Circulating long non-coding HOX transcript antisense intergenic ribonucleic acid in plasma as a potential biomarker for diagnosis of breast cancer

lncRNA Biomarkers of Glioblastoma Multiforme

Long noncoding RNAs (lncRNAs) are RNA molecules of 200 nucleotides or more in length that are not translated into proteins. Their expression is tissue-specific, with the vast majority involved in the regulation of cellular processes and functions. Many human diseases, including cancer, have been shown to be associated with deregulated lncRNAs, rendering them potential therapeutic targets and biomarkers for differential diagnosis. The expression of lncRNAs in the nervous system varies in different cell types, implicated in mechanisms of neurons and glia, with effects on the development and functioning of the brain. Reports have also shown a link between changes in lncRNA molecules and the etiopathogenesis of brain neoplasia, including glioblastoma multiforme (GBM). GBM is an aggressive variant of brain cancer with an unfavourable prognosis and a median survival of 14-16 months. It is considered a brain-specific disease with the highly invasive malignant cells spreading throughout the neural tissue, impeding the complete resection, and leading to post-surgery recurrences, which are the prime cause of mortality. The early diagnosis of GBM could improve the treatment and extend survival, with the lncRNA profiling of biological fluids promising the detection of neoplastic changes at their initial stages and more effective therapeutic interventions. This review presents a systematic overview of GBM-associated deregulation of lncRNAs with a focus on lncRNA fingerprints in patients' blood.

Harnessing the potential of long non-coding RNAs in breast cancer: from etiology to treatment resistance and clinical applications

Breast cancer (BC) is the most common malignancy among women and a leading cause of cancer-related deaths of females worldwide. It is a complex and molecularly heterogeneous disease, with various subtypes that require different treatment strategies. Despite advances in high-resolution single-cell and multinomial technologies, distant metastasis and therapeutic resistance remain major challenges for BC treatment. Long non-coding RNAs (lncRNAs) are non-coding RNAs with more than 200 nucleotides in length. They act as competing endogenous RNAs (ceRNAs) to regulate post-transcriptional gene stability and modulate protein-protein, protein-DNA, and protein-RNA interactions to regulate various biological processes. Emerging evidence suggests that lncRNAs play essential roles in human cancers, including BC. In this review, we focus on the roles and mechanisms of lncRNAs in BC progression, metastasis, and treatment resistance, and discuss their potential value as therapeutic targets. Specifically, we summarize how lncRNAs are involved in the initiation and progression of BC, as well as their roles in metastasis and the development of therapeutic resistance. We also recapitulate the potential of lncRNAs as diagnostic biomarkers and discuss their potential use in personalized medicine. Finally, we provide lncRNA-based strategies to promote the prognosis of breast cancer patients in clinical settings, including the development of novel lncRNA-targeted therapies.

Colorectal cancer: Genetic alterations, novel biomarkers, current therapeutic strategies and clinical trials

Colorectal cancer (CRC) is the third most commonly detected cancer with a serious global health issue. The rates for incidence and mortality for CRC are alarming, especially since the prognosis is abysmal when the CRC is diagnosed at an advanced or metastatic stage. Both type of (modifiable/ non-modifiable) types of risk factors are established for CRC. Despite the advances in recent technology and sophisticated research, the survival rate is still meager due to delays in diagnosis. Therefore, there is urgently required to identify critical biomarkers aiming at early diagnosis and improving effective therapeutic strategies. Additionally, a complete understanding of the dysregulated pathways like PI3K/Akt, Notch, and Wnt associated with CRC progression and metastasis is very beneficial in designing a therapeutic regimen. This review article focused on the dysregulated signaling pathways, genetics and epigenetics alterations, and crucial biomarkers of CRC. This review also provided the list of clinical trials targeting signaling cascades and therapies involving small molecules. This review discusses up-to-date information on novel diagnostic and therapeutic strategies alongside specific clinical trials.

Association of HOTAIR gene rs920778 (C > T) and rs4759314 (A > G) polymorphism with breast cancer in Egyptian women

BACKGROUND

Hox transcript antisense RNA (HOTAIR) is considered an oncogene associated with the initiation and progression of many malignancies. Previous studies have examined the connection between HOTAIR SNPs rs4759314 and rs920778 for breast cancer (BC), getting variable results in multiple ethnicities. Therefore, this study was designed to evaluate the connection between these two SNPs and disease vulnerability, clinic-laboratory, and hormonal parameters, featuring status associations with the BC risk in an Egyptian woman sample.

METHODS AND RESULTS

In this case-control study, DNA was taken from the blood of 100 BC patients and 100 unrelated healthy Egyptian females. The characterization of rs4759314 was genotyped using the T-ARMS-PCR method and rs920778 using the SNP-RFLP technique for all participants. The frequency of the rs4759314 A > G variation revealed a statistically significant increase in BC risk with dominant (p = 0.013, OR = 1.592, 95% Cl = 1.105-2.293), co-dominant (p = 0.006, OR = 2.314, 95%Cl = 1.278-4.191) and overdominant (p = 0.002, OR = 2.571, 95% Cl = 1.430-4.624) genetic models. On the other hand, the rs920778 C > T polymorphism was not significantly associated with BC. ER/PR positivity with HER2 negativity was significantly associated with the AA genotype compared to the AG genotype. Otherwise, no significant associations between the two SNPs and clinical stage or hormonal features could be found. In conclusion, the rs4759314 A > G SNP in the HOTAIR gene is strongly associated with BC, which might warrant its determination among affected families for prevention and early treatment.

miRNA-1246, HOTAIR, and IL-39 signature as potential diagnostic biomarkers in breast cancer

The molecular alterations in noncoding RNA can lead to a cellular storm that is correlated to higher mortality and morbidity rates and contributes to the progression and metastasis of cancer. Herein, we aim to evaluate the expression levels and correlations of microRNA-1246 (miR-1246), HOX transcript antisense RNA (HOTAIR), and interleukin-39 (IL-39) in patients with breast cancer (BC). In this study, 130 participants were recruited, including 90 breast cancer patients and 40 healthy control participants. Serum levels of miR-1246 and HOTAIR expression were assessed by quantitative real-time polymerase chain reaction (qRT-PCR). Also, the level of IL-39 expression was evaluated using a Western blot. All BC participants demonstrated a remarkable elevation in miR-1246 and HOTAIR expression levels. Moreover, IL-39 expression levels demonstrated a noticeable decline in BC patients. Furthermore, the differential expression fold of miR-1246 and HOTAIR revealed a strong positive correlation among breast cancer patients. In addition, a negative relationship between the IL-39 and the miR-1246 and HOTAIR differential expression was also noticed. This study revealed that HOTAIR/miR-1246 exerts an oncogenic impact in patients with breast cancer. The expression levels of circulation miR-1246, HOTAIR, and IL-39 could be considered early diagnostic biomarkers in BC patients.

Discovery and Validation of Clinically Relevant Long Non-Coding RNAs in Colorectal Cancer

Simple Summary

Recent efforts in biomedical research have focused on the identification of molecular biomarkers to improve the diagnosis, prognosis and eventually treatment of the most common human diseases worldwide, including cancer. In this context, a large number of studies point to a pivotal role of long non-coding RNAs (lncRNAs) in the pathophysiology of carcinogenesis, suggesting diagnostic or therapeutic potential. However, for most of them, supporting evidence is scarce and often based on a single large-scale analysis. Here, focusing on colorectal cancer (CRC), we present an overview of the main approaches for discovering and validating lncRNA candidate molecules, and provide a curated list of the most promising lncRNAs associated with this malignancy.

Abstract

Colorectal cancer (CRC) is the third most prevalent cancer worldwide, with nearly two million newly diagnosed cases each year. The survival of patients with CRC greatly depends on the cancer stage at the time of diagnosis, with worse prognosis for more advanced cases. Consequently, considerable effort has been directed towards improving population screening programs for early diagnosis and identifying prognostic markers that can better inform treatment strategies. In recent years, long non-coding RNAs (lncRNAs) have been recognized as promising molecules, with diagnostic and prognostic potential in many cancers, including CRC. Although large-scale genome and transcriptome sequencing surveys have identified many lncRNAs that are altered in CRC, most of their roles in disease onset and progression remain poorly understood. Here, we critically review the variety of detection methods and types of supporting evidence for the involvement of lncRNAs in CRC. In addition, we provide a reference catalog that features the most clinically relevant lncRNAs in CRC. These lncRNAs were selected based on recent studies sorted by stringent criteria for both supporting experimental evidence and reproducibility.

Genetic variants of HOTAIR are associated with susceptibility to recurrent spontaneous abortion: A preliminary case-control study

AIM

To investigate the association between Hox transcript antisenses RNA (HOTAIR) polymorphisms, rs12826786 C/T, rs920778 T/C, rs4759314 A/G, and rs1899663 G/T, with recurrent spontaneous abortion (RSA) susceptibility in the Iranian women.

METHODS

We enrolled 161 patients diagnosed with RSA and 177 healthy women with at least one live birth without a history of abortion. Genotyping of HOTAIR polymorphisms was carried out using both restriction fragment length polymorphism-polymerase chain reaction and amplification refractory mutation system-polymerase chain reaction methods. Odds ratios (ORs) with 95% confidence intervals (CIs) were assessed to estimate the strength of association.

RESULTS

Different inheritance models of rs12826786 C/T, rs920778 T/C, and rs1899663 G/T polymorphisms significantly enhanced the risk of RSA (p < 0.05), whereas the rs4759314 A/G polymorphism was correlated with diminished risk of developing RSA under recessive AA versus GA + GG (OR 0.42 [95% CI = 0.19-0.91]), log-additive GG versus GA vs. GG (OR 0.67 [95% CI = 0.48-0.93]), and allelic A versus G (OR 0.65 [95% CI = 0.47-0.92]) models. Moreover, the TGTC, TTCT, TTTC, CGTC, CGTT, CTCC, CTCT, CTTC, and CTTT haplotypes of rs920778/rs1899663/rs12826786/ significantly increased the risk of RSA. The studied variants were not in strong linkage disequilibrium.

CONCLUSIONS

Our results indicated that variations in the HOTAIR gene might serve as beneficial biomarkers for determining susceptibility to RSA. To confirm these findings, replication studies with a larger population and different races are needed.

Non-coding Natural Antisense Transcripts: Analysis and Application

Non-coding natural antisense transcripts (ncNATs) are regulatory RNA sequences that are transcribed in the opposite direction to protein-coding or non-coding transcripts. These transcripts are implicated in a broad variety of biological and pathological processes, including tumorigenesis and oncogenic progression. With this complex field still in its infancy, annotations, expression profiling and functional characterisations of ncNATs are far less comprehensive than those for protein-coding genes, pointing out substantial gaps in the analysis and characterisation of these regulatory transcripts. In this review, we discuss ncNATs from an analysis perspective, in particular regarding the use of high-throughput sequencing strategies, such as RNA-sequencing, and summarize the unique challenges of investigating the antisense transcriptome. Finally, we elaborate on their potential as biomarkers and future targets for treatment, focusing on cancer.

Current Knowledge of Long Non-Coding RNA HOTAIR in Breast Cancer Progression and Its Application

Breast cancer is one of the most devastating cancers with high morbidity and mortality in females worldwide. Breast tumorigenesis and further development present great uncertainty and complexity, and efficient therapeutic approaches still lack. Accumulating evidence indicates HOX transcript antisense intergenic RNA (HOTAIR) is dysregulated in cancers and has emerged as a novel hotspot in the field. In breast cancer, aberrant HOTAIR expression is responsible for advanced tumor progression by regulating multifarious signaling pathways. Besides, HOTAIR may act as competitive endogenous RNA to bind to several microRNAs and suppress their expressions, which can subsequently upregulate the levels of targeted downstream messenger RNAs, thereby leading to further cancer progression. In addition, HOTAIR works as a promising biomarker and predictor for breast cancer patients’ diagnosis or outcome prediction. Recently, HOTAIR is potentially considered to be a drug target. Here, we have summarized the induction of HOTAIR in breast cancer and its impacts on cell proliferation, migration, apoptosis, and therapeutic resistance, as well as elucidating the underlying mechanisms. This review aims to provide new insights into investigations between HOTAIR and breast cancer development and inspire new methods for studying the association in depth.

Long non-coding RNAs in brain tumors: roles and potential as therapeutic targets

Brain tumors are associated with adverse outcomes despite improvements in radiation therapy, chemotherapy, and photodynamic therapy. However, treatment approaches are evolving, and new biological phenomena are being explored to identify the appropriate treatment of brain tumors. Long non-coding RNAs (lncRNAs), a type of non-coding RNA longer than 200 nucleotides, regulate gene expression at the transcriptional, post-transcriptional, and epigenetic levels and are involved in a variety of biological functions. Recent studies on lncRNAs have revealed their aberrant expression in various cancers, with distinct expression patterns associated with their instrumental roles in cancer. Abnormal expression of lncRNAs has also been identified in brain tumors. Here, we review the potential roles of lncRNAs and their biological functions in the context of brain tumors. We also summarize the current understanding of the molecular mechanisms and signaling pathways related to lncRNAs that may guide clinical trials for brain tumor therapy.

HOX transcript antisense RNA: An oncogenic lncRNA in diverse malignancies

HOX transcript antisense RNA (HOTAIR) is a transcript produced from the antisense strand of the HOXC gene cluster and influencing expression of genes from the HOXD locus. HOTAIR has prominent roles in different aspects of carcinogenic process from cancer initiation to metastasis. A number of in vitro, in vivo and human investigations have confirmed the oncogenic impacts of HOTAIR. The diagnostic power of HOTAIR in distinguishing cancer status from healthy status has been optimal in gastric cancer, pancreatic adenocarcinoma and colorectal cancer. The most important achievement in this regard has been provided by studies that verified diagnostic value of this lncRNA in the serum samples, potentiating its application in non-invasive diagnosis of cancer. Moreover, HOTAIR has a crucial role in determination of response of cancer cells to therapeutic modalities. The current review aims to explain the outlines of these studies to emphasize its potential as a biomarker and therapeutic target for these conditions.

LncRNA SPINT1-AS1 promotes breast cancer proliferation and metastasis by sponging let-7 a/b/i-5p

BACKGROUND

A growing number of studies have shown that long non-coding RNAs (lncRNAs) play an important role in the occurrence and development of tumors. In this study, we explored the function and molecular mechanism of lncRNA SPINT1-AS1 in breast cancer progression.

METHODS

A total of 30 patients and 25 healthy controls were enrolled to detect the expression of SPINT1-AS1 in the serum by RT-qPCR. CCK-8 assay, clone formation assay, EdU assay, Transwell assay, Flow cytometry for apoptosis assay and wound healing assays were used to explore the effects of SPINT1-AS1 on the proliferation and migration of breast cancer cells. Bioinformatics analysis were used to enrich the downstream target genes and related pathways of miRNAs interacting with SPINT1-AS1, construct a competitive endogenous RNA (ceRNA) network diagram.

RESULTS

SPINT1-AS1 is up-regulated in the serum of breast cancer patients and breast cancer cell lines. The proliferation and migration ability of breast cancer cells were decreased significantly after SPINT1-AS1 knockdown, and it may inhibit its expression by sponging miR-let-7a/b/i-5p, thereby promoting breast cancer progression.

CONCLUSIONS

SPINT1-AS1 can promote the proliferation and migration of breast cancer cells by regulating miR-let-7a/b/i-5p, suggesting that it may be an important regulator of breast cancer progression.

Unleash multifunctional role of long noncoding RNAs biomarker panel in breast cancer: a predictor classification model

Aim: We aimed to explore the circulating expression profile of nine lncRNAs (MALAT1, HOTAIR, PVT1, H19, ROR, GAS5, ANRIL, BANCR, MIAT) in breast cancer (BC) patients relative to normal and risky individuals. Methods: Serum relative expressions of the specified long non-coding RNAs were quantified in 155 consecutive women, using quantitative reverse-transcription PCR. Random Forest (RF) and decision tree were also applied. Results: Significant MALAT1 upregulation and GAS5 downregulation could discriminate risky women from healthy controls. Overexpression of the other genes showed good diagnostic performances. Lower GAS5 levels were associated with metastasis and recurrence. RF model revealed a better performance when combining gene expression patterns with risk factors. Conclusion: The studied panel could be utilized as diagnostic/prognostic biomarkers in BC, providing promising epigenetic-based therapeutic targets.

Coding of Glioblastoma Progression and Therapy Resistance through Long Noncoding RNAs

Glioblastoma is the most aggressive and lethal primary brain malignancy, with an average patient survival from diagnosis of 14 months. Glioblastoma also usually progresses as a more invasive phenotype after initial treatment. A major step forward in our understanding of the nature of glioblastoma was achieved with large-scale expression analysis. However, due to genomic complexity and heterogeneity, transcriptomics alone is not enough to define the glioblastoma “fingerprint”, so epigenetic mechanisms are being examined, including the noncoding genome. On the basis of their tissue specificity, long noncoding RNAs (lncRNAs) are being explored as new diagnostic and therapeutic targets. In addition, growing evidence indicates that lncRNAs have various roles in resistance to glioblastoma therapies (e.g., MALAT1, H19) and in glioblastoma progression (e.g., CRNDE, HOTAIRM1, ASLNC22381, ASLNC20819). Investigations have also focused on the prognostic value of lncRNAs, as well as the definition of the molecular signatures of glioma, to provide more precise tumor classification. This review discusses the potential that lncRNAs hold for the development of novel diagnostic and, hopefully, therapeutic targets that can contribute to prolonged survival and improved quality of life for patients with glioblastoma.

A panel of circulating long non-coding RNAs as liquid biopsy biomarkers for breast and cervical cancers

The early detection and diagnosis of cancer is critical to optimize the treatment and management of cancer patients. Typical methods such as imaging and tissue biopsy are invasive, time-consuming, and often imprecise. Thus, recent technological advances of dependable, facile, and minimally invasive collectible oncogenic biomarkers using human biofluids and secretions have been an active area of research. Recently, circulating long non-coding RNAs (lncRNAs) have been identified as promising biomarkers that fulfill many recommended properties of successful biomarkers for cancer diagnosis and prognosis. LncRNAs play essential roles in many cellular processes including DNA repair, cell proliferation, and epithelial-to-mesenchymal transition (EMT) by regulating the expression of various genes associated with cancer development and progression. Herein, we discuss the regulatory functions/pathways associated with multiple cancer-associated lncRNAs and their potential as prognostic/diagnostic markers for breast and cervical cancers. Additionally, we provide a correlation between lncRNA levels in the blood and clinicopathological data, including sensitivity, specificity, and Area Under Curve (AUC) merits of model performance value.

Long Noncoding RNA Serve as a Potential Predictive Biomarker for Breast Cancer: A Meta-Analysis

Purpose

The detection of long noncoding RNA (lncRNA) is a novel method for breast cancer diagnosis. The purpose of this meta-analysis was to evaluate the clinical significance of lncRNAs in identification of human breast cancer.

Methods

Electronic databases, including PubMed (176), EMBASE (167), Cochrane Library (4), Web of Science (273), CNKI (41), VIP (18), and wanfang (21), were searched for relevant original articles. Diagnostic capacity of lncRNAs was assessed by pooled sensitivity and specificity, area under the summary receiver operating characteristic curve (AUC), diagnostic odds ratio (DOR), and subgroup and meta-regression analysis. Stata and Meta-Disc software were used to conduct the meta-analysis.

Results

33 articles including 4500 cases were identified in our meta-analysis. lncRNAs sustained a high diagnostic efficacy; the pooled sensitivity, specificity, AUC, and DOR of lncRNAs in differentiating BC from controls were 0.74 (95% CI: 0.69-0.78), 0.78 (95% CI: 0.72-0.83), 0.82 (95% CI: 0.79-0.85), and 10.01 (95% CI: 7.13-14.06), respectively. The subgroup analysis showed that the diagnostic efficacy of lncRNAs in Asian populations was higher than that in Caucasians; lncRNAs in BC were lower than those in TNBC and were higher in plasma and serum specimens than in tissues. In addition, heterogeneity was clearly apparent but was not caused by the threshold effect.

Conclusion

This meta-analysis suggested that lncRNAs might be promising biomarkers for identifying breast cancer, and its clinical application warrants further investigation.

Long Non-Coding RNA HOTAIR in Breast Cancer Therapy

Breast cancer (BC) is the most common cancer type among women, and morbidity and mortality rates are still very high. Despite new innovative therapeutic approaches for all BC molecular subtypes, the discovery of new molecular biomarkers involved in tumor progression has been fundamental for the implementation of personalized treatment strategies and improvement of patient management. Many experimental studies indicate that long non-coding RNAs (lncRNAs) are strongly involved in BC initiation, metastatic progression, and drug resistance. In particular, aberrant expression of HOX transcript antisense intergenic RNA (HOTAIR) lncRNA plays an important role in BC contributing to its progression and represents a predictor of BC metastasis. For its proven prognostic value, HOTAIR could represent a potential therapeutic target in BC. In the present review, we summarize the role of HOTAIR in cancer progression and drug resistance, in particular in BC, and we illustrate the main approaches for silencing it.

Diagnostic value of HOX transcript antisense RNA for cancer detection: a meta-analysis

Aim: Numerous studies have investigated the diagnostic role of long noncoding RNA HOX transcript antisense RNA in cancers, but its diagnostic efficacy is inconsistent. Methods: The PubMed, Embase, Web of Science and Cochrane Library databases are used to retrieve relevant studies. The bivariate effect model was used to compute the combined sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, diagnostic odds ratio and area under the receiver operating characteristic curve. Results: A total of 13 studies were included in this meta-analysis. The combined sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, diagnostic odds ratio and area under the receiver operating characteristic curve were: 0.77, 0.83, 4.7, 0.28, 17 and 0.87, respectively. Deeks' funnel plot test (p = 0.103) indicated no publication bias. Conclusion: Long noncoding RNA HOX transcript antisense RNA may be a useful biomarker for cancer detection.

Diagnostic roles of HOX transcript antisense intergenic RNA in cancer

HOX transcript antisense intergenic RNA (HOTAIR) is considered a diagnostic biomarker for cancer; however, results of previous studies on HOTAIR are inconsistent. In this meta-analysis, we aimed to investigate the role of HOTAIR in cancer diagnosis. Medline, PubMed, Embase, Ovid, Web of Science and Cochrane databases were searched for relevant literature up to May 2019. Over all, we included 20 studies from 17 articles on the role of HOTAIR in cancer diagnosis (individual diagnosis) and 7 studies from 6 articles on the role of HOTAIR along with other biomarkers in cancer diagnosis (combinative diagnosis). The sensitivity and specificity of HOTAIR-mediated individual diagnosis of cancers were 0.80 (95% confidence interval [CI], 0.74-0.85) and 0.74 (95% CI, 0.66-0.81), respectively. The sensitivity and specificity of HOTAIR-mediated combinative diagnosis of cancer were 0.82 (95% CI, 0.77-0.87) and 0.86 (95% CI, 0.80-0.91), respectively. The areas under the receiver operating characteristic curve for individual and combinative diagnoses was 0.84 (95% CI, 0.81-0.87) and 0.91 (95% CI, 0.88-0.93), respectively, indicating that a combinative diagnosis has a relatively better diagnostic accuracy (z = -2.22, P = 0.01) than individual diagnosis. In conclusion, HOTAIR levels might be a promising biomarker in cancer diagnosis. In addition, using HOTAIR in combination with other biomarkers showed a relatively better diagnostic accuracy than HOTAIR alone.

Does HOTAIR expression level in the peripheral blood have veritably predictive/prognostic impact on breast cancer patients?

As a peripheral blood biomarker, the crucial role of long non-coding RNA (lncRNA) HOTAIR has recently been suggested in many types of disorder. Among these reports, few investigations have indicated overexpression of HOTAIR transcript in the breast cancer patients' peripheral blood. In this regard, we studied the potential impact of radiotherapy on the peripheral blood HOTAIR expression of different breast cancer patients. Curiously, no significant expression level of HOTAIR was determined in the breast cancer patients' peripheral blood, before and after radiotherapy (10 Gy exposure). Deliberating these investigations raised some debates on the specificity of the utilized methods, the corresponding obtained findings and impact of HOTAIR expression on breast cancer predication, as a potential peripheral blood biomarker, which is discussed in this article.

Long Non-Coding RNA in the Pathogenesis of Cancers

The incidence and mortality rate of cancer has been quickly increasing in the past decades. At present, cancer has become the leading cause of death worldwide. Most of the cancers cannot be effectively diagnosed at the early stage. Although there are multiple therapeutic treatments, including surgery, radiotherapy, chemotherapy, and targeted drugs, their effectiveness is still limited. The overall survival rate of malignant cancers is still low. It is necessary to further study the mechanisms for malignant cancers, and explore new biomarkers and targets that are more sensitive and effective for early diagnosis, treatment, and prognosis of cancers than traditional biomarkers and methods. Long non-coding RNAs (lncRNAs) are a class of RNA transcripts with a length greater than 200 nucleotides. Generally, lncRNAs are not capable of encoding proteins or peptides. LncRNAs exert diverse biological functions by regulating gene expressions and functions at transcriptional, translational, and post-translational levels. In the past decade, it has been demonstrated that the dysregulated lncRNA profile is widely involved in the pathogenesis of many diseases, including cancer, metabolic disorders, and cardiovascular diseases. In particular, lncRNAs have been revealed to play an important role in tumor growth and metastasis. Many lncRNAs have been shown to be potential biomarkers and targets for the diagnosis and treatment of cancers. This review aims to briefly discuss the latest findings regarding the roles and mechanisms of some important lncRNAs in the pathogenesis of certain malignant cancers, including lung, breast, liver, and colorectal cancers, as well as hematological malignancies and neuroblastoma.

Role of epigenetics in transformation of inflammation into colorectal cancer

Molecular mechanisms associated with inflammation-promoted tumorigenesis have become an important topic in cancer research. Various abnormal epigenetic changes, including DNA methylation, histone modification, chromatin remodeling, and noncoding RNA regulation, occur during the transformation of chronic inflammation into colorectal cancer (CRC). These changes not only accelerate transformation but also lead to cancer progression and metastasis by activating carcinogenic signaling pathways. The NF-κB and STAT3 signaling pathways play a particularly important role in the transformation of inflammation into CRC, and both are critical to cellular signal transduction and constantly activated in cancer by various abnormal changes including epigenetics. The NF-κB and STAT3 signals contribute to the microenvironment for tumorigenesis through secretion of a large number of pro-inflammatory cytokines and their crosstalk in the nucleus makes it even more difficult to treat CRC. Compared with gene mutation that is irreversible, epigenetic inheritance is reversible or can be altered by the intervention. Therefore, understanding the role of epigenetic inheritance in the inflammation-cancer transformation may elucidate the pathogenesis of CRC and promote the development of innovative drugs targeting transformation to prevent and treat this malignancy. This review summarizes the literature on the roles of epigenetic mechanisms in the occurrence and development of inflammation-induced CRC. Exploring the role of epigenetics in the transformation of inflammation into CRC may help stimulate futures studies on the role of molecular therapy in CRC.

Clinical utility of circulating non-coding RNAs - an update

Over the past decade, the amount of research and the number of publications on associations between circulating small and long non-coding RNAs (ncRNAs) and cancer have grown exponentially. Particular focus has been placed on the development of diagnostic and prognostic biomarkers to enable efficient patient management - from early detection of cancer to monitoring for disease recurrence or progression after treatment. Owing to their high abundance and stability, circulating ncRNAs have potential utility as non-invasive, blood-based biomarkers that can provide information on tumour biology and the effects of treatments, such as targeted therapies and immunotherapies. Increasing evidence highlights the roles of ncRNAs in cell-to-cell communication, with a number of ncRNAs having the capacity to regulate gene expression outside of the cell of origin through extracellular vesicle-mediated transfer to recipient cells, with implications for cancer progression and therapy resistance. Moreover, 'foreign' microRNAs (miRNAs) encoded by non-human genomes (so-called xeno-miRNAs), such as viral miRNAs, have been shown to be present in human body fluids and can be used as biomarkers. Herein, we review the latest developments in the use of circulating ncRNAs as diagnostic and prognostic biomarkers and discuss their roles in cell-to-cell communication in the context of cancer. We provide a compendium of miRNAs and long ncRNAs that have been reported in the literature to be present in human body fluids and that have the potential to be used as diagnostic and prognostic cancer biomarkers.

Serum long noncoding RNA HOTAIR as a novel diagnostic and prognostic biomarker in glioblastoma multiforme

Glioblastoma multiforme (GBM) is the most common and aggressive malignant adult primary brain tumor. Despite surgical resection followed by radiotherapy and chemotherapy, the median survival rate is approximately 14 months. Although experimental therapies are in clinical trials for GBM, there is an urgent need for a peripheral GBM biomarker for measuring treatment response. As we have previously demonstrated that the long noncoding RNA HOX Transcript Antisense Intergenic RNA, or HOTAIR, is dysregulated in GBM and required for GBM cell proliferation, we hypothesized that HOTAIR expression may be utilized as a peripheral biomarker for GBM. HOTAIR expression was measured in serum from 43 GBM and 40 controls using quantitative real-time PCR (qRT-PCR). The PCR products were subsequently subcloned into pCR™4-TOPO®TA vectors for DNA sequencing. A ROC curve was also generated to examine HOTAIR's prognostic value. The amount of HOTAIR in serum exosomes and exosome-depleted supernatant was calculated by qRT-PCR. The relative HOTAIR expression was also investigated in 15 pairs of GBM serum and tumors. We detected HOTAIR in serum from GBM patients. HOTAIR levels in serum samples from GBM patients was significantly higher than in the corresponding controls (P < 0.0001). The area under the ROC curve distinguishing GBM patients from controls was 0.913 (95% CI: 0.845-0.982, P < 0.0001), with 86.1% sensitivity and 87.5% specificity at the cut-off value of 10.8. HOTAIR expression was significantly correlated with high grade brain tumors. In addition, Pearson correlation analysis indicated a medium correlation of serum HOTAIR levels and the corresponding tumor HOTAIR levels (r = 0.734, P < 0.01). We confirmed via sequencing that the amplified HOTAIR from serum contained the HOTAIR sequence and maps to the known HOTAIR locus at 12q13. The serum-derived exosomes contain HOTAIR and the purified exosomes were validated by western blot and nanoparticle tracking analysis. Importantly, our results demonstrate that serum HOTAIR can be used as a novel prognostic and diagnostic biomarker for GBM.

Radiation-Induced Long Noncoding RNAs in a Mouse Model after Whole-Body Irradiation

Long noncoding RNAs (lncRNAs) are emerging as key molecules in regulating many biological processes and have been implicated in development and disease pathogenesis. Biomarkers of cancer and normal tissue response to treatment are of great interest in precision medicine, as well as in public health and medical management, such as for assessment of radiation injury after an accidental or intentional exposure. Circulating and functional RNAs, including microRNAs (miRNAs) and lncRNAs, in whole blood and other body fluids are potential valuable candidates as biomarkers. Early prediction of possible acute, intermediate and delayed effects of radiation exposure enables timely therapeutic interventions. To address whether long noncoding RNAs (lncRNAs) could serve as biomarkers for radiation biodosimetry we performed whole genome transcriptome analysis in a mouse model after whole-body irradiation. Differential lncRNA expression patterns were evaluated at 16, 24 and 48 h postirradiation in total RNA isolated from whole blood of mice exposed to 1, 2, 4, 8 and 12 Gy of X rays. Sham-irradiated animals served as controls. Significant alterations in the expression patterns of lncRNAs were observed after different radiation doses at the various time points. We identified several radiation-induced lncRNAs known for DNA damage response as well as immune response. Long noncoding RNA targets of tumor protein 53 (P53), Trp53cor1, Dino, Pvt1 and Tug1 and an upstream regulator of p53, Meg3, were altered in response to radiation. Gm14005 ( Morrbid) and Tmevpg1 were regulated by radiation across all time points and doses. These two lncRNAs have important potential as blood-based radiation biomarkers; Gm14005 ( Morrbid) has recently been shown to play a key role in inflammatory response, while Tmevpg1 has been implicated in the regulation of interferon gamma. Precise molecular biomarkers, likely involving a diverse group of inducible molecules, will not only enable the development and effective use of medical countermeasures but may also be used to detect and circumvent or mitigate normal tissue injury in cancer radiotherapy.

Upregulated long non-coding RNAs demonstrate promising efficacy for breast cancer detection: a meta-analysis

PURPOSE

Focusing on the latest literature, dysregulated long non-coding RNAs (lncRNAs) have been extensively explored in breast cancer (BC) research. The purpose of this meta-analysis is to synthesize the evidence on the diagnostic performance of abnormally expressed lncRNAs for BC.

MATERIALS AND METHODS

Relevant studies were searched in multiple electronic databases. The Quality Assessment of Diagnosis Accuracy Studies II criteria were applied to assess the quality of included studies. The bivariate meta-analysis model was applied to synthesize the diagnostic parameters using Stata 12.0 software. Publication bias was judged in terms of the Deek's funnel plot asymmetry test.

RESULTS

We included 10 eligible studies, which comprised 835 BC patients and 725 paired controls for this meta-analysis. The pooled sensitivity, specificity, diagnostic odds ratio, likelihood ratio positive, likelihood ratio negative, and area under the curve (AUC) of upregulated lncRNA expression signature in confirming BC were 0.79 (95% CI: 0.70-0.85), 0.80 (95% CI: 0.73-0.85), 14.61 (95% CI: 10.91-19.55), 3.90 (95% CI: 3.03-5.02), 0.27 (95% CI: 0.20-0.36), and 0.86, respectively. Stratified analyses yielded a sensitivity of 0.83 (95% CI: 0.80-0.86) for serum-based analysis, which was higher than plasma-based analysis, whereas plasma-based analysis revealed a greater specificity of 0.88 (95% CI: 0.85-0.91). Moreover, lncRNA-homeotic genes (HOX) transcript antisense RNA showed a pooled specificity of 0.89 (95% CI: 0.84-0.93) and AUC of 0.86, which were superior to performances by lncRNA-metastasis-associated lung adenocarcinoma transcript-1 and -H19 in diagnosing BC. Notably, the analysis based on cancer subtypes demonstrated that lncRNA expression signature could distinguish triple-negative BC (lacks estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2 expression) from non-triple-negative BC, with an AUC of 0.85.

CONCLUSION

Upregulated lncRNAs reveal an immense potential as novel non-invasive biomarker(s) that could complement BC diagnosis.

Polymorphisms of long non-coding RNA HOTAIR with breast cancer susceptibility and clinical outcomes for a southeast Chinese Han population

Hox transcript antisense intergenic RNA (HOTAIR) is a well-known long non-coding RNA (lncRNA) which participates in tumorigenesis and progress of multiple cancers. However, the associations among polymorphisms on HOTAIR, breast cancer (BC) susceptibility and clinical outcomes have remained obscure. In this case-control study, we assessed the interaction between three lncRNA HOTAIR single nucleotide polymorphisms (SNPs) (rs1899663, rs4759314 and rs7958904) on the risk and clinical outcome of breast cancer in a Chinese Han population. In total, 969 breast cancer cases and 970 healthy controls were enrolled in this study. Associations among genotypes, BC risk and survival were evaluated by univariate and multivariate logistic regression to estimate the odds ratio (OR), hazard ratio (HR) and its 95% confidence interval (CI). The disease-free survival (DFS) and overall survival (OS) was calculated by the Kaplan–Meier method. We found that the T allele of rs1899663 and C allele of rs7958904 both achieved significant differences between cases and controls in the single locus analyses (P = 0.017 and 0.010, respectively). Multivariate analyses also revealed the rs1899663 TT genotype and rs7958904 CC genotype were both at higher risk of breast cancer compared with the GG homozygotes (OR = 2.08, 95% CI = 1.20–3.60 and OR = 1.45, 95% CI = 1.01–2.08, respectively). In survival analysis, we observed that the T allele of rs1899663 presented significant differences for both DFS (HR = 1.64, 95% CI = 1.12–2.40) and OS (HR = 2.10, 95% CI = 1.29–3.42) in younger subjects (age ≤ 40). Our findings may provide new insights into the associations among the genetic susceptibility, the fine classifications and the prognosis of breast cancer. Further studies with larger sample size and functional research should also be conducted to validate our findings and better elucidate the underlying biological mechanisms.

Detection and analysis of circulating large intergenic non-coding RNA regulator of reprogramming in plasma for breast cancer

Background

Previous studies have indicated that large intergenic non‐coding RNA regulator of reprogramming (lincRNA‐ROR) plays an important role in regulating tumor carcinogenesis and metastasis; however, whether circulating lincRNA‐ROR could function as a potential biomarker for breast cancer (BC) diagnosis and monitoring is unknown. This study was conducted to investigate circulating lincRNA‐ROR in plasma as a potential biomarker for BC diagnosis and monitoring.

Methods

We performed reverse transcription‐quantitative‐PCR to examine lincRNA‐ROR expression levels in cell lines, 24 pairs of BC tissue samples, and 94 plasma samples from BC patients. Potential correlations between plasma lincRNA‐ROR levels and clinicopathological characteristics were analyzed. A receiver operating characteristic curve was calculated to evaluate the diagnostic values for BC. Pearson correlation analysis of lincRNA‐ROR in plasma samples and the corresponding tissues of the same patients was performed to explore tumor monitoring values.

Results

LincRNA‐ROR expression was significantly increased in BC cell lines, tissues, and plasma (all P < 0.01). Plasma lincRNA‐ROR levels were associated with estrogen receptors (P = 0.042) and lymph node metastasis (P = 0.046). The area under the receiver operating characteristic curve of plasma lincRNA‐ROR was 0.844 (sensitivity 80.0%, specificity 56.7%), which was higher than carcinoembryonic and carbohydrate antigen 15‐3 values. Moreover, plasma lincRNA‐ROR levels were decreased in postoperative compared to preoperative samples (P < 0.0001). Plasma lincRNA‐ROR levels moderately correlated with the corresponding tissue level in the same patients (r² = 0.638, P < 0.0001).

Conclusion

Plasma lincRNA‐ROR may be a potential biomarker for BC diagnosis and a dynamic monitor.

Long non-coding RNA00544 serves as a potential novel predictive and prognostic marker for HR+ HER2- subtype breast cancer

Luminal breast cancers (BC) account for majority of breast cancer. Due to its heterogeneity and the development of treatment resistance, luminal BC patients can vary substantially. Long noncoding RNAs (lncRNAs), as we known, is involved in breast cancer progression. Here, we aim to identify the lncRNAs which are involved in the particular type luminal BC progression. By Gene Chips analysis, we found a novel lncRNA00544, which was highly expressed in the metastatic axillary nodes compared with corresponding luminal BC tissues (fold change = 2.26, P = 0.043). This result was confirmed in luminal BC cell lines (p = 0.0113) and 49 paired breast cancer samples compared with in corresponding controls (p = 0.011). Furthermore, Kaplan-Meier survival curves of 373 breast cancer patients indicated that disease-free survival was significantly poor in breast cancer patients with high lncRNA00544 expression (p < 0.001). Univariate and multivariate Cox regression analyses showed that lncRNA00544 was a significant independent prognostic biomarker in luminal BC patients. Further analysis showed that the prognosis of high lncRNA00544 expression in breast cancer patients was actually related to HR + HER2- subtype. Together, our studies indicate that lncRNA00544 may represent a novel predictive and prognostic indicator in luminal BC patients.

HOTAIR regulates HK2 expression by binding endogenous miR-125 and miR-143 in oesophageal squamous cell carcinoma progression

Esophageal Squamous Cell Carcinoma (ESCC) is one of the most common malignant cancers worldwide with a high death rate worldwide. Long non-coding RNA (LncRNA) has been recently demonstrated to play a critical role in ESCC. LncRNA HOTAIR played important regulatory roles in ESCC. We highlight the molecular mechanisms by which HOTAIR could influence the expression of Hexokinase 2 (HK2) in ESCC through binding miR-125 and miR-143 directly. Taken together, this study identified a functional lncRNA HOTAIR involved with regulation of glycolysis via miRNA-125/miRNA-143-HK2 in ESCC cells. The “competitive endogenous RNA” (ceRNA) model of HOTAIR/miR-125 and miR143/HK2 interaction might serve as important targets for ESCC diagnosis and therapy.

lncRNA HOTAIR Contributes to 5FU Resistance through Suppressing miR-218 and Activating NF-κB/TS Signaling in Colorectal Cancer

One major reason for the failure of advanced colorectal cancer (CRC) treatment is the occurrence of chemoresistance to fluoropyrimidine (FU)-based chemotherapy. Long non-coding RNA HOTAIR has been considered as a pro-oncogene in multiple cancers. However, the precise functional mechanism of HOTAIR in chemoresistance is not well known. In this study, we investigated the biological and clinical role of HOTAIR in 5FU resistance in CRC. Our results showed that HOTAIR negatively regulated miR-218 expression in CRC through an EZH2-targeting miR-218-2 promoter regulatory axis. HOTAIR knockdown dramatically inhibited cell viability and induced G1-phase arrest by promoting miR-218 expression. VOPP1 was shown to be a functional target of miR-218, and the main downstream signaling, NF-κB, was inactivated by HOTAIR through the suppression of miR-218 expression. Additionally, HOTAIR knockdown partially reversed 5FU resistance through promoting miR-218 and inactivating NF-κB signaling. Furthermore, HOTAIR restrained 5FU-induced cytotoxicity on CRC cells through promotion of thymidylate synthase expression. More importantly, high HOTAIR expression was associated with poor response to 5FU treatment. In conclusion, we demonstrated that HOTAIR contributes to 5FU resistance through suppressing miR-218 and activating NF-κB signaling in CRC. Thus, HOTAIR may serve as a promising therapeutic target for CRC patients.