Circulating microRNAs: Novel biomarkers for esophageal cancer

Esophageal carcinogenesis is a multi-stage process, involving a variety of changes in gene expression and physiological structure change. MicroRNAs (miRNAs) are a class of small non-coding endogenous RNA molecules. Recent innovation in miRNAs profiling technology have shed new light on the pathology of esophageal carcinoma (EC), and also heralded great potential for exploring novel biomarkers for both EC diagnosis and treatment. Frequent dysregulation of miRNA in malignancy highlights the study of molecular factors upstream of gene expression following the extensive investigation on elucidating the important role of miRNA in carcinogenesis. We herein present a thorough review of the role of miRNAs in EC, addressing miRNA functions, their putative role as oncogenes or tumor suppressors and their potential target genes. The recent progresses in discovering the quantifiable circulating cancer-associated miRNAs indicate the potential clinical use of miRNAs as novel minimally invasive biomarkers for EC and other cancers. We also discuss the potential role of miRNAs in detection, screening and surveillance of EC as miRNAs can be a potential target in personalized treatment of EC.

Circulating microRNAs as a liquid biopsy: a next generation clinical biomarker for diagnosis of gastric cancer

Accumulating evidence has suggested the potential clinical utility of novel body fluid biomarkers,or“liquid biopsy”,using circulating tumor cells and cell-free nucleic acids from cancer patients.Noninvasive and reproducible,liquid biopsy could provide the basis for individualized therapeutic strategies by identifying genetic and epigenetic aberrations that are closely associated with cancer initiation and progression.MicroRNAs(miRNAs)are short noncoding RNAs that post-transcriptionally regulate gene expression.They also play important roles in various physiological and developmental processes as oncogenic or tumor-suppressive regulators.Specific miRNA expression signatures have been identified in a number of human cancers.Circulating miRNAs have been detected in plasma and serum,and this in blood has attracted the attention of researchers for their potential as noninvasive biomarkers.Circulating miRNAs have emerged as tumor-associated biomarkers that reflect not only the existence of cancer,but also the dynamics,malignant potential,and drug resistance of tumors.Herein,we review the recent biological and clinical research on the circulating miRNAs of gastric cancer and discuss future perspectives for their clinical applications as a liquid biopsy.

Identification of circulating miRNA biomarkers based on global quantitative real-time PCR profiling

MicroRNAs （miRNAs） are small noncoding RNAs （18-25 nucleotides） that regulate gene expression at the posttranscriptional level. Recent studies have demonstrated the presence of miRNAs in the blood circulation. Deregulation of miRNAs i n serum or plasma has been associated with many diseases including cancers and cardiovascular diseases, suggesting the possible use of miRNAs as diagnostic biomarkers. However, the detection of the small amount of miRNAs found in serum or plasma requires a method with high sensitivity and accuracy. Therefore, the current study describes polymerase chain reaction （PCR）-based methods for measuring circulating miRNAs. Briefly, the procedure involves four major steps： （1） sample collection and preparation; （2） global miRNAs profiling using quantitative real-time PCR （qRT-PCR）; （3） data normalization and analysis; and （4） selection and validation of miRNA biomarkers. In conclusion, qRT-PCR is a promising method for profiling of circulating miRNAs as biomarkers.

4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone Induces Circulating MicroRNA Deregulation in Early Lung Carcinogenesis

Objective To study the alteration of circulating microRNAs in 4-（methylnitrosamino）-l-（3-pyridyl） -l-butanone （NNK）-induced early stage lung carcinogenesis. Methods A lung cancer model of male F344 rats was induced with systemic NNK and levels of 8 lung cancer-associated miRNAs in whole blood and serum of rats were measured by quantitative RT-PCR of each at weeks 2, 5, 20, and 20 following NNK treatment. Results No lung cancer was detected in control group and NNK treatment group at week 20 following NNK treatment. The levels of some circulating miRNAs were significantly higher in NNK treatment group than in control group. The miR-210 was down-regulated and the miR-206 was up-regulated in NNK treatment group. The expression level of circulating miRNAs changed from week 1 to week 20 following NNK treatment. Conclusion The expression level of circulating miRNAs is related to NNK-induced early stage lung carcinogenesis in rats and can therefore serve as its potential indicator.

Serum outperforms plasma in small extracellular vesicle microRNA biomarker studies of adenocarcinoma of the esophagus

BACKGROUND Circulating microRNAs(miRNAs)are potential biomarkers for many diseases.However,they can originate from non-disease specific sources,such as blood cells,and compromise the investigations for miRNA biomarkers.While small extracellular vesicles(sEVs)have been suggested to provide a purer source of circulating miRNAs for biomarkers discovery,the most suitable blood sample for sEV miRNA biomarker studies has not been defined.AIM To compare the mi RNA profiles between matched serum and plasma s EV preparations to determine their suitability for biomarker studies.METHODS Matched serum and plasma samples were obtained from 10 healthy controls and10 patients with esophageal adenocarcinoma.s EV isolates were prepared from serum and plasma using Exo Quick TM and quantified using Nano Sight.RNA was extracted from s EV preparations with the mi RNeasy Serum/Plasma kit and profiled using the Taqman Openarray q PCR.The overall mi RNA content and theexpression of specific mi RNAs of reported vesicular and non-vesicular origins were compared between serum and plasma s EV preparations.The diagnostic performance of a previously identified multi-mi RNA biomarker panel for esophageal adenocarcinoma was also compared.RESULTS The overall mi RNA content was higher in plasma s EV preparations(480 mi RNAs)and contained 97.5%of the mi RNAs found in the serum s EV preparations(412 mi RNAs).The expression of commonly expressed mi RNAs was highly correlated(Spearman’s R=0.87,P<0.0001)between the plasma and serum s EV preparations,but was consistently higher in the plasma s EV preparations.Specific blood-cell mi RNAs(hsa-mi R-223-3 p,hsa-mi R-451 a,mi R-19 b-3 p,hsa-mi R-17-5 p,hsa-mi R-30 b-5 p,hsa-mi R-106 a-5 p,hsa-mi R-150-5 p and hsa-mi R-92 a-3 p)were expressed at 2.7 to 9.6 fold higher levels in the plasma s EV preparations compared to serum s EV preparations(P<0.05).In plasma s EV preparations,the percentage of protein-associated mi RNAs expressed at relatively higher levels(Ct 20-25)was greater than serum s EV preparations(50%vs 31%).While the percentage of vesicle-associated mi RNAs expressed at relatively higher levels was greater in the serum s EV preparations than plasma s EV preparations(70%vs 44%).A 5-mi RNA biomarker panel produced a higher cross validated accuracy for discriminating patients with esophageal adenocarcinoma from healthy controls using serum s EV preparations compared with plasma s EV preparations(AUROC 0.80 vs 0.54,P<0.05).CONCLUSION Although plasma s EV preparations contained more mi RNAs than serum s EV preparations,they also contained more mi RNAs from non-vesicle origins.Serum appears to be more suitable than plasma for s EV mi RNAs biomarkers studies.

Liquid biopsies in cancer

Liquid biopsy,the detection of biomarkers from body fluids,has been widely used on circulating tumor cells(CTCs),circulating tumor DNA(ctD NA),circulating tumor microRNA,exosomes and other kinds of molecular characterization.Cancer,a series of comprehensive mechanisms,presents in different molecular forms that could be used in clinic for diagnosis,treatment,drug monitoring and prognosis judgement via liquid biopsies.Liquid biopsies are available to tumor heterogeneity,resistance,progression and metastases in clinic.Technologies for detection and analysis was improving for the obvious limitation of liquid biopsies,that leads the future directions.In this review,we provided critical views of liquid biopsies on cancer,including different methods of liquid biopsies and applications of liquid biopsies in current clinical trials and practice.

Macronutrient modulation of mRNA and microRNA function in animals:A review

Dietary macronutrients have been regarded as a basic source of energy and amino acids that are necessary for the maintenance of cellular homeostasis,metabolic programming as well as protein synthesis.Due to the emergence of"nutrigenomics",a unique discipline that combines nutritional and omics technologies to study the impacts of nutrition on genomics,it is increasingly evident that macro nutrients also have a significant role in the gene expression regulation.Gene expression is a complex phenomenon controlled by several signaling pathways and could be influenced by a wide variety of environmental and physiological factors.Dietary macronutrients are the most important environmental factor influencing the expression of both genes and microRNAs(miRNA).miRNA are tiny molecules of 18 to 22 nucleotides long that regulate the expression of genes.Therefore,dietary macro nutrients can influence the expression of genes in both direct and indirect manners.Recent advancements in the state-of-the-art technologies regarding molecular genetics,such as next-generation sequencing,quantitative PCR array,and microarray,allowed us to investigate the occurrence of genome-wide changes in the expression of genes in relation to augmented or reduced dietary macronutrient intake,The purpose of this review is to accumulate the current knowledge focusing on macronutrient mediated changes in the gene function.This review will discuss the impact of altered dietary carbohydrate,protein,and fat intake on the expression of coding genes and their functions.In addition,it will also summarize the regulation of miRNA,both cellular and extracellular miRNA,expression modulated by dietary macronutrients.