Treatment of metastatic renal cell carcinoma

Incidental discovery of metastatic renal cell carcinoma at the vaginal wall: A case report

Metastasis of renal cell carcinoma (RCC) to the vaginal wall has rarely been reported in the literature. We present a case of a 48-year-old who was found to have a solitary RCC metastasis at the vaginal wall, five years following radical nephrectomy. This case is noteworthy because this late presentation is unique, with prior reports of synchronous metastasis or metastasis within two years of nephrectomy, highlighting the need to consider metastatic RCC to the vagina a possibility even many years after treatment.

The role of immunotherapy treatment in non-clear cell renal cell carcinoma: an analysis of the literature

Non-clear cell renal cell carcinoma (nccRCC) is a heterogeneous group representing 15-30% of renal tumors. They are mostly excluded from immunotherapy trials due to their rarity and worse prognosis. This, alongside nccRCC misdiagnosis/misclassification, lack of immune-biomarker expression rate data, lack of homogeneous data reporting, the retrospective nature of many studies, small sample sizes, and the fact that high-grade evidence only stems from trials mostly addressing the clear cell subtype, result in poorly defined treatments. We thus reviewed available data from several clinical trials, retrospective studies, and meta-analyses on immunotherapy responses and their correlation with histological subtypes and prognostic biomarkers. The papillary and unclassified subtypes are the best candidate for immunotherapy, showing response rates up to ~35%. Chromophobe cancers, on the other end, have mostly null response rates. Cancers with sarcomatoid features respond very well to immunotherapy, regardless of their histology. Available data for translocation, medullary, collecting duct, and other nccRCCs are inconclusive. Regarding PD-L1, its expression correlates with better responses, but its prognostic value remains to be determined due to small sample sizes hindering direct statistical comparisons. It is necessary to involve a larger number of nccRCC patients and centers in clinical trials and report tumor response rates and PD-(L)1 and other markers' expression rates divided by nccRCC subtypes and not just for the whole cohorts. This will allow us to collect more robust data to best identify patients who can benefit from immunotherapy and ultimately define the standard of treatment. AVAILABILITY OF DATA AND MATERIAL: N/A.

Vascular mimicry induced by m6A mediated IGFL2-AS1/AR axis contributes to pazopanib resistance in clear cell renal cell carcinoma

Metastatic clear cell renal cell carcinoma (ccRCC) is a lethal sub-type of kidney cancer. Vascular mimicry (VM) has been postulated as an alternative route to supply tumors with nutrients, playing key role in tumor development. Whether VM development is linked to pazopanib efficacy, however, remains unclear. Here, our in vitro and in vivo models identified that VM development was profoundly increased in pazopanib resistant ccRCC as compared to the sensitive controls, which was due to the activation of IGFL2-AS1/AR/TWIST1 signaling. IGFL2-AS1, a m⁶A modified long coding RNA, was demethylated by METTL3/METTL14 complex and stabilized owing to its failing recognition by YTHDF2 upon chronic pazopanib treatment. Further mechanistic dissection illustrated that IGFL2-AS1 physically interacted with the 5'-UTR AR mRNA and neutralized the negative regulation of 5'-uORF (upstream open reading frame) on AR translation. Indeed, IGFL2-AS1 short of AR binding region failed to promote AR expression, VM formation and pazopanib resistance. In vivo xenografted mouse model also elucidated that inhibition of AR activity with enzalutamide or silence of IGFL2-AS1 with siRNAs all led to retarded growth of pazopanib resistant ccRCC tumors. Together, these results suggest that IGFL2-AS1 may represent a key player to mediate pazopanib-induced VM formation of ccRCC cells via regulating AR expression and targeting this newly identified IGFL2-AS1/AR signaling may help us to better suppress ccRCC VM formation and to increase the therapeutic efficacy of pazopanib.

Aurora-A/FOXO3A/SKP2 axis promotes tumor progression in clear cell renal cell carcinoma and dual-targeting Aurora-A/SKP2 shows synthetic lethality

Renal cell carcinoma (RCC) is a common malignant tumor in the world. Histologically, most of RCC is classified as clear cell renal cell carcinoma (ccRCC), which is the most prevalent subtype. The overall survival of patients with ccRCC is poor, thus it is urgent to further explore its mechanism and target. S-phase kinase-associated protein 2 (SKP2) is overexpressed in a variety of human cancers and is associated with poor prognosis by enhancing tumor progression. However, it is unclear whether or how SKP2 is involved in ccRCC progression. Here, we reported that overexpression of SKP2 enhanced cell proliferation of ccRCC, while SKP2 depletion exhibited the opposite effect. Bioinformatic analyses found that SKP2 was positively correlated with Aurora-A (Aur-A) in ccRCC. The protein and mRNA levels of SKP2 were elevated or reduced by Aur-A overexpression or silencing, respectively. It was further found that Aur-A caused an increase phosphorylation of FOXO3A, which is a negatively transcription factor for SKP2. Interestingly, SKP2 mediated ubiquitylation and degradation of FOXO3A depend on the kinase activity of Aur-A. The combination of Aur-A inhibitor MLN8237 and SKP2 inhibitor SZL P1-41 showed a synergistic tumor growth inhibition in vivo and in vitro of ccRCC models. Thus, our data reveal that Aurora-A/FOXO3A/SKP2 axis promotes tumor progression in ccRCC, and the double inhibition of SKP2 and Aur-A shows significant synergistic effect, which indicates a potential new therapeutic strategy for ccRCC.

Integrated bioinformatics analysis to identify the key gene associated with metastatic clear cell renal cell carcinoma

Metastasis of clear cell renal cell carcinoma (ccRCC) is a leading cause of death. The purpose of this research was to investigate the key gene in ccRCC tumor metastasis. Three microarray datasets (GSE22541, GSE85258, and GSE105261), which included primary and metastatic ccRCC tissues, were obtained from the Gene Expression Omnibus (GEO) database. Expression profiling and clinical data of ccRCC were downloaded from The Cancer Genome Atlas (TCGA) dataset. A total of 20 overlapping differentially expressed genes (DEGs) were identified using the R limma package. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis indicated that the DEGs were mainly enriched in tumor metastasis-related pathways. Gene expression analysis and survival analysis in the GEPIA2 database further identified the key gene HSD11B2. qRT-PCR result manifested that HSD11B2 level was significantly down-regulated in ccRCC tissues compared with adjacent normal tissues. ROC analysis showed that HSD11B2 exhibited good diagnostic efficiency for metastatic and non-metastatic ccRCC. Univariate and multivariate Cox regression analysis showed that HSD11B2 expression was an independent prognostic factor. To establish a nomogram combining HSD11B2 expression and clinical factors, and a new method for predicting the survival probability of ccRCC patients. Gene Set Enrichment Analysis (GSEA) enrichment results showed that low expression of HSD11B2 was mainly enriched in tumor signaling pathways and immune-related pathways. Immune analysis revealed a significant correlation between HSD11B2 and tumor immune infiltrates in ccRCC. This study suggests that HSD11B2 can serve as a potential biomarker and therapeutic target for ccRCC metastasis.

Nucleolar Proteins and Non-Coding RNAs: Roles in Renal Cancer

Renal cell cancer is the most frequent kidney malignancy. Most RCC cases are classified as clear cell renal cell carcinoma (ccRCC), characterized by high aggressiveness and poor prognosis for patients. ccRCC aggressiveness is defined by classification systems based on changes in morphology of nucleoli, the membraneless substructures of nuclei. The latter act as the sites of ribosome biogenesis as well as the hubs that trap and immobilize proteins, preventing their action in other cellular compartments. Thereby, nucleoli control cellular functioning and homeostasis. Nucleoli are also the sites of activity of multiple noncoding RNAs, including snoRNAs, IGS RNA, and miRNAs. Recent years have brought several remarkable discoveries regarding the role of nucleolar non-coding RNAs, in particular snoRNAs, in ccRCC. The expression of snoRNAs is largely dysregulated in ccRCC tumors. snoRNAs, such as SNHG1, SNHG4 and SNHG12, act as miRNA sponges, leading to aberrant expression of oncogenes and tumor suppressors, and directly contributing to ccRCC development and progression. snoRNAs can also act without affecting miRNA functioning, by altering the expression of key oncogenic proteins such as HIF1A. snoRNAs are also potentially useful biomarkers of ccRCC progression. Here, we comprehensively discuss the role of nucleolar proteins and non-coding RNAs in ccRCC.

Norcantharidin induces G2/M arrest and apoptosis via activation of ERK and JNK, but not p38 signaling in human renal cell carcinoma ACHN cells

Renal cell carcinoma (RCC) is generally acknowledged as the most resistant primary malignancy unresponsive to conventional radiotherapy and chemotherapy treatments. Norcantharidin (NCTD), a therapeutic compound derived from medicinal plants, has been shown to trigger apoptosis, as well as antimetastatic and antioxidant activities in several tumor cells. However, NCTD's mechanism of antitumor activity in the RCC cell line remains unclear. In this study, we report that NCTD led to a time- and dose-dependent inhibition of cell proliferation. It had also markedly induced apoptosis and G2/M phase cell cycle arrest in a dose-dependent manner by decreasing the expressions of pro-caspase-3, pro-caspase-9, cyclin B1, and pCDC25C while increasing active caspase-3, cleaved-PARP, P21, and pCDC2 levels. Interestingly, NCTD treatment provoked the phosphorylation of extracellular-regulated protein kinase (ERK) and c-Jun-N-terminal kinase (JNK), but not of p38 MAPK. Moreover, SCH772984 and SP600125, ERK and JNK inhibitors, respectively, could partially abolish NCTD-induced apoptosis and G2/M phase cell cycle arrest. Collectively, these findings suggest that NCTD might activate JNK and ERK signaling pathways, consequently inducing apoptosis and G2/M arrest through the modulation of related proteins. This study provided evidence that NCTD is a promising therapeutic drug for the treatment of RCC.

Carrier-Enhanced Anticancer Efficacy of Sunitinib-Loaded Green Tea-Based Micellar Nanocomplex beyond Tumor-Targeted Delivery

Although a few nanomedicines have been approved for clinical use in cancer treatment, that recognizes improved patient safety through targeted delivery, their improved efficacy over conventional drugs has remained marginal. One of the typical drawbacks of nanocarriers for cancer therapy is a low drug-loading capacity that leads to insufficient efficacy and requires an increase in dosage and/or frequency of administration, which in turn increases carrier toxicity. In contrast, elevating drug-loading would cause the risk of nanocarrier instability, resulting in low efficacy and off-target toxicity. This intractable drug-to-carrier ratio has imposed constraints on the design and development of nanocarriers. However, if the nanocarrier has intrinsic therapeutic effects, the efficacy would be synergistically augmented with less concern for the drug-to-carrier ratio. Sunitinib-loaded micellar nanocomplex (SU-MNC) was formed using poly(ethylene glycol)-conjugated epigallocatechin-3-O-gallate (PEG-EGCG) as such a carrier. SU-MNC specifically inhibited the vascular endothelial growth factor-induced proliferation of endothelial cells, exhibiting minimal cytotoxicity to normal renal cells. SU-MNC showed enhanced anticancer effects and less toxicity than SU administered orally/intravenously on human renal cell carcinoma-xenografted mice, demonstrating more efficient effects on anti-angiogenesis, apoptosis induction, and proliferation inhibition against tumors. In comparison, a conventional nanocarrier, SU-loaded polymeric micelle (SU-PM) comprised of PEG-b-poly(lactic acid) (PEG-PLA) copolymer, only reduced toxicity with no elevated efficacy, despite comparable drug-loading and tumor-targeting efficiency to SU-MNC. Improved efficacy of SU-MNC was ascribed to the carrier-drug synergies with the high-performance carrier of PEG-EGCG besides tumor-targeted delivery.

Patient derived renal cell carcinoma xenografts exhibit distinct sensitivity patterns in response to antiangiogenic therapy and constitute a suitable tool for biomarker development

Systemic treatment is necessary for one third of patients with renal cell carcinoma. No valid biomarker is currently available to tailor personalized therapy. In this study we established a representative panel of patient derived xenograft (PDX) mouse models from patients with renal cell carcinomas and determined serum levels of high mobility group B1 (HMGB1) protein under treatment with sunitinib, pazopanib, sorafenib, axitinib, temsirolimus and bevacizumab. Serum HMGB1 levels were significantly higher in a subset of the PDX collection, which exhibited slower tumor growth during subsequent passages than tumors with low HMGB1 serum levels. Pre-treatment PDX serum HMGB1 levels also correlated with response to systemic treatment: PDX models with high HMGB1 levels predicted response to bevacizumab. Taken together, we provide for the first time evidence that the damage associated molecular pattern biomarker HMGB1 can predict response to systemic treatment with bevacizumab. Our data support the future evaluation of HMGB1 as a predictive biomarker for bevacizumab sensitivity in patients with renal cell carcinoma.

βArrestin2 Mediates Renal Cell Carcinoma Tumor Growth

Renal Cell Carcinoma (RCC) is one of the most lethal urological cancers worldwide. The disease does not present early clinical symptoms and is commonly diagnosed at an advanced stage. Limited molecular drivers have been identified for RCC, resulting in the lack of effective treatment for patients with progressive disease. Ubiquitous βArrestin2 (βArr2) is well established for its function in the desensitization and trafficking of G protein-coupled receptors. More recently, βArr2 has been implicated in the regulation of fundamental cellular functions, including proliferation and invasion. We used bioinformatic and genetic approaches to determine role of βArr2 in RCC tumor growth. Analysis of published human datasets shows that ARRB2 (gene encoding βArr2) expression is increased in RCC tumor compared to normal tissue and that high levels of ARRB2 correlate with worse patient survival. Experimentally, we show that knockout of ARRB2 decreases rate of RCC cell proliferation and migration in vitro and xenograft tumor growth in animals. Mechanistically, βArr2 regulates c-Src activity, Cyclin A expression and cell cycle progression that are involved in tumor growth. These results show that βArr2 is a critical regulator of RCC tumor growth and suggest its utility as a potential marker and drug target to treat advanced disease.

A four-gene signature predicts survival in clear-cell renal-cell carcinoma

Clear-cell renal-cell carcinoma (ccRCC) is the most common pathological subtype of renal cell carcinoma (RCC), accounting for about 80% of RCC. In order to find potential prognostic biomarkers in ccRCC, we presented a four-gene signature to evaluate the prognosis of ccRCC. SurvExpress and immunohistochemical (IHC) staining of tissue microarrays were used to analyze the association between the four genes and the prognosis of ccRCC. Data from TCGA dataset revealed a prognostic prompt function of the four genes (PTEN, PIK3C2A, ITPA and BCL3). Further discovery suggested that the four-gene signature predicted survival better than any of the four genes alone. Moreover, IHC staining demonstrated a consistent result with TCGA, indicating that the signature was an independent prognostic factor of survival in ccRCC. Univariate and multivariate Cox proportional hazard regression analysis were conducted to verify the association of clinicopathological variables and the four genes' expression levels with survival. The results further testified that the risk (four-gene signature) was an independent prognostic factors of both Overall Survival (OS) and Disease-free Survival (DFS) (P<0.05). In conclusion, the four-gene signature was correlated with the survival of ccRCC, and therefore, may help to provide significant clinical implications for predicting the prognosis of patients.

Second Primary Cancer Risk among Kidney Cancer Patients in Korea: A Population-Based Cohort Study

PURPOSE

Secondary primary cancers (SPCs) commonly arise in patients with renal cell carcinoma (RCC). We designed the present study to estimate the SPC incidence in Korean patients with RCC.

MATERIALS AND METHODS

The study cohort was population-based and consisted of 40,347 individuals from the Korean Central Cancer Registry who were diagnosed with primary renal cancer between 1993 and 2013. Standardized incidence ratios (SIRs) for SPCs were estimated for different ages at diagnosis, latencies, diagnostic periods, and treatments.

RESULTS

For patients with primary RCC, the risk of developing a SPC was higher than the risk of developing cancer in the general population (SIR, 1.13; 95% confidence interval, 1.08 to 1.18). Most cancer types showed higher incidences in patients with RCC than in the general population. However, the relative incidence of gastric cancer as an SPC varied by age. Gastric cancer incidence was elevated in young patients (< 30 years) with RCC, but reduced in older (≥ 30) patients with RCC. Patients with advanced RCC died prematurely, regardless of SPC development. In contrast, those with early-stage RCC survived for longer periods, although SPC development affected their post-RCC survival. After SPC development, women had better survival than men.

CONCLUSION

In Korean patients with primary RCC, the incidence of SPC was 13% higher than the incidence of cancer in the general population. These findings may play important roles in the conduct of follow-up evaluations and education for patients with RCC.

Novel immunotherapy in metastatic renal cell carcinoma

Despite the rapid development of therapeutic modalities for metastatic renal cell carcinoma (mRCC) over the past decade to include a number of targeted antiangiogenic therapies and traditional immunotherapy, such as high-dose interleukin-2 and interferon-α, mRCC continues to be associated with poor prognosis. Currently, several novel immunotherapy agents, such as cancer vaccines, adoptive cell therapy, and checkpoint inhibitors, such as programmed cell death-1 (PD-1 present on T cells), one of its ligands (PD-L1 present on antigen-presenting cells and tumor cells), and cytotoxic T-lymphocyte-associated protein-4 pathways, are being studied in mRCC and are showing promise as important steps in the management of this disease. This review summarizes the current landscape of standard and emerging immune therapeutics and other modalities for mRCC.

Current status of clinical trials assessing oncolytic virus therapy for urological cancers

Oncolytic virus therapy has recently been recognized as a promising new option for cancer treatment. Oncolytic viruses replicate selectively in cancer cells, thus killing them without harming normal cells. Notably, T-VEC (talimogene laherparepvec, formerly called OncoVEX^GM-CSF ), an oncolytic herpes simplex virus type 1, was approved by the US Food and Drug Administration for the treatment of inoperable melanoma in October 2015, and was subsequently approved in Europe and Australia in 2016. The efficacies of many types of oncolytic viruses against urological cancers have been investigated in preclinical studies during the past decade, and some have already been tested in clinical trials. For example, a phase I trial of the third-generation oncolytic Herpes simplex virus type 1, G47Δ, in patients with prostate cancer was completed in 2016. We summarize the current status of clinical trials of oncolytic virus therapy in patients with the three major urological cancers: prostate, bladder and renal cell cancers. In addition to Herpes simplex virus type 1, adenoviruses, reoviruses, vaccinia virus, Sendai virus and Newcastle disease virus have also been used as parental viruses in these trials. We believe that oncolytic virus therapy is likely to become an important and major treatment option for urological cancers in the near future.

Correlation of c-Met Expression and Outcome in Patients With Renal Cell Carcinoma Treated With Sunitinib

BACKGROUND

Treatment of patients with metastatic renal cell carcinoma (mRCC) has improved substantially since the introduction of targeted therapies, but no predictive biomarkers are available. The proto-oncogene c-Met is involved in tumor angiogenesis, development, and metastasis. The main objective was to evaluate c-Met expression in sunitinib-treated patients with mRCC, including patients with bone metastases.

METHODS

c-Met expression was analyzed from 137 formalin-fixed paraffin-embedded tumor samples using a validated immunostaining protocol.

RESULTS

Patients with low c-Met expression (n = 78) had longer progression-free survival (PFS) (median 14.3 vs. 6.5 months; P < .001) and overall survival (OS) (median 32.1 vs. 20.1 months; P = .049) than those with high expression. High c-Met expression was an independent predictor of unfavorable PFS in a Cox proportional hazards model adjusted for the Heng risk criteria (HR 1.60 [1.09-2.35]; P = .016). In a subgroup of patients with no bone metastases (n = 106), low c-Met expression was associated with a both longer OS (unadjusted HR 0.63 [95% CI, 0.42-0.95]; P = .034) and PFS (unadjusted HR 0.47 [95% CI, 0.31-0.71]; P < .001).

CONCLUSIONS

High c-Met expression was associated with poor survival in patients with mRCC treated with sunitinib. Interestingly, the prognostic role may vary based on the location of metastases.

A New Carbon Nanotube-Based Breast Cancer Drug Delivery System: Preparation and In Vitro Analysis Using Paclitaxel

Paclitaxel (PTX) is one of the most important drugs for breast cancer; however, the drug effects are limited by its systematic toxicity and poor water solubility. Nanoparticles have been applied for delivery of cancer drugs to overcome their limitations. Toward this goal, a novel single-walled carbon nanotube (SWNT)-based drug delivery system was developed by conjugation of human serum albumin (HSA) nanoparticles for loading of antitumor agent PTX. The nanosized macromolecular SWNT-drug carrier (SWNT-HSA) was characterized by TEM, UV-Vis-NIR spectrometry, and TGA. The SWNT-based drug carrier displayed high intracellular delivery efficiency (cell uptake rate of 80%) in breast cancer MCF-7 cells, as examined by fluorescence-labeled drug carriers, suggesting the needle-shaped SWNT-HSA drug carrier was able to transport drugs across cell membrane despite its macromolecular structure. The drug loading on SWNT-based drug carrier was through high binding affinity of PTX to HSA proteins. The PTX formulated with SWNT-HSA showed greater growth inhibition activity in MCF-7 breast cancer cells than PTX formulated with HSA nanoparticle only (cell viability of 63 vs 70% in 48 h and 53 vs 62% in 72 h). The increased drug efficacy could be driven by SWNT-mediated cell internalization. These data suggest that the developed SWNT-based antitumor agent is functional and effective. However, more studies for in vivo drug delivery efficacy and other properties are needed before this delivery system can be fully realized.

Decreased Expression of SRSF2 Splicing Factor Inhibits Apoptotic Pathways in Renal Cancer

Serine and arginine rich splicing factor 2(SRSF2) belongs to the serine/arginine (SR)-rich family of proteins that regulate alternative splicing. Previous studies suggested that SRSF2 can contribute to carcinogenic processes. Clear cell renal cell carcinoma (ccRCC) is the most common subtype of kidney cancer, highly aggressive and difficult to treat, mainly due to resistance to apoptosis. In this study we hypothesized that SRSF2 contributes to the regulation of apoptosis in ccRCC. Using tissue samples obtained from ccRCC patients, as well as independent validation on The Cancer Genome Atlas (TCGA) data, we demonstrate for the first time that expression of SRSF2 is decreased in ccRCC tumours when compared to non-tumorous control tissues. Furthermore, by employing a panel of ccRCC-derived cell lines with silenced SRSF2 expression and qPCR arrays we show that SRSF2 contributes not only to splicing patterns but also to expression of multiple apoptotic genes, including new SRSF2 targets: DIABLO, BIRC5/survivin, TRAIL, BIM, MCL1, TNFRSF9, TNFRSF1B, CRADD, BCL2L2, BCL2A1, and TP53. We also identified a new splice variant of CFLAR, an inhibitor of caspase activity. These changes culminate in diminished caspase-9 activity and inhibition of apoptosis. In summary, we show for the first time that decreased expression of SRSF2 in ccRCC contributes to protection of cancer cells viability.

Recent advances in renal cell carcinoma from a pathological point of view

The purpose of this article is to review the recent advances in renal cell carcinoma (RCC) from a pathological point of view. Because the genetic features and morphological characteristics have become major criteria for the classification of RCC, special techniques, such as immunohistochemistry, are essential to the differential diagnosis of renal tumors. Metastasis is frequently observed among the RCC patients with curative nephrectomy, and extracellular matrix-degrading enzymes, such as matrix metalloproteinases (MMP) and heparanase, play a key role in invasion and metastasis of RCC. Snail and Slug, transcription factors of epithelial-mesenchymal transition (EMT), accelerate cancer cell invasion through downregulation of E-cadherin and up-regulation of MMP. Therapies targeted at the vascular endothelial growth factor pathway have become the standard treatment of metastatic RCC. Although they lead to tumor shrinkage mainly by inhibiting angiogenesis, they have typically been associated with drug resistance. The mechanism of the resistance remains largely unknown, but complex events including re-activation of angiogenesis, EMT and cancer stem cells, and immune escape are implicated in the refractory response to the therapy. Recent advances of the research on RCC have caused the changes of classification and therapy, and pathologists should take overall view of these as integrated pathology.

Recent advances in immuno-oncology and its application to urological cancers

Recent advances in immuno-oncology have the potential to transform the practice of medical oncology. Antibodies directed against negative regulators of T-cell function (checkpoint inhibitors), engineered cell therapies and innate immune stimulators, such as oncolytic viruses, are effective in a wide range of cancers. Immune'based therapies have had a clinically meaningful impact on the treatment of advanced melanoma, and the lessons regarding use of single agents and combinations in melanoma may be applicable to the treatment of urological cancers. Checkpoint inhibitors, cytokine therapy and therapeutic vaccines are already showing promise in urothelial bladder cancer, renal cell carcinoma and prostate cancer. Critical areas of future immuno-oncology research include the prospective identification of patients who will respond to current immune-based cancer therapies and the identification of new therapeutic agents that promote immune priming in tumours, and increase the rate of durable clinical responses.

Repurposing Sunitinib with Oncolytic Reovirus as a Novel Immunotherapeutic Strategy for Renal Cell Carcinoma

PURPOSE

In addition to their direct cytopathic effects, oncolytic viruses are capable of priming antitumor immune responses. However, strategies to enhance the immunotherapeutic potential of these agents are lacking. Here, we investigated the ability of the multi-tyrosine kinase inhibitor and first-line metastatic renal cell carcinoma (RCC) agent, sunitinib, to augment the antitumor immune response generated by oncolytic reovirus.

EXPERIMENTAL DESIGN

In vitro, oncolysis and chemokine production were assessed in a panel of human and murine RCC cell lines after exposure to reovirus, sunitinib, or their combination. In vivo, the RENCA syngeneic murine model of RCC was employed to determine therapeutic and tumor-specific immune responses after treatment with reovirus (intratumoral), sunitinib, or their combination. Parallel investigations employing the KLN205 syngeneic murine model of lung squamous cell carcinoma (NSCLC) were conducted for further validation.

RESULTS

Reovirus-mediated oncolysis and chemokine production was observed following RCC infection. Reovirus monotherapy reduced tumor burden and was capable of generating a systemic adaptive antitumor immune response evidenced by increased numbers of tumor-specific CD8⁺ IFNγ-producing cells. Coadministration of sunitinib with reovirus further reduced tumor burden resulting in improved survival, decreased accumulation of immune suppressor cells, and the establishment of protective immunity upon tumor rechallenge. Similar results were observed for KLN205 tumor-bearing mice, highlighting the potential broad applicability of this approach.

CONCLUSIONS

The ability to repurpose sunitinib for augmentation of reovirus' immunotherapeutic efficacy positions this novel combination therapy as an attractive strategy ready for clinical testing against a range of histologies, including RCC and NSCLC. Clin Cancer Res; 22(23); 5839-50. ©2016 AACR.

Emerging strategies for cancer immunoprevention

The crucial role of the immune system in the formation and progression of tumors has been widely accepted. On one hand, the surveillance role of the immune system plays an important role in endogenous tumor prevention, but on the other hand, in some special circumstances such as in chronic inflammation, the immune system can actually contribute to the formation and progression of tumors. In recent years, there has been an explosion of novel targeted immunotherapies for advanced cancers. In the present manuscript, we explore known and potential various types of cancer prevention strategies and focus on nonvaccine-based cancer preventive strategies targeting the immune system at the early stages of tumorigenesis.

Common gamma chain cytokines in combinatorial immune strategies against cancer

Common γ chain (γC) cytokines, namely IL-2, IL-4, IL-7, IL-9, IL-15, and IL-21 are important for the proliferation, differentiation, and survival of lymphocytes that display antitumor activity, thus stimulating considerable interest for the use of cytokines in cancer immunotherapy. In this review, we will focus on the γC cytokines that demonstrate the greatest potential for immunotherapy, IL-2, IL-7, IL-15, and IL-21. We will briefly cover their biological function, potential applications in cancer therapy, and update on their use in combinatorial immune strategies for eradicating tumors and hematopoietic malignancies.

Recurrent Renal Cell Carcinoma with Synchronous Tumor Growth in Azygoesophageal Recess and Duodenum: A Rare Cause of Anemia and Upper Gastrointestinal Bleeding

Renal cell carcinoma (RCC) has potential to present with distant metastasis several years after complete resection. The common sites of metastases include the lungs, bones, liver, renal fossa, and brain. RCCs metastasize rarely to the duodenum, and duodenal metastasis presenting with acute gastrointestinal bleed is infrequently reported in literature. We present a case of synchronous presentation of duodenal and azygoesophageal metastasis manifesting as acute upper gastrointestinal bleeding, four years after undergoing nephrectomy for RCC. The patient underwent further workup and was treated with radiation. The synchronous presentation is rare and stresses the importance of searching for recurrence of RCC in patients presenting with acute gastrointestinal bleeding.

Decrease of phosphorylated proto-oncogene CREB at Ser 133 site inhibits growth and metastatic activity of renal cell cancer

OBJECTIVE

Cyclic-AMP-responsive element-binding protein (CREB) is a proto-oncogenic transcription factor. The authors' previous reports showed that blocking the CREB binding site at Ser 133 inhibited the expression of target genes, which related to the progression of some tumors. In this study, the authors investigated the role of phosphorylated CREB (pCREB) at Ser133 in renal cell carcinoma (RCC) growth and metastases.

METHODS

Immunohistochemistry, xenograft model in nude mice, cell proliferation assay, cell invasion/migration assay, fluorescent immunocytochemistry and Western analysis were performed in an immortalized proximal tubule epithelial cell line and clear-cell RCC.

RESULTS

The authors' results showed that knockdown of pCREB inhibited kidney cancer cells growth in vivo. Furthermore, suppression of the pCREB level blunted the capabilities of cell migration and invasion in vitro and was accompanied with significantly decreased expression of MMP-2 and MMP-9, the filopodia formation and epithelial-mesenchymal transition-related proteins. Surprisingly, no changes of expression or location of vimentin were revealed in the experiment. Bioinformatic software explained the possible reason for this is that the promoter of vimentin does not contain the CRE sequence.

CONCLUSIONS

These data suggest that decreasing the level of pCREB inhibits the growth and metastasis of RCC by targeting the Ser 133 site.

Tumor suppressive microRNA-200a inhibits renal cell carcinoma development by directly targeting TGFB2

A large body of evidence indicates that microRNAs play a critical role in tumor initiation and progression by negatively regulating oncogenes or tumor suppressor genes. Here, we report that the expression of miR-200a was notably downregulated in 45 renal cell carcinoma (RCC) samples. Restoration of miR-200a suppressed cell proliferation, migration, and invasion in two RCC cell lines. Furthermore, we used an epithelial-to-mesenchymal transition PCR array to explore the putative target genes of miR-200a. By performing quantitative real-time PCR, ELISA, and luciferase reporter assays, transforming growth factor beta2 (TGFB2) was validated as a direct target gene of miR-200a. Moreover, siRNA-mediated knockdown of TGFB2 partially phenocopied the effect of miR-200a overexpression. These results suggest that miR-200a suppresses RCC development via directly targeting TGFB2, indicating that miR-200a may present a novel target for diagnostic and therapeutic strategies in RCC.

Oncolytic Viral Therapy Using Reovirus

Current mainstays in cancer treatment such as chemotherapy, radiation therapy, hormonal manipulation, and even targeted therapies such as Trastuzumab (herceptin) for breast cancer or Iressa (gefitinib) for non-small cell lung cancer among others are limited by lack of efficacy, cellular resistance, and toxicity. Dose escalation and combination therapies designed to overcome resistance and increase efficacy are limited by a narrow therapeutic index. Oncolytic viruses are one such group of new biological therapeutics that appears to have a wide spectrum of anticancer activity with minimal human toxicity. Since the malignant phenotype of tumors is the culmination of multiple mutations that occur in genes eventually leading to aberrant signaling pathways, oncolytic viruses either natural or engineered specifically target tumor cells taking advantage of this abnormal cellular signaling for their replication. Reovirus is one such naturally occurring double-stranded RNA virus that exploits altered signaling pathways (including Ras) in a myriad of cancers. The ability of reovirus to infect and lyse tumors under in vitro, in vivo, and ex vivo conditions has been well documented previously by us and others. The major mechanism of reovirus oncolysis of cancer cells has been shown to occur through apoptosis with autophagy taking place during this process in certain cancers. In addition, the synergistic antitumor effects of reovirus in combination with radiation or chemotherapy have also been demonstrated for reovirus resistant and moderately sensitive tumors. Recent progress in our understanding of viral immunology in the tumor microenvironment has diverted interest in exploring immunologic mechanisms to overcome resistance exhibited by chemotherapeutic drugs in cancer. Thus, currently several investigations are focusing on immune potentiating of reovirus for maximal tumor targeting. This chapter therefore has concentrated on immunologic cell death induction with reovirus as a novel approach to cancer therapy used under in vitro and in vivo conditions, as well as in a clinical setting. Reovirus phase I clinical trials have shown indications of efficacy, and several phase II/III trials are ongoing at present. Reovirus's extensive preclinical efficacy, replication competency, and low toxicity profile in humans have placed it as an attractive anticancer therapeutic for ongoing clinical testing that are highlighted in this chapter.

Sequential immune monitoring in patients with melanoma and renal cell carcinoma treated with high-dose interleukin-2: immune patterns and correlation with outcome

Interleukin-2 (IL-2) therapy leads to clinically relevant responses in 10-16 % of patients with metastatic melanoma (MMEL) or 10-30 % of patients with metastatic renal cell carcinoma (MRCC). To date, no biomarkers have been validated to identify patients who are likely to respond. We hypothesized that changes in T cell subset distribution in patients undergoing IL-2 therapy may correlate with treatment outcomes. Immune profiles of 64 patients (27-MMEL, 37-MRCC) were evaluated using flow cytometry at baseline, during (≥three doses) and at the end of treatment cycle (30 ± 6 h after last dose), through two courses of IL-2 therapy. Changes in distribution and phenotype of circulating CD4 and CD8 lymphocyte subsets were compared (1) based on cancer types and (2) intra-patient during the course of the IL-2 therapy. Exploratory analysis of immunologic profiles was also performed based on treatment outcome. Independent of cancer type, IL-2 led to a transient decrease of circulating effector lymphocytes, while regulatory T cells gradually increased. Interleukin-2 differentially affected a subset of CD8 T cell expressing Foxp3, depending on malignancy type. In MMEL patients, IL-2 gradually expanded circulating CD8 Foxp3+ cells; in MRCC patients, IL-2 transiently increased expression of CD103 and CCR4 homing markers. Monitoring of adaptive immune variables early on and during the course of IL-2 therapy revealed transient alterations in immune profiles, specific to MMEL and MRCC patients, related to immune balance (and ultimately response to IL-2 therapy) or T cell egress from the circulation.

Comparative effectiveness of second-line targeted therapies for metastatic renal cell carcinoma: synthesis of findings from two multi-practice chart reviews in the United States

BACKGROUND

Second-line targeted therapies for metastatic renal cell carcinoma (mRCC) include mammalian target of rapamycin (mTOR) inhibitors and tyrosine kinase inhibitors (TKIs). This study compares the effectiveness of these therapies in a multi-practice chart review and synthesizes the findings with those of a similarly designed study.

METHODS

Medical oncologists/hematologists (N = 36) were recruited to review charts for patients aged ≥18 years, received a first-line TKI and initiated second-line targeted therapy in 2010 or later. The primary outcome was time from second-line initiation to treatment failure (TTF; discontinuation, physician-assessed progression, or death, whichever occurred first). TTF was compared among patients receiving second-line everolimus (EVE), temsirolimus (TEM), or TKI as a class, using a Cox proportional hazards model adjusting for type of initial TKI and response, histological subtype, performance status, and sites of metastasis. Hazard ratios (HRs) for TTF were pooled, in a meta-analysis, with previously reported HRs for progression-free survival from a chart review with a similar design.

RESULTS

A total of 138, 64 and 79 patients received second-line therapy with EVE, TEM or a TKI, respectively. Adjusting for baseline characteristics, EVE was associated with numerical, but not statistically significant, reductions of 28% (HR = 0.72; 95% CI [0.45-1.16]) and 26% (HR = 0.74; 95% CI [0.48-1.15]) in the hazard of TTF compared to TEM and TKI, respectively. After pooling the HRs from both studies, EVE was associated with significantly reduced hazards of TTF compared to TEM and TKI (HR = 0.73; 95% CI [0.57-0.93]; and HR = 0.75; 95% CI [0.57-0.98], respectively).

LIMITATIONS

LIMITATIONS include retrospective analyses with possible missing or erroneous chart data, confounding of unobserved factors due to non-randomization, and limited data for axitinib during the study period.

CONCLUSIONS

In pooled results from two independent multi-practice chart reviews of second-line mRCC treatment, EVE was associated with significantly reduced hazards of treatment failure compared to TEM and to TKIs as a class.

Study of the effectiveness of first-line treatment in renal cell carcinoma

The emergence of novel drugs corresponds with the determination of the effectiveness of the current treatments used in clinical practice. A retrospective observational study was conducted to evaluate the effectiveness of first-line treatments and to test the influence of the prognostic factors established using the Memorial Sloan-Kettering Cancer Center (MSKCC) and the analysis of Mekhail's study for two or more metastatic sites. The primary endpoints were median progression-free survival (mPFS) and median overall survival (mOS) times. A total of 65 patients were enrolled and the mPFS and mOS of the patients treated with sunitinib (n=51) were 9.0 and 20.1 months, respectively, and for the patients treated with temsirolimus (n=14) these were 3.0 and 6.2 months, respectively. In the poor-prognosis (PP) group, a difference of 1.2 months (P=0.049) was found in mPFS depending on the first-line treatment. A difference of 4.1 months (P=0.023) was also found in mPFS when classified by histology (clear verses non-clear cell) in the sunitinib-treatment group. When stratified by the prognostic group, differences of >7 months (P<0.001) were found between the groups. Therefore, it was concluded that the effectiveness of the treatments was reduced compared to previous studies and differences were found in the PP group when classified by first-line drug and histology. Additionally, the influence of prognostic factors on OS and the value of stratifying patients using these factors have been confirmed.

Seminal plasma protein in renal cell carcinoma: expression of semenogelin I is a predictor for cancer progression and prognosis

The incidence of renal cell carcinoma (RCC) has been steadily rising each year. There are currently few recognized biomarkers for the diagnosis and prognosis of RCC. We investigated semenogelin I (Sg I) expression and its clinical significance in patients with RCC. The expression levels of Sg I and its protein were measured by qPCR and Western blotting, respectively. Immunohistochemistry was used to investigate the protein expression of Sg I in RCC and normal renal tissue from 53 patients. The Kaplan-Meier method and log-rank test were used to evaluate the data. By qRCR (p < 0.01) and Western blot, the level of Sg I expression in benign tissues was higher than that in RCC tissues. Expression of Sg I was observed in 30 (57 %) RCC cases, which was significantly lower than that observed in benign renal tissues from the same patients [Sg I positive in 53 (100 %) cases (p < 0.0001)] by immunohistochemistry. There was an inverse relation between Sg I expression and clinical stage (pT1-2 vs pT3-4, p < 0.0001). Patients with Sg I-negative tumor had a significantly higher risk of recurrence (Kaplan-Meier and log-rank tests, p < 0.0001). There was low Sg I expression in RCC. Sg I expression has potential value in predicting cancer progression and prognosis. These findings support the use of Sg I as a novel biomarker for RCC.

Efficacy of targeted therapy for metastatic renal cell carcinoma in the elderly patient population

INTRODUCTION/BACKGROUND

Targeted therapy has become the mainstay of treatment for mRCC. The efficacy of this therapy in the older population is poorly understood.

PATIENTS AND METHODS

Data from patients with mRCC treated with first-line anti-VEGF therapy were collected through the International mRCC Database Consortium from 12 centers. Patient characteristics, data on second-line therapy, and outcomes including treatment duration and overall survival, were evaluated using summary statistics and multivariate analysis.

RESULTS

All patients (n = 1381) were treated with front-line targeted therapy; 144 (10%) were 75 years old or older. Six patients (4%) were favorable risk, 99 patients (69%) intermediate risk, and 39 patients (27%) poor risk according to Heng Journal of Clinical Oncology 2009 prognostic factors. The initial treatment for those ≥ 75 years of age was sunitinib (n = 98), sorafenib (n = 35), bevacizumab (n = 7), and AZD217 (n = 4). Twenty-three percent of older patients and 39% of the younger patients went on to receive second-line therapy (P < .0001). The overall response rate, median treatment duration, and overall survival for the older versus younger group were 18% versus 25% (P = .0975), 5.5 months versus 7.5 months (P = .1388), and 16.8 months versus 19.7 months (P = .3321), respectively. When adjusted for poor prognostic factors, age 75 years and older was not found to be associated with poorer overall survival (hazard ratio [HR], 1.002; 95% confidence interval [CI], 0.781-1.285) or shorter treatment duration (HR, 1.018; 95% CI, 0.827-1.252). The retrospective study design was the primary limitation.

CONCLUSION

The use of advanced age as a selection criterion for targeted therapy requires further study, with data suggesting no clinically meaningful differences in overall response rate, treatment duration, and overall survival between older and younger age groups.

A novel personalized vaccine approach in combination with targeted therapy in advanced renal cell carcinoma

The historical treatment paradigm for metastatic renal cell carcinoma has focused on immunomodulatory agents, such as IFN-α and IL-2, which provide good clinical outcomes in only a subset of patients. The development of therapies that target the VEGF and mTOR pathways have significantly altered the treatment landscape for this disease, with novel inhibitors providing substantial improvements in progression-free and overall survival over previous standards of care. Despite these advances, toxicity from targeted therapy and the development of resistance results in disease progression. By contrast, vaccine-based immunotherapy represents a promising new approach for the treatment of patients with metastatic renal cell carcinoma; however, tumor-induced immunosuppression has limited the clinical efficacy of this modality until recently. Some evidence suggests that certain targeted therapies, such as sunitinib, may reduce this immunosuppression and enhance the tumor microenvironment to promote synergy with autologous dendritic cell vaccines.

Correlation of vascular endothelial growth factor and hypoxia-inducible factor-1α expression with pathological renal artery changes in patients with renal cell carcinoma

OBJECTIVE

The aim of this study was to correlate the expression of vascular endothelial growth factor (VEGF) and hypoxia-inducible factor-1α (HIF-1α) with pathological renal artery changes in patients with renal cell carcinoma (RCC). A further aim was to correlate intratumoral microvessel density (MVD) with VEGF and HIF-1α expression and prognostic factors for RCC, including tumour necrosis.

MATERIAL AND METHODS

Formalin-fixed and paraffin-embedded tissue blocks from 150 patients with RCC and 50 patients with non-tumorous kidney diseases were analysed. The control group consisted of specimens from both renal arteries obtained from 25 decedents at routine autopsy (50 cases in total). Immunohistochemistry was performed using primary antibodies to VEGF, HIF-1α and CD31.

RESULTS

Pathological renal artery changes were more common in patients with RCC and non-tumorous kidney diseases than in the control group. MVD was higher in the RCCs of patients with pathological renal artery changes. Tumours with higher HIF-1α expression had higher MVD; however, VEGF expression was not associated with MVD. A significant association was also found between MVD and the extent of tumour necrosis, in that less necrotic tumours had higher MVD. No association between renal artery changes and VEGF and HIF-1α expression was established.

CONCLUSION

Considering the results of this study, the evaluation of renal artery changes in forthcoming research on RCC would be helpful for several reasons: to estimate their incidence in a larger number of patients, to clarify their connection with RCC and to reveal their relationship with MVD in RCC.

Identification and validation of dysregulated metabolic pathways in metastatic renal cell carcinoma

Metastatic renal cell carcinoma (mRCC) is a devastating disease with a 5-year survival rate of approximately 9 % and low response to chemotherapy and radiotherapy. Targeted therapies have slightly improved patient survival, but are only effective in a small subset of patients, who eventually develop resistance. A better understanding of pathways contributing to tumor progression and metastasis will allow for the development of novel targeted therapies and accurate prognostic markers. We performed extensive bioinformatics coupled with experimental validation on proteins dysregulated in mRCC. Gene ontology analysis showed that many proteins are involved in oxidation reduction, metabolic processes, and signal transduction. Pathway analysis showed metabolic pathways are altered in mRCC including glycolysis and pyruvate metabolism, the citric acid cycle, and the pentose phosphate pathway. RT-qPCR analysis showed that genes involved in the citric acid cycle were downregulated in metastatic RCC while genes of the pentose phosphate pathway were overexpressed. Protein-protein interaction analysis showed that most of the 198 proteins altered in mRCC clustered together and many were involved in glycolysis and pyruvate metabolism. We identified 29 reported regions of chromosomal aberrations in metastatic disease that correlate with the direction of protein dysregulation in mRCC. Furthermore, 36 proteins dysregulated in mRCC are predicted to be targets of metastasis-related miRNAs. A more comprehensive understanding of the pathways dysregulated in metastasis can be useful for the development of new therapies and novel prognostic markers. Also, multileveled analyses provide a unique "snapshot" of the molecular "environment" in RCC with prognostic and therapeutic implications.

Integrin αvβ3 and fibronectin upregulate Slug in cancer cells to promote clot invasion and metastasis

The blood clotting cascade is selectively involved in lung metastasis, but the reason for this selectivity is unclear. Here, we show that tumor cells that metastasize predominantly to the lung, such as renal cell carcinoma (RCC) and soft tissue sarcoma (STS), have an inherent capacity to generate extensive invadopodia when embedded in a blood clot. Compared with other metastatic cancer cells tested, RCC and STS cells exhibited increased levels of expression of fibronectin and an activated form of the integrin αvβ3, which coordinately supported the generation of an elaborate fibronectin matrix and actin stress fibers in fibrin-embedded tumor cells. Together, fibronectin and αvβ3 induced upregulation of the transcription factor Slug, which mediates epithelial-mesenchymal transition as well as fibrin invasion and lung metastasis. This mechanism is clinically significant, because primary cancer cells from patients with metastatic RCC strongly invaded fibrin and this correlated with fibronectin matrix formation and Slug expression. In contrast, tumor cells from patients with localized RCC were largely noninvasive. Together, our findings establish that activated integrin αvβ3 and fibronectin promote lung metastasis by upregulating Slug, defining a mechanism through which cancer cells can colonize blood clots in the lung vasculature.

Recent advances in the treatment of metastatic renal cell carcinoma

In the past 5 years, the treatment of patients with metastatic renal cell carcinoma has changed dramatically from being largely cytokine-based with the emergence of targeted therapy. Following the elucidation of various molecular pathways in renal cell carcinoma, targeted agents (particularly vascular endothelial growth factor-targeting antiangiogenic agents) now form the backbone of most therapeutic strategies for patients with metastatic renal cell carcinoma and the outcome of treatment has improved. However, many tumors eventually develop resistance to targeted therapy due to secondary mutation of the target protein or compensatory changes within the target pathway that bypass the site of inhibition. On the other hand, there are new forms of immunotherapy that hold the promise of improving the outcome for patients with metastatic renal cell carcinoma. In this article, we describe some of these new therapies, including the anti-vascular endothelial growth factor monoclonal antibody bevacizumab, several receptor tyrosine kinase inhibitors (sorafenib, sunitinib, pazopanib, axitinib, and tivozanib), the mammalian target of rapamycin inhibitors temsirolimus and everolimus, and new immunotherapy modalities, such as anti-cytotoxic T-lymphocyte-associated antigen 4 antibody and anti-programmed cell death 1/programmed cell death-ligand 1 antibody. We also discuss their role in the current management of patients with metastatic renal cell carcinoma.

Sunitinib induces cellular senescence via p53/Dec1 activation in renal cell carcinoma cells

Although multitargeted tyrosine kinase inhibitor sunitinib has been used as first-line therapeutic agent against metastatic renal cell carcinoma (mRCC), the molecular mechanism and functional role per se for its therapeutic performance remains obscure. Our present study revealed that sunitinib-treated RCC cells exhibit senescence characteristics including increased SA-β-gal activity, DcR2 and Dec1 expression, and senescence-associated secretary phenotype (SASP) such as proinflammatory cytokines interleukin (IL)-1α, IL-6 and IL-8 secretion. Moreover, sunitinib administration also led to cell growth inhibition, G1-S cell cycle arrest and DNA damage response in RCC cells, suggesting therapeutic significance of sunitinib-induced RCC cellular senescence. Mechanistic investigations indicated that therapy-induced senescence (TIS) following sunitinib treatment mainly attributed to p53/Dec1 signaling activation mediated by Raf-1/NF-κB inhibition in vitro. Importantly, in vivo study showed tumor growth inhibition and prolonged overall survival were associated with increased p53 and Dec1 expression, decreased Raf-1 and Ki67 staining, and upregulated SA-β-gal activity after sunitinib treatment. Immunohistochemistry analysis of tumor tissues from RCC patients receiving sunitinib neoadjuvant therapy confirmed the similar treating phenotype. Taken together, our findings suggested that sunitinib treatment performance could be attributable to TIS, depending on p53/Dec1 activation via inhibited Raf-1/nuclear factor (NF)-κB activity. These data indicated potential insights into therapeutic improvement with reinforcing TIS-related performance or overcoming SASP-induced resistance.

Immunohistochemical expression of CD44s in renal cell carcinoma lacks independent prognostic significance

PURPOSE

To analyze the immunohistochemical expression of the standard isoform of CD44 (CD44s) adhesion molecule in clear cell renal cell carcinoma (CCRCC) and its impact on clinical outcomes.

MATERIALS AND METHODS

Ninety-nine consecutive patients treated surgically for RCC between 1992 and 2009 were selected. A single pathologist reviewed all cases to effect a uniform reclassification and determine the most representative tumor areas for construction of a tissue microarray. The same pathologist, who was blinded to the outcome of the cases, semi-quantitatively scored the staining intensity of CD44s in all specimens. The counting was done using the H-Score algorithm.

RESULTS

Of the 99 immunostained RCC specimens, 57(57.7 %) showed low expression, and 42(42.4 %) showed high expression levels of CD44s. The expression of CD44s was directly associated with tumor size (p = 0.03), clinical stage (p = 0.02) and Fuhrman grade (p = 0.02). Disease specifi c survival (DSS) rates for patients whose specimens expressed low and high levels of CD44s was 88.1 % and 67.5 %, respectively (p = 0.009). Progression free survival (PFS) rates in patients with low and high expression of CD44s were 78.8 % and 61.7 %, respectively (p = 0.05). Classical features such as the presence of metastasis and clinical stage remained isolated predictors of survival.

CONCLUSIONS

Immunohistochemical expression of CD44s was associated with important clinical variables such as stage and Fuhrman grade. However, it was not an independent predictor of survival. Therefore, we believe it has a limited role as a prognostic marker in patients with CCRCC.

Klotho suppresses tumor progression via inhibiting PI3K/Akt/GSK3β/Snail signaling in renal cell carcinoma

Klotho is an anti-aging protein predominantly expressed in renal tubular epithelial cells. Although Klotho was recently identified as a tumor suppressor gene in a variety of cancers, the potential role and molecular events for Klotho in renal cell carcinoma (RCC) remain obscure. In the present study, immunohistochemical staining in tissue microarrays containing 125 RCC samples showed that intratumoral Klotho levels were negatively correlated with tumor size, TNM stage and nuclear grade. The overall survival rate of RCC patients with high Klotho expression was significantly higher than that of patients with low Klotho expression. Functional analysis after gain and loss of Klotho expression revealed that Klotho blunted epithelial-mesenchymal transition and cellular migration and invasion in RCC. Also, no alteration of α-2,6-sialidase activity was found after Klotho overexpression in RCC. The molecular signals for this phenomenon involved the Klotho-mediated inhibition of PI3K/Akt/GSK3β/Snail pathway. Importantly, compared to localized RCC tissues, advanced RCC tissues exhibited low Klotho expression accompanied with high pAkt and Snail expression. These results indicate Klotho acts as a tumor suppressor by inhibiting PI3K/Akt/GSK3β/Snail signaling, thus suppressing epithelial-mesenchymal transition and tumor migration and invasion during RCC progression. As a result, Klotho might be used as a potential therapy for advanced RCC.

DNA methylation profiling distinguishes histological subtypes of renal cell carcinoma

Renal cell carcinoma (RCC) accounts for around 3% of cancers in the UK, and both incidence and mortality are increasing with the aging population. RCC can be divided into several subtypes: conventional RCC (the most common, comprising 75% of all cases), papillary RCC (15%) and chromophobe RCC (5%). Renal oncocytoma is a benign tumor and accounts for 5% of RCC. Cancer and epigenetics are closely associated, with DNA hypermethylation being widely accepted as a feature of many cancers. In this study the DNA methylation profiles of chromophobe RCC and renal oncocytomas were investigated by utilizing the Infinium HumanMethylation450 BeadChips. Cancer-specific hypermethylation was identified in 9.4% and 5.2% of loci in chromophobe RCC and renal oncocytoma samples, respectively, while the majority of the genome was hypomethylated. Thirty (hypermethylated) and 41 (hypomethylated) genes were identified as differentially methylated between chromophobe RCC and renal oncocytomas (p < 0.05). Pathway analysis identified some of the differentially hypermethylated genes to be involved in Wnt (EN2), MAPK (CACNG7) and TGFβ (AMH) signaling, Hippo pathway (NPHP4), and cell death and apoptosis (SPG20, NKX6-2, PAX3 and BAG2). In addition, we analyzed ccRCC and papillary RCC data available from The Cancer Genome Atlas portal to identify differentially methylated loci in chromophobe RCC and renal oncocytoma in relation to the other histological subtypes, providing insight into the pathology of RCC subtypes and classification of renal tumors.

Emerging immunotherapies for renal cell carcinoma

In recent years, an improved understanding of renal cell carcinoma (RCC) tumour biology has resulted in major advances in the treatment of patients with metastatic RCC (mRCC). Although immunotherapy with interleukin-2 and interferon-α was once the standard of care for mRCC, the introduction of novel agents targeting angiogenesis and signal transduction pathways has markedly improved patient outcomes. However, targeted agents rarely induce complete responses, and patients eventually develop resistance to therapy, prompting consideration of novel therapeutic approaches and a resurgence of interest in immunotherapy for RCC. Phase I/II trials of vaccination with allogeneic dendritic cell/tumour fusions in patients with mRCC have demonstrated immunological and clinical responses in some patients, and T-cell modulating agents (e.g. antibodies against programmed death 1 and cytotoxic T lymphocyte-associated antigen-4, or soluble lymphocyte activation gene-3) and dendritic cell-activating toll-like receptor agonists have also shown encouraging evidence of efficacy in early-phase clinical trials. These early studies suggest that immunotherapy may continue to be an effective approach for patients with mRCC. As such, a number of other strategies are currently under investigation, including adoptive cell transfer (ACT) with T cells modified to target proteins expressed by renal tumours such as MAGE-A3/12, DR4 and TRAIL, and ACT with autologous natural killer cells. Results from trials of novel immunotherapies are encouraging, with data from other indications helping to facilitate development. To realise the full benefit for patients, it is likely that immunotherapy will need to be combined with targeted agents or other agents. Novel therapies used in combination or sequentially have the potential to improve outcomes in mRCC, and results from ongoing/planned trials will shape future therapy.

c-Met is a prognostic marker and potential therapeutic target in clear cell renal cell carcinoma

BACKGROUND

Activation of the c-Met pathway occurs in a range of malignancies, including papillary renal cell carcinoma (RCC). Its activity in clear cell RCC is less clear. We investigated c-Met expression and inhibition in a large cohort of RCC tumors and cell lines.

METHODS

c-Met protein expression was determined by automated quantitative analysis (AQUA) on a tissue microarray (TMA) constructed from 330 RCC tumors paired with adjacent normal renal tissue. c-Met expression and selective inhibition with SU11274 and ARQ 197 were studied in clear cell RCC cell lines.

RESULTS

Higher c-Met expression was detected in all RCC subtypes than in the adjacent normal renal tissue (P < 0.0001). Expression was highest in papillary and sarcomatoid subtypes, and high-grade and stage tumors. Higher c-Met expression correlated with worse disease-specific survival [risk ratio = 1.36; 95% confidence interval (CI) 1.08-1.74; P = 0.0091] and was an independent predictor of survival, maintained in clear cell subset analyses. c-Met protein was activated in all cell lines, and proliferation (and colony formation) was blocked by SU11274 and ARQ 197.

CONCLUSIONS

c-Met is associated with poor pathologic features and prognosis in RCC. c-Met inhibition demonstrates in vitro activity against clear cell RCC. Further study of ARQ 197 with appropriate biomarker studies in RCC is warranted.

Sunitinib adverse events in metastatic renal cell carcinoma: a meta-analysis

BACKGROUND

Sunitinib, a multi-targeted receptor tyrosine kinase inhibitor, has demonstrated survival benefit in patients with metastatic renal cell carcinoma (mRCC); however, significant adverse events (AEs) have been associated with its use. The significant variation in the reported incidences of AEs has prompted this meta-analysis to quantify the risk and explore associated predictors.

METHODS

According to predefined selection criteria, a literature search identified 12 studies that were included in the analyses.

RESULTS

The meta-analysis included 5,658 patients; 66 % patients had prior systemic therapy whereas the remaining patients (34 %) received sunitinib in the first-line setting. For any grade toxicity, skin rash, fatigue, diarrhea, and mucositis were the most frequently encountered events (81, 52, 45, and 33 %, respectively). Anemia, neutropenia, or thrombocytopenia of any grade occurred in more than one-third of patients, although grades 3 or 4 were less common. Any grade raised by liver enzymes or serum creatinine occurred in 40 and 44 % of patients, respectively. Meta-regression analyses showed that study size was inversely related to the risk of experiencing fatigue, diarrhea, mucositis, anemia, and thrombocytopenia. In particular, the incidence of AEs was higher when sunitinib was used in pretreated versus naive patients; however, there was no significant difference between the two groups concerning the incidence of laboratory abnormalities. We addressed the limitations of reporting AEs in clinical studies.

CONCLUSIONS

The present meta-analysis quantified sunitinib-associated AEs. The derived estimates would be similar to that to be expected from the use of sunitinib in community practice in unselected patients with metastatic renal cell carcinoma (mRCC).