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The hepatic microRNA (miRNA), miR-122, is the most abundant miRNA within the liver, where it accounts for 70% of the total miRNA pool. It is known that miR-122, as an unusual host factor, increases the abundance of hepatitis C virus (HCV) RNA in HCV infection by binding directly to the 5’-UTR of the viral genome. Therefore, it has been suggested as a potential target for the treatment of hepatitis C. However, recent evidence shows that miR-122 decreases HBV replication through the inhibitory effect of p53 on HBV transcription, and consequently it acts as a tumor-suppressor through both a decrease in HBV replication and by directly targeting cyclin G1, as well as Wnt/beta-catenin, and NDRG3 pathways. This paper will briefly discuss the underlying mechanisms for the dual role of miR-122 in viral hepatitis, and explains why therapeutic applications of miR-122 may differ based on the underlying disease.

Journal article The early detection of oligonucleotide biomarkers of disease, such as microRNAs, has been established as a fundamental factor in cancer diagnosis. As the levels of these small molecules (microRNAs) in blood have recently been found to be significantly affected in cancer patients, they offer a means of early stage detection of cancer. Towards the goal of creating a novel method of DNA hybridization detection, we report the detection of specific sequences of small oligonucleotides in a model experiment carried out in serum. The results shown here display the versatility of the DE-ATRP method in synthesizing a specific polymer structure capable of changing its physical properties in the presence of double stranded DNA. The polymer was labeled and used to detect single-stranded DNA in serum successfully. peer-reviewed

Phenotypic plasticity is often postulated as a principal characteristic of tuber-bearing wild Solanum species. The hypotheses to explore this observation have been developed based on the presence of genetic variation. In this context, evolutionary changes and adaptation are impossible without genetic variation. However, epigenetic effects, which include DNA methylation and microRNAs expression control, could be another source of phenotypic variation in ecologically relevant traits. To achieve a detailed mechanistic understanding of these processes, it is necessary to separate epigenetic from DNA sequence-based effects and to evaluate their relative importance on phenotypic variability. We explored the potential relevance of epigenetic effects in individuals with the same genotype. For this purpose, a clone of the wild potato Solanum ruiz-lealii, a non-model species in which natural methylation variability has been demonstrated, was selected and its DNA methylation was manipulated applying 5-Azacytidine (AzaC), a demethylating agent. The AzaC treatment induced early flowering and changes in leaf morphology. Using quantitative real-time PCR, we identified four miRNAs up-regulated in the AzaC-treated plants. One of them, miRNA172, could play a role on the early flowering phenotype. In this work, we showed that the treatment with AzaC could provide meaningful results allowing to study both the phenotypic plasticity in tuber-bearing Solanum species and the inter-relation between DNA methylation and miRNA accumulations in a wide range of species. Fil: Marfil, Carlos Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Biología Agrícola de Mendoza. Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias. Instituto de Biología Agrícola de Mendoza; Argentina Fil: Asurmendi, Sebastian. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Biotecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Masuelli, Ricardo Williams. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Biología Agrícola de Mendoza. Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias. Instituto de Biología Agrícola de Mendoza; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Mendoza-San Juan. Estación Experimental Agropecuaria La Consulta; Argentina

MicroRNAs (miRNAs) play an important role in carcinogenesis through the regulation of their target genes. miRNA-related single nucleotide polymorphisms (miR-SNPs) can affect miRNA biogenesis and target sites and can alter microRNA expression and functions. We examined 11 miR-SNPs, including 5 in microRNA genes, 3 in microRNA binding sites and 3 in microRNA-processing machinery components, and evaluated time to recurrence (TTR) according to miR-SNP genotypes in 175 surgically resected non-small-cell lung cancer (NSCLC) patients. Significant differences in TTR were found according to KRT81 rs3660 (median TTR: 20.3 months for the CC genotype versus 86.8 months for the CG or GG genotype; P = 0.003) and XPO5 rs11077 (median TTR: 24.7 months for the AA genotype versus 73.1 months for the AC or CC genotypes; P = 0.029). Moreover, when patients were divided according to stage, these differences were maintained for stage I patients (P = 0.002 for KRT81 rs3660; P

International audience; BACKGROUND: Micro RNAs are small, non-coding, single-stranded RNAs that negatively regulate gene expression at the post-transcriptional level. Since miR-143 was found to be down-regulated in prostate cancer cells, we wanted to analyze its expression in human prostate cancer, and test the ability of miR-43 to arrest prostate cancer cell growth in vitro and in vivo. RESULTS: Expression of miR-143 was analyzed in human prostate cancers by quantitative PCR, and by in situ hybridization. miR-143 was introduced in cancer cells in vivo by electroporation. Bioinformatics analysis and luciferase-based assays were used to determine miR-143 targets. We show in this study that miR-143 levels are inversely correlated with advanced stages of prostate cancer. Rescue of miR-143 expression in cancer cells results in the arrest of cell proliferation and the abrogation of tumor growth in mice. Furthermore, we show that the effects of miR-143 are mediated, at least in part by the inhibition of extracellular signal-regulated kinase-5 (ERK5) activity. We show here that ERK5 is a miR-143 target in prostate cancer. CONCLUSIONS: miR-143 is as a new target for prostate cancer treatment.

MicroRNAs (miRNAs) are small, noncoding RNAs that can contribute to cancer development and progression by acting as oncogenes or tumor suppressor genes. Recent studies have also linked different sets of miRNAs to metastasis through either the promotion or suppression of this malignant process. Interestingly, epigenetic silencing of miRNAs with tumor suppressor features by CpG island hypermethylation is also emerging as a common hallmark of human tumors. Thus, we wondered whether there was a miRNA hypermethylation profile characteristic of human metastasis. We used a pharmacological and genomic approach to reveal this aberrant epigenetic silencing program by treating lymph node metastatic cancer cells with a DNA demethylating agent followed by hybridization to an expression microarray. Among the miRNAs that were reactivated upon drug treatment, miR-148a, miR-34b/c, and miR-9 were found to undergo specific hypermethylation-associated silencing in cancer cells compared with normal tissues. The reintroduction of miR-148a and miR-34b/c in cancer cells with epigenetic inactivation inhibited their motility, reduced tumor growth, and inhibited metastasis formation in xenograft models, with an associated down-regulation of the miRNA oncogenic target genes, such as C-MYC, E2F3, CDK6, and TGIF2. Most important, the involvement of miR-148a, miR-34b/c, and miR-9 hypermethylation in metastasis formation was also suggested in human primary malignancies ( n = 207) because it was significantly associated with the appearance of lymph node metastasis. Our findings indicate that DNA methylation-associated silencing of tumor suppressor miRNAs contributes to the development of human cancer metastasis.

[Background]: The molecular mechanisms by which PROS1 mutations result in protein S deficiency are still unknown for many of the mutations, particularly for those that result in a premature termination codon. The aim of this study was to analyze the functional relevance on mRNA and protein expression of 12 natural PROS1 mutations associated with protein S deficiency., [Design and methods]: Five mutations were nonsense, three were small frameshift deletions, one was c.258,259AG>GT at the 3' end of exon 3, one was p.M640T and the last two were c.-7C>G and p.L15H, found in double heterozygosis as [c.-7C>G;44T>A]. The apparently neutral variant p.R233K was also analyzed. PROS1 cDNA was assessed by reverse transcriptase polymerase chain reaction of platelet mRNA. Expression of mutant proteins was determined by site-directed mutagenesis and analyses of transiently transfected PROS1 mutants in COS-7 cells., [Results]: Only cDNA from the normal allele was observed from the five nonsense mutations, the frameshift deletion c.1731delT and from c.258,259AG>GT. Both the normal and the mutated alleles were observed from [c.-7C>G;44T>A], c.187,188delTG and p.M640T. Transient expression analyses of PROS1 mutants whose mRNA was normally expressed revealed greatly reduced secretion of p.L15H and c.1272delA, mild secretion values of p.M640T and normal secretion levels of c.-7C>G and, as expected, p.R233K., [Conclusions]: Whereas the main cause of quantitative protein S deficiency associated with missense mutations is defective synthesis, stability or secretion of the mutated protein, the main mechanism for the deficiency associated with mutations that generate a premature termination codon is not the synthesis of a truncated protein, but the exclusion of the mutated allele, probably by nonsense-mediated mRNA decay., Funding: we acknowledge grants ISCIII 01/1468, ISCIII network C03/07 and ISCIII PI051149, from the Instituto de Salud Carlos III; SAF 2001-1059 and SAF2004-07539, from the Spanish Ministry of Education and Science; and grant 2002-PIR-00333 from the AGAUR, Generalitat de Catalunya. BH is the recipient of a grant from the Institut d’Investigació Biomèdica de Bellvitge (IDIBELL06/IDB-001).

MicroRNAs have turned out to be important regulators of gene expression. These molecules originate from longer transcripts that are processed by ribonuclease III (RNAse III) enzymes. Dicer proteins are essential RNAse III enzymes that are involved in the generation of microRNAs (miRNAs) and other small RNAs. The correct function of Dicer relies on the participation of accessory dsRNA binding proteins, the exact function of which is not well-understood so far. In plants, the double stranded RNA binding protein Hyponastic Leaves 1 (HYL1) helps Dicer Like protein (DCL1) to achieve an efficient and precise excision of the miRNAs from their primary precursors. Here we dissected the regions of HYL1 that are essential for its function in Arabidopsis thaliana plant model. We generated mutant forms of the protein that retain their structure but affect its RNA-binding properties. The mutant versions of HYL1 were studied both in vitro and in vivo, and we were able to identify essential aminoacids/residues for its activity. Remarkably, mutation and even ablation of one of the purportedly main RNA binding determinants does not give rise to any major disturbances in the function of the protein. We studied the function of the mutant forms in vivo, establishing a direct correlation between affinity for the pri-miRNA precursors and protein activity., This work was supported by Grants PICT 2007-720 and 2008-318 from ANPCyT to RMR. PB and ALS are recipients of a fellowship from CONICET. JFP and RMR are members of CONICET.

Learning and memory difficulties observed in patients with fragile X syndrome, as well as in a mouse model for the syndrome, are partially due to impaired translational regulation of neuronal mRNAs encoding key molecules for the synaptic structure and function. There has been intense interest in characterizing the mRNAs that are regulated by the fragile X mental retardation protein (FMRP) in the neuronal cell. A large number of candidate FMRP-interacting mRNAs has been identified over the last few years and three models have been described so far to explain the specificity of these interactions. Here, we report our vision on how they could work in the same and/or in different pathways and suggest that the three mechanisms may not be mutually exclusive. ispartof: Neuroreport vol:15 issue:16 pages:2447-2450 ispartof: location:England status: published

In primary culture of adult rat hepatocytes, vanadate in the presence of glucose stimulates the expression of the liver (L-type) pyruvate kinase gene. Glucose by itself was inactive, and vanadate, like insulin, was also inefficient in the absence of glucose. Similar results were obtained on glucokinase gene expression. An analogue of cAMP, 8-(4-chlorophenylthio)-cAMP, inhibited the production of L-type pyruvate kinase and glucokinase mRNAs in the presence of glucose plus vanadate.

Intermittent hypoxia (IH) during sleep is one of the major abnormalities occurring in patients suffering from obstructive sleep apnea (OSA), a highly prevalent disorder affecting 6–15% of the general population, particularly among obese people. IH has been proposed as a major determinant of oncogenetically-related processes such as tumor growth, invasion and metastasis. During the growth and expansion of tumors, fragmented DNA is released into the bloodstream and enters the circulation. Circulating tumor DNA (cirDNA) conserves the genetic and epigenetic profiles from the tumor of origin and can be isolated from the plasma fraction. Here we report a microarray-based epigenetic profiling of cirDNA isolated from blood samples of mice engrafted with TC1 epithelial lung cancer cells and controls, which were exposed to IH during sleep (XenoIH group, n=3) or control conditions, (i.e., room air (RA); XenoRA group, n=3) conditions. To prepare the targets for microarray hybridization, we applied a previously developed method that enriches the modified fraction of the cirDNA without amplification of genomic DNA. Regions of differential cirDNA modification between the two groups were identified by hybridizing the enriched fractions for each sample to Affymetrix GeneChip Human Promoter Arrays 1.0R. Microarray raw and processed data were deposited in NCBI's Gene Expression Omnibus (GEO) database (accession number: GSE61070).

// Alfons Navarro 1 , Tania Diaz 2 , Natalia Tovar 2 , Fabiola Pedrosa 2 , Rut Tejero 1 , Maria Teresa Cibeira 2 , Laura Magnano 2 , Laura Rosinol 2 , Mariano Monzo 1 , Joan Blade 2 , Carlos Fernandez de Larrea 2 1 Molecular Oncology and Embryology Laboratory, Human Anatomy Unit, School of Medicine, University of Barcelona, 08036 Barcelona, Spain 2 Amyloidosis and Myeloma Unit, Department of Hematology, Hospital Clinic de Barcelona, Institut d’Investigacions Biomediques August Pi I Sunyer (IDIBAPS), University of Barcelona, 08036 Barcelona, Spain Correspondence to: Carlos Fernandez de Larrea, e-mail: cfernan1@clinic.ub.es Keywords: miRNA, serum, myeloma, autologous transplantation, complete remission Received: October 26, 2014 Accepted: November 17, 2014 Published: January 22, 2015 ABSTRACT We have examined serum microRNA expression in multiple myeloma (MM) patients at diagnosis and at complete response (CR) after autologous stem-cell transplantation (ASCT), in patients with stable monoclonal gammopathy of undetermined significance, and in healthy controls. MicroRNAs were first profiled using TaqMan Human MicroRNA Arrays. Differentially expressed microRNAs were then validated by individual TaqMan MicroRNA assays and correlated with CR and progression-free survival (PFS) after ASCT. Supervised analysis identified a differentially expressed 14-microRNA signature. The differential expression of miR-16 ( P = 0.028), miR-17 ( P = 0.016), miR-19b ( P = 0.009), miR-20a ( P = 0.017) and miR-660 ( P = 0.048) at diagnosis and CR was then confirmed by individual assays. In addition, high levels of miR-25 were related to the presence of oligoclonal bands ( P = 0.002). Longer PFS after ASCT was observed in patients with high levels of miR-19b (6 vs. 1.8 years; P < 0.001) or miR-331 (8.6 vs. 2.9 years; P = 0.001). Low expression of both miR-19b and miR-331 in combination was a marker of shorter PFS (HR 5.3; P = 0.033). We have identified a serum microRNA signature with potential as a diagnostic and prognostic tool in MM.

Unveiling the regulatory pathways maintaining hepatic stellate cells (HSC) in a quiescent (q) phenotype is essential to develop new therapeutic strategies to treat fibrogenic diseases. To uncover the miRNA-mRNA regulatory interactions in qHSCs, HSCs were FACS-sorted from healthy livers and activated HSCs (aHSCs) were generated in vitro. MiRNA Taqman array analysis showed HSCs expressed a low number of miRNAs (n = 259), from which 47 were down-regulated and 212 up-regulated upon activation. Computational integration of miRNA and gene expression profiles revealed that 66% of qHSC-associated miRNAs correlated with more than 6 altered target mRNAs (17,28 ± 10,7 targets/miRNA) whereas aHSC-associated miRNAs had an average of 1,49 targeted genes. Interestingly, interaction networks generated by miRNA-targeted genes in qHSCs were associated with key HSC activation processes. Next, selected miRNAs were validated in healthy and cirrhotic human livers and miR-192 was chosen for functional analysis. Down-regulation of miR-192 in HSCs was found to be an early event during fibrosis progression in mouse models of liver injury. Moreover, mimic assays for miR-192 in HSCs revealed its role in HSC activation, proliferation and migration. Together, these results uncover the importance of miRNAs in the maintenance of the qHSC phenotype and form the basis for understanding the regulatory networks in HSCs.

// Mercedes Ingelmo-Torres 1 , Juan Jose Lozano 2 , Laura Izquierdo 1 , Albert Carrion 1 , Meritxell Costa 1 , Lidia Gomez 1 , Maria Jose Ribal 1 , Antonio Alcaraz 1 , Lourdes Mengual 1 1 Laboratory and Department of Urology, Hospital Clinic de Barcelona, Centre de Recerca Biomedica CELLEX, Institut d’Investigacions Biomediques August Pi i Sunyer (IDIBAPS), Universitat de Barcelona, Barcelona, Spain 2 CIBERehd, Plataforma de Bioinformatica, Centro de Investigacion Biomedica en Red de Enfermedades Hepaticas y Digestivas, Hospital Clinic de Barcelona, Barcelona, Spain Correspondence to: Lourdes Mengual, email: lmengual@clinic.ub.es Keywords: biomarkers, bladder cancer, microRNA, tumour progression, urine Received: October 11, 2016 Accepted: November 30, 2016 Published: February 14, 2017 ABSTRACT Current prognostic tools for non-muscle invasive bladder cancer (NMIBC) do not have enough discriminative capacity to predict the risk of tumour progression. This study aimed to identify urinary cell microRNAs that may be useful as non-invasive predictive biomarkers of tumour progression in NMIBC patients. To this end, 210 urine samples from NMIBC patients were included in the study. RNA was extracted from urinary cells and expression of 8 microRNAs, previously described by our group, was analysed by quantitative PCR. A tumour progression predicting model was developed by Cox regression analysis and validated by bootstrapping. Regression analysis identified miR-140-5p and miR-92a-3p as independent predictors of tumour progression. The risk score derived from the model containing these two microRNAs was able to discriminate between two groups with a highly significant different probability of tumour progression (HR, 5.204; p

Background Numerous DNA-damaging cellular stresses, including oncogene activation and DNA-damage response (DDR), may lead to cellular senescence. Previous observations linked microRNA deregulation with altered senescent patterns, prompting us to investigate whether epigenetic repression of microRNAs expression might disrupt senescence in prostate cancer (PCa) cells. Methods Differential methylation mapping in prostate tissues was carried using Infinium HumanMethylation450 BeadChip. After validation of methylation and expression analyses in a larger series of prostate tissues, the functional role of the cluster miR-130b~301b was explored using in vitro studies testing cell viability, apoptosis, invasion and DNA damage in prostate cancer cell lines. Western blot and RT-qPCR were performed to support those observations. Results We found that the miR-130b~301b cluster directs epigenetic activation of cell cycle inhibitors required for DDR activation, thus stimulating the senescence-associated secretory phenotype (SASP). Furthermore, overexpression of miR-130b~301b cluster markedly reduced the malignant phenotype of PCa cells. Conclusions Altogether, these data demonstrate that miR-130b~301b cluster overexpression might effectively induce PCa cell growth arrest through epigenetic regulation of proliferation-blocking genes and activation of cellular senescence. Electronic supplementary material The online version of this article (doi:10.1186/s13045-017-0415-1) contains supplementary material, which is available to authorized users.

To assess the usefulness of circulating microRNAs (miRNAs) as non-invasive molecular biomarkers for early prediction of preeclampsia, a differential miRNA profiling analysis was performed in first-trimester pooled sera from 31 early preeclampsia patients, requiring delivery before 34 weeks of gestation, and 44 uncomplicated pregnancies using microfluidic arrays. Among a total of 754 miRNAs analyzed, the presence of 63 miRNAs (8%) was consistently documented in the sera from preeclampsia and control samples. Nevertheless, only 15 amplified miRNAs (2%) seemed to be differentially, although modestly, represented (fold change range: 0.4–1.4). After stem loop RT-qPCR from individual samples, the statistical analysis confirmed that none of the most consistent and differentially represented miRNAs (3 overrepresented and 4 underrepresented) were differentially abundant in serum from preeclamptic pregnancies compared with serum from normal pregnancies. Therefore, maternal serum miRNA assessment at first-trimester of pregnancy does not appear to have any predictive value for early preeclampsia.

PiwiRNAs, small non-coding RNAs processed by Piwi proteins, are involved in maintaining genome stability in germline cells. Recently, piwiRNA expression has been identified in some tumors. We have examined the potential reactivation of the Piwi/piwiRNA pathway in classical Hodgkin lymphoma (cHL). We found that Piwi proteins and three selected piwiRNAs, including piR-651, were expressed in cHL patients and cell lines, indicating that the Piwi/piwiRNA pathway is active in cHL. Interestingly, low levels of piR-651 were associated with lack of complete response to first-line treatment, as well as shorter disease-free and overall survival in a cohort of 94 cHL patients. At diagnosis, piR-651 was underexpressed in cHL serum samples compared to healthy controls, while after complete remission, piR-651 levels increased to levels similar to healthy controls. This is the first evidence that piwiRNAs are active in tumor and serum samples and impact prognosis in cHL.

Before reaching a peripheral vein (PV), miRNAs released by the tumor are diluted and dispersed throughout the body or even retained in a specific organ. We hypothesized that blood drawn from the tumor-draining vein could provide more homogeneous information than blood drawn from the PV as that blood would contain all the biomarkers released by the tumor before they reach a potential metastatic site. We have profiled 754 miRNAs in 15 colon cancer plasma samples from the tumor-draining vein, the mesenteric vein (MV), identifying 13 microRNAs associated with relapse. The prognostic impact of these miRNAs were validated in 50 MV and 50 paired PV plasma samples of stage I-III colon cancer patients. Four miRNAs, let-7g, miR-15b, miR-155 and miR-328, were found overexpressed in MV compared to PV, and patients with high levels of those miRNAs in MV plasma had shorter time to relapse. Interestingly, in patients developing liver metastases, the exosomal cargo of miR-328 was much greater in MV than in PV plasma indicating a possible role of miR-328 in the development of liver metastases. Our results indicate that in colon cancer, the primary tumor releases high concentrations of miRNAs through the MV, and some of them are contained in tumor derived exosomes.

Granulocyte colony-stimulating factor is the most commonly used cytokine for the mobilization of hematopoietic progenitor cells from healthy donors for allogeneic stem cell transplantation. Although the administration of this cytokine is considered safe, knowledge about its long-term effects, especially in hematopoietic progenitor cells, is limited. On this background, the aim of our study was to analyze whether or not granulocyte colony-stimulating factor induces changes in gene and microRNA expression profiles in hematopoietic progenitor cells from healthy donors, and to determine whether or not these changes persist in the long-term. For this purpose, we analyzed the whole genome expression profile and the expression of 384 microRNA in CD34(+) cells isolated from peripheral blood of six healthy donors, before mobilization and at 5, 30 and 365 days after mobilization with granulocyte colony-stimulating factor. Six microRNA were differentially expressed at all time points analyzed after mobilization treatment as compared to the expression in samples obtained before exposure to the drug. In addition, 2424 genes were also differentially expressed for at least 1 year after mobilization. Of interest, 109 of these genes are targets of the differentially expressed microRNA also identified in this study. These data strongly suggest that granulocyte colony-stimulating factor modifies gene and microRNA expression profiles in hematopoietic progenitor cells from healthy donors. Remarkably, some changes are present from early time-points and persist for at least 1 year after exposure to the drug. This effect on hematopoietic progenitor cells has not been previously reported.

INTRODUCTION: Preoperative chemoradiotherapy (CRT) is a standard treatment for locally advanced rectal cancer patients. Despite the benefits of CRT, its use in non-responder patients can be associated with increased toxicities and surgical resection delay. The identification of CRT response biomarkers, such as microRNAs, could improve the management of these patients. We have studied the microRNA expression in pretreatment endoscopy biopsies from rectal cancer patients treated with CRT to identify potential microRNAs able to predict CRT response and clinical outcome of these patients. MATERIAL AND METHODS: RNA from pretreatment endoscopy biopsies from 96 rectal cancer patients treated with preoperative CRT were studied. Pathological response was graded according to the tumor regression grade (TRG) Dworak classification. In the screening phase, 377 miRNAs were studied in 12 patients with extreme responses (TRG0-1 vs TRG4). The potential role as predictive biomarkers for CRT response, disease-free survival (DFS) and overall survival (OS) of the miRNAs identified in the screening phase were validated in the whole cohort. RESULTS: In the screening phase, an 8-miRNAs CRT-response signature was identified: let-7b, let-7e, miR-21, miR-99b, miR-183, miR-328, miR-375 and miR-483-5p. In the validation phase, miR-21, miR-99b and miR-375 emerged as CRT response-related miRNAs while miR-328 and let-7e emerged as prognostic markers for DFS and OS. Interestingly, ROC curve analysis showed that the combination of miR-21, miR-99b and miR-375 had the best capacity to distinguish patients with maximum response (TRG4) from others. CONCLUSIONS: miR-21, miR-99b and miR-375 could add valuable information for individualizing treatment in locally advanced rectal cancer patients.

Missense mutations in TP53 gene promote metastasis in human tumours. However, little is known about the complete loss of function of p53 in tumour metastasis. Here we show that squamous cell carcinomas generated by the specific ablation of Trp53 gene in mouse epidermis are highly metastatic. Biochemical and genome-wide mRNA and miRNA analyses demonstrated that metastases are associated with the early induction of epithelial-mesenchymal transition (EMT) and deregulated miRNA expression in primary tumours. Increased expression of miR-21 was observed in undifferentiated, prometastatic mouse tumours and in human tumours characterized by p53 mutations and distant metastasis. The augmented expression of miR-21, mediated by active mTOR and Stat3 signalling, conferred increased invasive properties to mouse keratinocytes in vitro and in vivo, whereas blockade of miR-21 in a metastatic spindle cell line inhibits metastasis development. Collectively these data identify novel molecular mechanisms leading to metastasis in vivo originated by p53 loss in epithelia.

// Laura Izquierdo 1, 2, * , Ruth Montalbo 1, 2, * , Mercedes Ingelmo-Torres 1, 2 , Carme Mallofre 3 , Miguel Ramirez-Backhaus 4 , Jose Rubio 4 , Antoine G. Van der Heijden 5 , Ewout Schaafsma 6 , Antonio Lopez-Beltran 7 , Ana Blanca 8 , Nathan Lawrentschuk 9 , Antonio Alcaraz 1, 2 and Lourdes Mengual 1, 2 1 Department of Urology, Hospital Clinic, IDIBAPS, Barcelona, Spain 2 Laboratory of Urology, Hospital Clinic, IDIBAPS, Barcelona, Spain 3 Department of Pathology, Hospital Clinic, Barcelona, Spain 4 Department of Urology of Fundacion IVO, Valencia, Spain 5 Department of Urology, Radboud University Centre, Nijmegen, Netherlands 6 Department of Pathology, Radboud University Centre, Nijmegen, Netherlands 7 Department of Pathology of Reina Sofia Hospital and Maimonides Biochemical Research Institute, Cordoba, Spain 8 Department of Urology, Maimonides Biochemical Research Institute of Cordoba, Cordoba, Spain 9 Department of Urology, University of Melbourne, Department of Surgery/Olivia Newton-John Cancer Research Institute, Melbourne, Australia * These authors have contributed equally to this work Correspondence to: Laura Izquierdo, email: lizquier@clinic.cat Keywords: microRNAs, prognosis, upper tract urothelial carcinoma Abbreviations: UTUC, upper urinary tract tumor; RNU, radical nephroureterectomy Received: November 25, 2016 Accepted: April 26, 2017 Published: May 16, 2017 ABSTRACT Objective: To validate previously discovered miRNAs (miR-31-5p and miR-149-5p) as prognostic factors for UTUC in an independent cohort of UTUC patients. Patients and Methods: Multicenter, international and retrospective study of formalin-fixed paraffin-embedded tissue samples from 103 UTUC patients (45 progressing and 58 non-progressing) who underwent radical nephroureterectomy. Total RNA was isolated and reverse transcribed. The expression of target miRNAs (miR-31-5p and miR-149-5p) and the endogenous control miR-218-5p was evaluated in all samples by reverse transcription quantitative PCR. Normalized miRNA expression values were evaluated by multivariate forward stepwise Cox regression analysis. Kaplan Meier curves were used to discriminate between two groups of patients with a different probability of tumour progression. Results: The mean age (range) of the series was 67 (33-94) years. Overall, 45 patients (43.7%) developed tumour progression and 32 patients (31.2%) died, 20 of these (62.5%) due to their UTUC, after a median follow-up of 36 months. The mean time for tumour progression and cancer-specific survival were 15 and 20 months, respectively. Five year tumour progression free survival and cancer-specific survival were 58% for ≤ pT2, 36% for pT3 and 0% for pT4 and 67.8% for ≤ pT2, 50.6% for pT3 and 0% for pT4, respectively. In the multivariate analysis, expression of miR-31-5p was found to be an independent prognostic factor of tumour progression (HR 1.1; 95% CI 1.039-1.273; p=0.02). Kaplan Meier curve shows that miR-31-5p expression values are able to discriminate between two groups of UTUC patients with a different probability of tumour progression (p=0.007). Conclusions: We have been able to validate our previous results in an independent multicentre international cohort of UTUC patients, suggesting that miRNA-31-5p could be a useful prognostic marker of UTUC progression. The application of miRNA expression values to clinical practice could refine the currently used clinicopathological-based approach for predicting UTUC patients’ outcome.

Review on MIR135A1, with data on DNA/RNA and where the gene is implicated.