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European Urology Aug 2016Short noncoding RNAs known as microRNAs (miRNAs) control protein expression through the degradation of RNA or the inhibition of protein translation. The miRNAs influence... (Review)
Review
CONTEXT
Short noncoding RNAs known as microRNAs (miRNAs) control protein expression through the degradation of RNA or the inhibition of protein translation. The miRNAs influence a wide range of biologic processes and are often deregulated in cancer. This family of small RNAs constitutes potentially valuable markers for the diagnosis, prognosis, and therapeutic choices in prostate cancer (PCa) patients, as well as potential drugs (miRNA mimics) or drug targets (anti-miRNAs) in PCa management.
OBJECTIVE
To review the currently available data on miRNAs as biomarkers in PCa and as possible tools for early detection and prognosis.
EVIDENCE ACQUISITION
A systematic review was performed searching the PubMed database for articles in English using a combination of the following terms: microRNA, miRNA, cancer, prostate cancer, miRNA profiling, diagnosis, prognosis, therapy response, and predictive marker.
EVIDENCE SYNTHESIS
We summarize the existing literature regarding the profiling of miRNA in PCa detection, prognosis, and response to therapy. The articles were reviewed with the main goal of finding a common recommendation that could be translated from bench to bedside in future clinical practice.
CONCLUSIONS
The miRNAs are important regulators of biologic processes in PCa progression. A common expression profile characterizing each tumor subtype and stage has still not been identified for PCa, probably due to molecular heterogeneity as well as differences in study design and patient selection. Large-scale studies that should provide additional important information are still missing. Further studies, based on common clinical parameters and guidelines, are necessary to validate the translational potential of miRNAs in PCa clinical management. Such common signatures are promising in the field and emerge as potential biomarkers.
PATIENT SUMMARY
The literature shows that microRNAs hold potential as novel biomarkers that could aid prostate cancer management, but additional studies with larger patient cohorts and common guidelines are necessary before clinical implementation.
Topics: Biomarkers, Tumor; Disease Management; Disease Progression; Gene Expression Profiling; Humans; Male; MicroRNAs; Prognosis; Prostatic Neoplasms
PubMed: 26806656
DOI: 10.1016/j.eururo.2015.12.054 -
Journal of Clinical Pathology Mar 2016It is well recognised that genomic, proteomic and biomarker studies require properly annotated and well-characterised biospecimens. Consequently, this necessitates... (Review)
Review
It is well recognised that genomic, proteomic and biomarker studies require properly annotated and well-characterised biospecimens. Consequently, this necessitates biobanks to collect, store and distribute biospecimens under stringent quality control and assurance measures. However, despite this realisation, there remains a lack of standardisation in quality management among biobanks and consensus as to which quality indicators provide the optimal molecular diagnostic performance tools and information for biospecimens. In an attempt to identify key factors that predict tissue specimen integrity and quality, this systematic review investigated the measures reported in the literature, which characterised the collection, processing and storage of high-quality tissue specimens. Our findings demonstrated RNA integrity, alone, may not be an effective measure of tissue quality. Furthermore, the frequently reported parameters related to biospecimen integrity, such as storage time, temperature, time to cryopreservation and tissue morphology were also not effective indicators of quality control and assurance. These findings suggest that it is unlikely that a single marker will provide the optimal diagnostic and performance information for biospecimens, but rather, a panel of markers assessing the molecular integrity of the lifespan of the biospecimen is required. Further work is needed to identify which factors predict specimen integrity and quality in biobanked tissue specimens.
Topics: Biological Specimen Banks; Cold Temperature; Cryopreservation; Genetic Markers; Guidelines as Topic; Humans; Quality Control; RNA; RNA Stability; Specimen Handling; Time Factors
PubMed: 26598626
DOI: 10.1136/jclinpath-2015-203384 -
PloS One 2015The choice of reference genes that are stably expressed amongst treatment groups is a crucial step in real-time quantitative PCR gene expression studies. Recent... (Review)
Review
The choice of reference genes that are stably expressed amongst treatment groups is a crucial step in real-time quantitative PCR gene expression studies. Recent guidelines have specified that a minimum of two validated reference genes should be used for normalisation. However, a quantitative review of the literature showed that the average number of reference genes used across all studies was 1.2. Thus, the vast majority of studies continue to use a single gene, with β-actin (ACTB) and/or glyceraldehyde 3-phosphate dehydrogenase (GAPDH) being commonly selected in studies of vertebrate gene expression. Few studies (15%) tested a panel of potential reference genes for stability of expression before using them to normalise data. Amongst studies specifically testing reference gene stability, few found ACTB or GAPDH to be optimal, whereby these genes were significantly less likely to be chosen when larger panels of potential reference genes were screened. Fewer reference genes were tested for stability in non-model organisms, presumably owing to a dearth of available primers in less well characterised species. Furthermore, the experimental conditions under which real-time quantitative PCR analyses were conducted had a large influence on the choice of reference genes, whereby different studies of rat brain tissue showed different reference genes to be the most stable. These results highlight the importance of validating the choice of normalising reference genes before conducting gene expression studies.
Topics: Animals; Gene Expression; Gene Expression Profiling; Genes; Humans; Mammals; RNA, Messenger; Real-Time Polymerase Chain Reaction; Reference Standards; Research Design; Specimen Handling; Statistics, Nonparametric; Transcription, Genetic
PubMed: 26555275
DOI: 10.1371/journal.pone.0141853 -
PloS One 2014HIV viral load (VL) testing is the gold standard for antiretroviral treatment monitoring, but many barriers exist to VL testing in resource-limited settings, including... (Review)
Review
BACKGROUND
HIV viral load (VL) testing is the gold standard for antiretroviral treatment monitoring, but many barriers exist to VL testing in resource-limited settings, including storage and transport limitations for whole blood and plasma. Data from various studies indicate that HIV RNA is stable beyond current recommendations. We conducted a systematic review to assess stability data of HIV RNA in whole blood and plasma across times and temperatures.
METHODS AND FINDINGS
Using a pre-defined protocol, five databases were searched for studies where blood samples from HIV patients were stored at time and temperature points that exceeded manufacturer recommendations. RNA stability, the primary outcome, was measured by the difference in means compared to samples stored within established thresholds. RNA stability was defined as ≤0.5 log degradation. The search identified 10,716 titles, of which nine full-text articles were included for review. HIV RNA maintained stability in EDTA whole blood and plasma at all measured time points up to 168 hours when stored at 4°C, while stability was detected at 72 hours (95% confidence) in whole blood at 25°C, with data points before and beyond 72 hours suggesting stability but not reaching statistical significance. For EDTA plasma stored at 30°C, stability was maintained up to 48 hours (95% confidence), with OLS linear regression estimates up to 127 hours, suggesting stability. Overall, quality of studies was moderate. Limitations included small sample sizes, few studies meeting inclusion criteria, and no studies examining RNA stability in low viremia (<3,000 copies/mL) environments.
CONCLUSIONS
Whole blood and plasma samples in EDTA may remain stable under conditions exceeding current manufacturer recommendations for HIV VL testing. However, given the limited number of studies addressing this question, especially at low levels of viremia, additional evaluations on HIV RNA stability in EDTA tubes and PPT in field conditions are needed.
Topics: Edetic Acid; HIV Infections; HIV-1; Humans; RNA Stability; RNA, Viral; Specimen Handling; Temperature; Viral Load
PubMed: 25437009
DOI: 10.1371/journal.pone.0113813 -
Journal of Viral Hepatitis Apr 2015The entry of new all-oral direct acting antiviral therapy for hepatitis C provides an opportunity to scale up HCV care in low- and middle-income countries. In HIV, use... (Review)
Review
The entry of new all-oral direct acting antiviral therapy for hepatitis C provides an opportunity to scale up HCV care in low- and middle-income countries. In HIV, use of dried blood spots (DBS) has facilitated the diagnosis and management of HIV in resource-poor settings. DBS may be used in a similar way to facilitate diagnosis and management of HCV. Here, we present a systematic review of the literature of DBS for HCV RNA detection and genotyping. Using an a priori review protocol, three databases were searched for studies published up to August 2013 that reported the use of dried blood and serum spots in genotyping, detection and measurement of HCV RNA, as well as the rate of degradation of HCV RNA when stored in DBS at room temperature. Nine papers were eligible for inclusion; eight studied DBS and one dried serum. Two studies measured concordance between genotype and subtype determined by DBS and whole plasma and both found 100% concordance. Four studies measured endpoint detection limits of HCV RNA-positive samples by DBS and found positive predictive values of 100% down to 250, 334, 2500 and 24160 IU/mL. Two studies found deterioration of HCV RNA in DBS samples stored at room temperature, while two others failed to detect such deterioration. These results support the potential use of DBS for genotyping and HCV RNA detection. Studies of the use of DBS for HCV RNA viral load measurement and of the rate of degradation of HCV RNA when stored in DBS at ambient temperatures remain inconclusive.
Topics: Blood; Desiccation; Genotyping Techniques; Hepacivirus; Hepatitis C; Humans; RNA, Viral; Specimen Handling
PubMed: 25367722
DOI: 10.1111/jvh.12345 -
World Journal of Gastrointestinal... May 2014Inflammatory bowel disease (IBD) is believed to develop via a complex interaction between genetic, environmental factors and the mucosal immune system. Crohn's disease... (Review)
Review
Inflammatory bowel disease (IBD) is believed to develop via a complex interaction between genetic, environmental factors and the mucosal immune system. Crohn's disease and ulcerative colitis are two major clinical forms of IBD. MicroRNAs (miRNAs) are a class of small, endogenous, noncoding RNA molecules, and evolutionary conserved in animals and plants. It controls protein production at the post-transcriptional level by targeting mRNAs for translational repression or degradation. MiRNAs are important in many biological processes, such as signal transduction, cellular proliferation, differentiation and apoptosis. Considerable attention has been paid on the key role of miRNAs in autoimmune and inflammatory disease, especially IBD. Recent studies have identified altered miRNA profiles in ulcerative colitis, Crohn's disease and inflammatory bowel disease-associated colorectal cancer. In addition, emerging data have implicated that special miRNAs which suppress functional targets play a critical role in regulating key pathogenic mechanism in IBD. MiRNAs were found involving in regulation of nuclear transcription factor kappa B pathway (e.g., miR-146a, miR-146b, miR-122, miR-132, miR-126), intestinal epithelial barrier function (e.g., miR-21, miR-150, miR-200b) and the autophagic activity (e.g., miR-30c, miR-130a, miR-106b, miR-93, miR-196). This review aims at discussing recent advances in our understanding of miRNAs in IBD pathogenesis, their role as disease biomarkers, and perspective for future investigation and clinical application.
PubMed: 24891977
DOI: 10.4291/wjgp.v5.i2.63 -
Cancer Cell International Aug 2013Despite advances in detection and therapy, epithelial ovarian cancer (EOC) still represents the most lethal gynecologic malignancy in women worldwide. The high mortality...
Despite advances in detection and therapy, epithelial ovarian cancer (EOC) still represents the most lethal gynecologic malignancy in women worldwide. The high mortality of EOC is mainly due to late-stage diagnosis for more than 70% of patients. There is an urgent need to search for specific and sensitive biomarkers for early diagnosis of EOC. Recently, the cumulative data indicated an essential role for microRNA (miRNA), a class of small non-coding RNAs targeting multiple mRNAs and triggering translation repression and/or RNA degradation, in ovarian caner carcinogenesis and progression. Here, we reviewed the published miRNA expression profiling studies that compared the miRNA expression profiles between EOC tissues or cell lines and normal ovarian tissues or benign ovarian tumor or human primary cultured ovarian surface epithelial cells. A miRNA ranking system that takes the number of comparisons in agreement and direction of differential expression into the consideration was devised and used. Finally, five promising differentially miRNAs (miR-200a, miR-100, miR-141, miR-200b, and miR-200c) were reported with the consistent direction in four or more studies. MiR-200a, miR-200b, miR-200c, and miR-141, all of them belong to miR-200 family, were reported with consistently up-regulated in at least 4 studies, whereas miR-100 was reported with down-regulated in 4 studies. Furthermore, we validated these miRNAs in a clinical setting using qRT-PCR and their dysregulations in EOC tissues confirmed the findings. Conclusively, the five most consistently expressed miRNAs might provide some clues of the potential biomarkers in EOC. Further mechanistic and precise validation studies are needed for their clinical significances and roles in the progression of EOC.
PubMed: 23978303
DOI: 10.1186/1475-2867-13-86 -
Antiviral Therapy 2009Dried spots on filter paper made of whole blood (dried blood spots; DBS), plasma (dried plasma spots; DPS) or serum (dried serum spots) hold promise as an affordable and... (Review)
Review
BACKGROUND
Dried spots on filter paper made of whole blood (dried blood spots; DBS), plasma (dried plasma spots; DPS) or serum (dried serum spots) hold promise as an affordable and practical alternative specimen source to liquid plasma for HIV type-1 (HIV-1) viral load determination and drug resistance genotyping in the context of the rapidly expanding access to antiretroviral therapy (ART) for HIV-1-infected individuals in low- and middle-income countries. This report reviews the current evidence for their utility.
METHODS
We systematically searched the English language literature published before 2009 on Medline, the websites of the World Health Organization and US Centers for Disease Control and Prevention, abstracts presented at relevant international conferences and references from relevant articles.
RESULTS
Data indicate that HIV-1 viral load determination and resistance genotyping from DBS and DPS is feasible, yielding comparable test performances, even after storage. Limitations include reduced analytical sensitivity resulting from small analyte volumes (approximately 3.5 log(10) copies/ml at 50 microl sample volume), nucleic acid degradation under extreme environmental conditions, impaired efficiency of nucleic acid extraction, potential interference of archived proviral DNA in genotypes obtained from DBS and the excision of spots from the filters in high-volume testing.
CONCLUSIONS
This technology offers the advantages of a stable specimen matrix, ease of sample collection and shipment. The current sensitivity in drug resistance testing is appropriate for public health surveillance among pretreatment populations. However, consistently improved analytical sensitivity is needed for their routine application in the therapeutic monitoring of individuals receiving ART, particularly at the onset of treatment failure.
Topics: Anti-HIV Agents; Blood Specimen Collection; Drug Resistance, Viral; HIV Infections; HIV-1; Humans; Plasma; RNA, Viral; Reverse Transcriptase Polymerase Chain Reaction; Viral Load
PubMed: 19704164
DOI: No ID Found