MicroRNA - Volume 7, Issue 3, 2018

MicroRNAs (miRNAs) constitute a class of short non coding RNAs that have crucial biological roles by acting mainly as negative regulators of gene expression. The alteration of miRNAs expression has been frequently demonstrated in cancer. Furthermore, miRNAs expression data clearly revealed their possible use as diagnostic, prognostic and predictive biomarkers. In this review, we focus on the biological role of human miR-23b-3p in cancer. Several data demonstrated that miR-23b-3p targeted different genes involved in cancer aggressive properties such as proliferation, migration, invasion, and metastasis. In this context, it is known that miR-23b-3p, as other miRNAs, can target either tumor-suppressor genes or oncogenes in different types of tumors. Therefore, its net biological effect can be tumor-specific, mainly depending on the consequent alterations on the downstream effects of the altered pathways. MiR-23b-3p has been found down-regulated or up-regulated in primary tumors and dysregulated in plasma and serum of cancer patients. Its expression levels correlate with the overall survival, disease-free survival and prognosis in several malignancies, thus assuming a remarkable role as molecular biomarker with clinical relevance. Finally, miR-23b-3p is generally considered a responsive molecular therapeutic target as reported in several in vitro and in vivo studies. This suggests that the ectopic modulation of its expression may potentially be important for translational medicine approaches.

Introduction: Colorectal cancer is one of the most common malignancies in both genders and liver metastasis appear in more than 50% of patients with colorectal cancer, worsening its morbidity and mortality rates. The existing methods for the diagnosis and prognosis of colorectal cancer seem to be insufficient to predict its aggressiveness, leading to poor outcomes for the patient. Objective: MicroRNAs are small non-coding RNAs, which interact with mRNAs in a posttranscriptional stage, and have been found to be involved in pathogenesis of cancer and its metastases. Their utility in diagnosis of colorectal liver metastasis gains ground through serum or tissue examination. Methods: Several miRNAs are related to colorectal cancer and its liver metastasis. Conclusion: Some of them have oncogenic and other tumor suppressive role in the development of colorectal liver metastasis, while many of them have been proved to be correlated with the overall survival and prognosis of patients with colorectal cancer. The aim of the present review is to give a detailed account of the different miRNAs that have been described as playing a role in hepatic metastases from colorectal cancer, emphasizing their diagnostic, prognostic and therapeutic implications.

The Homeodomain-Interacting Protein Kinases (HIPKs) HIPK1, HIPK2 and HIPK3 are Ser/Thr kinases which interact with homeobox proteins and other transcription factors, acting as transcriptional coactivators or corepressors. HIPKs contribute to regulate several biological processes, such as signal transduction, apoptosis, embryonic development, DNA-damage response, and cellular proliferation, in response to various extracellular stimuli. Recently it has emerged that, in addition to their role in cancer, fibrosis and diabetes, HIPKs may also be involved in other human diseases, including Amyotrophic Lateral Sclerosis (ALS), Rett syndrome, cerebellar diseases, and retinal vascular dysfunction. Methods: Here, we update our previous paper concerning the regulation of HIPK proteins expression by microRNAs (miRNAs), pointing out the most recent findings about new cellular mechanisms and diseases which are affected by the interplay between HIPKs and miRNAs. Conclusion: Recently, it has emerged that HIPKs and their related miRNAs are involved in diabetic nephropathy, gastric cancer chemoresistance, cervical cancer progression, and recombinant protein expression in cultured cells. Interestingly, circular RNAs (circRNAs) deriving from HIPK2 and HIPK3 loci also modulate cellular proliferation and viability by sponging several miRNAs, thus emerging as new putative therapeutic targets for diabetes-associated retinal vascular dysfunction, astrogliosis and cancer.

Background: The discovery of forensic DNA typing evolved molecular biology far beyond what could have been expected in terms of its forensic application, and now there exists other developments in molecular biology which are ready for application to forensic challenges. One such challenge is the identification of the body fluid source of stains recovered from evidence items and crime scenes. Currently, there are significant efforts in the research field to develop novel methods for the molecular identification of body fluids, with microRNAs (miRNAs) revealing great potential. MiRNAs have been shown to have high tissue specificity and are less susceptible to degradation as a result of their small size, which infers great advantages to their potential role for identifying forensically relevant body fluids. Objective: This study investigated the isolation and amplification of miRNAs from forensically relevant body fluids. Method: Venous blood, menstrual blood, semen, saliva, and vaginal material samples were extracted using; miRNeasy® mini kit (Qiagen), mirVana™ miRNA isolation kit (Ambion), and a modified mir- Vana™ method, and the quality/quantity of isolated miRNA was determined. miRNAs previously identified to show specificity for particular forensically relevant body fluids were examined. Real Time-Quantitative PCR (RT-qPCR) was performed targeting 5 miRNAs of interest, miR-451, miR- 412, miR-891a, miR-205 and miR-124a. Results: This study identified the miRNeasy® mini kit as the optimal method of the three methods investigated for the extraction of miRNAs from body fluids and further validates a selection of miRNAs previously suggested as potential biomarkers. Conclusion: This research highlights the potential of miRNAs as novel markers for the identification of forensically relevant body fluids.

Background: MicroRNAs (miRNA) are expected as useful biomarkers for various diseases. We studied the pre-analytical factors causing variation in the analysis of miRNA. Material and Methods: Blood samples were collected from 25 healthy subjects. Plasma and serum were obtained from the same samples. The levels of miR-451, -16, -126, and -223 were analyzed using RT-qPCR. Cel-miR-39 was added as a spiked-in control in each sample. Results: With the exception of miR-451, the levels of the miRNAs in plasma were higher than in serum. After high-speed centrifugation, the levels of miRNAs were almost equal between plasma and serum except for miR-451. Membrane filtration with 0.45 μm pore size reduced the levels of plasma miRNAs. The coagulation accelerators for serum processing did not affect the analysis of miRNA. The use of fraction containing particles of > 0.45 μm in size showed the inhibitory effect on the analysis of plasma miR-451. The RNase inhibitor was effective for protecting against the degradation of miRNAs. Conclusion: Plasma contains factors modifying miRNA profiles. The immediate processing of plasma with membrane filtration and RNase inhibitor may be a relevant method for achieving the stable analysis of miRNA.

Background: Influenza B virus causes influenza-like illness in humans. MicroRNAs (miRNAs) are small non-coding RNAs regulating gene expression through mRNA degradation or translational repression. MiRNAs have evolved to regulate many cellular processes including the viral infection response. Objective: This study aims to investigate the miRNA profiles of human cells infected with influenza B virus. Methods: A549 cells were infected with influenza B viruses (MOI = 0.5). MiRNAs were extracted at 24 and 48 hours post-infection. MiRNAs were used to construct four DNA libraries: influenza Binfected and an uninfected control for both time points. Then high-throughput sequencing was performed using the Miseq platform (Illumina). Sequencing data were analyzed by Miseq reporter software. The miRNAs were categorized and counted based on the frequency of reads. All filtered contigs were aligned with data from miRbase. The relative expression of each miRNA between uninfected and influenza B-infected cells was calculated. Results: There were 13 down-regulated miRNAs and 21 up-regulated miRNAs observed in influenza B infected cells at 24 hours post infection. At 48 hours post infection, 14 miRNAs were downregulated, whereas 8 miRNAs were up-regulated. Conclusion: This study suggested that miRNAs may play important roles in host gene regulation in response to viral infection.

Background: Non-Alcoholic Fatty Liver Disease (NAFLD) is an over accumulation of triglyceride in the liver without alcohol consumption. Its major cause is insulin resistance. Patients with NAFLD can develop liver fibrosis, cirrhosis and hepatocellular carcinoma (HCC). MicroRNAs (miRNAs) are non-coding RNAs that regulate post-transcriptional gene silencing. Previous research reported that miR-29 family (a, b and c) and miR-122 have an important role in regulating insulin resistance related to NAFLD. Objective: The purpose of this study was to investigate that miR-29 and miR-122 can be possible biomarkers for non-invasive diagnosis of NAFLD. Method: Serum samples were collected from 58 NAFLD patients and 34 healthy controls. MiRNAs were extracted from serum by using microRNA purification kit followed by polyuridylation, reverse transcription and quantitative real-time PCR. Also, we analyzed the correlation between miR-29 and miR-122 and level of liver inflammation in NAFLD patients. Results: We found that the serum miR-29a levels in NAFLD patients were significantly lower (P = 0.006) than the control group, while miR-29c levels were unchanged, and miR-29b levels were undetectable. However, we found that serum miR-122 levels in NAFLD patients were significantly higher (P < 0.001) than those found in the control group. For miR-29a, the area under curve (AUC) was 0.679 (P = 0.0065) with 60.87% sensitivity and 82.35% specificity. For miR-122, the AUC was 0.831 (P < 0.0001) with 75.00% sensitivity and 82.35% specificity. Interestingly, the levels of serum miR- 122 were significantly different between patients without steatohepatitis (NAS < 4) and steatohepatitis (NAS ≥ 4), indicating that the levels of miR-122 were related to the severity of NAFLD. Conclusion: The levels of miR-29a and miR-122 might be beneficial and compelling as possible biomarkers for non-invasive diagnosis of NAFLD.

Background: Septins have been identified to play important roles in platelets, but their regulation in platelets is unknown. Human platelet being an enucleated and terminally differentiated cell, mRNA downregulation by miRs is one of the posttranscriptional mechanisms operative in platelets. Objective: Since platelets are known to have miR-223 in abundance, the objective of this study is to test whether a) platelet septins have miR-223 interacting target sites in their mRNA 3'UTRs, b) septin mRNAs and miR-223 form complexes with Argonaute 2 (AGO2) protein in platelets, which is the catalytic component of an RNA Induced Silencing Complex (RISC), c) a reporter gene with septin mRNA 3' untranslated region (UTR) is subjected to downregulation by miR-223 and d) anti-miR-223 can suppress miR-223 activity and enhance septin-2 expression in platelets. Method: Bioinformatics tools were used to screen mRNA 3'UTRs of septin-2 and septin-6 for miR- 223 target sites. Subsequently, platelet extracts were immunoprecipitated by AGO2 antibodies to identify that the two septin mRNAs and miR-223 were in complex with AGO2. A luciferase reporter chimeric- gene expression system was utilized to monitor miR-223 mediated downregulation luciferase gene containing the 3'UTR of either septin-2 or septin-6. Further, anti-miR-223 was utilized in platelets to directly demonstrate the role of miR-223 on the expression of septin-2. Results: Our results demonstrate that in stored platelets a) septine-2 and septin-6 mRNAs have miR- 223 target sites, b) septin-2 and septin-6 are in complex with Ago-2, c) in luciferase reporter gene system, the interaction of miR-223 with 3' UTRs of septin-2 and septin-6 leads to downregulation of luciferase expression and d) anti-miR-223 downregulated miR-223 activity and thereby the expression of septin-2 is upregulated. Conclusion: The results demonstrate that like in nucleated cells, enucleated platelets also have miRbased mechanisms for the regulation of their septins.