Long Non-Coding RNAs: Key Regulators of Epithelial-Mesenchymal Transition, Tumour Drug Resistance and Cancer Stem Cells

siRNA-based knockdown of lncRNAs: A new modality to target tumor progression

This study examines the potential of small interfering RNA (siRNA) as a therapeutic agent for cancer targeting long non-coding RNAs (lncRNAs). The article begins with an analysis of the structure and biogenesis of lncRNA. It explains the diverse functions of lncRNAs in cancer, establishing a foundation for assessing approaches to inhibit these molecules. The analysis focuses on the consequences of lncRNA suppression through siRNA on signaling pathways associated with cancer, connecting theoretical understanding to practical applications. An evaluation of ongoing clinical trials and applications contributes to the discourse by revealing the potential for siRNA-mediated interventions to be practiced. Furthermore, an evaluation of the advantages and disadvantages of this therapeutic approach offers a nuanced viewpoint. In conclusion, the paper synthesizes significant discoveries and outlines potential avenues for future research, contributing to the dialogue surrounding personalized cancer therapeutics and precision medicine. Future challenges in using siRNA to target lncRNAs in oncology include optimizing delivery systems for efficient tumor cell uptake, minimizing off-target effects, enhancing RNA stability for a longer therapeutic window, and overcoming barriers in the tumor microenvironment. Addressing these factors is essential for the practical application of siRNA-based cancer therapies.

Natural products and long non-coding RNAs in prostate cancer: insights into etiology and treatment resistance

Globally, the incidence and death rates associated with cancer persist in rising, despite considerable advancements in cancer therapy. Although some malignancies are manageable by a mix of chemotherapy, surgery, radiation, and targeted therapy, most malignant tumors either exhibit poor responsiveness to early identification or endure post-treatment survival. The prognosis for prostate cancer (PCa) is unfavorable since it is a perilous and lethal malignancy. The capacity of phytochemical and nutraceutical chemicals to repress oncogenic lncRNAs and activate tumor suppressor lncRNAs has garnered significant attention as a possible strategy to diminish the development, proliferation, metastasis, and invasion of cancer cells. A potential technique to treat cancer and enhance the sensitivity of cancer cells to existing conventional therapies is the use of phytochemicals with anticancer characteristics. Functional studies indicate that lncRNAs modulate drug resistance, stemness, invasion, metastasis, angiogenesis, and proliferation via interactions with tumor suppressors and oncoproteins. Among them, numerous lncRNAs, such as HOTAIR, PlncRNA1, GAS5, MEG3, LincRNA-21, and POTEF-AS1, support the development of PCa through many molecular mechanisms, including modulation of tumor suppressors and regulation of various signal pathways like PI3K/Akt, Bax/Caspase 3, P53, MAPK cascade, and TGF-β1. Other lncRNAs, in particular, MALAT-1, CCAT2, DANCR, LncRNA-ATB, PlncRNA1, LincRNA-21, POTEF-AS1, ZEB1-AS1, SChLAP1, and H19, are key players in regulating the aforementioned processes. Natural substances have shown promising anticancer benefits against PCa by altering essential signaling pathways. The overexpression of some lncRNAs is associated with advanced TNM stage, metastasis, chemoresistance, and reduced survival. LncRNAs possess crucial clinical and transitional implications in PCa, as diagnostic and prognostic biomarkers, as well as medicinal targets. To impede the progression of PCa, it is beneficial to target aberrant long non-coding RNAs using antisense oligonucleotides or small interfering RNAs (siRNAs). This prevents them from transmitting harmful messages. In summary, several precision medicine approaches may be used to rectify dysfunctional lncRNA regulatory circuits, so improving early PCa detection and eventually facilitating the conquest of this lethal disease. Due to their presence in biological fluids and tissues, they may serve as novel biomarkers. Enhancing PCa treatments mitigates resistance to chemotherapy and radiation.

Development of a Novel Prognostic Model for Lung Adenocarcinoma Utilizing Pyroptosis-Associated LncRNAs

Lung cancer is a highly prevalent and fatal cancer that seriously threatens the safety of people in various regions around the world. Difficulty in early diagnosis and strong drug resistance have always been difficulties in the treatment of lung cancer, so the prognosis of lung cancer has always been the focus of scientific researchers. This study used genotype-tissue expression (GTEx) and the cancer genome atlas (TCGA) databases to obtain 477 lung adenocarcinoma (LUAD) and 347 healthy individuals' samples as research subjects and divided LUAD patients into low-risk and high-risk groups based on prognostic risk scores. Differentially expressed gene (DEG) analysis was performed on 25 pyroptosis-related genes obtained from GeneCards and MSigDB databases in cancer tissues of LUAD patients and noncancerous tissues of healthy individuals, and seven genes were significantly different in cancer tissues and noncancerous tissues among them. Coexpression analysis and differential expression analysis of these genes and long noncoding RNAs (lncRNAs) found that three lncRNAs (AC012615.1, AC099850.3, and AO0001453.2) had significant differences in expression between cancer tissues and noncancerous tissues. We used Cox regression and the least absolute shrinkage sum selection operator (LASSO) regression to construct a prognostic model for LUAD patients with these three pyroptosis-related lncRNAs (pRLs) and analyzed the prognostic value of the pRLs model by the Likaplan-Meier curve and Cox regression. The results show that the risk prediction model has good prediction ability. In addition, we also studied the differences in tumor mutation burden (TMB), tumor immune dysfunction and rejection (TIDE), and immune microenvironment with pRLs risk scores in low-risk and high-risk groups. This study successfully established a LUAD prognostic model based on pRLs, which provides new insights into lncRNA-based LUAD diagnosis and treatment strategies.

LncRNAs in modulating cancer cell resistance to paclitaxel (PTX) therapy

Paclitaxel (PTX) is widely used for treating several cancers, including breast, ovarian, lung, esophageal, gastric, pancreatic, and neck cancers. Despite its clinical utility, cancer recurrence frequently occurs in patients due to the development of resistance to PTX. Resistance mechanisms in cancer cells treated with PTX include alterations in β-tubulin, the target molecule involved in mitosis, activation of molecular pathways enabling drug efflux, and dysregulation of apoptosis-related proteins. Long non-coding RNAs (lncRNAs), which are RNA molecules longer than 200 nucleotides without protein-coding potential, serve diverse regulatory roles in cellular processes. Increasing evidence highlights the involvement of lncRNAs in cancer progression and their contribution to PTX resistance across various cancers. Consequently, lncRNAs have emerged as potential therapeutic targets for addressing drug resistance in cancer treatment. This review focuses on the current understanding of lncRNAs and their role in drug resistance mechanisms, aiming to encourage further investigation in this area. Key lncRNAs and their associated pathways linked to PTX resistance will be summarized.

Non-Coding RNA as a Biomarker in Lung Cancer

INTRODUCTION

Lung cancer remains one of the most prevalent and deadly cancers globally, with high mortality rates largely due to late-stage diagnosis, aggressive progression, and frequent recurrence. Despite advancements in diagnostic techniques and therapeutic interventions, the overall prognosis for lung cancer patients continues to be dismal.

METHOD

Emerging research has identified non-coding RNAs (ncRNAs), including microRNAs, long non-coding RNAs, and circular RNAs, as critical regulators of gene expression, significantly influencing cancer biology. These ncRNAs play pivotal roles in various aspects of lung cancer pathogenesis, including tumor initiation, progression, metastasis, and resistance to therapy.

RESULTS

We provide a comprehensive analysis of the current understanding of ncRNAs in lung cancer, emphasizing their potential as biomarkers for early diagnosis, prognostication, and the prediction of the therapeutic response. We explore the biological functions of ncRNAs, their involvement in key oncogenic pathways, and the molecular mechanisms by which they modulate gene expression and cellular processes in lung cancer. Furthermore, this review highlights recent advances in ncRNA-based diagnostic tools and therapeutic strategies, such as miRNA mimics and inhibitors, lncRNA-targeted therapies, and circRNA-modulating approaches, offering promising avenues for personalized medicine.

CONCLUSION

Finally, we discuss the challenges and future directions in ncRNA research, including the need for large-scale validation studies and the development of efficient delivery systems for ncRNA-based therapies. This review underscores the potential of ncRNAs to revolutionize lung cancer management by providing novel diagnostic and therapeutic options that could improve patient outcomes.

Boehmeria Nivea Extract (BNE-RRC) Reverses Epithelial-Mesenchymal Transition and Inhibits Anchorage-Independent Growth in Tumor Cells

The epithelial-mesenchymal transition (EMT) phenotype, identified as a significant clinical indicator in regard to cancer, manifests as a biological process wherein cells transition from having epithelial to mesenchymal characteristics. Physiologically, EMT plays a crucial role in tissue remodeling, promoting healing, repair, and responses to various types of tissue damage. This study investigated the impact of BNE-RRC on oral cancer cells (KB) and revealed its significant effects on cancer cell growth, migration, invasion, and the EMT. BNE-RRC induces the epithelial-like morphology in KB cells, effectively reversing the EMT to a mesenchymal-epithelial transition (MET). Extraordinarily, sustained culturing of cancer cells with BNE-RRC for 14 days maintains an epithelial status even after treatment withdrawal, suggesting that BNE-RRC is a potential therapeutic agent for cancer. These findings highlight the promise of BNE-RRC as a comprehensive therapeutic agent for cancer treatment that acts by inhibiting cancer cell growth, migration, and invasion while also orchestrating a reversal of the EMT process. In this study, we propose that BNE-RRC could be an effective agent for cancer treatment.

Genetic Biomarkers in Astrocytoma: Diagnostic, Prognostic, and Therapeutic Potential

Astrocytoma is the most common adult brain tumor, with glioblastoma being the deadliest neuro-related malignancy. Despite advances in oncology, the prognosis for astrocytoma, especially glioblastoma, remains poor, and tracking disease progression is challenging due to a lack of robust biomarkers. Genetic biomarkers, including microRNAs, cell-free DNA, circulating tumor DNA, circular RNA, and long noncoding RNA, can serve as potential diagnostic and therapeutic targets. In this review, we examine the existing literature, analyzing the various less established liquid and tumor genetic biomarkers and their potential to act as diagnostic, prognostic, and therapeutic targets. We highlight the clinical challenges and limitations in implementing liquid biopsy strategies in clinical practice. The article discusses the potential of liquid biopsies as valuable tools for personalized astrocytoma management while emphasizing the need for standardized protocols and further advancements to establish their clinical utility and therapeutic application.

LncRNA CARMN m6A demethylation by ALKBH5 inhibits mutant p53-driven tumour progression through miR-5683/FGF2

N-methyladenosine (m6A) represents a prevalent RNA modification observed in colorectal cancer. Despite its abundance, the biological implications of m6A methylation on the lncRNA CARMN remain elusive in colorectal cancer, especially for mutant p53 gain-of-function. Here, we elucidate that CARMN exhibits diminished expression levels in colorectal cancer patients with mutant p53, attributed to its rich m6A methylation, which promotes cancer proliferation, invasion and metastasis in vitro and in vivo. Further investigation illustrates that ALKBH5 acts as a direct demethylase of CARMN, targeting 477 methylation sites, thereby preserving CARMN expression. However, the interaction of mutant p53 with the ALKBH5 promoter impedes its transcription, enhancing m6A methylation levels on CARMN. Subsequently, YTHDF2/YTHDF3 recognise and degrade m6A-modified CARMN. Concurrently, overexpressing CARMN significantly suppressed colorectal cancer progression in vitro and in vivo. Additionally, miR-5683 was identified as a direct downstream target of lncRNA CARMN, exerting an antitumour effect by cooperatively downregulating FGF2 expression. Our findings revealed the regulator and functional mechanism of CARMN in colorectal cancer with mutant p53, potentially offering insights into demethylation-based strategies for cancer diagnosis and therapy. The m6A methylation of CARMN that is prime for mutant p53 gain-of-function-induced malignant progression of colorectal cancer, identifying a promising approach for cancer therapy.

Extracellular vesicle-mediated drug delivery in breast cancer theranostics

Breast cancer (BC) continues to be a significant global challenge due to drug resistance and severe side effects. The increasing prevalence is alarming, requiring new therapeutic approaches to address these challenges. At this point, Extracellular vesicles (EVs), specifically small endosome-released nanometer-sized EVs (SEVs) or exosomes, have been explored by literature as potential theranostics. Therefore, this review aims to highlight the therapeutic potential of exosomes in BC, focusing on their advantages in drug delivery and their ability to mitigate metastasis. Following the review, we identified exosomes' potential in combination therapies, serving as miRNA carriers and contributing to improved anti-tumor effects. This is evident in clinical trials investigating exosomes in BC, which have shown their ability to boost chemotherapy efficacy by delivering drugs like paclitaxel (PTX) and doxorubicin (DOX). However, the translation of EVs into BC therapy is hindered by various challenges. These challenges include the heterogeneity of EVs, the selection of the appropriate parent cell, the loading procedures, and determining the optimal administration routes. Despite the promising therapeutic potential of EVs, these obstacles must be addressed to realize their benefits in BC treatment.

Updated review on analysis of long non-coding RNAs as emerging diagnostic and therapeutic targets in prostate cancers

Despite advancements, prostate cancers (PCa) pose a significant global health challenge due to delayed diagnosis and therapeutic resistance. This review delves into the complex landscape of prostate cancer, with a focus on long-noncoding RNAs (lncRNAs). Also explores the influence of aberrant lncRNAs expression in progressive PCa stages, impacting traits like proliferation, invasion, metastasis and therapeutic resistance. The study elucidates how lncRNAs modulate crucial molecular effectors, including transcription factors and microRNAs, affecting signaling pathways such as androgen receptor signaling. Besides, this manuscript sheds light on novel concepts and mechanisms driving PCa progression through lncRNAs, providing a critical analysis of their impact on the disease's diverse characteristics. Besides, it discusses the potential of lncRNAs as diagnostics and therapeutic targets in PCa. Collectively, this work highlights state of art mechanistic comprehension and rigorous scientific approaches to advance our understanding of PCa and depict innovations in this evolving field of research.

Plasticity and resistance of cancer stem cells as a challenge for innovative anticancer therapies - do we know enough to overcome this?

According to the CSC hypothesis, cancer stem cells are pivotal in initiating, developing, and causing cancer recurrence. Since the identification of CSCs in leukemia, breast cancer, glioblastoma, and colorectal cancer in the 1990s, researchers have actively investigated the origin and biology of CSCs. However, the CSC hypothesis and the role of these cells in tumor development model is still in debate. These cells exhibit distinct surface markers, are capable of self-renewal, demonstrate unrestricted proliferation, and display metabolic adaptation. CSC phenotypic plasticity and the capacity to EMT is strictly connected to the stemness state. CSCs show high resistance to chemotherapy, radiotherapy, and immunotherapy. The plasticity of CSCs is significantly influenced by tumor microenvironment factors, such as hypoxia. Targeting the genetic and epigenetic changes of cancer cells, together with interactions with the tumor microenvironment, presents promising avenues for therapeutic strategies. See also the Graphical abstract(Fig. 1).

Evaluation of the Expression of Infection-Related Long Noncoding RNAs among COVID-19 Patients: A Case-Control Study

Background and Aims

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a worldwide pandemic, activates signaling cascades and leads to innate immune responses and secretion of multiple chemokines and cytokines. Long noncoding RNAs (lncRNAs) have a crucial role in inflammatory pathways. Through our search on the PubMed database, we discovered that existing research has primarily focused on examining the regulatory impacts of five lncRNAs in the context of viral infections. However, their role in regulating other conditions, including SARS-CoV-2, has not been explored. Therefore, this study aimed to investigate the expression pattern of lncRNAs in the peripheral blood mononuclear cells (PBMC) and their potential roles in SARS-CoV-2 infection. Potentially significant competing endogenous RNA (ceRNA) networks of these five lncRNAs were found using online in-silico techniques.

Methods

Ethylenediaminetetraacetic acid (EDTA) blood samples of the control group consisted of 45 healthy people, and a total of 53 COVID-19-infected patients in case group, with a written informed consent, was collected. PBMCs were extracted, and then, the RNA extraction and complementary DNA (cDNA) synthesis was performed. The expression of five lncRNAs (lnc ISR, lnc ATV, lnc PAAN, lnc SG20, and lnc HEAL) was assessed by real-time PCR. In order to evaluate the biomarker roles of genes, receiver operating characteristic (ROC) curve was drawn.

Results

Twenty-four (53.3%) and 29 (54.7%) of healthy and COVID-19-infected participants were male, respectively. The most prevalent symptoms were as follows: cough, general weakness, contusion, headache, and sore throat. The results showed that three lncRNAs, including lnc ISR, lnc ATV, and lnc HEAL, were expressed dramatically higher in the case group compared to healthy controls. According to ROC curve analysis, lnc ATV has a higher AUC and is a better biomarker to differentiate COVID-19 patients from the healthy controls. Then, using bioinformatics methods, the ceRNA network of these lncRNAs enabled the identification of mRNAs and miRNAs with crucial functions in COVID-19.

Conclusion

The considerable higher expression of ISR, ATV, and HEAL lncRNAs and the significant area under curve (AUC) in ROC curve demonstrate that these RNAs probably have a potential role in controlling the host innate immune responses and regulate the viral replication of SARS-CoV-2. However, these assumptions need further in vitro and in vivo investigations to be confirmed.

The pivotal role of long non-coding RNAs as potential biomarkers and modulators of chemoresistance in ovarian cancer (OC)

Ovarian cancer (OC) is a fatal gynecological disease that is often diagnosed at later stages due to its asymptomatic nature and the absence of efficient early-stage biomarkers. Previous studies have identified genes with abnormal expression in OC that couldn't be explained by methylation or mutation, indicating alternative mechanisms of gene regulation. Recent advances in human transcriptome studies have led to research on non-coding RNAs (ncRNAs) as regulators of cancer gene expression. Long non-coding RNAs (lncRNAs), a class of ncRNAs with a length greater than 200 nucleotides, have been identified as crucial regulators of physiological processes and human diseases, including cancer. Dysregulated lncRNA expression has also been found to play a crucial role in ovarian carcinogenesis, indicating their potential as novel and non-invasive biomarkers for improving OC management. However, despite the discovery of several thousand lncRNAs, only one has been approved for clinical use as a biomarker in cancer, highlighting the importance of further research in this field. In addition to their potential as biomarkers, lncRNAs have been implicated in modulating chemoresistance, a major problem in OC. Several studies have identified altered lncRNA expression upon drug treatment, further emphasizing their potential to modulate chemoresistance. In this review, we highlight the characteristics of lncRNAs, their function, and their potential to serve as tumor markers in OC. We also discuss a few databases providing detailed information on lncRNAs in various cancer types. Despite the promising potential of lncRNAs, further research is necessary to fully understand their role in cancer and develop effective strategies to combat this devastating disease.

KMT2D preferentially binds mRNAs of the genes it regulates, suggesting a role in RNA processing

Histone lysine methyltransferases (HKMTs) perform vital roles in cellular life by controlling gene expression programs through the posttranslational modification of histone tails. Since many of them are intimately involved in the development of different diseases, including several cancers, understanding the molecular mechanisms that control their target recognition and activity is vital for the treatment and prevention of such conditions. RNA binding has been shown to be an important regulatory factor in the function of several HKMTs, such as the yeast Set1 and the human Ezh2. Moreover, many HKMTs are capable of RNA binding in the absence of a canonical RNA binding domain. Here, we explored the RNA binding capacity of KMT2D, one of the major H3K4 monomethyl transferases in enhancers, using RNA immunoprecipitation followed by sequencing. We identified a broad range of coding and non-coding RNAs associated with KMT2D and confirmed their binding through RNA immunoprecipitation and quantitative PCR. We also showed that a separated RNA binding region within KMT2D is capable of binding a similar RNA pool, but differences in the binding specificity indicate the existence of other regulatory elements in the sequence of KMT2D. Analysis of the bound mRNAs revealed that KMT2D preferentially binds co-transcriptionally to the mRNAs of the genes under its control, while also interacting with super enhancer- and splicing-related non-coding RNAs. These observations, together with the nuclear colocalization of KMT2D with differentially phosphorylated forms of RNA Polymerase II suggest a so far unexplored role of KMT2D in the RNA processing of the nascent transcripts.

Molecular targets, therapeutic agents and multitasking nanoparticles to deal with cancer stem cells: A narrative review

There is increasing evidence that malignant tumors are initiated and maintained by a sub-population of tumor cells that have similar biological properties to normal adult stem cells. This very small population of Cancer Stem Cells (CSC) comprises tumor initiating cells responsible for cancer recurrence, drug resistance and metastasis. Conventional treatments such as chemotherapy, radiotherapy and surgery, in addition to being potentially toxic and non-specific, may paradoxically increase the population, spread and survival of CSCs. Next-generation sequencing and omics technologies are increasing our understanding of the pathways and factors involved in the development of CSCs, and can help to discover new therapeutic targets against CSCs. In addition, recent advances in nanomedicine have provided hope for the development of optimal specific therapies to eradicate CSCs. Moreover, the use of artificial intelligence and nano-informatics can elucidate new drug targets, and help to design drugs and nanoparticles (NPs) to deal with CSCs. In this review, we first summarize the properties of CSCs and describe the signaling pathways and molecular characteristics responsible for the emergence and survival of CSCs. Also, the location of CSCs within the tumor and the effect of host factors on the creation and maintenance of CSCs are discussed. Newly discovered molecular targets involved in cancer stemness and some novel therapeutic compounds to combat CSCs are highlighted. The optimum properties of anti-CSC NPs, including blood circulation and stability, tumor accumulation and penetration, cellular internalization, drug release, endosomal escape, and aptamers designed for specific targeting of CSCs are covered. Finally, some recent smart NPs designed for therapeutic and theranostic purposes to overcome CSCs are discussed.

MicroRNAs, long non-coding RNAs, and circular RNAs and gynecological cancers: focus on metastasis

Gynecologic cancer is a significant cause of death in women worldwide, with cervical cancer, ovarian cancer, and endometrial cancer being among the most well-known types. The initiation and progression of gynecologic cancers involve a variety of biological functions, including angiogenesis and metastasis-given that death mostly occurs from metastatic tumors that have invaded the surrounding tissues. Therefore, understanding the molecular pathways underlying gynecologic cancer metastasis is critical for enhancing patient survival and outcomes. Recent research has revealed the contribution of numerous non-coding RNAs (ncRNAs) to metastasis and invasion of gynecologic cancer by affecting specific cellular pathways. This review focuses on three types of gynecologic cancer (ovarian, endometrial, and cervical) and three kinds of ncRNAs (long non-coding RNAs, microRNAs, and circular RNAs). We summarize the detailed role of non-coding RNAs in the different pathways and molecular interactions involved in the invasion and metastasis of these cancers.

Construction of a cuproptosis-associated lncRNA prognostic signature for bladder cancer and experimental validation of cuproptosis-related lncRNA UBE2Q1-AS1

Introduction

Bladder cancer (BLCA) is the ninth most common malignancy worldwide and the fourth most common cancer in men. Copper levels are significantly altered in patients with thyroid, breast, lung, cervical, ovarian, pancreatic, oral, gastric, bladder, and prostate cancers. Outcomes can be predicted by constructing signatures using lncRNA-related genes associated with outcomes.

Methods

We identified lncRNAs related to outcomes, those differentially expressed in bladder cancer, and cuproptosis-related lncRNAs from TCGA. We identified the intersection to obtain 12 genes and established a prognostic risk signature consisting of eight genes using LASSO-penalized multivariate Cox analysis. We constructed a training set, performed survival analysis on the high-and low-risk groups, and performed validation in the test and full sets. There existed a substantial contrast in the likelihood of survival among the cohorts of high and low risk. An in-depth analysis of the gene mutations associated with tumors was conducted to evaluate the risk of developing cancer. We also performed gene analysis on neoadjuvant chemotherapy. We conducted experimental validation on the key gene UBE2Q1-AS1 in our prognostic signature.

Results

The risk signature we constructed shows significant differences between the high-risk group and the low-risk group. Univariate survival analysis of the eight genes in our signature showed that each gene distinguished between high- and low-risk groups. Sub-group analysis revealed that our risk score differed significantly in tumor stage, age, and gender. The analysis results of the tumor mutation burden (TMB) showed a significant difference in the TMB between the low- and high-risk groups, which had a direct impact on the outcomes. These findings highlight the importance of TMB as a potential prognostic marker in cancer detection and prevention. We analyzed the immune microenvironment and found significant differences in immune function, validation responses, immunotherapy-related positive markers, and critical steps in the tumor immunity cycle between the high- and low-risk groups. We found that the effect of anti-CTLA4 and PD-1 was higher in the high-risk group than in the low-risk group.Gene analysis of neoadjuvant chemotherapy revealed that the treatment effect in the high-risk group was better than in the low-risk group. The key gene UBE2Q1-AS1 in our prognostic signature can significantly influence the cell viability, migration, and proliferation of cancer cells.

Discussion

We established a signature consisting of eight genes constructed from cuproptosis-related lncRNAs that have potential clinical applications for outcomes prediction, diagnosis, and treatment.

Long non-coding RNAs modulate tumor microenvironment to promote metastasis: novel avenue for therapeutic intervention

Cancer is a devastating disease and the primary cause of morbidity and mortality worldwide, with cancer metastasis responsible for 90% of cancer-related deaths. Cancer metastasis is a multistep process characterized by spreading of cancer cells from the primary tumor and acquiring molecular and phenotypic changes that enable them to expand and colonize in distant organs. Despite recent advancements, the underlying molecular mechanism(s) of cancer metastasis is limited and requires further exploration. In addition to genetic alterations, epigenetic changes have been demonstrated to play an important role in the development of cancer metastasis. Long non-coding RNAs (lncRNAs) are considered one of the most critical epigenetic regulators. By regulating signaling pathways and acting as decoys, guides, and scaffolds, they modulate key molecules in every step of cancer metastasis such as dissemination of carcinoma cells, intravascular transit, and metastatic colonization. Gaining a good knowledge of the detailed molecular basis underlying lncRNAs regulating cancer metastasis may provide previously unknown therapeutic and diagnostic lncRNAs for patients with metastatic disease. In this review, we concentrate on the molecular mechanisms underlying lncRNAs in the regulation of cancer metastasis, the cross-talk with metabolic reprogramming, modulating cancer cell anoikis resistance, influencing metastatic microenvironment, and the interaction with pre-metastatic niche formation. In addition, we also discuss the clinical utility and therapeutic potential of lncRNAs for cancer treatment. Finally, we also represent areas for future research in this rapidly developing field.

LncRNA PCAT6 promotes proliferation, migration, invasion, and epithelial-mesenchymal transition of lung adenocarcinoma cell by targeting miR-545-3p

BACKGROUND

Lung cancer is a high incidence cancer on a worldwide basis and has become a major public health problem. Lung adenocarcinoma (LUAD) makes up approximately half of all lung cancers and is a threat to human health. Long non-coding RNAs (lncRNAs) is an important regulator of the development and progression of lung adenocarcinoma. In this manuscript we examined the role and potential mechanism of lncRNA PCAT6 in the development of LUAD.

METHODS AND RESULTS

Differences in lncRNA PCAT6 levels between LUAD samples and normal samples were first explored in the GEPIA database. We found that lncRNA PCAT6 expression was elevated, which was also validated in lung adenocarcinoma tissues and cell lines. Using western blotting, CCK-8, EdU, wound healing and transwell assays, we found that knockdown of lncRNA PCAT6 inhibited EMT, proliferation, migration, and invasion of LUAD cells. We noted a predicted a binding site for lncRNA PCAT6 and miR-545-3p through conducting bioinformatic analyses, and their binding was subsequently verified by a dual-luciferase reporter assay. Rescue experiments confirmed that miR-545-3p inhibitor partially abolished the inhibition function of lncRNA PCAT6 knockdown on LUAD cells. In addition, we predicted the downstream target genes of miR-545-3p and verified them by RT-qPCR. We found that EGFR was reduced in the silence of lncRNA PCAT6 and upregulated after miR-545-3p inhibition.

CONCLUSION

This study demonstrates that lncRNA PCAT6 promotes a more aggressive LUAD phenotype by sponging miR-545-3p. This finding may provide new ideas for the treatment of lung cancer.

Long non-coding RNAs in bone metastasis: progresses and perspectives as potential diagnostic and prognostic biomarkers

In a precision medicine perspective, among the biomarkers potentially useful for early diagnosis of cancers, as well as to define their prognosis and eventually to identify novel and more effective therapeutic targets, there are the long non-coding RNAs (lncRNAs). The term lncRNA identifies a class of non-coding RNA molecules involved in the regulation of gene expression that intervene at the transcriptional, post-transcriptional, and epigenetic level. Metastasis is a natural evolution of some malignant tumours, frequently encountered in patients with advanced cancers. Onset and development of metastasis represents a detrimental event that worsen the patient's prognosis by profoundly influencing the quality of life and is responsible for the ominous progression of the disease. Due to the peculiar environment and the biomechanical properties, bone is a preferential site for the secondary growth of breast, prostate and lung cancers. Unfortunately, only palliative and pain therapies are currently available for patients with bone metastases, while no effective and definitive treatments are available. The understanding of pathophysiological basis of bone metastasis formation and progression, as well as the improvement in the clinical management of the patient, are central but challenging topics in basic research and clinical practice. The identification of new molecular species that may have a role as early hallmarks of the metastatic process could open the door to the definition of new, and more effective, therapeutic and diagnostic approaches. Non-coding RNAs species and, particularly, lncRNAs are promising compounds in this setting, and their study may bring to the identification of relevant processes. In this review, we highlight the role of lncRNAs as emerging molecules in mediating the formation and development of bone metastases, as possible biomarkers for cancer diagnosis and prognosis, and as therapeutic targets to counteract cancer spread.

The expression of long non-coding RNA LINC01389, LINC00365, RP11-138J23.1, and RP11-354K4.2 in gastric cancer and their impacts on EMT

BACKGROUND

Epithelial cancers acquire the epithelial to mesenchymal transition (EMT), which leads tumor cells to invade and metastasize to adjacent and distant tissues. The mechanisms involved in EMT phenotype are controlled by numerous markers as well as signalling pathways. Recently, long non-coding RNAs (lncRNAs) were introduced that play the regulatory role in EMT via crosstalk with EMT-related transcription factors and signalling pathways. The present study aimed to investigate the expression of four lncRNAs in human GC and elucidate their probable role in EMT procedure and the pathogenesis of gastric cancer (GC).

METHODS

The expression profile of lncRNAs (LINC01389, LINC00365, RP11-138J23.1, and RP11-354K4.2) and mRNAs (TWIST1, MMP13, MAML1, CD44s, and SALL4) between eighty-three GC and adjacent non-cancerous tissues were assessed by quantitative real-time PCR.

RESULTS

The significant downregulation of LINC00365 (66.3%) and RP11-354K4.2 (62.7%) were observed in GC samples; while the upregulation of LINC01389, RP11-138J23.1, TWIST1, MMP13, MAML1, CD44s, and SALL4 were found in 67.5%, 45.8%, 56.6%, 44.6%, 59%, 55.4%, and 62.7% tumors samples at the mRNA level, respectively. Dysregulation of these lncRNAs and EMT-related markers was significantly related to each other in a variety of clinicopathological features of patients (P < 0.05), indicating positive correlations between LINC01389, LINC00365, RP11-138J23.1, and RP11-354K4.2 with EMT status in GC.

CONCLUSION

These EMT-regulating lncRNAs may play a key role in transforming gastric epithelial to mesenchymal phenotype and can be novel therapeutic targets for GC. Our results highlight the importance of discovering new lncRNAs involved in gastric carcinogenesis. Detailed molecular mechanisms of these noncoding-coding markers in GC are urgently required.

Circulating Long Non-Coding RNAs Could Be the Potential Prognostic Biomarker for Liquid Biopsy for the Clinical Management of Oral Squamous Cell Carcinoma

Long non-coding RNA (lncRNA) have little or no coding potential. These transcripts are longer than 200 nucleotides. Since lncRNAs are master regulators of almost all biological processes, recent evidence proves that aberrantly expressed lncRNAs are pathogenic for oral squamous cell carcinoma (OSCC) and other diseases. LncRNAs influence chromatin modifications, transcriptional modifications, post-transcriptional modifications, genomic imprinting, cell proliferation, invasion, metastasis, and apoptosis. Consequently, they have an impact on the disease transformation, progression, and morbidity in OSCC. Therefore, circulating lncRNAs could be the potential cancer biomarker for the better clinical management (diagnosis, prognosis, and monitoring) of OSCC to provide advanced treatment strategies and clinical decisions. In this review, we report and discuss the recent understandings and perceptions of dysregulated lncRNAs with a focus on their clinical significance in OSCC-disease monitoring and treatment. Evidence clearly indicates that a specific lncRNA expression signature could act as an indicator for the early prediction of diagnosis and prognosis for the initiation, progression, recurrence, metastasis and other clinical prognostic-factors (overall survival, disease-free survival, etc.) in OSCC. The present review demonstrates the current knowledge that all potential lncRNA expression signatures are molecular biomarkers for the early prediction of prognosis in OSCC. Finally, the review provides information about the clinical significance, challenges and limitations of the clinical usage of circulating lncRNAs in a liquid biopsy method in early, pre-symptomatic, sub-clinical, accurate OSCC prognostication. More studies on lncRNA are required to unveil the biology of the inherent mechanisms involved in the process of the development of differential prognostic outcomes in OSCC.

[Shenbai Jiedu Fang inhibits AOM/DSS-induced colorectal adenoma formation and carcinogenesis in mice via miRNA-22-mediated regulation of the PTEN/PI3K/AKT signaling pathway]

OBJECTIVE

To observe the inhibitory effect of Shenbai Jiedu Fang (SBJDF, a compound recipe of traditional Chinese herbal drugs) on chemically induced carcinogenesis of colorectal adenoma in mice and explore the role of PTEN/PI3K/AKT signaling pathway in mediating this effect.

METHODS

Four-week-old male C57BL/6 mice were randomly divided into control group (n=10), AOM/DSS model group (n=20), low-dose (14 g/kg) SBJDF group (n=10) and high-dose (42 g/kg) SBJDF group (n= 10). In the latter 3 groups, the mice were treated with azoxymethane (AOM) and dextran sodium sulphate (DSS) to induce carcinogenesis of colorectal adenoma. In the two SBJDF treatment groups, SBJDF was administered daily by gavage during the modeling. The survival rate, body weight, general condition of the mice, and intestinal adenoma formation and carcinogenesis were observed. The expressions of proteins associated with the PTEN/PI3K/AKT signaling pathway in the intestinal tissue were detected using immunohistochemistry.

RESULTS

Compared with those in the model group, the mice treated with SBJDF, especially at the high dose, showed a significantly lower incidence of intestinal carcinogenesis and had fewer intestinal tumors with smaller tumor volume. Pathological examination showed the occurrence of adenocarcinoma in the model group, while only low-grade and high-grade neoplasia were found in low-dose SBJDF group; the mice treated with high-dose SBJDF showed mainly normal mucosal tissues in the intestines with only a few lesions of low-grade neoplasia of adenoma. Compared with those in the control group, the mice in the model group had significantly elevated plasma miRNA-222 level (P < 0.05), which was obviously lowered in the two SBJDF groups (P < 0.01). The results of immunohistochemistry revealed that compared with the model group, the two SBJDF groups, especially the high-dose group, had significantly up-regulated expressions of PTEN, P-PTEN and GSK-3β and down-regulated expressions of p-GSK-3 β, PI3K, AKT, P-AKT, β-catenin, c-myc, cyclinD1 and survivin in the intestinal tissues.

CONCLUSION

SBJDF can significantly inhibit colorectal adenoma formation and carcino-genesis in mice possibly through regulating miRNA-222 and affecting PTEN/PI3K/AKT signaling pathway.

FAM201A Promotes Cervical Cancer Progression and Metastasis through miR-1271-5p/Flotillin-1 Axis Targeting-Induced Wnt/β-Catenin Pathway

This study investigated the role of the family with sequence similarity 201-member A (FAM201A), as previously reported oncogenic, in cervical cancer (CC). FAM201A expression in CC was analyzed through bioinformatics analyses, and its distribution in CC tissues/cells was determined by in situ hybridization. CC cells were transfected/cotransfected with FAM201A/flotillin-1 (FLOT1) overexpression plasmids and miR-1271-5p mimics, followed by functional analysis on viability, migration and invasion. Pearson's correlation tests were performed to analyze the correlation between FAM201A and miR-1271-5p in CC tissues. The targeting relationship between miR-1271-5p and FLOT1 was confirmed by dual-luciferase reporter assay. The expressions of FAM201A, miR-1271-5p, FLOT1, matrix metalloproteinases (MMP)-9, MMP-2, E-cadherin, N-cadherin, and the Wnt/β-catenin pathway-related molecules (Wnt1, β-catenin and p-β-catenin) in CC cells or tissues were assessed by quantitative reverse transcription polymerase chain reaction (qRT-PCR) and/or western blot. The results showed that FAM201A was abundantly expressed and miR-1271-5p expression was downregulated in CC. FAM201A was enriched in CC cell cytoplasm and negatively correlated with miR-1271-5p in CC tissues. FAM201A overexpression enhanced the cell viability, migration, invasion, and tumorigenesis of CC in vivo and increased FLOT1 expression. These trends were all reversed by upregulating miR-1271-5p, which induced opposite effects to FAM201A overexpression. MiR-1271-5p upregulation depleted the levels of MMP-9, MMP-2, N-cadherin, and the Wnt/β-catenin pathway-related molecules and upregulated E-cadherin expression. FLOT1 was a direct target of miR-1271-5p. FLOT1 overexpression induced effects contrary to the upregulation of miR-1271-5p and abolished miR-1271-5p upregulation-induced effects in CC cells. Overall, this study showed that FAM201A promoted cervical cancer progression and metastasis by targeting the miR-1271-5p/FLOT1 axis-induced Wnt/β-catenin pathway.

Development and validation of a novel cellular senescence-related prognostic signature for predicting the survival and immune landscape in hepatocellular carcinoma

Background: Cellular senescence is a typical irreversible form of life stagnation, and recent studies have suggested that long non-coding ribonucleic acids (lncRNA) regulate the occurrence and development of various tumors. In the present study, we attempted to construct a novel signature for predicting the survival of patients with hepatocellular carcinoma (HCC) and the associated immune landscape based on senescence-related (sr) lncRNAs.

Method: Expression profiles of srlncRNAs in 424 patients with HCC were retrieved from The Cancer Genome Atlas database. Lasso and Cox regression analyses were performed to identify differentially expressed lncRNAs related to senescence. The prediction efficiency of the signature was checked using a receiver operating characteristic (ROC) curve, Kaplan–Meier analysis, Cox regression analyses, nomogram, and calibration. The risk groups of the gene set enrichment analysis, immune analysis, and prediction of the half-maximal inhibitory concentration (IC50) were also analyzed. Quantitative real-time polymerase chain reaction (qPCR) was used to confirm the levels of AC026412.3, AL451069.3, and AL031985.3 in normal hepatic and HCC cell lines.

Results: We identified 3 srlncRNAs (AC026412.3, AL451069.3, and AL031985.3) and constructed a new risk model. The results of the ROC curve and Kaplan–Meier analysis suggested that it was concordant with the prediction. Furthermore, a nomogram model was constructed to accurately predict patient prognosis. The risk score also correlated with immune cell infiltration status, immune checkpoint expression, and chemosensitivity. The results of qPCR revealed that AC026412.3 and AL451069.3 were significantly upregulated in hepatoma cell lines.

Conclusion: The novel srlncRNA (AC026412.3, AL451069.3, and AL031985.3) signatures may provide insights into new therapies and prognosis predictions for patients with HCC.

Molecular Landscape of LncRNAs in Prostate Cancer: A focus on pathways and therapeutic targets for intervention

Background

One of the most malignant tumors in men is prostate cancer that is still incurable due to its heterogenous and progressive natures. Genetic and epigenetic changes play significant roles in its development. The RNA molecules with more than 200 nucleotides in length are known as lncRNAs and these epigenetic factors do not encode protein. They regulate gene expression at transcriptional, post-transcriptional and epigenetic levels. LncRNAs play vital biological functions in cells and in pathological events, hence their expression undergoes dysregulation.

Aim of review

The role of epigenetic alterations in prostate cancer development are emphasized here. Therefore, lncRNAs were chosen for this purpose and their expression level and interaction with other signaling networks in prostate cancer progression were examined.

Key scientific concepts of review

The aberrant expression of lncRNAs in prostate cancer has been well-documented and progression rate of tumor cells are regulated via affecting STAT3, NF-κB, Wnt, PI3K/Akt and PTEN, among other molecular pathways. Furthermore, lncRNAs regulate radio-resistance and chemo-resistance features of prostate tumor cells. Overexpression of tumor-promoting lncRNAs such as HOXD-AS1 and CCAT1 can result in drug resistance. Besides, lncRNAs can induce immune evasion of prostate cancer via upregulating PD-1. Pharmacological compounds such as quercetin and curcumin have been applied for targeting lncRNAs. Furthermore, siRNA tool can reduce expression of lncRNAs thereby suppressing prostate cancer progression. Prognosis and diagnosis of prostate tumor at clinical course can be evaluated by lncRNAs. The expression level of exosomal lncRNAs such as lncRNA-p21 can be investigated in serum of prostate cancer patients as a reliable biomarker.

LncRNA DLEU2 silencing impedes the migration, invasion and EMT in gastric cancer cell by suppressing PI3K/AKT signaling pathway

Context: The high expression of long non-coding RNA deleted in lymphocytic leukaemia 2 (lncRNA DLEU2) has been confirmed in gastric cancer (GC).Objective: However, the detailed mechanism concerning its involvement in GC remained unclear, which we aimed to explore in this study.Materials and methods: LncRNA DLEU2 expression in GC was estimated by bioinformatic analysis, and the relationship between the expression of DLEU2 and the clinicopathological characteristics of patients with GC was performed. qRT-PCR was employed to detect the expression of lncRNA DLEU2 and confirm the transfection efficiency following the knockdown or overexpression of DLEU2. Functional assays, including CCK-8, flow cytometry, scratching test and Transwell assays, were used to determine the role of DLEU2 in tumor phenotypes. The effects of DLEU2 on the PI3K/Akt pathway were detected by western blot. For elucidating the functions of DLEU2/PI3K/Akt axis in GC, we inhibited the PI3K/Akt pathway in rescue experiments, and evaluated the expression levels of epithelial-mesenchymal transition (EMT)-related proteins by western blot.Results: The expression of DLEU2 was aberrantly up-regulated in GC tissues and cells, which was correlated with the degree of tumor differentiation, cancer antigen 19-9 (CA19-9) and Lauren histologic classification of patients with GC. Silencing of DLEU2 induced apoptosis, attenuated viability, migration and invasion as well as inhibited the PI3K/Akt signaling pathway in GC cells. Mechanistically, the DLEU2/PI3K/Akt axis promoted the progression of GC and the EMT by down-regulating the expression of E-Cadherin and up-regulating those of N-Cadherin and Vimentin.Discussion and conclusions: LncRNA DLEU2 promoted the migration, invasion and EMT in GC by activating the PI3K/Akt pathway.

Long Non-Coding RNA MIR31HG Promotes the Transforming Growth Factor β-Induced Epithelial-Mesenchymal Transition in Pancreatic Ductal Adenocarcinoma Cells

The epithelial-to-mesenchymal transition (EMT) describes a biological process in which polarized epithelial cells are converted into highly motile mesenchymal cells. It promotes cancer cell dissemination, allowing them to form distal metastases, and also involves drug resistance in metastatic cancers. Transforming growth factor β (TGFβ) is a multifunctional cytokine that plays essential roles in development and carcinogenesis. It is a major inducer of the EMT. The MIR31 host gene (MIR31HG) is a newly identified long non-coding (lnc)RNA that exhibits ambiguous roles in cancer. In this study, a cancer genomics analysis predicted that MIR31HG overexpression was positively correlated with poorer disease-free survival of pancreatic ductal adenocarcinoma (PDAC) patients, which was associated with upregulation of genes related to TGFβ signaling and the EMT. In vitro evidence demonstrated that TGFβ induced MIR31HG expression in PDAC cells, and knockdown of MIR31HG expression reversed TGFβ-induced EMT phenotypes and cancer cell migration. Therefore, MIR31HG has an oncogenic role in PDAC by promoting the EMT.

The Emerging role of EMT-related lncRNAs in therapy resistance and their application as biomarkers

Cancer is the world's second largest cause of death. The most common cancer treatments are surgery, radiation therapy, and chemotherapy. Drug resistance, epithelial-to-mesenchymal transition (EMT), and metastasis are all pressing issues in cancer therapy today. Increasing evidence showed that drug-resistant and EMT are co-related with each other. Indeed, drug-resistant cancer cells possess enhanced EMT and invasive ability. Recent researches have demonstrated lncRNAs (long noncoding RNAs) are noncoding transcripts, which play an important role in the regulation of EMT, metastasis, and drug resistance in different cancers. However, the relationships among lncRNAs, EMT, and drug resistance are still unclear. These effects could be exerted via several signaling pathways such as TGF-β, PI3K-AKT, and Wnt/β-catenin. Identifying the crucial regulatory roles of lncRNAs in these pathways and processes leads to the development of novel targeted therapies. We review the key aspects of lncRNAs associated with EMT and therapy resistance. We focus on the crosstalk between lncRNAs and molecular signaling pathways affecting EMT and drug resistance. Moreover, each of the mentioned lncRNAs could be used as a potential diagnostic, prognostic, and therapeutic biomarker for cancer. Although, there are still many challenges to investigate lncRNAs for clinical applications.

The Epithelial-Mesenchymal Transition at the Crossroads between Metabolism and Tumor Progression

The transition between epithelial and mesenchymal phenotype is emerging as a key determinant of tumor cell invasion and metastasis. It is a plastic process in which epithelial cells first acquire the ability to invade the extracellular matrix and migrate into the bloodstream via transdifferentiation into mesenchymal cells, a phenomenon known as epithelial–mesenchymal transition (EMT), and then reacquire the epithelial phenotype, the reverse process called mesenchymal–epithelial transition (MET), to colonize a new organ. During all metastatic stages, metabolic changes, which give cancer cells the ability to adapt to increased energy demand and to withstand a hostile new environment, are also important determinants of successful cancer progression. In this review, we describe the complex interaction between EMT and metabolism during tumor progression. First, we outline the main connections between the two processes, with particular emphasis on the role of cancer stem cells and LncRNAs. Then, we focus on some specific cancers, such as breast, lung, and thyroid cancer.

A new insight into sex-specific non-coding RNAs and networks in response to SARS-CoV-2

SARS-CoV-2 is the RNA virus responsible for COVID-19, the prognosis of which has been found to be slightly worse in men. The present study aimed to analyze the expression of different mRNAs and their regulatory molecules (miRNAs and lncRNAs) to consider the potential existence of sex-specific expression patterns and COVID-19 susceptibility using bioinformatics analysis. The binding sites of all human mature miRNA sequences on the SARS-CoV-2 genome nucleotide sequence were predicted by the miRanda tool. Sequencing data was excavated using the Galaxy web server from GSE157103, and the output of feature counts was analyzed using DEseq2 packages to obtain differentially expressed genes (DEGs). Gene set enrichment analysis (GSEA) and DEG annotation analyses were performed using the ToppGene and Metascape tools. Using the RNA Interactome Database, we predicted interactions between differentially expressed lncRNAs and differentially expressed mRNAs. Finally, their networks were constructed with top miRNAs. We identified 11 miRNAs with three to five binding sites on the SARS-COVID-2 genome reference. MiR-29c-3p, miR-21-3p, and miR-6838-5p occupied four binding sites, and miR-29a-3p had five binding sites on the SARS-CoV-2 genome. Moreover, miR-29a-3p, and miR-29c-3p were the top miRNAs targeting DEGs. The expression levels of miRNAs (125, 181b, 130a, 29a, b, c, 212, 181a, 133a) changed in males with COVID-19, in whom they regulated ACE2 expression and affected the immune response by affecting phagosomes, complement activation, and cell-matrix adhesion. Our results indicated that XIST lncRNA was up-regulated, and TTTY14, TTTY10, and ZFY-AS1 lncRN as were down-regulated in both ICU and non-ICU men with COVID-19. Dysregulation of noncoding-RNAs has critical effects on the pathophysiology of men with COVID-19, which is why they may be used as biomarkers and therapeutic agents. Overall, our results indicated that the miR-29 family target regulation patterns and might become promising biomarkers for severity and survival outcome in men with COVID-19.

Berberine Suppresses EMT in Liver and Gastric Carcinoma Cells through Combination with TGFβR Regulating TGF-β/Smad Pathway

Berberine (BBR), a natural alkaloid derived from Coptis, has anticancer activity. Some researchers have found that it could restrain epithelial-mesenchymal transition (EMT) of melanoma, neuroblastoma, and other tumor cells. However, it is unclear whether BBR can reverse EMT in hepatocellular carcinoma (HCC) and gastric carcinoma (GC). In our study, BBR inhibited the migration and invasion of HepG2, MGC803, and SGC7901 cells in a dose-dependent manner. Transcription sequencing assays showed that Vimentin, MMP, and Smad3 were downregulated, but Smad2, Smad6, TAB2, ZO-1, and claudin 7 were upregulated when treated with BBR. GO Enrichment analysis of KEGG pathway showed that BBR significantly inhibited TGF-β/Smad at 12 h, then, PI3K/Akt and Wnt/β-catenin signaling pathways at 24 h, which were closely related to the proliferation, migration, and EMT. The results of the transcriptome sequencing analysis were verified by Western Blot. It showed that the expression of epithelial marker E-cadherin and ZO-1 remarkably augmented with BBR treatment, as well as declined mesenchymal markers, including N-cadherin and Vimentin, decreased transcription factor Snail and Slug. The effects of BBR were similar to those of the PI3K inhibitor LY294002 and TGF-β receptor inhibitor SB431542. Furthermore, β-catenin and phosphorylation of AKT, Smad2, and Smad3 were changed dose-dependently by BBR treatment, which upregulated p-Smad2 and downregulated the others. Combined with LY or SB, respectively, BBR could enhance the effects of the two inhibitors. Simultaneously, IGF-1 and TGF-β, which is the activator of PI3K/AKT and TGF-β/Smad, respectively, could reverse the anti-EMT effect of BBR. The Molecular Docking results showed BBR had a high affinity with the TGF-β receptor I (TGFβR1), and the binding energy was -7.5 kcal/mol, which is better than the original ligand of TGFβR1. Although the affinity of BBR with TGF-β receptor II (TGFβR2) was lower than the original ligand of TGFβR2, the more considerable negative binding energy (-8.54 kcal/mol) was obtained. BBR upregulated p-Smad2, which was different from other reports, indicating that the function of Smad2 was relatively complex. Combination BBR with SB could enhance the effect of the inhibitor on EMT, and the results indicated that BBR binding to TGFβR was not competitive with SB to TGFβR since different binding amino acid sites. Our experiments demonstrated BBR increased p-Smad2 and decreased p-Smad3 by binding to TGFβR1 and TGβFR2 inhibiting TGF-β/Smad, then, PI3K/AKT and other signaling pathways to restrain EMT, metastasis, and invasion in tumor cells. The effect of BBR was similar on the three tumor cells.

LncRNAs in tumor microenvironment: The potential target for cancer treatment with natural compounds and chemical drugs

It was thought that originally long non-coding RNAs (lncRNAs) were a kind of RNAs without any encoding function. Recently, a variety of studies have shown that lncRNAs play important roles in many life activities. The abnormal expression of lncRNAs in tumor microenvironment (TME) usually promotes the proliferation, migration, and drug resistance of tumor cells through direct or indirect effects, which also usually predicts the poor prognosis. The regulation of lncRNAs expression in TME could significantly inhibit tumor progress. However, the interaction between lncRNAs and TME has not been fully defined at present. Therefore, this paper provided the systemic summary of their interaction and natural products and chemicals targeting lncRNAs in cancer treatment. Currently, the strategies of cancer treatment still have their limits. Understanding the relationship between TME and lncRNAs can help us to realize breakthrough strategy for tumor treatment.

The nomogram based on the 6-lncRNA model can promote the prognosis prediction of patients with breast invasive carcinoma

Long non-coding RNA (lncRNA) is a prognostic biomarker for many types of cancer. Here, we aimed to study the prognostic value of lncRNA in Breast Invasive Carcinoma (BRCA). We downloaded expression profiles from The Cancer Genome Atlas (TCGA) datasets. Subsequently, we screened the differentially expressed genes between normal tissues and tumor tissues. Univariate Cox, LASSO regression, and multivariate Cox regression analysis were used to construct a lncRNA prognostic model. Finally, a nomogram based on the lncRNAs model was developed, and weighted gene co-expression network analysis (WGCNA) was used to predict mRNAs related to the model, and to perform function and pathway enrichment. We constructed a 6-lncRNA prognostic model. Univariate and multivariate Cox regression analysis showed that the 6-lncRNA model could be used as an independent prognostic factor for BRCA patients. We developed a nomogram based on the lncRNAs model and age, and showed good performance in predicting the survival rates of BRCA patients. Also, functional pathway enrichment analysis showed that genes related to the model were enriched in cell cycle-related pathways. Tumor immune infiltration analysis showed that the types of immune cells and their expression levels in the high-risk group were significantly different from those in the low-risk group. In general, the 6-lncRNA prognostic model and nomogram could be used as a practical and reliable prognostic tool for invasive breast cancer.

The long non-coding RNA HOTAIRM1 promotes tumor aggressiveness and radiotherapy resistance in glioblastoma

Glioblastoma is the most common malignant primary brain tumor. To date, clinically relevant biomarkers are restricted to isocitrate dehydrogenase (IDH) gene 1 or 2 mutations and O6-methylguanine DNA methyltransferase (MGMT) promoter methylation. Long non-coding RNAs (lncRNAs) have been shown to contribute to glioblastoma pathogenesis and could potentially serve as novel biomarkers. The clinical significance of HOXA Transcript Antisense RNA, Myeloid-Specific 1 (HOTAIRM1) was determined by analyzing HOTAIRM1 in multiple glioblastoma gene expression data sets for associations with prognosis, as well as, IDH mutation and MGMT promoter methylation status. Finally, the role of HOTAIRM1 in glioblastoma biology and radiotherapy resistance was characterized in vitro and in vivo. We identified HOTAIRM1 as a candidate lncRNA whose up-regulation is significantly associated with shorter survival of glioblastoma patients, independent from IDH mutation and MGMT promoter methylation. Glioblastoma cell line models uniformly showed reduced cell viability, decreased invasive growth and diminished colony formation capacity upon HOTAIRM1 down-regulation. Integrated proteogenomic analyses revealed impaired mitochondrial function and determination of reactive oxygen species (ROS) levels confirmed increased ROS levels upon HOTAIRM1 knock-down. HOTAIRM1 knock-down decreased expression of transglutaminase 2 (TGM2), a candidate protein implicated in mitochondrial function, and knock-down of TGM2 mimicked the phenotype of HOTAIRM1 down-regulation in glioblastoma cells. Moreover, HOTAIRM1 modulates radiosensitivity of glioblastoma cells both in vitro and in vivo. Our data support a role for HOTAIRM1 as a driver of biological aggressiveness, radioresistance and poor outcome in glioblastoma. Targeting HOTAIRM1 may be a promising new therapeutic approach.

Identification of Hub Gene TIMP1 and Relative ceRNAs Regulatory Network in Colorectal Cancer

Objective

This study aimed to discover the ceRNAs network in the pathophysiological development of human colorectal cancer (CRC) and to screen biomarkers for target therapy and prognosis by using integrated bioinformatics analysis.

Methods

Data on gene expressions of mRNAs, miRNAs, and circRNAs and clinical information were downloaded from The Cancer Genome Atlas and Gene Expression Omnibus databases, respectively. Differentially expressed mRNAs (DEmRNAs) were identified by using the DESeq2 package of R software. Functional enrichment analysis was conducted using the ClusterProfiler package of R software. The protein–protein interaction (PPI) network was shown by the STRING website. Survival analysis of hub genes was performed using the survival package in R software. Interactions among hub genes, differentially expressed miRNAs (DEmiRNAs), and differentially expressed circRNAs (DEcircRNAs) were used to construct the ceRNAs network.

Results

A total of 412 DEmRNAs including 82 upregulated and 330 downregulated genes were screened out between 473 CRC and 41 normal samples. Two hundred and sixty DEcircRNAs including 253 upregulated and 7 downregulated genes were altered between 23 CRC and 23 normal samples. One hundred and ninety DEmiRNAs including 82 upregulated and 108 downregulated genes were obtained between 450 CRC and 8 normal samples. A ceRNAs and PPI network were successfully constructed, and TIMP1 associated with prognosis was employed.

Conclusion

The present study identified a novel circRNAs-miRNAs-mRNA ceRNAs network, which implied that TIMP1 and related miRNAs, circRNAs were potential biomarkers underlying the development of CRC, providing new insights for survival predictions and therapeutic targets.

LncRNA-HEIH is a Novel Diagnostic and Predictive Biomarker in Gastric Cancer

Background: Gastric cancer (GC) is associated with a high mortality rate. Long noncoding RNA (lncRNA)-high expressed in hepatocellular carcinoma (HEIH) has recently gained interest as a marker for the detection of several cancer types. This study was designed to uncover the function of lncRNA-HEIH in GC. Materials and Methods: Oncomine was used to analyze HEIH expression in cancerous and paired noncancerous tissues of GC patients. Subsequently, the expression levels of HEIH in GC cells was determined by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). In addition, the effects of HEIH expression level on clinicopathological parameters and prognosis were further studied by statistical analysis and Kaplan-Meier survival curves. GC cell proliferation and the influence of HEIH on the sensitivity of cells to oxaliplatin following HEIH knockdown were assessed using sulforhodamine blue (SRB) assays in the MKN45 and AGS cell lines. In addition, the expression levels of p53 were detected by RT-qPCR following knockdown of HEIH. Results: The lncRNA-HEIH was highly expressed in both GC tissues and GC cell lines. Patients with high HEIH expression were associated with medium-high differentiation (p = 0.0058), distant metastasis (M, p = 0.0378), lymph node metastasis (N, p = 0.0083), and a deeper tumor invasion (T, p = 0.0204). The elevated expression levels of HEIH in GC patients were associated with a worse prognosis compared to GC patients with low HEIH expression. This finding was supported by the parameters overall survival (p = 3.3e-06), first progression (p = 0.00028), and postprogression (p = 1.5e-08). Downregulation of HEIH expression inhibited cell proliferation, enhanced oxaliplatin sensitivity, and induced the expression of p53 in MKN45 and AGC cells. Conclusion: These findings provide evidence that HEIH may be useful as a prognostic biomarker in GC. This lncRNA may also serve as a potential therapeutic target in GC patients.

Keep your eyes peeled for long noncoding RNAs: Explaining their boundless role in cancer metastasis, drug resistance, and clinical application

Cancer metastasis and drug resistance are two major obstacles in the treatment of cancer and therefore, the leading cause of cancer-associated mortalities worldwide. Hence, an in-depth understanding of these processes and identification of the underlying key players could help design a better therapeutic regimen to treat cancer. Earlier thought to be merely transcriptional junk and having passive or secondary function, recent advances in the genomic research have unravelled that long noncoding RNAs (lncRNAs) play pivotal roles in diverse physiological as well as pathological processes including cancer metastasis and drug resistance. LncRNAs can regulate various steps of the complex metastatic cascade such as epithelial-mesenchymal transition (EMT), invasion, migration and metastatic colonization, and also affect the sensitivity of cancer cells to various chemotherapeutic drugs. A substantial body of literature for more than a decade of research evince that lncRNAs can regulate gene expression at different levels such as epigenetic, transcriptional, posttranscriptional, translational and posttranslational levels, depending on their subcellular localization and through their ability to interact with DNA, RNA and proteins. In this review, we mainly focus on how lncRNAs affect cancer metastasis by modulating expression of key metastasis-associated genes at various levels of gene regulation. We also discuss how lncRNAs confer cancer cells either sensitivity or resistance to various chemo-therapeutic drugs via different mechanisms. Finally, we highlight the immense potential of lncRNAs as prognostic and diagnostic biomarkers as well as therapeutic targets in cancer.

Long Non-Coding RNA LINC00152 Regulates Self-Renewal of Leukemia Stem Cells and Induces Chemo-Resistance in Acute Myeloid Leukemia

Relapse of acute myeloid leukemia (AML) has a very poor prognosis and remains a common cause of treatment failure in patients with this disease. AML relapse is partially driven by the chemoresistant nature of leukemia stem cells (LSCs), which remains poorly understood, and our study aimed at elucidating the underlying mechanism. Accumulating evidences show that long noncoding RNAs (lncRNAs) play a crucial role in AML development. Herein, the lncRNA, LINC00152, was identified to be highly expressed in CD34+ LSCs and found to regulate the self-renewal of LSCs derived from AML patients. Importantly, LINC00152 upregulation was correlated with the expression of 16 genes within a 17-gene LSC biomarker panel, which contributed to the accurate prediction of initial therapy resistance in AML. Knockdown of LINC00152 markedly increased the drug sensitivity of leukemia cells. Furthermore, LINC00152 expression was found to be correlated with poly (ADP-ribose) polymerase 1 (PARP1) expression in AML, whereas LINC00152 knockdown significantly decreased the expression of PARP1. Upregulation of LINC00152 or PARP1 was associated with poor prognosis in AML patients. Collectively, these data highlight the importance and contribution of LINC00152 in the regulation of self-renewal and chemoresistance of LSCs in AML.

Long non-coding RNA PHACTR2-AS1 promotes tongue squamous cell carcinoma metastasis by regulating Snail

Long non-coding RNA is an endogenous non-coding RNA that has currently been proved to be an important player in cancer cell biology. In the present study, we investigated the biological role of PHACTR2-AS1 in tongue squamous cell carcinoma (TSCC). PHACTR2-AS1 was preferentially localized in the cytoplasm, and was notably upregulated in TSCC tissues. High PHACTR2-AS1 was correlated with tumour differentiation, metastatic clinical features, relapse and shortened survival time. Depletion of PHACTR2-AS1 did not affect TSCC cell viability and colony formation ability, whereas substantially inhibited cell migration and invasion in vitro and lung metastasis in vivo. Mechanistically, PHACTR2-AS1 could sponge miR-137 to increase Snail expression, resulting in triggering epithelial-mesenchymal transition process, thereby promoting TSCC cell metastasis. Taken together, our data for the first time elucidate the metastasis-promoting role of PHACTR2-AS1 in TSCC, hinting a new therapeutic target for metastatic TSCC patients.

Role of LncRNAs in the Epithelial-Mesenchymal Transition in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is a type of primary liver cancer with a high incidence and mortality rate. HCC develops insidiously, and most newly diagnosed cases are in the middle and advanced stages. The epithelial-mesenchymal transition (EMT) is a vital mechanism underlying metastasis in patients with advanced HCC. EMT is a multistep and complex procedure. The promotion and inhibition of EMT directly affect the migration and invasion of HCC. LncRNAs are involved in the epigenetic modification of genes, regulation of gene transcription, and posttranslational modification of proteins. LncRNAs also play important roles in regulating EMT progression in HCC and are promising biomarkers and therapeutic targets. This review focused on summarizing the mechanism by which lncRNAs regulate EMT in HCC. In particular, lncRNAs were reported to primarily act as RNA sponges, and the regulation of EMT involves major signaling pathways. Finally, we reviewed the mechanisms by which lncRNAs are involved in drug resistance and discussed the clinical prospects and potential challenges of utilizing lncRNAs to treat HCC.

Long Non-Coding RNA CRYBG3 Promotes Lung Cancer Metastasis via Activating the eEF1A1/MDM2/MTBP Axis

The occurrence of distant tumor metastases is a major barrier in non-small cell lung cancer (NSCLC) therapy, and seriously affects clinical treatment and patient prognosis. Recently, long non-coding RNAs (lncRNAs) have been demonstrated to be crucial regulators of metastasis in lung cancer. The aim of this study was to reveal the underlying mechanisms of a novel lncRNA LNC CRYBG3 in regulating NSCLC metastasis. Experimental results showed that LNC CRYBG3 was upregulated in NSCLC cells compared with normal tissue cells, and its level was involved in these cells' metastatic ability. Exogenously overexpressed LNC CRYBG3 increased the metastatic ability and the protein expression level of the metastasis-associated proteins Snail and Vimentin in low metastatic lung cancer HCC827 cell line. In addition, LNC CRYBG3 contributed to HCC827 cell metastasis in vivo. Mechanistically, LNC CRYBG3 could directly combine with eEF1A1 and promote it to move into the nucleus to enhance the transcription of MDM2. Overexpressed MDM2 combined with MDM2 binding protein (MTBP) to reduce the binding of MTBP with ACTN4 and consequently increased cell migration mediated by ACTN4. In conclusion, the LNC CRYBG3/eEF1A1/MDM2/MTBP axis is a novel signaling pathway regulating tumor metastasis and may be a potential therapeutic target for NSCLC treatment.

Effects of CDKN2B-AS1 on cellular proliferation, invasion and AKT3 expression are attenuated by miR-424-5p in a model of ovarian endometriosis

RESEARCH QUESTION

Endometriosis is a common and complicated gynaecologic disease. Long non-coding RNA CDKN2B-AS1 plays a crucial role in the development and progression of several cancers. Whether CDKN2B-AS1 contributes to endometriosis, however, remains unknown.

DESIGN

Cellular proliferation, invasion and DNA synthesis abilities were assessed by CCK8, transwell and 5-ethynyle-2'-deoxyuridine assays. The expression of epithelial-mesenchymal transition markers and three isoforms of AKT was detected using Western blot. Real-time polymerase chain reaction was used to determine the relative expression levels of CDKN2B-AS1 and candidate miRNAs in ectopic, eutopic endometria and normal endometrial tissues. The relationship between CDKN2B-AS1 and miRNA was determined by luciferase reporter assays.

RESULTS

The relative expression level of CDKN2B-AS1 was up-regulated in eutopic and ectopic endometria. In endometrial stromal cells and Ishikawa cells, CDKN2B-AS1 overexpression promoted cellular proliferation and invasion, and increased the protein expression of vimentin but decreased the expression of E-cadherin. miR-424-5p was confirmed the target of CDKN2B-AS1 through bioinformatics tools and luciferase reporter assays. In addition, the enhanced effect of cellular phenotype of CDKN2B-AS1 overexpression was significantly attenuated by miR-424-5p overexpression. Furthermore, miR-424-5p was able to directly target AKT3 through luciferase reporter assay. Mechanistically, CDKN2B-AS1 acts as a ceRNA by sponging miR-424-5p and targets AKT3.

CONCLUSIONS

The cellular mechanism of CDKN2B-AS1 in endometriosis was confirmed; CDKN2B-AS1 may be a potential target for ovarian endometriosis therapy.

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.

Colon cancer-associated transcript-1 enhances glucose metabolism and colon cancer cell activity in a high-glucose environment in vitro and in vivo

BACKGROUND

Our study aims to investigate the effect of colon cancer-associated transcript-1 (CCAT-1) on colon cancer cells' activity and metabolism under different glucose environments in vitro and in vivo.

METHODS

The levels of proliferation, migration, glucose, lactic acid, glucose metabolism-related enzymes, apoptosis genes, epithelial-mesenchymal transition (EMT) marker proteins, and PI3K/Akt/C-MYC pathway in CCAT-1-silenced SW620 cells cultured with different glucose levels were tested. Twenty BALB/C nude mice with hyperglycemia or normal blood sugar were transplanted with CCAT-1-silenced SW620 cells, blood glucose levels, lactic acid, insulin, and volume of transplanted tumor cells, the expression of EMT marker proteins, and PI3K/Akt/C-MYC pathway was detected.

RESULTS

The levels of proliferation, migration, glucose, lactic acid, LDH-A, PKM2, and HK2 decreased, apoptosis increased in SW620 cells cultured with low glucose or silenced CCAT-1 (P<0.05); levels of E-cadherin and ZO-1 significantly increased, and levels of N-cadherin, vimentin, and p-Akt decreased in CCAT-1-silenced SW620 cells cultured with high glucose (P<0.05). Hyperglycemic nude mice transplanted with CCAT-1-silenced colon cancer cells showed decreased tumor volume, blood glucose, lactic acid, insulin, P-AKT, and P-C-MYC than EV group (P<0.05).

CONCLUSIONS

CCAT-1 can enhance glucose metabolism and proliferation and migration of colon cancer cells by upregulating the expression of glycolysis enzymes, inhibiting apoptosis, activating the Akt/C-MYC pathway, and promoting EMT expression.

If Artificial In Vitro Microenvironment Can Influence Tumor Drug Resistance Network via Modulation of lncRNA Expression?-Comparative Analysis of Glioblastoma-Derived Cell Culture Models and Initial Tumors In Vivo

The tumor resistance of glioblastoma cells in vivo is thought to be enhanced by their heterogeneity and plasticity, which are extremely difficult to curb in vitro. The external microenvironment shapes the molecular profile of tumor culture models, thus influencing potential therapy response. Our study examines the expression profile of selected lncRNAs involved in tumor resistance network in three different glioblastoma-derived models commonly utilized for testing drug response in vitro. Differential expression analysis revealed significant divergence in lncRNA profile between parental tumors and tumor-derived cell cultures in vitro, including the following particles: MALAT1, CASC2, H19, TUSC7, XIST, RP11-838N2.4, DLX6-AS1, GLIDR, MIR210HG, SOX2-OT. The examined lncRNAs influence the phenomenon of tumor resistance via their downstream target genes through a variety of processes: multi-drug resistance, epithelial-mesenchymal transition, autophagy, cell proliferation and viability, and DNA repair. A comparison of in vivo and in vitro expression identified differences in the levels of potential lncRNA targets, with the highest discrepancies detected for the MDR1, LRP1, BCRP and MRP1 genes. Co-expression analyses confirmed the following interrelations: MALAT1-TYMS, MALAT1-MRP5, H19-ZEB1, CASC2-VIM, CASC2-N-CAD; they additionally suggest the possibility of MALAT1-BCRP, MALAT1-mTOR and TUSC7-PTEN interconnections in glioblastoma. Although our results clearly demonstrate that the artificial ex vivo microenvironment changes the profile of lncRNAs related to tumor resistance, it is difficult to anticipate the final phenotypic effect, since this phenomenon is a complex one that involves a network of molecular interactions underlying a variety of cellular processes.

LINC00152 upregulates ZEB1 expression and enhances epithelial-mesenchymal transition and oxaliplatin resistance in esophageal cancer by interacting with EZH2

BACKGROUND

Expression of the long non-coding mRNA LINC00152 has been reported to correlate with cancer cell resistance to oxaliplatin (L-OHP). However, little is known regarding the molecular mechanism of LINC00152 in esophageal cancer (EC). Hence, we intended to characterize the role of LINC00152 in EC, with a special focus on epithelial-mesenchymal transition (EMT) and L-OHP resistance.

METHODS

We collected EC tissues and identified EC cell lines with higher L-OHP resistance, and then characterized expression patterns of LINC00152, Zeste Homologue 2 (EZH2), Zinc finger e-box binding homeobox (ZEB1) and EMT-related genes using RT-qPCR and Western blot analysis. Furthermore, their functional significance was identified by gain and loss-of-function experiments. The relationship among LINC00152, EZH2 and ZEB1 was examined using RIP, RNA pull-down and ChIP assays. Additionally, resistance of EC cells to L-OHP was reflected by CCK-8 assay to detect cell viability. Animal experiments were also conducted to detect the effects of the LINC00152/EZH2/ZEB1 on EMT and L-OHP resistance.

RESULTS

LINC00152, EZH2 and ZEB1 were highly expressed in EC tissues and Kyse-150/TE-1 cells. As revealed by assays in vitro and in vivo, LINC00152 positively regulated ZEB1 expression through interaction with EZH2 to enhance EMT and L-OHP resistance in EC cells. In contrast, silencing of LINC00152 contributed to attenuated EMT and drug resistance of EC cells to L-OHP.

CONCLUSIONS

Our study demonstrates that LINC00152/EZH2/ZEB1 axis can regulate EMT and resistance of EC cells to L-OHP, thus presenting a potential therapeutic target for EC treatment.

Eradicating the Roots: Advanced Therapeutic Approaches Targeting Breast Cancer Stem Cells

Accumulating evidences have demonstrated that the existence of breast cancer-initiating cells, which drives the original tumorigenicity, local invasion and migration propensity of breast cancer. These cells, termed as breast cancer stem cells (BCSCs), possess properties including self-renewal, multidirectional differentiation and proliferative potential, and are believed to play important roles in the intrinsic drug resistance of breast cancer. One of the reasons why BCBCs cause difficulties in breast cancer treating is that BCBCs can control both genetic and non-genetic elements to keep their niches safe and sound, which allows BCSCs for constant self-renewal and differentiation. Therapeutic strategies designed to target BCSCs may ultimately result in effective interventions for the treatment of breast cancer. Novel strategies including nanomedicine, oncolytic virus therapy, immunotherapy and induced differentiation therapy are emerging and proved to be efficient in anti-BCSCs therapy. In this review, we summarized breast tumor biology and the current challenges of breast cancer therapies, focused on breast cancer stem cells, and introduced promising therapeutic strategies targeting BCSCs.