Epidemiologic and socioeconomic burden of metastatic renal cell carcinoma (mRCC): a literature review

Cellular hyaluronan is associated with a poor prognosis in renal cell carcinoma

PURPOSE

Hyaluronan, a major glycosaminoglycan of the extracellular matrix, can act as an oncogenic component of the tumor microenvironment in many human malignancies. We characterized the hyaluronan content of renal cell carcinomas (RCCs) and investigated its correlations with clinicopathological parameters and patient survival.

PATIENTS AND METHODS

This retrospective study included data from 316 patients that had undergone surgery for RCC in Kuopio University Hospital in 2000 to 2013. The hyaluronan content of surgical tumor samples were histochemically stained with a biotinylated hyaluronan-specific affinity probe. The amount of tumor infiltrating lymphocytes was evaluated in each tumor. Kaplan-Meier and univariate and multivariate Cox-regression analyses were performed to estimate the impact of hyaluronan content on overall survival, disease-specific survival, and metastasis-free survival.

RESULTS

Detectable cellular hyaluronan was associated with higher tumor grades and the presence of tumor infiltrating lymphocytes. Cellular hyaluronan identified a prognostically unfavourable subgroup among low-grade carcinomas. Multivariate analyses showed that measurable cellular hyaluronan was an independent negative prognostic factor for overall survival (hazard ratio [HR] 1.4; 95% confidence interval [CI]: 1.02-2.0; P = 0.039), Disease-specific survival (HR 2.07; 95% CI: 1.2-3.3; P = 0.002), and metastasis-free survival (HR 2.45; 95% CI: 1.37-4.4; P = 0.003).

CONCLUSIONS

Cellular hyaluronan was significantly associated with unfavourable features and a poor prognosis in RCC. Further studies are needed to investigate the biological mechanism underlying hyaluronan accumulation in RCC.

Tumor-infiltrating CD39+CD8+ T cells determine poor prognosis and immune evasion in clear cell renal cell carcinoma patients

PURPOSE

Tumor microenvironment is important in the progression of clear cell renal cell carcinoma (ccRCC), and its prognostic value is still unclear. Recent reports demonstrated tumor-infiltrating CD39⁺CD8⁺ T cells are abundant, but their function remains obscure. We aim to assess clinical value of CD39⁺CD8⁺ T cells and seek a potential therapeutic target in ccRCC.

EXPERIMENTAL DESIGN

We immunohistochemically evaluated clinical value of CD39⁺CD8⁺ T cells in a retrospective Zhongshan Hospital cohort of 243 ccRCC patients. Fresh tumor samples (n = 48), non-tumor tissues and peripheral blood for flow cytometry analyses were collected to analyze immune cell functions from Zhongshan Hospital. The survival benefit of tyrosine kinase inhibitors (TKIs) in this subpopulation was evaluated. Kaplan-Meier analysis and COX regression model were applied for survival analyses. Bioinformatics analysis performed in TCGA KIRC cohort and the scRNA-seq cohort.

RESULTS

We found that accumulation of CD39⁺CD8⁺ T cells indicated poor prognosis (p < 0.0001) and indicated therapeutic benefit of TKIs therapy (p = 0.015). CD39⁺CD8⁺ T cells showed decreased TNF-α and IFN-γ with elevated PD-1 and TIM-3 expression. Further analysis of tumor-infiltrating immune cell landscape in the ccRCC revealed the positive correlation between CD39⁺CD8⁺ T cells and Tregs (p = 0.037) and M2-polarized macrophages (p < 0.0001). Finally, inhibition of CD39 partially restores the anti-tumor function of CD8⁺ T cells.

CONCLUSIONS

High CD39⁺CD8⁺ T cells indicated poor prognosis in ccRCC, due to impaired anti-tumor function of CD39⁺CD8⁺ T cells and indicated therapeutic benefit of TKIs therapy.

ETV4 is a theranostic target in clear cell renal cell carcinoma that promotes metastasis by activating the pro-metastatic gene FOSL1 in a PI3K-AKT dependent manner

Distant metastasis is the major cause of short survival in ccRCC patients. However, the development of effective therapies for metastatic ccRCC is limited. Herein, we reported that ETV4 was selected from among 150 relevant genes with in vivo evidence of promoting metastasis. In this study, we identified that ETV4 promoted ccRCC cell migration and metastasis in vitro and in vivo, and a positive correlation between ETV4 and FOSL1 expression was found in ccRCC tissues and cell lines. Further investigation suggested that ETV4 increase FOSL1 expression through direct binding with the FOSL1 promoter. Furthermore, ETV4/FOSL1 was proved as a novel upstream and downstream causal relationship in ccRCC in an AKT dependent manner. In addition, both ETV4 and FOSL1 serve as an independent, unfavorable ccRCC prognostic indicator, and the accumulation of the ETV4 and FOSL1 in ccRCC patients result in a worse survival outcome in ccRCC patients. Taken together, our results suggest that the ETV4/FOSL1 axis acts as a prognostic biomarker and ETV4 directly up-regulates FOSL1 by binding with its promoter in a PI3K-AKT dependent manner, leading to metastasis and disease progression of ccRCC.

G6PD facilitates clear cell renal cell carcinoma invasion by enhancing MMP2 expression through ROS‑MAPK axis pathway

Glucose-6-phosphate dehydrogenase (G6PD) is crucial rate-limiting enzyme of the pentose phosphate pathway (PPP). G6PD dysregulation has been reported in various types of human cancer, and the role of G6PD in cancer progression was demonstrated in numerous studies. A previous study from our laboratory described the prognostic significance of G6PD in clear cell renal cell carcinoma (ccRCC), and demonstrated its proliferative role through positive feedback regulation of the phosphorylated form of signal transducer and activator of transcription 3. However, the role of G6PD in ccRCC invasion remains unclear. In the present study, reverse transcription-quantitative (RT-q) PCR, western blotting, enzyme activity assay, transwell assay and immunohistochemistry analysis in cell model, xenograft mice model and human specimen studies were performed to evaluate the role of G6PD in ccRCC invasion. The results from the present study demonstrated that G6PD may promote ccRCC cell invasive ability by increasing matrix metalloproteinase 2 (MMP2) mRNA and protein expression both in vitro and in vivo. In addition, a positive correlation between G6PD and MMP2 expression was demonstrated by RT-qPCR and western blotting in twenty pairs of ccRCC tumor specimens and matched adjacent normal tissues. Furthermore, G6PD promoted reactive oxygen species (ROS) generation and activated the MAPK signaling pathway in ccRCC cells. In addition, ROS significantly promoted the MAPK signaling pathway activation, which in turn contributed to MMP2 overexpression in ccRCC cells. In conclusion, the present study demonstrated that G6PD may facilitate ccRCC cell invasive ability by enhancing MMP2 expression through ROS-MAPK axis pathway.

A historical turning point for the treatment of advanced renal cell carcinoma: inhibition of immune checkpoint

Background: Renal cell carcinoma (RCC) is the most common type of renal malignancy with 87% frequency. As a global health problem, kidney cancer is responsible for 2.2% of new cancer cases. One of the highly effective mechanisms that renal cancer cells avoid in the immune system is PD-1 and PD-L1 interaction.Scope: Literature search is made from PubMed, Medline, and ASCO and ESMO Annual Meeting abstracts using the following search keywords: "nivolumab," "pembrolizumab," "atezolizumab," "avelumab," "durvalumab," and "renal cell cancer." The last search was on November 1, 2019.Findings: The combination of nivolumab and ipilimumab have better survival results than sunitinib for intermediate and poor risk patients but not for favorable risk groups. In 2019, two combination regimens with pembrolizumab plus axitinib and avelumab plus axitinib demonstrated efficacy over sunitinib for every risk group. The overall survival data of these trials are still immature.Conclusions: Advanced RCC has high morbidity and mortality with an increasing prevalence. Following tyrosine kinase inhibitors, checkpoint inhibitors have a great influence on treatment of advanced RCC, especially the combination of these two strategies. In 2019 these combined strategies demonstrated 5% complete remission with up to 60% objective response rate. While not immediately, but perhaps in the near future, advanced RCC will become a manageable chronic disease, even if a cure is not possible.

PCK1 Regulates Glycolysis and Tumor Progression in Clear Cell Renal Cell Carcinoma Through LDHA

Background

Suppressed gluconeogenesis and increased glycolysis are common in clear cell renal cell carcinoma (ccRCC). Phosphoenolpyruvate carboxykinase 1 (PCK1) is a rate-limiting gluconeogenesis enzyme. However, the role of PCK1 in tumor metabolism and progression remains unclear.

Methods

Artificial modulation of PCK1 (down- and upregulation) in two ccRCC cell lines was performed to explore the role of PCK1 in the glycolytic phenotype and in tumor growth and metastasis in vitro and in vivo. Sixty-two patients with ccRCC underwent ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography. The levels of PCK1 and lactate dehydrogenase A (LDHA) in ccRCC tissues and peritumor tissues were investigated with immunohistochemistry. The relationships between ¹⁸F-FDG accumulation and the expression of PCK1 and LDHA were analyzed. The mechanisms underlying the regulation of LDHA by PCK1 were analyzed using in vitro molecular techniques.

Results

PCK1 suppressed ccRCC cell growth and metastasis in vitro and inhibited tumorigenesis in nude mice by blocking the aerobic glycolysis pathway. Clinically, low levels of PCK1 expression were associated with poor prognosis in patients with ccRCC. The expression level of PCK1 was negatively correlated with tumor progression, the LDHA expression level and ¹⁸F-FDG accumulation in primary ccRCC tissue. We also demonstrated that PCK1 reduces the stability of LDHA through posttranslational regulation. Finally, we showed that the effects of PCK1 on glucose metabolism, cell proliferation and metastasis are mediated via the inhibition of LDHA.

Conclusion

Our study identified a novel molecular mechanism underlying the Warburg effect. PCK1 may serve as a candidate prognostic biomarker, and targeting the PCK1/LDHA pathway might be a new strategy to selectively inhibit tumor metabolism in human ccRCC.

A 2/1 Sunitinib Dosing Schedule Provides Superior Antitumor Effectiveness and Less Toxicity Than a 4/2 Schedule for Metastatic Renal Cell Carcinoma: A Systematic Review and Meta-Analysis

Background: The standard sunitinib schedule to treat metastatic renal cell carcinoma (mRCC) is 4 weeks on/2 weeks off (4/2). However, some studies revealed intolerable adverse events (AEs) in patients on this schedule. An alternative schedule, 2 weeks on/1 week off (2/1), may overcome this issue. This meta-analysis was performed to compare the effectiveness and toxicity between the 2/1 and 4/2 sunitinib dosing schedules.

Methods: We acquired relevant studies by searching PubMed, ScienceDirect, the Cochrane Library, Scopus, Ovid MEDLINE, Embase, Web of Science, and Google Scholar. Our main endpoints included overall survival (OS), progression-free survival (PFS), objective response rate (ORR), disease control rate (DCR), and AEs.

Results: We identified 9 medium- and high-quality studies. Both schedules were effective for mRCC, with comparable OS and similar ORR. However, the 2/1 schedule had better PFS (hazard ratio (HR) = 0.81, 95% confidence interval [CI]: 0.66–0.99, P = 0.04), higher DCR [risk rate (RR) = 1.22, 95% CI: 1.01–1.47, P = 0.04] and fewer dosage interruptions (RR = 0.60, 95% CI: 0.43–0.84, P = 0.003). Additionally, the 2/1 schedule elicited fewer specific severe AEs, including thrombocytopenia/platelet disorder, hand-foot syndrome, hypertension, and fatigue. In our subanalysis, PFS was better among East Asians using the 2/1 schedule than among other populations (HR= 0.75, 95% CI: 0.58–0.98, P = 0.03), and patients administered an initial dosage of 50 mg/d on the 2/1 schedule had superior PFS (HR = 0.76, 95% CI: 0.59–0.97, P = 0.03) than those others.

Conclusions: These findings suggest that the 2/1 schedule is more suitable for mRCC than 4/2, due to superior PFS, better DCR and fewer AEs. Nevertheless, more large-scale studies with good quality are needed.

TNFAIP8 promotes the migration of clear cell renal cell carcinoma by regulating the EMT

Background: Clear cell renal cell carcinoma (ccRCC) is characterized by high metastatic potential, and the epithelial-mesenchymal transition (EMT) has been shown to play a key role in multiple cancer progression, migration and metastasis and is the leading cause of poor prognosis. Currently, tumor necrosis factor-α-induced protein 8 (TNFAIP8/TIPE) is a newly discovered tumorigenesis factor, and TNFAIP8 and the EMT influence the migration of renal cancer cells.

Methods: In this study, we first analyzed the relationship between TNFAIP8 and ccRCC using bioinformatics, followed by immunohistochemistry to evaluate the relationship between the two in clinical samples. Subsequently, reverse transcription PCR and western blotting confirmed the expression of TNFAIP8 in ccRCC cells. Furthermore, we measured the migration and invasion abilities by using wound healing and transwell assays after overexpression or knockdown of TNFAIP8 in cells. In addition, we verified whether TNFAIP8 affects the EMT process in ccRCC by quantitative real-time PCR, western blotting, immunohistochemistry and immunofluorescence experiments.

Results: Through database analysis, we found that TNFAIP8 was highly expressed in ccRCC patients and was positively correlated with tumor stage and grade, indicating that TNFAIP8 is associated with the development of advanced ccRCC and poor prognosis. We subsequently confirmed that TNFAIP8 was abnormally overexpressed in clinical samples and ccRCC cell lines and that TNFAIP8 promoted ccRCC cell migration and invasion in vitro. Finally, we found that TNFAIP8 regulated EMT-related molecule expression and regulated the EMT process.

Conclusion: High expression of TNFAIP8 reinforces migration and regulates the EMT in ccRCC, conferring the metastatic potential of ccRCC and suggesting that TNFAIP8 may be a potential therapeutic target for the treatment of advanced ccRCC.

Metastatic renal cell carcinoma to the pancreas and subcutaneous tissue 10 years after radical nephrectomy: a case report

Background

Synchronous renal cell carcinoma metastasizing to the pancreas and subcutaneous tissue is very rare. Unusual metastatic sites require attention during follow-up of renal cell carcinoma. It is extremely rare for renal cell carcinoma to metastasize to the pancreas; it is also very rare for it to metastasize to the subcutaneous tissue and extremely rare for it to synchronously metastasize to the pancreas and subcutaneous tissue almost a decade after radical nephrectomy. It is well known that most pancreatic tumors are primary pancreatic adenocarcinoma. However, the pancreas can also be an uncommon site for metastasis. We present a rare case of synchronous metastasis of renal cell carcinoma to the pancreas and subcutaneous tissue; we believe it to be only the second such case reported to date.

Case presentation

We describe a case of a 74-year-old Chinese man who was diagnosed with metastatic renal cell carcinoma to the pancreas and subcutaneous tissue at the same time, 10 years after left radical nephrectomy. He received distal pancreatectomy with spleen preservation plus resection of the subcutaneous tissue lesions on the left side of the anterior abdominal wall and right waist. Pathology showed that all resected metastatic tumors were of the clear cell type. The patient was seen in regular follow-up afterward.

Conclusion

Synchronous metastatic renal cell carcinoma to the pancreas and subcutaneous tissue is very rare, and it might occur after primary tumor resection. Patients must undergo lifelong monitoring and follow-up with regular examination so that any possible metastasis can be detected early. The optimal resection strategy should involve adequate resection margins and maximal tissue preservation of the pancreas, because renal cell carcinoma metastasizing to the pancreas and subcutaneous tissue has a good prognosis with long-term survival.

The adjuvant treatment of kidney cancer: a multidisciplinary outlook

Approximately 70% of cases of kidney cancer are localized or locally advanced at diagnosis. Among patients who undergo surgery for these cancers, 30-35% will eventually develop potentially fatal metachronous distant metastases. Effective adjuvant treatments are urgently needed to reduce the risk of recurrence of kidney cancer and of dying of metastatic disease. To date, almost all of the tested adjuvant agents have failed to demonstrate any benefit. Only two trials of an autologous renal tumour cell vaccine and of the vascular endothelial growth factor receptor (VEGFR) tyrosine kinase inhibitor sunitinib have shown positive results, but these have been criticized for methodological reasons and conflicting data, respectively. The results of two additional trials of targeted agents as adjuvant therapies have not yet been published. Novel immune checkpoint inhibitors are promising approaches to adjuvant therapy in kidney cancer, and a number of trials are now underway. An important component of the management of patients with kidney cancer, particularly those who undergo radical resection for localized renal cell carcinoma, is the preservation of kidney function to reduce morbidity and mortality. The optimal management of these patients therefore requires a multidisciplinary approach involving nephrologists, oncologists, urologists and pathologists.

Different immunological effects of the molecular targeted agents sunitinib, everolimus and temsirolimus in patients with renal cell carcinoma

Treatment with molecular targeted agents together with immune checkpoint inhibitors will most likely improve the efficacy of current cancer immunotherapy. Because molecular targeted agents not only directly affect cancer cells, but also influence immune cells and modulate the tumor microenvironment, a better understanding of the overall immunological effects of these drugs will contribute to the rational design of combination therapies. Therefore, this study performed extensive immune monitoring of patients' peripheral blood mononuclear cells (PBMCs) to investigate the immunological effects of the molecular targeted agents sunitinib, everolimus and temsirolimus, which have been widely used for the treatment of renal cell carcinoma (RCC). Immunophenotyping and functional analysis of PBMCs revealed that these molecular targeted agents exerted different immunological effects on patients with RCC. Sunitinib decreased the percentage of early‑stage myeloid‑derived suppressor cells (eMDSCs) and increased natural killer cells, but did not affect the phenotypes and effector functions of CD4+ or CD8+ T cells. Everolimus decreased effector regulatory T cells, but also decreased IL‑2‑producing CD4+ T cells and increased dysfunctional CD8+ T cells. Conversely, temsirolimus decreased programmed cell death protein 1+CD8+ T cells and eMDSCs, but increased interferon‑γ and tumor necrosis factor‑α double producers at the same time as decreasing dysfunctional CD8+ T cells, albeit not significantly. In conclusion, although everolimus and temsirolimus are mTOR inhibitors, their effects on overall T‑cell functions are very different. Therefore, although it may increase the risk of immune‑related toxicity, temsirolimus is expected to offer the best outcome when combined with other immunomodulators for the development of cancer immunotherapy.

Understanding the adverse event experience in the S-TRAC adjuvant trial of sunitinib for high-risk renal cell carcinoma

Until recently, the sole treatment for patients with nonmetastatic renal cell carcinoma (RCC) was nephrectomy followed by observation. As metastatic RCC (mRCC) remains largely incurable (5-year survival rate ∼12%), adjuvant treatment, with potential to prevent/delay disease recurrence, is needed. In November 2017, sunitinib was approved in the USA as the first adjuvant therapy for patients at high risk for recurrent RCC postnephrectomy based on results from the S-TRAC trial. Patients eligible for adjuvant treatment have no evidence of disease and may be less willing to tolerate side effects. Therefore, proactive adverse event management is critical for keeping patients on adjuvant treatment and requires understanding the subtle differences in the adverse event profile of sunitinib in the adjuvant versus metastatic RCC setting.

Interleukin-2 chronotherapy for metastatic renal cell carcinoma: Results of a phase I-II study

BACKGROUND

Interleukin-2 (IL-2) was the cornerstone treatment for metastatic renal cell carcinoma (RCC) until the advent of tyrosine kinase inhibitors, but it still has therapeutic value. As a single bolus of IL-2 causes toxicity, there is interest in administration regimens with better tolerability and efficacy. Chronotherapy is the administration of therapy according to the circadian rhythm's influence on the immune and hormonal systems. This phase I-II trial evaluated the safety of IL-2 chronotherapy in metastatic RCC patients and determined the maximum tolerated dose. The secondary objective was to identify prognostic factors for survival.

METHODS

Three chronomodulation schedules (5:00-13:00, 13:00-21:00, and 21:00-5:00) were tested. Each schedule was an 8-h IL-2 infusion, with a Gaussian distribution of drug concentration peaking at 4 h. To identify the maximum tolerated dose, the dose for different patients was escalated from 2 MIU/m² (level I) to 18.6 MIU/m² (level VI).

RESULTS

Thirty patients were enrolled and completed treatment. Two patients were treated at 5:00-13:00, 15 at 13:00-21:00, and 13 at 21:00-5:00. Nine cases of grade 3 toxicity occurred in 7 patients at the highest dose (18.6 MIU/m²); no grade 4 toxicity occurred. The maximum tolerated dose was 14.0 MUI/m². Patients were followed for a median of 16 months (range, 2-107). One patient was lost to follow-up, 3 patients were alive at last contact, and 26 patients died. Six patients achieved long-term survival (≥48 months). There was one complete response, four partial responses, 11 cases of stable disease and 14 of progressive disease. The response rate was 16% (5/30) and disease-control rate was 53% (16/30). Median progression-free survival was 4.5 months, and median overall survival was 14.5 months. Kaplan-Meier analyses revealed significant associations between overall survival and ECOG performance score (0 vs. 1-2), MSKCC score (0-2 vs. ≥ 3), IMDC risk score (0-2 vs. ≥ 3), IL-2 dose level (IV-VI vs. I-III), and prolactin (increase vs. no increase), and but not for chronotherapy schedule.

CONCLUSION

IL-2 chronotherapy appears to be safe, moderately toxic and active in metastatic RCC. It may represent a new modality of IL-2 administration for these patients.

FOXM1-Activated LINC01094 Promotes Clear Cell Renal Cell Carcinoma Development via MicroRNA 224-5p/CHSY1

Clear cell renal cell carcinoma (ccRCC) is regarded as the most aggressive subtype of RCC, with high rates of metastasis and recurrence. An extensive body of studies had proved long noncoding RNAs (lncRNAs) play pivotal parts in the development and evolution of diverse malignant tumors. However, the potential of LINC01094 in ccRCC tumorigenesis is still unexplored. In the present research, with the aid of the TCGA database, we found that LINC01094 was highly expressed in ccRCC tissues. Upregulation of LINC01094 was also confirmed in ccRCC cell lines, and functional experiments delineated that LINC01094 knockdown led to inhibition on ccRCC cell growth and metastasis. Moreover, LINC01094 was activated by FOXM1 at the transcriptional level. Further assay demonstrated that LINC01094 worked as a sponge of microRNA 224-5p (miR-224-5p) and CHSY1 was a miR-224-5p-targeted mRNA. Further, we verified that LINC01094 acted as a competing endogenous RNA in ccRCC to regulate CHSY1 expression via competitively bind to miR-224-5p. Lastly, our results expounded that LINC01094 exerted its tumor-promoting performance in ccRCC development through miR-224-5p/CHSY1 regulatory axis, which shed light on the molecular mechanism underlying LINC01094 in ccRCC and opened a new prospective for the treatment of ccRCC.

Circular RNA circ-EGLN3 promotes renal cell carcinoma proliferation and aggressiveness via miR-1299-mediated IRF7 activation

Renal cell carcinoma (RCC) is a highly lethal cancer with increasing incidence worldwide. The purpose of the present study was to investigate the functions and molecular mechanisms of circular RNA (circRNA), circ-EGLN3, in RCC progression. The expression levels of circ-EGLN3 were assessed by a quantitative real-time polymerase chain reaction. Kaplan-Meier analysis was applied to uncover the prognostic role of circ-EGLN3 in patients with RCC. Cell viability was analyzed using cell counting kit-8 and cell apoptosis was assessed using flow cytometric experiment. Cell migratory and invasive abilities were determined by wound scratch and transwell experiments. Subcellular distribution detection was utilized to investigate the location of circ-EGLN3. Dual-luciferase reporter test was utilized for identifying the molecular mechanism of circ-EGLN3. The results indicated that circ-EGLN3 was elevated in RCC tissues and cell lines and predicted unfavorable prognosis for the patients with RCC. Silenced circ-EGLN3 hindered cell proliferation, migration, and invasion but facilitated apoptosis of RCC cells. Ectopic expressed circ-EGLN3 induced the opposite effects mentioned above. Mechanistically, circ-EGLN3 was mainly located at the cytoplasm. Circ-EGLN3 acted as a competing endogenous RNA (ceRNA) to enhance the IRF7 level via sponging miR-1299. Moreover, circ-EGLN3 mediated elevation of IRF7 is responsible for RCC cell proliferation and aggressiveness. Collectively, our study suggested that circ-EGLN3 knockdown suppressed RCC progression through acting as a ceRNA to regulate the IRF7 expression by targeting miR-1299. Circ-EGLN3 might be a potential therapeutic target for RCC management.

Molecular biology and targeted therapy in metastatic renal cell carcinoma

The treatment of metastatic renal cell carcinoma is challenging as it has proven to be relatively resistant to conventional oncological treatments. An improved understanding of the molecular biology of renal cell carcinoma has led to the development of a number of targeted therapies in metastatic renal cell carcinoma. This includes vascular endothelial growth factor inhibitors, tyrosine kinase inhibitors, mammalian target of rapamycin inhibitors and most recently immune checkpoint inhibitors. This article will review the mechanisms of development and progression of renal cell carcinoma as well as the mechanisms of current approved treatments in metastatic disease.

Level of evidence: Not applicable for this multicentre audit.

Real-World Effectiveness and Tolerability of Pazopanib as First Targeted Therapy in Metastatic Renal Cell Carcinoma: A Retrospective Chart Review in Latin America

INTRODUCTION

Pazopanib is approved in Latin America as first targeted therapy for patients with metastatic renal cell carcinoma (mRCC).

METHODS

A retrospective chart review of adult patients with mRCC who initiated pazopanib as first targeted therapy between January 2011 and March 2016 was conducted among oncology care centers in Argentina, Brazil, Chile, Colombia, and Mexico. Patient characteristics, treatment patterns, overall survival (OS), progression-free survival (PFS), and adverse events were summarized.

RESULTS

A total of 156 charts of patients with mRCC receiving first-line pazopanib were reviewed (29, 54, 27, 28, and 18 patients from Argentina, Brazil, Chile, Colombia, and Mexico, respectively). The mean age at initial mRCC diagnosis was 61.6 years, 73.7% were male, and 51.3% were Hispanic. The median dose of pazopanib was 800 mg and the median time from initial mRCC diagnosis to pazopanib start was 2.2 months. The median time on treatment was 10.0 months. At the time of data extraction, 16.7% of patients remained on pazopanib, with clinical progression listed as the main reason for discontinuation. Subsequent therapy was received by 25.6% of patients; the most common were everolimus (9.6%) and axitinib (5.8%). Overall, median PFS and OS were 10.8 and 16.9 months, respectively, and varied across countries. The most common all-grade adverse events were diarrhea (44.9%), asthenia/fatigue (43.6%), and nausea (28.8%).

CONCLUSIONS

Pazopanib was used for first-line mRCC treatment in a clinically diverse patient population across Latin America. Real-world PFS and tolerability were similar to clinical studies of pazopanib.

FUNDING

Novartis Pharmaceuticals Corporation, Inc.

CARD10 promotes the progression of renal cell carcinoma by regulating the NF‑κB signaling pathway

Previous studies have demonstrated that the expression of CARD10 is closely associated with the occurrence of tumors, and its role is mainly to promote tumor progression by activating the transcription factor NF-κB. However, the signaling pathway in renal cancer remains unclear. The objective of the present study was to investigate the ability of caspase recruitment domain 10 (CARD10) to regulate the NF-κB signaling pathway and promote the progression of renal cell carcinoma (RCC). Expression of CARD10 in ACHN, 786-O and HK-2 cells was evaluated via western blot analysis, as was the epidermal growth factor (EGF)-induced activation of NF-κB signaling pathway-related proteins in cells. The expression of CARD10 was inhibited by CARD10 short hairpin RNA transfection. Cell cycle analysis and MTT assays were used to evaluate cell proliferation. Cell apoptosis was analyzed via flow cytometry. The invasion of renal cell lines was detected via Transwell cell migration and invasion assays in vitro. The results showed that CARD10 expression was significantly higher in RCC cells than in normal renal tubular epithelial cells. CARD10 silencing inhibited the proliferation, invasion and migration of RCC cells. EGF stimulation upregulated the activation of the NF-κB pathway in RCC cells. Inhibition of CARD10 expression inhibited NF-κB activation in RCC cells. Taken together, these data suggested that CARD10 promotes the progression of renal cell carcinoma by regulating the NF-κB signaling pathway. Thus, this indicated that CARD10 may be a novel therapeutic target in RCC.

Characterization of the expression of LAT1 as a prognostic indicator and a therapeutic target in renal cell carcinoma

Large neutral amino acid transporter 1 (LAT1, SLC7A5) is abundantly expressed in various types of cancer, and it has been thought to assist cancer progression through its activity for uptake of neutral amino acids. However, the roles of LAT1 in renal cell carcinoma (RCC) prognosis and treatment remain uncharacterized. Therefore, we first retrospectively examined the LAT1 expression profile and its associations with clinical factors in RCC tissues (n = 92). The results of immunohistochemistry showed that most of the tissues examined (92%) had cancer-associated LAT1 expression. Furthermore, the overall survival (OS) and progression-free survival (PFS) were shorter in patients with high LAT1 expression levels than in those with low LAT1 expression levels (P = 0.018 and 0.014, respectively), and these associations were further strengthened by the results of univariate and multivariate analyses. Next, we tested the effects of JPH203, which is a selective LAT1 inhibitor, on RCC-derived Caki-1 and ACHN cells. It was found that JPH203 inhibited the growth of these cell types in a dose-dependent manner. Moreover, JPH203 clearly suppressed their migration and invasion activities. Thus, our results show that LAT1 has a great potential to become not only a prognosis biomarker but also a therapeutic target in RCC clinical settings.

A Phase 4 Study of Everolimus to Evaluate Efficacy and Safety in Patients with Metastatic Renal-Cell Carcinoma after Failure of First-Line Sunitinib or Pazopanib (SUNPAZ)

INTRODUCTION

Sunitinib and pazopanib are both standard first-line therapies for clear-cell metastatic renal-cell carcinoma (mRCC). Everolimus is a well-established second-line treatment.

OBJECTIVE

To estimate the efficacy and safety of second-line everolimus following pazopanib or sunitinib.

METHODS

SUNPAZ was an open-label, phase 4 clinical trial of everolimus in patients with clear-cell mRCC progressing after first-line sunitinib or pazopanib. The primary end point was the number of patients without progression 6 months after starting everolimus. Secondary end points included progression-free survival (PFS), overall survival (OS), and overall response rate. Enrollment was terminated early due to slow recruitment; all analyses are descriptive.

RESULTS

Patients who received prior sunitinib (n = 16) or pazopanib (n = 13) were enrolled. One of 12 patients in the sunitinib group and 6/13 patients in the pazopanib group were progression-free by month 6 in the full analysis set. Median PFS in the sunitinib and pazopanib groups was 2.8 and 8.0 months, and median OS was 14.8 months and 20.4 months, respectively. Fifteen patients in the sunitinib group and 13 in the pazopanib group experienced adverse events.

CONCLUSIONS

Safety and efficacy results confirm the second-line everolimus profile. However, baseline differences in patient populations should be taken into consideration.

Contralateral Testicular Metastasis of Renal Cell Carcinoma: A Case Report

Testicular metastasis of renal cell carcinoma (RCC) is a very rare condition in the literature. In this case report, a 56-year-old man with RCC in the right kidney and metastasis of RCC to the left testicle detected 12 months after nephrectomy was assessed and discussed in the context of literature information.

Immunotherapy for metastatic renal cell carcinoma: A systematic review

BACKGROUND

Various approaches have been developed for the treatment of metastatic renal cell carcinoma (MRCC). The objective was to assess the efficacy of immunotherapeutic approaches.

METHODS

We included participants diagnosed with all types of histologically confirmed MRCC, the test intervention was immunotherapy alone or combined with other immunotherapy or targeted therapies, and the study design was restricted to randomized controlled trials (RCTs). Primary outcomes were overall survival, adverse events, and health-related quality of life. We conducted the last search in March 31, 2018.

RESULTS

We included nine RCTs, and we established seven different treatment comparisons according to the type of data. Two RCTs favored nivolumab as monotherapy or combined with ipilimumab on account of all primary outcomes. The efficacy data of all other comparisons were either indifferent or favored the control group.

CONCLUSION

The immune checkpoint inhibitors nivolumab as monotherapy or combined with ipilimumab appears to be the only new immunotherapy that may improve overall survival in participants with metastatic renal cell carcinoma. Interferon-α alone is unfavorable to targeted therapies with respect to overall survival and adverse events.

LC-MS based metabolomic profiling for renal cell carcinoma histologic subtypes

Renal cell carcinomas (RCC) are classified according to their histological features. Accurate classification of RCC and comprehensive understanding of their metabolic dysregulation are of critical importance. Here we investigate the use of metabolomic analyses to classify the main RCC subtypes and to describe the metabolic variation for each subtype. To this end, we performed metabolomic profiling of 65 RCC frozen samples (40 clear cell, 14 papillary and 11 chromophobe) using liquid chromatography-mass spectrometry. OPLS-DA multivariate analysis based on metabolomic data showed clear discrimination of all three main subtypes of RCC (R² = 75.0%, Q² = 59.7%). The prognostic performance was evaluated using an independent cohort and showed an AUROC of 0.924, 0.991 and 1 for clear cell, papillary and chromophobe RCC, respectively. Further pathway analysis using the 21 top metabolites showed significant differences in amino acid and fatty acid metabolism between three RCC subtypes. In conclusion, this study shows that metabolomic profiling could serve as a tool that is complementary to histology for RCC subtype classification. An overview of metabolic dysregulation in RCC subtypes was established giving new insights into the understanding of their clinical behaviour and for the development of targeted therapeutic strategies.

Individualized immune-related gene signature predicts immune status and oncologic outcomes in clear cell renal cell carcinoma patients

OBJECTIVE

To develop an individualized immune-related gene signature that predicts oncologic outcomes and immune status of clear cell renal cell carcinoma (ccRCC).

MATERIALS AND METHODS

The immune-related gene pair (IGP) index was constructed and validated based on pairwise comparison in 634 ccRCC patients. Association with overall survival (OS), progression-free interval (PFI), and disease-specific survival (DSS) was evaluated by Kaplan-Meier analysis, univariate and multivariate cox regression survival analysis. Prognostic values of different risk models were compared using Harrell's C-index.

RESULTS

The IGP index of 17 gene pairs was an adverse independent risk factor in multivariate analyses for OS (hazard ratio [HR], 1.718; P = 0.001), PFI (HR, 1.550; P = 0.006), and DSS (HR, 2.201; P = 0.001) in ccRCC patients. It showed comparable prognostic accuracy with ccA/ccB signature (C-index for OS, 0.657 vs. 0.640; P = 0.686) and better intratumor homogeneity. Immunosuppressive immune cell, markers, and pathways were all enriched in high immune-risk tumors. The integrated immune-clinical prognostic score outperformed ccA/ccB signature and University of California Integrated Staging System risk model in terms of C-index for estimation of OS, PFI, and DSS (P < 0.001).

CONCLUSIONS

The proposed IGP index is a robust and promising biomarker for estimating oncologic outcomes in ccRCC. High immune-risk tumors are immunosuppressive.

Overexpression of steroid sulfotransferase genes is associated with worsened prognosis and with immune exclusion in clear cell-renal cell carcinoma

Aim: Steroid sulfotransferase (SULT) plays physiological roles but its role in clear cell-renal cell carcinoma (ccRCC) remains unclear. We therefore investigated genetic alteration of steroid SULT genes in ccRCC.

Results: Overexpression of any of SULT genes occurred in ~8% of ccRCC patients. Overexpression of steroid SULT genes was associated with worsened prognosis. Steroid SULT gene-upregulated ccRCC cases showed mutual exclusivity with mutations of VHL, SETD2 and PBRM1, and with focal deletions of 3p and 9p, respectively. Expressions of SULT genes were negatively correlated with that of VHL, SETD2 and PBRM1, respectively. While no cancer-intrinsic pathway was enriched, immune signatures were significantly enriched in SULT gene-overexpressed cases, resulting in significantly fewer infiltration of lymphocytes. Targeting SULT1B1 significantly inhibited growth of ccRCC cells.

Conclusion: Steroid SULT genes were associated with worsened prognosis and with immune exclusion in ccRCC.

Methods: In silico reproduction of TGGA and GTEx datasets was performed. Data were processed comprehensively using the platforms of cBioPotal, GEPIA, Human Protein Atlas, TIMER, respectively. Functional annotation was analyzed using platforms of NET-GE and GSEA, respectively. In vitro assays were performed for validation.

MicroRNA-429 inhibits cancer cell proliferation and migration by targeting AKT1 in renal cell carcinoma

MicroRNAs (miRNAs or miR) serve as oncogenes and tumor suppressors. In a previous study, it was revealed that has-miRNA-429 (miR-429) is a tumor suppressor in 786-O renal cell carcinoma (RCC) cells. However, its mechanism in RCC remains to be determined. The present study aimed to explain the functional role and mechanism of miR-429 in RCC pathogenesis. Luciferase reporter assays demonstrated that miR-429 overexpression reduced the transcriptional activity of AKT serine/threonine kinase 1 (AKT1). Reverse transcripton-quantitative (RT-q) PCR and western blot analysis indicated that the mRNA and protein expression of AKT1 was downregulated in 786-O RCC cell lines when miR-429 was overexpressed, indicating that miR-429 may directly target AKT1 in RCC. Therefore, miR-429 overexpression enhanced the inhibition of tumor size and weight in nude mice in vivo. The current study indicated that the novel miR-429-regulated pathway may provide insights into RCC oncogenesis and metastasis.

Upregulated expression of eIF3C is associated with malignant behavior in renal cell carcinoma

Eukaryotic initiation factor 3c (eIF3C) is involved in the initiation of protein translation. Aberrant eIF3C expression has been reported in different types of human cancer. The present study aimed to assess the role of eIF3C in the malignant behavior of renal cell carcinoma in vitro and in vivo. eIF3C expression was assessed in 16 pairs of renal cell carcinoma (RCC) and matched distant normal tissues, and in RCC cell lines using immunohistochemistry. Subsequently, eIF3C was depleted using lentiviral short hairpin RNA and cell proliferation, cell cycle distribution and apoptosis of these eIF3C‑depleted cells were examined. Additionally, tumor cell xenograft assays in nude mice, Affymetrix microarrays and ingenuity pathway analyses were performed. eIF3C expression was upregulated in RCC tissues and cell lines. Depletion of eIF3C reduced tumor cell proliferation and arrested them at the G1 stage, thus promoting their apoptosis in vitro. Depletion of eIF3C also inhibited the formation and growth of tumor cell xenografts in nude mice. In addition, depletion of eIF3C altered the expression levels of 994 differentially expressed genes in RCC cells (516 genes were upregulated and 478 genes were downregulated). The expression levels of phosphorylated‑AKT, c‑JUN and NFKB inhibitor α were lower in the shorth hairpin RNA eIF3C‑transfected RCC cells compared with in the control group. In conclusion, the present study demonstrated that upregulated eIF3C expression contributed to the development and progression of RCC. Future studies should further evaluate whether eIF3C could be used as a potential strategy for RCC targeting therapy.

Snail and E-Cadherin Immunoexpression in Clear Cell Renal Cell Carcinoma

Renal cell clear cell carcinomas (ccRCC) represent 75% of the malignant renal neoplasias. A critical molecular characteristic in the epithelial-mesenchymal transition (EMT) is the loss of E-cadherin expression, as well as the epithelial-mesenchymal transcription factors, one of the most important of which is Snail. In the current study, we analyzed the immunoexpression of the two markers in 46 cases of clear cell renal cell carcinomas, with reference to the most important prognosis histopathological factors. Our results indicated significant associations between the overexpression of Snail, under expression of E-cadherin and high Fuhrman grade. E-cadherin immunoexpression was high in incipient tumoral stages, and Snail was overexpressed in advanced tumoral stages of ccRCC. Our study supports the importance of this antibody panel in the prognosis of ccRCC.

Real-world Clinical Outcomes of Pazopanib Immediately After Discontinuation of Immunotherapy for Advanced Renal Cell Carcinoma

INTRODUCTION

In the first-line (1L) setting, pazopanib (PAZ) has been recommended by the National Comprehensive Cancer Network for the treatment of advanced renal cell carcinoma (aRCC). In 2018, immuno-oncology (IO) therapy became a commonly used 1L treatment option for aRCC. We report the real-world clinical outcomes of PAZ after IO therapy for patients with aRCC.

MATERIALS AND METHODS

We performed a longitudinal, retrospective medical record review study. The included patients were aged ≥ 18 years, had initiated second-line and/or beyond PAZ after IO therapy for clear cell aRCC on or before October 2017, and had complete medical records available from the diagnosis of aRCC to the discontinuation of PAZ, death, or the medical record extraction date (May 2018), whichever occurred first. The primary outcome variable was the PAZ duration of therapy. The secondary outcomes were progression-free survival and overall survival since PAZ initiation, the reasons for PAZ discontinuation, and the occurrence of adverse events (AEs).

RESULTS

A total of 258 eligible patients had initiated IO therapies before PAZ as follows: nivolumab (68%), nivolumab plus ipilimumab (14%), pembrolizumab (12%), and ipilimumab (3%). Overall, the median PAZ duration of therapy was 13.4 months (95% confidence interval [CI], 10.1-16.0 months). The median progression-free survival with PAZ after IO therapy was 13.5 months (95% CI, 11.8 months to not reached). The estimated overall survival rate of PAZ after IO therapy at 6 and 12 months was 93% and 89%, respectively. A total of 109 patients (42%) had reported an AE. The most frequently reported AEs were fatigue (29%) and diarrhea (14%). No additional safety signal of hepatotoxicity was observed (increased aspartate aminotransferase, 5%; increased alanine transaminase, 6%).

CONCLUSIONS

In the present real-world study, second-line and/or beyond PAZ after previous IO therapy was well-tolerated and effective for patients with aRCC.

Identification of Prognostic and Metastatic Alternative Splicing Signatures in Kidney Renal Clear Cell Carcinoma

Background: Kidney renal clear cell carcinoma (KIRC) is the malignancy originated from the renal epithelium, with a high rate of distant metastasis. Aberrant alternative splicing (AS) of pre-mRNA are widely reported to be involved in the tumorigenesis and metastasis of multiple cancers. The aim of this study is to explore the mechanism of alternative splicing events (ASEs) underlying tumorigenesis and metastasis of KIRC. Methods: RNA-seq of 537 KIRC samples downloaded from the TCGA database and ASEs data from the TCGASpliceSeq database were used to identify ASEs in patients with KIRC. The univariate and Lasso regression analysis were used to screen the most significant overall survival-related ASEs (OS-SEs). Based on those, the OS-SEs model was proposed. The interaction network of OS-SEs and splicing factors (SFs) with absolute value of correlation coefficient value >0.750 was constructed by Pearson correlation analysis. The OS-SEs significantly related to distant metastasis and clinical stage were identified by non-parametric test, and those were also integrated into co-expression analysis with prognosis-related Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways identified by Gene Set Variation Analysis (GSVA). ASEs with significance were selected for multiple online database validation. Results: A total of prognostic 6,081 overall survival-related ASEs (OS-SEs) were identified by univariate Cox regression analysis and a prediction model was constructed based on 5 OS-SEs screened by Lasso regression with the Area Under Curve of 0.788. Its risk score was also illustrated to be an independent predictor, which the good reliability of the model. Among 390 identified candidate SFs, DExD-Box Helicase 39B (DDX39B) was significantly correlated with OS and metastasis. After external database validation, Retained Intron of Ras Homolog Family Member T2 (RHOT2) and T-Cell Immune Regulator 1 (TCIRG1) were identified. In the co-expression analysis, overlapped co-expression signal pathways for RHOT2 and TCIRG1 were sphingolipid metabolism and N-glycan biosynthesis. Conclusions: Based on the results of comprehensive bioinformatic analysis, we proposed that aberrant DDX39B regulated RHOT2-32938-RI and TCIRG1-17288-RI might be associated with the tumorigenesis, metastasis, and poor prognosis of KIRC via sphingolipid metabolism or N-glycan biosynthesis pathway.

Chelerythrine induces apoptosis via ROS-mediated endoplasmic reticulum stress and STAT3 pathways in human renal cell carcinoma

Renal cell carcinoma (RCC) is a heterogeneous histological disease and it is one of the most common kidney cancer. The treatment of RCC has been improved for the past few years, but its mortality still remains high. Chelerythrine (CHE) is a natural benzo[c]phenanthridine alkaloid and a widely used broad‐range protein kinase C inhibitor which has anti‐cancer effect on various types of human cancer cells. However, its effect on RCC has not been fully elucidated. In this study, we evaluated the effect and mechanism of CHE on RCC cells. Our study showed that CHE induced colony formation inhibition and G2/M cell cycle arrest in a dose‐dependent manner in RCC cells. In addition, CHE increased cellular ROS level, leading to endoplasmic reticulum (ER) stress, inactivating STAT3 activities and inducing apoptosis in RCC cells which were suppressed by NAC, a special ROS inhibitor. We further found that both knockdown of ATF4 protein and overexpression of STAT3 protein could reduce CHE‐induced apoptosis in Caki cells. These results demonstrated that the apoptosis induced by CHE was mediated by ROS‐caused ER stress and STAT3 inactivation. Collectively, our studies provided support for CHE as a potential new therapeutic agent for the management of RCC.

Decreased SPTLC1 expression predicts worse outcomes in ccRCC patients

OBJECTIVE

Serine palmitoyltransferase, long chain base subunit 1 (SPTLC1) catalyzes the first step in sphingolipid synthesis and has been implicated in the progression of various cancers. However, its role in clear cell renal cell carcinoma (ccRCC) remains unclear. Here, we investigated the expression and prognostic value of SPTLC1 in ccRCC.

METHODS

Three ccRCC patient cohorts were studied. ccRCC and adjacent normal kidney tissue samples were obtained from 183 patients at the Fudan University Shanghai Cancer Center (FUSCC) and subjected to immunohistochemical staining and quantitative reverse-transcription polymerase chain reaction to evaluate SPTLC1 protein and messenger RNA (mRNA) expression. Two validation cohorts consisting of mRNA and clinicopathological data sets from patients with ccRCC were obtained from the Cancer Genome Atlas (TCGA, n = 429) and Oncomine (n = 178) databases. Associations between low and high SPTLC1 mRNA and protein expression and survival were evaluated using the Kaplan-Meier method and log-rank test. Independent prognostic factors were identified using univariate and multivariate Cox regression analysis.

RESULTS

SPTLC1 mRNA or protein were expressed at significantly lower levels in ccRCC tissues compared with normal kidney tissues in all three patient cohorts (P < .001). Low SPTLC1 expression was significantly associated with shorter overall survival in the FUSCC (P = .041) and Oncomine (P < .001) cohorts, and was significantly associated with shorter overall survival (P < .0001) and progression-free survival (P < .001) in the TCGA cohort. Bioinformatics analysis identified 10 genes significantly coregulated with SPTLC1 in ccRCC, most of which contributed to sphingomyelin metabolism (SPTLC2, SPTLC3, SPTSSA, SPTSSB, ORMDL1, ORMDL2, ORMDL3, ZDHHC9, GOLGA7B, and KDSR). Functional enrichment analysis predicted that SPTLC1 and its network play significant roles in inflammatory, hypoxia, and interferon gamma responses, and in allograft rejection pathways.

CONCLUSION

Low SPTLC1 expression is significantly associated with disease progression and poor survival in patients with ccRCC, suggesting that SPTLC1 may function as a tumor suppressor. Thus, SPTLC1 could be a potential new biomarker and/or therapeutic target for ccRCC.

Procollagen-lysine, 2-oxoglutarate 5-dioxygenases 1, 2, and 3 are potential prognostic indicators in patients with clear cell renal cell carcinoma

Intratumoral fibrosis is a frequent histologic finding in highly vascularized clear cell renal cell carcinoma (ccRCC). Here, we investigated the expression of a family of collagen-modifying enzymes, procollagen-lysine, 2-oxoglutarate 5-dioxygenases 1, 2, and 3 (PLOD1/2/3), in ccRCC tissues and assessed the prognostic value of wild-type and genetically mutated PLOD1/2/3 for ccRCC patients. Normal kidney and ccRCC mRNA and protein expression datasets were obtained from Oncomine, The Cancer Genome Atlas, and Human Protein Atlas databases. Associations between PLOD1/2/3 expression, clinicopathological variables, and patient survival were evaluated using Cox regression and Kaplan–Meier analyses. PLOD1/2/3 mRNA and protein expression levels were significantly elevated in ccRCC tissues compared with normal kidney. Increased PLOD1/2/3 mRNA expression was significantly associated with advanced tumor stage, high pathological grade, and shorter progression-free and overall survival (all p<0.01). Genetic mutation of PLOD1/2/3 was present in ~3% of ccRCC patients and was associated with significantly poorer prognosis compared with expression of wild-type PLOD1/2/3 (p<0.001). This study thus identifies tumor expression of wild-type or mutated PLOD1/2/3 mRNA as a potential predictive biomarker for ccRCC patients and sheds light on the underlying molecular pathogenesis of ccRCC.

LINC00997, a novel long noncoding RNA, contributes to metastasis via regulation of S100A11 in kidney renal clear cell carcinoma

Long noncoding RNAs (lncRNAs) play an essential role in cancer development. However, the contribution of the lncRNA LINC00997 to kidney renal clear cell carcinoma (KIRC) has not been thoroughly elucidated to date. In this study, we examined the expression and biological effect of LINC00997 in KIRC development. We also investigated the potential mechanism underlying the observed effects. We found that LINC00997 is highly expressed in multiple carcinomas, being highest in stage IV KIRC in our RNA-Seq datasets. In addition, our data demonstrated that in KIRC patients, higher levels of LINC00997 are correlated with lower overall survival (OS) and disease-free survival (DFS) rates. In 18 cases of KIRC, we found that LINC00997 expression was greater in cancer tissues and metastases than in normal tissues. These results revealed that S100A11 is positively associated with LINC00997 in KIRC, which is positively correlated with metastasis-associated molecules VIM, MMP2 and MMP7. Our in vitro wound healing assay and Transwell tests demonstrated that interfering with either LINC00997 or S100A11 expression reduced migration of 786-O cells by inhibiting VIM, MMP2 and MMP7 expression. Importantly, we verified LINC00997 and STAT3 binding by RIP and determined that both LINC00997 and STAT3 bind to the S100A11 promoter, as shown by dual-luciferase reporter gene assay. In addition, inhibiting LINC00997 or STAT3 expression attenuated S100A11 levels. Consequently, the LINC00997-STAT3-S100A11 axis may promote the development of KIRC, and LINC00997 may represent a potential prognostic biomarker and therapeutic target for KIRC patients.

Brain Metastasis From Renal-Cell Carcinoma: An Institutional Study

BACKGROUND

Brain metastases (BM) are frequently observed in advanced renal-cell carcinoma (RCC). Historically these individuals have been excluded from clinical trials, but recently, with better local control, many can receive aggressive therapy after treatment. We evaluate our single-institution experience over various treatment eras.

PATIENTS AND METHODS

Patients undergoing evaluation for RCC BM from 2001 to 2018 were identified from our institutional database. Clinical notes, demographics, comorbidities, histology, central nervous system (CNS) treatments, systemic therapy, and outcomes were reviewed. Overall survival (OS) and CNS recurrence-free survival (RFS) were evaluated by the Kaplan-Meier method. Cumulative incidence was evaluated using a competing risk model.

RESULTS

We identified 158 patients with RCC BM, of whom 94.4% had clear-cell RCC, and 90.6% had extracranial metastases at diagnosis. Of these patients, 94 (60%) developed RCC BM over time, while 46 (29.1%) had RCC BM at initial presentation. Clinical symptoms were noted in 81.9% of patients. The median OS after diagnosis of RCC BM was 8.4 months, with a 3-year OS of 28.2%. The median CNS RFS was 8.5 months overall; however, those with one and more than one lesion had median CNS RFS of 12.4 and 6 months, respectively (P < .001).

CONCLUSION

The majority of RCC patients with BM are symptomatic and had prior metastatic disease that progressed to the brain. Those with a solitary RCC BM are less likely to develop CNS recurrence after local therapy and are ideal candidates for enrollment onto clinical trials.

DNA methylation-regulated QPCT promotes sunitinib resistance by increasing HRAS stability in renal cell carcinoma

Rationale: Although sunitinib has been shown to improve the survival rate of advanced renal cell carcinoma (RCC) patients, poor drug response is a major challenge that reduces patient benefit. It is important to elucidate the underlying mechanism so that the therapeutic response to sunitinib can be restored. Methods: We used an Illumina HumanMethylation 850K microarray to find methylation-differentiated CpG sites between sunitinib-nonresponsive and -responsive RCC tissues and Sequenom MassARRAY methylation analysis to verify the methylation chip results. We verified glutaminyl peptide cyclotransferase (QPCT) expression in sunitinib-nonresponsive and -responsive RCC tissues via qRT-PCR, western blot and immunohistochemical assays. Then, cell counting kit 8 (CCK-8), plate colony formation and flow cytometric assays were used to verify the function of QPCT in RCC sunitinib resistance after QPCT intervention or overexpression. Chromatin immunoprecipitation (ChIP) was performed to clarify the upstream regulatory mechanism of QPCT. A human proteome microarray assay was used to identify downstream proteins that interact with QPCT, and co-immunoprecipitation (co-IP) and confocal laser microscopy were used to verify the protein chip results. Results: We found that the degree of methylation in the QPCT promoter region was significantly different between sunitinib-nonresponsive and -responsive RCC tissues. In the sunitinib-nonresponsive tissues, the degree of methylation in the QPCT promoter region was significantly reduced, and the expression of QPCT was upregulated, which correlated with a clinically poor response to sunitinib. A knockdown of QPCT conferred sunitinib sensitivity traits to RCC cells, whereas an overexpression of QPCT restored sunitinib resistance in RCC cells. Mechanistically, reducing the methylation degree of the QPCT promoter region by 5-aza-2'-deoxycytidine (decitabine) in RCC cells could increase the expression of QPCT and NF-κB (p65) bound to the QPCT promoter region, positively regulating its expression, while the hypermethylation in the QPCT promoter region could inhibit the binding of NF-κB (p65). QPCT could bind to HRAS and attenuate the ubiquitination of HRAS, thus increasing its stability and leading to the activation of the ERK pathway in RCC cells. Conclusion: QPCT may be a novel predictor of the response to sunitinib therapy in RCC patients and a potential therapeutic target.

Adverse Effect of Lymph Node Dissection in Metastatic Renal Cell Cancer Patients Treated with Cytoreductive Nephrectomy: A Contemporary Analysis of Survival

Background and objectives: In patients with metastatic renal cell cancer (mRCC), cytoreductive nephrectomy (CN) may occasionally be performed. However, the role of lymph node dissection (LND) for such cases is unknown in era of target therapy. To test the effect of LND at CN on cancer-specific survival (CSS), overall survival (OS) in era of target therapy compared with no LND in patients with mRCC. Methods: A total of 4690 mRCC patients treated with CN were identified within the Surveillance, Epidemiology, and End Result (SEER) database (2006-2015). Survival differences were assessed by Kaplan-Meier estimate and compared using log-rank test. Multivariable Cox regression analysis (MCR) was used to evaluate the effect of LND on CSS and OS. Results: Within the SEER database, 1902 (40.6%) of 4690 mRCC patients underwent LND at CN. MCR analysis showed that LND at CN exhibited lower CSS (hazard ratio [HR] 1.18, 95% confidence interval (CI) 1.09-1.27; p < 0.01) and OS (HR 1.13, 95% CI 1.05-1.21; p < 0.01) compared with non-LND in mRCC patients. The adverse effect of LND on CSS and OS were also detected in metastatic patients with clear cell RCC (ccRCC) and non-ccRCC (all p<0.0001). Additionally, the association of number of resected node with CSS (HR 0.98, 95% CI 0.88-1.10; p = 0.68) and OS (HR 1.00, 95% CI 0.89-1.11; p = 0.93) were not observed in MCR analysis. Conclusion: We are the first to demonstrate that LND at CN is associated with poor CSS and OS in metastatic patients with ccRCC and non-ccRCC. Considering that the current study is retrospective, these findings' impact on clinical practice needs to be further verified in future validation studies.

Can MRI be used to diagnose histologic grade in T1a (< 4 cm) clear cell renal cell carcinomas?

OBJECTIVE

To assess whether MRI can differentiate low-grade from high-grade T1a cc-RCC.

MATERIALS AND METHODS

With IRB approval, 49 consecutive solid < 4 cm cc-RCC (low grade [Grade 1 or 2] N = 38, high grade [Grade 3] N = 11) with pre-operative MRI before nephrectomy were identified between 2013 and 2018. Tumor size, apparent diffusion coefficient (ADC) histogram analysis, enhancement wash-in and wash-out rates, and chemical shift signal intensity index (SI index) were assessed by a blinded radiologist. Subjectively, two blinded Radiologists also assessed for (1) microscopic fat, (2) homogeneity (5-point Likert scale), and (3) ADC signal (relative to renal cortex); discrepancies were resolved by consensus. Outcomes were studied using Chi square, multivariate analysis, logistic regression modeling, and ROC. Inter-observer agreement was assessed using Cohen's kappa.

RESULTS

Tumor size was 24 ± 7 (13-39) mm with no association to grade (p = 0.45). Among quantitative features studied, corticomedullary phase wash-in index (p = 0.015), SI index (p = 0.137), and tenth-centile ADC (p = 0.049) were higher in low-grade tumors. 36.8% (14/38) low-grade tumors versus zero high-grade tumors demonstrated microscopic fat (p = 0.015; Kappa = 0.67). Microscopic fat was specific for low-grade disease (100.0% [71.5-100.0]) with low sensitivity (36.8% [21.8-54.6]). Other subjective features did not differ between groups (p > 0.05). A logistic regression model combining microscopic fat + wash-in index + tenth-centile-ADC yielded area under ROC curve 0.98 (Confidence Intervals 0.94-1.0) with sensitivity/specificity 87.5%/100%.

CONCLUSION

The combination of microscopic fat, higher corticomedullary phase wash-in and higher tenth-centile ADC is highly accurate for diagnosis of low-grade disease among T1a clear cell RCC.

Elevated CD36 expression correlates with increased visceral adipose tissue and predicts poor prognosis in ccRCC patients

Objective: Growing evidence has proved obesity one of the confirmed important etiologic indicators for renal cell carcinoma (RCC). CD36 is underpinned to be involved in adipose absorption, but its role in clear cell renal cell carcinoma (ccRCC) remains unclear. This study aimed to investigate the mRNA expression of CD36 in anthropometric measures of adipose tissue and defining its value in predicting prognosis in ccRCC patients. Methods: Real-Time qPCR gene expression analysis was detected from 367 paired ccRCC and adjacent normal tissues. Distributions of categorical clinical-pathological data together with levels of CD36 expression were compared with χ²-test in a contingency table. Subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) were measured by magnetic resonance imaging (MRI) and identified at the level of the umbilicus. Pearson's correlation coefficient was utilized to quantify relations between body mass index (BMI), VAT%, SAT and CD36 expression respectively. Partial likelihood test from univariate and multivariate Cox regression analysis were developed to address the influence of independent factors on progression-free survival (PFS) and overall survival (OS). The Kaplan-Meier method and log-rank test were performed to assess the survival benefits between discrete levels. Results: In the current study, CD36 mRNA was demonstrated highly expressed in ccRCC compared with normal tissues. In addition, CD36 mRNA expression was significantly increased in patients with advanced TNM stage (p=0.003, p<0.001, p<0.001), and high VAT% (p=0.004). Pearson's correlation coefficient indicated that CD36 amplification positively correlated with BMI (r=0.117, p=0.025), VAT% (r=0.465, p<0.001), while negatively associated with SAT (r=-0.296, p=0.002). Median PFS was 60 months and OS was 99 months. Meanwhile, ccRCC patients with elevated CD36 expression held shorter PFS and OS, with hazard ratios [HR; 95% confidence interval (CI)] of 4.873 (3.300-7.196, p<0.001) and 4.610 (2.956-7.189, p<0.001). In 104 cases with available MRI scans, VAT was significantly correlated with poor PFS and OS, with HR of 2.556 (1.036-6.310, p<0.042) and 3.291 (1.034-10.477, p<0.044). A total of 100 significant genes were obtained from GSEA, and CD36 was found involved in the most significant pathways including fatty acid metabolism, UV response, angiogenesis and transforming growth factor beta (TGF-β) signaling pathways. Conclusion: In conclusion, our study first reveal that elevated CD36 mRNA expression is positively correlated to distribution of abdominal adipose, particularly VAT%, which, in addition, notably predicts poor prognosis in ccRCC patients.

Prognostic factors for the survival of patients with papillary renal cell carcinoma after surgical management

PURPOSE

To examine the possible prognostic factors in patients with type 1 and type 2 papillary renal cell carcinoma (pRCC) after surgical management and to identify the independent predictive factors of the prognosis.

METHODS

From 2010 to 2017, 1405 patients underwent surgery for renal cell carcinoma, of whom 114 had type 1 or type 2 pRCC and follow-up data were available for 88 patients. Clinicopathological and prognostic parameters were compared between type 1 and type 2 pRCC. Possible prognostic factors were retrospectively analyzed by univariate and multivariate analyses with Cox regression.

RESULTS

The study included 63 males and 25 females with a mean age of 54.27 ± 12.91. 53 patients were diagnosed by regular physical examination and others presented with hematuria or lumbago. 53 (60.2%) underwent radical nephrectomy and 35 (39.8%) underwent nephron sparing surgery. After a mean follow-up of 46.08 ± 22.65 months, 16 patients died of pRCC metastasis and the 5-year disease-specific survival was 79.3%. The comparison of the 39 (44.3%) type 1 and 49 (55.7%) type 2 pRCCs revealed that type 2 pRCC had significantly higher grade and worse prognosis. Univariate analysis showed that symptomatic diagnosis, type, grade, and tumor stage were prognostic factors. Multivariate analysis identified that type and tumor stage were independent factors of the prognosis.

CONCLUSIONS

Pathological type and tumor stage could serve as independent factors for the prognosis of patients with pRCC.

Selenoprotein M stimulates the proliferative and metastatic capacities of renal cell carcinoma through activating the PI3K/AKT/mTOR pathway

High-throughput sequencing methods have facilitated the identification of novel selenoproteins, which exert a vital role in the development and progression of tumor diseases. Recently, Selenoprotein M (SELM) is upregulated in several types of cancer. However, the biological roles of SELM in renal cell carcinoma (RCC) remain unclear. In this paper, quantitative reverse transcription PCR (qRT-PCR) and Western blot were used to measure relative levels of SELM in a cohort of RCC tissues with matched normal tissues as well as human RCC cell lines. SELM expression was found to be upregulated in RCC. High level of SELM was related to poor prognosis of RCC. Furthermore, silence of SELM could inhibit the in vitro proliferative, migratory, and invasive capacities of RCC. In addition, downregulated SELM could impede in vivo tumorigenesis of RCC. SELM could activate the PI3K/Akt/mTOR pathway and mediate expressions of matrix metallopeptidase 2 and 9 (MMP2, MMP9). In conclusion, our study reveals the oncogenic function of SELM in RCC, and SELM may be a therapeutic and prognostic target for RCC.

Glutaminase inhibition in renal cell carcinoma therapy

Receptor tyrosine kinase inhibitors have been a standard first-line therapy for renal cell carcinoma (RCC) for over a decade. Although they stabilize the disease, they are unable to remove all tumor cells, leading to relapse. Moreover, both intrinsic and acquired resistance to therapy are a significant health burden. In order to overcome resistance, several combination therapies have been recently approved by the FDA. Another approach takes advantage of altered metabolism in tumor cells, which switch to alternative metabolic pathways to sustain their rapid growth and proliferation. CB-839 is a small molecule inhibitor of kidney type glutaminase (GLS). GLS is often upregulated in glutamine addicted cancers, enhancing glutamine metabolism for the production of energy and the biosynthesis of various cellular building blocks. CB-839 is currently in clinical trials for several tumors, including clear cell (cc)RCC, both as monotherapy and in combination with the approved therapeutic agents everolimus, cabozantinib and nivolumab. Early results of Phase 1/2 clinical trials look promising, especially for CB-839 plus cabozantinib, and all combinations seem to be well tolerated. However, cancer cells can activate compensatory pathways to overcome glutaminolysis inhibition. Therefore, genetic and metabolomic studies are crucial for the successful implementation of CB-839 alone or in combination in subgroups of ccRCC patients.

Impact of eIF4E phosphorylation at Ser209 via MNK2a on tumour recurrence after curative surgery in localized clear cell renal cell carcinoma

Background: We investigated the roles of eIF4E phosphorylation (Ser209) in tumour recurrence after curative nephrectomy for localized clear cell renal cell carcinoma (ccRCC).

Methods: Expression of eIF4E, p eIF4E and MNKs (MAPK interacting kinases), was evaluated in surgical specimens obtained from consecutive non metastatic ccRCC patients (n = 290) by immunohistochemistry (IHC), immunoblotting, and qRT PCR at the protein and mRNA levels. In human RCC cell lines, the effects of eIF4E phosphorylation were examined using immunoblotting, proliferation, migration and invasion assays with pharmacological inhibitors (CGP57380 or ETP45835) and specific small interfering (si) RNAs against MNK1/2(a/b).

Results: In postoperative follow-up (median, 7.9 y), 40 patients experienced metastatic recurrence. In multivariate Cox analyses, higher IHC expression of p eIF4E in ccRCC significantly predicted a longer recurrence-free interval. eIF4E is phosphorylated mainly by MNK2a in tumour specimens and cell lines. In 786-O and A-498 cell lines, pharmacological inhibition of MNKs decreased p-eIF4E and increased vimentin and N cadherin but did not influence proliferation. Similarly, MNK2 or MNK2a inhibition with siRNA reduced p-eIF4E and enhanced vimentin translation, cell migration and invasion in the cell lines.

Conclusions: MNK2a-induced eIF4E phosphorylation may suppress metastatic recurrence of ccRCC, partially due to vimentin downregulation at the translational level, consequently leading to inhibition of epithelial–mesenchymal transition.

Targeting the Tumor Microenvironment in Renal Cell Cancer Biology and Therapy

Renal cell cancer (RCC) is a highly vascularized and immunogenic tumor type. The inhibition of vessel formation by anti-angiogenic therapies, as well as the stimulation of the immune system by immunotherapy has revolutionized the therapeutic landscape of RCC in recent years. Nevertheless, both therapies are associated with therapy resistance due to a highly dynamic, adaptive and heterogeneous tumor microenvironment (TME). The aim of this short review article is to provide an overview of the components of the RCC TME as well as to discuss their contribution to disease progression. In addition, we report on preclinical and clinical findings and how the different TME components can be modulated to impede treatment progression as well as to overcome therapy resistance to anti-angiogenic or immunomodulating therapy concepts. Furthermore, we discuss the predictive and prognostic role of the TME in RCC therapy. We also report on the concept of combinational targeting of anti-angiogenic therapies and immune checkpoint inhibitor therapy, also including the latest results of clinical studies discussed at recent oncological meetings. Finally, promising new therapeutic targets within the TME are mentioned.

Cancers Attributable to Overweight and Obesity From 2012 to 2014 in Nigeria: A Population-Based Cancer Registry Study

Background: Overweight and obesity are known risk factors for chronic diseases including cancers. In this study, we evaluated the age standardized incidence rates (ASR) and proportion of cancers attributable to overweight and obesity in Nigeria. Methods: We obtained incidence data from the databases of two population-based cancer registries (PBCRs) in Nigeria (Abuja and Enugu cancer registries), on cancer site for which there is established evidence of an association with overweight or obesity based on the International Agency for Research on Cancer (IARC) and the World Cancer Research Fund (WCRF) classification. We analyzed the data using population attributable fraction (PAF) for overweight or obesity associated cancers calculated using prevalence data and relative risk estimates in previous studies. Results: The two PBCRs reported 4,336 new cancer cases (ASR 113.9 per 100,000) from 2012 to 2014. Some 21% of these cancers were associated with overweight and obesity. The ASR for overweight and obesity associated cancers was 24.5 per 100,000; 40.7 per 100,000 in women and 8.2 per 100,000 in men. Overall, only 1.4% of incident cancers were attributable to overweight and obesity. The ASR of cancers attributable to overweight and obesity was 2.0 per 100,000. Postmenopausal breast cancer was the most common cancer attributable to overweight and obesity (n = 25; ASR 1.2 per 100,000). Conclusion: Our results suggest that a small proportion of incident cancer cases in Nigeria are potentially preventable by maintaining normal body weight. The burden of cancer attributed to overweight and obesity in Nigeria is relatively small, but it may increase in future.