A functional lncRNA HOTAIR genetic variant contributes to gastric cancer susceptibility

Comprehensive investigation of long non-coding RNA HOTAIR polymorphisms and cancer risk: a current meta-analysis encompassing 96,458 participants

Cancer ranks as the second leading cause of mortality worldwide, prompting extensive investigations into factors contributing to its development. Among these factors, genetic variations, known as genotypic polymorphisms, have been identified as significant influencers in the susceptibility to various types of cancer. Recent research has focused on exploring the connection between polymorphisms in the Long Non-coding RNA HOTAIR and cancer risk. However, the results from these studies have been inconsistent, leading to ambiguity and controversy. To address this uncertainty, we conducted a systematic analysis by gathering relevant studies from PubMed, EMBASE, and Google Scholar. Specifically, we focused on three well-studied polymorphisms within the HOTAIR lncRNA (HOTAIR rs920778 C > T, HOTAIR rs1899663 G > T, HOTAIR rs4759314 A > G) and their association with cancer risk. Our meta-analysis included data from 48 case-control studies involving 42,321 cases and 54,137 controls. The results of our updated meta-analysis revealed a significant correlation between HOTAIR rs1899663 G > T and HOTAIR rs4759314 A > G polymorphisms and overall cancer risk, particularly in the homozygous and recessive genetic models. Subgroup analysis further revealed that these associations were notably pronounced in the Asian population but not observed in the Iranian population. Furthermore, our findings underscore the potential of HOTAIR polymorphisms as diagnostic markers for overall cancer risk, particularly in gynecological cancers, precisely, HOTAIR rs1899663 G > T polymorphism in breast cancer. In conclusion, our systematic analysis provides compelling evidence that Long Non-coding RNA HOTAIR polymorphisms are linked to cancer risk, particularly in certain populations and cancer types, suggesting their potential clinical relevance as diagnostic indicators.

The association of FSCN1 (rs852479, rs1640233) and HOTAIR (rs920778) polymorphisms with the risk of breast cancer in Egyptian women

BACKGROUND

Breast cancer (BC) is one of the most prevalent cancers that contribute to mortality among women worldwide. Despite contradictory findings, considerable evidence suggests that single nucleotide polymorphisms (SNPs) in the FSCN1 and HOTAIR genes may have a causative impact on the development of BC. This case-control study was conducted to evaluate the association of genotype frequency in FSCN1 rs852479, rs1640233, and HOTAIR rs920778 with susceptibility and prognosis of BC, as well as the impact of clinical stages and hormonal features.

METHODS AND RESULTS

FSCN1 (rs852479, rs1640233) and HOTAIR (rs920778) were genotyped using TaqMan real-time PCR assay in 200 BC patients and 200 cancer-free controls, all representing Egyptian women. Genotypic analyses in association with clinicopathological factors and disease risk were assessed. As a result, a significant association with BC risk was observed for CC genotype frequency of FSCN1 rs852479 A > C (OR = 0.395, 95% CI 0.204-0.76, p-value = 0.005). However, no significant correlation was detected between the FSCN1 rs1640233 C > T and HOTAIR rs920778 C > T polymorphic variants and susceptibility to BC. Interestingly, CC genotype of FSCN1 rs1640233 was more likely to progress tumor size and lymph node invasion in BC cases (p-value = 0.04 and 0.02, respectively). Moreover, it was revealed that there was a non-significant correlation between the haplotype distributions of FSCN1 rs852479 and rs1640233 and the probability of BC.

CONCLUSIONS

Based on the sample size and genetic characteristics of the subjects involved in the present study, our findings indicated that FSCN1 rs852479 may contribute to BC susceptibility in a sample of the Egyptian population.

Association of HOTAIR, MIR155HG, TERC, miR-155, -196a2, and -146a Genes Polymorphisms with Papillary Thyroid Cancer Susceptibility and Prognosis

Polymorphisms in long non-coding RNA and microRNA genes may play a significant role in the susceptibility and progression of papillary thyroid carcinoma (PTC). The current study investigates the polymorphisms HOTAIR rs920778, MIR155HG rs1893650, TERC rs10936599, miR-155 rs767649, miR-196a2 rs11614913 and miR-146a rs2910164 in 102 PTC patients and 106 age- and sex-matched controls of the Caucasian Serbian population, using real-time PCR. We observed differences in genotype distributions of the HOTAIR rs920778 (p = 0.016) and MIR155HG rs1893650 (p = 0.0002) polymorphisms between PTC patients and controls. HOTAIR rs920778 was associated with increased PTC susceptibility (adjusted OR = 1.497, p = 0.021), with the TT variant genotype increasing the risk compared to the CC genotype (OR = 2.466, p = 0.012) and C allele carriers (CC + CT) (OR = 1.585, p = 0.006). The HOTAIR rs920778 TT genotype was associated with lymph node metastasis (p = 0.022), tumor recurrence (p = 0.016), and progression-free survival (p = 0.010) compared to C allele carriers. Multivariate Cox regression revealed that ATA risk (HR = 14.210, p = 0.000004) and HOTAIR rs920778 (HR = 2.811, p = 0.010) emerged as independent prognostic factors in PTC. A novel polymorphism, MIR155HG rs1893650, was negatively correlated with susceptibility to PTC, with TC heterozygotes exerting a protective effect (OR = 0.268, p = 0.0001). These results suggest that the polymorphisms HOTAIR rs920778 and MIR155HG rs1893650 could be potential prognostic and risk biomarkers in papillary thyroid carcinomas.

Relevance of HOTAIR rs920778 and rs12826786 Genetic Variants in Bladder Cancer Risk and Survival

The long non-coding RNA HOX transcript antisense intergenic RNA (HOTAIR) is associated with oncogenic features in bladder cancer and is predictive of poor clinical outcomes in patients diagnosed with this disease. In this study, we evaluated the impact of the HOTAIR single nucleotide polymorphisms rs920778 and rs12826786 on bladder cancer risk and survival. This case-control study included 106 bladder cancer patients and 199 cancer-free controls. Polymorphisms were evaluated through PCR-restriction fragment length polymorphism. The odds ratio and 95% confidence intervals were tested using univariable and multivariable logistic regressions. The effects on patient survival were evaluated using the log-rank test and Cox regression models. Our data showed that the HOTAIR rs920778 and rs12826786 genetic variants are not associated with the risk of developing bladder cancer. Nevertheless, survival analyses suggested that the HOTAIR rs920778 TT genotype and rs12826786 CC genotype are associated with increased survival in male bladder cancer patients and in patients, both male and female, who have primary tumors with a pathological stage of pT2. Together, these results suggest that, despite not being associated with bladder cancer risk, HOTAIR rs920778 and rs12826786 polymorphisms might represent new prognostic factors in this type of cancer. This is particularly important as these polymorphisms might be easily evaluated in bladder cancer patients in a minimally invasive manner to better predict their clinical outcomes.

Role of lncRNAs in Helicobacter pylori and Epstein-Barr virus associated gastric cancers

Helicobacter pylori infection is a risk factor for the development of gastric cancer (GC), and the role of co-infection with viruses, such as Epstein-Barr virus, in carcinogenesis cannot be ignored. Furthermore, it is now known that genetic factors such as long non-coding RNAs (lncRNAs) are involved in many diseases, including GC. On the other side, they can also be used as therapeutic goals. Modified lncRNAs can cause aberrant expression of genes encoding proximal proteins, which are essential for the development of carcinoma. In this review, we present the most recent studies on lncRNAs in GC, concentrating on their roles in H. pylori and EBV infections, and discuss some of the molecular mechanisms of these GC-related pathogens. There was also a discussion of the research gaps and future perspectives.

Large-scale integration of the non-coding RNAs with DNA methylation in human cancers

Characterizing influences of DNA methylation (DNAm) on non-coding RNAs (ncRNAs) is important to understand the mechanisms of gene regulation and cancer outcome. In our study, we describe the results of ncRNA quantitative trait methylation sites (ncQTM) analyses on 8,545 samples from The Cancer Genome Atlas (TCGA), 763 samples from the Clinical Proteomic Tumor Analysis Consortium (CPTAC), and 516 samples from Genotype-Tissue Expression (GTEx) to identify the significant associations between DNAm sites and ncRNAs (miRNA, long non-coding RNA [lncRNA], small nuclear RNA [snRNA], small nucleolar RNA [snoRNA], and rRNA) across 32 cancer types. With more than 22 billion tests, we identify 302,764 cis-ncQTMs (6.28% of all tested) and 79,841,728 trans-ncQTMs (1.15% of all tested). Most DNAm sites (70.6% on average) are in trans association, while only 25.2% DNAm sites are in cis association. Further, we develop a subtype named ncm_cluster based on cancer-specific ncRNAs thatis associated with tumor microenvironment, clinical outcome, and biological pathways. To comprehensively describe the ncQTM patterns, we developed a database named Pancan-ncQTM (http://bigdata.njmu.edu.cn/Pancan-ncQTM/).

The Role of Single-Nucleotide Polymorphisms in Cholangiocarcinoma: A Systematic Review

Single-nucleotide polymorphisms (SNPs) play an essential role in various malignancies, but their role in cholangiocarcinoma (CCA) remains to be elucidated. Therefore, the purpose of this systematic review was to evaluate the association between SNPs and CCA, focusing on tumorigenesis and prognosis. A systematic literature search was carried out using PubMed, Embase, Web of Science and the Cochrane database for the association between SNPs and CCA, including literature published between January 2000 and April 2022. This systematic review compiles 43 SNPs in 32 genes associated with CCA risk, metastatic progression and overall prognosis based on 34 studies. Susceptibility to CCA was associated with SNPs in genes related to inflammation (PTGS2/COX2, IL6, IFNG/IFN-γ, TNF/TNF-α), DNA repair (ERCC1, MTHFR, MUTYH, XRCC1, OGG1), detoxification (NAT1, NAT2 and ABCC2), enzymes (SERPINA1, GSTO1, APOBEC3A, APOBEC3B), RNA (HOTAIR) and membrane-based proteins (EGFR, GAB1, KLRK1/NKG2D). Overall oncological prognosis was also related to SNPs in eight genes (GNB3, NFE2L2/NRF2, GALNT14, EGFR, XRCC1, EZH2, GNAS, CXCR1). Our findings indicate that multiple SNPs play different roles at various stages of CCA and might serve as biomarkers guiding treatment and allowing oncological risk assessment. Considering the differences in SNP detection methods, patient ethnicity and corresponding environmental factors, more large-scale multicentric investigations are needed to fully determine the potential of SNP analysis for CCA susceptibility prediction and prognostication.

Association of Long Noncoding RNA HOTAIR Polymorphism and the Clinical Manifestations of Diabetic Retinopathy

The aim of the current study is to evaluate the possible correlation between the single-nucleotide polymorphisms (SNP) of HOX transcript antisense intergenic RNA (HOTAIR) and the clinical characteristics of diabetic retinopathy (DR). Four loci of HOTAIR SNPs, including rs920778 (T/C), rs12427129 (C/T), rs4759314 (A/G), and rs1899663 (G/T), were genotyped via the TaqMan allelic discrimination for 276 DR individuals and 452 non-DR patients. The distribution frequency of HOTAIR SNP rs12427129 CT [adjusted odds ratio (AOR): 1.571, 95% CI: 1.025-2.408, p = 0.038], HOTAIR SNP rs12427129 CT+TT (AOR: 1.611, 95% CI: 1.061-2.446, p = 0.025), and HOTAIR SNP rs1899663 TT (AOR: 2.443, 95% CI: 1.066-5.595, p = 0.035) were significantly higher in the DR group. Moreover, the proliferative diabetic retinopathy (PDR) subgroup revealed a significantly higher distribution of HOTAIR SNP rs12427129 CT+TT (AOR: 2.016, 95% CI: 1.096-3.710, p = 0.024) and HOTAIR SNP rs1899663 TT (AOR: 4.693, 95% CI: 1.765-12.479, p = 0.002), and the distribution frequencies of HOTAIR SNP rs12427129 CT (AOR: 3.722, 95% CI: 1.555-8.909, p = 0.003), HOTAIR SNP rs12427129 CT+TT (AOR: 4.070, 95% CI: 1.725-9.600, p = 0.001), and HOTAIR SNP rs1899663 TT (AOR: 11.131, 95% CI: 1.521-81.490, p = 0.018) were significantly higher in the female PDR subgroup. Regarding the clinical characters, the DR patients with HOTAIR SNP rs1899663 GT+TT revealed a significantly shorter duration of diabetes compared to the DR patients with HOTAIR SNP rs1899663 GG (10.54 ± 8.19 versus 12.79 ± 7.73, p = 0.024). In conclusion, HOTAIR SNP rs12427129 and rs1899663 are strongly correlated to the presence of DR, especially for a female with PDR.

Long noncoding RNA (lncRNA) HOTAIR: Pathogenic roles and therapeutic opportunities in gastric cancer

Gastric cancer is one of the first malignant cancers in the world and a large number of people die every year due to this disease. Many genetic and epigenetic risk factors have been identified that play a major role in gastric cancer. HOTAIR is an effective epigenetic agent known as long noncoding RNA (lncRNA). HOTAIR has been described to have biological functions in biochemical and cellular processes through interactions with many factors, leading to genomic stability, proliferation, survival, invasion, migration, metastasis, and drug resistance. In the present article, we reviewed the prognostic value of the molecular mechanisms underlying the HOTAIR regulation and its function in the development of Gastric Cancer, whereas elucidation of HOTAIR–protein and HOTAIR–DNA interactions can be helpful in the identification of cancer processes, leading to the development of potential therapeutic strategies.

Association between long non‑coding RNA HOTAIR polymorphism and lung cancer risk: A systematic review and meta‑analysis

Single nucleotide polymorphism (SNP) of long noncoding RNA (lnc)RNA has been reported to be an important factor in cancer development. Recently, lncRNA homeobox transcript antisense intergenic RNA (HOTAIR) was indicated to induce tumorigenesis of several cancer types, but the association between the SNP of lncRNA HOTAIR and lung cancer susceptibility has remained undetermined. The present meta-analysis aimed to investigate the effect of HOTAIR polymorphism on susceptibility to lung cancer. The PubMed, Ovid Medline, Embase and Cochrane Library databases were thoroughly searched. Studies containing data on the incidence of lung cancer in patients with different HOTAIR SNPs were included. The Hardy-Weinberg equilibrium was analyzed to determine genotype distribution and allele frequencies. The odds ratio (OR) was pooled to evaluate the association of different SNPs with the susceptibility to lung cancer. A total of six studies comprising 1,715 patients with lung cancer and 2,745 healthy controls were finally included. A total of 4 SNPs (rs12826786, rs1899663, rs920778 and rs4759314) were reported. Analyses for all of these SNPs individually indicated that the lncRNA HOTAIR rs1899663 C>A polymorphism was a risk factor for lung cancer (dominant mode, AA+CA vs. CC: OR=0.816, 95% CI=0.707-0.942, P=0.005). The present study was the first meta-analysis investigating the association between lncRNA HOTAIR and lung cancer susceptibility. The results indicated that the lncRNA HOTAIR rs1899663 C>A polymorphism is a risk factor for lung cancer. LncRNA HOTAIR may be of value in lung cancer screening, particularly for populations with high-risk factors, as well as prognosis prediction. Future investigations are required to further clarify the intrinsic mechanism of the role of HOTAIR in the oncogenesis of lung cancer.

Long intergenic non-protein coding RNA 467 inhibition elevates microRNA-27b-3p to repress malignant behaviors of gastric cancer cells via reducing STAT3

Emerging evidence indicated that long noncoding RNAs (lncRNAs) and microRNAs (miRNAs) exert critical effects on tumorigenesis of multiple malignancies, including gastric cancer (GC). We aim to explore the effects of long intergenic non-protein coding RNA 467 (LINC00467) and miR-27b-3p on GC. GC cells were initially cultured. LINC00467, miR-27b-3p, and signal transducer and activator of transcription 3 (STAT3) expression in GC were detected. The altered LINC00467 and/or miR-27b-3p were transfected into screened cells. Then, the biological activities of GC cells and the tumor growth in vivo were examined. The binding relationships among LINC00467, miR-27b-3p, and STAT3 were confirmed. It was indicated that LINC00467 was increased while miR-27b-3p was decreased in GC tissues and cells. Inhibition of LINC00467 hindered GC cell malignancy and blocked tumor development by upregulating miR-27b-3p. LINC00467 sponged miR-27b-3p and STAT3 was targeted by miR-27b-3p. It was discovered that LINC00467 reduction upregulates miR-27b-3p to repress malignant GC cell growth via inhibiting STAT3. This research may deepen the insight of molecular mechanisms on GC.

LINC00520 up-regulates SOX5 to promote cell proliferation and invasion by miR-4516 in human hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most common human cancers. Long non-coding RNA (lncRNA) has been demonstrated to play an important role in regulating tumor development. The current study aims to explore the specific role of LINC00520 during HCC progression. The present study identified that LINC00520 was upregulated in HCC tissues and indicated poor patient survival. Overexpression of LINC00520 promoted HCC cell proliferation, migration and invasion, while LINC00520 downregulation led to the opposite effects. Besides, LINC00520 knockdown was found to inhibit tumor growth in vivo. Furthermore, LINC00520 acted as a sponge of miR-4516 to regulate SRY-related high mobility group box 5 (SOX5). In addition, the inhibition of miR-4516 partly reversed the inhibitory effect of LINC00520 silencing on HCC cell proliferation, migration and invasion. In conclusion, the inhibition of LINC00520 suppressed HCC cell proliferation, migration and invasion through mediating miR-4516/SOX5 axis. Therefore, our study provides a basis for the development of treatment strategies for HCC.

LncPSCA in the 8q24.3 risk locus drives gastric cancer through destabilizing DDX5

Genome-wide association studies (GWAS) have identified multiple gastric cancer risk loci and several protein-coding susceptibility genes. However, the role of long-noncoding RNAs (lncRNAs) transcribed from these risk loci in gastric cancer development and progression remains to be explored. Here, we functionally characterize a lncRNA, lncPSCA, as a novel tumor suppressor whose expression is fine-regulated by a gastric cancer risk-associated genetic variant. The rs2978980 T > G change in an intronic enhancer of lncPSCA interrupts binding of transcription factor RORA, which down-regulates lncPSCA expression in an allele-specific manner. LncPSCA interacts with DDX5 and promotes DDX5 degradation through ubiquitination. Increased expression of lncPSCA results in low levels of DDX5, less RNA polymerase II (Pol II) binding with DDX5 in the nucleus, thus activating transcription of multiple p53 signaling genes by Pol II. These findings highlight the importance of functionally annotating lncRNAs in GWAS risk loci and the great potential of modulating lncRNAs as innovative cancer therapy.

Non-Coding RNA Polymorphisms (rs2910164 and rs1333049) Associated With Prognosis of Lung Cancer Under Platinum-Based Chemotherapy

Purpose: Lung cancer is the largest cause of cancer deaths in the world. Platinum-based chemotherapy is a foundation of first-line chemotherapy. However, the prognosis of lung cancer treated with platinum-based chemotherapy is still a challenge. Single nucleotide polymorphism of non-coding RNA has the potential to be a biomarker, but its effectiveness has yet to be comprehensively assessed. In this study, we explored the association between polymorphisms of non-coding RNA and prognosis of lung cancer patients receiving platinum-based chemotherapy.

Materials and Methods: For 446 lung cancer patients receiving platinum-based chemotherapy, 22 single nucleotide polymorphisms of microRNA and long noncoding RNA were genotyped by MALDI-TOF mass spectrometry. Cox regression analysis, Kaplan-Meier method, and long-rank test have been performed to assess the association of overall and progression-free survival with polymorphisms.

Results: In the additive and dominant models, genetic polymorphism of ANRIL rs1333049 (G > C) was significantly associated with progression-free survival. Additive model: CC vs GC vs GG [HR = 0.84, p = 0.021, 95% CI (0.73–0.97)]; Recessive model: CC vs GG + GC [HR = 0.77, p = 0.026, 95% CI (0.61–0.97)]. In the dominant model, compared with the CC genotype patients, lower risk of death [HR = 0.81, p = 0.036, 95% CI (0.66–0.99)] and lower risk of progression [HR = 0.81, p = 0.040, 95% CI (0.67–0.99)] have been observed on the patients with CG or GG genotype in miR-146A rs2910164.

Conclusion: Our research demonstrated the potential of using ANRIL rs1333049 (G > C) and miR-146A rs2910164 (C > G) as biomarkers to support the prediction of a better prognosis for lung cancer patients receiving platinum-based chemotherapy.

HOTAIR beyond repression: In protein degradation, inflammation, DNA damage response, and cell signaling

Long noncoding RNAs (lncRNAs) are pervasively transcribed from the mammalian genome as transcripts that are usually >200 nucleotides long. LncRNAs generally do not encode proteins but are involved in a variety of physiological processes, principally as epigenetic regulators. HOX transcript antisense intergenic RNA (HOTAIR) is a well-characterized lncRNA that has been implicated in several cancers and in various other diseases. HOTAIR is a repressor lncRNA and regulates various repressive chromatin modifications. However, recent studies have revealed additional functions of HOTAIR in regulation of protein degradation, microRNA (miRNA) sponging, NF-κB activation, inflammation, immune signaling, and DNA damage response. Herein, we have summarized the diverse functions and modes of action of HOTAIR in protein degradation, inflammation, DNA repair, and diseases, beyond its established functions in gene silencing.

N6-methyladenosine Demethylase FTO Induces the Dysfunctions of Ovarian Granulosa Cells by Upregulating Flotillin 2

Polycystic ovarian syndrome (PCOS) is often accompanied by overweight/obesity and insulin resistance. The dysfunctions of ovarian granulosa cells (GCs) are closely linked with the pathogenesis of PCOS. Fat mass and obesity-associated gene (FTO), an N6-methyladenosine (m6A) demethylase, has been reported to be implicated in the risks and insulin resistance of PCOS. However, the roles of FTO in the development of GCs along with its m6A-related regulatory mechanisms are poorly defined. Cell proliferative ability was detected by MTT assay. Cell apoptotic rate was measured via flow cytometry. Insulin resistance was assessed by GLUT4 transport potential. The mRNA and protein levels of FTO and flotillin 2 (FLOT2) were determined by RT-qPCR and western blot assays, respectively. FLOT2 was screened out to be a potential FTO target through differential expression analysis for the GSE95728 dataset and target prediction analysis by POSTAR2 and STARBASE databases. The interaction between FTO and FLOT2 was analyzed by RNA immunoprecipitation (RIP) assay. The effect of FTO upregulation on FLOT2 m6A level was measured by methylated RIP (meRIP) assay. FLOT2 mRNA stability was examined by actinomycin D assay. FTO overexpression facilitated cell proliferation, hindered cell apoptosis, and induced insulin resistance in GCs. FTO promoted FLOT2 expression by reducing m6A level on FLOT2 mRNA and increasing FLOT2 mRNA stability. FLOT2 loss weakened the effects of FTO overexpression on cell proliferation/apoptosis and insulin resistance in GCs. FTO induced the dysfunctions of GCs by upregulating FLOT2, suggesting that FTO/FLOT2 might play a role in the pathophysiology of PCOS.

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.

Dysregulation of lncRNA in Helicobacter pylori-Infected Gastric Cancer Cells

Helicobacter pylori (H. pylori) infection is the most common cause of gastric cancer (GC). This microorganism is genetically diverse; GC is caused by several genetic deregulations in addition to environmental factors and bacterial virulence factors. lncRNAs (long noncoding RNAs) are significant biological macromolecules in GC, have specific functions in diseases, and could be therapeutic targets. Altered lncRNAs can lead to the abnormal expression of adjacent protein-coding genes, which may be important in cancer development. Their mechanisms have not been well understood, so we are going to investigate the risk of GC in a population with both high lncRNA and H. pylori infection.

The Influence of rs1859168 Polymorphism on Serum Expression of HOTTIP and Its Target miR-615-3p in Egyptian Patients with Breast Cancer

BACKGROUND

Polymorphisms of long noncoding RNAs are lately documented as hazardous factors for the development of numerous tumors. Furthermore, the evaluation of noncoding RNAs has emerged as a novel detector of breast cancer patients. We aimed to genotype the HOXA transcript at the distal tip (HOTTIP) rs1859168 and assess its relationship with the levels of the serum HOTTIP and its target miR-615-3p in patients with breast cancer (BC).

METHODS

One hundred and fifty-one patients with BC, 139 patients with fibroadenoma (FA), and 143 healthy participants were incorporated into the current study. The genotyping of rs1859168 and the measurements of the HOTTIP and miR-615-3p levels were assessed using quantitative real-time PCR.

RESULTS

We revealed a significant association between each of the CC genotypes, C allele, dominant and recessive models, and the increased risk of BC (p = 0.013, p < 0.001, p < 0.001, and p < 0.001, respectively) relative to the healthy controls. Similarly, the CC genotype, C allele, and recessive model were observed to be related to the increased incidence of BC with respect to FA (p < 0.001 for all). A significant upregulation of HOTTIP and a marked decrease of miR-615-3p were verified in patients with BC compared to each of the healthy individuals, patients with FA, and the non-BC group (healthy subjects + FA) (p < 0.001 for all). A significant negative correlation was demonstrated between the expression of HOTTIP and miR-615-3p in the serum of patients with BC. The HOTTIP expression was upregulated, while that of miR-615-3p was downregulated in patients with BC who carried the CC genotype with respect to those who carried the AA or AC genotypes (p < 0.05 for all).

CONCLUSIONS

The genetic variants of rs1859168 are linked to an increased susceptibility to BC. Moreover, HOTTIP and miR-615-3p may be used as novel indicators and targets for the treatment of patients with BC.

Inhibition of lncRNA DILC attenuates neuropathic pain via the SOCS3/JAK2/STAT3 pathway

Long noncoding RNAs (lncRNAs) have been involved in the development of multiple pathological processes including neuropathic pain. The aim of the present study is to investigate the role of lncRNA down-regulated in liver cancer stem cells (DILC) in the progression of neuropathic pain and its underlying mechanism. Neuropathic pain rat model was established with the bilateral chronic constriction injury (bCCI) method. The results from quantitative PCR analysis in the spinal cord showed that DILC was significantly up-regulated in rats with bCCI compared with the sham group. DILC down-regulation mediated by intrathecal administration of DILC siRNA significantly increased the mechanical shrinkage threshold (MWT) and paw withdrawal threshold latency (PWTL), decreased the positive frequency for nerve sensitivity to cold and suppressed the expression of inflammatory genes in bCCI rats. Down-regulation of DILC induced suppressor of cytokine signaling (SOCS3) expression and inhibited the phosphorylation of signal transducer and activator of transcription 3 (p-STAT3) in spinal cord tissues. Western blotting showed that down-regulation of DILC by DILC siRNA transfection induced SOCS3 expression and inhibited the expression of p-Janus kinase 2 (p-JAK2) and p-STAT3 and their downstream genes in primary microglia. Furthermore, down-regulation of DILC increased the viability of primary microglia, suppressed apoptosis, and inhibited the production of interleukin (IL)-6 and IL-1β in microglia. In contrast, overexpression of DILC showed the opposite functions to those of DILC knockdown. In conclusion, silence of lncRNA DILC attenuates neuropathic pain via SOCS3-induced suppression of the JAK2/STAT3 pathway.

lncRNA OGFRP1 promotes tumor progression by activating the AKT/mTOR pathway in human gastric cancer

As biomolecules of great clinical value, lncRNAs play a crucial role as regulators in the processes of tumor origin, metastasis, and recurrence. Thus, lncRNAs are urgently needed for research in gastric cancer. We elucidated the specific function of OGFRP1, both in vitro and in vivo. OGFRP1 was expressed at abnormally high levels in gastric cancer samples (n = 408) compared to normal samples (n = 211). Similar results were obtained in 30 clinical case samples. Interference of OGFRP1 markedly blocked cell proliferation and migration, and it induced cell cycle arrest and the apoptosis of gastric cancer cells in vitro. Phosphorylation of AKT was inhibited in cells transfected with OGFRP1 siRNA, as compared to their control cells. The in vivo results further confirmed the antitumor effects of OGFRP1 knockdown on gastric cancer. Decreases in tumor volume (104.23±62.27 mm³) and weight (0.1006±0.0488 g) in nude mice were observed during the OGFRP1 interference, as compared with the control group (418.96±211.96 mm³ and 0.2741±0.0769 g). OGFRP1 promotes tumor progression through activating the AKT/mTOR pathway. Our findings provide a new potential target for the clinical treatment of human gastric cancer.

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.

Contributions of HOTAIR polymorphisms to the susceptibility of cancer

OBJECTIVE

Hox transcript antisense intergenic RNA (HOTAIR), a lncRNA, functions as a critical regulator in cancer development. A plenty of case-control studies were conducted to assess the actual relationship of HOTAIR gene generic variants on cancer susceptibility, yet conflicting conclusions remain. Herein, we carried out this up-to-date meta-analysis to get a better understanding of such relationship by incorporating all eligible case-control studies.

MATERIALS AND METHODS

Six widely investigated polymorphisms were included in this meta-analysis: rs920778, rs4759314, rs7958904, rs874945, rs1899663, and rs12826786. We retrieved relevant studies from databases PubMed, EMBASE, Medline, CNKI and Wanfang update to June 2020. We applied odds ratios (ORs) and 95% confidence intervals (CIs) to estimate the relationship strengths.

RESULTS

Our findings indicate that rs920778, rs4759314, rs874945, rs12826786 polymorphism significantly increased with susceptibility to overall cancer. However, rs7958904, rs1899663 under any five genetic models could not impact susceptibility to overall cancer. Furthermore, altered cancer risk was detected when the data were stratified by cancer type, ethnicity, the source of controls, and HWE in all the SNPs.

CONCLUSIONS

These findings of the meta-analysis suggest that HOTAIR polymorphisms may predispose to cancer susceptibility.

Long Noncoding RNAs: New Regulators of Resistance to Systemic Therapies for Gastric Cancer

Gastric cancer (GC) is the second leading cause of cancer mortality and the fourth most commonly diagnosed malignant disease, with approximately 951,000 new cases diagnosed and approximately 723,000 cases of mortality each year. The highest mortality rate of GC is in East Asia, and the lowest is in North America. A large number of studies have demonstrated that GC patients are characterized by higher morbidity, metastasis rates, and mortality and lower early diagnosis rates, radical resection rates, and 5-year survival rates. All cases of GC can be divided into two important stages, namely, early- and advanced-stage GC, and the stage mainly determines the treatment strategy for and the therapeutic effect in GC patients. Patients with early-stage GC undergo radical surgery followed by chemotherapy, and the 5-year survival rate can be as high as 90%. However, patients with advanced-stage GC cannot undergo radical surgery because they are at risk for metastasis; therefore, they can choose only radiotherapy or chemotherapy and have a poor prognosis. Based on the lack of specific clinical manifestations and detection methods, most GC patients (>70%) are diagnosed in the advanced stage; therefore, continued efforts toward developing treatments have been focused on advanced-stage GC patients and include molecular targeted therapy, immunotherapy, and small molecular therapy. Nevertheless, in recent years, accumulating evidence has indicated that small molecules, especially long noncoding RNAs (lncRNAs), are involved in the occurrence, development, and progression of GC, and their abundantly dysregulated expression has been identified in GC tissues and cell lines. Therefore, lncRNAs are considered easily detectable molecules and ideal biomarkers or target-specific agents for the future diagnosis or treatment of GC. In this review, we primarily discuss the status of GC, the role of lncRNAs in GC, and the emerging systemic treatments for GC.

Association of CDKN2A/CDKN2B Gene Polymorphisms with Increased Susceptibility to Intracranial Aneurysm in a Chinese Han Population

OBJECTIVE

Several studies have reported that single-nucleotide polymorphisms (SNPs) of the CDKN2A/CDKN2B gene on chromosome 9p21.3 are associated with increased risk of intracranial aneurysm (IA). However, the association between IAs and SNPs of CDKN2A/CDKN2B in Chinese Han people is yet to be evaluated. This study examined the association of the SNPs rs10811661 and rs4977574 with IA in the Chinese Han population.

METHODS

A total of 595 IA patients and 600 sex- and age-matched controls were enrolled in the study. Peripheral blood was collected and stored at -80°C until use. CDKN2A/CDKN2B was identified using polymerase chain reaction-ligase detection reaction. SNP genotyping was performed for rs10811661 and rs4977574 using a MassArray system. Associations between these two SNPs and IAs was tested with χ² or Fisher's exact tests and multivariate logistic regression.

RESULTS

rs10811661 and rs4977574 were significantly associated with IA. The frequency of rs10811661-T in IA was higher than in controls (OR 1.26, 95% CI 1.07-1.49; P<0.01). There was no significant difference in frequency of haplotype between control subjects and IA patients.

CONCLUSION

rs10811661 and rs4977574 on 9p21.3 were strongly associated with genetic susceptibility to IA in the Chinese Han population, which emphasizes a need for further investigation.

Association of Long Non-Coding RNA Polymorphisms with Gastric Cancer and Atrophic Gastritis

Long non-coding RNAs (lncRNA) play an important role in the carcinogenesis of various tumours, including gastric cancer. This study aimed to assess the associations of lncRNA ANRIL, H19, MALAT1, MEG3, HOTAIR single-nucleotide polymorphisms (SNPs) with gastric cancer and atrophic gastritis. SNPs were analyzed in 613 gastric cancer patients, 118 patients with atrophic gastritis and 476 controls from three tertiary centers in Germany, Lithuania and Latvia. Genomic DNA was extracted from peripheral blood leukocytes. SNPs were genotyped by the real-time polymerase chain reaction. Results showed that carriers of MALAT1 rs3200401 CT genotype had the significantly higher odds of atrophic gastritis than those with CC genotype (OR-1.81; 95% CI 1.17–2.80, p = 0.0066). Higher odds of AG were found in a recessive model (CC vs. TT + CT) for ANRIL rs1333045 (OR-1.88; 95% CI 1.19–2.95, p = 0.0066). Carriers of ANRIL (rs17694493) GG genotype had higher odds of gastric cancer (OR-4.93; 95% CI 1.28–19.00) and atrophic gastritis (OR-5.11; 95% CI 1.10–23.80) compared with the CC genotype, and carriers of HOTAIR rs17840857 TG genotype had higher odds of atrophic gastritis (OR-1.61 95% CI 1.04–2.50) compared with the TT genotype; however, the ORs did not reach the adjusted significance threshold (p < 0.007). In summary, our data provide novel evidence for a possible link between lncRNA SNPs and premalignant condition of gastric cancer, suggesting the involvement of lncRNAs in gastric cancer development.

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.

Associations between HOTAIR polymorphisms rs4759314, rs920778, rs1899663, and rs7958904 and risk of primary ovarian insufficiency in Korean women

BACKGROUND

We investigated the association between the Hox transcript antisense RNA (HOTAIR) polymorphisms rs4759314, rs920778, rs1899663, and rs7958904 and primary ovarian insufficiency (POI) in Korean women.

METHODS

We conducted a case-control study of 134 Korean women with POI and 383 control individuals with at least one live birth and no history of pregnancy loss.

RESULTS

The GT genotype of rs1899663 was associated with a decreased risk of POI compared with other genotypes at that locus. In addition, compared with the wild-type homozygous genotypes, the combination of the AA genotype of rs4759314 and the GC genotype of rs7958904 was associated with a decreased risk of POI (P < 0.05), whereas the combination of the GG genotype of rs1899663 and the GC genotype of rs7958904 was associated with an increased risk of POI (P = 0.003). Haplotype analysis revealed that certain haplotypes involving some or all of the polymorphisms were associated with a decreased risk of POI, whereas other haplotypes were associated with an increased risk of POI. Serum levels of luteinizing hormone, follicle-stimulating hormone, and estradiol differed between patients with POI and control individuals (P < 0.05).

CONCLUSIONS

Our results suggest that the HOTAIR polymorphisms rs4759314, rs920778, rs1899663, and rs7958904 are involved in POI.

Critical role of HOX transcript antisense intergenic RNA (HOTAIR) in gliomas

Despite extensive research, gliomas are associated with high morbidity and mortality, mainly attributed to the rapid growth rate, excessive invasiveness, and molecular heterogeneity, as well as regenerative potential of cancer stem cells. Therefore, elucidation of the underlying molecular mechanisms and the identification of potential molecular diagnostic and prognostic biomarkers are of paramount importance. HOX transcript antisense intergenic RNA (HOTAIR) is a well-studied long noncoding RNA, playing an emerging role in tumorigenesis of several human cancers. A growing amount of preclinical and clinical evidence highlights the pro-oncogenic role of HOTAIR in gliomas, mainly attributed to the enhancement of proliferation and migration, as well as inhibition of apoptosis. In vitro and in vivo studies demonstrate that HOTAIR modulates the activity of specific transcription factors, such as MXI1, E2F1, ATF5, and ASCL1, and regulates the expression of cell cycle-associated genes along with related signaling pathways, like the Wnt/β-catenin axis. Moreover, it can interact with specific miRNAs, including miR-326, miR-141, miR-148b-3p, miR-15b, and miR-126-5p. Of importance, HOTAIR has been demonstrated to enhance angiogenesis and affect the permeability of the blood-tumor barrier, thus modulating the efficacy of chemotherapeutic agents. Herein, we provide evidence on the functional role of HOTAIR in gliomas and discuss the benefits of its targeting as a novel approach toward glioma treatment.

Mechanisms of long non-coding RNA function in colorectal cancer tumorigenesis

Colorectal cancer (CRC) is one of the most common cancers globally. Although a variety of CRC screening methods have been developed, many patients are diagnosed at advanced stages of CRC with tumor invasion and distance metastasis. Several studies have suggested the long noncoding RNAs (lncRNAs) as one of the main contributors in CRC tumorigenesis, although the exact underlying mechanism of lncRNAs in CRC is still unknown. Numerous studies have indicated aberrant expression of lncRNAs in CRC through different modes of action such as cell proliferation, apoptosis, cell cycle, DNA repair response, drug-resistance, migration, and metastasis. Furthermore, lncRNA polymorphisms can influence the risk of CRC development. Accordingly, lncRNAs can be served as promising diagnostic or prognostic biomarkers and also desired therapeutic targets affecting the outcome of patients with CRC. In this review, we summarized the updated and novel evidence that identifies different roles of lncRNAs in the tumorigenesis of CRC.

lncRNA-uc003opf.1 rs11752942 A>G polymorphism decreases neuroblastoma risk in Chinese children

Recent studies have revealed that long non-coding RNAs (lncRNAs) play critical roles in the tumorigenesis and proliferation of human cancer. Several polymorphisms of lncRNAs have been found to be involved in the risk of neuroblastoma (NB). However, studies on the relationship between polymorphisms in lncRNA exons and NB are infrequent. We evaluated the association between rs11752942 A > G polymorphism in lnc-RNA-uc003opf.1 exon and neuroblastoma susceptibility by performing a hospital-based study with 275 patients and 531 controls. Odds ratios (ORs) and 95% confidence intervals (CIs) assessed by using logistic regression models were used to determine the strength of the association. We found that the rs11752942 G allele is significantly associated with decreased neuroblastoma risk (AG vs. AA: adjusted OR = 0.72, 95% CI = 0.53-0.98, P = 0.038; and AG/GG vs. AA: adjusted OR = 0.74, 95% CI = 0.55-0.99, P = 0.045) after adjusting for age and gender. This association was more prominent in females, subjects with tumor in the mediastinum or early-stage. Furthermore, the expression quantitative trait locus analysis indicated that rs11752942 G was associated with decreased expression of its neighboring gene LRFN2 mRNA. These results indicate that lncRNA-uc003opf.1 may be a novel potentially functional lncRNA that may be used as a predictive marker, for it might contribute to decreased neuroblastoma risk.

IKBKB rs2272736 is Associated with Gastric Cancer Survival

Background

IKBKB/IKKβ, as the core catalytic subunit of IκB kinase complex, participates in mediation of the classical NF-κB pathway, which has been linked to inflammation and tumorigenesis. Previous studies have shown that single nucleotide polymorphisms in IKBKB have been related to gastric cancer, but how they associate to the clinical outcome is not yet clear. In this study, we retrospectively investigated the associations between single nucleotide polymorphisms located in IKBKB and gastric cancer survival.

Materials and Methods

IKBKB rs2272736 was genotyped in 1210 patients with primary gastric cancer in a Han Chinese population, and the relationships between rs2272736 and overall survival were evaluated. We conducted Cox proportional hazards regression, which was performed to estimate the effects of single nucleotide polymorphisms on the overall survival of patients, adjusted for potential confounding variables.

Results

We found that patients with rs2272736 A allele in IKBKB had significantly prolonged overall survival time compared to those with the G allele (HR = 0.83, 95% CI = 0.68–1.00, P = 0.050). In addition, AA genotype was demonstrated to have reduced risk of death for gastric cancer compared with that associated with the GG/GA genotypes, which was more common in patients with cardiac carcinoma, well-differentiated and moderately differentiated tumors, TNM Ⅰ/Ⅱ stages and intestinal type.

Conclusion

Our findings have shown that single nucleotide polymorphism rs2272736 in IKBKB may be a promising prognostic biomarker which should promote personalized treatment.

HOTAIR induces EGFR-TKIs resistance in non-small cell lung cancer through epithelial-mesenchymal transition

OBJECTIVE

Previous research found that HOTAIR, a long non-coding RNA, is aberrantly expressed and associated with tumor invasion, metastasis and chemo-resistance in many cancers. The aim of this study was to investigate the role of HOTAIR in resistance of EGFR-TKIs in NSCLC.

METHODS

HOTAIR expression level was detected by quantitative reverse transcription polymerase chain reaction (qRT-PCR) in NSCLC cell lines or tumor tissues. A total of 62 samples with EGFR-mutant and EGFR-TKI-sensitive NSCLCs, 42 with acquired resistance and 27 with primary resistance to EGFR-TKIs were analyzed. The effect of HOTAIR on cell proliferation and apoptosis was undergone by CCK-8 and flow cytometry assays. The expression of EMT proteins was assessed by western blot.

RESULTS

HOTAIR was significantly down-regulated in lung cancer cells (PC9/R, H1975, H1299 and A549) and patients with primary and acquired resistance to EGFR-TKIs. In clinical setting, high levels of HOTAIR expression was significantly correlated with longer progression-free survival (PFS) [P < 0.01] compared with low HOTAIR expression subgroup in tumors which respond to EGFR-TKIs. In vitro, over-expression HOTAIR could restore gefitinib sensitivity in gefitinib-resistant cells (PC9/R, H1299 and A549), but this change in sensitivity was not observed in H1975. Up-regulated HOTAIR induced cell apoptosis in PC9/R, H1299 and A549, and activated epithelial-mesenchymal transition (EMT).

CONCLUSIONS

HOTAIR expression was associated with primary and acquired resistance to EGFR-TKIs and could regulate cell proliferation through activating cell apoptosis and EMT, which suggest that HOTAIR might be able to act as a biomarker to predict the EGFR-TKIs resistance.

The New Frontier of Functional Genomics: From Chromatin Architecture and Noncoding RNAs to Therapeutic Targets

Common diseases are complex, multifactorial disorders whose pathogenesis is influenced by the interplay of genetic predisposition and environmental factors. Genome-wide association studies have interrogated genetic polymorphisms across genomes of individuals to test associations between genotype and susceptibility to specific disorders, providing insights into the genetic architecture of several complex disorders. However, genetic variants associated with the susceptibility to common diseases are often located in noncoding regions of the genome, such as tissue-specific enhancers or long noncoding RNAs, suggesting that regulatory elements might play a relevant role in human diseases. Enhancers are cis-regulatory genomic sequences that act in concert with promoters to regulate gene expression in a precise spatiotemporal manner. They can be located at a considerable distance from their cognate target promoters, increasing the difficulty of their identification. Genomes are organized in domains of chromatin folding, namely topologically associating domains (TADs). Identification of enhancer-promoter interactions within TADs has revealed principles of cell-type specificity across several organisms and tissues. The vast majority of mammalian genomes are pervasively transcribed, accounting for a previously unappreciated complexity of the noncoding RNA fraction. Particularly, long noncoding RNAs have emerged as key players for the establishment of chromatin architecture and regulation of gene expression. In this perspective, we describe the new advances in the fields of transcriptomics and genome organization, focusing on the role of noncoding genomic variants in the predisposition of common diseases. Finally, we propose a new framework for the identification of the next generation of pharmacological targets for common human diseases.

Long noncoding RNAs in gastric cancer: From molecular dissection to clinical application

Long noncoding RNAs (lncRNAs) are important regulators of cell processes that are usually dysregulated in gastric cancer (GC). Based on their high specificity and ease of detection in tissues and body fluids, increasing attention has spurred the study of the roles of lncRNAs in GC patients. Thus, it is necessary to elucidate the molecular mechanisms and further explore the clinical applications of lncRNAs in GC. In this review, we summarize current knowledge to examine dysregulated lncRNAs in GC and their underlying molecular mechanisms and activities in GC, which involve microRNA sponging, mRNA stability, genetic variants, alternative splicing, transcription factor binding, and epigenetic modification. More significantly, the potential of lncRNAs as prognostic, circulating, and drug-resistant biomarkers for GC is also described. This review highlights the method of dissecting molecular mechanisms to explore the clinical application of lncRNAs in GC. Overall, this review offers assistance in using lncRNAs as novel candidates for molecular mechanisms and for the identification of revolutionary biomarkers for GC.

Cervical cancer in low and middle-income countries

Cervical cancer is a malignant tumour that occurs in the cervix and is classified into two histological types, adenocarcinoma and squamous cell carcinoma (SCC); SCC is more common and accounts for 70% of all cases. In 2018 there were ~569,000 new cases of cervical cancer diagnosed worldwide and ~311,000 deaths were attributed to cervical cancer. Of these, between 84 and 90% occurred in low- and middle-income countries (LMICs) such as South Africa, India, China and Brazil. The most common cause of cervical cancer is persistent infection caused by the sexually transmitted human papilloma virus. Other factors that contribute to the incidence of cervical cancer include geography, traditional practices and beliefs, the screening levels, socioeconomic status, healthcare access, public awareness, use of oral contraceptives, smoking and co-infection with HIV. An estimated 11 million women from LMICs will be diagnosed with cervical cancer in the next 10-20 years. The aim of this review was to explore various types of genetic and epigenetic factors that influence the development, progression or suppression of cervical cancer.

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.

LnCeVar: a comprehensive database of genomic variations that disturb ceRNA network regulation

LnCeVar (http://www.bio-bigdata.net/LnCeVar/) is a comprehensive database that aims to provide genomic variations that disturb lncRNA-associated competing endogenous RNA (ceRNA) network regulation curated from the published literature and high-throughput data sets. LnCeVar curated 119 501 variation–ceRNA events from thousands of samples and cell lines, including: (i) more than 2000 experimentally supported circulating, drug-resistant and prognosis-related lncRNA biomarkers; (ii) 11 418 somatic mutation–ceRNA events from TCGA and COSMIC; (iii) 112 674 CNV–ceRNA events from TCGA; (iv) 67 066 SNP–ceRNA events from the 1000 Genomes Project. LnCeVar provides a user-friendly searching and browsing interface. In addition, as an important supplement of the database, several flexible tools have been developed to aid retrieval and analysis of the data. The LnCeVar–BLAST interface is a convenient way for users to search ceRNAs by interesting sequences. LnCeVar–Function is a tool for performing functional enrichment analysis. LnCeVar–Hallmark identifies dysregulated cancer hallmarks of variation–ceRNA events. LnCeVar–Survival performs COX regression analyses and produces survival curves for variation–ceRNA events. LnCeVar–Network identifies and creates a visualization of dysregulated variation–ceRNA networks. Collectively, LnCeVar will serve as an important resource for investigating the functions and mechanisms of personalized genomic variations that disturb ceRNA network regulation in human diseases.

Roles of HOTAIR in lung cancer susceptibility and prognosis

Background

Long noncoding (lncRNA) single‐nucleotide polymorphisms (SNPs) are associated with the susceptibility to the development of various malignant tumors. The aim of this study was to investigate the roles of HOX transcript antisense intergenic RNA (HOTAIR) and its SNPs in lung cancer.

Methods

Initially, the expression of HOTAIR in different tumors was investigated using the online Gene Expression Profiling Interactive Analysis (GEPIA) resource. Three SNPs (rs920778, rs1899663, and rs4759314) of HOTAIR were identified using the MassArray system. Following this, the relationship between these SNPs and susceptibility to lung cancer was investigated.

Results

Expression of HOTAIR was found to increase in a variety of cancers, including nonsmall cell lung cancer (NSCLC). We found that the genotypes of these SNPs (rs920778, rs1899663, and rs4759314) were not significantly associated with lung cancer type, family history, lymph node metastasis, or lung cancer stage. In gender stratification, the results of rs920778 genotypes showed that, compared to genotype AA, the AG (OR = 0.344, 95% CI: 0.133–0.893, p = .028) and AG + GG (OR = 0.378, 95% CI: 0.153–0.932, p = .035) genotypes of rs920778 are protective factors against NSCLC in females. In smoking stratification, compared with AA of rs920778, the genotype AG + GG (OR = 0.507, 95% CI: 0.263–0.975, p = .042) was a protective factor against NSCLC in nonsmoking people. No statistical differences were observed in the classifications of rs1899663 and rs4759314 genotypes. Linkage disequilibrium analysis revealed a high linkage disequilibrium between the rs920778 and rs1899663 (D′ = 0.99, r² = .74), rs920778 and rs4759314 (D′ = 0.85, r² = .13), and rs1899663 and rs4759314 (D′ = 0.79, r² = .00).

Conclusion

Our study demonstrated that HOTAIR expression increased in NSCLC, and that the genotypes of rs920778 could be useful in the diagnosis and prognosis of lung cancer.

LncRNA COL1A1-014 is involved in the progression of gastric cancer via regulating CXCL12-CXCR4 axis

BACKGROUND

The aberrant expression of long noncoding RNAs (lncRNAs) is found in various types of cancers and also showed its association with the occurrence and development of gastric cancer (GC). We found lncRNA COL1A1-014 was frequently upregulated in GC.

METHODS

This study investigated COL1A1-014 for its biological function at both cellular and animal levels, using MTT, flow cytometry, colony formation and transwell assays. The expression levels of COL1A1-014 and other genes were detected by RT-PCR and western blot. Luciferase reporter assay was used to detect the potential binding of miR-1273h-5p to COL1A1-014 and CXCL12.

RESULTS

We found that COL1A1-014 was frequently upregulated in GC tissues as well as cells. COL1A1-014 increased cell proliferation, colony forming efficiency, migration ability, invasion ability, and weight and volume of grafted tumors, while reduced cell apoptosis. Overexpression of COL1A1-014 increased the mRNA expression of chemokine (CXCmotif) ligand (CXCL12) and high levels of CXCL12 and CXCR4 proteins in GC cells. The levels of miR-1273h-5p showed an inverse correlation with COL1A1-014 and CXCL12 in GC cells transfected with miR-1273h-5p. The mRNAs of wild-type COL1A1-014 and CXCL12 showed reduction in HEK293 cells transfected with miR-1273h-5p. This suggested that COL1A1-014 functions as an efficient miR-1273h-5p sponge and as a competing endogenous RNA (ceRNA) to regulate CXCL12. The proliferative activity of COL1A1-014 on GC cells was blocked by CXCL12-CXCR4 axis inhibitor AMD-3100.

CONCLUSIONS

These findings demonstrated that COL1A1-014 play an important regulatory role in GC development by functioning as a ceRNA in regulating the CXCL12/CXCR4 axis via sponging miR-1273h-5p.

Long non-coding RNA polymorphisms on 8q24 are associated with the prognosis of gastric cancer in a Chinese population

Background

Gastric cancer (GC) remains the third leading cause of cancer death in China. Although genome-wide association studies have identified the association between several single nucleotide polymorphisms (SNPs) on 8q24 and the risk of GC, the role of these SNPs in the prognosis of GC in Chinese populations has not yet been fully evaluated. Therefore, this study was conducted to explore the association between long non-coding RNA (lncRNA) polymorphisms on 8q24 and the prognosis of GC.

Methods

We genotyped 726 surgically resected GC patients to explore the association between eight SNPs in the lncRNAs CCAT1 (rs10087719, rs7816475), PCAT1 (rs1026411), PRNCR1 (rs12682421, rs13252298), and CASC8 (rs1562430, rs4871789, rs6983267) transcribed from the 8q24 locus and the prognosis of GC in a Chinese population.

Results

We found that the patients carrying rs12682421 AA genotypes survived for a shorter time than those with the GG/GA genotype (HR = 1.39, 95% confidence interval (CI) [1.09-1.78]). Compared with the CC/CT genotype, the TT genotype of rs1562430 was associated with an increased risk of death (HR = 1.38, 95% CI [1.06-1.80]). Furthermore, the results also identified the rs1026411 SNP as an independent prognostic factor for poor survival in GC patients. Patients carrying AA/AG variant genotypes had a 36% increased risk of death compared to those carrying the GG genotype (HR = 1.36, 95% CI [1.06-1.74]). These findings suggested that the rs12682421, rs1026411 and rs1562430 SNPs may contribute to the survival of GC and be prognostic markers for GC.

TRlnc: a comprehensive database for human transcriptional regulatory information of lncRNAs

Long noncoding RNAs (lncRNAs) have been proven to play important roles in transcriptional processes and biological functions. With the increasing study of human diseases and biological processes, information in human H3K27ac ChIP-seq, ATAC-seq and DNase-seq datasets is accumulating rapidly, resulting in an urgent need to collect and process data to identify transcriptional regulatory regions of lncRNAs. We therefore developed a comprehensive database for human regulatory information of lncRNAs (TRlnc, http://bio.licpathway.net/TRlnc), which aimed to collect available resources of transcriptional regulatory regions of lncRNAs and to annotate and illustrate their potential roles in the regulation of lncRNAs in a cell type-specific manner. The current version of TRlnc contains 8 683 028 typical enhancers/super-enhancers and 32 348 244 chromatin accessibility regions associated with 91 906 human lncRNAs. These regions are identified from over 900 human H3K27ac ChIP-seq, ATAC-seq and DNase-seq samples. Furthermore, TRlnc provides the detailed genetic and epigenetic annotation information within transcriptional regulatory regions (promoter, enhancer/super-enhancer and chromatin accessibility regions) of lncRNAs, including common SNPs, risk SNPs, eQTLs, linkage disequilibrium SNPs, transcription factors, methylation sites, histone modifications and 3D chromatin interactions. It is anticipated that the use of TRlnc will help users to gain in-depth and useful insights into the transcriptional regulatory mechanisms of lncRNAs.

LncRNA LOC285194 modulates gastric carcinoma progression through activating Wnt/β-catenin signaling pathway

Emerging evidences have revealed long noncoding RNAs (lncRNAs’) critical roles in diverse human carcinoma. Among these cancers, lncRNA LOC285194 has been extensively investigated in several types of carcinomas in the recent years. Nevertheless, the biological function, clinical relevance, and the influence of LOC285194 in gastric cancer (GC) are not fully understood. The present study aims to explore the biological function of LOC285194 in the progression and development of GC. First, LOC285194 expressions were detected in GC tissues and cell lines. The functional role of LOC285194 in GC was evaluated both in vitro and in vivo. Our data found that LOC285194 was lowly expressed both in human GC tissues and GC cell lines compared with corresponding normal controls. Moreover, LOC285194 was mitigated by transfection with LV‐LOC285194 in both HGC‐27 and MKN45 cell lines. Silencing of LOC285194 remarkably induced GC cell livability and cell proliferation. On the contrary, the LOC285194 overexpression suppressed MKN45 and HGC‐27 cell proliferation and promoted cell apoptosis. Additionally, silencing of LOC285194 increased the ability of colony formation, cell migration, and invasive capacities, together with blocking the apoptotic rates of GC cells. Correspondently, LOC285194 overexpression exerted the opposite effects. Mechanistically, silencing of LOC285194 promoted GC progression via inducing Wnt signaling activity. Moreover, in vivo xenografts nude mice model results showed that LOC285194 inhibited GC progression through targeting Wnt signaling. Taken together, LOC285194 is associated with GC progression by regulating the Wnt signaling transduction, potentiating LOC285194's promising role as a novel treatment biomarker in GC.

SNHG16 Silencing Inhibits Neuroblastoma Progression by Downregulating HOXA7 via Sponging miR-128-3p

Neuroblastoma (NB) is a common intracranial solid tumor with high mortality. Small nucleolar RNA host gene 16 (SNHG16), one of the long noncoding RNAs (lncRNAs), has been reported to be linked to the poor prognosis of NB. However, the mechanisms of SNHG16 in regulating NB progression remain poorly understood. The expression level of SNHG16 was measured by quantitative real time polymerase chain reaction (qRT-PCR). The starBase was employed to predict the interaction of miR-128-3p and SNHG16 or HOXA7, which was verified by dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay. Cell proliferation and apoptosis were assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and flow cytometry, respectively. Transwell assay was used to detect cell invasion or migration. The mRNA and protein levels of homeobox protein A7 (HOXA7) were determined by qRT-PCR and western blot, respectively. The levels of SNHG16 and HOXA7 were conspicuously increased in NB tissues and cells, while the expression of miR-128-3p was obviously declined, compared with corresponding normal tissues and cells. SNHG16 silencing inhibited proliferation, migration and invasion and induced apoptosis of NB cells. We identified that SNHG16 directly interacted with miR-128-3p, and miR-128-3p could target the 3'UTR of HOXA7 in NB cells. Simultaneously, miR-128-3p expression was negatively associated with SNHG16 or HOXA7. Further studies indicated that SNHG16 overexpression rescued the effects of miR-128-3p-mediated on inhibiting proliferation, migration, invasion and promoting apoptosis of NB cells. Moreover, SNHG16 could modulate HOXA7 by sponging miR-128-3p in NB cells. Besides, SNHG16 silencing suppressed tumor growth in vivo. Knockdown of SNHG16 impeded proliferation, migration, invasion and induced apoptosis through the SNHG16/miR-128-3p/HOXA7 axis in NB cells.

Investigation of metastasis-associated in colon cancer-1 genetic variants in the development and clinicopathologcial characteristics of uterine cervical cancer in Taiwanese women

The objectives of this study were to define the associations among single nucleotide polymorphisms (SNPs) of metastasis-associated in colon cancer-1 (MACC1) gene, development and clinicopathological characteristics of uterine cervical cancer, and patient survival in Taiwan. Genotypic frequencies of 5 MACC1 SNPs rs975263, rs3095007, rs4721888, rs3735615 and rs1990172 were identified for 132 patients with invasive cancer, 99 with high-grade cervical intraepithelial neoplasia and 338 normal controls using real-time polymerase chain reaction. It revealed that there were no associations of these MACC1 SNPs with cervical carcinogenesis. In the meantime, cervical cancer patients with genotype GG in MACC1 SNP rs975263 tended to display more risk to have vaginal invasion than those with AA/AG (p=0.042, OR: 8.70, 95% CI: 0.81-433.22). In multivariate analysis, positive pelvic lymph node metastasis could significantly predict worse 5 years survival rate (p=0.001; HR=9.98, 95% CI=2.64-37.77) for cervical cancer patients. In conclusion, pelvic lymph node status rather than MACC1 SNPs was the only independent parameter that could significantly predict 5 years survival rate in Taiwanese women with cervical cancer.

Polymorphisms of a novel long non-coding RNA RP11-108K3.2 with colorectal cancer susceptibility and their effects on its expression

BACKGROUND

RP11-108K3.2 was recently identified as a novel long non-coding RNA (lncRNA) transcript, and several single nucleotide polymorphisms (SNPs) have been identified in its coding region. This study aimed to explore the associations of tagSNPs in RP11-108K3.2 with the risk of colorectal cancer and their effects on its expression.

METHODS

A total of 821 colorectal cancer cases and 857 healthy controls were enrolled into this two-stage case-control study. Demographic characteristics and lifestyle information were collected by a validated questionnaire. Six tagSNPs were genotyped by using Sequenom MassARRAY platform. A total of 71 additional colorectal cancer cases were recruited, of which the genotypes of potential polymorphisms and the RP11-108K3.2 expression levels were determined.

RESULTS

In the discovery set, only the rs2470151 C/T polymorphism was found to have a promising association with the risk of colorectal cancer, and this polymorphism was further replicated in the validation set with a significantly decreased risk of colorectal cancer (adjusted odds ratio 0.73; 95% confidence interval 0.55, 0.97). Combined discovery set and validation set together, this negative association was found both in the heterozygote codominant model and the dominant model. Furthermore, colorectal cancer patients carrying rs2470151 CT/TT genotypes had a marginally lower RNA expression of RP11-108K3.2 than those carrying the CC genotype. Stratified analyses showed the association between rs2470151 and the risk of colorectal cancer were influenced by family history of cancer, smoking, alcohol consumption, and tea drinking.

CONCLUSIONS

These findings suggest that RP11-108K3.2 rs2470151 had a significant association with the risk of colorectal cancer; this may help to predict the susceptibility of colorectal cancer in Chinese populations.