MiR-891a-5p as a prognostic marker and therapeutic target for hormone receptor-positive breast cancer

MicroRNAs as behind-the-scenes molecules in breast cancer metastasis and their therapeutic role through novel microRNA-based delivery strategies

Breast cancer is the primary cause of cancer-related death and the most frequent malignancy among women in Western countries. Although there have been advancements in combination treatments and targeted therapies for the metastatic diseases management, metastatic breast cancer is still the second most common cause of cancer-related deaths among U.S. women. The routes of metastasis encompass invasion, intravasation, circulation, extravasation, infiltration into a remote location to establish a metastatic niche, and the formation of micro-metastases in a new environment. Each of these processes is regulated by changes in gene expression. MicroRNAs (miRNAs) are widely expressed by a variety of organisms and have a key role in cell activities including suppressing or promoting cancer through regulating various pathways. Target gene expression is post-transcriptionally regulated by miRNAs, which contribute to the development, spread, and metastasis of breast cancer. In this study, we comprehensively discussed the role of miRNAs as predictors of breast cancer metastasis, their correlation with the spread of the disease to certain organs, and their potential application as targets for breast cancer treatment. We also provided molecular mechanisms of miRNAs in the progression of breast cancer, as well as current challenges in miRNA-based therapeutic approaches. Furthermore, as one of the primary issues with the treatment of solid malignancies is the efficient delivery of miRNAs, we examined a number of cutting-edge carriers for miRNA-based therapies and CRISPR/Cas9 as a targeted therapy for breast cancer.

Computational Screening to Predict MicroRNA Targets in the Flavivirus 3' UTR Genome: An Approach for Antiviral Development

MicroRNAs (miRNAs) are molecules that influence messenger RNA (mRNA) expression levels by binding to the 3' untranslated region (3' UTR) of target genes. Host miRNAs can influence flavivirus replication, either by inducing changes in the host transcriptome or by directly binding to viral genomes. The 3' UTR of the flavivirus genome is a conserved region crucial for viral replication. Cells might exploit this well-preserved region by generating miRNAs that interact with it, ultimately impacting viral replication. Despite significant efforts to identify miRNAs capable of arresting viral replication, the potential of all these miRNAs to interact with the flavivirus 3' UTR is still poorly characterised. In this context, bioinformatic tools have been proposed as a fundamental part of accelerating the discovery of interactions between miRNAs and the 3' UTR of viral genomes. In this study, we performed a computational analysis to reveal potential miRNAs from human and mosquito species that bind to the 3' UTR of flaviviruses. In humans, miR-6842 and miR-661 were found, while in mosquitoes, miR-9-C, miR-2945-5p, miR-11924, miR-282-5p, and miR-79 were identified. These findings open new avenues for studying these miRNAs as antivirals against flavivirus infections.

The high expression of ADRM1 in hepatocellular carcinoma is closely related to tumor immune infiltration and is regulated by miR-891a-5p

Liver cancer is one of the most common malignant tumors worldwide. Although some progress has been made in the diagnosis and treatment of Hepatocellular carcinoma (HCC), the diagnosis and treatment of HCC is still facing great challenges because of the high mortality rate and poor prognosis of HCC. The purpose of this study was to explore the relationship between adhesion-regulating molecule1 (ADRM1), and liver cancer, and the relationship between prognoses. ADRM1 is highly expressed in tumors and is closely associated with the prognosis of patients with liver cancer. In our previous study, we found that ADRM1 was highly expressed in HCC and was closely related to tumor immune and immune checkpoint levels in HCC. We validated the immune expression of ADRM1 in liver cancer cells using flow cytometry. In hepatocellular carcinoma tissues, miR-891a-5p regulates ADRM1. Upregulation of miR-891a-5p upregulates ADRM1, and downregulation of miR-891a-5p downregulates ADRM1. It is suggested that ADRM1 plays a key role in the occurrence and development of hepatocellular carcinoma. This study is expected to provide new ideas for the research and development of anti-HCC drugs targeting miR-891a-5p/ADRM1. However, further trials are needed to confirm these results and explore the actual results in patients with HCC.

A novel miRNA-based signature as predictive tool of survival outcome of colorectal cancer patients

It is great significance of identifying valuable biomarkers for early diagnosis and prognostic prediction of colorectal cancer (CRC) patients. This study aimed at developing and validating a miRNAs-based signature as prognostic tool for CRC patients. The miRNA expression profile of 624 CRC samples (613 tumor tissues and 11 normal tissues) was analyzed, and 523 differentially expressed miRNAs (DEmiRNAs) were identified, in which 191 were downregulated and 332 were upregulated. All patients were randomly divided into a training cohort (N = 308) and an internal validation cohort (N = 200). Using the least absolute shrinkage and selection operator (LASSO) and Cox regression model, a prognostic signature of 10 miRNAs (hsa-miR-149-5p, hsa-miR-193b-5p, hsa-miR-193a-3p, hsa-miR-3677-3p, hsa-miR-29a-3p, hsa-miR-200c-5p, hsa-miR-200a-5p, hsa-miR-6854-5p, hsa-miR-216a-5p and hsa-miR-891a-5p) was developed in the training cohort. The risk score was calculated by the product of the expression level and the coefficients of each miRNA. The prognostic value of 10 miRNAs-based signature for CRC patients was tested and validated. Survival analysis indicated that high-risk patients (> 1.10) had a worse overall survival (OS) than low-risk (≤ 1.10) patients (5-year OS rate for training cohort: 59.3% vs. 78.9%, p < .001; validation cohort: 48.3% vs. 69.3%, p = .011). The miRNA-based signature was an independent prognostic factor for CRC patients (HR for training cohort:2.476, 95% CI:1.202-5.098, p = .014; HR for validation cohort:2.050, 95% CI:1.087-3.869, p = .027). The AUC values for 3-year and 5-year OS prediction were 0.718 and 0.784 in the training cohort, 0.659 and 0.614 in the validation cohort, respectively. The 10 miRNAs-based signature provided a proper prognostic stratification for CRC patients, and it might be a promising tool for survival prediction.

The Role of MicroRNAs in Breast Cancer and the Challenges of Their Clinical Application

MicroRNAs (miRNAs) constitute a subclass of non-coding RNAs that exert substantial influence on gene-expression regulation. Their tightly controlled expression plays a pivotal role in various cellular processes, while their dysregulation has been implicated in numerous pathological conditions, including cancer. Among cancers affecting women, breast cancer (BC) is the most prevalent malignant tumor. Extensive investigations have demonstrated distinct expression patterns of miRNAs in normal and malignant breast cells. Consequently, these findings have prompted research efforts towards leveraging miRNAs as diagnostic tools and the development of therapeutic strategies. The aim of this review is to describe the role of miRNAs in BC. We discuss the identification of oncogenic, tumor suppressor and metastatic miRNAs among BC cells, and their impact on tumor progression. We describe the potential of miRNAs as diagnostic and prognostic biomarkers for BC, as well as their role as promising therapeutic targets. Finally, we evaluate the current use of artificial intelligence tools for miRNA analysis and the challenges faced by these new biomedical approaches in its clinical application. The insights presented in this review underscore the promising prospects of utilizing miRNAs as innovative diagnostic, prognostic, and therapeutic tools for the management of BC.

Exploring the Therapeutic Potential of trans-Chalcone: Modulation of MicroRNAs Linked to Breast Cancer Progression in MCF-7 Cells

Breast cancer is responsible for 25% of all cancers that affect women. Due to its high heterogeneity pattern in clinical diagnosis and its molecular profile differences, researchers have been seeking new targets and therapies, with more specificity and fewer side effects. Thus, one compound that has garnered our attention is trans-chalcone, which is naturally occurring in various plants and possesses promising biological properties, including antitumor effects. MiRNA is an extensive class of non-coding small, endogenous, and single-stranded RNAs, and it is involved in post-translational gene regulation. Therefore, the objective of this study was to investigate the effects of TChal on miRNAs expression and its relationship with anticancer activity against MCF-7. Initially, the trans-chalcone IC50 value was established by MTT assay for MCF-7and HaCat (non-cancer cell), in which we found out that it was 53.73 and 44.18 μM, respectively. Subsequently, we treated MCF-7 cells with trans-chalcone at its IC50 concentration and performed Mi-seq analysis, which unveiled 23 differentially expressed miRNAs. From this set, we selected five miRNAs (miR-25-5p, miR-27a-3p, miR-891a, miR-449a, and miR-4485) for further validation using qRT-PCR, guided by in silico analysis and their known association with tumorigenesis. In conclusion, our research provides valuable insights into the potential use of TChal to reveal MicroRNAs molecular targets that can be applied in breast cancer therapy.

Assessing the Role of MicroRNAs in Predicting Breast Cancer Recurrence-A Systematic Review

Identifying patients likely to develop breast cancer recurrence remains a challenge. Thus, the discovery of biomarkers capable of diagnosing recurrence is of the utmost importance. MiRNAs are small, non-coding RNA molecules which are known to regulate genetic expression and have previously demonstrated relevance as biomarkers in malignancy. To perform a systematic review evaluating the role of miRNAs in predicting breast cancer recurrence. A formal systematic search of PubMed, Scopus, Web of Science, and Cochrane databases was performed. This search was performed according to the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) checklist. A total of 19 studies involving 2287 patients were included. These studies identified 44 miRNAs which predicted breast cancer recurrence. Results from nine studies assessed miRNAs in tumour tissues (47.4%), eight studies included circulating miRNAs (42.1%), and two studies assessed both tumour and circulating miRNAs (10.5%). Increased expression of 25 miRNAs were identified in patients who developed recurrence, and decreased expression of 14 miRNAs. Interestingly, five miRNAs (miR-17-5p, miR-93-5p, miR-130a-3p, miR-155, and miR-375) had discordant expression levels, with previous studies indicating both increased and reduced expression levels of these biomarkers predicting recurrence. MiRNA expression patterns have the ability to predict breast cancer recurrence. These findings may be used in future translational research studies to identify patients with breast cancer recurrence to improve oncological and survival outcomes for our prospective patients.

Hyperglycemia induces miR-26-5p down-regulation to overexpress PFKFB3 and accelerate epithelial–mesenchymal transition in gastric cancer

Gastric cancer (GC) is one of the most deadly malignancies with high morbidity worldwide. Cancer cells exhibited higher level of glucose catabolism than normal cells to meet the needs for rapid growth. Emerging evidences indicated that hyperglycemia has positive effects on the progression of tumor. As a vital regulator of glycolysis, 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase 3 (PFKFB3) was confirmed to have a higher expression level in tumor tissue and correlated with the prognosis of GC patients. However, the role of PFKFB3 in GC patients with hyperglycemia remains unclear. The data from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) were utilized to analyze the expression level of PFKFB3 and conducted survival analysis of GC patients. Western blot assay was used to detect gene expression at the protein level. Small interfering RNA (siRNA) transfection assay was conducted to down-regulate the expression of PFKFB3. Cell functional assays were carried out to reflect the ability of cell proliferation and migration. The results indicated that PFKFB3 was significantly upregulated and its overexpression was associated with poor prognosis of GC patients. Besides, hyperglycemia stimulated the higher expression of PFKFB3 along with the enhanced proliferation, migration and epithelial–mesenchymal transition (EMT) in GC cells. Knocking down of PFKFB3 effectively reversed the effects of high glucose concentration on GC malignant phenotype and the opposite results were gained when miR-26-5p was inhibited. Therefore, PFKFB3 down-regulated by miR-26-5p inhibited the malignant phenotype of GC with hyperglycemia.

Liquiritigenin Blocks Breast Cancer Progression by Inhibiting Connective Tissue Growth Factor Expression via Up-Regulating miR-383-5p

The objective of this study was to investigate the effect of liquiritigenin (LQ) on breast cancer (BC) and its mechanism. After BC cell lines and normal mammary epithelial cells were cultured with LQ, CCK-8, and Scratch, Transwell assays and flow cytometry were applied to test the effect of LQ on cell proliferation, migration, invasion, and apoptosis. The effect of LQ on the expression of microRNA-383-5p (miR-383-5p) and connective tissue growth factor (CTGF) was measured by qRT-PCR and Western blotting. Bioinformatics prediction was used to evaluate the binding relationship between miR-383-5p and CTGF, which was verified by dual-luciferase reporter assay. After miR-383-5p and/or CTGF expression was upregulated through cell transfection, the relationship between miR-383-5p and CTGF, as well as their effects on BC, was further assessed. The results showed that LQ can significantly inhibit CTGF expression and the proliferative, migratory, and invasive abilities of BC cells, while facilitating apoptosis of BC cells and miR-383-5p expression. The inhibiting effect of LQ was dose-dependently enhanced in BC cells. Dual-luciferase reporter assay verified that miR-383-5p targeted CTGF. CTGF expression was inversely regulated by miR-383-5p. CTGF upregulation repressed the suppressive effect of miR-385-5p on BC cell development. In conclusion, LQ can inhibit CTGF expression by upregulating miR-383-5p, thereby inhibiting proliferative, migratory, and invasive abilities and promoting apoptosis of BC cells.

MiR-200c-3p aggravates gastric cell carcinoma via KLF6

Background

Gastric cell carcinoma (GCC) is a common and high-incidence malignant gastrointestinal cancer that seriously threatens human life and safety. Evidences suggest that microRNAs (miRNAs) exhibit an essential role in regulating the occurrence and development of GCC, while the effects and possible mechanisms remain to be further explored.

Objective

This study was designed to explore whether miR-200c-3p exerted its functional role in the growth and metastasis of GCC, and investigate the possible mechanisms.

Methods

The expression levels of miR-200c-3p in GCC tissues and cell lines were detected by qRT-PCR analysis. The functional role of miR-200c-3p in the viability, proliferation, migration and invasion of GCC cells were evaluated by CCK-8, EdU, wound healing and Transwell assays. In addition, the candidate targets of miR-200c-3p was predicted and confirmed by dual-luciferase reporter assay. Moreover, the relationship between miR-200c-3p and target (Krüppel like factor 6, KLF6) was assessed by qRT-PCR and western blot assays. Besides, the expression levels of KLF6 in GCC cells were determined by qRT-PCR and western blot assays. Furthermore, the role of KLF6 in the viability, proliferation, migration and invasion of GCC cells mediated with miR-200c-3p mimics was evaluated by CCK-8, EdU, wound healing and Transwell assays.

Results

In the present study, a new tumor promoting function of miR-200c-3p was disclosed in GCC. We found that the expression of miR-200c-3p was obviously increased in clinic GCC tissues and cell lines. In addition, down-regulation of miR-200c-3p suppressed cell viability, proliferation, migration, and invasion in GCC cells. Moreover, KLF6 was verified as a direct target of miR-200c-3p by binding its 3’-UTR. Additionally, KLF6 was remarkably decreased and was negatively associated with the miR-200c-3p expression in GCC cell lines. Furthermore, over-expression of KLF6 retarded the effects of miR-200c-3p on the growth and metastasis of GCC cell lines.

Conclusions

MiR-200c-3p potentially played a tumor-promoting role in the occurrence and development of GCC, which may be achieved by targeting KLF6.

Graphic abstract

Establishing a three-miRNA signature as a prognostic model for colorectal cancer through bioinformatics analysis

Background: Identification of more promising microRNAs (miRNAs) are being extensively studied with respect to colorectal cancer (CRC), since CRC is the leading cause of cancer deaths and most common malignant tumors worldwide. A series of colon cancer (CCa) samples from The Cancer Genome Atlas (TCGA) were analyzed to provide a new perspective into this field.

Methods: The expression of miRNAs, mRNAs and the clinical data of 437 CRC patients were downloaded from the TCGA database. The survival-related differentially expressed miRNAs (sDMIRs) and mRNAs were detected by COX regression analysis. The high-risk group and low-risk group were separated by the median risk score of the risk score model. The potential clinical characteristics of these sDMIRs were analyzed by R software. The potential molecular mechanisms of these sDMIRs were explored by computational biology. The expression levels of three sDMIRs were explored by qPCR in CRC samples.

Results: Three DMIRs (hsa-miR-21-3p, hsa-miR-194-3p and hsa-miR-891a-5p) correlated with the most remarkable prognostic values of CRC patients were selected to establish the risk score model (RSM) by univariate and multivariate COX regression analysis and the survival probability of the low-risk group was longer than that in the high-risk group. We detected the target genes of three sDMIRs and the potential molecular mechanisms of these sDMIRs. We further verified the high expression levels of hsa-miR-21-3p and hsa-miR-194-3p were associated with the early T-stages, while hsa-miR-891a-5p illustrated the reversed result.

Conclusion: Our study demonstrated three sDMIRs with significantly clinical values illustrated the potential predicting values in the prognosis of CRC patients. Our results may provide a new perspective for the diagnostic methods and treatment strategies in CRC patients.

miR-383-5p inhibits human malignant melanoma cells function via targeting CENPF

Human malignant melanoma (MM), is a type of skin cancer with high morbidity and mortality. In this study, we investigated the role of miR-383-5p in human MM cells in vitro. miR-383-5p expression was downregulated in MM cell lines compared with the human normal melanocyte cell line, and miR-383-5p overexpression inhibited the proliferation, migration, and invasion of M14 and A375 cells. Furthermore, miR-383-5p was able to effectively bind to the 3'UTR of CENPF mRNA. miR-383-5p expression was negatively correlated with CENPF expression and miR-383-5p overexpression inhibited CENPF protein expression in M14 and A375 cells. The overexpression of CENPF could effectively rescue the inhibitory effect on proliferation and invasion caused by miR-383-5p. Additionally, using publicly available databases, we showed that CENPF expression was upregulated in human MM tissues and could predict the prognosis of MM. In conclusion, miR-383-5p acts as a tumor suppressor in human MM by targeting CENPF, suggesting CENPF as a potential therapeutic target for human MM.

MicroRNA-891a-5p is a novel biomarker for non-small cell lung cancer and targets HOXA5 to regulate tumor cell biological function

Numerous studies have shown that the dysregulation of microRNA (miRNA/miR) is an important factor in the pathogenesis of lung cancer. However, the role of miR-891a-5p in non-small cell lung cancer (NSCLC) remains unclear. Therefore, the present study aimed to examine the clinical value and biological function of miR-891a-5p in NSCLC. The mRNA expression level of miR-891a-5p in NSCLC was determined using reverse transcription-quantitative PCR and was used to determine the diagnostic value of miR-891a-5p, by creating a receiver operating characteristic curve. Kaplan-Meier and Cox regression analyses were used to evaluate its prognostic value in patients with NSCLC. Furthermore, cell experiments were performed to investigate the underlying mechanisms and functional role of miR-891a-5p in NSCLC progression. The results indicated that miR-891a-5p expression level was significantly higher in serum and tissues from patients with NSCLC and NSCLC cell lines. In addition, serum miR-891a-5p was found to have a diagnostic value in patients with NSCLC, and the increase in the expression level of miR-891a-5p in tumor tissues was associated with differentiation, and the tumor, node and metastases stages of cancer, which could be used for NSCLC prognosis. In addition, the experiments revealed that NSCLC cell proliferation, invasion and migration were significantly increased by the overexpression of miR-891a-5p and were significantly reduced by its downregulation. Furthermore, a luciferase reporter assay and the protein expression levels of HOXA5 showed that HOXA5 might be a miR-891a-5p target gene. In summary, the results indicated that high miR-891a-5p expression level could be a novel biomarker in patients with NSCLC and that it promoted tumor cell proliferation, invasion and migration. HOXA5 may be a target of miR-891a-5p, which may mediate miR-891a-5p function in NSCLC.

Potential treatment for chronic myeloid leukemia using microRNA: in silico comparison between plants and human microRNAs in targeting BCR-ABL1 gene

Background

Chronic myeloid leukemia (CML) is a myeloproliferative disorder characterized by the expression of the BCR-ABL1 fusion gene. Tyrosine kinase inhibitors (TKI) are used to treat CML, but mutations in the tyrosine kinase domain contribute to CML chemo-resistance. Therefore, finding alternative molecular-targeted therapy is important for the comprehensive treatment of CML. MicroRNAs (miRNA) are small non-coding regulatory RNAs which suppress the expression of their target genes by binding to the 3′ untranslated region (3′UTR) of the target mRNA. Hypothetically, the miRNA-mRNA interaction would suppress BCR-ABL1 expression and consequently reduce and inhibit CML cell proliferation. Thus, our objective was to determine the target interaction of human and plant miRNAs targeting the 3′UTR region of BCR-ABL1 in terms of miRNA binding conformity, protein interaction network, and pathways using in silico analysis. The 3′UTR sequence of BCR-ABL1 is obtained from Ensembl Genome Browser while the binding conformity was determined using the PsRNATarget Analysis Server, RNA22, Target Rank Server, and DIANA TOOLS. Protein-protein interaction network and pathway analysis are determined using STRING, Cytoscape, and KEGG pathway analysis.

Results

Five plants and five human miRNAs show strong binding conformity with 3′UTR of BCR-ABL1. The strongest binding conformity was shown by Oryza sativa’s Osa-miR1858a and osa-miR1858b with −24.4 kcal/mol folding energy and a p value of 0.0077. Meanwhile, in human miRNA, the hsa-miR-891a-3p shows the highest miTG score of 0.99 with −12 kcal/mol folding energy and a p value of 0.037. Apart from ABL1, osa-miR1858a/osa-miR1858b and hsa-miR891a-3p also target other 720 and 645 genes, respectively. The interaction network of Osa-miR1858a/osa-miR1858b and hsa-miR891a-3p identifies nineteen and twelve ABL1’s immediate neighboring proteins, respectively. The pathways analysis focuses on the RAS, MAPK, CML, and hematopoietic cell lineage pathway.

Conclusion

Both plant and human miRNAs tested in this study could be a potential therapeutic prospect in CML treatment, but thermodynamically, osa-miR1858a/osa-miR1858b binding to ABL1 is more favorable. However, it is important to carry out more research in vitro and in vivo and clinical studies to assess its efficacy as a targeted therapy for CML.

Graphical abstract

LncRNA CASC9 attenuates lactate dehydrogenase-mediated oxidative stress and inflammation in spinal cord injury via sponging miR-383-5p

Long non-coding RNAs (lncRNAs) play important roles in various diseases, but the effect of lncRNA CASC9 on spinal cord injury (SCI) remains unclear. Therefore, the present study was conducted to explore the role of this lncRNA in SCI. SCI model was established by laminectomy in rats in vivo or induced by LPS in PC12 cells in vitro. Methylprednisolone (MP) was used for treatment in vivo. Spinal cord tissues were stained with H&E, and the oxidative stress- and inflammation-related factors were detected using their commercial kits. Cell apoptosis was determined using flow cytometry assay. Relative expression of corresponding genes was measured using qRT-PCR and western blotting. Luciferase reporter assay was used to verify binding site between CASC9 and miR-383-5p, as well as miR-383-5p and LDHA. The results showed that lncRNA CASC9 was downregulated and miR-383-5p was upregulated in SCI rats and LPS-induced PC12 cells. Severe histological injury and increased water content were also found in SCI rats. Increased levels of LDH, MDA, lactic acid, TNF-α, and IL-1β were found in SCI rats and LPS-induced PC12 cells. These changes could be reversed by MP treatment in vivo or overexpression of CASC9 in vitro. Besides, overexpression of CASC9 decreased cell apoptosis and protein expression of LDHA and increased protein expression of Nrf2 and HO-1 in LPS-induced PC12 cells. Furthermore, miR-383-5p was a direct target of CASC9 and was negatively regulated by CASC9. LDHA was a direct target of miR-383-5p and was negatively regulated by CASC9. In conclusion, lncRNA CASC9 exerted a protective role against oxidative stress, inflammation, and cell apoptosis in SCI, providing a novel therapeutic target or prognostic factor for SCI.

The Status of EGFR Modulates the Effect of miRNA-200c on ZEB1 Expression and Cell Migration in Glioblastoma Cells

Migration of glioblastoma cells into surrounding tissue is one of the main features that makes this tumor incurable. We evaluated whole-genome miRNA expression profiling associated with different EGFR amplification patterns in 30 cases of primary glioblastoma. From the 64 miRNAs that showed differential expression between tumors with a high level of EGFR amplification and tumors without EGFR amplification, 40% were related with cell migration, being miR-200c the most differentially expressed between these two groups. We investigated the effect of miR-200c on ZEB1 expression and cell migration in an in vitro transfection model with a miR-200c mimic, a miR-200c inhibitor and siRNA targeting EGFR in three short-term cultures with different levels of EGFR amplification obtained from resected glioblastomas. The cell culture with the highest EGFR amplification level presented the lowest miR-200c expression and the status of EGFR modulated the effect of miR-200c on ZEB1 expression. Silencing EGFR led to miR-200c upregulation and ZEB1 downregulation in transfected cultures, except in the presence of high levels of EGFR. Likewise, miR-200c upregulation decreased ZEB1 expression and inhibited cell migration, especially when EGFR was not amplified. Our results suggest that modulating miR-200c may serve as a novel therapeutic approach for glioblastoma depending on EGFR status.

miRNA Expression Profiles in Luminal A Breast Cancer-Implications in Biology, Prognosis, and Prediction of Response to Hormonal Treatment

Breast cancer, which is the most common malignancy in women, does not form a uniform nosological unit but represents a group of malignant diseases with specific clinical, histopathological, and molecular characteristics. The increasing knowledge of the complex pathophysiological web of processes connected with breast cancercarcinogenesis allows the development of predictive and prognostic gene expressionand molecular classification systems with improved risk assessment, which could be used for individualized treatment. In our review article, we present the up-to-date knowledge about the role of miRNAs and their prognostic and predictive value in luminal A breast cancer. Indeed, an altered expression profile of miRNAs can distinguish not only between cancer and healthy samples, but they can classify specific molecular subtypes of breast cancer including HER2, Luminal A, Luminal B, and TNBC. Early identification and classification of breast cancer subtypes using miRNA expression profilescharacterize a promising approach in the field of personalized medicine. A detection of sensitive and specific biomarkers to distinguish between healthy and early breast cancer patients can be achieved by an evaluation of the different expression of several miRNAs. Consequently, miRNAs represent a potential as good diagnostic, prognostic, predictive, and therapeutic biomarkers for patients with luminal A in the early stage of BC.