ｍｉＲＮＡ：新一代肿瘤生物标志

微小ＲＮＡ（ｍｉＲＮＡ）是一类小分子非编码ＲＮＡ,能够在转录后水平调控蛋白合成,几乎参与了调控细胞活动的各个环节。到目前为止,ｍｉＲＮＡ给予人们一个新的视野理解肿瘤的发生发展,展示了作为肿瘤标志物以及肿瘤治疗靶点的巨大潜能。作者从肿瘤标志物的角度,归纳了ｍｉＲＮＡ用于肿瘤诊断、药物疗效预测以及预后判断所获得的成就,并对其临床应用前景作了展望。     

Plasma microRNA profiling in nasopharyngeal carcinoma patients revealsmiR-548q andmiR-483-5p as potential biomarkers

MicroRNAs （miRNAs）, which play a role in tumorigenesis, may also serve as diagnostic or prognostic biomarkers. However, studies on human miRNA profiles in plasma from nasopharyngeal carcinoma （NPC） patients are in their infancy. Here, we used microarrays to perform systematic profiling of human miRNAs in plasma from NPC patients. We subsequently used realtime quantitative polymerase chain reaction （Q-PCR） to validate miRNAs with aberrant expression that could serve as potential biomarkers. By comparing the plasma miRNA profiles of 31 NPC patients and 19 controls, 39 of 887 human miRNAs were found to be aberrantly expressed. Considering the fold change and P value, miR-548q and miR-483- 5p were validated in 132 samples from 82 NPC patients and 50 controls. Moreover, high expression of miR-548q and miR483-5p was further found in 3 NPC cell lines and clinical biopsy tissues from 54 NPC patients and 22 controls. Our results revealed that miR-548q and miR-483-5p are potential biomarkers of NPC. Combining the receiver operating characteristic （ROC） analyses of these 2 miRNAs, an area under the ROC curve （AUC） of 0.737 with 67.1% sensitivity and 68.0% specificity were obtained, showing the preliminary diagnostic value of plasma miRNAs. Moreover, most NPC patients with a poor outcome exhibited high expression （〉 median） of miR548q （70.6%） and miR-483-5p （64.7%） in tissue samples, indicating their prognostic value. The high expression levels of miR-548q and miR-483-5p in plasma, cell lines, and clinical tissues of NPC patients indicate that their roles in NPC should be explored in the future.     

Vesicle-bound EBV-BART13-3p miRNA in circulation distinguishes nasopharyngeal from other head and neck cancer and asymptomatic EBV-infections

Cell-free microRNA (miRNA) in biofluids released by tumors in either protein or vesicle-bound form, represent promising minimally-invasive cancer biomarkers. However, a highly abundant non-tumor background in human plasma and serum complicates the discovery and detection of tumor-selective circulating miRNAs. We performed small RNA sequencing on serum and plasma RNA from Nasopharyngeal Carcinoma (NPC) patients. Collectively, Epstein Barr virus-encoded miRNAs, more so than endogenous miRNAs, signify presence of NPC. However, RNAseq-based EBV miRNA profiles differ between NPC patients, suggesting inter-tumor heterogeneity or divergent secretory characteristics. We determined with sensitive qRT-PCR assays that EBV miRNAs BART7-3p, BART9-3p and BART13-3p are actively secreted by C666.1 NPC cells bound to extracellular vesicles (EVs) and soluble ribonucleoprotein complexes. Importantly, these miRNAs are expressed in all primary NPC tumor biopsies and readily detected in nasopharyngeal brushings from both early and late-stage NPC patients. Increased levels of BART7-3p, BART9-3p and particularly BART13-3p, distinguish NPC patient sera from healthy controls. Receiver operating characteristic curve analysis using sera from endemic NPC patients, other head and neck cancers and individuals with asymptomatic EBV-infections reveals a superior diagnostic performance of EBV miRNAs over anti-EBNA1 IgA serology and EBV-DNA load (AUC 0.87–0.96 vs 0.86 and 0.66 respectively). The high specificity of circulating EBV-BART13-3p (97%) for NPC detection is in agreement with active secretion from NPC tumor cells. We conclude EV-bound BART13-3p in circulation is a promising, NPC-selective, biomarker that should be considered as part of a screening strategy to identify NPC in endemic regions.     

Five miRNAs as Novel Diagnostic Biomarker Candidates for Primary Nasopharyngeal Carcinoma

MicroRNAs (miRNAs) play an essential role in the development and progression of nasopharyngeal carcinomas(NPC). Despite advances in the field of cancer molecular biology and biomarker discovery, the development ofclinically validated biomarkers for primary NPC has remained elusive. In this study, we investigated the expressionand clinical significance of miRNAs as novel primary NPC diagnostic biomarkers. We used an array containing 2,500 miRNAs to identify 22 significant miRNAs, and these candidate miRNAs were validated using 67 fresh NPCand 25 normal control tissues via quantitative real-time PCR (qRT-PCR). Expression and correlation analyseswere performed with various statistical approaches, in addition to logistic regression and receiver operatingcharacteristic curve analyses to evaluate diagnostic efficacy. qRT-PCR revealed five differentially expressedmiRNAs (miR-93-5p, miR-135b-5p, miR-205-5p and miR-183-5p) in NPC tissue samples relative to controlsamples (p<0.05), with miR-135b-5p and miR-205-5p being of significant diagnostic value (p<0.01). Moreover,comparison of NPC patient clinicopathologic data revealed a negative correlation between miR-93-5p and miR-183-5p expression levels and lymph node status (p<0.05). These findings display an altered expression of manymiRNAs in NPC tissues, thus providing information pertinent to pathophysiological and diagnostic research.Ultimately, miR-135b-5p and miR-205-5p may be implicated as novel NPC candidate biomarkers, while miR-93-5p, miR-650 and miR-183-5p may find application as relevant clinical pathology and diagnostic candidatebiomarkers.     

Role of miRNA in head and neck squamous cell carcinoma

Head and neck squamous cell carcinoma (HNSCC) is the sixth most common malignancy worldwide. Evidence suggests that miRNAs play an important role in progression, recurrence, metastasis and postoperative survival of HNSCC. Studies have investigated the utility of miRNAs as diagnostic/prognostic tools and as potential therapeutic targets and biomarkers that may improve the management and outcomes of HNSCC. The aim of this article is to review the current literature on aberrant expression profiles of miRNAs in biopsy samples of HNSCC and their role in cancer development, metastasis, prognosis and survival of these patients. This review gives an overview that miRNAs deregulation play major role in the development of HNSCC. They offer the potential to be used as biomarkers or novel therapeutic targets. Future research is required to test their use in both of these fields.     

Hypoxic nasopharyngeal carcinoma-derived exosomal miR-455 increases vascular permeability by targeting ZO-1 to promote metastasis

Nasopharyngeal carcinoma (NPC), the most frequent reason for treatment failure in head and neck tumors, has the greatest incidence of distant metastases. Increased vascular permeability facilitates metastasis. Exosomal microRNAs (miRNAs) have been implicated in the development of the premetastatic niche and are emerging as prospective biomarkers in cancer patients. We discovered that a higher level of miR-455 was connected to a larger propensity for NPC metastasis based on deep sequencing and RT-qPCR. We found that hypoxia promoted NPC exosomes release and increased miR-455 expression in a way that was hypoxia-inducible factor 1-alpha (HIF-1α) dependent. Exosomes from NPC cells with high levels of miR-455 were found to specifically target zonula occludens 1 (ZO-1), increasing the permeability of endothelial monolayers in vitro vascular permeability and transendothelial invasion experiments. Additional in vivo studies showed that zebrafish with sustained miR-455-overexpressing NPC cell xenografts displayed increased tumor cell mass throughout the body. In vivo, zebrafish vascular tight junction integrity was disrupted by exosomes produced by NPC cells with elevated miR-455 expression. Mice-bearing xenografts further supported the finding that exosomes containing miR-455 might reduce ZO-1 expression in addition to promote NPC cell growth. These findings suggest that in a hypoxic microenvironment, exosomal miR-455 released by NPC cells enhances vascular permeability and promotes metastasis by targeting ZO-1. The HIF-1α-miR-455-ZO-1 signaling pathway may be a promising predictor and potential therapeutic target for NPC with metastasis.     

MicroRNA在乳腺癌中作用的研究进展

MicroRNA（miRNA,miRNAs)是广泛存在于生物中,长度约为20-24个核苷酸的非编码微小RNA分子。目前研究发现,miRNA与肿瘤的发生、进展有紧密联系,且逐渐成为癌症研究的热点。近年来,miRNA在乳腺癌发生与进展中起到的重要作用逐渐被揭示,已迅速发展为乳腺癌等癌症的重要生物标记物。本综述将就微小RNA在乳腺癌的发生、进展、远处转移、早期诊断以及化学治疗耐药性方面的作用进行论述。     

Exploring circulating micro‐RNA in the neoadjuvant treatment of breast cancer

Breast cancer is the most frequently diagnosed malignancy amongst females worldwide. In recent years the management of this disease has transformed considerably, including the administration of chemotherapy in the neoadjuvant setting. Aside from increasing rates of breast conserving surgery and enabling surgery via tumour burden reduction, use of chemotherapy in the neoadjuvant setting allows monitoring of in vivo tumour response to chemotherapeutics. Currently, there is no effective means of identifying chemotherapeutic responders from non‐responders. Whilst some patients achieve complete pathological response (pCR) to chemotherapy, a good prognostic index, a proportion of patients derive little or no benefit, being exposed to the deleterious effects of systemic treatment without any knowledge of whether they will receive benefit. The identification of predictive and prognostic biomarkers could confer multiple benefits in this setting, specifically the individualization of breast cancer management and more effective administration of chemotherapeutics. In addition, biomarkers could potentially expedite the identification of novel chemotherapeutic agents or increase their efficacy. Micro‐RNAs (miRNAs) are small non‐coding RNA molecules. With their tissue‐specific expression, correlation with clinicopathological prognostic indices and known dysregulation in breast cancer, miRNAs have quickly become an important avenue in the search for novel breast cancer biomarkers. We provide a brief history of breast cancer chemotherapeutics and explore the emerging field of circulating (blood‐borne) miRNAs as breast cancer biomarkers for the neoadjuvant treatment of breast cancer. Established molecular markers of breast cancer are outlined, while the potential role of circulating miRNAs as chemotherapeutic response predictors, prognosticators or potential therapeutic targets is discussed.     

MicroRNA in lung cancer

MicroRNAs (miRNAs) are small non-protein-coding RNAs that function as endogenous negative gene regulators. Dysfunctions of miRNAs are frequently found in malignancies, including lung cancer. In this review, we summarise the current understanding of miRNAs in lung cancer tumourigenesis, and highlight their potential in overcoming drug resistance, abetting histological sub-classification techniques, and serving as biomarkers for lung cancer risk stratification and outcome prediction.     

循环血液外泌体miRNA在卵巢癌发生发展中作用及其诊断价值的研究进展

卵巢癌（ovarian cancer,OC）是女性恶性肿瘤死亡的主要原因。由于卵巢癌无症状发展,缺乏早期诊断标志物,大多数患者在晚期才被诊断出来。早期检测卵巢癌可显著提高总生存率,在过去的几十年里,微小RNA（miRNA）在癌症的发展中起着重要的作用,因此引起了极大的关注。miRNA可以在循环血液中稳定存在(如包裹在外泌体中),并可通过外泌体的分泌和转移在肿瘤细胞之间和肿瘤细胞微环境的沟通中发挥重要的作用。此外,外泌体miRNA在卵巢癌中的表达是失调的,可能反映肿瘤的恶性特征。因此评估外泌体来源的循环miRNA可能会为卵巢癌提供一类新的非侵袭性生物标志物。本综述概述了有关外泌体miRNA在卵巢癌发生发展过程中的作用以及循环血液外泌体miRNA作为卵巢癌早期诊断潜在生物标志物的现状。     

microRNA expression profiling of nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is posing a serious health problem worldwide. The association between its pathogenesis and microRNAs (miRNA) has not been elucidated. In this study, miRNA expression profiling was performed to screen the miRNA expression changes in 8 NPC tissues and 4 normal nasopharyngeal tissues. Thirty-four miRNAs were identified to be differentially expressed; of these, one miRNA (miR-18a) was overexpressed and 33 miRNAs (miR-34b, miR-34c, let-7 family, etc.) were underexpressed in NPC tissues compared to the normal samples. Validation was performed by real-time quantitative PCR for two altered miRNAs (miR-34b and let-7g) and one non-differentially expressed miRNA (miR-30c). Unsupervised hierarchical clustering analysis showed that the aberrant miRNAs were correlated with the clinical stage of NPC patients. In addition to several biological pathways that are well characterised in NPC and which were significantly targeted by the underexpressed miRNAs, two novel pathways, nervous system development and sensory perception of sound, were identified to be strongly associated with NPC development. Furthermore, a c-Myc centered miRNA regulatory network was inferred in NPC. Our study reveals that aberrantly expressed miRNAs play important roles in NPC tumorigenesis and may serve as potential targets for novel therapeutic strategies in the future.     

MicroRNAs in body fluids--the mix of hormones and biomarkers

Since the discovery of microRNAs (miRNAs), the study of these small noncoding RNAs has steadily increased and more than 10,000 papers have already been published. The great interest in miRNAs reflects their central role in gene-expression regulation and the implication of miRNA-specific aberrant expression in the pathogenesis of cancer, cardiac, immune-related and other diseases. Another avenue of current research is the study of circulating miRNAs in serum, plasma, and other body fluids--miRNAs may act not only within cells, but also at other sites within the body. The presence of miRNAs in body fluids may represent a gold mine of noninvasive biomarkers in cancer. Since deregulated miRNA expression is an early event in tumorigenesis, measuring circulating miRNA levels may also be useful for early cancer detection, which can contribute greatly to the success of treatment. In this Review, we discuss the role of fluid-expressed miRNAs as reliable cancer biomarkers and treatment-response predictors as well as potential new patient selection criteria for clinical trials. In addition, we explore the concept that miRNAs could function as hormones.     

鼻咽癌放射抗拒相关microRNAs研究进展

鼻咽癌是一种起源于鼻咽部上皮组织的鳞状细胞恶性肿瘤,在东南亚和中国华南地区具有很高的发病率,目前放疗已成为鼻咽癌的首选治疗方式。放射抗拒是鼻咽癌放疗成功的主要障碍,寻找鼻咽癌放射抗拒相关的生物标志物,明确放射抗拒的产生机制,对治疗具有重大意义。MicroRNAs通过结合靶mRNA的3’UTR 从而诱导其翻译抑制或降解,调节蛋白的表达,参与放疗反应相关的所有重要的细胞过程如DNA损伤反应与修复、细胞凋亡、增殖以及血管生成的调节。近年来鼻咽癌放射抗拒相关microRNAs的研究成为热点,本文就microRNAs及其潜在的作用机制进行综述。