Differential expression of serum miR-126,miR-141 and miR-21 as novel biomarkers for early detection of liver metastasis in colorectal cancer

Objective：MicroRNAs （miRNAs） have potential as diagnostic biomarkers in cancer.Evaluation of the association between miRNA expression patterns and early detection of liver metastasis in colorectal cancer （CRC） has not been reported.Methods：We investigated the expression of metastasis-associated miRs-31,335,206,141,126,200b,200c,21,Let7a,Let7b and Let7c in localized,liver-metastatic and other organ-metastatic CRC （OM-CRC）.Expressions of target miRNAs in serum were evaluated in 116 consecutive localized CRC （L-CRC）,72 synchronous liver-metastatic CRC （SLM-CRC） and 36 other OM-CRC by quantitative real-time PCR.Results：Seven of 11 tested miRNAs could be detected from serum.Four miRNAs,miR-126,Let-7a,miR141 and miR-21 were identified as metastasis-associated miRNAs.Compared with L-CRC,significant upregulated expression was observed for miR-141 and miR-21 in SLM-CRC and OM-CRC,down-regulated expression was observed for miR-126 in SLM-CRC and OM-CRC,and up-regulated expression of Let-7a in OM-CRC.The receiver operating characteristic （ROC） curve showed serum miR-126 had a cut-off [log10 relative quantity （log10RQ）=--0.2005] with 77.78％ sensitivity and 68.97％ specificity with an area under curve （AUC） of 0.7564,miR-141 had a cut-off （1og10RQ=-0.2285） with 86.11％ sensitivity and 76.11％ specificity with an AUC of 0.8279,and miR-21 had a cut-off （log10RQ=-0.1310） with 73.61％ sensitivity and 66.38％ specificity with an AUC of 0.7479.Conclusions：We identified liver metastasis-associated miRNAs,suggesting serum miR-126,miR-141 and miR-21 may be novel biomarkers for clinical diagnosis of early stage liver-metastatic CRC.

Research of the relationship between radiotherapy and microRNAs

MicroRNAs(miRNAs) are endogenous short non-coding RNAs,and play a pivotal role in regulating a variety of cellular processes,including proliferation and apoptosis,both of which are cellular responses to radiation treatment.In response to radiation,multiple miRNAs show altered expression,which act as oncogenes or tumor suppressors.Recent evidence has also shown that some miRNAs have radiotherapy sensitization or radiation resistance role in malignant tumors.This review focuses on analysis of these characteristics and mechanisms of miRNAs,and will provide some insight into the therapeutic application of radiation.

A study on the overexpression of microRNAs and lung cancer

MicroRNAs(miRNAs),which contains approximately 22 nt,belong to a small endogenous,non-coding regulatory single-stranded RNA molecules.They are posttranscriptional regulators of gene expression and highly conserved in evolution.Many researches show that miRNAs involved in many processes,including tumor formation,cell proliferation and apoptosis and proliferation and metastasis of cancer cells.Among that,the relationship between miRNAs and lung cancer is one of the most focal areas for the researchers,because the abnormal expressions of miRNAs were significantly associated with the occurrence and development of lung cancer.The expression level of different miRNAs in lung cancer cells exist differences,compared with normal lung tissue cells,there are two classes of expression:over-expression level and low expression level.In this review,we focused on studying the mechanism of overexpression miRNAs in lung cancer.

Differential expression of microRNA clusters in bladder transitional cell carcinoma

Objective： The aim of the study was to investigate the differential expression of microRNAs （miRNAs） in bladder transitional cell carcinoma （BTC）. Methods： Fresh tissues were obtained from patients with BTC （9 cases; 3 cases with grade Ⅰ, 3 cases with grade Ⅱ, 3 cases with grade III） and those with normal bladder mucosa （3 cases） and stored in liquid nitrogen. Total RNA was extracted using TRizol reagent and RNA was quantified and quality control was performed, miRNA probes were labeled with Hy3TM fluorescence, then hybridized with a miRCUR^M array labeling kit. miRNAarrays were scanned and analyzed and the scanned result was validated using reverse transcription-polymerase chain reaction （RT-PCR）. Results： In four groups of differentially expressed genes obtained from grade Ⅰ, grade Ⅱ, grade Ⅲ, and grade Ⅰ ＋ grade Ⅱ ＋ grade Ⅲ BTC tissues compared with normal bladder mucosa, hsa-miR-29b-1＊ was upregulated, and hsa-miR-923 and hsa-miR-300 were downregulated. The hsa-miR-29b-1＊, hsa-miR-300, and hsa-miR-923 findings were confirmed by real-time RT-PCR. Conclusion： Genes that were differentially expressed between BTC and normal bladder mucosa may be involved in the pathogenesis and development of BTC, and may be useful for further studies of BTC-related genes.

A microRNA encoded by HSV-1 inhibits a cellular transcriptional repressor of viral immediate early and early genes

Viral microRNAs are one component of the RNA interference phenomenon generated during viral infection. They were first identified in the Herpesviridae family, where they were found to regulate viral mRNA translation. In addition, prior work has suggested that Kaposi＇s sarcoma-associated herpesvirus （KSHV） is capable of regulating cellular gene transcription by miRNA. We demonstrate that a miRNA, hsvl-mir-H27, encoded within the genome of herpes simplex virus 1 （HSV-1）, targets the mRNA of the cellular transcriptional repressor Kelch-like 24 （KLHL24） that inhibits transcriptional efficiency of viral imme- diate-early and early genes. The viral miRNA is able to block the expression of KLHL24 in cells infected by HSV-1. Our dis- covery reveals an effective viral strategy for evading host cell defenses and supporting the efficient replication and prolifera- tion of HSV- 1.

Cellular, physiological and pathological aspects of the long non-coding RNA NEAT1

BACKGROUND： The majority of mammalian genomes have been found to be transcribed into non-coding RNAs. One category of non-coding RNAs is classified as long non-coding RNAs （lncRNAs） based on their transcript sizes larger than 200 nucleotides. Growing evidence has shown that lncRNAs are not junk transcripts and play regulatory roles in multiple aspects of biological processes. Dysregulation of lncRNA expression has also been linked to diseases, in particular cancer. Therefore, studies of lncRNAs have attracted significant interest in the field of medical research. Nuclear enriched abundant transcript 1 （NEAT1）, a nuclear lncRNA, has recently emerged as a key regulator involved in various cellular processes, physiological responses, developmental processes, and disease development and progression. OBJECTIVE： This review will summarize and discuss the most recent findings with regard to the roles of NEAT1 in the function of the nuclear paraspeckle, cellular pathways, and physiological responses and processes. Particularly, the most recently reported studies regarding the pathological roles of deregulated NEAT1 in cancer are highlighted in this review. METHODS： We performed a systematic literature search using the Pubmed search engine. Studies published over the past 8 years （between January 2009 and August 2016） were the sources of literature review. The following keywords were used： ＂Nuclear enriched abundant transcript 1,＂ ＂NEATI,＂ and ＂paraspeckles.＂ RESULTS： The Pubmed search identified 34 articles related to the topic of the review. Among the identified literature, 13 articles report findings related to cellular functions of NEAT1 and eight articles are the investigations of physiological functions of NEAT1. The remaining 13 articles are studies of the roles of NEAT1 in cancers. CONCLUSION： Recent advances in NEAT1 studies reveal the multifimctional roles of NEAT1 in various biological processes, which are beyond its role in nuclear paraspeckles. Recent studies also indicate that dysregulation of NEAT1 function contributes to the development and progression of various cancers. More investigations will be needed to address the detailed mechanisms regarding how NEAT1 executes its cellular and physiological functions and how NEAT1 dysregulation results in tumorigenesis, and to explore the potential of NEAT1 as a target in cancer diagnosis, prognosis and therapy.