Absence of VHL gene alteration and high VEGF expression are associated with tumour aggressiveness and poor survival of renal-cell carcinoma

Whole genome sequencing refines stratification and therapy of patients with clear cell renal cell carcinoma

Clear cell renal cell carcinoma (ccRCC) is the most common form of kidney cancer, but a comprehensive description of its genomic landscape is lacking. We report the whole genome sequencing of 778 ccRCC patients enrolled in the 100,000 Genomes Project, providing the most detailed somatic mutational landscape to date. We identify new driver genes, which as well as emphasising the major role of epigenetic regulation in ccRCC highlight additional biological pathways extending opportunities for drug repurposing. Genomic characterisation identified patients with divergent clinical outcome; higher number of structural copy number alterations associated with poorer prognosis, whereas VHL mutations were independently associated with a better prognosis. The twin observations that higher T-cell infiltration is associated with better outcome and that genetically predicted immune evasion is not common supports the rationale for immunotherapy. These findings should inform personalised surveillance and treatment strategies for ccRCC patients.

Renal Carcinoma and Angiogenesis: Therapeutic Target and Biomarkers of Response in Current Therapies

Due to the aberrant hypervascularization and the high immune infiltration of renal tumours, current therapeutic regimens of renal cell carcinoma (RCC) target angiogenic or immunosuppressive pathways or both. Tumour angiogenesis plays an essential role in tumour growth and immunosuppression. Indeed, the aberrant vasculature promotes hypoxia and can also exert immunosuppressive functions. In addition, pro-angiogenic factors, including VEGF-A, have an immunosuppressive action on immune cells. Despite the progress of treatments in RCC, there are still non responders or acquired resistance. Currently, no biomarkers are used in clinical practice to guide the choice between the different available treatments. Considering the role of angiogenesis in RCC, angiogenesis-related markers are interesting candidates. They have been studied in the response to antiangiogenic drugs (AA) and show interest in predicting the response. They have been less studied in immunotherapy alone or combined with AA. In this review, we will discuss the role of angiogenesis in tumour growth and immune escape and the place of angiogenesis-targeted biomarkers to predict response to current therapies in RCC.

Evaluation of a seven gene mutational profile as a prognostic factor in a population-based study of clear cell renal cell carcinoma

In this study, we investigate the influence of the seven genes (VHL, PBRM1, SETD2, BAP1, KDM5C, MTOR and TP53) most frequently mutated in clear cell renal cell cancer (ccRCC) on cancer-specific survival (CSS) in the prospective Netherlands Cohort Study on diet and cancer. DNA isolated from routinely archived formalin-fixed paraffin-embedded tumour blocks from 252 incident ccRCC cases was available for targeted next generation sequencing. Based on the sequencing quality and the completeness of information on clinical characteristics and follow-up, we could use 110 cases for survival analysis. The association with CSS for each mutated gene in these cases was tested using multivariable Cox proportional hazards models to estimate hazards ratios (HR) and confidence intervals (CIs), and we observed mutations in one or more of the seven genes in 64 out of 110 cases (58%). In the multivariable-adjusted analyses, mutations in VHL and PBRM1 were associated with better CSS (HRs (95% CI) 0.34 (0.13‒0.89) and 0.17 (0.04–0.66), respectively), although these results were not statistically significant after multiple testing correction. No association was observed for the other five genes, which may be attributable to limited power.

Association of AXL and PD-L1 expression with clinical outcomes in patients with advanced renal cell carcinoma treated with PD-1 blockade

PURPOSE

A minority of patients currently respond to single agent immune checkpoint blockade (ICB) and strategies to increase response rates are urgently needed. AXL is receptor tyrosine kinase commonly associated with drug-resistance and poor prognosis in many cancer types including in clear-cell renal cell carcinoma (ccRCC). Recent experimental cues in breast, pancreatic and lung cancer models have linked AXL with immune suppression and resistance to antitumor immunity. However, its role in intrinsic and acquired resistance to ICB remains largely unexplored.

EXPERIMENTAL DESIGN

In this study, tumoral expression of AXL was examined in ccRCC specimens from 316 metastatic patients receiving PD-1 inhibitor, nivolumab, in the GETUG AFU 26 NIVOREN trial after failure of anti-angiogenic therapy. We assessed associations between AXL and patient outcomes following PD-1 blockade, as well as the relationship with various markers including PD-L1, VEGFA, the immune markers CD3, CD8, CD163, CD20, and the mutational status of the tumor suppressor gene VHL Results: Our results show that high AXL expression levels in tumor cells is associated with lower response rates and a trend to shorter progression-free survival following anti-PD-1 treatment. AXL expression was strongly associated with tumor PD-L1 expression, especially in tumors with VHL inactivation. Moreover, patients with tumors displaying concomitant PD-L1 expression and high AXL expression had the worst overall survival.

CONCLUSIONS

Our findings propose AXL as candidate factor of resistance to PD-1 blockade, and provide compelling support for screening both AXL and PD-L1 expression in the management of advanced ccRCC.

The Most Common VHL Point Mutation R167Q in Hereditary VHL Disease Interferes with Cell Plasticity Regulation

Von Hippel-Lindau disease (VHL) is a rare hereditary syndrome due to mutations of the VHL tumor suppressor gene. Patients harboring the R167Q mutation of the VHL gene have a high risk of developing ccRCCs. We asked whether the R167Q mutation with critical aspects of pseudo-hypoxia interferes with tumor plasticity. For this purpose, we used wild-type VHL (WT-VHL) and VHL-R167Q reconstituted cells. We showed that WT-VHL and VHL-R167Q expression had a similar effect on cell morphology and colony formation. However, cells transfected with VHL-R167Q display an intermediate, HIF2-dependent, epithelial-mesenchymal phenotype. Using RNA sequencing, we showed that this mutation upregulates the expression of genes involved in the hypoxia pathway, indicating that such mutation is conferring an enhanced pseudo-hypoxic state. Importantly, this hypoxic state correlates with the induction of genes belonging to epithelial-mesenchymal transition (EMT) and stemness pathways, as revealed by GSEA TCGA analysis. Moreover, among these deregulated genes, we identified nine genes specifically associated with a poor patient survival in the TCGA KIRC dataset. Together, these observations support the hypothesis that a discrete VHL point mutation interferes with tumor plasticity and may impact cell behavior by exacerbating phenotypic switching. A better understanding of the role of this mutation might guide the search for more effective treatments to combat ccRCCs.

Tumor Hypoxia Regulates Immune Escape/Invasion: Influence on Angiogenesis and Potential Impact of Hypoxic Biomarkers on Cancer Therapies

The environmental and metabolic pressures in the tumor microenvironment (TME) play a key role in molding tumor development by impacting the stromal and immune cell fractions, TME composition and activation. Hypoxia triggers a cascade of events that promote tumor growth, enhance resistance to the anti-tumor immune response and instigate tumor angiogenesis. During growth, the developing angiogenesis is pathological and gives rise to a haphazardly shaped and leaky tumor vasculature with abnormal properties. Accordingly, aberrantly vascularized TME induces immunosuppression and maintains a continuous hypoxic state. Normalizing the tumor vasculature to restore its vascular integrity, should hence enhance tumor perfusion, relieving hypoxia, and reshaping anti-tumor immunity. Emerging vascular normalization strategies have a great potential in achieving a stable normalization, resulting in mature and functional blood vessels that alleviate tumor hypoxia. Biomarkers enabling the detection and monitoring of tumor hypoxia could be highly advantageous in aiding the translation of novel normalization strategies to clinical application, alone, or in combination with other treatment modalities, such as immunotherapy.

Algorithmic assessment of missense mutation severity in the Von-Hippel Lindau protein

Von Hippel-Lindau disease (VHL) is an autosomal dominant rare disease that causes the formation of angiogenic tumors. When functional, pVHL acts as an E3 ubiquitin ligase that negatively regulates hypoxia inducible factor (HIF). Genetic mutations that perturb the structure of pVHL result in dysregulation of HIF, causing a wide array of tumor pathologies including retinal angioma, pheochromocytoma, central nervous system hemangioblastoma, and clear cell renal carcinoma. These VHL-related cancers occur throughout the lifetime of the patient, requiring frequent intervention procedures, such as surgery, to remove the tumors. Although VHL is classified as a rare disease (1 in 39,000 to 1 in 91,000 affected) there is a large heterogeneity in genetic mutations listed for observed pathologies. Understanding how these specific mutations correlate with the myriad of observed pathologies for VHL could provide clinicians insight into the potential severity and onset of disease. Using a select set of 285 ClinVar mutations in VHL, we developed a multiparametric scoring algorithm to evaluate the overall clinical severity of missense mutations in pVHL. The mutations were assessed according to eight weighted parameters as a comprehensive evaluation of protein misfolding and malfunction. Higher mutation scores were strongly associated with pathogenicity. Our approach establishes a novel in silico method by which VHL-specific mutations can be assessed for their severity and effect on the biophysical functions of the VHL protein.

ApoC1 promotes the metastasis of clear cell renal cell carcinoma via activation of STAT3

Clear cell renal cell carcinoma (ccRCC) is the most common renal cancer and frequently diagnosed at an advanced stage. It is prone to develop unpredictable metastases even with proper treatment. Antiangiogenic therapy is the most effective medical treatment for metastatic ccRCC. Thus, exploration of novel approaches to inhibit angiogenesis and metastasis may potentially lead to a better therapeutic option for ccRCC. Among all the types of cancer, renal cancer samples exhibited the maximum upregulation of ApoC1 as referred to in the Oncomine database. The expression of ApoC1 was increased accompanied by ccRCC progression. A high level of ApoC1 was closely related to poor survival time in ccRCC patients. Furthermore, ApoC1 was over-expressed in the highly invasive ccRCC cells as compared to that in the low-invasive ccRCC cells. Besides, ApoC1 promoted metastasis of ccRCC cells via EMT pathway, whereas depletion of ApoC1 alleviated these effects. ApoC1 as a novel pro-metastatic factor facilitates the activation of STAT3 and enhances the metastasis of ccRCC cells. Meanwhile, ApoC1 in the exosomes were transferred from the ccRCC cells to the vascular endothelial cells and promoted metastasis of the ccRCC cells via activating STAT3. Finally, the metastatic potential of the ccRCC cells driven by ApoC1 was suppressed by DPP-4 inhibition. Our study not only identifies a novel ApoC1-STAT3 pathway in ccRCC metastasis but also provides direction for the exploration of novel strategies to predict and treat metastatic ccRCC in the future.

Anterior gradient 2 promotes tumorigenesis through upregulation of CCAAT-enhancer binding protein beta and hypoxia-inducible factor-2α and subsequent secretion of interleukin-6, interleukin-8, and vascular endothelial growth factor in the Caki-1 clear cell renal cell carcinoma cell line

It has been previously established that hypoxia leads to tumor development, treatment resistance, and a poor prognosis. Under oxygen deprivation, hypoxia-inducible factors (HIFs) are stimulated to activate the genes necessary for tumor development in a low-oxygen environment. These genes encode regulators of angiogenesis, epithelial-mesenchymal transition, and cellular metabolism. A disulfide isomerase, anterior gradient 2 (AGR2), has been shown to increase hypoxia-inducible factor 1, alpha subunit (HIF-1α) stability in breast cancer. Our goal was to determine if AGR2 affects the level of transcription factor hypoxia-inducible factor 2, alpha subunit (HIF-2α). As a model, we used the clear cell renal cell carcinoma (ccRCC) cell line Caki-1. The cells were transduced with lentiviral vector (Tet-On) encoding AGR2. After induction of AGR2 expression, cells were grown under either hypoxic (0.5% O₂ ) or normoxic (21% O₂ ) conditions. Our data showed that AGR2 upregulated both HIF-1α and HIF-2α expression in Caki-1 cells increasing the expression of HIF-activated genes (glucose transporter 1, phosphoglycerate kinase 1, vascular endothelial growth factor A, and transforming growth factor-alpha) under the hypoxic conditions. Under the normoxic conditions, AGR2 strongly activated CCAAT-enhancer binding protein beta (C/EBPβ). Upregulation of C/EBPβ correlated with increased expression and secretion of the interleukin-6 and interleukin-8, inducing angiogenesis and inflammation in Caki-1 cells. In summary, our studies revealed that AGR2 has essential functions in ccRCC progression through upregulation of C/EBPβ and HIF-2α expressions, which affects cell signaling and metabolism.

Phase 1 trial of vorolanib (CM082) in combination with everolimus in patients with advanced clear-cell renal cell carcinoma

Background

Vorolanib (X-82, CM082) is a multi-target tyrosine kinase inhibitor. This study aimed to evaluate the tolerability, safety, pharmacokinetics and antitumor activities of vorolanib plus everolimus (an inhibitor of mammalian target of rapamycin).

Methods

Patients had histologically or cytologically confirmed advanced RCC and failed with standard therapy were eligible for this study. Dose-escalated combinations of vorolanib (100, 150 or 200 mg once daily) with everolimus (5 mg once daily) were administered on 28-day cycles until disease progression or unacceptable toxicity using a conventional 3 + 3 dose-escalation design.

Findings

22 patients (100 mg n = 4, 150 mg n = 3, 200 mg n = 15) were enrolled. Only one patient experienced dose-limiting toxicity (DLT, grade 4 thrombocytopenia) in the vorolanib 200 mg combination cohort, and the maximum tolerated dose (MTD) was not reached. The most common treatment-related adverse events were proteinuria (100%), leukopenia (77%), hypercholesterolaemia (77%), increased low-density lipoprotein (68%), hypertriglyceridaemia (64%), hyperglycaemia (59%), and fatigue (55%). Most treatment-related adverse events were grade 1 to 2, with grade 3 or higher toxicities mostly seen in the 200 mg cohort. Single dosing of vorolanib demonstrated dose-proportional increases in the C_max and AUC, and observed short t_1/2z ranging from 4.74±1.44 to 12.89±7.49 h. The pharmacokinetic parameters for everolimus were similar among all cohorts. Of 19 evaluable patients, the ORR and DCR was 32% (n = 6, 95% CI, 13–57%) and 100% (95% CI, 82–100%), respectively.

Interpretation

Combination therapy of vorolanib 200 mg plus everolimus 5 mg once daily is potentially effective with potential activity. Further evaluation of the combination in advanced RCC patients is ongoing (NCT03095040).

Funding

Betta Pharmaceutical Co., Ltd., Hangzhou, China.

Synchronous inhibition of mTOR and VEGF/NRP1 axis impedes tumor growth and metastasis in renal cancer

Clear cell renal cell carcinoma (ccRCC) is known for its highly vascular phenotype which is associated with elevated expression of vascular endothelial growth factor A (VEGF), also known as vascular permeability factor (VPF). Accordingly, VEGF has been an attractive target for antiangiogenic therapies in ccRCC. Two major strategies have hitherto been utilized for VEGF-targeted antiangiogenic therapies: targeting VEGF by antibodies, ligand traps or aptamers, and targeting the VEGF receptor signaling via antibodies or small-molecule tyrosine-kinase inhibitors (TKIs). In the present article we utilized two entirely different approaches: targeting mammalian target of rapamycin (mTOR) pathway that is known to be involved in VEGF synthesis, and disruption of VEGF/Neuroplin-1 (NRP1) axis that is known to activate proangiogenic and pro-tumorigenic signaling in endothelial and tumor cells, respectively. Everolimus (E) and a small-molecule inhibitor EG00229 (G) were used for the inhibition of mTOR and the disruption of VEGF/NRP1 axis, respectively. We also exploited a liposomal formulation decorated with a proprietary tumor-targeting-peptide (TTP) to simultaneously deliver these two agents in a tumor-targeted manner. The TTP-liposomes encapsulating both Everolimus and EG00229 (EG-L) demonstrated higher in vitro and in vivo growth retardation than the single drug-loaded liposomes (E-L and G-L) in two different ccRCC models and led to a noticeable reduction in lung metastasis in vivo. In addition, EG-L displayed remarkable inhibition of tumor growth in a highly aggressive syngeneic immune-competent mouse model of ccRCC developed in Balb/c mice. Taken together, this study demonstrates an effective approach to achieve improved therapeutic outcome in ccRCC.

Prognostic significance of VHL, HIF1A, HIF2A, VEGFA and p53 expression in patients with clear‑cell renal cell carcinoma treated with sunitinib as first‑line treatment

Clear cell renal cell carcinoma (ccRCC) is the most common subtype of renal cell cancer, characterized by the highest mortality rate among other RCC subtypes due to the occurrence of metastasis and drug resistance following surgery. The Von Hippel-Lindau tumor suppressor (VHL)-hypoxia-inducible factor 1 subunit α (HIF1A)/hypoxia-inducible factor 2α (HIF2A)-vascular endothelial growth factor A (VEGFA) protein axis is involved in the development and progression of ccRCC, whereas sunitinib, a tyrosine kinase inhibitor, blocks the binding of VEGFA to its receptor. The aim of the present study was to examine the possible association of the gene expression of VHL, HIF1A, HIF2A, VEGFA and tumor protein P53 (P53) in cancer tissue with the outcome of ccRCC patients who were treated with sunitinib as first-line therapy following nephrec-tomy. A total of 36 ccRCC patients were enrolled, 11 of whom were administered sunitinib post-operatively. Tumor and control samples were collected, and mRNA and protein levels were assessed by reverse transcription-quantitative polymerase chain reaction and western blot analysis, respectively. High mRNA and protein expression levels of HIF2A and VEGFA were found to be associated with shorter overall survival (OS) and progression-free survival (PFS) rates, as well as with unfavorable risk factors of cancer recurrence and mortality. Resistance to sunitinib was also observed; the OS and PFS rates were shorter (median OS and PFS: 12 and 6 months, respectively, vs. undetermined). Sunitinib resistance was associated with high HIF2A and VEGFA protein levels (b=0.57 and b=0.69 for OS and PFS, respectively; P<0.001). Taken together, the findings of this study suggest that the protein levels of HIF2A and VEGFA in tumor tissue may serve as independent prognostic factors in ccRCC. ccRCC patients with increased intratumoral HIF2A and VEGFA protein levels, and unaltered VHL protein levels, are not likely to benefit from sunitinib treatment following nephrectomy; however, this hypothesis requires verification by large-scale replication studies.

The Association Between Ascorbate and the Hypoxia-Inducible Factors in Human Renal Cell Carcinoma Requires a Functional Von Hippel-Lindau Protein

Hypoxia-inducible transcription factors (HIFs) drive angiogenesis and cancer cell growth, contributing to an aggressive tumor phenotype. HIF-α protein levels and activity are controlled at the post-translational level by HIF hydroxylases. Hydroxylated HIF-α is recognized by the von Hippel Lindau (VHL) tumor suppressor and targeted for degradation. The HIF hydroxylases are members of the iron and 2-oxoglutarate-dependent dioxygenases, which require ascorbate as cofactor for activity. Clear cell renal cell carcinomas (ccRCC) harbor mutations in the VHL gene, whereas papillary RCC (pRCC) have a functional VHL. These natural occurring VHL variants in RCC enable the testing, in clinical samples, of the hypothesis that ascorbate modulates HIF-α levels through its role as a cofactor for the HIF hydroxylases. We measured ascorbate, HIF-1α, and HIF-2α protein and HIF downstream targets BNIP3, CA9, cyclin D1, GLUT1, and VEGF (combined to generate the HIF pathway score) in VHL-defective ccRCC (n = 73) and VHL-proficient pRCC human tumor tissue (n = 41). HIF and ascorbate levels were increased in ccRCC and pRCC tumors compared to matched renal cortex. HIF-1 and total HIF pathway activation scores were decreased with higher ascorbate in pRCC tumors (Spearman r = −0.38, p < 0.05 and r = −0.35, p < 0.05). This was not evident for ccRCC tumors. In mechanistic studies in vitro, ascorbate influenced HIF-1 activity in VHL-proficient, but not VHL-defective ccRCC cells. Our results indicate that ccRCC, which lacks a functional VHL, does not respond to ascorbate-mediated modulation of the HIF response. This contrasts with the demonstrated association between ascorbate content and the HIF pathway observed in pRCC and other tumors with a functional VHL. The results support a role for ascorbate as a modulator of HIF activity and tumor aggression in cancer types with a functional hypoxic response.

Circulating Tumor Cells for the Management of Renal Cell Carcinoma

Renal cell carcinoma is a highly malignant cancer that would benefit from non-invasive innovative markers providing early diagnosis and recurrence detection. Circulating tumor cells are a particularly promising marker of tumor invasion that could be used to improve the management of patients with RCC. However, the extensive genetic and immunophenotypic heterogeneity of cells from RCC and their trend to transition to the mesenchymal phenotype when they circulate in blood constitute a challenge for their sensitive and specific detection. This review analyzes published studies targeting CTC in patients with RCC, in the context of the biological, pathological, and molecular complexity of this particular cancer. Although further analytical and clinical studies are needed to pinpoint the most suitable approach for highly sensitive CTC detection in RCC patients, it is clear that this field can bring a relevant guide to clinicians and help to RCC patients. Furthermore, as described, a particular subtype of RCC-the ccRCC-can be used as a model to study the relationship between cytomorphological and genetic cellular markers of malignancy, an important issue for the study of CTC from any type of solid cancer.

A Distributed Classifier for MicroRNA Target Prediction with Validation Through TCGA Expression Data

BACKGROUND

MicroRNAs (miRNAs) are approximately 22-nucleotide long regulatory RNA that mediate RNA interference by binding to cognate mRNA target regions. Here, we present a distributed kernel SVM-based binary classification scheme to predict miRNA targets. It captures the spatial profile of miRNA-mRNA interactions via smooth B-spline curves. This is accomplished separately for various input features, such as thermodynamic and sequence-based features. Further, we use a principled approach to uniformly model both canonical and non-canonical seed matches, using a novel seed enrichment metric. Finally, we verify our miRNA-mRNA pairings using an Elastic Net-based regression model on TCGA expression data for four cancer types to estimate the miRNAs that together regulate any given mRNA.

RESULTS

We present a suite of algorithms for miRNA target prediction, under the banner Avishkar, with superior prediction performance over the competition. Specifically, our final kernel SVM model, with an Apache Spark backend, achieves an average true positive rate (TPR) of more than 75 percent, when keeping the false positive rate of 20 percent, for non-canonical human miRNA target sites. This is an improvement of over 150 percent in the TPR for non-canonical sites, over the best-in-class algorithm. We are able to achieve such superior performance by representing the thermodynamic and sequence profiles of miRNA-mRNA interaction as curves, devising a novel seed enrichment metric, and learning an ensemble of miRNA family-specific kernel SVM classifiers. We provide an easy-to-use system for large-scale interactive analysis and prediction of miRNA targets. All operations in our system, namely candidate set generation, feature generation and transformation, training, prediction, and computing performance metrics are fully distributed and are scalable.

CONCLUSIONS

We have developed an efficient SVM-based model for miRNA target prediction using recent CLIP-seq data, demonstrating superior performance, evaluated using ROC curves for different species (human or mouse), or different target types (canonical or non-canonical). We analyzed the agreement between the target pairings using CLIP-seq data and using expression data from four cancer types. To the best of our knowledge, we provide the first distributed framework for miRNA target prediction based on Apache Hadoop and Spark.

AVAILABILITY

All source code and sample data are publicly available at https://bitbucket.org/cellsandmachines/avishkar. Our scalable implementation of kernel SVM using Apache Spark, which can be used to solve large-scale non-linear binary classification problems, is available at https://bitbucket.org/cellsandmachines/kernelsvmspark.

Methods for the evaluation of biomarkers in patients with kidney and liver diseases: multicentre research programme including ELUCIDATE RCT

Background

Protein biomarkers with associations with the activity and outcomes of diseases are being identified by modern proteomic technologies. They may be simple, accessible, cheap and safe tests that can inform diagnosis, prognosis, treatment selection, monitoring of disease activity and therapy and may substitute for complex, invasive and expensive tests. However, their potential is not yet being realised.

Design and methods

The study consisted of three workstreams to create a framework for research: workstream 1, methodology – to define current practice and explore methodology innovations for biomarkers for monitoring disease; workstream 2, clinical translation – to create a framework of research practice, high-quality samples and related clinical data to evaluate the validity and clinical utility of protein biomarkers; and workstream 3, the ELF to Uncover Cirrhosis as an Indication for Diagnosis and Action for Treatable Event (ELUCIDATE) randomised controlled trial (RCT) – an exemplar RCT of an established test, the ADVIA Centaur® Enhanced Liver Fibrosis (ELF) test (Siemens Healthcare Diagnostics Ltd, Camberley, UK) [consisting of a panel of three markers – (1) serum hyaluronic acid, (2) amino-terminal propeptide of type III procollagen and (3) tissue inhibitor of metalloproteinase 1], for liver cirrhosis to determine its impact on diagnostic timing and the management of cirrhosis and the process of care and improving outcomes.

Results

The methodology workstream evaluated the quality of recommendations for using prostate-specific antigen to monitor patients, systematically reviewed RCTs of monitoring strategies and reviewed the monitoring biomarker literature and how monitoring can have an impact on outcomes. Simulation studies were conducted to evaluate monitoring and improve the merits of health care. The monitoring biomarker literature is modest and robust conclusions are infrequent. We recommend improvements in research practice. Patients strongly endorsed the need for robust and conclusive research in this area. The clinical translation workstream focused on analytical and clinical validity. Cohorts were established for renal cell carcinoma (RCC) and renal transplantation (RT), with samples and patient data from multiple centres, as a rapid-access resource to evaluate the validity of biomarkers. Candidate biomarkers for RCC and RT were identified from the literature and their quality was evaluated and selected biomarkers were prioritised. The duration of follow-up was a limitation but biomarkers were identified that may be taken forward for clinical utility. In the third workstream, the ELUCIDATE trial registered 1303 patients and randomised 878 patients out of a target of 1000. The trial started late and recruited slowly initially but ultimately recruited with good statistical power to answer the key questions. ELF monitoring altered the patient process of care and may show benefits from the early introduction of interventions with further follow-up. The ELUCIDATE trial was an ‘exemplar’ trial that has demonstrated the challenges of evaluating biomarker strategies in ‘end-to-end’ RCTs and will inform future study designs.

Conclusions

The limitations in the programme were principally that, during the collection and curation of the cohorts of patients with RCC and RT, the pace of discovery of new biomarkers in commercial and non-commercial research was slower than anticipated and so conclusive evaluations using the cohorts are few; however, access to the cohorts will be sustained for future new biomarkers. The ELUCIDATE trial was slow to start and recruit to, with a late surge of recruitment, and so final conclusions about the impact of the ELF test on long-term outcomes await further follow-up. The findings from the three workstreams were used to synthesise a strategy and framework for future biomarker evaluations incorporating innovations in study design, health economics and health informatics.

Trial registration

Current Controlled Trials ISRCTN74815110, UKCRN ID 9954 and UKCRN ID 11930.

Funding

This project was funded by the NIHR Programme Grants for Applied Research programme and will be published in full inProgramme Grants for Applied Research; Vol. 6, No. 3. See the NIHR Journals Library website for further project information.

Correlation of c-MET Expression with PD-L1 Expression in Metastatic Clear Cell Renal Cell Carcinoma Treated by Sunitinib First-Line Therapy

BACKGROUND

Clear cell renal cell carcinoma (ccRCC) is highly metastatic. Cabozantinib, an anti-angiogenic tyrosine kinase inhibitor that targets c-MET, provided interesting results in metastatic ccRCC treatment.

OBJECTIVE

To understand better the role of c-MET in ccRCC, we assessed its status in a population of patients with metastatic ccRCC.

PATIENTS AND METHODS

For this purpose, tumor samples were analyzed for c-MET expression by immunohistochemistry (IHC), for c-MET copy number alterations by fluorescence in situ hybridization (FISH), and for c-MET mutations by next generation sequencing (NGS) in a retrospective cohort of 90 primary ccRCC of patients with metastases treated by first-line sunitinib. The expression of c-MET was correlated with pathological, immunohistochemical (VEGFA, CAIX, PD-L1), clinical, and molecular criteria (VHL status) by univariate and multivariate analyses and to clinical outcome using Kaplan-Meier curves compared by log-rank test.

RESULTS

Of ccRCC, 31.1% had low c-MET expression (absent to weak intensity by IHC) versus 68.9% with high expression (moderate to strong intensity). High expression of c-MET was associated with a gain in FISH analysis (p=0.0284) without amplification. No mutations were detected in NGS. Moreover, high c-MET expression was associated with lymph node metastases (p=0.004), sarcomatoid component (p=0.029), VEGFA (p=0.037), and PD-L1 (p=0.001) overexpression, the only factor that remained independently associated (p<0.001) after logistic regression. No difference was observed in clinical outcomes.

CONCLUSION

This study is the first to analyse c-MET status in metastatic ccRCC. The high expression of c-MET in the majority of ccRCC and its independent association with PD-L1 expression, may suggest a potential benefit from combining c-MET inhibitors and targeted immunotherapy.

Genetic characterization of Polish ccRCC patients: somatic mutation analysis of PBRM1, BAP1 and KDMC5, genomic SNP array analysis in tumor biopsy and preliminary results of chromosome aberrations analysis in plasma cell free DNA

BACKGROUND

Mutation analysis and cytogenetic testing in clear cell renal cell carcinoma (ccRCC) is not yet implemented in a routine diagnostics of ccRCC.

MATERIAL AND METHODS

We characterized the chromosomal alterations in 83 ccRCC tumors from Polish patients using whole genome SNP genotyping assay. Moreover, the utility of next generation sequencing of cell free DNA (cfDNA) in patients plasma as a potential tool for non-invasive cytogenetic analysis was tested. Additionally, tumor specific somatic mutations in PBRM1, BAP1 and KDM5C were determined.

RESULTS

We confirmed a correlation between deletions at 9p and higher tumor size, and deletion of chromosome 20 and the survival time. In Fuhrman grade 1, only aberrations of 3p and 8p deletion, gain of 5q and 13q and gains of chromosome 7 and 16 were present. The number of aberrations increased with Fuhrman grade, all chromosomes displayed cytogenetic changes in G3 and G4. ccRCC specific chromosome aberrations were observed in cfDNA, although discrepancies were found between cfDNA and tumor samples. In total 12 common and 94 rare variants were detected in PBRM1, BAP1 and KDM5C, with four potentially pathogenic variants. We observed markedly lower mutation load in PBRM1.

CONCLUSIONS

Cytogenetic analysis of cfDNA may allow more accurate diagnosis of tumor aberrations and therefore the correlation between the chromosome aberrations in cfDNA and clinical outcome should be studied in larger cohorts. The functional studies on in BAP1, KDM5C, PBRM1 mutations in large, independent sample set would be necessary for the assessment of their prognostic and diagnostic potential.

Clinical diagnosis and detection of genetic mutations of pancreatic metastases: A report of four cases and review of the literature

The present study aimed to report our clinical experience regarding the diagnosis and detection of genetic mutations of pancreatic metastases, and to review the relevant literature to expand knowledge of this disease. A total of 4 cases involving pancreatic metastases, which were treated at The First Affiliated Hospital of Soochow University between January 2013 and July 2016, were retrospectively analyzed. This retrospective study considered the clinicopathological variables of the 4 patients, and compared this data with those from the literature, which was searched using PubMed, EMBASE and the Cochrane Library. All 4 patients with pancreatic metastases were diagnosed by computed tomography (CT) scan and confirmed by pathological staining and immunohistochemistry. Mutation analysis was performed in 3 patients to obtain precise mutation information for guiding and evaluating the use of molecularly targeted drugs. In summary, pancreatic metastases are rare and the majority of pancreatic metastases develop from renal cell carcinoma. Diagnoses of pancreatic metastases predominantly rely on CT, pathology and immunohistochemistry. Detection of mutations has clinical value in auxiliary diagnosis and therapy of pancreatic metastases. Based on mutation information, molecularly targeted drugs may prolong the survival of patients with unresectable pancreatic metastases.

Stratification of clear cell renal cell carcinoma (ccRCC) genomes by gene-directed copy number alteration (CNA) analysis

Tumorigenic processes are understood to be driven by epi-/genetic and genomic alterations from single point mutations to chromosomal alterations such as insertions and deletions of nucleotides up to gains and losses of large chromosomal fragments including products of chromosomal rearrangements e.g. fusion genes and proteins. Overall comparisons of copy number alterations (CNAs) presented in 48 clear cell renal cell carcinoma (ccRCC) genomes resulted in ratios of gene losses versus gene gains between 26 ccRCC Fuhrman malignancy grades G1 (ratio 1.25) and 20 G3 (ratio 0.58). Gene losses and gains of 15762 CNA genes were mapped to 795 chromosomal cytoband loci including 280 KEGG pathways. CNAs were classified according to their contribution to Fuhrman tumour gradings G1 and G3. Gene gains and losses turned out to be highly structured processes in ccRCC genomes enabling the subclassification and stratification of ccRCC tumours in a genome-wide manner. CNAs of ccRCC seem to start with common tumour related gene losses flanked by CNAs specifying Fuhrman grade G1 losses and CNA gains favouring grade G3 tumours. The appearance of recurrent CNA signatures implies the presence of causal mechanisms most likely implicated in the pathogenesis and disease-outcome of ccRCC tumours distinguishing lower from higher malignant tumours. The diagnostic quality of initial 201 genes (108 genes supporting G1 and 93 genes G3 phenotypes) has been successfully validated on published Swiss data (GSE19949) leading to a restricted CNA gene set of 171 CNA genes of which 85 genes favour Fuhrman grade G1 and 86 genes Fuhrman grade G3. Regarding these gene sets overall survival decreased with the number of G3 related gene losses plus G3 related gene gains. CNA gene sets presented define an entry to a gene-directed and pathway-related functional understanding of ongoing copy number alterations within and between individual ccRCC tumours leading to CNA genes of prognostic and predictive value.

The long noncoding RNA urothelial carcinoma-associated 1 overexpression as a poor prognostic biomarker in clear cell renal cell carcinoma

Long noncoding RNA urothelial carcinoma-associated 1 has previously played important roles in cancer. However, its role is still unknown in clear cell renal cell carcinoma. We utilized the most recent molecular and clinical data of clear cell renal cell carcinoma from The Cancer Genome Atlas project, and the relationship between urothelial carcinoma-associated 1 expression and the clinicopathological features was analyzed. Our results indicated that urothelial carcinoma-associated 1 overexpression was associated with male ( p = 0.003), wild-type PBRM1 ( p = 0.021), and BAP1 mutation ( p = 0.022) in clear cell renal cell carcinoma, although lower expression was found in tumors compared with normal controls, validated in tumor tissues from The Cancer Genome Atlas and 21 clear cell renal cell carcinoma patients at our hospital. Moreover, urothelial carcinoma-associated 1 overexpression indicated poor prognosis independently (Hazard Ratio [HR]: 1.92, p = 0.000) in clear cell renal cell carcinoma; it might be a potential detrimental gene considered as a predictive biomarker involved in clear cell renal cell carcinoma.

Implication of VHL, ERK5, and HIF-1alpha in clear cell renal cell carcinoma: Molecular basis

OBJECTIVES

To determine the expression status of several proteins related to VHL gene function and its relationship with common clinicopathological parameters.

MATERIAL AND METHODS

Observational, analytical, cross-sectional study with 50 patients diagnosed with clear cell renal cell carcinoma. The study analyzed VHL mutations and hypermethylation as well as protein expression of VHL, CA-IX, HIF-1alpha, VEGF, ERK1/2, and ERK5, relating them to clinical variables. A bivariate and multivariate descriptive logistical regression analysis was performed, using the presence of metastasis at diagnosis as dependent variable.

RESULTS

The study identified 13 (26%) VHL mutations related to nuclear grade (P = 0.036). VHL hypermethylation was found in 20% of cases. VHL expression was associated with the presence of mutations (P = 0.013), and the absence of expression was associated with nuclear grade and the presence of metastasis (P<0.05). HIF-1alpha was negative in only 5 cases. Vascular endothelial growth factor (VEGF) was positive in 31 of 47 cases and was associated with Fuhrman nuclear grade, presence of metastasis, and stage (P<0.05). ERK5 expression was increased in 58% of cases and associated with the presence of metastasis and more advanced stages (P<0.05). In the logistic regression analysis, the only variable remaining in the model was VEGF expression (P = 0.014).

CONCLUSIONS

VEGF has prognostic value in clear cell renal cell carcinoma, and ERK5 may be a new prognostic marker in this type of tumor owing to its relationship with metastasis and more advanced stages.

Independent association of PD-L1 expression with noninactivated VHL clear cell renal cell carcinoma-A finding with therapeutic potential

Clear cell renal cell carcinoma (ccRCC) is an aggressive tumor that is characterized in most cases by inactivation of the tumor suppressor gene VHL. The VHL/HIF/VEGF pathway thus plays a major role in angiogenesis and is currently targeted by anti-angiogenic therapy. The emergence of resistance is leading to the use of targeted immunotherapy against immune checkpoint PD1/PDL1 that restores antitumor immune response. The correlation between VHL status and PD-L1 expression has been little investigated. In this study, we retrospectively reviewed 98 consecutive cases of ccRCC and correlated PD-L1 expression by immunohistochemistry (IHC) with clinical data (up to 10-year follow-up), pathological criteria, VEGF, PAR-3, CAIX and PD-1 expressions by IHC and complete VHL status (deletion, mutation and promoter hypermethylation). PD-L1 expression was observed in 69 ccRCC (70.4%) and the corresponding patients had a worse prognosis, with a median specific survival of 52 months (p = 0.03). PD-L1 expression was significantly associated with poor prognostic factors such as a higher ISUP nucleolar grade (p = 0.01), metastases at diagnosis (p = 0.01), a sarcomatoid component (p = 0.04), overexpression of VEGF (p = 0.006), and cytoplasmic PAR-3 expression (p = 0.01). PD-L1 expression was also associated with dense PD-1 expression (p = 0.007) and with ccRCC with 0 or 1 alteration(s) (non-inactivated VHL tumors; p = 0.007) that remained significant after multivariate analysis (p = 0.004 and p = 0.024, respectively). Interestingly, all wild-type VHL tumors (no VHL gene alteration, 11.2%) expressed PD-L1. In this study, we found PD-L1 expression to be associated with noninactivated VHL tumors and in particular wild-type VHL ccRCC, which may benefit from therapies inhibiting PD-L1/PD-1.

Synchronous Metastatic Clear-Cell Renal Cell Carcinoma: A Distinct Morphologic, Immunohistochemical, and Molecular Phenotype

INTRODUCTION

Clear cell renal cell carcinomas (ccRCCs) are highly metastatic tumors with metastases detected at diagnosis (synchronous) or during follow-up (metachronous). To date, there have been no reports comparing primary ccRCC of patients with synchronous and metachronous metastases, who are different in terms of prognosis. Determining whether there is a phenotypic difference between these 2 groups could have important clinical implications.

PATIENTS AND METHODS

In a retrospective consecutive cohort of 98 patients with ccRCC, 48 patients had metastases, including 28 synchronous and 20 metachronous presentations, with a follow-up of 10 years. For each primary tumor in these metastatic patients, pathologic criteria, expression of vascular endothelial growth factor, partitioning-defective 3, CAIX, and programmed death ligand 1 as detected by immunohistochemistry, and complete VHL status were analyzed. Univariate analysis was performed, and survival was assessed using Kaplan-Meier curves compared by log-rank test.

RESULTS

Compared with primary ccRCC in patients with metachronous metastases, primary ccRCC in patients with synchronous metastases were significantly associated with a poorer Eastern Cooperative Oncology Group performance (P = .045), higher pT status (P = .038), non-inactivated VHL gene (P = .01), sarcomatoid component (P = .007), expression of partitioning-defective 3 (P = .007), and overexpressions of vascular endothelial growth factor (> 50%) (P = .017) and programmed death ligand 1 (P = .019). Patients with synchronous metastases had a worse cancer-specific survival than patients with metachronous metastases even from metastatic diagnosis (median survival, 16 months vs. 46 months, respectively; P = .01).

CONCLUSION

This long-term study is the first to support the notion that synchronous m-ccRCC has a distinct phenotype. This is probably linked to the occurrence of oncogenic events that could explain the worse prognosis. These particular patients with metastases could benefit from specific therapy.

Recent aspects of sunitinib therapy in patients with metastatic clear-cell renal cell carcinoma: a systematic review of the literature

Sunitinib is an orally available inhibitor of multiple tyrosine-kinase receptors approved for the treatment of advanced clear-cell renal cell carcinoma (ccRCC), a disease which has habitually had a very poor patient survival rate. Although it has become the most widely used drug for this disease, it remains not completely clear the best treatment strategy with these agent. The aim of this review is to highlight the most recent and interesting aspects of the research on treatment of advanced ccRCC with sunitinib and eventually determine alternative treatment schedule to reduce the incidence of side effects; we also wanted to review recent biomarkers able to predict response to therapy and also to point out the mechanism of acquired resistance to this drug.

Genomic characterization of sarcomatoid transformation in clear cell renal cell carcinoma

The presence of sarcomatoid features in clear cell renal cell carcinoma (ccRCC) confers a poor prognosis and is of unknown pathogenesis. We performed exome sequencing of matched normal-carcinomatous-sarcomatoid specimens from 21 subjects. Two tumors had hypermutation consistent with mismatch repair deficiency. In the remainder, sarcomatoid and carcinomatous elements shared 42% of somatic single-nucleotide variants (SSNVs). Sarcomatoid elements had a higher overall SSNV burden (mean 90 vs. 63 SSNVs, P = 4.0 × 10(-4)), increased frequency of nonsynonymous SSNVs in Pan-Cancer genes (mean 1.4 vs. 0.26, P = 0.002), and increased frequency of loss of heterozygosity (LOH) across the genome (median 913 vs. 460 Mb in LOH, P < 0.05), with significant recurrent LOH on chromosomes 1p, 9, 10, 14, 17p, 18, and 22. The most frequent SSNVs shared by carcinomatous and sarcomatoid elements were in known ccRCC genes including von Hippel-Lindau tumor suppressor (VHL), polybromo 1 (PBRM1), SET domain containing 2 (SETD2), phosphatase and tensin homolog (PTEN). Most interestingly, sarcomatoid elements acquired biallelic tumor protein p53 (TP53) mutations in 32% of tumors (P = 5.47 × 10(-17)); TP53 mutations were absent in carcinomatous elements in nonhypermutated tumors and rare in previously studied ccRCCs. Mutations in known cancer drivers AT-rich interaction domain 1A (ARID1A) and BRCA1 associated protein 1 (BAP1) were significantly mutated in sarcomatoid elements and were mutually exclusive with TP53 and each other. These findings provide evidence that sarcomatoid elements arise from dedifferentiation of carcinomatous ccRCCs and implicate specific genes in this process. These findings have implications for the treatment of patients with these poor-prognosis cancers.

Atezolizumab, an Anti-Programmed Death-Ligand 1 Antibody, in Metastatic Renal Cell Carcinoma: Long-Term Safety, Clinical Activity, and Immune Correlates From a Phase Ia Study

PURPOSE

The objective was to determine the safety and clinical activity of atezolizumab (MPDL3280A), a humanized programmed death-ligand 1 (PD-L1) antibody, in renal cell carcinoma (RCC). Exploratory biomarkers were analyzed and associated with outcomes.

PATIENTS AND METHODS

Seventy patients with metastatic RCC, including clear cell (ccRCC; n = 63) and non-clear cell (ncc; n = 7) histologies, received atezolizumab intravenously every 3 weeks. PD-L1 expression was scored at four diagnostic levels (0/1/2/3) that were based on PD-L1 staining on tumor cells and tumor-infiltrating immune cells (IC) with the SP142 assay. Primary end points were safety and toxicity; secondary end points assessed clinical activity per Response Evaluation Criteria in Solid Tumors version 1.1 and immune-related response criteria. Plasma and tissue were analyzed for potential biomarkers of atezolizumab response.

RESULTS

Grade 3 treatment-related and immune-mediated adverse events occurred in 17% and 4% of patients, respectively, and there were no grade 4 or 5 events. Sixty-three patients with ccRCC were evaluable for overall survival (median, 28.9 months; 95% CI, 20.0 months to not reached) and progression-free survival (median, 5.6 months; 95% CI, 3.9 to 8.2 months), and 62 patients were evaluable for objective response rate (ORR; 15%; 95% CI, 7% to 26%). ORR was evaluated on the basis of PD-L1 IC expression (IC1/2/3: n = 33; 18%; 95% CI, 7% to 35%; and IC0: n = 22; 9%; 95% CI, 1% to 29%). The ORR for patients with Fuhrman grade 4 and/or sarcomatoid histology was 22% (n = 18; 95% CI, 6% to 48%). Decreases in circulating plasma markers and acute-phase proteins and an increased baseline effector T-cell-to-regulatory T-cell gene expression ratio correlated with response to atezolizumab.

CONCLUSION

Atezolizumab demonstrated a manageable safety profile and promising antitumor activity in patients with metastatic RCC. Correlative studies identified potential predictive and pharmacodynamic biomarkers. These results have guided ongoing studies and combinations with atezolizumab in RCC.

Genetic and Chromosomal Aberrations and Their Clinical Significance in Renal Neoplasms

The most common form of malignant renal neoplasms is renal cell carcinoma (RCC), which is classified into several different subtypes based on the histomorphological features. However, overlaps in these characteristics may present difficulties in the accurate diagnosis of these subtypes, which have different clinical outcomes. Genomic and molecular studies have revealed unique genetic aberrations in each subtype. Knowledge of these genetic changes in hereditary and sporadic renal neoplasms has given an insight into the various proteins and signalling pathways involved in tumour formation and progression. In this review, the genetic aberrations characteristic to each renal neoplasm subtype are evaluated along with the associated protein products and affected pathways. The potential applications of these genetic aberrations and proteins as diagnostic tools, prognostic markers, or therapeutic targets are also assessed.

ROTS: reproducible RNA-seq biomarker detector-prognostic markers for clear cell renal cell cancer

Recent comprehensive assessments of RNA-seq technology support its utility in quantifying gene expression in various samples. The next step of rigorously quantifying differences between sample groups, however, still lacks well-defined best practices. Although a number of advanced statistical methods have been developed, several studies demonstrate that their performance depends strongly on the data under analysis, which compromises practical utility in real biomedical studies. As a solution, we propose to use a data-adaptive procedure that selects an optimal statistic capable of maximizing reproducibility of detections. After demonstrating its improved sensitivity and specificity in a controlled spike-in study, the utility of the procedure is confirmed in a real biomedical study by identifying prognostic markers for clear cell renal cell carcinoma (ccRCC). In addition to identifying several genes previously associated with ccRCC prognosis, several potential new biomarkers among genes regulating cell growth, metabolism and solute transport were detected.

The von Hippel-Lindau tumour suppressor gene: uncovering the expression of the pVHL172 isoform

BACKGROUND

The von Hippel-Lindau (VHL) gene encodes two mRNA variants. Variant 1 encodes two protein isoforms, pVHL213 and pVHL160, that have been extensively documented in the literature. Variant 2 is produced by alternative splicing of exon 2 and encodes a pVHL isoform of 172 amino acids with a theoretical molecular weight of 19 kDa (pVHL172), the expression of which has never been demonstrated so far due to the absence of suitable antibodies.

METHODS

We have generated an anti-pVHL monoclonal antibody (JD-1956) using pVHL172 recombinant protein. We tested the antibody against exogenous or endogenous expressed proteins in different cell lines. We identified the pVHL172 using a silencing RNA strategy. The epitope of the antibody was mapped using a peptide array.

RESULTS

We efficiently detected the three different isoforms of pVHL in cell lines and tumorigenic tissues by western blotting and immunohistochemistry and confirmed for the first time the endogenous expression of pVHL172.

CONCLUSIONS

The endogenous expression of the three isoforms and particularly the pVHL172 has never been shown before due to a lack of a highly specific antibody since none of the available commercial antibodies distinguish the three isoforms of pVHL in cells or in both normal and cancerous human tissues. Evidence of pVHL172 expression emphasises the need to further study its implication in renal tumorigenesis and VHL disease.

Wild-type VHL Clear Cell Renal Cell Carcinomas Are a Distinct Clinical and Histologic Entity: A 10-Year Follow-up

BACKGROUND

Clear cell renal cell carcinoma (ccRCC) is an aggressive tumor with 50% risk of metastases at initial diagnosis or at follow-up. An inactivation of the tumor-suppressor gene von Hippel-Lindau (VHL) is present in >70% of sporadic cases by two of three different mechanisms: locus deletion, gene mutation, or promoter hypermethylation.

OBJECTIVE

To correlate the complete status of the VHL gene with clinical and pathologic criteria.

DESIGN, SETTING, AND PARTICIPANTS

We retrospectively included 98 patients with ccRCC who underwent surgery between 2002 and 2005. VHL gene deletions (71 of 98; 72.4%), mutations (68 of 98; 69.4%), and promoter hypermethylations (13 of 98; 13.3%) were screened by gene copy analysis, gene sequencing, and methylation-specific multiplex ligation-dependent probe amplification, respectively.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Relationships between VHL subgroups and the studied criteria were analyzed using chi-square and Student t tests. Survival was analyzed with the log-rank test and Kaplan-Meier curves.

RESULTS AND LIMITATIONS

Compared with ccRCCs with two events (66.3%), tumors with no or one genetic event (33.6%) were associated with a higher nuclear grade IV (p=0.02), metastases (p=0.04), sarcomatoid component (p=0.01), dense lymphocyte infiltrate (p=0.013), and vascular endothelial growth factor overexpression (>30%) (p=0.003), which was also an independent factor after multivariate analysis. Furthermore, wild-type VHL tumors (no inactivating event, 11.2%) were associated with nodal involvement (p=0.019), and patients with this type of tumor had a specific survival of 33 mo compared with patients with ccRCCs having one or two VHL inactivating events (107 mo; p=0.016). The retrospective design with small number of wild-type tumors was a limitation of this work.

CONCLUSIONS

This long-term study (10-yr clinical follow-up) confirms that ccRCCs with wild-type VHL are highly aggressive tumors that need to be formally identified.

PATIENT SUMMARY

Among activated VHL tumors, the wild-type subgroup defines an aggressive phenotype with worse survival rates, suggesting that these tumors must be more thoroughly screened.

Triptolide: A Critical Review on Antiangiogenesis in Cancer and Scope in Therapeutics

Triptolide (TPL) is a traditional Chinese medicine and an active component of a Chinese herbTripterygium wilfordiiF. (Celastraceae). Triptolide has been used to treat a variety of ailments, including rheumatoid arthritis, nephritic syndrome and Lupus erythematosus. It is also a strong antitumor agent. Several angiogenesis assays in numerous research studies have shown that triptolide is an angiogenesis inhibitor. Numerous preclinical studies have shown that TPL inhibits cell proliferation, induces apoptosis and limits tumor metastasis. TPL also has a synergistic action with other treatment methods whereby, it enhances the effects of other antitumor treatments, as studied in various cancer cell lines. This review summarizes the recent developments and discussion of antiangiogenic mechanisms of TPL in cancer, brief outline of its clinical trials and its future in cancer therapeutics.

Renal cell carcinoma risk is associated with the interactions of APOE, VHL and MTHFR gene polymorphisms

OBJECTIVE

The study was designed to explore the association of renal cell carcinoma (RCC) with VHL (rs779805), MTHFR (rs1801133) and APOE (rs8106822 and rs405509) polymorphisms, investigate the interactions among the single nucleotide polymorphisms (SNPs), and explore roles of the interactions in the pathogenesis of RCC in Chinese Han population.

METHODS

81 RCC patients and 80 healthy controls were included in the study. Polymerase chain reaction (PCR) and direct sequencing methods were used in the analysis on the genotypes of APOE, VHL and MTHFR gene polymorphisms. Multifactor dimensionality reduction (MDR) method was adopted to conduct gene-gene interaction analysis. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were utilized to evaluate the correlation between gene-gene interactions and RCC risk.

RESULTS

Significant correlations were found between RCC risk and 3 SNPs (rs8106822, rs779805 and rs1801133). Genotype AA and allele A of APOE rs8106822 were significantly associated with RCC susceptibility (OR=2.65, 95% CI=1.05-6.69). Meanwhile, we found that the frequencies of genotype GG and allele G were much higher in case group, compared with controls (P<0.05 for both) and they appeared to be risk factors for RCC (OR=2.90, 95% CI=1.22-6.87; OR=1.78, 95% CI=1.14-2.27). While, allele T of MTHFR rs1801133 could decrease the risk of RCC (OR=0.62, 95% CI=0.40-0.97). MDR analysis showed that gene-gene interactions among APOE, VHL and MTHFR SNPs were closely related with RCC susceptibility.

CONCLUSION

APOE, VHL and MTHFR gene polymorphisms were related to the risk of RCC. The interactions among APOE, VHL and MTHFR genes could increase the risk of RCC.

MicroRNA-185 inhibits cell proliferation and induces cell apoptosis by targeting VEGFA directly in von Hippel-Lindau-inactivated clear cell renal cell carcinoma

OBJECTIVES

The von Hippel-Lindau (VHL) gene acts as a tumor suppressor in most clear cell renal cell carcinomas (ccRCCs). Tumor growth in ccRCCs relies on many factors that result from the loss of VHL. This study aims to identify new microRNAs with therapeutic potential for VHL-inactivated ccRCCs.

MATERIALS AND METHODS

We used 786O, A498 (VHL inactivated), and Caki-1 (VHL intact) ccRCC cell lines and 40 ccRCC samples and their adjacent nontumor tissues to measure the expression of microRNA-185 (miR-185) by real-time quantitative polymerase chain reaction. Overexpression or knockdown of VEGFA expression in renal cancer cells was fulfilled by transfecting expression plasmids or small interfering RNAs. Overexpression of miR-185 in ccRCC cell lines was fulfilled by transfecting chemically synthesized miR-185 mimics. The effects of miR-185 on ccRCC cell lines were detected by MTS assay, colony formation assay, and flow cytometric analysis.

RESULTS

Compared with adjacent nontumor renal tissues, miR-185 expression levels decreased significantly in ccRCC tissues. The expression of miR-185 had a negative correlation with tumor size, Fuhrman grade, and TNM staging. Luciferase assay showed that VEGFA was a direct target gene of miR-185. The overexpression of miR-185 significantly inhibited cell proliferation and induced cell apoptosis by down-regulating VEGFA expression in VHL-inactivated ccRCC cells.

CONCLUSIONS

Our results suggest that the miR-185, as a tumor suppressor, plays a pivotal role by inhibiting VEGFA in VHL-inactivated ccRCC.

Stem cells increase in numbers in perinecrotic areas in human renal cancer

PURPOSE

Developing strategies to overcome resistance to sunitinib is a major challenge in human renal cell carcinoma (RCC). We hypothesized that sunitinib-induced tumor necrosis-associated hypoxia could interact with renal cancer stem cells in patients with metastatic RCC.

EXPERIMENTAL DESIGN

We studied tissue samples from 7 patients with primary metastatic RCC, before and after sunitinib treatment, and from six xenograft models derived from human RCC. Two xenograft models were responders to sunitinib, the four others were nonresponders. CD133/CXCR4-coexpressing cells derived from the two responder xenograft models were used for in vitro studies.

RESULTS

In the seven primary RCCs, we identified a significantly larger number of CD133/CXCR4-coexpressing cells in perinecrotic versus perivascular areas. Their numbers also significantly increased after treatment, in perinecrotic areas. We reproduced these clinical and pathologic results in all six RCC xenograft models with again a preferential perinecrotic distribution of CD133-expressing cells. Necrosis occurred at day 7 in the two responder models treated with sunitinib, whereas it occurred at day 21 in the untreated controls and in the four nonresponder models. Strikingly, when we studied the six RCC xenograft models at the time necrosis, whether spontaneous or sunitinib-induced, occurred, necrosis area correlated with stem-cell number in all 120 xenografted RCCs. When studied under experimental hypoxia, the number of CD133/CXCR4-coexpressing cells and their tumorigenic potency increased whereas their sensitivity to sunitinib decreased.

CONCLUSIONS

In human RCC, sunitinib was able to generate resistance to its own therapeutic effect via induced hypoxia in perinecrotic areas where cancer stem cells were found in increased numbers.

Identification and significance of mobilized endothelial progenitor cells in tumor neovascularization of renal cell carcinoma

Neovascularization is a key role of renal cell carcinoma (RCC) and the status of neovascularization in RCC is closely correlated with the tumor development and patient prognosis. Endothelial progenitor cells (EPCs) are considered as important building blocks for neovascularization. However, the role of mobilized EPCs in RCC remains unknown. In this study, the orthotopic RCC model was established to investigate the distribution, frequency, and significance of mobilized EPCs. We found that circulating endothelial progenitor cell (CEPC) levels and plasma angiogenic factors (vascular endothelial growth factor (VEGF) and stromal cell-derived factor-1 (SDF-1) were higher in peripheral blood (PB) of the RCC than those in the normal group and positively correlated with each other. EPC levels in adjacent nonmalignant kidney tissue (AT) were significantly higher than those in tumor tissue (TT) and normal kidney tissue (NT), which were positively correlated with CEPC levels. VEGF, VEGF receptor-2 (Flk), and SDF-1 and its SDF-1 receptor (CXCR4) expression in AT was significantly higher than that in TT and NT. Levels of these angiogenic factors in AT were positively correlated with those in PB. Mean microvessel density (MVD) was higher in AT than in TT, and that in TT was slightly lower than that in NT. Our findings propose that mobilized EPCs play an important role in RCC neovascularization. EPCs in PB and AT can be used as a biomarker for predicting RCC progression.

Stage-dependent prognostic impact of molecular signatures in clear cell renal cell carcinoma

Purpose

To enhance prognostic information of protein biomarkers for clear cell renal cell carcinomas (ccRCCs), we analyzed them within prognostic groups of ccRCC harboring different tumor characteristics of this clinically and molecularly heterogeneous tumor entity.

Methods

Tissue microarrays from 145 patients with primary ccRCC were immunohistochemically analyzed for VHL (von Hippel-Lindau tumor suppressor), Ki67 (marker of proliferation 1), p53 (tumor protein p53), p21 (cyclin-dependent kinase inhibitor 1A), survivin (baculoviral IAP repeat containing 5), and UEA-1 (Ulex europaeus agglutinin I) to assess microvessel-density.

Results

When analyzing all patients, nuclear staining of Ki67 (hazard ratio [HR] 1.08, 95% confidence interval [CI] 1.04–1.12) and nuclear survivin (nS; HR 1.04, 95% CI 1.01–1.08) were significantly associated with disease-specific survival (DSS). In the cohort of patients with advanced localized or metastasized ccRCC, high staining of Ki67, p53 and nS predicted shorter DSS (Ki67: HR 1.07, 95% CI 1.02–1.11; p53: HR 1.05, 95% CI 1.01–1.09; nS: HR 1.08, 95% CI 1.02–1.14). In organ-confined ccRCC, patients with high p21-staining had a longer DSS (HR 0.96, 95% CI 0.92–0.99). In a multivariate model with stepwise backward elimination, tumor size and p21-staining showed a significant association with DSS in patients with “organ-confined” ccRCCs. The p21-staining increased the concordance index of tumor size from 0.75 to 0.78. In patients with “organ-confined” ccRCC, no disease-related deaths occurred in the group with p21-expression below the threshold of 32.5% p21-positive cells (log rank test: P=0.002).

Conclusion

The prognostic information of the studied protein biomarkers depended on anatomic tumor stages, which displayed different acquired biological tumor characteristics. Analysis of prognostic factors within different clinical ccRCC groups could help to enhance their prognostic power. The p21-staining was an independent prognostic factor and increased prognostic accuracy in a predictive model in “organ-confined” ccRCC.

Sorafenib cardiotoxicity increases mortality after myocardial infarction

RATIONALE

Sorafenib is an effective treatment for renal cell carcinoma, but recent clinical reports have documented its cardiotoxicity through an unknown mechanism.

OBJECTIVE

Determining the mechanism of sorafenib-mediated cardiotoxicity.

METHODS AND RESULTS

Mice treated with sorafenib or vehicle for 3 weeks underwent induced myocardial infarction (MI) after 1 week of treatment. Sorafenib markedly decreased 2-week survival relative to vehicle-treated controls, but echocardiography at 1 and 2 weeks post MI detected no differences in cardiac function. Sorafenib-treated hearts had significantly smaller diastolic and systolic volumes and reduced heart weights. High doses of sorafenib induced necrotic death of isolated myocytes in vitro, but lower doses did not induce myocyte death or affect inotropy. Histological analysis documented increased myocyte cross-sectional area despite smaller heart sizes after sorafenib treatment, further suggesting myocyte loss. Sorafenib caused apoptotic cell death of cardiac- and bone-derived c-kit+ stem cells in vitro and decreased the number of BrdU+ (5-bromo-2'-deoxyuridine+) myocytes detected at the infarct border zone in fixed tissues. Sorafenib had no effect on infarct size, fibrosis, or post-MI neovascularization. When sorafenib-treated animals received metoprolol treatment post MI, the sorafenib-induced increase in post-MI mortality was eliminated, cardiac function was improved, and myocyte loss was ameliorated.

CONCLUSIONS

Sorafenib cardiotoxicity results from myocyte necrosis rather than from any direct effect on myocyte function. Surviving myocytes undergo pathological hypertrophy. Inhibition of c-kit+ stem cell proliferation by inducing apoptosis exacerbates damage by decreasing endogenous cardiac repair. In the setting of MI, which also causes large-scale cell loss, sorafenib cardiotoxicity dramatically increases mortality.

Overexpression of the polarity protein PAR-3 in clear cell renal cell carcinoma is associated with poor prognosis

The partition-defective 3 (PAR-3) protein is implicated in the development and maintenance of cell polarity and is associated with proteins that mediate the changes in cytoskeleton organization required for cell polarity establishment. In this work, we used two original primary cell lines (R-180 and R-305) derived from clear cell Renal Cell Carcinoma (ccRCC) surgical specimens of a patient with unfavorable clinical course (R-180 cells) and a patient with favorable prognosis (R-305 cells) to identify genetic and molecular features that may explain the survival difference of the two patients. The cytogenetic analysis of these cell lines revealed that the PARD3 gene was amplified only in the R-180 cell line that was derived from an aggressive ccRCC. PARD3 gene amplification was associated with overexpression of the encoded protein and altered cytoskeleton organization. Consistently, PARD3 knockdown in R-180 cells restored the cytoskeleton organization and reduced cell migration in comparison to non-transfected cells. Immunohistochemical analysis of ccRCC samples from a cohort of 96 patients with a follow-up of 6 years revealed that PAR-3 overexpression was correlated with poor survival. Our results suggest that PAR-3 has a role in the clinical aggressiveness of ccRCC, possibly by promoting cell migration.