Prognostic significance of serum miR-17-5p in lung cancer

miRNA detection methods and clinical implications in lung cancer

Lung cancer is the leading cause of cancer death worldwide. Therefore, advances in the diagnosis and treatment of the disease are urgently needed. miRNAs are a family of small, noncoding RNAs that regulate gene expression at the transcriptional level. miRNAs have been reported to be deregulated and to play a critical role in different types of cancer, including lung cancer. Thus, miRNA profiling in lung cancer patients has become the core of several investigations. To this end, the development of a multitude of platforms for miRNA profiling analysis has been essential. This article focuses on the different technologies available for assessing miRNAs and the most important results obtained to date in lung cancer.

Prognostic and predictive biomarkers in early stage NSCLC: CTCs and serum/plasma markers

Resection of early stage non-small cell lung cancer (NSCLC) offers patients the best hope of cure, however recurrence rates post-resection remain high suggesting the presence of micro-metastatic disease at the time of surgery undetected by standard staging methods. A critical step in the metastatic cascade is the entry of tumor cells into the circulation enabling their distribution to and seeding of distant organs. This review explores the evidence for predictive and prognostic circulating biomarkers in the early stage NSCLC population. We summarize studies that have explored a variety of targets including circulating proteins, nucleic acids and more recently circulating tumor cells (CTCs) as potentially clinically relevant biomarkers in the early stage setting. Circulating biomarkers may add clinically relevant information about the biological behavior of tumors over and above that provided by pathological staging. Improvement in the stratification of patients according to the likelihood of metastatic relapse after radical treatments such as surgical resection could allow more effective targeting of systemic therapies such as adjuvant chemotherapy.

The oncogenic and prognostic potential of eight microRNAs identified by a synergetic regulatory network approach in lung cancer

Transcription factors (TFs) and microRNAs (miRNAs), the two main gene regulators in the biological system, control the gene expression at the transcriptional and post-transcriptional level, respectively. However, little is known regarding whether the miRNATF co-regulatory mechanisms, predicted by several studies, truly reflect the molecular interactions in cellular systems. To tackle this important issue, we developed an integrative framework by utilising four independent miRNA and matched mRNA expression profiling datasets to identify reproducible regulations, and demonstrated this approach in non-small cell lung cancer (NSCLC). Our analyses pinpointed several reproducible miRNA-TF co-regulatory networks in NSCLC from which we systematically prioritised eight hub miRNAs that may have strong oncogenic characteristics. Here, we discussed the major findings of our study and explored the oncogenic and prognostic potential of eight prioritised miRNAs through literature-mining based analysis and patient survival analysis. The findings provide additional insights into the miRNA-TF co-regulation in lung cancer.

MicroRNAs as biomarkers in pituitary tumors

The use of extracellular microRNAs (miRNAs) as circulating biomarkers is currently leading to relevant advances in the diagnosis and assessment of prognosis of several diseases. Specific miRNAs have also been shown to play a role in the pathophysiology of many neoplastic and non-neoplastic diseases. A number of studies have demonstrated that miRNAs show differential expression in various tumors, such as in the prostate, ovary, lung, breast, brain, and pituitary. Recent findings have built connections between miRNAs that are deregulated within the tumor and their presence in peripheral blood. MiRNAs have been shown to be stable in the blood where they are present in either free and/or uncomplexed form, as well as packed in microvesicles, exosomes, and apoptotic bodies, or bound to different proteins. Because the pituitary is a highly vascularized organ that releases hormones into the circulation, miRNAs would be useful biomarkers for the diagnosis of pituitary tumors, as well as for predicting or detecting recurrence after surgery. Here we review the biological significance of miRNAs in pituitary tumors and the potential value of circulating miRNAs as biomarkers.

Prognostic implications for high expression of MiR-25 in lung adenocarcinomas of female non-smokers

BACKGROUND

Adenocarcinoma (ADC) is the most common histological type of lung cancer and its proportion is rising, especially in Asian non-smoking women. Recent studies suggest miR-25 may have diverse effects on the pathogenesis of different types of cancer. However, the role of miR-25 in lung cancer is still unknown. The aim of this study was to investigate the potential clinical value of miR-25 in non-smoking women with lung ADC.

PATIENTS AND METHODS

Quantitative RT-PCR was performed to evaluate the expression of miR-25 in 100 lung ADC tumor tissues and matched plasma samples and Pearson correlation tests were used to analyze the relationship between values. Associations of miR-25 expression with clinicopathological features were determined using the Student's t-test. To determine prognostic value, overall survival (OS) was evaluated using the Kaplan-Meier method. Univariate and multivariate analyses were performed using the Cox proportional hazard model.

RESULTS

Expression of miR-25 in tissue was found to be associated with lymph node metastasis (P=0.021) and disease stage (P=0.012). Moreover, high miR-25 expression was also associated with poorer overall survival of women with lung ADC (P=0.008).

CONCLUSION

Tissue miR-25 expression may be associated with tumor progression and have prognostic implications in female lung ADC patients.

Upregulation of miR-301a correlates with poor prognosis in triple-negative breast cancer

Identification of biomarkers is important not only for cancer diagnosis, prognosis and treatment, but also provides new insight into cancer biology. The aim of this study was to evaluate the clinical significance of miR-301a in patients with triple-negative breast cancer (TNBC). The expression level of miR-301a was examined by quantitative reverse transcription polymerase chain reaction in 118 pairs of TNBC and adjacent noncancerous tissues. The relationships between miR-301a expression and clinical features, and prognosis of patients with TNBC were analyzed. miR-301a was upregulated in cancer tissues compared with adjacent noncancerous tissues. Furthermore, the level of miR-301a was positively correlated with tumor size, depth of invasion, TNM stage and LNM. High miR-301a expression was significantly associated with larger tumor size and LNM. Multivariate analysis suggested that miR-301a expression was an independent prognostic factor for the survival of patients with TNBC, and the effect remained significant after further stratified by clinical features. In conclusion, miR-301a may be involved in the progression of TNBC and has strong potential to serve as a biomarker for the prognosis of TNBC.

Serum levels of miR-19b and miR-146a as prognostic biomarkers for non-small cell lung cancer

MicroRNA (miRNA) is a type of small non-coding RNA molecule that has important roles in cancer initiation, promotion and progression by negatively regulating gene expression. In this study, we explored the role of miRNAs in the prognosis of patients with non-small cell lung cancer (NSCLC). The miRNA expression profiles were determined in 5 pairs of NSCLC and paracancerous tissues (3 adenocarcinomas and 2 squamous cell carcinomas). Aberrantly expressed miRNAs were validated by quantitative real-time PCR (qRT-PCR) in 61 pairs of NSCLC and paracancerous tissues. Differentially expressed miRNAs were further analyzed in sera from 94 healthy subjects and 94 advanced NSCLC patients receiving platinum-based chemotherapy. Three miRNAs (miR-19b, miR-146a, and miR-223) were significantly dysregulated in NSCLC tissues (P < 0.05). High miR-19b and low miR-146a expression in NSCLC tissues were associated with higher TNM stage, lymph node metastasis and poorer survival (P < 0.05). The serum levels of miR-19b in NSCLC patients were significantly higher (P < 0.001), whereas serum levels of miR-146a were significantly lower (P < 0.001), compared with those in controls. Serum levels of miR-19b and miR-146a were associated with overall survival of NSCLC patients (P < 0.05). Patients with low serum level of miR-19b and high serum level of miR-146a achieved a higher overall response rate and longer survival time (P < 0.05). These data suggest that miR-19b and miR-146a are potential biomarkers for the prediction of survival and response to chemotherapy in NSCLC.

miRNAs as non-invasive biomarkers for lung cancer diagnosis

Lung cancer is a leading cause of cancer death and late diagnosis is one of the most important reasons for the high mortality rate. Circulating microRNAs (miRNAs) represent stable and reproducible markers for numerous solid tumors, including lung cancer, and have been hypothesized as non-invasive diagnostic markers. Serum, plasma or whole peripheral blood can be used as starting material, and several methodological approaches have been proposed to evaluate miRNA expression. The present review provides an in depth summary of current knowledge on circulating miRNAs in different types of biological samples used as diagnostic markers of lung cancer. We also evaluate the diagnostic accuracy of each miRNA or group of miRNAs in relation to the different housekeeping miRNAs used. Finally, the limitations and potential of miRNA analysis are discussed.

The miR-17/92 cluster: a comprehensive update on its genomics, genetics, functions and increasingly important and numerous roles in health and disease

The miR-17/92 cluster is among the best-studied microRNA clusters. Interest in the cluster and its members has been increasing steadily and the number of publications has grown exponentially since its discovery with more than 1000 articles published in 2012 alone. Originally found to be involved in tumorigenesis, research work in recent years has uncovered unexpected roles for its members in a wide variety of settings that include normal development, immune diseases, cardiovascular diseases, neurodegenerative diseases and aging. In light of its ever-increasing importance and ever-widening regulatory roles, we review here the latest body of knowledge on the cluster's involvement in health and disease as well as provide a novel perspective on the full spectrum of protein-coding and non-coding transcripts that are likely regulated by its members.

The role of miRNAs in cancer: from pathogenesis to therapeutic implications

ABSTRACT: 

Cancer is still one of the dominating causes of deaths worldwide, although there have been important enhancements for detection and diagnosis of cancer recently. miRNAs are shown to participate in carcinogenesis of several types of tumors and their aberrant expression of miRNAs has been detected in cell lines, xenografts and clinical samples. miRNAs are thought to target and modulate the expression of more than 60% of human genes, which makes the expressional regulation by miRNAs the most abundant post-transcriptional regulation mode. Here, we have reviewed the most current literature to shed a light on the functions of miRNAs on human carcinogenesis. Possible roles of miRNAs in oncogenesis through both genetic and epigenetic changes occurring during cancer initiation, progression, invasion or metastasis are summarized.

Prognostic role of microRNA polymorphisms in patients with advanced esophageal squamous cell carcinoma receiving platinum-based chemotherapy

PURPOSE

MicroRNA (miRNA) polymorphisms contribute to cancer susceptibility and prognosis. The aim of this study was to evaluate the effects of miRNA polymorphisms on clinical outcomes in patients with advanced esophageal squamous cell carcinoma (ESCC) treated with platinum-based chemotherapy.

METHODS

Five polymorphisms (miR-146a rs2910164, miR-196a2 rs11614913, miR-100 rs1834306, miR-125a rs12976445 and miR-26a1 rs7372209) were genotyped in 378 patients with advanced ESCC recruited at Zhongshan Hospital. The associations between genotypes and drug response, toxicity, and overall survival were analyzed.

RESULTS

miR-146a rs2910164 was significantly associated with an increased risk of severe hematological toxicity [odds ratio = 0.374, 95 % confidence interval (CI) 0.171-0.819, P = 0.014]. The TT genotypes of both miR-196a2 rs11614913 and miR-125a rs12976445 were associated with worse survival [hazard ratio (HR) = 1.552, 95 % CI 1.112-2.165, P = 0.010; HR = 2.171, 95 % CI 1.173-4.017, P = 0.014, respectively]. Combined analysis revealed a 4.073-fold increased risk of death in patients carrying two unfavorable genotypes (P = 0.002).

CONCLUSIONS

Taken together, these findings indicate that miRNA polymorphisms may predict prognosis in advanced ESCC patients receiving platinum-based chemotherapy.

Circulating microRNAs in relation to EGFR status and survival of lung adenocarcinoma in female non-smokers

Objectives

Lung adenocarcinoma is considered a unique disease for Asian female non-smokers. We investigated whether plasma microRNA (miRNA) expression profiles are different by the EGFR status and are associated with survival outcomes of the patients.

Methods

Using real-time RT-PCR, we analyzed the expression of 20 miRNAs in the plasma of 105 female patients with lung adenocarcinoma. Kaplan-Meier survival analysis and Cox proportional hazards regression were performed to determine the association between miRNA expression and overall survival. Time dependent receiver operating characteristic (ROC) analysis was also performed.

Results

In the 20 miRNAs, miR-122 were found differently expressed between wild and mutant EGFR carriers (P=0.018). Advanced disease stage and tumor metastasis were independently associated with poor prognosis of patients with lung adenocarcinoma (P=0.010 and 1.0×10^-4). Plasma levels of miR-195 and miR-122 expression were also associated with overall survival in the patients, especially in those with advanced stage (HR=0.23, 95%CI:0.07-0.84; and HR=0.22, 95%CI:0.06-0.77) and EGFR mutation (HR=0.27, 95%CI:0.08-0.96; and HR=0.23, 95%CI=0.06-0.81). Moreover, a model including miR-195, miR-122 may predict survival outcomes of female patients with lung adenocarcinoma (AUC=0.707).

Conclusions

Circulating miR-195 and miR-122 may have prognostic values in predicting the overall survival as well as predicting EGFR mutation status in non-smoking female patients with lung adenocarcinoma. Measuring plasma levels of miR-195 and miR-122 may especially be useful in EGFR mutant patients with lung adenocarcinoma.