Molecular diagnosis and therapy of kidney cancer

Alterations of the AKT Pathway in Sporadic Human Tumors, Inherited Susceptibility to Cancer, and Overgrowth Syndromes

The AKT kinases are critical signaling molecules that regulate cellular physiology upon the activation of tyrosine kinase receptors and phosphatidylinositol 3-kinases (PI3K). AKT kinases govern many cellular processes considered hallmarks of cancer, including cell proliferation and survival, cell size, tumor invasion, metastasis, and angiogenesis. AKT signaling is regulated by multiple tumor suppressors and oncogenic proteins whose loss or activation, respectively, leads to dysregulation of this pathway, thereby contributing to oncogenesis. Herein, we review the enormous body of literature documenting how the AKT pathway becomes hyperactivated in sporadic human tumors and various hereditary cancer syndromes. We also discuss the role of activating mutations of AKT pathway genes in various chimeric overgrowth disorders, including Proteus syndrome, hypoglycemia with hypertrophy, CLOVES and SOLAMEN syndromes, and hemimegalencephaly.

Exosome-related lncRNA score: A value-based individual treatment strategy for predicting the response to immunotherapy in clear cell renal cell carcinoma

BACKGROUND

Exosomes play a crucial role in intercellular communication in clear cell renal cell carcinoma (ccRCC), while the long non-coding RNAs (lncRNAs) are implicated in tumorigenesis and progression.

AIMS

The purpose of this study is to construction a exosomes-related lncRNA score and a ceRNA network to predict the response to immunotherapy and potential targeted drug in ccRCC.

METHODS

Data of ccRCC patients were obtained from the TCGA database. Pearson correlation analysis was used to identify eExosomes-related lncRNAs (ERLRs) from Top10 exosomes-related genes that have been screened. The entire cohort was randomly divided into a training cohort and a validation cohort in equal scale. LASSO regression and multivariate cox regression was used to construct the ERLRs-based score. Differences in clinicopathological characteristics, immune microenvironment, immune checkpoints, and drug susceptibility between the high- and low-risk groups were also investigated. Finally, the relevant ceRNA network was constructed by machine learning to analyze their potential targets in immunotherapy and drug use of ccRCC patients.

RESULTS

A score consisting of 4ERLRs was identified, and patients with higher ERLRs-based score tended to have a worse prognosis than those with lower ERLRs-based score. ROC curves and multivariate Cox regression analysis demonstrated that the score could be considered as a risk factor for prognosis in both training and validation cohorts. Moreover, patients with high scores are predisposed to experience poor overall survival, a larger prevalence of advanced stage (III-IV), a greater tumor mutational burden, a higher infiltration of immunosuppressive cells, and a greater likelihood of responding favorably to immunotherapy. The importance of EMX2OS was determined by mechanical learning, and the ceRNA network was constructed, and EMX2OS may be a potential therapeutic target, possibly exerting its function through the EMX2OS/hsa-miR-31-5p/TLN2 axis.

CONCLUSIONS

Based on machine learning, a novel ERLRs-based score was constructed for predicting the survival of ccRCC patients. The ERLRs-based score is a promising potential independent prognostic factor that is closely correlated with the immune microenvironment and clinicopathological characteristics. Meanwhile, we screened out key lncRNAEMX2OS and identified the EMX2OS/hsa-miR-31-5p/TLN2 axis, which may provide new clues for the targeted therapy of ccRCC.

Analysis of SIGLEC12 expression, immunomodulation and prognostic value in renal cancer using multiomic databases

Siglecs belong to a family of immune regulatory receptors predominantly found on hematopoietic cells. They interact with Sia, resulting in the activation or inhibition of the immune response. Previous reports have suggested that the SIGLEC12 gene, which encodes the Siglec-XII protein, is expressed in the epithelial tissues and upregulated in carcinomas. However, studies deciphering the role of Siglec-XII in renal cancer (RC) are still unavailable, and here we provide insights on this question. We conducted expression analysis using the Human Protein Atlas and UALCAN databases. The impact of SIGLEC12 on RC prognosis was determined using the KM plotter, and an assessment of immune infiltration with SIGLEC12 was performed using the TIMER database. GSEA was conducted to identify the pathways affected by SIGLEC12. Finally, using GeneMania, we identified Siglec-XII interacting proteins. Our findings indicated that macrophages express SIGLEC12 in the kidney. Furthermore, we hypothesize that Siglec-XII expression might be involved in the increase of primary RC, but this effect may not be dependent on the age of the patient. In the tumour microenvironment, oncogenic pathways appeared to be upregulated by SIGLEC12. Similarly, our analysis suggested that SIGLEC12-related kidney renal papillary cell carcinomas may be more suitable for targeted immunotherapy, such as CTLA-4 and PD-1/PD-L1 inhibitors. These preliminary results suggested that high expression of SIGLEC12 is associated with poor prognosis for RC. Future studies to assess its clinical utility are necessitated.

The application of peroxidase mimetic nanozymes in cancer diagnosis and therapy

In recent decades, scholarly investigations have predominantly centered on nanomaterials possessing enzyme-like characteristics, commonly referred to as nanozymes. These nanozymes have emerged as viable substitutes for natural enzymes, offering simplicity, stability, and superior performance across various applications. Inorganic nanoparticles have been extensively employed in the emulation of enzymatic activity found in natural systems. Nanoparticles have shown a strong ability to mimic a number of enzyme-like functions. These systems have made a lot of progress thanks to the huge growth in nanotechnology research and the unique properties of nanomaterials. Our presentation will center on the kinetics, processes, and applications of peroxidase-like nanozymes. In this discourse, we will explore the various characteristics that exert an influence on the catalytic activity of nanozymes, with a particular emphasis on the prevailing problems and prospective consequences. This paper presents a thorough examination of the latest advancements achieved in the domain of peroxidase mimetic nanozymes in the context of cancer diagnosis and treatment. The primary focus is on their use in catalytic cancer therapy, alongside chemotherapy, phototherapy, sonodynamic therapy, radiation, and immunotherapy. The primary objective of this work is to offer theoretical and technical assistance for the prospective advancement of anticancer medications based on nanozymes. Moreover, it is anticipated that this will foster the investigation of novel therapeutic strategies aimed at achieving efficacious tumor therapy.

Smart Nanozymes for Cancer Therapy: The Next Frontier in Oncology

Nanomaterials that mimic the catalytic activity of natural enzymes in the complex biological environment of the human body are called nanozymes. Recently, nanozyme systems have been reported with diagnostic, imaging, and/or therapeutic capabilities. Smart nanozymes strategically exploit the tumor microenvironment (TME) by the in situ generation of reactive species or by the modulation of the TME itself to result in effective cancer therapy. This topical review focuses on such smart nanozymes for cancer diagnosis, and therapy modalities with enhanced therapeutic effects. The dominant factors that guide the rational design and synthesis of nanozymes for cancer therapy include an understanding of the dynamic TME, structure-activity relationships, surface chemistry for imparting selectivity, and site-specific therapy, and stimulus-responsive modulation of nanozyme activity. This article presents a comprehensive analysis of the subject including the diverse catalytic mechanisms of different types of nanozyme systems, an overview of the TME, cancer diagnosis, and synergistic cancer therapies. The strategic application of nanozymes in cancer treatment can well be a game changer in future oncology. Moreover, recent developments may pave the way for the deployment of nanozyme therapy into other complex healthcare challenges, such as genetic diseases, immune disorders, and ageing.

Preclinical optimization of a diode laser-based clamp-free partial nephrectomy in a large animal model

Kidney cancer is a common urologic malignancy with either laparoscopic (LPN) or robotic partial nephrectomy as therapeutic options of choice for localized tumors. However, renal resection and suturing are challenging steps of the procedure that can lead to complications such as prolonged warm ischemia, bleeding, and urinary fistulas. LPN with a diode laser is an efficient technique due to its cutting and/or coagulation attributes. Surprisingly, key laser features such as wavelength and power remain undefined. Using a large porcine model, we evaluated the laser range of wavelength and power in a clamp-free LPN and compared it to the established gold-standard LPN technique (i.e., cold-cutting and suturing). By analyzing surgery duration, bleeding, presence of urine leak, tissue damage related to the resected renal fragment and the remaining organ, hemoglobin levels, and renal function, we show that an optimized experimental diode laser clamp-free LPN (wavelength, 980 nm; power, 15 W) had shorter surgery time with less bleeding, and better postoperative renal function recovery when compared to the well-established technique. Together, our data indicate that partial nephrectomy with a diode laser clamp-free LPN technique is an improved alternative to the gold-standard technique. Therefore, translational clinical trials towards human patient applications are readily feasible.

Distinguishing Renal Cell Carcinoma From Normal Kidney Tissue Using Mass Spectrometry Imaging Combined With Machine Learning

PURPOSE

Accurately distinguishing renal cell carcinoma (RCC) from normal kidney tissue is critical for identifying positive surgical margins (PSMs) during partial and radical nephrectomy, which remains the primary intervention for localized RCC. Techniques that detect PSM with higher accuracy and faster turnaround time than intraoperative frozen section (IFS) analysis can help decrease reoperation rates, relieve patient anxiety and costs, and potentially improve patient outcomes.

MATERIALS AND METHODS

Here, we extended our combined desorption electrospray ionization mass spectrometry imaging (DESI-MSI) and machine learning methodology to identify metabolite and lipid species from tissue surfaces that can distinguish normal tissues from clear cell RCC (ccRCC), papillary RCC (pRCC), and chromophobe RCC (chRCC) tissues.

RESULTS

From 24 normal and 40 renal cancer (23 ccRCC, 13 pRCC, and 4 chRCC) tissues, we developed a multinomial lasso classifier that selects 281 total analytes from over 27,000 detected molecular species that distinguishes all histological subtypes of RCC from normal kidney tissues with 84.5% accuracy. On the basis of independent test data reflecting distinct patient populations, the classifier achieves 85.4% and 91.2% accuracy on a Stanford test set (20 normal and 28 RCC) and a Baylor-UT Austin test set (16 normal and 41 RCC), respectively. The majority of the model's selected features show consistent trends across data sets affirming its stable performance, where the suppression of arachidonic acid metabolism is identified as a shared molecular feature of ccRCC and pRCC.

CONCLUSION

Together, these results indicate that signatures derived from DESI-MSI combined with machine learning may be used to rapidly determine surgical margin status with accuracies that meet or exceed those reported for IFS.

Candidate variants in DNA replication and repair genes in early-onset renal cell carcinoma patients referred for germline testing

BACKGROUND

Early-onset renal cell carcinoma (eoRCC) is typically associated with pathogenic germline variants (PGVs) in RCC familial syndrome genes. However, most eoRCC patients lack PGVs in familial RCC genes and their genetic risk remains undefined.

METHODS

Here, we analyzed biospecimens from 22 eoRCC patients that were seen at our institution for genetic counseling and tested negative for PGVs in RCC familial syndrome genes.

RESULTS

Analysis of whole-exome sequencing (WES) data found enrichment of candidate pathogenic germline variants in DNA repair and replication genes, including multiple DNA polymerases. Induction of DNA damage in peripheral blood monocytes (PBMCs) significantly elevated numbers of [Formula: see text]H2AX foci, a marker of double-stranded breaks, in PBMCs from eoRCC patients versus PBMCs from matched cancer-free controls. Knockdown of candidate variant genes in Caki RCC cells increased [Formula: see text]H2AX foci. Immortalized patient-derived B cell lines bearing the candidate variants in DNA polymerase genes (POLD1, POLH, POLE, POLK) had DNA replication defects compared to control cells. Renal tumors carrying these DNA polymerase variants were microsatellite stable but had a high mutational burden. Direct biochemical analysis of the variant Pol δ and Pol η polymerases revealed defective enzymatic activities.

CONCLUSIONS

Together, these results suggest that constitutional defects in DNA repair underlie a subset of eoRCC cases. Screening patient lymphocytes to identify these defects may provide insight into mechanisms of carcinogenesis in a subset of genetically undefined eoRCCs. Evaluation of DNA repair defects may also provide insight into the cancer initiation mechanisms for subsets of eoRCCs and lay the foundation for targeting DNA repair vulnerabilities in eoRCC.

The Underestimated Role of the p53 Pathway in Renal Cancer

The TP53 tumor suppressor gene is known as the guardian of the genome, playing a pivotal role in controlling genome integrity, and its functions are lost in more than 50% of human tumors due to somatic mutations. This percentage rises to 90% if mutations and alterations in the genes that code for regulators of p53 stability and activity are taken into account. Renal cell carcinoma (RCC) is a clear example of cancer that despite having a wild-type p53 shows poor prognosis because of the high rate of resistance to radiotherapy or chemotherapy, which leads to recurrence, metastasis and death. Remarkably, the fact that p53 is poorly mutated does not mean that it is functionally active, and increasing experimental evidences have demonstrated this. Therefore, RCC represents an extraordinary example of the importance of p53 pathway alterations in therapy resistance. The search for novel molecular biomarkers involved in the pathways that regulate altered p53 in RCC is mandatory for improving early diagnosis, evaluating the prognosis and developing novel potential therapeutic targets for better RCC treatment.

CDH13 is a prognostic biomarker and a potential therapeutic target for patients with clear cell renal cell carcinoma

CDH13 is an atypical member of the cadherin family and is closely related to the clinicopathological factors and prognosis of many types of cancer. However, the role of CDH13 in clear cell renal cell carcinoma (ccRCC) remains unknown. Therefore, we comprehensively analyzed the expression level, diagnostic efficacy, clinical significance, prognostic value, immune infiltration, methylation status, genetic alteration, and biological functions of CDH13 in ccRCC patients. The results showed that CDH13 was significantly upregulated in ccRCC and strongly correlated with better survival, lower cancer stages, and lower tumor grades of ccRCC patients. Additionally, the immune infiltration analysis indicated that CDH13 might play a crucial role in regulating the tumor microenvironment of ccRCC. The results of methylation analysis showed that the epigenetic status of CDH13 was altered, and the prognosis of ccRCC patients was related not only to DNA methylation but also to m6A modification of CDH13. Finally, the results based on clinical samples further elucidated the expression pattern of CDH13 in ccRCC. In conclusion, CDH13 might be a novel prognostic biomarker and therapeutic target for patients with ccRCC. And our study provides new insights into the potential molecular changes and strategies for the treatment of ccRCC.

Evaluating Established Roles, Future Perspectives and Methodological Heterogeneity for Wilms’ Tumor 1 (WT1) Antigen Detection in Adult Renal Cell Carcinoma, Using a Novel N-Terminus Targeted Antibody (Clone WT49)

Renal cell carcinoma (RCC) is arguably the deadliest form of genitourinary malignancy and is nowadays viewed as a heterogeneous series of cancers, with the same origin but fundamentally different metabolisms and clinical behaviors. Immunohistochemistry (IHC) is increasingly necessary for RCC subtyping and definitive diagnosis. WT1 is a complex gene involved in carcinogenesis. To address reporting heterogeneity and WT1 IHC standardization, we used a recent N-terminus targeted monoclonal antibody (clone WT49) to evaluate WT1 protein expression in 56 adult RCC (aRCC) cases. This is the largest WT1 IHC investigation focusing exclusively on aRCCs and the first report on clone WT49 staining in aRCCs. We found seven (12.5%) positive cases, all clear cell RCCs, showing exclusively nuclear staining for WT1. We did not disregard cytoplasmic staining in any of the negative cases. Extratumoral fibroblasts, connecting tubules and intratumoral endothelial cells showed the same exclusively nuclear WT1 staining pattern. We reviewed WT1 expression patterns in aRCCs and the possible explanatory underlying metabolomics. For now, WT1 protein expression in aRCCs is insufficiently investigated, with significant discrepancies in the little data reported. Emerging WT1-targeted RCC immunotherapy will require adequate case selection and sustained efforts to standardize the quantification of tumor-associated antigens for aRCC and its many subtypes.

Bibliometric Analysis of Birt-Hogg-Dubé Syndrome From 2001 to 2021

Background

Birt-Hogg-Dubé syndrome (BHD) is a rare autosomal dominant inherited disorder caused by germline mutations in folliculin (FLCN). Despite our significantly evolved understanding of BHD over the past decades, no bibliometric analyses have been conducted in this field. This study aimed to analyze and visualize the characteristics of publication outputs, the research hotspots, and scientific frontiers about BHD using bibliometric analysis.

Methods

All relevant literature on BHD was culled from the Web of Science Core Collection (WoSCC) database. Valid data were extracted from the articles and visually analyzed using CiteSpace and VOSviewer.

Results

A total of 751 qualifying papers were included. Publication outputs concerning BHD increased over time. The dominant position of the United States and Japan in BHD research field was evident. National Cancer Institute (the USA) and Yokohama City University (Japan) were the two most productive organizations. W. Marston Linehan exerted a considerable publication impact and had made the most remarkable contributions in the field of BHD. Plos One was the journal with the highest publication outputs, and half of the top 10 journals and co-cited journals belonged to Q1 or Q2. Keyword citation bursts revealed that management, tumor suppressor, flcn gene, spectrum, diagnosis, risk, computed tomography were the emerging research hotspots.

Conclusion

Research on BHD is prosperous. International cooperation between countries and organizations is also expected to deepen and strengthen in the future. Our results indicated that FLCN-associated pathways involved in the pathogenesis of BHD, specific options for early diagnosis, and molecular-targeting therapies will remain research hotspots in the future.

Nanozymes: Versatile Platforms for Cancer Diagnosis and Therapy

Natural enzymes usually suffer from high production cost, ease of denaturation and inactivation, and low yield, making them difficult to be broadly applicable. As an emerging type of artificial enzyme, nanozymes that combine the characteristics of nanomaterials and enzymes are promising alternatives. On the one hand, nanozymes have high enzyme-like catalytic activities to regulate biochemical reactions. On the other hand, nanozymes also inherit the properties of nanomaterials, which can ameliorate the shortcomings of natural enzymes and serve as versatile platforms for diverse applications. In this review, various nanozymes that mimic the catalytic activity of different enzymes are introduced. The achievements of nanozymes in different cancer diagnosis and treatment technologies are summarized by highlighting the advantages of nanozymes in these applications. Finally, future research directions in this rapidly developing field are outlooked.

Gender-Specific Metabolomics Approach to Kidney Cancer

Renal cell carcinoma (RCC) is the most common form of kidney malignancy. RCC is more common among men with a 2/1 male/female incidence ratio worldwide. Given the underlying epidemiological differences in the RCC incidence between males and females, we explored the gender specific ¹H NMR serum metabolic profiles of RCC patients and their matched controls. A number of differential metabolites were shared by male and female RCC patients. These RCC specific changes included lower lactate, threonine, histidine, and choline levels together with increased levels of pyruvate, N-acetylated glycoproteins, beta-hydroxybutyrate, acetoacetate, and lysine. Additionally, serum lactate/pyruvate ratio was a strong predictor of RCC status regardless of gender. Although only moderate changes in metabolic profiles were observed between control males and females there were substantial gender related differences among RCC patients. Gender specific metabolic features associated with RCC status were identified suggesting that different metabolic panels could be leveraged for a more precise diagnostic.

NCF1/2/4 Are Prognostic Biomarkers Related to the Immune Infiltration of Kidney Renal Clear Cell Carcinoma

Neutrophil cytoplasmic factor 1/2/4 (NCF1/2/4) belongs to the NADPH oxidase complex, which is a cytoplasmic component, and its polymorphism is the main factor related to autoimmune diseases, which is probably caused by the regulation of peroxide. They also play a role in tumor growth and metastasis. This research is aimed at evaluating the biological function and prognostic role of NCF1, NCF2, and NCF4 genes in kidney renal clear cell carcinoma (KIRC) by using multiple online bioinformatics website, including Oncomine, GEPIA, UALCAN, Kaplan-Meier Plotter, TIMER, TISIDB, cBioPortal, LinkedOmics, GeneMANIA, and DAVID databases. The mRNA levels of NCFs were higher in KIRC tissues than in normal tissues. The overexpression of NCFs was significantly correlated with advanced pathological grades and individual cancer stages in KIRC. Meanwhile, the expressions of NCFs played an important role in the tumorigenesis and progression of KIRC. Prognostic value analysis suggested that high transcription levels of NCF1/4 were associated with poor overall survival in KIRC patients. In addition, results from the LinkedOmics database showed that the KEGG pathway related to NCFs mainly focused on immune activation and immune regulation function. NCF genetic alterations, including copy number amplification, missense mutation, and deep deletion, could be found through the cBioPortal database. Further, NCF expression was significantly correlated with infiltration levels of various immune cells as well as immune signatures. Protein-protein interaction network and enrichment analysis of NCF1/2/4 in KIRC showed that NCF coexpressed genes mainly associated with diverse immune marker sets showed significance. Overall, these results indicated that NCFs could be prognostic biomarkers as well as effective targets for diagnosis in KIRC.

Pediatric onco-nephrology: time to spread the word : Part I: early kidney involvement in children with malignancy

Onco-nephrology has been a growing field within the adult nephrology scope of practice. Even though pediatric nephrologists have been increasingly involved in the care of children with different forms of malignancy, there has not been an emphasis on developing special expertise in this area. The fast pace of discovery in this field, including the development of new therapy protocols with their own kidney side effects and the introduction of the CD19-targeted chimeric antigen receptor T cell (CAR-T) therapy, has introduced new challenges for general pediatric nephrologists because of the unique effects of these treatments on the kidney. Moreover, with the improved outcomes in children receiving cancer therapy come an increased number of survivors at risk for chronic kidney disease related to both their cancer diagnosis and therapy. Therefore, it is time for pediatric onco-nephrology to take its spot on the expanding subspecialties map in pediatric nephrology.

Imaging evaluation of hereditary renal tumors: a pictorial review

More than 10 hereditary renal tumor syndromes (HRTSs) and related germline mutations have been reported with HRTS-associated renal and extrarenal manifestations with benign and malignant tumors. Radiologists play an important role in detecting solitary or multiple renal masses with or without extrarenal findings on imaging and may raise the possibility of an inherited predisposition to renal cell carcinoma, providing direction for further screening, intervention and surveillance of the patients and their close family members before the development of potentially lethal renal and extrarenal tumors. Renal cell carcinomas (RCCs) associated with von Hippel-Lindau disease are typically slow growing while RCCs associated with HRTSs, such as hereditary leiomyomatosis and renal cell carcinoma syndrome, are highly aggressive. Therefore, radiologists need to be familiar with clinical and imaging findings of renal and extrarenal manifestations of HRTSs. This article reviews clinical and imaging findings for the evaluation of patients with well-established HRTSs from a radiologist's perspective to facilitate the clinical decision-making process for patient management.

Ciliary localization of folliculin mediated via a kinesin-2-binding motif is required for its functions in mTOR regulation and tumor suppression

Folliculin (FLCN) is a tumor suppressor protein involved in many cellular processes, including cell signaling, apoptosis, and autophagy. In ciliated cells, FLCN localizes to primary cilia and controls mTORC1 signaling in response to flow stress. Here, we show that the ciliary localization of FLCN requires its interaction with kinesin-2, the motor protein for anterograde intraflagellar transport. FLCN binds to kinesin-2 through a loop region in the middle of the protein. Single point mutations within this region of FLCN disrupt its kinesin-2 binding and ciliary entry. The mutants lose the ability to suppress the abnormal mTORC1/2 signaling activities and anchorage-independent growth of FLCN-deficient tumor cells. These observations suggest that ciliary localization of FLCN is essential for its function as a tumor suppressor.

A pan-kidney cancer study identifies subtype specific perturbations on pathways with potential drivers in renal cell carcinoma

BACKGROUND

Renal cell carcinoma (RCC) is a complex disease and is comprised of several histological subtypes, the most frequent of which are clear cell renal cell carcinoma (ccRCC), papillary renal cell carcinoma (PRCC) and chromophobe renal cell carcinoma (ChRCC). While lots of studies have been performed to investigate the molecular characterizations of different subtypes of RCC, our knowledge regarding the underlying mechanisms are still incomplete. As molecular alterations are eventually reflected on the pathway level to execute certain biological functions, characterizing the pathway perturbations is crucial for understanding tumorigenesis and development of RCC.

METHODS

In this study, we investigated the pathway perturbations of various RCC subtype against normal tissue based on differential expressed genes within a certain pathway. We explored the potential upstream regulators of subtype-specific pathways with Ingenuity Pathway Analysis (IPA). We also evaluated the relationships between subtype-specific pathways and clinical outcome with survival analysis.

RESULTS

In this study, we carried out a pathway-based analysis to explore the mechanisms of various RCC subtypes with TCGA RNA-seq data. Both commonly altered pathways and subtype-specific pathways were detected. To identify the distinctive characteristics of each subtype, we focused on subtype-specific perturbed pathways. Specifically, we observed that some of the altered pathways were regulated by several recurrent upstream regulators which presenting different expression patterns among distinct RCC subtypes. We also noticed that a large number of perturbed pathways were controlled by the subtype-specific upstream regulators. Moreover, we also evaluated the relationships between perturbed pathways and clinical outcome. Prognostic pathways were identified and their roles in tumor development and progression were inferred.

CONCLUSIONS

In summary, we evaluated the relationships among pathway perturbations, upstream regulators and clinical outcome for differential subtypes in RCC. We hypothesized that the alterations of common upstream regulators as well as subtype-specific upstream regulators work together to affect the downstream pathway perturbations and drive cancer initialization and prognosis. Our findings not only increase our understanding of the mechanisms of various RCC subtypes, but also provide targets for personalized therapeutic intervention.

Mass Spectrometry-Based Metabolic Fingerprinting Contributes to Unveil the Role of RSUME in Renal Cell Carcinoma Cell Metabolism

Clear cell renal cell carcinoma (ccRCC) is a heterogeneous disease with 50-80% patients exhibiting mutations in the von Hippel-Lindau (VHL) gene. RSUME (RWD domain (termed after three major RWD-containing proteins: RING finger-containing proteins, WD-repeat-containing proteins, and yeast DEAD (DEXD)-like helicases)-containing protein small ubiquitin-related modifier (SUMO) enhancer) acts as a negative regulator of VHL function in normoxia. A discovery-based metabolomics approach was developed by means of ultraperformance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry (MS) for fingerprinting the endometabolome of a human ccRCC cell line 786-O and three other transformed cell systems (n = 102) with different expressions of RSUME and VHL. Cross-validated orthogonal projection to latent structures discriminant analysis models were built on positive, negative, and a combination of positive- and negative-ion mode MS data sets. Discriminant feature panels selected by an iterative multivariate classification allowed differentiating cells with different expressions of RSUME and VHL. Fifteen identified discriminant metabolites with level 1, including glutathione, butyrylcarnitine, and acetylcarnitine, contributed to understand the role of RSUME in ccRCC. Altered pathways associated with the RSUME expression were validated by biological and bioinformatics analyses. Combined results showed that in the absence of VHL, RSUME is involved in the downregulation of the antioxidant defense system, whereas in the presence of VHL, it acts in rerouting energy-related pathways, negatively modulating the lipid utilization, and positively modulating the fatty acid synthesis, which may promote deposition in droplets.

The immune-checkpoint HLA-G/ILT4 is involved in the regulation of VEGF expression in clear cell renal cell carcinoma

Background

Clear cell renal cell carcinoma (ccRCC), the most aggressive renal cancer, is characterized by early lymph node metastases and bad prognosis. Most therapies targeting advanced or metastatic ccRCC are based, as first-line treatment, on the administration of the vascular endothelial growth factor (VEGF) neutralizing antibody termed Bevacizumab. Despite proven benefits, the expected results were not obtained for the majority of patients. The possibility that an intricate interplay between angiogenesis and immune-checkpoints might exist lead us to evaluate tumor angiogenesis, by means of VEGF expression together with the immune checkpoint HLA-G/ILT4.

Methods

Tumor specimens were obtained from patients from two separate cohorts: One from “Evita Pueblo” Hospital from Berazategui, (Buenos Aires, Argentina) and the second includes patients surgically operated at the Urology Department of Saint-Louis Hospital (Paris, France) with a confirmed ccRCC diagnosis. Immunohistochemistry was performed with specific antibodies directed against HLA-G, VEGF-A, VEGF-C, D240, CD34, ILT4 and Ca-IX. In addition, gene expression levels were measured in a cell line derived from a ccRCC patient by semi-quantitative RT-PCR.

Results

Our results show that the highly vascularized tumors of ccRCC patients express high levels of VEGF and the immune-checkpoint HLA-G. In addition, ILT4, one of the HLA-G receptors, was detected on macrophages surrounding tumor cells, suggesting the generation of an immune-tolerant microenvironment that might favor tumorigenesis. Notably, RT-qPCR analysis provided the first evidence on the transcriptional relationship between HLA-G/ILT4 and the VEGF family. Namely, in the presence of HLA-G or ILT4, the levels of VEGF-A are diminished whereas those of VEGF-C are increased.

Conclusions

In an effort to find new therapeutic molecules and fight against metastasis dissemination associated with the poor survival rates of ccRCC patients, these findings provide the rationale for co-targeting angiogenesis and the immune checkpoint HLA-G.

Identification of diagnostic metabolic signatures in clear cell renal cell carcinoma using mass spectrometry imaging

Clear cell renal cell carcinoma (ccRCC) is the most common and lethal subtype of kidney cancer. Intraoperative frozen section (IFS) analysis is used to confirm the diagnosis during partial nephrectomy. However, surgical margin evaluation using IFS analysis is time consuming and unreliable, leading to relatively low utilization. In our study, we demonstrated the use of desorption electrospray ionization mass spectrometry imaging (DESI-MSI) as a molecular diagnostic and prognostic tool for ccRCC. DESI-MSI was conducted on fresh-frozen 23 normal tumor paired nephrectomy specimens of ccRCC. An independent validation cohort of 17 normal tumor pairs was analyzed. DESI-MSI provides two-dimensional molecular images of tissues with mass spectra representing small metabolites, fatty acids and lipids. These tissues were subjected to histopathologic evaluation. A set of metabolites that distinguish ccRCC from normal kidney were identified by performing least absolute shrinkage and selection operator (Lasso) and log-ratio Lasso analysis. Lasso analysis with leave-one-patient-out cross-validation selected 57 peaks from over 27,000 metabolic features across 37,608 pixels obtained using DESI-MSI of ccRCC and normal tissues. Baseline Lasso of metabolites predicted the class of each tissue to be normal or cancerous tissue with an accuracy of 94 and 76%, respectively. Combining the baseline Lasso with the ratio of glucose to arachidonic acid could potentially reduce scan time and improve accuracy to identify normal (82%) and ccRCC (88%) tissue. DESI-MSI allows rapid detection of metabolites associated with normal and ccRCC with high accuracy. As this technology advances, it could be used for rapid intraoperative assessment of surgical margin status.

Cell Adhesion-Related Molecules Play a Key Role in Renal Cancer Progression by Multinetwork Analysis

Renal cell carcinoma (RCC) is one of the most common malignancies in the urinary system. The study aimed to identify genetic characteristics and reveal the underlying mechanisms in RCC. GSE53757, GSE46699, and TCGA KIRC database (n = 897) were analyzed to screen differentially expressed genes (DEGs) in RCC. The gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were performed, followed by the analysis of the protein-protein interaction (PPI) network of the DEGs by Cytoscape software. In all, 834 DEGs were identified in RCC, including 416 upregulated genes and 418 downregulated genes. The top 10 hub genes, VEGFA, EGFR, EGF, CD44, CD86, FN1, ITGAM, ITGB2, TLR2, and PTPRC, were identified from the PPI network according to the core degree. The following subnetwork revealed that these significant modules were enriched in positive regulation of response to external stimulus, regulation of leukocyte-mediated immunity, and regulation of exocytosis. The expressions of these hub genes were also validated using qRT-PCR and IHC in Changzheng RCC database (n = 160). We especially found that half of the top ten hub genes were cell adhesion-related molecules, which were associated with RCC progression and poor prognosis. In conclusion, these hub genes, particularly cell adhesion-related molecules, could be used as prognostic biomarkers and potential therapeutic targets for RCC.

Improving diagnosis of genitourinary cancers: Biomarker discovery strategies through mass spectrometry-based metabolomics

The genitourinary oncology field needs integration of results from basic science, epidemiological studies, clinical and translational research to improve the current methods for diagnosis. MS-based metabolomics can be transformative for disease diagnosis and contribute to global health parity. Metabolite panels are promising to translate metabolomic findings into the clinics, changing the current diagnosis paradigm based on single biomarker analysis. This review article describes capabilities of the MS-based oncometabolomics field for improving kidney, prostate, and bladder cancer detection, early diagnosis, risk stratification, and outcome. Published works are critically discussed based on the study design; type and number of samples analyzed; data quality assessment through quality assurance and quality control practices; data analysis workflows; confidence levels reported for identified metabolites; validation attempts; the overlap of discriminant metabolites for the different genitourinary cancers; and the translation capability of findings into clinical settings. Ongoing challenges are discussed, and future directions are delineated.

Preclinical efficacy of dual mTORC1/2 inhibitor AZD8055 in renal cell carcinoma harboring a TFE3 gene fusion

Background

Renal cell carcinomas (RCC) harboring a TFE3 gene fusion (TfRCC) represent an aggressive subset of kidney tumors. Key signaling pathways of TfRCC are unknown and preclinical in vivo data are lacking. We investigated Akt/mTOR pathway activation and the preclinical efficacy of dual mTORC1/2 versus selective mTORC1 inhibition in TfRCC.

Methods

Levels of phosphorylated Akt/mTOR pathway proteins were compared by immunoblot in TfRCC and clear cell RCC (ccRCC) cell lines. Effects of the mTORC1 inhibitor, sirolimus, and the dual mTORC1/2 inhibitor, AZD8055, on Akt/mTOR activation, cell cycle progression, cell viability and cytotoxicity were compared in TfRCC cells. TfRCC xenograft tumor growth in mice was evaluated after 3-week treatment with oral AZD8055, intraperitoneal sirolimus and respective vehicle controls.

Results

The Akt/mTOR pathway was activated to a similar or greater degree in TfRCC than ccRCC cell lines and persisted partly during growth factor starvation, suggesting constitutive activation. Dual mTORC1/2 inhibition with AZD8055 potently inhibited TfRCC viability (IC50 = 20-50 nM) due at least in part to cell cycle arrest, while benign renal epithelial cells were relatively resistant (IC50 = 400 nM). Maximal viability reduction was greater with AZD8055 than sirolimus (80–90% versus 30–50%), as was the extent of Akt/mTOR pathway inhibition, based on significantly greater suppression of P-Akt (Ser473), P-4EBP1, P-mTOR and HIF1α. In mouse xenograft models, AZD8055 achieved significantly better tumor growth inhibition and prolonged mouse survival compared to sirolimus or vehicle controls.

Conclusions

Akt/mTOR activation is common in TfRCC and a promising therapeutic target. Dual mTORC1/2 inhibition suppresses Akt/mTOR signaling more effectively than selective mTORC1 inhibition and demonstrates in vivo preclinical efficacy against TFE3-fusion renal cell carcinoma.

Electronic supplementary material

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Practical Molecular Testing in a Clinical Genitourinary Service

CONTEXT.—

Molecular testing is increasingly playing a key role in the diagnosis, prognosis, and treatment of neoplasms of the genitourinary system.

OBJECTIVE.—

To provide a general overview of the clinically relevant molecular tests available for neoplasms of the genitourinary tract.

DATA SOURCES.—

Relevant medical literature indexed on PubMed.

CONCLUSIONS.—

Understanding of the molecular oncology of genitourinary neoplasms is rapidly advancing, and the pathologist must be aware of the practical implications of molecular testing. While many genomic abnormalities are not yet clinically relevant, there is an increasing library of ancillary tests that may guide diagnosis, prognosis, and/or treatment of many neoplasms. Recurrent genomic abnormalities have been identified in many types of renal cell carcinoma, and some types of renal cell carcinoma are specifically defined by the molecular abnormality. Two major routes of developing urothelial carcinoma have been molecularly described. Recurrent translocations involving ETS family genes are found in approximately half of prostate cancer cases. Testicular germ cell tumors typically harbor i(12p). Penile neoplasms are often high-risk human papillomavirus-driven cancers. Nonetheless, even as genitourinary neoplasms are increasingly better understood at the molecular level, further research with eventual clinical validation is needed for optimal diagnosis, prognosis, and treatment of aggressive malignancies in the genitourinary tract.

Cost-utility of Sunitinib Versus Pazopanib in Metastatic Renal Cell Carcinoma in Canada using Real-world Evidence

BACKGROUND AND OBJECTIVE

The development of new targeted therapies in kidney cancer has shaped disease management in the metastatic phase. Our study aims to conduct a cost-utility analysis of sunitinib versus pazopanib in first-line setting in Canada for metastatic renal cell carcinoma (mRCC) patients using real-world data.

METHODS

A Markov model with Monte-Carlo microsimulations was developed to estimate the clinical and economic outcomes of patients treated in first-line with sunitinib versus pazopanib. Transition probabilities were estimated using observational data from a Canadian database where real-life clinical practice was captured. The costs of therapies, disease progression, and management of adverse events were included in the model in Canadian dollars ($Can). Utility and disutility values were included for each health state. Incremental cost-utility ratio (ICUR) and incremental cost-effectiveness ratios (ICER) were calculated for a time horizon of 5 years, from the Canadian Healthcare System perspective.

RESULTS

The cost difference was $36,303 and the difference in quality-adjusted life year (QALY) was 0.54 in favour of sunitinib with an ICUR of $67,227/QALY for sunitinib versus pazopanib. The major cost component (56%) is related to best supportive care (BSC) where patients tend to stay for a longer period of time compared to other states. The difference in life years gained (LYG) between sunitinib and pazopanib was 1.21 LYG (33.51 vs 19.03 months) and the ICER was $30,002/LYG. Sensitivity analysis demonstrated the robustness of the model with a high probability of sunitinib being a cost-effective option when compared to pazopanib.

CONCLUSION

When using real-world evidence, sunitinib is found to be a cost-effective treatment compared to pazopanib in mRCC patients in Canada.

Metabolic Footprinting of a Clear Cell Renal Cell Carcinoma in Vitro Model for Human Kidney Cancer Detection

A protocol for harvesting and extracting extracellular metabolites from an in vitro model of human renal cell lines was developed to profile the exometabolome by means of a discovery-based metabolomics approach using ultraperformance liquid chromatography coupled to quadrupole-time-of-flight mass spectrometry. Metabolic footprints provided by conditioned media (CM) samples ( n = 66) of two clear cell Renal Cell Carcinoma (ccRCC) cell lines with different genetic backgrounds and a nontumor renal cell line, were compared with the human serum metabolic profile of a pilot cohort ( n = 10) comprised of stage IV ccRCC patients and healthy individuals. Using a cross-validated orthogonal projection to latent structures-discriminant analysis model, a panel of 21 discriminant features selected by iterative multivariate classification, allowed differentiating control from tumor cell lines with 100% specificity, sensitivity, and accuracy. Isoleucine/leucine, phenylalanine, N-lactoyl-leucine, and N-acetyl-phenylalanine, and cysteinegluthatione disulfide (CYSSG) were identified by chemical standards, and hydroxyprolyl-valine was identified with MS and MS/MS experiments. A subset of 9 discriminant features, including the identified metabolites except for CYSSG, produced a fingerprint of classification value that enabled discerning ccRCC patients from healthy individuals. To our knowledge, this is the first time that N-lactoyl-leucine is associated with ccRCC. Results from this study provide a proof of concept that CM can be used as a serum proxy to obtain disease-related metabolic signatures.

Patterns of management of translocation renal cell carcinoma

OBJECTIVE

Translocation renal cell carcinoma (TRCC) represents 1% to 5% of all cases of renal cell carcinoma (RCC), with the highest frequency among children and young adults. Management of these tumors is ill defined. We sought to characterize clinicopathological features of TRCC and patterns of medical and surgical management in a middle eastern health institute.

MATERIAL AND METHODS

Clinical and pathological data of 23 patients from a single institution diagnosed with TRCC between January 2005 and July 2017 were retrospectively reviewed. We dichotomized patients based on demographics, methods of surgical approach and pathologic tumor stage. We then evaluated the methods of medical management for metastatic disease and response to treatment based on cancer-specific survival (CSS) and progression-free survival (PFS).

RESULTS

The median age at diagnosis was 37 years. Fifteen (65%) patients were male. Most of the patients were diagnosed incidentally (65%) during abdominal imaging for other reasons. The mean tumor size was 9 cm, 47% of the patients had pathologic ≥ T3 stage. Eleven patients had lymph node dissection for clinically enlarged lymph nodes, 7 of which (64%) had lymph node metastasis. Partial nephrectomies were performed for three tumors. Eight patients had metastasis (34.7%), and 3 of them had metastasis at the time of diagnosis. Six patients received sunitinib for the treatment of metastatic disease, one patient had complete response, 4 patients had stable disease and one had disease progression. Three patients died during follow-up period because of development of metastasis at postoperative 4 (n=1), and 21 (n=1) months, and cerebral hemorrhage (n=1). The mean follow-up period was 35 months and 3-year disease-free survival was 75%.

CONCLUSION

TRCC is rarely seen but carries significant risk of disease progression with potential response to targeted therapy.

The complex relationship between TFEB transcription factor phosphorylation and subcellular localization

The MiT-TFE family of basic helix-loop-helix leucine-zipper transcription factors includes four members: TFEB, TFE3, TFEC, and MITF Originally described as oncogenes, these factors play a major role as regulators of lysosome biogenesis, cellular energy homeostasis, and autophagy. An important mechanism by which these transcription factors are regulated involves their shuttling between the surface of lysosomes, the cytoplasm, and the nucleus. Such dynamic changes in subcellular localization occur in response to nutrient fluctuations and various forms of cell stress and are mediated by changes in the phosphorylation of multiple conserved amino acids. Major kinases responsible for MiT-TFE protein phosphorylation include mTOR, ERK, GSK3, and AKT In addition, calcineurin de-phosphorylates MiT-TFE proteins in response to lysosomal calcium release. Thus, through changes in the phosphorylation state of MiT-TFE proteins, lysosome function is coordinated with the cellular metabolic state and cellular demands. This review summarizes the evidence supporting MiT-TFE regulation by phosphorylation at multiple key sites. Elucidation of such regulatory mechanisms is of fundamental importance to understand how these transcription factors contribute to both health and disease.

Activation of G protein coupled estrogen receptor (GPER) promotes the migration of renal cell carcinoma via the PI3K/AKT/MMP-9 signals

Renal cell carcinoma (RCC) is the third most frequent malignancy within urological oncology. However, the mechanisms responsible for RCC metastasis are still needed further illustration. Our present study revealed that a seven-transmembrane receptor G-protein coupled estrogen receptor (GPER) was highly detected in various RCC cell lines such as ACHN, OS-RC-2 and SW839. The activation of GPER by its specific agonist G-1 significantly promoted the in vitro migration and invasion of ACHN and OS-RC-2 cells. G-1 also up regulated the expression of matrix metalloproteinase-2 (MMP-2) and MMP-9. The inhibitor of MMP-9 (Cat-444278), but not MMP-2 (Sc-204092), abolished G-1 induced cell migration, which suggested that MMP-9 is the key molecule mediating G-1 induced RCC progression. Further, G-1 treatment resulted in phosphorylation of AKT and ERK in RCC cells. PI3K/AKT inhibitor (LY294002), while not ERK inhibitor (PD98059), significantly abolished G-1 induced up regulation of MMP-9 in both AHCN and OS-RC-2 cells. Generally, our data revealed that activation of GPER by its specific agonist G-1 promoted the metastasis of RCC cells through PI3K/AKT/MMP-9 signals, which might be a promising new target for drug discovery of RCC patients.

Increased B4GALT1 expression associates with adverse outcome in patients with non-metastatic clear cell renal cell carcinoma

B4GALT1 is one of seven beta-1, 4-galactosyltransferase (B4GALT) genes, which has distinct functions in various malignances. Here, we evaluate the association of B4GALT1 expression with oncologic outcome in patients with non-metastatic clear cell renal cell carcinoma (ccRCC). A retrospective analysis of 438 patients with non-metastatic ccRCC at two academic medical centers between 2005 and 2009 was performed. The first cohort with 207 patients was treated as training cohort and the other as validation cohort. Tissue microarrays (TMAs) were created in triplicate from formalin-fixed, paraffin embedded specimens. Immunohistochemistry (IHC) was performed and the association of B4GALT1 expression with standard pathologic features and prognosis were evaluated. B4GALT1 expression was significantly associated with tumor T stage (P<0.001 and P<0.001, respectively), Fuhrman grade (P<0.001 and P<0.001, respectively) and necrosis (P=0.021 and P=0.002, respectively) in both training and validation cohorts. And high B4GALT1 expression indicated poor overall survival (OS) (P<0.001 and P<0.001, respectively) in the two cohorts. Furthermore, B4GALT1 expression was identified as an independent adverse prognostic factor for survival (P=0.007 and P=0.002, respectively). Moreover, the accuracy of established prognostic models was improved when B4GALT1 expression was added. Therefore, a predictive nomogram was generated with identified independent prognosticators to assess patients' OS at 5 and 10 years. Increased B4GALT1 expression is a potential independent adverse prognostic factor for OS in patients with non-metastatic ccRCC.

Extracellular miR-224 as a prognostic marker for clear cell renal cell carcinoma

Exosome-miRNAs (exo-miR) have recently been identified as modulators of cancer progression and distant metastasis. We previously found that intracellular miR-224 is up-regulated and significantly related to cancer invasion and metastasis in clear cell renal cell carcinoma (ccRCC). We therefore investigated the role of exosome miR-224 in ccRCC and explored the interaction between intra- and extracellular miR-224 in renal cell carcinoma. To validate the method for isolating exosomes from blood samples or cell culture media, we examined exosome morphology using transmission electron microscope (TEM). We investigated the relationship between exo-miR-224 expression and patient prognosis in 108 ccRCC patients. We isolated exosomes from a metastatic renal cancer cell line and tested their effects on a primary renal cancer cell line with several functional analyses. We found that the high expression level exo-miR-224 group has significantly shorter progression-free survival, cancer-specific survival, and overall survival compared with the low expression group. In multivariate analysis, a high level of exo-miR-224 was a significant risk factor related to all prognoses investigated. After adding exosomes from a metastatic RCC cell line to a primary RCC cell line, cell proliferation and invasion were increased while the percentage of apoptotic cells was significantly decreased. Intracellular levels of miR-224 were significantly up-regulated in the primary renal cancer cell line. Extracellular miR-224 in exosomes impacts on patient prognosis and is a potential prognostic biomarker for ccRCC patients.

Therapeutic Strategies for Hereditary Kidney Cancer

The study of hereditary forms of kidney cancer has vastly increased our understanding of metabolic and genetic pathways involved in the development of both inherited and sporadic kidney cancers. The recognition that diverse molecular events drive different forms of kidney cancers has led to the preclinical and clinical development of specific pathway-directed strategies tailored to treat distinct subgroups of kidney cancer. Here, we describe the molecular mechanisms underlying the pathogenesis of several different types of hereditary renal cancers, review their clinical characteristics, and summarize the treatment strategies for the management of these cancers.

KRT8 upregulation promotes tumor metastasis and is predictive of a poor prognosis in clear cell renal cell carcinoma

Keratin 8 (KRT8) plays an essential role in the development and metastasis of multiple human cancers. However, its role in clear cell renal cell carcinoma (ccRCC) remains unexplored. Here, we investigated the expression pattern, clinical significance, and function of KRT8 in ccRCC. KRT8 mRNA and protein levels were determined in two large cohorts using quantitative real-time polymerase chain reaction (qRT-PCR) and tissue microarray (TMA) immunohistochemistry (IHC), respectively. We found that KRT8 expression was upregulated in ccRCC and vein tumor thrombi (VTTs). KRT8 overexpression in ccRCC was significantly correlated with aggressive characteristics and was predictive of a poor prognosis in ccRCC patients. Moreover, KRT8 overexpression in renal cancer cell lines promoted cell migration and invasion. In contrast, KRT8 knockdown suppressed ccRCC metastasis both in vitro and in vivo. In addition, our findings showed that KRT8 promoted ccRCC metastasis by increasing IL-11 expression, causing IL-11 autocrine induction, and triggering STAT3 signaling. Overall, this study established the significance of KRT8-IL-11 axis activation in aggressive ccRCC and defined a novel critical signaling mechanism that drives human ccRCC invasion and metastasis.

FGFR2 overexpression predicts survival outcome in patients with metastatic papillary renal cell carcinoma

BACKGROUND

Up to date, there are no data about FGFR2 expression and its predictive role in papillary RCC (pRCC) patients. The aim of the present study was to test FGFR2 expression and mutations for association with survival outcome in patients with pRCC.

METHODS

Specimens of removed primary tumors from 214 untreated metastatic pRCC patients were evaluated by immunohistochemistry with FGFR2 antibody. FGFR2 mutations were assessed by PCR and direct sequencing, with DNA obtained from 62 paraffin-embedded pRCC samples. FGFR2 expression was tested for associations with progression-free survival (PFS), overall survival (OS) and best objective response.

RESULTS

Expression of FGFR2 was observed in 23 % (49/214) of primary pRCC, mostly in cytoplasm of tumor cells. Expression of FGFR2 was significant lower in normal tissue of kidney (1 %, P = 0.001). FGFR2 S252W mutation was found in one patient (1.6 %), and no N549K mutation was detected. FGFR2 expression was strongly associated with a number of metastatic sites, type 2 of pRCC, lower nucleolar grade (P < 0.001). FGFR2-positive patients had significantly shorter OS and PFS (P < 0.05). On multivariate analysis, FGFR2 expression, MSKCC risk group and type of pRCC were found to be independent predictors of survival.

CONCLUSIONS

In this study, we described immunohistochemical expression of FGFR2 in a large series of pRCC specimens. FGFR2 expression was found to be prognostic factor for survival in patients with metastatic pRCC. FGFR2 mutations are rare across papillary types of RCC.

Inherited renal carcinomas

Hereditary forms of kidney carcinoma account for 5-8% of all malignant kidney neoplasms. The renal tumors are often multiple and bilateral and occur at an earlier age. Each of the hereditary kidney carcinoma syndromes is associated with specific gene mutations as well as a specific histologic type of kidney carcinoma. The presence of associated extrarenal manifestations may suggest a hereditary kidney cancer syndrome. Radiology is most commonly used to screen and manage patients with hereditary kidney cancer syndromes. This manuscript reviews the clinical and imaging findings of well-defined inherited kidney cancer syndromes including von Hippel-Lindau disease, Birt-Hogg-Dubé syndrome, hereditary papillary renal carcinoma syndrome, hereditary leiomyomatosis and RCC syndrome, tuberous sclerosis complex, and Lynch syndrome.

Metabolism-related enzyme alterations identified by proteomic analysis in human renal cell carcinoma

The renal cell carcinoma (RCC) is one of the most common types of kidney neoplasia in Western countries; it is relatively resistant to conventional chemotherapy and radiotherapy. Metabolic disorders have a profound effect on the degree of malignancy and treatment resistance of the tumor. However, the molecular characteristics related to impaired metabolism leading to the initiation of RCC are still not very clear. In this study, two-dimensional electrophoresis (2-DE) and mass spectra (MS) technologies were utilized to identify the proteins involved in energy metabolism of RCC. A total of 73 proteins that were differentially expressed in conventional RCC, in comparison with the corresponding normal kidney tissues, were identified. Bioinformatics analysis has shown that these proteins are involved in glycolysis, urea cycle, and the metabolic pathways of pyruvate, propanoate, and arginine/proline. In addition, some were also involved in the signaling network of p53 and FAS. These results provide some clues for new therapeutic targets and treatment strategies of RCC.

MiT Family Translocation-Associated Renal Cell Carcinoma: A Contemporary Update With Emphasis on Morphologic, Immunophenotypic, and Molecular Mimics

Translocation-associated renal cell carcinoma (t-RCC) is a relatively uncommon subtype of renal cell carcinoma characterized by recurrent gene rearrangements involving the TFE3 or TFEB loci. TFE3 and TFEB are members of the microphthalmia transcription factor (MiT) family, which regulates differentiation in melanocytes and osteoclasts, and MiT family gene fusions activate unique molecular programs that can be detected immunohistochemically. Although the overall clinical behavior of t-RCC is variable, emerging molecular data suggest the possibility of targeted approaches to advanced disease. Thus, distinguishing t-RCC from its morphologic, immunophenotypic, and molecular mimics may have important clinical implications. The differential diagnosis for t-RCC includes a variety of common renal neoplasms, particularly those demonstrating clear cell and papillary features; in addition, because of immunophenotypic overlap and/or shared molecular abnormalities (ie, TFE3 gene rearrangement), a distinctive set of nonepithelial renal tumors may also warrant consideration. Directed ancillary testing is an essential aspect to the workup of t-RCC cases and may include a panel of immunohistochemical stains, such as PAX8, pancytokeratins, epithelial membrane antigen, carbonic anhydrase IX, HMB-45, and Melan-A. Dual-color, break-apart fluorescent in situ hybridization for TFE3 or TFEB gene rearrangement may be helpful in diagnostically challenging cases or when molecular confirmation is needed.

Diagnosis and Management of Hereditary Renal Cell Cancer

Renal cell cancer (RCC) is the common denominator for a heterogeneous group of diseases. The subclassification of these tumours is based on histological type and molecular pathogenesis. Insight into molecular pathogenesis has led to the development of targeted systemic therapies. Genetic susceptibility is the principal cause of RCC in about 2-4% of cases. Hereditary RCC is the umbrella term for about a dozen different conditions, the most frequent of which is von Hippel-Lindau disease . Here, we describe the main hereditary RCC syndromes, consider criteria for referral of RCC patients for clinical genetic assessment and discuss management options for patients with hereditary RCC and their at-risk relatives.

Mitochondrial DNA mutations distinguish bilateral multifocal renal oncocytomas from familial Birt-Hogg-Dubé tumors

Oncocytomas are mostly benign tumors characterized by accumulation of defective mitochondria, and in sporadic cases, are associated with disruptive mitochondrial DNA (mtDNA) mutations. However, the role mtDNA mutations have in renal tumors of Birt-Hogg-Dubé (BHD) patients and other renal oncocytomas with an apparent genetic component has not been investigated to date. Here we characterize the mitochondrial genome in different renal tumors and investigate the possibility of employing mtDNA sequencing analyses of biopsy specimens to aid in the differential diagnosis of oncocytomas. The entire mitochondrial genome was sequenced in 25 samples of bilateral and multifocal (BMF) renal oncocytomas, 30 renal tumors from BHD patients and 36 non-oncocytic renal tumors of different histologies as well as in biopsy samples of kidney tumors. mtDNA sequencing in BMF oncocytomas revealed that all tumors carry disruptive mutations, which impair the assembly of the NADH-ubiquinone oxidoreductase. Multiple tumors from a given BMF oncocytoma patient mainly harbor the same somatic mutation and the kidneys of these patients display diffuse oncocytosis. In contrast, renal oncocytomas of patients with BHD syndrome and renal tumors with different histologies do not show disruptive mtDNA mutations. Moreover, we demonstrate that it is feasible to amplify and sequence the entire mtDNA in biopsy specimens, and that these sequences are representative of the tumor DNA. These results show that pathogenic mtDNA mutations affecting complex I of the respiratory chain are strongly correlated with the oncocytoma phenotype in non-BHD-related renal tumors and that mtDNA sequences from biopsies are predictive of the tumor genotype. This work supports a role for mtDNA mutations in respiratory chain complexes as diagnostic markers for renal oncocytomas.

How should clinicians address intratumour heterogeneity in clear cell renal cell carcinoma?

PURPOSE OF REVIEW

Despite the availability of multiple targeted therapies, the 5-year survival rate of patients with metastatic clear cell renal cell carcinoma (ccRCC) rarely exceeds 10%. Recent insights into the mutational landscape and evolutionary dynamics of ccRCC have offered up a plausible explanation for these outcomes. The purpose of this review is to link the research findings to potential changes in clinical practice.

RECENT FINDINGS

Intratumour heterogeneity (ITH) dominates the evolutionary landscape in ccRCC at the genetic, transcriptomic and proteomic level. Spatial and temporal separation of tumour subclones within the primary tumour as well as between primary and metastatic sites has been demonstrated at single nucleotide resolution. In the cases analysed to date, approximately two-thirds of somatic mutations are not shared between multiple biopsies from the same primary tumour. Very few of the key disease-driving events are shared across all primary tumour regions (with the exception of VHL and loss of chromosome 3p), whereas the majority are restricted to one or more tumour regions (TP53, SETD2, BAP1, PTEN, mTOR, PIK3CA and KDM5C).

SUMMARY

ITH must be considered in the management of ccRCC with respect to diagnostic procedures, prognostic and predictive biomarkers and drug development.

TRIM8 anti-proliferative action against chemo-resistant renal cell carcinoma

In some tumours, despite a wild-type p53 gene, the p53 pathway is inactivated by alterations in its regulators or by unknown mechanisms, leading to resistance to cytotoxic therapies. Understanding the mechanisms of functional inactivation of wild-type p53 in these tumours may help to define prospective targets for treating cancer by restoring p53 activity.

Recently, we identified TRIM8 as a new p53 modulator, which stabilizes p53 impairing its association with MDM2 and inducing the reduction of cell proliferation.

In this paper we demonstrated that TRIM8 deficit dramatically impairs p53-mediated cellular responses to chemotherapeutic drugs and that TRIM8 is down regulated in patients affected by clear cell Renal Cell Carcinoma (ccRCC), an aggressive drug-resistant cancer showing wild-type p53. These results suggest that down regulation of TRIM8 might be an alternative way to suppress p53 activity in RCC. Interestingly, we show that TRIM8 expression recovery in RCC cell lines renders these cells sensitive to chemotherapeutic treatments following p53 pathway re-activation.

These findings provide the first mechanistic link between TRIM8 and the drug resistance of ccRCC and suggest more generally that TRIM8 could be used as enhancer of the chemotherapy efficacy in cancers where p53 is wild-type and its pathway is defective.

RLIP76 Targeted Therapy for Kidney Cancer

Despite recent improvements in chemotherapeutic approaches to treating kidney cancer, this malignancy remains deadly if not found and removed at an early stage of the disease. Kidney cancer is highly drug-resistant, which may at least partially result from high expression of transporter proteins in the cell membranes of kidney cells. Although these transporter proteins can contribute to drug-resistance, targeting proteins from the ATP-binding cassette transporter family has not been effective in reversing drug-resistance in kidney cancer. Recent studies have identified RLIP76 as a key stress-defense protein that protects normal cells from damage caused by stress conditions, including heat, ultra-violet light, X-irradiation, and oxidant/electrophilic toxic chemicals, and is crucial for protecting cancer cells from apoptosis. RLIP76 is the predominant glutathione-electrophile-conjugate (GS-E) transporter in cells, and inhibiting it with antibodies or through siRNA or antisense causes apoptosis in many cancer cell types. To date, blocking of RLIP76, either alone or in combination with chemotherapeutic drugs, as a therapeutic strategy for kidney cancer has not yet been evaluated in human clinical trials, although there is considerable potential for RLIP76 to be developed as a therapeutic agent for kidney cancer. In the present review, we discuss the mechanisms underlying apoptosis caused by RLIP76 depletion, the role of RLIP76 in clathrin-dependent endocytosis deficiency, and the feasibility of RLIP76-targeted therapy for kidney cancer.

Current and proposed molecular diagnostics in a genitourinary service line laboratory at a tertiary clinical institution

The idea that detailed knowledge of molecular oncogenesis will drive diagnostic, prognostic, and therapeutic clinical decision making in an increasingly multidisciplinary practice of oncologic care has been anticipated for many years. With the recent rapid advancement in our understanding of the molecular underpinnings of genitourinary malignancies, this concept is now starting to take shape in the fields of prostate, kidney, bladder, testicular, and penile cancer. Such breakthroughs necessitate the development of robust clinical-grade assays that can be quickly made available for patients to facilitate diagnosis in challenging cases, risk-stratify patients for subsequent clinical management, select the appropriate targeted therapy from among increasingly diverse and numerous options, and enroll patients in advanced clinical trials. This rapid translation of basic and clinical cancer research requires a streamlined, multidisciplinary approach to clinical assay development, termed here the molecular diagnostics service line laboratory. In this review, we summarize the current state and explore the future of molecular diagnostics in genitourinary oncology to conceptualize a genitourinary service line laboratory at a tertiary clinical institution.