Pro-angiogenic gene expression is associated with better outcome on sunitinib in metastatic clear-cell renal cell carcinoma

Identification of miRNAs and Their Target Genes Associated with Sunitinib Resistance in Clear Cell Renal Cell Carcinoma Patients

Sunitinib has greatly improved the survival of clear cell renal cell carcinoma (ccRCC) patients in recent years. However, 20-30% of treated patients do not respond. To identify miRNAs and genes associated with a response, comparisons were made between biopsies from responder and non-responder ccRCC patients. Using integrated transcriptomic analyses, we identified 37 miRNAs and 60 respective target genes, which were significantly associated with the NF-kappa B, PI3K-Akt and MAPK pathways. We validated expression of the miRNAs (miR-223, miR-155, miR-200b, miR-130b) and target genes (FLT1, PRDM1 and SAV1) in 35 ccRCC patients. High levels of miR-223 and low levels of FLT1, SAV1 and PRDM1 were associated with worse overall survival (OS), and combined miR-223 + SAV1 levels distinguished responders from non-responders (AUC = 0.92). Using immunohistochemical staining of 170 ccRCC patients, VEGFR1 (FLT1) expression was associated with treatment response, histological grade and RECIST (Response Evaluation Criteria in Solid Tumors) score, whereas SAV1 and BLIMP1 (PRDM1) were associated with metachronous metastatic disease. Using in situ hybridisation (ISH) to detect miR-155 we observed higher tumoural cell expression in non-responders, and non-tumoural cell expression with increased histological grade. In summary, our preliminary analysis using integrated miRNA-target gene analyses identified several novel biomarkers in ccRCC patients that surely warrant further investigation.

Unraveling the Synergy between Atezolizumab and Bevacizumab for the Treatment of Hepatocellular Carcinoma

Tyrosine kinase inhibitors (TKIs) with antiangiogenic properties, such as sorafenib, have been the standard choice to systemically treat hepatocellular carcinoma for over a decade. More recently, encouraging results were obtained using immune checkpoint inhibitors, although head-to-head comparisons with sorafenib in phase 3 trials could not demonstrate superiority in terms of overall survival. The IMbrave150 was a breakthrough study that resulted in atezolizumab/bevacizumab, a combination of an antiangiogenic and an immune checkpoint inhibitor, as a new standard of care for advanced HCC. This review discusses the mode of action, clinical efficacy, and biomarker research for both drug classes and for the combination therapy. Moreover, the synergy between atezolizumab and bevacizumab is highlighted, unraveling pathophysiological mechanisms underlying an enhanced anticancer immunity by changing the immunosuppressed to a more immunoreactive tumor microenvironment (TME). This is achieved by upregulation of antigen presentation, upregulation of T-cell proliferation, trafficking and infiltration, impairing recruitment, and proliferation of immunosuppressive cells in the TME. However, more insights are needed to identify biomarkers of response that may improve patient selection and outcome.

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

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

Identification of a claudin-low subtype in clear cell renal cell carcinoma with implications for the evaluation of clinical outcomes and treatment efficacy

Background

In bladder and breast cancer, the claudin-low subtype is widely identified, revealing a distinct tumor microenvironment (TME) and immunological feature. Although we have previously identified individual claudin members as prognostic biomarkers in clear cell renal cell carcinoma (ccRCC), the existence of an intrinsic claudin-low subtype and its interplay with TME and clinical outcomes remains unclear.

Methods

Transcriptomic and clinical data from The Cancer Genome Atlas (TCGA)- kidney clear cell carcinoma (KIRC) cohort and E-MTAB-1980 were derived as the training and validation cohorts, respectively. In addition, GSE40435, GSE53757, International Cancer Genome Consortium (ICGC) datasets, and RNA-sequencing data from local ccRCC patients were utilized as validation cohorts for claudin clustering based on silhouette scores. Using weighted correlation network analysis (WGCNA) and multiple machine learning algorithms, including least absolute shrinkage and selection operator (LASSO), CoxBoost, and random forest, we constructed a claudin-TME related (CTR) risk signature. Furthermore, the CTR associated genomic characteristics, immunity, and treatment sensitivity were evaluated.

Results

A claudin-low phenotype was identified and associated with an inferior survival and distinct TME and cancer immunity characteristics. Based on its interaction with TME, a risk signature was developed with robust prognostic prediction accuracy. Moreover, we found its association with a claudin-low, stem-like phenotype and advanced clinicopathological features. Intriguingly, it was also effective in kidney chromophobe and renal papillary cell carcinoma. The high CTR group exhibited genomic characteristics similar to those of claudin-low phenotype, including increased chromosomal instability (such as deletions at 9p) and risk genomic alterations (especially BAP1 and SETD2). In addition, a higher abundance of CD8 T cells and overexpression of immune checkpoints, such as LAG3, CTLA4 and PDCD1, were identified in the high CTR group. Notably, ccRCC patients with high CTR were potentially more sensitive to immune checkpoint inhibitors; their counterparts could have more clinical benefits when treated with antiangiogenic drugs, mTOR, or HIF inhibitors.

Conclusion

We comprehensively evaluated the expression features of claudin genes and identified a claudin-low phenotype in ccRCC. In addition, its related signature could robustly predict the prognosis and provide guide for personalizing management strategies.

The unique genomic landscape and prognostic mutational signature of Chinese clear cell renal cell carcinoma

Background

The genomic background affects the occurrence and metastasis of cancers, including clear cell renal cell carcinoma (ccRCC). However, reports focusing on the prognostic mutational signature of Chinese ccRCC are lacking.

Methods

Overall, 929 patients, including a training cohort with Chinese patients (n = 201), a testing cohort with Caucasian patients (n = 274), and a validation cohort (n = 454) were analyzed for the genomic landscape of ccRCC. Then, machine-learning algorithms were used to identify and evaluate the genomic mutational signature (GMS) in ccRCC. Analyses for prognosis, immune microenvironment, association with independent clinicopathological features, and predictive responses for immune checkpoint therapies (ICTs) were performed.

Results

The DNA variation data of 929 patients with ccRCC suggested markedly differential genomic mutational frequency of the most frequent genes, such as VHL, PBRM1, BAP1, SETD2, and KDM5C between the Chinese and Caucasian populations. PBRM1 showed significant co-occurrence with VHL and SETD2. We then successfully identified a seven-gene mutational signature (GMSMut) that included mutations in FBN1, SHPRH, CELSR1, COL6A6, DST, ABCA13, and BAP1. The GMSMut significantly predicted progressive progression (P < 0.0001, HR = 2.81) and poor prognosis (P < 0.0001, HR = 3.89) in the Chinese training cohort. Moreover, ccRCC patients with the GMSMut had poor survival rates in the testing cohort (P = 0.020) and poor outcomes were predicted for those treated with ICTs in the validation cohort (P = 0.036). Interestingly, a favorable clinical response to ICTs, elevated expression of immune checkpoints, and increased abundance of tumor-infiltrated lymphocytes, specifically CD8+ T cells, Tregs, and macrophages, were observed in the GMSMut cluster.

Conclusions

This study described the pro-tumorigenic GMSMut cluster that improved the prognostic accuracy in Chinese patients with ccRCC. Our discovery of the novel independent prognostic signature highlights the relationship between tumor phenotype and genomic mutational characteristics of ccRCC.

Genomic alteration of MTAP/CDKN2A predicts sarcomatoid differentiation and poor prognosis and modulates response to immune checkpoint blockade in renal cell carcinoma

Sarcomatoid differentiation is a highly aggressive pathological characteristic of renal cell carcinoma (RCC) and is characterized by susceptibility to progression and extremely poor prognosis. In this study, we included all genomic alteration events that led to a loss of protein function of MTAP and CDKN2A, and enrolled 5,307 RCC patients with genomic sequencing data from Western and Chinese cohorts. Notably, MTAP/CDKN2A^MUT occurred in the Chinese population ~2 times more frequently than in the Western cohort and showed significant co-mutation trends. We found significantly higher proportions of sarcomatoid-positive patients with MTAP^MUT or CDKN2A^MUT compared with MTAP/CDKN2A wild-type (WT) patients (P < 0.001). Of the 574 RCC samples from the FUSCC cohort and 3,563 RCC samples from 17 independent cohorts, the MTAP/CDKN2A^MUT significantly predicted extremely poor outcomes (P < 0.0001). The Western cohort suggested a concordant relationship between MTAP/CDKN2A^MUT and sarcomatoid differentiation in RCC. Moreover, although MTAP/CDKN2A^MUT RCC may be insensitive to targeted therapy, the high degree of tumor heterogeneity and higher PD-L1 and CXCL13 expression characterizations reflected that MTAP/CDKN2A-deficient features could benefit from immunotherapy for patients with RCC. This study utilized RCC samples from large-scale, global, multicenter sequencing cohorts and first proved that MTAP/CDKN2A deficiency significantly correlates with sarcomatoid differentiation in RCC and predicts aggressive progression, poor prognosis, and primary resistance to targeted therapy and potential favorable responses to immune checkpoint blockade. Unlike conventional targeted therapies, emerging drugs such as immunotherapies or synthetic lethal PRMT5 inhibitors may become novel therapeutic options for patients with MTAP/CDKN2A^MUT RCC.

Pbrm1 intrinsically controls the development and effector differentiation of iNKT cells

Under static condition, the pool size of peripheral invariant natural killer T (iNKT) cells is determined by their homeostatic proliferation, survival and thymic input. However, the underlying mechanism is not fully understood. In the present study, we found that the percentage and number of iNKT cells were significantly reduced in the spleen, but not in the thymus of mice with deletion of polybromo‐1 (Pbrm1) compared to wild type (WT) mice. Pbrm1 deletion did not affect iNKT cell proliferation and survival, instead significantly impaired their development from stage 1 to stage 2. Importantly, loss of Pbrm1 led to a dysfunction of RORγt expression and iNKT17 cell differentiation, but not iNKT1 and iNKT2 proportion. Collectively, our study reveals a novel mechanism of Pbrm1 controlling the peripheral size of iNKT cells through regulating their development and differentiation.

Prognostic Immunophenotyping Clusters of Clear Cell Renal Cell Carcinoma Defined by the Unique Tumor Immune Microenvironment

Background: The tumor microenvironment affects the occurrence and development of cancers, including clear cell renal cell carcinoma (ccRCC). However, how the immune contexture interacts with the cancer phenotype remains unclear.

Methods: We identified and evaluated immunophenotyping clusters in ccRCC using machine-learning algorithms. Analyses for functional enrichment, DNA variation, immune cell distribution, association with independent clinicopathological features, and predictive responses for immune checkpoint therapies were performed and validated.

Results: Three immunophenotyping clusters with gradual levels of immune infiltration were identified. The intermediate and high immune infiltration clusters (Clusters B and C) were associated with a worse prognosis for ccRCC patients. Tumors in the immune-hot Clusters B and C showed pro-tumorigenic immune infiltration, and these patients showed significantly worse survival compared with patients in the immune-cold Cluster A in the training and testing cohorts (n = 422). In addition to distinct immune cell infiltrations of immunophenotyping, we detected significant differences in DNA variation among clusters, suggesting a high degree of genetic heterogeneity. Furthermore, expressions of multiple immune checkpoint molecules were significantly increased. Clusters B and C predicted favorable outcomes in 64 ccRCC patients receiving immune checkpoint therapies from the FUSCC cohort. In 360 ccRCC patients from the FUSCC validation cohort, Clusters B and C significantly predicted worse prognosis compared with Cluster A. After immunophenotyping of ccRCC was confirmed, significantly increased tertiary lymphatic structures, aggressive phenotype, elevated glycolysis and PD-L1 expression, higher abundance of CD8⁺ T cells, and TCRn cell infiltration were found in the immune-hot Clusters B and C.

Conclusion: This study described immunophenotyping clusters that improved the prognostic accuracy of the immune contexture in the ccRCC microenvironment. Our discovery of the novel independent prognostic indicators in ccRCC highlights the relationship between tumor phenotype and immune microenvironment.

Clear cell renal cell carcinoma with prominent microvascular hyperplasia: Morphologic, immunohistochemical and molecular-genetic analysis of 7 sporadic cases

Clear cell renal cell carcinoma (CCRCC) is well known for intratumor heterogeneity. An accurate mapping of the tumor is crucial for assessing prognosis, and perhaps this can be linked to potential success/failure of targeted therapies. We assembled a cohort of 7 CCRCCs with prominent vasculature and microvascular hyperplasia (ccRCCPV), resembling those seen in high grade gliomas. A control group of classic CCRCC with no variant morphologies was also included. Both groups were analyzed for clinicopathologic, morphologic, immunohistochemical, and molecular genetic features. No statistically significant differences in mRNA expression of studied genes between the two groups were found. Using NGS panel Trusight Oncology 500 (TSO500), only one clinically significant gene mutation, VHL c.263G > A, p. (Trp88Ter), was found. TMB (Tumor Mutation Burden) and MSI (MicroSatellite Instability) were low, and no copy number variations (CNVs) were detected in the study cohort. Prominent microvascular hyperplasia in CCRCC is a rare phenomenon. From molecular genetic point of view, these tumors do not appear to be different from classic CCRCC. Prognostically, they also demonstrated similar clinical behaviors.

Molecular underpinnings of glandular tropism in metastatic clear cell renal cell carcinoma: therapeutic implications

BACKGROUND

Glandular metastases (GM) have been associated with improved survival in metastatic clear cell renal cell carcinoma (m-ccRCC). We aimed to molecularly characterize m-ccRCC with GM.

MATERIAL AND METHODS

We performed a retrospective cohort study on all m-ccRCC patients with available tissue at our institution, diagnosed with metastatic disease from 2000 to 2019. We determined previously described angiogenesis- and immune-related gene expression signatures (GES) and ccrcc molecular subtypes through whole transcriptome RNA sequencing of primary tumors and metastases. We tested differences in GES and molecular subtypes across groups and studied overall (OS) and progression-free survival (PFS) using Kaplan-Meier survival analysis and Cox regression models.

RESULTS

Primary tumors of patients who developed GM (n = 55) had higher IMmotion Angio (p < 0.001) and JAVELIN Angio (p = 0.003) GES as well as a higher proportion of angiogenic ccrcc2 molecular subtypes (p = 0.008) than primary tumors of patients with non-GM (n = 128). Metastatic lesions in glandular organs (n = 32) also had higher IMmotion Angio (p = 0.008) and JAVELIN Angio (p = 0.02) GES and were more frequently of the ccrcc2 molecular subtype (p = 0.03), compared to metastatic lesions in non-glandular organs in patients who did not develop any GM (n = 231), but not compared to metastatic lesions in non-glandular organs in patients who also developed GM (n = 18). Patients with GM had better OS (HR 0.49, p < 0.001) and PFS on first-line vascular endothelial growth factor receptor tyrosine kinase inhibitors (VEGFR-TKIs) (HR 0.64, p = 0.045) than patients with non-GM. PFS on first- or any-line immuno-oncology (IO) was not different. IMmotion Angio, JAVELIN Angio GES, and ccrcc2 molecular subtype were associated with better OS and PFS on first-line VEGFR-TKIs, but not PFS on first or any-line IO.

CONCLUSIONS

Patients with m-ccRCC who develop GM are molecularly characterized by heightened angiogenesis, translating into better prognosis and better outcomes on VEGFR-TKIs, but not IO. Based on these findings, VEGFR-TKIs should be included in the first-line treatment of m-ccRCC patients with GM.

Leukotriene B4 receptor 2 correlates with prognosis and immune infiltration in clear cell renal cell carcinoma

BACKGROUND

Clear cell renal cell carcinoma (ccRCC) is the most common renal cancer. According to reports, leukotriene B4 receptor 2 (LTB4R2, also known as BLT2), a chemokine receptor, is upregulated in different tumors. However, the correlation between BLT2 expression and its prognostic value in ccRCC remains to be explored.

METHODS

This study used the The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases to evaluate the association between BLT2 expression and the clinical outcome of ccRCC. Based on TIMER2.0, the correlation between BLT2 expression in ccRCC and tumor immune characteristics was evaluated.

RESULTS

The expression of BLT2 in ccRCC was higher than that in normal tissues. Kaplan-Meier survival analysis indicated that high BLT2 expression was significantly correlated with poor overall survival (HR = 1.75, p < 0.001) and disease-specific survival (HR = 1.60, p = 0.014) for patients with ccRCC. In addition, our findings revealed that there was no significant correlation between the M1 marker genes and the expression of BLT2 in ccRCC, while moderate correlations were observed between the BLT2 expression and the M2 marker genes. Tregs and T cell exhaustion marker genes were positively correlated with BLT2 expression in ccRCC (p < 0.001).

CONCLUSION

BLT2 may serve as a novel prognostic biomarker and is related to the shaping of tumor immune microenvironment in ccRCC. The expression of BLT2 potentially contributes to the regulation of TAMs, T cell exhaustion, and Tregs activation in ccRCC, providing new approaches to promote the development of new immunotherapeutic strategies for ccRCC.

Transgelin Contributes to a Poor Response of Metastatic Renal Cell Carcinoma to Sunitinib Treatment

Renal cell carcinoma (RCC) represents about 2-3% of all cancers with over 400,000 new cases per year. Sunitinib, a vascular endothelial growth factor tyrosine kinase receptor inhibitor, has been used mainly for first-line treatment of metastatic clear-cell RCC with good or intermediate prognosis. However, about one-third of metastatic RCC patients do not respond to sunitinib, leading to disease progression. Here, we aim to find and characterize proteins associated with poor sunitinib response in a pilot proteomics study. Sixteen RCC tumors from patients responding (8) vs. non-responding (8) to sunitinib 3 months after treatment initiation were analyzed using data-independent acquisition mass spectrometry, together with their adjacent non-cancerous tissues. Proteomics analysis quantified 1996 protein groups (FDR = 0.01) and revealed 27 proteins deregulated between tumors non-responding vs. responding to sunitinib, representing a pattern of deregulated proteins potentially contributing to sunitinib resistance. Gene set enrichment analysis showed an up-regulation of epithelial-to-mesenchymal transition with transgelin as one of the most significantly abundant proteins. Transgelin expression was silenced by CRISPR/Cas9 and RNA interference, and the cells with reduced transgelin level exhibited significantly slower proliferation. Our data indicate that transgelin is an essential protein supporting RCC cell proliferation, which could contribute to intrinsic sunitinib resistance.

Molecular Subtypes and Gene Expression Signatures as Prognostic Features in Fully Resected Clear Cell Renal Cell Carcinoma: A Tailored Approach to Adjuvant Trials

BACKGROUND

Trials with adjuvant vascular endothelial growth factor receptor tyrosine kinase inhibitors (VEGFR-TKIs) failed to demonstrate meaningful benefit in clinically high-risk, fully resected clear cell renal cell carcinoma (ccRCC). We evaluated whether the ccrcc1-4 molecular subtypes and gene expression signatures (GES) are associated with outcomes in this setting.

MATERIALS AND METHODS

We determined molecular subtypes as well as angiogenesis- and immune-related GES through RNA sequencing of 75 fresh frozen (FF) and 62 formalin-fixed, paraffin-embedded (FFPE) tumor samples. We studied disease-free (DFS) and overall survival (OS) and determined correlations among GES and Leibovich score.

RESULTS

Angiogenesis-related GES and molecular subtypes were associated with longer DFS and OS across both cohorts, whereas immune-related GES were not. In the FF cohort, molecular subtypes (ccrcc2 & 3 vs. ccrcc1 & 4) were associated with DFS and OS, on bivariable analysis with Leibovich score (HR 0.62, 95%CI 0.39-0.98, P = .04 and HR 0.35, 95%CI 0.19-0.64, P < .001). In the FFPE cohort, molecular subtypes (ccrcc2 & 3 vs. ccrcc1&4) were also associated with DFS (HR 0.53, 95%CI 0.31-0.93, P = .03), but not OS (HR 0.59, 95%CI 0.31-1.13, P = .11) on bivariable analysis with Leibovich score. Leibovich score was significantly inversely correlated with all angiogenesis-related GES (all P < .01), but not correlated with immune-related GES.

CONCLUSIONS

Molecular subtypes and angiogenesis-related GES are prognostic for DFS and OS in fully resected, localized ccRCC. Favorable ccrcc2 & 3 molecular subtypes with high angiogenesis-related GES, which respond best to VEGFR-TKIs, are at lower risk of relapse but were probably underrepresented in the adjuvant VEGFR-TKI trials since they inversely correlate with Leibovich score. Conversely, immune-related GES are not correlated with Leibovich score and clinically high-risk tumors can display both high and low immune-related GES. Therefore, molecular characterization could guide patient selection for adjuvant treatment.

MicroRNAs Targeting HIF-2α, VEGFR1 and/or VEGFR2 as Potential Predictive Biomarkers for VEGFR Tyrosine Kinase and HIF-2α Inhibitors in Metastatic Clear-Cell Renal Cell Carcinoma

Metastatic clear-cell renal cell carcinoma (m-ccRCC) is characterized by increased hypoxia-induced factor (HIF)-2α and vascular endothelial growth factor receptor (VEGFR)-dependent angiogenesis through loss of function of the von Hippel-Lindau protein. VEGFR tyrosine kinase inhibitors (VEGFR-TKIs) are a cornerstone of m-ccRCC treatment, and new treatments targeting HIF-2α are currently under investigation. However, predictive biomarkers for these treatments are lacking. In this retrospective cohort study including 109 patients treated with VEGFR-targeted therapies as first-line treatment, we aimed to study the possible predictive function of microRNAs (miRNAs) targeting HIF-2α, VEGFR1 and VEGFR2. We selected miRNAs inversely correlated with HIF-2α, VEGFR1 and/or VEGFR2 expression and with predicted target sites in the respective genes and subsequently studied their impact on therapeutic outcomes. We identified four miRNAs (miR-34c-5p, miR-221-3p, miR-222-3p and miR-3529-3p) inversely correlated with VEGFR1 and/or VEGFR2 expression and associated with tumor shrinkage and progression-free survival (PFS) upon treatment with VEGFR-TKIs, highlighting the potential predictive value of these miRNAs. Moreover, we identified three miRNAs (miR-185-5p, miR-223-3p and miR-3529-3p) inversely correlated with HIF-2α expression and associated with tumor shrinkage and PFS upon treatment with VEGFR-TKIs. These three miRNAs can have a predictive value not only upon treatment with VEGFR-TKIs but possibly also upon treatment with the upcoming HIF-2α inhibitor belzutifan.

Prolyl Hydroxylase 3 Knockdown Accelerates VHL-Mutant Kidney Cancer Growth In Vivo

Von Hippel Lindau (VHL) inactivation, which is common in clear cell renal cell carcinoma (ccRCC), leads directly to the disruption of oxygen homoeostasis. VHL works through hypoxia-inducible factors (HIFs). Within this VHL-HIF system, prolyl hydroxylases (PHDs) are the intermediary proteins that initiate the degradation of HIFs. PHD isoform 3's (PHD3) role in ccRCC growth in vivo is poorly understood. Using viral transduction, we knocked down the expression of PHD3 in the human ccRCC cell line UMRC3. Compared with control cells transduced with scrambled vector (UMRC3-SC cells), PHD3-knockdown cells (UMRC3-PHD3KD cells) showed increased cell invasion, tumor growth, and response to sunitinib. PHD3 knockdown reduced HIF2α expression and increased phosphorylated epidermal growth factor (EGFR) expression in untreated tumor models. However, following sunitinib treatment, expression of HIF2α and phosphorylated EGFR were equivalent in both PHD3 knockdown and control tumors. PHD3 knockdown changed the overall redox state of the cell as seen by the increased concentration of glutathione in PHD3 knockdown tumors relative to control tumors. UMRC3-PHD3KD cells had increased proliferation in cell culture when grown in the presence of hydrogen peroxide compared to UMRC3-SC control cells. Our findings illustrate (1) the variable effect of PHD3 on HIF2α expression, (2) an inverse relationship between PHD3 expression and tumor growth in ccRCC animal models, and (3) the role of PHD3 in maintaining the redox state of UMRC3 cells and their proliferative rate under oxidative stress.

Radical metastasectomy followed by sorafenib versus observation in patients withclear cell renal cell carcinoma: extended follow -up of efficacy results from the randomized phase II RESORT trial

Background: The RESORT trial showed no longer relapse free survival (RFS) with sorafenib following radical metastasectomy in metastatic renal cell carcinoma. We present the updated 42-month follow-up data.Methods: The phase II RESORT trial randomized patients to sorafenib or observation within 12 weeks from surgery. RFS was the primary endpoint.Results: We analyzed 68 patients (32 in sorafenib and 36 in the observation arm), randomized between November 2012 and November 2017. Eighty-one percent in the sorafenib arm and 80% in the observation arm had one metastasis . At a median follow-up of 42 months (interquartile range 31-58), in the observation arm the median RFS was 35 months, RFS probability was 57% (95% CI 42-76%) at 24 and 44% (95% CI 30-65%) at 48 months. In the sorafenib arm, median RFS was 21 months, RFS probability was 50% (95% CI 34-71%) at 24 and 32% (95% CI 18-57%) at 48 months (p = 0.342;HR 1.35;95% CI 0.72-2.54). Forty-seven percent and 37.5% of the patients in the two arms, respectively, are disease free. The site of relapses was independent of the previous metastasectomy site.Expert commentary: Sorafenib after metastasectomy did not improve RFS, but surgery in selected patients should be considered in order to potentially improve survival.Clinical trial registration: www.clinicaltrials.gov identifier is NCT0144480.

Tissue Based Biomarkers for Metastatic Clear Cell Renal Carcinoma: A Systematic Review

Background: Treatments for metastatic clear cell renal carcinoma (mccRCC) are evolving with multiple targeted and immune therapy drugs currently approved by regulatory agencies as single agents or in combination. Developing predictive biomarkers to determine which patients derive a differential benefit from a particular treatment is an area of ongoing clinical research. Objective: We sought to systematically evaluate the role of tumour tissue-based biomarkers that assist in selection of therapy for mccRCC. Methods: Literature addressing the role of biomarkers in mccRCC was identified through a search of the electronic databases MEDLINE, Embase, and the Web of Science and a hand search of major conference abstracts (from Jan 2010 –Sep 2020). Abstracts were screened to identify papers meriting full-text review. Studies with a comparison arm were included to assess biomarker relevance. A narrative review of studies was performed. Results: The literature search yielded 6784 potentially relevant articles. 133 articles met criteria for full text review, and 10 articles were identified by scanning bibliographies of relevant studies. A total of 33 articles (involving 13 studies) were selected for data extraction and subsequent review. Conclusions: Predictive biomarkers for immediate use in the clinic are lacking, and embedding their evaluation and validation in future clinical trials is needed to refine practice and patient selection.

Liquid Biopsies in Renal Cell Carcinoma-Recent Advances and Promising New Technologies for the Early Detection of Metastatic Disease

Clear cell renal cell carcinoma (ccRCC) displays a highly varying clinical progression, from slow growing localized tumors to very aggressive metastatic disease (mRCC). Almost a third of all patients with ccRCC show metastatic dissemination at presentation while another third develop metastasis during the course of the disease. Survival rates of mRCC patients remain low despite the development of novel targeted treatment regimens. Biomarkers indicating disease progression could help to define its aggressive potential and thus guide patient management. However, molecular markers that can reliably assess metastatic dissemination and disease recurrence in ccRCC have not been recommended for clinical practice to date. Liquid biopsies could provide an attractive and non-invasive method to determine the risk of recurrence or metastatic dissemination during follow-up and thus assist the search for surveillance biomarkers in ccRCC tumors. A wide spectrum of circulating molecules have already shown considerable potential for ccRCC diagnosis and prognostication. In this review, we outline state of the art of the key circulating analytes such as cfDNA, cfRNA, proteins, and exosomes that may serve as biomarkers for the longitudinal monitoring of ccRCC progression to metastasis. Moreover, we address some of the prevailing limitations in the past approaches and present promising adoptable technologies that could help to pursue the implementation of liquid biopsies as a prognostic tool for mRCC.

Validation of the Correlation Between Single Nucleotide Polymorphism rs307826 in VEGFR3 and Outcome in Metastatic Clear-Cell Renal Cell Carcinoma Patients Treated with Sunitinib

BACKGROUND: Previously, we have shown a correlation between single nucleotide polymorphism (SNP) rs307826 in vascular endothelial growth factor receptor-3 (VEGFR3) and outcome in metastatic clear-cell renal cell carcinoma (m-ccRCC) patients treated with sunitinib. OBJECTIVE: We aimed to validate this finding in an independent patient series. METHODS: m-ccRCC patients receiving sunitinib as first-line targeted therapy were included in a validation cohort. Endpoints were response rate (RR), progression-free survival (PFS) and overall survival (OS). We also updated survival data of our discovery cohort as described previously. RESULTS: Eighty-four patients were included in the validation cohort. rs307826 AG/GG-carriers had a shorter PFS (8 versus 12 months, p = 0.04) and a trend towards a shorter OS (18 versus 27 months, p = 0.22) compared to AA-carriers. In the total series of 168 patients (from the discovery cohort, as described previously, and the validation cohort), rs307826 AG/GG-carriers had a poorer RR (29% versus 53%, p = 0.008), PFS (8 versus 15 months, p = 0.0002) and OS (22 versus 31 months, p = 0.004) compared to AA-carriers. rs307826 was independently associated with PFS and OS on multivariate analysis. CONCLUSION: VEGFR3 rs307826 seems to be associated with outcome on sunitinib in m-ccRCC. Its impact highlights the role of VEGFR3 in ccRCC pathogenesis and as a target of sunitinib.

Expression of vascular endothelial growth factor C in renal cell carcinoma and its correlation with pathological parameters and prognosis

BACKGROUND

Renal cell carcinoma (RCC) is a common malignant tumor of the urinary system. This study aimed to analyze the expression of vascular endothelial growth factor C (VEGF-C) in RCC and its relationship with pathological parameters and prognosis.

METHODS

The clinical data of 68 patients who underwent surgical treatment and confirmed to be RCC by pathology from February 2012 to January 2014 were collected. The specimens of carcinoma tissues of the 68 patients were collected, among which 20 patients were collected from normal tissue specimens adjacent to the cancer more than 5 cm away from the tumor as controls. The VEGF-C expression level was detected by immunohistochemistry, and the relationship between VEGF-C expression and clinical pathological parameters and prognosis of RCC was analyzed.

RESULTS

The positive expression rate of VEGF-C in cancer tissues of RCC patients was significantly higher than the adjacent tissues (85.29% vs. 15.00%) (P<0.05). The positive expression rate of VEGF-C in cancer tissues of RCC patients with low-to- moderate differentiation, stage III-IV, and lymph node metastasis was higher than that of RCC patients with high differentiation, stage I-II, and no lymph node metastasis (P<0.05). The survival rates of RCC patients at 1-, 3- and 5-year follow-up were 82.35% (56/68), 54.41% (37/68), and 32.35% (22/68), and the survival time of patients with positive VEGF-C expression was shorter than patients with negative expression (P<0.05). There was no significant difference in the 5-year survival rate among RCC patients according to sex or presence of muscular infiltration (P>0.05). Meanwhile, the 5-year survival rate was higher in patients with tumor diameter <5 cm, high differentiation, stage I-II, no lymph node metastasis, VEGF-C-negative expression, and aged <55 years old (P<0.05). The Cox regression model analysis showed that differentiation degree, clinical stage, lymph node metastasis, and VEGF-C expression were all independent risk factors affecting the prognosis of RCC patients (P<0.05).

CONCLUSIONS

VEGF-C is highly expressed in cancer tissues of RCC patients, and is related to clinical stage, pathological differentiation, and lymph node metastasis, which maybe an effective factor of prognosis prediction.

The immunology of renal cell carcinoma

Renal cell carcinoma (RCC) is the most common type of kidney cancer and comprises several subtypes with unique characteristics. The most common subtype (~70% of cases) is clear-cell RCC. RCC is considered to be an immunogenic tumour but is known to mediate immune dysfunction in large part by eliciting the infiltration of immune-inhibitory cells, such as regulatory T cells and myeloid-derived suppressor cells, into the tumour microenvironment. Several possible mechanisms have been proposed to explain how these multiple tumour-infiltrating cell types block the development of an effective anti-tumour immune response, including inhibition of the activity of effector T cells and of antigen presenting cells via upregulation of suppressive factors such as checkpoint molecules. Targeting immune suppression using checkpoint inhibition has resulted in clinical responses in some patients with RCC and combinatorial approaches involving checkpoint blockade are now standard of care in patients with advanced RCC. However, a substantial proportion of patients do not benefit from checkpoint blockade. The identification of reliable biomarkers of response to checkpoint blockade is crucial to facilitate improvements in the clinical efficacy of these therapies. In addition, there is a need for the development of other immune-based strategies that address the shortcomings of checkpoint blockade, such as adoptive cell therapies.

Impact of concomitant acid suppressive therapy on pazopanib efficacy and dose reductions in patients with metastatic renal cell carcinoma

PURPOSE

The aim of this study was to investigate the impact of acid suppressive therapy on clinical efficacy and safety of pazopanib in patients with metastatic renal cell carcinoma (mRCC).

METHODS

A single-center retrospective study was carried out. Charts of mRCC patients who received pazopanib as first-line treatment were reviewed and concomitant use of proton pump inhibitors (PPI) and histamine 2 receptor antagonists (H2RA) was studied. Two groups of patients were identified, namely patients receiving PPI/H2RA and patients without acid suppressive therapy. Both groups were compared with regard to progression free survival (PFS), overall survival (OS), tumor response, and time to dose reduction of pazopanib.

RESULTS

Ninety-one patients were included. Median PFS was 8 months in the PPI/H2RA group vs. 7 months in the no PPI/H2RA group (hazard ratio (HR) 0.76 (95% confidence interval (CI) 0.42-1.35)), p = 0.35. Median OS was 27 months in the PPI/H2RA group vs. 23 months in the no PPI/H2RA group (HR 0.87 (95% CI 0.46-1.66)), p = 0.68. Mean tumor response was 17% (95% CI 8-25%) in the PPI/H2RA group vs. 11% (95% CI 0-21%) in the no PPI/H2RA group, p = 0.52. Median time to first dose reduction was 9 months in both subgroups (HR 1.25 (95% CI 0.65-2.39)), p = 0.51. Median time to second dose (< 600 mg) reduction was 17 months in the PPI/H2RA group vs. 7 months in the no PPI/H2RA group (HR 0.26 (95% CI 0.07-0.89)), p = 0.03.

CONCLUSION

In this limited patient series, no evidence of a negative impact of PPI/H2RA on clinical outcome and time to first dose reduction was observed. These results suggest that PPI/H2RA might be considered, when there is a clinical need, in patients treated with pazopanib for mRCC. However, a prospective study is warranted to confirm these results.

Anti-angiogenesis and Immunotherapy: Novel Paradigms to Envision Tailored Approaches in Renal Cell-Carcinoma

Although decision making strategy based on clinico-histopathological criteria is well established, renal cell carcinoma (RCC) represents a spectrum of biological ecosystems characterized by distinct genetic and molecular alterations, diverse clinical courses and potential specific therapeutic vulnerabilities. Given the plethora of drugs available, the subtype-tailored treatment to RCC subtype holds the potential to improve patient outcome, shrinking treatment-related morbidity and cost. The emerging knowledge of the molecular taxonomy of RCC is evolving, whilst the antiangiogenic and immunotherapy landscape maintains and reinforces their potential. Although several prognostic factors of survival in patients with RCC have been described, no reliable predictive biomarkers of treatment individual sensitivity or resistance have been identified. In this review, we summarize the available evidence able to prompt more precise and individualized patient selection in well-designed clinical trials, covering the unmet need of medical choices in the era of next-generation anti-angiogenesis and immunotherapy.

Bioinformatics profiling integrating a three immune-related long non-coding RNA signature as a prognostic model for clear cell renal cell carcinoma

Background

Renal cell carcinoma (RCC) is one of the most common aggressive malignant tumors in urogenital system, and the clear cell renal cell carcinoma (ccRCC) is the most common subtype of renal carcinoma. Immune related long non-coding RNAs (IRlncRs) plentiful in immune cells and immune microenvironment (IME) are potential in evaluating prognosis and assessing the effects of immunotherapy. A completed and meaningful IRlncRs analysis based on abundant ccRCC gene samples from The Cancer Genome Atlas (TCGA) will provide insight in this field.

Methods

Based on the TCGA dataset, we integrated the expression profiles of IRlncRs and overall survival (OS) in the 611 ccRCC patients. The immune score of each sample was calculated based on the expression level of immune-related genes and used to identify the most meaningful IRlncRs. Survival-related IRlncRs (sIRlncRs) was estimated by calculating the algorithm of difference and COX regression analysis in ccRCC patients. Based on the median immune-related risk score (IRRS) developed from the screened sIRlncRs, the high-risk and low-risk components were distinguished. Functional annotation was detected by gene set enrichment analysis (GSEA) and principal component analysis (PCA), and the immune composition and purity of the tumor was evaluated by microenvironment cell population records. The expression levels of three sIRlncRs were verified in various tissues and cell lines.

Results

A total of 39 IRlncRs were collected by Pearson correlation analyses among immune score and the lncRNA expression. A total of 7 sIRlncRs were significantly associated with the clinical outcomes of ccRCC patients. Three sIRlncRs (ATP1A1-AS1, IL10RB-DT and MELTF-AS1) with the most significant prognostic values were enrolled to build the IRRS model in which the OS of in the high-risk group was shorter than that in the low-risk group. The IRRS was identified as an independent prognosis factor and correlated with the OS. The high-risk group and low-risk group illustrated different distributions in PCA and different immune status in GSEA. Besides, we found the more significant expression in certain ccRCC cell lines and tumor tissues of ccRCC patients compared with the HK-2 and adjacent tissues respectively. Additionally, the expression levels of lncR-MELTF-AS1 and IL10RB-DT were remarkably enhanced along the more advanced T-stages, but the lncR-ATP1A1-AS1 showed the inverse gradient.

Conclusion

Our results demonstrate some sIRlncRs with remark clinical relevance show the latent monitoring and prognosis values for ccRCC patients and may provide new insight in immunological researches and treatment strategies of ccRCC patients.

Clinical Outcomes of First-line Sunitinib Followed by Immuno-oncology Checkpoint Inhibitors in Patients With Metastatic Renal Cell Carcinoma

BACKGROUND

The present retrospective, longitudinal cohort study assessed the association between the first-line sunitinib treatment duration and clinical outcomes with second-line immuno-oncology (IO) therapy among patients with metastatic renal cell carcinoma (mRCC).

PATIENTS AND METHODS

A total of 161 patients with mRCC who had been treated with first-line sunitinib and subsequent IO therapy from select International mRCC Database Consortium centers were included. The overall survival, time to next therapy, time to treatment discontinuation, and real-world physician-assessed best response measured from IO therapy initiation were analyzed and compared between patients treated with first-line sunitinib for ≥ 6 months and those treated for < 6 months.

RESULTS

The 116 patients treated with sunitinib for ≥ 6 months tended to be older and to have a better International mRCC Database Consortium risk than the 45 patients treated for < 6 months (favorable, 36% vs. 8%, P = .001; intermediate, 59% vs. 70%, P = .21; poor, 5% vs. 22%, P = .007). The receipt of sunitinib for ≥ 6 months versus < 6 months was associated with longer survival (hazard ratio [HR], 0.42; 95% confidence interval [CI], 0.21-0.87; P = .02). No significant association was observed between the first-line sunitinib duration and second-line IO outcomes, including the time to next therapy (HR, 0.89; 95% CI, 0.52-1.51; P = .66), time to treatment discontinuation (HR, 0.85; 95% CI, 0.54-1.34; P = .49), and tumor response (odds ratio, 0.73; 95% CI, 0.22-2.49; P = .62).

CONCLUSIONS

We found no statistically significant association between the first-line sunitinib duration and clinical outcomes with second-line IO therapy. Patients receiving first-line sunitinib for ≥ 6 months compared with < 6 months was associated with better overall survival, although potential unadjusted confounders could have been present. These findings support the paradigm that previous therapy will not dictate the effectiveness of subsequent immunotherapy.

Biomarkers of Prognosis and Efficacy of Anti-angiogenic Therapy in Metastatic Clear Cell Renal Cancer

In the last decades, the prognosis of metastatic renal cell carcinoma (mRCC) has remarkably improved following the advent of the "targeted therapy" era. The expanding knowledge on the prominent role played by angiogenesis in RCC pathogenesis has led to approval of multiple anti-angiogenic agents such as sunitinib, pazopanib, axitinib, cabozantinib, sorafenib, and bevacizumab. These agents can induce radiological responses and delay cancer progression for months or years before onset of resistance, with a clinically meaningful activity. The need for markers of prognosis and efficacy of anti-angiogenic agents has become more compelling as novel systemic immunotherapy agents have also been approved in RCC and can be administered as an alternative to angiogenesis inhibitors. Anti PD-1 monoclonal antibody nivolumab has been approved in the second-line setting after tyrosine kinase inhibitors failure, while combination of nivolumab plus anti CTLA-4 monoclonal antibody ipilimumab has been approved as first-line therapy of RCC patients at intermediate or poor prognosis. In this review article, biomarkers of prognosis and efficacy of antiangiogenic therapies are summarized with a focus on those that have the potential to affect treatment decision-making in RCC. Biomarkers predictive of toxicity of anti-angiogenic agents have also been discussed.

Adenosine 2A Receptor Blockade as an Immunotherapy for Treatment-Refractory Renal Cell Cancer

Adenosine mediates immunosuppression within the tumor microenvironment through triggering adenosine 2A receptors (A2AR) on immune cells. To determine whether this pathway could be targeted as an immunotherapy, we performed a phase I clinical trial with a small-molecule A2AR antagonist. We find that this molecule can safely block adenosine signaling in vivo. In a cohort of 68 patients with renal cell cancer (RCC), we also observe clinical responses alone and in combination with an anti-PD-L1 antibody, including subjects who had progressed on PD-1/PD-L1 inhibitors. Durable clinical benefit is associated with increased recruitment of CD8⁺ T cells into the tumor. Treatment can also broaden the circulating T-cell repertoire. Clinical responses are associated with an adenosine-regulated gene-expression signature in pretreatment tumor biopsies. A2AR signaling, therefore, represents a targetable immune checkpoint distinct from PD-1/PD-L1 that restricts antitumor immunity. SIGNIFICANCE: This first-in-human study of an A2AR antagonist for cancer treatment establishes the safety and feasibility of targeting this pathway by demonstrating antitumor activity with single-agent and anti-PD-L1 combination therapy in patients with refractory RCC. Responding patients possess an adenosine-regulated gene-expression signature in pretreatment tumor biopsies.See related commentary by Sitkovsky, p. 16.This article is highlighted in the In This Issue feature, p. 1.

YY1 Promotes Endothelial Cell-Dependent Tumor Angiogenesis in Hepatocellular Carcinoma by Transcriptionally Activating VEGFA

Hepatocellular carcinoma (HCC) is a typical hypervascular solid tumor that requires neoangiogenesis for growth. The vascular endothelial growth factor (VEGF) is the most potent proangiogenic factor in neovascularization. The multifunctional Yin-Yang 1 (YY1) is involved in the regulation of tumor malignancy of HCC. However, the relationship between YY1 and endothelial cell-dependent tumor angiogenesis in HCC remains unclear. In this study, we observed that YY1 is positively correlated with microvessel density (MVD) and poor prognosis in HCC tissues. We further found that YY1 promotes the transcriptional activity of VEGFA by binding its promoter in HCC. The secreted VEGFA from HCC cells activates phosphorylation of VEGFR2 to promotes tube formation, cell migration, and invasion of vascular endothelial cells in vitro, and promotes tumor growth and angiogenesis in vivo. In addition, upregulation of YY1 enhanced resistance of bevacizumab in HCC cells. These results indicate that YY1 plays essential roles in HCC angiogenesis and resistance of bevacizumab by inducing VEGFA transcription and that YY1 may represent a potential molecular target for antiangiogenic therapy during HCC progression.

The prognostic value of hypoxia-inducible factor-1α in advanced cancer survivors: a meta-analysis with trial sequential analysis

Background:

Expression of hypoxia-inducible factors (HIFs) has been observed, but their prognostic role in advanced cancers remains uncertain. We conducted a meta-analysis to establish the prognostic effect of HIFs and to better guide treatment planning for advanced cancers.

Methods:

Pooled hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated. Trial sequential analysis (TSA) was also performed. The clinical outcomes included overall survival (OS), disease-free survival (DFS), progression-free survival (PFS), cancer-specific survival (CSS), relapse/recurrence-free survival (RFS), and metastasis-free survival (MFS) in patients with advanced tumors according to multivariate analysis.

Results:

A total of 31 studies including 3453 cases who received chemotherapy, radiotherapy, or chemoradiotherapy were identified. Pooled analyses revealed that HIF-1α expression was correlated with worse OS (HR = 1.61, p < 0.001), DFS (HR = 1.61, p < 0.001), PFS (HR = 1.49, p = 0.01), CSS (HR = 1.65, p = 0.056), RFS (HR = 2.10, p = 0.015), or MFS (HR = 2.36, p = 0.002) in advanced cancers. HIF-1α expression was linked to shorter OS in the digestive tract, epithelial ovarian, breast, non-small cell lung, and clear cell renal cell carcinomas. Subgroup analysis by study region showed that HIF-1α expression was correlated with poor OS in Europeans and Asians, while an analysis by histologic subtypes found that HIF-1α expression was not associated with OS in squamous cell carcinoma. No relationship was found between HIF-2α expression and OS, DFS, PFS, or CSS.

Conclusions:

Targeting HIF-1α may be a useful therapeutic approach to improve survival for advanced cancer patients. Based on TSA, more randomized controlled trials are strongly suggested.

The evolving role of cytoreductive nephrectomy: incorporating genomics of metastatic renal cell carcinoma into treatment decisions

PURPOSE OF REVIEW

Recent publications evaluating cytoreductive nephrectomy in the era of targeted therapy emphasize the importance of patient selection. We reviewed the predictive role of genetic alterations in patients with metastatic renal cell carcinoma (mRCC) undergoing cytoreductive nephrectomy.

RECENT FINDINGS

Studies evaluating the association between genetic alterations and outcomes following systemic treatment for mRCC include mainly patients after cytoreductive nephrectomy. Expression of proangiogenic genes, single nucleotide polymorphisms involving genes of the vascular-endothelial growth factor (VEGF) pathway and somatic mutations of chromatin remodeling genes were associated with response to VEGF-targeted therapy. Outcomes following treatment with mammalian target of rapamycin (mTOR) inhibitors were initially associated with mTOR/TSC1/TSC2 mutations; however, subsequent studies did not validate these findings but rather found an association between loss of PTEN expression and PBRM1 mutations and improved outcomes. Loss of PBRM1 was initially linked to response to immunotherapy; however, larger studies question this association and showed high expression of T-effector gene signature predicted improved outcome. Primary tumors with low intratumor heterogeneity but elevated somatic copy-number alterations were associated with rapid progression at multiple sites.

SUMMARY

Genetic alterations may help select patients for cytoreductive nephrectomy and optimize timing of treatment. Intratumor heterogeneity and genetic discordance between primary and metastatic tumors may limit clinical applicability. Future studies should evaluate approaches to overcome these limitations.

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

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

PBRM1 Regulates Stress Response in Epithelial Cells

Polybromo1 (PBRM1) is a chromatin remodeler subunit highly mutated in cancer, particularly clear cell renal carcinoma. PBRM1 is a member of the SWI/SNF subcomplex, PBAF (PBRM1-Brg1/Brm-associated factors), and is characterized by six tandem bromodomains. Here we establish a role for PBRM1 in epithelial cell maintenance through the expression of genes involved in cell adhesion, metabolism, stress response, and apoptosis. In support of a general role for PBRM1 in stress response and apoptosis, we observe that loss of PBRM1 results in an increase in reactive oxygen species generation and a decrease in cellular viability under stress conditions. We find that loss of PBRM1 promotes cell growth under favorable conditions but is required for cell survival under conditions of cellular stress.

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PBRM1 facilitates the expression of stress response genes in epithelial cells

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Deletion of PBRM1 promotes growth under low-stress conditions

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PBRM1 restrains ROS generation and induces apoptosis under high-stress conditions

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Under H₂O₂ stress, PBRM1 cooperates with cJun and NRF2 to induce gene expression

Transcriptomic Profiling of the Tumor Microenvironment Reveals Distinct Subgroups of Clear Cell Renal Cell Cancer: Data from a Randomized Phase III Trial

Metastasis remains the main reason for renal cell carcinoma (RCC)-associated mortality. Tyrosine kinase inhibitors (TKI) impart clinical benefit for most patients with RCC, but the determinants of response are poorly understood. We report an integrated genomic and transcriptomic analysis of patients with metastatic clear cell RCC (ccRCC) treated with TKI therapy and identify predictors of response. Patients in the COMPARZ phase III trial received first-line sunitinib or pazopanib with comparable efficacy. RNA-based analyses revealed four distinct molecular subgroups associated with response and survival. Characterization of these subgroups identified mutation profiles, angiogenesis, and macrophage infiltration programs to be powerful predictors of outcome with TKI therapy. Notably, predictors differed by the type of TKI received. Our study emphasizes the clinical significance of angiogenesis and immune tumor microenvironment and suggests that the critical effects its various aspects have on TKI efficacy vary by agent. This has broad implications for optimizing precision treatment of RCC. SIGNIFICANCE: The determinants of response to TKI therapy in metastatic ccRCC remain unknown. Our study demonstrates that key angiogenic and immune profiles of the tumor microenvironment may affect TKI response. These findings have the potential to inform treatment personalization in patients with RCC.This article is highlighted in the In This Issue feature, p. 453.