Common Subtype Of Renal Cell Carcinoma Research Articles

The tumour microenvironment and metabolism in renal cell carcinoma targeted or immune therapy.

Renal cell carcinoma (RCC) is one of the most common tumours of the urinary system, andis insidious and not susceptible to chemoradiotherapy. As the most common subtype of RCC (70-80% of cases), clear cell renal cell carcinoma (ccRCC) is characterized by the loss of von Hippel-Lindau and the accumulation of robust lipid and glycogen. For advanced RCC, molecular-targeted drugs, tyrosine kinase inhibitors (TKIs) and the immune checkpoint inhibitors (ICIs) have been increasingly recommended and investigated. Due to the existence of a highly dynamic, adaptive and heterogeneous tumour microenvironment (TME), and due to the glucose and lipid metabolism in RCC, this cancer may be accompanied by various types of resistance to TKIs and ICIs. With the increased production of lactate, nitric oxide, and other new by-products of metabolism, novel findings of the TME and key metabolic enzymes drived by HIF and other factors have been increasingly clarified in RCC carcinogenesis and therapy. However, there are few summaries of the TME and tumour metabolism for RCC progression and therapy. Here, we summarize and discuss the relationship of the important implicated characteristics of the TME as well as metabolic molecules and RCC carcinogenesis to provide prospects for future treatment strategies to overcome TME-related resistance in RCC.

Exploration of immune-related genes in high and low tumor mutation burden groups of chromophobe renal cell carcinoma.

Renal cell carcinoma (RCC) is one of most common cancers with gradually increasing incidence and high mortality. Chromogenic RCC (chRCC) is the third most common histological subtype of RCC, accounting for approximately 5–7% of RCC. In our study, the transcriptome expression profile data (n=89) of chRCC, corresponding clinical data (n=113) and the somatic mutation data (n=66) were obtained from the TCGA database. We first analyzed the mutation data of chRCC patients and divided chRCC patients into high and low tumor mutation burden (TMB) groups based on the median TMB. We found that high TMB was significantly associated with worse prognosis and could promote tumor metastasis and development. Moreover, four different immune-related genes (BIRC5, PDGFRL, INHBE, IL20RB) were also identified. We found that BIRC5 was significantly overexpressed in the high TMB group and correlated with worse prognosis. The results of univariate and multivariate COX analyses demonstrated that BIRC5 (hazard ratio (HR) = 2.094) may serve as a prognostic indicator for patients with chRCC with high TMB. In addition, we identified the possible functional pathways of BIRC5 through gene set enrichment analysis (GSEA) enrichment. A positive correlation was obtained between BIRC5 and the abundance of CD4+ T cells. The results of our study revealed their correlation between the immune-related genes and clinicopathologic features as well as potential functional pathways as well as immune infiltrating cells, which may provide more data about the development of chRCC immunotherapy.

Abstract D121: Predicting African American and European American patient response to kidney cancer immunotherapy by stage using the tumor microenvironment

Abstract Background Kidney cancer ranks as a top ten leading site of new cancer cases (~64,000) in the US each year. Renal Cell Carcinoma (RCC) is the predominant type of kidney cancer (~90% cases). The most common RCC subtypes include clear cell RCC (ccRCC, 75%), papillary RCC types I and II (pRCC I and II, 5% and 10%), and chromophobe RCC (chRCC, 5%). RCC subtypes have distinct responses to immunotherapy. Combination checkpoint inhibitors are the first-line treatment for advanced stage ccRCC. Unfortunately, response varies in advanced stage patients, suggesting stage-specific differences in tumor biology. Tumor infiltrating lymphocytes (TILs) in the tumor microenvironment (TME) have been shown to directly influence checkpoint inhibitor response. African Americans (AAs) have higher RCC incidence rates than European Americans (EAs) for reasons that are unclear. Biological determinants of this cancer health disparity have been largely understudied. To our knowledge, no study to date has profiled the TME by stage in AA and EA RCC patients and explored its usefulness as a predictor of checkpoint inhibitor response. Hypothesis TIL abundances and composition varies by stage between AAs and EAs with RCC. Methods Downloaded mRNA-sequencing and clinical data for 531 ccRCC patients, 52 Type I pRCC patients, 66 Type II pRCC patients, and 66 chRCC patients in the TCGA discovery cohort. Differential expression analyses for checkpoint inhibitor drug targets (PD-1, PD-L1, and CTLA-4) were carried out. CIBERSORT, a computation tool that quantifies abundances for 22 TILs based on gene expression, was used to characterize the TME. 1-way ANOVAs between Stages I-IV were performed with GraphPad Prism 8. Significant racial differences for relevant TILs were determined using two-tailed unpaired Welch t tests. Kidney cancer immunotherapy drug responses were inferred based on published clinical studies. Results PD-1 and CTLA-4 significantly increased in advanced stage ccRCC patients. 6/22 TILs showed stage-specific increases and decreases in ccRCC patients. Interestingly, three of these (follicular helper T cells, regulatory T cells, and CD8+ T cells) showed the same trend as the checkpoint inhibitor targets. In pRCC I and II, some TILs also demonstrated a linear increase by stage (Both: regulatory T cells, M1 macrophages; Type II only: naive B cells). M2 macrophage abundance increased significantly by stage in chRCC patients. When comparing AA (n=55) and EA (n=461) ccRCC patients, follicular helper T cells and regulatory T cells increased by stage in EA only. CD8+ T cells increased in abundance in both racial groups. Regulatory T cells and M2 macrophages have been reported to mediate clinical response to checkpoint inhibitor immunotherapy. Conclusions/Future Directions Our data suggests AA and EA RCC patients with advanced stage disease will respond differently to kidney cancer immunotherapy due to TME differences, namely TIL abundance and composition. Future studies include validating these findings in the expO cohort. Citation Format: Jacquelyn Cobb, Heinric Williams, Khadijah A. Mitchell. Predicting African American and European American patient response to kidney cancer immunotherapy by stage using the tumor microenvironment [abstract]. In: Proceedings of the Twelfth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2019 Sep 20-23; San Francisco, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl_2):Abstract nr D121.

Available markers in the diagnosis and prognosis of kidney cancer

Introduction and purpose:Renal cell carcinoma (RCC) is the most common kidney cancer that has no symptoms for a long time. It is most often diagnosed accidentally during abdominal ultrasound or abdominal computed tomography, performed primarily due to non-specific clinical symptoms. Despite progress in treatment, late detection is associated with poor prognosis. The aim of the study is to analyze literature (database PubMed) for potential prognostic markers and those used in RCC diagnostics.A brief description of the state of knowledge: The most common RCC subtype is clear cell renal cell carcinoma(ccRCC). Metastatic ccRCC is associated with poor prognosis. The pathogenesis of ccRCC includes, among others, disorders of miRNA change. These molecules are described as a promising marker of both diagnostic and prognostic. Detection of CD163 + antigen on cancer cells may be useful in assessing the clinical course of ccRCC patients. In clinical diagnosis of RCC, the presence of mutations and epigenetic inactivation of the von Hippel-Lindau (VHL) gene, vascular endothelial growth factor (VEGF) and carbonic anhydrase IX (CIAX) genes are particularly important. Plasma CIAX levels are described as not only a diagnostic and prognostic marker, but also lymph node involvement. There are studies on molecular markers that can also be a therapeutic target, including Caveolin-1 (CAV1), CCL5. Recent research results show a link between PDL1 expression and high-grade tumors. PDL-1 may also be an important prognostic factor.Conclusions:Research on molecular markers is a promising personalized diagnostic and prognostic route. The limitation is the nonspecificity of molecular markers, so research on new and current markers is needed.

Comprehensive landscape of immune-checkpoints uncovered in clear cell renal cell carcinoma reveals new and emerging therapeutic targets.

Clear cell renal cell carcinoma (ccRCC) constitutes the most common renal cell carcinoma subtype and has long been recognized as an immunogenic cancer. As such, significant attention has been directed toward optimizing immune-checkpoints (IC)-based therapies. Despite proven benefits, a substantial number of patients remain unresponsive to treatment, suggesting that yet unreported, immunosuppressive mechanisms coexist within tumors and their microenvironment. Here, we comprehensively analyzed and ranked forty-four immune-checkpoints expressed in ccRCC on the basis of in-depth analysis of RNAseq data collected from the TCGA database and advanced statistical methods designed to obtain the group of checkpoints that best discriminates tumor from healthy tissues. Immunohistochemistry and flow cytometry confirmed and enlarged the bioinformatics results. In particular, by using the recursive feature elimination method, we show that HLA-G, B7H3, PDL-1 and ILT2 are the most relevant genes that characterize ccRCC. Notably, ILT2 expression was detected for the first time on tumor cells. The levels of other ligand-receptor pairs such as CD70:CD27; 4-1BB:4-1BBL; CD40:CD40L; CD86:CTLA4; MHC-II:Lag3; CD200:CD200R; CD244:CD48 were also found highly expressed in tumors compared to adjacent non-tumor tissues. Collectively, our approach provides a comprehensible classification of forty-four IC expressed in ccRCC, some of which were never reported before to be co-expressed in ccRCC. In addition, the algorithms used allowed identifying the most relevant group that best discriminates tumor from healthy tissues. The data can potentially assist on the choice of valuable immune-therapy targets which hold potential for the development of more effective anti-tumor treatments.

LncRNA-LET inhibits cell growth of clear cell renal cell carcinoma by regulating miR-373-3p

BackgroundClear cell renal cell carcinoma (ccRCC) is the most common renal cell carcinoma subtype with a poor prognosis. LncRNA-LET is a long non-coding RNA (lncRNA) that is down-regulated in ccRCC tissues. However, its role in ccRCC development and progress is unclear.MethodsLncRNA-LET expression was detected in ccRCC tissues and ccRCC cells using quantitative real-time PCR. The overexpression and knockdown experiments were performed in ccRCC cells and xenograft mouse model to evaluate role of lncRNA-LET. Cell cycle, apoptosis and JC-1 assays were conducted via flow cytometer. The protein levels were measured through western blot analysis and the interaction between lncRNA-LET and miR-373-3p was identified via luciferase reporter assay.ResultsLncRNA-LET expression was lower in ccRCC tissues than that in the matched adjacent non-tumor tissues (n = 16). In vitro, lncRNA-LET overexpression induced cell cycle arrest, promoted apoptosis and impaired mitochondrial membrane potential, whereas its knockdown exerted opposite effects. Moreover, we noted that lncRNA-LET may act as a target for oncomiR miR-373-3p. In contrast to lncRNA-LET, miR-373-3p expression was higher in ccRCC tissues. The binding between lncRNA-LET and miR-373-3p was validated. Two downstream targets of miR-373-3p, Dickkopf-1 (DKK1) and tissue inhibitor of metalloproteinase-2 (TIMP2), were positively regulated by lncRNA-LET in ccRCC cells. MiR-373-3p mimics reduced lncRNA-LET-induced up-regulation of DKK1 and TIMP2 levels, and attenuated lncRNA-LET-mediated anti-tumor effects in ccRCC cells. In vivo, lncRNA-LET suppressed the growth of ccRCC xenograft tumors.ConclusionThese findings indicate that lncRNA-LET plays a tumor suppressive role in ccRCC by regulating miR-373-3p.

Von Hippel-Lindau Gene Mutations and Vascular Endothelial Growth Factor Immunoexpression in Clear Cell Renal Cell Carcinoma

Renal cell carcinoma (RCC) is the most common type of kidney cancer in adults representing about 3% of all newly diagnosed cancers in the United States. Clear cell RCC is the most common subtype (70-80%) of RCC. Clear cell RCC can be familial, but 95% of cases are sporadic resulting from the germline or acquired mutation of Von Hippel-Lindau (VHL) gene. VHL tumor suppressor gene functions as a down regulator of vascular endothelial growth factor (VEGF). Mutations of VHL gene result in overexpression of VEGF, neoangiogenesis and tumor metastasis. Nowadays, anti-VEGF targeted therapy is used for treating metastasis clear cell RCC. However, drug resistance occurs over time. VHL gene targeted therapy combined with anti-VEGF therapy should be considered and detection of VHL gene mutations status becomes essential in these cases. The present study was aimed to detect the VHL gene mutations status and VEGF immunoexpression in 62 clear cell RCC patients by conventional polymerase chain reaction and immunohistochemistry. Three primer pairs were used to detect the mutations of 3 exons in VHL gene. The positive cases for VHL exon 1 mutation, exon 2 mutation and exon 3 mutation were checked by 2% agarose gel electrophoresis. Tumor grading was done by Fuhrman nuclear grading system and staging was done by pathologic TNM staging system. Fifty cases (80.65%) were VHL gene mutation positive and 12 cases (19.35%) were negative. VHL gene mutations were significantly associated with histological grades (p=0.005). Out of 62 cases, 24 cases were weakly positive (1+) and 38 cases were strongly positive (2+) VEGF immuno-reactivity. There was statistically significant association between VEGF immunoexpression and histological grades of clear cell renal cell carcinoma (p=0.00) as well as tumor stage (p=0.01). It was also found that VEGF immunoexpression of clear cell RCC was significantly associated with VHL gene mutation positive tumours (p=0.00). These results can be helpful in further invention of molecular targeted therapy for drug-resistant clear cell RCC patients.

New entities, new technologies, new findings: A review of the cytologic features of recently established subtypes of renal cell carcinoma.

Several new renal tumor types with distinctive pathologic, epidemiologic, and genetic signatures have recently been adopted in the fourth edition of the World Health Organization classification. In succeeding years, the cytologic features of most of these new types have been described, adding to the trend of increasing diagnostic accuracy for most common renal cell carcinoma subtypes and the important diagnostic role of cytologic sampling in the management and personalization of therapy. The current article reviews the cytologic findings from these recently established renal cell carcinoma subtypes. Emphasis is placed on cytologic diagnostic clues, confirmatory ancillary testing, salient differential diagnoses, and challenges that can be encountered in an attempt to render accurate interpretations in small samples.

Chromosome 3p Loss-Orchestrated VHL, HIF, and Epigenetic Deregulation in Clear Cell Renal Cell Carcinoma.

Clear cell renal cell carcinoma (ccRCC) is the most common renal cell carcinoma subtype, and metastatic ccRCC is associated with 5-year survival rates of 10% to 20%. Genetically, ccRCC originates from sequential losses of multiple tumor suppressor genes. Remarkably, chromosome 3p loss occurs in more than 90% of sporadic ccRCCs. This results in concurrent one-copy loss of four tumor suppressor genes that are also mutated individually at high frequency in ccRCC (ie, VHL, 80%; PBRM1, 29% to 46%; BAP1, 6% to 19%; and SETD2, 8% to 30%). Pathogenically, 3p loss probably represents the first genetic event that occurs in sporadic ccRCC and the second genetic event in VHL-mutated hereditary ccRCC. VHL constitutes the substrate recognition module of the VCB-Cul2 E3 ligase that degrades HIF1/2α, whereas PBRM1, BAP1, and SETD2 are epigenetic modulators that regulate gene transcription. Because 3p loss and VHL inactivation are nearly universal truncal events in ccRCC, the resulting HIF1/2 signaling overdrive and accompanied tumor hypervascularization probably underlie the therapeutic benefits observed with vascular endothelial growth factor receptor inhibitors, including sorafenib, sunitinib, pazopanib, axitinib, bevacizumab, cabozantinib, and lenvatinib. Furthermore, recent marked advances in ccRCC genomics, transcriptomics, proteomics, metabolomics, molecular mechanisms, mouse models, prognostic and predictive biomarkers, and clinical trials have rendered invaluable translational insights concerning precision kidney cancer therapeutics. With an armamentarium encompassing 13 drugs that exploit seven unique therapeutic mechanisms (ie, cytokines, vascular endothelial growth factor receptor, mTORC1, cMET/AXL, fibroblast growth factor receptor, programmed cell death-1 and programmed death-ligand 1, and cytotoxic T-cell lymphocyte associated-4) to treat metastatic renal cell carcinoma, one of the imminent clinical questions concerning care of patients with metastatic ccRCC is how a personalized treatment strategy, through rationally combining and sequencing different therapeutic modalities, can be formulated to offer the best clinical outcome for individual patients. Here, we attempt to integrate recent discoveries of immediate translational impacts and discuss future translational challenges and opportunities.

Renal Tumors of Childhood: Radiologic-Pathologic Correlation Part 2. The 2nd Decade: From the Radiologic Pathology Archives.

Malignant renal tumors account for 7% of childhood cancers, and Wilms tumors are by far the most common-but not in older children and adolescents. Among individuals in the latter half of their 2nd decade of life, renal cell carcinoma (RCC) is more common than Wilms tumor. The histopathologic spectrum of RCCs in children differs from that in adults. The most common subtype of RCC in children and adolescents is Xp11.2 translocation RCC, which is distinguished by hyperattenuation at nonenhanced computed tomography, a defined capsule, and associated retroperitoneal lymphadenopathy. Papillary RCC is the second most common histologic subtype. It enhances less intensely compared with the adjacent renal parenchyma and has a propensity for calcification. Clear cell RCC is seen in patients with von Hippel-Lindau disease and is distinguished by its relatively hypervascular nature. Medullary carcinoma affects adolescents with the sickle cell trait and is characterized by an infiltrative growth pattern and extensive metastasis at presentation. Angiomyolipoma is seen in children with tuberous sclerosis complex and is often multifocal and hypervascular, with macroscopic fat. Metanephric tumors are central, circumscribed, and typically calcified. Lymphoma usually manifests as multifocal masses, but it may involve a solitary mass or infiltrative pattern. Extensive adenopathy and involvement of the gastrointestinal tract or other organs also may be seen. Primitive neuroectodermal tumor is an aggressive neoplasm that is typically quite large at diagnosis. Knowledge of the clinical, biologic, and histopathologic features of renal tumors in older children and adolescents and their effects on the imaging appearance can help the radiologist offer a useful preoperative differential diagnosis.

Sarcomatoid Renal Cell Carcinoma and Collecting Duct Carcinoma: Discrimination From Common Renal Cell Carcinoma Subtypes and Benign RCC Mimics on Multiphasic MDCT

To investigate whether imaging features on multiphasic multidetector computed tomography (MDCT) can help discriminate sarcomatoid renal cell carcinoma (RCC) and collecting duct carcinoma (CDC) from other solid renal masses. With institutional review board approval for this HIPAA-compliant study, we derived a cohort of 7 sarcomatoid RCCs, 4 CDCs, 165 clear cell RCCs, 56 papillary RCCs, 22 chromophobe RCCs, 49 oncocytomas, and 16 lipid-poor angiomyolipomas with preoperative multiphasic MDCT with up to four phases (unenhanced, corticomedullary, nephrographic, and excretory). Each lesion was reviewed for contour, spread pattern, pattern of enhancement, neovascularity, and calcification. Sarcomatoid RCCs and CDCs were more likely than other solid renal masses to have an irregular contour (64% vs 2%, P < 0.001) and an infiltrative spread pattern, defined as infiltration into adjacent renal parenchyma, collecting system, or neighboring structures (82% vs 7%, P < 0.001). When used to discriminate sarcomatoid RCC and CDC from other solid renal masses, an infiltrative spread pattern had a specificity of 93% (287/308) and sensitivity of 82% (9/11), and an irregular contour had a specificity of 98% (303/308) and sensitivity of 64% (7/11). Solid renal lesions with an irregular contour or an infiltrative spread pattern are suspicious for sarcomatoid RCC or CDC.

Body mass index and the clinicopathological characteristics of clinically localized renal masses—An international retrospective review

ObjectivesTo investigate the potential association between body mass index (BMI) and clinicopathological features of clinically localized renal masses. Materials and methodsAn international, multi-institutional retrospective review of patients who underwent surgery for clinically localized renal masses between 2000 and 2010 was undertaken after an institutional review board approval. Patients were divided into 4 absolute BMI groups based on the entire cohort׳s percentiles and 4 relative BMI groups based on their respective population (American or Italian). Renal mass pathological diagnosis, renal cell carcinoma (RCC) subtype, Fuhrman grade (low and high), and clinical stage were compared among groups using Fisher׳s exact test, Kruskal-Wallis test, and the Cochran-Armitage trend test. A multivariate logistic analysis was performed to evaluate independent association between tumor and patient characteristics with tumor pathology (Fuhrman grade). ResultsA total of 1,748 patients having a median BMI of 28 (interquartile range 25–32) were evaluated. Benign masses and RCC cases had similar proportion across BMI groups (P = 0.4). The most common RCC subtype was clear cell followed by papillary carcinoma, chromophobe, and other subtypes. Their distribution was comparable across BMI groups (P = 0.7). Similarly, clinical stage distribution was comparable with the overall cohort. The distribution of Fuhrman grade in RCC, however, demonstrated an increased proportions of low grade with increasing BMI (P<0.05). This trend was maintained in subgroups according to gender, stage and age (P<0.05 in all subgroup analysis). In a multivariable model that included potential confounders (i.e., age, sex, and tumor size) higher BMI groups had lower odds of presenting a high Fuhrman grade. ConclusionIn this study, higher BMI was associated with lower grade of RCC in clinically localized renal masses. This may, in part, explain better survival rates in patients with higher BMI and may correlate with a possible link between adipose tissue and RCC biology.

Kindlin‑2 promotes clear cell renal cell carcinoma progression through the Wnt signaling pathway.

Kindlin‑2 is an integrin-interacting, FERM-domain containing protein, which plays a critical role in tumor progression. However, the specific role of Kindlin‑2 in renal cell carcinoma (RCC) progression has not been described. In this study we investigated the role of Kindlin‑2 in progression of clear cell RCC (CCRCC), which is the most common RCC subtype, and its underlying mechanisms. Immunohistochemistry studies show that expression of Kindlin‑2 in CCRCC is positively correlated with tumor grade, and Kindlin‑2 expression in advanced CCRCC with lymph node metastasis was greater than in localized CCRCC. Kindlin‑2 expression in CCRCC tumor specimens is also correlated with short patient survival, but is not an independent prognostic factor. Kindlin‑2 promotes CCRCC cell migration and invasion invitro, whereas knockdown of Kindlin‑2 inhibited cell migration and invasion. Knockdown of Kindlin‑2 also inhibits ACHN cell proliferation invitro and tumorigenesis invivo. Kindlin‑2 may be required for Wnt pathway activation which underlies the mechanisms of Kindlin‑2 promoting CCRCC progression. These findings demonstrate that expression of Kindlin‑2 is associated with tumor grade, lymph node metastasis and poor prognosis in CCRCC patients. Kindlin‑2 may regulate CCRCC progression through the Wnt signaling pathway, promoting CCRCC cell proliferation, migration and invasion.

Multimodality Imaging Characteristics of the Common Renal Cell Carcinoma Subtypes: An Analysis of 544 Pathologically Proven Tumors.

Objectives:The objective of this study was to define the characteristic imaging appearances of the common renal cell carcinoma (RCC) subtypes.Materials and Methods:The Institutional Review Board approval was obtained for this HIPAA-compliant retrospective study, and informed consent was waived. 520 patients (336 men, 184 women; age range, 22–88 years) underwent preoperative cross-sectional imaging of 544 RCCs from 2008 to 2013. The imaging appearances of the RCCs and clinical information were reviewed. Data analysis was performed using parametric and nonparametric statistics, descriptive statistics, and receiver operating characteristic analysis.Results:The RCC subtypes showed significant differences (P < 0.001) in several imaging parameters such as tumor margins, tumor consistency, tumor homogeneity, the presence of a central stellate scar, T2 signal intensity, and the degree of tumor enhancement. Low T2 signal intensity on magnetic resonance imaging (MRI) allowed differentiation of papillary RCC from clear cell and chromophobe RCCs with 90.9% sensitivity and 93.1% specificity. A tumor-to-cortex ratio ≥1 on the corticomedullary phase had 98% specificity for clear cell RCC.Conclusion:The T2 signal intensity of the tumor on MRI and its degree of enhancement are useful imaging parameters for discriminating between the RCC subtypes while gross morphological findings offer additional value in RCC profiling.

MP85-10 IDENTIFICATION OF WDR20 AS A NEW TUMOR SUPPRESSOR GENE PREFERENTIALLY ALTERED IN HIGH-GRADE CLEAR CELL RENAL CELL CARCINOMA.

INTRODUCTION AND OBJECTIVES: There are more than 200,000 cases of renal cell carcinoma (RCC) each year in the world, accounting for approximately 2% of all cancers. RCC clear cell type (ccRCC) is the most common subtype of RCC and accounts for 75 to 80% of the cases with highest rates of local invasion, development of metastasis and mortality. New target therapy is based on antiangiogenic antibodies and molecules, changing the course of the disease, but the results so far are disappointing. Our aim is to study miRNAs and their target genes related to angiogenesis in ccRCC trying to bring some new knowledge to the molecular pathways related to the disease METHODS: The expression levels of miRNAs miR-99a, 99b, 100; 199a; 106a; 106b; 29a; 29b; 29c; 126; 200a, 200b and their respective target genes: mTOR, HIF1-a, VHL, PDGF, VEGF, VEGFR1 and VEGFR2 were evaluated using qRT-PCR.in snap-frozen tumor tissue samples from 56 patients diagnosed with ccRCC and 5 samples of benign renal tissue as control. The results were related to tumor size, Fuhrman nuclear grade and microvascular invasion, considering the risk criteria proposed by Dall’Oglio et al. (2007). RESULTS: We found an underexpression of the most genes except the VEGFA and PDGF, while the analysis of miRNAs showed underexpression only the miR 199a, 100 and 126. We compared the expression of genes with their possible regulatory miRNAs, and we found that mTOR was underexpressed while miR99a was overexpressed in most samples. This relationship also occurs between VEGFA and miR126 and between miRNAs 106a, 106b, and their target gene VHL. Considering the risk groups the overexpression of miR200b was associated with high-risk patients (p 1⁄4 0.01) and the overexpression of miR126 was associated with lower Fuhrman grade (I-II) (p 1⁄4 0.03). CONCLUSIONS: Our results show that in ccRCC there is an unbalance in the expression of genes and miRNAs related to angiogenesis and cell proliferation and survival. Furthermore with our findings we can speculate the role of miR200b and miR126 in the prognostic of ccRCC. We believe that the relationship between miRNAs and their respective genes should be more profoundly searched as markers and possible therapeutic agents in this neoplasia.

MP85-11 GENETIC DELETION OF SAV1 ENHANCES PROLIFERATION AND NUCLEAR IRREGULARITY IN RENAL TUBULAR EPITHELIAL CELLS

INTRODUCTION AND OBJECTIVES: There are more than 200,000 cases of renal cell carcinoma (RCC) each year in the world, accounting for approximately 2% of all cancers. RCC clear cell type (ccRCC) is the most common subtype of RCC and accounts for 75 to 80% of the cases with highest rates of local invasion, development of metastasis and mortality. New target therapy is based on antiangiogenic antibodies and molecules, changing the course of the disease, but the results so far are disappointing. Our aim is to study miRNAs and their target genes related to angiogenesis in ccRCC trying to bring some new knowledge to the molecular pathways related to the disease METHODS: The expression levels of miRNAs miR-99a, 99b, 100; 199a; 106a; 106b; 29a; 29b; 29c; 126; 200a, 200b and their respective target genes: mTOR, HIF1-a, VHL, PDGF, VEGF, VEGFR1 and VEGFR2 were evaluated using qRT-PCR.in snap-frozen tumor tissue samples from 56 patients diagnosed with ccRCC and 5 samples of benign renal tissue as control. The results were related to tumor size, Fuhrman nuclear grade and microvascular invasion, considering the risk criteria proposed by Dall’Oglio et al. (2007). RESULTS: We found an underexpression of the most genes except the VEGFA and PDGF, while the analysis of miRNAs showed underexpression only the miR 199a, 100 and 126. We compared the expression of genes with their possible regulatory miRNAs, and we found that mTOR was underexpressed while miR99a was overexpressed in most samples. This relationship also occurs between VEGFA and miR126 and between miRNAs 106a, 106b, and their target gene VHL. Considering the risk groups the overexpression of miR200b was associated with high-risk patients (p 1⁄4 0.01) and the overexpression of miR126 was associated with lower Fuhrman grade (I-II) (p 1⁄4 0.03). CONCLUSIONS: Our results show that in ccRCC there is an unbalance in the expression of genes and miRNAs related to angiogenesis and cell proliferation and survival. Furthermore with our findings we can speculate the role of miR200b and miR126 in the prognostic of ccRCC. We believe that the relationship between miRNAs and their respective genes should be more profoundly searched as markers and possible therapeutic agents in this neoplasia.

Genetic alterations of HER genes in chromophobe renal cell carcinoma

Chromophobe (ch) renal cell carcinoma (RCC) is the 3rd most common subtype of RCC and occurs in 5% of all RCCs. Although chRCC generally demonstrates more favorable outcomes compared with other subtypes of RCC, there is a 6-7% probability of tumor progression and metastasis in this disease. The subclassification of a more aggressive subtype of chRCC may be useful for the management of this cancer. The Erb-B2 receptor tyrosine kinase 2 [also known as human epidermal growth factor receptor (HER) 2] gene has been reported to be important in chRCC. The present study aimed to further investigate the abnormalities of the HER family genes and their potential association with chRCC. Fluorescence in situ hybridization was performed on 11 chRCC tissue specimens, and the Spearman's rank correlation coefficient analysis was used to assess the results. The loss of one copy of the HER2 and HER4 genes was observed to be the major alteration of the tumor cells in all chRCC cases. Statistical data indicated that loss of the HER2 gene was strongly correlated with loss of the HER4 gene (P=0.019). The findings of previous studies were also combined for analysis, and were consistent with those of the present study. In addition, the amplification of HER1 was also strongly correlated with the amplification of HER4 (P=0.004). Furthermore, a high percentage of genetic structural rearrangements was observed in HER3 genes, which was significantly associated with amplification of HER2 (P=0.005). Certain alterations in the HER gene family were also noted as a phenomenom in chRCC. Therefore, the characterization of the underlying aberrant functions of HER genes may be of interest for additional studies in the context of using HER genes to distinguish between RCC subtypes in order to establish improved treatment guidelines.

Review of renal cell carcinoma and its common subtypes in radiology.

Representing 2%-3% of adult cancers, renal cell carcinoma (RCC) accounts for 90% of renal malignancies and is the most lethal neoplasm of the urologic system. Over the last 65 years, the incidence of RCC has increased at a rate of 2% per year. The increased incidence is at least partly due to improved tumor detection secondary to greater availability of high-resolution cross-sectional imaging modalities over the last few decades. Most RCCs are asymptomatic at discovery and are detected as unexpected findings on imaging performed for unrelated clinical indications. The 2004 World Health Organization Classification of adult renal tumors stratifies RCC into several distinct histologic subtypes of which clear cell, papillary and chromophobe tumors account for 70%, 10%-15%, and 5%, respectively. Knowledge of the RCC subtype is important because the various subtypes are associated with different biologic behavior, prognosis and treatment options. Furthermore, the common RCC subtypes can often be discriminated non-invasively based on gross morphologic imaging appearances, signal intensity on T2-weighted magnetic resonance images, and the degree of tumor enhancement on dynamic contrast-enhanced computed tomography or magnetic resonance imaging examinations. In this article, we review the incidence and survival data, risk factors, clinical and biochemical findings, imaging findings, staging, differential diagnosis, management options and post-treatment follow-up of RCC, with attention focused on the common subtypes.

Urine screening by Seldi-Tof, followed by biomarker identification, in a Brazilian cohort of patients with Renal Cell Carcinoma (RCC)

To screen proteins/peptides in urine of Renal Cell Carcinoma (RCC) patients by SELDI-TOF (Surface Enhanced Laser Desorption Ionization - Time of Flight) in search of possible biomarkers. Sixty-one urines samples from Clear Cell RCC and Papillary RCC were compared to 29 samples of control urine on CM10 chip. Mass analysis was performed in a ProteinChip Reader PCS 4,000 (Ciphergen Biosystems, Fremont, CA) with the software Ciphergen Express 3.0. All chips were read at low and at high laser energy. For statistical analysis the urine samples were clustered according to the histological classification (Clear Cell and Papillary Carcinoma). For identification urine was loaded on a SDS PAGE gel and bands of most interest were excised, trypsinized and identified by MS/MS. Databank searches were performed in Swiss-Prot database using the MASCOT search algorithm and in Profound. Proteins that were identified from urine of controls included immunoglobulin light chains, albumin, secreted and transmembrane 1 precursor (protein K12), mannan-binding lectin-associated serine protease-2 (MASP-2) and vitelline membrane outer layer 1 isoform 1. Identification of immunoglobulins and isoforms of albumin are quite common by proteomics and therefore cannot be considered as possible molecular markers. K12 and MASP-2 play important physiological roles, while vitellite membrane outer layer 1 role is unknown since it was never purified in humans. The down expression of Protein K-12 and MASP-2 make them good candidates for RCC urine marker and should be validated in a bigger cohort including the other less common histological RCC subtypes.

Mutational activation of FGFR3: no involvement in the development of renal cell carcinoma

Somatic point mutations in the fibroblast growth factor receptor 3 (FGFR3) gene have been identified in certain types of urological cancers, especially urothelial carcinoma of the bladder and the renal pelvis, and could be correlated with a favourable outcome. However, comprehensive data on the FGFR3 mutation status in renal cell carcinoma (RCC) are still missing. In order to investigate a possible role for FGFR3 mutations in renal cell carcinogenesis, we performed a sequence-based mutational analysis of FGFR3 in 238 primary RCC. The cohort obtained the common RCC subtypes including 101 clear cell, 50 papillary and 68 chromophobe RCC specimens. The analysed regions encompassed all FGFR3 point mutations previously described in epithelial tumours and other noncutaneous epithelial malignancies. No mutations were detected in any renal tumour type examined, and all cases showed wild-type sequence. Our results argue against an involvement of mutational activation of FGFR3 in the development of RCC. A recently described cystic renal dysplasia in a patient with thanatophoric dysplasia type 1 due to a germ line FGFR3 mutation might portend to an involvement of mutational FGFR3 activation in renal cyst formation, but this speculation needs further evaluation.