Research progresses in roles of LncRNA and its relationships with breast cancer

Deciphering the oncogenic landscape: Unveiling the molecular machinery and clinical significance of LncRNA TMPO-AS1 in human cancers

The in-depth exploration of long non-coding RNAs (lncRNAs) reveals their pivotal and diverse roles in various disorders, particularly cancer. Within this intricate landscape, thymopoietin-antisense RNA-1 (TMPO-AS1) emerges as a noteworthy instigator of oncogenesis in humans. This exhaustive review seeks to intricately unravel the present understanding of TMPO-AS1, emphasizing its molecular foundations and highlighting its clinical applications in the realm of cancer research. TMPO-AS1 consistently exhibits heightened expression across a spectrum of cancer types, encompassing lung, colorectal, breast, cervical, bladder, pancreatic, hepatocellular, gastric, ovarian, and osteosarcoma. Elevated levels of TMPO-AS1 are intricately linked to unfavorable prognoses, accompanied by distinctive clinical and pathological characteristics. Functionally, TMPO-AS1 showcases its prowess in enhancing cancer cell migration, invasion, proliferation, and orchestrating epithelial-mesenchymal transition (EMT) through a myriad of molecular mechanisms. These mechanisms entail intricate interactions with proteins, microRNAs, and intricate signaling pathways. Furthermore, TMPO-AS1 is intricately involved in regulating critical cellular processes, including apoptosis and the cell cycle. The mounting evidence converges towards the potential of TMPO-AS1 serving as a diagnostic and prognostic biomarker, further entwined with its potential role in influencing chemoresistance in cancer. This potential is underscored by its consistent associations with clinical outcomes and treatment responses. This comprehensive investigation not only consolidates our existing knowledge of TMPO-AS1's multifaceted roles but also sheds illuminating insights on its profound significance in the intricate landscape of cancer biology, paving the way for potential applications in clinical practice.

Downregulation of long noncoding RNA B4GALT1-AS1 is associated with breast cancer development

The misregulation of long non-coding RNAs (lncRNAs) is related to the progressive evolution of various human cancers, such as Breast cancer (BC). The role of lncRNA B4GALT1-AS1 has been investigated in some human cancers. Therefore, studying B4GALT1-AS1 expression was aimed for the first time in the tumor and marginal tissues of BC in this study. The cancer genome atlas (TCGA) database was utilized to evaluate the relative expression of B4GALT1-AS1 in BC and other cancers. RNA was extracted from twenty-eight paired BC and marginal tissues, and cDNA was synthesized. The quantitative expression level of B4GALT1-AS1 was evaluated using real-time PCR. The bioinformatics analyses were performed to identify co-expression genes and related pathways. B4GALT1-AS1 was significantly downregulated in BC specimens compared to tumor marginal samples. The TCGA data analysis confirmed the downregulation of B4GALT1-AS1 in BC. The bioinformatics analysis discovered the correlation between 700 genes and B4GALT1-AS1 and identified GNAI1 as the high degree gene which was positively correlated with B4GALT1-AS1 expression. It seems B4GALT1-AS1 provides its function, at least partly, in association with one of the hippo pathway components, YAP, in other cancers. This protein has the opposite role in BC and its loss of function can result in poor survival in BC. Further research is needed to investigate the interaction between B4GALT1-AS1 and YAP in various subtypes of BC.

Long noncoding RNA DLEU2 and ROR1 pathway induces epithelial-to-mesenchymal transition and cancer stem cells in breast cancer

Breast cancer (BC) patient who receives chemotherapy for an extended length of time may experience profound repercussions in terms of metastases and clinical outcomes due to the involvement of the epithelial-to-mesenchymal transition (EMT) mechanism and enriched cancer stem cells (CSCs). BC cells that express high levels of lncRNA deleted in lymphocytic leukemia-2 (lncRNA DLEU2) and type I tyrosine kinase-like orphan receptor ROR1 (ROR1) may play roles in the enhanced ability of the activation EMT and CSC induction. Here we find that lncRNA DLEU2 and ROR1 are specifically upregulated in tumor tissues compared to their normal counterparts in TCGA, PubMed GEO datasets, and samples from archived breast cancer tumor tissues. Following chemotherapy, lncRNA DLEU2 and ROR1 were enhanced in BC tumor cells, coupled with the expression of CSCs, EMT-related genes, and BMI1. Mechanistically, ROR1 and lncRNA DLEU2 overexpression led to enhanced tumor cell proliferation, inhibition of apoptosis, cell-cycle dysregulation, chemoresistance, as well as BC cell's abilities to invade, migrate, develop spheroids. These findings imply that the role of lncRNA DLEU2 and ROR1 in BC therapeutic failure is largely attributed to EMT, which is intricately linked to enriched CSCs. In conclusion, our findings indicate that a lncRNA DLEU2 and ROR1-based regulatory loop governs EMT and CSC self-renewal, implying that targeting this regulatory pathway may improve patients' responses to chemotherapy and survival.

LUNCRW: Prediction of potential lncRNA-disease associations based on unbalanced neighborhood constraint random walk

Accumulating evidence suggests that long non-coding RNAs (lncRNAs) are associated with various complex human diseases. They can serve as disease biomarkers and hold considerable promise for the prevention and treatment of various diseases. The traditional random walk algorithms generally exclude the effect of non-neighboring nodes on random walking. In order to overcome the issue, the neighborhood constraint (NC) approach is proposed in this study for regulating the direction of the random walk by computing the effects of both neighboring nodes and non-neighboring nodes. Then the association matrix is updated by matrix multiplication for minimizing the effect of the false negative data. The heterogeneous lncRNA-disease network is finally analyzed using an unbalanced random walk method for predicting the potential lncRNA-disease associations. The LUNCRW model is therefore developed for predicting potential lncRNA-disease associations. The area under the curve (AUC) values of the LUNCRW model in leave-one-out cross-validation and five-fold cross-validation were 0.951 and 0.9486 ± 0.0011, respectively. Data from published case studies on three diseases, including squamous cell carcinoma, hepatocellular carcinoma, and renal cell carcinoma, confirmed the predictive potential of the LUNCRW model. Altogether, the findings indicated that the performance of the LUNCRW method is superior to that of existing methods in predicting potential lncRNA-disease associations.

Role of long non-coding RNAs and TGF-β signaling in the regulation of breast cancer pathogenesis and therapeutic targets

The cytokine known as transforming growth factor (TGF) is essential for cell development, differentiation, and apoptosis in BC. TGF-β dysregulation can either promote or inhibit tumor development, and it is a key signaling pathway in BC spread. A recently identified family of ncRNAs known as lncRNAs has received a great deal of effort and is an important regulator of many cellular processes, including transcription of genes, chromatin remodeling, progression of the cell cycle, and posttranscriptional processing. Furthermore, both TGF-β signaling and lncRNAs serve as important early-stage biomarkers for BC diagnosis and prognosis and also play a significant role in BC drug resistance. According to recent studies, lncRNAs can regulate TGF-β by modulating its cofactors in BC. However, the particular functions of lncRNAs and the TGF-β pathway in controlling BC progression are not well understood yet. This review explores the lncRNAs' functional properties in BC as tumor suppressors or oncogenes in the regulation of genes, with a focus on dysregulated TGF-β signaling. Further, we emphasize the functional roles of lncRNAs and TGF-β pathway in the progression of BC to discover new treatment strategies and better comprehend the fundamental cellular pathways.

An insight into the potential role of LINC00968 in luminal breast cancer: Case-control study and bioinformatics analysis

Background

Luminal A and B subtypes of breast cancer (BC) comprises up to 70% of all BC patients. LncRNAs can affect many biological and pathological processes, and dysregulation of them is related to human cancers. The potential role of lncRNA LINC00968 in luminal BC is still unclear.

Materials and methods

We analyzed the LINC00968 expression across 44 paired luminal BC tissues from the TCGA-BRCA RNA sequencing dataset. Besides, we used the GEPIA2 web server and GENEVESTIGATOR software, as well. Real-Time Quantitative Reverse Transcription PCR (qRT-PCR) assay was performed to confirm the LINC00968 expression in 71 paired luminal BC tissues and two luminal A cell lines (MCF7 and T47D). Moreover, to better understanding the potential role of LINC00968 in luminal BC, computational data analyses including co-expression analysis, functional annotation analysis, and genetic alteration analysis have been done.

Results

The results of data analyses retrieved from BRCA dataset and databases revealed the significant downregulation of LINC00968 in luminal A and B BC. Also, the results of qRT-PCR in luminal BC tissues and cell lines confirmed the earlier data. LINC00968 expression was negatively associated with tumor stage and lymph node metastasis. Additionally, functional annotation analyses revealed that LINC00968 might be involved in vascular development and angiogenesis, extracellular matrix organization, and cell motility and migration. LINC00968 might play role in some cancer-related signaling pathways.

Conclusion

Our study found that downregulation of LINC00968 might promote tumorigenesis, invasion, and metastasis of luminal BC.

Epigenetic regulation of LINC01270 in breast cancer progression by mediating LAMA2 promoter methylation and MAPK signaling pathway

Application of long non-coding RNAs (lncRNAs) for modulation of breast cancer (BC) has attracted much attention. Here, we probed into the role and underlying mechanism of long intergenic non-coding RNA 01270 (LINC01270) in BC. With the help of bioinformatics tools, we identified laminin subunit alpha 2 (LAMA2) as a BC-related differentially expressed gene to discern the effect of LAMA2 in BC cells. LAMA2 was initially poorly expressed while LINC01270 was highly expressed in BC. BC cells were subsequently treated with sh-LINC01270 or/and sh-LAMA2 for exploration of their regulatory mechanism in BC, which unfolded that LINC01270 inhibition up-regulated LAMA2 and inactivated the MAPK signaling pathway to suppress malignant characteristics of BC cells. Functional assays demonstrated that LINC01270 bound to DNMT1, DNMT3a, and DNMT3b promoted the methylation of CpG islands in LAMA2 promoter and inhibited the LAMA2 expression. Moreover, our data suggested that LAMA2 suppressed MAPK signaling pathway to inhibit BC cell malignant characteristics. The in vitro results were re-produced with the help of the in vivo experimentations. In conclusion, LINC01270 silencing inhibited the methylation of LAMA2 promoter to suppress the activation of MAPK signaling pathway, which subsequently restrained the BC progression. 1, Overexpression of LAMA2 inhibits malignant features of BC cells. 2, LINC01270 promotes LAMA2 promoter methylation by recruiting DNMTs to the LAMA2 promoter region. 3, 5-aza-dc reverses the promotion of LAMA2 promoter methylation by LINC01270. 4, LAMA2 inhibits malignant features of BC cells by suppressing the activation of MAPK signaling pathway.

Long Noncoding RNAs in Taxane Resistance of Breast Cancer

Breast cancer is a common cancer in women and a leading cause of mortality. With the early diagnosis and development of therapeutic drugs, the prognosis of breast cancer has markedly improved. Chemotherapy is one of the predominant strategies for the treatment of breast cancer. Taxanes, including paclitaxel and docetaxel, are widely used in the treatment of breast cancer and remarkably decrease the risk of death and recurrence. However, taxane resistance caused by multiple factors significantly impacts the effect of the drug and leads to poor prognosis. Long noncoding RNAs (lncRNAs) have been shown to play a significant role in critical cellular processes, and a number of studies have illustrated that lncRNAs play vital roles in taxane resistance. In this review, we systematically summarize the mechanisms of taxane resistance in breast cancer and the functions of lncRNAs in taxane resistance in breast cancer. The findings provide insight into the role of lncRNAs in taxane resistance and suggest that lncRNAs may be used to develop therapeutic targets to prevent or reverse taxane resistance in patients with breast cancer.

Insights into the Role of LncRNAs and miRNAs in Glioma Progression and Their Potential as Novel Therapeutic Targets

Accumulating evidence supports that both long non-coding and micro RNAs (lncRNAs and miRNAs) are implicated in glioma tumorigenesis and progression. Poor outcome of gliomas has been linked to late-stage diagnosis and mostly ineffectiveness of conventional treatment due to low knowledge about the early stage of gliomas, which are not possible to observe with conventional diagnostic approaches. The past few years witnessed a revolutionary advance in biotechnology and neuroscience with the understanding of tumor-related molecules, including non-coding RNAs that are involved in the angiogenesis and progression of glioma cells and thus are used as prognostic biomarkers as well as novel therapeutic targets. The emerging research on lncRNAs and miRNAs highlights their crucial role in glioma progression, offering new insights into the disease. These non-coding RNAs hold significant potential as novel therapeutic targets, paving the way for innovative treatment approaches against glioma. This review encompasses a comprehensive discussion about the role of lncRNAs and miRNAs in gene regulation that is responsible for the promotion or the inhibition of glioma progression and collects the existing links between these key cancer-related molecules.

Underexplored reciprocity between genome-wide methylation status and long non-coding RNA expression reflected in breast cancer research: potential impacts for the disease management in the framework of 3P medicine

Breast cancer (BC) is the most common female malignancy reaching a pandemic scale worldwide. A comprehensive interplay between genetic alterations and shifted epigenetic regions synergistically leads to disease development and progression into metastatic BC. DNA and histones methylations, as the most studied epigenetic modifications, represent frequent and early events in the process of carcinogenesis. To this end, long non-coding RNAs (lncRNAs) are recognized as potent epigenetic modulators in pathomechanisms of BC by contributing to the regulation of DNA, RNA, and histones' methylation. In turn, the methylation status of DNA, RNA, and histones can affect the level of lncRNAs expression demonstrating the reciprocity of mechanisms involved. Furthermore, lncRNAs might undergo methylation in response to actual medical conditions such as tumor development and treated malignancies. The reciprocity between genome-wide methylation status and long non-coding RNA expression levels in BC remains largely unexplored. Since the bio/medical research in the area is, per evidence, strongly fragmented, the relevance of this reciprocity for BC development and progression has not yet been systematically analyzed. Contextually, the article aims at:consolidating the accumulated knowledge on both-the genome-wide methylation status and corresponding lncRNA expression patterns in BC andhighlighting the potential benefits of this consolidated multi-professional approach for advanced BC management. Based on a big data analysis and machine learning for individualized data interpretation, the proposed approach demonstrates a great potential to promote predictive diagnostics and targeted prevention in the cost-effective primary healthcare (sub-optimal health conditions and protection against the health-to-disease transition) as well as advanced treatment algorithms tailored to the individualized patient profiles in secondary BC care (effective protection against metastatic disease). Clinically relevant examples are provided, including mitochondrial health control and epigenetic regulatory mechanisms involved.

Non-coding RNAs in breast cancer: with a focus on glucose metabolism reprogramming

Breast cancer is the tumor with the highest incidence in women worldwide. According to research, the poor prognosis of breast cancer is closely related to abnormal glucose metabolism in tumor cells. Changes in glucose metabolism in tumor cells are an important feature. When sufficient oxygen is available, cancer cells tend to undergo glycolysis rather than oxidative phosphorylation, which promotes rapid proliferation and invasion of tumor cells. As research deepens, targeting the glucose metabolism pathway of tumor cells is seen as a promising treatment. Non-coding RNAs (ncRNAs), a recent focus of research, are involved in the regulation of enzymes of glucose metabolism and related cancer signaling pathways in breast cancer cells. This article reviews the regulatory effect and mechanism of ncRNAs on glucose metabolism in breast cancer cells and provides new ideas for the treatment of breast cancer.

Whole transcriptome sequencing and competitive endogenous RNA regulation network construction analysis in benzo[a]pyrene-treated breast cancer cells

Breast cancer is the most common malignant tumor in women worldwide, and environmental pollutants are considered to be risk factors. Currently, most studies into benzo[a]pyrene (B[a]P)-induced breast cancer focus on biological effects such as proliferation, invasion, and metastasis, DNA damage, estrogen receptor (ER)-related molecular mechanisms, oxidative damage, and other metabolic pathways. This study aims to provide insights into the role of B[a]P in breast cancer development through RNA-seq and bioinformatics analysis and construction of a competing endogenous RNA (ceRNA) regulatory network. By analyzing RNA-seq results, we identified 144 differentially-expressed circRNAs, 69 differentially-expressed lncRNAs, 20 differentially-expressed miRNAs, and 212 differentially-expressed mRNAs. Following on, we analyzed the gene ontology (GO) and KEGG enrichment functions of the differentially-expressed RNAs. In addition, the protein-protein interaction (PPI) network was mapped for differentially-expressed mRNAs. Subsequently, we constructed ceRNA networks, one of which consisted of 45 dysregulated circRNAs, 11 miRNAs, and 9 mRNAs, and a second consisted of 40 lncRNAs, 11 miRNAs, and 9 mRNAs. Finally, 6 circRNAs, 4 lncRNAs, 1 miRNA, and 4 mRNAs were randomly selected for quantitative real-time PCR verification. PCR results were further verified by Western blotting assays. These results show that the expression level of differentially-expressed RNA was consistent with the sequencing data, and the Western blotting results were highly consistent with the PCR results, confirming that the sequencing result was very reliable. This study systematically explores the ceRNA atlas of differentially-expressed genes related to B[a]P exposure in breast cancer cells, providing new insights into mechanisms of environmental pollutants in breast cancer.

CapsNet-LDA: predicting lncRNA-disease associations using attention mechanism and capsule network based on multi-view data

Cumulative studies have shown that many long non-coding RNAs (lncRNAs) are crucial in a number of diseases. Predicting potential lncRNA-disease associations (LDAs) can facilitate disease prevention, diagnosis and treatment. Therefore, it is vital to develop practical computational methods for LDA prediction. In this study, we propose a novel predictor named capsule network (CapsNet)-LDA for LDA prediction. CapsNet-LDA first uses a stacked autoencoder for acquiring the informative low-dimensional representations of the lncRNA-disease pairs under multiple views, then the attention mechanism is leveraged to implement an adaptive allocation of importance weights to them, and they are subsequently processed using a CapsNet-based architecture for predicting LDAs. Different from the conventional convolutional neural networks (CNNs) that have some restrictions with the usage of scalar neurons and pooling operations. the CapsNets use vector neurons instead of scalar neurons that have better robustness for the complex combination of features and they use dynamic routing processes for updating parameters. CapsNet-LDA is superior to other five state-of-the-art models on four benchmark datasets, four perturbed datasets and an independent test set in the comparison experiments, demonstrating that CapsNet-LDA has excellent performance and robustness against perturbation, as well as good generalization ability. The ablation studies verify the effectiveness of some modules of CapsNet-LDA. Moreover, the ability of multi-view data to improve performance is proven. Case studies further indicate that CapsNet-LDA can accurately predict novel LDAs for specific diseases.

LINC02381 suppresses cell proliferation and promotes apoptosis via attenuating IGF1R/PI3K/AKT signaling pathway in breast cancer

Identification of the genes and genetic networks involved in breast cancer development is a major need for prevention and therapy. LINC02381 (lncRNA) has already been introduced as a tumor suppressor in colorectal and gastric cancers. Here, we intended to investigate its potential functional effects on breast cancer. In the analysis performed on RNA-Seq and microarray data, the LINC02381 lncRNA was found to be significantly downregulated in the breast tumors and associated with poor survival of the patients. Then, the differential expression of LINC02381 was confirmed in breast tumor tissues and cancer cell lines using RT-qPCR. Overexpression of LINC02381 resulted in reduced IGF1R and p-AKT expression levels which indicates decreased PI3K pathway activity, detected by RT-qPCR and western blotting. At the cellular level, LINC02381 overexpression was followed by a decreased proliferation rate of transfected breast cell lines, detected by PI flow cytometry, RT-qPCR, colony formation, and MTT assays. Consistently, the results of Annexin-V/PI flow cytometry, RT-qPCR, caspase3/7 activity, and AO/EB-H33342/PI dual staining revealed that LINC02381 overexpression induced apoptosis and cell death. The reduced migration rate of these cells was also verified through wound healing assay and RT-qPCR against the EMT-involved genes. Our data show that LINC02381 exerts its tumor suppressor effect at least partly through attenuation of the IGF1R/PI3K/AKT signaling pathway, which originated from IGF1R downregulation.

Long-stranded non-coding RNAs temporal-specific expression profiles reveal longissimus dorsi muscle development and intramuscular fat deposition in Tianzhu white yak

The process of muscle development and intramuscular fat (IMF) deposition is quite complex and controlled by both mRNAs and ncRNAs. Long-stranded non-coding RNAs (LncRNAs) are involved in various biological processes in mammals while also playing a critical role in muscle development and fat deposition. In the present study, RNA-Seq was used to comprehensively study the expression of lncRNAs and mRNAs during muscle development and intramuscular fat deposition in postnatal Tianzhu white yaks at three stages, including 6 mo of age (calve, n = 6), 30 mo of age (young cattle, n = 6) and 54 mo of age (adult cattle, n = 6). The results indicated that a total of 2,101 lncRNAs and 20,855 mRNAs were screened across the three stages, of which the numbers of differential expression (DE) lncRNAs and DE mRNAs were 289 and 1,339, respectively, and DE lncRNAs were divided into eight different expression patterns based on expression trends. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis revealed that some DE mRNAs overlapped with target genes of lncRNAs, such as NEDD4L, SCN3B, AGT, HDAC4, DES, MYH14, KLF15 (muscle development), ACACB, PCK2, LIPE, PIK3R1, PNPLA2, and MGLL (intramuscular fat deposition). These DE mRNAs were significantly enriched in critical muscle development and IMF deposition-related pathways and GO terms, such as AMPK signaling pathway, PI3K-Akt signaling pathway, PPAR signaling pathway, etc. In addition, lncRNA-mRNA co-expression network analysis revealed that six lncRNAs (MSTRG.20152.2, MSTRG.20152.3, XR_001351700.1, MSTRG.8190.1, MSTRG.4827.1, and MSTRG.11486.1) may play a major role in Tianzhu white yak muscle development and lipidosis deposition. Therefore, this study enriches the database of yak lncRNAs and could help to further explore the functions and roles of lncRNAs in different stages of muscle development and intramuscular fat deposition in the Tianzhu white yak.

The clinical prognostic value of lncRNA LINC00473 in cancer patients: A meta-analysis

BACKGROUND

LINC00473 is a promising long non-coding RNA. There is increasing evidence that SNHG7 is abnormally expressed in various tumors and is associated with cancer prognosis. However, identification of the effect of long non-coding RNA LINC00473 in tumors remains necessary.

METHODS

Up to August 15, 2021, we searched electronic databases, including PubMed, Cochrane Library, EMBASE, Medline, and Web of Science. The results were evaluated by pooled odds ratios (ORs) and hazard ratios (HRs) with 95% confidence intervals (CIs).

RESULTS

There weres 13 included literature totaling cancer patients involved in this meta-analysis. The aggregated results revealed that high expression of LINC00473 was significantly associated with unfavorable overall survival (HR = 1.66, 95% CI: 1.48-1.86, P < .00001), disease-free survival (HR = 1.59, 95% CI: 1.09-2.32, P = .02) in a variety of cancers. Additionally, increased LINC00473 expression was also correlated with tumor node metastasis stage ((III/IV vs I/II) OR = 4.67, 95% CI = 3.11-7.02, P < .00001), differentiation ((poor/moderately vs well) OR = 3.25, 95% CI = 1.41-7.50, P = .006), tumor size ((larger vs smaller) OR = 2.49, 95% CI = 1.26-4.91, P = .03), and lymph node metastasis ((positive vs negative) OR = 3.10, 95% CI = 2.13-4.51, P = .008) in patients with cancers. Besides, the Gene Expression Profiling Interactive Analysis dataset evaluated that LINC00473 was upregulated in a variety of tumors and predicted worse prognosis.

CONCLUSION

Our results of this meta-analysis demonstrated that high LINC00473 expression may become a potential target for predicting prognosis of human cancers.

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.

Construction of prognostic signature of breast cancer based on N7-Methylguanosine-Related LncRNAs and prediction of immune response

Background: Long non-coding RNA (LncRNA) is a prognostic factor for malignancies, and N7-Methylguanosine (m7G) is crucial in the occurrence and progression of tumors. However, it has not been documented how well m7G-related LncRNAs predict the development of breast cancer (BC). This study aims to develop a predictive signature based on long non-coding RNAs (LncRNAs) associated with m7G to predict the prognosis of breast cancer patients.

Methods: The Cancer Genome Atlas (TCGA) database provided us with the RNA-seq data and matching clinical information of individuals with breast cancer. To identify the signature of N7-Methylguanosine-Related LncRNAs and create a prognostic model, we employed co-expression network analysis, least absolute shrinkage selection operator (LASSO) regression analysis, univariate Cox regression analysis, and multivariate Cox regression analysis. The signature was assessed using the Kaplan-Meier analysis and Receiver Operating Characteristic (ROC) curve. A nomogram and principal component analysis (PCA) were employed to confirm the predictive signature’s usefulness. Then, we examined the drug sensitivity between the two risk groups and utilized single-sample gene set enrichment analysis (ssGSEA) to investigate the association between predictive factors and the tumor immune microenvironment in high-risk and low-risk groups.

Results: Nine m7G-related LncRNAs (LINC01871, AP003469.4, Z68871.1, AC245297.3, EGOT, TFAP2A-AS1, AL136531.1, SEMA3B-AS1, AL606834.2) that are independently associated with the overall survival time (OS) of BC patients make up the signature we developed. For predicting 1-, 3-, and 5-year survival rates, the areas under the ROC curve (AUC) were 0.715, 0.724, and 0.726, respectively. The Kaplan-Meier analysis revealed that the prognosis of BC patients in the high-risk group was worse than that of those in the low-risk group. When compared to clinicopathological variables, multiple regression analysis demonstrated that risk score was a significant independent predictive factor for BC patients. The results of the ssGSEA study revealed a substantial correlation between the predictive traits and the BC patients’ immunological status, low-risk BC patients had more active immune systems, and they responded better to PD1/L1 immunotherapy.

Conclusion: The prognostic signature, which is based on m7G-related LncRNAs, can be utilized to inform patients’ customized treatment plans by independently predicting their prognosis and how well they would respond to immunotherapy.

Epigenetic factors in breast cancer therapy

Epigenetic modifications are inherited differences in cellular phenotypes, such as cell gene expression alterations, that occur during somatic cell divisions (also, in rare circumstances, in germ line transmission), but no alterations to the DNA sequence are involved. Histone alterations, polycomb/trithorax associated proteins, short non-coding or short RNAs, long non—coding RNAs (lncRNAs), & DNA methylation are just a few biological processes involved in epigenetic events. These various modifications are intricately linked. The transcriptional potential of genes is closely conditioned by epigenetic control, which is crucial in normal growth and development. Epigenetic mechanisms transmit genomic adaptation to an environment, resulting in a specific phenotype. The purpose of this systematic review is to glance at the roles of Estrogen signalling, polycomb/trithorax associated proteins, DNA methylation in breast cancer progression, as well as epigenetic mechanisms in breast cancer therapy, with an emphasis on functionality, regulatory factors, therapeutic value, and future challenges.

Long Non-Coding RNA T Cell Leukemia/Lymphoma 6 Inhibits the Proliferation and Invasion of Breast Cancer Cells by Down-Regulating miR-665

Breast cancer (BC), which is most commonly seen in women, has become the second most common cause of cancer death in the United States. The number of women dying from BC is increasing every year, especially in the developing countries that fall behind in terms of economy and technologies. Therefore, it is of great necessity to find potential targets to effectively treat this disease. In this study, RT-qPCR was performed to detect the expressions of TCL6, miR-665, and CD82. CCK-8 and immunofluorescence assays were conducted for the assessment of BC cell proliferation. The invasion and migration of BC cells were detected by transwell and wound healing assays, respectively. Luciferase reporter assay was used to verify the combination of TCL6 and miR-665, and the binding of miR-665 and CD82. Moreover, the proliferation and migration of related proteins were measured by western blot. The results showed that TCL6 was low expressed in BC cells, but overexpression of TCL6 inhibited the proliferation, migration, and invasion of BC cells. On the contrary, miR-665 was highly expressed in BC cells, while its expression was negatively correlated with TCL6 as suggested by RT-qPCR assay. Furthermore, the inhibitory effects of TCL6 overexpression on the proliferation, migration, and invasion of BC cells were reversed by miR-665 mimic. Afterwards, the binding sites between miR-665 and CD82 were verified by luciferase reporter assay. Overexpression of TCL6 increased the level of CD82 in BC cells, but this effect was reversed by miR-665 mimic as well. In conclusion, the present study has presented the fact that TCL6 could enhance the expression of CD82 by down-regulating the expression of miR-665.

RAMP2-AS1 inhibits CXCL11 expression to suppress malignant phenotype of breast cancer by recruiting DNMT1 and DNMT3B

BACKGROUND

Breast cancer is the most common malignancy in women populations.

METHODS

RAMP2-AS1 and CXCL11 expression in breast cancer tissues and cells were determined using RT-qPCR or Western blot. RIP analysis confirmed the interaction between DNMT1, DNMT3B and RAMP2-AS1. ChIP assay verified that RAMP2-AS1 recruited DNMT1 and DNMT3B to the promoter region of CXCL11. FISH detected the sub-localization of RAMP2-AS1 in breast cancer cells. Bisulfite sequencing PCR (BSP) tested the methylation level of CXCL11. The cell viability, proliferation, migration and apoptosis were assessed by CCK-8, colony formation, transwell and flow cytometry assays, respectively. IHC was performed to evaluate the expression of Ki67, CXCL11, MMP2 in tumor tissues.

RESULTS

The level of RAMP2-AS1 was decreased in breast cancer tissues and cells, whereas CXCL11 was highly expressed. Patients with decreased RAMP2-AS1 had a poor prognosis. RAMP2-AS1 inhibited breast cancer cell malignant phenotype. Besides, RAMP2-AS1 regulated the methylation of CXCL11 by recruiting DNMT1 and DNMT3B to the promoter region of CXCL11. RAMP2-AS1 overexpression suppressed the malignant phenotype through CXCL11 and inhibited tumor growth in vivo.

CONCLUSION

RAMP2-AS1 suppresses breast cancer malignant phenotype via DNMT1 and DNMT3B mediated inhibition of CXCL11.

Immune-Related LncRNAs as Prognostic Factors for Pediatric Rhabdoid Tumor of the Kidney

Background

Immune-related long noncoding RNAs (IrlncRNAs) are recognized as important prognostic factors in a variety of cancers, but thus far, their prognostic value in pediatric rhabdoid tumor of the kidney (pRTK) has not been reported. Here, we clarified the associations between IrlncRNAs and overall survival (OS) of pRTK patients and constructed a model to predict their prognosis.

Methods

We accessed RNA sequencing data and corresponding clinical data of pRTK from the Therapeutically Applicable Research to Generate Effective Treatments (TARGET) database. An expression profile of immune-related genes (Irgenes) and lncRNAs of pRTK was extracted from the RNA sequencing data. IrlncRNAs were defined by co-expression analysis of lncRNAs and Irgenes. The limma R package was used to identify differential expression IrlncRNAs. Univariate and multivariate Cox regression analyses were conducted to build a prognostic IrlncRNAs model. The performance of this prognostic model was validated by multimethods, like ROC curve analysis.

Results

A total of 1097 IrlncRNAs were defined. Univariate Cox regression analysis identified 7 IrlncRNAs (AC004791.2, AP003068.23, RP11-54O7.14, RP11-680F8.1, TBC1D3P1-DHX40P1, TUNAR, and XXbac-BPG308K3.5) and were significantly associated with OS. Multivariate regression analysis constructed the best prognostic model based on the expression of AC004791.2, AP003068.23, RP11-54O7.14, TBC1D3P1-DHX40P1, and TUNAR. According to the prognostic model, a risk score of each patient was calculated, and patients were divided into high-risk and low-risk groups accordingly. The survival time of low-risk patients was significantly better than high-risk patients (p < 0.001). Univariate (hazard ratio 1.098, 95% confidence interval 1.048-1.149, p value <0.001) and multivariate (hazard ratio 1.095, 95% confidence interval 1.043-1.150, p value <0.001) analyses confirmed that the prognostic model was reliable and independent in prediction of OS. Time-dependent ROC analysis showed that 1-year survival AUC of prognostic model, stage, age, and sex was 0.824, 0.673, 0.531, and 0.495, respectively, which suggested that the prognostic model was the best predictor of survival in pRTK patients.

Conclusions

The prognostic model based on 5 IrlncRNAs was robust and could better predict the survival of pRTK than other clinical factors. Additionally, the mechanism of regulation and action of prognosis-associated lncRNAs could provide new avenues for basic research to explore the mechanism of tumor initiation and development in order to prevent and treat pRTK.

HBRWRLDA: predicting potential lncRNA-disease associations based on hypergraph bi-random walk with restart

Accumulating evidence indicates that the regulation of long non-coding RNAs (lncRNAs) is closely related to a variety of diseases. Identifying meaningful lncRNA-disease associations will help to contribute to the understanding of the molecular mechanisms underlying these diseases. However, only a limited number of associations between lncRNAs and diseases have been inferred from traditional biological experiments due to the high cost and highly specialized. Therefore, computational methods are increasingly used to reduce time of biological experiments and complement biological research. In this paper, a computational method called HBRWRLDA is proposed to predict lncRNA-disease associations. First, HBRWRLDA models the relationships between multiple nodes using hypergraphs, which allows HBRWRLDA to integrate the expression similarity of lncRNAs and the semantic similarity of diseases to construct hypergraphs. Then, a bi-random walk on hypergraphs is used to predict potential lncRNA-disease associations. HBRWRLDA achieves a higher area under the curve value of 0.9551 and [Formula: see text], respectively, compared with the other five advanced methods under the framework of one-leave cross validation (LOOCV) and five-fold cross-validation (5-fold CV). In addition, the prediction effect of HBRWRLDA was confirmed case studies of three diseases: renal cell carcinoma, gastric cancer, and hepatocellular carcinoma. Case studies demonstrates the capacity of HBRWRLDA to identify potentially disease-associated lncRNAs. Overall, HBRWRLDA is excellent at predicting potential lncRNA-disease associations and could be useful in conducting further biological experiments by helping researchers identify candidates of lncRNA-disease association.

MiR-146a alleviates lung injury caused by RSV infection in young rats by targeting TRAF-6 and regulating JNK/ERKMAPK signaling pathways

Respiratory syncytial virus (RSV) is a major cause of acute lower respiratory tract infection in infants and children. The present study aimed to investigate the effects of miR-146a on RSV replication and the related mechanisms. Material and methods: We pretreated A549 and HEp-2 cells and young rats with miR-146a mimic before infection with RSV. The expressions of miR-146a and RSV-F mRNA in cells and lung tissues were detected by RT-qPCR, and production of IL-1β, IL-6, IL-18, and TNF-α in bronchial alveolar lavage fluid (BALF) were determined by ELISA. The expression level of TRAF-6 and activation of the JNK/ERK/MAPK/NF-κB signaling pathway was detected by Western blotting. Results: RSV infection significantly reduced miR-146a levels in both A549 and HEp-2 cells and rat lung tissues. RSV infection resulted in accelerated growth, increased release of inflammatory cytokines, increased expression of TRAF-6, and activation of the JNK pathway in cells, and the lung inflammatory infiltration and the pathological score increased in rats. Overexpression of miR-146a targeted down-regulation of TRAF-6 expression and JNK/ERK/MAPK/NF-κB pathway induced by RSV infection, reduced the production of inflammatory cytokines IL-1β, IL-6 and TNF-α, and alleviate lung injury in young rats. We got similar results in both A549 and HEp-2 cell experiments. Conclusion: MiR-146a alleviates lung injury caused by RSV infection in young rats by targeting TRAF-6 and regulating JNK/ERK/MAPK signaling pathways.

LncRNA HCG11 represses ovarian cancer cell growth via AKT signaling pathway

AIM

Ovarian cancer is a main contributor of cancer-relevant deaths among women worldwide due to high incidence and mortality. Mounting evidence has unveiled that lncRNAs play critical roles in malignancies, including ovarian cancer. Although the tumor suppressor function of HCG11 in prostate cancer and glioma has been proved, investigations on HCG11 role in ovarian cancer are still scarce.

METHODS

Gene or protein expression was quantified by RT-qPCR or western blot. HCG11 effects on ovarian cancer were assessed by functional assays. Bioinformatics analysis and mechanism experiments were implemented to identify the association among HCG11, miR-1270, and PTEN.

RESULTS

HCG11 was weakly expressed in ovarian cancer and functioned as a tumor suppressor in ovarian cancer by retarding cell proliferation, migration, and EMT. Besides, HCG11 could bind to miR-1270 and PTEN was a target gene of miR-1270. Mechanically, HCG11 competitively bound with miR-1270 to upregulate PTEN. From rescue experiments, HCG11 impeded AKT/mTOR pathway to retard ovarian cancer cell growth by miR-1270/PTEN.

CONCLUSIONS

HCG11 was a tumor suppressor in ovarian cancer cells and additionally, HCG11 regulated AKT/mTOR pathway to hinder ovarian cancer cell growth via modulating miR-1270/PTEN, indicating that HCG11 may represent a promising target for effective treatment of ovarian cancer patients.

Development and Validation of a Novel Hypoxia-Related Long Noncoding RNA Model With Regard to Prognosis and Immune Features in Breast Cancer

Background: Female breast cancer is currently the most frequently diagnosed cancer in the world. This study aimed to develop and validate a novel hypoxia-related long noncoding RNA (HRL) prognostic model for predicting the overall survival (OS) of patients with breast cancer. Methods: The gene expression profiles were downloaded from The Cancer Genome Atlas (TCGA) database. A total of 200 hypoxia-related mRNAs were obtained from the Molecular Signatures Database. The co-expression analysis between differentially expressed hypoxia-related mRNAs and lncRNAs based on Spearman's rank correlation was performed to screen out 166 HRLs. Based on univariate Cox regression and least absolute shrinkage and selection operator Cox regression analysis in the training set, we filtered out 12 optimal prognostic hypoxia-related lncRNAs (PHRLs) to develop a prognostic model. Kaplan-Meier survival analysis, receiver operating characteristic curves, area under the curve, and univariate and multivariate Cox regression analyses were used to test the predictive ability of the risk model in the training, testing, and total sets. Results: A 12-HRL prognostic model was developed to predict the survival outcome of patients with breast cancer. Patients in the high-risk group had significantly shorter median OS, DFS (disease-free survival), and predicted lower chemosensitivity (paclitaxel, docetaxel) compared with those in the low-risk group. Also, the risk score based on the expression of the 12 HRLs acted as an independent prognostic factor. The immune cell infiltration analysis revealed that the immune scores of patients in the high-risk group were lower than those of the patients in the low-risk group. RT-qPCR assays were conducted to verify the expression of the 12 PHRLs in breast cancer tissues and cell lines. Conclusion: Our study uncovered dozens of potential prognostic biomarkers and therapeutic targets related to the hypoxia signaling pathway in breast cancer.

The Role of Long Non-Coding RNAs (lncRNAs) in Female Oriented Cancers

Recent advances in molecular biology have discovered the mysterious role of long non-coding RNAs (lncRNAs) as potential biomarkers for cancer diagnosis and targets for advanced cancer therapy. Studies have shown that lncRNAs take part in the incidence and development of cancers in humans. However, previously they were considered as mere RNA noise or transcription byproducts lacking any biological function. In this article, we present a summary of the progress on ascertaining the biological functions of five lncRNAs (HOTAIR, NEAT1, H19, MALAT1, and MEG3) in female-oriented cancers, including breast and gynecological cancers, with the perspective of carcinogenesis, cancer proliferation, and metastasis. We provide the current state of knowledge from the past five years of the literature to discuss the clinical importance of such lncRNAs as therapeutic targets or early diagnostic biomarkers. We reviewed the consequences, either oncogenic or tumor-suppressing features, of their aberrant expression in female-oriented cancers. We tried to explain the established mechanism by which they regulate cancer proliferation and metastasis by competing with miRNAs and other mechanisms involved via regulating genes and signaling pathways. In addition, we revealed the association between stated lncRNAs and chemo-resistance or radio-resistance and their potential clinical applications and future perspectives.

Identification of Potential Long Non-Coding RNA Candidates that Contribute to Triple-Negative Breast Cancer in Humans through Computational Approach

Breast cancer (BC) is the most frequent malignancy identified in adult females, resulting in enormous financial losses worldwide. Owing to the heterogeneity as well as various molecular subtypes, the molecular pathways underlying carcinogenesis in various forms of BC are distinct. Therefore, the advancement of alternative therapy is required to combat the ailment. Recent analyses propose that long non-coding RNAs (lncRNAs) perform an essential function in controlling immune response, and therefore, may provide essential information about the disorder. However, their function in patients with triple-negative BC (TNBC) has not been explored in detail. Here, we analyzed the changes in the genomic expression of messenger RNA (mRNA) and lncRNA in standard control in response to cancer metastasis using publicly available single-cell RNA-Seq data. We identified a total of 197 potentially novel lncRNAs in TNBC patients of which 86 were differentially upregulated and 111 were differentially downregulated. In addition, among the 909 candidate lncRNA transcripts, 19 were significantly differentially expressed (DE) of which three were upregulated and 16 were downregulated. On the other hand, 1901 mRNA transcripts were significantly DE of which 1110 were upregulated and 791 were downregulated by TNBCs subtypes. The Gene Ontology (GO) analyses showed that some of the host genes were enriched in various biological, molecular, and cellular functions. The Kyoto encyclopedia of genes and genomes (KEGG) pathway analysis showed that some of the genes were involved in only one pathway of prostate cancer. The lncRNA-miRNA-gene network analysis showed that the lncRNAs TCONS_00076394 and TCONS_00051377 interacted with breast cancer-related micro RNAs (miRNAs) and the host genes of these lncRNAs were also functionally related to breast cancer. Thus, this study provides novel lncRNAs as potential biomarkers for the therapeutic intervention of this cancer subtype.

LncRNAs as Therapeutic Targets and Potential Biomarkers for Lipid-Related Diseases

Lipid metabolism is an essential biological process involved in nutrient adjustment, hormone regulation, and lipid homeostasis. An irregular lifestyle and long-term nutrient overload can cause lipid-related diseases, including atherosclerosis, myocardial infarction (MI), obesity, and fatty liver diseases. Thus, novel tools for efficient diagnosis and treatment of dysfunctional lipid metabolism are urgently required. Furthermore, it is known that lncRNAs based regulation like sponging microRNAs (miRNAs) or serving as a reservoir for microRNAs play an essential role in the progression of lipid-related diseases. Accordingly, a better understanding of the regulatory roles of lncRNAs in lipid-related diseases would provide the basis for identifying potential biomarkers and therapeutic targets for lipid-related diseases. This review highlighted the latest advances on the potential biomarkers of lncRNAs in lipid-related diseases and summarised current knowledge on dysregulated lncRNAs and their potential molecular mechanisms. We have also provided novel insights into the underlying mechanisms of lncRNAs which might serve as potential biomarkers and therapeutic targets for lipid-related diseases. The information presented here may be useful for designing future studies and advancing investigations of lncRNAs as biomarkers for diagnosis, prognosis, and therapy of lipid-related diseases.

An updated review of the role of lncRNAs and their contribution in various molecular subtypes of breast cancer

Introduction: Breast cancer (BC) is the most significant threat to women's life. To demonstrate its molecular mechanisms, which results in BC progression, it is crucial to develop approaches to enhance prognosis and survival in BC cases.Areas covered: In the current study, we aimed to highlight the updated data on the oncogenic and tumor suppressive roles of lncRNAs in the progression of various subtypes of BC by specifically putting importance on the functional characteristics, modulatory agents, therapeutic potential, future perspectives and challenges of lncRNAs in BC. We reviewed recent studies published between 2019 and 2020.Expert opinion: The latest investigations have demonstrated that the long non-coding RNAs (lncRNAs) participate in different BC molecular subtypes via different molecular mechanisms; however, the exact functional information of the lncRNAs has yet to be elucidated. The studied lncRNAs could be more applicable as therapeutic targets in BC treatment after pre-clinical and clinical studies.

Exosomal lncRNA LINC01711 facilitates metastasis of esophageal squamous cell carcinoma via the miR-326/FSCN1 axis

Esophageal cancer is a malignant tumor with a five-year survival rate of less than 20%. Early diagnosis and exploration of esophageal cancer pathogenesis are of great significance for the treatment and prognosis of esophageal cancer. Long non-coding RNA (lncRNA) plays a vital role in the occurrence and development of different types of tumors. However, the role of exosome LncRNA in esophageal squamous cell carcinoma (ESCC) is rarely reported. In this study, we detected high expression of lncRNA LINC01711 in ESCC tissues and was associated with poor prognosis. Silencing LINC01711 can inhibit the proliferation, migration, invasion, and growth of ESCC cell lines, and induce apoptosis. Linc01711 was identified as a competitive endogenous RNA that suppressed miR-326, and up-regulated the expression of fascin actin-bundling protein 1 (FSCN1). Besides, in vivo experiments showed that the administration of exosome-derived LINC01711 (LINC01711-Exo) promoted the growth of tumors in nude mice. In general, exosomal LINC01711 promoted the proliferation, migration, and invasion of esophageal cancer cells by up-regulating FSCN1 and down-regulating miR-326, thus improved the occurrence and development of ESCC.

LncRNA NEAT1 accelerates breast cancer progression through regulating miR-410-3p/ CCND1 axis

BACKGROUND

Breast cancer is the most common malignant tumor and usually occurs in women. Studies have shown that lncRNA nuclear enriched abundant transcript 1 (NEAT1) contributes to breast cancer progression. This study intends to further investigate the molecular mechanism of NEAT1 in breast cancer.

METHODS

The expression levels of NEAT1, miR-410-3p and Cyclin D1 (CCND1) were detected by quantitative real-time PCR (qRT-PCR) in breast cancer tissues and cells. Kaplan-Meier analysis and the log-rank test were performed to determine the relationship between NEAT1 and overall survival. Cell Counting Kit-8 (CCK-8) assay analyzed cell proliferation. Transwell assay was performed to examine cell migration and invasion. The protein levels of CCND1 and epithelial-mesenchymal transition (EMT)-related proteins (E-cadherin, N-cadherin and Vimentin) were measured by western blot. The target relationship was predicted by bioinformatics analysis, and confirmed by luciferase reporter assay and RNA Immunoprecipitation (RIP) assay. Xenograft analysis was used to evaluate the tumor growth in vivo.

RESULTS

NEAT1 and CCND1 were upregulated, while miR-410-3p was down-regulated in breast cancer tissues and cells. Higher NEAT1 expression level was associated with lower survival rate of breast cancer patients. Knockdown of miR-410-3p restored silenced NEAT1-mediated the inhibition of on proliferation, migration, invasion and EMT of breast cancer cells. In addition, NEAT1 regulated CCND1 expression by sponging miR-410-3p in breast cancer cells. NEAT1 knockdown blocked the tumor growth in vivo.

CONCLUSION

NEAT1 induced breast cancer progression by regulating the miR-410-3p/CCND1 axis, indicating that NEAT1 may be a potential therapeutic target in breast cancer.

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

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

The Clinical Prognostic Value of lncRNA SBF2-AS1 in Cancer Patients: A Meta-Analysis

Background:

The mortality and recurrence of patients with cancer is of high prevalence. SET-binding factor 2 (SBF2) antisense RNA1 (lncRNA-SBF2-AS1) is a promising long non-coding RNA. There is increasing evidence that SBF2-AS1 is abnormally expressed in various tumors and is associated with cancer prognosis. However, the identification of the effect of lncRNA SBF2-AS1 in tumors remains necessary.

Materials and Methods:

Up to November 2, 2020, electronic databases, including PubMed, Cochrane Library, EMBASE, Medline, and Web of Science, were searched. The results were evaluated by pooled odds ratios (ORs) and hazard ratios (HRs) with 95% confidence intervals (CIs).

Results:

A total of 11 literatures on cancer patients were included for the present meta-analysis. The combined results revealed that high expression of SBF2-AS1 was significantly associated with unfavorable overall survival (OS) (HR = 1.48, 95% CI: 1.34-1.62, P < 0.00001) in a variety of cancers. In additional, the increase in SBF2-AS1 expression was also correlated with tumor size ((larger vs. smaller) OR = 2.34, 95% CI: 1.47-3.70, P = 0.0003), advanced TNM stage ((III/IV vs. I/II) OR = 2.78, 95% CI: 1.75-4.41, P < 0.0001), lymph node metastasis ((Positive vs. Negative) OR = 3.06, 95% CI: 1.93-4.86, P < 0.00001), and histological grade ((poorly vs. well/moderately) OR = 2.58, 95% CI: 1.47-4.52, P = 0.001) in patients with cancer. Furthermore, The Cancer Genome Atlas (TCGA) dataset valuated that SBF2-AS1 was upregulated in a variety of tumors, and predicted the worse prognosis.

Conclusions:

Our results of this meta-analysis demonstrate that high SBF2-AS1 expression may become a potential target for predicting the prognosis of human cancers.

lncRNA APOC1P1-3 promoting anoikis-resistance of breast cancer cells

BACKGROUND

Anoikis resistance plays a critical role in the tumor metastasis by allowing survival of cancer cells in the systemic circulation. We previously showed that long non-coding RNAs APOC1P1-3 (lncRNA APOC1P1-3) inhibit apoptosis of breast cancer cells. In this study, we explored its role in anoikis resistance.

METHODS

We induced anoikis resistance in two breast cancer cell lines (MCF-7 and MDA-MB-231) under anchorage-independent culture conditions and studied lncRNA APOC1P1-3 effects on apoptosis. Using Dual-Luciferase activity assay, we determined whether it specifically binds to miRNA-188-3P. We further explored its role in lung metastasis by injecting MDA-MB-231 and MDA-MB-231-APOC1P1-3-knock-down cells in female BALB/c nude mice.

RESULTS

We found that lncRNA APOC1P1-3 suppressed early apoptosis of these cells (demonstrated by gain or loss of their function, respectively) and promoted anoikis resistance via reducing activated- Caspase 3, 8, 9 and PARP. Moreover, it specifically binds to the target miRNA-188-3p acting as a "sponge" to block the inhibition of Bcl-2 (an anti-apoptosis protein).

CONCLUSIONS

Our study supports a theory that lncRNA APOC1P1-3 can promote development of breast cancer metastasis via anoikis resistance by specifically binding to miRNA-188-3p to block the inhibition of Bcl-2.

The role of M6A modification in the regulation of tumor-related lncRNAs

N⁶-methyladenosine (m⁶A) is the most abundant modification in eukaryotic cells, and it regulates RNA transcription, processing, splicing, degradation, and translation. Long non-coding RNAs (lncRNAs), as transcriptional products with no or limited protein coding ability more than 200 nt in length, play an important role in epigenetic modification, mRNA transcription, splicing, stability, translation, and other biological functions. Extensive studies have shown that both m⁶A modification and lncRNAs are involved in the pathogenesis of various diseases, such as kinds of cancers, heart failure, Alzheimer’s disease, periodontitis, human abdominal aortic aneurysm, and obesity. To date, m⁶A modification has been identified as an important biological function in enrichment and regulation of lncRNAs. In this review, we summarize the role of m⁶A modification in the regulation and function of tumor-related lncRNAs. Moreover, we discuss the potential applications and possible future directions in the field.

The role of EMT-related lncRNA in the process of triple-negative breast cancer metastasis

Triple-negative breast cancer (TNBC) is the most malignant and fatal subtype of breast cancer, which has characterized by negativity expression of ER, PR, and HER2. Metastasis is the main factor affecting the prognosis of TNBC, and the process of metastasis is related to abnormal activation of epithelial–mesenchymal transition (EMT). Recent studies have shown that long non-coding RNA (LncRNA) plays an important role in regulating the metastasis and invasion of TNBC. Therefore, based on the metastasis-related EMT signaling pathway, great efforts have confirmed that LncRNA is involved in the molecular mechanism of TNBC metastasis, which will provide new strategies to improve the treatment and prognosis of TNBC. In this review, we summarized many signal pathways related to EMT involved in the transfer process. The advances from the most recent studies of lncRNAs in the EMT-related signal pathways of TNBC metastasis. We also discussed the clinical research, application, and challenges of LncRNA in TNBC.

A Novel Framework to Predict Breast Cancer Prognosis Using Immune-Associated LncRNAs

Background: Breast cancer (BC) is one of the most frequently diagnosed malignancies among females. As a huge heterogeneity of malignant tumor, it is important to seek reliable molecular biomarkers to carry out the stratification for patients with BC. We surveyed immune- associated lncRNAs that may be used as potential therapeutic targets in BC.

Methods: LncRNA expression data and clinical information of BC patients were downloaded from the TCGA database for a comprehensive analysis of candidate genes. A model consisting of immune-related lncRNAs enriched in BC cancerous tissues was established using the univariate Cox regression analysis and the iterative Lasso Cox regression analysis. The prognostic performance of this model was validated in two independent cohorts (GSE21653 and BC-KR), and compared with known prognostic biomarkers. A nomogram that integrated the immune-related lncRNA signature and clinicopathological factors was constructed to accurately assess the prognostic value of this signature. The correlation between the signature and immune cell infiltration in BC was also analyzed.

Results: The Kaplan-Meier analysis showed that the OS of Patients in the low-risk group had significantly better survival than those in the high-risk group, Clinical subgroup analysis showed that the predictive ability was independent of clinicopathological factors. Univariate/multivariate Cox regression analysis showed immune lncRNA signature is an important prognostic factor and an independent prognostic marker. In addition, GSEA and GSVA analysis as well as comprehensive analysis of immune cells showed that the signature was significantly correlated with the infiltration of immune cells.

Conclusion: We successfully constructed an immune-associated lncRNA signature that can accurately predict BC prognosis.

Dual relationship between long non-coding RNAs and STAT3 signaling in different cancers: New insight to proliferation and metastasis

Uncontrolled growth and metastasis of cancer cells is an increasing challenge for overcoming cancer, and improving survival of patients. Complicated signaling networks account for proliferation and invasion of cancer cells that need to be elucidated for providing effective cancer therapy, and minimizing their malignancy. Long non-coding RNAs (lncRNAs) are RNA molecules with a length of more than 200 nucleotides. They participate in cellular events, and their dysregulation in a common phenomenon in different cancers. Noteworthy, lncRNAs can regulate different molecular pathways, and signal transducer and activator of transcription 3 (STAT3) is one of them. STAT3 is a tumor-promoting factors in cancers due to its role in cancer proliferation (cell cycle progression and apoptosis inhibition) and metastasis (EMT induction). LncRNAs can function as upstream mediators of STAT3 pathway, reducing/enhancing its expression. This dual relationship is of importance in affecting proliferation and metastasis of cancer cells. The response of cancer cells to therapy such as chemotherapy and radiotherapy is regulated by lncRNA/STAT3 axis. Tumor-promoting lncRNAs including NEAT1, SNHG3 and H19 induces STAT3 expression, while tumor-suppressing lncRNAs such as MEG3, PTCSC3 and NKILA down-regulate STAT3 expression. Noteworthy, upstream mediators of STAT3 such as microRNAs can be regulated by lncRNAs. These complicated signaling networks are mechanistically described in the current review.

A systematic review of long non-coding RNAs with a potential role in breast cancer

The human transcriptome contains many non-coding RNAs (ncRNAs), which play important roles in gene regulation. Long noncoding RNAs (lncRNAs) are an important class of ncRNAs with lengths between 200 and 200,000 bases. Unlike mRNA, lncRNA lacks protein-coding features, specifically, open-reading frames, and start and stop codons. LncRNAs have been reported to play a role in the pathogenesis and progression of many cancers, including breast cancer (BC), acting as tumor suppressors or oncogenes. In this review, we systematically mined the literature to identify 65 BC-related lncRNAs. We then perform an integrative bioinformatics analysis to identify 14 lncRNAs with a potential regulatory role in BC. The biological function of these 14 lncRNAs, their regulatory mechanisms, and roles in the initiation and progression of BC are discussed in this review. Additionally, we elaborate on the current and future applications of lncRNAs as diagnostic and/or therapeutic biomarkers in BC.

miR-205 in Breast Cancer: State of the Art

Despite its controversial roles in different cancer types, miR-205 has been mainly described as an oncosuppressive microRNA (miRNA), with some contrasting results, in breast cancer. The role of miR-205 in the occurrence or progression of breast cancer has been extensively studied since the first evidence of its aberrant expression in tumor tissues versus normal counterparts. To date, it is known that the expression of miR-205 in the different subtypes of breast cancer is decreasing from the less aggressive subtype, estrogen receptor/progesterone receptor positive breast cancer, to the more aggressive, triple negative breast cancer, influencing metastasis capability, response to therapy and patient survival. In this review, we summarize the most important discoveries that have highlighted the functional role of this miRNA in breast cancer initiation and progression, in stemness maintenance, in the tumor microenvironment, its potential role as a biomarker and its relevance in normal breast physiology—the still open questions. Finally, emerging evidence reveals the role of some lncRNAs in breast cancer progression as sponges of miR-205. Here, we also reviewed the studies in this field.

Extracellular Matrix-Related Six-lncRNA Signature as a Novel Prognostic Biomarker for Bladder Cancer

Introduction

Bladder cancer (BC) is the fourth-commones cancer and the sixth-leading cause of cancer-related death among men. However, a lack of reliable biomarkers remains a problem forprognosis and treatment of BC. lncRNAs have been shown to play important roles in various cancers, and have emerged as promising biomarkers for cancer prognosis and treatment.

Methods

In this study, using univariate and multivariate Cox regression analysis, we examined the differential expression profiles of 1,651 lncRNAs in the TCGA BLCA cohort and created a prognostic gene signature composed of six lncRNAs (for SNHG12, MAFG-DT, ASMTL-AS1, LINC02321, LINC01322, and LINC00922), designed the SMALLL signature.

Results

The SMALLL signature displayed significant prognostic power for overall survival for BC patients in multiple cohorts. Gene Ontology analysis showed that genes coexpressed with the SMALLL signature were associated with the extracellular matrix network, and immune cell–infiltration analysis showed that activated naïve B cells, regulatory T cells, M0 macrophages, eosinophils, resting memory CD4 T cells and resting NK cells were significantly different in high- and low-risk groups. We also confirmed differential expression of the lncRNAs of the SMALLL signature in BC tissue and paracancer normal tissue by qRT-PCR analysis. Cell-invasion and -migration experiments showed that MAFG-AS1, ASMTL-AS1, LINC02321, and LINC00922 significantly affected cell invasion and migration.

Conclusion

Our study revealed that the lncRNA signature is an important predictive factor of prognosis and provides a promising biomarker for BC.

Immune-related lncRNAs as predictors of survival in breast cancer: a prognostic signature

Background

Breast cancer is a highly heterogeneous disease, this poses challenges for classification and management. Long non-coding RNAs play acrucial role in the breast cancersdevelopment and progression, especially in tumor-related immune processes which have become the most rapidly investigated area. Therefore, we aimed at developing an immune-related lncRNA signature to improve the prognosis prediction of breast cancer.

Methods

We obtained breast cancer patient samples and corresponding clinical data from The Cancer Genome Atlas (TCGA) database. Immune-related lncRNAs were screened by co-expression analysis of immune-related genes which were downloaded from the Immunology Database and Analysis Portal (ImmPort). Clinical patient samples were randomly separated into training and testing sets. In the training set, univariate Cox regression analysis and LASSO regression were utilized to build a prognostic immune-related lncRNA signature. The signature was validated in the training set, testing set, and whole cohorts by the Kaplan–Meier log-rank test, time-dependent ROC curve analysis, principal component analysis, univariate andmultivariate Cox regression analyses.

Results

A total of 937 immune- related lncRNAs were identified, 15 candidate immune-related lncRNAs were significantly associated with overall survival (OS). Eight of these lncRNAs (OTUD6B-AS1, AL122010.1, AC136475.2, AL161646.1, AC245297.3, LINC00578, LINC01871, AP000442.2) were selected for establishment of the risk prediction model. The OS of patients in the low-risk group was higher than that of patients in the high-risk group (p = 1.215e − 06 in the training set; p = 0.0069 in the validation set; p = 1.233e − 07 in whole cohort). The time-dependent ROC curve analysis revealed that the AUCs for OS in the first, eighth, and tenth year were 0.812, 0.81, and 0.857, respectively, in the training set, 0.615, 0.68, 0.655 in the validation set, and 0.725, 0.742, 0.741 in the total cohort. Multivariate Cox regression analysis indicated the model was a reliable and independent indicator for the prognosis of breast cancer in the training set (HR = 1.432; 95% CI 1.204–1.702, p < 0.001), validation set (HR = 1.162; 95% CI 1.004–1.345, p = 0.044), and whole set (HR = 1.240; 95% CI 1.128–1.362, p < 0.001). GSEA analysis revealed a strong connection between the signature and immune-related biological processes and pathways.

Conclusions

We constructed and verified a robust signature of 8 immune-related lncRNAs for the prediction of breast cancer patient survival.

Long Non-Coding RNA Associated with Cholesterol Homeostasis and Its Involvement in Metabolic Diseases

Cholesterol is an essential cell component that functions to create and maintain all kinds of cell membranes and lipoprotein particles. It is crucial to maintain the proper amount of cholesterol at both the cellular and systemic level. Recently, the importance of cholesterol has been reported not only in various cell development processes but also in the development of diseases. Furthermore, the involvement of long non-coding RNAs (lncRNAs), which are regarded as important epigenetic regulators in gene expression, has also been reported in cholesterol homeostasis. It is thus necessary to summarize the research on lncRNAs related to cholesterol with increased interest. This review organized the role of lncRNAs according to the major issues in cholesterol homeostasis: efflux, metabolism and synthesis, and disease process.

Global profiling of lncRNAs-miRNAs-mRNAs reveals differential expression of coding genes and non-coding RNAs in the lung of beagle dogs at different stages of Toxocara canis infection

The roundworm Toxocara canis causes toxocariasis in dogs and larval migrans in humans. Better understanding of the lung response to T. canis infection could explain why T. canis must migrate to and undergoes part of its development inside the lung of the definitive host. In this study, we profiled the expression patterns of long non-coding RNAs (lncRNAs), microRNAs (miRNAs), and mRNAs in the lungs of Beagle dogs infected by T. canis, using high throughput RNA sequencing. At 24 h p.i., 1,012 lncRNAs, 393 mRNAs and 10 miRNAs were differentially expressed (DE). We also identified 883 DElncRNAs, 264 DEmRNAs and 20 DEmiRNAs at 96 h p.i., and 996 DElncRNAs, 342 DEmRNAs and eight DEmiRNAs at 36 days p.i., between infected and control dogs. Significant changes in the levels of expression of transcripts related to immune response and inflammation were associated with the antiparasitic response of the lung to T. canis. The remarkable increase in the expression of scgb1a1 at all time points after infection suggests the need for consistent moderation of the excessive inflammatory response. Also, upregulation of foxj1 at 24 h p.i., and downregulation of IL-1β and IL-21 at 96 h p.i., suggest an attenuation of the humoral immunity of infected dogs. These results indicate that T. canis pathogenesis in the lung is mediated through contributions from both pro-inflammatory and anti-inflammatory mechanisms. Competing endogenous RNA (ceRNA) network analysis revealed significant interactions between DElncRNAs, DEmiRNAs and DEmRNAs, and improved our understanding of the ceRNA regulatory mechanisms in the context of T. canis infection. These data provide comprehensive understanding of the regulatory networks that govern the lung response to T. canis infection and reveal new mechanistic insights into the interaction between the host and parasite during the course of T. canis infection in the canine.

The roles of long noncoding RNAs in breast cancer metastasis

Breast cancer is the most significant threat to female health. Breast cancer metastasis is the major cause of mortality in breast cancer patients. To fully unravel the molecular mechanisms that underlie the breast cancer cell metastasis is critical for developing strategies to improve survival and prognosis in breast cancer patients. Recent studies have revealed that the long noncoding RNAs (lncRNAs) are involved in breast cancer metastasis through a variety of molecule mechanisms, though the precise functional details of these lncRNAs are yet to be clarified. In the present review, we focus on the functions of lncRNAs in breast cancer invasion and metastasis, with particular emphasis on the functional properties, the regulatory factors, the therapeutic promise, as well as the future challenges in studying these lncRNA.

Overexpression of long non-coding RNA MCM3AP-AS1 in breast cancer tissues compared to adjacent non-tumour tissues

BACKGROUND

Altered expression of several long non-coding RNAs (lncRNAs) has been described in numerous malignancies, including breast cancer, and some may have a role in carcinogenesis. We hypothesised differences in the expression of lncRNA MCM3AP-AS1 in breast cancer tissues compared to nearby healthy tissues and potential links with clinical features.

METHODS

We tested our hypothesis in 102 pairs of breast cancer tumours and adjacent non-tumour tissues from female patients. After RNA extraction, cDNA synthesis was performed for all specimens. The differential gene expression was assessed using Quantitative Real-Time PCR Technique.

RESULTS

There was a significant overexpression of the lncRNAs in tumour tissues as compared with their adjacent non-tumour tissues (P < 0.001). Expression was significantly linked with the tumour oestrogen receptor expression (P = 0.023) and tumour progesterone receptor expression (P < 0.001). ROC analysis showed an AUC of 0.67 (95% CI 0.60-0.75) (P < 0.001) with sensitivity and specificity of 58% and 76%, respectively.

CONCLUSION

The lncRNA MCM3AP-AS1 may be a novel breast cancer lncRNA with high expression levels in breast cancer patients' tissue. Further investigations are needed to confirm its uses as a potential molecular marker and therapeutic target.

Long Intergenic Non-Coding RNA LINC00922 Aggravates the Malignant Phenotype of Breast Cancer by Regulating the microRNA-424-5p/BDNF Axis

PURPOSE

Long intergenic non-coding RNA 922 (LINC00922) plays a critical role in the progression of lung cancer. In this study, we aimed to quantify LINC00922 expression in breast cancer and determine its influence on the malignant behavior of breast cancer cells in vitro and in vivo. We also investigated the mechanism by which LINC00922 affects the progression of breast cancer.

MATERIALS AND METHODS

Reverse transcription-quantitative polymerase chain reaction was performed to quantify LINC00922 expression in breast cancer tissues and cell lines. The cell counting kit-8 assay, flow cytometry, Transwell migration and invasion assays, and tumor model assays were performed to determine the effects of LINC00922 deficiency on breast cancer cell proliferation, apoptosis, migration and invasion in vitro, and tumor growth in vivo, respectively. Furthermore, bioinformatics analysis was performed to predict the potential target microRNA of LINC00922. The prediction was further evaluated using luciferase reporter and RNA immunoprecipitation assays.

RESULTS

LINC00922 was clearly overexpressed in breast cancer tissues and cell lines. LINC00922 depletion restricted breast cancer cell proliferation, migration, and invasion but induced cell apoptosis in vitro. Additionally, its knockdown evidently repressed tumor growth of breast cancer cells in vivo. Mechanistically, LINC00922 was demonstrated to serve as a molecular sponge for miR-424-5p in breast cancer cells. Furthermore, brain-derived neurotrophic factor (BDNF) was verified as a direct target of miR-424-5p in breast cancer cells, and BDNF expression was found to be positively regulated by LINC00922 through sponging miR-425-5p. Rescue experiments further revealed that the influences on breast cancer cell proliferation, apoptosis, migration, and invasion induced by LINC00922 silencing were abrogated by increasing the output of the miR-424-5p/BDNF axis.

CONCLUSION

The LINC00922/miR-424-5p/BDNF pathway is implicated in the acceleration of the malignant behavior of breast cancer cells. These findings suggest that this pathway is a promising novel molecular target in breast cancer therapy.