Sunitinib induces early histomolecular changes in a subset of renal cancer cells that contribute to resistance.

Sunitinib is the standard-of-care, first-line treatment for advanced renal cell carcinoma (RCC). Characteristics of treatment-resistant RCC have been described; however, complex tumor adaptation mechanisms obstruct the identification of significant operators in resistance. We hypothesized that resistance is a late manifestation of early, treatment-induced histomolecular alterations; therefore, studying early drug response may identify drivers of resistance. We describe an epithelioid RCC growth pattern in RCC xenografts, which emerges in sunitinib-sensitive tumors and is augmented during resistance. This growth modality is molecularly and morphologically related to the RCC spheroids that advance during in vitro treatment. Based on time-lapse microscopy, mRNA and microRNA screening, and tumor behavior-related characteristics, we propose that the spheroid and adherent RCC growth patterns differentially respond to sunitinib. Gene expression analysis indicated that sunitinib promoted spheroid formation, which provided a selective survival advantage under treatment. Functional studies confirm that E-cadherin is a key contributor to the survival of RCC cells under sunitinib treatment. In summary, we suggest that sunitinib-resistant RCC cells exist in treatment-sensitive tumors and are histologically identifiable.-Lichner, Z., Saleeb, R., Butz, H., Ding, Q., Nofech-Mozes, R., Riad, S., Farag, M., Varkouhi, A. K., dos Santos, C. C., Kapus, A., Yousef, G. M. Sunitinib induces early histomolecular changes in a subset of renal cancer cells that contribute to resistance.

Integrative bioinformatics analysis reveals new prognostic biomarkers of clear cell renal cell carcinoma.

BACKGROUND: The outcome of clear cell renal cell carcinoma (ccRCC) is still unpredictable. Even with new targeted therapies, the average progression-free survival is dismal. Markers for early detection and progression could improve disease outcome. METHODS: To identify efficient and hitherto unrecognized pathogenic factors of the disease, we performed a uniquely comprehensive pathway analysis and built a gene interaction network based on large publicly available data sets assembled from 28 publications, comprising a 3-prong approach with high-throughput mRNA, microRNA, and protein expression profiles of 593 ccRCC and 389 normal kidney samples. We validated our results on 2 different data sets of 882 ccRCC and 152 normal tissues. Functional analyses were done by proliferation, migration, and invasion assays following siRNA (small interfering RNA) knockdown. RESULTS: After integration of multilevel data, we identified aryl-hydrocarbon receptor (AHR), grainyhead-like-2 (GRHL2), and KIAA0101 as new pathogenic factors. GRHL2 expression was associated with higher chances for disease relapse and retained prognostic utility after controlling for grade and stage [hazard ratio (HR), 3.47, P = 0.012]. Patients with KIAA0101-positive expression suffered worse disease-free survival (HR, 3.64, P < 0.001), and in multivariate analysis KIAA0101 retained its independent prognostic significance. Survival analysis showed that GRHL2- and KIAA0101-positive patients had significantly lower disease-free survival (P = 0.002 and P < 0.001). We also found that KIAA0101 silencing decreased kidney cancer cell migration and invasion in vitro. CONCLUSIONS: Using an integrative system biology approach, we identified 3 novel factors as potential biomarkers (AHR, GRHL2 and KIAA0101) involved in ccRCC pathogenesis and not linked to kidney cancer before.

Elucidating mechanisms of sunitinib resistance in renal cancer: an integrated pathological-molecular analysis.

Upon sunitinib treatment of metastatic renal cell carcinoma patients eventually acquire resistance. Our aim was to investigate microRNAs behind sunitinib resistance. We developed an in vivo xenograft and an in vitro model and compared morphological, immunhistochemical, transcriptomical and miRNome data changes during sunitinib response and resistance by performing next-generation mRNA and miRNA sequencing. Complex bioinformatics (pathway, BioFunction and network) analysis were performed. Results were validated by in vitro functional assays. Our morphological, immunhistochemical, transcriptomical and miRNome data all pointed out that during sunitinib resistance tumor cells changed to migratory phenotype. We identified the downregulated miR-1 and miR-663a targeting FRAS1 (Fraser Extracellular Matrix Complex Subunit 1) and MDGA1 (MAM Domain Containing Glycosylphosphatidylinositol Anchor 1) in resistant tumors. We proved firstly miR-1-FRAS1 and miR-663a-MDGA1 interactions. We found that MDGA1 knockdown decreased renal cancer cell migration and proliferation similarly to restoration of levels of miR-1 and miR-663. Our results support the central role of cell migration as an adaptive mechanism to secure tumor survival behind sunitinib resistance. MDGA1, FRAS1 or the targeting miRNAs can be potential adjuvant therapeutic targets, through inhibition of cancer cell migration, thus eliminating the development of resistance and metastasis.

miR-10b is a prognostic marker in clear cell renal cell carcinoma.

AIMS: Clear cell renal cell carcinoma (ccRCC) is the most common adult kidney cancer. It is an aggressive tumour with unpredictable outcome. The currently used clinical parameters are not always accurate for predicting disease behaviour. miR-10b is dysregulated in different malignancies including RCC. METHODS: We assessed the clinical utility of miR-10b as a prognostic marker in 250 patients with primary ccRCC. We examined the correlation between miR-10b and clinicopathological parameters. We compared miR-10b expression among different RCC subtypes and normal kidney tissue. RESULTS: We observed a stepwise decrease of miR-10b expression from normal kidney to primary ccRCC and a further decrease from primary to metastatic RCC. miR-10b expression was significantly lower in stages III/IV compared with stages I/II (p=0.038). Using a binary cut-off, miR-10b-positive patients had significantly longer disease-free survival (HR=0.47, CI 0.28 to 0.79, p=0.004). In the subgroup of patients with tumour size >4 cm, higher miR-10b expression was associated with significant longer disease-free and overall survival (p=0.001 and p=0.036, respectively). miR-10b was significantly downregulated in ccRCC compared with normal kidney (p<0.0001), and oncocytoma (p=0.031). It was also downregulated in chromophobe RCC. In addition, we identified a number of miR-10b-predicted targets and pathways that are involved in tumourigenesis. CONCLUSIONS: Our data point to miR-10b as a promising prognostic marker in ccRCC with potential therapeutic applications.

MicroRNA-194 is a Marker for Good Prognosis in Clear Cell Renal Cell Carcinoma.

Clear cell renal cell carcinoma (ccRCC) is the most prevalent adult kidney cancer. Prognostic markers are needed to guide patient management toward aggressive versus more conservative approaches, especially for small tumors ≤4 cm. miR-194 was reported to be downregulated in several cancers and is involved in epithelial to mesenchymal transition. We evaluated miR-194 as a prognostic marker in ccRCC. In a cohort of 234 patients with primary ccRCC, we correlated miR-194 expression level with multiple clinicopathological features including disease-free and overall survival, tumor size, clinical stage, and histological grade. Our results shows a stepwise decrease in miR-194 expression from normal kidney to primary ccRCC (P = 0.0032) and a subsequent decrease from primary to metastatic lesions. Additionally, patients with higher miR-194 expression has significantly longer disease-free survival (P = 0.041) and overall survival (P = 0.031) compared to those with lower expression. In multivariate analysis, miR-194-positive tumors retain significance in disease-free survival and overall survival, suggesting miR-194 is an independent marker for good prognosis in ccRCC. Moreover, miR-194 is a marker for good prognosis for patients with small renal masses (P = 0.014). These findings were validated on an independent data set from The Cancer Genome Atlas. We also compared miR-194 expression between RCC subtypes. ccRCC had the highest levels, whereas chromophobe RCC and oncocytoma had comparable lower levels. Target prediction coupled with pathway analysis show that miR-194 is predicted to target key molecules and pathways involved in RCC progression. miR-194 represents a prognostic biomarker in ccRCC.

Exosomal MicroRNAs Are Diagnostic Biomarkers and Can Mediate Cell-Cell Communication in Renal Cell Carcinoma.

BACKGROUND: Apart from an invasive biopsy, currently no tools are available to confirm the diagnosis of clear cell renal cell carcinoma (ccRCC); this resulted in approximately 30% of patients being diagnosed with metastatic disease. OBJECTIVE: To determine whether urinary microRNAs (miRNAs) can serve as biomarkers to confirm the diagnosis of ccRCC. DESIGN, SETTING, AND PARTICIPANTS: Global miRNA expression was assessed in 28 preoperative urine samples from patients with ccRCC and 18 healthy participants. The independent validation set consisted of 81 ccRCC patients, 24 patients with benign lesions, and 33 healthy participants. We extracted both cell-free and exosomal RNA for miRNA expression analysis using miRNA-specific polymerase chain reaction assays. We also investigated exosomal miRNA secretion in cell line models and performed exosome transfer between RCC and endothelial cell types. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Receiver operating characteristic analysis was applied to identify the discrimination power of miRNAs. RESULTS AND LIMITATIONS: Overall, miR-126-3p combined with miR-449a or with miR-34b-5p could significantly distinguish ccRCC patients from healthy participants (miR-126-3p-miR-449a: area under the curve [AUC]: 0.84; 95% confidence interval [CI], 0.7620-0.9151; p<0.001; miR-126-3p-miR-34b-5p: AUC: 0.79; 95% CI, 0.7013-0.8815; p<0.001). The combination of miR-126-3p and miR-34b-5p was also able to distinguish small renal masses (pT1a, ≤4cm) from healthy controls (AUC: 0.79; 95% CI, 0.6848-0.8980; p<0.001). Using miR-126-3p and miR-486-5p in combination, we were able to differentiate between benign lesions and ccRCC (AUC: 0.85; 95% CI, 0.7295-0.9615; p<0.01). The expression of a number of miRNAs returned to a level comparable with health after surgery. Kidney cancer cell lines were found to secrete exosomal miR-126-3p, miR-17-5p, miR-21-3p, and miR-25-3p, and these miRNAs were found to be internalized by other cell types. CONCLUSIONS: We identified exosomal miRNAs as potential noninvasive diagnostic urinary biomarkers for ccRCC and provided evidence that miRNAs are secreted by the tumor and can function as a tool for intercellular communication. PATIENT SUMMARY: We identified urinary microRNAs that can serve as diagnostic biomarkers for clear cell renal cell carcinoma.

miRNA-target network reveals miR-124as a key miRNA contributing to clear cell renal cell carcinoma aggressive behaviour by targeting CAV1 and FLOT1.

Clear cell renal cell carcinoma (ccRCC) is an aggressive tumor with frequent metastatic rate and poor survival. Integrated analyses allow understanding the interplay between different levels of molecular alterations.We integrated miRNA and gene expression data from 458 ccRCC and 254 normal kidney specimens to construct a miRNA-target interaction network.We identified the downregulated miR-124-3p, -30a-5p and -200c-3p as the most influential miRNAs in RCC pathogenesis.miR-124-3p and miR-200c-3p expression showed association with patient survival, miR-30a-5p was downregulated in metastases compared to primary tumors. We used an independent set of 87 matched samples for validation. We confirmed the functional impact of these miRNAs by in vitro assays. Restoration of these miRNAs reduced migration, invasion and proliferation. miR-124-3p decreased the S phase of cell cycle, as well. We compared transcriptome profiling before and after miRNA overexpression, and validated CAV1 and FLOT1 as miR-124-3p targets. Patients with higher CAV1 and FLOT1 had lower miR-124-3p expression and shorter overall survival.We hypothesize that these three miRNAs are fundamental contributing to ccRCC aggressive/metastatic behavior; and miR-124-3p especially has a key role through regulating CAV1 and FLOT1 expression. Restoration of the levels of these miRNAs could be considered as a potential therapeutic strategy for ccRCC.

Ethanol induced impairment of glucose metabolism involves alterations of GABAergic signaling in pancreatic ß-cells.

Alcohol overindulgence is a risk factor of type 2 diabetes mellitus. However, the mechanisms by which alcohol overindulgence damages glucose metabolism remain unclear. Pancreatic islet ß-cells are endowed with type-A γ-aminobutyric acid receptor (GABAAR) mediated autocrine signaling mechanism, which regulates insulin secretion and fine-tunes glucose metabolism. In neurons GABAAR is one of the major targets for alcohol. This study investigated whether ethanol alters glucose metabolism by affecting GABAAR signaling in pancreatic ß-cells. Blood glucose level of test mice was measured using a blood glucose meter. Insulin secretion by the pancreatic ß-cell line INS-1 cells was examined using a specific insulin ELISA kit. Whole-cell patch-clamp recording was used to evaluate GABA-elicited current in INS-1 cells. Western blot and immunostaining were used to measure the expression of GABAAR subunits in mouse pancreatic tissues or in INS-1 cells. Intraperitoneal (i.p.) administration of ethanol (3.0g/kg body weight) to mice altered glucose metabolism, which was associated with decreased expression of GABAAR α1- and δ- subunits on the surface of pancreatic ß-cells. Acute treatment of cultured INS-1cells with ethanol (60mM) decreased the GABA-induced current and reduced insulin secretion. In contrast, treating INS-1 cells with GABA (100µM) largely prevented the ethanol-induced reduction of insulin release. Importantly, pre-treating mice with GABA (i.p., 1.5mg/kg body weight) partially reversed ethanol-induced impairment of glucose homeostasis in mice. Our data suggest a novel role of pancreatic GABA signaling in protecting pancreatic islet ß-cells from ethanol-induced dysfunction.