A genetic variant in long non-coding RNA HULC contributes to risk of HBV-related hepatocellular carcinoma in a Chinese population

LncRNA MALAT1 Expression Regulates Breast Cancer Progression via PI3K/AKT/mTOR Pathway Modulation

Breast cancer is a significant health challenge for women globally, including the Pakistani population. Numerous pathways and small molecules like noncoding ribonucleotides are implicated in breast cancer development and progression. Among these, lncRNAs, have garnered considerable attention due to their role in breast cancer tumorigenesis and metastasis. In the current study involving 52 mammary tumor samples from the Pakistani population, the expression of lncRNA MALAT1 (metastasis associated lung adenocarcinoma transcript 1) was studied via RT-PCR (Real-Time polymerase chain reaction). In addition, PI3K/AKT/mTOR pathway expression was also assessed through RT-PCR and immunohistochemistry in breast cancer patient samples. The study also investigated the cross-talk of lncRNA MALAT1 and PI3K pathway genes by inhibiting it with PI3K inhibitor (LY294002) in MDA-MB-231 cell line. Furthermore, lncRNA MALAT1 was silenced in MDA-MB-231 cells using siRNA to determine its impact on breast cancer proliferation and metastasis. The results revealed an upregulated expression of MALAT1 and PI3K/AKT/mTOR pathway genes in grade II and III breast tissue samples before chemotherapy. The proliferation, growth, and invasion of breast cancer cells were significantly reduced upon MALAT1 silencing in MDA-MB-231. Further, its downregulation substantially reduced the PI3K pathway expression levels at mRNA and protein levels. In conclusion, the current study suggests that MALAT1 could serve as a therapeutic target for breast cancer, underscoring its role in breast cancer proliferation and metastasis. Moreover, the study proposes a mechanism of action of MALAT1, demonstrating that its inhibition can reduce the expression of the PI3K/AKT/mTOR axis. These findings emphasize the potential significance of targeting MALAT1 as a therapeutic strategy for breast cancer, and further exploration of this interaction is warranted to gain deeper insight into the molecular mechanism of this lncRNA.

The expression and function of long noncoding RNAs in hepatocellular carcinoma

With the deepening of the genome project study, attention on noncoding RNAs is increasing. Long noncoding RNAs (lncRNAs) have become a new research hotspot. A growing number of studies have revealed that lncRNAs are involved in tumorigenesis and tumor suppressor pathways. Aberrant expressions of lncRNAs have been found in a variety of human tumors including hepatocellular carcinoma (HCC). In this review, we provide a brief introduction to lncRNA and highlight recent research on the functions and clinical significance of lncRNAs in HCC.

Long noncoding RNA polymorphisms and hepatocellular carcinoma and pancreatic cancer risk

Hepatocellular carcinoma (HCC) and pancreatic cancer (PC) are among serious malignancies with no proper biomarker suffering from poor prognosis and late onset. Regulation of long noncoding RNAs (lncRNAs) is disturbed in tumors, making them appropriate diagnostic markers or therapeutic targets in systemic therapies. The expression and function of some significant lncRNAs are under the influence of SNPs, highlighting their key role in carcinogenesis. This review assesses the associations between SNPs in lncRNAs and HCC and PC risk. A panel of cancer-associated SNPs in lncRNA genes could help evaluate the clinical use of lncRNAs, including their role as diagnostic markers and therapeutic targets. Nonetheless, more large-scale surveys on various ethnic groups are required to validate results.

Non-coding RNA and hepatitis B virus-related hepatocellular carcinoma: A bibliometric analysis and systematic review

Objectives

A bibliometric analysis for non-coding RNA and hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC) was performed to describe international research status and visualize the research scope and emerging trends over the last two decades on this topic.

Materials and methods

Research data of non-coding RNA and HBV-related HCC were retrieved and extracted from the Web of Science Core Collection (WoSCC) database from 1 January 2003 to 13 June 2022 and then analyzed by means of bibliometric methods. A total of 1,036 articles published in this field were assessed for specific characteristics, including the year of publication, journal, author, institution, country/region, references, and keywords. VOSviewer was employed to perform co-authorship, co-occurrence, and co-citation analyses accompanied by constructing a visual network.

Results

Overall, 1,036 reports on non-coding RNA and HBV-related HCC from 2003 to 2022 were retrieved from WoSCC. The publication has gradually increased during the last two decades with 324 journals involved. Most research records (748 publications and 23,184 citations) were concentrated in China. A co-occurrence cluster analysis for the top 100 keywords was performed and four clusters were generated: (1) non-coding RNA as a molecular marker for the diagnosis and prognosis of HBV-related HCC; (2) dysregulation of non-coding RNA by hepatitis B virus X protein (HBx); (3) non-coding RNA affecting the biological behaviors of HBV-related HCC; and (4) epidemiological study for the effects of non-coding RNA on the risk of HBV-related HCC.

Conclusion

The publications and citations involved in non-coding RNA and HBV-related HCC have increased over the last two decades associated with many countries, institutions, and authors. Our study revealed current development trends, global cooperation models, basic knowledge, research hotspots, and emerging frontiers in this field.

MALAT1 Polymorphisms and Lung Cancer Susceptibility in a Chinese Northeast Han Population

Background: LncRNA MALAT1 (metastasis-associated lung adenocarcinoma transcript 1) was competitive endogenous RNA (ceRNA) involved in various molecular processes for metastasis development in lung cancer. Single nucleotide polymorphisms (SNPs) in MALAT1 gene might be predictive markers for lung cancer. In our study, we selected rs619586 and rs3200401 in MALAT1 gene to explore their effects on lung cancer susceptibility. Methods: The case-control study included 444 lung cancer cases and 460 healthy controls. Genotyping was performed by Taqman allelic discrimination method. Logistic regression, Student t-test, and Chi-square test (χ² ) were used to analyze the data. Results: The findings of the study showed that rs3200401 was significantly associated with the risk of non-small cell lung cancer (NSCLC) and lung squamous cell carcinoma (LUSC). Compared with homozygous CC genotype, CT heterozygous genotype decreased risk of NSCLC (P^a = 0.034) and LUSC (P^a = 0.025). In addition, no statistical association was detected between rs619586 and lung cancer susceptibility. The interactions between genes and cigarette smoking were discovered via crossover analysis. However, there were no remarkable gene-environment interactions in additive and multiplicative model. Conclusion: Rs3200401 in lncRNA MALAT1 was associated with the susceptibility of non-small-cell lung cancer and lung squamous cell carcinoma. The gene-environmental (cigarette smoking) interactions were not notable.

Association between HULC rs7763881 and cancer risk: an updated Meta-analysis

In recent years, several case-control studies have explored the association between the rs7763881 locus polymorphism of the HULC gene and cancer risk, however, the findings have been inconsistent. Therefore, a meta-analysis was conducted to clarify the association. Relevant case-control studies were obtained from CNKI, Embase, Web of Science and PubMed databases. RevMan software was used to perform data analysis. A total of 8 case-control studies containing 4036 cases and 5286 controls were included in the current meta-analysis. The overall analysis results showed no significant association between the rs7763881 locus polymorphism and cancer risk. However, stratified analysis based on cancer type showed that the rs7763881 locus polymorphism was associated with the decreased risk of hepatocellular cancer, colorectal cancer and esophageal cancer. In conclusion, the current findings suggest that the rs7763881 polymorphic loci located on the HULC gene may serve as a biomarker for determining an individual's risk of hepatocellular cancer, colorectal cancer and esophageal cancer.

GAS5 rs2067079 and miR-137 rs1625579 functional SNPs and risk of chronic hepatitis B virus infection among Egyptian patients

Hepatitis B virus (HBV) infection is a significant health issue worldwide.. We attempted to fulfill the molecular mechanisms of epigenetic and genetic factors associated with chronic HBV (CHBV). Expression levels of the lncRNA growth arrest-specific 5 (GAS5) and miR-137 and their corresponding SNPs, rs2067079 (C/T) and rs1625579 (G/T) were analyzed in 117 CHBV patients and 120 controls to investigate the probable association between these biomarkers and CHBV pathogenesis in the Egyptian population. Serum expression levels of GAS5 and miR-137 were significantly down-regulated in cases vs controls. Regarding GAS5 (rs2067079), the mutant TT genotype showed an increased risk of CHBV (p < 0.001), while the dominant CC was a protective factor (p = 0.004). Regarding miR-137 rs1625579, the mutant genotype TT was reported as a risk factor for CHBV (p < 0.001) and the normal GG genotype was a protective factor, p < 0.001. The serum GAS5 was significantly higher in the mutant TT genotype of GAS5 SNP as compared to the other genotypes (p = 0.007). Concerning miR-137 rs1625579, the mutant TT genotype was significantly associated with a lower serum expression level of miR-137 (p = 0.018). We revealed the dysregulated expression levels of GAS5 and miR-137 linked to their functioning SNPs were associated with CHBV risk and might act as potential therapeutic targets.

Effects of the lncRNA ENST00000623984 on colon cancer and the biological characteristics of colon cancer cells

The aim of this study was to explore the effects of the lncRNA ENST00000623984 on colorectal cancer. In this study, the expression levels of ENST000000623984 were first examined in tumor tissue and adjacent normal tissue from 40 patients with colorectal cancer and LoVo cells using quantitative real-time PCR. By siRNA transfection, ENST00000623984 expression was knocked down. Using flow cytometry, cell cycle progression and cell viability were examined in basal and knockdown LoVo cells. The CCK-8 assay was used to assess the cell proliferation rate, and the Transwell assay was used to determine the migration and invasion abilities. The ENST000000623984 expression level was increased in colorectal cancer. Knockdown of ENST000000623984 reduced cell viability, proliferation rate, cell migration and invasion. These results suggested that lncRNA ENST000000623984 may be involved in colorectal cancer development.

Interaction of HULC polymorphisms with Helicobacter pylori infection plays a strong role for the prediction of gastric cancer risk

Aim: Gene-environment interactions have better efficacy in predicting cancer susceptibility than a single gene. Materials & methods: Eight tag single nucleotide polymorphisms encompassing the whole HULC gene were detected by KASP platform (LGC Genomics, Hoddesdon, UK) in 631 gastric cancer (GC) cases and 953 controls. Results: The HULC gene rs7770772 polymorphism could increase GC risk (recessive model: odds ratio = 1.95). The multifactor dimensionality reduction (MDR) analysis suggested that the 2D model HULC rs7770772-Helicobacter pylori had better effect on GC risk prediction (maximum testing accuracy = 0.7005). No significant result was observed in our experimental expression quantitative trait loci analysis. Conclusion: 2D model HULC rs7770772-H. pylori might have superior efficacy for GC risk than a single factor.

Meta-analysis of the association between MALAT1 rs619586 A>G polymorphism and cancer risk

Objective

This study aimed to systematically assess the effect of the metastasis associated lung adenocarcinoma transcript 1 (MALAT1) long noncoding RNA rs619586 polymorphism on cancer risk.

Methods

We conducted a literature search of the PubMed, Embase, and China National Knowledge Internet databases to identify relevant studies, and calculated the pooled odds ratios (ORs) and 95% confidence intervals (CIs) for the retrieved studies using RevMan software.

Results

Nine eligible studies including 5968 cases and 7439 controls were included in the meta-analysis. The pooled results showed that MALAT1 rs619586 polymorphism was significantly associated with cancer risk [(AG + GG) vs. AA: OR = 0.88; GG vs. (AG + AA): OR = 0.64; GG vs. AA: OR = 0.63; AG vs. AA: OR = 0.91; G vs. A: OR = 0.87]. However, subgroup analyses based on ethnicity and cancer type showed significant associations between MALAT1 rs619586 polymorphism and cancer risk in Asians and for cancers other than hepatocellular carcinoma, but not for Caucasians and hepatocellular carcinoma.

Conclusions

MALAT1 rs619586 polymorphism may play a role in cancer risk. However, further studies are needed to confirm these findings.

MALAT1 gene rs600231 polymorphism positively associated with acute coronary syndrome in Chinese population: a case-control study

Background

Metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) has been recognized as a major player in the pathogenesis of coronary artery disease (CAD). The aim of the study was to determine the association between polymorphisms of the MALAT1 gene and acute coronary syndrome (ACS) in a Chinese population in Xinjiang.

Methods

In the case-control study, we genotyped three nucleotide polymorphisms (rs3200401, rs4102217, rs600231) of the MALAT1 gene using SNPscan^TM typing assays (1,053 controls and 929 ACS patients). Furthermore, we explored a predictive model using MALAT1 rs600231 and clinical variables to predict the risk of ACS. Finally, the relative expression of long noncoding RNA (lncRNA) MALAT1 was also measured in 92 ACS patients and 92 controls using quantitative real-time polymerase chain reaction (qRT-PCR).

Results

The prevalence of the GG genotype of rs600231 in ACS group was higher than that in control group (15.7% vs. 14.7%, P=0.048). The dominant model differed (AG + GG vs. AA) and the G allele of rs600231 in ACS group was higher than that in control group (for dominant model: 66.2% vs. 60.9%, P=0.014; for allele: 41.0% vs. 37.8%, P=0.042). Multivariate logistic regression analysis and the predictive nomogram model showed that the dominant model of rs600231 remained an independent risk factor for ACS [odds ratio (OR) =1.32, 95% confidence interval (CI): 1.07-1.63, P=0.009]. The area under the receiver operating characteristic (ROC) curve (AUC) for the nomogram model for the prediction of ACS was 0.738 (95% CI: 0.716-0.761). In addition, in the AG and GG phenotypes, the relative expression of lncRNA MALAT1 was significantly higher in ACS patients than in controls with the same phenotypes (P<0.05). Among ACS group, compared to other genotype carriers, the relative expression level of MALAT1 in GG genotype carriers was higher (P<0.05).

Conclusions

The present study suggested that the AG and GG genotype of rs600231 in MALAT1 gene was independently associated with ACS, and could be a risk genetic marker of ACS in a Chinese population in Xinjiang.

LINC00978 promotes hepatocellular carcinoma carcinogenesis partly via activating the MAPK/ERK pathway

Objective: To study the role of long non-coding RNA (lncRNA) LINC00978 in hepatocellular carcinoma (HCC) carcinogenesis.

Materials and methods: LINC00978 expression level was measured by reverse transcription quantitative real-time PCR (RT-qPCR) in HCC tissues and adjacent healthy liver tissues from 49 HCC patients. MTT assay, colony forming assay, and flow cytometry were performed to evaluate the effects of shRNA-mediated LINC00978 knockdown on HCC cell proliferation, cell cycle progression, and apoptosis in vitro. Xenograft tumor model was performed to determine the effects of LINC00978 knockdown on HCC tumor growth in vivo. Western blot was used to assess the activation of signaling molecules in the apoptosis and mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) pathway.

Results: LINC00978 expression was significantly up-regulated in human HCC tissue relative to adjacent normal tissue, and LINC00978 high expression was correlated with poor HCC overall survival. LINC00978 was up-regulated in HCC cell lines. ShRNA-mediated LINC00978 knockdown significantly decreased HCC cell proliferation, and induced HCC cell cycle arrest and apoptosis in vitro. LINC00978 knockdown led to significant decrease in tumor xenograft size in vivo. Western blots revealed LINC00978 inhibition decreased ERK, p38, and c-Jun N-terminal kinase (JNK) phosphorylation in HCC cells.

Conclusions: LINC00978 is highly expressed in human HCC tissue and correlates with poor HCC prognosis. LINC00978 promotes HCC cell proliferation, cell cycle progression, and survival, partially by activating the MAPK/ERK pathway. Our findings partially elucidated the roles of LINC00978 in HCC carcinogenesis, and identified a therapeutic target for HCC.

Associations between lncRNA-related polymorphisms and hepatocellular carcinoma risk: A two-stage case-control study

BACKGROUND AND AIM

Single-nucleotide polymorphisms (SNPs) in long non-coding RNAs (lncRNAs) are potential biomarkers for cancer risk, but their association with hepatocellular carcinoma (HCC) is unclear. We examined the association of lncRNA-related SNPs with HCC susceptibility and explored the optimal genetic models for SNPs.

METHODS

Five candidate SNPs linked with digestive tumors were first genotyped in a screening population of 700 HCC and 2800 control cases. The association between each SNP and HCC risk was estimated by multivariate logistic regression adjusted by sex and age and recorded as odds ratio (OR) with 95% confidence interval. Significant associations were further tested in a validation population with 1140 HCC and 5115 control cases. Finally, the most appropriate genetic models for HCC-associated SNPs were identified using pairwise allele differences; the overall gene effects of each SNP were further evaluated based on optimal genetic models.

RESULTS

Three candidate SNPs, rs7315438, rs6983267, and rs10795668, showed statistical connections with HCC risk in the discovery stage. Among these, rs7315438 remained steadily significant in the validation stage; rs7315438 and rs10795668 both reached statistical threshold in the combined analysis of both stages. SNP rs7315438 (TC vs TT/CC, OR = 1.410, P < 0.001) was associated with increased risk of HCC in a complete overdominant model, whereas rs10795668 (AG vs AA/GG, OR = 0.892, P = 0.035) exerted a protective effect on HCC risk in a complete overdominant model.

CONCLUSIONS

Long non-coding RNA-related SNPs rs7315438 and rs10795668 are potential biomarkers for HCC susceptibility, especially when evaluated based on their optimal genetic models.

Disease-Causing Mutations and Rearrangements in Long Non-coding RNA Gene Loci

The classic understanding of molecular disease-mechanisms is largely based on protein-centric models. During the past decade however, genetic studies have identified numerous disease-loci in the human genome that do not encode proteins. Such non-coding DNA variants increasingly gain attention in diagnostics and personalized medicine. Of particular interest are long non-coding RNA (lncRNA) genes, which generate transcripts longer than 200 nucleotides that are not translated into proteins. While most of the estimated ~20,000 lncRNAs currently remain of unknown function, a growing number of genetic studies link lncRNA gene aberrations with the development of human diseases, including diabetes, AIDS, inflammatory bowel disease, or cancer. This suggests that the protein-centric view of human diseases does not capture the full complexity of molecular patho-mechanisms, with important consequences for molecular diagnostics and therapy. This review illustrates well-documented lncRNA gene aberrations causatively linked to human diseases and discusses potential lessons for molecular disease models, diagnostics, and therapy.

Associations of genetic polymorphisms within MALAT1, UCA1, FAM211A-AS1 and AC000111.6 with genetic susceptibility to rheumatoid arthritis

Recently, several long non-coding RNAs (lncRNAs) including MALAT1, UCA1, ENST00000483588, and ENST00000456270 have been implicated in the pathogenesis of rheumatoid arthritis (RA), and we hypothesized that polymorphisms within these lncRNA genes might be genetic modifiers for the development of RA. A total of 10 potentially functional single-nucleotide polymorphisms (SNPs) were selected and genotyped in 1198 participants, including 594 RA patients and 604 healthy controls. Significant associations of FAM211A-AS1 rs2882581 (G vs. A, OR = 1.31, 95%CI 1.07-1.62, p = .01; G/G + A/G vs. A/A, OR = 1.40, 95%CI 1.08-1.83, p = .01), rs3744281 (T vs. A, OR = 1.25, 95%CI 1.02-1.54, p = .03; T/T vs. A/T + A/A, OR = 1.69, 95%CI 1.01-2.82, p = 4.59 × 10^-2), and rs3760235 (A vs. G, OR = 1.32, 95%CI 1.04-1.68, p = .02; A/A vs. A/G + G/G, OR = 1.32, 95%CI 1.00-1.74, p = 4.89 × 10^-2) with RF-positive RA were found. Functional annotation results indicated that these identified polymorphisms might regulate the expression of FAM211A-AS1 and nearby genes via impacting on transcription factor binding. Taken together, our results indicated that FAM211A-AS1 rs2882581, rs3744281, and rs3760235 were involved in the genetic background of RF-positive RA.

Long non-coding RNA LINC00473 acts as a microRNA-29a-3p sponge to promote hepatocellular carcinoma development by activating Robo1-dependent PI3K/AKT/mTOR signaling pathway

Background:

Long non-coding RNAs have suppressive or oncogenic effects in various types of cancers by serving as competing endogenous RNAs for specific microRNAs. In the present study, we aim to delineate the underlying mechanism by which the LINC00473/miR-29a-3p/Robo1 axis affects cell proliferation, migration, invasion, and metastasis in hepatocellular carcinoma (HCC).

Methods:

The level of Robo1 was examined in HCC tissues and cells, along with its regulatory effects on proliferation, migration, and invasion of HCC cells. Afterwards, the possible involvement of the PI3K/AKT/mTOR signaling pathway was determined. Next, miR-29a-3p expression was overexpressed or inhibited to investigate its regulatory role on HCC cell activities. The interaction among miR-29a-3p, Robo1, and LINC00473 was further characterized. Finally, a xenograft tumor in nude mice was conducted to measure tumorigenesis and metastasis in vivo.

Results:

miR-29a-3p was downregulated while Robo1 was upregulated in HCC tissues and cells. miR-29a-3p targeted Robo1 and negatively regulated its expression. In response to miR-29a-3p overexpression, Robo1 silencing or LINC00473 silencing, HCC cell proliferation, migration, invasion, tumor progression, and metastasis were impeded, which was involved with the inactivation of the PI3K/AKT/mTOR signaling pathway. Notably, LINC00473 could competitively bind to miR-29a-3p to upregulate Robo1 expression.

Conclusion:

LINC00473 might be involved in HCC progression by acting as a miR-29a-3p sponge to upregulate the expression of Robo1 that activates the PI3K/AKT/mTOR signaling pathway, which leads to enhanced cell proliferation, migration, invasion, tumor progression, and metastasis in HCC.

Association Between lncRNA HULC rs7763881 Polymorphism and Gastric Cancer Risk

Purpose

Gastric cancer (GC) is one of the most common cancers in the world. Recently, several studies have suggested that single-nucleotide polymorphisms (SNPs) of long noncoding RNA (lncRNA) are associated with GC risk. However, the association of the lncRNA highly upregulated in liver cancer (HULC) SNP with GC risk is not yet known. The aims of this study were to evaluate the association between HULC rs7763881 SNP and the risk of GC and GC subgroups via a case–control study.

Patients and Methods

rs7763881 was genotyped using TaqMan genotyping assay with 459 GC patients and 379 controls.

Results

A significant association between HULC rs7763881 SNP and GC risk was not found. However, after adjustment for age and gender, the rs7763881 recessive model (CC) showed a significant association with an increased GC risk in the undifferentiated (odds ratio (OR) = 1.85, 95% confidence interval (CI) = 1.17–2.94, P = 0.009), diffuse-type GC (OR = 1.72, 95% CI = 1.05–2.82, P = 0.033), LNM-positive (OR = 2.02, 95% CI = 1.24–3.27, P = 0.004), T3/T4 (OR = 1.75, 95% CI = 1.05–2.91, P = 0.032), and tumor stage III (OR = 2.01, 95% CI = 1.17–3.45, P = 0.011) subgroups when compared to the rs7763881 combined genotypes (AA+AC). Furthermore, after adjusting for age and gender, the rs7763881 additive model (CC) indicated a significantly higher GC risk than rs7763881 AA genotype in the undifferentiated (OR = 1.96, 95% CI = 1.15–3.32, P = 0.013), diffuse-type GC (OR = 2.08, 95% CI = 1.23–3.52, P = 0.004), and LNM-positive (OR = 2.00, 95% CI = 1.14–3.49, P = 0.016) subgroups.

Conclusion

Our findings suggest that the HULC rs7763881 SNP is associated with increased susceptibility to GC. However, further studies are required to validate our results in large populations as well as different ethnic groups.

LncRNAs Act as a Link between Chronic Liver Disease and Hepatocellular Carcinoma

Long non-coding RNAs (lncRNAs) are emerging as important contributors to the biological processes underlying the pathophysiology of various human diseases, including hepatocellular carcinoma (HCC). However, the involvement of these molecules in chronic liver diseases, such as nonalcoholic fatty liver disease (NAFLD) and viral hepatitis, has only recently been considered in scientific research. While extensive studies on the pathogenesis of the development of HCC from hepatic fibrosis have been conducted, their regulatory molecular mechanisms are still only partially understood. The underlying mechanisms related to lncRNAs leading to HCC from chronic liver diseases and cirrhosis have not yet been entirely elucidated. Therefore, elucidating the functional roles of lncRNAs in chronic liver disease and HCC can contribute to a better understanding of the molecular mechanisms, and may help in developing novel diagnostic biomarkers and therapeutic targets for HCC, as well as in preventing the progression of chronic liver disease to HCC. Here, we comprehensively review and briefly summarize some lncRNAs that participate in both hepatic fibrosis and HCC.

Significant association between long non-coding RNA H19 polymorphisms and cancer susceptibility: A PRISMA-compliant meta-analysis and bioinformatics prediction

BACKGROUND

H19, a well-known long non-coding RNA, is involved in carcinogenesis and progression of multiple cancers. Molecular epidemiological research suggests that polymorphisms in H19 are associated with an increased risk of cancer, but the results are inconsistent. Thus, we performed a meta-analysis to estimate the associations between H19 polymorphisms and cancer susceptibility.

METHODS

PubMed, Embase, and Web of Science databases were searched. Odds ratios with 95% confidence interval were applied to assess the association between H19 rs2107425, rs217727, rs2839698, rs2735971, rs3024270, and rs3741219 polymorphisms and cancer susceptibility in all 5 models. We also predicted the H19 secondary structure, as well as the generation and abolishment of miRNA binding sites on H19 through the selected SNPs.

RESULTS

Eighteen related studies, involving 17,090 patients and 23,532 control samples, were analyzed. The pooled data showed that rs2839698 polymorphism was significantly associated with an increased cancer susceptibility. As for rs217727 and rs3024270 polymorphisms, similarly increased risks were found in specific genetic models and stratified groups. However, significant decreases in cancer risk were observed for rs2107425 and rs2735971 in the total population, as well as in subgroup analyses. In addition, no significant associations were found in all 5 models for rs3741219 polymorphism. Furthermore, RNAfold prediction revealed that the centroid secondary structure was markedly altered in rs217727 and rs2735971. We also identified that rs217727 G>A and rs2839689 G>A alleles could create and destroy miRNA binding sites on H19.

CONCLUSION

The results of our meta-analyses suggest that H19 polymorphisms may be associated with the risk of cancer development.

Bioinformatics analyses and biological function of lncRNA ZFPM2-AS1 and ZFPM2 gene in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) remains one of the most lethal malignant tumors worldwide; however, the etiology of HCC still remains poorly understood. In the present study, cancer-omics databases, including The Cancer Genome Atlas, GTEx and Gene Expression Omnibus, were systematically analyzed in order to investigate the role of the long non-coding RNA (lncRNA) zinc finger protein, FOG family member 2-antisense 1 (ZFPM2-AS1) and the zinc finger protein, FOG family member 2 (ZFPM2) gene in the occurrence and progression of HCC. It was identified that the expression levels of lncRNA ZFPM2-AS1 were significantly increased in HCC tissues, whereas expression levels of the ZFPM2 gene were significantly decreased in HCC tissues compared with normal liver tissues. Higher expression levels of ZFPM2-AS1 were significantly associated with a less favorable prognosis of HCC, whereas higher expression levels of the ZFPM2 gene were associated with a more favorable prognosis of HCC. Genetic alterations in the ZFPM2 gene may contribute to a worse prognosis of HCC. Validation of the GSE14520 dataset also demon stared that ZFPM2 gene expression levels were significantly decreased in HCC tissues (P<0.001). The receiver operating characteristic (ROC) analysis of the ZFPM2 gene indicated high accuracy of this gene in distinguishing between HCC tissues and non-tumor tissues. The areas under the ROC curves were >0.8. Using integrated strategies, the present study demonstrated that lncRNA ZFPM2-AS1 and the ZFPM2 gene may contribute to the occurrence and prognosis of HCC. These findings may provide a novel understanding of the molecular mechanisms underlying the occurrence and prognosis of HCC.

Genome wide analysis of gene expression changes in skin from patients with type 2 diabetes

Non-healing chronic ulcers are a serious complication of diabetes and are a major healthcare problem. While a host of treatments have been explored to heal or prevent these ulcers from forming, these treatments have not been found to be consistently effective in clinical trials. An understanding of the changes in gene expression in the skin of diabetic patients may provide insight into the processes and mechanisms that precede the formation of non-healing ulcers. In this study, we investigated genome wide changes in gene expression in skin between patients with type 2 diabetes and non-diabetic patients using next generation sequencing. We compared the gene expression in skin samples taken from 27 patients (13 with type 2 diabetes and 14 non-diabetic). This information may be useful in identifying the causal factors and potential therapeutic targets for the prevention and treatment of diabetic related diseases.

Long Noncoding RNA HULC Promoter Polymorphism rs1041279 Is Associated with an Increased Risk of Cervical Squamous Cell Carcinoma

Hepatocellular carcinoma upregulated long noncoding RNA (HULC), identified as an oncogene in cervical cancer, is involved in not only the clinical stage, lymph node metastasis, and depth of cervical invasion but also outcome. In this study, we aimed to investigate the association between 3 polymorphisms (i.e., rs1041279, rs3005167, and rs7770772) in the promoter of HULC and the risk of cervical squamous cell carcinoma (CSCC). The polymorphisms were genotyped using the multiplex ligase detection reaction assay. The promoter activity was measured using the dual-luciferase reporter assay kit. The rs1041279 GG genotype and G allele revealed a significantly higher risk of CSCC compared with the rs1041279 CC genotype and C allele (GG vs. CC, adjusted OR = 1.79, 95% CI, 1.17-2.73, P = 0.007; G vs. C, adjusted OR = 1.36, 95% CI, 1.09-1.69, P = 0.006). Haplotype analysis revealed that the rs3005167C-rs7770772G-rs1041279C or rs3005167C-rs7770772G-rs1041279G haplotype had a significantly higher risk of CSCC compared to the rs3005167G-rs7770772G-rs1041279C haplotype (CGC vs. GGC, OR = 2.38, 95% CI, 1.53-3.75, P < 0.001; CGG vs. GGC, OR = 3.76, 95% CI, 2.12-6.68, P < 0.001). Dual-luciferase reporter assay showed that the rs1041279 G promoter resulted in higher transcriptional activity compared with the rs1041279 C (P < 0.01). Additionally, the rs1041279 GG genotype carriers had an increased level of HULC expression (P = 0.03). These findings suggest that the HULC rs1041279 may be a useful marker for the etiology of CSCC.

Long noncoding RNA AURKAPS1 potentiates malignant hepatocellular carcinoma progression by regulating miR-142, miR-155 and miR-182

The mitotic serine/threonine kinase aurora kinase-A (AURKA) has been identified as carcinogenic in hepatocellular carcinoma (HCC). AURKAPS1, a long non-coding RNA (lncRNA), is the pseudo-gene of AURKA, which play important roles in the cancer. Its underlying functions and mechanisms in liver cancer progression remain largely unknown. The mRNA expression of AURKAPS1 in HCC tumor tissues was significantly higher, which is associated with tumor size and TNM stage. The high expression of AURKAPS1 promotes cell movement, migration and invasion. AURKAPS1 can increases the protein expression of RAC1, promotes the activation of ERK, and enhance the formation of membrane ruffles by binding with miR-182, miR-155 and miR-142 competively. Thus, AURKAPS1 could be a useful marker, and the combination of AURKAPS1/miRNAs (miR-142, miR-155 and miR-182) may be a new theoretical basis for the treatment of HCC.

Long non‑coding RNAs in HBV‑related hepatocellular carcinoma (Review)

Hepatitis B virus (HBV)‑related hepatocellular carcinoma (HCC) is a global health problem that accounts for more than half of total liver cancer cases in developing countries. Despite the growing number of researches conducted, the molecular mechanism underlying the development of HCC remains elusive. Long non‑coding RNAs (lncRNAs), which are non‑coding RNAs >200 nt in length that were previously considered to be transcriptional noise, have been found to be dysregulated in HBV‑related HCC with the help of high‑throughput omics techniques. Subsequent investigations revealed that aberrant expression of lncRNAs may affect the risk of HBV‑related HCC through diverse mechanisms, including epigenetic silencing of transcriptional activation, alternative splicing, molecular sponging, modulating protein stability, and by serving as precursors of miRNAs. Although the sensitivity and specificity of lncRNAs must be further validated, a number of circulating lncRNAs have been identified as useful biomarkers for HBV‑related HCC. In addition to these findings, recent studies also unveiled that certain genetic polymorphisms in lncRNAs may affect the occurrence and prognosis of HBV‑related HCC. The aim of the present review was to provide an overview of the mechanisms underlying the involvement of lncRNAs in HBV‑related HCC. Subsequently, lncRNAs found to be dysregulated in HBV‑related HCC were focused on and current findings on circulating lncRNAs and their genetic polymorphisms were discussed.

Impact of four lncRNA polymorphisms (rs2151280, rs7763881, rs1136410, and rs3787016) on glioma risk and prognosis: A case-control study

Long noncoding RNA (lncRNA) polymorphisms are reportedly in connection with tumor susceptibility and prognosis. Glioma is one of the most aggressive and common cancers of the central nervous system. This study aimed to investigate the relationship between four lncRNA variants and glioma susceptibility and prognosis in a Chinese Han population. Sequenom Mass-ARRAY was used to genotype 605 patients with glioma and 1300 cancer-free individuals. Odds ratios or hazard ratios and related 95% confidence intervals were calculated to estimate the correlations. Logistic and Cox regression models, log-rank tests, and Kaplan-Meier curves were used for the statistical analysis. Six inheritance models showed that ANRIL rs2151280 variant genotype (A>G) was related to the susceptibility of glioma, while the other three lncRNAs showed no association. Patients treated with temozolomide or nimustine had better progression-free survival (PFS) and overall survival (OS) than those treated with platinum. Besides, patients aged older than 40 years showed a poorer OS. The Cox multivariate analysis revealed that the rs1136410 GG genotype (A>G) was beneficial for OS and PFS. The Kaplan-Meier analyses indicated that rs1136410 A>G and the rs7763881 A>C were associated with longer OS. ANRIL rs2151280 variant genotype might increase susceptibility of glioma. In addition, PARP1 rs1136410 variant genotype could be beneficial for the overall survival of patients with glioma. More research data are needed to further validate our results.

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.

LncRNA HULC promotes lung squamous cell carcinoma by regulating PTPRO via NF-κB

Accumulating studies have implicated that long noncoding RNA (lncRNA) plays a vital role in lung cancer. However, little is known of the role of lncRNA highly upregulated in liver cancer (HULC) in the pathogenesis of lung squamous cell carcinoma (LSCC). In this study, we investigated the modifying effects and underlying mechanisms of lncRNA HULC in LSCC. Significantly decreased level of lncRNA HULC was observed in LSCC samples compared with adjacent tissues. Besides, the expression of lncRNA HULC was negatively associated with protein tyrosine phosphatase receptor type O (PTPRO) in LSCC. Moreover, lncRNA HULC could promote the proliferation of LSCC cells by downregulating the expression PTPRO dependent on the phosphorylation and activation of nuclear factor-κB (NF-κB). The present study firstly shows strong evidence supporting a critical role of lncRNA HULC in promoting LSCC by regulating PTPRO/NF-κB signaling pathway, which provides new promising biomarkers for LSCC.

GOLGA7 rs11337, a Polymorphism at the MicroRNA Binding Site, Is Associated with Glioma Prognosis

MicroRNAs bind to the 3' untranslated regions of mRNAs, affecting translation, tumorigenesis, and apoptosis. This study evaluated the role of TYMS (rs1059394, C > T, and rs2847153, G > A), RYR3 (rs1044129, G > A), KIAA0423 (rs1053667, T > C), and GOLGA7 (rs11337, G > T) polymorphisms for assessment of glioma risk and prognosis among the Chinese Han population. Five single-nucleotide polymorphisms were assessed in 605 glioma patients and 1,300 controls. We found a significant correlation between rs1059394 and glioma susceptibility in the homozygote and dominant genetic models (TT versus CC, odds ratio [OR] = 0.71, 95% confidence interval [CI] = 0.52-0.97, p = 0.03; CT+TT versus CC, OR = 0.74, 95% CI = 0.55-0.99, p = 0.04). The results of the Kaplan-Meier and log rank tests revealed that the rs11337 GG genotype correlated with better overall survival of glioma patients (p = 0.017) than the GT genotype. Multivariate Cox regression analysis results also showed that the rs11337 GT genotype correlated with worse overall survival (p = 0.017, hazard ratio [HR] = 1.25, 95% CI = 1.04-1.5) than the GG genotype. These results suggest that GOLGA7 (rs11337) polymorphism may play a role in the prognosis of glioma patients and that TYMS (rs1059394) is associated with glioma risk.

Association of tagSNPs at lncRNA MALAT-1 with HCC Susceptibility in a Southern Chinese Population

As a long non-coding RNA (lncRNA) and a transcriptional regulator, Metastasis associated lung adenocarcioma transcript-1 (MALAT-1) has been reported to be associated with proliferation and metastasis of hepatocellular carcinoma (HCC). However, the effects of MALAT-1 single nucleotide polymorphisms (SNPs) on HCC remains poorly understood. This study, including 624 HCC cases and 618 controls, aimed to explore the potential associations between three common tagSNPs at MALAT-1 and HCC risk in a Southern Chinese population. No significant associations were observed between the three tagSNPs and HCC risk under any genetic models after adjusting for potential confounders. Additionally, there were no any significant associations in the stratified analysis, combined effect analysis, and multifactor dimensionality reduction (MDR) analysis. Unification analysis of mediation and interaction on HCC risk further showed that four decomposition of total effects ((controlled direct effect (CDE), the reference interaction effect (INTref), the mediated interaction effect (INTmed), or the pure indirect effect (PIE)) were also not significant. Neither was the association between the MALAT-1 SNPs and progression factors of HCC, including TNM staging, metastasis, and cancer embolus; Overall, this study suggested that tagSNPs rs11227209, rs619586, and rs3200401 at MALAT-1 were not significantly associated with HCC susceptibility. Nevertheless, large population-based studies are warranted to further explore the role of MALAT-1 SNPs in HCC incidence and development.

lncRNA HULC facilitates efficient loading of HCV-core protein onto lipid droplets and subsequent virus-particle release

The cellular lipid pool plays a central role in hepatitis C virus (HCV) life cycle, from establishing infection to virus propagation. Here, we show that a liver abundant long noncoding RNA, highly upregulated in liver carcinoma (HULC), is upregulated during HCV infection and manipulates the lipid pool to favour virus life cycle. Interestingly, HULC was found to be crucial for the increase in number of lipid droplets in infected cells. This effect was attributed to the role of HULC in lipid biogenesis. Further, we demonstrated that HULC knockdown decreases the association of HCV-core protein with lipid droplets. This exhibited a direct consequence on the release of HCV particles. The role of HULC in HCV-particle release was further substantiated by additional knockdown and mutation experiments. Additionally, we found that increased level of HULC in HCV-infected cells was a result of Retinoid X Receptor Alpha (RXRA)-mediated transcription, which seemed to be aided by HCV-core protein. Taken together, the results identify a distinct role of long noncoding RNA HULC in lipid dynamics during HCV infection, which provides new insights into the complex process of HCV propagation and pathogenesis.

Up-regulation of long non-coding RNA-PCAT-1 promotes invasion and metastasis in esophageal squamous cell carcinoma

Long non-coding RNA prostate cancer associated transcript-1 ncRNA (lncRNA-PCAT-1) plays an important role in the progression of prostate cancer. The present investigation was aimed to evaluate the potential roles of the lncRNA-PCAT-1 gene expression changes in esophageal squamous cell carcinoma (ESCC) between Iranian population. In the case-control investigation, we have analyzed a total of 150 fresh tissue samples, compromising of 75 cancerous tissues and 75 adjacent normal tissues from patients with ESCC. We used quantitative Real-time polymerase chain reaction (qRT-PCR) to evaluate the lncRNA-PCAT-1 gene expression levels in ESCC patients and correlation between the lncRNA-PCAT-1 expression changes and clinical characteristics. Our findings showed that the lncRNA-PCAT-1 gene was up-regulated in cancerous tissues compared with the adjacent non-cancerous tissues (p=0.0016). In addition, the results revealed a significant correlation between up-regulating of lncRNA-PCAT-1 and hot liquid drinking (p =0.017). These findings offer the potential roles of lncRNA-PCAT-1 in the pathogenesis of ESCC and may consider as a candidate prognostic biomarker for ESCC in an Iranian population.

LncRNAs with miRNAs in regulation of gastric, liver, and colorectal cancers: updates in recent years

Long noncoding RNA (lncRNA) is a kind of RNAi molecule composed of hundreds to thousands of nucleotides. There are several major types of functional lncRNAs which participate in some important cellular pathways. LncRNA-RNA interaction controls mRNA translation and degradation or serves as a microRNA (miRNA) sponge for silencing. LncRNA-protein interaction regulates protein activity in transcriptional activation and silencing. LncRNA guide, decoy, and scaffold regulate transcription regulators of enhancer or repressor region of the coding genes for alteration of expression. LncRNA plays a role in cellular responses including the following activities: regulation of chromatin structural modification and gene expression for epigenetic and cell function control, promotion of hematopoiesis and maturation of immunity, cell programming in stem cell and somatic cell development, modulation of pathogen infection, switching glycolysis and lipid metabolism, and initiation of autoimmune diseases. LncRNA, together with miRNA, are considered the critical elements in cancer development. It has been demonstrated that tumorigenesis could be driven by homeostatic imbalance of lncRNA/miRNA/cancer regulatory factors resulting in biochemical and physiological alterations inside the cells. Cancer-driven lncRNAs with other cellular RNAs, epigenetic modulators, or protein effectors may change gene expression level and affect the viability, immortality, and motility of the cells that facilitate cancer cell cycle rearrangement, angiogenesis, proliferation, and metastasis. Molecular medicine will be the future trend for development. LncRNA/miRNA could be one of the potential candidates in this category. Continuous studies in lncRNA functional discrepancy between cancer cells and normal cells and regional and rational genetic differences of lncRNA profiles are critical for clinical research which is beneficial for clinical practice.

The expression of long non coding RNA genes is associated with expression with polymorphisms of HULC rs7763881 and MALAT1 rs619586 in hepatocellular carcinoma and HBV Egyptian patients

Long noncoding RNAs (lncRNAs), highly upregulated liver cancer (HULC), metastasis-associated lung adenocarcinoma transcript 1 (MALAT1), lncRNA-AF085935, and lncRNA-uc003wbd have been implicated in hepatocellular carcinoma (HCC). Single-nucleotide polymorphism (SNP) in HULC and MALAT1 are associated with HCC susceptibility. However, association between these SNPs and lncRNA-AF085935 and lncRNA-uc003wbd expression and their potential clinical value in differentiating HCC from both hepatitis B virus (HBV)-infected Egyptian patients and the healthy specimens have not been explored yet. In the present study, SNPs rs7763881 in HULC and rs619586 in MALAT1 were genotyped in 70 HBV-positive HCC, 70 HBV patients, and 70 healthy controls in Egyptian population and the level of serum lncRNA-AF085935 and lncRNA-uc003wbd of all the subjects was assayed by quantitative real-time polymerase chain reaction. HULC rs7763881 AC/CC genotype was significantly associated with decreased HCC risk. Similarly, AG/GG of MALAT1 rs619586 was associated with decreased HCC risk with a borderline significance. Serum lncRNA-AF085935 and lncRNA-uc003wbd levels were upregulated in HBV-positive HCC and HBV patients vs controls and discriminated these groups by receiver operating characteristic analysis. Patients carrying AC/CC genotype of rs7763881 and AG/GG of rs619586 had lower serum lncRNA-AF085935 and lncRNA-uc003wbd levels compared with AA genotype. In conclusion, genetic variants of lncRNA HULC and lncRNA MALAT1 are associated with the decreased susceptibility to HCC in HBV-persistent carriers and are correlated with serum lncRNA-AF085935 and lncRNAuc003wbd levels, two potential noninvasive diagnostic biomarkers for HCC.

The lncRNA MALAT1 rs619586 G Variant Confers Decreased Susceptibility to Recurrent Miscarriage

Cardiovascula disease and recurrent miscarriage have shared risk factors, and some cardiovascular disease-related candidate genes have been confirmed to be associated with recurrent miscarriage. Metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) is a long non-coding RNA (lncRNA) that is considered to be associated with susceptibility to cardiovascular disease. However, whether lncRNA MALAT1 polymorphisms are related to recurrent miscarriage susceptibility is unclear. We genotyped three lncRNA MALAT1 polymorphisms (rs591291, rs619586, and rs3200401) in 284 patients and 392 controls using TaqMan methods. Logistic regression was used to evaluate the odds ratios (ORs) and 95% confidence intervals (CIs) adjusted for age. Our results showed that the rs619586 G variant had protective effects against recurrent miscarriage (AG vs. AA: adjusted OR = 0.670, 95% CI = 0.457–0.982, p = 0.040; GG vs. AA: adjusted OR = 0.278, 95% CI = 0.079–0.975, p = 0.046; GG/AG vs. AA adjusted OR = 0.621, 95% CI = 0.429–0.900, p = 0.012). In a combined analyses of protective genotypes, with regard to the three single nucleotide polymorphisms (SNPs), we found that individuals with two or three protective genotypes exhibited a significantly lower risk of recurrent miscarriage than those with no or only one protective genotype (adjusted OR = 0.369, 95% CI = 0.199–0.684, p = 0.002). Moreover, the decrease in recurrent miscarriage risk with two or three protective genotypes was most pronounced in women less than 35 years of age (OR = 0.290, 95% CI = 0.142–0.589, p < 0.001) and in women with 2–3 miscarriages (adjusted OR = 0.270, 95% CI = 0.126–0.580, p < 0.001). In conclusion, our study suggests that the rs619586 G variant may have potential protective effects conferring a decreased risk of recurrent miscarriage in the southern Chinese population.

Interplay Between Long Noncoding RNAs and MicroRNAs in Cancer

In the last decade noncoding RNAs (ncRNAs) have been extensively studied in several biological processes and human diseases including cancer. microRNAs (miRNAs) are the best-known class of ncRNAs. miRNAs are small ncRNAs of around 20-22 nucleotides (nt) and are crucial posttranscriptional regulators of protein coding genes. Recently, new classes of ncRNAs, longer than miRNAs have been discovered. Those include intergenic noncoding RNAs (lincRNAs) and circular RNAs (circRNAs). These novel types of ncRNAs opened a very exciting field in biology, leading researchers to discover new relationships between miRNAs and long noncoding RNAs (lncRNAs), which act together to control protein coding gene expression. One of these new discoveries led to the formulation of the "competing endogenous RNA (ceRNA) hypothesis." This hypothesis suggests that an lncRNA acts as a sponge for miRNAs reducing their expression and causing the upregulation of miRNA targets. In this chapter we first discuss some recent discoveries in this field showing the mutual regulation of miRNAs, lncRNAs, and protein-coding genes in cancer. We then discuss the general approaches for the study of ceRNAs and present in more detail a recent computational approach to explore the ability of lncRNAs to act as ceRNAs in human breast cancer that has been shown to be, among the others, the most precise and promising.

Involvement of long non-coding RNA HULC (highly up-regulated in liver cancer) in pathogenesis and implications for therapeutic intervention

INTRODUCTION

HULC (highly upregulated in liver cancer) is a long non-coding RNA (lncRNA) which is, as its name suggests, highly upregulated in hepatocellular carcinoma and in several other cancers. Increased HULC expression levels are strongly associated with clinicopathologic features such as tumor stages and overall survival and is a driver of tumor proliferation, migration, and invasion. Areas covered: This review addresses the discovery of HULC and discusses the consequences of HULC deregulation in cancer, the underlying molecular mechanisms and the potential of HULC as a biomarker and therapeutic target. Expert opinion: HULC is a promising candidate as a therapeutic target in cancer; however, more studies are necessary to further elucidate the underlying molecular mechanism(s), especially in cancer types other than hepatocellular carcinomas. Future studies that focus on an optimized HULC-targeting approach are necessary to clarify the best strategy to target this lncRNA in vivo and in patients.

Epithelial Mesenchymal and Endothelial Mesenchymal Transitions in Hepatocellular Carcinoma: A Review

PURPOSE

To present a comprehensive review of the literature data, published between 2000 and 2019 on the PubMed and Web of Science databases, in the field of the tumor microenvironment in hepatocellular carcinoma (HCC). All the data were combined with the personal experiences of the authors.

DESIGN

From 1002 representative papers, we selected 86 representative publications which included data on epithelial-to-mesenchymal transition (EMT), angiogenesis, cancer stem-like cells (CSCs), and molecular background of chemoresistance or resistance to radiotherapy.

RESULTS

Although the central event concerns activation of the Wnt/β-catenin pathway, other signal pathways, such as c-Met/HGF/Snail, Notch-1/NF-κB, TGF-β/SMAD, and basic fibroblast growth factor-related signaling, play a role in the EMT of HCC cells. This pathway is targeted by specific miRNAs and long noncoding RNAs, as explored in this paper. A central player in the tumor microenvironment proved to be the CSCs which can be marked by CD133, CD44, CD90, EpCAM, and CD105. CSCs can induce resistance to cytotoxic therapy or, alternatively, can be synthesized, de novo, after chemo- or radiotherapy, especially after transarterial chemoembolization- or radiofrequency ablation-induced hypoxia. The circulating tumor cells proved to have epithelial, intermediate, or mesenchymal features; their properties have a critical prognostic role.

CONCLUSION

The metastatic pathway of HCC seems to be related to the Wnt- or, rather, TGFβ1-mediated inflammation-angiogenesis-EMT-CSCs crosstalk link. Molecular therapy should target this molecular axis controlling the HCC microenvironment.

The Interaction of lncRNA-HEIH and lncRNA-HULC with HBXIP in Hepatitis B Patients

Hepatitis B virus (HBV) infection is a major risk factor for the development of hepatic cirrhosis (HC) and hepatocellular carcinoma (HCC), which are associated with very high morbidity and mortality rates worldwide. Many studies have shown that long noncoding RNAs (lncRNAs) that are highly expressed in HCC (lncRNA-HEIH) and highly upregulated in liver cancer (lncRNA-HULC) have been implicated in the development and progression of hepatitis B-related HC and HCC. In this study, reverse transcription and quantitative PCR were used to detect the expression of lncRNA-HEIH and lncRNA-HULC and western blot analysis to detect the expression of hepatitis B X-interacting protein (HBXIP). RNA immunoprecipitation was used to detect the interaction of HBXIP with lncRNA-HULC and lncRNA-HEIH. The results showed that lncRNA-HEIH, lncRNA-HULC, and HBXIP were upregulated in hepatitis B patients, particularly those with hepatitis B-related HCC. Both lncRNA-HEIH and lncRNA-HULC interacted with HBXIP. These results suggest that lncRNA-HEIH and lncRNA-HULC interact with HBXIP in hepatitis B-related diseases.

The rs2147578 C > G polymorphism in the Inc-LAMC2-1:1 gene is associated with increased neuroblastoma risk in the Henan children

BACKGROUND

The rs2147578 C > G polymorphism in the long non-coding RNA gene Lnc-LAMC2-1:1 is associated with increased susceptibility to a few types of cancers. However, its role in neuroblastoma has not been evaluated yet.

METHODS

We investigated the association between the lnc-LAMC2-1:1 rs2147578 C > G polymorphism and neuroblastoma susceptibility in Chinese Han populations. A total of 393 neuroblastoma cases and 812 healthy individuals from the Henan and Guangdong provinces were enrolled and subjected to genotyping. Odds ratio (OR) and 95% confidence interval (CI) were used to determine the strength of the association of interest.

RESULTS

Combined analysis revealed that the lnc-LAMC2-1:1 rs2147578 C > G polymorphism was associated with increased neuroblastoma susceptibility (CG vs. CC: adjusted OR = 1.33, 95% CI = 1.01-1.75, P = 0.045; CG/GG vs. CC: adjusted OR = 1.34, 95% CI = 1.03-1.74, P = 0.028). In stratification analysis, children under 18 months with rs2147578 CG/GG genotypes had an increased neuroblastoma risk (adjusted OR = 1.70, 95% CI = 1.08-2.67, P = 0.022). Females with rs2147578 CG/GG genotypes also had increased neuroblastoma susceptibility (adjusted OR = 2.08, 95% CI = 1.37-3.18, P = 0.0007). In addition, children with lnc-LAMC2-1:1 rs2147578 CG/GG genotypes were prone to develop earlier stages of neuroblastoma (adjusted OR = 1.46, 95% CI = 1.01-2.12, P = 0.046).

CONCLUSIONS

The Lnc-LAMC2-1:1 rs2147578 C > G polymorphism may contribute to increased neuroblastoma susceptibility in children of Henan province.

Variation in the Untranslated Genome and Susceptibility to Infections

The clinical outcomes of infections are highly variable among individuals and are determined by complex host-pathogen interactions. Genome-wide association studies (GWAS) are powerful tools to unravel common genetic variations that are associated with disease risk and clinical outcomes. However, GWAS has only rarely revealed information on the exact genetic elements and their effects underlying an association because the majority of the hits are within non-coding regions. Some of the variants or the linked polymorphisms are now being discovered to have functional significance, such as regulatory elements in the promoter and enhancer regions or the microRNA binding sites in the 3′untranslated region of the protein-coding genes, which influence transcription, RNA stability, and translation of the protein-coding genes. However, only 3% of the entire transcriptome is protein-coding, signifying that non-coding RNAs represent most of the transcripts. Thus, a large portion of previously identified intergenic GWAS single nucleotide polymorphisms (SNPs) is in the non-coding RNAs. The non-coding RNAs form a large-scale regulatory network across the transcriptome, greatly expanding the complexity of gene regulation. Accumulating evidence also suggests that the “non-coding” genome regions actively regulate the highly dynamic three dimensional (3D) chromatin structures, which are critical for genome function. Epigenetic modulation like DNA methylation and histone modifications further affect chromatin accessibility and gene expression adding another layer of complexity to the functional interpretation of genetic variation associated with disease outcomes. We provide an overview of the current information on the influence of variation in these “untranslated” regions of the human genome on infectious diseases. The focus of this review is infectious disease-associated polymorphisms and gene regulatory mechanisms of pathophysiological relevance.

Association between H19 SNP rs217727 and lung cancer risk in a Chinese population: a case control study

Background

H19 was the first long non-coding RNA (lncRNA) to be confirmed. Recently, studies have suggested that H19 may participate in lung cancer (LC) development and progression. This study assessed whether single nucleotide polymorphisms (SNPs) in H19 are associated with the risk of LC in a Chinese population.

Methods

A case-control study was performed, and H19 SNP rs217727 was analyzed in 555 lung cancer patients from two hospitals and 618 healthy controls to test the association between this SNP and the susceptibility to LC.

Results

The A/A homozygous genotype of rs217727 was significantly associated with an increased LC risk (odds ratio (OR) = 1.661, 95% confidence interval (CI) = 1.155 to 2.388, P = 0.006). Significant associations remained after stratification by smoking status (P < 0.001). Furthermore, the A/A genotype had a higher risk of LC than those of G/G in the squamous cell carcinoma (OR = 2.022, P = 0.004) and adenocarcinoma (OR = 1.606, P = 0.045) subgroups.

Conclusions

The rs217727 SNP in lncRNA H19 was significantly associated with susceptibility to LC, particularly in squamous cell carcinoma and adenocarcinoma, and identified the homozygous A/A genotype as a risk factor for LC.

Association between long non-coding RNA polymorphisms and cancer risk: a meta-analysis

Several studies have suggested that long non-coding RNA (lncRNA) gene polymorphisms are associated with cancer risk. In the present study, we conducted a meta-analysis related to studies on the association between lncRNA single-nucleotide polymorphisms (SNPs) and the overall risk of cancer. A total of 12 SNPs in five common lncRNA genes were finally included in the meta-analysis. In the lncRNA antisense non-coding RNA (ncRNA) in the INK4 locus (ANRIL), the rs1333048 A/C, rs4977574 A/G, and rs10757278 A/G polymorphisms, but not rs1333045 C/T, were correlated with overall cancer risk. Our study also demonstrated that other SNPs were correlated with overall cancer risk, namely, metastasis-associated lung adenocarcinoma transcript 1 (MALAT1, rs619586 A/G), HOXA distal transcript antisense RNA (HOTTIP, rs1859168 A/C), and highly up-regulated in liver cancer (HULC, rs7763881 A/C). Moreover, four prostate cancer-associated ncRNA 1 (PRNCR1, rs16901946 G/A, rs13252298 G/A, rs1016343 T/C, and rs1456315 G/A) SNPs were in association with cancer risk. No association was found between the PRNCR1 (rs7007694 C/T) SNP and the risk of cancer. In conclusion, our results suggest that several studied lncRNA SNPs are associated with overall cancer risk. Therefore, they might be potential predictive biomarkers for the risk of cancer. More studies based on larger sample sizes and more lncRNA SNPs are warranted to confirm these findings.

Association of twelve polymorphisms in three onco-lncRNA genes with hepatocellular cancer risk and prognosis: A case-control study

AIM

To evaluate the association of 12 tag single nucleotide polymorphisms (tagSNPs) in three onco-long non-coding RNA (lncRNA) genes (HOTTIP, CCAT2, MALAT1) with the risk and prognosis of hepatocellular cancer (HCC).

METHODS

Twelve tagSNPs covering the three onco-lncRNAs were genotyped by the KASP method in a total of 1338 samples, including 521 HCC patients and frequency-matched 817 controls. The samples were obtained from an unrelated Chinese population at the First Hospital of China Medical University from 2012-2015. The expression quantitative trait loci (eQTL) analyses were conducted to explore further the potential function of the promising SNPs.

RESULTS

Three SNPs in HOTTIP, one promoter SNP in MALAT1, and one haplotype of HOTTIP were associated with HCC risk. The HOTTIP rs17501292, rs2067087, and rs17427960 SNPs were increased to 1.55-, 1.20-, and 1.18-fold HCC risk under allelic models (P = 0.012, 0.017 and 0.049, respectively). MALAT1 rs4102217 SNP was increased to a 1.32-fold HCC risk under dominant models (P = 0.028). In addition, the two-way interaction of HOTTIP rs17501292-MALAT1 rs619586 polymorphisms showed a decreased effect on HCC risk (P_interaction = 0.028, OR = 0.30) and epistasis with each other. HOTTIP rs3807598 variant genotype showed significantly longer survival time in HBV negative subgroup (P = 0.049, HR = 0.12), and MALAT1 rs591291 showed significantly better prognosis in female and HBV negative subgroups (P = 0.022, HR = 0.37; P = 0.042, HR = 0.25, respectively). In the study, no significant effect was observed in eQTL analysis.

CONCLUSION

Specific lncRNA (HOTTIP and MALAT1) SNPs have potential to be biomarkers for HCC risk and prognosis.

Association of polymorphisms in MALAT1 with risk of coronary atherosclerotic heart disease in a Chinese population

Background

Metastasis associated lung adenocarcinoma transcript 1 (MALAT1) plays an important role in vascular remodeling. Down-regulation of MALAT1 can inhibit the proliferation of vascular endothelial cells and vascular smooth muscle cells, reduce cardiomyocyte apoptosis and improve left ventricular function, which is closely linked to numerous pathological processes such as coronary atherosclerotic heart disease (CAD). The aim of this study was to investigate whether polymorphisms in MALAT1 were associated with the susceptibility to CAD.

Methods

A total of 508 CAD patients and 562 age-, gender-, and ethnicity-matched controls were enrolled in this study. Four polymorphisms in MALAT1 (i.e., rs11227209, rs619586, rs664589, and rs3200401) were genotyped using a TaqMan allelic discrimination assay.

Results

The rs619586 AG/GG genotypes and G allele were associated with a reduced risk of CAD (AG/GG vs. AA: adjusted OR = 0.66, 95% CI: 0.48–0.91; G vs. A: adjusted OR = 0.68, 95% CI: 0.51–0.90). Stratification analyses showed that CAD patients with rs11227209 CG/GG, rs619586 AG/GG, and rs3200401 CT/TT genotypes exhibited lower levels of TCH (P = 0.02, 0.04, and 0.02, respectively). Moreover, CGCC haplotype was associated with a decreased risk of CAD (OR = 0.28, 95% CI: 0.16–0.48). Multivariate logistic regression analysis identified some independent risk factors for CAD, including rs619586 and rs664589. Subsequent combined analysis showed that the combined genotypes of rs619586AG/GG and rs664589CC were associated with a reduced risk of CAD (OR = 0.29; 95%CI, 0.16–0.53).

Conclusions

These findings indicate that rs619586AG/GG genotypes in MALAT1 may protect against the occurrence of CAD.

Electronic supplementary material

The online version of this article (10.1186/s12944-018-0728-2) contains supplementary material, which is available to authorized users.

Oncogenic long noncoding RNA MALAT1 and HCV-related hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the second leading cause of cancer-related mortality worldwide. The oncogenic function of the long non-coding RNA; metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) in HCC remains unclear. We aimed to evaluate MALAT1 serum expression profile in HCC and explore its relation to the clinicopathological features. Quantitative Real Time-Polymerase Chain Reaction was applied in 70 cohorts (30 HCC, 20 HCV, 20 controls). Further meta-analysis of clinical studies and in vitro validated experiments was employed. Serum MALAT1 showed area under the curve of 0.79 and 0.70 to distinguish patients with cancer from normal and cirrhotic individuals at fold change of 1.0 and 1.26, respectively. Expression level was significantly higher in males (P <0.001) and patients with massive ascites (P = 0.005). Correlation analysis showed positive correlation of MALAT1 with total bilirubin (r = 0.456, P <0.001) and AST (r = 0.280, P = 0.019), and negative correlation with the hemoglobin level (r = 0.312, P = 0.009). Meta-analysis showed that the over-expressed MALAT1 was linked to tumor number [Cohen's d = 0.450, 95% CI (0.21 to 0.68)], clinical stage [Cohen's d = 0.048, 95% CI (-0.83 to 0.74)], and AFP level [Cohen's d = 0.354, 95% CI (0.1 to 0.57)]. In silico data analysis and systematic review confirmed MALAT1 oncogenic function in cancer development and progression. In conclusion, circulatory MALAT1 might represent a putative non-invasive prognostic biomarker indicating worse liver failure score in HCV-related HCC patients with traditional markers. Large-scale verification is warranted in future studies.

The Role of Long Non-Coding RNAs in Hepatocarcinogenesis

Whole-transcriptome analyses have revealed that a large proportion of the human genome is transcribed in non-protein-coding transcripts, designated as long non-coding RNAs (lncRNAs). Rather than being “transcriptional noise”, increasing evidence indicates that lncRNAs are key players in the regulation of many biological processes, including transcription, post-translational modification and inhibition and chromatin remodeling. Indeed, lncRNAs are widely dysregulated in human cancers, including hepatocellular carcinoma (HCC). Functional studies are beginning to provide insights into the role of oncogenic and tumor suppressive lncRNAs in the regulation of cell proliferation and motility, as well as oncogenic and metastatic potential in HCC. A better understanding of the molecular mechanisms and the complex network of interactions in which lncRNAs are involved could reveal novel diagnostic and prognostic biomarkers. Crucially, it may provide novel therapeutic opportunities to add to the currently limited number of therapeutic options for HCC patients. In this review, we summarize the current status of the field, with a focus on the best characterized dysregulated lncRNAs in HCC.