Critical roles of long noncoding RNAs in breast cancer

Expression profiles of the lncRNA antisense GAS5-AS1 in colon biopsies from pediatric inflammatory bowel disease patients and its role in regulating sense transcript GAS5

The long non-coding RNA (lncRNA) growth arrest-specific transcript 5 (GAS5) level was demonstrated as involved in pediatric inflammatory bowel disease (IBD) pathogenesis. Since its antisense transcript GAS5-AS1 has never been investigated in IBD, this study aims to detect whether GAS5-AS1 and GAS5 levels are related to IBD clinical parameters and investigate their correlation in vitro. Twenty-six IBD pediatric patients were enrolled; paired inflamed and non-inflamed intestinal biopsies were collected. We evaluated GAS5 and GAS5-AS1 levels by real-time PCR. The role of GAS5 and GAS5-AS1 was assessed in vitro by transient silencing in THP1-derived macrophages. GAS5-AS1 and GAS5 levels were associated with patients' clinical parameters; GAS5-AS1 expression was downregulated in inflamed tissues and inversely correlated with disease activity. A positive correlation between GAS5-AS1 and GAS5 levels was observed in non-inflamed biopsies. On THP1-derived macrophages, a reduced amount of both GAS5-AS1 and GAS5 was observed; accordingly, matrix metalloproteinase (MMP) 9 was increased. After GAS5-AS1 silencing, a downregulation of GAS5 was found, whereas no effect was detected on GAS5-AS1 after GAS5 silencing.    Conclusion: This study provided for the first time new insights into the potential role of GAS5-AS1 in IBD. GAS5-AS1 modulates GAS5 levels in vitro and may serve as a potential IBD diagnostic biomarker. What is Known: • GAS5 is involved in regulating intestinal MMP-2 and MMP-9 in pediatric patients with IBD; • GAS5-AS1 has never been investigated in the context of IBD; • GAS5-AS1 regulates the expression of GAS5, increasing its stability in tissues and in vitro cell models of cancer. What is New: • GAS5-AS1 correlated with GAS5 and IBD clinical parameters; • GAS5-AS1 can modulate GAS5 levels in macrophages; • GAS5-AS1 may serve as potential IBD diagnostic biomarker.

Decoding contextual crosstalk: revealing distinct interactions between non-coding RNAs and unfolded protein response in breast cancer

Breast cancer is significantly influenced by endoplasmic reticulum (ER) stress, impacting both its initiation and progression. When cells experience an accumulation of misfolded or unfolded proteins, they activate the unfolded protein response (UPR) to restore cellular balance. In breast cancer, the UPR is frequently triggered due to challenging conditions within tumors. The UPR has a dual impact on breast cancer. On one hand, it can contribute to tumor growth by enhancing cell survival and resistance to programmed cell death in unfavorable environments. On the other hand, prolonged and severe ER stress can trigger cell death mechanisms, limiting tumor progression. Furthermore, ER stress has been linked to the regulation of non-coding RNAs (ncRNAs) in breast cancer cells. These ncRNAs, including microRNAs (miRNAs) and long non-coding RNAs (lncRNAs), play essential roles in cancer development by influencing gene expression and cellular processes. An improved understanding of how ER stress and ncRNAs interact in breast cancer can potentially lead to new treatment approaches. Modifying specific ncRNAs involved in the ER stress response might interfere with cancer cell survival and induce cell death. Additionally, focusing on UPR-associated proteins that interact with ncRNAs could offer novel therapeutic possibilities. Therefore, this review provides a concise overview of the interconnection between ER stress and ncRNAs in breast cancer, elucidating the nuanced effects of the UPR on cell fate and emphasizing the regulatory roles of ncRNAs in breast cancer progression.

The Critical Function of microRNAs in Developing Resistance against 5- Fluorouracil in Cancer Cells

Although there have been significant advancements in cancer treatment, resistance and recurrence in patients make it one of the leading causes of death worldwide. 5-fluorouracil (5-FU), an antimetabolite agent, is widely used in treating a broad range of human malignancies. The cytotoxic effects of 5-FU are mediated by the inhibition of thymidylate synthase (TYMS/TS), resulting in the suppression of essential biosynthetic activity, as well as the misincorporation of its metabolites into RNA and DNA. Despite its huge benefits in cancer therapy, the application of 5-FU in the clinic is restricted due to the occurrence of drug resistance. MicroRNAs (miRNAs) are small, non-coding RNAs that act as negative regulators in many gene expression processes. Research has shown that changes in miRNA play a role in cancer progression and drug resistance. This review examines the role of miRNAs in 5-FU drug resistance in cancers.

Multiple novel functions of circular RNAs in diabetes mellitus

Circular RNAs (circRNAs), as an emerging group of non-coding RNAs (ncRNAs), have received the attention given evidence indicating that these novel ncRNAs are implicated in various biological processes. Due to the absence of 5' and 3' ends in circ-RNAs, their two ends are covalently bonded together, and they are synthesised from pre-mRNAs in a process called back-splicing, which makes them more stable than linear RNAs. There is accumulating evidence showing that circRNAs play a critical role in the pathogenesis of diabetes mellitus (DM). Moreover, it has been indicated that dysregulation of circRNAs has made them promising diagnostic biomarkers for the detection of DM. Recently, increasing attention has been paid to investigate the mechanisms underlying the DM process. It has been demonstrated that there is a strong correlation between the expression of circRNAs and DM. Hence, our aim is to discuss the crosstalk between circRNAs and DM and its complications.

Expression analysis of cell cycle related lncRNAs in breast cancer tissues

Cell cycle regulation is an important cellular function. Abnormal regulation of this process can cause cancer. Several genes are involved in this process. There is no comprehensive study on expression pattern of cell cycle related lncRNAs in breast cancer patients. In the current study, we evaluated expressions of LINC00668, PRDM16-DT, SNHG7 and CDKN2A in 42 pairs of breast cancer tissues and adjacent non-tumoral tissues. Expression of SNHG7 was significantly lower in tumoral tissues compared with non-tumoral tissues. However, expressions of LINC00668, PRDM16-DT and CDKN2A were not significantly different between these two sets of samples. Expression levels of SNHG7 could separate tumoral tissues from non-tumoral tissues with AUC value= 0.66, sensitivity= 61% and specificity= 73%. Expression of CDKN2A was associated with clinical stage (P value=0.01). Expression levels of LINC00668, PRDM16-DT, SNHG7 and CDKN2A were higher in estrogen receptor (ER) positive samples compared with ER negative ones (P values=0.044, 0.008, 0.002 and 0.022, respectively). Moreover, expression of SNHG7 was higher in progesterone receptor (PR) positive samples compared with PR negative ones (P value=0.02). Finally, expressions of PRDM16-DT, SNHG7 and CDKN2A were higher in HER2/neu positive samples compared with HER2/neu negative ones (P values=0.017, 0.02 and 0.021, respectively). Taken together, our study demonstrates possible roles of these genes in breast cancer and warrants further functional studies.

The critical role of circular RNAs in drug resistance in gastrointestinal cancers

Nowadays, drug resistance (DR) in gastrointestinal (GI) cancers, as the main reason for cancer-related mortality worldwide, has become a serious problem in the management of patients. Several mechanisms have been proposed for resistance to anticancer drugs, including altered transport and metabolism of drugs, mutation of drug targets, altered DNA repair system, inhibited apoptosis and autophagy, cancer stem cells, tumor heterogeneity, and epithelial-mesenchymal transition. Compelling evidence has revealed that genetic and epigenetic factors are strongly linked to DR. Non-coding RNA (ncRNA) interferences are the most crucial epigenetic alterations explored so far, and among these ncRNAs, circular RNAs (circRNAs) are the most emerging members known to have unique properties. Due to the absence of 5' and 3' ends in these novel RNAs, the two ends are covalently bonded together and are generated from pre-mRNA in a process known as back-splicing, which makes them more stable than other RNAs. As far as the unique structure and function of circRNAs is concerned, they are implicated in proliferation, migration, invasion, angiogenesis, metastasis, and DR. A clear understanding of the molecular mechanisms responsible for circRNAs-mediated DR in the GI cancers will open a new window to the management of GI cancers. Hence, in the present review, we will describe briefly the biogenesis, multiple features, and different biological functions of circRNAs. Then, we will summarize current mechanisms of DR, and finally, discuss molecular mechanisms through which circRNAs regulate DR development in esophageal cancer, pancreatic cancer, gastric cancer, colorectal cancer, and hepatocellular carcinoma.

Interactions of melatonin with various signaling pathways: implications for cancer therapy

Melatonin is a neuro-hormone with conserved roles in evolution. Initially synthetized as an antioxidant molecule, it has gained prominence as a key molecule in the regulation of the circadian rhythm. Melatonin exerts its effect by binding to cytoplasmic and intra-nuclear receptors, and is able to regulate the expression of key mediators of different signaling pathways. This ability has led scholars to investigate the role of melatonin in reversing the process of carcinogenesis, a process in which many signaling pathways are involved, and regulating these pathways may be of clinical significance. In this review, the role of melatonin in regulating multiple signaling pathways with important roles in cancer progression is discussed, and evidence regarding the beneficence of targeting malignancies with this approach is presented.

A novel melanoma prognostic model based on the ferroptosis-related long non-coding RNA

Ferroptosis is an iron-dependent programmed cell death related to the biological process of many kinds of tumors. Long noncoding RNAs (LncRNA) have been found to play essential roles in the tumor, and their functions in the ferroptosis of tumor cells have been partially discovered. However, there is no summary of ferroptosis-related LncRNA and its functions in melanoma. In the present study, we aim to explore the expression profile of ferroptosis-related LncRNA genes and their value in melanoma prognosis by bioinformatics analysis. The expression of ferroptosis-related gene (FRG) from melanoma clinical data was extracted based on the Cancer Genome Atlas (TCGA) database. By screening the RNA expression data of 472 cases of melanoma and 810 cases of normal skin, eighteen ferroptosis-related differential genes were found to be related to the overall survival rate. Furthermore, 384 ferroptosis-related LncRNAs were discovered through constructing the mRNA-LncRNA co-expression network, and ten of them were found with prognostic significance in melanoma by multivariate Cox analysis. Risk assessment showed that the high expression of LncRNA00520 is associated with poor prognosis, while the increased expression of the other LncRNA is beneficial to the prognosis of patients with melanoma. From univariate and multivariate Cox regression analysis, there were ten ferroptosis-related LncRNA risk models towards to be significant independent prognostic factors for patients with melanoma and valuable predictive factors for overall survival (OS)(P<0.05). The ROC curve further suggested that the risk score has relatively reliable predictive ability (AUC=0.718). The protein level of ferroptosis-related genes was verified by the HPA database and IHC test, leading to the discovery that the expressions of ALOX5, PEBP1, ACSL4, and ZEB1 proteins up-regulated in tumor tissues, and existed differences between tumor tissues and normal tissues. In conclusion, we identified ten ferroptosis-related LncRNA and constructed a prognosis model base.

Long noncoding RNA ST8SIA6-AS1 promotes cell proliferation and metastasis in triple-negative breast cancer by targeting miR-145-5p/CDCA3 to inactivate the p53/p21 signaling pathway

BACKGROUND

Triple-negative breast cancer (TNBC), the most aggressive subtype of breast cancer, always exhibits a poor prognosis due to high risk of early recurrence and distant metastasis. Long noncoding RNAs (lncRNAs) have been reported as crucial regulators in breast cancer. However, the functions and action mechanisms of lncRNA ST8SIA6-AS1 in TNBC are largely unknown.

METHODS

Quantitative real-time PCR and western blot assays were used to measure the expression levels of different genes and proteins. Cell proliferation ability was monitored by CCK-8, colony forming and flow cytometry assays. Wound healing and transwell assays were performed to evaluate cell migration and invasion. The regulatory mechanisms of ST8SIA6-AS1 in TNBC were confirmed by dual luciferase reporter and RIP assays. A mouse xenograft model was established to investigate the role of ST8SIA6-AS1 in TNBC tumor growth.

RESULTS

ST8SIA6-AS1 displayed a higher expression in TNBC cells. Silencing ST8SIA6-AS1 impaired cell proliferation, cell cycle progression, migration, and invasion in vitro, and slowed tumor growth in vivo. Mechanistically, ST8SIA6-AS1 could facilitate the expression of its target CDCA3 (cell division cycle associated protein 3) and inactivate the p53/p21 signaling by inhibiting miR-145-5p. Moreover, miR-145-5p exerted a tumor-suppressive activity by targeting CDCA3. The tumor-suppressive effects induced by ST8SIA6-AS1 knockdown were abated by the down-regulation of miR-145-5p or the up-regulation of CDCA3.

CONCLUSION

ST8SIA6-AS1 exerts an oncogenic role in TNBC by interacting with miR-145-5p to up-regulate CDCA3 expression and inactivate the p53/p21 signaling, highlighting ST8SIA6-AS1 as a promising molecular target to combat TNBC.

Magnetic resonance imaging correlation with molecular and epigenetic markers in assessment of breast cancer

Background

Breast cancer is a heterogeneous disease with a wide range of clinical behavior, histologic subtypes, therapeutic options, and outcomes. The different biology and histology of breast cancer display different tumor morphology at breast magnetic resonance imaging (MRI). However, few studies have examined the relationship between the MRI morphological, kinetic features and molecular and epigenetic markers in breast cancer assessment. The study aimed to evaluate the correlation between MRI morphological and kinetic features, molecular and an epigenetic marker (linc-ITGB1) in breast cancer cases. A total of 115 women (80 cases and 35 controls) with BIRAD 4 category breast lesions were included. The association between the MRI morphological & kinetic features, apparent diffusion coefficient (ADC) values, and molecular and the epigenetic marker (linc-ITGB1) was evaluated using Mann–Whitney and Chi-square tests.

Results

The shape (p = 0.009), size of the lesion (p = 0.003), and pattern of enhancement (p ≤ 0.001) were significantly correlated with the molecular markers. Luminal subtypes are more likely to be presented with irregular shaped and non-circumscribed margin masses (97% for luminal A and 94.1% for luminal B). Triple-negative cancers are frequently presented with regular masses, circumscribed margins, and peripheral rim enhancement (50% of TN tumors). HER2-positive cancers are more likely to be multifocal/multicentric and are more associated with non-mass pattern of enhancement as compared to HER2-negative cancers. Perilesional edema was also significantly correlated with HER2-positive lesions (p = 0.009). Although the epigenetic marker linc-ITGB1 was overexpressed by 4.85-folds in breast cancer cases compared to benign controls, we could not find any significant correlation between its expression level and the MRI features or molecular subtypes (p = 0.948).

Conclusions

MRI features can be a reliable predictor of breast cancer molecular subtypes. The epigenetic marker linc-ITGB1 has a potential role in breast cancer pathogenesis but with no significant correlation with either the MRI features or molecular subtypes of the lesions.

Overview of MicroRNA Expression in Predicting Response to Neoadjuvant Therapies in Human Epidermal Growth Receptor-2 Enriched Breast Cancer - A Systematic Review

Purpose:

Increased appreciation of the human epidermal growth factor receptor-2 (HER2/neu) signalling pathway has led to the development of targeted therapeutic agents used in conjunction with chemotherapy to improve outcomes for HER2 overexpressing (HER2+) breast cancer. For neoadjuvant therapy, response rates can be unpredictable – novel biomarkers predicting effectiveness are required to enhance oncological outcomes for these patients, and microRNA may prove effective. Our objective was to identify microRNA (miRNA) expression patterns predictive of response to neoadjuvant chemotherapy (NAC) and/or anti-HER2 targeted therapies in patients being treated for early-stage HER2+ breast cancer.

Methods:

A search was performed of the PUBMED, SCOPUS, Web of Science, and EMBASE in accordance to Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guidelines.

Results:

Overall, 15 studies including 1335 patients were included. These studies highlighted an expression profile of 73 miRNA and their ability to predict tumour response to neoadjuvant therapies was correlated. Results from 11 studies were in relation to circulatory miRNA and 4 studies included data from tumour tissue. Overall, upregulation and downregulation of 41 miRNA and 29 miRNA, respectively, predicted differential response to neoadjuvant therapy. Expression levels of 3 miRNA (miR-21, miR-210, and miR-376c-3p) were inconclusive in predicting therapeutic response, while ‘aberrant’ expression of circulating miR-199a predicted pathological complete response (pCR) to NAC.

Conclusions:

This systematic review outlines expression patterns of a number of miRNA which correlate with response to NAC and/or anti-HER2 therapies. Future translational research evaluating predictive biomarkers of primary response to neoadjuvant therapy in HER2+ breast cancer may consider these results.

Functions of non-coding RNAs in regulating cancer drug targets

With the development of precision medicine, the efficiency of tumor treatment has been significantly improved. More attention has been paid to targeted therapy and immunotherapy as the key to precision treatment of cancer. Targeting epidermal growth factor receptor (EGFR) has become one of the most important targeted treatments for various cancers. Comparing with traditional chemotherapy drugs, targeting EGFR is highly selective in killing tumor cells with better safety, tolerability and less side effect. In addition, tumor immunotherapy has become the fourth largest tumor therapy after surgery, radiotherapy and chemotherapy, especially immune checkpoint inhibitors. However, these treatments still produce a certain degree of drug resistance. Non-coding RNAs (ncRNAs) were found to play a key role in carcinogenesis, treatment and regulation of the efficacy of anticancer drugs in the past few years. Therefore, in this review, we aim to summarize the targeted treatment of cancers and the functions of ncRNAs in cancer treatment.

Emerging Roles of Long Non-Coding RNAs in Ankylosing Spondylitis

Ankylosing spondylitis (AS) is a chronic systemic autoimmune disease characterized by inflammation, bone erosion, spur formation of the spine and the sacroiliac joints. However, the etiology and molecular pathogenesis of AS remain largely unclear. Recently, a growing number of studies showed that long non-coding RNAs (lncRNAs) played critical roles in the development and progression of autoimmune and orthopedic conditions, including AS. Studies demonstrated that a myriad of lncRNAs (e.g. H19, MEG3, LOC645166) pertinent to regulation of inflammatory signals were deregulated in AS. A number of lncRNAs might also serve as new biomarkers for the diagnosis and predicting the outcomes of AS. In this review, we summarize lncRNA profiling studies on AS and the functional roles and mechanism of key lncRNAs relevant to AS pathogenesis. We also discuss their potential values as biomarkers and druggable targets for this potentially disabling condition.

LncRNA ubiquitin-binding protein domain protein 10 antisense RNA 1 inhibits colon adenocarcinoma progression via the miR-515-5p/slit guidance ligand 3 axis

Dysregulated long non-coding RNAs (lncRNAs) play an important role in cancer progression. However, there have been limited reports to date of the involvement of ubiquitin-binding protein domain protein 10 antisense RNA 1 (UBXN10-AS1) in cancer. Our aim was to explore the role and underlying mechanism of UBXN10-AS1 in the occurrence of colon adenocarcinoma (COAD). Real-time quantitative PCR and Western blotting were performed to determine the expression of UBXN10-AS1, miR-515-5p, and Slit guidance ligand 3 (SLIT3). Cell Counting Kit-8 and wound healing scratch assays were performed to measure COAD cell proliferation and migration. A xenograft assay was performed to examine tumor growth in vivo. Luciferase reporter and RNA immunoprecipitation (RIP) assays were used to determine the binding interaction among miR-515-5p, UBXN10-AS1, and SLIT3. The results showed that UBXN10-AS1 and SLIT3 were expressed at low levels in COAD tissues, while miR-515-5p was expressed at high levels. UBXN10-AS1 overexpression suppressed tumor growth in vitro and in vivo. The luciferase reporter and RNA RIP assays demonstrated that UBXN10-AS1 targeted miR-515-5p, which in turn targeted SLIT3. Functionally, miR-515-5p overexpression reversed the inhibition of COAD cell proliferation and migration by UBXN10-AS1 overexpression, and SLIT3 overexpression counteracted the oncogenicity of miR-515-5p. Our study shows that UBXN10-AS1 modulates the miR-515-5p/SLIT3 axis, thereby resulting in the inhibition of COAD cell proliferation and migration.

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

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

Down-regulation of MEG3, PANDA and CASC2 as p53-related lncRNAs in breast cancer

TP53 encodes a major tumor suppressor protein which blocks carcinogenesis process in a variety of tissues including breast tissue. Expression and function of this gene is regulated by a number of long non-coding RNAs (lncRNAs) among them are PANDA, MEG3 and CASC2. We measured expression of TP53 and these transcripts in a cohort of Iranian breast cancer patients. Expression levels of TP53, MEG3, CASC2 and PANDA were significantly lower in tumoral samples compared with non-tumoral samples (Posterior mean differences =  -4.26, -1.66, -5.98 and -3.13, respectively; P values < 0.0001). Expression of CASC2 was higher in Her2 1+ cases compared with Her2 negative cases (Beta = 1.85, P value = 0.037). Expression levels of MEG3 and TP53 were lower in grade 2 samples compared with grade 1 (Beta = -1.86, P value = 0.006 and Beta = -2.24, P value = 0.003, respectively). There was no other significant association between expression of genes and clinical variables. CASC2 had the best performance among these genes with area under curve value of 0.78 and sensitivity and specificity values of 56.33% and 88.73%, respectively (P value < 0.0001). The current investigation supports the role of TP53-related lncRNAs in the pathogenesis of breast cancer.

LncRNAs in breast cancer: a link to future approaches

Breast cancer affects millions of women each year. Despite recent advances in targeted treatments breast cancer remains a significant threat to women's health. In recent years the development of high-throughput sequencing technologies has advanced the field of transcriptomics shedding light on the role of non-coding RNAs (ncRNAs), including long ncRNAs (lncRNAs), in human cellular function and disease. LncRNAs are classified as transcripts longer than 200nt with no coding potential. These transcripts constitute a diverse group of regulatory molecules essential to the modulation of crucial cellular processes, which dysregulation of leads to disease. LncRNAs exert their regulatory functions through their sequences and by forming complex secondary and tertiary structures that interact with other transcripts, chromatin and/or proteins. Numerous studies have provided evidence of the involvement of LncRNAs in tumor development and disease progression. They possess multiple characteristics that make them novel therapeutic and diagnostic targets. Indeed, the discovery of a novel mechanism by which lncRNAs associated with proteins can induce the formation of phase-separated droplets broadens our understanding of the spatiotemporal control of cellular processes and opens up developing a new treatment. Nevertheless, the role and the molecular mechanisms of many lncRNAs in the regulation of cellular processes and cancer still remain elusive. This is due to the absence of a thorough characterization of the regulatory role of their loci and the functional impact of their aberrations in cancer biology. Here, we present some of the latest advances concerning the role of LncRNAs in breast cancer.

The bioinformatics analysis of quercetin in octagonal lotus for the screening of breast cancer MYC, CXCL10, CXCL11, and E2F1

Background

Comprehensive bioinformatics analysis of the effective molecular screening of Podophyllum octagonal in breast cancer treatment by using network pharmacology.

Methods

We collected the active ingredients and target genes of Chinese medicine octagonal lotus through the Traditional Chinese Medicine System Pharmacology Analysis Platform (TCMSP); downloaded human protein annotation information on the protein database Uniport; and collected data from five databases: GeneCards, OMIM, PharmGkb, TDD, and DrugBank. Construct the practical ingredient-target gene data intersection to obtain the target gene-disease gene and draw the Venn diagram. We use Cytoscape 3.8.0 software to construct the effective component-target gene-disease gene network. The STRING database protein interaction (PPI) networks were erected, and we used Cytoscape 3.8.0 software to screen out its core sub-networks and hub gene networks. Through survival analysis, core genes and hub genes were screened to identify several key genes. We performed key target gene ontology (GO) analysis and gene interaction (KEGG) analysis, which were followed by molecular docking of the key active ingredients in the star anise corresponding to several key genes.

Results

19 active ingredients, 444 drug targets, and 10,941 disease-related genes were obtained. The key active ingredient was quercetin. GO analysis revealed 2471 affected biological processes, and 167 pathways were obtained in KEGG enrichment analysis.

Conclusion

This study initially screened the key active ingredients of star aniseed lotus and analyzed key genes and several essential pathways. Traditional Chinese medicine is expected to provide new evidence and research ideas to prevent and treat breast cancer.

The role of long noncoding RNAs in patients with Luminal A invasive breast ductal carcinoma

Breast cancer is the most common form of cancer in women around the world. The molecular mechanisms of this heterogeneous disease have been extensively investigated; but yet; It requires a lot of sensitive and specific markers for prognosis and early detection approaches. Non-protein coding RNAs known as lncRNAs have been reported in tumorigenic involvement so they can be used for therapeutic purposes. In the present study, the expression levels of CCAT1, PDCD4, PDCD4-AS1, and MEG3 LncRNA in adjacent tumor and breast tissue in 88 Iranian patients were evaluated by quantitative real-time PCR. CCAT1 was significantly expressed and PDCD4-AS1 decreased in tumor samples, PDCD4 and PDCD4-AS1 showed a positive correlation with each other, higher levels of PDCD4-AS1 were associated with better survival, tumor samples showed lower levels of PDCD4 in Showed comparisons with normal tissue. Our findings suggest that lncRNAs play an important role in controlling gene expression after transcription of major tumor suppressors or carcinogenic genes, leading to the development of triple-negative breast cancer (TNBC). In conclusion, this study investigated the prognostic role of lncRNA in breast cancer patients.

Quercetin Impairs HuR-Driven Progression and Migration of Triple Negative Breast Cancer (TNBC) Cells

In the present study, we have explored the prognostic value of HuR gene as well as protein in breast cancers. Furthermore, we have also investigated the HuR therapeutic relevance in TNBCs, which is an aggressive breast cancer subtype. Using an online meta-analysis tool, we found that HuR protein overexpression positively correlates with reduced overall survival of TNBC patients (p = 0.028). Furthermore, we demonstrated that the TNBC breast cancer cell lines i.e., MDA-MB-231 and MDA-MB-468 are good model systems to study HuR protein, as they both exhibit a significant amount of cytoplasmic HuR (active form). Quercetin treatment significantly inhibited the cytoplasmic HuR in both TNBC cell lines. By using specific HuR siRNA, we established that quercetin-mediated inhibition of adhesion and migration of TNBC cells is dependent on HuR. Upon analyzing adhesion proteins i.e., β-catenin and CD44, we found that quercetin mediated effect on TNBC adhesion and migration was through the HuR-β-catenin axis and CD44, independently. Overall, the present results demonstrate that elevated HuR levels are associated with TNBC progression and relapse, and the ability of quercetin to inhibit cytoplasmic HuR protein provides a rationale for using it as an anticancer agent for the treatment of aggressive TNBCs.Supplemental data for this article is available online at at 10.1080/01635581.2021.1952628.

The potential roles of lncRNAs DUXAP8, LINC00963, and FOXD2-AS1 in luminal breast cancer based on expression analysis and bioinformatic approaches

Numerous studies have demonstrated that lncRNAs participate in regulatory networks of different cancers. Dysregulation of various lncRNAs such as DUXAP8, LINC00963, and FOXD2-AS1 has been reported in the development of various cancers. The aim of this study was investigation of the importance and potential roles of DUXAP8, LINC00963, and FOXD2-AS1 in ER⁺ breast cancer (BC). We examined the expression levels of DUXAP8, LINC00963, and FOXD2-AS1 in 71 luminal A and B tumor tissues and two luminal A cell lines (MCF7 and T47D) compared with adjacent non-tumor tissues and MCF10A cell line by qRT-PCR assay, respectively. For identifying the relation between three lncRNAs and luminal BC, bioinformatic analyses were performed using some databases and software including GENEVESTIGATOR software, GEPIA2, DAVID, REVIGO, STRING, lncATLAS, Kaplan-Meier plotter, starBase, and miRNet tool. The results showed the significant upregulation of all three lncRNAs in luminal A and B tumor specimens and cell lines. Upregulation of DUXAP8 and FOXD2-AS1 was significantly associated with progesterone receptor-positive (PR⁺) and p53 protein expression in luminal BC patients, respectively. Based on bioinformatic analyses, DUXAP8 can be considered as a prognostic biomarker for patients with luminal BC. DUXAP8, LINC00963, and FOXD2-AS1 are involved in several cancer-associated signaling pathways and multiple cancer-related processes. In addition, bioinformatic analyses indicated that LINC00963/hsa-mir-130a-3p/HSPA8 axis might have potential regulatory role in BC. In conclusion, dysregulation of DUXAP8, LINC00963, and FOXD2-AS1 can play roles in the development of luminal BC. They may exert their functions through involvement in some cancer signaling pathways and processes. In addition, they may interact with miRNAs like predicted interaction of LINC00963 with miR-130a-3p.

Emerging role of circular RNAs in breast cancer

Circular RNAs (cirRNAs) are generally considered as non-coding RNAs which can act as molecular sponges for miRNAs, exert regulatory roles in transcription or splicing, and interplay with RNA binding proteins. These single-stranded transcripts can affect tumor growth, the metastatic ability of cancer cells, stemness properties, and resistance to therapeutic options. Recent investigations have shown the crucial effects of circrNAs in the evolution of breast cancer. Signature of circRNAs in breast cancer samples has been mostly assessed through microarray-based methods revealing up-regulation of some circRNAs such as circ-TFF1, circACAP2, circ-TFCP2L1, hsa_circ_0000519, circDENND4C, circPLK1 and circRNA_069718, while down-regulation of other circRNAs such as hsa_circ_0000375, circYap, hsa_circ_0025202, circTADA2A-E6, circASS1 and circRNA_BARD1 in breast cancer samples. Mechanistically, these transcripts mainly affect breast cancer tumorigenesis via serving as sponges for miRNAs. In the current manuscript, we explore the results of researches that appraised the role of circRNAs in breast cancer.

Long noncoding RNAs as a piece of polycystic ovary syndrome puzzle

Polycystic ovary syndrome (PCOS) is an endocrine disorder and affects 5-10% of reproductive-age women. Chronic anovulation, polycystic ovaries, and hyperandrogenism are the important features of this syndrome. Furthermore, hyperinsulinemia and central obesity are frequent in PCOS women. In recent years, noncoding RNAs detection provided new ideas to explain the etiology of female reproductive disorders. Long noncoding RNAs (lncRNAs) as a subset of noncoding RNAs are associated with the pathogenesis of manifold reproductive-related disorders. Various investigations emphasized the potential involvement of lncRNAs in PCOS development. Therefore, in this paper, we will summarize the function of numerous lncRNAs in the apoptosis and proliferation of granulosa cells (GCs), insulin resistance (IR), and steroidogenesis in PCOS.

Novel insights into the interaction between long non-coding RNAs and microRNAs in glioma

Glioma is the most common brain tumor of the central nervous system. Long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) have been identified to play a vital role in the initiation and progression of glioma, including tumor cell proliferation, survival, apoptosis, invasion, and therapy resistance. New documents emerged, which indicated that the interaction between long non-coding RNAs and miRNAs contributes to the tumorigenesis and pathogenesis of glioma. LncRNAs can act as competing for endogenous RNA (ceRNA), and molecular sponge/deregulator in regulating miRNAs. These interactions stimulate different molecular signaling pathways in glioma, including the lncRNAs/miRNAs/Wnt/β-catenin molecular signaling pathway, the lncRNAs/miRNAs/PI3K/AKT/mTOR molecular signaling pathway, the lncRNAs-miRNAs/MAPK kinase molecular signaling pathway, and the lncRNAs/miRNAs/NF-κB molecular signaling pathway. In this paper, the basic roles and molecular interactions of the lncRNAs and miRNAs pathway glioma were summarized to better understand the pathogenesis and tumorigenesis of glioma.

Critical review of Epstein-Barr virus microRNAs relation with EBV-associated gastric cancer

Epstein-Barr virus (EBV)-associated gastric cancer (EBVaGC) is regarded as the most prevalent malignant tumor triggered by EBV infection. In recent years, increasing attention has been considered to recognize more about the disease process's exact mechanisms. There is accumulating evidence that showing epigenetic modifications play critical roles in the EBVaGC pathogenesis. MicroRNAs (miRNAs), as critical epigenetic modulators, are single-strand short noncoding RNA (length ~ <200 bp), which regulate gene expression through binding to the 3'-untranslated region (3'-UTR) of target RNA transcripts and either degrade or repress their activities. In the latest research on EBV, it was found that this virus could encode miRNAs. Mechanistically, EBV-encoded miRNAs are involved in carcinogenesis and the progression of EBV-associated malignancies. Moreover, these miRNAs implicated in immune evasion, identification of pattern recognition receptors, regulation of lymphocyte activation and lethality, modulation of infected host cell antigen, maintain of EBV infection status, promotion of cell proliferation, invasion and migration, and reduction of apoptosis. As good news, not only has recent data demonstrated the crucial function of EBV-encoded miRNAs in the pathogenesis of EBVaGC, but it has also been revealed that aberrant expression of exosomal miRNAs in EBVaGC has made them biomarkers for detection of EBVaGC. Regarding these substantial characterizes, the critical role of EBV-encoded miRNAs has been a hot topic in research. In this review, we will focus on the multiple mechanisms involved in EBVaGC caused by EBV-encoded miRNAs and briefly discuss their potential application in the clinic as a diagnostic biomarker.

LncRNAs and miRNAs participate in determination of sensitivity of cancer cells to cisplatin

Cisplatin is an extensively used chemotherapeutic substance for various types of human malignancies including sarcomas, carcinomas and lymphomas. Yet, the vast application of this drug is hampered by the emergence of chemoresistance in some treated patients. Several mechanisms such as degradation of the membrane transporters by cisplatin have been implicated in the pathogenesis of this event. Recent researches have also indicated the role of long non-coding RNAs (lncRNAs) as well as micoRNAs (miRNAs) in the emergence of resistance to cisplatin in several cancer types. For instance, up-regulation of miR-21 has been associated with resistance to this agent in ovarian cancer, oral squamous cell cancer, gastric malignancy and non-small cell lung cancer (NSCLC). On the other hand, down-regulation of miR-218 has been implicated in emergence of chemoresistance in breast cancer and esophageal squamous cell carcinoma. MALAT1 is implicated in the chemoresistance of bladder cancer cells, NSCLC, gastric cancer and cervical cancer. Most notably, the expression profile of resistance-associated miRNAs and lncRNAs can predict overall survival of cancer patients. Mechanistic assays have revealed that interference with expression of some miRNAs and lncRNAs can reverse the resistance phenotype in cancer cells. In this paper, we review the scientific writings on the role of lncRNAs and miRNAs in the evolution of chemoresistance to cisplatin in cancer cells.

MicroRNA-mediated autophagy regulation in cancer therapy: The role in chemoresistance/chemosensitivity

Chemoresistance has doubled the effort needed to reach an effective treatment for cancer. Now, scientists should consider molecular pathways and mechanisms involved in chemoresistance to overcome cancer. Autophagy is a "self-digestion" mechanism in which potentially toxic and aged organelles and macromolecules are degraded. Increasing evidence has shown that autophagy possesses dual role in cancer cells (onco-suppressor or oncogene). So, it is vital to identify its role in cancer progression and malignancy. MicroRNAs (miRs) are epigenetic factors capable of modulation of autophagy in cancer cells. In the current review, we emphasize on the relationship between miRs and autophagy in cancer chemotherapy. Besides, we discuss upstream mediators of miR/autophagy axis in cancer chemotherapy including long non-coding RNAs, circular RNAs, Nrf2 c-Myc, and HIF-1α. At the final section, we provide a discussion about how anti-tumor compounds affect miR/autophagy axis in ensuring chemosensitivity. These topics are described in this review to show how autophagy inhibition/induction can lead to chemosensitivity/chemoresistance, and miRs are considered as key players in these discussions.

MicroRNAs and Their Influence on the ZEB Family: Mechanistic Aspects and Therapeutic Applications in Cancer Therapy

Molecular signaling pathways involved in cancer have been intensively studied due to their crucial role in cancer cell growth and dissemination. Among them, zinc finger E-box binding homeobox-1 (ZEB1) and -2 (ZEB2) are molecules that play vital roles in signaling pathways to ensure the survival of tumor cells, particularly through enhancing cell proliferation, promoting cell migration and invasion, and triggering drug resistance. Importantly, ZEB proteins are regulated by microRNAs (miRs). In this review, we demonstrate the impact that miRs have on cancer therapy, through their targeting of ZEB proteins. MiRs are able to act as onco-suppressor factors and inhibit the malignancy of tumor cells through ZEB1/2 down-regulation. This can lead to an inhibition of epithelial-mesenchymal transition (EMT) mechanism, therefore reducing metastasis. Additionally, miRs are able to inhibit ZEB1/2-mediated drug resistance and immunosuppression. Additionally, we explore the upstream modulators of miRs such as long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs), as these regulators can influence the inhibitory effect of miRs on ZEB proteins and cancer progression.

LINC01224 Exhibits Cancer-Promoting Activity in Epithelial Ovarian Cancer Through microRNA-485-5p-Mediated PAK4 Upregulation

Purpose

Long intergenic non-protein coding RNA 1224 (LINC01224) plays vital roles in the tumorigenesis and progression of hepatocellular carcinoma. Here, we determined LINC01224 expression in epithelial ovarian cancer (EOC) tissues and cells. We also assessed the effects of LINC01224 knockdown on the malignant phenotype of EOC cells both in vitro and in vivo. Furthermore, the detailed molecular mechanisms underlying the oncogenic actions of LINC01224 in EOC cells were elucidated.

Methods

Quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect LINC01224 expression in EOC tissues and cells. EOC cells were transfected with small interfering RNAs, and cell proliferation, apoptosis, migration, and invasion were assessed using Cell Counting Kit-8 assay, flow cytometry, cell migration assays, and cell invasion assays, respectively. Using tumor xenografts, the effects of LINC01224 silencing on EOC tumor growth were analyzed in vivo. The mechanism underlying LINC01224 regulation of malignant processes in EOC cells was explored using bioinformatics, RNA immunoprecipitation assay, qRT-PCR, Western blotting, and rescue experiments.

Results

LINC01224 expression was upregulated in EOC tissues and cells. LINC01224 upregulation was correlated to tumor size, the International Federation of Gynecology and Obstetrics stage, and lymph node metastasis. LINC01224 depletion in EOC cells suppressed cell proliferation, migration, and invasion and facilitated cell apoptosis in vitro. LINC01224 downregulation also hindered EOC tumor growth in vivo. Mechanistically, LINC01224 served as a competing endogenous RNA for microRNA-485-5p (miR-485-5p) and consequently increased p21-activated kinase 4 (PAK4) expression in EOC cells. Furthermore, miR-485-5p inhibition or PAK4 upregulation significantly abrogated the effects of LINC01224 depletion in EOC cells.

Conclusion

LINC01224/miR-485-5p/PAK4 formed a competing endogenous RNA network regulating the aggressive behavior of EOC. Therefore, targeting this pathway may be an attractive therapeutic strategy for EOC.

Diagnostic, prognostic, and therapeutic significance of miR-139-5p in cancers

miRNAs are a group of non-coding RNAs that have regulatory functions in post-transcriptional gene expression. These molecules play a fundamental role in cellular processes, for instance cell proliferation, apoptosis, migration, and invasion. Scientific investigations have previously established that miRNAs can either promote or suppress tumor development by mediating different signaling pathways. miR-139-5p, located on chromosome 11q13.4, has been examined extensively in cancers. Studies have demonstrated that miR-139-5p might be an attractive cancer biomarker. Herein, we will review how miR-139-5p acts in cancer diagnosis, prognosis, and therapy, as well as elucidating its major target genes and associated signaling pathways.

Expression analysis of vimentin and the related lncRNA network in breast cancer

Vimentin (VIM) is a mesenchymal marker which is expressed in some cancer types including breast cancer. A long non-coding RNA (lncRNA) has been identified to be transcribed from VIM gene locus and positively regulate expression of VIM. This lncRNA has been named as VIM-antisense 1 (VIM-AS1). Expression of VIM is also regulated by another lncRNA namely AGAP2-antisense RNA 1 (AGAP2-AS1). In the current study, we aimed at identification of the expression pattern of VIM, VIM-AS1, AGAP2 and AGAP2-AS1 in 78 breast cancer samples and their paired adjacent non-cancerous tissues (ANCTs) by means of real time PCR. All mentioned genes were significantly down-regulated in tumoral tissues compared with ANCTs (P values less than 0.000). Relative expression of VIM-AS1 in tumoral tissues versus ANCTs was associated with menopause age (P = .02) in a way that this gene was down-regulated in most of patients whose menopause age was between 40 and 50 years. Moreover, AGAP2-AS1 relative expression was associated with patients' body mass index (P = .03). There were trends toward association between VIM relative expression and tumor size (P = .07) and association between VIM-AS1 relative expression and obesity (P = .06). Expression of VIM was significantly higher in tumoral tissues of patients who had history of hormone replacement therapy compared with those without such history (P = .03). Moreover, expression levels of both VIM and AGAP2-AS1 were lower in patients whose menarche age was between 10 and 12 years old compared with those whose menarche age was between 13 and 15 years old (P values = .01 and 0.04, respectively). Transcript quantities of VIM, VIM-AS1, AGAP2 and AGAP2-AS1 were correlated with each other both in tumoral tissues and in ANCTs. Among four assessed genes, AGAP2 had the best diagnostic power for discrimination of tumoral tissues from ANCTs (AUC value = 0.87). Combination of four genes led to enhancement of AUC value to 0.94. The current study shows the importance of VIM and its associated lncRNAs in breast cancer and potentiates these genes as biomarkers for this malignancy. Moreover, these lncRNAs might be regarded as therapeutic targets in breast cancer.

PCAT1: An oncogenic lncRNA in diverse cancers and a putative therapeutic target

The critical roles of long non-coding RNAs (lncRNAs) in the regulation of diverse biological functions has potentiated them as cancer biomarkers. Among these transcripts is the prostate cancer associated transcript 1 (PCAT1) which has been initially shown to exert oncogenic roles in prostate cancer. Further studies revealed its similar roles in various kinds of human malignancies including both solid tumors and hematological malignancies. Animal studies have shown that down-regulation of this lncRNA can attenuate tumor growth in a wide array of cancers including prostate cancer, colorectal cancer, squamous cell carcinoma lung cancer and hepatocellular carcinoma. Studies aimed at identification of diagnostic value of this lncRNA in human cancers reported various values ranging from 0.66 to 0.89 in diverse cancers with the best value reported in multiple myeloma. This lncRNA has a number of putative functional genomic variants such as rs1902432, rs2632159, rs1026411, rs710886, rs16901904 and rs710886 which can modify expression or function of PCAT1 thus altering the risk of human cancers. Based on aberrant expression of PCAT1 in malignancies of diverse origins, this lncRNA can be regarded as a therapeutic target in a vast array of cancers. Thus, modalities for efficient reduction of its expression would be beneficial for several patients.