MicroRNAs in Serum Exosomes as Potential Biomarkers in Clear-cell Renal Cell Carcinoma

BACKGROUND

Circulating microRNAs (miRNAs) in exosomes are emerging as clinically useful tools for cancer detection. However, little is known about their diagnostic impact in clear-cell renal cell carcinoma (ccRCC).

OBJECTIVE

To investigate whether miRNAs in serum exosomes can serve as biomarkers in ccRCC.

DESIGN, SETTING, AND PARTICIPANTS

Serum samples were obtained from 82 patients with ccRCC and 80 healthy volunteers. Exosomes were extracted and purified to selectively capture exosomes positive for tumor-associated epithelial cell adhesion molecule (EpCAM) via a magnetic bead technique. Total RNA was extracted and expression levels of miR-210, miR-1233, and miR-15a miRNAs were quantified and normalized to U6 levels.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Expression levels were compared using a Mann-Whitney U-test, Friedman test, or Wilcoxon test. Receiver operating characteristic (ROC) curves were plotted to assess the diagnostic value of exosomal miRNAs for differentiation between ccRCC patients and controls.

RESULTS AND LIMITATIONS

Expression levels of exosomal miR-210 and miR-1233 were significantly higher in ccRCC patients than in healthy individuals (both p<0.01). No significant difference was observed for exosomal miR-15a. Exosomal miR-210 and miR-1233 expression levels in different TNM stages were significantly higher than in the controls (all p<0.01). Exosomal miR-210 and miR-1233 expression levels were significantly lower in postoperative than in preoperative samples (both p<0.01). ROC analysis demonstrated that exosomal expression levels distinguished ccRCC patients from healthy individuals with 70% sensitivity and 62.2% specificity for miR-210, and 81% sensitivity and 76% specificity for miR-1233. The retrospective design and lack of other tumor subtypes are limitations of the study.

CONCLUSIONS

Serum exosomal miRNAs might represent potential diagnostic biomarkers in ccRCC in the future.

PATIENT SUMMARY

Circulating levels of exosomal microRNAs miR-210 and miR-1233 have potential as biomarkers for diagnostic and monitoring purposes in renal cancer in the future. These molecules can be measured in serum in so-called liquid biopsy.

Molecular Subtypes of Clear-cell Renal Cell Carcinoma are Prognostic for Outcome After Complete Metastasectomy

BACKGROUND

Metastasectomy is routinely performed in selected patients with metastatic clear-cell renal cell carcinoma (ccRCC) as an alternative to systemic therapy. In the absence of randomized trials, the benefit and best way of patient selection remain unclear. Earlier, we described four molecular ccRCC-subtypes (ccrcc1-4) that have a prognostic and predictive value upon first-line sunitinib or pazopanib.

OBJECTIVE

Assess the prognostic value of ccrcc1-4 subtypes after complete metastasectomy. (1) Compare outcomes of good-prognosis ccrccc2&3-tumors with intermediate/poor-prognosis ccrcc1&4-tumors. (2) Compare outcomes of the four subtypes separately.

DESIGN, SETTING, AND PARTICIPANTS

Single-center retrospective study (1995-2017), assessing 43 ccRCC patients undergoing complete metastasectomy without systemic treatment.

INTERVENTION

Molecular subtype determined with established 35-gene expression classifier.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Median disease-free survival (DFS), time to systemic therapy, cancer-specific (CSS) and overall survival (OS) from metastasectomy, estimated with Kaplan-Meier method and tested against other predictors with multivariable Cox regression.

RESULTS AND LIMITATIONS

Median DFS was 23 mo for ccrcc2&3-tumors versus 9 mo for ccrcc1&4-tumors (p=0.011, hazard ratio [HR]=2.6). Median time to systemic therapy was 92 mo versus 28 mo (p=0.003, HR=3.3). Median CSS was 133 mo versus 50 mo (p<0.001, HR=2.7). Median OS was 127 mo versus 50 mo (p=0.011, HR=2.5). The classification remained independent upon multivariable analysis. Outcomes remained significantly different when comparing four subtypes separately. The intrinsic heterogeneity of expression profiles is a limitation of this approach.

CONCLUSION

Even after clinical patient selection, patients with a ccrcc1- or ccrcc4-tumor are at a higher risk of relapse after complete metastasectomy. Patients with a ccrcc2- or ccrcc3-tumor usually experience a long DFS. These results need validation in a larger cohort to establish the subtypes as prognostic marker.

PATIENT SUMMARY

Metastasectomy is recommended for some patients with metastatic clear-cell kidney cancer; however, we do not know who will benefit the most. We show that molecular subtypes increase the possibility to predict which patients are at risk for early relapse after metastasectomy and who may benefit more from other treatment options.

Comprehensive evaluation of 68Ga-PSMA-11 PET/CT parameters for discriminating pathological characteristics in primary clear-cell renal cell carcinoma

PURPOSE

To evaluate parameters derived from ⁶⁸Ga-PSMA-11 PET/CT images for discriminating pathological characteristics in primary clear-cell renal cell carcinoma (ccRCC).

METHODS

The study retrospectively examined data for 36 ccRCC patients with preoperative ⁶⁸Ga-PSMA-11 PET/CT scan and surgical specimens. Radiological parameters including maximal tumor diameter, mean CT value, and maximal standard uptake value (SUV_max) were derived from PET/CT images. Pathological characteristics included WHO/ISUP grade and adverse pathology (tumor necrosis or sarcomatoid or rhabdoid feature). Values of radiological parameters were compared within subgroups of pathological characteristics. Receiver operating characteristic (ROC) curve analysis was used for the effectiveness of radiological parameters in differentiating pathological characteristics, estimating area under the ROC curve (AUC) and 95% confidence intervals (CIs).

RESULTS

The WHO/ISUP grade distribution for 36 tumors was grade 1, 9 (25.0%); grade 2, 12 (33.3%); grade 3, 9 (25.0%); and grade 4, 6 (16.7%). Adverse pathology was positive for 15 (41.7%). Radiological tumor diameter and SUVmax significantly differed by WHO/ISUP grade, pT stage, and adverse pathology (all P < 0.05), with no difference by CT value. Tumor diameter demonstrated sensitivity 86% and specificity 88% for pT stage, with cutoff 6.70 and AUC 0.91 (95% CI, 0.79-1.00, P < 0.001). SUV_max could effectively differentiate WHO/ISUP grade (3-4 vs. 1-2) and adverse pathology (positive vs. negative), with AUC 0.89 (95% CI, 0.81-0.98, P < 0.001), cutoff 16.4, sensitivity 100%, and specificity 71% and AUC 0.92 (95% CI, 0.85-0.99, P < 0.001), cutoff 18.5, sensitivity 94%, and specificity 87%, respectively.

CONCLUSION

⁶⁸Ga-PSMA-11 PET/CT could effectively identify aggressive pathological features of ccRCC.

Chromophobe Renal Cell Carcinoma: Results From a Large Single-Institution Series

BACKGROUND

The purpose of the study was to evaluate clinical features and prognostic factors in a large single institutional cohort of chromophobe renal cell carcinoma (ChRCC) patients for identification of tumors with the highest metastatic potential.

PATIENTS AND METHODS

Clinicopathological parameters of all patients with ChRCC diagnosed and surgically treated at Memorial Sloan Kettering Cancer Center between 1990 and 2016 were identified and compared with patients treated for clear-cell renal cell carcinoma (ccRCC) in the same study period using Wilcoxon test for continuous variables and Fisher exact test for categorical variables. Recurrence-free survival (RFS) and overall survival (OS) were analyzed using the Kaplan-Meier method, log rank test, and Cox proportional hazards regression.

RESULTS

Four hundred ninety-six patients with ChRCC (10-year RFS, 91.7% and OS, 82.1%) and 3312 patients with ccRCC (10-year RFS, 79.4% and OS, 63.6%) were included in the analysis. Patients with ChRCC were younger (median 59 vs. 61 years; P = .0015), less frequently male (54.8% vs. 66.3%; P < .0001), showed more favorable T stages (T1-2 in 78% vs. 67%; P < .0001) and less frequent sarcomatoid differentiation (1.2 % vs. 4%; P = .0008) and showed lower rates of metastatic development compared with ccRCC patients. Larger tumor size, sarcomatoid differentiation, and higher T-stage are significantly associated with adverse RFS and OS in chromophobe tumors.

CONCLUSION

ChRCC is more commonly diagnosed in female and younger patients and is associated with a more favorable clinical outcome and a lower propensity for metastatic development than ccRCC. Larger tumors and sarcomatoid differentiation of ChRCC might be considered as risk factors for metastatic development.

P2X7 receptor predicts postoperative cancer-specific survival of patients with clear-cell renal cell carcinoma

The P2X7 receptor, an ATP-gated plasma membrane ion channel, is involved in inflammation, apoptosis and cell proliferation, and thereby plays a crucial role during oncogenic transformation in various malignancies. This study aims to evaluate the impact of P2X7 receptor expression on postoperative cancer-specific survival of patients with clear-cell renal cell carcinoma (ccRCC). A total of 273 patients with ccRCC undergoing nephrectomy at a single institution were retrospectively enrolled in this study, among which 86 patients died of this disease and six patients died of other causes. Clinicopathologic features and cancer-specific survival (CSS) were recorded. P2X7 expression was assessed by immunohistochemistry in clinical specimens. Kaplan–Meier method with log rank test was performed to compare survival curves. Cox regression models were used to evaluate the prognostic values of variables on CSS. Concordance index was calculated to assess prognostic accuracy of prognostic models. Median follow-up period was 90 months (range, 11–120 months). Intratumoral P2X7 expression was significantly lower than peritumoral tissues (P < 0.001). Moreover, high intratumoral P2X7 expression, which was significantly associated with shorten CSS (P < 0.001), high TNM stage (P = 0.038), Fuhrman grade (P = 0.035), SSIGN (stage, size, grade, and necrosis) score (P = 0.021) and University of California Integrated Staging System (UISS) score (P = 0.007), was indicated to be an independent prognostic factor for CSS (hazard ratio [HR], 1.693; P = 0.034). The prognostic accuracy of TNM stage, UISS and SSIGN scoring models was improved when intratumoral P2X7 expression was added. Intratumoral P2X7 expression is a potential independent adverse prognostic indicator for postoperative CSS of patients with ccRCC.

High expression of interleukin-11 is an independent indicator of poor prognosis in clear-cell renal cell carcinoma

Interleukin-11 (IL-11), a member of the IL-6 family of cytokines, exerts pleiotropic oncogenic activities by stimulating angiogenesis and metastasis in many cancer types. The present study aims to evaluate the impact of IL-11 expression on recurrence and mortality of patients with clear-cell renal cell carcinoma (ccRCC). We retrospectively enrolled 193 ccRCC patients undergoing nephrectomy at a single center. Clinicopathologic features, recurrence-free survival (RFS) and overall survival (OS) were recorded. IL-11 intensity was assessed by immunohistochemistry in tumor specimens. The Kaplan–Meier method was applied to compare survival curves. Cox regression models were used to analyze the impact of prognostic factors on RFS and OS. The concordance index (C-index) was calculated to assess predictive accuracy. High IL-11 expression is associated with increased risk of recurrence and poor survival for ccRCC patients (P < 0.001 and P < 0.001, respectively), especially those with early-stage disease (TNM stage I + II). Multivariate analyses confirmed that IL-11 expression was an independent prognostic factor for RFS and OS (P = 0.006 and P = 0.008, respectively). The predictive accuracy of well-established prognostic models was improved when IL-11 expression was integrated. In conclusion, high IL-11 expression is an independent predictor of poor prognosis in ccRCC patients. It may help identify patients who could benefit from additional treatments and closer follow up.

PFKFB4 is overexpressed in clear-cell renal cell carcinoma promoting pentose phosphate pathway that mediates Sunitinib resistance

BACKGROUND

Kinases play critical role in clear-cell renal cell carcinoma (ccRCC). We aim to exploit novel kinase that is both protumorigenic and drugable in ccRCC.

METHODS

Reproduction of public datasets with validation using microarray was performed to identify candidate gene. Functionality was studied using multi-omics with validation in vitro and in vivo.

RESULTS

6-Phosphofructo-2-Kinase/Fructose-2,6-Biphosphatase 4 (PFKFB4) was differentially expressed showing significantly higher expression in tumor than in normal kidney. PFKFB4 overexpression was associated with advanced tumor grade, stage and worsened prognosis. PFKFB4-knockdown significantly impaired fitness in cell proliferation, migration and wound healing. Despite being recurrently deleted on 3p, PFKFN4 mRNA remained actively transcribed by HIF1α. Metabolomics showed overexpressed PFKFB4 showed enriched metabolites in pentose phosphate pathway (PPP). Phosphoproteomics and immunoprecipitation showed PFKFB4 also phosphorylated NCOA3 which interacted with FBP1 to counteract overactive PPP flux, forming a regulatory loop. PFKFB4-knockdown overcame resistance to Sunitinib in vitro and in vivo both in xenograft and tail-vein injection murine models.

CONCLUSION

We concluded PFKFB4 was associated with PPP activity and the fine-tuning of which was mediated by its phosphorylation of NCOA3. Targeting PFKFB4 held promise to combat resistance to Sunitinib.

Sinomenine hydrochloride attenuates the proliferation, migration, invasiveness, angiogenesis and epithelial-mesenchymal transition of clear-cell renal cell carcinoma cells via targeting Smad in vitro

New strategies for the treatment of clear-cell renal cell carcinoma (ccRCC) are urgently needed. Recently, accumulating evidence has demonstrated that sinomenine hydrochloride (SH), extracted from the plant sinomenium acutum, has potent anti-cancer activity in multiple human malignant solid tumors. However, the underlying molecular mechanism by which SH treatment exerts its antagonizing tumorigenic effects has not been clearly elucidated. In this study, we showed that SH treatment exerted profound effects on cell growth in ccRCC in a dose- and time-dependent manner in vitro. Furthermore, treatment with SH significantly suppressed the migration, invasiveness and angiogenesis of ccRCC cells in vitro. Mechanistically, we revealed that SH treatment blocked epithelial-mesenchymal transition (EMT) through the downregulation of the expression of the transcription factors Snail1 and Twist in ccRCC cells. Additionally, the depletion of p-Smad2 and p-Smad3 was required for SH treatment to inhibit EMT effectively. Taken together, these findings indicate an anti-cancer role for SH in ccRCC cells and reveal a potential molecular mechanism by which Smad / EMT axis functions in ccRCC, as its hyperactivation has been associated with cell proliferation, migration, invasiveness and angiogenesis in this cancer type. These observations suggest that SH can act as an efficacious adjuvant chemotherapeutic candidate that targets the Smad/EMT axis in patients with ccRCC.

Single-cell transcriptome analysis revealing the intratumoral heterogeneity of ccRCC and validation of MT2A in pathogenesis

Clear-cell renal cell carcinoma (ccRCC) appears as the most common type of kidney cancer, the carcinogenesis of which has not been fully elucidated. Tumor heterogeneity plays a crucial role in cancer progression, which could be largely deciphered by the implement of scRNA-seq. The bulk and single-cell RNA expression profile is obtained from TCGA and study conducted by Young et al. We utilized UMAP, TSNE, and clustering algorithm Louvain for dimensionality reduction and FindAllMarkers function for determining the DEGs. Monocle2 was utilized to perform pseudo-time series analysis. SCENIC was implemented for transcription factor analysis of each cell subgroup. A series of WB, CFA, CCK-8, and EDU analysis was utilized for the validation of the role of MT2A in ccRCC carcinogenesis. We observed higher infiltration of T/NK and B cells in tumorous tissues, indicating the role of immune cells in ccRCC carcinogenesis. Transcription factor analysis revealed the activation of EOMES and ETS1 in CD8 + T cells, while CAFs were divided into myo-CAFs and i-CAFs, with i-CAFs showing distinct enrichment of ATF3, JUND, JUNB, EGR1, and XBP1. Through cell trajectory analysis, we discerned three distinct stages of cellular evolution, where State2 symbolizes normal renal tubular cells that underwent transitions into State1 and State3 as the CNV score ascended. Functional enrichment examination revealed an amplification of interferon gamma and inflammatory response pathways within tumor cells. The consensus clustering algorithm yielded two molecular subtypes, with cluster 2 being associated with advanced tumor stages and an abundance of infiltrated immune cells. We identified 17 prognostic genes through Cox and LASSO regression models and used them to construct a prognostic model, the efficacy of which was verified in multiple cohorts. Furthermore, we investigated the role of MT2A, one of our hub genes, in ccRCC carcinogenesis, and found it to regulate proliferation and migration of malignant cells. We depicted a detailed single-cell landscape of ccRCC, with special focus on CAFs, endothelial cells, and renal tubular cells. A prognostic model of high stability and accuracy was constructed based on the DEGs. MT2A was found to be actively implicated in ccRCC carcinogenesis, regulating proliferation and migration of the malignant cells.

Overexpression of low density lipoprotein receptor-related protein 1 (LRP1) is associated with worsened prognosis and decreased cancer immunity in clear-cell renal cell carcinoma

AIM

Clear-cell renal cell carcinoma (ccRCC) is characterized with underlying genetic disorders and the role of low density lipoprotein receptor-related protein 1 (LRP1) in ccRCC is unknown.

METHOD

An in silico exploratory analysis using multiple public genetic datasets was used to establish association between LRP1 expression and clinicopathological parameters. Associations of interest were validated using 155 ccRCC samples using immunohistochemistry.

RESULTS

LRP1 was overexpressed in tumor compared with normal kidney tissue. Increased LRP1 expression in ccRCC was associated with advanced stage, grade and worsened overall survival and progression-free survival. Functional annotation indicated an immune-modulatory role of LRP1 in ccRCC. LRP1 expression was significantly correlated with expressions of PBRM1, SETD2, and KDM5C. Positive correlations between LRP1 and pro-angiogenic factors ERAP1, SCG2, STAB1, and RUNX1 were observed. LRP1 expression was positively correlated with PD-L2 level. Negative correlations between LRP1 and anti-angiogenic factors EMCN and IL18 were observed. LRP1 expression was not associated with microvessel density (MVD) yet was negatively correlated with tumor-infiltrating lymphocytes (TIL).

CONCLUSION

LRP1 is associated with worsened prognosis in ccRCC and is related to cancer immune modulation. LRP1-targeted therapy can be of therapeutic potential.

IL-33 is associated with unfavorable postoperative survival of patients with clear-cell renal cell carcinoma

The aim of this study was to evaluate the potential prognostic significance of interleukin-33 (IL-33) in patients with clear-cell renal cell carcinoma (ccRCC) after surgical resection. In this retrospective research, we enrolled 203 patients with ccRCC undergoing nephrectomy between 2003 and 2004 in a single institution. We recorded clinicopathologic features, overall survival (OS), and recurrence-free survival (RFS) and assessed IL-33 expression by immunohistochemical staining. On such bases, the correlations between IL-33 expression and clinicopathologic features and prognosis were evaluated. A high expression of IL-33 was significantly associated with advanced TNM stage and Fuhrman grade (p = 0.017 and p < 0.001, respectively) in patients with ccRCC. Moreover, multivariate analysis identified IL-33 as an independent prognostic factor of OS for patients with ccRCC after surgery (hazard ratio = 2.050; 95 % CI 1.223-3.447; p = 0.006). The incorporation of IL-33 into the TNM stage and Fuhrman grade might help to refine individual risk stratification. The IL-33 expression may serve as an independent negative predictor of survival for patients with ccRCC after surgery.

High expression of chemokine CCL2 is associated with recurrence after surgery in clear-cell renal cell carcinoma

PURPOSE

Chemokine (C-C motif) ligand 2 (CCL2) is known to recruit monocytes and macrophages to sites of inflammation. Recent studies suggest CCL2 is overexpressed in multiple cancer types and may play a role in the tumor progression. The aim of this study was to assess the association between CCL2 expression and the risk of recurrence after surgery in patients with clear-cell renal cell carcinoma (ccRCC).

METHODS

This study included 268 ccRCC patients who underwent nephrectomy at a single institute between 2001 and 2004. Clinicopathologic variables and recurrence-free survival (RFS) were recorded. CCL2 expression levels were evaluated by immunohistochemical staining in tumor tissues. Kaplan-Meier method was applied to compare survival curves. Cox regression models were fitted to analyze the effect of prognostic factors on recurrence-free survival (RFS). Harrell's concordance index was calculated to assess predictive accuracy.

RESULTS

High CCL2 expression was associated with a greater risk of recurrence in ccRCC patients (P<0.001). Multivariate analysis confirmed that CCL2 expression was an independent prognostic factor for RFS (P = 0.045). The predictive accuracy of the Leibovich prognostic score was improved when CCL2 expression was added (0.76 vs. 0.71, P<0.001). Notably, the improvement in prediction was more pronounced in patients with low-risk disease. A nomogram integrating CCL2 expression and pathologic factors was then constructed, which predicted 5- and 10-year RFS well for ccRCC patients.

CONCLUSIONS

High chemokine CCL2 expression is an independent predictor of recurrence in ccRCC patients. Evaluation of CCL2 could help guide postsurgical management for ccRCC patients.

High mucin-7 expression is an independent predictor of adverse clinical outcomes in patients with clear-cell renal cell carcinoma

Mucin-7 is a member of the secreted mucins family. Mucins might play a crucial role during tumor development and its aberrant expression was observed in several types of tumor. Our study aims to evaluate the prognostic significance of Mucin-7 expression in postoperative clear-cell renal cell carcinoma (ccRCC) patients. In this retrospective study, we enrolled 392 patients with ccRCC undergoing nephrectomy between 2008 and 2009 in a single center. The median follow-up was 73 months (range 39-74 months). Mucin-7 expression was evaluated by immunohistochemistry protocol on ccRCC specimens. Kaplan-Meier survival analysis was conducted to compare survival curves. Univariate and multivariate Cox regression models were applied to assess the impact of prognostic factors in overall survival (OS) and recurrence-free survival (RFS). A nomogram was then constructed based on the independent prognosticators identified on multivariate analysis. The results displayed that Mucin-7 expression was significantly associated with tumor size (p = 0.034), pT stage (p = 0.004), TNM stage (p = 0.008), and necrosis (p = 0.043). Patients with high Mucin-7 expression had significant worse outcomes in both OS (p < 0.001) and RFS (p < 0.001) compared to those with low Mucin-7 expression. MUC7 expression was considered as an independent predictive factor for OS (HR 2.286; 95 %CI 1.167-4.475; p = 0.016) and RFS (HR 2.055; 95 %CI 1.086-3.887; p = 0.027). A nomogram integrating Mucin-7 expression and other independent prognosticators was constructed. In summary, the high Mucin-7 expression is a potential prognosticator of adverse clinical outcome in ccRCC patients after surgery.

Engrailed-2 might play an anti-oncogenic role in clear-cell renal cell carcinoma

Our preliminary study indicated that Engrailed-2 (EN2) is downregulated but also ectopically expressed in clear-cell renal cell carcinoma (CCRCC), and the absence of EN2 expression was associated with poor histological grade. However, the specific roles of EN2 in CCRCC have yet to be elucidated. In the present study, we examined the effects of inhibiting EN2 expression by human renal tubular epithelial cells (HK-2) and overexpressing EN2 by human clear-cell renal cells (786-O). Results showed that EN2 inhibition accelerated HK-2 cell proliferation, shortened the cell cycle, reduced apoptosis, and acted more invasively. By contrast, EN2 overexpression in 786-O cells decelerated the proliferative ability of 786-O, increased the percentage of cell apoptosis, and weakened the invasive ability. Overall, the results demonstrated that EN2 might play an anti-oncogenic role in oncogenesis and development of CCRCC, thereby maintaining the normal growth of human renal tubular epithelial cells.

β1,6-N-acetylglucosaminyltransferase V predicts recurrence and survival of patients with clear-cell renal cell carcinoma after surgical resection

PURPOSE

β1,6-N-acetylglucosaminyltransferase V (MGAT5), which is required for the biosynthesis of β1,6GlcNAc-branched N-linked glycans attached to cell surface and secreted glycoproteins, accounts for oncogenic growth signal transduction during the development and progression of various malignancies. Our present study aimed to evaluate the impact of MGAT5 expression on recurrence and survival of patients with clear-cell renal cell carcinoma (ccRCC) following surgery.

METHODS

We retrospectively enrolled 265 patients (196 in the training cohort and 69 in the validation cohort) with ccRCC undergoing nephrectomy at a single institution. Clinicopathologic features, overall survival (OS) and recurrence-free survival (RFS) were recorded. MGAT5 intensities were assessed by immunohistochemistry in specimens of patients. Kaplan-Meier method was applied to compare survival curves. Cox regression models were used to analyze the impact of prognostic factors on OS and RFS. Concordance index (C-index) was calculated to assess predictive accuracy.

RESULTS

In both cohorts, MGAT5 expression positively correlated with metastatic and advanced TNM stage. High MGAT5 expression indicated poor survival (P < 0.001 in training set and P < 0.001 in validation set) and early recurrence (P < 0.001 in training set and P = 0.004 in validation set) of patients with ccRCC. After multivariate Cox regression analysis, MGAT5 expression was identified as an independent adverse prognostic factor for survival and recurrence. The predictive accuracy of TNM, UISS and SSIGN prognostic models was improved when MGAT5 expression was added.

CONCLUSIONS

MGAT5 expression is a potential independent adverse prognostic biomarker for recurrence and survival of patients with ccRCC after nephrectomy.

Low level of isocitrate dehydrogenase 1 predicts unfavorable postoperative outcomes in patients with clear cell renal cell carcinoma

Background

The purpose of this study was to investigate the role of isocitrate dehydrogenase 1 (IDH1) expression on prognosis of patients with clear cell renal cell carcinoma (ccRCC) following nephrectomy.

Methods

We retrospectively enrolled 358 ccRCC patients undergoing nephrectomy in Renji Hospital. Clinicopathologic features, overall survival (OS) and recurrence-free survival (RFS) of ccRCC patents were all collected. IDH1 expression level was assessed by immunohistochemistry and its association with clinicopathologic features and outcomes were also evaluated. Kaplan-Meier method with the log-rank test was applied to compare survival curves. Multivariate cox regression models were applied to analyze the prognostic value of each factor on OS and RFS of ccRCC patients. Moreover, two nomograms with factors selected by multivariate analysis were constructed to evaluate the prognosis of ccRCC patients, and the calibration plots were built to assess the predictive accuracy of nomograms.

Results

Our data indicated that IDH1 expression level was down-regulated in ccRCC tissues, and it negatively correlated with tumor Fuhrman grade (p = 0.025). Low IDH1 expression was associated with worse OS and RFS for cccRCC patients (OS, p = 0.004; RFS, p = 0.03). In addition, IDH1 could significantly stratify patients’ OS and RFS in intermediate/high risk patients (UISS score ≥ 4) (p = 0.049 and p = 0.004, respectively). Furthermore, incorporating IDH1 with other prognostic factors could predict ccRCC patients’ OS and RFS (OS, c-index = 0.779; RFS, c-index = 0.798) and perform better than TNM and SSIGN system.

Conclusions

Low IDH1 expression level might be an adverse prognostic biomarker for clinical outcomes of ccRCC patients, and two nomograms with IDH1 are potential effective prognostic models for ccRCC.

Tuberous sclerosis complex protein 1 expression is affected by VHL Gene alterations and HIF-1α production in sporadic clear-cell renal cell carcinoma

Alterations in von Hippel-Lindau gene (VHL) do not determine deregulation of hypoxia-inducible factors (HIFs) in clear-cell renal carcinoma (ccRCC). Their effects on tuberous sclerosis proteins (TSC1/2) and heat shock protein 90 (Hsp90) expressions in sporadic ccRCC are unknown. Therefore, we analyze the impact of VHL alterations and HIF-α production on the expression of TSC proteins and Hsp90 in these tumors. Alterations in VHL gene region exhibited 37/47 (78.7%) tumors. Monoallelic inactivation (intragenic mutation or LOH) was found in 10 (21.3%) and biallelic inactivation (intragenic mutation plus LOH) in 27 (57.4%) ccRCCs. Tumorous expression of HIF-α mRNAs, HIF-α, Hsp90 and TSC2 were VHL independent; TSC2 was underexpressed in all tumors by immunostaining (P<0.001). Immunoblotting revealed that TSC1 production was lower in tumors with monoallelic VHL inactivation than in control (P=0.01) and tissues with biallelic VHL inactivation (P=0.019), while tumors lacking HIF-1α (16/47) concurrently overexpressed HIF-2α and underexpressed TSC1 in comparison to controls (P=0.01 for both) and HIF-1α positive tumors (P=0.015 and P=0.050). Significant portion of variability (56.4%) in tumor diameter was explained by oscillations in nuclear grade, and TSC1 and HIF-2α expression in VHL altered tumors. In conclusion, while TSC2 is broadly downregulated in sporadic ccRCC, TSC1 expression is reduced in two subsets of these tumors, those with monoallelic VHL gene inactivation and those with concurrent low HIF-1α and high HIF-2α expression. Hence, the involvement of nuclear grade, TSC1 and HIF-2α in the progression of VHL altered tumors, implies the interplay between pVHL and TSC1.

Statistical clustering of parametric maps from dynamic contrast enhanced MRI and an associated decision tree model for non-invasive tumour grading of T1b solid clear cell renal cell carcinoma

OBJECTIVES

To apply a statistical clustering algorithm to combine information from dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) into a single tumour map to distinguish high-grade from low-grade T1b clear cell renal cell carcinoma (ccRCC).

METHODS

This prospective, Institutional Review Board -approved, Health Insurance Portability and Accountability Act -compliant study included 18 patients with solid T1b ccRCC who underwent pre-surgical DCE MRI. After statistical clustering of the parametric maps of the transfer constant between the intravascular and extravascular space (K ^trans ), rate constant (K _ep ) and initial area under the concentration curve (iAUC) with a fuzzy c-means (FCM) algorithm, each tumour was segmented into three regions (low/medium/high active areas). Percentages of each region and tumour size were compared to tumour grade at histopathology. A decision-tree model was constructed to select the best parameter(s) to predict high-grade ccRCC.

RESULTS

Seven high-grade and 11 low-grade T1b ccRCCs were included. High-grade histology was associated with higher percent high active areas (p = 0.0154) and this was the only feature selected by the decision tree model, which had a diagnostic performance of 78% accuracy, 86% sensitivity, 73% specificity, 67% positive predictive value and 89% negative predictive value.

CONCLUSIONS

The FCM integrates multiple DCE-derived parameter maps and identifies tumour regions with unique pharmacokinetic characteristics. Using this approach, a decision tree model using criteria beyond size to predict tumour grade in T1b ccRCCs is proposed.

KEY POINTS

• Tumour size did not correlate with tumour grade in T1b ccRCC. • Tumour heterogeneity can be analysed using statistical clustering via DCE-MRI parameters. • High-grade ccRCC has a larger percentage of high active area than low-grade ccRCCs. • A decision-tree model offers a simple way to differentiate high/low-grade ccRCCs.

The Early Diagnostic and Prognostic Value of BIRC5 in Clear-Cell Renal Cell Carcinoma Based on the Cancer Genome Atlas Data

PURPOSE

The aim of this study was to investigate the role of BIRC5 for early diagnosis and prognosis in clear-cell renal cell carcinoma (ccRCC) by studying the expression of BIRC5 and the correlation between BIRC5 expression and clinicopathological parameters and prognosis in ccRCC.

METHODS

The BIRC5 expression in ccRCC tissues and normal kidney tissues was measured using the Cancer Genome Atlas database and the Human Protein Atlas database. The correlation between BIRC5 expression and clinicopathological parameters and prognosis in ccRCC was analyzed using UALCAN, the Kaplan-Meier plotter, GEPIA, and SurvExpress. Thirteen-paired ccRCC plasma samples were used to verify the BIRC5 early diagnosis value of ccRCC.

RESULTS

The BIRC5 expression is significantly higher in ccRCC than in normal kidney tissues, and is correlated with the clinical stage and pathological grade of ccRCC (p < 0.05). The result of analyzing the relationship between BIRC5 expression and outcomes in ccRCC indicates that a high BIRC5 expression is an independent prognostic factor affecting the overall survival and disease-free survival of ccRCC (p < 0.05). Compared with normal kidney tissues, the immunohistochemical test shows that BIRC5 is significantly upregulated in ccRCC tissues. mRNA expression levels of BIRC5 were significantly higher in the ccRCC plasma than normal (p < 0.05).

CONCLUSIONS

The high expression of BIRC5 is an important indicator for the prognosis of ccRCC, which makes BIRC5 an effective biomarker for predicting the prognosis of patients in ccRCC. BIRC5 may be a great potential biomarker for early diagnosis of ccRCC.

Phase II Study of Carfilzomib in Patients With Refractory Renal Cell Carcinoma

BACKGROUND

A von Hippel Lindau (VHL) mutation or functional inactivation occurs in the a large proportion of patients with clear-cell renal cell carcinoma (ccRCC), which results in the dysregulation of a number of key cellular functions. A high throughput screen and candidate compound assessment revealed that agents with proteasome inhibition properties were able to stabilize point-mutated VHL and restore some of its functions.

PATIENTS AND METHODS

Nine patients with histologically confirmed metastatic ccRCC with disease progression during at least 1 previous systemic therapy were treated with carfilzomib at a dose of 20 mg/m² over 30 minutes via intravenous (I.V.) infusion on days 1 and 2 and a dose of 56 mg/m² over 30 minutes via I.V. infusion on days 8, 9, 15, and 16 of each 4-week cycle.

RESULTS

The study was stopped after 9 patients were enrolled because of futility. Of the 9 patients treated in the study, all patients had disease progression within 4 months, with a median time of 1.8 months (95% confidence interval, 0.8-3.6 months). No patient showed a response according to Response Evaluation Criteria In Solid Tumors. Three patients showed a best response of stable disease. The most common side effects were musculoskeletal pain, elevated creatinine level, anemia, hyperkalemia, leukopenia, lymphopenia, and fatigue.

CONCLUSION

Although the negative safety and efficacy results of this study do not favor the use of carfilzomib for the treatment of ccRCC, previous studies have shown selected patients achieved partial or complete response to this class of agent. Further preclinical investigations to evaluate the molecular characteristics of the patients who respond to proteasome inhibitors will better characterize the underlying mechanism of response, and might allow for the selection of an appropriate patient population in future studies.

The Significance of INHBE Expression in the Cancer Cells of Clear-Cell Renal Cell Carcinoma

BACKGROUND

Activins and inhibins are structurally related dimeric glycoprotein hormones belonging to the transforming growth factor-β superfamily but whether they are also involved in malignancy is far from clear. No study has reported the expression of INHBE in kidney cancer. The purpose of this study was to examine the expressions of INHBE in the tumor tissue of patients with clear-cell renal cell carcinoma (ccRCC) and to explore the pathologic significance.

METHODS

The INHBE mRNA expression in the tumor tissue of ccRCC patients was analyzed by using RNA sequencing data from the TCGA database. To examine the expression of inhibin βE protein, 241 ccRCC patients were recruited and immunohistochemistry was performed on the tumor tissue of these patients along with 39 normal renal samples. The association between the inhibin βE expression level and patient's clinicopathological indices was evaluated.

RESULTS

In the normal renal tissue, inhibin βE was found to be expressed mainly by renal tubular epithelial cells. In the tumor tissue, inhibin βE was expressed mainly in cancer cells. The expressions of INHBE mRNA and protein in the tumor tissue of ccRCC patients increased significantly compared with those in normal renal samples. There was a significant correlation between the level of inhibin βE in the tumor tissue and tumor grade. Patients with a lower inhibin βE expression in the tumor tissue were found to have a longer overall survival and disease-specific survival.

CONCLUSIONS

INHBE might be involved in the pathogenesis of ccRCC and function as a tumor promoter.

Pancreatic ductal adenocarcinoma concomitant with pancreatic metastases of clear-cell renal cell carcinoma: a case report

Background

Metastatic spread to the pancreas is a rare event. Renal cell carcinoma represents one possible site of origin of pancreatic metastases. Renal cell carcinoma often metastasizes late and exclusively to the pancreas, suggesting a special role of renal cell carcinoma among primaries metastasizing to the pancreas. Even rarer, renal cell carcinoma may occur simultaneously with pancreatic ductal adenocarcinoma.

Case presentation

We present the case of a 78-year-old male Caucasian patient with a history of clear-cell renal cell carcinoma treated with oncological left nephrectomy 20 years before. The patient was diagnosed with pancreatic ductal adenocarcinoma by fine-needle aspiration cytology. At our institution, he received neoadjuvant therapy with folic acid, fluorouracil, irinotecan, oxaliplatin for borderline-resectable pancreatic ductal adenocarcinoma, and subsequently underwent total pancreatectomy. Upon resection, pancreatic ductal adenocarcinoma as well as two metachronous metastases of clear-cell renal cell carcinoma occurring simultaneously and cospatially with pancreatic ductal adenocarcinoma were diagnosed in the pancreatic body.

Conclusions

Renal cell carcinoma metastases of the pancreas are rare and often occur decades after the initial diagnosis of renal cell carcinoma. The combination of renal cell carcinoma metastases and pancreatic ductal adenocarcinoma is even rarer. However, the possibility should be considered by clinicians, radiologists, and pathologists. The special role of renal cell carcinoma as a site of origin of pancreatic metastasis should be further elucidated.

What Do International Guidelines Say About First-line Therapy for Clear-cell Metastatic Renal Cell Carcinoma?

Treatment options for clear-cell metastatic renal cell carcinoma (mRCC) have increased significantly. Clinical practice guidelines aim to aid with decision-making about treatment selection through evidence-based recommendations. In this article, recommendations on first-line treatment for clear-cell mRCC in guidelines from three international organizations are reviewed and summarized. Future guideline development should focus on dynamic updates based on practice-changing data and guidance regarding therapy selection. PATIENT SUMMARY: International guidelines for first-line treatment of metastatic renal cell carcinoma are reviewed in this article. The main differences between guidelines appear to be how quickly the newest evidence is included.

Identification of BRAF, CCND1, and MYC mutations in a patient with multiple primary malignant tumors: a case report and review of the literature

BACKGROUND

Multiple primary malignant tumors (MPMTs), usually associated with worse malignant behavior and prognosis comparing to a single primary tumor, and have recently been found to have an increasing incidence globally. However, the pathogenesis of MPMTs remains to be clarified. Here, we report a unique case of the coexistence of malignant melanoma (MM), papillary thyroid carcinoma (PTC), and clear-cell renal cell carcinoma (ccRCC) along with our perceptions on its pathogenesis.

CASE PRESENTATION

The case reported is of a 59-year-old male patient with unilateral nasal obstruction as well as a renal occupying lesion. Positron emission tomography-computed tomography (PET-CT) revealed a palpable mass of 32 × 30 mm on the posterior and left walls of the nasopharynx. In addition, an isodense nodule was observed in the right superior renal pole, approximately 25 mm in diameter, as well as a slightly hypodense shadow in the right leaf of the thyroid, approximately 13 mm in diameter. Nasal endoscopy and magnetic resonance imaging (MRI) confirmed the existence of a nasopharyngeal neoplasm. Afterward, biopsies of the nasopharyngeal neoplasm, thyroid gland and kidney were performed, and the patient was diagnosed with MM, PTC, and ccRCC according to the pathological and immunohistochemical results. Moreover, mutation of BRAF^V600E was detected in bilateral thyroid tissues, and amplification of both CCND1 and MYC oncogenes were detected in the nasopharyngeal melanoma. After chemotherapy, the patient is now in good overall condition.

CONCLUSIONS

This is the first reported case of a patient with the co-existence of MM, PTC and ccRCC undergoing chemotherapy with a favorable prognosis. Herein, we suggest that such a combination may be non-random, as for mutation of BRAF^V600E might account for the co-occurrence of PTC and MM, while mutations of CCND1 and MYC cause the coexistence of MM and ccRCC. This finding may provide valuable guidance on the diagnosis and treatment of such disease, as well as the prevention of developing a second or third tumor for patients with a single primary.

Association between copy-number alteration of +20q, -14q and -18p and cross-sensitivity to tyrosine kinase inhibitors in clear-cell renal cell carcinoma

Background

We aim to explore association between copy number alteration (CNA) and sensitivity to common tyrosine kinase inhibitors (TKIs) used in clear-cell renal cell carcinoma (ccRCC) treatment.

Methods

CNA with related sensitivity profiles were extracted from the Genomics of Drug Sensitivity in Cancer (GDSC) dataset and was cross-referenced with common CNA in ccRCC in the Cancer Genome Atlas (TCGA) dataset. Functional annotation was profiled using GSEA and NET-GE. Target genes within cytobands of interest were screened in silico and validated in vitro using proliferation assays in A498 and 786-O ccRCC cells.

Results

Four TKIs (Sunitinib, Cabozantinib, Axitinib and Sorafenib) that were clinically used in ccRCC were selected. In silico analysis showed gain of 20q (+20q) occurred in ~ 23% of cases and was associated with resistance to all four TKIs; loss of 14q (−14q) occurred in ~ 39% of cases and was associated with resistance to Sunitinib and Sorafenib; loss of 18p (−18p) occurred in ~ 39% of cases and was associated with sensitivity to Sunitinib and Sorafenib. All 3 CNAs were associated with worsened prognosis, respectively. Candidate target genes included of RBL1 on 20q, KLHL33 on 14q and ARHGAP28 on18q. In vitro validation showed RBL1 overexpression induced resistance to Sunitinib and Cabozantinib; KLHL33 silencing induced resistance to Sunitinib; ARHGAP28 silencing induced sensitivity to Cabozantinib. Functional annotation indicated FoxO signaling, hypoxic response and Wnt pathway, and Rho-related cellular adhesion were mechanistically associated with +20q, −14q and −18p, respectively.

Conclusion

Common CNAs in ccRCC are associated with cancer-intrinsic cross-sensitivity to common TKIs. Further validation and functional analyses are therefore needed.