Elevated microRNA-125b levels predict a worse prognosis in HER2-positive breast cancer patients

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.

Resistance of breast cancer cells to paclitaxel is associated with low expressions of miRNA-186 and miRNA-7

Aim: Neo-adjuvant chemotherapy is a common approach for the complex treatment of breast cancer (BC) and paclitaxel (PTX) is frequently included in the therapeutic regimen. However, the effect of PTX-based treatment is hard to predict precisely based on routinely used markers. As microRNAs are considered a new promising class of biomarkers, the link between miRNA expression and PTX resistance of BC cells needs to be well investigated. This study aimed at the identification of miRNAs associated with responses of BC cells to PTX. Methods: Intrinsic PTX sensitivity and miRNA profiling were assayed in five BC cell lines to identify candidate miRNAs. Selected miRNA (n. 15) expressions were analyzed by real-time-quantitative polymerase chain reaction (RT-qPCR) in BC tissue samples (n. 31) obtained from a diagnostic biopsy. Results were analyzed in the context of the effect of two cycles of PTX and the effect of the completed scheme of neoadjuvant therapy. The study's design facilitated the evaluation of the effect of PTX on cells and the identification of features of the microRNA expression profiles associated exclusively with sensitivity to this drug. Results: miR-186 and miR-7 expression in BC tissues was higher in patients with better outcomes of PTX-based neoadjuvant therapy. Conclusion: High expressions of miR-186 and miR-7 are associated with good response to PTX, whereas their low expressions may be associated with resistance to PTX in BC, indicating the possibility of developing innovative test systems for the prediction of the PTX response, which can be used before the start of neo-adjuvant chemotherapy for BC.

Association Between the Expression of MicroRNA-125b and Survival in Patients With Acute Coronary Syndrome and Coronary Multivessel Disease

Background

MicroRNAs (miRNA, miR) have an undeniable physiological and pathophysiological significance and act as promising novel biomarkers. The aim of the study was to investigate blood-derived miRNAs and their association with long-term all-cause mortality in patients with multivessel disease (MVD) suffering from acute coronary syndrome (ACS).

Materials and Methods

This study was an observational prospective study, which included 90 patients with MVD and ACS. Expression of miR-125a, miR-125b, and miR-223 was analysed by polymerase chain reaction (PCR). Patients were followed-up for a median of 7.5 years. All-cause mortality was considered as the primary endpoint. Adjusted Cox-regression analysis was performed for prediction of events.

Results

Elevated expression of miR-125b (>4.6) at the time-point of ACS was associated with increased long-term all-cause mortality (adjusted [adj.] hazard ratio [HR] = 11.26, 95% confidence interval [95% CI]: 1.15–110.38; p = 0.038). The receiver operating characteristic (ROC) analysis showed a satisfactory c-statistics for miR-125b for the prediction of long-term all-cause mortality (area under the curve [AUC] = 0.76, 95% CI: 0.61–0.91; p = 0.034; the negative predictive value of 98%). Kaplan–Meier time to event analysis confirmed an early separation of the survival curves between patients with high vs low expression of miR-125b (p = 0.003). An increased expression of miR-125a and miR-223 was found in patients with non-ST-segment elevation ACS (NSTE-ACS) as compared to those with ST-segment elevation myocardial infarction (STEMI) (p = 0.043 and p = 0.049, respectively) with no difference in the expression of miR-125b between the type of ACS.

Conclusion

In this hypothesis generating study, lower values of miR-125b were related to improved long-term survival in patients with ACS and MVD. Larger studies are needed to investigate whether miR-125b can be used as a suitable predictor for long-term all-cause mortality.

Breast Cancer Subtype-Specific miRNAs: Networks, Impacts, and the Potential for Intervention

The regulatory and functional roles of non-coding RNAs are increasingly demonstrated as critical in cancer. Among non-coding RNAs, microRNAs (miRNAs) are the most well-studied with direct regulation of biological signals through post-transcriptional repression of mRNAs. Like the transcriptome, which varies between tissue type and disease condition, the miRNA landscape is also similarly altered and shows disease-specific changes. The importance of individual tumor-promoting or suppressing miRNAs is well documented in breast cancer; however, the implications of miRNA networks is less defined. Some evidence suggests that breast cancer subtype-specific cellular effects are influenced by distinct miRNAs and a comprehensive network of subtype-specific miRNAs and mRNAs would allow us to better understand breast cancer signaling. In this review, we discuss the altered miRNA landscape in the context of breast cancer and propose that breast cancer subtypes have distinct miRNA dysregulation. Further, given that miRNAs can be used as diagnostic and/or prognostic biomarkers, their impact as novel targets for subtype-specific therapy is also possible and suggest important implications for subtype-specific miRNAs.

Ratiometric Detection of microRNA Using Hybridization Chain Reaction and Fluorogenic Silver Nanoclusters

miRNA (miR)-155 is a potential biomarker for breast cancers. We aimed at developing a nanosensor for miR-155 detection by integrating hybridization chain reaction (HCR) and silver nanoclusters (AgNCs). HCR serves as an enzyme-free and isothermal amplification method, whereas AgNCs provide a built-in fluorogenic detection probe that could simplify the downstream analysis. The two components were integrated by adding a nucleation sequence of AgNCs to the hairpin of HCR. The working principle was based on the influence of microenvironment towards the hosted AgNCs, whereby unfolding of hairpin upon HCR has manipulated the distance between the hosted AgNCs and cytosine-rich toehold region of hairpin. As such, the dominant emission of AgNCs changed from red to yellow in the absence and presence of miR-155, enabling a ratiometric measurement of miR with high sensitivity. The limit of detection (LOD) of our HCR-AgNCs nanosensor is 1.13 fM in buffered solution. We have also tested the assay in diluted serum samples, with comparable LOD of 1.58 fM obtained. This shows the great promise of our HCR-AgNCs nanosensor for clinical application.

Circulating and Intracellular miRNAs as Prognostic and Predictive Factors in HER2-Positive Early Breast Cancer Treated with Neoadjuvant Chemotherapy: A Review of the Literature

MicroRNAs (miRNA) are small noncoding RNAs that can act as both oncogene and tumor suppressors. Deregulated miRNA expression has been detected in human cancers, including breast cancer (BC). Considering their important roles in tumorigenesis, miRNAs have been investigated as potential prognostic and diagnostic biomarkers. Neoadjuvant setting is an optimal model to investigate in vivo the mechanism of treatment resistance. In the management of human epidermal growth factor receptor-2 (HER2)-positive early BC, the anti-HER2-targeted therapies have drastically changed the survival outcomes. Despite this, growing drug resistance due to the pressure of therapy is relatively frequent. In the present review, we focused on the main miRNAs involved in HER2-positive BC tumorigenesis and discussed the recent evidence on their predictive and prognostic value.

Reversal of Radiotherapy Resistance of Ovarian Cancer Cell Strain CAOV3/R by Targeting lncRNA CRNDE

Radiotherapy resistance is one of the key factors of poor prognosis of ovarian cancer clinical treatment. The search for key targets of ovarian cancer radiotherapy resistance has become a high priority. Long noncoding RNA plays an important role in tumor development. However, the key lncRNA in ovarian cancer radiotherapy resistance is not identified. Our finding that lncRNA CRNDE is highly expressed in the radiotherapy resistance cell line CAOV3/R drew our attention. Therefore, in this study, we targeted lncRNA CRNDE to analyze whether it is a key factor of radiotherapy resistance in ovarian cancer. Ultimately, we found that silencing lncRNA CRNDE could reverse CAOV3/R radiotherapy resistance, which would be a boon to clinical treatment.

miRNA-148a and miRNA-30c expressions as potential biomarkers in breast cancer patients

Background

Breast cancer is an extensively identified malignant tumor and is a prime cause of cancer mortalities in females. It has been shown that alteration of miRNAs expression (up or down regulation) can affect the initiation and progression of many malignancies. We aimed to evaluate the role of circulating miRNA-148a and miRNA-30c in female patients with breast cancer and estimate their usage as potential biomarkers in the diagnosis, prognosis and survival of breast cancer.

Methods

This study included 75 breast cancer female patients.They were compared with 55 apparently healthy female subjects. miRNAs expression analysis was assessed via real-time PCR.

Results

To discriminate breast cancer patients from controls, miR-30c showed the best performance at a cut off value of ≤20.6 (AUC = 0.998, 97.33% sensitivity, 96.36% specificity, p < 0.001), followed by miR-148a (AUC = 0.995, 94.67% sensitivity, 90.91% specificity, p < 0.001 at a cut off value of ≤0.1), CA 15-3 (AUC = 0.930, 88.0% sensitivity, 81.82% specificity, p < 0.001 at a cut off value of >21.3), and finally CEA (AUC = 0.751, 70.67% sensitivity, 63.64% specificity, p < 0.001 at a cut off value of >2.5).

Conclusion

miRNA-148a and miRNA-30c expressions were down regulated in female patients with breast cancer and might be considered as potential blood biomarkers. Both also might have rule in disease treatment and selection of therapeutic targets. Future studies are needed to improve their role in predicting response to treatment and prognosis.

Urinary Exosomal MicroRNAs as Potential Non-invasive Biomarkers in Breast Cancer Detection

INTRODUCTION

Breast cancer (BC) is the most frequent malignant disease in women worldwide and is therefore challenging for the healthcare system. Early BC detection remains a leading factor that improves overall outcome and disease management. Aside from established screening procedures, there is a constant demand for additional BC detection methods. Routine BC screening via non-invasive liquid biopsy biomarkers is one auspicious approach to either complete or even replace the current state-of-the-art diagnostics. The study explores the diagnostic potential of urinary exosomal microRNAs with specific BC biomarker characteristics to initiate the potential prospective application of non-invasive BC screening as routine practice.

METHODS

Based on a case-control study (69 BC vs. 40 healthy controls), expression level quantification and subsequent biostatistical computation of 13 urine-derived microRNAs were performed to evaluate their diagnostic relevance in BC.

RESULTS

Multilateral statistical assessment determined and repeatedly confirmed a specific panel of four urinary microRNA types (miR-424, miR-423, miR-660, and let7-i) as a highly specific combinatory biomarker tool discriminating BC patients from healthy controls, with 98.6% sensitivity and 100% specificity.

DISCUSSION

Urine-based BC diagnosis may be achieved through the analysis of distinct microRNA panels with proven biomarker abilities. Subject to further validation, the implementation of urinary BC detection in routine screening offers a promising non-invasive alternative in women's healthcare.

A parallel and cascade control system: magnetofection of miR125b for synergistic tumor-association macrophage polarization regulation and tumor cell suppression in breast cancer treatment

Polarization regulation of tumor-association macrophages (TAMs) is a promising treatment method for tumors, but aiming at TAMs alone shows unsatisfactory therapeutic efficiency. Therefore, we designed a parallel and cascade control system for both macrophage polarization and tumor cell inhibition. The system is composed of cationic lipopeptides with an arginine-rich periphery (RLS) and anionic magnetic nanoparticles (MNPs) for fleet transfection of miR-125b. Based on the highly efficient magnetofection, miR-125b successfully shows a parallel effect on both M1, promoting polarization by targeting interferon regulatory factor 4 (IRF4) in macrophages, and tumor cell inhibition, by targeting ETS proto-oncogene 1 and cyclin- J. The cascading effect on M1-associated genes is upregulated by up to two orders of magnitude, while M2-associated genes are downregulated. Meanwhile, MNPs also have an effect on the TAM polarization and 4T1 tumor cell inhibition via inflammatory related gene expression and Fenton reaction. Further mimicking the co-culture of RAW264.7 and 4T1 cells in vitro confirmed the synergistic therapy effect. In the treatment of orthotopic breast cancer in mice, considerable M1 macrophage polarization was observed in the RM125b treated group, showing distinct tumor-suppressive effects, with a tumor weight reduction of 60% and tumor metastasis suppression of 50%.

miR-224 is an early-stage biomarker of hepatocellular carcinoma with miR-224 and miR-125b as prognostic biomarkers

Aim: The aim was to systematically investigate the miRNA biomarkers for early diagnosis of hepatocellular carcinoma (HCC). Materials & methods: A systematic review and meta-analysis of miRNA expression in HCC were performed. Results: A total of 4903 cases from 30 original studies were comprehensively analyzed. The sensitivity and specificity of miR-224 in discriminating early-stage HCC patients from benign lesion patients were 0.868 and 0.792, which were superior to α-fetoprotein. Combined miR-224 with α-fetoprotein, the sensitivity and specificity were increased to 0.882 and 0.808. Prognostic survival analysis showed low expression of miR-125b and high expression of miR-224 were associated with poor prognosis. Conclusion: miR-224 had a prominent diagnostic efficiency in early-stage HCC, with miR-224 and miR-125b being valuable in the prognostic diagnosis.

Tumor-Derived Exosomal miRNAs as Diagnostic Biomarkers in Non-Small Cell Lung Cancer

Background

Delayed diagnosis is the main obstacle to improve prognosis of non-small cell lung cancer (NSCLC). Novel biomarkers for the diagnosis of NSCLC are urgently needed. This study aimed to identify the specific exosomal miRNAs with diagnostic and prognostic potential in NSCLC patients.

Materials and Methods

Transmission electron microscopy (TEM), qNano and western blots were used to characterize the exosomes isolated from the serum of NSCLC patients (n=330) and healthy donors (n=312) by ultracentrifugation. Exosomal miRNAs were profiled by miRNA microarrays and verified by quantitative PCR (qPCR). The diagnostic accuracy was determined by receiver operating characteristic (ROC) analysis.

Results

A total of differential 22 miRNAs were screened out based on P < 0.05 and fold difference>2.0 by miRNA microarrays, among which, exosomal miR-5684 and miR-125b-5p were significantly down-regulated in NSCLC patients compared to healthy donors, processing favorable diagnostic efficiency for (early) NSCLC. Importantly, the exosomal miR-125b-5p were associated with metastasis (P < 0.0001), chemotherapeutic effect (P=0.007) and survival (P=0.008).

Conclusion

Exosomal miR-5684 and miR-125b-5p levels are significantly down-regulated in NSCLC patients, and serve as the promising diagnostic and prognostic biomarkers for NSCLC.

The effect of oleuropein on apoptotic pathway regulators in breast cancer cells

In spite of advancements in breast cancer therapy, this disease is still one of the significant causes of women fatalities globally. Dysregulation of miRNA plays a pivotal role in the initiation and progression of cancer. Therefore, the administration of herbal compounds with anticancer effects through controlling microRNA expression can be considered as a promising therapy for cancer. Oleuropein is the most prevalent phenolic compound in olive. Given its domestic consumption, low cost, and nontoxicity for human beings, oleuropein can be used in combination with the standard chemotherapy drugs. To this end, we examined the effect of oleuropein on two breast cancer cell lines (MCF7 and MDA-MB-231). Our findings revealed that oleuropein significantly decreased cell viability in a dose- and time-dependent manner, while it increased the apoptosis in MCF7 and MDA-MB-231 cells. In the presence of oleuropein, the expression levels of miR-125b, miR-16, miR-34a, p53, p21, and TNFRS10B increased, while that of bcl-2, mcl1, miR-221, miR-29a and miR-21 decreased. The findings pointed out that oeluropein may induce apoptosis via not only increasing the expression of pro-apoptotic genes and tumor suppressor miRNAs, but also decreasing the expression of anti-apoptotic genes and oncomiR. Consequently, oleuropein can be regarded as a suitable herbal medication for cancer therapy.

Therapeutic effects of ginsenosides on breast cancer growth and metastasis

Breast cancer is the most common cause of cancer-related deaths among women worldwide. Thus, the development of new and effective low-toxicity drugs is vital. The specific characteristics of breast cancer have allowed for the development of targeted therapy towards each breast cancer subtype. Nevertheless, increasing drug resistance is displayed by the changing phenotype and microenvironments of the tumor through mutation or dysregulation of various mechanisms. Recently, emerging data on the therapeutic potential of biocompounds isolated from ginseng have been reported. Therefore, in this review, various roles of ginsenosides in the treatment of breast cancer, including apoptosis, autophagy, metastasis, epithelial-mesenchymal transition, epigenetic changes, combination therapy, and drug delivery system, have been discussed.

Intratumoral Heterogeneity of Expression of 16 miRNA in Luminal Cancer of the Mammary Gland

The purpose of this work is to determine the intratumoral distribution of miRNA expression profiles in luminal breast cancer (BC). The study included 33 certain BC cases of the luminal A or luminal B (Her2-) subtypes. The relative expression levels of miRNA-20a; -21; -125b; -126; -200b; -181a; -205; -221; -222; -451a; -99a; -145; -200a; -214; -30a; -191; and small nuclear RNAs U6, U54, and U58 were measured by RT-qPCR in four intratumor areas in each of 33 luminal BC specimens and in surrounding normal mammary gland tissues. Comparative analysis of miRNA expression levels between normal mammary gland tissue and different intratumor areas revealed that only four miRNAs (miRNA-21, -200b, -200a, -191) appear as consistently differentiating markers. A comparative analysis of miRNA expression levels between normal mammary gland tissue and the tumor border revealed statistically significant differences for ten miRNAs; 10 miRNAs show differential expression between normal mammary gland tissue and central tumor specimens; 9 miRNAs show differential expression between normal mammary gland tissue and tumor periphery 1; 13 miRNAs show differential expression between normal mammary gland tissue and tumor periphery 2. After comparing the tumor periphery 1 and tumor center, we found statistically significant differences in expression between five miRNAs and after comparing the tumor periphery 2 and tumor center, differences were observed for 12 miRNAs. MiRNA expression levels are subject to considerable variation, depending on the intratumor area. This may explain the inconsistency in miRNA expression estimates in BC coming from different laboratories.

The Emerging Roles of miR-125b in Cancers

MicroRNAs (miRNAs) are endogenous, noncoding, single-stranded RNA molecules of 22 nucleotides in length. MiRNAs have both tumor-suppressive properties and oncogenic properties that can control critical processes in tumors. Mature miR-125b originates from miR-125b-1 and miR-125b-2 and leads to the degradation of target mRNAs or the inhibition of translation through binding to the 3′ untranslated regions (3′-UTR) of target mRNAs. Importantly, miR-125b is involved in regulating NF-κB, p53, PI3K/Akt/mTOR, ErbB2, Wnt, and another signaling pathways, thereby controlling cell proliferation, differentiation, metabolism, apoptosis, drug resistance and tumor immunity. This review aims to summarize the recent literature on the role of miR-125b in the regulation of tumorigenesis and to explore its potential clinical application in the diagnosis, prognosis and clinical treatment of tumors.

miRNA expression in advanced Algerian breast cancer tissues

Breast cancer is one of the commonest cancers among Algerian females. Compared to Western populations, the median age of diagnosis of breast cancer is much lower in Algeria. The objective of this study is to explore the expression of several miRNAs reported to be deregulated in breast cancer. The miRNAs miR-21, miR-125b, miR-100, miR-425-5p, miR-200c, miR-183 and miR-182 were studied on tumor and normal adjacent Algerian breast tissues using quantitative reverse transcription real time PCR, and the results were analyzed according to clinical characteristics. Compared to the normal adjacent tissues, miR-21, miR-183, miR-182, miR-425-5p and miR-200c were found to be upregulated while miR-100 and miR-125b were insignificantly deregulated. A positive correlation was noted among miR-183, miR-182 and miR-200c and among miR-425-5p, miR-183, miR-200c and miR-21. Further global miRNA microarray profiling studies can aid in finding ethnic specific miRNA biomarkers in the Algerian breast cancer population.

Prognostic role of microRNAs in breast cancer: A systematic review

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

Circulating miR-34a and miR-125b as Promising non Invasive Biomarkers in Egyptian Locally Advanced Breast Cancer Patients

Background:

Breast cancer (BC) is the second most common cancer worldwide. MicroRNAs are a group of non-coding, single stranded RNAs of ~ 22 nucleotides, which regulate gene expression at the post-transcriptional level. Circulating miRNAs have been found as potential blood based predictive biomarkers.

Purpose:

we aim to evaluate miR-34a and miR-125b to predict outcome from neoadjuvant chemotherapy in Egyptian BC patients.

Methodology:

Quantitative assessment of plasma miR-34a and miR-125b expression was performed by qRT-PCR. Thirty nine newly diagnosed locally advanced BC female patients with 10 age and sex matched healthy volunteers were included in the study.

Results:

We performed ROC curve analysis to evaluate the diagnostic value for the miR-34a with AUCs = 0.995, cutoff point of 2.57 sensitivity 97.4%, specificity 100%, PPV 100%, NPV 83.3% and accuracy 97.7%.miR-125b had AUC = 0.68 and a cutoff point of 8.69 with sensitivity 66.7%, specificity 70.0%, PPV 90.6%, NPV 41.2% and accuracy 73.5%. miR-34a expression were significantly higher in BC patients compared to controls with p value <0.001*. Also, miR-34a expression level was significantly higher in patients with progressive disease with P value =0.03*. However, miR-125b expression levels were insignificantly higher in responsive patients with p value = 0.2.

Conclusion:

miRNAs are crucial candidates for novel molecular targeted therapies due to their capability to regulate numerous genes in molecular pathways. Our data suggest that circulating miR-34a and miR-125b expression levels could be promising highly accurate non-invasive biomarkers in diagnosing BCs. miR-34a can predict chemotherapeutic resistance associated with higher expression levels in non-responsive patients.

Silibinin encapsulation in polymersome: A promising anticancer nanoparticle for inducing apoptosis and decreasing the expression level of miR-125b/miR-182 in human breast cancer cells

Silibinin, a polyphenolic flavonolignan, is well-known as a safe therapeutic drug without any side effects in the treatment of many malignancies especially cancerous cells. In this study, to overcome problems such as low solubility of silibinin and to enhance its delivery to cancerous cells, we encapsulated silibinin in polymersome nanoparticles. Physicochemical measurements such as dynamic light scattering, transmission electron microscopy, scanning electron microscopy, and atomic force microscopy confirmed the proper encapsulation of silibinin in nanoparticles. Furthermore, antiproliferative and apoptotic activities of silibinin encapsulated in polymersome nanoparticles (SPNs) on MDA-MB-231 breast cancer cell line were validated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, Annexin V/Propidium Iodide measurement, and cell cycle analysis. In addition, quantitative reverse transcription polymerase chain reaction analysis confirmed that SPNs can repress oncogenic microRNAs (miRNAs) such as miR-125b and miR-182, as well as antiapoptotic genes such as Bcl2. SPNs can also induce overexpression of proapoptotic target genes such as P53, CASP9, and BAX directly and/or indirectly (through regulation of miRNAs). Our results suggested that polymersomes can be used as stable carriers in nano-dimensions and SPNs can be considered as a promising pharmacological agent for cancer therapy.

p53/Lactate dehydrogenase A axis negatively regulates aerobic glycolysis and tumor progression in breast cancer expressing wild-type p53

Tumor suppressor p53 is a master regulator of apoptosis and plays key roles in cell cycle checkpoints. p53 responds to metabolic changes and alters metabolism through several mechanisms in cancer. Lactate dehydrogenase A (LDHA), a key enzyme in glycolysis, is highly expressed in a variety of tumors and catalyzes pyruvate to lactate. In the present study, we first analyzed the association and clinical significance of p53 and LDHA in breast cancer expressing wild-type p53 (wt-p53) and found that LDHA mRNA levels are negatively correlated with wt-p53 but not with mutation p53 mRNA levels, and low p53 and high LDHA expression are significantly associated with poor overall survival rates. Furthermore, p53 negatively regulates LDHA expression by directly binding its promoter region. Moreover, a series of LDHA gain-of-function and rescore experiments were carried out in breast cancer MCF7 cells expressing endogenous wt-p53, showing that ectopic expression of p53 decreases aerobic glycolysis, cell proliferation, migration, invasion and tumor formation of breast cancer cells and that restoration of the expression of LDHA in p53-overexpressing cells could abolish the suppressive effect of p53 on aerobic glycolysis and other malignant phenotypes. In conclusion, our findings showed that repression of LDHA induced by wt-p53 blocks tumor growth and invasion through downregulation of aerobic glycolysis in breast cancer, providing new insights into the mechanism by which p53 contributes to the development and progression of breast cancer.

Bromodomain‑containing protein 7 sensitizes breast cancer cells to paclitaxel by activating Bcl2‑antagonist/killer protein

Our previous study demonstrated that bromodomain‑containing protein 7 (BRD7) inhibits cell proliferation and tumor growth, restoring the expression of B‑cell lymphoma 2 antagonist/killer (Bak) sensitized breast cancer cells to paclitaxel. However, the association between BRD7 and paclitaxel sensitization, as well as BRD7 and Bak in breast cancer remains unknown. In the present study, immunochemical staining was performed to measure the expression of BRD7 and Bak in breast cancer tissues. Cell Counting Kit‑8 assay, flow cytometry and tumor xenograft procedures were performed to evaluate the biological role of BRD7 and Bak in breast cancer cells. Western blotting, reverse transcription‑quantitative polymerase chain reaction, chromatin immunoprecipitation and luciferase reporter assays were also performed. BRD7 was positively correlated with Bak levels in breast cancer tissues, and the survival rate of patients with low Bak and BRD7 expression was significantly lower than that of patients with high Bak and BRD7 expression. In addition, BRD7 activated Bak promoter activity and induced Bak expression in an indirect manner. Furthermore, ectopic expression of BRD7 inhibited cell proliferation, tumor growth and sensitized cancer cells to paclitaxel, while knockdown of Bak abolished BRD7‑mediated inhibitory effects on cell proliferation and paclitaxel sensitization in breast cancer cells whether in vitro and in vivo. The results demonstrated that BRD7 inhibits cell proliferation and sensitizes breast cancer cells to paclitaxel by activating Bak; they also provide promising targets for the diagnosis and treatment of breast cancer.

Dynamic microRNA activity identifies therapeutic targets in trastuzumab-resistant HER2+ breast cancer

MicroRNAs (miRNAs) are implicated in numerous physiologic and pathologic processes, such as the development of resistance to chemotherapy. Determining the role of miRNAs in these processes is often accomplished through measuring miRNA abundance by polymerase chain reaction, sequencing, or microarrays. We have developed a system for the large-scale monitoring of dynamic miRNA activity and have applied this system to identify the contribution miRNA activity to the development of trastuzumab resistance in a cell model of HER2⁺ breast cancer. MiRNA activity measurements identified significantly different activity levels between BT474 cells (HER2 ⁺ breast cancer) and BT474R cells (HER2 ⁺ breast cancer cells selected for resistance to trastuzumab). We created a library of 32 miRNA reporter constructs, which were delivered by lentiviral transduction into cells, and miRNA activity was quantified by bioluminescence imaging. Upon treatment with the bioimmune therapy, trastuzumab, the activity of 11 miRNAs were significantly altered in parental BT474 cells, and 20 miRNAs had significantly altered activity in the therapy-resistant BT474R cell line. A combination of statistical, network and classification analysis was applied to the dynamic data, which identified miR-21 as a controlling factor in trastuzumab response. Our data suggested downregulation of miR-21 activity was associated with resistance, which was confirmed in an additional HER2 ⁺ breast cancer cell line, SKBR3. Collectively, the dynamic miRNA activity measurements and analysis provided a system to identify new potential therapeutic targets in treatment-resistant cancers.

Long noncoding RNA LINC00152 promotes cell proliferation through competitively binding endogenous miR-125b with MCL-1 by regulating mitochondrial apoptosis pathways in ovarian cancer

Recently, an increasing number of studies have focused on the key function of long noncoding RNAs (lncRNAs) in biological activity. Abnormal lncRNA expression was found to relate to the development and pathogenesis of multiple cancers. LncRNA LINC00152 served as an oncogene in multiple cancers; however, its role in ovarian cancer remains unknown. In our research study, LINC00152 was upregulated in ovarian cancer tissues and cell lines. An increasing LINC00152 level was positively correlated with the histological grade, clinical stage, and poor prognosis of ovarian cancer patients. In addition, knockdown of LINC00152 reduced cell growth, induced cell apoptosis, and suppressed tumor growth. Moreover, we revealed that LINC00152 and Myeloid cell leukemia‐1 (MCL‐1) were targeted by miR‐125b and had the same miR‐125b combining site. The miR‐125b level was negatively correlated with the expression of LINC00152, while MCL‐1 was positively related to the LINC00152 level. MiR‐125b could affect LINC00152 levels as evaluated by qRT‐PCR. Finally, we affirmed that LINC00152 mediated cell proliferation by affecting MCL‐1 expression and MCL‐1‐mediated mitochondrial apoptosis pathways and by working as a competitive endogenous RNA (ceRNA) of miR‐125b. In summary, based on ceRNA theory, the combined research on miR‐125b and MCL‐1, and taking LINC00152 as a new study point, we provide new insight into the molecular mechanism of reversing cell proliferation in ovarian cancer.

MiR-539 inhibits proliferation and migration of triple-negative breast cancer cells by down-regulating LAMA4 expression

Background

Recent studies have shown that laminin subunit alpha 4 (LAMA4) plays an important role in carcinogenesis. However, its molecular biological function in triple-negative breast cancer (TNBC) has not been entirely clarified. This study investigated the expression of LAMA4 in TNBC and its effect on cell proliferation, migration and invasion. Furthermore, we also identified the potential miRNA directly targeting LAMA4.

Methods

Western blot, Real-time quantitative PCR (qPCR) and immunohistochemical staining (IHC) were used to detect the expression of LAMA4 in TNBC. The effects of LAMA4 on TNBC cell proliferation, migration and invasion were also explored in vitro. The potential miRNA that targets LAMA4 was determined by dual luciferase reporter assay and verified by qPCR and western blot analysis.

Results

Our study showed LAMA4 mRNA (p = 0.001) and protein (p = 0.005) expression in TNBC tissue samples were elevated compared with adjacent normal tissue samples, and LAMA4 was mainly expressed in the cytoplasm of breast carcinoma cells. Knockdown of LAMA4 inhibited TNBC cell proliferation, migration and invasion in vitro. Moreover, further study revealed that LAMA4 was a putative target of miR-539, and miR-539 negatively regulated LAMA4 expression by directly targeting its 3′-UTR.

Conclusions

Our study suggested that miR-539 suppressed the expression of LAMA4. LAMA4 plays an important role in tumor progression and may be an important target in treatment of TNBC.

microRNA involvement in the onset and progression of Barrett's esophagus: a systematic review

Esophageal adenocarcinoma (EAC) is a highly aggressive malignancy that develops from Barrett's esophagus (BE), an intestinal metaplasia of the distal esophagus. microRNAs (miRNAs), short non-coding regulatory RNAs, are frequently dysregulated in BE and are thought to play key roles in the onset of BE and its progression to EAC. miRNAs thus have potential diagnostic and prognostic value and are increasingly being used as cancer biomarkers. This review summarizes the current literature related to miRNAs that are dysregulated in BE within the context of Hedgehog, Notch, MAPK, NF kappa-B, Wnt and epithelial-mesenchymal transition (EMT) signaling which are thought to drive BE onset and progression. This comprehensive analysis of miRNAs and their associated signaling in the regulation of BE provides an overview of vital discoveries in this field and highlights gaps in our understanding of BE pathophysiology that warrant further investigation.

Displacement of Bax by BMF Mediates STARD13 3'UTR-Induced Breast Cancer Cells Apoptosis in an miRNA-Depedent Manner

The balance of pro- and antiapoptotic gene expression programs dominates the apoptotic progress of cancer cells. We previously demonstrated that STARD13 3'UTR suppressed breast cancer metastasis via inhibiting epithelial-mesenchymal transition (EMT). However, the roles of STARD13 3'UTR in breast cancer apoptosis remain elusive. Here, we identified that STARD13 3'UTR promoted cell apoptosis in vitro and in vivo. Mechanistically, STARD13 3'UTR acted as a ceRNA for BMF (Bcl-2 modifying factor), thus increasing BMF expression in an miRNA-dependent manner. Meanwhile, STARD13 3'UTR enhanced the interaction of BMF/Bcl-2 to release Bax (Bcl-2 associated X protein) in breast cancer cells. Finally, we verified the ceRNA relationship between STARD13 and BMF in vivo. Collectively, these findings suggest that STARD13 3'UTR could act as a ceRNA for BMF to promote apoptosis and recognize STARD13 3'UTR as a potential therapeutic target in breast cancer cells.

miR-125b-5p functions as a tumor suppressor gene partially by regulating HMGA2 in esophageal squamous cell carcinoma

MicroRNAs (miRNAs) play important roles in the progression of human cancer including esophageal squamous cell carcinoma (ESCC). Although previous reports showed that miR-125b-5p was down-regulated in ESCC, the roles and mechanisms of loss of function of miR-125b-5p in ESCC were still unknown. Using microRNA microarray and GEO datasets, we found and confirmed that miR-125b-5p was down-regulated in ESCC tissues. In-vitro assays showed that ectopic miR-125b-5p expression repressed cell proliferation, migration and invasion, and induced cell senescence. We also found that miR-125b-5p reduced the expressions of cell cycle regulatory genes including CCNA2, CCND1 and CCNE1, and regulated the markers of epithelial to mesenchymal transition (EMT) including E-cadherin, N-cadherin and EMT associated transcription factor Slug, and also decreased the MMPs including MMP2, MMP7 and MMP13. Furthermore, the candidate target gene HMGA2 was negatively regulated by miR-125b-5p both in mRNA and protein levels. Importantly, knockdown of HMGA2 partially phenocopied the effects of miR-125b-5p overexpression on cell cycle regulators and EMT markers. In conclusion, our results suggested that overexpression of miR-125b-5p inhibited cell proliferation, migration and invasion partially by down-regulating HMGA2 in ESCC.

Pathological significance and prognostic significance of FES expression in bladder cancer vary according to tumor grade

Purpose

The feline sarcoma oncogene protein (FES) is a non-receptor tyrosine kinase implicated in both oncogenesis and tumor suppression. Here, cancer cell lines and human tissues were employed to clarify the pathological and prognostic significance of FES in bladder cancer.

Methods

The relationship between FES expression and cancer aggressiveness was investigated using 3 cell lines (T24: corresponding to grade 3, 5637: corresponding to grade 2, and RT4: corresponding to grade 1) and 203 tissues derived from human bladder malignancies. Proliferation, invasion, and migration of cancer cells were assessed following the knockdown (KD) of FES expression by the siRNA method. Relationships between FES expression and pathological features, aggressiveness, and outcome were investigated.

Results

FES-KD inhibited the proliferation, migration, and invasion of T24 cells but not of RT4 cells and 5637 cells. Considering all patients, FES expression demonstrated a negative relationship with grade but no association with muscle invasion or cancer cell proliferation. However, it was positively correlated with pT stage and cell proliferation in high-grade tumors (p = 0.002); no such association was found for low-grade tumors. In addition, elevated FES expression was a negative prognostic indicator of metastasis after radical surgery for patients with high-grade tumors (p = 0.021) but not for those with low-grade malignancies.

Conclusions

FES appeared to act as a suppressor of carcinogenesis, being associated with low tumor grade in the overall patient group. However, its expression correlated with cancer aggressiveness and poor outcome in high-grade bladder cancer. FES, therefore, represents a potential therapeutic target and useful prognostic factor for such patients.

Whole-exome sequencing reveals novel mutations and epigenetic regulation in hypopharyngeal carcinoma

Hypopharyngeal cancer (HPC) frequently presents at an advanced stage, resulting in poor prognosis. Although combined surgical therapy and chemoradiotherapy have improved the survival for patients with HPC over the past 3 decades, the mortality rate in late-stage diagnosis of HPC is unsatisfactory. In this study, we performed whole-exome sequencing (WES) of 23 hypopharyngeal tumor and paired adjacent normal tissue to identify novel candidate driver genes associated with hypopharyngeal carcinoma. We identified several copy number variants (CNVs) and 15 somatic mutation genes that were associated with hypopharyngeal carcinoma. Mutations in nine new genes (PRB4, NSD1, REC8, ZNF772, ZNF69, EI24, CYFIP2, NEFH, KRTAP4-5) were also indentified. PRB4 and NSD1 expression were significantly upregulated in hypopharyngeal carcinoma, which was confirmed in an independent cohort using IHC. There was a positive relationship between PRB4 and NSD1. Downregulation of PRB4 by siRNA could inhibit cell growth, colony formation and cell invasion. Notably, we here demonstrate that NSD1 could bind to the promoter regions of PRB4 and activate promoter activity by reducing the binding of H3K27me2 and increasing the binding of H3K36me2 on PRB4 promoter. In summary, we pinpoint the predominant mutations in hypopharyngeal carcinoma by WES, highlighting the substantial genetic alterations contributing to hypopharyngeal carcinoma tumorigenesis. We also indentify a novel epigenetically regulatory between PRB4 and NSD1 that contribute to hypopharyngeal carcinoma tumorigenesis. They may become potential prognostic biomarkers and therapeutic target for hypopharyngeal carcinoma treatment.