Long Non-Coding RNA NEAT1 Promotes the Proliferation, Migration, and Metastasis of Human Breast-Cancer Cells by Inhibiting miR-146b-5p Expression

Advanced Insights into Competitive Endogenous RNAs (ceRNAs) Regulated Pathogenic Mechanisms in Metastatic Triple-Negative Breast Cancer (mTNBC)

Triple-negative breast cancer is aggressive and challenging to treat because of a lack of targets and heterogeneity among tumors. A paramount factor in the mortality from breast cancer is metastasis, which is driven by genetic and phenotypic alterations that drive epithelial-mesenchymal transition, stemness, survival, migration and invasion. Many genetic and epigenetic mechanisms have been identified in triple-negative breast cancer that drive these metastatic phenotypes; however, this knowledge has not yet led to the development of effective drugs for metastatic triple-negative breast cancer (mTNBC). One that may not have received enough attention in the literature is post-translational regulation of broad sets of cancer-related genes through inhibitory microRNAs and the complex competitive endogenous RNA (ceRNA) regulatory networks they are influenced by. This field of study and the resulting knowledge regarding alterations in these networks is coming of age, enabling translation into clinical benefit for patients. Herein, we review metastatic triple-negative breast cancer (mTNBC), the role of ceRNA network regulation in metastasis (and therefore clinical outcomes), potential approaches for therapeutic exploitation of these alterations, knowledge gaps and future directions in the field.

Lipoic acid alters the microRNA signature in breast cancer cells

BACKGROUND

Breast cancer, the deadliest disease affecting women globally, exhibits heterogeneity with distinct molecular subtypes. Despite advances in cancer therapy, the persistence of high mortality rates due to chemotherapy resistance remains a major challenge. Lipoic acid (LA), a natural antioxidant, has proven potent anticancer properties. Yet, the impact of LA on microRNA (miRNA) expression profile in breast cancer remains unexplored.

AIM

The aim of this study was to unravel the effect of LA on miRNA expression profiles in different breast cancer cell lines.

METHODS

The MiRCURY LNA miRNA miRNome qPCR Panel was used to compare the miRNA signature in MDA-MB-231 and MCF-7 cells treated or not with LA.

RESULTS

We identified six upregulated and six downregulated miRNAs in LA-treated MDA-MB-231 cells and 14 upregulated and four downregulated miRNAs in LA-treated MCF-7 cells compared to control cells. KEGG (Kyoto Encyclopedia of Genes and Genomes) pathway analysis revealed that the deregulated miRNAs could alter different signaling cascades including FoxO, P53 and Hippo pathways.

CONCLUSION

The outcome of this study provides further insights into the molecular mechanisms underlying the therapeutic benefit of LA. This in turn could assist the amelioration of LA-based anticancer therapies.

NEAT1 in inflammatory infectious diseases: An integrated perspective on molecular modulation

The long non-coding RNA (lncRNA), NEAT1, has emerged as a central figure in the intricate network of molecular regulators in inflammatory infectious diseases (IIDs). The review initiates a comprehensive exploration of NEAT1's multifaceted roles and molecular interactions in the context of these complex diseases. The study begins by acknowledging the global health burden of IIDs, underscoring the urgency for innovative insights into their pathogenesis and therapeutic avenues. NEAT1 is introduced as a pivotal lncRNA with growing relevance in immune responses and inflammatory processes. The core of this review unravels the NEAT1 landscape, elucidating its involvement in the modulation of immune signalling pathways, regulation of inflammatory cytokines, and interactions with various immune cells during infection. It explores NEAT1's role in orchestrating immune responses and balancing host defence mechanisms with the risk of immunopathology. Furthermore, the review underscores the clinical significance of NEAT1 in infectious diseases, discussing its associations with disease severity, prognosis, and potential as a diagnostic and therapeutic target. It provides insights into ongoing research endeavours aimed at harnessing NEAT1 for innovative disease management strategies, including developing RNA-based therapeutics. Concluding on a forward-looking note, the review highlights the broader implications of NEAT1 in the context of emerging infectious diseases and the possibility for precision medicine approaches that leverage NEAT1's regulatory capacities. In summary, this review illuminates the pivotal role of NEAT1 in IIDs by navigating its complex landscape, offering profound insights into its implications for disease pathogenesis and the development of targeted therapies.

Long noncoding RNAs as regulators of epithelial mesenchymal transition in breast cancer: A recent review

AIMS

Breast cancer (BC) is the most frequently occurring cancer in women worldwide. BC patients are often diagnosed at advanced stages which are characterized by low survival rates. Distant metastasis is considered a leading cause of mortalities among BC patients. Epithelial-to-mesenchymal transition (EMT) is a transdifferentiation program that is necessary for cancer cells to acquire metastatic potential. In the last decade, long noncoding RNAs (lncRNAs) proved their significant contribution to different hallmarks of cancer, including EMT and metastasis. The primary aim of our review is to analyze recent studies concerning the molecular mechanisms of lncRNAs implicated in EMT regulation in BC.

MATERIALS AND METHODS

We adopted a comprehensive search on databases of PubMed, Web of Science, and Google Scholar using the following keywords: lncRNAs, EMT, breast cancer, and therapeutic targeting.

KEY FINDINGS

The different roles of lncRNAs in the mechanisms and signaling pathways governing EMT in BC were summarized. LncRNAs could induce or inhibit EMT through WNT/β-catenin, transforming growth factor-β (TGF-β), Notch, phosphoinositide 3-kinase/protein kinase B (PI3K/AKT), signal transducer and activator of transcription 3 (STAT3), and nuclear factor kappa B (NF-κB) pathways as well as via their interaction with histone modifying complexes and miRNAs.

SIGNIFICANCE

LncRNAs are key regulators of EMT and BC metastasis, presenting potential targets for therapeutic interventions. Further research is necessary to investigate the practical application of lncRNAs in clinical therapeutics.

Emerging roles of the long non-coding RNA NEAT1 in gynecologic cancers

Gynecologic cancers are a worldwide problem among women. Recently, molecular targeted therapy opened up an avenue for cancer diagnosis and treatment. Long non-coding RNAs (lncRNAs) are RNA molecules (> 200 nt) that are not translated into protein, and interact with DNA, RNA, and proteins. LncRNAs were found to play pivotal roles in cancer tumorigenesis and progression. Nuclear paraspeckle assembly transcript 1 (NEAT1) is a lncRNA that mediates cell proliferation, migration, and EMT in gynecologic cancers by targeting several miRNAs/mRNA axes. Therefore, NEAT1 may function as a potent biomarker for the prediction and treatment of breast, ovarian, cervical, and endometrial cancers. In this narrative review, we summarized various NEAT1-related signaling pathways that are critical in gynecologic cancers. Long non-coding RNA (lncRNA) by targeting various signaling pathways involved in its target genes can regulate the occurrence of gynecologic cancers.

Clinical significance of long non-coding RNA ZEB2-AS1 and EMT-related markers in ductal and lobular breast cancer

BACKGROUND

Breast cancer is considered the most prevalent type of cancer in women and accounts for a high rate of death. A body of research has demonstrated that lncRNAs have a regulatory function in human diseases, especially cancers. ZEB2-AS1 is known as an oncogenic lncRNA in various types of cancers, and its deregulation may contribute to cancer development and progression. Therefore, we aimed to reveal the association of ZEB2-AS1 expression with epithelial-mesenchymal transition (EMT) markers, as a hallmark of cancer progression, in a clinical setting.

METHODS

A recent study suggested that ZEB2-AS1 is significantly involved in EMT. Here we intended to explore the roles of lncRNA ZEB2-AS1 in breast cancer (BC) using bioinformatics tools and laboratory settings. We first evaluated the expression of ZEB2-AS1 mRNA in tumor and healthy control tissues by lnCAR database. Furthermore, ZEB2-AS1 expression level, ZEB2, E-cadherin, and vimentin was measured via qRT-PCR in 30 paired ductal and lobular carcinoma tissues from breast cancer patients and the normal adjacent ones. The correlation between the lncRNA ZEB2-AS1 expression and clinicopathological characteristics of the breast cancer patients was evaluated.

RESULTS

ZEB2-AS1 showed an upregulation in breast cancer tissues (p = .04) compared to normal adjacent samples. In addition, its level was higher in breast cancer patients with advanced Stages (III & IV) (n = 18) compared to early Stages (I & II) (n = 12) (p = .04). Moreover, ZEB2 (p = .01) and vimentin (p = .02) expression were upregulated in the BC sample, but the expression level of E-cadherin (p = .02) was downregulated when compared with the adjacent normal tissues. By comparison of the expression of EMT-markers between different stages of breast cancer, overexpression of ZEB2 (p = .04) and vimentin (p = .04) and down expression of E-cadherin (p = .03) was observed in advance stages.

CONCLUSIONS

Collectively, our findings suggest that ZEB2-AS1 expression is significantly upregulated in tumor tissues, especially in advanced stages and ZEB2-AS1 is associated with the aggressiveness of tumors by functioning as putative oncogenic lncRNA. In addition, a combination of ZEB2-AS1 and these EMT markers in breast cancer potentiates these genes as biomarkers for tumor progression.

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

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

LINC01311 exerts an inhibitory effect in thyroid cancer progression by targeting the miR-146b-5p/IMPA2 axis

BACKGROUND

A growing body of research suggests that long non-coding RNA (lncRNA) play an important role during the tumorigenesis and progression of cancers, including thyroid cancer (TC). Herein, we intended to uncover the role and mechanisms of LINC01311 in TC.

METHODS

The relative LINC01311, miR-146b-5p, and IMPA2 expressions were quantified by subjecting TC cells and tissues to western blotting and RT-qPCR. CCK-8 and scratch-wound healing assays were carried out for the evaluation of the proliferation and migration of TC cells. The apoptosis was evaluated by flow cytometry assay and western blotting of Bax and Bcl-2 proteins. Xenograft tumor model was also used to study how LINC01311 functions during TC cell growth. Luciferase reporter and RNA immunoprecipitation (RIP) assays were performed to ascertain miR-146b-5p's interactions with LINC01311 and IMPA2 3'UTR.

RESULTS

The TC cells and tissues exhibited a downregulation of LINC01311 and IMPA2 and an upregulation of miR-146b-5p. LINC01311 overexpression retarded TC cell growth in vitro as well as in vivo. The luciferase reporter and RIP assays verified that miR-146b-5p recognizes LINC01311 and IMPA2 3'UTR by base pairing. LINC01311 overexpression could counteract the oncogenic effect of miR-146b-5p in vitro. Moreover, IMPA2 upregulation could offset the tumor-promoting effect of miR-146b-5p.

CONCLUSION

LINC01311-mediated inhibition of TC cell growth was achieved by targeting the miR-146b-5p/IMPA2 axis. These findings support that targeting the LINC01311/miR-146b-5p/IMPA2 axis may be a promising approach against TC progression.

Correlation and predictive value of serum miR-146b-5p expression during the first trimester of pregnancy with pre-eclampsia

The aim of this study was to investigate the correlation and predictive value of serum miR-146b-5p expression during the first trimester of pregnancy with pre-eclampsia (PE). In total, 32 normal pregnant women (the control group) and 58 subjects with PE were randomly selected from eligible case data. The serum levels of miR-146b-5p, pregnancy associated plasma protein A (PAPP-A) and free beta subunit of human chorionic gonadotropin (free β-hCG) were then detected. Next, we established predictive models of single or multiple markers for PE. The levels of miR-146b-5p in the mild pre-eclampsia (mPE) and severe pre-eclampsia (sPE) groups were higher than the control group and there were significant differences between the three groups (F = 3.424, P = 0.037). The statistical results of the model before and after 200 times 10-fold cross-validation were as follows: miR-146b-5p (AUC = 0.723 vs AUC = 0.710); miR-146b-5p + BMI + MAP + free β-hCG MoM + PAPP-A MoM (AUC = 0.929 vs AUC = 0.851). We found that expression levels of miR-146b-5p in the first trimester were significantly higher in the serum of pregnant women with PE than in the normal pregnancy group. A prediction model in combination with miR-146b-5p and other markers improved the early predictive value for PE.IMPACT STATEMENTWhat is already known on this subject? Pre-eclampsia is a complex systemic disease with hypertension as the main clinical manifestation and causes extensive damage to the body. Some existing maternal biochemical markers have limited value in predicting PE, and new biomarkers with high sensitivity and specificity are urgently needed in clinical practice. There are a variety of abnormal expression miRNAs in PE, however, the relationship between miR-146b-5p and PE has yet to be fully elucidated.What do the results of this study add? We first found that expression levels of serum miR-146b-5p in the first trimester were significantly higher in PE than in a normal pregnancy group. A prediction model a combination of miR-146b-5p and other maternal characteristics and biochemical markers can improve the early predictive value for PE.What are the implications of these findings for clinical practice and/or further research? PE progresses rapidly and has become a severe target organ complication when discovered. Therefore, the early prediction of a high risk of PE, along with early intervention and prevention measures, are of great significance. Compared to maternal biochemical markers, combination of miR-146b-5p and maternal characteristics and biochemical markers can improve the early predictive value for PE.

RT-qPCR Expression Profiles of Selected Oncogenic and Oncosuppressor miRNAs in Formalin-Fixed, Paraffin-Embedded Canine Mammary Tumors

MicroRNAs (miRNAs) can act as oncogenes or oncosuppressor genes, and their involvement in nearly all cancer-associated processes makes these small molecules promising diagnostic and prognostic biomarkers in cancer, as well as specific targets for cancer therapy. This study aimed to investigate the expression of 7 miRNAs (miR-18a, miR-18b, miR-22, miR-124, miR-145, miR-21, miR-146b) in formalin-fixed, paraffin-embedded canine mammary tumors (CMTs) by quantitative reverse transcription polymerase chain reaction (RT-qPCR). Twenty-six mammary samples were selected, including 22 CMTs (7 benign; 15 malignant) and 4 control samples (3 normal mammary gland and 1 case of lobular hyperplasia). Oncogenic miR-18a, miR-18b and miR-21 were significantly upregulated in malignant tumors compared with control tissues (p < 0.05). Conversely, oncosuppressor miR-146b was significantly downregulated in benign and malignant mammary tumors compared with control samples (p < 0.05) while, no group-related differences in the expression levels of miR-22, miR-124 and miR-145 were found (p > 0.05). Upregulated miRNAs found here, may regulate genes involved in receptor-mediated carcinogenesis and proteoglycan remodeling in cancer; while miRNA with reduced expression can regulate genes involved in Toll-like receptor and MAPK signaling pathways. According to the results obtained in the current study, the oncogenic and oncosuppressor miRNAs analyzed here are dysregulated in CMTs and the dysregulation of miRNA targets may lead to specific altered cellular processes and key pathways involved in carcinogenesis. Of note, since oncogenic miRNAs predicted to regulate neoplastic cell proliferation and hormonal activities, they may play an active role in neoplastic transformation and/or progression, having mechanistic and prognostic relevance in CMTs.

LncRNA OR2A1-AS1 index predicts survival in germinal center-like diffuse large B-cell lymphoma

BACKGROUND

Diffuse large B-cell lymphoma (DLBCL) is a highly aggressive form of non-Hodgkin lymphoma. Long noncoding RNA (lncRNA) has been evaluated as prognostic markers in various carcinomas. However, the prognostic value of the lncRNA index in DLBCL has not been fully understood. Hence, this study aimed to identify the prognostic value of lncRNA olfactory receptor family 2 subfamily A member 1-antisense RNA 1 (OR2A1-AS1) in DLBCL.

METHODS

The Gene Expression Omnibus (GEO) database was used to obtain the GSE97336 dataset comprising lncRNA expression profiles. Quantitative reverse transcription polymerase chain reaction (QRT-PCR) was conducted to evaluate the expression of OR2A1-AS1 in 98 cases of DLBCL.

RESULTS

OR2A1-AS1 expression was considerably reduced in DLBCL patients, reduced OR2A1-AS1 expression was linked to a shorter overall survival (OS) and progression-free survival (PFS) in DLBCL patients, especially those with the germinal center B-cell-like subtype (GCB). Multivariate analysis (MVA) revealed that the OR2A1-AS1 index had prognostic significance. Patients with low OR2A1-AS1 expression have a poor prognosis.

CONCLUSIONS

OR2A1-AS may represent an effective predictor of patients' outcomes with DLBCL.

The Long Noncoding RNA MEG3 Retains Epithelial-Mesenchymal Transition by Sponging miR-146b-5p to Regulate SLFN5 Expression in Breast Cancer Cells

More and more studies have shown that long noncoding RNAs (lncRNAs) play essential roles in malignant tumors. The lncRNA MEG3 serves as a crucial molecule in breast cancer development, but the specific molecular mechanism needs to be further explored. We previously reported that Schlafen family member 5 (SLFN5) inhibits breast cancer malignant development by regulating epithelial-mesenchymal transition (EMT), invasion, and proliferation/apoptosis. Herein, we demonstrated that MEG3 was downregulated in pan-cancers and correlated with SLFN5 expression positively in breast cancer by bioinformatics analysis of TCGA and UCSC Xena data. Intervention with MEG3 positively affected SLFN5 expression in breast cancer cells. MEG3 repressed EMT and migration/invasion, similar to our previously reported functions of SLFN5 in breast cancer. Through bioinformatics analysis of starBase and LncBase data, 12 miRNAs were found to regulate both SLFN5 and MEG3, in which miR-146b-5p was confirmed to be regulated by MEG3 using MEG3 siRNA and overexpression method. MiR-146b-5p could bind to both SLFN5 3′UTR and MEG3, and inhibit their expression in a competing endogenous RNA mechanism, assayed by luciferase reporter and RNA pull down methods. Therefore, we conclude that MEG3 positively modulates SLFN5 expression by sponging miR-146b-5p and inhibits breast cancer development.

Construction of ceRNA Networks Associated With CD8 T Cells in Breast Cancer

Background

The infiltration of CD8 T cells is usually linked to a favorable prognosis and may predict the therapeutic response of breast cancer patients to immunotherapy. The purpose of this research is to investigate the competing endogenous RNA (ceRNA) network correlated with the infiltration of CD8 T cells.

Methods

Based on expression profiles, CD8 T cell abundances for each breast cancer (BC) patient were inferred using the bioinformatic method by immune markers and expression profiles. We were able to extract the differentially expressed RNAs (DEmRNAs, DEmiRNAs, and DElncRNAs) between low and high CD8 T-cell samples. The ceRNA network was constructed using Cytoscape. Machine learning models were built by lncRNAs to predict CD8 T-cell abundances. The lncRNAs were used to develop a prognostic model that could predict the survival rates of BC patients. The expression of selected lncRNA (XIST) was validated by quantitative real-time PCR (qRT-PCR).

Results

A total of 1,599 DElncRNAs, 89 DEmiRNAs, and 1,794 DEmRNAs between high and low CD8 T-cell groups were obtained. Two ceRNA networks that have positive or negative correlations with CD8 T cells were built. Among the two ceRNA networks, nine lncRNAs (MIR29B2CHG, NEAT1, MALAT1, LINC00943, LINC01146, AC092718.4, AC005332.4, NORAD, and XIST) were selected for model construction. Among six prevalent machine learning models, artificial neural networks performed best, with an area under the curve (AUC) of 0.855. Patients from the high-risk category with BC had a lower survival rate compared to those from the low-risk group. The qRT-PCR results revealed significantly reduced XIST expression in normal breast samples, which was consistent with our integrated analysis.

Conclusion

These results potentially provide insights into the ceRNA networks linked with T-cell infiltration and provide accurate models for T-cell prediction.

Exosomal LINC01213 Plays a Role in the Transition of Androgen-Dependent Prostate Cancer Cells into Androgen-Independent Manners

Background

Castration-resistant prostate cancer (CRPC), one of the prostate cancers, is a medical conundrum around the world. Some studies have demonstrated that many long noncoding RNAs in exosomes are very important in many types of cancer, including prostate cancer. However, until now, the function of exosomes in the occurrence and development of CRPC has not been reported.

Methods

In vitro, cell coculture was used in LNCap cells and PC-3 cells, while the isolation and purification of exosomes and the subsequent treatment assays were used in functional studies. In vitro assays were performed to detect the transformation of ADPC cells (androgen-dependent prostate cancer) into AIPC cells (androgen-independent prostate cancer). Subsequently, a lncRNA-sequencing assay was performed to detect different lncRNA expression profiles in ADPC cells cocultured with or without AIPC exosomes. The role of LINC01213 was analysed by a TCGA database after silencing the expression of LINC01213. CCK-8, qRT-PCR, and Western blotting studies were performed to analyse the possible mechanism by which exosomes participate in prostate cancer progression.

Results

In the coculture system, ADPC cells acquired androgen deprivation tolerance through exosome-mediated intercellular communication. Exosomes secreted by AIPC cells can promote the transformation of ADPC cells into androgen-independent cells in vitro and in vivo. lncRNA sequencing showed that LINC01213 was upregulated in exosomes derived from AIPC cell lines. The rescue experiments were preformed, and the results revealed that most of the functions of LINC01213 were performed by Wnt/β-catenin.

Conclusions

All the findings showed that exosomes play a key role in CRPC progression by upregulating LINC01213 and activating Wnt/β-catenin signalling.

Recent advances of NEAT1-miRNA interactions in cancer

With high incidence rate, cancer is the main cause of death in humans. Non-coding RNAs, as novel master regulators, especially long non-coding RNAs (lncRNAs) and microRNAs (miRNAs), play important roles in the regulation of tumorigenesis. lncRNA NEAT1 has recently gained much attention, as it is dysregulated in a broad spectrum of cancers, where it acts as either an oncogene or a tumor suppressor gene. Accumulating evidence shows that NEAT1 is correlated with the process of carcinogenesis, including proliferation, invasion, survival, drug resistance, and metastasis. NEAT1 is considered to be a biomarker and a novel therapeutic target for the diagnosis and prognosis of different cancer types. The mechanisms by which NEAT1 plays a critical role in cancers are mainly via interactions with miRNAs. NEAT1-miRNA regulatory networks play significant roles in tumorigenesis, which has attracted much attention from researchers around the world. In this review, we summarize the interaction of NEAT1 with miRNAs in the regulation of protein-coding genes in cancer. A better understanding of the NEAT1-miRNA interactions in cancer will help develop new diagnostic biomarkers and therapeutic approaches.

miR‑146b‑5p promotes colorectal cancer progression by targeting TRAF6

Increasing evidence highlights the multiple roles of microRNAs (miRs) in the tumorigenesis of colorectal cancer (CRC); however, the molecular mechanism, particularly the target of miR-146b-5p in CRC has not been fully elucidated. The present study aimed to elucidate the influence of miR-146b-5p via regulating tumor necrosis factor receptor-associated factor 6 (TRAF6) in CRC. The expression levels of miR-146b-5p and TRAF6 in CRC tissue and cells were determined by reverse transcription quantitative PCR and western blotting. Binding between miR-146b-5p and TRAF6 was examined using a dual luciferase reporter gene assay. The impact of miR-146b-5p and TRAF6 on proliferation and migration of CRC cells was determined using Cell Counting Kit-8 and Transwell assays, respectively. An animal model of CRC was established to determine the carcinogenic effect of the miR-146b-5p-TRAF6 axis. The results demonstrated that miR-146b-5p was highly expressed in CRC tissue samples compared with in normal adjacent tissue samples and in CRC cells compared with in the normal NCM460 cell line, whereas TRAF6 was expressed at low levels. Overexpression of miR-146b-5p decreased TRAF6 expression in CRC HT29 and SW620 cells. miR-146b-5p targeted and inhibited TRAF6 expression in CRC cells. Furthermore, transfection with a miR-146b-5p mimic promoted the proliferation, migration and invasion of CRC cells and tumor growth; however, these effects were abolished by TRAF6 overexpression. Transfection with a miR-146b-5p inhibitor suppressed the proliferation of CRC cells. Taken together, the results from the present study demonstrated that miR-146b-5p could enhance the initiation and tumorigenesis of CRC by targeting TRAF6. These results will help elucidate the mechanisms underlying CRC development and will facilitate the development of targeted therapy for CRC.

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

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

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

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

Nuclear receptor binding SET domain protein 1 promotes epithelial-mesenchymal transition in paclitaxel-resistant breast cancer cells via regulating nuclear factor kappa B and F-box and leucine-rich repeat protein 11

Breast cancer (BC) is regarded as the major cause of cancer-associated deaths in women. Paclitaxel exerts a critical impact on the chemotherapy of BC, but the resistance to paclitaxel becomes a great obstacle in treating the disease. It is reported that noncoding RNA nuclear receptor binding SET domain protein 1 (NSD1) plays a significant role in drug resistance; however, the special role of NSD1 in paclitaxel-resistant BC is unclear. Human BC cell line MCF-7 was used to establish paclitaxel-resistant BC cells (MCF-7/PR). Reverse transcription quantitative polymerase chain reaction (RT-qPCR) displayed that NSD1 and F-box and leucine-rich repeat protein 11 (FBXL11) were highly expressed in BC tissues. Western blotting was utilized for protein level assessment. Cell counting kit-8 (CCK-8), Transwell, wound healing assays, and animal experiments were conducted to examine the influence of NSD1 or FBXL11 on the malignant behaviors of BC in vitro and in vivo, respectively. Transfected MCF-7/PR cells were injected subcutaneously into BALB/c nude mice with or without treatment of paclitaxel. The nuclear factor kappa B (NF-kB) activity was evaluated by the luciferase reporter assay. Results showed that NSD1 knockdown inhibited the epithelial-mesenchymal transition (EMT), migration and invasiveness of BC in vitro, which was rescued by FBXL11 overexpression. Furthermore, NSD1 silencing promoted paclitaxel sensitivity of paclitaxel-resistant BC cells and suppressed tumor growth and paclitaxel resistance in vivo. NSD1 knockdown reduced NF-kB activity, while FBXL11 inhibition markedly increased NF-kB activity. Collectively, NSD1 facilitates the EMT, migration and invasion in paclitaxel-resistant BC cells via regulating NF-kB and FBXL11.

Progestins as Anticancer Drugs and Chemosensitizers, New Targets and Applications

Progesterone and its synthetic analogues, progestins, participate in the regulation of cell differentiation, proliferation and cell cycle progression. Progestins are usually applied for contraception, maintenance of pregnancy, and hormone replacement therapy. Recently, their effectiveness in the treatment of hormone-sensitive tumors was revealed. According to current data, the anticancer activity of progestins is mainly mediated by their cytotoxic and chemosensitizing influence on different cancer cells. In connection with the detection of previously unknown targets of the progestin action, which include the membrane-associated progesterone receptor (PR), non-specific transporters related to the multidrug resistance (MDR) and mitochondrial permeability transition pore (MPTP), and checkpoints of different signaling pathways, new aspects of their application have emerged. It is likely that the favorable influence of progestins is predominantly associated with the modulation of expression and activity of MDR-related proteins, the inhibition of survival signaling pathways, especially TGF-β and Wnt/β-catenin pathways, which activate the proliferation and promote MDR in cancer cells, and the facilitation of mitochondrial-dependent apoptosis. Biological effects of progestins are mediated by the inhibition of these signaling pathways, as well as the direct interaction with the nucleotide-binding domain of ABC-transporters and mitochondrial adenylate translocase as an MPTP component. In these ways, progestins can restore the proliferative balance, the ability for apoptosis, and chemosensitivity to drugs, which is especially important for hormone-dependent tumors associated with estrogen stress, epithelial-to-mesenchymal transition, and drug resistance.

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

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

Long Non-Coding RNAs as Potential Diagnostic and Prognostic Biomarkers in Breast Cancer: Progress and Prospects

Breast cancer is the most common malignancy among women worldwide, excluding non-melanoma skin cancer. It is now well understood that breast cancer is a heterogeneous entity that exhibits distinctive histological and biological features, treatment responses and prognostic patterns. Therefore, the identification of novel ideal diagnostic and prognostic biomarkers is of utmost importance. Long non-coding RNAs (lncRNAs) are commonly defined as transcripts longer than 200 nucleotides that lack coding potential. Extensive research has shown that lncRNAs are involved in multiple human cancers, including breast cancer. LncRNAs with dysregulated expression can act as oncogenes or tumor-suppressor genes to regulate malignant transformation processes, such as proliferation, invasion, migration and drug resistance. Intriguingly, the expression profiles of lncRNAs tend to be highly cell-type-specific, tissue-specific, disease-specific or developmental stage-specific, which makes them suitable biomarkers for breast cancer diagnosis and prognosis.

Non-coding RNAs in necroptosis, pyroptosis and ferroptosis in cancer metastasis

Distant metastasis is the main cause of death for cancer patients. Recently, the newly discovered programmed cell death includes necroptosis, pyroptosis, and ferroptosis, which possesses an important role in the process of tumor metastasis. At the same time, it is widely reported that non-coding RNA precisely regulates programmed death and tumor metastasis. In the present review, we summarize the function and role of necroptosis, pyrolysis, and ferroptosis involving in cancer metastasis, as well as the regulatory factors, including non-coding RNAs, of necroptosis, pyroptosis, and ferroptosis in the process of tumor metastasis.

The nuclear functions of long noncoding RNAs come into focus

Long noncoding RNAs (lncRNAs), defined as untranslated and tightly-regulated transcripts with a length exceeding 200 nt, are common outputs of the eukaryotic genome. It is becoming increasingly apparent that many lncRNAs likely serve as important regulators in a variety of biological processes. In particular, some of them accumulate in the nucleus and function in diverse nuclear events, including chromatin remodeling, transcriptional regulation, RNA processing, DNA damage repair, etc. Here, we unite recent progresses on the functions of nuclear lncRNAs and provide insights into the future research directions of this field.

LncRNA NEAT1 Promotes High Glucose-Induced Mesangial Cell Hypertrophy by Targeting miR-222-3p/CDKN1B Axis

Glomerular hypertrophy is an early morphological alteration in diabetic nephropathy. Cyclin-Dependent Kinases have been shown to be required for high glucose (HG)-induced hypertrophy; however, the upstream regulators of CDKN1B in glomerular hypertrophy remain unclear. Herein we describe a novel pathway in which Long noncoding RNA (lncRNA) NEAT1 regulates the progression of mesangial cell hypertrophy via a competing endogenous RNA (ceRNA) mechanism. Real-time PCR was performed to detect the relative NEAT1 and miR-222-3p expressions and further confirmed the relationship between NEAT1 and miR-222-3p. Cell cycle was evaluated by flow cytometry. The related mechanisms were explored by Western blot, RNA immunoprecipitation and chromatin immunoprecipitation assay. We show that NEAT1 forms double stranded RNA (dsRNA) with miR-222-3p, thus limiting miR-222-3p's binding with CDKN1B. This release of CDKN1B mRNA leads to elevated CDKN1B protein expression, resulting in hypertrophy. In addition, we demonstrated that STAT3 which is activated by HG induces the transcription of NEAT1 by binding to its promoter. Our findings underscore an unexpected role of lncRNAs on gene regulation and introduce a new mode of proliferation regulation in mesangial cells.

Long non-coding RNA ATB is associated with metastases and promotes cell invasion in colorectal cancer via sponging miR-141-3p

Long non-coding RNAs (lncRNAs) serve crucial roles in cancer development and progression. lncRNA-activated by transforming growth factor-β (lncRNA-ATB) mediates cell proliferation. However, the association between lncRNA-ATB and human colorectal cancer (CRC) is not completely understood. Therefore, the present study aimed to investigate the role of lncRNA-ATB in CRC, as well as the underlying mechanism. 50 pairs of tumor tissues and adjacent normal tissues from patients with primary CRC were collected. The expression of lncRNA-ATB and microRNA (miR)-141-3p in CRC tissues, adjacent normal tissues and cell lines was detected using reverse transcription-quantitative PCR. CCK-8, colony formation, Transwell, western blot, dual luciferase reporter gene, RNA immunoprecipitation and immunohistochemistry staining assays were conducted to assess the biological function of lncRNA-ATB and miR-141-3p in CRC progression. lncRNA-ATB was upregulated in CRC tissues and cell lines compared with healthy tissues and cells, respectively. Moreover, high expression of lncRNA-ATB was significantly associated with advanced TNM stage and metastasis in CRC. In addition, the results indicated that lncRNA-ATB expression predicted the prognosis and overall survival of patients with CRC. Compared with small interfering RNA-negative control, lncRNA-ATB knockdown inhibited CRC cell proliferation, migration and invasion, whereas, compared with vector, lncRNA-ATB overexpression promoted CRC cell proliferation, migration and invasion. Furthermore, the in vivo experiment suggested that lncRNA-ATB knockdown inhibited tumor growth. The results also indicated that lncRNA-ATB may contribute to CRC progression via binding to tumor suppressor microRNA-141-3p. Collectively, the present study suggested a crucial role of lncRNA-ATB in CRC tumorigenesis, suggesting that lncRNA-ATB may serve as an important marker for the diagnosis and development of CRC.