biomarkers. We applied the proposed method to the expression data of five cancer types. The experiments indicated that our network-constrained ILFS (NCILFS) provides an improved prediction of the diagnosis of the samples and locates many more known oncogenes than the original ILFS and some other existing methods. We also performed functional enrichment analysis by inspecting the over-represented gene ontology (GO) biological process (BP) terms and applying the gene set enrichment analysis (GSEA) method on selected biomarkers for each feature selection method. The enrichments analysis reports show that our network-constraint ILFS can produce more biologically significant gene sets than other methods. The results suggest that network-constrained ILFS can identify cancer-related genes with a higher discriminative power and biological significance.

Emerging Therapies for Advanced Clear Cell Renal Cell Carcinoma

Multiple combinational regimens have recently been approved and are now considered the standard of care for patients with advanced clear cell renal cell carcinoma (RCC). Several additional combinational regimens are deep in clinical assessment and are likely to soon join the crowded front-line therapeutic landscape. Most of these regimens are combinations of agents already approved as single-agents in RCC including tyrosine kinase inhibitors (TKI) and immune checkpoint inhibitors. While these new front-line regimens are associated with reliably high response rates and prolonged survival, complete and durable remissions remain limited to a small subset of patients and the vast majority of patients continue to require subsequent therapy. The need for the continued development of novel agents in RCC persists and efforts have focused on agents targeting the molecular biology of clear cell RCC and novel immunotherapies including cytokines. In this review, we discuss the progress in the development of these novel therapies in the context of the evolving standard of care for patients with advanced clear cell RCC.

Construction of a Novel Multigene Panel Potently Predicting Poor Prognosis in Patients with Clear Cell Renal Cell Carcinoma

Simple Summary

Clear cell renal cell carcinoma (ccRCC) is the predominant cause of kidney cancer death attributed to its prevalence (70%) and its nature being the most aggressive form of kidney cancer. Most ccRCC deaths are resulted from metastasis. It is essential to know which ccRCCs are at risk of metastasis and the development to lethal disease; however, our capacity for such analysis remains poor. To improve this diagnostic capacity, we have examined a comprehensive ccRCC dataset containing 512 patients and have produced a 9-gene signature. This signature is novel; all its 9 components genes are unknown to be related to ccRCC. Importantly, all 9 individual genes possess significant ability in diagnosis of ccRCC metastasis and fatality; the combination of these genes or this signature predicts deadly ccRCCs at an impressive efficiency. This research will open new avenues in ccRCC research and will have a major impact in reducing ccRCC-associated deaths.

Abstract

We observed associations of IQGAP1 downregulation with poor overall survival (OS) in clear cell renal cell carcinoma (ccRCC). Differentially expressed genes (DEGs, n = 611) were derived from ccRCCs with (n = 111) and without IQGAP1 (n = 397) reduction using the TCGA PanCancer Atlas ccRCC dataset. These DEGs exhibit downregulations of immune response and upregulations of DNA damage repair pathways. Through randomization of the TCGA dataset into a training and testing subpopulation, a 9-gene panel (SigIQGAP1NW) was derived; it predicts poor OS in training, testing, and the full population at a hazard ratio (HR) 2.718, p < 2 × 10⁻¹⁶, p = 1.08 × 10⁻⁵, and p < 2 × 10⁻¹⁶, respectively. SigIQGAP1NW independently associates with poor OS (HR 1.80, p = 2.85 × 10⁻⁶) after adjusting for a set of clinical features, and it discriminates ccRCC mortality at time-dependent AUC values of 70% at 13.8 months, 69%/31M, 69%/49M, and 75.3%/71M. All nine component genes of SigIQGAP1NW are novel to ccRCC. The inclusion of RECQL4 (a DNA helicase) in SigIQGAP1NW agrees with IQGAP1 DEGs enhancing DNA repair. THSD7A affects kidney function; its presence in SigIQGAP1NW is consistent with our observed THSD7A downregulation in ccRCC (n = 523) compared to non-tumor kidney tissues (n = 100). Collectively, we report a novel multigene panel that robustly predicts poor OS in ccRCC.

Identification of anti-tumoral feedback loop between VHLα and hnRNPA2B1 in renal cancer

Our previous study identified a novel VHLα isoform which negatively modulated hnRNPA2B1 expression and therefore influenced pyruvate kinase transcript splicing in renal cancer, while the regulation and initiation of alternative translation are largely unknown. Here we unraveled the CUG-mediated translation start of VHLα, which was subjected to the regulation by both eukaryotic initiator factor eIF2A and RNA helicase eIF4A. Unexpectedly, we found hnRNPA2B1 promoted VHLα alternative translation as well via direct interaction with its octadic pentamer region of VHL transcript. The N-terminal of VHLα was indispensable in mediating ubiquitination of hnRNPA2B1 at lysine residues 274 and 305. We further identified aberrant overexpression of c-myc as upstream oncogenic signaling to positively regulate hnRNPA2B1 transcription in renal cancer. Therefore, our data suggested an anti-tumoral feedback loop between VHLα and hnRNPA2B1.

Exploiting the circuit breaker cancer evolution model in human clear cell renal cell carcinoma

The incessant interactions between susceptible humans and their respective macro/microenvironments registered throughout their lifetime result in the ultimate manifestation of individual cancers. With the average lifespan exceeding 50 years of age in humans since the beginning of 20th century, aging - the "time" factor - has played an ever-increasing role alongside host and environmental factors in cancer incidences. Cancer is a genetic/epigenetic disease due to gain-of-function mutations in cancer-causing genes (oncogene; OG) and/or loss-of-function mutations in tumor-suppressing genes (tumor suppressor genes; TSG). In addition to their integral relationship with cancer, a timely deployment of specific OG and/or TSG is in fact needed for higher organisms like human to cope with respective physiological and pathological conditions. Over the past decade, extensive human kidney cancer genomics have been performed and novel mouse models recapitulating human kidney cancer pathobiology have been generated. With new genomic, genetic, mechanistic, clinical and therapeutic insights accumulated from studying clear cell renal cell carcinoma (ccRCC)-the most common type of kidney cancer, we conceived a cancer evolution model built upon the OG-TSG signaling pair analogous to the electrical circuit breaker (CB) that permits necessary signaling output and at the same time prevent detrimental signaling overdrive. Hence, this viewpoint aims at providing a step-by-step mechanistic explanation/illustration concerning how inherent OG-TSG CBs intricately operate in concert for the organism's wellbeing; and how somatic mutations, the essential component for genetic adaptability, inadvertently triggers a sequential outage of specific sets of CBs that normally function to maintain and protect and individual tissue homeostasis.

Oncometabolites in renal cancer

The study of cancer metabolism has evolved vastly beyond the remit of tumour proliferation and survival with the identification of the role of 'oncometabolites' in tumorigenesis. Simply defined, oncometabolites are conventional metabolites that, when aberrantly accumulated, have pro-oncogenic functions. Their discovery has led researchers to revisit the Warburg hypothesis, first postulated in the 1950s, of aberrant metabolism as an aetiological determinant of cancer. As such, the identification of oncometabolites and their utilization in diagnostics and prognostics, as novel therapeutic targets and as biomarkers of disease, are areas of considerable interest in oncology. To date, fumarate, succinate, L-2-hydroxyglutarate (L-2-HG) and D-2-hydroxyglutarate (D-2-HG) have been characterized as bona fide oncometabolites. Extensive metabolic reprogramming occurs during tumour initiation and progression in renal cell carcinoma (RCC) and three oncometabolites - fumarate, succinate and L-2-HG - have been implicated in this disease process. All of these oncometabolites inhibit a superfamily of enzymes known as α-ketoglutarate-dependent dioxygenases, leading to epigenetic dysregulation and induction of pseudohypoxic phenotypes, and also have specific pro-oncogenic capabilities. Oncometabolites could potentially be exploited for the development of novel targeted therapies and as biomarkers of disease.

Characterization of renal cell carcinoma-associated constitutional chromosome abnormalities by genome sequencing

Constitutional translocations, typically involving chromosome 3, have been recognized as a rare cause of inherited predisposition to renal cell carcinoma (RCC) for four decades. However, knowledge of the molecular basis of this association is limited. We have characterized the breakpoints by genome sequencing (GS) of constitutional chromosome abnormalities in five individuals who presented with RCC. In one individual with constitutional t(10;17)(q11.21;p11.2), the translocation breakpoint disrupted two genes: the known renal tumor suppressor gene (TSG) FLCN (and clinical features of Birt‐Hogg‐Dubé syndrome were detected) and RASGEF1A. In four cases, the rearrangement breakpoints did not disrupt known inherited RCC genes. In the second case without chromosome 3 involvement, the translocation breakpoint in an individual with a constitutional t(2;17)(q21.1;q11.2) mapped 12 Kb upstream of NLK. Interestingly, NLK has been reported to interact indirectly with FBXW7 and a previously reported RCC‐associated translocation breakpoint disrupted FBXW7. In two cases of constitutional chromosome 3 translocations, no candidate TSGs were identified in the vicinity of the breakpoints. However, in an individual with a constitutional chromosome 3 inversion, the 3p breakpoint disrupted the FHIT TSG (which has been reported previously to be disrupted in two apparently unrelated families with an RCC‐associated t(3;8)(p14.2;q24.1). These findings (a) expand the range of constitutional chromosome rearrangements that may be associated with predisposition to RCC, (b) confirm that chromosome rearrangements not involving chromosome 3 can predispose to RCC, (c) suggest that a variety of molecular mechanisms are involved the pathogenesis of translocation‐associated RCC, and (d) demonstrate the utility of GS for investigating such cases.

The von Hippel-Lindau Tumor Suppressor Gene: Implications and Therapeutic Opportunities

The discovery of the von Hippel-Lindau (VHL) gene marked a milestone in our understanding of clear cell renal cell carcinoma (ccRCC) pathogenesis. VHL inactivation is not only a defining feature of ccRCC, but also the initiating event. Herein, we discuss canonical and noncanonical pVHL functions, as well as breakthroughs shaping our understanding of ccRCC evolution and evolutionary subtypes. We conclude by presenting evolving strategies to therapeutically exploit effector mechanisms downstream of pVHL.

von Hippel-Lindau Disease: an Update

Purpose of Review

In this review, we discuss the key molecular and clinical developments in VHL disease that have the potential to impact on the natural history of the disease and improve patient outcomes.

Recent Findings

Identifiable mutations in VHL underlie most cases of VHL and define clear genotype-phenotype correlations. Detailed clinical and molecular characterisation has allowed the implementation of lifelong screening programmes that have improved clinical outcomes. Functional characterisation of the VHL protein complex has revealed its role in oxygen sensing and the mechanisms of tumourigenesis that are now being exploited to develop novel therapies for VHL and renal cancer.

Summary

The molecular and cellular landscape of VHL-associated tumours is revealing new opportunities to modify the natural history of the disease and develop therapies. Drugs are now entering clinical trials and combined with improved clinical and molecular diagnosis, and lifelong surveillance programmes, further progress towards reducing the morbidity and mortality associated with VHL disease is anticipated.

Clinical significance of glutamate metabotropic receptors in renal cell carcinoma risk and survival

Accumulating evidence suggests the roles of glutamate metabotropic receptors (GRMs) in cancer, in addition to synaptic signalling. The present study assessed the associations of genetic variants in eight GRM genes with regard to risk and overall survival (OS) in 780 renal cell carcinoma (RCC) patients and controls. After adjustment for known risk factors, GRM5 rs7102764 T was associated with an increased risk of RCC (P = 0.006). Additional analysis has provided evidence that rs7102764 T was correlated with a higher expression of GRM5, which is consistently found to be upregulated in tumours, compared to normal tissues. Furthermore, the GRM3 rs701332 C, GRM4 rs2499707 T, and GRM4 rs4713742 T alleles were significantly associated with a poorer OS (P ≤ 0.030). The three loci were also observed to have strong cumulative effects on OS. Additional analysis has revealed a significant genotype‐expression correlation of rs2499707 T with increased GRM4 expression, which in turn leads to poorer OS in patients with RCC. GRMs might be involved in RCC development and progression, and genetic variants in GRMs might be promising biomarkers.

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

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

Loss of Estrogen-Regulated MIR135A1 at 3p21.1 Promotes Tamoxifen Resistance in Breast Cancer

The dysregulation of miRNAs has been increasingly recognized as a critical mediator of cancer development and progression. Here, we show that frequent deletion of the MIR135A1 locus is associated with poor prognosis in primary breast cancer. Forced expression of miR-135a decreased breast cancer progression, while inhibition of miR-135a with a specific miRNA sponge elicited opposing effects, suggestive of a tumor suppressive role of miR-135a in breast cancer. Estrogen receptor alpha (ERα) bound the promoter of MIR135A1 for its transcriptional activation, whereas tamoxifen treatment inhibited expression of miR-135a in ERα+ breast cancer cells. miR-135a directly targeted ESR1, ESRRA, and NCOA1, forming a negative feedback loop to inhibit ERα signaling. This regulatory feedback between miR-135a and ERα demonstrated that miR-135a regulated the response to tamoxifen. The tamoxifen-mediated decrease in miR-135a expression increased the expression of miR-135a targets to reduce tamoxifen sensitivity. Consistently, miR-135a expression was downregulated in ERα+ breast cancer cells with acquired tamoxifen resistance, while forced expression of miR-135a partially resensitized these cells to tamoxifen. Tamoxifen resistance mediated by the loss of miR-135a was shown to be partially dependent on the activation of the ERK1/2 and AKT pathways by miR-135a-targeted genes. Taken together, these results indicate that deletion of the MIR135A1 locus and decreased miR-135a expression promote ERα+ breast cancer progression and tamoxifen resistance.Significance: Loss of miR-135a in breast cancer disrupts an estrogen receptor-induced negative feedback loop, perpetuating disease progression and resistance to therapy.Graphical Abstract: http://cancerres.aacrjournals.org/content/canres/78/17/4915/F1.large.jpg Cancer Res; 78(17); 4915-28. ©2018 AACR.

Clinicopathologic Significance of VHL Gene Alteration in Clear-Cell Renal Cell Carcinoma: An Updated Meta-Analysis and Review

The von Hippel-Lindau (VHL) gene is inactivated frequently in sporadic clear-cell renal cell carcinomas (ccRCCs) by genetic alteration (mutation, loss of heterozygosity, or promoter hypermethylation). However, the pathological or prognostic significance of VHL gene alteration has not been well defined. We conducted this meta-analysis to evaluate the association between VHL alteration and clinopathologic findings in ccRCCs. We performed a systematic computerized search of online databases, including PubMed, EMBASE, Web of Science, and Google Scholar (up to July 2018). From ten studies, 1,082 patients were included in the pooled analyses of odds ratios (ORs) with 95% confidence intervals (CIs) for pathological features (nuclear grade and disease stage) or hazard ratios (HRs) with 95% CIs for overall survival (OS). VHL alteration was not significantly associated with nuclear grade (OR = 0.79, 95% CI: 0.59–1.06, p = 0.12) or disease stage (OR = 1.07, 95% CI: 0.79–1.46, p = 0.65). There was also no significant correlation between VHL alteration and OS (HR = 0.75, 95% CI: 0.43–1.29, p = 0.30). When we pooled HRs for OS according to the VHL alteration types, the combined HRs were 0.72 (95% CI: 0.47–1.11, p = 0.14) for VHL mutations and 1.32 (95% CI: 0.70–2.47, p = 0.39) for methylation. In conclusion, this meta-analysis indicates that VHL gene alteration is not significantly associated with the pathological features and survival in patients with ccRCC.

A phase II evaluation of sunitinib in the treatment of persistent or recurrent clear cell ovarian carcinoma: An NRG Oncology/Gynecologic Oncology Group Study (GOG-254)

OBJECTIVES

To determine the efficacy and tolerability of sunitinib in recurrent or persistent clear cell ovarian cancer patients.

METHODS

All patients had one or two prior regimens with measurable disease. Tumors were at least 50% clear cell histomorphology and negative for WT-1 antigen and estrogen receptor expression by immunohistochemistry. Sunitinib 50 mg per day for 4 weeks was administered in repeated 6-week cycles until disease progression or prohibitive toxicity. Primary end points were progression-free survival (PFS) at 6 months and clinical response. The study was designed to determine if the drug had a response rate of at least 20% or 6-month PFS of at least 25%.

RESULTS

Of 35 patients enrolled, 30 were treated and eligible (median age: 51, range: 27-73). Twenty-five (83%) were White, 4 (13%) Asian, and 1 (3%) unknown. The majority 28 (83%) patients, underwent ≤3 but 2 (7%) had 16 courses of study therapy. Five (16.7%) patients had PFS ≥6 months (90% CI: 6.8%-31.9%). Two (6.7%) patients had a partial or complete response (90% CI: 1.2%-19.5%). The median PFS was 2.7 months. The median overall survival was 12.8 months. The most common grade 3 adverse events were fatigue (4), hypertension (4), neutropenia (4), anemia (3), abdominal pain (3), and leukopenia (3). Grade 4-5 adverse events included: thrombocytopenia (5), anemia (2), acute kidney Injury (1), stroke (1), and allergic reaction (1).

CONCLUSION

Sunitinib demonstrated minimal activity in the second- and third-line treatment of persistent or recurrent clear cell ovarian carcinoma. ClinicalTrials.gov number, NCT00979992.

Timing the Landmark Events in the Evolution of Clear Cell Renal Cell Cancer: TRACERx Renal

Clear cell renal cell carcinoma (ccRCC) is characterized by near-universal loss of the short arm of chromosome 3, deleting several tumor suppressor genes. We analyzed whole genomes from 95 biopsies across 33 patients with clear cell renal cell carcinoma. We find hotspots of point mutations in the 5' UTR of TERT, targeting a MYC-MAX-MAD1 repressor associated with telomere lengthening. The most common structural abnormality generates simultaneous 3p loss and 5q gain (36% patients), typically through chromothripsis. This event occurs in childhood or adolescence, generally as the initiating event that precedes emergence of the tumor's most recent common ancestor by years to decades. Similar genomic changes drive inherited ccRCC. Modeling differences in age incidence between inherited and sporadic cancers suggests that the number of cells with 3p loss capable of initiating sporadic tumors is no more than a few hundred. Early development of ccRCC follows well-defined evolutionary trajectories, offering opportunity for early intervention.

Genomic Alterations in Human Breast Cancer: A Review

We review and discuss data on the genetic alterations documented in human breast carcinomas at the molecular level. These alterations may result in: 1) deletion of genetic material (chromosome 11p, 13q, 3p, 1q, 17p); 2) amplification of genes or entire chromosomal segments (c-myc, c-erb-B2, locus DF3/PUM, loci on 11q13); 3) rearrangements (c-myc); 4) point mutations (c-ras). Presently available informations do not allow the development of cohesive pathogenetic models but indicate that the molecular basis of human breast cancer is heterogeneous.

Second Primary Renal Cell Carcinomas following Solid Tumors. Four Case Reports and Review of the Literature

We report multiple malignancies in four patients with metachronous renal adenocarcinomas. The group of patients includes two women treated for primary breast and ovarian cancer and two men with prostate and colon cancer respectively. The occurrence of renal cancer following these primary solid tumors was not associated with previous treatments. The authors review the literature and discuss pathogenic mechanisms underlying renal cell carcinoma.

Integrated genomic analysis identifies clinically relevant subtypes of renal clear cell carcinoma

Background

Renal cell carcinoma (RCC) account for over 80% of renal malignancies. The most common type of RCC can be classified into three subtypes including clear cell, papillary and chromophobe. ccRCC (the Clear Cell Renal Cell Carcinoma) is the most frequent form and shows variations in genetics and behavior. To improve accuracy and personalized care and increase the cure rate of cancer, molecular typing for individuals is necessary.

Methods

We adopted the genome, transcriptome and methylation HMK450 data of ccRCC in The Cancer Genome Atlas Network in this research. Consensus Clustering algorithm was used to cluster the expression data and three subtypes were found. To further validate our results, we analyzed an independent data set and arrived at a consistent conclusion. Next, we characterized the subtype by unifying genomic and clinical dimensions of ccRCC molecular stratification. We also implemented GSEA between the malignant subtype and the other subtypes to explore latent pathway varieties and WGCNA to discover intratumoral gene interaction network. Moreover, the epigenetic state changes between subgroups on methylation data are discovered and Kaplan-Meier survival analysis was performed to delve the relation between specific genes and prognosis.

Results

We found a subtype of poor prognosis in clear cell renal cell carcinoma, which is abnormally upregulated in focal adhesions and cytoskeleton related pathways, and the expression of core genes in the pathways are negatively correlated with patient outcomes.

Conclusions

Our work of classification schema could provide an applicable framework of molecular typing to ccRCC patients which has implications to influence treatment decisions, judge biological mechanisms involved in ccRCC tumor progression, and potential future drug discovery.

Electronic supplementary material

The online version of this article (10.1186/s12885-018-4176-1) contains supplementary material, which is available to authorized users.

RNA sequencing reveals widespread transcriptome changes in a renal carcinoma cell line

We used RNA sequencing (RNA-Seq) technology to investigate changes in the transcriptome profile in the Caki-1 clear cell renal cell carcinoma (ccRCC) cells, which overexpress monocyte chemoattractant protein-induced protein 1 (MCPIP1). RNA-Seq data showed changes in 11.6% and 41.8% of the global transcriptome of Caki-1 cells overexpressing wild-type MCPIP1 or its D141N mutant, respectively. Gene ontology and KEGG pathway functional analyses showed that these transcripts encoded proteins involved in cell cycle progression, protein folding in the endoplasmic reticulum, hypoxia response and cell signalling. We identified 219 downregulated transcripts in MCPIP1-expressing cells that were either unchanged or upregulated in D141N-expressing cells. We validated downregulation of 15 transcripts belonging to different functional pathways by qRT-PCR. The growth and viability of MCPIP1-expressing cells was reduced because of elevated p21Cip1 levels. MCPIP1-expressing cells also showed reduced levels of DDB1 transcript that encodes component of the E3 ubiquitin ligase that degrades p21Cip1. These results demonstrate that MCPIP1 influences the growth and viability of ccRCC cells by increasing or decreasing the transcript levels for proteins involved in cell cycle progression, protein folding, hypoxia response, and cell signaling.

Loss of PBRM1 rescues VHL dependent replication stress to promote renal carcinogenesis

Inactivation of the VHL (Von Hippel Lindau) tumour suppressor has long been recognised as necessary for the pathogenesis of clear cell renal cancer (ccRCC); however, the molecular mechanisms underlying transformation and the requirement for additional genetic hits remain unclear. Here, we show that loss of VHL alone results in DNA replication stress and damage accumulation, effects that constrain cellular growth and transformation. By contrast, concomitant loss of the chromatin remodelling factor PBRM1 (mutated in 40% of ccRCC) rescues VHL-induced replication stress, maintaining cellular fitness and allowing proliferation. In line with these data we demonstrate that combined deletion of Vhl and Pbrm1 in the mouse kidney is sufficient for the development of fully-penetrant, multifocal carcinomas, closely mimicking human ccRCC. Our results illustrate how VHL and PBRM1 co-operate to drive renal transformation and uncover replication stress as an underlying vulnerability of all VHL mutated renal cancers that could be therapeutically exploited.

Modern Systemic Therapy for Metastatic Renal Cell Carcinoma of the Clear Cell Type

In the last 30 years, there have been many advances in the treatment of metastatic renal cell carcinoma of the clear cell type. Renal cell carcinoma has long been understood to have a component of immune mediation and has been responsive to immune-based therapies; in addition to early cytokine therapy, newer checkpoint inhibition therapies have also demonstrated activity. Molecular characterization of the genome of clear cell renal cell carcinoma enabled identification of the roles of angiogenesis and hypoxic stress. This led to development of small-molecule tyrosine kinase inhibitors and inhibitors of mammalian target of rapamycin that have provided additional benefit to patients. Ongoing strategies of combinations of immune and antiangiogenic therapies may lead to further advancements.

Management of Locally Advanced Renal Cell Carcinoma

Background

Renal cell carcinoma accounts for approximately 3% of adult malignancies and over 90% of primary renal tumors. Recurrence rates for patients with locally advanced renal cell carcinoma (LARCC) remain high.

Methods

The authors review literature regarding prognostic factors, potential biomarkers, surgical strategies, and adjuvant therapy trials for patients with LARCC.

Results

Molecular tumor markers may improve existing staging systems for predicting prognosis. Surgery is the best initial treatment for most patients with clinically localized renal tumors, although complete surgical resection can be challenging for patients with large tumors, bulky regional lymph node involvement, or inferior vena cava tumor thrombus. Significant recurrence rates for patients with LARCC undergoing nephrectomy indicate the presence of undetected micrometastases at the time of surgery. Adjuvant radiation, chemotherapy, and immunotherapy have been ineffective. Other trials of adjuvant therapy are ongoing.

Conclusions

Aggressive surgical resection alone for LARCC is not sufficient to prevent disease recurrence in a significant number of patients. Adjuvant therapies are needed to improve cancer-specific survival.

Assessment of circulating copy number variant detection for cancer screening

Current high-sensitivity cancer screening methods, largely utilizing correlative biomarkers, suffer from false positive rates that lead to unnecessary medical procedures and debatable public health benefit overall. Detection of circulating tumor DNA (ctDNA), a causal biomarker, has the potential to revolutionize cancer screening. Thus far, the majority of ctDNA studies have focused on detection of tumor-specific point mutations after cancer diagnosis for the purpose of post-treatment surveillance. However, ctDNA point mutation detection methods developed to date likely lack either the scope or analytical sensitivity necessary to be useful for cancer screening, due to the low (<1%) ctDNA fraction derived from early stage tumors. On the other hand, tumor-derived copy number variant (CNV) detection is hypothetically a superior means of ctDNA-based cancer screening for many tumor types, given that, relative to point mutations, each individual tumor CNV contributes a much larger number of ctDNA fragments to the overall pool of circulating free DNA (cfDNA). A small number of studies have demonstrated the potential of ctDNA CNV-based screening in select cancer types. Here we perform an in silico assessment of the potential for ctDNA CNV-based cancer screening across many common cancers, and suggest ctDNA CNV detection shows promise as a broad cancer screening methodology.

SETting the Stage for Cancer Development: SETD2 and the Consequences of Lost Methylation

The H3 lysine 36 histone methyltransferase SETD2 is mutated across a range of human cancers. Although other enzymes can mediate mono- and dimethylation, SETD2 is the exclusive trimethylase. SETD2 associates with the phosphorylated carboxy-terminal domain of RNA polymerase and modifies histones at actively transcribed genes. The functions associated with SETD2 are mediated through multiple effector proteins that bind trimethylated H3K36. These effectors directly mediate multiple chromatin-regulated processes, including RNA splicing, DNA damage repair, and DNA methylation. Although alterations in each of these processes have been associated with SETD2 loss, the relative role of each in the development of cancer is not fully understood. Critical vulnerabilities resulting from SETD2 loss may offer a strategy for potential therapeutics.

Excess of a Rassf1-targeting microRNA, miR-193a-3p, perturbs cell division fidelity

Background:

Several microRNA (miRNA) molecules have emerged as important post-transcriptional regulators of tumour suppressor and oncogene expression. Ras association domain family member 1 (RASSF1) is a critical tumour suppressor that controls multiple aspects of cell proliferation such as cell cycle, cell division and apoptosis. The expression of RASSF1 is lost in a variety of cancers due to the promoter hypermethylation.

Methods:

miR-193a-3p was identified as a RASSF1-targeting miRNA by a dual screening approach. In cultured human cancer cells, immunoblotting, qRT–PCR, luciferase reporter assays, time-lapse microscopy and immunofluorescence methods were used to study the effects of excess miR-193a-3p on RASSF1 expression and cell division.

Results:

Here, we report a new miRNA-mediated mechanism that regulates RASSF1 expression: miR-193a-3p binds directly to RASSF1-3′UTR and represses the mRNA and protein expression. In human cancer cells, excess of miR-193a-3p causes polyploidy through impairment of the Rassf1-Syntaxin 16 signalling pathway that is needed for completion of cytokinesis. In the next cell cycle the miR-193a-3p-overexpressing cells exhibit multipolar mitotic spindles, mitotic delay and elevated frequency of cell death.

Conclusions:

Our results suggest that besides epigenetic regulation, altered expression of specific miRNAs may contribute to the loss of Rassf1 in cancer cells and cause cell division errors.

MCPIP1 contributes to clear cell renal cell carcinomas development

Monocyte Chemoattractant protein-induced protein 1 (MCPIP1), also known as Regnase-1, is encoded by the ZC3H12a gene, and it mediates inflammatory processes by regulating the stability of transcripts coding for proinflammatory cytokines and controlling activity of transcription factors, such as NF-κB and AP1. We found that MCPIP1 transcript and protein levels are strongly downregulated in clear cell renal cell carcinoma (ccRCC) samples, which were derived from patients surgically treated for renal cancer compared to surrounded normal tissues. Using Caki-1 cells as a model, we analyzed the role of MCPIP1 in cancer development. We showed that MCPIP1 expression depends on the proteasome activity; however, hypoxia and hypoxia inducible factor 2 alfa (HIF2α) are key factors lowering MCPIP1 expression. Furthermore, we found that MCPIP1 negatively regulates HIF1α and HIF2α levels and in the case of the last one, the mechanism is based on the regulation of the half time of transcript coding for HIF2α. Enhanced expression of MCPIP1 in Caki-1 cells results in a downregulation of transcripts encoding VEGFA, GLUT1, and IL-6. Furthermore, MCPIP1 decreases the activity of mTOR and protein kinase B (Akt) in normoxic conditions. Taken together, MCPIP1 contributes to the ccRCC development.

PD-1/PD-L1 blockade in renal cell cancer

INTRODUCTION

Immunotherapy using checkpoint inhibitors is providing significant benefit to patients with renal cell carcinoma (RCC), both in overall survival and tolerability of treatment. Given the recent approval of the first checkpoint inhibitor in RCC, this review discusses the background and clinical data for checkpoint inhibition in RCC. Areas covered: This review introduces and discusses the basic biologic mechanisms of checkpoint inhibitor function and focuses on the current evidence in clinical trials for the use of immunotherapy in RCC. Expert commentary: Immunotherapy has been a mainstay of therapy in RCC, but the recent approval of nivolumab with ORR of 25% and durable responses has provided a transformative new therapeutic option.