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

Investigation of the Use of Circulating Long Non-coding RNA HOXA Transcript at the Distal Tip (LncRNA HOTTIP) as a Biomarker in Breast Cancer

The critical need for new diagnostic and prognostic methods is highlighted by the fact that breast cancer continues to be the top cause of cancer-related deaths globally. Due to the dysregulation of long non-coding RNAs (lncRNAs) in numerous malignancies, they have become potential biomarkers in cancer. Recent research has focused on the lncRNA HOTTIP (HOXA transcript at the distal tip), which has a function in breast cancer metastasis and carcinogenesis. Until recently, HOTTIP had only been measured in cancer tissues and specimens. The aim of this study is to assess the amounts of the lncRNA HOTTIP in the blood serum of 46 breast cancer patients using real-time PCR analysis and identify the relationships between HOTTIP expression and several known clinical and pathological factors, including tumor grade, stage, lymph node involvement, hormone receptor status, and cell proliferation. The results of the study confirmed a positive relation of HOTTIP expression and breast cancer aggressiveness and metastatic behavior. The analysis results showed elevated HOTTIP values in stage III and T3/T4 tumors with multifocal characteristics and in lymph node involvement. Our findings raise the possibility of HOTTIP serving as a future prognostic biomarker for breast cancer patients.

Epigenome editing in cancer: Advances and challenges for potential therapeutic options

Cancers are diseases caused by genetic and non-genetic environmental factors. Epigenetic alterations, some attributed to non-genetic factors, can lead to cancer development. Epigenetic changes can occur in tumor suppressors or oncogenes, or they may contribute to global cell state changes, making cells abnormal. Recent advances in gene editing technology show potential for cancer treatment. Herein, we will discuss our current knowledge of epigenetic alterations occurring in cancer and epigenetic editing technologies that can be applied to developing therapeutic options.

Coding roles of long non-coding RNAs in breast cancer: Emerging molecular diagnostic biomarkers and potential therapeutic targets with special reference to chemotherapy resistance

Dysregulation of epigenetic mechanisms have been depicted in several pathological consequence such as cancer. Different modes of epigenetic regulation (DNA methylation (hypomethylation or hypermethylation of promotor), histone modifications, abnormal expression of microRNAs (miRNAs), long non-coding RNAs, and small nucleolar RNAs), are discovered. Particularly, lncRNAs are known to exert pivot roles in different types of cancer including breast cancer. LncRNAs with oncogenic and tumour suppressive potential are reported. Differentially expressed lncRNAs contribute a remarkable role in the development of primary and acquired resistance for radiotherapy, endocrine therapy, immunotherapy, and targeted therapy. A wide range of molecular subtype specific lncRNAs have been assessed in breast cancer research. A number of studies have also shown that lncRNAs may be clinically used as non-invasive diagnostic biomarkers for early detection of breast cancer. Such molecular biomarkers have also been found in cancer stem cells of breast tumours. The objectives of the present review are to summarize the important roles of oncogenic and tumour suppressive lncRNAs for the early diagnosis of breast cancer, metastatic potential, and chemotherapy resistance across the molecular subtypes.

A systematic review and meta-analysis of the association between HOTAIR polymorphisms and susceptibility to breast cancer

INTRODUCTION

Many studies are drawing attention to the associations of HOTAIR polymorphisms and susceptibility to breast cancer, while the results remain inconsistent. We conducted a meta-analysis on the association of four common HOTAIR polymorphisms with breast cancer susceptibility.

MATERIAL AND METHODS

Eligible published articles were searched in PubMed, Embase, Cochrane library databases and Web of Science databases up to July 2019. Odds ratios with 95% confidence intervals were used to identify potential links between lncRNA HOTAIR polymorphisms and the risk of breast cancer.

RESULTS

Our results showed no significance in all genetic models of all four SNPs. Pooled analyses detected crucial links between the rs1899663 polymorphism and decreased susceptibility to breast cancer in five genetic models rather than the dominant model in the hospital-based control subgroup. For the rs920778 polymorphism, we found that it significantly decreased breast cancer risk under recessive, homozygous and heterozygous models within the west Asian subgroup and increased breast cancer risk under allele and dominant models within the East Asian subgroup. Additionally, rs920778 polymorphism decreased breast cancer risk under recessive and heterozygous models in the hospital-based control subgroup. However, no significant association was observed between the rs4759314 polymorphism and breast cancer risk in overall and stratified analyses. For rs12826786 polymorphism, it was greatly associated with decreased breast cancer risk under recessive, homozygous and heterozygous models in the hospital-based control subgroup.

CONCLUSIONS

HOTAIR rs920778, rs1899663 and rs12826786 polymorphisms may contribute to breast cancer susceptibility.

Long noncoding RNA HOTAIR polymorphisms and susceptibility to bipolar disorder: a preliminary case-control study

Recent studies have shown that long noncoding RNAs contribute to the pathogenesis of bipolar disorder (BD). In this study, we genotyped four HOX Transcript Antisense Intergenic RNA (HOTAIR) gene polymorphisms to investigate if these variations could affect the risk of BD and its clinical subtypes. A total of 357 subjects, comprised of 194 BD patients and 163 age-matched healthy controls, were enrolled. Genotyping was carried out using PCR-RFLP and ARMS-PCR methods. We detected significant associations between the HOTAIR gene rs1899663 G/T, rs12826786 C/T, rs4759314 A/G, and rs920778 C/T polymorphism and the risk of BD under allelic, recessive, dominant, and codominant contrasted genetic models. The CT genotype of rs920778 C/T, GT genotype of rs1899663 G/T, and CT genotype of rs12826786 C/T polymorphisms enhanced the risk of BD type II (BDII). In contrast, the GG genotype of rs4759314 A/G polymorphism significantly diminished BDII risk by 83%. A positive association was noticed between CTTA and CTCG haplotypes of rs920778/rs1899663/rs12826786/rs4759314 and BD risk. Our findings reveal an interactive effect of HOTAIR polymorphisms on the development of BD and its subtypes. Further functional studies are needed to elucidate the role of these variations on HOTAIR expression and epigenetic status.

Long Non-Coding RNAs at the Chromosomal Risk Loci Identified by Prostate and Breast Cancer GWAS

Long non-coding RNAs (lncRNAs) are emerging as key players in a variety of cellular processes. Deregulation of the lncRNAs has been implicated in prostate and breast cancers. Recently, germline genetic variations associated with cancer risk have been correlated with lncRNA expression and/or function. In addition, single nucleotide polymorphisms (SNPs) at well-characterized cancer-associated lncRNAs have been analyzed for their association with cancer risk. These SNPs may occur within the lncRNA transcripts or spanning regions that may alter the structure, function, and expression of these lncRNA molecules and contribute to cancer progression and may have potential as therapeutic targets for cancer treatment. Additionally, some of these lncRNA have a tissue-specific expression profile, suggesting them as biomarkers for specific cancers. In this review, we highlight some of the cancer risk-associated SNPs that modulated lncRNAs with a potential role in prostate and breast cancers and speculate on how these lncRNAs may contribute to cancer development.

LncRNA polymorphisms and breast cancer risk

Breast cancer (BC) is the most prevalent cancer in females and the second reason of cancer-related mortality in females in the world. It is thought to be a complex interaction of variables like personal lifestyle, climate, genetics, and reproductive factors. Many polymorphisms have been linked to cancer in genome-wide association experiments, and they are linked to long non-coding RNAs (lncRNAs). LncRNAs, which have > 200 nucleotides in their transcripts, affect many biological processes, including differentiation, migration, apoptosis, cell cycle, and cell proliferation. Different lncRNAs with tumor suppressor and oncogenic roles have been shown to have elevated expression levels in the development of BC. Single-nucleotide polymorphisms (SNPs) in lncRNAs can affect the expression level, structure, and function of lncRNAs. LncRNA polymorphisms are predictive of cancer incidence, making them useful for early detection and customized therapy control. SNPs may affect genetic susceptibility to BC. This study was set to see whether there was a link between lncRNA polymorphisms and the risk of BC. Accordingly, the individual and combined genotypes of lncRNA-related variants could predict BC and clinical and care outcomes. However, further large-scale trials of diverse ethnic groups and comprehensive health records should be performed to validate the results. Furthermore, adequate functional assessments should be carried out to shed light on the etiology of BC. DATA AVAILABILITY: Not applicable.

Multifaceted roles of long non-coding RNAs in triple-negative breast cancer: biology and clinical applications

Triple-negative breast cancer (TNBC) is a heterogeneous breast cancer subtype that lacks targeted therapy due to the absence of estrogen, progesterone, and HER2 receptors. Moreover, TNBC was shown to have a poor prognosis, since it involves aggressive phenotypes that confer significant hindrance to therapeutic treatments. Recent state-of-the-art sequencing technologies have shed light on several long non-coding RNAs (lncRNAs), previously thought to have no biological function and were considered as genomic junk. LncRNAs are involved in various physiological as well as pathological conditions, and play a key role in drug resistance, gene expression, and epigenetic regulation. This review mainly focuses on exploring the multifunctional roles of candidate lncRNAs, and their strong association with TNBC development. We also summarise various emerging research findings that establish novel paradigms of lncRNAs function as oncogenes and/or tumor suppressors in TNBC development, suggesting their role as prospective therapeutic targets.

Single Nucleotide Polymorphisms in HOTAIR Are Related to Breast Cancer Risk and Prognosis in the Northeastern Chinese Population

Background

The long noncoding RNA HOX transcript antisense RNA (HOTAIR) is highly expressed in breast cancer (BC) tissues and is associated with the recurrence and metastasis of BC. Until now, the results of studies on associations between several functional single nucleotide polymorphisms(SNPs) (rs920778, rs1899663, and rs4759314) in HOTAIR with BC susceptibility carried out in different regions of China are still inconsistent. There is no study on correlation between HOTAIR SNPs and prognosis of Chinese population. Therefore, we investigated the relationship between HOTAIR SNPs and susceptibility to and prognosis of BC.

Method

We conducted a population-based case-control study involving 828 BC cases and 905 healthy controls. Peripheral blood DNA was used for genotyping. The association between HOTAIR genotypes and BC risk were estimated by odds ratios (ORs) computed using the binary logistic regression model. The relationships between HOTAIR SNPs and clinicopathological features were tested by Pearson’s chi-square test or Fisher’s exact test. Survival was analyzed using the Kaplan-Meier method.

Results

The functional rs920778 genetic variant increased BC risk in the codominant model. Individuals with the rs920778 GG genotype had an OR of 2.426 (95% confidence interval [CI] = 1.491–3.947, P < 0.001) for developing BC compared to individuals with the AA genotype. Individuals with the AG genotype had an OR of 1.296 (95% CI = 1.040–1.614, P = 0.021) for developing BC compared to individuals with the AA genotype. Individuals with the rs4759314 GA genotype had a lower BC risk than individuals with the rs4759314 AA/GG genotype (OR = 0.566, 95% CI = 0.398–0.803, P = 0.001). The rs1899663 genotype had no correlation with BC susceptibility. Haplotypes composed of rs920778–rs1899663 and rs920778–rs1899663–rs4759314 could increase BC risk (all P < 0.001). There were no statistically significant associations between HOTAIR SNPs and clinicopathological characteristics. The rs920778 GG/AG genotypes were associated with worse disease-free survival (DFS) (p = 0.012), and the rs4759314 GA genotype was associated with worse DFS and overall survival (OS) (p = 0.011).

Conclusion

HOTAIR SNPs(rs920778 and rs4759314) are significantly related to BC susceptibility and prognosis in the northeastern Chinese population, indicating the significance in the occurrence and development of BC.

Association between homeobox protein transcript antisense intergenic ribonucleic acid genetic polymorphisms and cholangiocarcinoma

BACKGROUND

Cholangiocarcinoma (CCA) represents a rare but highly aggressive malignancy that is often challenging to diagnose, especially in early stages. The role of existing tumor biomarkers for CCA diagnosis, remains controversial due to their low sensitivity and specificity. Increasing evidence has implicated long non-coding ribonucleic acid polymorphisms with cancer susceptibility in a variety of tumor types. The association between long non-coding ribonucleic acid homeobox protein transcript antisense intergenic ribonucleic acid (HOTAIR) polymorphisms and CCA risk has not been reported yet.

AIM

To investigate the influence of HOTAIR variants on the risk of CCA development.

METHODS

We conducted a case-control study in which three HOTAIR single nucleotide polymorphisms (rs920778, rs4759314 and rs7958904) were genotyped in a Greek cohort. Our study population included 122 CCA patients (80 males and 42 females) and 165 healthy controls. The polymorphisms under investigation were examined in peripheral blood samples.

RESULTS

HOTAIR rs4759314 AG and GG genotypes were associated with a significantly increased CCA risk [P = 0.004, odds ratio: 3.13; 95% confidence interval: 1.65-5.91 and P = 0.005, odds ratio: 12.31; 95% confidence interval: 1.48-101.87, respectively]. However, no significant associations of HOTAIR rs920778, and rs7958904 were detected. Similarly, we found no significant associations between rs4759314 AA genotype and CCA susceptibility.

CONCLUSION

HOTAIR rs4759314 AG and GG genotypes may be implicated with CCA development and may serve as a potential diagnostic biomarker.

LncRBase V.2: an updated resource for multispecies lncRNAs and ClinicLSNP hosting genetic variants in lncRNAs for cancer patients

The recent discovery of long non-coding RNA as a regulatory molecule in the cellular system has altered the concept of the functional aptitude of the genome. Since our publication of the first version of LncRBase in 2014, there has been an enormous increase in the number of annotated lncRNAs of multiple species other than Human and Mouse. LncRBase V.2 hosts information of 549,648 lncRNAs corresponding to six additional species besides Human and Mouse, viz. Rat, Fruitfly, Zebrafish, Chicken, Cow and C.elegans. It provides additional distinct features such as (i) Transcription Factor Binding Site (TFBS) in the lncRNA promoter region, (ii) sub-cellular localization pattern of lncRNAs (iii) lnc-pri-miRNAs (iv) Possible small open reading frames (sORFs) within lncRNA. (v) Manually curated information of interacting target molecules and disease association of lncRNA genes (vi) Distribution of lncRNAs across multiple tissues of all species. Moreover, we have hosted ClinicLSNP within LncRBase V.2. ClinicLSNP has a comprehensive catalogue of lncRNA variants present within breast, ovarian, and cervical cancer inferred from 561 RNA-Seq data corresponding to these cancers. Further, we have checked whether these lncRNA variants overlap with (i)Repeat elements,(ii)CGI, (iii)TFBS within lncRNA loci (iv)SNP localization in trait-associated Linkage Disequilibrium(LD) region, (v)predicted the potentially pathogenic variants and (vi)effect of SNP on lncRNA secondary structure. Overall, LncRBaseV.2 is a user-friendly database to survey, search and retrieve information about multi-species lncRNAs. Further, ClinicLSNP will serve as a useful resource for cancer specific lncRNA variants and their related information. The database is freely accessible and available at http://dibresources.jcbose.ac.in/zhumur/lncrbase2/.

Polymorphism of lncRNAs in breast cancer: Meta-analysis shows no association with susceptibility

BACKGROUND

Long non-coding RNAs (lncRNAs) have been the target of considerable attention for their roles in many biological processes. Only a small portion of lncRNAs are functionally characterized, and several approaches have been proposed for investigating the roles of these molecules, including how polymorphisms in lncRNA genomic sites may interfere with their function. Allele frequency variation in single nucleotide polymorphisms (SNPs), for example, has been associated with several diseases, including breast cancer (BC), the most common type of cancer in women.

METHODS

In the present study, we performed a systematic review of lncRNA SNPs associated with BC and a meta-analysis of some lncRNA SNPs. We found 31 SNPs mapped in 12 lncRNAs associated with BC in 28 case-control studies.

RESULTS

Our meta-analysis showed an insignificant difference between the SNPs rs217727, rs3741219, rs2107425 and rs2839698 on H19, as well as rs920778, rs1899663, rs12826786 and rs4759314 on HOTAIR, and BC susceptibility.

CONCLUSIONS

The present analysis recognized the importance of extensive association studies, including different populations, and further evaluation of potential functional effects caused by lncRNA SNPs. Nevertheless, genetic variants such as SNPs in lncRNAs may play many other essential roles, although this field is still under explored.

Association of HOTAIR (rs920778 and rs1899663) and NME1 (rs16949649 and rs2302254) gene polymorphisms with breast cancer risk in India

BACKGROUND

Until now, no study has reported the combined effect of genetic variants of HOTAIR and NME1 towards breast cancer (BC) pathogenesis. Hence, the aim of the present study is to determine the risk of breast cancer development with HOTAIR (rs920778 C > T and rs1899663 G > T) and NME1 (rs16949649 T > C and rs2302254 C > T) genetic polymorphisms in the Indian population for the first time.

MATERIALS AND METHODS

To investigate the genetic association of these four SNPs, we conducted a population-based case-control study involving 1011 subjects (502 histologically confirmed BC patients and 509 disease-free controls) using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method.

RESULTS

HOTAIR rs920778 TC genotype elevated the risk of BC (OR = 1.39, 95% CI = 1.06-1.83, p = 0.018) and individuals carrying the mutant allele (T) of rs1899663 had increased BC risk (OR = 1.23, 95% CI = 1.02-1.47, p = 0.026). The presence of the NME1 rs16949649 CC genotype increased the risk of BC (OR = 1.76, 95% CI = 1.15-2.71, p = 0.009). Moreover, the HOTAIR rs920778 variant (TC + CC) increased the risk of BC in pre-menopausal women (OR = 5.86; p < 0.0001). Women carrying 2 or 3 mutant alleles for the investigated SNPs were observed to have an elevated risk of BC.

CONCLUSION

The results of the present study highlight the presence of significant associations between NME1 rs16949649 and HOTAIR (rs920778 and rs1899663) polymorphisms and breast cancer development in Indian women.

Long Non-Coding RNA THOR Enhances the Stem Cell-Like Traits of Triple-Negative Breast Cancer Cells Through Activating β-Catenin Signaling

Background

The oncogenic roles of lncRNA THOR have been revealed in several tumors, however, its functions in breast cancer are still unclear.

Material/Methods

Real-time quantitative polymerase chain reaction (RT-qPCR) was used to detect THOR expression in clinical samples and the expression of stemness regulatory factors. ALDH1 assay and sphere-formation analysis were constructed to examine the stemness of cells. Cell viability assay was constructed to determine the cell proliferation capacity. In vitro RNA-RNA interaction and messenger RNA (mRNA) stability assays were performed to explore the mechanisms.

Results

THOR was overexpressed in triple-negative breast cancer (TNBC) compared to that in luminal A- and B-type breast cancer. THOR silencing reduced TNBC cell stemness, which was evident by the decreased sphere-formation ability, stemness marker expression and ALDH1 activity. Mechanistically, THOR directly bound to β-catenin mRNA, enhanced β-catenin mRNA stability and thus increased its expression. Furthermore, overexpression of β-catenin partially diminished THOR silencing-mediated inhibition on TNBC cell stemness.

Conclusions

This work proposes that THOR facilitates TNBC cell stemness through activating β-catenin signaling.

Association between HOTAIR genetic polymorphisms and cancer susceptibility: A meta-analysis involving 122,832 subjects

The association between polymorphisms in HOTAIR gene and cancer susceptibility has been analyzed intensively, but the conclusions are inconsistent. Therefore, we carried out a meta-analysis aiming to assess the relationship exactly. Eligible studies were searched in PubMed and Embase databases up to October 31, 2019. Odds ratios with 95% confidence intervals were used to assess the strength of association. Sensitivity analysis and publication bias were applied to evaluate the reliability of the study. Moreover, TSA was conducted to estimate the robustness of the results. Totally, 116 studies involving 122,832 subjects were analyzed in our meta-analysis. Significant increased risk of cancer was detected for the rs4759314, rs920778, rs1899663, rs12826786 and rs874945 polymorphisms. Further subgroup analyses according to cancer type revealed that different polymorphisms were associated with the risk of specific type of cancer. For example, the rs4759314 polymorphism was significantly associated with the risk of estrogen-dependent cancer, whereas the rs920778 polymorphism was associated with the risk of gastrointestinal cancer. In conclusion, our findings indicated that the rs4759314, rs920778, rs1899663, rs12826786 and rs874945 polymorphisms in HOTAIR may serve as genetic biomarkers of cancer.

Long Non-coding RNAs Mechanisms of Action in HIV-1 Modulation and the Identification of Novel Therapeutic Targets

This review aims to highlight the role of long non-coding RNAs in mediating human immunodeficiency virus (HIV-1) viral replication, latency, disease susceptibility and progression. In particular, we focus on identifying possible lncRNA targets and their purported mechanisms of action for future drug design or gene therapeutics.

Association Analysis Between the rs1899663 Polymorphism of HOTAIR and Risk of Psychiatric Conditions in an Iranian Population

Recent studies have shown contribution of long non-coding RNAs (lncRNAs) in the pathogenesis of a number of psychiatric disorders. In the current study, we investigated the association between a single nucleotide polymorphism in the lncRNA HOX transcript antisense intergenic RNA (HOTAIR) and risk of diverse neuropsychiatric conditions in Iranian population. The selected polymorphism (rs1899663) is an intronic variant of this lncRNA which has been associated with several cancers in different populations. This SNP was genotyped in 323 individuals with methamphetamine addiction, 55 children with attention-deficit hyperactive disorder (ADHD), 138 patients with bipolar disorder 1 (BPD1), 86 patients with BPD2, 53 patients with major depressive disorder (MDD), and 194 patients with schizophrenia (SCZ). There was no significant association between rs1899663 genotypes and risk of methamphetamine addiction or SCZ in any assessed inheritance model. There was a significant association between rs1899663 SNP and risk of BPD1 in allelic, co-dominant, and dominant models (P values of 0.003, 0.009, and 0.003, respectively). The T allele of this SNP conferred risk of BPD1 (OR (95% CI) = 1.70 (1.20-2.41)). This SNP was associated with risk of BPD2 in allelic and dominant models (P values of 0.02 and 0.04). The T allele of this SNP was revealed to be the risk allele for BPD2 as well (OR (95% CI) = 1.61 (1.09-2.40)). Besides, the mentioned SNP was associated with susceptibility to MDD in allelic and dominant models (P values of 0.01 and 0.03). Finally, the rs1899663 was associated with risk of ADHD in allelic, co-dominant, and dominant models (P values of 3.6E-4, 0.002, and 1.2E-4, respectively). The current investigation highlights the role of rs1899663 in conferring risk of BPD1, BPD2, MDD, and ADHD and suggests a similar underlying genetic background for these conditions.

Tumor suppressor and oncogenic role of long non-coding RNAs in cancer

Non-coding RNAs are RNA molecules that are not translated into the protein, making up the vast majority of the human genome. Long non-coding RNAs (lncRNA) are in the RNA group that has longer than 200 nucleotides, and non-protein coding transcripts. In recent years, the potential has attracted considerable attention as new important biological regulators. LncRNAs play a critical role in regulating the activity and localization of proteins, processing the production of small RNAs, and processing other RNAs. They are also involved in cell differentiation, cell cycle, proliferation, apoptosis, migration and invasion by modulation of gene expression. Abnormal expression of LncRNAs has an important role in the function of oncogenes and tumor suppressor genes. Recently, there has been an increasing number of studies on the tumorigenic effects of specific lncRNAs in the initiation and progression of cancer. In this review, general information about lncRNAs is provided, including the biological importance of lncRNAs in cancer diseases and their potential development in therapeutic applications.

Association study of long non-coding RNA HOTAIR rs920778 polymorphism with the risk of cancer in an elderly Japanese population

The HOTAIR gene encodes a long noncoding RNA (lncRNA), which functions in development and tumorigenesis. A single nucleotide polymorphism (SNP) rs920778 in the HOTAIR gene, has been recurrently studied for susceptibility to many cancers including oesophageal cancer, gastric cancer, lung cancer, and hepatocellular carcinoma. Most of these studies were conducted in Chinese populations, and a few in Turkish, Iranian, and Portuguese populations. They mostly give rise to controversial results. It still remains largely unknown whether the cancer risk is conferred in a Japanese population. Here, we established an association study on the representative SNP rs920778, to examine its contribution to the presence of cancer in consecutive autopsy cases in the JG-SNP database. A total of 1373 subjects (mean age 80) including 827 cancer positive and 546 cancer negative subjects were analyzed. As a result, the occurrence of overall cancer was not associated with the rs920778 polymorphism (p > 0.05). For each cancer type, we did not find association except for lung cancer (p = 0.04) which was more likely a by-chance association after multiple testing. Our findings imply that rs920778 polymorphism does not affect total cancer presence and the effect on specific cancer types is also weak in the Japanese population.

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.

Association of HOTAIR gene polymorphisms and haplotypes with uterine leiomyoma susceptibility in southeast of Iran

Uterine leiomyoma (UL) is the most common benign tumor of the uterus. HOX transcript antisense RNA (HOTAIR) as a lncRNAs is the product of HOXC gene that plays a major role in the invasion and development of different tumors. Several lines of evidence have been suggested the effects of HOTAIR polymorphisms on cancer risk. The aim of the present study was to analyze the effects of HOTAIR polymorphisms (rs12826786, rs920778, rs4759314 and rs1899663) on UL in southeast of Iran. A total of 152 women with UL and 182 age-matched healthy women were selected in the case-control study. The PCR-RFLP and ARMS-PCR methods were used for genotyping. HOTAIR rs920778 polymorphism was associated with a lower risk of UL in dominant [OR, 0.5 (95% CI, 0.3-0.9); P = 0.03], recessive [OR, 0.6 (95% CI, 0.4-0.9; P = 0.016] and allelic models [OR, 0.6(95% CI, 0.5-0.9); P = 0.004]. However, HOTAIR rs12826786 polymorphism was associated with a higher risk of UL in dominant [OR, 2.6 (95% CI, 1.6-4.1); P = 0.0001], recessive [OR, 1.9 (95% CI, 1-3.6); P = 0.04] and allelic models [OR, 1.8 (95% CI, 1.3-2.4); P = 0.0003]. There was no association between HOTAIR rs4759314 and rs1899663 polymorphisms and UL susceptibility. The frequency of CTGA haplotype was lower in UL women; however, the CCGA, TCGA, TTTA, and TTGA haplotypes were more frequent in UL women. Our results indicated that HOTAIR rs12826786 and rs920778 polymorphisms had a significant effect on UL susceptibility. The HOTAIR haplotypes could affect UL susceptibility.

Long non-coding RNA MIF-AS1 promotes breast cancer cell proliferation, migration and EMT process through regulating miR-1249-3p/HOXB8 axis

Breast cancer (BC) is one of the leading cause of cancer-related death among females worldwide. Mounting evidences indicate that long non-coding RNAs (lncRNAs) were involved in tumor progression by acting as either oncogenes or tumor suppressors in multiple cancers. In this study, we focused on the function and mechanism of lncRNA Migration Inhibitory Factor Antisense RNA 1 (MIF-AS1) in BC. qRT-PCR showed that MIF-AS1 was upregulated in BC tissues and cells. To detect its bio-function, a series of loss-of-function assays were carried out. Thereafter, we found that MIF-AS1 depletion inhibited BC cell proliferation, migration and epithelial-mesenchymal transition (EMT). Recently, increasing studies indicate that lncRNAs can function as competing endogenous RNAs (ceRNAs). Using bioinformatics analysis and luciferase reporter assay, we identified that MIF-AS1 regulated the level of Homeobox B8 (HOXB8) via binding to miR-1249-3p. Taken all together, our findings proved that MIF-AS1 acted as a ceRNA by modulating miR-1249-3p/HOXB8 axis in breast cancer. LncRNA MIF-AS1 might be a new biomarker and therapeutic target for BC patients.

The effect of long noncoding RNAs HOX transcript antisense intergenic RNA single-nucleotide polymorphisms on breast cancer, cervical cancer, and ovarian cancer susceptibility: A meta-analysis

Recent studies have shown that long noncoding RNAs (lncRNA) HOX transcript antisense intergenic RNA (HOTAIR) polymorphisms are associated with cancer susceptibility. The greatest threat to women's health among a variety of cancers is breast cancer (BC), cervical cancer (CC), and ovarian cancer (OC), and the incidence of it is increasing. We performed a meta-analysis to clarify the relationship between lncRNA HOTAIR expression and BC, CC, and OC susceptibility. We thoroughly searched PubMed, Embase, and the Cochrane Library to obtain the relevant literature. We extracted data from case groups and control groups for each single-nucleotide polymorphism (SNP) (rs4759314, rs920778, rs189663, rs12826786, rs7958904, and rs874945) and compared the relationship between alleles, codominance models, dominant and invisible models and BC, CC, and OC susceptibility. Our study included 11 studies with a total of 5322 patients. There was a significant association between the rs4759314 polymorphism of HOTAIR and susceptibility to BC, CC, and OC (codominant model: AG/AA odds ratio [OR] = 1.13 [95% confidence intervals [CI], 1.00-1.29], GG/AA OR = 1.54 [95% CI, 1.06-2.23]; dominant model: GG + AG/AA OR = 1.16 [95% CI, 1.02-1.32]; and recessive model: GG/AA + AG OR = 1.51 [95% CI, 1.05-2.19]). The association between the expression of rs920778 and BC, CC, and OC susceptibility was not clear (alleles T/C: OR = 1.28 [95% CI, 0.87-1.89]; in codominant model: CT/CC OR = 1.10, [95% CI, 0.71-1.71], TT/CC OR = 1.29 [95% CI, 0.59-2.80]; dominant model: TC + TT/CC OR = 1.16, [95% CI, 0.73-1.86]; and recessive model: TT/TC + CC OR = 1.43, [95% CI, 0.83-2.47]). HOTAIR polymorphism rs1899663 was associated with BC, CC, and OC susceptibility to a certain extent, (alleles T/G OR = 0.90 [95% CI, 0.69-1.16]; in the codominant model: GT/GG OR = 0.81 [95% CI, 0.50-1.30], TT/GG OR = 1.04 [95% CI, 0.63-1.72]; dominant model: GT + TT/GG OR = 0.82 [95% CI, 0.52-1.29]; and recessive model: TT/GT + GG OR = 1.21 [95% CI, 0.76-1.94]). The rs12826786, rs7958904, and rs874945 polymorphisms were associated with a certain degree of BC, CC, and OC susceptibility, but they were not statistically significant. HOTAIR rs4759314 increased susceptibility to BC, CC, and OC in some patients; rs029778 and rs1899663 also increased susceptibility to some extent. SNPs rs12826786, rs7958904, and rs874945 did not correlate with an effect on patient susceptibility to BC, CC, and OC.

HOTAIR lncRNA SNPs rs920778 and rs1899663 are associated with smoking, male gender, and squamous cell carcinoma in a Chinese lung cancer population

The abnormal expression of the long noncoding RNA (lncRNA) HOX transcript intergenic antisense RNA (HOTAIR) plays an important role in the development of various cancers; however, single nucleotide polymorphisms (SNPs) in HOTAIR and their association with primary lung cancer susceptibility have not yet been reported. Here, we performed a case-control study including 262 primary lung cancer patients and 451 cancer-free control individuals to investigate the association between four haplotype-tagging SNPs (rs920778, rs12826786, rs4759314, and rs1899663) in the HOTAIR lncRNA and the risk of developing primary lung cancer. We found a significant association between the SNPs rs920778 and rs1899663 in the HOTAIR and primary lung cancer susceptibility (P < 0.05). Moreover, homozygous C/T (C/T + TT) for rs920778 (C > T) sites was significantly associated with gender, smoking history, and pathological type. In addition, linkage disequilibrium and haplotype analysis of HOTAIR gene polymorphisms for susceptibility to lung cancer revealed a high degree of linkage disequilibrium between the rs920778 and rs1899663 loci (D' = 0.86, r2 = 0.52). The population of rs920778, rs1899663, and rs4759314 had a significantly increased risk of lung cancer (P < 0.001). In summary, the present study provides persuasive evidence that SNP rs920778 is closely correlated with susceptibility to primary lung cancer. Future studies are warranted to validate and expand these findings, and to further dissect the importance of these SNPs in the development of primary lung cancer.

Emerging roles of long non-coding RNA in cancer

Since comprehensive analysis of the mammalian genome revealed that the majority of genomic products are transcribed in long non‐coding RNA (lncRNA), increasing attention has been paid to these transcripts. The applied next‐generation sequencing technologies have provided accumulating evidence of dysregulated lncRNA in cancer. The implication of this finding can be seen in many forms and at multiple levels. With impacts ranging from integrating chromatin remodeling complexes to regulating transcription and post‐transcriptional processes, aberrant expression of lncRNA may have repercussions in cell proliferation, tumor progression or metastasis. lncRNA may act as enhancers, scaffolds or decoys by physically interacting with other RNA species or proteins, resulting in a direct impact on cell signaling cascades. Even though their functional classification is well‐established in the context of cancer, clearer characterization in terms of their phenotypic outputs is needed to optimize and identify suitable candidates that enable the development of new therapeutic strategies and the design of novel diagnostic approaches. The present article aims to outline different cancer‐associated lncRNA according to their contribution to tumor suppression or tumor promotion based on their most current functional annotations.