Long Non-Coding RNA HOTAIR in Breast Cancer Therapy

Innovative therapeutic strategies to overcome radioresistance in breast cancer

Despite a comparatively favorable prognosis relative to other malignancies, breast cancer continues to significantly impact women's health globally, partly due to its high incidence rate. A critical factor in treatment failure is radiation resistance - the capacity of tumor cells to withstand high doses of ionizing radiation. Advancements in understanding the cellular and molecular mechanisms underlying radioresistance, coupled with enhanced characterization of radioresistant cell clones, are paving the way for the development of novel treatment modalities that hold potential for future clinical application. In the context of combating radioresistance in breast cancer, potential targets of interest include long non-coding RNAs (lncRNAs), micro RNAs (miRNAs), and their associated signaling pathways, along with other signal transduction routes amenable to pharmacological intervention. Furthermore, technical, and methodological innovations, such as the integration of hyperthermia or nanoparticles with radiotherapy, have the potential to enhance treatment responses in patients with radioresistant breast cancer. This review endeavors to provide a comprehensive survey of the current scientific landscape, focusing on novel therapeutic advancements specifically addressing radioresistant breast cancer.

An extensive overview of the role of lncRNAs generated from immune cells in the etiology of cancer

Long non-coding RNAs (lncRNAs) are involved in the control of critical tumor-suppressor and oncogenic pathways in cancer. These types of non-coding RNAs could affect both immune and cancer cells. The thorough analysis of lncRNAs derived from immune cells and the incorporation of new findings significantly advance our understanding of the complex role of lncRNAs in the context of cancer. This work highlights the promise of lncRNAs for translational therapeutic approaches while also establishing a solid foundation for comprehending the complex link between lncRNAs and cancer through a coherent narrative. The main findings of this article are that types of lncRNAs derived from immune cells, such as MM2P and MALAT1, can affect the behaviors of cancer cells, like invasion, angiogenesis, and proliferation. As research in this area grows, the therapeutic potential of targeting these lncRNAs offers promising opportunities for expanding our understanding of cancer biology and developing cutting-edge, precision-based therapies for cancer therapy.

Targeting long non-coding RNAs in cancer therapy using CRISPR-Cas9 technology: A novel paradigm for precision oncology

Cancer is the second leading cause of death worldwide, despite recent advances in its identification and management. To improve cancer patient diagnosis and care, it is necessary to identify new biomarkers and molecular targets. In recent years, long non-coding RNAs (lncRNAs) have surfaced as important contributors to various cellular activities, with growing proof indicating their substantial role in the genesis, development, and spread of cancer. Their unique expression profiles within specific tissues and their wide-ranging functionalities make lncRNAs excellent candidates for potential therapeutic intervention in cancer management. They are implicated in multiple hallmarks of cancer, such as uncontrolled proliferation, angiogenesis, and immune evasion. This review article explores the innovative application of CRISPR-Cas9 technology in targeting lncRNAs as a cancer therapeutic strategy. The CRISPR-Cas9 system has been widely applied in functional genomics, gene therapy, and cancer research, offering a versatile platform for lncRNA targeting. CRISPR-Cas9-mediated targeting of lncRNAs can be achieved through CRISPR interference, activation or the complete knockout of lncRNA loci. Combining CRISPR-Cas9 technology with high-throughput functional genomics makes it possible to identify lncRNAs critical for the survival of specific cancer subtypes, opening the door for tailored treatments and personalised cancer therapies. CRISPR-Cas9-mediated lncRNA targeting with other cutting-edge cancer therapies, such as immunotherapy and targeted molecular therapeutics can be used to overcome the drug resistance in cancer. The synergy of lncRNA research and CRISPR-Cas9 technology presents immense potential for individualized cancer treatment, offering renewed hope in the battle against this disease.

HOTAIR: A key regulator of the Wnt/β-catenin signaling cascade in cancer progression and treatment

The long non-coding RNA (lncRNA) HOTAIR occupies a central position in the complex domain of cancer biology, particularly concerning its intricate interplay with the Wnt/β-catenin signaling pathway. This comprehensive review explores the multifaceted interactions between HOTAIR and the Wnt/β-catenin cascade, elucidating their profound function in cancer growth, progression, and therapeutic strategies. The study commences by underscoring the pivotal role of the Wnt/β-catenin cascade in governing essential cellular activities, emphasizing its dysregulation as a linchpin in cancer initiation and advancement. It introduces HOTAIR as a crucial regulatory entity, influencing gene expression in both healthy and diseased. The core of this review plunges into the intricacies of HOTAIR's engagement with Wnt/β-catenin signaling. It unravels how HOTAIR, through epigenetic modifications and transcriptional control, exerts its influence over key pathway constituents, including β-catenin, Wnt ligands, and target genes. This influence drives unchecked cancer cell growth, invasion, and metastasis. Furthermore, the review underscores the clinical significance of the HOTAIR-Wnt/β-catenin interplay, elucidating its associations with diverse cancer subtypes, patient prognoses, and prospects as a therapy. It provides insights into ongoing research endeavors to develop HOTAIR-targeted treatments and initiatives to facilitate aberrant Wnt/β-catenin activation. Concluding on a forward-looking note, the article accentuates the broader implications of HOTAIR's involvement in cancer biology, including its contributions to therapy resistance and metastatic dissemination. It underscores the importance of delving deeper into these intricate molecular relationships to pave the way for groundbreaking cancer treatment.

Circulating ESR1, long non-coding RNA HOTAIR and microRNA-130a gene expression as biomarkers for breast cancer stage and metastasis

Breast cancer, the most prevalent cancer among women, has posed a significant challenge in identifying biomarkers for early diagnosis and prognosis. This study aimed to elucidate the gene expression profile of Estrogen Receptor-1 (ESR-1), long non-coding RNA HOTAIR, and microRNA-130a in the serum of Egyptian breast cancer patients, evaluating the potential of HOTAIR and miR-130a as biomarkers for predicting pathological parameters in BC. The study involved 45 patients with primary BC, with serum samples collected preoperatively and postoperatively twice. The expression levels of ESR-1, HOTAIR, and miR-130a were quantified using real-time PCR and analyzed for correlations with each other and with the clinical and pathological parameters of the patients. Serum HOTAIR levels exhibited a strong positive association with metastasis and demonstrated a significant increase after 6 months in all patients with locally advanced and stage IV BC. Conversely, tumors with advanced stages and metastatic lesions showed significantly lower expression levels of miR-130a. Notably, a significant positive correlation was observed between preoperative ESR-1 expression and both HOTAIR and miR-130a levels. Serum HOTAIR and miR-130a levels have emerged as promising non-invasive biomarkers with the potential to predict the pathological features of BC patients. HOTAIR, an oncogenic long non-coding RNA (lncRNA), and miR-130a, a tumor suppressor miRNA, play crucial roles in tumor progression. Further investigations are warranted to elucidate the intricate interplay between HOTAIR and miR-130a and to fully comprehend the contribution of HOTAIR to BC recurrence and its potential utility in early relapse prediction.

Targeting non-coding RNAs: Perspectives and challenges of in-silico approaches

The growing information currently available on the central role of non-coding RNAs (ncRNAs) including microRNAs (miRNAS) and long non-coding RNAs (lncRNAs) for chronic and degenerative human diseases makes them attractive therapeutic targets. RNAs carry out different functional roles in human biology and are deeply deregulated in several diseases. So far, different attempts to therapeutically target the 3D RNA structures with small molecules have been reported. In this scenario, the development of computational tools suitable for describing RNA structures and their potential interactions with small molecules is gaining more and more interest. Here, we describe the most suitable strategies to study ncRNAs through computational tools. We focus on methods capable of predicting 2D and 3D ncRNA structures. Furthermore, we describe computational tools to identify, design and optimize small molecule ncRNA binders. This review aims to outline the state of the art and perspectives of computational methods for ncRNAs over the past decade.

DNA methylation of HOX genes and its clinical implications in cancer

Homeobox (HOX) genes encode highly conserved transcription factors that play vital roles in embryonic development. DNA methylation is a pivotal regulatory epigenetic signaling mark responsible for regulating gene expression. Abnormal DNA methylation is largely associated with the aberrant expression of HOX genes, which is implicated in a broad range of human diseases, including cancer. Numerous studies have clarified the mechanisms of DNA methylation in both physiological and pathological processes. In this review, we focus on how DNA methylation regulates HOX genes and briefly discuss drug development approaches targeting these mechanisms.

Non-Coding RNAs in Human Cancer and Other Diseases: Overview of the Diagnostic Potential

Non-coding RNAs (ncRNAs) are abundant single-stranded RNA molecules in human cells, involved in various cellular processes ranging from DNA replication and mRNA translation regulation to genome stability defense. MicroRNAs are multifunctional ncRNA molecules of 18-24 nt in length, involved in gene silencing through base-pair complementary binding to target mRNA transcripts. piwi-interacting RNAs are an animal-specific class of small ncRNAs sized 26-31 nt, responsible for the defense of genome stability via the epigenetic and post-transcriptional silencing of transposable elements. Long non-coding RNAs are ncRNA molecules defined as transcripts of more than 200 nucleotides, their function depending on localization, and varying from the regulation of cell differentiation and development to the regulation of telomere-specific heterochromatin modifications. The current review provides recent data on the several forms of small and long non-coding RNA's potential to act as diagnostic, prognostic or therapeutic target for various human diseases.

Long non-coding RNAs and pancreatic cancer: A multifaceted view

Pancreatic cancer (PC) is a highly malignant disease with a 5-year survival rate of only 10%. Families with PC are at greater risk, as are type 2 diabetes, pancreatitis, and other factors. Insufficient early detection methods make this cancer have a poor prognosis. Additionally, the molecular mechanisms underlying PC development remain unclear. Increasing evidence suggests that long non-coding RNAs (lncRNAs) contribute to PC pathology,which may control gene expression by recruiting histone modification complexes to chromatin and interacting with proteins and RNAs. In recent studies, abnormal regulation of lncRNAs has been implicated in PC proliferation, metastasis, invasion, angiogenesis, apoptosis, and chemotherapy resistance suggesting potential clinical implications. The paper reviews the progress of lncRNA research in PC about diabetes mellitus, pancreatitis, cancer metastasis, tumor microenvironment regulation, and chemoresistance. Furthermore, lncRNAs may serve as potential therapeutic targets and biomarkers for PC diagnosis and prognosis. This will help improve PC patients' survival rate from a lncRNA perspective.

The human long non-coding RNA LINC00941 and its modes of action in health and disease

Long non-coding RNAs have gained attention in recent years as they were shown to play crucial roles in the regulation of cellular processes, but the understanding of the exact mechanisms is still incomplete in most cases. This is also true for long non-coding RNA LINC00941, which was recently found to be highly upregulated in various types of cancer influencing cell proliferation and metastasis. Initial studies could not elucidate the mode of action to understand the role and real impact of LINC00941 in tissue homeostasis and cancer development. However, recent analyses have demonstrated multiple potential modes of action of LINC00941 influencing the functionality of various cancer cell types. Correspondingly, LINC00941 was proposed to be involved in regulation of mRNA transcription and modulation of protein stability, respectively. In addition, several experimental approaches suggest a function of LINC00941 as competitive endogenous RNA, thus acting in a post-transcriptional regulatory fashion. This review summarizes our recent knowledge about the mechanisms of action of LINC00941 elucidated so far and discusses its putative role in miRNA sequestering processes. In addition, the functional role of LINC00941 in regulating human keratinocytes is discussed to also highlight its role in normal tissue homeostasis tissue aside from its involvement in cancer.

Roles of long noncoding RNA in triple-negative breast cancer

INTRODUCTION

Long noncoding RNAs (lncRNAs) play crucial roles in regulating various hallmarks in cancers. Triple-negative (Estrogen receptor, ER; Human epidermal growth factor receptor 2, HER2; Progesterone receptor, PR) breast cancer (TNBC) is the most aggressive form of breast cancers with a poor prognosis and no available molecular targeted therapy.

METHODS

We reviewed the current literature on the roles of lncRNAs in the pathogenesis, therapy resistance, and prognosis of patients with TBNC.

RESULTS

LncRNAs are associated with TNBC pathogenesis, therapy resistance, and prognosis. For example, lncRNAs such as small nucleolar RNA host gene 12 (SNHG12), highly upregulated in liver cancer (HULC) HOX transcript antisense intergenic RNA (HOTAIR), lincRNA-regulator of reprogramming (LincRNA-ROR), etc., are aberrantly expressed in TNBC and are involved in the pathogenesis of the disease. LncRNAs act as a decoy, scaffold, or sponge to regulate the expression of genes, miRNAs, and transcription factors associated with pathogenesis and progression of TNBC. Moreover, lncRNAs such as ferritin heavy chain 1 pseudogene 3 (FTH1P3), BMP/OP-responsive gene (BORG) contributes to the therapy resistance property of TNBC through activating ABCB1 (ATP-binding cassette subfamily B member 1) drug efflux pumps by increasing DNA repair capacity or by inducing signaling pathway involved in therapeutic resistance.

CONCLUSION

In this review, we outline the functions of various lncRNAs along with their molecular mechanisms involved in the pathogenesis, therapeutic resistance of TBNC. Also, the prognostic implications of lncRNAs in patients with TNBC is illustrated. Moreover, potential strategies targeting lncRNAs against highly aggressive TNBC is discussed in this review.

Identification of monotonically expressed long non-coding RNA signatures for breast cancer using variational autoencoders

As breast cancer is a multistage progression disease resulting from a genetic sequence of mutations, understanding the genes whose expression values increase or decrease monotonically across pathologic stages can provide insightful clues about how breast cancer initiates and advances. Utilizing variational autoencoder (VAE) networks in conjunction with traditional statistical testing, we successfully ascertain long non-coding RNAs (lncRNAs) that exhibit monotonically differential expression values in breast cancer. Subsequently, we validate that the identified lncRNAs really present monotonically changed patterns. The proposed procedure identified 248 monotonically decreasing expressed and 115 increasing expressed lncRNAs. They correspond to a total of 65 and 33 genes respectively, which possess unique known gene symbols. Some of them are associated with breast cancer, as suggested by previous studies. Furthermore, enriched pathways by the target mRNAs of these identified lncRNAs include the Wnt signaling pathway, human papillomavirus (HPV) infection, and Rap 1 signaling pathway, which have been shown to play crucial roles in the initiation and development of breast cancer. Additionally, we trained a VAE model using the entire dataset. To assess the effectiveness of the identified lncRNAs, a microarray dataset was employed as the test set. The results obtained from this evaluation were deemed satisfactory. In conclusion, further experimental validation of these lncRNAs with a large-sized study is warranted, and the proposed procedure is highly recommended.

PTHrP Regulates Fatty Acid Metabolism via Novel lncRNA in Breast Cancer Initiation and Progression Models

Parathyroid hormone-related peptide (PTHrP) is the primary cause of malignancy-associated hypercalcemia (MAH). We previously showed that PTHrP ablation, in the MMTV-PyMT murine model of breast cancer (BC) progression, can dramatically prolong tumor latency, slow tumor growth, and prevent metastatic spread. However, the signaling mechanisms using lineage tracing have not yet been carefully analyzed. Here, we generated Pthrpflox/flox; Cre+ mT/mG mice (KO) and Pthrpwt/wt; Cre+ mT/mG tumor mice (WT) to examine the signaling pathways under the control of PTHrP from the early to late stages of tumorigenesis. GFP+ mammary epithelial cells were further enriched for subsequent RNA sequencing (RNAseq) analyses. We observed significant upregulation of cell cycle signaling and fatty acid metabolism in PTHrP WT tumors, which are linked to tumor initiation and progression. Next, we observed that the expression levels of a novel lncRNA, GM50337, along with stearoyl-Coenzyme A desaturase 1 (Scd1) are significantly upregulated in PTHrP WT but not in KO tumors. We further validated a potential human orthologue lncRNA, OLMALINC, together with SCD1 that can be regulated via PTHrP in human BC cell lines. In conclusion, these novel findings could be used to develop targeted strategies for the treatment of BC and its metastatic complications.

Functional impact of non-coding RNAs in high-grade breast carcinoma: Moving from resistance to clinical applications: A comprehensive review

Despite the recent advances in cancer therapy, triple-negative breast cancers (TNBCs) are the most relapsing cancer sub-type. It is partly due to their propensity to develop resistance against the available therapies. An intricate network of regulatory molecules in cellular mechanisms leads to the development of resistance in tumors. Non-coding RNAs (ncRNAs) have gained widespread attention as critical regulators of cancer hallmarks. Existing research suggests that aberrant expression of ncRNAs modulates the oncogenic or tumor suppressive signaling. This can mitigate the responsiveness of efficacious anti-tumor interventions. This review presents a systematic overview of biogenesis and down streaming molecular mechanism of the subgroups of ncRNAs. Furthermore, it explains ncRNA-based strategies and challenges to target the chemo-, radio-, and immunoresistance in TNBCs from a clinical standpoint.

Epigenetic Alterations in DCIS Progression: What Can lncRNAs Teach Us?

Some transcripts that are not translated into proteins can be encoded by the mammalian genome. Long noncoding RNAs (lncRNAs) are noncoding RNAs that can function as decoys, scaffolds, and enhancer RNAs and can regulate other molecules, including microRNAs. Therefore, it is essential that we obtain a better understanding of the regulatory mechanisms of lncRNAs. In cancer, lncRNAs function through several mechanisms, including important biological pathways, and the abnormal expression of lncRNAs contributes to breast cancer (BC) initiation and progression. BC is the most common type of cancer among women worldwide and has a high mortality rate. Genetic and epigenetic alterations that can be regulated by lncRNAs may be related to early events of BC progression. Ductal carcinoma in situ (DCIS) is a noninvasive BC that is considered an important preinvasive BC early event because it can progress to invasive BC. Therefore, the identification of predictive biomarkers of DCIS-invasive BC progression has become increasingly important in an attempt to optimize the treatment and quality of life of patients. In this context, this review will address the current knowledge about the role of lncRNAs in DCIS and their potential contribution to the progression of DCIS to invasive BC.

Advancing in Schaaf-Yang syndrome pathophysiology: from bedside to subcellular analyses of truncated MAGEL2

BACKGROUND

Schaaf-Yang syndrome (SYS) is caused by truncating mutations in MAGEL2, mapping to the Prader-Willi region (15q11-q13), with an observed phenotype partially overlapping that of Prader-Willi syndrome. MAGEL2 plays a role in retrograde transport and protein recycling regulation. Our aim is to contribute to the characterisation of SYS pathophysiology at clinical, genetic and molecular levels.

METHODS

We performed an extensive phenotypic and mutational revision of previously reported patients with SYS. We analysed the secretion levels of amyloid-β 1-40 peptide (Aβ_1-40) and performed targeted metabolomic and transcriptomic profiles in fibroblasts of patients with SYS (n=7) compared with controls (n=11). We also transfected cell lines with vectors encoding wild-type (WT) or mutated MAGEL2 to assess stability and subcellular localisation of the truncated protein.

RESULTS

Functional studies show significantly decreased levels of secreted Aβ_1-40 and intracellular glutamine in SYS fibroblasts compared with WT. We also identified 132 differentially expressed genes, including non-coding RNAs (ncRNAs) such as HOTAIR, and many of them related to developmental processes and mitotic mechanisms. The truncated form of MAGEL2 displayed a stability similar to the WT but it was significantly switched to the nucleus, compared with a mainly cytoplasmic distribution of the WT MAGEL2. Based on the updated knowledge, we offer guidelines for the clinical management of patients with SYS.

CONCLUSION

A truncated MAGEL2 protein is stable and localises mainly in the nucleus, where it might exert a pathogenic neomorphic effect. Aβ_1-40 secretion levels and HOTAIR mRNA levels might be promising biomarkers for SYS. Our findings may improve SYS understanding and clinical management.

HMGA2 regulation by miRNAs in cancer: affecting cancer hallmarks and therapy response

High mobility group A 2 (HMGA2) is a protein that modulates the structure of chromatin in the nucleus. Importantly, aberrant expression of HMGA2 occurs during carcinogenesis, and this protein is an upstream mediator of cancer hallmarks including evasion of apoptosis, proliferation, invasion, metastasis, and therapy resistance. HMGA2 targets critical signaling pathways such as Wnt/β-catenin and mTOR in cancer cells. Therefore, suppression of HMGA2 function notably decreases cancer progression and improves outcome in patients. As HMGA2 is mainly oncogenic, targeting expression by non-coding RNAs (ncRNAs) is crucial to take into consideration since it affects HMGA2 function. MicroRNAs (miRNAs) belong to ncRNAs and are master regulators of vital cell processes, which affect all aspects of cancer hallmarks. Long ncRNAs (lncRNAs) and circular RNAs (circRNAs), other members of ncRNAs, are upstream mediators of miRNAs. The current review intends to discuss the importance of the miRNA/HMGA2 axis in modulation of various types of cancer, and mentions lncRNAs and circRNAs, which regulate this axis as upstream mediators. Finally, we discuss the effect of miRNAs and HMGA2 interactions on the response of cancer cells to therapy. Regarding the critical role of HMGA2 in regulation of critical signaling pathways in cancer cells, and considering the confirmed interaction between HMGA2 and one of the master regulators of cancer, miRNAs, targeting miRNA/HMGA2 axis in cancer therapy is promising and this could be the subject of future clinical trial experiments.

Metformin and long non-coding RNAs in breast cancer

Breast cancer (BC) is the second most common cancer and cause of death in women. In recent years many studies investigated the association of long non-coding RNAs (lncRNAs), as novel genetic factors, on BC risk, survival, clinical and pathological features. Recent studies also investigated the roles of metformin treatment as the firstline treatment for type 2 diabetes (T2D) played in lncRNAs expression/regulation or BC incidence, outcome, mortality and survival, separately. This comprehensive study aimed to review lncRNAs associated with BC features and identify metformin-regulated lncRNAs and their mechanisms of action on BC or other types of cancers. Finally, metformin affects BC by regulating five BC-associated lncRNAs including GAS5, HOTAIR, MALAT1, and H19, by several molecular mechanisms have been described in this review. In addition, metformin action on other types of cancers by regulating ten lncRNAs including AC006160.1, Loc100506691, lncRNA-AF085935, SNHG7, HULC, UCA1, H19, MALAT1, AFAP1-AS1, AC026904.1 is described.

miRNA-1246, HOTAIR, and IL-39 signature as potential diagnostic biomarkers in breast cancer

The molecular alterations in noncoding RNA can lead to a cellular storm that is correlated to higher mortality and morbidity rates and contributes to the progression and metastasis of cancer. Herein, we aim to evaluate the expression levels and correlations of microRNA-1246 (miR-1246), HOX transcript antisense RNA (HOTAIR), and interleukin-39 (IL-39) in patients with breast cancer (BC). In this study, 130 participants were recruited, including 90 breast cancer patients and 40 healthy control participants. Serum levels of miR-1246 and HOTAIR expression were assessed by quantitative real-time polymerase chain reaction (qRT-PCR). Also, the level of IL-39 expression was evaluated using a Western blot. All BC participants demonstrated a remarkable elevation in miR-1246 and HOTAIR expression levels. Moreover, IL-39 expression levels demonstrated a noticeable decline in BC patients. Furthermore, the differential expression fold of miR-1246 and HOTAIR revealed a strong positive correlation among breast cancer patients. In addition, a negative relationship between the IL-39 and the miR-1246 and HOTAIR differential expression was also noticed. This study revealed that HOTAIR/miR-1246 exerts an oncogenic impact in patients with breast cancer. The expression levels of circulation miR-1246, HOTAIR, and IL-39 could be considered early diagnostic biomarkers in BC patients.

Long Non-Coding RNA LINC00052 Targets miR-548p/Notch2/Pyk2 to Modulate Tumor Budding and Metastasis of Human Breast Cancer

Abnormal expression of long non-coding RNAs (lncRNAs) is involved in many pathological processes of cancers. However, the role of lncRNA LINC00052 in breast cancer progression is still unclear. Here, LINC00052 expression was detected by in situ hybridization and quantitative real-time PCR assays. Cell Counting Kit-8, wound healing, and transwell assays were used to investigate changes in the proliferation, migration, and invasion of breast cancer cells. MiR-548p was found associated with LINC00052 or Notch2 by RNA pull-down, dual-luciferase reporter, and qRT-PCR assays. The effect of LINC00052 on lung metastasis was explored through in vivo experiments. High LINC00052 expression was observed in breast cancer tissues and cells. LINC00052 silencing inhibited the proliferation, migration, and invasion of MCF7 cells, and LINC00052 overexpression produced the opposite results. MiR-548p, a target gene of LINC00052, partially rescued the effects of LINC00052 on proliferation, migration, and invasion of MCF7. Notch2 was the target of miR-548p and LINC00052 could promote Notch2 expression. Moreover, the phosphorylation of proline-rich tyrosine kinase 2 (Pyk2), a downstream factor of Notch2, was increased by LINC00052, and a Pyk2 mutant could inhibit the cell migration and invasion induced by LINC00052 overexpression in MDA-MB-468 cells, which was similar to the function of the miR-548p mimic. We further demonstrated that LINC00052 exacerbated the metastases of breast cancer cells in vivo. Our research demonstrated that LINC00052 is highly expressed in breast cancer and promotes breast cancer proliferation, migration, and invasion via the miR-548p/Notch2/Pyk2 axis. LINC00052 could serve as a potential therapeutic target for breast cancer.

Downregulation of MDM2 by small interference RNA induces apoptosis and sensitizes MCF-7 breast cells to resveratrol

Recent studies have demonstrated the mouse double minute gene (MDM2), a main oncogene, as a novel and interesting therapeutic target for cancer therapy. The aim of this study was to investigate the involvement of MDM2 in antiproliferative and antimetastatic effects of resveratrol in breast cancer cells. MCF-7 cells were transfected with siRNA against MDM2 and resveratrol. Proliferation and apoptosis were evaluated by MTT assay and cell death ELISA assay, respectively. MDM2, p53, Bax, Bcl-2, caspase-3, MMP-2, and MMP9 expressions were determined by qRT-PCR and Western blotting. Transfection with si-MDM2 significantly suppressed the expression of MDM2 expression, resulting in MCF-7 cell growth inhibition and spontaneous apoptosis. Pretreatment with Si-MDM2 synergically increased antiproliferation and antimetatstatic effects of resveratrol. No significant anticancer effects were detected with negative control siRNA treatment. Our findings suggest that silencing of MDM2 by specific siRNA effectively induce apoptosis and also enhanced anticancer effects of resveratrol. Therefore, siMDM2 may be a potent combination in breast therapy.

Nucleic acid therapies for CNS diseases: Pathophysiology, targets, barriers, and delivery strategies

Nucleic acid therapeutics have emerged as one of the very advanced and efficacious treatment approaches for debilitating health conditions, including those diseases affecting the central nervous system (CNS). Precise targeting with an optimal control over gene regulation confers long-lasting benefits through the administration of nucleic acid payloads via viral, non-viral, and engineered vectors. The current review majorly focuses on the development and clinical translational potential of non-viral vectors for treating CNS diseases with a focus on their specific design and targeting approaches. These carriers must be able to surmount the various intracellular and extracellular barriers, to ensure successful neuronal transfection and ultimately attain higher therapeutic efficacies. Additionally, the specific challenges associated with CNS administration also include the presence of blood-brain barrier (BBB), the complex pathophysiological and biochemical changes associated with different disease conditions and the existence of non-dividing cells. The advantages offered by lipid-based or polymeric systems, engineered proteins, particle-based systems coupled with various approaches of neuronal targeting have been discussed in the context of a variety of CNS diseases. The possibilities of rapid yet highly efficient gene modifications rendered by the breakthrough methodologies for gene editing and gene manipulation have also opened vast avenues of research in neuroscience and CNS disease therapy. The current review also underscores the extensive scientific efforts to optimize specialized, efficacious yet non-invasive and safer administration approaches to overcome the therapeutic delivery challenges specifically posed by the CNS transport barriers and the overall obstacles to clinical translation.

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

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

LncRNA HOTAIR regulates cell invasion and migration in endometriosis through miR-519b-3p/PRRG4 pathway

Endometriosis is a common benign disease in gynecology and has malignant biological behaviors, such as hyperplasia, invasion, metastasis, and recurrence. However, the pathogenesis of endometriosis remains unclear. The present study aimed to investigate whether LncRNA HOTAIR regulates cell invasion and migration in endometriosis by regulating the miR-519b-3p/PRRG4 pathway. The qRT-PCR results showed that the average relative expression of LncRNA HOTAIR was much higher in ectopic endometrial tissues than in eutopic endometrial tissues. Scratch and transwell assays showed that the cell migration and invasion ability of LncRNA HOTAIR overexpression group was significantly higher than those in the control group. Conversely, the LncRNA HOTAIR knockdown group showed the opposite results. Bioinformatics analysis suggested that the downstream target genes of LncRNA HOTAIR were miR-519b-3p and Prrg4. Knockdown of LncRNA HOTAIR can reduce the up-regulation of Prrg4 by miR-519b-3p and then inhibit the invasion and migration ability of endometrial stromal cells. In Conclusion, LncRNA HOTAIR can regulate the ability of invasion and migration of endometrial stromal cells, and its mechanism is proved by regulating the miR-519b-3p/PRRG4 pathway.

HOTAIR/miR-203/CAV1 Crosstalk Influences Proliferation, Migration, and Invasion in the Breast Cancer Cell

In recent years, malignant breast cancer metastasis has caused a great increase in mortality. Research on the genetic and molecular mechanisms of malignant breast cancer has continued to deepen, and targeted therapy has become the general trend. Among them, competing endogenous RNA (ceRNA)-related molecules have received much attention. Homeobox transcript antisense RNA (HOTAIR) has been reported to function extensively as a ceRNA in breast cancer. Notably, miR-203 and Caveolin 1 (CAV1) have also been found to play a role in breast cancer. However, the relationship between the three remains unclear. In this study, we present a new mechanic through bioinformatics tool and basic experiments: the HOTAIR/miR-203/CAV1 axis, which complemented the role network of HOTAIR as a ceRNA, thus, it will provide a novel potential idea for breast cancer research and therapy.

Unveiling caspase-2 regulation by non-coding RNAs

Non-coding RNAs (ncRNAs) are a group of RNA molecules, such as small nucleolar RNAs, circular RNAs (circRNAs), microRNAs (miRNAs) and long-noncoding RNAs (ncRNAs), that do not encode proteins. Although their biofunctions are not well-understood, many regulatory ncRNAs appear to be highly involved in regulating the transcription and translation of several genes that have essential biological roles including cell differentiation, cell death, metabolism, tumorigenesis and so on. A growing number of studies have revealed the associations between dysregulated ncRNAs and caspases involved in cell death in numerous human diseases. As one of the initiator and executor caspases, caspase-2 is the most evolutionally conserved caspase in mammals, exerting both apoptotic and non-apoptotic functions. A great deal of studies has shown the involvement of caspase-2 as a tumor suppressor in multiple oncogene-driven cancers, and yet a comprehensive understanding of its biological roles remains largely unknown. In this review, we highlight a compilation of studies focused on the interaction between caspase-2 and miRNAs/lncRNAs in the context of different diseases in order to deepen our knowledge on the regulatory biofunctions of caspase-2 and, furthermore, provide more insight into understanding the role that ncRNAs/caspase-2 axis plays in the development of human diseases.

Functional interplay between long non-coding RNAs and Breast CSCs

Breast cancer (BC) represents aggressive cancer affecting most women’s lives globally. Metastasis and recurrence are the two most common factors in a breast cancer patient's poor prognosis. Cancer stem cells (CSCs) are tumor cells that are able to self-renew and differentiate, which is a significant factor in metastasis and recurrence of cancer. Long non-coding RNAs (lncRNAs) describe a group of RNAs that are longer than 200 nucleotides and do not have the ability to code for proteins. Some of these lncRNAs can be mainly produced in various tissues and tumor forms. In the development and spread of malignancies, lncRNAs have a significant role in influencing multiple signaling pathways positively or negatively, making them promise useful diagnostic and prognostic markers in treating the disease and guiding clinical therapy. However, it is not well known how the interaction of lncRNAs with CSCs will affect cancer development and progression.

Here, in this review, we attempt to summarize recent findings that focus on lncRNAs affect cancer stem cell self-renewal and differentiation in breast cancer development and progression, as well as the strategies and challenges for overcoming lncRNA's therapeutic resistance.

Innovative targets of the lncRNA-miR-mRNA network in response to low-dose aspirin in breast cancer patients

This study aimed to investigate innovative targets in breast cancer patients by considering the interaction of the lncRNA-miR-mRNA network in response to low-dose aspirin. The candidate miRs were first taken from the GEO and TCGA databases. Then, the candidate network was constructed using the high-throughput sequencing data. The expression levels of candidate targets were finally measured using Real-Time PCR in luminal A breast cancer patients undergoing aspirin (80 mg daily for three months) and non-aspirin groups during chemotherapy after surgery. The expression levels of TGFβ, IL-17, IFNγ, and IL-β proteins were measured using the ELISA technique. 5 lncRNAs, 12 miRs, and 10 genes were obtained in the bioinformatic phase. A significant expression increase of the candidate tumor suppressor lncRNAs, miRs, and genes and a substantial expression decrease of the candidate onco-lncRNAs, oncomiRs, and oncogenes were achieved after the aspirin consumption. Unlike the non-aspirin group, the expression levels of TGFβ, IL-17, IFNγ, and IL-β proteins were significantly decreased following aspirin consumption. The Kaplan-Meier analysis indicated a longer overall survival rate in the patients after aspirin consumption. Our results showed that the lncRNA-miR-mRNA network might be a significant target for aspirin; their expression changes may be a new strategy with potential efficacy for cancer therapy or prevention.

MicroRNA-21 is immunosuppressive and pro-metastatic via separate mechanisms

MiR-21 was identified as a gene whose expression correlated with the extent of metastasis of murine mammary tumours. Since miR-21 is recognised as being associated with poor prognosis in cancer, we investigated its contribution to mammary tumour growth and metastasis in tumours with capacity for spontaneous metastasis. Unexpectedly, we found that suppression of miR-21 activity in highly metastatic tumours resulted in regression of primary tumour growth in immunocompetent mice but did not impede growth in immunocompromised mice. Analysis of the immune infiltrate of the primary tumours at the time when the tumours started to regress revealed an influx of both CD4⁺ and CD8⁺ activated T cells and a reduction in PD-L1⁺ infiltrating monocytes, providing an explanation for the observed tumour regression. Loss of anti-tumour immune suppression caused by decreased miR-21 activity was confirmed by transcriptomic analysis of primary tumours. This analysis also revealed reduced expression of genes associated with cell cycle progression upon loss of miR-21 activity. A second activity of miR-21 was the promotion of metastasis as shown by the loss of metastatic capacity of miR-21 knockdown tumours established in immunocompromised mice, despite no impact on primary tumour growth. A proteomic analysis of tumour cells with altered miR-21 activity revealed deregulation of proteins known to be associated with tumour progression. The development of therapies targeting miR-21, possibly via targeted delivery to tumour cells, could be an effective therapy to combat primary tumour growth and suppress the development of metastatic disease.

LncRNA HOTAIR promotes the proliferation and invasion/metastasis of breast cancer cells by targeting the miR-130a-3p/Suv39H1 axis

Long noncoding RNAs (lncRNAs) are a group of transcripts, more than 200 bp in size and regulate cell proliferation, differentiation and apoptosis. LncRNA HOX Transcript Antisense Intergenic RNA (HOTAIR) promotes tumor progression and increases cancer susceptibility by regulating microRNA expression and function. HOTAIR regulates miR-130a-3p expression in hepatocellular carcinoma cells. Bioinformatics analysis revealed that Suv39H1 contained a putative binding site for miR-130a-3p. We speculate that LncRNA HOTAIR promotes the proliferation and invasion/metastasis of breast cancer (BC) cells by targeting the miR-130a-3p/Suv39H1 axis. High HOTAIR expression facilitated BC cell growth and metastasis. HOTAIR functioned as a ceRNA by sponging miR-130a-3p and subsequently promoted Suv39H1-mediated AKT/mTOR signaling. Suv39H1 restoration abolished the effects of HOTAIR knockdown on BC cell growth and metastasis. HOTAIR facilitated the Suv39H1-mediated AKT/mTOR pathway by acting as a molecular sponge of miR-130a-3p.Our results provide a better understanding of the interactions of HOTAIR and miR-103a-3p/Suv39H1 in BC and a potential prognostic biomarker and therapeutic target for BC.

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HOTAIR expression is frequently up-regulated in BC.

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HOTAIR promotes BC cell proliferation and metastasis.

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HOTAIR acts as a ceRNA by sponging miR-130a-3p.

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Suv39H1 is a direct target of miR-130a-3p.

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HOTAIR plays a concogenic role in BC via Suv39H1-mediated AKT/mTOR pathway.

Navigating the genomic instability mine field of osteosarcoma to better understand implications of non-coding RNAs

Osteosarcoma is one of the most genomically complex cancers and as result, it has been difficult to assign genomic aberrations that contribute to disease progression and patient outcome consistently across samples. One potential source for correlating osteosarcoma and genomic biomarkers is within the non-coding regions of RNA that are differentially expressed. However, it is unsurprising that a cancer classification that is fraught with genomic instability is likely to have numerous studies correlating non-coding RNA expression and function have been published on the subject. This review undertakes the formidable task of evaluating the published literature of noncoding RNAs in osteosarcoma. This is not the first review on this topic and will certainly not be the last. The review is organized with an introduction into osteosarcoma and the epigenetic control of gene expression before reviewing the molecular function and expression of long non-coding RNAs, circular RNAs, and short non-coding RNAs such as microRNAs, piwi RNAs, and short-interfering RNAs. The review concludes with a review of the literature and how the biology of non-coding RNAs can be used therapeutically to treat cancers, especially osteosarcoma. We conclude that non-coding RNA expression and function in osteosarcoma is equally complex to understanding the expression differences and function of coding RNA and proteins; however, with the added lens of both coding and non-coding genomic sequence, researchers can begin to identify the patterns that consistently associate with aggressive osteosarcoma.

Zooming in on Long Non-Coding RNAs in Ewing Sarcoma Pathogenesis

Ewing sarcoma (ES) is a rare aggressive cancer of bone and soft tissue that is mainly characterized by a reciprocal chromosomal translocation. As a result, about 90% of cases express the EWS-FLI1 fusion protein that has been shown to function as an aberrant transcription factor driving sarcomagenesis. ES is the second most common malignant bone tumor in children and young adults. Current treatment modalities include dose-intensified chemo- and radiotherapy, as well as surgery. Despite these strategies, patients who present with metastasis or relapse still have dismal prognosis, warranting a better understanding of treatment resistant-disease biology in order to generate better prognostic and therapeutic tools. Since the genomes of ES tumors are relatively quiet and stable, exploring the contributions of epigenetic mechanisms in the initiation and progression of the disease becomes inevitable. The search for novel biomarkers and potential therapeutic targets of cancer metastasis and chemotherapeutic drug resistance is increasingly focusing on long non-coding RNAs (lncRNAs). Recent advances in genome analysis by high throughput sequencing have immensely expanded and advanced our knowledge of lncRNAs. They are non-protein coding RNA species with multiple biological functions that have been shown to be dysregulated in many diseases and are emerging as crucial players in cancer development. Understanding the various roles of lncRNAs in tumorigenesis and metastasis would determine eclectic avenues to establish therapeutic and diagnostic targets. In ES, some lncRNAs have been implicated in cell proliferation, migration and invasion, features that make them suitable as relevant biomarkers and therapeutic targets. In this review, we comprehensively discuss known lncRNAs implicated in ES that could serve as potential biomarkers and therapeutic targets of the disease. Though some current reviews have discussed non-coding RNAs in ES, to our knowledge, this is the first review focusing exclusively on ES-associated lncRNAs.

New therapy strategies in the management of breast cancer

Breast cancer (BC), the second leading cause of cancer-related deaths after lung cancer, is the most common cancer type among women worldwide. BC comprises multiple subtypes based on molecular properties. Depending on the type of BC, hormone therapy, targeted therapy, and immunotherapy are the current systemic treatment options along with conventional chemotherapy. Several new molecular targets, miRNAs, and long non-coding RNAs (lncRNAs), have been discovered over the past few decades and are powerful potential therapeutic targets. Here, we review advanced therapeutics as new players in BC management.

Vitamin D May Protect against Breast Cancer through the Regulation of Long Noncoding RNAs by VDR Signaling

Dietary vitamin D3 has attracted wide interest as a natural compound for breast cancer prevention and therapy, supported by in vitro and animal studies. The exact mechanism of such action of vitamin D3 is unknown and may include several independent or partly dependent pathways. The active metabolite of vitamin D3, 1α,25-dihydroxyvitamin D3 (1,25(OH)2D, calcitriol), binds to the vitamin D receptor (VDR) and induces its translocation to the nucleus, where it transactivates a myriad of genes. Vitamin D3 is involved in the maintenance of a normal epigenetic profile whose disturbance may contribute to breast cancer. In general, the protective effect of vitamin D3 against breast cancer is underlined by inhibition of proliferation and migration, stimulation of differentiation and apoptosis, and inhibition of epithelial/mesenchymal transition in breast cells. Vitamin D3 may also inhibit the transformation of normal mammary progenitors into breast cancer stem cells that initiate and sustain the growth of breast tumors. As long noncoding RNAs (lncRNAs) play an important role in breast cancer pathogenesis, and the specific mechanisms underlying this role are poorly understood, we provided several arguments that vitamin D3/VDR may induce protective effects in breast cancer through modulation of lncRNAs that are important for breast cancer pathogenesis. The main lncRNAs candidates to mediate the protective effect of vitamin D3 in breast cancer are lncBCAS1-4_1, AFAP1 antisense RNA 1 (AFAP1-AS1), metastasis-associated lung adenocarcinoma transcript 1 (MALAT1), long intergenic non-protein-coding RNA 511 (LINC00511), LINC00346, small nucleolar RNA host gene 6 (SNHG6), and SNHG16, but there is a rationale to explore several other lncRNAs.

Molecular and cellular functions of long non-coding RNAs in prostate and breast cancer

Long noncoding RNAs (lncRNAs) are defined as noncoding RNA transcripts with a length greater than 200 nucleotides. Research over the last decade has made great strides in our understanding of lncRNAs, especially in the biology of their role in cancer. In this article, we will briefly discuss the biogenesis and characteristics of lncRNAs, then review their molecular and cellular functions in cancer by using prostate and breast cancer as examples. LncRNAs are abundant, diverse, and evolutionarily, less conserved than protein-coding genes. They are often expressed in a tumor and cell-specific manner. As a key epigenetic factor, lncRNAs can use a wide variety of molecular mechanisms to regulate gene expression at each step of the genetic information flow pathway. LncRNAs display widespread effects on cell behavior, tumor growth, and metastasis. They act intracellularly and extracellularly in an autocrine, paracrine and endocrine fashion. Increased understanding of lncRNA's role in cancer has facilitated the development of novel biomarkers for cancer diagnosis, led to greater understanding of cancer prognosis, enabled better prediction of therapeutic responses, and promoted identification of potential targets for cancer therapy.

Nimbolide, a Neem Limonoid, Inhibits Angiogenesis in Breast Cancer by Abrogating Aldose Reductase Mediated IGF-1/PI3K/Akt Signaling

Background & Objectives:

There is growing evidence to implicate the insulin/IGF-1R/PI3K/Akt signaling cascade in breast cancer development and the central role of aldose reductase (AR) in mediating the crosstalk between this pathway and angiogenesis. The current study was designed to investigate whether nimbolide, a neem limonoid, targets this oncogenic signaling network to prevent angiogenesis in breast cancer.

Methods:

Breast cancer cells (MCF-7, MDA-MB-231), EAhy926 endothelial cells, MDA-MB-231 xenografted nude mice, and tumour tissues from breast cancer patients were used for the study. Expression of AR and key players in IGF-1/PI3K/Akt signaling and angiogenesis was evaluated by qRT-PCR, immunoblotting, and immunohistochemistry. Molecular docking and simulation, overexpression, and knockdown experiments were performed to determine whether nimbolide targets AR and IGF-1R

Results:

Nimbolide inhibited AR with consequent blockade of the IGF-1/PI3K/Akt and HIF-1/VEGF signaling circuit by influencing the phosphorylation and intracellular localisation of key signaling molecules. Downregulation of DNMT-1, HDAC-6, miR-21, HOTAIR, and H19 with upregulation of miR-148a/miR-152 indicated that nimbolide regulates AR and IGF-1/PI3K/Akt signaling via epigenetic modifications. Coadministration of nimbolide with metformin and the chemotherapeutic drugs tamoxifen/cisplatin displayed higher efficacy than single agents in inhibiting IGF-1/PI3K/Akt/AR signaling. Grade-wise increases in IGF-1R and AR expression in breast cancer tissues underscore their value as biomarkers of progression.

Conclusions:

This study provides evidence for the anticancer effects of nimbolide in cellular and mouse models of breast cancer besides providing leads for new drug combinations. It has also opened up avenues for investigating potential molecules such as AR for therapeutic targeting of cancer.

A diagnostic and prognostic value of blood-based circulating long non-coding RNAs in Thyroid, Pancreatic and Ovarian Cancer

Several studies have demonstrated the potential of circulating long non-coding RNAs (lncRNAs) as promising cancer biomarkers. Herein, we addressed the regulatory role of circulating lncRNAs and their potential value as diagnostic/prognostic markers for thyroid, pancreatic and ovarian cancers. Furthermore, we analyzed and measured the clinical implications and association of lncRNAs with sensitivity, specificity, and area under the ROC curve (AUC). Based on our meta-analysis, we found that GAS8-AS1 could discriminate thyroid cancer from non-cancer and other cancers with higher accuracy (AUC = 0.746; sensitivity = 61.70%, and specificity = 90.00%). Similarly, for ovarian cancer, lncRNA RP5-837J1.2 was found to have ideal diagnostic potential with critical clinical specifications of AUC = 0.996; sensitivity = 97.30% and specificity = 94.60%. Whereas we could not find any lncRNA having high diagnostic/prognostic efficiency in pancreatic cancer. We believe that lncRNAs mentioned above may explore clinical settings for the diagnosis and prognosis of cancer patients.

HOTAIR Modulated Pathways in Early-Stage Breast Cancer Progression

The long-non-coding HOX transcript antisense intergenic RNA (HOTAIR) was identified as significantly upregulated in breast ductal carcinoma in situ (DCIS). The aim of this study was to characterize the phenotypic effects and signaling pathways modulated by HOTAIR in early-stage breast cancer progression. We determined that HOTAIR induces premalignant phenotypic changes by increasing cell proliferation, migration, invasion and in vivo growth in normal and DCIS breast cell lines. Transcriptomic studies (RNA-seq) identified the main signaling pathways modulated by HOTAIR which include bioprocesses related to epithelial to mesenchymal transition, cell migration, extracellular matrix remodeling and activation of several signaling pathways (HIF1A, AP1 and FGFR). Similar pathways were identified as activated in primary invasive breast carcinomas with HOTAIR over-expression. We conclude that HOTAIR over-expression behaves as a positive regulator of cell growth and migration both in normal and DCIS breast cells involved with early-stage breast cancer progression.

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.

What is beyond LncRNAs in breast cancer: A special focus on colon cancer-associated Transcript-1 (CCAT-1)

Long non-coding RNAs (LncRNAs) play a vital role in the process of malignant transformation. In breast cancer (BC), lncRNAs field is currently under intensive investigations. Yet, the role of lncRNAs as promising diagnostic and/or prognostic biomarkers and as therapeutic target/tool among BC patients still needs a special focus from the biomedical scientists. In BC, triple negative breast cancer patients (TNBC) are the unlucky group as they are always represented with the worst prognosis and the highest mortality rates. For that reason, a special focus on TNBC and associated lncRNAs was addressed in this review. Colon cancer-associated transcript 1 (CCAT-1) is a newly discovered oncogenic lncRNA that has been emerged as a vital biomarker for diagnosis, prognosis and therapeutic interventions in multiple malignancies and showed differential expression among TNBC patients. In this review, the authors shed the light onto the general role of lncRNAs in BC and the specific functional activities, molecular mechanisms, competing endogenous ncRNA role of CCAT-1 in TNBC.

Homeobox Genes in Cancers: From Carcinogenesis to Recent Therapeutic Intervention

The homeobox (HOX) genes encoding an evolutionarily highly conserved family of homeodomain-containing transcriptional factors are essential for embryogenesis and tumorigenesis. HOX genes are involved in cell identity determination during early embryonic development and postnatal processes. The deregulation of HOX genes is closely associated with numerous human malignancies, highlighting the indispensable involvement in mortal cancer development. Since most HOX genes behave as oncogenes or tumor suppressors in human cancer, a better comprehension of their upstream regulators and downstream targets contributes to elucidating the function of HOX genes in cancer development. In addition, targeting HOX genes may imply therapeutic potential. Recently, novel therapies such as monoclonal antibodies targeting tyrosine receptor kinases, small molecular chemical inhibitors, and small interfering RNA strategies, are difficult to implement for targeting transcriptional factors on account of the dual function and pleiotropic nature of HOX genes-related molecular networks. This paper summarizes the current state of knowledge on the roles of HOX genes in human cancer and emphasizes the emerging importance of HOX genes as potential therapeutic targets to overcome the limitations of present cancer therapy.

Novel lncRNA Panel as for Prognosis in Esophageal Squamous Cell Carcinoma Based on ceRNA Network Mechanism

Background

The competitive endogenous RNA (ceRNA) mechanism has been discovered recently and regulating cancer-related gene expressions. The ceRNA network participates in multiple processes, such as cell proliferation and metastasis, and potentially drives the progression of cancer. In this study, we focus on the ceRNA networks of esophageal squamous cell carcinoma and discovered a novel biomarker panel for cancer prognosis.

Methods

RNA expression data of esophageal carcinoma from the TCGA database were achieved and constructed ceRNA network in esophageal carcinoma using R packages.

Results

Four miRNAs were discovered as the core of the ceRNA model, including miR-93, miR-191, miR-99b, and miR-3615. Moreover, we constructed a ceRNA network in esophageal carcinoma, which included 4 miRNAs and 6 lncRNAs. After ceRNA network modeling, we investigated six lncRNAs which could be taken together as a panel for prognosis prediction of esophageal cancer, including LINC02575, LINC01087, LINC01816, AL136162.1, AC012073.1, and AC117402.1. Finally, we tested the predictive power of the panel in all TCGA samples.

Conclusions

Our study discovered a new biomarker panel which may have potential values in the prediction of prognosis of esophageal carcinoma.

Long Noncoding RNAs Regulate the Radioresistance of Breast Cancer

Breast cancer (BRCA) has severely threatened women's health worldwide. Radiotherapy is a treatment for BRCA, which applies high doses of ionizing radiation to induce cancer cell death and reduce disease recurrence. Radioresistance is one of the most important elements that affect the therapeutic efficacy of radiotherapy. Long noncoding RNAs (lncRNAs) are suggested to dominate crucial roles in regulating the biological behavior of BRCA. Currently, some studies indicate that overexpression or inhibition of lncRNAs can greatly alter the radioresistance of BRCA. In this review, we summarized the knowledge on the classification and function of lncRNAs and the molecular mechanism of BRCA radioresistance, listed lncRNAs related to the BRCA radioresistance, highlighted their underlying mechanisms, and discussed the potential application of these lncRNAs in regulating BRCA radioresistance.

The Role of lncRNAs in Rare Tumors with a Focus on HOX Transcript Antisense RNA (HOTAIR)

Rare cancers are identified as those with an annual incidence of fewer than 6 per 100,000 persons and includes both epithelial and stromal tumors from different anatomical areas. The advancement of analytical methods has produced an accurate molecular characterization of most human cancers, suggesting a “molecular classification” that has allowed the establishment of increasingly personalized therapeutic strategies. However, the limited availability of rare cancer samples has resulted in very few therapeutic options for these tumors, often leading to poor prognosis. Long non coding RNAs (lncRNAs) are a class of non-coding RNAs mostly involved in tumor progression and drug response. In particular, the lncRNA HOX transcript antisense RNA (HOTAIR) represents an emergent diagnostic, prognostic and predictive biomarker in many human cancers. The aim of this review is to highlight the role of HOTAIR in rare cancers, proposing it as a new biomarker usable in the management of these tumors.

Diagnostic significance of serum lncRNA HOTAIR and its predictive value for the development of chronic complications in patients with type 2 diabetes mellitus

BACKGROUND

Type 2 diabetes mellitus (T2DM) affects the social economy and quality of life, and has become a major threat to human health. This observation aimed to study the possibility of serum HOTAIR as a diagnostic index in patients with T2DM and to explore the prognostic potential of HOTAIR in the development of T2DM.

METHODS

The expression of HOTAIR in serum of 96 patients with T2DM and 82 healthy controls was detected by the qRT-PCR technique. The related biochemical indexes of all participants were determined, such as total cholesterol (TC) and fasting blood glucose (FBG). The value of serum HOTAIR in the diagnosis of T2DM in the two groups was analyzed by the ROC curve. Moreover, the prognostic value of HOTAIR on T2DM was examined by the K-M curve and COX multivariate analysis.

RESULTS

The results of the qRT-PCR analysis showed that the serum level of HOTAIR in patients with T2DM was significantly higher than that in healthy controls. ROC analysis showed that HOTAIR in serum was a diagnostic factor of T2DM. Further multivariate analysis showed that HOTAIR could be an independent biomarker in the prediction of chronic complications for T2DM patients, such as diabetic retinopathy and diabetic nephropathy.

CONCLUSIONS

We found the augment of HOTAIR expression was a character of T2DM. The high expression of serum HOTAIR was a potential non-invasive diagnostic marker and independent prognostic factor in patients with T2DM.

lncRNA and breast cancer: Progress from identifying mechanisms to challenges and opportunities of clinical treatment

Breast cancer is a malignant tumor that has a high mortality rate and mostly occurs in women. Although significant progress has been made in the implementation of personalized treatment strategies for molecular subtypes in breast cancer, the therapeutic response is often not satisfactory. Studies have reported that long non-coding RNAs (lncRNAs) are abnormally expressed in breast cancer and closely related to the occurrence and development of breast cancer. In addition, the high tissue and cell-type specificity makes lncRNAs particularly attractive as diagnostic biomarkers, prognostic factors, and specific therapeutic targets. Therefore, an in-depth understanding of the regulatory mechanisms of lncRNAs in breast cancer is essential for developing new treatment strategies. In this review, we systematically elucidate the general characteristics, potential mechanisms, and targeted therapy of lncRNAs and discuss the emerging functions of lncRNAs in breast cancer. Additionally, we also highlight the advantages and challenges of using lncRNAs as biomarkers for diagnosis or therapeutic targets for drug resistance in breast cancer and present future perspectives in clinical practice.

LncRNA HOTAIR: A Potential Prognostic Factor and Therapeutic Target in Human Cancers

Long non-coding RNAs (lncRNAs) are emerging as crucial regulators of gene expression and physiological processes. LncRNAs are a class of ncRNAs of 200 nucleotides in length. HOX transcript antisense RNA (HOTAIR), a trans-acting lncRNA with regulatory function on transcription, can repress gene expression by recruiting chromatin modifiers. HOTAIR is an oncogenic lncRNA, and numerous studies have determined that HOTAIR is highly upregulated in a wide variety of human cancers. In this review, we briefly summarize the impact of lncRNA HOTAIR expression and functions on different human solid tumors, and emphasize the potential of HOTAIR on tumor prognosis and therapy. Here, we review the recent studies that highlight the prognostic potential of HOTAIR in drug resistance and survival, and the progress of therapies developed to target HOTAIR to date. Furthermore, targeting HOTAIR results in the suppression of HOTAIR expression or function. Thus, HOTAIR knockdown exhibits great therapeutic potential in various cancers, indicating that targeting lncRNA HOTAIR may serve as a promising strategy for cancer therapy. We also propose that preclinical studies involving HOTAIR are required to provide a better understanding of the exact molecular mechanisms underlying the dysregulation of its expression and function in different human cancers and to explore effective methods of targeting HOTAIR and engineering efficient and targeted drug delivery methods in vivo.

Aberrant Expression of Long Non Coding RNA HOTAIR and De-Regulation of the Paralogous 13 HOX Genes Are Strongly Associated with Aggressive Behavior of Gastro-Entero-Pancreatic Neuroendocrine Tumors

Gastro-entero-pancreatic neuroendocrine neoplasms (GEP-NENs) are rare diseases occurring in the gastrointestinal tract and pancreas. They are characterized by the loss of epithelial tubular gland elements, and by the increased expression of neuroendocrine markers. GEP-NENs are subdivided into two histo-pathological types, gastro-entero-pancreatic neuroendocrine tumors (GEP-NETs) and gastro-entero-pancreatic neuroendocrine carcinomas (GEP-NECs). According to WHO 2017 and 2019 classification criteria are graded and staged in four categories, NET-G1, NET-G2, NET-G3, and NEC-G3. The molecular characterization of these tumors can be fundamental for the identification of new diagnostic, prognostic and predictive biomarkers. The main purpose of this study was to analyze the expression of the paralogous 13 HOX genes, normally involved in embryogenic development and frequently deregulated in human cancers, and of the HOX regulating lncRNA HOTAIR in GEP-NENs. The expression of HOX genes is gradually lost in the transition from GEP NET G1 to NET/NEC G3 tumors, while HOTAIR expression, inversely correlated with HOX genes expression and weakly expressed in low-grade GEP NENs, becomes aberrant in NET G3 and NEC G3 categories. Our data highlights their potential role in the molecular stratification of GEP-NENs by suggesting new prognostic markers and potential therapeutic targets.

Long non-coding RNA A1BG-AS1 promotes tumorigenesis in breast cancer by sponging microRNA-485-5p and consequently increasing expression of FLOT1 expression

The dysregulated long non-coding RNA A1BG antisense RNA 1 (A1BG-AS1) has been implicated in the oncogenicity of hepatocellular carcinoma. Using reverse transcription quantitative polymerase chain reaction in this study, we detected A1BG-AS1 expression in breast cancer and elucidated the regulatory functions and exact mechanisms of A1BG-AS1 in breast cancer cells. The regulatory functions of A1BG-AS1 were examined in vitro using the Cell Counting Kit-8 assay, flow cytometric, and Transwell migration and invasion assays and in vivo through tumor xenograft experiments. In addition, we performed bioinformatics analysis, luciferase reporter assay, RNA immunoprecipitation, and rescue experiments to verify the interaction among A1BG-AS1, microRNA-485-5p (miR-485-5p), and flotillin-1 (FLOT1) in breast cancer. We found A1BG-AS1 to be highly expressed in breast cancer tissues and cell lines. In terms of function, depleted A1BG-AS1 markedly suppressed cell proliferation, accelerated cell apoptosis, and hindered cell migration and invasion in breast cancer. Furthermore, A1BG-AS1 interference reduced tumor growth in vivo. Mechanistic investigations confirmed that A1BG-AS1 directly interacted with miR-485-5p as a molecular sponge. We demonstrated that FLOT1 is a direct target of miR-485-5p, which could be positively regulated by A1BG-AS1 by competing for miR-485-5p. Rescue experiments clearly showed that the downregulation of miR-485-5p and upregulation of FLOT1 were capable of reversing the anticancer activities of A1BG-AS1 deficiency in terms of breast cancer cell malignancy. A1BG-AS1 acts as a miR-485-5p sponge and subsequently increases FLOT1 expression in breast cancer cells, ultimately facilitating cancer progression. Hence, the A1BG-AS1/miR-485-5p/FLOT1 pathway might offer a novel therapeutic perspective for breast cancer.