A tissue miRNA expression pattern is associated with disease aggressiveness of localized prostate cancer.

BACKGROUND: Prostate cancer (PCa) is a heterogeneous malignancy with high variability in clinical course. Insufficient stratification according to the aggressiveness at the time of diagnosis causes unnecessary or delayed treatment. Current stratification systems are not effective enough because they are based on clinical, surgical or biochemical parameters, but do not take into account molecular factors driving PCa cancerogenesis. MicroRNAs (miRNAs) are important players in molecular pathogenesis of PCa and could serve as valuable biomarkers for the assessment of disease aggressiveness and its prognosis. METHODS: In the study, in total, 280 PCa patients were enrolled. The miRNA expression profiles were analyzed in FFPE PCa tissue using the miRCURY LNA miRNA PCR System. The expression levels of candidate miRNAs were further verified by two-level validation using the RT-qPCR method and evaluated in relation to PCa stratification reflecting the disease aggressiveness. RESULTS: MiRNA profiling revealed 172 miRNAs dysregulated between aggressive (ISUP 3-5) and indolent PCa (ISUP 1) (p < 0.05). In the training and validation cohort, miR-15b-5p and miR-106b-5p were confirmed to be significantly upregulated in tissue of aggressive PCa when their level was associated with disease aggressiveness. Furthermore, we established a prognostic score combining the level of miR-15b-5p and miR-106b-5p with serum PSA level, which discriminated indolent PCa from an aggressive form with even higher analytical parameters (AUC being 0.9338 in the training set and 0.8014 in the validation set, respectively). The score was also associated with 5-year biochemical progression-free survival (bPFS) of PCa patients. CONCLUSIONS: We identified a miRNA expression pattern associated with disease aggressiveness in prostate cancer patients. These miRNAs may be of biological interest as the focus can be also set on their specific role within the molecular pathology and the molecular mechanism that underlies the aggressivity of prostate cancer.

Thermal Ablation and Transarterial Chemoembolization are Characterized by Changing Dynamics of Circulating MicroRNAs.

PURPOSE: To determine whether the levels of circulating microRNAs (miRNAs) are altered in patients undergoing thermal ablation and chemoembolization and whether these changes are predictive of a clinical outcome. MATERIAL AND METHODS: This prospective study consisted of 43 patients diagnosed with hepatocellular carcinoma (n = 15) and intrahepatic colorectal cancer metastases (n = 28) treated with thermal ablation (n = 23; radiofrequency [n = 6] or microwave [n = 19]), chemoembolization using drug-eluting embolics (n = 18), or both (n = 2). Four blood samples (immediately before the intervention and 60-90 minutes, 24 hours, and 7 days after the intervention) were taken to measure the plasma concentrations of miRNAs related to hypoxia (miR-21 and miR-210), liver injury (miR-122), epithelial-mesenchymal transition (miR-200a), and apoptosis (miR-34a) using miRNA-specific TaqMan assays and quantitative real-time polymerase chain reaction. Tumor burden and treatment response at 3 months were evaluated using the modified response evaluation criteria in solid tumors. The miRNA results were compared with clinical outcomes (Mann-Whitney U test, Wilcoxon matched-pair test). RESULTS: Dynamic changes in the circulating miRNA levels were observed following both the interventions. For thermal ablation, significant increases in miR-21, miR-210, miR-122, miR-200a, and miR-34a concentrations peaked 60-90 minutes after the intervention (P < .01). However, for transarterial chemoembolization, maximum increases in the miRNA concentrations were observed at 24 hours after the intervention for miR-21, miR-210, miR-122, miR-200a, and miR-34a (P < .05). The increased concentrations of the circulating miRNAs were followed by a subsequent decline to baseline by 7 days. For the thermal ablation (but not chemoembolization) patients, elevations in the miR-210 and miR-200a levels were associated with early progressive disease at 3 months (P = .040 and P = .012, respectively). CONCLUSIONS: Increased but dynamic levels of circulating miRNAs are present following interventional oncologic procedures and may prove useful as biomarkers for the monitoring of clinical outcomes.

Non-Coding RNAs as Cancer Hallmarks in Chronic Lymphocytic Leukemia.

The discovery of non-coding RNAs (ncRNAs) and their role in tumor onset and progression has revolutionized the way scientists and clinicians study cancers. This discovery opened new layers of complexity in understanding the fine-tuned regulation of cellular processes leading to cancer. NcRNAs represent a heterogeneous group of transcripts, ranging from a few base pairs to several kilobases, that are able to regulate gene networks and intracellular pathways by interacting with DNA, transcripts or proteins. Deregulation of ncRNAs impinge on several cellular responses and can play a major role in each single hallmark of cancer. This review will focus on the most important short and long non-coding RNAs in chronic lymphocytic leukemia (CLL), highlighting their implications as potential biomarkers and therapeutic targets as they relate to the well-established hallmarks of cancer. The key molecular events in the onset of CLL will be contextualized, taking into account the role of the "dark matter" of the genome.

Genome-wide identification of urinary cell-free microRNAs for non-invasive detection of bladder cancer.

Urinary microRNAs (miRNAs) are emerging as clinically useful tool for early and non-invasive detection of various types of cancer including bladder cancer (BCA). In this study, 205 patients with BCA and 99 healthy controls were prospectively enrolled. Expression profiles of urinary miRNAs were obtained using Affymetrix miRNA microarrays (2578 miRNAs) and candidate miRNAs further validated in independent cohorts using qRT-PCR. Whole-genome profiling identified 76 miRNAs with significantly different concentrations in urine of BCA compared to controls (P < 0.01). In the training and independent validation phase of the study, miR-31-5p, miR-93-5p and miR-191-5p were confirmed to have significantly higher levels in urine of patients with BCA in comparison with controls (P < 0.01). We further established 2-miRNA-based urinary DxScore (miR-93-5p, miR-31-5p) enabling sensitive BCA detection with AUC being 0.84 and 0.81 in the training and validation phase, respectively. Moreover, DxScore significantly differed in the various histopathological subgroups of BCA and decreased post-operatively. In conclusion, we identified and independently validated cell-free urinary miRNAs as promising biomarkers enabling non-invasive detection of BCA.

Utilization and efficacy of second-line targeted therapy in metastatic renal cell carcinoma: data from a national registry.

BACKGROUND: It is well known that patient characteristics and survival outcomes in randomized trials may not necessarily be similar to those in real-life clinical practice. The aim of the present study was to analyse second line treatment strategies in the real-world practice and to estimate the outcomes of patients treated with second-line targeted therapy for metastatic renal cell carcinoma (mRCC). METHODS: This is a retrospective, registry-based study using data from the national registry of targeted therapies for mRCC. The RENIS registry contains data on 3049 patients who started the therapy with at least one targeted agent before 31 December, 2014. Of these patients, 1029 had a record of at least two different targeted therapies and sufficient data for analysis. Survival analysis was carried out using the Kaplan-Meier method. Statistical significance of differences in survival between subgroups was assessed using the log-rank test. RESULTS: The median overall survival from the start of second-line treatment was 17.0 months (95% confidence interval [CI] 14.5-19.5 months), 17.1 months (95% CI 14.5-19.8), and 15.4 months (95% CI 11.0-19.7) for second-line everolimus, sorafenib, and sunitinib, respectively. Patients receiving second-line everolimus were older at the start of second-line treatment, more likely to have metachronous disease, and less likely to be previously treated with cytokines or to continue to third-line treatment than patients treated with second-line sunitinib or sorafenib. Progression-free survival (PFS) correlated with PFS on first-line treatment only for everolimus. CONCLUSIONS: In this retrospective study, no significant differences in survival were observed between the cohorts treated with different second-line agents including everolimus, sorafenib, and sunitinib.

Overexpression of long non-coding RNA TUG1 predicts poor prognosis and promotes cancer cell proliferation and migration in high-grade muscle-invasive bladder cancer.

Long non-coding RNA TUG1 is involved in the development and progression of a variety of tumors. Little is known about TUG1 function in high-grade muscle-invasive bladder cancer (MIBC). The aims of our study were to determine expression levels of long non-coding RNA TUG1 in tumor tissue, to evaluate its relationship with clinico-pathological features of high-grade MIBC, and to describe its function in MIBC cells in vitro. TUG1 expression levels were determined in paired tumor and adjacent non-tumor bladder tissues of 47 patients with high-grade MIBC using real-time PCR. Cell line T-24 and siRNA silencing were used to study the TUG1 function in vitro. We observed significantly increased levels of TUG1 in tumor tissue in comparison to adjacent non-tumor bladder tissue (P < 0.0001). TUG1 levels were significantly increased in metastatic tumors (P = 0.0147) and were associated with shorter overall survival of MIBC patients (P = 0.0241). TUG1 silencing in vitro led to 34 % decrease in cancer cell proliferation (P = 0.0004) and 23 % reduction in migration capacity of cancer cells (P < 0.0001). We did not observe any significant effects of TUG1 silencing on cell cycle distribution and number of apoptotic cells. Our study confirmed overexpression of TUG1 in MIBC tumor tissue and described its association with worse overall survival in high-grade MIBC patients. Together with in vitro observations, these data suggest an oncogenic role of TUG1 and its potential usage as biomarker or therapeutic target in MIBC.

Dynamic changes in microRNA expression profiles reflect progression of Barrett's esophagus to esophageal adenocarcinoma.

Esophageal adenocarcinoma (EAC) is highly aggressive malignancy that frequently develops from Barrett's esophagus (BE), a premalignant pathologic change occurring in the lower end of the esophagus. MicroRNAs (miRNAs) are small, non-coding RNAs that function as posttranscriptional regulators of gene expression and were repeatedly proved to play key roles in pathogenesis of BE as well as EAC. In our study, we used Affymetrix GeneChip miRNA arrays to obtain miRNA expression profiles in total of 119 tissue samples [24 normal esophageal mucosa (EM), 60 BE and 35 EAC]. We identified a number of miRNAs, that showed altered expression progressively in sequence EM, BE and EAC, including for instance miR-21, miR-25, miR-194 and miR-196a with increasing levels (P < 0.0015) and miR-203, miR-205, miR-210 and miR-378 with decreasing levels (P < 0.0001). The subsequent analysis revealed four diagnostic miRNA signatures enabling to distinguish EM and BE [12 miRNAs, area under curve (AUC) = 0.971], EM and EAC (13 miRNAs, AUC = 1.0), BE without and BE with dysplasia (21 miRNAs, AUC = 0.856) and BE without dysplastic changes and BE with dysplasia together with EAC (2 miRNAs, AUC = 0.886). We suggest that miRNA expression profiling expands current knowledge in molecular pathology of Barrett's-based carcinogenesis and enables identification of molecular biomarkers for early detection of BE dysplasia and progression to EAC.

Combination of Urinary MiR-501 and MiR-335 With Current Clinical Diagnostic Parameters as Potential Predictive Factors of Prostate Biopsy Outcome.

BACKGROUND: The detection of prostate cancer (PCa) is currently based on prostate-specific antigen (PSA) quantification as an initial screening followed by ultrasound-guided transrectal biopsy. However, the high rate of false-negative biopsies often leads to inappropriate treatment. Therefore, new molecular biomarkers, such as urine microRNAs (miRNAs), are a possible way to redefine PCa diagnostics. PATIENTS AND METHODS: Urine samples of 356 patients undergoing prostate biopsy (256 cases with confirmed prostate cancer, 100 cases with negative prostate biopsy) at the Masaryk Memorial Cancer Institute (Czech Republic) and additional 36 control subjects (healthy controls, benign prostatic hyperplasia - BPH) were divided into the discovery and validation cohorts and analyzed. In the discovery phase, small RNA sequencing was performed using the QIAseq miRNA Library Kit and the NextSeq 500 platform. Identified miRNA candidates were validated by the RT-qPCR method in the independent validation phase. RESULTS: Using the small RNA sequencing method, we identified 12 urine miRNAs significantly dysregulated between PCa patients and controls. Furthermore, independent validation showed the ability of miR-501-3p and the quantitative miR-335:miR-501 ratio to distinguish between PCa patients and patients with negative prostate biopsy. The subsequent combination of the miR-335:miR-501 ratio with PSA and total prostate volume (TPV) using logistic regression exceeded the analytical accuracy of standalone parameters [area under curve (AUC)=0.75, positive predictive value (PPV)=0.85, negative predictive value (NPV)=0.51)] and discriminated patients according to biopsy outcome. CONCLUSION: Combination of miR-335:miR-501 ratio with PSA and total prostate volume was able to identify patients with negative prostate biopsy and could potentially streamline decision making for biopsy indication.

Urinary microRNAs and Their Significance in Prostate Cancer Diagnosis: A 5-Year Update.

Current routine screening methods for the diagnosis of prostate cancer (PCa) have significantly increased early detection of the disease but often show unsatisfactory analytical parameters. A class of promising markers represents urinary microRNAs (miRNAs). In the last five years, there has been an extensive increase in the number of studies on this topic. Thus, this review aims to update knowledge and point out technical aspects affecting urinary miRNA analysis. The review of relevant literature was carried out by searching the PubMed database for the keywords: microRNA, miRNA, urine, urinary, prostate cancer, and diagnosis. Papers discussed in this review were retrieved using PubMed, and the search strategy was as follows: (urine OR urinary) WITH (microRNA OR miRNA) AND prostate cancer. The search was limited to the last 5 years, January 2017 to December 2021. Based on the defined search strategy, 31 original publications corresponding to the research topic were identified, read and reviewed to present the latest findings and to assess possible translation of urinary miRNAs into clinical practice. Reviews or older publications were read and cited if they valuably extended the context and contributed to a better understanding. Urinary miRNAs are potentially valuable markers for the diagnosis of prostate cancer. Despite promising results, there is still a need for independent validation of exploratory data, which follows a strict widely accepted methodology taking into account the shortcomings and factors influencing the analysis.

Urinary MicroRNAs as Emerging Class of Noninvasive Biomarkers.

MicroRNAs (miRNAs) are endogenous noncoding RNAs, which regulate gene expression on the post-transcriptional level. Since miRNAs are involved in the regulation of apoptosis, cellular proliferation, differentiation, and other important cellular processes, their deregulation is important for the development of a wide range of diseases including cancer. Apart from tissue, specific disease-related miRNA signatures can be found in body fluids as well. Especially for urologic diseases or injuries, urine miRNAs represent a promising group of biomarkers. Despite a large number of studies describing the importance of urinary miRNAs, there is a lack of recommendations for urine management and subsequent miRNA analysis. Thus, in this chapter, we aim to describe the origin and functions of urinary miRNAs and discuss the technical aspects of their detection including the pre-analytical phase principles and new directions in quantification, which could forward urine miRNA into clinical practice.

lncRNA and Mechanisms of Drug Resistance in Cancers of the Genitourinary System.

Available systemic treatment options for cancers of the genitourinary system have experienced great progress in the last decade. However, a large proportion of patients eventually develop resistance to treatment, resulting in disease progression and shorter overall survival. Biomarkers indicating the increasing resistance to cancer therapies are yet to enter clinical routine. Long non-coding RNAs (lncRNA) are non-protein coding RNA transcripts longer than 200 nucleotides that exert multiple types of regulatory functions of all known cellular processes. Increasing evidence supports the role of lncRNAs in cancer development and progression. Additionally, their involvement in the development of drug resistance across various cancer entities, including genitourinary malignancies, are starting to be discovered. Consequently, lncRNAs have been suggested as factors in novel therapeutic strategies to overcome drug resistance in cancer. In this review, the existing evidences on lncRNAs and their involvement in mechanisms of drug resistance in cancers of the genitourinary system, including renal cell carcinoma, bladder cancer, prostate cancer, and testicular cancer, will be highlighted and discussed to facilitate and encourage further research in this field. We summarize a significant number of lncRNAs with proposed pathways in drug resistance and available reported studies.

Identification of microRNA signatures in umbilical cord blood associated with maternal characteristics.

BACKGROUND: Umbilical cord blood could serve as useful source of blood markers enabling more efficient and reliable prenatal and neonatal diagnostics. MicroRNAs (miRNAs) are ubiquitous in body fluids where they were used for detecting and monitoring various physiological and pathological conditions. In this descriptive study, we aimed to identify changes in miRNA expression profiles associated with basic maternal somatic and epidemiological characteristics. METHODS: Study is based on 24 mothers from the Pilot phase of CELSPAC: TNG (Central European Longitudinal Studies of Parents and Children: The Next Generation) study. Cord blood was collected at time of delivery and global miRNA profiling was performed using microRNA Ready-to-use PCR Human Panel I+II TaqMan microarrays. Expression profiles were statistically evaluated in relation to maternal age, BMI, pregnancy weight gain, blood type, Rh factor status, allergies during pregnancy, addictive substance abuse and smoking status. RESULTS: We analyzed expression of 752 human mature miRNAs in 24 samples of umbilical cord blood. For all maternal characteristics tested we described a specific signature of significantly deregulated miRNAs (P < 0.05). Analysis revealed seven miRNA associated with maternal age (three increased and four decreased in women younger than 35 years), 14 miRNAs associated with BMI status (five miRNAs increased and nine miRNAs decreased in women with BMI > 25) and nine miRNAs associated with maternal weight gain during pregnancy (eight miRNAs increased, and one miRNA decreased in women with weight gain < 12 kg). Additionally, 17 miRNAs correlated to blood type (two miRNAs decreased in blood type A, 11 increased in blood type B, two miRNAs increased in blood type AB and two miRNAs increased in blood type 0) and 17 miRNAs to Rh status of mother. We also detected seven miRNAs deregulated in umbilical cord blood of women with allergy (four increased and three decreased in women with allergy), four miRNAs associated to addictive substance abuse status (two up- and two downregulated in women with addictive substance abuse) and eight miRNAs associated with maternal cigarette smoking during pregnancy. CONCLUSIONS: We successfully described differences in miRNA profiles in umbilical cord blood associated with basic characteristics connected with mother. Our data suggest that miRNAs in umbilical cord blood are detectable and associated with a wide range of maternal characteristics. These results indicate that miRNAs could potentially serve, and should be studied, as biomarkers for screening and diagnosis of pregnancy-associated complications and pathologies.

Tumor expression of miR-34a-3p is an independent predictor of recurrence in non-muscle-invasive bladder cancer and promising additional factor to improve predictive value of EORTC nomogram.

OBJECTIVES: Non-muscle-invasive bladder cancer (NMIBC) is a heterogeneous disease characterized by a high primary tumor recurrence rate. Current prognostic systems used for predicting recurrence in individual patients have limitations and do not consider the biological background of this tumor type. Our study aimed to find microRNAs (miRNAs) associated with NMIBC recurrence. METHODS: Seventy-eight NMIBC patients were prospectively enrolled and divided into exploratory and validation cohorts. Out of these patients, 32 developed recurrence within 18 months after surgery, while 46 did not show any sign of recurrence after 30 months. Expression profiles of 2,578 miRNAs were obtained using Affymetrix miRNA microarrays and candidate miRNAs validated using the individual quantitative reverse-transcription polymerase chain reaction (qRT-PCR). RESULTS: The expression profiling revealed a set of 137 miRNAs differentially expressed between NMIBC patients with and without recurrence (P < 0.05). In the validation phase, miR-34a-3p had a significantly higher expression in tumors of NMIBC patients without recurrence (P = 0.0155). Decreased expression of miR-34a-3p was associated with significantly shorter recurrence-free survival (P = 0.009). Cox regression analysis confirmed that miR-34a-3p is an independent biomarker associated with a lower risk of recurrence (hazard ratio (HR) = 0.3184, 95% confidence interval = 0.003-0.681, P = 0.0258). Combination of miR-34a-3p and European Organization for Research and Treatment of Cancer risk score into one predictive model enabled to predict individual risk of recurrence with high statistical significance and analytical performance (P < 0.0001; area under curve = 0.8368; sensitivity 83%, and specificity 75%). CONCLUSIONS: Our data suggest that miR-34a-3p is an independent biomarker of NMIBC recurrence and a promising candidate for further independent validations as an additional factor to improve predictive value of European Organization for Research and Treatment of Cancer nomogram.

Current Concepts of Non-Coding RNAs in the Pathogenesis of Non-Clear Cell Renal Cell Carcinoma.

Renal cell carcinoma (RCC) is a relatively rare malignancy of the urinary tract system. RCC is a heterogenous disease in terms of underlying histology and its associated underlying pathobiology, prognosis and treatment schedule. The most prevalent histological RCC subtype is clear-cell renal cell carcinoma (ccRCC), accounting for about 70-80% of all RCCs. Though the pathobiology and treatment schedule for ccRCC are well-established, non-ccRCC subtypes account for 20%-30% of RCC altogether, and their underlying molecular biology and treatment options are poorly defined. The class of non-coding RNAs-molecules that are generally not translated into proteins-are new cancer drivers and suppressors in all types of cancer. Of these, small non-coding microRNAs (miRNAs) contribute to carcinogenesis by regulating posttranscriptional gene silencing. Additionally, a growing body of evidence supports the role of long non-coding RNAs (lncRNAs) in cancer development and progression. Most studies on non-coding RNAs in RCC focus on clear-cell histology, and there is a relatively limited number of studies on non-ccRCC subtypes. The aim of this review is to give an overview of the current knowledge regarding the role of non-coding RNAs (including short and long non-coding RNAs) in non-ccRCC and to highlight possible implications as diagnostic, prognostic and predictive biomarkers.

MiR-376b-3p Is Associated With Long-term Response to Sunitinib in Metastatic Renal Cell Carcinoma Patients.

BACKGROUND/AIM: Sunitinib is a tyrosine kinase inhibitor routinely used as first-line therapy in metastatic renal cell carcinoma (mRCC). Emerging evidence suggests that microRNAs (miRNAs) could be suitable biomarkers with predictive potential in mRCC. The aim of this study was to identify miRNA-based predictive biomarkers of therapy response to avoid unnecessary therapy to non-responding patients. PATIENTS AND METHODS: High-throughput miRNA microarray profiling was performed on a cohort of 47 patients treated with sunitinib. Validation of candidate miRNAs was carried out on an independent cohort of 132 mRCC patients using qRT-PCR. RESULTS: Out of 158 miRNAs (65 down-regulated, 93 up-regulated), six miRNAs were chosen for independent validation and miR-376b-3p was confirmed to be differentially expressed in tumors of patients with primary resistance versus long-term response (p<0.0002). CONCLUSION: A predictive miRNA associated with progression-free survival in metastatic renal cell carcinoma patients treated with sunitinib was identified.

Tyrosine kinase inhibitors in the first-line treatment for metastatic nonclear cell renal carcinoma: A retrospective analysis of a national database.

BACKGROUND: Nonclear cell renal cell carcinoma (nccRCC) is a heterogeneous group of primary kidney tumors. The aim of the present retrospective study was to analyze outcomes of patients with nccRCC treated with tyrosine-kinase inhibitors (TKIs) based on a national registry. METHODS: The registry contained evaluable data of 93 nccRCC patients treated with first-line TKIs, including 87 patients with papillary renal cell carcinoma (RCC) and 6 patients with chromophobe RCC. The control cohort consisted of 1,788 patients with clear-cell RCC treated with first-line TKIs. Multivariable Cox proportional hazard model was used to evaluate the effect of potential prognostic factors on the survival measures. RESULTS: Median progression-free survival was 11.8 and 6.5 months in the clear cell renal cell carcinoma and nccRCC patients, respectively (P = 0.018), and median overall survival was 33.2 and 22.0 months, respectively (P = 0.007). In the multivariate analysis, independent factors associated with inferior progression-free survival included high tumor grade, worse Memorial Sloan Kettering Cancer Center risk group, absence of nephrectomy, and sunitinib (as opposed to pazopanib) as first-line targeted therapy. Independent predictors of inferior overall survival included nonclear cell histology, tumor grade, worse Memorial Sloan Kettering Cancer Center risk group, absence of nephrectomy, older age, and sunitinib as first-line targeted therapy. CONCLUSIONS: The present retrospective, registry-based study confirms that patients with nccRCC treated with TKIs have worse clinical outcomes compared to clear cell renal cell carcinoma patients with similar baseline characteristics.

Candidate MicroRNA Biomarkers of Therapeutic Response to Sunitinib in Metastatic Renal Cell Carcinoma: A Validation Study in Patients with Extremely Good and Poor Response.

BACKGROUND/AIM: Targeted therapy with the tyrosine kinase inhibitor sunitinib is used in the first line of metastatic renal cell carcinoma (mRCC) treatment. The aim of the present study was independent validation of microRNAs (miRNAs) identified in previous studies as biomarkers predicting response to sunitinib therapy. MATERIALS AND METHODS: Based on a literature search, 10 miRNAs were chosen from six relevant studies as candidates for validation: miR-155, miR-484, miR-221, miR-222, miR-425, miR-133, miR-410, miR-141, miR-628 and miR-942. Validation of these miRNAs was performed on cohort of 56 patients with mRCC with extremely good or poor response responses to sunitinib treatment using quantitative reverse transcription-polymerase chain reaction. Patients were divided into either responding (n=24) or non-responding (n=32) groups to sunitinib treatment according to Response Evaluation Criteria in Solid Tumors and progression-free survival (PFS). All patients in the responding group had PFS longer than 18 months, PFS of non-responders was shorter than 6 months in all cases. RESULTS: miR-942 and miR-133 were confirmed as being differentially expressed in tumors of responding and non-responding patients. It was not possible to validate the predictive value of other tested miRNAs, however, expression of miR-221 and miR-425 tended to be positively associated with therapeutic response (p<0.1). We further developed a model based on the combination of miR-942 and miR-133 expression, that enabled identification of non-responding patients with mRCC with sensitivity of 78% and specificity of 79% (area under the curve=0.8071). CONCLUSION: Following further independent validation, detection of these miRNAs may prevent unnecessary and costly approaches to therapy in non-responding patients with mRCC.

MicroRNA isolation and quantification in cerebrospinal fluid: A comparative methodical study.

Associated with the pathogenesis of many cancers, including brain tumors, microRNAs (miRNAs) present promising diagnostic biomarkers. These molecules have been also studied in cerebrospinal fluid (CSF), showing great potential as a diagnostic tool in patients with brain tumors. Even though there are some biological and technological factors that could affect the results and their biological and clinical interpretation, miRNA analysis in CSF is not fully standardized. This study aims to compare several RNA extraction and miRNA quantification approaches, including high-throughput technologies and individual miRNA detection methods, thereby contributing to the optimization and standardization of quantification of extracellular miRNAs in CSF. Such knowledge is essential for the potential use of miRNAs as diagnostic biomarkers in brain tumors.

Detection of let-7 miRNAs in urine supernatant as potential diagnostic approach in non-metastatic clear-cell renal cell carcinoma.

INTRODUCTION: Urinary microRNAs (miRNAs) are emerging as a clinically useful tool for early and non-invasive detection of various types of cancer. The aim of this study was to evaluate whether let-7 family miRNAs differ in their urinary concentrations between renal cell carcinoma (RCC) cases and healthy controls. MATERIALS AND METHODS: In the case-control study, 69 non-metastatic clear-cell RCC patients and 36 gender/age-matched healthy controls were prospectively enrolled. Total RNA was purified from cell-free supernatant of the 105 first morning urine specimens. Let-7 family miRNAs were determined in cell-free supernatant using quantitative miRNA real-time reverse-transcription PCR and absolute quantification approach. RESULTS: Concentrations of all let-7 miRNAs (let-7a, let-7b, let-7c, let-7d, let-7e and let-7g) were significantly higher in urine samples obtained from RCC patients compared to healthy controls (P < 0.001; P < 0.001; P = 0.005; P = 0.006; P = 0.015 and P = 0.002, respectively). Subsequent ROC analysis has shown that let-7a concentration possesses good ability to differentiate between cases and controls with area under curve being 0.8307 (sensitivity 71%, specificity 81%). CONCLUSIONS: We have shown that let-7 miRNAs are abundant in the urine samples of patients with clear-cell RCC, and out of six let-7 family members, let-7a outperforms the others and presents promising non-invasive biomarker for the detection of RCC.

MicroRNAs in the pathogenesis of renal cell carcinoma and their diagnostic and prognostic utility as cancer biomarkers.

PURPOSE: To provide information about the role of microRNAs in the pathogenesis of renal cell carcinoma (RCC) and their diagnostic and prognostic utility as cancer biomarkers. METHODS: A literature search was performed in the PubMed and Web of Science databases using the keywords "renal cancer/renal cell carcinoma/kidney cancer" and "miR*/miRNA*/microRNA*". Articles dealing with the role of miRNAs in the pathogenesis of RCC, diagnostic miRNAs and prognostic miRNAs were separated. RESULTS: MiRNAs act both as oncogenes and tumor suppressors. They regulate apoptosis, cell growth, migration, invasion, proliferation, colony formation and angiogenesis through target proteins involved in several signaling pathways, and they are involved in key pathogenetic mechanisms such as hypoxia (HIF/VHL dependent) and epithelial-to-mesenchymal transition. Differentially expressed miRNAs can discriminate either tumor tissue from healthy renal tissue or different RCC subtypes. Circulating miRNAs are promissing as diagnostic biomarkers of RCC. Information about urinary miRNAs associated with RCC is sparse. Detection of a relapse is another implication of diagnostic miRNAs. The expression profiles of several miRNAs correlate with the prognosis of RCC patients. Comparison between primary tumor tissue and metastasis may help identify high-risk primary tumors. Finally, response to target therapy can be estimated thanks to differences in miRNA expression in tissue and serum of therapy-resistant versus therapy-sensitive patients. CONCLUSIONS: Our understanding of the role of microRNAs in RCC pathogenesis has been increasing dramatically. Identification and validation of their gene targets may have direct impact on developing microRNA-based anticancer therapy. Several microRNAs can serve as diagnostic and prognostic biomarkers.