Radiotherapy for renal-cell carcinoma

Intramedullary Spinal Metastatic Renal Cell Carcinoma: Systematic Review of Disease Presentation, Treatment, and Prognosis with Case Illustration

OBJECTIVE

Renal cell carcinoma (RCC) metastases to the intramedullary spinal cord carry a grim prognosis. The purpose of this review is to provide the reader with a comprehensive and systematic review of the current literature, and to present an illustrative case that would aid in the future management of similar scenarios.

METHODS

A systematic review of the literature using the PubMed electronic database was made according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Only human clinical reports of intramedullary RCC metastasis were included. We also present an illustrative case that was treated at our institution.

RESULTS

We identified 23 reports with a total of 31 patients. Of the tumors, 47% were located at the cervical level. Brain metastases were present in 41% of cases. Limb weakness (72%), urinary incontinence (41%), dysesthesia (47%), and localized spinal pain (38%) were the most frequently reported symptoms. Surgical resection alone was used in 34% of cases, followed by a combination of surgery and radiotherapy (31%), and radiotherapy alone (25%). Spinal metastases were detected an average of 32.1 months after the diagnosis of RCC, and mean patient survival after that was 8 months (range, 0-65 months). Reported survival after radiotherapy appeared to be the longest (11.2 months) compared with surgery (9.1 months) and combination therapy (5 months).

CONCLUSIONS

Intramedullary spinal metastatic RCC is a rare entity with debilitating neurologic potential. Survival appears to be affected by the treatment method but is also likely influenced by the stage of discovery of the disease.

Stereotactic body radiation therapy in combination with systemic therapy for metastatic renal cell carcinoma: a prospective multicentre study

Background

Tyrosine kinase inhibitors (TKIs) and checkpoint inhibitors have been established as effective treatment for metastatic renal cell carcinoma (mRCC), but only a minority of patients achieve complete response. Additional strategies are necessary to improve these agents’ efficacy.

Methods

Patients with stable disease for at least 4 months on TKI or checkpoint inhibitors were included. Stereotactic body radiotherapy (SBRT) was delivered to an organ with comparable lesions, where one lesion was in the treatment target and the other one was intentionally left untreated (control lesion). Response in both lesions was scored using the Response Evaluation Criteria in Solid Tumors V.1.1 criteria 2 months after completion of SBRT. The primary endpoint was the rate of SBRT adverse events, and the secondary endpoints included the rate of reduction in target lesion size.

Results

17 patients were enrolled (14 men and 3 women, median age: 54.5 years old). SBRT was delivered to the lungs (n=5), bones (n=4), lymph nodes (n=4), liver (n=1), primary renal cell carcinoma (RCC) (n=1) and locally recurrent RCC (n=2). The equivalent dose in 2 Gy with an alpha to beta ratio of 2.6 was 114 Gy. With a median follow-up of 8 months, the cumulative rate of SBRT-related toxicity (grade 1) was 12% (n=2), consisting of oesophagitis and skin erythema. No grade 2 or higher toxicity was detected. Radiographic response in the target lesion was seen in 13 patients (76%), with complete response in 5 (29%) patients and partial response in 8 (47%), including abscopal effect in 1 patient. Control lesions remained stable in 16 patients. The difference between response in the target and control lesions as judged by the mean sizes of these lesions before and at 2 months after SBRT was statistically significant (p<0.01). Fraction size of 10 Gy or greater was associated with complete response (p<0.01).

Conclusion

Extracranial SBRT in patients with mRCC treated with TKI or checkpoint inhibitors is well tolerated and could be effective.

Trial registration number

NCT02864615

Improving diagnosis of genitourinary cancers: Biomarker discovery strategies through mass spectrometry-based metabolomics

The genitourinary oncology field needs integration of results from basic science, epidemiological studies, clinical and translational research to improve the current methods for diagnosis. MS-based metabolomics can be transformative for disease diagnosis and contribute to global health parity. Metabolite panels are promising to translate metabolomic findings into the clinics, changing the current diagnosis paradigm based on single biomarker analysis. This review article describes capabilities of the MS-based oncometabolomics field for improving kidney, prostate, and bladder cancer detection, early diagnosis, risk stratification, and outcome. Published works are critically discussed based on the study design; type and number of samples analyzed; data quality assessment through quality assurance and quality control practices; data analysis workflows; confidence levels reported for identified metabolites; validation attempts; the overlap of discriminant metabolites for the different genitourinary cancers; and the translation capability of findings into clinical settings. Ongoing challenges are discussed, and future directions are delineated.

First-line Treatment of Metastatic Renal Cell Carcinoma: A Systematic Review and Network Meta-analysis

CONTEXT

No head-to-head clinical trials compare contemporary first-line therapies for metastatic renal cell carcinoma (mRCC). A network meta-analysis provides an approach for quantitative analysis.

OBJECTIVE

To indirectly compare the efficacy and safety of first-line treatments for mRCC in the intention-to-treat (ITT) population and by clinical risk group.

EVIDENCE ACQUISITION

An updated systematic review from database inception to February 17, 2019 identified all parallel-group randomized controlled trials assessing first-line therapy for mRCC. "Clinically relevant" studies were selected for a network meta-analysis. Progression-free survival (PFS) was the primary outcome. Overall survival (OS), overall response rate (ORR), and grade 3 and 4 adverse events (AEs) were secondary outcomes.

EVIDENCE SYNTHESIS

We identified 12 relevant trials: 12 reported outcomes for PFS, nine for OS, 10 for ORR, and nine for AEs. In the ITT population, cabozantinib (surface under the cumulative ranking curves [SUCRA] 84%), avelumab plus axitinib (SUCRA 68%), and pembrolizumab plus axitinib (SUCRA 82%) were superior to the other agents for PFS; pembrolizumab plus axitinib appeared superior for OS (SUCRA 95%); and atezolizumab demonstrated the lowest likelihood of AEs (SUCRA 100%). Findings were similar in the intermediate/poor-risk subgroup. Based on the limited data available, avelumab plus axitinib may be preferred in patients with favorable-risk disease.

CONCLUSIONS

The optimal first-line treatment for mRCC appears to differ by efficacy endpoint, toxicity, and clinical risk group. Direct comparative studies remain important in guiding treatment choice.

PATIENT SUMMARY

Head-to-head comparisons do not exist for the newest treatments of metastatic renal cell carcinoma (mRCC). In an indirect comparison, we found that pembrolizumab plus axitinib and cabozantinib are good options for most patients with mRCC.

miR-221-5p acts as an oncogene and predicts worse survival in patients of renal cell cancer

BACKGROUND

Renal cell carcinoma(RCC) is one of the most common malignancies in kidney, and usually leads to poor prognosis. Therefore, identifying novel biomarkers for predicting the progression and prognosis of RCC is essential. The purpose of this study is aimed to evaluate the function of miR-221-5p in RCC and the clinical value of miR-221-5p in RCC prognosis after surgery.

MATERIALS AND METHODS

In our study, RT-qPCR, wound scratch assay, cell proliferation assay, transwell assay, and flow cytometry assay were performed to explore miR-221-5p expression level and its proliferation, migration and apoptosis in clear cell RCC(ccRCC). Besides, we collected 196 formalin-fixed and paraffin-embedded (FFPE) tissue samples of patients who received partial or radical nephrectomy from May 2006 to October 2016 at Shenzhen Traditional Chinese Medicine Hospital and People's Liberation Army 303 Hospital. The relative levels of miR-221-5p from the FFPE tissue samples was detected by RT-qPCR. The Kaplan-Meier method, Cox regression analyses, and ROC curve analysis were performed to approve the effect of the miR-221-5p expression on patient survival.

RESULTS

In our study, we found that miR-221-5p is significantly upregulated in ccRCC tissues and ccRCC cell lines. Moreover, miR-221-5p promotes cell proliferation, mobility, and inhibits cell apoptosis in 786-O and ACHN cell lines. The Kaplan-Meier analysis indicated that patients with high expression of miR-221-5p had a significantly poor prognosis (P = 0.013). The Cox regression analyses showed that patients with high expression of miR-221-5p remained to have a shorter overall survival (P = 0.025). The ROC curve of miR-221-5p expression combined with tumor stage showed an area under the curve of 0.658 (P < 0.001).

CONCLUSION

Our results indicated that miR-221-5p might not only be an oncogene in ccRCC cells but also might be an independent prognosis factor of ccRCC.

An interdisciplinary consensus on the management of bone metastases from renal cell carcinoma

Bone is a major site of haematogenous tumour cell spread in renal cell carcinoma (RCC), and most patients with RCC will develop painful and functionally disabling bone metastases at advanced disease stages. The prognosis of these patients is generally poor and the treatment is, therefore, aimed at palliation. However, RCC-associated bone metastases can be curable in select patients. Current data support a multimodal management strategy that includes wide resection of lesions, radiotherapy, systemic therapy, and other local treatment options, which can improve quality of life and survival. Nevertheless, the optimal approach for metastatic bone disease in RCC has not yet been defined and practical recommendations are rare. To improve the management and outcomes of patients with RCC and bone metastases, the International Kidney Cancer Coalition and the interdisciplinary working group on renal tumours of the German Cancer Society convened a meeting of experts with a global perspective to perform an unstructured review and elaborate on current treatment strategies on the basis of published data and expertise. The panel formulated recommendations for the diagnosis and treatment of patients with RCC and metastasis to the bone. Furthermore, the experts summarized current challenges and unmet patient needs that should be addressed in the future.

In this Expert Consensus, Grünwald et al. summarize their recommendations for the diagnosis and treatment of patients with renal cell carcinoma and metastasis to the bone. They also outline current challenges and unmet patient needs that should be addressed in the future.

Emerging therapeutic agents for genitourinary cancers

The treatment of genitourinary malignancies has dramatically evolved over recent years. Renal cell carcinoma, urothelial carcinoma of the bladder, and prostate adenocarcinoma are the most commonly encountered genitourinary malignancies and represent a heterogeneous population of cancers, in both histology and approach to treatment. However, all three cancers have undergone paradigm shifts in their respective therapeutic landscapes due to a greater understanding of their underlying molecular mechanisms and oncogenic drivers. The advance that has gained the most recent traction has been the advent of immunotherapies, particularly immune checkpoint inhibitors. Immunotherapy has increased overall survival and even provided durable responses in the metastatic setting in some patients. The early success of immune checkpoint inhibitors has led to further drug development with the emergence of novel agents which modulate the immune system within the tumor microenvironment. Notwithstanding immunotherapy, investigators are also developing novel agents tailored to a variety of targets including small-molecule tyrosine kinase inhibitors, mTOR inhibitors, and novel fusion proteins to name a few. Erdafitinib has become the first targeted therapy approved for metastatic bladder cancer. Moreover, the combination therapy of immune checkpoint inhibitors with targeted agents such as pembrolizumab or avelumab with axitinib has demonstrated both safety and efficacy and just received FDA approval for their use. We are in an era of rapid progression in drug development with multiple exciting trials and ongoing pre-clinical studies. We highlight many of the promising new emerging therapies that will likely continue to improve outcomes in patients with genitourinary malignancies.

microRNA-505 negatively regulates HMGB1 to suppress cell proliferation in renal cell carcinoma

microRNAs have been recognized to regulate a wide range of biology of renal cell carcinoma (RCC). Although miR-505 has been reported to play as a suppressor in several human tumors, the physiological function of miR-505 in RCC still remain unknown. Therefore, the role of miR-505 and relevant regulatory mechanisms were investigated in RCC in this study. Quantitative real-time polymerase chain reaction was conducted to detect the expression of miR-505 and high mobility group box 1 (HMGB1) in both RCC tissues and cell lines. Immunohistochemical staining was used to assess the correlation between HMGB1 expression and PCNA expression in RCC tissues. Subsequently, the effects of miR-505 on proliferation were determined in vitro using cell counting kit-8 proliferation assays and 5-ethynyl-2'-deoxyuridine incorporation. The molecular mechanism underlying the relevance between miR-505 and HMGB1 was confirmed by luciferase assay. Xenograft tumor formation was used to reflect the proliferative capacity of miR-505 in vivo experiments. Overall, a relatively lower miR-505 and higher HMGB1 expression in RCC specimens and cell lines were found. HMGB1 was verified as a direct target of miR-505 by luciferase assay. In vitro, overexpression of miR-505 negatively regulates HMGB1 to suppress the proliferation in Caki-1; meanwhile, knock-down of miR-505 negatively regulates HMGB1 to promote the proliferation in 769P. In addition, in vivo overexpression of miR-505 could inhibit tumor cell proliferation in RCC by xenograft tumor formation. Therefore, miR-505, as a tumor suppressor, negatively regulated HMGB1 to suppress the proliferation in RCC, and might serve as a novel therapeutic target for RCC clinical treatment.

Is there a role for stereotactic radiotherapy in the treatment of renal cell carcinoma?

Renal cell carcinoma (RCC) has traditionally been regarded as radioresistant tumor based on preclinical data and negative clinical trials using conventional fractionated radiotherapy. However, there is emerging evidence that radiotherapy delivered in few fractions with high single-fraction and total doses may overcome RCC s radioresistance. Stereotactic radiotherapy (SRT) has been successfully used in the treatment of intra- and extracranial RCC metastases showing high local control rates accompanied by low toxicity. Although surgery is standard of care for non-metastasized RCC, a significant number of patients is medically inoperable or refuse surgery. Alternative local approaches such as radiofrequency ablation or cryoablation are invasive and often restricted to small RCC, so that there is a need for alternative local therapies such as stereotactic body radiotherapy (SBRT). Recently, both retrospective and prospective trials demonstrated that SBRT is an attractive treatment alternative for localized RCC. Here, we present a comprehensive review of the published data regarding SBRT for primary RCC. The radiobiological rationale to use higher radiation doses in few fractions is discussed, and technical aspects enabling the safe delivery of SBRT despite intra- and inter-fraction motion and the proximity to organs at risk are outlined.

DYSF expression in clear cell renal cell carcinoma: A retrospective study of 2 independent cohorts

OBJECTIVE

Renal cell carcinoma (RCC) is the most typical type of kidney cancer in adults. Hypercalcemia is a well known paraneoplastic syndrome associated with RCC and recent studies have reported that hypercalcemia is closely related to the poor prognosis of RCC patients. Clear cell RCC (ccRCC) is the most common and aggressive subtype of RCC. Although the histological classification of RCC is important for determination of appropriate treatment strategies, effective biomarkers for predicting prognosis of ccRCC have not yet been identified. Since calcium levels affect the prognosis of RCC patients, we evaluated whether the calcium-sensing genes on the plasma membrane, including those encoding calcium channels, CaSR, GPRC6a, and DYSF, could be used as biomarkers to predict the prognosis of ccRCC patients.

METHODS

Information from 537 patients from The Cancer Genome Atlas (TCGA; n = 446) and International Cancer Genome Consortium (ICGC; n = 91) was used in this study. Among these genes, DYSF was the only gene whose expression correlated with overall survival of both TGCA and ICGC patients.

RESULTS

Although DYSF gene expression was higher in ccRCC tissue than in normal kidney tissue, Kaplan-Meier curves showed that the survival rate of ccRCC patients with high DYSF expression was significantly higher than that of patients with low DYSF expression (TCGA, P < 0.0001; ICGC, P = 0.0011). We also validated the potential of DYSF as a prognostic biomarker for ccRCC by conducting a time-dependent area under the curve (AUC) analysis and 5-years receiver operating characteristic curve analysis. Finally, multivariate regression analysis revealed that the expression of DYSF is independent of other prognostic parameters (TCGA, P = 0.017; ICGC, P = 0.006).

CONCLUSIONS

These results suggested that DYSF may play a suppressive role in the progression of ccRCC and could act as a promising prognostic biomarker for predicting the survival of ccRCC patients.

Radiogenomics of Clear Cell Renal Cell Carcinoma: Associations Between mRNA-Based Subtyping and CT Imaging Features

PURPOSE

To investigate associations between clear-cell renal cell carcinoma mRNA-based subtyping and CT features.

MATERIALS AND METHODS

The CT data from 177 patients generated with The Cancer Imaging Archive were reviewed. The correlation was analyzed using chi-square test and univariate regression analysis.

RESULTS

Identified were 124 (53.2%) m1, 67 (28.8%) m2, 17 (7.3%) m3, and 14 (8.7%) m4 subtypes. m1-subtype rates were significantly higher in well-defined margin lesions (p = 0.041). m3-subtype rates were significantly higher in ill-defined margin lesions (p = 0.012), in collecting system invasion lesions (p = 0.028) and collecting system invasion lesions (p = 0.026).On univariate logistic regression analysis, tumor margin (well-defined margin vs ill-defined margin, OR: 2.104; p = 0.041; 95% CI: 1.024-4.322) was associated with m1-subtype. Tumor margin (well-defined margin vs ill-defined margin, OR: 2.104; p = 0.012; 95% CI: 0.212-0.834) and collecting system invasion (yes vs no, OR: 0.421; p = 0.028; 95% CI: 0.212-0.834) and renal vein invasion (yes vs no, OR: 2.164; p = 0.026; 95% CI: 1.090-4.294) were associated with m3-subtype. There was no significant difference between mRNA-based subtyping (m2 vs other; m4 vs other) and the CT features.

CONCLUSIONS

This preliminary radiogenomics analysis of clear-cell renal cell carcinoma revealed associations between CT features and mRNA-based subtyping which warrant further investigation and validation.

Treating the Chameleon: Radiotherapy in the management of Renal Cell Cancer

PURPOSE

To review the role of radiotherapy (RT) in the treatment of renal cell cancer (RCC) in the curative and palliative setting.

CONTENT

Details related to the clinical outcomes of primary, preoperative, postoperative and palliative RT are discussed, along with a presentation of the established role of surgery and systemic therapy. An overview of data derived from mono- and multi-institutional trials is provided.

CONCLUSION

Radiotherapy has been shown to provide good symptom palliation and local control in RCC depending on the dose that can be delivered. There is emerging data suggesting that with the use of high-precision RT methods the indication spectrum of RT can be exploited covering different clinical situations particularly for unresectable local recurrences and oligometastatic disease.

Downregulation of Human DAB2IP Gene Expression in Renal Cell Carcinoma Results in Resistance to Ionizing Radiation

PURPOSE

Renal cell carcinoma (RCC) is known to be highly radioresistant but the mechanisms associated with radioresistance have remained elusive. We found DOC-2/DAB2 interactive protein (DAB2IP) frequently downregulated in RCC, is associated with radioresistance. In this study, we investigated the underlying mechanism regulating radioresistance by DAB2IP and developed appropriate treatment.

EXPERIMENTAL DESIGN

Several RCC lines with or without DAB2IP expression were irradiated with ionizing radiation (IR) for determining their radiosensitivities based on colony formation assay. To investigate the underlying regulatory mechanism of DAB2IP, immunoprecipitation-mass spectrometry was performed to identify DAB2IP-interactive proteins. PARP-1 expression and enzymatic activity were determined using qRT-PCR, Western blot analysis, and ELISA. In vivo ubiquitination assay was used to test PARP-1 degradation. Furthermore, in vivo mice xenograft model and patient-derived xenograft (PDX) model were used to determine the effect of combination therapy to sensitizing tumors to IR.

RESULTS

We notice that DAB2IP-deficient RCC cells acquire IR-resistance. Mechanistically, DAB2IP can form a complex with PARP-1 and E3 ligases that is responsible for degrading PARP-1. Indeed, elevated PARP-1 levels are associated with the IR resistance in RCC cells. Furthermore, PARP-1 inhibitor can enhance the IR response of either RCC xenograft model or PDX model.

CONCLUSIONS

In this study, we unveil that loss of DAB2IP resulted in elevated PARP-1 protein is associated with IR-resistance in RCC. These results provide a new targeting strategy to improve the efficacy of radiotherapy of RCC.

miR-4521-FAM129A axial regulation on ccRCC progression through TIMP-1/MMP2/MMP9 and MDM2/p53/Bcl2/Bax pathways

Clear cell renal cell carcinoma (ccRCC) is the most aggressive RCC subtype with high metastasis, chemotherapy and radiotherapy resistance, and poor prognosis. This study attempted to establish the deregulations of miR-4521 and FAM129A together with their correlation to and mechanism of regulation of ccRCC development and progression. FAM129A acted as tumor promotor and miR-4521 acted as a suppressor in ccRCC. As measured in surgical tumorous tissues from ccRCC patients, FAM129A overexpression and miR-4521 deficiency together contributed to ccRCC progression by promoting advances in patients' TNM stage and Fuhrman grade. Both the FAM129A knockdown and miR-4521 overexpression could reduce the in vitro migration and invasion abilities of renal cancer cells 786-O and ACHN, through the TIMP-1/MMP2/MMP9 pathway and could decrease their proliferation by promoting their apoptosis through the MDM2/p53/Bcl2/Bax pathway. By directly targeting the 3'-UTR domain of FAM129A, miR-4521 was negatively correlated with FAM129A/FAM129A levels in ccRCC progression and renal cancer cell malignancies. This work establishes the miR-4521-FAM129A axial regulation mechanism in ccRCC. Micro-4521 deficiency leads to FAM129A/FAM129A upregulation, which synergistically enhances the migration and invasion of renal cancer cells due to the induced decrease of TIMP-1 and increases of MMP2 and MMP9, and increases their growth through escaping apoptosis by suppressing p53 by way of upregulation of induced MDM2. The current work provides new clues to assist fundamental research into the diagnosis and treatment of ccRCC.

miR-10b suppresses cell invasion and metastasis through targeting HOXA3 regulated by FAK/YAP signaling pathway in clear-cell renal cell carcinoma

Background

MicroRNAs have been related to tumor progression in diverse human cancers including clear-cell renal cell carcinoma (ccRCC). Previous study has suggested the important regulation function of miR-10b in ccRCC. However, the direct target of miR-10b in ccRCC and the related molecular mechanisms has not yet been revealed.

Methods

miR-10b and HOXA3 was detected by qRT-PCR. MTT, colony formation assay, wound-healing and transwell assays were performed to detect cell proliferation, colony formation, migration, and invasion abilities in ccRCC. Western blot analyses were performed to evaluate the protein expression of HOXA3, YAP, FAK and MMP-9. Dual luciferase reporter assay was employed to measure potential molecular mechanism of miR-10b in ccRCC.

Results

miR-10b was down-regulated in 786-O and A498 cells as compared to renal tubular HK-2 cells. By contrast, HOXA3 and YAP was up-regulated in ccRCC cells and tissues. Functionally, knockdown of YAP inhibited cell proliferation, migration and invasion. Knockdown of FAK downregulated YAP, in turn, resulted in a decrease of HOXA3 expression. Mechanically, miR-10b targets HOXA3 to exert its tumor-suppressive effect on ccRCC in vitro.

Conclusions

These novel data suggest that miR-10b suppresses cell invasion and metastasis through targeting HOXA3, which partially passed through the FAK/YAP signaling pathway.

MiR-23a-3p acts as an oncogene and potential prognostic biomarker by targeting PNRC2 in RCC

BACKGROUND

Renal cell carcinoma (RCC) is a most common kidney malignancy, with atypical symptoms in the early stage and poor outcome in the late stage. Recently, emerging evidence revealed that some miRNAs play an essential role in the tumorigenesis and progression of RCC. Therefore, the aim of this study is that understand the detailed molecular mechanism of miR-23a-3p in RCC and identify its potential clinical value.

METHODS

In this study, RT-qPCR, wound scratch assay, cell proliferation assay, transwell assay and flow cytometry assay were performed to detect miR-23a-3p expression and its proliferation, migration and apoptosis in RCC. The bioinformatics analysis, RT-qPCR, western blot and luciferase reporter assay were performed to discern and examine the relationship between miR-23a-3p and its potential targets. Moreover, we analyzed the relationship between miR-23a-3p expression and clinicopathological variables or overall survival (OS) from 118 formalin-fixed paraffin-embedded RCC samples.

RESULTS

miR-23a-3p is significantly up-regulated in RCC tissue samples, RCC cell lines and the TCGA database. Upregulating miR-23a-3p enhances, while silencing miR-23a-3p suppresses cell viability, proliferation and mobility in ACHN and 786-O cell lines. Besides, overexpression of miR-23a-3p inhibits the cell apoptosis. Then our study further reveals that miR-23a-3p regulates tumorigenesis by targeting Proline-Rich Nuclear Receptor Coactivator 2 (PNRC2). Also, the cox proportional hazard regression analysis indicates that low expression of miR-23a-3p patients has a remarkable longer OS.

CONCLUSIONS

Our results reveals that miR-23a-3p may not only serve as a new biomarker for prognosis but also serve as a new therapeutic strategy in the RCC treatment.

MicroRNA-218 inhibits the cell proliferation and migration in clear cell renal cell carcinoma through targeting cancerous inhibitor of protein phosphatase 2A

MicroRNAs (miRs) have emerged as critical modulators of tumor initiation and progression in numerous types of human cancer, including clear cell renal cell carcinoma (ccRCC), which is the most common subtype of renal cell carcinoma. Cancerous inhibitor of protein phosphatase 2A (CIP2A) is a newly characterized oncoprotein and its overexpression has been reported to promote cellular epithelial-mesenchymal transition and the tumor progression of ccRCC. The present study examined the effects of miR-218 on CIP2A expression in ccRCC cells. The results demonstrated that the expression level of miR-218 was lower in ccRCC tissues compared with that in adjacent non-tumor renal tissues. In addition, it was identified that miR-128 could directly bind to the 3'-untranslated region of CIP2A. Furthermore, a negative correlation between the expression levels of miR-218 and CIP2A was detected in ccRCC. Additionally, the downregulation of CIP2A or overexpression of miR-218 in ccRCC cells was revealed to inhibit cell proliferation and migration. In summary, these data suggest that miR-218 serves a role in the regulation of CIP2A and elucidate its consequences on tumor progression, tumor cell proliferation and migration. These results indicate that miR-218 may exhibit potential as a molecular target for the treatment of ccRCC.

Cancer du rein et radiothérapie : radiorésistance et au-delà

KIDNEY CANCER AND RADIOTHERAPY

RADIORESISTANCE AND BEYOND: Metastatic renal cancer has a poor prognosis because of the limited impact of usual treatment modalities, and notably radiotherapy. Renal cell carcinoma is traditionally considered to be radioresistant, and conventional radiotherapy fraction sizes of 1.8 to 2 Gy are thought to have little role in its management. Technological advances in radiation oncology have led to stereotactic approaches that overcome radio resistance mechanisms of renal cancer cells and could be successful. The technical ability of applying high dose per fraction, leads to a distinct biological response which is different from the one observed with conventional irradiation through high responses rates. The increased radiobiological effect is attributed to endothelial apoptosis triggered by high fractional dose. The combination of such radiotherapy regimens with targeted drugs paves the way for new therapeutic opportunities.

Cancer du rein : tendances et perspectives

NEW TRENDS AND PERSPECTIVES IN RENAL CELL CANCER

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Soy Isoflavones Protect Normal Tissues While Enhancing Radiation Responses

Soy isoflavones have demonstrated chemopreventive and anticancer properties in epidemiology and biological studies, in addition to their function as antioxidants in prevention of cardiovascular disease. We have explored the potential of soy isoflavones, as a safe biological approach, to enhance the efficacy of radiotherapy for local tumor control and limit normal tissue damage in solid tumors. This review presents studies investigating the interaction between soy isoflavones and radiation in different malignancies, including prostate cancer, renal cell carcinoma, and nonsmall cell lung cancer. Soy isoflavones were found to be potent sensitizers of cancer cells to radiation causing increased cell killing in vitro in human tumor cell lines and greater tumor inhibition in vivo in preclinical orthotopic murine tumor models. In the course of these studies, radioprotection of normal tissues and organs in the field of radiation was observed both in a clinical trial for prostate cancer and in preclinical models. The mechanisms of radiosensitization and radioprotection mediated by soy isoflavones are discussed and emphasize the role of soy isoflavones in increasing radiation effect on tumor and mitigating inflammatory responses induced by radiation in normal tissues. Soy isoflavones could be used as a safe, nontoxic complementary strategy that simultaneously increases radiation effectiveness on the malignancy while reducing damage in normal tissues in the field of radiation.

The influence of histology on the response of brain metastases to gamma knife radiosurgery: a propensity score-matched study

BACKGROUND

In terms of response to fractionated radiotherapy, metastatic brain tumors of certain origins are considered radioresistant.

OBJECTIVE

To determine the influence of "radioresistant" histology on outcomes of brain metastases treated with radiosurgery.

METHODS

Between 2001 and 2017, 121 patients with brain metastases from renal cell carcinoma (RCC) and 2151 from non-small cell lung cancer (NSCLC) were reviewed. Eighty-seven pairs were derived using propensity score matching. Local progression-free survival (PFS), progression patterns, distant PFS, and overall survival were investigated.

RESULTS

The median follow-up period was 13.7 months (range, 1.6-78.4 months). A total of 536 lesions were treated using gamma knife radiosurgery (GKS), with a median dose of 20 Gy (range, 12-28 Gy). The actuarial local PFS rates in the RCC group were 91% and 89% at 6 and 12 months, respectively, and did not differ from the NSCLC group (97% and 83% at 6 and 12 months, respectively). Continuous progression, without response to GKS, was noted in seven of the eight progressed RCCs. However, six of the seven progressed NSCLCs showed transient shrinkage before progression. The median distant PFS was 9.3 months (95% CI, 6.3-12.2) in the RCC group and 8.0 months (95% CI, 5.5-10.4) in the NSCLC group. The median overall survival was 16.1 months (95% CI, 11.3-20.8) and 14.9 months (95% CI, 11.9-17.8) in RCC and NSCLC groups, respectively.

CONCLUSION

Histological differences had no effect on local control in the single high-dose range used for radiosurgery. However, changes in tumor volume during progression varied across tumor histology.

Marked response to nivolumab combined with external radiation therapy for metastatic renal cell carcinoma: report of two cases

Although nivolumab has been regarded as a standard agent for patients with previously treated advanced renal cell carcinoma (RCC), a significant proportion of these patients fail to achieve a response to nivolumab. In recent years, several studies have reported the favorable therapeutic impact of combined therapy with immune checkpoint inhibitors and radiotherapy on a wide variety of advanced malignant tumors, such as melanoma and lung cancer; however, the significance of this combined treatment for advanced RCC patients has not been well characterized. Here, we report two patients with metastatic RCC showing a marked response to nivolumab and external radiation therapy, including one with an abscopal response, after progression on prior treatment with multiple targeted agents. Based on the clinical courses of these two patients suggesting additive or synergistic efficacies on combining radiation with nivolumab, it might be worthwhile to consider the addition of radiotherapy for metastatic RCC patients treated with nivolumab.

Adjuvant Radiation Therapy After Radical Nephrectomy in Patients with Localized Renal Cell Carcinoma: A Systematic Review and Meta-analysis

CONTEXT

Adjuvant radiation therapy has been recommended for patients at higher risk of relapse from renal cell carcinoma (RCC) to improve disease-free survival (DFS) and overall survival (OS) after radical nephrectomy.

OBJECTIVE

To quantify the benefit of adjuvant radiation therapy.

EVIDENCE ACQUISITION

A systematic review of electronic databases identified publications exploring the association between adjuvant radiation therapy and locoregional recurrence (LRR), DFS, and OS among patients after radical nephrectomy for early-stage RCC. Hazard ratios for DFS were weighted and pooled using the generic inverse variance and random effects model. Odds ratios for LRR, DFS, and OS at 5yr were weighted and pooled in a meta-analysis using Mantel-Haenszel random-effects modeling.

EVIDENCE SYNTHESIS

Twelve studies comprising 1624 patients were included in the analysis. Ten studies were retrospective and two were randomized controlled trials. Adjuvant radiation therapy was delivered to 37% of patients. The median follow-up was 49mo. Adjuvant radiation therapy was not associated with better DFS or OS at 5yr, but was associated with less LRR.

CONCLUSIONS

With the caveat that confounding by indication may result from pooling data from predominantly nonrandomized studies, adjuvant radiation after radical nephrectomy was not associated with improved DFS or OS but was associated with less LRR.

PATIENT SUMMARY

Radiation therapy after resection of renal cell carcinoma with a high risk of relapse may reduce the risk of local recurrence but not the risk of disease recurrence or death after 5yr.

Stereotactic body radiation therapy (SBRT) on renal cell carcinoma, an overview of technical aspects, biological rationale and current literature

BACKGROUND

Stereotactic body radiotherapy (SBRT) is characterized by the delivery of high doses of ionizing radiation in few fractions. It is highly effective in achieving local control, and, due to the high biological effective dose administered, it seems to overcome the radioresistance of renal cell carcinoma (RCC). Thus, SBRT could constitute a treatment option for the management of localized RCC in patients who are not surgical candidates. In this paper, we report an overview about data from the current evidence about SBRT in patients affected by localized RCC.

MATERIALS AND METHODS

A non-systematic review was performed, including data from both retrospective and prospective studies focusing on the use of SBRT for localized RCC and its biological rationale. Furthermore, ongoing trials on this issue are reported.

CONCLUSION

Currently, SBRT might be considered a treatment alternative in inoperable patients affected by primary RCC. Currently, dose-escalation to 48 Gy in 3-4 fractions are effective and well tolerated. Emerging role of immune therapies in RCC patients warrant further studies to explore interactions between SBRT and immune response.

Prognostic nomograms based on log odds of positive lymph nodes for patients with renal cell carcinoma: A retrospective cohort study

OBJECTIVES

The aim of the current study is to build prognostic nomograms for patients with renal cell carcinoma (RCC) and compare the predictive performance with the American Joint Committee on Cancer (AJCC) staging system.

METHODS

A total of 9453 patients were identified (2005-2015) from the Surveillance Epidemiology and End Results (SEER) database. Propensity-score matching (PSM) was conducted to reduce selective bias. The matched cohort was further divided equally into the development and the validation cohort. Nomograms based on log odds of positive lymph nodes (LODDS) were formulated to predict individualized cancer-specific survival (CSS) and overall survival (OS) for RCC. Then, the performance of nomograms was internally and externally validated via the concordance index (C-index) and calibration plots. Decision curve analysis (DCA) was used to compare the clinical practicable between nomograms and AJCC staging system.

RESULTS

LODDS was identified as an independent prognostic indicator for CSS and OS using univariate and multivariate Cox regression analyses. Two nomograms incorporating LODDS were formulated. The C-indices of the nomograms for predicting CSS and OS were 0.7561 (95% CI, 0.7356-0.7766) and 0.7140 (95% CI, 0.6936-0.7343) in the development cohort, which was higher than C-index of the AJCC staging system. The results were reproducible in the validation cohort. Moreover, internal and external calibration plots showed that the nomograms-predicted was consistent with the actual observation. Additionally, DCA demonstrated that the nomograms were superior to the AJCC staging system with obtaining more clinical net benefit.

CONCLUSIONS

LODDS could be considered as a reliable prognostic factor for patients with RCC. Two nomograms were able to more accurately and applicable than the AJCC staging system for predicting CSS and OS.

Metabolic Footprinting of a Clear Cell Renal Cell Carcinoma in Vitro Model for Human Kidney Cancer Detection

A protocol for harvesting and extracting extracellular metabolites from an in vitro model of human renal cell lines was developed to profile the exometabolome by means of a discovery-based metabolomics approach using ultraperformance liquid chromatography coupled to quadrupole-time-of-flight mass spectrometry. Metabolic footprints provided by conditioned media (CM) samples ( n = 66) of two clear cell Renal Cell Carcinoma (ccRCC) cell lines with different genetic backgrounds and a nontumor renal cell line, were compared with the human serum metabolic profile of a pilot cohort ( n = 10) comprised of stage IV ccRCC patients and healthy individuals. Using a cross-validated orthogonal projection to latent structures-discriminant analysis model, a panel of 21 discriminant features selected by iterative multivariate classification, allowed differentiating control from tumor cell lines with 100% specificity, sensitivity, and accuracy. Isoleucine/leucine, phenylalanine, N-lactoyl-leucine, and N-acetyl-phenylalanine, and cysteinegluthatione disulfide (CYSSG) were identified by chemical standards, and hydroxyprolyl-valine was identified with MS and MS/MS experiments. A subset of 9 discriminant features, including the identified metabolites except for CYSSG, produced a fingerprint of classification value that enabled discerning ccRCC patients from healthy individuals. To our knowledge, this is the first time that N-lactoyl-leucine is associated with ccRCC. Results from this study provide a proof of concept that CM can be used as a serum proxy to obtain disease-related metabolic signatures.

Novel Insights into the Management of Oligometastatic Prostate Cancer: A Comprehensive Review

CONTEXT

The current standard of care for metastatic prostate cancer (PCa) is androgen deprivation therapy (ADT) plus either docetaxel or abiraterone. Growing evidence suggests that metastasis-directed therapy (MDT) and/or local therapy targeted to the primary tumour (ie, prostate) may be of benefit in the setting of oligometastatic disease. Several prospective studies are underway; however, until robust evidence is available to guide treatment decisions, physicians are challenged with how best to manage patients with oligometastases.

OBJECTIVE

This comprehensive review aims to collate the available evidence to date for a role of MDT and/or prostate-targeted therapy in the setting of oligometastatic PCa, as well as discuss ongoing trials in this setting.

EVIDENCE ACQUISITION

We searched PubMed for the combination of "prostate cancer" and "oligometastatic", "oligometastases", "oligometastasis", "solitary metastases", "stereotactic body radiotherapy", "SBRT", "stereotactic ablative radiotherapy", "SABR", "salvage lymphadenectomy", or "metastasectomy" in publications over the last 20yr. We also searched ClinicalTrials.gov to identify relevant ongoing trials.

EVIDENCE SYNTHESIS

The studies were divided according to the timing of metastasis into synchronous (ie, detected at the time of primary PCa diagnosis) and metachronous (ie, detected after treatment of the primary tumour), and according to treatment modality into MDT (including salvage lymph node dissection [sLND]) and prostate-targeted treatment. For MDT of synchronous/metachronous metastases, we included 16 completed studies and 11 ongoing prospective studies. In the case of sLND for nodal-only recurrence after primary treatment with curative intent, we included 11 completed studies. Finally, for prostate-targeted treatment of synchronous metastatic PCa, we included 25 completed studies and 11 ongoing prospective studies. In selected patients with oligorecurrent disease, early detection and aggressive treatment of metastatic lesions (surgery or radiotherapy) appears to be a feasible strategy and may delay the use of systemic therapies. MDT is a promising option in oligometastatic PCa patients, but more robust data are needed. In the setting of synchronous oligometastatic disease, aggressive cytoreductive treatment needs further data to confirm the benefits.

CONCLUSIONS

In this review, we provide a comprehensive overview of the current literature on the treatment of patients with oligometastatic PCa. The data suggest that although ADT plus either docetaxel or abiraterone remains the mainstay of treatment for mPCa, in oligometastatic PCa, improved outcomes may be achieved with metastasis- and prostate-targeted therapies. The studies included in this review are mainly retrospective in nature, limiting the strength of the evidence they provide. Prospective studies are ongoing, and their results are eagerly awaited.

PATIENT SUMMARY

We reviewed the treatment of patients with prostate cancer that has spread to five sites or fewer. We conclude that while androgen deprivation plus either docetaxel or abiraterone should remain the standard of care, there is evidence that treatment targeted at the metastases and the primary tumour may improve the outcome for the patient and potentially delay the use of systemic treatment.

Intrafraction Motion Management of Renal Cell Carcinoma With Magnetic Resonance Imaging-Guided Stereotactic Body Radiation Therapy

PURPOSE

One of the major challenges in stereotactic body radiation therapy (SBRT) of renal cell carcinoma is internal motion during treatment. Previous literature has aimed to mitigate the effects of motion by expanding the treatment margins or respiratory tracking. Online magnetic resonance imaging (MRI)-guided radiation therapy has the potential to further improve the treatment of renal cell carcinoma by direct visualization of the tumor during treatment. The efficacy of 2 motion management techniques were assessed: tumor trailing and respiratory tracking. The simulation of a single-fraction, MRI-based SBRT was performed to quantify intrafraction motion and assess the efficacy of the different motion management strategies.

METHODS AND MATERIALS

Fifteen patients were included in the study. At the beginning and end of the scanning protocol, 2 cine-MRI scans were acquired to assess cyclic respiratory motion. In addition, 3-dimensional spoiled gradient echo scans were acquired at 4 different time points to assess the slow drifts over 25 minutes. The systematic and random errors owing to intrafraction drift were calculated, as well as the random error induced by respiratory motion. The motion margins were calculated for tumor trailing and respiratory tracking and compared with the margin when no motion compensation would be performed to assess the relative efficacy of each technique.

RESULTS

The largest respiratory tumor motion was observed along the caudo-cranial direction with a median 95% maximum amplitude of approximately 12 mm. Σ_DRIFT, σ_DRIFT, and σ_RESP were determined to be 1.0 mm 1.8 mm, and 3.8 mm, respectively. Without mechanical immobilization, intrafraction drift accounted for 75% of the total intrafraction motion margin for online midposition-based SBRT treatments.

CONCLUSIONS

The contribution of intrafraction drift to the total internal motion margin is much larger than periodic respiratory motion. This makes tumor trailing a viable option to consider on the MRI linac because it allows for 3-dimensional MRI acquisitions during beam delivery, which simplifies the introduction of new techniques, such as dose accumulation and online intrafraction replanning.

A phase I dose-escalation trial of stereotactic ablative body radiotherapy for non-spine bone and lymph node metastases (DESTROY-trial)

Background

In an oligometastatic setting, metastasis-directed treatment could render patients disease free, possibly for a protracted interval. Stereotactic ablative radiotherapy (SABR) is one of the treatment modalities that can be offered to these patients. In addition, the radiobiological qualities of SABR are promising for the use in perceived radioresistant tumours. There is also emerging evidence that SABR can stimulate the immune response, and a specific therapeutic window may exist for the optimal use of radiotherapy as an immune adjuvant. However, when SABR is considered for non-spine bone or lymph node metastases, the optimal fractionation schedule is not yet known.

Methods

The DESTROY-trial is a non-randomized prospective phase I trial determining a regimen of choice for patients with non-spine bone and lymph node metastases. A total of 90 patients will be included in three different treatment regimens. They will be offered stereotactic ablative radiotherapy in 5, 3 or 1 fractions. Dose-limiting toxicity will be recorded as primary endpoint. Acute and late toxicity, local response and local recurrence, and progression-free survival are secondary endpoints. Liquid biopsies will be collected throughout the course of this study from the second fractionation schedule on.

Discussion

Despite its almost universal use in (oligo-)metastatic patients, the level of evidence supporting radical local treatment in general, and stereotactic radiotherapy in particular, is low. This prospective phase I trial will evaluate different SABR regimens for metastases and the differences in immune-stimulatory effects.

Trial registration

The Ethics committee of the GZA Hospitals (B099201732915) approved this study on 05/07/2017. Amendment for translational research was approved on 06/02/2018. Trial registered on Clinicaltrials.gov (NCT03486431) on 03/04/2018 – Retrospectively registered.

Systematic Review of the Management of Local Kidney Cancer Relapse

CONTEXT

Management of locally recurrent renal cancer is complex.

OBJECTIVE

In this systematic review we analyse the available literature on the management of local renal cancer recurrence.

EVIDENCE ACQUISITION

A systematic search (PubMed, Web of Science, CINAHL, Clinical Trials, and Scopus) of English literature from 2000 to 2017 was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines.

EVIDENCE SYNTHESIS

The search identified 1838 articles. Of those, 36 were included in the evidence synthesis. The majority of the studies identified were retrospective and not controlled. Local recurrence after thermal ablation (TA) may be managed with repeat TA. Alternatively, salvage nephrectomy is possible. However, a higher rate of complications should be expected than after primary nephrectomy. Salvage nephrectomy and TA represent treatment options for local recurrence after partial nephrectomy. Local retroperitoneal recurrence after radical nephrectomy is ideally treated with surgical resection, for which minimally invasive approaches might be applicable to select patients. For large recurrences, addition of intraoperative radiation may improve local control. Local tumour destruction appears to be more beneficial than systemic therapy alone for local recurrences.

CONCLUSIONS

Management of local renal cancer relapse varies according to the clinical course and prior treatments. The available data are mainly limited to noncontrolled retrospective series. After nephron-sparing treatment, TA represents an effective treatment with low morbidity. For local recurrence after radical nephrectomy, the low-level evidence available suggests superiority of surgical excision relative to systemic therapy or best supportive care. As a consequence, surgery should be prioritised when feasible and applicable.

PATIENT SUMMARY

In renal cell cancer, the occurrence and management of local recurrence depend on the initial treatment. This cancer is a disease with a highly variable clinical course. After initial organ-sparing treatment, thermal ablation offers good cancer control and low rates of complications. For recurrence after radical nephrectomy, surgical excision seems to provide the best long-term cancer control and it is superior to medical therapy alone.

Radiation therapy in renal cell carcinoma

Renal cell carcinoma (RCC) is classically regarded as extremely resistant to classical fractionated radiation therapy (RT). Nowadays, there is convincing data supporting RCC radiosensitivity to high fraction doses, which may represent an ideal issue for new treatment strategies in primary and oligometastatic RCC disease. This review discusses the role of RT in RCC and its potential therapeutic scenario focusing on the most interesting clinical trials.

Neutrophil-Based Drug Delivery Systems

White blood cells (WBCs) are a major component of immunity in response to pathogen invasion. Neutrophils are the most abundant WBCs in humans, playing a central role in acute inflammation induced by pathogens. Adhesion to vasculature and tissue infiltration of neutrophils are key processes in acute inflammation. Many inflammatory/autoimmune disorders and cancer therapies have been found to be involved in activation and tissue infiltration of neutrophils. A promising strategy to develop novel targeted drug delivery systems is the targeting and exploitation of activated neutrophils. Herein, a new drug delivery platform based on neutrophils is reviewed. There are two types of drug delivery systems: neutrophils as carriers and neutrophil-membrane-derived nanovesicles. It is discussed how nanoparticles hijack neutrophils in vivo to deliver therapeutics across blood vessel barriers and how neutrophil-membrane-derived nanovesicles target inflamed vasculature. Finally, the potential applications of neutrophil-based drug delivery systems in treating inflammation and cancers are presented.

Role of metastasis-directed treatment in kidney cancer

Despite the rapid elaboration of multiple, novel systemic agents introduced for metastatic renal cell carcinoma (mRCC) in recent years, a durable complete response remains elusive with systemic therapy alone. Definitive treatment of the metastatic deposit remains the sole potentially curative option and is a cornerstone of mRCC therapy, offering potential for both local control and palliation of tumor-related symptoms. In this review, the evidence supporting the definitive treatment of mRCC is examined and summarized, including the use of surgical metastasectomy, thermal ablation, radiotherapy, and other minimally invasive options. Multimodal approaches, including the combination of metastasectomy with novel systemic agents, are discussed. Finally, the authors review considerations for patient selection for this type of therapy and summarize available risk-stratification tools that may help guide shared decision making.

Cancer immunotherapy: new applications in urologic oncology

PURPOSE OF REVIEW

Immunotherapy in urological cancer has made substantial progress during the last 20 years, but recent advances in immunotherapy have completely transformed the present treatment landscape. In this review, we summarize major clinical achievements of immunotherapy in genitourinary cancers, as well as address potential new directions for these therapies, including new agents, combinations, and biomarkers.

RECENT FINDINGS

Recently, nivolumab and atezolizumab have joined sipuleucel-T as Food and Drug Administration-approved therapies in urological malignancies. Additional checkpoint inhibitors and vaccines are being tested in clinical trials. Furthermore, significant work has been done exploring predictors of response to therapy.

SUMMARY

Immunotherapy has changed the treatment of urologic malignancies. New immunotherapies and novel combinations will continue to create new treatment options in urologic tumors.

Current and Emerging Therapeutic Targets for Metastatic Renal Cell Carcinoma

PURPOSE OF REVIEW

The treatment of advanced renal cell carcinoma has evolved dramatically over recent years. In this review, we will summarize current and emerging therapies based on molecular targets and provide insight into treatment strategy for metastatic renal cell carcinoma.

RECENT FINDINGS

We have witnessed a paradigm shift in the therapeutic landscape as treatment was formerly reliant on cytokine-based agents which have now been replaced with therapies targeting angiogenesis, mammalian target of rapamycin pathways, and immune responses. These dramatic changes are primarily due to our improved understanding of the underlying mutations and molecular mechanisms leading to tumorigenesis and progression. We now have targeted agents in the form of small-molecule tyrosine kinase inhibitors, monoclonal antibodies, and mTOR inhibitors. Moreover, immunotherapy-targeting checkpoints of T-lymphocyte activity has provided increased overall survival and a new class of agents with potential to radically change the treatment options. With these agents and their combination, durable responses are increasingly seen even though treatment resistance remains a huge challenge. New treatment strategies are rapidly developing and the therapeutic landscape is expected for further evolution.

Wilms' tumor 1-associating protein promotes renal cell carcinoma proliferation by regulating CDK2 mRNA stability

Background

Wilms’ tumor 1-associating protein (WTAP) plays an important role in physiological processes and the development of tumor such as cell cycle regulation. The regulation of cell cycle is mainly dependent on cyclins and cyclin-dependent protein kinases (CDKs). Recent studies have shown that CDKs are closely related to the tumor diagnosis, progression and response to treatment. However, their specific biological roles and related mechanism in renal cell carcinoma (RCC) remain unknown.

Methods

Quantitative real-time PCR, western blotting and immunohistochemistry were used to detect the expression of WTAP and CDK2. The survival analysis was adopted to explore the association between WTAP expression and the prognosis of RCC. Cells were stably transfected with lentivirus approach and cell proliferation and cell cycle, as well as tumorigenesis in nude mice were performed to assess the effect of WTAP in RCC. RNA immunoprecipitation, Luciferase reporter assay and siRNA were employed to identify the direct binding sites of WTAP with CDK2 transcript. Colony formation assay was conducted to confirm the function of CDK2 in WTAP-induced growth promoting.

Results

In RCC cell lines and tissues, WTAP was significantly over-expressed. Compared with patients with low expression of WTAP, patients with high expression of WTAP had lower overall survival rate. Additionally, cell function test indicated that cell proliferation abilities in WTAP over-expressed group were enhanced, while WTAP knockdown showed the opposite results. Subcutaneous xenograft tumor model displayed that knockdown of WTAP could impede tumorigenesis in vivo. Mechanism study exhibited that CDK2 expression was positively associated with the expression of WTAP. Moreover, WTAP stabilized CDK2 transcript to enhance CDK2 expression via binding to 3′-UTR of CDK2 transcript. Additionally, specific inhibitors of CDK2 activity and small interfering RNA (siRNA) of CDK2 expression inhibited WTAP-mediated promotion of proliferation.

Conclusions

These findings suggest that WTAP may have an oncogenic role in RCC through physically binding to CDK2 transcript and enhancing its transcript stability which might provide new insights into RCC therapy.

Electronic supplementary material

The online version of this article (10.1186/s13046-018-0706-6) contains supplementary material, which is available to authorized users.

Overview of Current and Future First-Line Systemic Therapy for Metastatic Clear Cell Renal Cell Carcinoma

OPINION STATEMENT

Treatment of metastatic clear cell renal cancer (mccRCC) has seen substantial progress over the last 20 years, with many regulatory approvals since 2006 culminating in a substantial increase to overall survival (OS). Six therapies are currently available for first-line use, with additional treatments currently being tested in this setting, some of which are expected to be approved soon based on new data from the CABOSUN and CheckMate-214 trials. Based on the available evidence, we strongly believe that vascular endothelial growth factor tyrosine kinase inhibitor (VEGF-TKI) therapy over mechanistic target or rapamycin (mTOR; formerly known as mammalian target of rapamycin) inhibitor therapy is the most effective first-line option regardless of risk category assignment. High-dose interleukin-2 (HDIL-2) therapy remains a reasonable treatment option in patients with Eastern Cooperative Oncology Group (ECOG) performance status 0-1 and have minimal comorbid conditions. In the near future, these agents are likely to be surpassed by cabozantinib and by combination immune checkpoint inhibitor therapy with nivolumab and ipilimumab. Independent review has recently confirmed superiority of first-line cabozantinib over sunitinib in a phase 2 trial of 157 patients with intermediate or poor risk mccRCC (progression-free survival [PFS] 8.6 vs 5.3 months, hazard ratio [HR] 0.48, p = 0.0008). In a separate study of 1096 patients treated with either upfront sunitinib or the combination of nivolumab and ipilimumab, those with intermediate and poor risk had significant improvement in both PFS (11.6 vs 8.4 months, HR 0.82, p = 0.0331) and OS (not reached vs 26 months, p < 0.0001). Responses were greater in patients with positive programmed death receptor ligand-1 (PD-L1) tumor staining, and pending regulatory approval may become standard of care in untreated patients with intermediate to poor risk disease with positive PD-L1 status. This likely represents the beginning of additional novel immunotherapy combinations for the first-line treatment of mccRCC.

The Role of YB1 in Renal Cell Carcinoma Cell Adhesion

Background: Y-box binding protein 1 (YB1) is a multifunctional protein involved in many processes related to cancer progression and metastasis. Methods: In this study, we constructed YB1 knockdown stable renal cell carcinoma (RCC) cell line 786-0. The gene expression profile of 786-0 was performed by DNA microarray analysis to identify genes that were regulated by YB1. Real-time PCR and western blotting were used to test the genes and proteins expression. Transforming growth factor-β (TGF-β) activity was detected by dual-luciferase reporter assay. Cell adhesion assay was used to determine RCC cell adhesion ability. Results: Pathway analysis revealed that YB1 knockdown influenced cell adhesion molecules (CAMs). We further verified four genes (CLDN4, NRXN3, ITGB8, and VCAN) related to CAMs by real-time PCR, and confirmed that YB1 regulated the expression of ITGB8 in RCC. Functional assays demonstrated that knockdown of YB1 significantly inhibited the cell adhesion of 786-0 cells in vitro. In addition, YB1 affected TGF-β activation. Conclusion: Our study demonstrated that YB1 modulated the adhesion ability of renal cell carcinoma cells by regulating ITGB8 and TGF-β.

Renal Cell Carcinoma in von Hippel-Lindau Disease-From Tumor Genetics to Novel Therapeutic Strategies

von Hippel-Lindau (VHL) disease is an autosomal dominant syndrome caused by mutations in the VHL tumor-suppressor gene, leading to the dysregulation of many hypoxia-induced genes. Affected individuals are at increased risk of developing recurrent and bilateral kidney cysts and dysplastic lesions which may progress to clear cell renal cell carcinoma (ccRCC). Following the eponymous VHL gene inactivation, ccRCCs evolve through additional genetic alterations, resulting in both intratumor and intertumor heterogeneity. Genomic studies have identified frequent mutations in genes involved in epigenetic regulation and phosphoinositide 3-kinase-AKT-mechanistic target of rapamycin (mTOR) pathway activation. Currently, local therapeutic options include nephron-sparing surgery and alternative ablative procedures. For advanced metastatic disease, systemic treatment, including inhibition of vascular endothelial growth factor pathways and mTOR pathways, as well as immunotherapy are available. Multimodal therapy, targeting multiple signaling pathways and/or enhancing the immune response, is currently being investigated. A deeper understanding of the fundamental biology of ccRCC development and progression, as well as the development of novel and targeted therapies will be accelerated by new preclinical models, which will greatly inform the search for clinical biomarkers for diagnosis, prognosis, and response to treatment.