miR-139-5p is a regulator of metastatic pathways in breast cancer

LINC00534 promotes breast cancer progression by targeting the miR-139-5p/HMGB2 axis

BACKGROUND

Breast cancer is the most prevalent malignancy among women, it is crucial to identify sensitive biomarkers for prognosis and treatment of breast cancer patients. Emerging research has demonstrated the involvement of long noncoding RNAs (lncRNAs) in the advancement of breast cancer. LINC00534 has recently emerged as a potential regulator in multiple malignancies, yet its clinical significance and molecular mechanisms in breast cancer remain poorly characterized.

OBJECTIVE

The purpose of this study was to explore the function of LINC00534 and miR-139-5p in breast cancer progression, as well as the mechanisms that underpin its actions.

METHODS

Tumor and normal tissues were collected from 80 breast cancer patients. qRT-PCR was performed to detect LINC00534 expression in tissues. Kaplan-Meier analysis was used to assess survival differences between groups and the correlation between LINC00534 expression and clinical outcomes. CCK-8 assay was used to evaluate cell proliferation to assess LINC00534's effect on tumor growth. To evaluate the impact of LINC00534 on tumor metastasis, transwell assay was used to detect the migration and invasion abilities of cells. Moreover, dual-luciferase assay was used to verify the relationship within the LINC00534/miR-139-5p/HMGB2 axis.

RESULT

LINC00534 was significantly upregulated in breast cancer tumor tissues and cell lines (p < 0.001). Higher LINC00534 expression correlated with poorer prognosis in breast cancer patients, including shorter survival and higher recurrence risk (Log-rank p = 0.014). Furthermore, LINC00534 promoted breast cancer cell proliferation, migration, and invasion (all p < 0.001) via its interaction with the miR-139-5p/HMGB2 axis.

CONCLUSION

LINC00534 may serve as a prognostic marker and the LINC00534/miR-139-5p/HMGB2 axis could be a therapeutic target for breast cancer.

MicroRNA as Key Players in Hepatocellular Carcinoma: Insights into Their Role in Metastasis

Liver cancer or hepatocellular carcinoma (HCC) remains the most common cancer in global epidemiology. Both the frequency and fatality of this malignancy have shown an upward trend over recent decades. Liver cancer is a significant concern due to its propensity for both intrahepatic and extrahepatic metastasis. Liver cancer metastasis is a multifaceted process characterized by cell detachment from the bulk tumor, modulation of cellular motility and invasiveness, enhanced proliferation, avoidance of the immune system, and spread either via lymphatic or blood vessels. MicroRNAs (miRNAs) are small non-coding ribonucleic acids (RNAs) playing a crucial function in the intricate mechanisms of tumor metastasis. A number of miRNAs can either increase or reduce metastasis via several mechanisms, such as control of motility, proliferation, attack by the immune system, cancer stem cell properties, altering the microenvironment, and the epithelial-mesenchymal transition (EMT). Besides, two other types of non-coding RNAs, such as long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs) can competitively bind to endogenous miRNAs. This competition results in the impaired ability of the miRNAs to inhibit the expression of the specific messenger RNAs (mRNAs) that are targeted. Increasing evidence has shown that the regulatory axis comprising circRNA/lncRNA-miRNA-mRNA is correlated with the regulation of HCC metastasis. This review seeks to present a thorough summary of recent research on miRNAs in HCC, and their roles in the cellular processes of EMT, invasion and migration, as well as the metastasis of malignant cells. Finally, we discuss the function of the lncRNA/circRNA-miRNA-mRNA network as a crucial modulator of carcinogenesis and the regulation of signaling pathways or genes that are relevant to the metastasis of HCC. These findings have the potential to offer valuable insight into the discovery of novel therapeutic approaches for management of liver cancer metastasis.

Non-Coding RNAs as Potential Diagnostic/Prognostic Markers for Hepatocellular Carcinoma

The increasing incidence of hepatocellular carcinoma (HCC), together with the poor effectiveness of the available treatments, make early diagnosis and effective screening of utmost relevance. Liquid biopsy represents a potential novel approach to early HCC detection and monitoring. The identification of blood markers has many desirable features, including the absence of any significant risk for the patients, the possibility of being used as a screening tool, and the ability to perform multiple tests, thus allowing for the real-time monitoring of HCC evolution. Unfortunately, the available blood markers for HCC have several limitations, mostly related to specificity and sensitivity. In this context, employing non-coding RNAs (ncRNAs) may represent an interesting and novel diagnostic approach. ncRNAs, which include, among others, micro interfering RNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs), regulate human gene expression via interactions with their target mRNA. Notably, their expression can be altered in HCC, thus reflecting disease status. In this review, we discuss some notable works that describe the use of miRNAs, lncRNAs, and circRNAs as HCC biomarkers. Despite some open aspects related to ncRNA use, the presented works strongly support the potential effectiveness of these molecules as diagnostic/prognostic markers for HCC.

Identifying miRNA as biomarker for breast cancer subtyping using association rule

- This paper presents a comprehensive study focused on breast cancer subtyping, utilizing a multifaceted approach that integrates feature selection, machine learning classifiers, and miRNA regulatory networks. The feature selection process begins with the CFS algorithm, followed by the Apriori algorithm for association rule generation, resulting in the identification of significant features tailored to Luminal A, Luminal B, HER-2 enriched, and Basal-like subtypes. The subsequent application of Random Forest (RF) and Support Vector Machine (SVM) classifiers yielded promising results, with the SVM model achieving an overall accuracy of 76.60 % and the RF model demonstrating robust performance at 80.85 %. Detailed accuracy metrics revealed strengths and areas for refinement, emphasizing the potential for optimizing subtype-specific recall. To explore the regulatory landscape in depth, an analysis of selected miRNAs was conducted using MIENTURNET, a tool for visualizing miRNA-target interactions. While FDR analysis raised concerns for HER-2 and Basal-like subtypes, Luminal A and Luminal B subtypes showcased significant miRNA-gene interactions. Functional enrichment analysis for Luminal A highlighted the role of Ovarian steroidogenesis, implicating specific miRNAs such as hsa-let-7c-5p and hsa-miR-125b-5p as potential diagnostic biomarkers and regulators of Luminal A breast cancer. Luminal B analysis uncovered associations with the MAPK signaling pathway, with miRNAs like hsa-miR-203a-3p and hsa-miR-19a-3p exhibiting potential diagnostic and therapeutic significance. In conclusion, this integrative approach combines machine learning techniques with miRNA analysis to provide a holistic understanding of breast cancer subtypes. The identified miRNAs and associated pathways offer insights into potential diagnostic biomarkers and therapeutic targets, contributing to the ongoing efforts to improve breast cancer diagnostics and personalized treatment strategies.

ASSESSMENT OF CIRCULATING miRNA LEVELS IN BREAST CANCER PATIENTS DEPENDING ON CLINICAL CHARACTERISTICS AND CHEMOTHERAPY

BACKGROUND

Breast cancer (BC) stands out as the most prevalent cancer in women. The levels of miRNA expression before and after chemotherapy are considered a potential indicator for the prognosis of the disease.

AIM

To study blood plasma miRNA levels in BC patients and to assess their correlation with the menopausal status, disease stage, and molecular BC subtype.

MATERIALS AND METHODS

Blood plasma levels of 6 miRNAs (miRNA-25, miRNA-27, miRNA-155, miRNA-200, miRNA-335, and miRNA-497) were studied in 70 BC patients and 18 healthy individuals using RT-PCR.

RESULTS

miRNA-25, miRNA-335, and miRNA-497 levels were significantly higher in BC patients, while a tendency toward a decrease in the miRNA-27 and miRNA-335 levels in premenopausal patients and high miRNA-27 levels in menopausal patients was established. After neoadjuvant chemotherapy, a decrease in the miRNA-25 and miRNA-335 levels was registered.

CONCLUSIONS

The results indicated that miRNA-25, miRNA-27, miRNA-335, and miRNA-497 deserve attention as markers for assessing the efficacy of treatment of BC patients.

Comprehensive analysis of miRNA-mRNA regulatory pairs associated with colorectal cancer and the role in tumor immunity

BACKGROUND

MicroRNA (miRNA) which can act as post-transcriptional regulators of mRNAs via base-pairing with complementary sequences within mRNAs is involved in processes of the complex interaction between immune system and tumors. In this research, we elucidated the profiles of miRNAs and target mRNAs expression and their associations with the phenotypic hallmarks of colorectal cancers (CRC) by integrating transcriptomic, immunophenotype, methylation, mutation and survival data.

RESULTS

We conducted the analysis of differential miRNA/mRNA expression profile by GEO, TCGA and GTEx databases and the correlation between miRNA and targeted mRNA by miRTarBase and TarBase. Then we detected using qRT-PCR and validated the diagnostic value of miRNA-mRNA regulator pairs by the ROC, calibration curve and DCA. Phenotypic hallmarks of regulatory pairs including tumor-infiltrating lymphocytes, tumor microenvironment, tumor mutation burden, global methylation and gene mutation were also described. The expression levels of miRNAs and target mRNAs were detected in 80 paired colon tissue samples. Ultimately, we picked up two pivotal regulatory pairs (miR-139-5p/ STC1 and miR-20a-5p/ FGL2) and verified the diagnostic value of the complex model which is the combination of 4 signatures above-mentioned in 3 testing GEO datasets and an external validation cohort.

CONCLUSIONS

We found that 2 miRNAs by targeting 2 metastasis-related mRNAs were correlated with tumor-infiltrating macrophages, HRAS, and BRAF gene mutation status. Our results established the diagnostic model containing 2 miRNAs and their respective targeted mRNAs to distinguish CRCs and normal controls and displayed their complex roles in CRC pathogenesis especially tumor immunity.

Tumor-suppressive role of miR-139-5p in angiogenesis and tumorigenesis of ovarian cancer: Based on GEO microarray analysis and experimental validation

This study clarified the possible molecular mechanisms by which the miR-139-5p/SOX4/TMEM2 axis affected angiogenesis and tumorigenesis of ovarian cancer (OC) based on GEO microarray datasets and experimental support. The expression of miR-139-5p and SOX4 was examined in clinical OC samples. Human umbilical vein endothelial cells (HUVECs) and human OC cell lines were included in vitro experiments. Tube formation assay was conducted in HUVECs. The expression of SOX4, SOX4, and VEGF in OC cells was identified using Western blot and immunohistochemistry. Luciferase assays were conducted to validate the targeting relationship between miR-139-5p and SOX4 and between SOX4 and TMEM2. A RIP assay assessed the binding of SOX4 and miR-139-5p. The impact of miR-139-5p and SOX4 on OC tumorigenesis in vivo was evaluated in nude mice. SOX4 was up-regulated, while miR-139-5p was down-regulated in OC tissues and cells. Ectopic miR-139-5p expression or SOX4 knockdown inhibited angiogenesis and tumorigenicity of OC. By targeting SOX4 in OC, miR-139-5p lowered VEGF expression, angiogenesis, and TMEM2 expression. The miR-139-5p/SOX4/TMEM2 axis also reduced VEGF expression and angiogenesis, which might curtail OC growth in vivo. Collectively, miR-139-5p represses VEGF expression and angiogenesis by targeting the transcription factor SOX4 and down-regulating TMEM2 expression, thereby impeding OC tumorigenesis.

MicroRNA-139-5p suppresses non-small cell lung cancer progression by targeting ATAD2

MiR-139-5p is a suppressor in multiple types of cancer. However, whether miR-139-5p affects NSCLC is unknown. In this study, miR-139-5p expression in clinical samples was examined by real-time PCR and in situ hybridization (ISH). MiR-139-5p mimic was transfected to monitor NSCLC cell behaviors. Potential target was predicated using bioinformatics database. Next, whether miR-139-5p impacted cell behaviors via regulation of its predicted target gene were further evaluated. The result revealed that miR-139-5p was lower in NSCLC samples/cells. MiR-139-5p restrained A549 cell proliferation, accelerated apoptosis, and inhibited the β-catenin signaling. ATAD2 was a predicted target of miR-139-5p, and it was highly expressed in NSCLC tissues. ATAD2 overexpression abolished the miR-139-5p's anti-tumor effect on cell proliferation and apoptosis. TWS119 (a β-catenin signaling activator) partially reversed miR-139-5p overexpression-induced suppression of cell proliferation and promotion of cell apoptosis. In tumor xenografts, miR-139-5p restrained tumor growth. MiR-139-5p was a tumor suppressor in NSCLC by regulating the oncogene ATAD2 and β-catenin signaling. Our study provides a promising target for cancer treatment.

ER Negative Breast Cancer and miRNA: There Is More to Decipher Than What the Pathologist Can See!

Breast cancer (BC), the most prevalent cancer in women, is a heterogenous disease. Despite advancements in BC diagnosis, prognosis, and therapeutics, survival rates have drastically decreased in the metastatic setting. Therefore, BC still remains a medical challenge. The evolution of high-throughput technology has highlighted gaps in the classification system of BCs. Of particular interest is the notorious triple negative BC, which was recounted as being heterogenous itself and it overlaps with distinct subtypes, namely molecular apocrine (MA) and luminal androgen (LAR) BCs. These subtypes are, even today, still misdiagnosed and poorly treated. As such, researchers and clinicians have been looking for ways through which to refine BC classification in order to properly understand the initiation, development, progression, and the responses to the treatment of BCs. One tool is biomarkers and, specifically, microRNA (miRNA), which are highly reported as associated with BC carcinogenesis. In this review, the diverse roles of miRNA in estrogen receptor negative (ER-) and androgen receptor positive (AR+) BC are depicted. While highlighting their oncogenic and tumor suppressor functions in tumor progression, we will discuss their diagnostic, prognostic, and predictive biomarker potentials, as well as their drug sensitivity/resistance activity. The association of several miRNAs in the KEGG-reported pathways that are related to ER-BC carcinogenesis is presented. The identification and verification of accurate miRNA panels is a cornerstone for tackling BC classification setbacks, as is also the deciphering of the carcinogenesis regulators of ER - AR + BC.

Omics-Based Investigations of Breast Cancer

Breast cancer (BC) is characterized by an extensive genotypic and phenotypic heterogeneity. In-depth investigations into the molecular bases of BC phenotypes, carcinogenesis, progression, and metastasis are necessary for accurate diagnoses, prognoses, and therapy assessments in predictive, precision, and personalized oncology. This review discusses both classic as well as several novel omics fields that are involved or should be used in modern BC investigations, which may be integrated as a holistic term, onco-breastomics. Rapid and recent advances in molecular profiling strategies and analytical techniques based on high-throughput sequencing and mass spectrometry (MS) development have generated large-scale multi-omics datasets, mainly emerging from the three "big omics", based on the central dogma of molecular biology: genomics, transcriptomics, and proteomics. Metabolomics-based approaches also reflect the dynamic response of BC cells to genetic modifications. Interactomics promotes a holistic view in BC research by constructing and characterizing protein-protein interaction (PPI) networks that provide a novel hypothesis for the pathophysiological processes involved in BC progression and subtyping. The emergence of new omics- and epiomics-based multidimensional approaches provide opportunities to gain insights into BC heterogeneity and its underlying mechanisms. The three main epiomics fields (epigenomics, epitranscriptomics, and epiproteomics) are focused on the epigenetic DNA changes, RNAs modifications, and posttranslational modifications (PTMs) affecting protein functions for an in-depth understanding of cancer cell proliferation, migration, and invasion. Novel omics fields, such as epichaperomics or epimetabolomics, could investigate the modifications in the interactome induced by stressors and provide PPI changes, as well as in metabolites, as drivers of BC-causing phenotypes. Over the last years, several proteomics-derived omics, such as matrisomics, exosomics, secretomics, kinomics, phosphoproteomics, or immunomics, provided valuable data for a deep understanding of dysregulated pathways in BC cells and their tumor microenvironment (TME) or tumor immune microenvironment (TIMW). Most of these omics datasets are still assessed individually using distinct approches and do not generate the desired and expected global-integrative knowledge with applications in clinical diagnostics. However, several hyphenated omics approaches, such as proteo-genomics, proteo-transcriptomics, and phosphoproteomics-exosomics are useful for the identification of putative BC biomarkers and therapeutic targets. To develop non-invasive diagnostic tests and to discover new biomarkers for BC, classic and novel omics-based strategies allow for significant advances in blood/plasma-based omics. Salivaomics, urinomics, and milkomics appear as integrative omics that may develop a high potential for early and non-invasive diagnoses in BC. Thus, the analysis of the tumor circulome is considered a novel frontier in liquid biopsy. Omics-based investigations have applications in BC modeling, as well as accurate BC classification and subtype characterization. The future in omics-based investigations of BC may be also focused on multi-omics single-cell analyses.

Major regulators of the multi-step metastatic process are potential therapeutic targets for breast cancer management

Metastasis is a multi-step process that leads to the dissemination of tumor cells to new sites and, consequently, to multi-organ neoplasia. Although most lethal breast cancer cases are related to metastasis occurrence, little is known about the dysregulation of each step, and clinicians still lack reliable therapeutic targets for metastasis impairment. To fill these gaps, we constructed and analyzed gene regulatory networks for each metastasis step (cell adhesion loss, epithelial-to-mesenchymal transition, and angiogenesis). Through topological analysis, we identified E2F1, EGR1, EZH2, JUN, TP63, and miR-200c-3p as general hub-regulators, FLI1 for cell-adhesion loss specifically, and TRIM28, TCF3, and miR-429 for angiogenesis. Applying the FANMOD algorithm, we identified 60 coherent feed-forward loops regulating metastasis-related genes associated with distant metastasis-free survival prediction. miR-139-5p, miR-200c-3p, miR-454-3p, and miR-1301-3p, among others, were the FFL's mediators. The expression of the regulators and mediators was observed to impact overall survival and to go along with metastasis occurrence. Lastly, we selected 12 key regulators and observed that they are potential therapeutic targets for canonical and candidate antineoplastics and immunomodulatory drugs, like trastuzumab, goserelin, and calcitriol. Our results highlight the relevance of miRNAs in mediating feed-forward loops and regulating the expression of metastasis-related genes. Altogether, our results contribute to understanding the multi-step metastasis complexity and identifying novel therapeutic targets and drugs for breast cancer management.

Targeting Non-Coding RNAs for the Development of Novel Hepatocellular Carcinoma Therapeutic Approaches

Hepatocellular carcinoma (HCC) remains a global health challenge, representing the third leading cause of cancer deaths worldwide. Although therapeutic advances have been made in the few last years, the prognosis remains poor. Thus, there is a dire need to develop novel therapeutic strategies. In this regard, two approaches can be considered: (1) the identification of tumor-targeted delivery systems and (2) the targeting of molecule(s) whose aberrant expression is confined to tumor cells. In this work, we focused on the second approach. Among the different kinds of possible target molecules, we discuss the potential therapeutic value of targeting non-coding RNAs (ncRNAs), which include micro interfering RNAs (miRNAs), long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs). These molecules represent the most significant RNA transcripts in cells and can regulate many HCC features, including proliferation, apoptosis, invasion and metastasis. In the first part of the review, the main characteristics of HCC and ncRNAs are described. The involvement of ncRNAs in HCC is then presented over five sections: (a) miRNAs, (b) lncRNAs, (c) circRNAs, (d) ncRNAs and drug resistance and (e) ncRNAs and liver fibrosis. Overall, this work provides the reader with the most recent state-of-the-art approaches in this field, highlighting key trends and opportunities for more advanced and efficacious HCC treatments.

Circulating miRNAs in Women with Polycystic Ovary Syndrome: A Longitudinal Cohort Study

BACKGROUND

Women with polycystic ovary syndrome (PCOS) often change their metabolic profile over time to decrease levels of androgens while often gaining a propensity for the development of the metabolic syndrome. Recent discoveries indicate that microRNAs (miRNAs) play a role in the development of PCOS and constitute potential biomarkers for PCOS. We aimed to identify miRNAs associated with the development of an impaired metabolic profile in women with PCOS, in a follow-up study, compared with women without PCOS.

METHODS AND MATERIALS

Clinical measurements of PCOS status and metabolic disease were obtained twice 6 years apart in a cohort of 46 women with PCOS and nine controls. All participants were evaluated for degree of metabolic disease (hypertension, dyslipidemia, central obesity, and impaired glucose tolerance). MiRNA levels were measured using Taqman^® Array cards of 96 pre-selected miRNAs associated with PCOS and/or metabolic disease.

RESULTS

Women with PCOS decreased their levels of androgens during follow-up. Twenty-six of the miRNAs were significantly changed in circulation in women with PCOS during the follow-up, and twenty-four of them had decreased, while levels did not change in the control group. Four miRNAs were significantly different at baseline between healthy controls and women with PCOS; miR-103-3p, miR-139-5p, miR-28-3p, and miR-376a-3p, which were decreased in PCOS. After follow-up, miR-28-3p, miR-139-5p, and miR-376a-3p increased in PCOS women to the levels observed in healthy controls. Of these, miR-139-5p correlated with total testosterone levels (rho = 0.50, p_adj = 0.013), while miR-376-3p correlated significantly with the waist-hip ratio at follow-up (rho = 0.43, p_adj = 0.01). Predicted targets of miR-103-3p, miR-139-5p, miR-28-3p, and miR-376a-3p were enriched in pathways associated with Insulin/IGF signaling, interleukin signaling, the GNRH receptor pathways, and other signaling pathways. MiRNAs altered during follow-up in PCOS patients were enriched in pathways related to immune regulation, gonadotropin-releasing hormone signaling, tyrosine kinase signaling, and WNT signaling.

CONCLUSIONS

These studies indicate that miRNAs associated with PCOS and androgen metabolism overall decrease during a 6-year follow-up, reflecting the phenotypic change in PCOS individuals towards a less hyperandrogenic profile.

Tear Film MicroRNAs as Potential Biomarkers: A Review

MicroRNAs are non-coding RNAs that serve as regulatory molecules in a variety of pathways such as inflammation, metabolism, homeostasis, cell machinery, and development. With the progression of sequencing methods and modern bioinformatics tools, novel roles of microRNAs in regulatory mechanisms and pathophysiological states continue to expand. Advances in detection methods have further enabled larger adoption of studies utilizing minimal sample volumes, allowing the analysis of microRNAs in low-volume biofluids, such as the aqueous humor and tear fluid. The reported abundance of extracellular microRNAs in these biofluids has prompted studies to explore their biomarker potential. This review compiles the current literature reporting microRNAs in human tear fluid and their association with ocular diseases including dry eye disease, Sjögren's syndrome, keratitis, vernal keratoconjunctivitis, glaucoma, diabetic macular edema, and diabetic retinopathy, as well as non-ocular diseases, including Alzheimer's and breast cancer. We also summarize the known roles of these microRNAs and shed light on the future progression of this field.

Circ_0068631 sponges miR-139-5p to promote the growth and metastasis of cutaneous squamous cell carcinoma by upregulating HOXB7

BACKGROUND

Circular RNAs (circRNAs) are often dysregulated in cancers and closely related to cancer progression, including cutaneous squamous cell carcinoma (CSCC). However, the role and mechanism of circ_0068631 in CSCC progression have not been reported.

METHODS

The expression of circ_0068631, microRNA-139-5p (miR-139-5p), and homeobox B7 (HOXB7) was measured by real-time quantitative polymerase chain reaction (RT-qPCR). Cell counting kit-8 (CCK-8) assay, 5-ethynyl-2'-deoxyuridine (EdU) assay, and colony formation assay were used to measure cell proliferation. Cell apoptosis was assessed by flow cytometry. Cell migration was detected by transwell assay. The interaction between miR-139-5p and circ_0068631 or HOXB7 was confirmed by dual-luciferase reporter assay. A xenograft tumor model was established to confirm the function of circ_0068631 in vivo.

RESULTS

Circ_0068631 was upregulated in CSCC tissues and cells, and its silencing could inhibit CSCC cell proliferation and metastasis while promoting apoptosis in vitro, as well as restrain CSCC tumor growth in vivo. Circ_0068631 acted as a sponge of miR-139-5p, and miR-139-5p inhibition reversed the repressive effect of circ_0068631 knockdown on CSCC cell progression. Furthermore, HOXB7 was a target of miR-139-5p, and miR-139-5p inhibited the malignant behaviors by downregulating HOXB7 expression in CSCC cells. Further, circ_0068631 sponged miR-139-5p to regulate HOXB7 expression.

CONCLUSION

Circ_0068631 functioned as a novel oncogene in CSCC progression by regulating miR-139-5p/HOXB7 axis, suggesting that circ_0068631 may be a potential target for CSCC treatment.

HIGHLIGHTS

Circ_0068631 was overexpressed in CSCC tissues and cells. Circ_0068631 downregulation suppressed CSCC progression via miR-139-5p. Circ_0068631 regulated HOXB7 via sponging miR-139-5p.

5-Azacytidine Downregulates the Proliferation and Migration of Hepatocellular Carcinoma Cells In Vitro and In Vivo by Targeting miR-139-5p/ROCK2 Pathway

BACKGROUND

For hepatocellular carcinoma (HCC), effective therapeutic approaches are lacking. As aberrant gene methylation is a major contributor to HCC development, demethylating drugs such as 5-azacytidine (5-Aza) have been proposed. As most 5-Aza mechanisms of action are unknown, we investigated its phenotypic/molecular effects.

METHODS

5-Aza effects were examined in the human HCC cell lines JHH-6/HuH-7 and in the rat cell-line N1-S1. We also employed a xenograft mouse model (HuH-7), a zebrafish model (JHH-6), and an orthotopic syngeneic rat model (N1-S1) of HCC.

RESULTS

5-Aza downregulated cell viability/growth/migration/adhesion by upregulating miR-139-5p, which in turn downregulated ROCK2/cyclin D1/E2F1 and increased p27kip1, resulting in G1/G0 cell accumulation. Moreover, a decrease in cyclin B1 and an increase in p27kip1 led to G2/M accumulation. Finally, we observed a decrease in MMP-2 levels, a stimulator of HCC cell migration. Aza effects were confirmed in the mouse model; in the zebrafish model, we also demonstrated the downregulation of tumor neo-angiogenesis, and in the orthotopic rat model, we observed impaired N1-S1 grafting in a healthy liver.

CONCLUSION

We demonstrate for the first time that 5-Aza can impair HCC development via upregulation of miR-139-5p, which in turn impairs the ROCK2/cyclin D1/E2F1/cyclin B1 pro-proliferative pathway and the ROCK2/MMP-2 pro-migratory pathway. Thus, we provide novel information about 5-Aza mechanisms of action and deepen the knowledge about the crosstalk among ROCK2/cyclin D1/E2F1/cyclin B1/p27kip1/MMP-2 in HCC.

Current Status and Prospects of Anesthesia and Breast Cancer: Does Anesthetic Technique Affect Recurrence and Survival Rates in Breast Cancer Surgery?

The relationship between the anesthetic technique and cancer recurrence has not yet been clarified in cancer surgery. Surgical stress and inhalation anesthesia suppress cell-mediated immunity (CMI), whereas intravenous (IV) anesthesia with propofol and regional anesthesia (RA) are known to be protective for CMI. Surgical stress, general anesthesia (GA) with inhalation anesthesia and opioids contribute to perioperative immunosuppression and may increase cancer recurrence and decrease survival. Surgical stress and GA activate the hypothalamic-pituitary-adrenal axis and release neuroendocrine mediators such as cortisol, catecholamines, and prostaglandin E₂, which may reduce host defense immunity and promote distant metastasis. On the other hand, IV anesthesia with propofol and RA with paravertebral block or epidural anesthesia can weaken surgical stress and GA-induced immunosuppression and protect the host defense immunity. IV anesthesia with propofol and RA or in combination with GA may reduce cancer recurrence and improve patient survival compared to GA alone. We review the current status of the relationship between anesthesia and breast cancer recurrence using retrospective and prospective studies conducted with animal models and clinical samples, and discuss the future prospects for reducing breast cancer recurrence and improving survival rates in breast cancer surgery.

MiR-139-5p Targeting CCNB1 Modulates Proliferation, Migration, Invasion and Cell Cycle in Lung Adenocarcinoma

Lung adenocarcinoma (LUAD) is the most frequent histological subtype of non-small cell lung cancer. Cyclin B1 (CCNB1) is the vital initiator and controller of mitosis. Studies have indicated that CCNB1 overexpression is closely associated with cell proliferation and tumorigenesis in many cancers. Thus, discovery of molecular mechanism of CCNB1 in LUAD is conducive to developing new diagnostic or therapeutic targets for LUAD. We acquired mature miRNA and mRNA expression information of LUAD from TCGA database, as well as related clinical data. CCNB1 expression in normal and LUAD tissue was analyzed. Relationship between CCNB1 and patient's survival and clinical stage was analyzed. Upstream regulatory gene miRNA of CCNB1 was predicted. qRT-PCR and western blot examined expression levels of CCNB1 and miR-139-5p in cells. CCK-8 tested cell proliferation. Scratch healing and Transwell determined cell migration and invasion. Flow cytometry analyzed the cell cycle. Dual-luciferase verified targeting relationship between the two genes. Compared to controls, CCNB1 expression was prominently high in LUAD patient samples, and associated with advanced tumor stages and shorter overall survival. MiR-139-5p expressed an evidently negative correlation with CCNB1 and was predicted to target CCNB1. MiR-139-5p mimics reduced CCNB1 mRNA and protein expression, and suppressed luciferase activity in a target-specific manner, as confirmed by a control construct with a mutated miR-139-5p binding site. CCNB1 overexpression fostered progression of LUAD cells. Mechanistically, miR-139-5p might negatively regulate CCNB1 in LUAD, thereby suppressing cell proliferation, migration, invasion and cell cycle.

MicroRNA-139 Expression Is Dispensable for the Generation of Influenza-Specific CD8+ T Cell Responses

MicroRNAs (miRNAs/miRs) are small, endogenous noncoding RNAs that are important post-transcriptional regulators with clear roles in the development of the immune system and immune responses. Using miRNA microarray profiling, we characterized the expression profile of naive and in vivo generated murine effector antiviral CD8⁺ T cells. We observed that out of 362 measurable mature miRNAs, 120 were differentially expressed by at least 2-fold in influenza-specific effector CD8⁺ CTLs compared with naive CD8⁺ T cells. One miRNA found to be highly downregulated on both strands in effector CTLs was miR-139. Because previous studies have indicated a role for miR-139-mediated regulation of CTL effector responses, we hypothesized that deletion of miR-139 would enhance antiviral CTL responses during influenza virus infection. We generated miR-139^-/- mice or overexpressed miR-139 in T cells to assess the functional contribution of miR-139 expression in CD8⁺ T cell responses. Our study demonstrates that the development of naive T cells and generation or differentiation of effector or memory CD8⁺ T cell responses to influenza virus infection are not impacted by miR-139 deficiency or overexpression; yet, miR-139^-/- CD8⁺ T cells are outcompeted by wild-type CD8⁺ T cells in a competition setting and demonstrate reduced responses to Listeria monocytogenes Using an in vitro model of T cell exhaustion, we confirmed that miR-139 expression similarly does not impact the development of T cell exhaustion. We conclude that despite significant downregulation of miR-139 following in vivo and in vitro activation, miR-139 expression is dispensable for influenza-specific CTL responses.

FAM87A as a Competing Endogenous RNA of miR-424-5p Suppresses Glioma Progression by Regulating PPM1H

Far less has been unveiled about the functions of lncRNAs on cancers yet. Here, we reported that lncRNA FAM87A, as a ceRNA of miR-424-5p, played a vital role in glioma development. qRT-PCR result indicated that FAM87A was abnormally downregulated in glioma tissue and cells. Survival analysis suggested that the FAM87A expression was negatively correlated with the survival rate. Effects of FAM87A on human glioma cell lines were also analyzed by MTT, Edu, and transwell assays. FAM87A hastened proliferation and migration of glioma cells. MiR-424-5p, predicted target of FAM87A, was fostered in glioma, which was examined by qRT-PCR. A negative correlation was indicated between FAM87A and miR-424-5p. Results of bioinformatics, dual luciferase, and RIP assays unveiled that FAM87A and miR-424-5p act upon each other. In addition, miR-424-5p targeted 3'-UTR of PPM1H. Also, effects of miR-424-5p/FAM87A on glioma cells were identified via the cell function experiments. FAM87A suppressed PPM1H by binding to miR-424-5p competitively, thereby restraining cell proliferation, migration, and invasion. Collectively, these findings illuminated a new mechanism for glioma progression. Therefore, FAM87A may act as a feasible target for glioma treatment.

Plasma Extracellular Vesicles Enhance HIV-1 Infection of Activated CD4+ T Cells and Promote the Activation of Latently Infected J-Lat10.6 Cells via miR-139-5p Transfer

HIV latency is a challenge to the success of antiretroviral therapy (ART). Hence patients may benefit from interventions that efficiently reactivate the latent virus to be eliminated by ARTs. Here we show that plasma extracellular vesicles (pEVs) can enhance HIV infection of activated CD4⁺ T cells and reactivate the virus in latently infected J-Lat 10.6 cells. Evaluation of the extravesicular miRNA cargo by a PCR array revealed that pEVs from HIV patients express miR-139-5p. Furthermore, we found that increased levels of miR-139-5p in J-Lat 10.6 cells incubated with pEVs corresponded with reduced expression of the transcription factor, FOXO1. pEV treatment also corresponded with increased miR-139-5p expression in stimulated PD1+ Jurkat cells, but with concomitant upregulation of FOXO1, Fos, Jun, PD-1 and PD-L1. However, J-Lat 10.6 cells incubated with miR-139-5p inhibitor-transfected pEVs from HIV ART-naïve and on-ART patients expressed reduced levels of miR-139-5p than cells treated with pEVs from healthy controls (HC). Collectively, our results indicate that pEV miR-139-5p belongs to a network of miRNAs that can promote cell activation, including latent HIV-infected cells by regulating the expression of FOXO1 and the PD1/PD-L1 promoters, Fos and Jun.

Highly connected, non-redundant microRNA functional control in breast cancer molecular subtypes

Breast cancer is a complex, heterogeneous disease at the phenotypic and molecular level. In particular, the transcriptional regulatory programs are known to be significantly affected and such transcriptional alterations are able to capture some of the heterogeneity of the disease, leading to the emergence of breast cancer molecular subtypes. Recently, it has been found that network biology approaches to decipher such abnormal gene regulation programs, for instance by means of gene co-expression networks, have been able to recapitulate the differences between breast cancer subtypes providing elements to further understand their functional origins and consequences. Network biology approaches may be extended to include other co-expression patterns, like those found between genes and non-coding transcripts such as microRNAs (miRs). As is known, miRs play relevant roles in the establishment of normal and anomalous transcription processes. Commodore miRs (cdre-miRs) have been defined as miRs that, based on their connectivity and redundancy in co-expression networks, are potential control elements of biological functions. In this work, we reconstructed miR–gene co-expression networks for each breast cancer molecular subtype, from high throughput data in 424 samples from the Cancer Genome Atlas consortium. We identified cdre-miRs in three out of four molecular subtypes. We found that in each subtype, each cdre-miR was linked to a different set of associated genes, as well as a different set of associated biological functions. We used a systematic literature validation strategy, and identified that the associated biological functions to these cdre-miRs are hallmarks of cancer such as angiogenesis, cell adhesion, cell cycle and regulation of apoptosis. The relevance of such cdre-miRs as actionable molecular targets in breast cancer is still to be determined from functional studies.

A Signature of Four Circulating microRNAs as Potential Biomarkers for Diagnosing Early-Stage Breast Cancer

Breast cancer (BC) is the most predominant type of cancer among women. The aim of this study is to find new biomarkers that can help in early detection of BC, especially for those who are too young to be screened using mammography as per guidelines. Using microRNA microarray, we previously showed dysregulation of 74 microRNAs in tumors from early BC patients as compared with normal adjacent tissues, which we were interested in studying in blood circulation. In this study, we investigated the expression of 12 microRNA (miR-21/miR-155/miR-23a/miR-130a/miR-145/miR-425-5p/miR-139-5p/miR-451/miR-195/miR-125b/miR-100, and miR-182) in the plasma of 41 newly diagnosed Lebanese BC patients with early invasive ductal carcinoma as compared with 32 healthy controls. Total RNA was extracted from plasma, and expression levels of miRNA of interest were measured using RT-qPCR followed by statistical analysis; miR-21, miR-155, miR-23a, miR-130a, miR-145, miR-425-5p, and miR-139-5p were significantly upregulated and miR-451 was significantly downregulated, in the plasma of BC patients as compared with healthy controls. The positively correlated miR-23a, miR-21, and miR-130a had a high diagnostic accuracy (86%). Importantly, the combination of miR-145/miR-425-5p/miR-139-5p/miR-130a scored the highest diagnostic accuracy of 95% with AUC = 0.97 (sensitivity 97% and specificity 91%). MicroRNAs are promising non-invasive diagnostic biomarkers for early-stage BC with the panel of miR-145/miR-425-5p/miR-139-5p/miR-130a having the highest diagnostic accuracy.

Identification of dysregulated competing endogenous RNA networks in glioblastoma: A way toward improved therapeutic opportunities

Glioblastoma is recognized as one of the leading causes of death worldwide. Although there have been considerable advancements in understanding the causative molecular mechanisms of this malignancy, effective therapeutic strategies are still in limited use. It has been revealed that non-coding RNAs (ncRNAs) play critical roles in glioblastoma development, while interactions between the regulatory molecules such as long ncRNAs (lncRNAs), microRNAs (miRNAs), transcribed pseudogenes, and circular RNAs (circRNAs) remain to be fully deciphered. Over the recent years, researchers have discovered a new category of RNA molecules called competing endogenous RNA (ceRNA). This kind of RNA can contribute to molecular interactions in the form of ceRNA networks (ceRNETs). Multiple lines of evidence have demonstrated that dysregulation of various ceRNA networks is involved in glioblastoma development. Therefore, gaining insights into these dysregulations might offer potential for the early diagnosis of glioblastoma patients and identification of efficient therapeutic targets. In this review, we provide an overview of recent discoveries on ceRNA networks and the involvement of dysregulated networks in posing limitations to temozolomide therapy. We also describe signaling pathways relevant to the progression of glioblastoma.

Construction and validation of a three-microRNA signature as prognostic biomarker in patients with hepatocellular carcinoma

Hepatocellular carcinoma (HCC), a common type of primary liver cancer, is one of the most aggressive malignant tumors worldwide. Although overall survival (OS) rates for HCC has significantly improved in recent years, however, the exact predictive value of microRNA (miRNA) for the prognosis of HCC has not yet been recognized. Here, we aimed to identify potential prognostic miRNAs involved in HCC by bioinformatics analysis and validated expression levels through quantitative polymerase chain reaction (qPCR) and GEO database. The RNA expression profiles and corresponding clinical information of HCC were available from The Cancer Genome Atlas (TCGA) datasets. Differentially expression and standardization analysis of miRNAs, Kaplan-Meier curve and time dependent ROC curve were performed by using R tools. Differentially expressed miRNAs (DEmiRNAs) and clinical parameters involved in the OS of HCC were confirmed by Cox regression models. And functional enrichment analysis was used to establish functions of the targeted genes of DEmiRNAs. A total of 300 DEmiRNAs were significantly related with HCC, of which 40 were down-regulated and 260 were up-regulated. A total of 344 patients with DEmiRNAs, status, overall survival (OS) time were randomized into training group (172) and test group (172). Multivariate Cox regression analyses revealed that 3 miRNA (hsa-miR-139-3p, hsa-miR-760, hsa-miR-7-5p) had independent prognostic significance for the OS of HCC in both training and test group. Moreover, according to Kaplan Meier analysis, the OS of HCC patients with high-risk score was shorter in validation and entire series. The time dependent ROC curve demonstrated high accuracy of the signature for OS. Besides, target genes of three miRNAs were analyzed by functional enrichment analysis and 20 genes associated with OS were verified by using Kaplan-Meier method. Compared with normal and benign group, the relative expression level of hsa-miR-139-3p was significantly decreased, while hsa-miR-7-5p and hsa-miR-760 were distinctly increased in the plasma of HCC patients. The same results were observed in the independent cohort. Collectively, our research suggested that three-miRNA signature could serve as an independent prognostic indicator for HCC patients.

miR-139-5p protects septic mice with acute lung injury by inhibiting Toll-like receptor 4/Myeloid differentiation factor 88/Nuclear factor-&mac_kgr;B signaling pathway

OBJECTIVES

To investigate the role of miR-139-5p and the TLR4/MyD88/NF-κB signaling pathway in acute lung injury in septic mice.

METHOD

A total of 140 healthy male SPF C57BL/6 mice were divided into seven groups, i.e., Normal, Control, NC, miR-139-5p mimic, miR-139-5p inhibitor, TAK-242, and miR-139-5p inhibitor+TAK-242 groups. The levels of miR-139-5p, proteins related to the TLR4/MyD88/NF-κB signaling pathway (TLR4, MyD88, and p-NF-κB p50), and MPO, SOD, GSH, and MDA in lung tissue were measured. The lung tissue wet-to-dry mass ratio (W/D), arterial oxygen partial pressure (PaO2), and carbon dioxide partial pressure (PaCO2) were measured.

RESULTS

A web-based bioinformatic tool predicted that MyD88 was a target of miR-139-5p, which was verified by a dual luciferase reporter assay. Compared with those in the Normal group, the levels of miR-139-5p, PaO2, SOD, and GSH were significantly lower, while those of TLR4, MyD88, p-NF-κB p50, W/D, PaCO2, IL-1β, TNF-α, IL-6, MPO, and MDA were higher in all other groups. Moreover, compared with their levels in the Control group, these indicators exhibited contrasting results in the miR-139-5p mimic and TAK-242 groups, but were similar in the miR-139-5p inhibitor group. In the miR-139-5p inhibitor+TAK-242 group, acute lung injury, aggravated by miR-139-5p inhibitor, was partially rescued by TAK-242.

CONCLUSION

miR-139-5p inhibits the TLR4/MyD88/NF-κB signaling pathway to alleviate acute lung injury in septic mice.

Triple negative breast cancer in the era of miRNA

The objective of this review is to elucidate the role of miRNAs in triple negative breast cancer (TNBC). To achieve our goal, we searched databases such as PubMed, ScienceDirect, Springer, Web of Science and Scopus. We retrieved up to 1233 articles, based a rigorous selection criterion, only 197 articles were extensively reviewed. We selected articles only addressing TNBC, but not other types of breast cancer, with the employed approach being miRNA analysis and/or profiling. Our extensive review resulted in grouping of miRNAs into categories in which specific members of miRNAs have roles in specific mechanism in TNBC i.e., carcinogenesis, invasion, metastasis, apoptosis, diagnosis, prognosis, and treatment. TNBC is an aggressive subtype of breast cancer; therefore, different approaches for accurate diagnosis, prognosis and treatment are needed. In this review we summarize the up-to-date miRNA profiling, prognostic, and therapeutic findings that add to the route of controlling TNBC.

MicroRNA-139 inhibits pancreatic-cancer carcinogenesis by suppressing RalB via the Ral/RAC/PI3K pathway

Micro-ribonucleic acids (miRNAs) are a class of conserved small non-coding RNAs (sncRNAs) that post-transcriptionally regulate their downstream target genes. Existing evidence indicates that abnormal expression of mRNAs results in the occurrence and development of pancreatic cancer (PC). In this study, we explored the potential role of miRNA-139 (miR-139) as a biomarker in the monitoring and treatment of PC. We demonstrated that expression of miR-139 was significantly downregulated in PC cells and tissues. In addition, both in vitro and in vivo experiments showed that miR-139 significantly inhibited the growth, migration, and invasion of PC cells. We carried out microarray analysis and transcriptome sequencing to find the potential target of miR-139 in PC cells, and the results showed that miR-139 targeted Ras-like proto-oncogene B (RalB). Luciferase reporter experiments verified that high level of RalB could reverse the proliferation and invasion of PC cells overexpressing miR-139. Using Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses, we found that miR-139 likely affected PC cell cycle by targeting RalB via the Ral/protein kinase B (Akt) serine/threonine kinase 1 (RAC)/phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K) pathway, thus affecting cell proliferation. This presumption was further confirmed in our in vitro and in vivo experiments. Our examination of PC tissues suggested that the expression of miR-139 was negatively correlated with that of RalB. Taken together, our results implied that miR-139 could suppress tumor growth and metastasis in PC by targeting RalB, revealing the potential role of miR-139 as a biomarker for the monitoring and treatment of PC.

Novel miRNA Targets and Therapies in the Triple-Negative Breast Cancer Microenvironment: An Emerging Hope for a Challenging Disease

Treatment of triple-negative breast cancer (TNBC) remains challenging because of the heterogeneity of the disease and lack of single targetable driving mutations. TNBC does not rely on estrogen, progesterone or epidermal growth factor receptors and is associated with aggressive disease progression and poor prognosis. TNBC is also characterized by resistance to chemotherapeutics, and response to immunotherapies is limited despite promising results in a subset of TNBC patients. MicroRNAs (miRNAs) have emerged as significant drivers of tumorigenesis and tumor progression in triple-negative breast cancer (TNBC) and present unique opportunities to target various components of the TNBC microenvironment for improved efficacy against this difficult to treat cancer. Effects of miRNAs on multiple targets may improve response rates in the context of this genetically and biologically heterogeneous disease. In this review, we offer a comprehensive view of miRNA regulation in TNBC, treatment challenges presented by TNBC in the context of the tumor microenvironment and stem cell subpopulations, and current and emerging miRNA-based therapeutic strategies targeting various components of the TNBC microenvironment. In addition, we offer insight into novel targets that have potential for treating TNBC through multiple mechanisms in the tumor microenvironment simultaneously and those that may be synergistic with standard chemotherapies.

Sevoflurane Suppresses the Migration, Invasion, and Epithelial-Mesenchymal Transition of Breast Cancer Cells Through the miR-139-5p/ARF6 Axis

BACKGROUND

Breast cancer (BC) is common cancer in female globally. Sevoflurane (SEV) has been reported to inhibit the metastasis of multiple cancers, including glioma, colorectal cancer, and hepatocellular carcinoma. However, the role of SEV in the metastasis of BC cells remains poorly understood.

METHODS

Transwell migration and invasion assays were performed to detect the migration and invasion of BC cells. Western blot assay was carried out to measure epithelial-mesenchymal transition (EMT)-related proteins in BC cells, including E-cadherin, N-cadherin, and fibronectin. Quantitative real-time polymerase chain reaction was conducted to determine the enrichment of miR-139-5p and ADP-ribosylation factor 6 (ARF6) in BC tissues and cells. The protein expression of ARF6 in BC tissues and cells was measured by western blot assay. The target of miR-139-5p was predicted by starBase software, and the target relationship between miR-139-5p and ARF6 in BC cells was confirmed by dual-luciferase reporter assay.

RESULTS

SEV suppressed the migration, invasion, and EMT of BC cells, especially in the high-concentration SEV group. The level of miR-139-5p was lower in BC tissues and cells than that in paired normal tissues and normal mammary epithelial cells MCF-10A. MiR-139-5p was upregulated in BC cells treated with SEV. ARF6 was upregulated in BC tissues and cells compared with that in corresponding normal tissues and normal mammary epithelial cells MCF-10A. SEV reduced the mRNA and protein expression of ARF6 in BC cells. The accumulation of ARF6 or the interference of miR-139-5p reversed the suppressive effects of SEV treatment on the migration, invasion, and EMT of BC cells. MiR-139-5p bound to ARF6 and inversely modulated the level of ARF6 in BC cells. The transfection of si-ARF6 attenuated the promoting effects of miR-139-5p depletion on the migration, invasion, and EMT of BC cells treated with SEV.

CONCLUSIONS

SEV suppressed the migration, invasion, and EMT of BC cells through downregulating the abundance of ARF6 by upregulating miR-139-5p. The miR-139-5p/ARF6 axis might be a promising target for the treatment of BC.

High mobility group box 2 modulates the progression of osteosarcoma and is related with poor prognosis

Background

Increased expression of high mobility group box 2 (HMGB2) has been reported to promote the progression of several malignancies and be related to poor outcome. However, few studies have explored the relationship between HMGB2 and osteosarcoma. In this study, we aimed to obtain a better understanding of HMGB2 and its function in osteosarcoma.

Methods

Utilizing osteosarcoma paraffin sections and osteosarcoma cell lines, we observed the clinico-pathological relationship of osteosarcoma with HMGB2 expression and investigated the functions of HMGB2 in vitro. The possible pathways and regulation networks in which HMGB2 is involved were further explored through analysis of miRNA, mRNA and lncRNA micro array data sets.

Results

Strong expression of HMGB2 was found to be related with Enneking staging (P=0.002), tumor size (P=0.006), metastasis (P<0.001), and survival (P=0.011) in osteosarcoma. Multivariate analysis revealed that HMGB2 might have independent prognostic value in osteosarcoma (P=0.022). Kaplan-Meier curves and the log-rank test showed that survival time was significantly reduced in OS patients with strong HMGB2 expression (P=0.0056). In vitro experiments showed that HMGB2 overexpression promoted cell proliferation and enhanced the migration and invasion ability of osteosarcoma cells. Gene Ontology (GO) term analysis of osteosarcoma cell lines revealed HMGB2 to have various functions and to be mainly enriched in regulation of cell proliferation, cell death, and DNA binding. A competing endogenous RNA (ceRNA) network of miR-139-5p and six candidate lncRNAs was also suggested as targeting HMGB2 in osteosarcoma.

Conclusions

Our findings suggest that HMGB2 might have various functions in promoting the progression of osteosarcoma and may serve as a new target for osteosarcoma research.

Potential miRNAs for miRNA-Based Therapeutics in Breast Cancer

MicroRNAs (miRNAs) are small non-coding RNAs that can post-transcriptionally regulate the genes involved in critical cellular processes. The aberrant expressions of oncogenic or tumor suppressor miRNAs have been associated with cancer progression and malignancies. This resulted in the dysregulation of signaling pathways involved in cell proliferation, apoptosis and survival, metastasis, cancer recurrence and chemoresistance. In this review, we will first (i) provide an overview of the miRNA biogenesis pathways, and in vitro and in vivo models for research, (ii) summarize the most recent findings on the roles of microRNAs (miRNAs) that could potentially be used for miRNA-based therapy in the treatment of breast cancer and (iii) discuss the various therapeutic applications.

A panel of eight microRNAs is a good predictive parameter for triple-negative breast cancer relapse

Rationale: Triple-negative breast cancer (TNBC), which has the highest recurrence rate and shortest survival time of all breast cancers, is in urgent need of a risk assessment method to determine an accurate treatment course. Recently, miRNA expression patterns have been identified as potential biomarkers for diagnosis, prognosis, and personalized therapy. Here, we investigate a combination of candidate miRNAs as a clinically applicable signature that can precisely predict relapse in TNBC patients after surgery. Methods: Four total cohorts of training (TCGA_TNBC and GEOD-40525) and validation (GSE40049 and GSE19783) datasets were analyzed with logistic regression and Gaussian mixture analyses. We established a miRNA signature risk model and identified an 8-miRNA signature for the prediction of TNBC relapse. Results: The miRNA signature risk model identified ten candidate miRNAs in the training set. By combining 8 of the 10 miRNAs (miR-139-5p, miR-10b-5p, miR-486-5p, miR-455-3p, miR-107, miR-146b-5p, miR-324-5p and miR-20a-5p), an accurate predictive model of relapse in TNBC patients was established and was highly correlated with prognosis (AUC of 0.80). Subsequently, this 8-miRNA signature prognosticated relapse in the two validation sets with AUCs of 0.89 and 0.90. Conclusion: The 8-miRNA signature predictive model may help clinicians provide a prognosis for TNBC patients with a high risk of recurrence after surgery and provide further personalized treatment to decrease the chance of relapse.

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.

MiR-139-5p/SLC7A11 inhibits the proliferation, invasion and metastasis of pancreatic carcinoma via PI3K/Akt signaling pathway

OBJECTIVE

Pancreatic carcinoma (PANC) is one of the important aggressive cancers, with deficiency in effective therapeutics. The study aimed to investigate the effects and molecular mechanism of miR-139-5p/SLC7A11 on the proliferation and metastasis of PANC.

METHODS

Bioinformatics was used to analyze the differentially expressed genes in the TCGA database. PANC cell lines with overexpressed miR-139-5p and Solute Carrier Family 7, Member 11 (SLC7A11) was established, and have been used to detect cell proliferation, invasion and metastasis of PANC Subsequently, bioinformatic analysis and dual luciferase reporter assay were performed to confirm that SLC7A11 was a target gene of miR-139-5p. Xenograft mice model was used to explore the functions of miR-139-5p in PANC tumorigenicity.

RESULTS

MiR-139-5p could regulate and affect the protein expression of P13K and Akt associated with phosphatidylinositol signaling pathway by inhibiting SLC7A11. MiR-139-5p was found to be lowly expressed in PANC tissues, while SLC7A11 was highly expressed. Low expression of miR-139-5p and high expression of SLC7A11 were positively associated with poor clinical outcomes. PANC cell proliferation, invasion and metastasis could be inhibited by miR-139-5p overexpression and be promoted by SLC7A11 overexpression. MiR-139-5p overexpression could suppress PANC tumor growth and the expressions of SLC7A11, p-PI3K, p-Akt in tumor tissues. Therefore, the inhibitory of miR-139-5p to PANC cell proliferation, invasion and metastasis was partly due to its inhibiting effect on SLC7A11 expression.

CONCLUSION

Our study proves that miR-139-5p/SLC7A11 has important functions on PANC, suggesting that miR-139-5p can be used as a biomarker for PANC patients.

3'-UTR Shortening Contributes to Subtype-Specific Cancer Growth by Breaking Stable ceRNA Crosstalk of Housekeeping Genes

Shortening of 3'UTRs (3'US) through alternative polyadenylation is a post-transcriptional mechanism that regulates the expression of hundreds of genes in human cancers. In breast cancer, different subtypes of tumor samples, such as estrogen receptor positive and negative (ER+ and ER-), are characterized by distinct molecular mechanisms, suggesting possible differences in the post-transcriptional regulation between the subtype tumors. In this study, based on the profound tumorigenic role of 3'US interacting with competing-endogenous RNA (ceRNA) network (3'US-ceRNA effect), we hypothesize that the 3'US-ceRNA effect drives subtype-specific tumor growth. However, we found that the subtypes are available in different sample sizes, biasing the ceRNA network size and disabling the fair comparison of the 3'US-ceRNA effect. Using normalized Laplacian matrix eigenvalue distribution, we addressed this bias and built tumor ceRNA networks comparable between the subtypes. Based on the comparison, we identified a novel role of housekeeping (HK) genes as stable and strong miRNA sponges (sponge HK genes) that synchronize the ceRNA networks of normal samples (adjacent to ER+ and ER- tumor samples). We further found that distinct 3'US events in the ER- tumor break the stable sponge effect of HK genes in a subtype-specific fashion, especially in association with the aggressive and metastatic phenotypes. Knockdown of NUDT21 further suggested the role of 3'US-ceRNA effect in repressing HK genes for tumor growth. In this study, we identified 3'US-ceRNA effect on the sponge HK genes for subtype-specific growth of ER- tumors.

MiR-139-5p negatively regulates PMP22 to repress cell proliferation by targeting the NF-κB signaling pathway in gastric cancer

Gastric cancer (GC) is one of the most common malignant tumors worldwide. Peripheral myelin protein 22 (PMP22) is a 22-kDa tetraspan glycoprotein that is predominantly expressed by myelinating Schwann cells. However, recent studies have shown that PMP22 is closely related to cell proliferation and tumorigenesis in different cancers. In this study, we discovered a new miRNA that regulates PMP22 and gastric cancer cell prolifration. Our bioinformatics analysis suggested that there is a conserved miRNA recognition site for miR-139-5p on the 3' UTR of PMP22. Interestingly, our results showed overexpression of miR-139-5p significantly suppressed growth and prolifration in GC cells and inhibited tumor growth in nude mice xenografted with GC cells. MiR-139-5p suppressed the activity of a luciferase reporter containing the PMP22-3' UTR, and the ectopic expression of PMP22 rescued the miR-139-5p-mediated inhibition of cell proliferation in GC cells. Mechanistically, miR-139-5p may negatively regulate PMP22 to repress cell proliferation by targeting the NF-κB signaling pathway in gastric cancer. Finally, overexpression of miR-139-5p significantly inhibited tumor growth in nude mice xenografted with GC cells.and the miR-139-5p levels were inversely correlated with PMP22 expression in nude mice tumor. Taken together, our data suggest an important regulatory role of miR-139-5p in gastric cancer, suggesting that miR-139-5p and PMP22 might be important diagnostic or therapeutic targets for gastric cancer and other human diseases.

Ultrasound-Mediated Gene Therapy of Hepatocellular Carcinoma Using Pre-microRNA Plasmid-Loaded Nanodroplets

The PIK3 CA gene encodes the p110α protein subunit and is one of the most efficient cancer genes in solid and hematological tumors including hepatocellular carcinoma (HCC). There are currently ongoing therapies against tumors based on PIK3 CA inhibition. Because microRNAs (miRNAs) play an important role in post-transcriptional regulation and are also involved in the inhibition of PIK3 CA expression to suppress cancer cell proliferation, overexpression of tumor-suppressive miRNA is a promising therapeutic approach for HCC therapy. The successful and localized delivery of miRNA overexpression vectors (pre-miRNA plasmids) is very important in improving the therapeutic efficacy of this miRNA therapy strategy. In the study described here, submicron acoustic phase-shifted nanodroplets were used to efficiently deliver pre-miRNA plasmid in vitro and in vivo for HCC therapy under focused ultrasound (US) activation. Briefly, six miRNAs, inhibiting PIK3 CA and downregulated in HCC, were selected through summary and analysis of the currently existing literature data. Quantitative real-time polymerase chain reaction (qRT-PCR), Western blot and cell apoptosis assay revealed that pre-miR-139, -203a, -378a and -422a plasmids among the six miRNA overexpression vectors could suppress growth of the hepatoma cell line SMMC-7721. These four pre-miRNA plasmids were then electrostatically adhered to positively charged lipid-shelled nanodroplets to obtain plasmid-loaded nanodroplets (PLNDs). The PLND-generated microbubbles oscillated and even collapsed under US exposure to release the loaded pre-miRNA plasmids and enhance their cellular uptake through consequent sonoporation, that is, formation of small pores on the cell membrane induced by the mechanical effects of PLND cavitation. Fluorescence microscopy results revealed that PLNDs could effectively deliver the aforementioned four pre-miRNA plasmids into SMMC-7721 cells in vitro under 1.2-MHz 60-cycle sinusoid US exposure with a peak negative pressure >5.5 MPa at a 40-Hz pulse repetition frequency. Plasmid delivery efficiency and cell viability positively correlated with the inertial cavitation dose that was determined mainly by peak negative pressure. Furthermore, PLNDs combined with US were evaluated in vivo to deliver these four pre-miRNAs plasmids and verify their therapeutic efficacy in subcutaneous tumor of the mouse xenograft HCC model. The results revealed that the PLNDs loaded with pre-miR-139 and -378a plasmids could effectively suppress tumor growth after US treatment. Thus, combination of pre-miRNA PLNDs with US activation seems to constitute a potential strategy for HCC therapy.

The long non-coding RNA MIAT/miR-139-5p/MMP2 axis regulates cell migration and invasion in non-small-cell lung cancer

Non-small-cell lung cancer (NSCLC) is a complex disease which is influenced by multiple factors. Recent studies demonstrated that long non-coding RNA (lncRNA) MIAT was involved in tumor metastasis. However, the underlying mechanism of MIAT in NSCLC remains largely unknown. In this study, MIAT, miR-139-5p and MMP2 expression were measured by quantitative reverse transcriptase PCR (QRT-PCR) or Western blotting, respectively, and we found the expression of MIAT and MMP2 were elevated, while miR-139-5p was decreased in NSCLC tissues and cell lines. Transwell assay showed MIAT and MMP2 functioned as an oncogene to induce cell migration and invasion in NSCLC, but miR-139-5p served as a tumor suppressor in NSCLC to inhibit cell migration and invasion. Besides that, in vivo experiments also indicated MIAT deletion inhibited tumor growth. The relationship between miR-139-5p and MIAT or MMP2 was then confirmed by Luciferase reporter assay, and the results showed that MIAT directly interacted with miR-139-5p and miR-139- 5p targetedly suppressed MMP2 in NSCLC cells. Furthermore, expression analysis showed that MIAT indirectly regulated MMP2 by sponging miR-139-5p. Finally, rescue assay suggested that miR-139-5p restoration reversed MIAT-overexpression-induced promotion on the migration and invasion of NSCLC cells. In conclusion, our results demonstrated that lncRNA MIAT modulated the migration and invasion of NSCLC by regulating miR-139-5p and MMP2.

MicroRNA-139-3p Inhibits The Growth And Metastasis Of Ovarian Cancer By Inhibiting ELAVL1

Background

The aberrant expression of microRNA-139-3p (miR-139-3p) has been recently involved in the development of multiple tumor types, but its function in ovarian cancer remains not well investigated. In this study, we mainly investigated the function of miR-139-3p in the progression of ovarian cancer.

Methods

The levels of miR-139-3p in ovarian cancer cells and tissues were detected using quantitative real-time-PCR (qRT-PCR) assay. The proliferation, colony formation, migration and invasion of ovarian cancer cell were determined, respectively. A luciferase reporter assay was used to confirm ELAV Like RNA Binding Protein 1 (ELAVL1) was a target gene of miR-139-3p. The expression of ELAVL1 was detected using Western blotting and immunofluorescence staining assay. The roles of miR-139-3p on the growth and metastasis of ovarian cancer cell in vivo were explored using transplanted tumor model and experimental lung metastasis model.

Results

MiR-139-3p was down-regulated in ovarian cancer tissues and ovarian cancer cell lines (SK-OV-3, A2780 and OVCAR-3). Overexpression of miR-139-3p decreased the growth, colony formation, migration and invasiveness of SK-OV-3 and OVCAR-3 cells. Moreover, overexpression of miR-139-3p reduced the growth and lung metastasis of ovarian cancer cells in vivo. The luciferase reporter gene assay indicated that ELAVL1 was a target of miR-139-3p and its expression was negatively regulated by miR-139-3p. Furthermore, the expression of ELAVL1 was inversely correlated with miR-139-3p level in ovarian cancer tissue.

Conclusion

Taken together, we demonstrated that miR-139-3p regulated ovarian cancer growth and metastasis by modulating the expression of ELAVL1.

MicroRNA-139 is a predictor of prostate cancer recurrence and inhibits growth and migration of prostate cancer cells through cell cycle arrest and targeting IGF1R and AXL

BACKGROUND

We previously identified a panel of five microRNAs (miRNAs) associated with biochemical recurrence and metastasis following prostatectomy from prostate cancer patients using next-generation sequencing-based whole miRNome sequencing and quantitative polymerase chain reaction-based validation analysis. In this study, we examined the mechanism of action of miR-139-5p, one of the downregulated miRNAs identified in the panel.

METHODS

Using a cohort of 585 patients treated with radical prostatectomy, we examined the prognostic significance of miR-139 (dichotomized around the median) using the Kaplan-Meier method and Cox proportional hazard models. We validated these results using The Cancer Genome Atlas (TCGA) data. We created cell lines that overexpressed miR-139 to confirm its targets as well as examine pathways through which miR-139 may function using cell-based assays.

RESULTS

Low miR-139 expression was significantly associated with a variety of prognostic factors in prostate cancer, including Gleason score, pathologic stage, margin positivity, and lymph node status. MiR-139 expression was associated with prognosis: the cumulative incidence of biochemical recurrence and metastasis were significantly lower among patients with high miR-139 expression (P = .0004 and .038, respectively). Validation in the TCGA data set showed a significant association between dichotomized miR-139 expression and biochemical recurrence (odds ratio, 0.52; 95% confidence interval, 0.33-0.82). Overexpression of miR-139 in prostate cancer cells led to a significant reduction in cell proliferation and migration compared with control cells, with cells arrested in G2 of cell cycle. IGF1R and AXL were identified as potential targets of miR-139 based on multiple miRNA-binding sites in 3'-untranslated regions of both the genes and their association with prostate cancer growth pathways. Luciferase assays verified AXL and IGF1R as direct targets of miR-139. Furthermore, immunoblotting of prostate cancer cells demonstrated IGF1R and AXL protein expression were inhibited by miR-139 treatment, which was reversed by the addition of miR-139 antagomir. Examination of the molecular mechanism of growth inhibition by miR-139 revealed the downregulation of activated AKT and cyclin D1, with upregulation of the CDK inhibitor p21.

CONCLUSIONS

miR-139 is associated with improved prognosis in patients with localized prostate cancer, which may be mediated through downregulation of IGF1R and/or AXL and associated signaling pathway components.

Expression pattern of microRNAs related with response to trastuzumab in breast cancer

BACKGROUND

Although an immense effort has been made to develop a novel biomarker for response to trastuzumab, no reliable biomarkers are available to guide management, expect for HER2. The aim of this study was to examine the relationship between microRNA (miRNA) expression and resistance to trastuzumab.

METHODS

Differentially expressed miRNAs between trastuzumab-resistant and trastuzumab-sensitive cell lines were analyzed using microarrays. We performed Gene Ontology and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses to determine the functions of differentially expressed miRNA and their targeted genes. Furthermore, the protein-protein interactions (PPI) network was analyzed. Serum samples were collected from patients with HER2-positive breast cancer who were treated with trastuzumab. We validated the miRNAs expression levels by quantitative reverse-transcription polymerase chain reaction (qRT-PCR) in these serums. Receiver operating characteristic (ROC) curve analysis was performed to evaluate the predictive performance of the miRNA.

RESULTS

Using miRNA microarrays, 151 miRNAs that significant differentially expressed between the trastuzumab-resistant and sensitive cells were identified, including 46 upregulated and 105 downregulated miRNAs. Results of real-time PCR confirmed seven miRNAs in cell lines. PI3K-Akt signaling pathway was involved in regulating biological function according to KEGG analysis. Compared with the serums of trastuzumab-sensitive patients, three miRNAs, namely miR-200b, miR-135b, and miR-29a, were identified to be upregulated, and miR-224 was downregulated in the trastuzumab-resistant serums. ROC analysis showed that four miRNAs were correlated with trastuzumab resistance. Furthermore, three subnetwork modules of PPI network were obtained.

CONCLUSION

The results indicated that miRNAs were reliable predictive biomarkers for response to trastuzumab.

LncSNHG3/miR-139-5p/BMI1 axis regulates proliferation, migration, and invasion in hepatocellular carcinoma

OBJECTIVE

Emerging evidence has revealed that lncRNA small nucleolar RNA host gene 3 (SNHG3) is involved in cell proliferation, migration, and invasion in various tumors. However, the underlying molecular mechanism of SNHG3 in hepatocellular carcinoma (HCC) is still not fully explored.

METHODS

Quantitative reverse transcriptase PCR was employed to detect the expression of SNHG3, miR-139-5p, and BMI1. Colony assay and MTT assay were used to detect the proliferation. Transwell assay was introduced to measure the migration and invasion ability. Bioinformatics analysis and luciferase reporter assay were used to confirm the relationship between SNHG3, miR-139-5p, and BMI1. An animal experiment was adopted to detect the function of SNHG3 in vivo.

RESULTS

SNHG3 and BMI1 were upregulated in HCC, while miR-139-5p was downregulated. Knockdown of SNHG3 or BMI1 and overexpression of miR-139-5p could inhibit cell proliferation, migration, and invasion in HCC. miR-139-5p was a target of SNHG3 and BMI1 was a direct target mRNA of miR-139-5p. Silencing SNHG3 could impair the tumor progression in vivo.

CONCLUSION

The lncRNA SNHG3/miR-139-5p/BMI1 axis plays an important role in cell proliferation, migration, and invasion in HCC.

Low microRNA-139 expression associates with poor prognosis in patients with tumors: A meta-analysis

BACKGROUND

microRNA-139 (miR-139) is dysregulated in various types of tumors and plays a key role in carcinogenesis. miR-139 may be used as a diagnostic and prognostic biomarker of cancers. However, the data from the literature are not consistent. The present study aimed to verify the prognostic and diagnostic values of miR-139 in solid tumors.

DATA SOURCES

PubMed, Web of Science and Embase databases were searched and publications from January 2011 to August 2017 were included. We used Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) database to further validate this meta-analysis.

RESULTS

Eight individual studies from seven articles were included. Pooled analyses showed that low miR-139 expression was related to worse overall survival (OS) [hazard ratio (HR) = 2.27; 95% confidence intervals (CI): 1.74-2.95; P < 0.001] in solid tumors, including hepatocellular carcinoma (HCC) and glioblastoma multiforme (GBM), consisting with the results of TCGA. However, our results of CRC showed that low miR-139 expression was associated with poor OS which was contradictory with the results in TCGA database and need larger samples to validate the phenomenon; whereas for CRC patients, high miR-139 expression predicted poor RFS, which was in good accordance with TCGA results. The results of 27 microarrays from GEO database showed that miR-139 expression levels were lower in tumor tissues compared to adjacent non-tumor tissues or healthy tissues. Decreased miR-139 expression was also significantly correlated with poor differentiation grade (OR = 3.57; 95% CI: 1.44-8.85; P = 0.006). However, the combined data indicated that no associations between miR-139 expression and the following parameters such as age (pooled OR = 1.50; 95% CI: 0.69-3.24; P = 0.304), gender (pooled OR = 0.92; 95% CI: 0.56-1.51; P = 0.738), tumor size (pooled OR = 1.51; 95% CI: 0.69-3.31; P = 0.298), late tumor-node-metastasis stage (pooled OR = 1.63; 95% CI: 0.99-2.68; P = 0.057) and lymph-node-metastasis (pooled OR = 0.66; 95% CI: 0.34-1.28; P = 0.222).

CONCLUSIONS

Low miR-139 expression was related to poor prognosis in HCC and GBM, which could be regarded as a potential prognostic biomarker. However, its precise functional role in CRC still need to be further investigated through larger samples and multicenter studies.

Overexpression of miRNA-25-3p inhibits Notch1 signaling and TGF-β-induced collagen expression in hepatic stellate cells

During chronic liver injury hepatic stellate cells (HSCs), the principal source of extracellular matrix in the fibrotic liver, transdifferentiate into pro-fibrotic myofibroblast-like cells - a process potentially regulated by microRNAs (miRNAs). Recently, we found serum miRNA-25-3p (miR-25) levels were upregulated in children with Cystic Fibrosis (CF) without liver disease, compared to children with CF-associated liver disease and healthy individuals. Here we examine the role of miR-25 in HSC biology. MiR-25 was detected in the human HSC cell line LX-2 and in primary murine HSCs, and increased with culture-induced activation. Transient overexpression of miR-25 inhibited TGF-β and its type 1 receptor (TGFBR1) mRNA expression, TGF-β-induced Smad2 phosphorylation and subsequent collagen1α1 induction in LX-2 cells. Pull-down experiments with biotinylated miR-25 revealed Notch signaling (co-)activators ADAM-17 and FKBP14 as miR-25 targets in HSCs. NanoString analysis confirmed miR-25 regulation of Notch- and Wnt-signaling pathways. Expression of Notch signaling pathway components and endogenous Notch1 signaling was downregulated in miR-25 overexpressing LX-2 cells, as were components of Wnt signaling such as Wnt5a. We propose that miR-25 acts as a negative feedback anti-fibrotic control during HSC activation by reducing the reactivity of HSCs to TGF-β-induced collagen expression and modulating the cross-talk between Notch, Wnt and TGF-β signaling.

MicroRNA-139 inhibits hepatocellular carcinoma cell growth through down-regulating karyopherin alpha 2

BACKGROUND

MicroRNA-139-5p (miR-139) has been shown to play important roles in hepatocellular carcinoma (HCC) development. However, the exact mechanism of miR-139 in HCC remains largely unknown.

METHODS

We investigated the function in human cell lines and patient tissue samples by experimental techniques in molecular biology including Co-IP assay, cell viability assay, quantitative real-time-PCR, et al. In addition, datasets were used to verify the results by database analysis. Statistical analysis was performed by using the GraphPad Prism 6 (GraphPad Software Inc., USA). A P value < 0.05 was defined as statistically significant.

RESULTS

In this study, we found that miR-139 was significantly down-regulated in HCC. MiR-139 level was negatively associated with the stage of HCC, and HCC patients with higher miR-139 level had longer overall survival (OS) than these having lower miR-139 expression. Overexpression of miR-139 led to reduced cell viability, elevated apoptosis, and decreased colony forming, migratory and invasive capacities in HCC cells, while down-regulation of miR-139 led to opposite phenotypes. MiR-139 also inhibited HCC growth in a xenograft mouse model. We identified karyopherin alpha 2 (KPNA2) as a direct target of miR-139. KPNA2 is up-regulated in HCC and higher KPNA2 level is associated with poor patient prognosis. Silencing of KPNA2 expression led to similar phenotypic changes as miR-139 overexpression. Restoration of KPNA2 attenuated the suppressive effects of miR-139 overexpression on cell viability, apoptosis, colony formation, migration and invasion. In addition, miR-139 overexpression and KPNA2 depletion led to decreased nucleus level of POU class 5 homeobox 1 (POU5F1) and c-myc, two well-known pro-oncogenes.

CONCLUSION

In together, these data revealed the essential roles of the miR-139/KPNA2 axis in HCC.

New Insights into the Implication of Epigenetic Alterations in the EMT of Triple Negative Breast Cancer

Breast cancer is the most common cancer and leading cause of cancer death among women worldwide, encompassing a wide heterogeneity of subtypes with different clinical features. During the last two decades, the use of targeted therapies has emerged in clinical research in order to increase treatment efficiency, improve prognosis and reduce recurrence. However, the triple negative breast cancer (TNBC) subtype remains a clinical challenge, with poor prognosis since no therapeutic targets have been identified. This aggressive breast cancer entity lacks expression of oestrogen receptor (ER) and progesterone receptor (PR), and it does not overexpress human epidermal growth factor receptor 2 (HER2). The major reason for TNBC poor prognosis is early therapeutic escape from conventional treatments, leading to aggressive metastatic relapse. Metastases occur after an epithelial-mesenchymal transition EMT of epithelial cells, allowing them to break free from the primary tumour site and to colonize distant organs. Cancer-associated EMT consists not only of acquired migration and invasion ability, but involves complex and comprehensive reprogramming, including changes in metabolism, expression levels and epigenetic. Recently, many studies have considered epigenetic alterations as the primary initiator of cancer development and metastasis. This review builds a picture of the epigenetic modifications implicated in the EMT of breast cancer. It focuses on TNBC and allows comparisons with other subtypes. It emphasizes the role of the main epigenetic modifications lncRNAs, miRNAs, histone and DNA- modifications in tumour invasion and appearance of metastases. These epigenetic alterations can be considered biomarkers representing potential diagnostic and prognostic factors in order to define a global metastatic signature for TNBC.