Positive expression of miR-361-5p indicates better prognosis for breast cancer patients

Correlation of Wilms' Tumor 1 (WT1) with Oxidative Stress Markers and Expression of miR-361-5p; New Aspect of WT1 in Breast Cancer

Breast carcinoma is a heterogeneous disease that affects millions of women worldwide. Wilms' tumor 1 (WT1) is an oncogene that promotes proliferation, metastasis and reduces apoptosis. MicroRNAs (miR) are short noncoding RNAs with a major role in cancer metastasis. In present study, we investigated the association of serum level of WT1 with oxidative stress and expression of miR-361-5p in breast cancer. Serum samples of 45 patients and of 45 healthy women analyzed for protein level of WT1, malondialdehyde (MDA), total oxidant status (TOS), and total antioxidant capacity (TAC). Serum and tissue expression of miR-361-5p in 45 tumor tissues and 45 paired non-tumor adjacent tissues and 45 serum samples of patients and healthy women analyzed by qRT-PCR. Protein levels of WT1 not significantly difference in serum of patients compared to healthy controls. Serum levels of MDA and TOS in patients were higher, but TAC level was lower than healthy controls (p < 0.001). There was a positive correlation between WT1 with MDA and TOS, and a negative correlation between WT1 with TAC in patients. miR-361-5p expression in tumor tissues and serum of patients was lower than non-tumor adjacent tissues and serum of healthy controls, respectively (p < 0.001). Moreover, there was a negative correlation between miR-361-5p and WT1 in patients. The positive correlation between WT1 with MDA and TOS and negative correlation between TAC and miR-361-5p suggests that this gene can play an important role in worse prognoses in breast cancer. Additionally, miR-361-5p may serve as an invasive biomarker for early detection of breast cancer.

Bioinformatic Analysis Divulged Novel Prognostic Circulating MicroRNAs and Their Potential Target Genes in Breast Cancer

Breast cancer (BC) is both an inherited and environmental-based disease which is the leading cause of death among women. Early detection of BC can prevent invasion and metastasis in patients. Currently, researchers endeavor to find non-invasive biological markers from body fluids. Circulating non-coding RNAs such as microRNAs (miRNAs) can potentially be valuable prognostic and detective biomarkers. To identify novel miRNA-based biomarkers, we utilized bioinformatic tools. To reach this goal, the miRNA expression profiles of GSE31309, GSE 44,281, GSE98181, and GSE118782 were analyzed through a limma package of R. Target gene prediction of differentially expressed miRNAs, called differentially expressed miRNAs (DEMs), between samples of healthy individuals and BC patients was implemented through Multimir package of R. Functional enrichment analysis of predicted target genes through Enrich R (online database) revealed that most of the genes are enriched in the mitochondrial outer membrane for cellular component, intrinsic apoptotic signaling regulations for biological processes, transcription co-receptor activity for molecular functions, and dopaminergic synapse pathway. Furthermore, our survival analysis results revealed that miR-29c and mir-361 have the potential to serve as prognostic biomarkers.

The Role of miRNAs in the Prognosis of Triple-Negative Breast Cancer: A Systematic Review and Meta-Analysis

Breast cancer is one of the most common malignancies among women around the world. The basal or triple-negative subtype (TNBC) is a heterogeneous group of tumors, characterized by its aggressive and metastatic nature, with low survival and worse prognosis. Research on genetic biomarkers, such as microRNAs (miRs) in TNBC, demonstrate their relevance in the prognosis of the disease. Therefore, the objective of this research was to verify the role of miRs in the prognosis of TNBC. A search was carried out in the PubMed (MEDLINE), Web of Science, and Scopus databases, with articles in the English language from 2010 to 2022. Only articles that analyzed the role of miRNAs in the prognosis of TNBC and that met the criteria of the MOOSE method were included. For the preparation and planning of this systematic review, a PRISMA checklist and the MOOSE method were used. The Newcastle-Ottawa Scale was used to analyze the quality of the included studies. The excluded criteria considered were: (1) studies that presented duplication in the databases; (2) reviews of the literature, clinical case reports, meta-analyses, conference abstracts, letters to the editor, theses, dissertations, and book chapters; (3) studies that stratified only women diagnosed with other subtypes of breast cancer subtypes; (4) experiments without a control or comparison group. After the bibliographic survey of the 2.274 articles found, 43 articles met the inclusion criteria, totaling 5421 patients with TNBC analyzed for this review. Six miRs (miR-155, miR-21, miR-27a/b/, miR-374a/b, miR-30a/c/e, and miR-301a) were included in the meta-analysis. A low expression of miR-155 was associated with reduced overall survival (OS) (HR: 0.68, 95% CI: 0.58-0.81). A high expression of miR-21 was a predictor of OS reduction (HR: 2.56; 95% CI: 1.49-4.40). In addition, high levels of miR-27a/b and miR-301a/b were associated with lower OS, while the decreased expression levels of miR-30 and miR-374a/b were associated with worse relapse-free survival (RFS) and shorter disease-free survival (DFS), respectively. The present study revealed that miRs play essential roles in the development of metastases, in addition to acting as suppressors of the disease, thus improving the prognosis of TNBC. However, the clinical application of these findings has not yet been investigated.

ALDH1A3–Linc00284 Axis Mediates the Invasion of Colorectal Cancer by Targeting TGFβ Signaling via Sponging miR-361-5p

ALDH1A3 and Linc00284 involve in colorectal cancer (CRC) development; however, the regulatory mechanism is still unclear. In this study, we collected clinicopathological characteristics and tissue samples from 73 CRC patients to analyze the expression of ALDH1A3, Linc00284, TGFβ signaling and miR-361-5p using qPCR, Western blotting, and ELISA. Multiple CRC cell lines were evaluated in this study, and the highest level of ALDH1A3 was observed in SW480 cells. To investigate the regulatory mechanism, RIP and luciferase assays were used to validate the interaction between Linc00284, miR-361-5p, and TGFβ. Proliferation, viability, migration, and invasion assays were performed to profile the effects of the ALDH1A3–Linc00284 axis in CRC cell functions, which was upregulated in CRC tissues. Knockdown ALDH1A3 or Linc00284 significantly reduced TGFβ expression and suppressed the EMT process, while overexpression had opposite effects. miR-361-5p targeted TGFβ directly, which negatively correlated with ALDH1A3–Linc00284 expression and CRC progression. Mechanistically, upregulation of ALDH1A3–Linc00284 promotes colorectal cancer invasion and migration by regulating miR-361-5p/TGFβ signaling pathway. Dysregulation of the ALDH1A3–Linc00284-miR-361-5p-TGFβ axis causes CRC invasion, which might provide a new insight into the treatment of CRC.

Stability of circulating microRNAs in serum

There is a strong body of evidence by several translational studies which demonstrate the potential of circulating miRNAs as a potential biomarker in oncology. However, recent reports documented varying stability of these small RNA molecules in serum samples. The aim of our pilot study was to evaluate the stability of miRNAs in serum in relation to food intake and sample storage. Serum miRNA expression levels of 16 different miRNAs from 8 healthy volunteers were quantified by real-time PCR. 4 samples from each donor were analysed—2 samples (fasting, in the morning and after food intake, at noon) were analysed within 24h and 2 samples (fasting and after food intake, at noon) were stored at -80°C for 14 days and subsequently analysed. Student´s t-test was used to determine significant differences. The detectability of the distinct miRNA as a surrogate for the stability of these small RNA molecules was slightly altered by the storage conditions, but only a miRNA 22-3p, out of the analysed 16 miRNAs, shows significant lower dCq expression (3.821 vs. 4.530; p<0,01) by qPCR dependent on storage conditions (-80°C vs. 4°C). However, miRNA levels were not affected by food intake. The difference between samples taken in the morning (fasting) and at noon (after a normal meal) did not show any significant differences. MiRNAs can be considered to be a relatively stable tool in laboratory diagnostics, but clearly every new assay needs thorough evaluation. The stability of miRNAs documented here in healthy volunteers shows their potential in the search for innovative biomarkers in oncology.

MMP1 regulated by NEAT1/miR-361-5p axis facilitates the proliferation and migration of cutaneous squamous cell carcinoma via the activation of Wnt pathway

Cutaneous squamous cell carcinoma (CSCC) is one of the most malignant tumors worldwide. It has been validated that matrix metallopeptidase 1 (MMP1) expression was obviously up-regulated in CSCC tissues. However, its specific role in CSCC is still unclear. RT-qPCR analysis and western blot assays were used to measure the mRNA and protein expressions, respectively. MTT and colony formation assays were conducted to assess proliferative ability. Transwell assays were adopted to evaluate migratory and invasive abilities. Flow cytometry and caspase-3/8/9 activity assays were carried out to evaluate cell apoptosis. Relevant mechanism experiments were finally performed to delineate molecular relationship among genes. We found that the expression of MMP1 was up-regulated in CSCC cells, and knockdown of MMP1 suppressed cell proliferation and invasion in CSCC. Subsequently, miR-361-5p was validated to target MMP1. Moreover, miR-361-5p was proved to be sponged by nuclear paraspeckle assembly transcript 1 (NEAT1) in CSCC. We further demonstrated that NEAT1 could activate Wnt pathway to affect cell proliferation and invasion. Finally, miR-361-5p inhibition rescued the suppressing effects of NEAT1 depletion on cell proliferation, invasion as well as Wnt pathway in CSCC. In summary, MMP1 regulated by NEAT1/miR-361-5p axis facilitated CSCC malignant behaviors via Wnt pathway activation.

miR-361-5p as a promising qRT-PCR internal control for tumor and normal breast tissues

BACKGROUND

One of the most widely used evaluation methods in miRNA experiments is qRT-PCR. However, selecting suitable internal controls (IC) is crucial for qRT-PCR experiments. Currently, there is no consensus on the ICs for miRNA qRT-PCR experiments in breast cancer. To this end, we tried to identify the most stable (the least expression alteration) and promising miRNAs in normal and tumor breast tissues by employing TCGA miRNA-Seq data and then experimentally validated them on fresh clinical samples.

METHODS

A multi-component scoring system was used which takes into account multiple expression stability criteria as well as correlation with clinical characteristics. Furthermore, we extended the scoring system for more than two biological sub-groups. TCGA BRCA samples were analyzed based on two grouping criteria: Tumor & Normal samples and Tumor subtypes. The top 10 most stable miRNAs were further investigated by differential expression and survival analysis. Then, we examined the expression level of the top scored miRNA (hsa-miR-361-5p) along with two commonly used ICs hsa-miR-16-5p and U48 on 34 pairs of Primary breast tumor and their adjacent normal tissues using qRT-PCR.

RESULTS

According to our multi-component scoring system, hsa-miR-361-5p had the highest stability score in both grouping criteria and hsa-miR-16-5p showed significantly lower scores. Based on our qRT-PCR assay, while U48 was the most abundant IC, hsa-miR-361-5p had lower standard deviation and also was the only IC capable of detecting a significant up-regulation of hsa-miR-21-5p in breast tumor tissue.

CONCLUSIONS

miRNA-Seq data is a great source to discover stable ICs. Our results demonstrated that hsa-miR-361-5p is a highly stable miRNA in tumor and non-tumor breast tissue and we recommend it as a suitable reference gene for miRNA expression studies in breast cancer. Additionally, although hsa-miR-16-5p is a commonly used IC, it's not a suitable one for breast cancer studies.

Competing Endogenous RNA Networks in Glioma

Gliomas are the most common and malignant primary brain tumors. Various hallmarks of glioma, including sustained proliferation, migration, invasion, heterogeneity, radio- and chemo-resistance, contribute to the dismal prognosis of patients with high-grade glioma. Dysregulation of cancer driver genes is a leading cause for these glioma hallmarks. In recent years, a new mechanism of post-transcriptional gene regulation was proposed, i.e., "competing endogenous RNA (ceRNA)." Long non-coding RNAs, circular RNAs, and transcribed pseudogenes act as ceRNAs to regulate the expression of related genes by sponging the shared microRNAs. Moreover, coding RNA can also exert a regulatory role, independent of its protein coding function, through the ceRNA mechanism. In the latest glioma research, various studies have reported that dysregulation of certain ceRNA regulatory networks (ceRNETs) accounts for the abnormal expression of cancer driver genes and the establishment of glioma hallmarks. These achievements open up new avenues to better understand the hidden aspects of gliomas and provide new biomarkers and potential efficient targets for glioma treatment. In this review, we summarize the existing knowledge about the concept and logic of ceRNET and highlight the emerging roles of some recently found ceRNETs in glioma progression.

High Expression of microRNA-223 Indicates a Good Prognosis in Triple-Negative Breast Cancer

Purpose

MicroRNAs can influence many biological processes and have shown promise as cancer biomarkers. Few studies have focused on the expression of microRNA-223 (miR-223) and its precise role in breast cancer (BC). We aimed to examine the expression level of miR-223 and its prognostic value in BC.

Methods

Tissue microarray (TMA)-based miRNA detection in situ hybridization (ISH) with a locked nucleic acid (LNA) probe was used to detect miR-223 expression in 450 BC tissue samples. Overall survival (OS) and disease-free survival (DFS) were compared between two groups using the Kaplan-Meier method and Cox regression model.

Results

OS and DFS were prolonged in the high miR-223 expression group compared to the low miR-223 expression group (p < 0.0001 and p = 0.017, respectively), especially in patients with the triple-negative breast cancer (TNBC) subtype (p = 0.046 and p < 0.001, respectively). Univariate and multivariate Cox regression analyses revealed that TNM stage (p = 0.008), the molecular subtype (p = 0.049), and miR-223 (p < 0.001) were independently associated with OS and DFS. External validation was performed with the METABRIC and The Cancer Genome Atlas (TCGA) databases via online webtools and was consistent with the data described above.

Conclusions

This study provides evidence that high miR-223 expression at diagnosis is associated with improved DFS and OS for BC patients, especially those with the TNBC subtype. miR-223 is a valid and independent prognostic biomarker in BC.

Genome-wide microRNA expression analysis in human placenta reveals sex-specific patterns: an ENVIRONAGE birth cohort study

There is an increasing interest in microRNAs (miRNAs) as they are of utmost importance in gene regulation at the posttranscriptional level. Sex-related susceptibility for non-communicable diseases later in life could originate in early life. Until now, no data on sex-specific miRNA expression are available for the placenta. Therefore, we investigated the difference by sex of newborn's miRNA expression in human placental tissue. Within the ENVIRONAGE birth cohort, miRNA and mRNA expression profiling was performed in 60 placentae (50% boys) using Agilent (8 × 60 K) microarrays. The distribution of chromosome locations was studied and pathway analysis of the identified sex-specific miRNAs in the placenta was carried out. Of the total 2558 miRNAs on the array, 597 miRNAs were expressed in over 70% of the samples and were included for further analyses. A total of 142 miRNAs were significantly (FDR<0.05) associated with the newborn's sex. In newborn girls, 76 miRNAs had higher expression (hsa-miR-361-5p as most significant) and 66 miRNAs had lower expression (hsa-miR-4646-5p as most significant) than in newborn boys. In the same study population, placental differentially expressed genes by sex were also identified using a whole genome approach. The placental gene expression revealed 27 differentially expressed genes by comparing girls to boys. Ultimately, we studied the miRNA-RNA interactome and identified 14 miRNA-mRNA interactions as sex-specific. Sex differences in placental m(i)RNA expression may reveal sex-specific patterns already present during pregnancy, which may influence physiological conditions in early or later life. These molecular processes might play a role in sex-specific disease susceptibility in later life.

Extracellular vesicles derived from M1 macrophages deliver miR-146a-5p and miR-146b-5p to suppress trophoblast migration and invasion by targeting TRAF6 in recurrent spontaneous abortion

Rationale: Emerging evidence demonstrates that insufficient migration and invasion of trophoblasts play critical roles in the pathogenesis of recurrent spontaneous abortion (RSA). Cell-to-cell communication at the maternal-fetal interface is essential to maintain the invasion and migration of trophoblasts. M1 macrophages, important immune cellular components at the maternal-fetal interface, have been reported to be elevated in decidua tissues from patients with RSA. Recent studies indicate that M1 macrophages modulate trophoblast biological behaviors; however, the underlying mechanisms remain poorly understood. Methods: Extracellular vesicles (EVs) were isolated from the supernatant of M1 macrophages inducted from THP-1 cells (M1-EVs) by ultracentrifugation, identified by transmission electron microscopy, nanoparticle tracking analysis, and western blotting, and their miRNA profile was characterized by miRNA sequencing. Scratch wound healing and transwell assays were used to investigate the effect of M1-EVs on trophoblast migration and invasion. RT-PCR, western blotting, and luciferase reporter assays were conducted to uncover the underlying mechanism. Finally, animal experiments were employed to explore the effect of M1-EVs on embryo absorption in mice. Results: M1 macrophages suppressed trophoblast EMT to reduce their migration and invasion abilities in vitro by secreting EVs. Through miRNA sequencing, miR-146a-5p and miR-146b-5p were identified as the most upregulated miRNAs in trophoblasts treated with M1-EVs. Further functional experiments showed that M1-EVs inhibited trophoblast migration and invasion by transferring miR-146a-5p and miR-146b-5p. Mechanistically, EV miR-146a-5p and miR-146b-5p inhibited EMT of trophoblasts by directly suppressing TNF receptor-associated factor 6 (TRAF6) expression at the post-transcriptional level. Furthermore, M1-EVs aggravated embryo absorption in mice. Clinically, expression of miR-146a-5p, miR-146b-5p, and TRAF6 were aberrant in placental villous tissues from patients with RSA, and negative correlations were found between miR-146a-5p/miR-146b-5p and TRAF6 expression levels. Conclusions: Our findings indicate that miR-146a-5p and miR-146b-5p derived from EVs play important roles in intercellular communication between M1 macrophages and trophoblasts, illuminating a novel mechanism in M1 macrophage regulation of trophoblasts and their role in RSA.

Dysregulation of serum miR-361-5p serves as a biomarker to predict disease onset and short-term prognosis in acute coronary syndrome patients

Background

Serum microRNAs (miRNAs) have been used as novel biomarkers for various diseases, including acute coronary syndrome (ACS). This study aimed to investigate the expression and clinical significance of microRNA-361-5p (miR-361-5p) in patients with ACS.

Methods

This study included 118 ACS patients, 78 patients with stable coronary heart disease (SCHD) and 66 healthy controls. MiR-361-5p expression was measured by qRT-PCR. The diagnostic value of miR-361-5p was evaluated by the ROC analysis. A 30-day follow-up was performed for the patients from hospitalization, and Kaplan–Meier curves and logistics analysis were used to evaluate the ability of miR-361-5p to predict the occurrence of major adverse cardiac events (MACE). ELISA kits were used to detect the levels of endothelial dysfunction (ED) markers, including vascular cell adhesion molecule 1 (VCAM-1), intercellular adhesion molecule 1 (ICAM-1) and E-selectin.

Results

The expression of miR-361-5p was significantly increased in patients with SCHD and ACS, and positively correlated with Gensini scores. Serum miR-361-5p expression had a high diagnostic accuracy for distinguishing ACS from health controls and SCHD patients. ACS patients with high expression of miR-361-5p had a higher probability of developing MACE. MiR-361-5p expression was an independent risk factor for the occurrence of MACE in ACS patients, and was positively correlated with the levels of VCAM-1, ICAM-1 and E-selectin.

Conclusion

All data indicated that miR-361-5p expression was significantly increased in ACS patients. Aberrant miR-361-5p expression in ACS might be a candidate biomarker for ACS diagnosis and the the prediction of MACE onset.

CircPOSTN/miR-361-5p/TPX2 axis regulates cell growth, apoptosis and aerobic glycolysis in glioma cells

Background

Glioma is the most primary central nervous system tumor in adults. The 5 year survival rate for glioma patients remains poor, although treatment strategies had improved in the past few decades. The cumulative studies have shown that circular RNA (circRNA) is associated with glioma process, so the purpose of this study is to clarify the function of circPOSTN in glioma.

Methods

The expression levels of circPOSTN, miR-361-5p, and targeting protein for Xenopus kinesin-like protein 2 (TPX2) were assessed with real-time quantitative polymerase chain reaction (RT-qPCR). The 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl-2H-tetrazol-3-ium bromide (MTT) and flow cytometry assays were executed to examine proliferation and apoptosis of glioma cells, respectively. Western blot was applied to assess protein expression. The glucose metabolism of glioma cells was analyzed by testing the glucose consumption, lactate production, ATP level, reactive oxygen species (ROS) accumulation and performing Seahorse XF assay. The interaction relationship between miR-361-5p and circPOSTN or TPX2 was analyzed by bioinformatics database and dual-luciferase reporter assay. The influences of circPOSTN silencing in vivo were observed by a xenograft experiment.

Results

CircPOSTN was overexpressed in glioma tissues and cells. Absence of circPOSTN in glioma cells promoted apoptosis while impeded proliferation and aerobic glycolysis, which were mitigated by silencing miR-361-5p. What’s more, loss-of-functional experiment suggested that knockdown of TPX2 repressed proliferation and aerobic glycolysis, while induced apoptosis in glioma cells. In addition, circPOSTN targetedly regulated TPX2 expression in glioma cells via sponging miR-361-5p. In vivo study revealed that deficiency of circPOSTN restrained tumor growth.

Conclusion

Mechanistically, circPOSTN regulated cell growth, apoptosis, and aerobic glycolysis in glioma through miR-361-5p/TPX2 axis.

Systematic characterization of non-coding RNAs in triple-negative breast cancer

Triple‐negative breast cancer (TNBC) is one of the most aggressive subtypes of breast cancer with negativity for oestrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor (HER2). Non‐coding RNAs (ncRNAs) make up most of the transcriptome and are widely present in eukaryotic cells. In recent years, emerging evidence suggests that ncRNAs, mainly microRNAs (miRNAs), long ncRNAs (lncRNAs) and circular RNAs (circRNAs), play prominent roles in the tumorigenesis and development of TNBC, but the functions of most ncRNAs have not been fully described. In this review, we systematically elucidate the general characteristics and biogenesis of miRNAs, lncRNAs and circRNAs, discuss the emerging functions of these ncRNAs in TNBC and present future perspectives in clinical practice.

Non-coding RNAs: Key regulators of aerobic glycolysis in breast cancer

Although extensive research progress has been made in breast cancer in recent years, yet the morbidity and mortality rates of breast cancer are rising, making it the major disease that endangers women's health. Energy metabolism reprogramming is featured by a state termed "aerobic glycolysis" or the Warburg effect that glycolysis is preferred even under aerobic conditions in neoplastic diseases. Widely acknowledged as an emerging hallmark in cancers, this metabolic switch shows a sophisticated role in the pathogenesis of breast cancer. The regulating effect of non-coding RNAs (ncRNAs) composed of microRNAs, long non-coding RNAs and circular RNAs is closely related to the glycolysis in breast cancer. Therefore, understand the mechanisms of ncRNAs of aerobic glycolysis in breast cancer may provide new strategy for the disease.

MicroRNA-361-3p promotes human breast cancer cell viability by inhibiting the E2F1/P73 signalling pathway

Analysis of the microRNA (miRNA) expression signature of breast cancer based on RNA sequencing demonstrated that miR-361-3p was significantly upregulated in breast cancer tissues. miR-361-3p is a novel miRNA, and its role in breast cancer is currently unclear. The aim of the present study was to investigate the functions of miR-361-3p in breast carcinoma. In this study, it was observed that the expression of miR-361-3p in cancer tissues was significantly higher compared with that in para-cancerous tissues and was correlated with advanced TNM stage, Ki-67 overexpression and shorter disease-free survival. Overexpression of miR-361-3p promoted proliferation and inhibited apoptosis of breast cancer cells. Through RNA sequencing, multi-library retrieval, luciferase reporter assays, quantitative polymerase chain reaction analysis, western blotting and other methods, it was verified that E2F1 was directly downregulated by miR-361-3p. The knockdown of E2F1 by siRNA promoted breast cancer cell proliferation and inhibited apoptosis, similar to miR-361-3p. In addition, miR-361-3p was able to decrease the expression of P73 by targeting E2F1, whereas overexpression of P73 reversed the effect of miR-361-3p on the viability of breast cancer cell lines. Thus, the present study demonstrated that miR-361-3p acts as an oncomiR in breast cancer to promote proliferation and inhibit apoptosis through inhibiting the P73 pathway by downregulating E2F1 expression, which may uncover valuable prognostic factors or treatment targets.

Prognostic role of microRNAs in breast cancer: A systematic review

MicroRNAs (miRNAs) have been found to play an important role in breast cancer, functioning either as potential oncogenes or tumor suppressor genes, but their role in the prognosis of patients remains unclear. The aim of the present review study is to highlight recent preclinical and clinical studies performed on both circulating and tissue-specific miRNAs and their potential role as prognostic markers in breast cancer. We systematically searched the PubMed database to explore the prognostic value of miRNAs in breast cancer. After performing the literature search and review, 117 eligible studies were identified. We found that 110 aberrantly expressed miRNAs have been associated with prognosis in breast cancer. In conclusion, the collective data presented in this review indicate that miRNAs could serve as novel prognostic tools in breast cancer, while the clinical application of these findings has yet to be verified.

Differentially expressed microRNAs in exosomes of patients with breast cancer revealed by next‑generation sequencing

MicroRNAs (miRNAs/miRs) in exosomes play crucial roles in the onset, progression and metastasis of cancer by regulating the stability of target mRNAs or by inhibiting translation. In the present study, differentially expressed miRNAs were identified in exosomes of 27 breast cancer patients and 3 healthy controls using RNA sequencing. The differentially expressed microRNAs were selected by bioinformatic analysis. Subjects were followed up for 2 years and exosomal miRNA profiles were compared between patients with and without recurrence of breast cancer. A total of 30 complementary DNA libraries were constructed and sequenced and 1,835 miRNAs were detected. There were no significant differences in the expression of miRNAs between the basal-like, human epidermal growth factor receptor-2⁺, luminal A, luminal B and healthy control (HC) groups. A total of 54 differentially expressed miRNAs were identified in triple-negative breast cancer (TNBC) patients vs. HCs, including 20 upregulated and 34 downregulated miRNAs. The results of the reverse transcription-quantitative PCR were consistent with this. Receiver operating characteristic curve analyses indicated that miR-150-5p [area under the curve (AUC)=0.705, upregulated], miR-576-3p (AUC=0.691, upregulated), miR-4665-5p (AUC=0.681, upregulated) were able to distinguish breast cancer patients with recurrence from those without recurrence. In conclusion, the present results indicated differences in miRNA expression profiles between patients with TNBC and healthy controls. Certain exosomal miRNAs were indicated to have promising predictive value as biomarkers for distinguishing breast cancer with recurrence from non-recurrence, which may be utilized for preventive strategies.

MicroRNA-361: A Multifaceted Player Regulating Tumor Aggressiveness and Tumor Microenvironment Formation

MicroRNA-361-5p (miR-361) expression frequently decreases or is lost in different types of cancers, and contributes to tumor suppression by repressing the expression of its target genes implicated in tumor growth, epithelial-to-mesenchymal transition (EMT), metastasis, drug resistance, glycolysis, angiogenesis, and inflammation. Here, we review the expression pattern of miR-361 in human tumors, describe the mechanisms responsible for its dysregulation, and discuss how miR-361 modulates the aggressive properties of tumor cells and alter the tumor microenvironment by acting as a novel tumor suppressor. Furthermore, we describe its potentials as a promising diagnostic or prognostic biomarker for cancers and a promising target for therapeutic development.

MicroRNA-361-3p regulates retinoblastoma cell proliferation and stemness by targeting hedgehog signaling

Retinoblastoma (RB) is the most common type of intraocular malignancy in children. During RB oncogenesis, sonic hedgehog (SHH) is commonly differentially expressed. Additionally, microRNAs (miRs) are known to serve crucial roles as oncogenes or tumor suppressors. Specifically, miR-361-3p has been revealed to serve a vital role in cutaneous squamous cell carcinoma, cervical cancer, prostate cancer, colorectal cancer, gastric cancer, hepatocellular carcinoma, breast cancer and lung cancer. However, the role of miR-361-3p in RB and the potential molecular mechanisms involved remain unknown. Therefore, the current study aimed to determine the involvement of miR-361-3p in the development of RB by targeting SHH signaling. In the present study, miR-361-3p expression levels in RB tissue and serum samples obtained from 10 patients with RB, normal retinal tissue and serum samples obtained from 10 healthy controls, and two human RB cell lines (Y79 and Weri-Rb-1) were determined using reverse transcription-quantitative polymerase chain reaction. In addition, a cell counting kit-8 assay, a cell transfection assay, a MTT assay, western blotting, a tumor sphere formation assay and a luciferase assay were used to assess the expression, function and molecular mechanism of miR-361-3p in human RB. It was demonstrated that miR-361-3p was significantly downregulated in RB tissues, RB serum and RB cell lines compared with normal retinal tissues and normal serum. The ectopic expression of miR-361-3p decreased RB cell proliferation and stemness. Furthermore, GLI1 and GLI3 were verified as potential direct targets of miR-361-3p. miR-361-3p was also revealed to exhibit a negative correlation with GLI1/3 expression in RB samples. Taken together, the results indicate that miR-361-3p functions as a tumor suppressor in the carcinogenesis and progression of RB by targeting SHH signaling. Thus, miR-361-3p should be further assessed as a potential therapeutic target for RB treatment.

Identifying a miRNA signature for predicting the stage of breast cancer

Breast cancer is a heterogeneous disease and one of the most common cancers among women. Recently, microRNAs (miRNAs) have been used as biomarkers due to their effective role in cancer diagnosis. This study proposes a support vector machine (SVM)-based classifier SVM-BRC to categorize patients with breast cancer into early and advanced stages. SVM-BRC uses an optimal feature selection method, inheritable bi-objective combinatorial genetic algorithm, to identify a miRNA signature which is a small set of informative miRNAs while maximizing prediction accuracy. MiRNA expression profiles of a 386-patient cohort of breast cancer were retrieved from The Cancer Genome Atlas. SVM-BRC identified 34 of 503 miRNAs as a signature and achieved a 10-fold cross-validation mean accuracy, sensitivity, specificity, and Matthews correlation coefficient of 80.38%, 0.79, 0.81, and 0.60, respectively. Functional enrichment of the 10 highest ranked miRNAs was analysed in terms of Kyoto Encyclopedia of Genes and Genomes and Gene Ontology annotations. Kaplan-Meier survival analysis of the highest ranked miRNAs revealed that four miRNAs, hsa-miR-503, hsa-miR-1307, hsa-miR-212 and hsa-miR-592, were significantly associated with the prognosis of patients with breast cancer.

Overexpression of miR‑361‑5p plays an oncogenic role in human lung adenocarcinoma through the regulation of SMAD2

The silencing of Bcl‑xL in the non‑small cell lung cancer (NSCLC) cell line, A549, downregulates miR‑361‑5p expression. This study aimed to determine the biological effects of miR‑361‑5p on NSCLC, and to elucidate the molecular mechanisms through which apoptosis is regulated. MicroRNA (miRNA or miR) functional analyses were performed via transfection of miR‑361‑5p mimics and inhibitors, demonstrating that the inhibition of miR‑361‑5p induced the apoptosis of NSCLC cells. To elucidate the function of miR‑361‑5p in vivo, cells transfected with miR‑361‑5p inhibitors were microinjected into zebrafish embryos, and immunostained using antibodies to detect the active form of caspase‑3. Co-transfection with siBcl‑xL and miR‑361‑5p mimics illustrated the association between Bcl‑xL, miR‑361‑5p and apoptosis; miR‑361‑5p mimics blocked the apoptosis initiated by siBcl‑xL. Luciferase reporter assays identified mothers against decapentaplegic homolog 2 (SMAD2) as a novel target of miR‑361‑5p and the reduction of its protein level was validated by western blot analysis. To confirm the molecular mechanisms through which apoptosis is regulated, gene rescue experiments revealed that the ectopic expression of SMAD2 attenuated the inhibitory effects on apoptosis induced by miR‑361‑5p. In this study, to the best of our knowledge, we provide the first evidence that miR‑361‑5p functions as an oncomiR in A549 and SK‑LU‑1 cells through the regulation of SMAD2, suggesting that miR‑361‑5p may be employed as a potential therapeutic target for the miRNA-based therapy of NSCLC.

Cancer-associated fibroblasts contribute to oral cancer cells proliferation and metastasis via exosome-mediated paracrine miR-34a-5p

Background

Cancer-associated fibroblasts (CAFs) play an important role in regulating tumor progression by transferring exosomes to neighboring cells. Our aim was to clarify the role of microRNA encapsulated in the exosomes derived from CAFs in oral squamous cell carcinoma (OSCC).

Methods

We examined the microRNA expression profiles of exosomes derived from CAFs and donor-matched normal fibroblasts (NFs) from patients with OSCC. We used confocal microscopy to examine the transportation of exosomal miR-34a-5p between CAFs and OSCC cells. Next, luciferase reporter and its mutant plasmids were used to confirm direct target gene of miR-34a-5p. Phenotypic assays and in vivo tumor growth experiments were used to investigate the functional significance of exosomal miR-34a-5p.

Findings

We found that the expression of miR-34a-5p in CAF-derived exosomes was significantly reduced, and fibroblasts could transfer exosomal miR-34a-5p to OSCC cells. In xenograft experiments, miR-34a-5p overexpression in CAFs could inhibit the tumorigenesis of OSCC cells. We further revealed that miR-34a-5p binds to its direct downstream target AXL to suppress OSCC cell proliferation and metastasis. Stable ectopic expression of AXL in OSCC cells overexpressing miR-34a-5p restored proliferation and motility abolished by the miRNA. The miR-34a-5p/AXL axis promoted OSCC progression via the AKT/GSK-3β/β-catenin signaling pathway, which could induce the epithelial-mesenchymal transition (EMT) to promote cancer cells metastasis. The miR-34a-5p/AXL axis enhanced nuclear translocation of β-catenin and then induced transcriptional upregulation of SNAIL, which in turn activated both MMP-2 and MMP-9.

Interpretation

The miR-34a-5p/AXL axis confers aggressiveness in oral cancer cells through the AKT/GSK-3β/β-catenin/Snail signaling cascade and might represent a therapeutic target for OSCC.

Fund

National Natural Science Foundation of China.

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CAFs transfer miR-34a-5p-devoid exosomes to OSCC cells.

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Exosomal miR-34a-5p mediates the proliferation and motility of OSCC cells through regulating AXL.

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MiR-34a-5p/AXL axis confers aggressiveness in OSCC through AKT/GSK-3β/β-catenin/Snail signaling cascade.

MicroRNA-493 is a prognostic factor in triple-negative breast cancer

Breast cancer is one of the most common malignant diseases in women. Triple‐negative breast cancer (TNBC) shows higher aggressiveness and recurrence rates than other subtypes, and there are no effective targets or tailored treatments for TNBC patients. Thus, finding effective prognostic markers for TNBC could help clinicians in their ability to care for their patients. We used tissue microarrays (TMAs) to detect microRNA‐493 (miR‐493) expression in breast cancer samples. A miRCURY LNA detection probe specific for miR‐493 was used in in situ hybridization assays. Staining results were reviewed by two independent pathologists and classified as high or low expression of miR‐493. Kaplan–Meier survival plots and multivariate Cox analysis were carried out to clarify the relationship between miR‐493 and survival. In the Kaplan–Meier analysis, patients with high miR‐493 expression had better disease‐free survival than patients with low miR‐493 expression. After adjusting for common clinicopathological factors in breast cancer, the expression level of miR‐493 was still a significant prognostic factor in breast cancer. Further subtype analysis revealed that miR‐493 expression levels were only significantly prognostic in TNBC patients. These results were validated in the Molecular Taxonomy of Breast Cancer International Consortium database for overall survival. We proved the prognostic role of miR‐493 in TNBC by using one of the largest breast cancer TMAs available and validated it in a large public RNA sequencing database.

RETRACTED: MicroRNA-361-5p inhibits papillary thyroid carcinoma progression by targeting ROCK1

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Authors and Editor-in-Chief. The authors notified the journal and requested retraction of the article, stating: “We recently found that miR-361 did not affect the tumor growth in vivo. All the authors want to retract this paper. Furthermore, we apologize to the readership of the Journal for any inconvenience caused”. The journal was also alerted to an associated PubPeer post, in which images of xenograft tumors within Figure 6B, and images of colony formation assays within Figure 2C, appear to have been published in other articles, as detailed here: https://pubpeer.com/publications/0DA940799BE0D567BAC4659CDAB13F#. The journal requested the corresponding author provide a more detailed explanation to these concerns and associated raw data, but this request was not satisfactorily fulfilled. The Editor-in-Chief assessed the case and decided to retract the article.

Diagnostic and prognostic value of microRNA-628 for cancers

Background: Many studies manifested miRNA-628 (miR-628) was deregulated in various cancers, indicating that miR-628 might serve as a novel biomarker of cancer diagnosis and prognosis, but it's role was still uncertain. This study aimed to evaluate the value of miR-628 in various cancers for diagnosis and prognosis, as well as its predictive power in combination biomarkers.

Materials and Methods: A literature search was performed using Medline (via PubMed), Embase, Web of Science databases, and Ovid platform up to November 2017. Meta-analysis was performed to provide summative outcomes. Quality assessment of each included study was performed.

Results: Twelve articles with 20 studies were included in our meta-analysis, including 8 articles with 15 studies for diagnostic meta-analysis and 4 articles with 5 studies for prognostic meta-analysis. For the diagnostic meta-analysis of miR-628 alone, the overall pooled results for sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR), and the area under the summary receiver operating characteristic (SROC) curve (AUC) were 0.81 (95% CI: 0.62-0.91), 0.72 (95% CI: 0.48-0.88), 2.90 (95% CI: 1.50-5.40), 0.27 (95% CI: 0.14-0.50), 11.0 (95% CI: 4.00-25.00), and 0.84 (95% CI: 0.80-0.87), respectively. For the diagnostic meta-analysis of miR-628-related combination biomarkers, the above six parameters were 0.89 (95% CI: 0.84-0.92), 0.93 (95% CI: 0.82-0.97), 12.30 (95% CI: 4.70-32.50), 0.12 (95% CI: 0.08-0.19), and 100.00 (95% CI: 28.00-354.00), 0.93 (95% CI: 0.90-0.95), respectively. For the prognostic meta-analysis, patients with lower miR-628 had significant shorter overall survival than high expression of miR-628 (HR = 1.553, 95% CI: 1.041-2.318, z = 2.16, P = 0.031).

Conclusions: This study confirms that miR-628 may be a promising biomarker for cancer diagnosis and prognosis. Expertly, microRNAs combination biomarkers could be a new alternative for clinical application.

Elevated miR-301a expression indicates a poor prognosis for breast cancer patients

Although microRNA-301a (miR-301a) has been reported to function as an oncogene in many human cancers, there are limited data regarding miR-301a and breast tumours. In this study, we first detected the expression of miR-301a using an in situ hybridization (ISH) -based classification system in 380 samples of BC tissue, including both non-TNBC (triple-negative breast cancer) and TNBC specimens. Our results suggest that analysing miR-301a expression in breast tissue biopsy specimens at the time of diagnosis could have the potential to identify patients who might be candidates for active surveillance. We validated our results that higher expression of miR-301a is associated with a decreased OS in independent public breast cancer databases, such as TCGA and METABRIC, using the online webtool Kaplan-Meier Plotter, which provided additional powerful evidence to confirm the prognostic value of miR-301a. MiR-301a may serve as a potential therapeutic target for patients with breast cancer. According to our results, miR-301a should be considered, and novel therapeutic options are needed to target this aggressive miR-301a-positive type of breast cancer to reduce recurrence and the mortality rate.

MiR-361-5p inhibits glycolytic metabolism, proliferation and invasion of breast cancer by targeting FGFR1 and MMP-1

Background

MicroRNAs function as key regulators in various human cancers, including breast cancer (BC). MiR-361-5p has been proved to be a tumor suppressor in colorectal cancer and gastric cancer in our previous study. In this study, we aim to find out the function of miR-361-5p in breast cancer progression and elaborate the mechanism that miR-361-5p acts its function in breast cancer.

Methods and results

Here we reported that miR-361-5p was down-regulated in breast cancer tissue compared with normal breast tissue and the expression of miR-361-5p was positively associated with prognosis in BC patients. Functional studies showed that overexpression of miR-361-5p suppressed the proliferation, invasion and metastasis of breast cancer cells both in vivo and in vitro. Mechanistically, we found that miR-361-5p inhibited the proliferation of BC cells by suppressing glycolysis. FGFR1, a promoter of glycolysis-related enzyme, was identified as the target of miR-361-5p that promoted glycolysis and repressed oxidative phosphorylation. Furthermore, we demonstrated that miR-361-5p inhibited breast cancer cells invasion and metastasis by targeting MMP-1. An inverse expression pattern was also found between miR-361-5p and FGFR1 or MMP-1 in a cohort of 60 BC tissues.

Conclusion

Our results indicate that miR-361-5p inhibits breast cancer cells glycolysis and invasion by respectively repressing FGFR1 and MMP-1, suggesting that miR-361-5p and its targets may serve as therapeutic targets in breast cancer treatment.

Apelin-13 inhibits lipoprotein lipase expression via the APJ/PKCα/miR-361-5p signaling pathway in THP-1 macrophage-derived foam cells

Atherosclerotic lesions are characterized by the accumulation of abundant lipids and chronic inflammation. Previous researches have indicated that macrophage-derived lipoprotein lipase (LPL) promotes atherosclerosis progression by accelerating lipid accumulation and pro-inflammatory cytokine secretion. Although apelin-13 has been regarded as an atheroprotective factor, it remains unclear whether it can regulate the expression of LPL. The aim of this study was to explore the effects of apelin-13 on the expression of LPL and the underlying mechanism in THP-1 macrophage-derived foam cells. Apelin-13 significantly decreased cellular levels of total cholesterol, free cholesterol, and cholesterol ester at the concentrations of 10 and 100 nM. ELISA analysis confirmed that treatment with apelin-13 reduced pro-inflammatory cytokine secretion, such as interleukin-6 (IL-6), interleukin-1β (IL-1β) and tumor necrosis factor-alpha (TNF-α). It was also found that apelin-13 inhibited the expression of LPL as revealed by western blot and real-time PCR analyses. Bioinformatics analyses and dual-luciferase reporter assay indicated that miR-361-5p directly downregulated the expression of LPL by targeting the 3'UTR of LPL. In addition, apelin-13 + miR-361-5p mimic significantly downregulated the expression of LPL in cells. Finally, we demonstrated that apelin-13 downregulated the expression of LPL through activating the activity of PKCα. Taken together, our results showed that apelin-13 downregulated the expression of LPL via activating the APJ/PKCα/miR-361-5p signaling pathway in THP-1 macrophage-derived foam cells, leading to inhibition of lipid accumulation and pro-inflammatory cytokine secretion. Therefore, our studies provide important new insight into the inhibition of lipid accumulation and pro-inflammatory cytokine secretion by apelin-13, and highlight apelin-13 as a promising therapeutic target in atherosclerosis.

MicroRNAs in the prognosis of triple-negative breast cancer: A systematic review and meta-analysis

BACKGROUND

Triple-negative breast cancer (TNBC) is a heterogeneous group of tumors characterized by their aggressive nature and poor associated survival. MicroRNAs (miRs) have been found to play an important role in the occurrence and development of human cancers, but their role in the prognosis of TNBC patients remains unclear. We performed a meta-analysis to explore the prognostic value of miRs in TNBC.

METHODS

We systematically searched the PubMed, Embase, and Web of Science databases to identify eligible studies. A meta-analysis was performed to estimate the pooled hazard ratios (HRs) and their corresponding 95% confidence intervals (CIs) for the associations between levels of miR expression (predictive factors) and overall survival (OS) and disease-free survival (DFS) (outcomes) in patients with TNBC.

RESULTS

After performing the literature search and review, 21 relevant studies including 2510 subjects were identified. Six miRs (miR-155, miR-21, miR-27a/b, miR-374a/b, miR-210, and miR-454) were assessed in the meta-analysis. Decreased expression of miR-155 was associated with reduced OS (adjusted HR = 0.58, 95% CI: 0.34-0.99; crude HR = 0.67, 95% CI: 0.58-0.79). High miR-21 expression was also predictive of reduced OS (crude HR = 2.50, 95% CI: 1.56-4.01). We found that elevated levels of miR-27a/b, miR-210, and miR-454 expression were associated with shorter OS, while the levels of miR-454 and miR-374a/b expression were associated with DFS.

CONCLUSIONS

Specific miRs could serve as potential prognostic biomarkers in TNBC. Due to the limited research available, the clinical application of these findings has yet to be verified.