Long non-coding RNA in lung cancer

LncRNA HAR1A inhibits non-small cell lung cancer growth by downregulating c-MYC transcripts and facilitating its proteasomal degradation

Non-small cell lung cancer (NSCLC) is a primary cause of cancer-related mortality on a global scale. Research increasingly shows that long non-coding RNAs (lncRNAs) play crucial regulatory roles and serve as biomarkers for diagnosis, prognosis, therapy monitoring, and druggable targets in NSCLC. We previously identified HAR1A as a tumor-suppressing lncRNA in NSCLC, with its loss also observed in oral and hepatocellular carcinoma. This study aimed to expand the understanding of the functional role of HAR1A in NSCLC and uncover its underlying mechanisms. Our results demonstrated that elevating HAR1A levels impeded NSCLC cell proliferation and migration but promoted apoptosis, thereby boosting their susceptibility to cisplatin. Subsequently, we discovered that HAR1A enhanced cisplatin's cytotoxicity in NSCLC cells by curbing adaptive autophagy through the downregulation of MYC. Further analysis revealed that HAR1A suppresses MYC by both lowering its transcript levels and promoting protein ubiquitination and degradation, thereby restricting tumor cell proliferation, migration, and adaptive autophagy. In exploring MYC's targets, we observed that MYC upregulated the transcription of heat shock protein 90 alpha family class B member 1 (HSP90AB1/HSP90β) gene. Rescue experiments verified that HAR1A mitigated NSCLC cell proliferation and migration and induced apoptosis through the MYC/HSP90β axis. Finally, we confirmed that HAR1A overexpression increased cisplatin efficacy in nude mouse NSCLC xenograft models.In conclusion, the findings suggest that HAR1A could be a promising therapeutic target in treating NSCLC and biomarkers for predicting chemotherapy outcomes. This study provides new insights into the molecular mechanisms of chemoresistance in NSCLC and underscores the potential of lncRNA-based strategies in cancer therapy.

"Crosstalk between non-coding RNAs and transcription factor LRF in non-small cell lung cancer"

Epigenetic approaches in direct correlation with assessment of critical genetic mutations in non-small cell lung cancer (NSCLC) are currently very intensive, as the epigenetic components underlying NSCLC development and progression have attained high recognition. In this level of research, established human NSCLC cell lines as well as experimental animals are widely used to detect novel biomarkers and pharmacological targets to treat NSCLC. The epigenetic background holds a great potential for the identification of epi-biomarkers for treatment response however, it is highly complex and requires precise definition as these phenomena are variable between NSCLC subtypes and systems origin. We engaged an in-depth characterization of non-coding (nc)RNAs prevalent in human KRAS-mutant NSCLC cell lines A549 and H460 and mouse KRAS-mutant NSCLC tissue by Next Generation Sequencing (NGS) and quantitative Real Time PCRs (qPCRs). Also, the transcription factor (TF) LRF, a known epigenetic silencer, was examined as a modulator of non-coding RNAs expression. Finally, interacting networks underlying epigenetic variations in NSCLC subtypes were created. Data derived from our study highlights the divergent epigenetic profiles of NSCLC of human and mouse origin, as well as the significant contribution of 12qf1: 109,709,060-109,747,960 mouse chromosomal region to micro-RNA upregulated species. Furthermore, the novel epigenetic miR-148b-3p/lncPVT1/ZBTB7A axis was identified, which differentiates human cell line of lung adenocarcinoma from large cell lung carcinoma, two characteristic NSCLC subtypes. The detailed recording of epigenetic events in NSCLC and combinational studies including networking between ncRNAs and TFs validate the identification of significant epigenetic features, prevailing in NSCLC subtypes and among experimental models. Our results enrich knowledge in the field and empower research on the epigenetic prognostic biomarkers of the disease progression, NSCLC subtypes discrimination and advancement to patient-tailored treatments.

Unveiling the functions of five recently characterized lncRNAs in cancer progression

Numerous studies over the past few decades have shown that RNAs are multifaceted, multifunctional regulators of most cellular processes, contrary to the initial belief that they only act as mediators for translating DNA into proteins. LncRNAs, which refer to transcripts longer than 200nt and lack the ability to code for proteins, have recently been identified as central regulators of a variety of biochemical and cellular processes, particularly cancer. When they are abnormally expressed, they are closely associated with tumor occurrence, metastasis, and tumor staging. Therefore, through searches on Google Scholar, PubMed, and CNKI, we identified five five recently characterized lncRNAs-Lnc-SLC2A12-10:1, LncRNA BCRT1, lncRNA IGFBP4-1, LncRNA PCNAP1, and LncRNA CDC6-that have been linked to the promotion of cancer cell proliferation, invasion, and metastasis. Consequently, this review encapsulates the existing research and molecular underpinnings of these five newly identified lncRNAs across various types of cancer. It suggests that these novel lncRNAs hold potential as independent biomarkers for clinical diagnosis and prognosis, as well as candidates for therapeutic intervention. In parallel, we discuss the challenges inherent in the research on these five newly discovered lncRNAs and look forward to the avenues for future exploration in this field.

Modulation of long noncoding RNAs by polyphenols as a novel potential therapeutic approach in lung cancer: A comprehensive review

Lung cancer stands as a formidable global health challenge, necessitating innovative therapeutic strategies. Polyphenols, bioactive compounds synthesized by plants, have garnered attention for their diverse health benefits, particularly in combating various cancers, including lung cancer. The advent of whole-genome and transcriptome sequencing technologies has illuminated the pivotal roles of long noncoding RNAs (lncRNAs), operating at epigenetic, transcriptional, and posttranscriptional levels, in cancer progression. This review comprehensively explores the impact of polyphenols on both oncogenic and tumor-suppressive lncRNAs in lung cancer, elucidating on their intricate regulatory mechanisms. The comprehensive examination extends to the potential synergies when combining polyphenols with conventional treatments like chemotherapy, radiation, and immunotherapy. Recognizing the heterogeneity of lung cancer subtypes, the review emphasizes the need for the integration of nanotechnology for optimized polyphenol delivery and personalized therapeutic approaches. In conclusion, we collect the latest research, offering a holistic overview of the evolving landscape of polyphenol-mediated modulation of lncRNAs in lung cancer therapy. The integration of polyphenols and lncRNAs into multidimensional treatment strategies holds promise for enhancing therapeutic efficacy and navigating the challenges associated with lung cancer treatment.

An exosomes-related lncRNA prognostic model correlates with the immune microenvironment and therapy response in lung adenocarcinoma

Recent research highlights the significance of exosomes and long noncoding RNAs (lncRNAs) in cancer progression and drug resistance, but their role in lung adenocarcinoma (LUAD) is not fully understood. We analyzed 121 exosome-related (ER) mRNAs from the ExoBCD database, along with mRNA and lncRNA expression profiles of TCGA-LUAD using "DESeq2", "survival," "ConsensusClusterPlus," "GSVA," "estimate," "glmnet," "clusterProfiler," "rms," and "pRRophetic" R packages. This comprehensive approach included univariate cox regression, unsupervised consensus clustering, GSEA, functional enrichment analysis, and prognostic model construction. Our study identified 134 differentially expressed ER-lncRNAs, with 19 linked to LUAD prognosis. These ER-lncRNAs delineated two patient subtypes, one with poorer outcomes. Additionally, 286 differentially expressed genes were related to these ER-lncRNAs, 261 of which also correlated with LUAD prognosis. We constructed an ER-lncRNA-related prognostic model and calculated an ER-lncRNA-related risk score (ERS), revealing that a higher ERS correlates with poor overall survival in both the Meta cohort and two validation cohorts. The ERS potentially serves as an independent prognostic factor, and the prognostic model demonstrates superior predictive power. Notably, significant differences in the immune landscape were observed between the high- and low-ERS groups. Drug sensitivity analysis indicated varying responses to common chemotherapy drugs based on ERS stratification, with the high-ERS group showing greater sensitivity, except to rapamycin and erlotinib. Experimental validation confirmed that thymidine kinase 1 enhances lung cancer invasion, metastasis, and cell cycle progression. Our study pioneers an ER-lncRNA-related prognostic model for LUAD, proposing that ERS-based risk stratification could inform personalized treatment strategies to improve patient outcomes.

Dysregulation of lncRNA MALAT1 Contributes to Lung Cancer in African Americans by Modulating the Tumor Immune Microenvironment

African American (AA) populations present with notably higher incidence and mortality rates from lung cancer in comparison to other racial groups. Here, we elucidated the contribution of long non-coding RNAs (lncRNAs) in the racial disparities and their potential clinical applications in both diagnosis and therapeutic strategies. AA patients had elevated plasma levels of MALAT1 and PVT1 compared with cancer-free smokers. Incorporating these lncRNAs as plasma biomarkers, along with smoking history, achieved 81% accuracy in diagnosis of lung cancer in AA patients. We observed a rise in MALAT1 expression, correlating with increased levels of monocyte chemoattractant protein-1 (MCP-1) and CD68, CD163, CD206, indicative of tumor-associated macrophages in lung tumors of AA patients. Forced MALAT1 expression led to enhanced growth and invasiveness of lung cancer cells, both in vitro and in vivo, accompanied by elevated levels of MCP-1, CD68, CD163, CD206, and KI67. Mechanistically, MALAT1 acted as a competing endogenous RNA to directly interact with miR-206, subsequently affecting MCP-1 expression and macrophage activity, and enhanced the tumorigenesis. Targeting MALAT1 significantly reduced tumor sizes in animal models. Therefore, dysregulated MALAT1 contributes to lung cancer disparities in AAs by modulating the tumor immune microenvironment through its interaction with miR-206, thereby presenting novel diagnostic and therapeutic targets.

LncRNA MIR100HG affects the proliferation and metastasis of lung cancer cells through mediating the microRNA-5590-3p/DCBLD2 axis

OBJECTIVE

The aim of this paper is to investigate the effect of long noncoding RNA (lncRNA) MIR100HG on the proliferation and metastasis of lung cancer cells by mediating the microRNA (miR)-5590-3p/DCBLD2 axis.

METHODS

RNA levels of MIR100HG, miR-5590-3p, and DCBLD2 in lung cancer tissues and cells were detected by quantitative reverse-transcription polymerase chain reaction, and protein level was assessed by Western blot. Effects of MIR100HG or miR-5590-3p on proliferation, migration, and invasion of lung cancer cells were detected by Cell Counting Kit-8, colony formation, and Transwell assays. Luciferase reporter assay and RNA-immunoprecipitation assay confirmed the target relationship between miR-5590-3p and MIR100HG or DCBLD2.

RESULTS

MIR100HG and DCBLD2 were highly expressed, while miR-5590-3p was lowly expressed in lung cancer tissues and cells. Silencing MIR100HG or upregulating miR-5590-3p impeded lung cancer cell proliferation, migration, and invasion. MIR100HG could up-regulate DCBLD2 by sponging miR-5590-3p. Downregulation of miR-5590-3p partly overturned the suppressive effect of silencing MIR100HG on lung cancer cell proliferation and metastasis, and overexpression of DCBLD2 also reversed the effect of overexpression of miR-5590-3p on lung cancer cell proliferation and metastasis.

CONCLUSION

LncRNA MIR100HG promotes lung cancer progression by targeting and negatively regulating DCBLD2 through binding with miR-5590-3p.

Maimendong and Qianjinweijing Tang combined with cisplatin suppressed lung cancer through targeting lncRNA-p21

ETHNOPHARMACOLOGICAL RELEVANCE

Maimendong and Qianjinweijing Tang (Jin formula) is a traditional Chinese medicine formula that has been proven effective in the treatment of lung cancer in long-term clinical practice.

AIM OF THE STUDY

To evaluate the anti-tumor effects of Jin formula combined with cisplatin (JIN + DDP) in vivo and in vitro, as well as to explore the role of long non-coding RNA (lncRNA) in the anti-lung cancer mechanism of its action.

MATERIALS AND METHODS

A Lewis lung cancer model was established in C57 BL/6 mice to study the in vivo anti-tumor effect of Jin formula combined with cisplatin. TUNEL staining and western blot were applied to study the effects of Jin formula combined cisplatin on apoptosis. The in vitro anti-cancer function of Jin formula combined with cisplatin was explored by cell viability assay, flow cytometry, wound healing assay and transwell assay. The changes in lncRNA expression profiles were determined by lncRNA microarray, and the differentially expressed lncRNA-p21 was verified by quantitative reverse-transcription polymerase chain reaction (qRT-PCR) analysis. The expression differences of lncRNA-p21 in tumor and normal tissues were analyzed by bioinformatics, and the expression differences of lncRNA-p21 in tumor cells and normal cells were detected by qRT-PCR. The role of lncRNA-p21 in the anti-cancer effect of Jin formula combined cisplatin was investigated by knockdown or overexpression of lncRNA-p21 and a series of cell experiments. The expression of MAPK pathway-related proteins was analyzed by western blot.

RESULTS

Jin formula combined with cisplatin (JIN + DDP) can suppress tumor growth and promote apoptosis in Lewis lung cancer mouse model. LncRNA-p21 was significantly up-regulated in the JIN and JIN + DDP groups, and the expression of lncRNA-p21 in lung cancer tissues and cells was lower than that in normal tissues and cells. In vitro, JIN + DDP significantly induced apoptosis and inhibited the proliferation, migration, and invasion of H460 and H1650 lung cancer cells. The above effects can be enhanced by the overexpression of lncRNA-p21 and eliminated by knock-down of lncRNA-p21. Further studies revealed that JIN + DDP inhibited the expression of mitogen-activated protein kinase (MAPK) pathway-related proteins, whereas knock-down of lncRNA-p21 abrogated the inhibition of the MAPK signaling pathway.

CONCLUSIONS

This study showed that Jin formula combined with cisplatin could effectively inhibit the progression of lung cancer partially through targeting lncRNA-p21.

LncRNA linc01194 promotes the progress of endometrial carcinoma by up-regulating SOX2 through binding to IGF2BP1

OBJECTIVE

Endometrial carcinoma (EC) is one of the most common gynecological malignant tumors. Our study showed that long non-coding RNA (lncRNA) linc01194 plays an important role in EC. We explored the mechanism of lncRNA linc01194 in EC.

METHODS

The expression of lncRNA linc01194 was detected in The Cancer Genome Atlas database and starBase database. The potential targeted protein of linc01194 was predicted through the starBase database. To determine the role of linc01194 in EC, we downregulated or upregulated the level of linc01194 in EC cell lines and analyzed the cell behaviors and the changes of its potential target proteins.

RESULTS

The expression of linc01194 in EC tissues is higher than that in normal endometrial tissues. The knockdown of linc01194 inhibited the cell proliferation, invasion and migration and promoted the apoptosis of EC cells, while overexpression of linc01194 promoted cell proliferation, invasion and migration and inhibited the apoptosis of EC cells. The starBase database revealed that linc01194 could bind to insulin-like growth factor 2 binding protein 1 (IGF2BP1). Previous results showed that in EC, IGF2BP1 could promote the expression of sex-determining region Y-box 2 (SOX2) by promoting the stability of SOX2 mRNA. Our results showed that linc01194 regulate the expression of IGF2BP1 and SOX2.

CONCLUSION

Linc01194 can promote the expression of downstream protein SOX2 through binding to IGF2BP1, thus promoting the occurrence and development of EC.

LncRNA RP11-58O9.2 predicts poor prognosis and promotes progression of non-small cell lung cancer

OBJECTIVE

Long non-coding RNAs (lncRNAs) play a crucial role in non-small cell lung cancer (NSCLC). This study aimed to investigate the novel biomarker, lncRNA RP11-58O9.2, in patients with NSCLC.

METHODS

RP11-58O9.2 expression in NSCLC cells and tissues was detected by reverse transcription-quantitative polymerase chain reaction. Patient survival was analyzed in relation to RP11-58O9.2 expression levels. RP11-58O9.2 expression was knocked down and endogenous expression was verified in two NSCLC cell lines. Cell proliferation was then assessed by Cell Counting Kit-8 and colony-formation assays, and cell invasion and migration were assessed by Transwell and wound-healing assays, respectively. In vivo experiments were performed in mice, and the combination of RP11-58O9.2 and miR-6749-3p was predicted by miRanda.

RESULTS

RP11-58O9.2 was highly expressed in NSCLC cell lines and tissues, and was associated with advanced stage, lymphatic metastasis, and differentiation group. High RP11-58O9.2 levels were also associated with shorter survival. RP11-58O9.2 knockdown inhibited the proliferation, invasion, and migration of lung cancer cells, and tumor growth in mouse xenografts in vivo. RP11-58O9.2 may target and regulate miR-6749-3p.

CONCLUSIONS

LncRNA RP11-58O9.2 is associated with NSCLC prognosis and promotes lung cancer progression. Further studies are needed to investigate the mechanisms and the regulatory association between RP11-58O9.2 and miR-6749-3p.

Epigenetic regulation in major depression and other stress-related disorders: molecular mechanisms, clinical relevance and therapeutic potential

Major depressive disorder (MDD) is a chronic, generally episodic and debilitating disease that affects an estimated 300 million people worldwide, but its pathogenesis is poorly understood. The heritability estimate of MDD is 30-40%, suggesting that genetics alone do not account for most of the risk of major depression. Another factor known to associate with MDD involves environmental stressors such as childhood adversity and recent life stress. Recent studies have emerged to show that the biological impact of environmental factors in MDD and other stress-related disorders is mediated by a variety of epigenetic modifications. These epigenetic modification alterations contribute to abnormal neuroendocrine responses, neuroplasticity impairment, neurotransmission and neuroglia dysfunction, which are involved in the pathophysiology of MDD. Furthermore, epigenetic marks have been associated with the diagnosis and treatment of MDD. The evaluation of epigenetic modifications holds promise for further understanding of the heterogeneous etiology and complex phenotypes of MDD, and may identify new therapeutic targets. Here, we review preclinical and clinical epigenetic findings, including DNA methylation, histone modification, noncoding RNA, RNA modification, and chromatin remodeling factor in MDD. In addition, we elaborate on the contribution of these epigenetic mechanisms to the pathological trait variability in depression and discuss how such mechanisms can be exploited for therapeutic purposes.

Exosome nanovesicles as potential biomarkers and immune checkpoint signaling modulators in lung cancer microenvironment: recent advances and emerging concepts

Lung cancer remains the leading cause of cancer-related deaths globally, and the survival rate remains low despite advances in diagnosis and treatment. The progression of lung cancer is a multifaceted and dynamic phenomenon that encompasses interplays among cancerous cells and their microenvironment, which incorporates immune cells. Exosomes, which are small membrane-bound vesicles, are released by numerous cell types in normal and stressful situations to allow communication between cells. Tumor-derived exosomes (TEXs) possess diverse neo-antigens and cargoes such as proteins, RNA, and DNA and have a unique molecular makeup reflecting tumor genetic complexity. TEXs contain both immunosuppressive and immunostimulatory factors and may play a role in immunomodulation by influencing innate and adaptive immune components. Moreover, they transmit signals that contribute to the progression of lung cancer by promoting metastasis, epithelial-mesenchymal transition (EMT), angiogenesis, and immunosuppression. This makes them a valuable resource for investigating the immune environment of tumors, which could pave the way for the development of non-invasive biomarkers that could aid in the prognosis, diagnosis, and immunotherapy of lung cancer. While immune checkpoint inhibitor (ICI) immunotherapy has shown promising results in treating initial-stage cancers, most patients eventually develop adaptive resistance over time. Emerging evidence demonstrates that TEXs could serve as a prognostic biomarker for immunotherapeutic response and have a significant impact on both systemic immune suppression and tumor advancement. Therefore, understanding TEXs and their role in lung cancer tumorigenesis and their response to immunotherapies is an exciting research area and needs further investigation. This review highlights the role of TEXs as key contributors to the advancement of lung cancer and their clinical significance in lung immune-oncology, including their possible use as biomarkers for monitoring disease progression and prognosis, as well as emerging shreds of evidence regarding the possibility of using exosomes as targets to improve lung cancer therapy.

Advances in the Molecular Landscape of Lung Cancer Brain Metastasis

Lung cancer is one of the most frequent tumors that metastasize to the brain. Brain metastasis (BM) is common in advanced cases, being the major cause of patient morbidity and mortality. BMs are thought to arise via the seeding of circulating tumor cells into the brain microvasculature. In brain tissue, the interaction with immune cells promotes a microenvironment favorable to the growth of cancer cells. Despite multimodal treatments and advances in systemic therapies, lung cancer patients still have poor prognoses. Therefore, there is an urgent need to identify the molecular drivers of BM and clinically applicable biomarkers in order to improve disease outcomes and patient survival. The goal of this review is to summarize the current state of knowledge on the mechanisms of the metastatic spread of lung cancer to the brain and how the metastatic spread is influenced by the brain microenvironment, and to elucidate the molecular determinants of brain metastasis regarding the role of genomic and transcriptomic changes, including coding and non-coding RNAs. We also present an overview of the current therapeutics and novel treatment strategies for patients diagnosed with BM from NSCLC.

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

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

Long Noncoding RNA IPW Is a Novel Diagnostic and Predictive Biomarker in Lung Adenocarcinoma

Background: Long non-coding RNAs (lncRNAs), as functional components of the human genome, are widely involved in cell proliferation, differentiation, apoptosis, migration and invasion by several types of cancer, including lung cancer. However, the role of lncRNA IPW in lung cancer has not been fully elucidated. The aim of the present study was to characterize the expression and clinical significance of lncRNA IPW in lung cancer. Materials and Methods: IPW expression in tumor samples and cells was assessed using the Oncomine and Cancer Cell Line Encyclopedia (CCLE) database, respectively. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was used to determine IPW expression and microRNA-370 (miR-370) expression. The clinical significance of IPW was evaluated by Chi-square test and Kaplan-Meier pot analyses. In addition, the sulforhodamine blue (SRB) assays was used to detect cell proliferation in IPW-overexpressed A549 cells. Results: IPW expression was significantly down-regulated in NSCLC tissues and was significantly associated with many clinicopathological data, including smoking history, differentiation, pT factor, pN factor and pTNM stage (p < 0.05). Decreased IPW expression was correlated with poor survival (p = 1.5e-05) and was positively associated with first progression in patients with lung adenocarcinoma (p = 0.00041). Furthermore, IPW could inhibit A549 cell proliferation and expression of miR-370. High miR-370 expression was associated with poor overall survival (OS) among lung adenocarcinoma patients (p = 0.045). Conclusions: These findings provide evidence that down-regulation of IPW might be considered as a beneficial prognostic biomarker and that it could potentially serve as therapeutic target in lung adenocarcinoma.

LncRNA BBOX1-AS1 Contributes to the Progression of Esophageal Carcinoma by Targeting the miR-361-3p/COL5A1 Axis

Long noncoding RNAs (lncRNAs) are known to participate in the progression of several cancers, including esophageal carcinoma (EC), a common malignancy of the digestive system. Although the role of the lncRNA-miRNA-mRNA regulatory network is crucial for the growth and progression of EC, the regulation of lncRNA BBOX1-AS1 (BBOX1 antisense RNA1) remains unclear. We performed reverse transcription-quantitative PCR (RT-qPCR) and western blotting to evaluate miR-361-3p, collagen type V alpha 1 chain (COL5A1), and BBOX1-AS1 expression levels in EC cells and tissues. The colony formation assay (CFA) and Cell Counting Kit-8 (CCK-8) were employed to identify EC cell proliferation, while western blotting was used to examine EC cell apoptosis and Bax and Bcl-2 expression levels. The effect of BBOX1-AS1 on EC proliferation was determined using an in vivo carcinogenesis assay. Correlation between COL5A1, BBOX1-AS1, and miR-361-3p was examined using the luciferase reporter system and RNA immunoprecipitation assay (RIP). Herein, we observed that BBOX1-AS1 expression levels were upregulated in EC cells and tissues. BBOX1-AS1 knockdown inhibited EC cell proliferation and conferred a pro-apoptotic effect. These results indicated a positive interaction between BBOX1-AS1 and miR-361-3p in EC and a negative association with miR-361-3p. COL5A1 was recognized as a downstream miR-361-3p target and was inversely related to miR-361-3p in EC. Therefore, BBOX1-AS1 expression suppressed cell apoptosis and promoted cell proliferation via the downregulation of miR-361-3p and upregulation of COL5A1 expression. Overall, BBOX1-AS1 facilitates EC progression via the miR-361-3p or COL5A1 axis, indicating that BBOX1-AS1 might be a potential therapeutic target for EC therapy.

Gene amplification-driven lncRNA SNHG6 promotes tumorigenesis via epigenetically suppressing p27 expression and regulating cell cycle in non-small cell lung cancer

Long non-coding RNAs (lncRNAs) have been validated to play essential roles in non-small cell lung carcinoma (NSCLC) progression. In this study, through systematically screening GSE33532 and GSE29249 from Gene Expression Omnibus (GEO) database and bioinformatics analysis, we found the significant upregulation of SNHG6 in NSCLC. The activation of SNHG6 was driven by copy number amplification and high expression of SNHG6 indicated a poor prognosis. Functionally, the knockdown of SNHG6 inhibited NSCLC cell proliferation, migration, and suppressed the G1/S transition of the cell cycle. SNHG6 overexpression had the opposite effects. Mechanically, SNHG6 recruited EZH2 to the promoter region of p27 and increased H3K27me3 enrichment, thus epigenetically repressing the expression of p27, regulating the cell cycle, and promoting tumorigenesis of NSCLC. SNHG6 silencing restrained tumor growth in vivo and suppressed the expressions of cell cycle-related proteins in the G1/S transition. In conclusion, our study uncovered a novel mechanism of SNHG6 activation and its function. SNHG6 can be considered a potential target for the diagnosis and treatment of NSCLC in the future.

An overview of long noncoding RNAs: Biology, functions, therapeutics, analysis methods, and bioinformatics tools

Long noncoding RNAs (lncRNAs) are a diverse class of RNAs whose functions are widespread in all branches of life and have been the focus of attention in the last decade. While a huge number of lncRNAs have been identified, there is still much work to be done and plenty to be learned. In the current review, we begin with the biogenesis and function of lncRNAs as they are involved in the different cellular processes from regulating the architecture of chromosomes to controlling translation and post-translation modifications. Questions on how overexpression, mutations, or deficiency of lncRNAs can affect the cellular status and result in the pathogenesis of various human diseases are responded to. Besides, we allocate an overview of several studies, concerning the application of lncRNAs either as diagnostic and prognostic biomarkers or novel therapeutics. We also introduce the currently available techniques to explore details of lncRNAs such as their function, cellular localization, and structure. In the last section, as exponentially growing data in this area need to be gathered and organized in comprehensive databases, we have a particular focus on presenting general and specialized databases. Taken together, with this review, we aim to provide the latest information on different aspects of lncRNAs to highlight their importance in physiopathologic states and take a step towards helping future studies.

Epigenetics and genetics of hepatoblastoma: Linkage and treatment

Hepatoblastoma is a malignant embryonal tumor with multiple differentiation modes and is the clearest liver malignancy in children. However, little is known about genetic and epigenetic events in Hepatoblastoma. Increased research has recently demonstrated, unique genetic and epigenetic events in Hepatoblastoma, providing insights into its origin and precise treatment. Some genetic disorders and congenital factors are associated with the risk of Hepatoblastoma development, such as the Beckwith-Wiedemann syndrome, Familial Adenomatous polyposis, and Hemihypertrophy. Epigenetic modifications such as DNA modifications, histone modifications, and non-coding RNA regulation are also essential in the development of Hepatoblastoma. Herein, we reviewed genetic and epigenetic events in Hepatoblastoma, focusing on the relationship between these events and cancer susceptibility, tumor growth, and prognosis. By deciphering the genetic and epigenetic associations in Hepatoblastoma, tumor pathogenesis can be clarified, and guide the development of new anti-cancer drugs and prevention strategies.

RBM10 regulates alternative splicing of lncRNA Neat1 to inhibit the invasion and metastasis of NSCLC

Background

Non-small cell lung cancer (NSCLC) accounts for more than 85% of the total cases with lung cancer. NSCLC is characterized by easy metastasis, which often spreads to bones, brains and livers. RNA-binding motif protein 10 (RBM10) is an alternative splicing (AS) regulator frequently mutated in NSCLC. We found that there were multiple peak binding sites between RBM10 and long non-coding RNA nuclear enriched abundant transcript 1 (LncRNA Neat1) by crosslinking-immunprecipitation and high-throughput sequencing (Clip-Seq). LncRNA Neat1 plays an indispensable role in promoting cancer in a variety of tumors and produces two splicing variants: Neat1_1 and Neat1_2. This study aims to explore the mechanism of RBM10 and LncRNA Neat1 in invasion and metastasis of NSCLC.

Methods

Through histological and cytological experiments, we assessed the expression level of RBM10 protein expression. The interaction between RBM10 and Neat1 was evaluated via Clip-Seq and RNA immunoprecipitation assay. The effect of RBM10 on Neat1 and its splicing variants was identified by RT-qPCR. The effect of RBM10 and Neat1 on invasive and metastasis phenotypes of NSCLC was analyzed using transwell invasion assay and scratch test. Additionally, downstream signaling pathway of RBM10 were identified by immunofluorescence and western blot.

Results

RBM10 exhibited low levels of expression in NSCLC tissues and cells. RBM10 inhibited the invasion and metastasis of NSCLC and recruited Neat1 and Neat1_2. Overexpression of RBM10 simultaneously inhibited Neat1 and Neat1_2, and promoted the expression of Neat1_1. On the other hand, silencing RBM10 promoted Neat1 and Neat1_2, and inhibited the expression of Neat1_1. From this, we concluded that RBM10 regulated AS of Neat1, and the tumor-promoting effect of Neat1 was mainly attributed to Neat1_2. RBM10 had a negative correlation with Neat1_2. In addition, RBM10 upregulated the expression of PTEN and downregulated the phosphorylation of PI3K/AKT/mTOR through Neat1_2, which ultimately inhibited the invasion and metastasis of NSCLC.

Conclusion

The RBM10 regulated AS of Neat1 to cause the imbalance of Neat1_1 and Neat1_2, and RBM10 suppressed the activation of the PTEN/PI3K/AKT/mTOR signal by downregulating Neat1_2, finally affected the invasion and metastasis of NSCLC.

Comprehensive Analysis of Immune Cell Infiltration of m6a-Related lncRNA in Lung Squamous Cell Carcinoma and Construction of Relevant Prognostic Models

Lung squamous cell carcinoma (LUSC) is the main cause of cancer-related mortality. Some studies demonstrate that m6a and long noncoding RNA (lncRNA) are vital in the pathogenesis of LUSC. In this study, we aimed to further understand the prognostic value of m6a-related lncRNAs in LUSC and their role in the immune microenvironment. For this, we obtained LUSC transcriptome and clinical data from the TCGA database. Further, the identified m6a-related and prognostically relevant lncRNAs were clustered into groups based on prognostic lncRNA expression. Further analysis of the differences between clusters was performed. Five m6A-related lncRNAs were used for model construction using the LASSO regression. The receiver-operating characteristic curve (ROC curves) and decision curve analysis (DCA) were used to assess the model accuracy. Finally, the model was validated using polymerase chain reaction (PCR). We identified 12 m6a-related lncRNAs that were associated with prognosis and were lowly expressed in tumors. Cytotoxic T-lymphocyte-associated protein 4 (CTLA4) highly correlated with prognostic genes, and differential analysis indicated that it was highly expressed in the tumor group and cluster 1. In cluster 2 TIME, tumor cells were less pure and more immune, and stromal-associated cells were present. A prognostic model was constructed based on five m6a-lncRNAs. The area under the curve (AUC) was >0.5 in test group and train group. The PCR results showed that the genes in the prognostic model were lowly expressed in the tumor and were statistically significant ( $p<0.05$ ). We noted that m6a-lncRNAs were strongly associated with LUSC prognosis and the immune microenvironment. Thus, PRC1-AS1, AL132780.2, AC013731.1, SNHG30, and AL358472.2 can be considered as new targets for the treatment of patients with LUSC.

Long Non-Coding RNA LINC01929 Facilitates Cell Proliferation and Metastasis as a Competing Endogenous RNA Against MicroRNA miR-1179 in Non-Small Cell Lung Carcinoma

Introduction: Non-small cell lung carcinoma (NSCLC) constitutes most lung cancers and has a poor prognosis. LncRNAs are a potential repository for the discovery of cancer prognostic markers. This study explored the role of LINC01929 in NSCLC, both the clinical prognostic significance and the mechanism of its influence on cells.

Materials and Methods: LINC01929 levels in 143 pairs of NSCLC tissues and non-cancerous tissues were detected by RT-qPCR. Kaplan-Meier curves and multivariate Cox regression assays were generated for evaluating the prognostic values of LINC01929. To evaluate the cellular function, an XTT assay and transwell invasion assays were performed.

Results: LINC01929 was up-regulated in NSCLC tissues compared with healthy tissues. A positive correlation was observed between LINC01929 expression level and tumor T (p = 0.002) or N stage (p = 0.010). Patients with higher LINC01929 levels had shorter overall survival (p = 0.009). Compared with other factors, high LINC01929 expression was significantly associated with poor survival in univariate Cox analysis (HR: 2.485, 95%CI: 1.220–5.060, p = 0.012). After multivariate Cox regression assays, LINC01929 was a independent prognostic factor (HR: 3.021, 95%CI: 1.377–6.628, p = 0.006). miR-1179 was a target miRNA of LINC01929. Inhibited expression of LINC01929 significantly reduced the proliferation, migration, and invasion of NSCLC cells by targeting miR-1179.

Discussion: This study revealed the upregulation of LINC01929 in NSCLC. This study supports previous studies showing LINC01929 as a potential prognostic factor for NSCLC.

Long Noncoding RNAs and Circular RNAs in the Metabolic Reprogramming of Lung Cancer: Functions, Mechanisms, and Clinical Potential

As key regulators of gene function, long noncoding RNAs (lncRNAs) and circular RNAs (circRNAs) are generally accepted to be involved in lung cancer pathogenesis and progression. Recent research has clarified the phenomenon of metabolic reprogramming in lung cancer because of its significant role in tumor proliferation, migration, invasion, metastasis, and other malignant biological behaviors. Emerging evidence has also shown a relationship between the aberrant expression of lncRNAs and circRNAs and metabolic reprogramming in lung cancer tumorigenesis. This review provides insight regarding the roles of different lncRNAs and circRNAs in lung cancer metabolic reprogramming, by how they target transporter proteins and key enzymes in glucose, lipid, and glutamine metabolic signaling pathways. The clinical potential of lncRNAs and circRNAs as early diagnostic biomarkers and components of therapeutic strategies in lung cancer is further discussed, including current challenges in their utilization from the bench to the bedside and how to adopt a proper delivery system for their therapeutic use.

Long Non-Coding RNA MCM3AP-AS1: A Crucial Role in Human Malignancies

The incidence of cancer continues to grow and is one of the leading causes of death in the world. Long noncoding RNAs (LncRNAs) is a group of RNA transcripts greater than 200 nucleotides in length, and although it cannot encode proteins, it can regulate different biological functions by controlling gene expression, transcription factors, etc. LncRNA micro-chromosome maintenance protein 3-associated protein antisense RNA 1 (MCM3AP-AS1) is involved in RNA processing and cell cycle-related functions, and MCM3AP-AS1 is dysregulated in expression in various types of cancers. This biomarker is involved in many processes related to carcinogens, such as cell proliferation, apoptosis, cell cycle, and migration. In this review, we summarize the roles of MCM3AP-AS1 in different human cancers and its biological functions with a view to providing ideas for future research.

Long Non-Coding RNA AP000695.2 Acts as a Novel Prognostic Biomarker and Regulates the Cell Growth and Migration of Lung Adenocarcinoma

Long non-coding RNAs (lncRNAs) are tumor-associated biological molecules and have been found to be implicated in the progression of lung adenocarcinoma (LUAD). LncRNA-AP000695.2 (ENSG00000248538) is a long non-coding RNA (lncRNA) that is widely increased in many tumor types including lung adenocarcinoma (LUAD). However, the aberrant expression profile, clinical significance, and biological function of AP000695.2 in human lung adenocarcinoma (LUAD) need to be further investigated. This study mines key prognostic AP000695.2 and elucidates its potential role and molecular mechanism in regulating the proliferation and metastasis of LUAD. Here, we discovered that AP000695.2 was significantly upregulated in lung adenocarcinoma tissues compared with healthy adjacent lung tissue and higher in LUAD cell lines than in normal human bronchial epithelial cell lines. A higher expression of AP000695.2 was positively correlated with aggressive clinicopathological characteristics, and AP000695.2 served as an independent prognostic indicator for the overall survival, disease-free survival, and progression-free survival in patients with LUAD. Receiver operating curve (ROC) analysis revealed the significant diagnostic ability of AP000695.2 (AUC = 0.838). Our in vivo data confirmed that AP000695.2 promotes the proliferation, migration, and invasion of LUAD cells. GSEA results suggested that AP000695.2 co-expressed genes were mainly enriched in immune-related biological processes such as JAK-STAT signaling pathway and toll-like receptor signaling pathway. Single-sample GSEA analysis showed that AP000695.2 is correlated with tumor-infiltrating immune cells in lung adenocarcinoma. Our findings confirmed that AP000695.2 was involved in the progression of lung adenocarcinoma, providing a novel prognostic indicator and promising diagnostic biomarker in the future.

lncRNA RP11-10A14.5: a potential prognosis biomarker for LUAD through regulation on proliferation and metastasis

Lung cancer is the malignancy most commonly seen worldwide. Emerging evidences indicated that lncRNAs may serve as a prognosis marker and play important role in NSCLC tumor biology. In this work, we analyzed the prognosis value of RP11-10A14.5 using TCGA and GEPIA database and expression profiles using PCR and FISH assay. The biological roles of RP11-10A14.5 in cell growth and invasion were determined by in vitro and in vivo experiments. Expression of RP11-10A14.5 is correlated with increased clinical stage and poor survival prognosis. In vitro experiments revealed that RP11-10A14.5 was widely expressed in lung cancer cell lines and mainly distributed in the cytoplasm and enhanced the growth, invasion and migration ability of NSCLC cell lines. Immunofluorescence assay suggested that RP11-10A14.5 may promote EMT by downregulating E-cadherin and upregulating N-cadherin and Vimentin. Flow cytometry results suggested that RP11-10A14.5 did not significantly affect cell cycle function, but could significantly inhibit apoptosis which may further enhance metastasis cell survival. In conclusion, RP11-10A14.5 is associated with clinical stage and poor survival outcome, may serve as a diagnosis and prognosis predictor for LUAD. Further, RP11-10A14.5 could promote LUAD cell growth and metastasis.

[LINC00668 is Highly Expressed in Lung Squamous Cell Carcinoma and Promotes Tumor Cell Migration and Invasion]

BACKGROUND

A lack of effective treatment for lung squamous cell carcinoma (LUSC) makes it an important factor restricting the 5-year survival rate of non-small cell lung cancer (NSCLC). Long non-coding RNA 00668 (LINC00668) was reported to play crucial regulatory roles in the tumorigenesis and progression of various cancers; however, its role in LUSC is unclear. The aim of this study was to investigate the prognosis value and biological function of LINC00668 in NSCLC, especially in LUSC.

METHODS

The expression pattern of LINC00668 and its relationship with clinical characteristics and prognosis of patients were investigated in the NSCLC especially LUSC based on The Cancer Genome Altas (TCGA) database. Its function in LUSC cells was explored in vitro.

RESULTS

LINC00668 expression was significantly up-regulated in LUSC patients and high expression level of LINC00668 was associated with advanced tumor-node-metastasis (TMN) stage. Moreover, the expression of LINC00668 significantly increased in smoking patients, and was a prognostic indicator for overall survival (OS) of smoking patients with LUSC. In vitro experiments showed that LINC00668 has significantly higher expression level in LUSC cell lines and tissues compared to normal bronchial epithelial cell and para-tumor tissues; meanwhile, functional assay indicated knockdown of LINC00668 effectively inhibited the migration and invasion of LUSC cells.

CONCLUSIONS

LINC00668 might closely relate to the development of LUSC, and inhibition of LINC00668 may reduce the metastasis of LUSC.

LncRNA-AC02278.4 Is a Novel Prognostic Biomarker That Promotes Tumor Growth and Metastasis in Lung Adenocarcinoma

LncRNA-AC02278.4 (ENSG00000248538) is a long non-coding RNA (lncRNA) found to be highly expressed in multiple human cancers including lung adenocarcinoma (LUAD). However, the underlying biological function and potential mechanisms of AC02278.4 driving the progression of LUAD remain unclear. In this study, we investigated the role of AC02278.4 in LUAD and found that AC02278.4 expression was significantly increased in datasets extracted from The Cancer Genome Atlas. Increased expression of lncRNA-AC02278.4 was correlated with advanced clinical parameters. Receiver operating characteristic (ROC) curve analysis revealed the significant diagnostic ability of AC02278.4 [area under the ROC curve (AUC) = 0.882]. In addition, gene set enrichment analysis (GSEA) enrichment showed that AC02278.4 expression was correlated with immune response-related signaling pathways. Finally, we determined that AC02278.4 regulated cell proliferation and migration of LUAD in vitro. Our clinical sample results also confirmed that AC02278.4 was highly expressed in LUAD and correlated with adverse clinical outcomes. In conclusion, our data demonstrated that AC02278.4 was correlated with progression and immune infiltration and could serve as a prognostic biomarker for LUAD.

Targeting lncRNAs in programmed cell death as a therapeutic strategy for non-small cell lung cancer

Lung cancer is a leading cause of cancer-related mortality worldwide, with non-small cell lung cancer (NSCLC) being the most common histological type. Owing to the limited therapeutic efficacy and side effects of currently available therapies for NSCLC, it is necessary to identify novel therapeutic targets for NSCLC. Long non-coding RNAs (lncRNAs) are non-protein-coding RNAs with a transcript length of more than 200 nucleotides, which play a vital role in the tumorigenesis and progression of multiple cancers, including NSCLC. Induction of programmed cell death (PCD) is the main mechanism leading to tumour cell death in most cancer treatments. Recent studies have demonstrated that lncRNAs are closely correlated with PCD including apoptosis, pyroptosis, autophagy and ferroptosis, which can regulate PCD and relevant death pathways to affect NSCLC progression and the efficacy of clinical therapy. Therefore, in this review, we focused on the function of lncRNAs in PCD of NSCLC and summarized the therapeutic role of targeting lncRNAs in PCD for NSCLC treatment, aiming to provide new sights into the underlying pathogenic mechanisms and propose a potential new strategy for NSCLC therapy so as to improve therapeutic outcomes with the ultimate goal to benefit the patients.

LncRNA-AC068228.1 Is a Novel Prognostic Biomarker That Promotes Malignant Phenotypes in Lung Adenocarcinoma

Background

The crucial roles played by lncRNA-AC068228.1 in primary malignant cancer remain poorly understood. This study aimed at examining the clinical significance and evaluating the biological function of AC068228.1 in lung adenocarcinoma (LUAD).

Methods

We used data obtained from The Cancer Genome Atlas (TCGA), Genotype-Tissue Expression (GTEx), and the Gene Expression Omnibus (GEO) database to examine the expression of AC068228.1 in LUAD patients, and the prognostic and diagnostic value of those levels. Functional experiments were conducted to determine the function of AC068228.1 on LUAD cells. Signaling pathway enrichment analysis of AC068228.1 was conducted using the clusterProfiler and Gene Set Enrichment Analysis (GSEA) software. We analyzed the correlation between AC068228.1 expression and immune infiltration level in LUAD using the single-sample gene set enrichment analysis (ssGSEA) method by the R package GSVA.

Results

AC068228.1 expression was significantly elevated in LUAD tissues compared with normal tissues. Higher expression of AC068228.1 was strongly correlated with adverse clinical outcomes and was identified as an independent prognostic marker for LUAD patients. GSEA and infiltration analysis confirmed that AC068228.1 expression was significantly correlated with immune cells infiltrating in LUAD. Knockdown of AC068228.1 inhibited the cell proliferation and cell migration of LUAD.

Conclusions

AC068228.1 was upregulated in LUAD and was significantly correlated with adverse clinical outcomes. Meanwhile, it was associated with immune cell infiltration and could be used as a promising diagnostic and prognostic biomarker for LUAD patients.

Long Noncoding RNA LAMTOR5-AS1 Interference Affects MicroRNA-506-3p/E2F6-Mediated Behavior of Non-Small Cell Lung Cancer Cells

Long noncoding RNA LAMTOR5 antisense RNA 1 (LAMTOR5-AS1) has been certified as a risk predictor and diagnostic biomarker of prostate cancer. However, the expression and exact roles of LAMTOR5-AS1 in non-small cell lung cancer (NSCLC) remain unclear. Thus, we measured LAMTOR5-AS1 expression in NSCLC and gauged its clinical value. The detailed roles and downstream working mechanism of LAMTOR5-AS1 in NSCLC were comprehensively unraveled. qRT-PCR was applied to measure gene expression. Functionally, utilizing small interfering RNA, LAMTOR5-AS1 was ablated, and the functional alterations were addressed by means of different experiments. The targeting activities between LAMTOR5-AS1 and microRNA-506-3p (miR-506-3p) and between miR-506-3p and E2F transcription factor 6 (E2F6) were confirmed by RNA immunoprecipitation and luciferase reporter assays. LAMTOR5-AS1 overexpression in NSCLC was verified in TCGA datasets and our own cohort and manifested an evident relationship with poor prognosis. Interference with LAMTOR5-AS1 led to repression of the proliferation, cloning, and metastasis abilities of NSCLC cells in vitro. We further confirmed an obvious increase in LAMTOR5-AS1-silenced NSCLC cell apoptosis. Furthermore, the absence of LAMTOR5-AS1 restricted tumor growth in vivo. Mechanistically, LAMTOR5-AS1 sponged miR-506-3p in NSCLC cells. Furthermore, E2F6, a downstream target of miR-506-3p, was under the control of LAMTOR5-AS1, which was realized by decoying miR-506-3p. Rescue experiments showed that miR-506-3p suppression or E2F6 reintroduction was capable of remitting LAMTOR5-AS1 deficiency-triggered anticarcinogenic actions in NSCLC. Our study confirmed the exact roles of LAMTOR5-AS1 for the first time and revealed that LAMTOR5-AS1 knockdown disrupts the malignancy of NSCLC by targeting the miR-506-3p/E2F6 axis. Targeting the LAMTOR5-AS1/miR-506-3p/E2F6 pathway may be instrumental for managing patients with NSCLC.

A Signature of 14 Long Non-Coding RNAs (lncRNAs) as a Step towards Precision Diagnosis for NSCLC

LncRNAs have arisen as new players in the world of non-coding RNA. Disrupted expression of these molecules can be tightly linked to the onset, promotion and progression of cancer. The present study estimated the usefulness of 14 lncRNAs (HAGLR, ADAMTS9-AS2, LINC00261, MCM3AP-AS1, TP53TG1, C14orf132, LINC00968, LINC00312, TP73-AS1, LOC344887, LINC00673, SOX2-OT, AFAP1-AS1, LOC730101) for early detection of non-small-cell lung cancer (NSCLC). The total RNA was isolated from paired fresh-frozen cancerous and noncancerous lung tissue from 92 NSCLC patients diagnosed with either adenocarcinoma (LUAD) or lung squamous cell carcinoma (LUSC). The expression level of lncRNAs was evaluated by a quantitative real-time PCR (qPCR). Based on Ct and delta Ct values, logistic regression and gradient boosting decision tree classifiers were built. The latter is a novel, advanced machine learning algorithm with great potential in medical science. The established predictive models showed that a set of 14 lncRNAs accurately discriminates cancerous from noncancerous lung tissues (AUC value of 0.98 ± 0.01) and NSCLC subtypes (AUC value of 0.84 ± 0.09), although the expression of a few molecules was statistically insignificant (SOX2-OT, AFAP1-AS1 and LOC730101 for tumor vs. normal tissue; and TP53TG1, C14orf132, LINC00968 and LOC730101 for LUAD vs. LUSC). However for subtypes discrimination, the simplified logistic regression model based on the four variables (delta Ct AFAP1-AS1, Ct SOX2-OT, Ct LINC00261, and delta Ct LINC00673) had even stronger diagnostic potential than the original one (AUC value of 0.88 ± 0.07). Our results demonstrate that the 14 lncRNA signature can be an auxiliary tool to endorse and complement the histological diagnosis of non-small-cell lung cancer.

New Insights into the Importance of Long Non-Coding RNAs in Lung Cancer: Future Clinical Approaches

In mammals, a large part of the gene expression products come from the non-coding ribonucleotide sequences of the protein. These short and long sequences are within the range of tens to hundreds of nucleotides, encompassing more than 200 RNA molecules, and their function is known as the molecular structure of long non-coding RNA (lncRNA). LncRNA molecules are unique nucleotides that have a substantial role in epigenetic regulation, transcription, and post-transcriptional modifications in different ways. According to the results of recent studies, lncRNAs have been shown to assume various roles, including tumor suppression or oncogenic functions in common types of cancer such as lung and breast cancer. These non-coding RNAs (ncRNAs) play a pivotal role in activating transcription factors, managing the ribonucleoproteins, the framework for collecting co-proteins, intermittent processing regulations, chromatin status alterations, and maintaining the control within the cell. Cutting-edge technologies have been introduced to disclose several types of lncRNAs within the nucleus and the cytoplasm, which have accomplished important achievements that are applicable in medicine. Due to these efforts, various data centers have been created to facilitate and modify scientific information related to these molecules, including detection, classification, biological evolution, gene status, spatial structure, status, and location of these small molecules. In the present study, we attempt to present the impacts of these ncRNAs on lung cancer with an emphasis on their mechanisms and functions.

Analysis of Long Noncoding RNAs in Aila-Induced Non-Small Cell Lung Cancer Inhibition

Non-small cell lung cancer (NSCLC) has the highest morbidity and mortality among all carcinomas. However, it is difficult to diagnose in the early stage, and current therapeutic efficacy is not ideal. Although numerous studies have revealed that Ailanthone (Aila), a natural product, can inhibit multiple cancers by reducing cell proliferation and invasion and inducing apoptosis, the mechanism by which Aila represses NSCLC progression in a time-dependent manner remains unclear. In this study, we observed that most long noncoding RNAs (lncRNAs) were either notably up- or downregulated in NSCLC cells after treatment with Aila. Moreover, alterations in lncRNA expression induced by Aila were crucial for the initiation and metastasis of NSCLC. Furthermore, in our research, expression of DUXAP8 was significantly downregulated in NSCLC cells after treatment with Aila and regulated expression levels of EGR1. In conclusion, our findings demonstrate that Aila is a potent natural suppressor of NSCLC by modulating expression of DUXAP8 and EGR1.

Simultaneous Enzyme-Free Detection of Multiple Long Noncoding RNAs in Cancer Cells at Single-Molecule/Particle Level

Aberrant change in long noncoding RNA (lncRNA) is associated with various diseases and cancers. So far, simultaneous detection of lncRNAs has remained a great challenge due to their large size and extensive secondary structure. Herein, we develop an enzyme-free single-molecule/particle detection method for simultaneous detection of multiple lncRNAs in cancer cells based on target-catalyzed strand displacement. We designed the magnetic bead-capture probe-multiple Cy5/Cy3-modified reporter unit complexes to isolate and identify lncRNA MALAT1 and lncRNA HOTAIR. The target-catalyzed strand displacement reactions lead to the release of Cy5 and Cy3 fluorescent molecules from the complexes, which can be subsequently quantified by single-molecule/particle detection. The dual-targetability, good selectivity and high sensitivity of this method enables simultaneous detection of multiple lncRNAs in even single cancer cell. Importantly, this method can discriminate cancer cells from normal cells and has significant advantages in the simple sequence design and in being free of enzymes, holding great potential in living cell imaging and early clinical diagnosis.

TP53-Activated lncRNA GHRLOS Regulates Cell Proliferation, Invasion, and Apoptosis of Non-Small Cell Lung Cancer by Modulating the miR-346/APC Axis

Non-small cell lung cancer (NSCLC) is the main type of lung cancer with high mortality worldwide. To improve NSCLC therapy, the exploration of molecular mechanisms involved in NSCLC progression and identification of their potential therapy targeting is important. Long noncoding RNAs (lncRNAs) have shown important roles in regulating various tumors progression, including NSCLC. We found lncRNA GHRLOS was decreased in NSCLC cell lines and tissues which correlated with poor prognosis of NSCLC patients. However, the role and underlying mechanisms of lncRNA GHRLOS in NSCLC progression remains elusive. The expression of lncRNA GHRLOS was examined in NSCLC cell lines and biopsy specimens of patients with NSCLC by quantitative real time polymerase chain reaction (qRT-PCR). The effects of GHRLOS on proliferation, invasion and apoptosis of NSCLC cells were determined by both in vitro and in vivo experiments. The interaction between GHRLOS and TP53 was determined by dual-luciferase reporter assay and chromatin immunoprecipitation (ChIP) combined with qRT-PCR analysis. RNA immunoprecipitation (RIP) was conducted to validate the binding between GHRLOS and microRNA-346 (miR-346). Dual-luciferase reporter assays were also carried out to reveal the interaction between miR-346 and the 3’ untranslated region (3’UTR) of adenomatous polyposis coli (APC) mRNA.Our data demonstrated that overexpression of lncRNA GHRLOS suppressed cancer cell proliferation and invasion as well as promoted cell apoptosis by regulating the expression of CDK2, PCNA, E-cadherin, N-cadherin, Bax, and Bcl-2 in NSCLC cells. Moreover, lncRNA GHRLOS was upregulated by the binding of TP53 to the GHRLOS promoter. The binding target of lncRNA GHRLOS was identified to be miR-346. Impressively, overexpression of miR-346 promoted cell proliferation and invasion, as well as inhibited cell apoptosis, however, these effects can be blocked by overexpression of lncRNA GHRLOS both in vitro and in vivo. In summary, this study reveals lncRNA GHRLOS, upregulated by TP53, acts as a molecule sponge of miR-346 to cooperatively modulates expression of APC, a miR-346 target, and potentially inhibits NSCLC progression via TP53/lncRNA GHRLOS/miR-346/APC axis, which represents a novel pathway that could be useful in targeted therapy against NSCLC.

DLX6-AS1 is a potential biomarker and therapeutic target in cancer initiation and progression

Long noncoding RNAs (lncRNAs) are involved in multiple functions such as the regulation of cellular homeostasis. They play prominent roles in the pathogenesis of human cancer, and contribute to every hallmark of cancer. The novel cancer-related lncRNA DLX6 antisense RNA 1 (DLX6-AS1) plays an essential regulatory role in enhancing and initiating carcinogenesis and tumor progression. This progression is due to the aberrant regulation of downstream factors in vitro as well as in vivo. DLX6-AS1 is significantly dysregulated in various cancers. DLX6-AS1 functions in tumor initiation and progression are regulated at the epigenetic, transcription, and posttranscriptional regulation levels. DLX6-AS1 functions as an oncogene, binding to miRNA targeting sites competing endogenous RNAs and causing the upregulation of downstream tumor-related genes and carcinogenesis. The regulation and detailed molecular mechanisms of DLX6-AS1 and its potential role in malignancies are comprehensively described in this paper. DLX6-AS1 has the potential to become a novel biomarker and therapeutic target for cancer.

Downregulation of lncRNA HCP5 has inhibitory effects on gastric cancer cells by regulating DDX21 expression

LncRNA HCP5 has been confirmed to play crucial roles in many types of cancers. However, the role of lncRNA HCP5 in regulating the occurrence and development of gastric cancer (GC) remains unknown. In the current study, we aimed to investigate the precise effects of lncRNA HCP5 on cell proliferation, migration and invasion and molecular mechanisms in gastric cancer. Using RT-qPCR analysis, we found that lncRNA HCP5 was differentially expressed in GC cell lines. CCK-8, wound healing and transwell assay indicated that the proliferation, migration and invasion of gastric cancer cells were inhibited by downregulation of lncRNA HCP5 and lncRNA HCP5 overexpression exhibited the opposite effects in gastric cancer cells. Mechanistically, RNA binding protein immunoprecipitation and dual luciferase reporter assay confirmed the interaction between lncRNA HCP5 and DDX21. The effects of lncRNA HCP5 overexpression the proliferation, migration and invasion of GC cells were partly rescued by DDX21 silencing. Taken together, downregulation of lncRNA HCP5 exerted inhibitory effects on GC cell proliferation, migration and invasion through modulation of DDX21 expression, demonstrating the function of lncRNA HCP5 and DDX21 in GC progression.

Long Noncoding RNA LINC01426 Sequesters microRNA-519d-5p to Promote Non-Small Cell Lung Cancer Progression by Increasing ETS1 Expression

PURPOSE

Recent studies have identified important roles for long intergenic non-protein coding RNA 1426 (LINC01426) in glioma and clear cell renal cell carcinoma. The present study evaluated the expression profile of LINC01426 in non-small cell lung cancer (NSCLC) tissues and cell lines. Furthermore, the function of LINC01426 in NSCLC and the molecular mechanisms involved were extensively studied.

METHODS

The abundance of LINC01426 in NSCLC tissues and cell lines was determined using quantitative reverse transcription-polymerase chain reaction. The cell counting kit-8 assay, flow cytometry, transwell experiments for migration and invasion, and xenograft tumor model were used to assess the function of LINC01426 in NSCLC cells. Mechanistic studies were performed using the luciferase reporter assay and RNA immunoprecipitation.

RESULTS

Significant LINC01426 upregulation was observed in NSCLC tissues and cell lines. Silencing LINC01426 inhibited proliferation, migration, and invasion of NSCLC cells and facilitated cell apoptosis in vitro. Furthermore, interference of LINC01426 restricted tumor growth of NSCLC cells in vivo. In addition, LINC01426 showed the ability to directly bind to microRNA-519d-5p (miR-519d-5p) and act as a molecular sponge for miR-519d-5p in NSCLC cells. Furthermore, the ETS proto-oncogene 1 (ETS1) was identified as a direct target of miR-519d-5p and LINC01426 could indirectly upregulate ETS1 expression by sponging miR-519d-5p. Moreover, the cancer-inhibiting activities of LINC01426 knockdown in NSCLC cells were partially offset by miR-519d-5p inhibition.

CONCLUSION

LINC01426 increases ETS1 expression by sequestering miR-519d-5p, thereby aggravating the malignant progression of NSCLC. The LINC01426/miR-519d-5p/ETS1 competing endogenous RNA pathway may provide a target for designing therapeutic agents for NSCLC treatment.

LncRNA SNHG6 Inhibits Apoptosis by Regulating EZH2 Expression via the Sponging of MiR-101-3p in Esophageal Squamous-Cell Carcinoma

Background

The long non-coding RNA (lncRNA) SNHG6 was significantly upregulated in esophageal squamous-cell carcinoma (ESCC), and it promoted ESCC cell proliferation, invasion, and migration. However, the effects of SNHG6 on cell apoptosis and the corresponding underlying mechanisms have not yet reported.

Methods

Apoptosis was detected by flow cytometric analysis. Quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting were used for mRNA and protein quantification, respectively. A luciferase reporter assay was performed to verify downstream target genes for SNHG6 and miR-101-3p.

Results

Dysregulation of SNHG6 inhibited apoptosis in ESCC cells and regulated the expression of apoptosis-related proteins such as Bcl-2, Mcl-1, Bax and Caspase-3. Functionally, miR-101-3p could compete binding with 3′-untranslated region of SNHG6 and downregulation of miR-101-3p reversed its effect on cell apoptosis in SNHG6 knockdown cells. EZH2 was confirmed as a downstream target gene of miR-101-3p, silencing EZH2 expression had the same effect on apoptosis and protein expression as knocking down SNHG6. Overexpression of EZH2 reversed the effects of miR-101-3p overexpression on cell apoptosis in ESCC cells.

Conclusion

In this study, we found that upregulation of the lncRNA SNHG6 inhibited apoptosis via miR-101-3p/EZH2 axis in ESCC. These findings may contribute to the diagnosis and treatment of ESCC.

Long noncoding RNA NR2F1-AS1 promotes the malignancy of non-small cell lung cancer via sponging microRNA-493-5p and thereby increasing ITGB1 expression

Several studies have reported that the long noncoding ribonucleic acid (lncRNA) NR2F1 antisense RNA 1 (NR2F1-AS1) affects multiple cellular pathways that are involved in tumorigenesis and tumor progression. The present study aimed to detect NR2F1-AS1 expression in non-small cell lung cancer (NSCLC), investigate the role of NR2F1-AS1 in promoting the tumorigenic behavior of NSCLC cells, and elucidate the mechanism underlying the effect of NR2F1-AS1 on NSCLC progression. Our results showed that NR2F1-AS1 expression was upregulated in NSCLC cells, and notably, its upregulation was correlated with adverse clinical characteristics and shorter overall survival in patients with NSCLC. The absence of NR2F1-AS1 functionally decreased NSCLC cell proliferation, migration, and invasion and promoted tumor cell apoptosis. In addition, the tumor growth of NSCLC cells in vivo was inhibited after NR2F1-AS1 silencing. Mechanistically, NR2F1-AS1 functioned as a competing endogenous RNA for miR-493-5p and consequently increased ITGB1 expression. Rescue assays further validated that an increased output of the miR-493-5p/ITGB1 axis could neutralize the regulatory impact of NR2F1-AS1 knockdown on the malignant phenotype of NSCLC cells. In summary, the NR2F1-AS1/miR-493-5p/ITGB1 pathway initiates pro-oncogenic behavior in NSCLC tumor progression, and the NR2F1-AS1/miR-493-5p/ITGB1 axis may provide new molecular targets for anticancer therapy against NSCLC.

Long Non-Coding RNA LINC00491 Contributes to the Malignancy of Non-Small-Cell Lung Cancer via Competitively Binding to microRNA-324-5p and Thereby Increasing Specificity Protein 1 Expression

Background

A long non-coding RNA termed as long intergenic non-protein coding RNA 491 (LINC00491) has been validated as an oncogene to promote cancer progression in colon adenocarcinoma. The goal of this study was to determine the expression and carcinogenic functions of LINC00491 in non-small-cell lung cancer (NSCLC). Besides, it was aimed to understand how LINC00491 affects the malignant processes of NSCLC cells.

Methods

The expression of LINC00491 in NSCLC was investigated by bioinformatic analysis and reverse transcription-quantitative PCR. After LINC00491 knockdown, cell counting kit-8 assay, flow cytometry, migration and invasion detection assays as well as nude mice xenograft assay were conducted to test the roles of LINC00491 in NSCLC cells. Two online databases, StarBase 3.0 and miRDB, were utilized to determine the putative target miRNA of LINC00491, and the prediction was subsequently confirmed by luciferase reporter assay, RNA immunoprecipitation assay, reverse transcription-quantitative PCR, Western blotting, and rescue assays.

Results

LINC00491 was overexpressed in both NSCLC tissues and cell lines. Functional investigation revealed that depleted LINC00491 facilitated cell apoptosis and decreased cell proliferation, migration, and invasion in vitro. Additionally, the downregulation of LINC00491 impaired NSCLC cell tumor growth in vivo. Mechanistically, LINC00491 functioned as a competing endogenous RNA by sponging microRNA-324-5p (miR-324-5p) in NSCLC cells. miR-324-5p was weakly expressed in NSCLC and exerted tumor-suppressing actions during cancer progression. Furthermore, specificity protein 1 (SP1) was validated as the direct target of miR-324-5p in NSCLC and was under the regulation of LINC00491 via sponging miR-324-5p. Rescue experiments reconfirmed that miR-324-5p inhibition and SP1 overexpression both abrogated the suppressive roles of LINC00491 deficiency in NSCLC cells.

Conclusion

LINC00491 promoted the oncogenicity of NSCLC via serving as a miR-324-5p sponge, which further upregulated the expression of SP1. The LINC00491/miR-324-5p/SP1 pathway disclosed a new mechanism of NSCLC pathogenesis and may provide effective targets for better NSCLC treatment.

Long-Chain Non-Coding RNA Metastasis-Related Lung Adenocarcinoma Transcript 1 (MALAT1) Promotes the Proliferation and Migration of Human Pulmonary Artery Smooth Muscle Cells (hPASMCs) by Regulating the MicroRNA-503 (miR-503)/Toll-Like Receptor 4 (TLR4) Signal Axis

Background

To study the role of the long-chain noncoding RNA (lncRNA) metastasis-related lung adenocarcinoma transcript 1 (MALAT1), microRNA-503 (miR-503), Toll-like receptor 4 (TLR4) signal axis in the pathogenesis of pulmonary arterial hypertension (PAH).

Material/Methods

Total RNA was extracted from the plasma of 45 PAH patients and 45 healthy subjects, and the expression of lncRNA MALAT1 and miR-503 was measured by quantitative real-time polymerase chain reaction (qRT-PCR). The effects of lncRNA MALAT1 and miR-503 on Toll-like receptor 4 (TLR4) and the proliferation, migration, and apoptosis of human pulmonary artery smooth muscle cells (hPASMCs) were tested following in vitro transfection of hPASMCs.

Results

lncRNA MALAT1 was highly expressed in the plasma of PAH patients and in hypoxia-induced hPASMCs. Silencing lncRNA MALAT1 inhibited the proliferation and migration of hPASMC cells while promoting their apoptosis. MiR-503 is underexpressed in plasma and hPASMCs of patients with PAH. TLR4 was a target gene of miR-503 and was highly expressed in peripheral blood mononuclear cells (PBMCs) of PAH patients. lncRNA MALAT1 was a “molecular sponge” of miR-503, regulating the expression of TLR4 and the proliferation, migration, and apoptosis of hPASMCs through miR-503.

Conclusions

lncRNA MALAT1 promotes the proliferation and migration of hPASMCs and inhibits their apoptosis by inhibiting the miR-503/TLR4 signal axis.

Detection of Allosteric Effects of lncRNA Secondary Structures Altered by SNPs in Human Diseases

Recent studies have shown that structuralized long non-coding RNAs (lncRNAs) play important roles in genetic and epigenetic processes. The spatial structures of most lncRNAs can be altered by distinct in vivo and in vitro cellular environments, as well as by DNA structural variations, such as single-nucleotide polymorphisms (SNPs) and variants (SNVs). In the present study, we extended candidate SNPs that had linkage disequilibria with those significantly associated with lung diseases in genome-wide association studies in order to investigate potential disease mechanisms originating from SNP structural changes of host lncRNAs. Following accurate alignments, we recognized 115 ternary-relationship pairs among 41 SNPs, 10 lncRNA transcripts, and 1 type of lung disease (adenocarcinoma of the lung). Then, we evaluated the structural heterogeneity induced by SNP alleles by developing a local-RNA-structure alignment algorithm and employing randomized strategies to determine the significance of structural variation. We identified four ternary-relationship pairs that were significantly associated with SNP-induced lncRNA allosteric effects. Moreover, these conformational changes disrupted the interactive regions and binding affinities of lncRNA-HCG23 and TF-E2F6, suggesting that these may represent regulatory mechanisms in lung diseases. Taken together, our findings support that SNP-induced changes in lncRNA conformations regulate many biological processes, providing novel insight into the role of the lncRNA “structurome” in human diseases.

Non-Coding RNAs in Lung Tumor Initiation and Progression

Lung cancer is one of the deadliest forms of cancer affecting society today. Non-coding RNAs, such as microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs), through the transcriptional, post-transcriptional, and epigenetic changes they impose, have been found to be dysregulated to affect lung cancer tumorigenesis and metastasis. This review will briefly summarize hallmarks involved in lung cancer initiation and progression. For initiation, these hallmarks include tumor initiating cells, immortalization, activation of oncogenes and inactivation of tumor suppressors. Hallmarks involved in lung cancer progression include metastasis and drug tolerance and resistance. The targeting of these hallmarks with non-coding RNAs can affect vital metabolic and cell signaling pathways, which as a result can potentially have a role in cancerous and pathological processes. By further understanding non-coding RNAs, researchers can work towards diagnoses and treatments to improve early detection and clinical response.