Renal cell carcinoma: Current status and future prospects

Cooperation between SIX1 and DHX9 transcriptionally regulates integrin-focal adhesion signaling mediated metastasis and sunitinib resistance in KIRC

High invasive capacity and acquired tyrosine kinase inhibitors (TKI) resistance of kidney renal clear cell carcinoma (KIRC) cells remain obstacles to prolonging the survival time of patients with advanced KIRC. In the present study, we reported that sine oculis homeobox 1 (SIX1) was upregulated in sunitinib-resistant KIRC cells and metastatic KIRC tissues. Subsequently, we found that SIX1 mediated metastasis and sunitinib resistance via Focal adhesion (FA) signaling, and knockdown of SIX1 enhanced the antitumor efficiency of sunitinib in KIRC. Mechanistically, Integrin subunit beta 1 (ITGB1), an upstream gene of FA signaling, was a direct transcriptional target of SIX1. In addition, we showed that DExH-box helicase 9 (DHX9) was an important mediator for SIX1-induced ITGB1 transcription, and silencing the subunits of SIX1/DHX9 complex significantly reduced transcription of ITGB1. Downregulation of SIX1 attenuated nuclear translocation of DHX9 and abrogated the binding of DHX9 to ITGB1 promoter. Collectively, our results unveiled a new signal axis SIX1/ITGB1/FAK in KIRC and identified a novel therapeutic strategy for metastatic KIRC patients.

Unveiling the multi-target compounds of Rhazya stricta: Discovery and inhibition of novel target genes for the treatment of clear cell renal cell carcinoma

Clear cell renal cell carcinoma (ccRCC) is a prevalent kidney malignancy with a pressing need for innovative therapeutic strategies. In this context, emerging research has focused on exploring the medicinal potential of plants such as Rhazya stricta. Nevertheless, the complex molecular mechanisms underlying its potential therapeutic efficacy remain largely elusive. Our study employed an integrative approach comprising data mining,network pharmacology,tissue cell type analysis, and molecular modelling approaches to identify potent phytochemicals from R. stricta, with potential relevance for ccRCC treatments. Initially, we collected data on R. stricta's phytochemical from public databases. Subsequently, we integrated this information with differentially expressed genes (DEGs) in ccRCC, which were derived from microarray datasets(GSE16441,GSE66270, and GSE76351). We identified potential intersections between R. stricta and ccRCC targets, which enabled us to construct a compound-genes-pathway network using Cytoscape software. This helped illuminate R. stricta's multi-target pharmacological effects on ccRCC. Moreover, tissue cell type analysis added another layer of insight into the cellular specificity of potential therapeutic targets in the kidney. Through further Kaplan-Meier survival analysis, we pinpointed MMP9,ACE,ERBB2, and HSP90AA1 as prospective diagnostic and prognostic biomarkers for ccRCC. Notably, our study underscores the potential of R. stricta derived compounds-namely quebrachamine,corynan-17-ol, stemmadenine,strictanol,rhazinilam, and rhazimolare-to impede ccRCC progression by modulating the activity of MMP9,ACE,ERBB2, and HSP90AA1 genes. Further, molecular docking and dynamic simulations confirmed the plausible binding affinities of these compounds. Despite these promising findings, we recognize the need for comprehensive in vivo and in vitro studies to further investigate the pharmacokinetics and biosafety profiles of these compounds.

The Efficacy of Adjuvant Targeted Therapy in Patients with Advanced Renal Cell Carcinoma: A Systematic Review and Meta-Analysis

Background

The aim of this systematic evaluation and meta-analysis was to analyze the efficacy and adverse effects of adjuvant targeted therapy regimens in advanced or metastatic renal cell carcinoma (RCC).

Methods

Studies eligible for the efficacy of adjuvant targeted therapy regimens in advanced or metastatic RCC published before December 2021 in PubMed, Embase, Cochrane Clinical Trials Database (CENTRAL), and Web of Science were searched for (1) patients with locally advanced renal cell carcinoma (RCC) who received adjuvant postoperative targeted therapy versus those not receiving active treatment; (2) primary endpoint outcomes of disease-free survival (DFS), overall survival (OS), and adverse events (AEs); and (3) design: randomized controlled trial (RCT) as inclusion criteria. Data on DFS and OS were extracted or recalculated by meta-analysis as hazard ratios (HRs), and AEs were compared using a dominance ratio (OR).

Result

This systematic evaluation will provide evidence on the effectiveness and adverse effects of adjuvant targeted therapy in patients with advanced RCC. The results of meta-analysis showed that all of the three adjuvant targeted therapeutic drugs (sorafenib, sunitinib, and pazopanib) did not benefit from the adjuvant targeted therapy for DFS and OS and even increase the incidence of AEs compared to the placebo.

Conclusions

The aim of this study was to summarize data on DFS, OS, and AEs in patients with advanced RCC treated with targeted therapies. The evidence provided by this systematic evaluation and meta-analysis will help guide clinical decision-making and provide insight into the future management of patients with advanced RCC.

miR-221/222 as biomarkers and targets for therapeutic intervention on cancer and other diseases: A systematic review

Among deregulated microRNAs (miRs) in human malignancies, miR-221 has been widely investigated for its oncogenic role and as a promising biomarker. Moreover, recent evidence suggests miR-221 as a fine-tuner of chronic liver injury and inflammation-related events. Available information also supports the potential of miR-221 silencing as promising therapeutic intervention. In this systematic review, we selected papers from the principal databases (PubMed, MedLine, Medscape, ASCO, ESMO) between January 2012 and December 2020, using the keywords "miR-221" and the specific keywords related to the most important hematologic and solid malignancies, and some non-malignant diseases, to define and characterize deregulated miR-221 as a valuable therapeutic target in the modern vision of molecular medicine. We found a major role of miR-221 in this view.

Inverse correlation of miR-27a-3p and CDH5 expression serves as a diagnostic biomarker of proliferation and metastasis of clear cell renal carcinoma

BACKGROUND

Cadherin-5 (CDH5) is aberrantly expressed in a variety of human cancers and plays an important role in angiogenesis. The present study provides further insight into the role of miR-27a-3p in the regulation of CDH5 expression in renal clear cell carcinoma (ccRCC).

METHODS

Thedysregulation of CDH5 expression in ccRCC and its association with clinicopathological characteristics were analyzed using the TCGA database. A meta-analysis was performed to verify the alteration of CDH5 expression in ccRCC using the GEO database. Quantitative RT-PCR and immunohistochemical staining were applied to assess the transcriptional and protein levels of CDH5. TargetScan and Tarbase were employed to predict the miRNAs with the potential to target mRNA of CDH5.

RESULTS

The mRNA level of CDH5 in ccRCCwas significantly higher than in normal tissue. CDH5 mRNA expression could therefore serve as a potential diagnostic biomarker for ccRCC (AUC = 0.844). However, the reduced CDH5 transcription levels were significantly correlated with patients in the T3-4 stage, lymph node, and distant metastasis, as well as with a worse clinical outcome. We further observed that CDH5, at the protein level, was almost absent in ccRCC samples. In addition, a few databases screen showed that mir-27a-3p is a highly conserved miRNA targeting CDH5. The expression of mir-27a-3p was significantly elevated in ccRCC tissues in contrast to normal tissues. Importantly, it was positively associated with the T3-4 stage and M stage, respectively, suggesting that the expression level of mir-27a-3p could serve as a diagnostic biomarker for ccRCC (AUC = 0.775).

CONCLUSION

Our data suggest that thereduced translational level of CDH5 in ccRCC was related to the overexpression of mir-27a-3p. The higher mir-27a-3p and lower CDH5 expression significantly correlated with advanced clinical stages for ccRCC patients.

Identification of RNA Transcript Makers Associated With Prognosis of Kidney Renal Clear Cell Carcinoma by a Competing Endogenous RNA Network Analysis

Objective

This study aims to identify several RNA transcripts associated with the prognosis of kidney renal clear cell carcinoma (KIRC).

Methods

The differentially expressed mRNAs, lncRNAs, and miRNAs (DEmRNAs, DElncRNAs, and DEmiRNAs) between KIRC cases and controls were screened based on an RNA-seq dataset from The Cancer Genome Atlas (TCGA) database. Subsequently, miRcode, miRDB, and TargetScan database were used to predict interactions between lncRNAs, miRNAs and target mRNAs. Then, a ceRNA network was built using miRNAs-mRNAs and lncRNAs-miRNAs pairs. Functional analysis of mRNAs in ceRNA was performed. Finally, the survival analysis of RNA transcripts in ceRNA network and correlation analysis for key RNA regulators were carried out.

Results

There were 1527 DElncRNAs, 54 DEmiRNAs, and 2321 DEmRNAs. A ceRNA network was constructed among 81 lncRNAs, 9 miRNAs, and 197 mRNAs. Functional analysis showed that numerous mRNAs were significantly associated with regulation of cellular glucuronidation. In addition, 35 lncRNAs, 84 mRNAs and two miRNAs were significantly corelated to the survival of patients with KIRC (P < 0.05). Among them, miRNA-21 and miRNA-155 were negatively related to three lncRNAs (LINC00472, SLC25A5.AS1, and TCL6). Seven mRNA targets of miRNA-21 (FASLG, FGF1, TGFBI, ALX1, SLC30A10, ADCY2, and ABAT) and 12 mRNAs targets of miRNA-155 (STXBP5L, SCG2, SPI1, C12orf40, TYRP1, CTHRC1, TDO2, PTPRQ, TRPM8, ERMP1, CD36, and ST9SIA4) also acted as prognostic biomarkers for KIRC patients.

Conclusion

We screened numerous novel prognosis-related RNA markers for KIRC patients by a ceRNA network analysis, providing deeper understandings of prognostic values of RNA transcripts for KIRC.

A Two-DNA Methylation Signature to Improve Prognosis Prediction of Clear Cell Renal Cell Carcinoma

PURPOSE

Effective biomarkers and models are needed to improve the prognostic prospects of clear cell renal cell carcinoma (ccRCC). The purpose of this work was to identify DNA methylation biomarkers and to evaluate the utility of DNA methylation analysis for ccRCC prognosis.

MATERIALS AND METHODS

An overview of genome-wide methylation of ccRCC tissues derived from The Cancer Genome Atlas (TCGA) database was download for analysis. DNA methylation signatures were identified using Cox regression methods. The potential clinical significance of methylation biomarkers acting as a novel prognostic markers was analyzed using the Kaplan-Meier method and receiver operating characteristic (ROC) curves.

RESULTS

This study analyzed data for 215 patients with information on 23171 DNA methylation sites and identified a two-DNA methylation signature (cg18034859, cg24199834) with the help of a step-wise multivariable Cox regression model. The area under the curve of ROCs for the two-DNA methylation signature was 0.819. The study samples were stratified into low- and high-risk classifications based on an optimal threshold, and the two groups showed markedly different survival rates. Moreover, the two-DNA methylation marker was suitable for patients of varying ages, sex, stages (I and IV), and histologic grade (G2).

CONCLUSION

The two-DNA methylation signature was deemed to be a potential novel prognostic biomarker of use in increasing the accuracy of predicting overall survival of ccRCC patients.

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.

Knockdown of TACC3 Inhibits the Proliferation and Invasion of Human Renal Cell Carcinoma Cells

Transforming acidic coiled-coil protein 3 (TACC3) is a member of the TACC family and plays an important role in regulating cell mitosis, transcription, and tumorigenesis. However, the expression pattern and roles of TACC3 in renal cell carcinoma (RCC) remain unclear. The aim of this study was to investigate the role of TACC3 in RCC. We demonstrated overexpression of TACC3 in human RCC cell lines at both RNA and protein levels. Moreover, knockdown of TACC3 repressed RCC cell proliferation, migration, and invasion in vitro. In addition, knockdown of TACC3 inactivated PI3K/Akt signaling in RCC cells. Furthermore, knockdown of TACC3 significantly reduced tumor growth in xenograft tumor-bearing mice. Taken together, our findings showed that TACC3 was increased in human RCC cell lines, and knockdown of TACC3 inhibited the ability of cell proliferation, migration, invasion, and tumorigenesis in vivo. Therefore, TACC3 may act as a therapeutic target for the treatment of human RCC.

ARHGAP24 inhibits cell cycle progression, induces apoptosis and suppresses invasion in renal cell carcinoma

Renal cell carcinoma (RCC) is the major cause of kidney malignancy-related deaths. Rho GTPases are key regulators in cancer cell metastasis. ARHGAP24, a Rac-specific member of the Rho GTPase-activating protein family, acts as a functional target of cancer cell migration and invasion. In the present study, we identified ARHGAP24 expression is downregulated in renal cancer tissues and is highly correlated with long-term survival in RCC patients. Therefore, we investigated the biological functions of ARHGAP24 in renal cancer cells. Ectopic expression of ARHGAP24 resulted in inhibited cell proliferation and arrested cell cycle in two renal cancer cell lines (786-0 and Caki-2); the results were confirmed by ARHGAP24 knocking down. In addition, ARHGAP24 significantly reduced the cell invasion ability and induced apoptosis in renal cancer cells. In addition, overexpressing ARHGAP24 impaired tumor formation in vivo. In summary, our results illustrated that ARHGAP24 plays a unique role in RCC progression as a tumor repressor.

Overexpression of NEDD9 in renal cell carcinoma is associated with tumor migration and invasion

Scaffold protein neural precursor cell expressed, developmentally downregulated 9 (NEDD9) is a member of the Crk-associated substrate protein family and is known to be a biomarker in multiple cancer types. It serves a critical function in regulating cell proliferation, migration, invasion and survival. The objective of this study was to evaluate the potential effects of NEDD9 in renal cell carcinoma (RCC). The expression of NEDD9 was analyzed by immunohistochemistry, western blotting and reverse transcription-quantitative polymerase chain reaction. NEDD9 protein and mRNA levels were significantly upregulated in RCC tissues compared with normal tissues (P<0.001). Furthermore, the NEDD9 immunostaining level was significantly associated with primary tumor stage and tumor, node, metastasis stage (P<0.05). High NEDD9 expression resulted in significantly lower survival rates for patients compared with normal NEDD9 expression (P<0.01). In addition, wound healing and transwell assays indicated that NEDD9 depletion by small interfering RNA significantly attenuated the migration and invasion of RCC cells (P<0.001). The present data suggested that NEDD9 may be a novel target for prevention and treatment of RCC metastasis and recurrence.

Epigenome Aberrations: Emerging Driving Factors of the Clear Cell Renal Cell Carcinoma

Clear cell renal cell carcinoma (ccRCC), the most common form of Kidney cancer, is characterized by frequent mutations of the von Hippel-Lindau (VHL) tumor suppressor gene in ~85% of sporadic cases. Loss of pVHL function affects multiple cellular processes, among which the activation of hypoxia inducible factor (HIF) pathway is the best-known function. Constitutive activation of HIF signaling in turn activates hundreds of genes involved in numerous oncogenic pathways, which contribute to the development or progression of ccRCC. Although VHL mutations are considered as drivers of ccRCC, they are not sufficient to cause the disease. Recent genome-wide sequencing studies of ccRCC have revealed that mutations of genes coding for epigenome modifiers and chromatin remodelers, including PBRM1, SETD2 and BAP1, are the most common somatic genetic abnormalities after VHL mutations in these tumors. Moreover, recent research has shed light on the extent of abnormal epigenome alterations in ccRCC tumors, including aberrant DNA methylation patterns, abnormal histone modifications and deregulated expression of non-coding RNAs. In this review, we discuss the epigenetic modifiers that are commonly mutated in ccRCC, and our growing knowledge of the cellular processes that are impacted by them. Furthermore, we explore new avenues for developing therapeutic approaches based on our knowledge of epigenome aberrations of ccRCC.

MicroRNA-186 Suppresses Cell Proliferation and Metastasis Through Targeting Sentrin-Specific Protease 1 in Renal Cell Carcinoma

Recent evidence suggests that dysregulation of microRNAs is associated with the development of multiple malignancies. miR-186 has been reported as a critical cancer regulator in several types of cancers. However, its functional significance and molecular mechanism underlying renal cell carcinoma (RCC) remain unknown. In this study, our results showed that miR-186 expression was dramatically downregulated in RCC tissues and cell lines compared to that in adjacent normal tissues and cell lines. Overexpression of miR-186 significantly inhibited cell growth, colony formation, and cell invasion; caused cell cycle arrest at the G₀/G₁ phase; and induced cell apoptosis as detected by MTT, colony formation, Transwell assay, and flow cytometry assays in RCC cells. In addition, inhibition of miR-186 expression promoted RCC cell proliferation, invasion, and cell cycle progression and reduced apoptosis. Bioinformatics analysis and luciferase reporter assay confirmed that the 3′-UTR of sentrin-specific protease 1 (SENP1) was a direct target of miR-186. A remarkably reverse correlation was observed between miR-186 and SENP1 mRNA in RCC tissues. Furthermore, immunohistochemical staining revealed that SENP1 was positively expressed in RCC specimens. Restoration of SENP1 expression could partially abrogate the inhibitory effect of miR-186 overexpression on RCC cell proliferation through activating NF-κB signaling and its downstream proteins. These data demonstrated that miR-186 acted as a novel tumor suppressor and potential therapeutic biomarker in the progression of RCC by directly targeting SENP1.

Adjuvant Therapy for High Risk Localized Kidney Cancer: Emerging Evidence and Future Clinical Trials

PURPOSE

We reviewed the literature on adjuvant therapies for patients with high risk localized kidney cancer following surgical resection. In this analysis we merge 2 recently published prospective trials with conflicting results within the context of their respective designs. In addition, we spotlight upcoming trials that use novel immunotherapy based checkpoint inhibitors and have the potential to establish a new standard of care.

MATERIALS AND METHODS

We searched PubMed^® for English language articles published through January 2017 using the keywords "renal cell carcinoma," "kidney cancer," "immunotherapy," "targeted therapy" and "adjuvant therapy." ClinicalTrials.gov was queried for ongoing studies. Relevant data recently presented at major urology and medical oncology meetings are also included.

RESULTS

Adjuvant therapies for high risk localized kidney cancer can be grouped into the categories of 1) traditional immunotherapy, 2) inhibitors of the vascular endothelial growth factor and mTOR (mammalian target of rapamycin) pathways, 3) vaccines and antibody dependent cytotoxic agents, and 4) immune checkpoint inhibitors. Several trials of traditional immunotherapy, such as interferon-α and high dose interleukin-2, failed to demonstrate benefit as adjuvant treatment and were associated with significant adverse events. Vascular endothelial growth factor and mTOR inhibitors have less severe toxicity in metastatic disease and, therefore, are natural considerations for adjuvant trials. However, current data are conflicting. The ASSURE (Sunitinib Malate or Sorafenib Tosylate in Treating Patients with Kidney Cancer that was Removed by Surgery, NCT00326898) trial found no recurrence-free survival benefit of sorafenib or sunitinib over placebo, while S-TRAC (Clinical Trial Comparing Efficacy and Safety of Sunitinib versus Placebo for the Treatment of Patients at High Risk of Recurrent Renal Cell Cancer, NCT00375674) revealed that 1 year of sunitinib improved recurrence-free survival by 1.2 years. Vaccine based treatments and antibody dependent cytotoxic agents have had mixed results. New trials evaluating immune checkpoint inhibitors are planned, given the impressive efficacy and tolerability as second line agents in metastatic disease. Future adjuvant trials are likely to be guided by molecular signatures to treat patients most likely to benefit.

CONCLUSIONS

Based on the available data, there appears to be no role for traditional immunotherapy as adjuvant treatment in patients with high risk localized kidney cancer following surgical resection. S-TRAC provides evidence that 1 year of adjuvant sunitinib in patients with higher risk locoregional disease increases the median time to recurrence. However, the data on overall survival are immature and adverse effects are common. Results from trials investigating immune checkpoint inhibitors are highly anticipated.

Genetic variation in IGF1 predicts renal cell carcinoma susceptibility and prognosis in Chinese population

Insulin-like growth factor 1 (IGF1) and IGF binding protein 3 (IGFBP3) play an important role in the development and progression of renal cell carcinoma (RCC). We evaluated the association of functional polymorphisms in IGF1 and IGFBP3 with susceptibility and prognosis of RCC. We genotyped nine potentially functional polymorphisms in IGF1 and IGFBP3 and assessed their association with risk of RCC in a two-stage case-control study compromising 1027 cases and 1094 controls, and with prognosis in a cohort of 311 patients. We found rs5742714 in the 3'-UTR of IGF1 was significantly associated with risk and prognosis of RCC. In the combined set, the rs5742714 GC/CC genotypes were significantly associated with decreased risk of RCC compared with the GG genotype (OR = 0.82; 95% CI = 0.68-0.98, P = 0.002). Furthermore, patients with the rs5742714 GC/CC genotypes showed improved survival than those with the GG genotype (Log-rank P = 0.025, HR = 0.36, 95% CI = 0.14-0.93). Besides, the rs5742714 GC/CC genotypes were associated with significantly decreased expression of IGF1 mRNA and lower IGF1 serum levels. Moreover, the luciferase reporter assays revealed the potential effect of rs5742714 genotype on the binding of microRNAs to IGF1. Our findings suggest that the IGF1 polymorphism rs5742714 may be a genetic predictor of susceptibility and prognosis of RCC.

Impact of Sequencing Targeted Therapies With High-dose Interleukin-2 Immunotherapy: An Analysis of Outcome and Survival of Patients With Metastatic Renal Cell Carcinoma From an On-going Observational IL-2 Clinical Trial: PROCLAIMSM

BACKGROUND

This analysis describes the outcome for patients who received targeted therapy (TT) prior to or following high-dose interleukin-2 (HD IL-2).

PATIENTS AND METHODS

Patients with renal cell carcinoma (n = 352) receiving HD IL-2 were enrolled in Proleukin^R Observational Study to Evaluate the Treatment Patterns and Clinical Response in Malignancy (PROCLAIM^SM) beginning in 2011. Statistical analyses were performed using datasets as of September 24, 2015.

RESULTS

Overall, there were 4% complete response (CR), 13% partial response (PR), 39% stable disease (SD), and 43% progressive disease (PD) with HD IL-2. The median overall survival (mOS) was not reached in patients with CR, PR, or SD, and was 15.5 months in patients with PD (median follow-up, 21 months). Sixty-one patients had prior TT before HD IL-2 with an overall response rate (ORR) to HD IL-2 of 19% (1 CR, 9 PR) and an mOS of 22.1 months. One hundred forty-nine patients received TT only after HD IL-2 with an mOS of 35.5 months. One hundred forty-two patients had no TT before or after HD IL-2, and mOS was not reached. The mOS was 8.5 months in PD patients who received HD IL-2 without follow-on TT and 29.7 months in PD patients who received follow-on TT after HD IL-2.

CONCLUSIONS

HD IL-2 as sole front-line therapy, in the absence of added TT, shows extended clinical benefit (CR, PR, and SD). Patients with PD after HD IL-2 appear to benefit from follow-on TT. Patients who progressed on TT and received follow-on HD IL-2 experienced major clinical benefit. HD IL-2 therapy should be considered in eligible patients.

Combination of mTOR and MAPK Inhibitors-A Potential Way to Treat Renal Cell Carcinoma

Renal cell carcinoma (RCC) is the most common neoplasm that occurs in the kidney and is marked by a unique biology, with a long history of poor response to conventional cancer treatments. In the past few years, there have been significant advancements to understand the biology of RCC. This has led to the introduction of novel targeted therapies in the management of patients with metastatic disease. Patients treated with targeted therapies for RCC had shown positive impact on overall survival, however, no cure is possible and patients need to undergo treatment for long periods of time, which raises challenges to manage the associated adverse events. Moreover, many patients may not respond to it and even response may not last long enough in the responders. Many inhibitors of the Mammalian target of Rapamycin (mTOR) signaling pathway are currently being used in treatment of advanced RCC. Studies showed that inhibitions of mTOR pathways induce Mitogen-Activated Protein Kinase (MAPK) escape cell death and cells become resistant to mTOR inhibitors. Because of this, there is a need to inhibit both pathways with their inhibitors comparatively for a better outcome and treatment of patients with RCC.

A novel method for texture-mapping conoscopic surfaces for minimally invasive image-guided kidney surgery

PURPOSE

Organ-level registration is critical to image-guided therapy in soft tissue. This is especially important in organs such as the kidney which can freely move. We have developed a method for registration that combines three-dimensional locations from a holographic conoscope with an endoscopically obtained textured surface. By combining these data sources clear decisions as to the tissue from which the points arise can be made.

METHODS

By localizing the conoscope's laser dot in the endoscopic space, we register the textured surface to the cloud of conoscopic points. This allows the cloud of points to be filtered for only those arising from the kidney surface. Once a valid cloud is obtained we can use standard surface registration techniques to perform the image-space to physical-space registration. Since our methods use two distinct data sources we test for spatial accuracy and characterize temporal effects in phantoms, ex vivo porcine and human kidneys. In addition we use an industrial robot to provide controlled motion and positioning for characterizing temporal effects.

RESULTS

Our initial surface acquisitions are hand-held. This means that we take approximately 55 s to acquire a surface. At that rate we see no temporal effects due to acquisition synchronization or probe speed. Our surface registrations were able to find applied targets with submillimeter target registration errors.

CONCLUSION

The results showed that the textured surfaces could be reconstructed with submillimetric mean registration errors. While this paper focuses on kidney applications, this method could be applied to any anatomical structures where a line of sight can be created via open or minimally invasive surgical techniques.

The influence of genetic variants of sorafenib on clinical outcomes and toxic effects in patients with advanced renal cell carcinoma

The purpose of the present study was to investigate whether genetic variants that influence angiogenesis and sorafenib pharmacokinetics are associated with clinical outcomes and toxic effects in advanced renal cell carcinoma patients treated with this drug. One hundred patients with advanced renal cell carcinoma were enrolled. Forty-two polymorphisms in 15 genes were selected for genotyping and analyzed for associations with progression-free survival, overall survival, and toxic effects. We found that rs1570360 in VEGF and rs2239702 in VEGFR2 were significantly associated with progression-free. Specifically, patients carrying the variant genotypes (AG + AA) of these two polymorphisms both had an unfavorable progression-free. In addition, compared with those with the rs2239702 GG genotype, patients with the AG + AA genotype suffered an unfavorable OS. We found that the VEGF rs2010963 CG + GG genotypes had a significantly increased risk of hand-foot syndrome, and the ABCB1 rs1045642 CT + TT genotypes had an increased risk of high blood pressure. Our results suggest that polymorphisms in VEGF and VEGFR2 are associated with sorafenib clinical outcomes, and polymorphisms in VEGF and ABCB1 are associated with sorafenib-related toxicities. Larger studies are warranted to validate our findings.

A large-scale prospective registration study of the safety and efficacy of sorafenib tosylate in unresectable or metastatic renal cell carcinoma in Japan: results of over 3200 consecutive cases in post-marketing all-patient surveillance

Objective

Real-life safety and efficacy of sorafenib in advanced renal cell carcinoma in a nationwide patient population were evaluated by post-marketing all-patient surveillance.

Methods

All patients with unresectable or metastatic renal cell carcinoma in Japan who started sorafenib therapy from February 2008 to September 2009 were registered and followed for up to 12 months. Baseline characteristics, treatment status, tumor response, survival and safety data were recorded by the prescribing physicians.

Results

Safety and efficacy were evaluated in 3255 and 3171 patients, respectively. The initial daily dose was 800 mg in 78.2% of patients. Median duration of treatment was 6.7 months and the mean relative dose intensity was 68.4%. Overall, 2227 patients (68.4%) discontinued the treatment by 12 months, half of which (52.0% of discontinued patients) were due to adverse events. The most common adverse drug reactions were hand–foot skin reaction (59%), hypertension (36%), rash (25%) and increase in lipase/amylase (23%). The median progression-free survival was 7.3 months (95% confidence intervals: 6.7–8.1), and the overall survival rate at 1 year was 75.4% (73.5–77.1). Prognostic factors for overall survival were mostly consistent with those in previous clinical trials in the univariate analysis and largely similar to those for progression-free survival and duration of treatment in the multivariate analysis.

Conclusions

Sorafenib for the treatment of advanced renal cell carcinoma under the labeled dose was feasible in daily medical practice, for its acceptable toxicity profile and favorable clinical benefit that were consistent with those in clinical trials.

The Potential Role of Lysosomal Sequestration in Sunitinib Resistance of Renal Cell Cancer

Renal cell carcinoma (RCC) is a highly vascularized tumor type, which is often associated with inactivated mutations in the von Hippel-Lindau gene that drives proangiogenic signaling pathways. As such, new therapies for the treatment of RCC have largely been focused on blocking angiogenesis. Sunitinib, an antiangiogenic tyrosine kinase inhibitor, is the most frequently used first-line drug for the treatment of RCC. Although treatment with sunitinib improves patient outcome considerably, acquired resistance will emerge in all cases. The molecular mechanisms of resistance to sunitinib are poorly understood, but in the past decade, several of these have been proposed. Lysosomal sequestration of sunitinib was reported as a potential resistance mechanism to sunitinib. In this review, the underlying molecular mechanisms of lysosomal sunitinib sequestration and the potential strategies to overcome this resistance are discussed to be able to further improve the treatment of RCC.

Clinical efficacy and prognostic factors of tumor progression in Japanese patients with advanced renal cell carcinoma treated with sorafenib

OBJECTIVE

Result of clinical trial for registration purpose is often difficult to generalize because of its limited population in number and inclusion criteria.

METHODS

To understand the efficacy of sorafenib under daily medical practice, we retrospectively investigated therapeutic outcomes of 175 Japanese patients with advanced renal cell carcinoma treated with sorafenib at 15 centers.

RESULTS

The objective response rate and disease control rate were 15.4 and 77.1%, respectively, being similar to those in the Phase II study in Japanese patients (19.4 and 73.6 months). Any tumor shrinkage was observed with 53% of patients, while tumor control without growth was in 61%. Lung lesions were more sensitive to sorafenib than other lesions, in terms of any tumor shrinkage (54%) and the extent of maximal shrinkage, while tumor control was better in lymph node metastases (77%) than in lung (69%). Liver was worse in any tumor shrinkage (35%), tumor control (55%) and the extent of tumor growth. Slightly, shorter median overall survival of 21.1 months compared with Phase II clinical trial (25.3 months) is likely to be attributable to different patient population, because median overall survival was improved to 26.4 months when the population was matched to that in Phase II trial. Univariate and multivariate analyses identified prognostic factors for worse overall survival, including intermediate and poor Memorial Sloan-Kettering Cancer Center risk, Eastern Cooperative Oncology Group performance status ≥1, the presence of non-clear cell component and the presence of liver metastasis.

CONCLUSIONS

In conclusion, the present study confirmed the efficacy of sorafenib in the real-world setting on advanced renal cell carcinoma.

Aberrant methylation of PCDH8 is a potential prognostic biomarker for patients with clear cell renal cell carcinoma

BACKGROUND

PCDH8 is a tumor suppressor that regulates cell adhesin, proliferation, and migration. It is often inactivated by aberrant promoter methylation in several human cancers, including clear cell renal cell carcinoma (CCRCC). The clinical significance of PCDH8 methylation in CCRCC remains unclear. The aim of this study was to investigate the relationship between PCDH8 methylation and clinicopathological characteristics as well as outcome of patients with CCRCC.

MATERIAL/METHODS

The methylation status of PCDH8 in 153 CCRCC tissues and 97 paired adjacent normal renal tissues were examined using methylation-specific PCR (MSP). Then the relationships between PCDH8 methylation and clinicopathological features as well as progression-free survival of CCRCC patients were evaluated.

RESULTS

PCDH8 methylation was significantly more frequent in CCRCC tissues compared with normal renal tissues. Moreover, PCDH8 methylation was significantly correlated with advanced clinical stage (P=0.0141), higher grade (P=0.0190), and lymph node metastasis (P=0.0098). In addition, multivariate analysis showed that PCDH8 methylation was independently associated with poor progression-free survival (P=0.0316).

CONCLUSIONS

PCDH8 methylation is a frequent event in CCRCC and is correlated with unfavorable clinicopathological features. Moreover, PCDH8 methylation may be a useful biomarker to predict the progression of CCRCC.

Diagnostic accuracy of contrast-enhanced ultrasound for renal cell carcinoma: a meta-analysis

This meta-analysis aimed to identify the accuracy of contrast-enhanced ultrasonography (CEUS) for the diagnosis of renal cell carcinoma (RCC). We searched PubMed, Web of Science, Google Scholar, Cochrane Library, CISCOM, CINAHL, EBSCO, and CBM databases from inception through August 1, 2013 without language restrictions. Meta-analysis was conducted using STATA version 12.0 and Meta-Disc version 1.4 softwares. We calculated the summary statistics for sensitivity (Sen), specificity (Spe), positive and negative likelihood ratio (LR+/LR-), diagnostic odds ratio (DOR), and receiver operating characteristic (SROC) curve. Eleven studies that met all inclusion criteria were included in this meta-analysis. A total of 567 RCC patients and 313 patients with benign renal tumors were assessed. All renal lesions were histologically confirmed after CEUS. The pooled Sen was 0.88 (95 %CI = 0.85 ∼ 0.90); the pooled Spe was 0.80 (95 %CI = 0.75 ∼ 0.85). The pooled LR+ was 4.30 (95 %CI = 2.65 ∼ 6.99); the pooled negative LR- was 0.11 (95 %CI = 0.05 ∼ 0.22). The pooled DOR of CEUS in the diagnosis of RCC was 46.97 (95 % CI = 16.72 ∼ 131.97). The area under the SROC curve was 0.922 (standard error [SE] = 0.039). We found no evidence for publication bias (t = -1.00, P = 0.342). Our meta-analysis indicates that CEUS may have high diagnostic accuracy in differential diagnosis between benign and malignant renal tumors. Thus, CEUS may be a good tool for the diagnosis of RCC.

Nuclear medicine in urological cancers: what is new?

ABSTRACT 

The diffusion of PET/computed tomography has opened up a new role for nuclear imaging in urological oncology. Prostate cancer is evaluated with choline (11C or 18F) PET due to a lack of sensitivity of 18F-fluorodeoxyglucose (FDG). However, many new tracers, such as 18F-fluorocyclobutane-1-carboxylic acid and 68Ga-prostate-specific membrane antigen, are under investigation, offering promising results in the particular setting of radically treated patients with biochemical relapse. The performance of 18F-FDG depends on the histological type; indeed, renal cell cancer may present variable metabolic uptake. In this field, mainly antibodies labeled with positron emitters are under clinical evaluation. Finally, 18F-FDG PET/computed tomography has been proven to show good accuracy in detecting metastatic testicular and bladder cancers, despite not having valid results in detecting local disease. The urological cancer diagnostic process is currently under continuous development.

GPC3 reduces cell proliferation in renal carcinoma cell lines

BACKGROUND

Glypican 3 (GPC3) is a member of the family of glypican heparan sulfate proteoglycans (HSPGs). The GPC3 gene may play a role in controlling cell migration, negatively regulating cell growth and inducing apoptosis. GPC3 is downregulated in several cancers, which can result in uncontrolled cell growth and can also contribute to the malignant phenotype of some tumors. The purpose of this study was to analyze the mechanism of action of the GPC3 gene in clear cell renal cell carcinoma.

METHODS

Five clear cell renal cell carcinoma cell lines and carcinoma samples were used to analyze GPC3 mRNA expression (qRT-PCR). Then, representative cell lines, one primary renal carcinoma (786-O) and one metastatic renal carcinoma (ACHN), were chosen to carry out functional studies. We constructed a GPC3 expression vector and transfected the renal carcinoma cell lines, 786-O and ACHN. GPC3 overexpression was analyzed using qRT-PCR and immunocytochemistry. We evaluated cell proliferation using MTT and colony formation assays. Flow cytometry was used to evaluate apoptosis and perform cell cycle analyses.

RESULTS

We observed that GPC3 is downregulated in clear cell renal cell carcinoma samples and cell lines compared with normal renal samples. GPC3 mRNA expression and protein levels in 786-O and ACHN cell lines increased after transfection with the GPC3 expression construct, and the cell proliferation rate decreased in both cell lines following overexpression of GPC3. Further, apoptosis was not induced in the renal cell carcinoma cell lines overexpressing GPC3, and there was an increase in the cell population during the G1 phase in the cell cycle.

CONCLUSION

We suggest that the GPC3 gene reduces the rate of cell proliferation through cell cycle arrest during the G1 phase in renal cell carcinoma.

Reduced L/B/K alkaline phosphatase gene expression in renal cell carcinoma: plausible role in tumorigenesis

Renal cell carcinoma (RCC) is the most common kidney cancer in adults. Although several genes have been found to be involved in carcinogenesis of RCC, more great efforts are needed to identify new genes which are responsible for the process. Clear cell RCC, originates from proximal tubule cells, is the most common pathological type of RCC. Alkaline phosphatase (ALP) is a marker enzyme of brush border membrane of proximal tubular cells. Our previous studies showed a significant decreased activity of Liver/Bone/Kidney (L/B/K) alkaline phosphatase in RCC. In the present study, we explored the molecular basis of the decreased activity of ALP in RCC. Immunohistochemistry, immunofluorescence and flow cytometry analysis showed decreased ALP protein in RCC. Additionally, real time PCR documented significantly reduced ALP gene expression (P = 0.009). Moreover, RCC cell lines (ACHN and A498) transfected with full length L/B/K cDNA showed decreased migratory property as well as viability of these cells as compared with controls (P = 0.000). Further, L/B/K ALP cDNA transfected cells (ACHN and A498) showed significant increased apoptosis as compared to control (P = 0.000). These findings suggest the new role of ALP in cell viability and apoptosis and involvement in RCC tumorigenesis. However, further studies are needed to explore the exact molecular mechanism.

The current status of tailor-made medicine with molecular biomarkers for patients with clear cell renal cell carcinoma

Appropriate use of multiple reliable molecular biomarkers in the right context will play a role in tailormade medicine of clear cell renal cell carcinoma (RCC) patients in the future. A total of 11,056 patients from 53 studies were included in this review. The article numbers of the each evidence levels, using the grading system defined by the Oxford Centre for Evidence-based Medicine, in 1b, 2a, 2b, and 3b were 5 (9%), 18 (34%), 29 (55%), and 1 (2%), respectively. The main goal of using biomarkers is to refine predictions of tumor progression, pharmacotherapy responsiveness, and cancer-specific and/or overall survival. Currently, carbonic anhydrase (CA9) and vascular endothelial growth factor (VEGF) in peripheral blood and p53 in tumor tissues are measured to predict metastasis, while VEGF-related proteins in peripheral blood are used to assess pharmacotherapy responsiveness with sunitinib. Furthermore, interleukin 8, osteopontin, hepatocyte growth factor, and tissue inhibitors of metalloproteinases-1 in peripheral blood enable assessment of responsiveness to pazopanib treatment. Other reliable molecular biomarkers include von Hippel–Lindau gene alteration, hypoxia-inducible factor-1a, CA9, and survivin in tumor tissues and VEGF in peripheral blood for predicting cancer-specific survival. In the future, studies should undergo external validation for developing tailored management of clear cell RCC with molecular biomarkers, since individual institutional studies lack the generalization and consistency required to maintain accuracy among different patient series.

Stratification of clear cell renal cell carcinoma by signaling pathway analysis

Investigation of cell signaling pathways in 16 clear cell renal cell carcinomas to identify groups based on commonly shared phosphorylation-driven signaling networks. Using laser capture microdissection and reverse-phase protein arrays, we profiled 75 key nodes spanning signaling pathways important in tumorigenesis. Analysis revealed significantly different (P < 0.05) signaling levels for 27 nodes between two groups of samples, designated A (4 samples; high EGFR, RET, and RASGFR1 levels, converging to activate AKT/mTOR) and B (12 samples; high ERK1/2 and STAT phosphorylation). Group B was further partitioned into groups C (7 samples; elevated expression of LC3B) and D (5 samples; activation of Src and STAT). Network analysis indicated that group A was characterized by signaling pathways related to cell cycle and proliferation, and group B by pathways related to cell death and survival. Homogeneous clear cell renal cell carcinomas could be stratified into at least two major functional groups.

Quantitative proteomics in resected renal cancer tissue for biomarker discovery and profiling

Background:

Proteomics-based approaches for biomarker discovery are promising strategies used in cancer research. We present state-of-art label-free quantitative proteomics method to assess proteome of renal cell carcinoma (RCC) compared with noncancer renal tissues.

Methods:

Fresh frozen tissue samples from eight primary RCC lesions and autologous adjacent normal renal tissues were obtained from surgically resected tumour-bearing kidneys. Proteins were extracted by complete solubilisation of tissues using filter-aided sample preparation (FASP) method. Trypsin digested proteins were analysed using quantitative label-free proteomics approach followed by data interpretation and pathways analysis.

Results:

A total of 1761 proteins were identified and quantified with high confidence (MASCOT ion score threshold of 35 and P-value <0.05). Of these, 596 proteins were identified as differentially expressed between cancer and noncancer tissues. Two upregulated proteins in tumour samples (adipose differentiation-related protein and Coronin 1A) were further validated by immunohistochemistry. Pathway analysis using IPA, KOBAS 2.0, DAVID functional annotation and FLink tools showed enrichment of many cancer-related biological processes and pathways such as oxidative phosphorylation, glycolysis and amino acid synthetic pathways.

Conclusions:

Our study identified a number of differentially expressed proteins and pathways using label-free proteomics approach in RCC compared with normal tissue samples. Two proteins validated in this study are the focus of on-going research in a large cohort of patients.

Nuclear factor-κB signaling pathway is involved in phospholipase Cε-regulated proliferation in human renal cell carcinoma cells

Phospholipase Cε (PLCε), a downstream effector of small GTPase superfamily, has been identified to play a crucial role in tumorigenesis. Previously, our studies have showed that PLCε promotes proliferation of renal cell carcinoma (RCC) cells. However, the molecular mechanisms by which PLCε enhances the survival phenotype of RCC cells are still not fully instructed. In the present study, we first demonstrated that PLCε was highly expressed and had a close correlation with Ki67 protein expression in RCC tissue samples. Further, we found that downregulation of PLCε expression repressed growth and induced apoptosis in RCC cells. In addition, we reported a mechanism by which knockdown of PLCε gene potently suppressed the nuclear factor kappa (NF-κB) signaling pathway through action on inhibitor of κB kinase. Moreover, silencing PLCε gene decreased vascular endothelial growth factor (VEGF) expression, which was a downstream growth factor of NF-κB signaling pathway. Finally, downregulation of VEGF was severely enhanced by treatment cells with NF-κB specific inhibitor BAY11-7028 in PLCε knockdown cells. Taken together, these findings suggest that PLCε promotes RCC cell growth via NF-κB-mediated upregulation of VEGF.

Active surveillance for small renal masses diagnosed in elderly or comorbid patients: looking for the best treatment strategy

INTRODUCTION

Aim of this study is to provide our results after long-term active surveillance (AS) protocol for small renal masses (SRMs), and to report the outcomes of patients who remained in AS compared to those who underwent delayed surgical intervention.

PATIENTS AND METHODS

We retrospectively reviewed our database of 58 patients diagnosed with 60 contrast enhancing SRMs suspicious for renal cell carcinoma (RCC). All patients had clinical and radiological follow-up every 6 months. We evaluated the differences between patients who remained on AS and those who underwent surgical delayed intervention.

RESULTS

The mean age was 75 years, the mean follow-up was 88.5 months. The median initial tumor size at presentation was 2.6cm, and the median estimated tumor volume was 8.7cm(3). The median linear growth rate of the cohort was 0.7cm/year, and the median volumetric growth rate was 8.8 cm(3)/year. Death for metastatic disease occurred in 2 patients (3.4%). No correlation was found between initial tumor size and size growth rate. The mean linear and volumetric growth rates of the group of patients who underwent surgery was higher than in those who remained on surveillance (1.9 vs. 0.4cm/year and 16.1 vs. 4.6 cm(3)/year, respectively; P<.001).

CONCLUSIONS

Most of SRMs demonstrate to have an indolent course and low metastatic potential. Malignant disease could have faster linear and volumetric growth rates, thus suggesting the need for a delayed surgical intervention. In properly selected patients with low life-expectancy, AS could be a reasonable option in the management of SRMs.

Auto localization and segmentation of occluded vessels in robot-assisted partial nephrectomy

Hilar dissection is an important and delicate stage in partial nephrectomy during which surgeons remove connective tissue surrounding renal vasculature. Potentially serious complications arise when vessels occluded by fat are missed in the endoscopic view and are not appropriately clamped. To aid in vessel discovery, we propose an automatic method to localize and label occluded vasculature. Our segmentation technique is adapted from phase-based video magnification, in which we measure subtle motion from periodic changes in local phase information albeit for labeling rather than magnification. We measure local phase through spatial decomposition of each frame of the endoscopic video using complex wavelet pairs. We then assign segmentation labels based on identifying responses of regions exhibiting temporal local phase changes matching the heart rate frequency. Our method is evaluated with a retrospective study of eight real robot-assisted partial nephrectomies demonstrating utility for surgical guidance that could potentially reduce operation times and complication rates.

Tpl2 kinase impacts tumor growth and metastasis of clear cell renal cell carcinoma

Due to the innate high metastatic ability of renal cell carcinoma (RCC), many patients with RCC experience local or systemic relapses after surgical resection. A deeper understanding of the molecular pathogenesis underlying advanced RCC is essential for novel innovative therapeutics. Tumor progression locus 2 (Tpl2), upregulated in various tumor types, has been reported to be associated with oncogenesis and metastatic progression via activation of the MAPK signaling pathway. Herein, the relevance of Tpl2 in tumor growth and metastasis of RCC is explored. Inspection of The Cancer Genome Atlas (TCGA) indicated that Tpl2 overexpression was significantly related to the presence of metastases and poor outcome in clear cell RCC (ccRCC), which is the most aggressive subtype of RCC. Moreover, expression of Tpl2 and CXCR4 showed a positive correlation in ccRCC patients. Depletion of Tpl2 by RNAi or activity by a Tpl2 kinase inhibitor in human ccRCC cells remarkably suppressed MAPK pathways and impaired in vitro cell proliferation, clonogenicity, anoikis resistance, migration, and invasion capabilities. Similarly, orthotopic xenograft growth and lung metastasis were significantly inhibited by Tpl2 silencing. Furthermore, Tpl2 knockdown reduced CXCL12-directed chemotaxis and chemoinvasion accompanied with impaired downstream signaling, indicating potential involvement of Tpl2 in CXCR4-mediated metastasis. Taken together, these data indicate that Tpl2 kinase is associated with and contributes to disease progression of ccRCC.

IMPLICATIONS

Tpl2 kinase activity has prognostic and therapeutic targeting potential in aggressive clear cell renal cell carcinoma.

Genomics and epigenomics of clear cell renal cell carcinoma: recent developments and potential applications

Majority of clear cell renal cell carcinomas (ccRCCs) are diagnosed in the advanced metastatic stage resulting in dramatic decrease of patient survival. Thereby, early detection and monitoring of the disease may improve prognosis and treatment results. Recent technological advances enable the identification of genetic events associated with ccRCC and reveal significant molecular heterogeneity of ccRCC tumors. This review summarizes recent findings in ccRCC genomics and epigenomics derived from chromosomal aberrations, DNA sequencing and methylation, mRNA, miRNA expression profiling experiments. We provide a molecular insight into ccRCC pathology and recapitulate possible clinical applications of genomic alterations as predictive and prognostic biomarkers.

Differential diagnosis of renal tumors with clear cytoplasm: clinical relevance of renal tumor subclassification in the era of targeted therapies and personalized medicine

CONTEXT

The World Health Organization classification of renal tumors synthesizes morphologic, immunohistochemical, and molecular findings to define more than 40 tumor types. Of these, clear cell (conventional) renal cell carcinoma is the most common malignant tumor in adults and-with the exception of some rare tumors-the most deadly. The diagnosis of clear cell renal cell carcinoma on morphologic grounds alone is generally straightforward, but challenging cases are not infrequent. A misdiagnosis of clear cell renal cell carcinoma has clinical consequences, particularly in the current era of targeted therapies.

OBJECTIVE

To highlight morphologic mimics of clear cell renal cell carcinoma and provide strategies to help differentiate clear cell renal cell carcinoma from other renal tumors and lesions. The role of the pathologist in guiding treatment for renal malignancies will be emphasized to stress the importance of proper tumor classification in patient management.

DATA SOURCES

Published literature and personal experience.

CONCLUSIONS

In challenging cases, submission of additional tissue is often an inexpensive and effective way to facilitate a correct diagnosis. If immunohistochemical stains are to be used, it is best to use a panel of markers, as no one marker is specific for a given renal tumor subtype. Selection of limited markers, based on a specific differential diagnosis, can be as useful as a large panel in reaching a definitive diagnosis. For renal tumors, both the presence and absence of immunoreactivity and the pattern of labeling (membranous, cytoplasmic, diffuse, focal) are important when interpreting the results of immunohistochemical stains.

Dendritic cell-based vaccination for renal cell carcinoma: challenges in clinical trials

After decades of research, dendritic cell (DC)-based vaccines for renal cell carcinoma have progressed from preclinical rodent models and safety assessments to Phase I/II clinical trials. DC vaccines represent a promising therapy that has produced measurable immunological responses and prolonged survival rates. However, there is still much room to improve in terms of therapeutic efficacy. The key issues that affect the efficiency and reliability of DC therapy include the selection of patients who will respond best to treatment, the proper preparation and administration of DC vaccines, and a combination of DC vaccination with other immune-enhancing therapies (e.g., removal of Tregs, CTLA-4 blockade and lymphodepletion). Additional antiangiogenic agents will hopefully lead to greater survival benefits for patients in early disease stages. This review focuses on the different approaches of DC-based vaccination against renal cell carcinoma and potential strategies to enhance the efficacy of DC vaccination.

Proteomic identification of angiomotin by ProteomeLab PF-2D and correlation with clinical outcome in human clear cell renal cell carcinoma

Identification of new therapeutic and prognostic biomarkers for clear cell renal cell carcinoma (ccRCC) is urgently required since most patients are in advanced stages of ccRCC at initial diagnosis and the recurrence rate is high. Differentially expressed proteins between the ccRCC cell line RLC-310 and the normal renal cell line HK-2 were identified by a comparative proteomic approach based on a protein fractionation two-dimensional (PF-2D) liquid-phase fractionation system and capillary liquid chromatography electrospray ionization mass spectrometry/mass spectrometry (LC-ESI-MS/MS). Differentially expressed proteins (n=196) were identified. Of the 13 differentially expressed proteins newly discovered in ccRCC, angiomotin (Amot) was the focus of this study since its role in ccRCC progression has been obscure. The overexpression of Amot in ccRCC tissues was confirmed by comparing Amot expression in 18 primary ccRCC tissues and adjacent normal renal tissues (ANRT) using western blot analysis. Quantitative RT-PCR using 127 ccRCC tissues revealed that high levels of Amot transcripts were associated with poor differentiation, venous invasion and decreased survival (p<0.0001, <0.05 and <0.05). Multivariate analysis indicated that Amot transcript was an independent prognostic factor for the survival of ccRCC patients (p<0.05). These data suggest that Amot may serve as a novel prognostic factor of ccRCC.

Effects of open versus laparoscopic nephrectomy techniques on oxidative stress markers in patients with renal cell carcinoma

The aim of the study was to determine the concentration of lipid peroxidation products, the activity of selected antioxidant and lysosomal enzymes, and protease inhibitor in patients with renal cell carcinoma who underwent radical nephrectomy. The studied group included 44 patients: 21 of them underwent open surgery, while 23 underwent laparoscopy. Blood samples were collected three times: before treatment and 12 hours and five days after nephrectomy. In blood of participants, the concentration of thiobarbituric acid reactive substances (TBARS), the activity of catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GPx), and the activity of acid phosphatase (AcP), arylsulfatase (ASA), cathepsin D (CTSD), and α 1-antitrypsin (AAT) were assayed. No statistically significant differences in investigated parameters were found between studied groups. Moreover, TBARS concentration and CAT, SOD, and GPx activity were not altered in the course of both types of surgery. Five days after both open and laparoscopic nephrectomy techniques, AAT activity was higher than its activity 12 hours after the procedure. The obtained results suggest that laparoscopy may be used for nephrectomy as effectively as open surgery without creating greater oxidative stress. Reduced period of convalescence at patients treated with laparoscopy may be due to less severe response of acute-phase proteins.

Differential protein profiling of renal cell carcinoma urinary exosomes

Renal cell carcinoma (RCC) accounts for about 3% of all human malignancies and its incidence is increasing. There are no standard biomarkers currently used in the clinical management of patients with renal cell carcinoma. A promising strategy for new biomarker detection is comparative proteomics of urinary exosomes (UE), nanovesicles released by every epithelial cell facing the urinary space, enriched in renal proteins and excluding high-abundance plasmatic proteins, such as albumin. Aim of the work is to establish the protein profile of exosomes isolated from urines of RCC patient compared with control subjects. We enrolled 29 clear cell RCC patients and 23 control healthy subjects (CTRL), age and sex-matched, for urine collection and vesicle isolation by differential centrifugation. Such vesicles were morphologically and biochemically characterized and proved to share exosome properties. Proteomic analysis, performed on 9 urinary exosome (UE) pooled samples by gel based digestion followed by LC-MS/MS, led to the identification of 261 proteins from CTRL subject UE and 186 from RCC patient UE, and demonstrated that most of the identified proteins are membrane associated or cytoplasmic. Moreover, about a half of identified proteins are not shared between RCC and control UE. Starting from these observations, and from the literature, we selected a panel of 10 proteins, whose UE differential content was subjected to immunoblotting validation. Results show for the first time that RCC UE protein content is substantially and reproducibly different from control UE, and that these differences may provide clues for new RCC biomarker discovery.

Induction of cell death in renal cell carcinoma with combination of D-fraction and vitamin C

HYPOTHESIS

Although several conventional therapeutic options for advanced renal cell carcinoma (RCC) are currently available, the unsatisfactory outcomes demand establishing more effective interventions. D-fraction (PDF), a bioactive proteoglucan of Maitake mushroom, demonstrates anticancer and immunomodulatory activities, which are also shown to be potentiated by vitamin C (VC). We thus hypothesized that a combination of PDF and VC (PDF + VC) could be an alternative approach to more effectively inhibit the growth of RCC.

STUDY DESIGN

We examined the dose-dependent effects of PDF + VC on RCC cell viability and also performed biochemical assays to explore the growth regulatory mechanism.

METHODS

Human RCC, ACHN cell line, was employed and exposed to varying concentrations of PDF or VC and their combinations. Cell viability at specified times was determined by MTT assay. Lipid peroxidation assay, cell cycle analysis, and Western blot analysis were also performed.

RESULTS

PDF or VC alone led to the significant reduction in cell viability at 72 hours with PDF >500 µg/mL and VC ≥300 µM. When various combinations of PDF and VC were tested, the combination of the ineffective concentrations of PDF (300 µg/mL) and VC (200 µM) resulted in ~90% cell death in 24 hours. Lipid peroxidation assay then indicated significantly (~2.5 fold) elevated oxidative stress with this PDF + VC. Cell cycle analysis also indicated a G1 cell cycle arrest following a 6-hour PDF + VC treatment. Western blots further revealed a downregulation of Bcl2, an upregulation of Bax, and proteolytic activation of PARP (poly[ADP-ribose] polymerase) in PDF + VC-treated cells, indicating induction of apoptosis.

CONCLUSION

The present study demonstrates that the combination of PDF and VC can become highly cytotoxic, inducing severe cell death in ACHN cells. This cytotoxic mechanism appears to be primarily attributed to oxidative stress, accompanied by a G1 cell cycle arrest. Such cell death induced by PDF + VC could be more likely linked to apoptosis, as indicated by the modulation of apoptosis regulators (Bcl2, Bax, and PARP). Therefore, as PDF and VC may work synergistically to induce apoptotic cell death, they may have clinical implications in an alternative, improved therapeutic modality for advanced RCC.