Nuclear and stromal expression of Manic fringe in renal cell carcinoma.

Renal cell carcinoma (RCC) is the most common type of kidney cancer and has the highest mortality rate among genitourinary cancers. Despite the advances in molecular targeted therapies to treat RCC, the inevitable emergence of resistance has delineated the need to uncover biomarkers to prospectively identify patient response to treatment and more accurately predict patient prognosis. Fringe is a fucose specific ß1, 3N-acetylglucosaminyltransferase that modifies the Notch receptors. Given the link between its function and aberrant Notch activation in RCC, Fringe may be implicated in this disease. The Fringe homologs comprise of Lunatic fringe (LFng), Manic fringe (MFng) and Radical fringe (RFng). MFng has been reported to play a role in cancer. MFng is also essential in the development of B cells. However, the expression profile and clinical significance of MFng, and its association with B cells in RCC are unknown. CD20 is a clinically employed biomarker for B cells. This pilot study aimed to determine if MFng protein expression can be utilized as a prospective biomarker for therapeutics and prognosis in RCC, as well as to determine its association with CD20+ B cells. Analysis of publicly available MFng gene expression datasets on The Cancer Genome Atlas Netlwork (TCGA) identified MFng gene expression to be up-regulated in Kidney Clear Cell Renal Carcinoma (KIRC) patients. However there was no significant association between the patient survival probability and the level of MFng expression in this cohort. Immunohistochemistry performed on a tissue microarray containing cores from 64 patients revealed an elevated MFng protein expression in the epithelial and stromal tissues of RCC compared to the normal kidney, suggesting a possible role in tumorigenesis. Our study describes for the first time to our knowledge, the protein expression of MFng in the nuclear compartment of normal kidney and RCC, implicating a prospective involvement in gene transcription. At the cellular level, cytoplasmic MFng was also abundant in the normal kidney and RCC. However, MFng protein expression in the malignant epithelial and stromal tissue of RCC had no positive correlation with the patients' overall survival, progression-free survival and time to metastasis, as well as the gender, age, tumor stage and RCC subtype, indicating that MFng may not be an appropriate prognostic marker. The association between CD20+ B cells and epithelial MFng was found to approach borderline insignificance. Nonetheless, these preliminary findings may provide valuable information on the suitability of MFng as a potential therapeutic molecular marker for RCC, thus warrants further investigation using a larger cohort.

A minority-group of renal cell cancer patients with high infiltration of CD20+B-cells is associated with poor prognosis.

BACKGROUND: The role of B-lymphocytes in solid tumours is unclear. Tumour biology studies have implied both anti- and pro-tumoural effects and prognostic studies have mainly linked B-cells to increased survival. This study aimed to analyse the clinical relevance of B-lymphocytes in renal cell cancer (RCC), where information on the prognostic impact is lacking. METHODS: Following immunohistochemistry (IHC) stainings with a CD20 antibody, density of CD20+ B-cells was quantified in an RCC discovery- and validation cohort. Associations of B-cell infiltration, determined by CD20 expression or a B-cell gene-signature, and survival was also analysed in 14 publicly available gene expression datasets of cancer, including the kidney clear cell carcinoma (KIRC) dataset. RESULTS: IHC analyses of the discovery cohort identified a previously unrecognised subgroup of RCC patients with high infiltration of CD20+ B-cells. The B-cell-high subgroup displayed significantly shorter survival according to uni- and multi-variable analyses. The association between poor prognosis and high density of CD20+ B-cells was confirmed in the validation cohort. Analyses of the KIRC gene expression dataset using the B-cell signature confirmed findings from IHC analyses. Analyses of other gene expression datasets, representing 13 different tumour types, indicated that the poor survival-association of B-cells occurred selectively in RCC. CONCLUSION: This exploratory study identifies a previously unrecognised poor-prognosis subset of RCC with high density of CD20-defined B-cells.

Perivascular PDGFR-ß is an independent marker for prognosis in renal cell carcinoma.

BACKGROUND: Renal cell carcinoma (RCC) is a highly vascularised tumour, where anti-angiogenic treatment with multi-tyrosine-kinase-inhibitor, is used for first-line treatment of metastatic disease. Variations in vascular characteristics are likely to contribute to variations in intrinsic aggressiveness of the disease. Emerging studies are identifying perivascular status, including perivascular PDGFR-ß, as a determinant of prognosis in other tumour types. METHODS: This work explored the impact on prognosis of vascular characteristics in RCC through analyses of a population-based collection of tumours from surgery-alone-treated patients. The quantitative data from a panel of vascular metrics were obtained through computerised image analysis of sections double-stained for expression of the endothelial cell marker CD34 together with perivascular markers α-SMA or PDGFR-ß. RESULTS: Perivascular expression of PDGFR-ß and α-SMA were positively correlated to each other, and negatively correlated to vessel density. High expression of PDGFR-ß and α-SMA as well as low vessel density was significantly associated with short survival in uni- and multivariate analyses. Subgroup analyses demonstrated that the prognostic impact of the perivascular markers was particularly prominent in the T4-subgroup. A novel metric, related to PDGFR-ß perivascular heterogeneity, was also associated with prognosis in uni-and multi-variate analyses. This novel metric also acted as a prognosis marker in ovarian cancer. CONCLUSIONS: The study demonstrates previously unrecognised associations between RCC survival and the absolute levels, and variability, of perivascular PDGFR-ß. This marker should be further explored in other RCC cohorts. Findings also suggest mechanistic analyses and studies on the relationship between perivascular status and efficacy of multi-tyrosine-kinase-inhibitors.

Multi-parametric profiling of renal cell, colorectal, and ovarian cancer identifies tumour-type-specific stroma phenotypes and a novel vascular biomarker.

A novel set of integrated procedures for quantification of fibroblast-rich stroma and vascular characteristics has recently been presented allowing discovery of novel perivascular and stromal biomarkers in colorectal, renal cell, and ovarian cancer. In the present study, data obtained through these procedures from clinically well-annotated collections of these three tumour types have been used to address two novel questions. First, data have been used to investigate if the three tumour types demonstrate significant differences regarding features such as vessel diameter, vessel density, and perivascular marker expression. Second, analyses of the cohorts have been used to explore the prognostic significance of a novel vascular metric, 'vessel distance inter-quartile range (IQR)' that describes intra-case heterogeneity regarding vessel distribution. The comparisons between the three tumour types demonstrated a set of significant differences. Vessel density of renal cell cancer was statistically significantly higher than in colorectal and ovarian cancer. Vessel diameter was statistically significantly higher in ovarian cancer. Concerning perivascular status, colorectal cancer displayed significantly higher levels of perivascular PDGFR-ß expression than the other two tumour types. Intra-case heterogeneity of perivascular PDGFR-ß expression was also higher in colorectal cancer. Notably, these fibroblast-dominated stroma phenotypes matched previously described experimental tumour stroma characteristics, which have been linked to differential sensitivity to anti-VEGF drugs. High 'vessel distance IQR' was significantly associated with poor survival in both renal cell cancer and colorectal cancer. In renal cell cancer, this characteristic also acted as an independent prognostic marker according to multivariate analyses including standard clinico-pathological characteristics. Explorative subset analyses indicated particularly strong prognostic significance of 'vessel distance IQR' in T stage 4 of this cancer type. Together, these analyses identified tumour-type-specific vascular-stroma phenotypes of possible functional significance, and suggest 'vessel distance IQR' as a novel prognostic biomarker.