Clinical Value of miR-101-3p and Biological Analysis of its Prospective Targets in Breast Cancer: A Study Based on The Cancer Genome Atlas (TCGA) and Bioinformatics

Exosome miR-101-3p derived from bone marrow mesenchymal stem cells promotes radiotherapy sensitivity in non-small cell lung cancer by regulating DNA damage repair and autophagy levels through EZH2

BACKGROUND AND OBJECTIVE

The morbidity rate of non-small cell lung cancer (NSCLC) increases with age, highlighting that NSCLC is a serious threat to human health. The aim of this study was mainly to describe the role of exosomal miR-101-3p derived from bone marrow mesenchymal stem cells (BMSCs) in NSCLC.

METHODS

A549 or NCI-H1703 cells (1×105/mouse) were injected into nude mice to establish an NSCLC animal model. RTqPCR, Western blotting and comet assays were used to assess the changes in gene expression, proteins and DNA damage repair.

RESULTS

miR-101-3p and RAI2 were found to be expressed at low levels in NSCLC, while EZH2 was highly expressed. In terms of function, miR-101-3p downregulated EZH2. In addition, exosomal miR-101-3p derived from BMSCs promoted the expression of RAI2, inhibited DNA damage repair, and inhibited the activation of the PI3K/AKT/mTOR signaling pathway by inhibiting EZH2, thereby promoting autophagy and decreasing cell viability and finally enhancing the sensitivity of NSCLC to radiotherapy and inhibiting the malignant biological behavior of NSCLC.

CONCLUSION

Exosomal miR-101-3p derived from BMSCs can inhibit DNA damage repair, promote autophagy, enhance the radiosensitivity of NSCLC, and inhibit the progression of NSCLC by inhibiting EZH2.

Differential miRNA expression of hypoxic MCF7 and PANC-1 cells

Background

Hypoxia plays a critical role in the tumor microenvironment by affecting cellular proliferation, metabolism, apoptosis, DNA repair, and chemoresistance. Since hypoxia provokes a distinct shift of microRNA, it is important to illustrate the relative contribution of each hypoxamiR to cancer progression.

Aims

The present study aims to shed light on the hypoxamiRs that are involved in pancreatic and breast cancer progression to highlight novel targets for the development of new therapies.

Methods

For 20 cycles, MCF7 breast cancer cells and PANC-1 pancreatic cancer cells were subjected to chronic cyclic hypoxia, which consisted of 72 hours of hypoxia followed by 24 hours of reoxygenation. After 10 and 20 cycles of hypoxia, miRNA expression alterations were profiled using RT-PCR array and further analyzed using a visual analytics platform. The MTT cell proliferation assay was used to determine hypoxic cells' chemoresistance to doxorubicin.

Results

Under chronic cyclic hypoxia, hypoxic PANC-1 cells have a comparable doubling time with their normoxic counterparts, whereas hypoxic MCF7 cells show a massive increase in doubling time when compared to their normoxic counterparts. Both hypoxic cell lines developed EMT-like phenotypes as well as doxorubicin resistance. According to the findings of miRNet, 6 and 10 miRNAs were shown to play an important role in enriching six hallmarks of pancreatic cancer in the 10th and 20th cycles of hypoxia, respectively, while 7 and 11 miRNAs were shown to play an important role in enriching the four hallmarks of breast cancer in the 10th and 20th cycles of hypoxia, respectively.

Conclusions

miR-221, miR-21, miR-155, and miR-34 were found to be involved in the potentiation of hypoxic PANC-1 hallmarks at both the 10th and 20th cycles, while miR-93, miR-20a, miR-15, and miR-17 were found to be involved in the potentiation of hypoxic MCF7 hallmarks at both the 10th and 20th cycles. This variation in miRNA expression was also connected to the emergence of an EMT-like phenotype, alterations in proliferation rates, and doxorubicin resistance. The chemosensitivity results revealed that chronic cyclic hypoxia is critical in the formation of chemoresistant phenotypes in pancreatic and breast cancer cells. miR-181a and let-7e expression disparities in PANC1, as well as miR-93, miR-34, and miR-27 expression disparities in MCF7, may be associated with the formation of chemoresistant MCF7 and PANC-1 cells following 20 cycles of chronic cyclic hypoxia. Indeed, further research is needed since the particular mechanisms that govern these processes are unknown.

Predictive and Prognostic Value of Non-Coding RNA in Breast Cancer

For decades since the central dogma, cancer biology research has been focusing on the involvement of genes encoding proteins. It has been not until more recent times that a new molecular class has been discovered, named non-coding RNA (ncRNA), which has been shown to play crucial roles in shaping the activity of cells. An extraordinary number of studies has shown that ncRNAs represent an extensive and prevalent group of RNAs, including both oncogenic or tumor suppressive molecules. Henceforth, various clinical trials involving ncRNAs as extraordinary biomarkers or therapies have started to emerge. In this review, we will focus on the prognostic and diagnostic role of ncRNAs for breast cancer.

Verbascoside enhances radiosensitivity of hepatocellular carcinoma cells through regulating miR-101-3p/Wee1 axis

Verbascoside is a kind of phenylpropanoid glycoside derived from multiple medicinal plants, exerting anti-tumor effects in diverse human malignancies. However, the function of Verbascoside on the radiosensitivity of hepatocellular carcinoma (HCC) cells remains unknown. Human Huh7 and HepG2 cell lines were treated with Verbascosideis, and cell viability was detected with cell counting kit-8 (CCK-8) assay. Quantitative real-time polymerase chain reaction (qRT-PCR) was applied to detect miR-101-3p expression, and Western blot was used to quantify the expression of WEE1 G2 checkpoint kinase (WEE1). Then, CCK-8 and flow cytometry assays were used to detect the proliferation and apoptosis of HCC cells after Verbascoside and X-ray combined treatment, and the expressions of WEE1 and apoptosis-related proteins Bax and Bcl-2 were detected by Western blot. Verbascoside could improve the radiosensitivity of HCC cells in a dose-dependent manner. Verbascoside increased the expression of miR-101-3p but reduced WEE1 expression in HCC cells. Additionally, WEE1 was identified as a target of miR-101-3p. MiR-101-3p inhibition or WEE1 overexpression could reverse the effect of Verbascoside on the viability and apoptosis of HCC cells. Verbascoside increases the radiosensitivity of hepatocellular carcinoma cells via modulating miR-101-3p/WEE1 axis.

miR-101-5p Acts as a Tumor Suppressor in HER2-Positive Breast Cancer Cells and Improves Targeted Therapy

Purpose

Human epidermal growth factor receptor 2 positive (HER2+) breast cancers responding poorly to targeted therapy need improved treatment options. miR-101-5p has shown tumor-suppressive properties in multiple cancer forms, and we assessed the effect and mechanism of action of this miRNA in HER2+ breast cancer.

Methods

Expression levels of miR-101-5p in two clinical datasets, TCGA and METABRIC, were compared between tumor and normal adjacent samples, and across molecular subtypes and HER2 status. The ability of miR-101-5p to sensitize for treatment with lapatinib, tucatinib and trastuzumab was explored in HER2+ breast cancer cells responding poorly to such targeted drugs. Proliferation and apoptosis assays and downstream protein analysis were performed.

Results

Expression levels of miR-101-5p were significantly lower in tumor compared to normal adjacent tissue (p < 0.001), and particularly low in HER2+ tumors, both the HER2-enriched subtype (p ≤ 0.037) and clinical HER2-status (p < 0.001). In a HER2+ cell line (KPL4) responding poorly to targeted drugs, miR-101-5p overexpression inhibited proliferation (p < 0.001), and combinatorial treatment with lapatinib and trastuzumab significantly further decreased this inhibition (p = 0.004). Proteomic data and in silico analyses revealed PI3K/Akt- and HER2-pathways among the predicted regulated pathways. miR-101-5p alone (p = 0.018) and in combination with lapatinib and trastuzumab (p < 0.001) induced apoptosis, while the targeted drugs alone did not exert any significant effect neither on proliferation nor apoptosis.

Conclusion

miR-101-5p acts as a tumor suppressor by inducing apoptosis in HER2+ breast cancer and sensitizes cells with initially poor response to lapatinib and trastuzumab.

Circulating microRNAs in Early Breast Cancer Patients and Its Association With Lymph Node Metastases

MicroRNAs have emerged as important regulators of the metastatic process. In addition, circulating miRNAs appear to be surprisingly stable in peripheral blood making them ideal noninvasive biomarkers for disease diagnosis. Here, we performed a proof-of-principle study to investigate the expression profile of circulating miRNAs and their association with the metastatic lymph node status in early breast cancer patients. Sentinel lymph node status was detected by one-step nucleic acid (OSNA) analysis. We performed RNA-sequencing in 16 plasma samples and validated the results by qPCR. Gene Ontology term enrichment and KEGG pathway analyses were carried out using DAVID tools. We found16 differentially expressed miRNAs (q < 0.01) in patients with positive SLNs. Fourteen miRNAs were down-regulated (miR-339-5p, miR-133a-3p, miR-326, miR-331-3p, miR-369-3p, miR-328-3p, miR-26a-3p, miR-139-3p, miR-493-3p, miR-664a-5p, miR-146a-5p, miR-323b-3p, miR-1307-3p and miR-423-3p) and 2 were up-regulated (miR-101-3pand miR-144-3p). Hierarchical clustering using differentially expressed miRNAs clearly distinguished patients according to their lymph node status. Gene ontology analysis showed a significant enrichment of biological processes associated with the regulation of the epithelial mesenchymal transition, cell proliferation and transcriptional regulation. Our results suggest the potential role of several circulating miRNAs as surrogate markers of lymph node metastases in early breast cancer patients. Further validation in a larger cohort of patients will be necessary to confirm our results.

Bone Mesenchymal Stem Cells Promote Extracellular Matrix Remodeling of Degenerated Nucleus Pulposus Cells via the miR-101-3p/EIF4G2 Axis

The etiology of lumbocrural pain is tightly concerned with intervertebral disk degeneration (IDD). Bone mesenchymal stem cell (BMSC)-based therapy bears potentials for IDD treatment. The properties of microRNA (miRNA)-modified BMSCs may be altered. This study investigated the role and mechanism of BMSCs promoting extracellular matrix (ECM) remodeling of degenerated nucleus pulposus cells (NPCs) via the miR-101-3p/EIF4G2 axis. NPCs were collected from patients with IDD and lumbar vertebral fracture (LVF). The expressions of miR-101-3p and ECM-related proteins, Collagen-I (Col-I) and Collagen-II (Col-II), were detected using the reverse transcription-quantitative polymerase chain reaction. The expressions of Col-I and Col-II, major non-collagenous component Aggrecan, and major catabolic factor Matrix metalloproteinase-13 (MMP-13) were detected using Western blotting. BMSCs were cocultured with degenerated NPCs from patients with IDD. Viability and apoptosis of NPCs were measured using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and flow cytometry. After the degenerated NPCs were transfected with the miR-101-3p inhibitor, the expressions of ECM-related proteins, cell viability, and apoptosis were detected. The targeting relationship between miR-101-3p and EIF4G2 was verified. Functional rescue experiments verified the effects of miR-101-3p and EIF4G2 on ECM remodeling of NPCs. Compared with the NPCs of patients with LVF, the degenerated NPCs of patients with IDD showed downregulated miR-101-3p, Col-II, and Aggrecan expressions and upregulated MMP-13 and Col-I expressions. BMSCs increased the expressions of miR-101-3p, Aggrecan, and Col-II, and decreased the expressions of MMP-13 and Col-I in degenerated NPCs. BMSCs enhanced NPC viability and repressed apoptosis. Downregulation of miR-101-3p suppressed the promoting effect of BMSCs on ECM remodeling. miR-101-3p targeted EIF4G2. Downregulation of EIF4G2 reversed the inhibiting effect of the miR-101-3p inhibitor on ECM remodeling. In conclusion, BMSCs increased the miR-101-3p expression in degenerated NPCs to target EIF4G2, thus promoting the ECM remodeling of NPCs.

MicroRNA and cyclooxygenase-2 in breast cancer

Cancer remains a major public health problem worldwide and the latest statistics show that breast cancer (BC) is among the most frequent in women. MicroRNAs (miRNAs; miRs) and cyclooxygenase-2 (COX-2) are new diagnostic and therapeutic biomarkers for monitoring BC. COX-2 is a prominent tumor-associated inflammatory factor highly expressed in human tumor cells, including BC. Expression of COX-2 contributes to tumor growth, metastasis and recurrence. MiRs are a group of short (~22 nucleotides), noncoding regulatory RNAs that downregulate gene expression post-transcriptionally and play vital roles in regulating cancer development and progression. Interestingly, there are a group of miRNAs differentially expressed in breast tumor tissue. Understanding the pathway linking miRNAs to COX-2 can provide novel insight for suppressing COX-2 expression via gene silencing thereby leading to the development of selective miRNA inhibitors. Further research can also reveal key intermediate players and their potential as therapeutic targets. Given the association between different miRNAs and COX-2 expression in BC, this review presents a comprehensive overview of the current literature concerning how miRNAs and COX-2 signaling interact in BC progression.

LncRNA TUG1 silencing enhances proliferation and migration of ox-LDL-treated human umbilical vein endothelial cells and promotes atherosclerotic vascular injury repairing via the Runx2/ANPEP axis

The role of vascular endothelial cell injury in the course of atherosclerosis (AS) has attracted increasing attention. Long non-coding RNAs (LncRNAs) are demonstrated to be the biomarker for the diagnosis of AS. This study investigated the mechanism of lncRNA taurine upregulated gene 1 (TUG1) in AS. Microarray data of AS obtained from GEO database showed that lncRNA TUG1 was differentially expressed in AS samples. TUG1 expression was upregulated in ox-LDL-treated human umbilical vein endothelial cells (HUVECs). Oxidized low density lipoprotein (ox-LDL)-treated HUVECs were then transfected with sh-TUG1. TUG1 silencing promoted proliferation and migration of ox-LDL-treated HUVECs. TUG1 bound to Runt-related transcription factor 2 (Runx2). Runx2 silencing promoted proliferation and migration of HUVECs. The downstream genes of Runx2 were predicted by hTFtarget database. The binding site of Runx2 and Aminopeptidase N (ANPEP) was determined. Runx2 silencing reversed the repression effect of overexpressing ANPEP on cell proliferation and migration. TUG1 silencing inhibited ANPEP expression via Runx2 to promote HUVEC proliferation and migration. A mouse model of AS was established. The area of atherosclerotic lesions of mouse aorta was detected, and vascular re-endothelialization was evaluated. TUG1 silencing promoted vascular injury repairing and inhibited AS in vivo. In conclusion, TUG1 silencing enhanced proliferation and migration of ox-LDL-treated HUVECs and promoted vascular injury repairing in vivo via the Runx2/ANPEP axis.

Inhibition of miR‑101‑3p protects against sepsis‑induced myocardial injury by inhibiting MAPK and NF‑κB pathway activation via the upregulation of DUSP1

Numerous studies have found that microRNAs (miRNAs or miRs) are aberrantly expressed when sepsis occurs. The present study aimed to investigate the role of miR-101-3p in sepsis-induced myocardial injury and to elucidate the underlying mechanisms. Models of myocardial injury were established both in vivo and in vitro. The results revealed that miR-101-3p was upregulated in the serum of patients with sepsis-induced cardiomyopathy (SIC) and positively correlated with the levels of pro-inflammatory cytokines (including IL-1β, IL-6 and TNF-α). Subsequently, rats were treated with miR-101-3p inhibitor to suppress miR-101-3p and were then exposed to lipopolysaccharide (LPS). The results revealed that LPS induced marked cardiac dysfunction, apoptosis and inflammation. The inhibition of miR-101-3p markedly attenuated sepsis-induced myocardial injury by attenuating apoptosis and the expression of pro-inflammatory cytokines. Mechanistically, dual specificity phosphatase-1 (DUSP1) was found to be a functional target of miR-101-3p. The downregulation of miR-101-3p led to the overexpression of DUSP1, and the inactivation of the MAPK p38 and NF-κB pathways. Moreover, blocking DUSP1 by short hairpin RNA against DUSP1 (sh-DUSP1) significantly reduced the myocardial protective effects mediated by the inhibition of miR-101-3p. Collectively, the findings of the present study demonstrate that the inhibition of miR-101-3p exerts cardioprotective effects by suppressing MAPK p38 and NF-κB pathway activation, and thus attenuating inflammation and apoptosis dependently by enhancing DUSP1 expression.

lncRNA-Xist/miR-101-3p/KLF6/C/EBPα axis promotes TAM polarization to regulate cancer cell proliferation and migration

The phenotypic switch in tumor-associated macrophages (TAMs) mediates immunity escape of cancer. However, the underlying mechanisms in the TAM phenotypic switch have not been systematically elucidated. In this study, long noncoding RNA (lncRNA)-Xist, CCAAT/enhancer-binding protein (C/EBP)α, and Kruppel-like factor 6 (KLF6) were upregulated, whereas microRNA (miR)-101 was downregulated in M1 macrophages-type (M1). Knockdown of Xist or overexpression of miR-101 in M1 could induce M1-to-M2 macrophage-type (M2) conversion to promote cell proliferation and migration of breast and ovarian cancer by inhibiting C/EBPα and KLF6 expression. Furthermore, miR-101 could combine with both Xist and C/EBPα and KLF6 through the same microRNA response element (MRE) predicted by bioinformatics and verified by luciferase reporter assays. Moreover, we found that miR-101 knockdown restored the decreased M1 marker and the increased M2 marker expression and also reversed the promotion of proliferation and migration of human breast cancer cells (MCF-7) and human ovarian cancer (OV) cells caused by silencing Xist. Generally, the present study indicates that Xist could mediate macrophage polarization to affect cell proliferation and migration of breast and ovarian cancer by competing with miR-101 to regulate C/EBPα and KLF6 expression. The promotion of Xist expression in M1 macrophages and inhibition of miR-101 expression in M2 macrophages might play an important role in inhibiting breast and ovarian tumor proliferation and migration abilities.

Non coding RNAs as the critical factors in chemo resistance of bladder tumor cells

BACKGROUND

Bladder cancer (BCa) is the ninth frequent and 13th leading cause of cancer related deaths in the world which is mainly observed among men. There is a declining mortality rates in developed countries. Although, the majority of BCa patients present Non-Muscle-Invasive Bladder Cancer (NMIBC) tumors, only 30% of patients suffer from muscle invasion and distant metastases. Radical cystoprostatectomy, radiation, and chemotherapy have proven to be efficient in metastatic tumors. However, tumor relapse is observed in a noticeable ratio of patients following the chemotherapeutic treatment. Non-coding RNAs (ncRNAs) are important factors during tumor progression and chemo resistance which can be used as diagnostic and prognostic biomarkers of BCa.

MAIN BODY

In present review we summarized all of the lncRNAs and miRNAs associated with chemotherapeutic resistance in bladder tumor cells.

CONCLUSIONS

This review paves the way of introducing a prognostic panel of ncRNAs for the BCa patients which can be useful to select a proper drug based on the lncRNA profiles of patients to reduce the cytotoxic effects of chemotherapy in such patients.

Loss of miR-101-3p Promotes Transmigration of Metastatic Breast Cancer Cells through the Brain Endothelium by Inducing COX-2/MMP1 Signaling

Brain metastases represent one of the incurable end stages in breast cancer (BC). Developing effective or preventive treatments is hampered by a lack of knowledge on the molecular mechanisms driving brain metastasis. Transmigration of BC cells through the brain endothelium is a key event in the pathogenesis of brain metastasis. In this study, we identified miR-101-3p as a critical micro-RNA able to reduce transmigration of BC cells through the brain endothelium. Our results revealed that miR-101-3p expression is downregulated in brain metastatic BC cells compared to less invasive variants, and varies inversely compared to the brain metastatic propensity of BC cells. Using a loss-and-gain of function approach, we found that miR-101-3p downregulation increased transmigration of BC cells through the brain endothelium in vitro by inducing COX-2 expression in cancer cells, whereas ectopic restoration of miR-101-3p exerted a metastasis-reducing effect. In regulatory experiments, we found that miR-101-3p mediated its effect by modulating COX-2-MMP1 signaling capable of degrading the inter-endothelial junctions (claudin-5 and VE-cadherin), key components of the brain endothelium. These findings suggest that miR-101-3p plays a critical role in the transmigration of breast cancer cells through the brain endothelium by modulating the COX-2-MMP1 signaling and thus may serve as a therapeutic target that can be exploited to prevent or suppress brain metastasis in human breast cancer.

Identification of miRNA-Based Signature as a Novel Potential Prognostic Biomarker in Patients with Breast Cancer

To identify the novel, noninvasive biomarkers to assess the outcome and prognosis of breast cancer (BC), patients with high sensitivity and specificity are greatly desired. Herein, the miRNA expression profile and matched clinical features of BC patients were extracted from The Cancer Genome Atlas (TCGA) database. The preliminary candidates were screened out by the univariate Cox regression test. Then, with the help of LASSO Cox regression analysis, the hsa-let-7b, hsa-mir-101-2, hsa-mir-135a-2, hsa-mir-22, hsa-mir-30a, hsa-mir-31, hsa-mir-3130-1, hsa-mir-320b-1, hsa-mir-3678, hsa-mir-4662a, hsa-mir-4772, hsa-mir-493, hsa-mir-556, hsa-mir-652, hsa-mir-6733, hsa-mir-874, and hsa-mir-9-3 were selected to construct the overall survival (OS) predicting signature, while the hsa-mir-130a, hsa-mir-204, hsa-mir-217, hsa-mir-223, hsa-mir-24-2, hsa-mir-29b-1, hsa-mir-363, hsa-mir-5001, hsa-mir-514a-1, hsa-mir-624, hsa-mir-639, hsa-mir-659, and hsa-mir-6892 were adopted to establish the recurrence-free survival (RFS) predicting signature. Referring to the median risk scores generated by the OS and RFS formulas, respectively, subgroup patients with high risk were strongly related to a poor OS and RFS revealed by Kaplan-Meier (K-M) plots. Meanwhile, receiver operating curve (ROC) analysis validated the accuracy and stability of these two signatures. When stratified by clinical features, such as tumor stage, age, and molecular subtypes, we found that the miRNA-based OS and RFS classifiers were still significant in predicting OS/RFS and showed the best predictive values than any other features. Besides, functional prediction analyses showed that these targeted genes of the enrolled miRNAs were enriched in cancer-associated pathways, such as MAPK/RTK, Ras, and PI3K-Akt signaling pathways. In summary, our observations demonstrate that the novel miRNA-based OS and RFS signatures are independent prognostic indicators for BC patients and worthy to be validated by further prospective studies.

TRIM59 as a novel molecular biomarker to predict the prognosis of patients with NSCLC

As a member of the tripartite motif family, tripartite motif-containing protein 59 (TRIM59) serves as an E3 ubiquitin ligase in various cellular processes, including intracellular signaling, development, apoptosis, protein quality control, innate immunity, autophagy and carcinogenesis. The present study aimed to investigate the expression and prognostic value of TRIM59 in patients with non-small cell lung cancer (NSCLC). Expression of TRIM59 in patients with NSCLC was measured by immunohistochemistry in tissue microarrays. Datasets from The Cancer Genome Atlas (TCGA) were used to further verify the expression level of TRIM59 in NSCLC, lung adenocarcinoma and lung squamous cell carcinoma (LUSC). The prognostic value of TRIM59 in NSCLC was also analyzed. Immunohistochemistry revealed that TRIM59 was primarily located in the cytoplasm of tumor cells. Analysis of TCGA datasets revealed that TRIM59 was more highly expressed in tumor tissues than in normal tissues (P<0.0001). Furthermore, the TRIM59 expression level was associated with tumor differentiation (P=0.012), while no association was observed between TRIM59 expression and any other clinicopathological parameters. However, the average overall survival rate of patients with NSCLC in the high TRIM59 expression group was significantly lower than that in the low expression group (P=0.014), especially in patients with LUSC (P=0.016) and patients with poor differentiation (P=0.033). The multivariate analysis indicated that high TRIM59 expression is an independent prognostic factor in patients with NSCLC (P=0.018) and was associated with poor prognosis in patients with NSCLC. Therefore, TRIM59 may serve as a novel molecular biomarker to predict the prognosis of patients with NSCLC.

HNRNPA2/B1 is upregulated in endocrine-resistant LCC9 breast cancer cells and alters the miRNA transcriptome when overexpressed in MCF-7 cells

MicroRNAs are dysregulated in breast cancer. Heterogeneous Nuclear Ribonucleoprotein A2/B1 (HNRNPA2/B1) is a reader of the N(6)-methyladenosine (m6A) mark in primary-miRNAs (pri-miRNAs) and promotes DROSHA processing to precursor-miRNAs (pre-miRNAs). We examined the expression of writers, readers, and erasers of m6A and report that HNRNPA2/B1 expression is higher in tamoxifen-resistant LCC9 breast cancer cells as compared to parental, tamoxifen-sensitive MCF-7 cells. To examine how increased expression of HNRNPA2/B1 affects miRNA expression, HNRNPA2/B1 was transiently overexpressed (~5.4-fold) in MCF-7 cells for whole genome miRNA profiling (miRNA-seq). 148 and 88 miRNAs were up- and down-regulated, respectively, 48 h after transfection and 177 and 172 up- and down-regulated, respectively, 72 h after transfection. MetaCore Enrichment analysis identified progesterone receptor action and transforming growth factor β (TGFβ) signaling via miRNA in breast cancer as pathways downstream of the upregulated miRNAs and TGFβ signaling via SMADs and Notch signaling as pathways of the downregulated miRNAs. GO biological processes for mRNA targets of HNRNPA2/B1-regulated miRNAs included response to estradiol and cell-substrate adhesion. qPCR confirmed HNRNPA2B1 downregulation of miR-29a-3p, miR-29b-3p, and miR-222 and upregulation of miR-1266-5p, miR-1268a, miR-671-3p. Transient overexpression of HNRNPA2/B1 reduced MCF-7 sensitivity to 4-hydroxytamoxifen and fulvestrant, suggesting a role for HNRNPA2/B1 in endocrine-resistance.

MicroRNA-101-3p advances cisplatin sensitivity in bladder urothelial carcinoma through targeted silencing EZH2

Objective: Chemotherapy is a major therapeutic method for bladder urothelial carcinoma (BUC), which can effectively improve the prognosis of BUC patients, but the chemoresistance often leads to chemotherapy failure. This study will research the regulatory roles and molecular mechanism of miR-101-3p in BUC chemoresistance.

Materials and Methods: The quantitative real-time PCR was used to detect the expression of miRNA-101-3p and EZH2. The proliferation and chemoresistance were analyzed by CCK8 assay. Luciferase reporter assay was used to verify the combination between miR-101-3p and EZH2. Protein expression was detected by Western blotting. Flow cytometry was used to examine apoptosis rate.

Results: The miR-101-3p expression was down-regulated in cisplatin (CDDP) resistant BUC cell line (T24/CDDP) and tissues, and was positively related to sensitivity of BUC to CDDP. In T24/CDDP cells, the up-regulation of miR-101-3p decreased the half maximal inhibitory concentration (IC50) to CDDP, depressed the expression of MRP1 protein, promote the CDDP-induced cytotoxicity, and advanced CDDP sensitivity. A series of in vitro experiments certified the EZH2 gene was a target gene of miR-101-3p, including luciferase reporter assay, western blotting and so on. Up-regulation of EZH2 largely reversed the regulatory effects of miR-101-3p enhancement on CDDP sensitivity in T24/CDDP cells.

Conclusion: The expression of miR-101-3p is positively related to CDDP sensitivity of BUC, miR-101-3p advances sensitivity of BUC to CDDP through targeted silencing EZH2.

Differentially expressed gene profile and relevant pathways of the traditional Chinese medicine cinobufotalin on MCF‑7 breast cancer cells

Cinobufotalin is a chemical compound extracted from the skin of dried bufo toads that may have curative potential for certain malignancies through different mechanisms; however, these mechanisms remain unexplored in breast cancer. The aim of the present study was to investigate the antitumor mechanism of cinobufotalin in breast cancer by using microarray data and in silico analysis. The microarray data set GSE85871, in which cinobufotalin exerted influences on the MCF‑7 breast cancer cells, was acquired from the Gene Expression Omnibus database, and the differentially expressed genes (DEGs) were analyzed. Subsequently, protein interaction analysis was conducted, which clarified the clinical significance of core genes, and Gene Ontology and Kyoto Encyclopedia of Genes and Genomes were used to analyze cinobufotalin‑related pathways. The Connectivity Map (CMAP) database was used to select existing compounds that exhibited curative properties similar to those of cinobufotalin. A total of 1,237 DEGs were identified from breast cancer cells that were treated with cinobufotalin. Two core genes, SRC proto‑oncogene non‑receptor tyrosine kinase and cyclin‑dependent kinase inhibitor 2A, were identified as serving a vital role in the onset and development of breast cancer, and their expression levels were markedly reduced following cinobufotalin treatment as detected by the microarray of GSE85871. It also was revealed that the 'neuroactive ligand‑receptor interaction' and 'calcium signaling' pathways may be crucial for cinobufotalin to perform its functions in breast cancer. Conducting a matching search in CMAP, miconazole and cinobufotalin were indicated to possessed similar molecular mechanisms. In conclusion, cinobufotalin may serve as an effective compound for the treatment of a subtype of breast cancer that is triple positive for the presence of estrogen, progesterone and human epidermal growth factor receptor‑2 receptors, and its mechanism may be related to different pathways. In addition, cinobufotalin is likely to exert its antitumor influences in a similar way as miconazole in MCF‑7 cells.

Estrogen-Mediated MicroRNA-101-3p Expression Represses Hyaluronan Synthase 2 in Synovial Fibroblasts From Idiopathic Condylar Resorption Patients

PURPOSE

Idiopathic condylar resorption (ICR) is an aggressive form of osteoarthritis that is frequently observed in adolescent female patients. We hypothesized that an estrogen-mediated pathway may contribute to ICR development.

MATERIALS AND METHODS

An enzyme-linked immunosorbent assay was used to detect the levels of estradiol (E2) and hyaluronan in synovial fluid. Immunohistochemistry, real-time polymerase chain reaction, and Western blotting were used to detect the expression of microRNAs (miRNAs) and related genes after transfection of miRNA-101-3p mimics, inhibitor, or short interfering RNA into synovial fibroblasts. Dual-luciferase activity was determined to identify the direct effect of miRNA-101-3p on hyaluronan synthase 2 (HAS2). Linear regression analysis, the nonparametric Mann-Whitney U test, the Student t test, and 1-way analysis of variance were carried out to analyze the results of each group.

RESULTS

The relationship between hyaluronan and E2 was negatively correlated in synovial fluid (Pearson r = -0.3179, P = .0230). Among the screened miRNAs, miRNA-101-3p was the most overexpressed in ICR. E2 mostly upregulated the expression of miRNA-101-3p at a dose of 10 nmol/L 12 hours after transfection in synovial fibroblasts of patients with ICR. However, E2 induction of miRNA-101-3p expression was significantly repressed by estrogen receptor α interference (P = 0.0286). The dual-luciferase assay showed that miRNA-101-3p regulated the expression of HAS2 by directly targeting its 3' untranslated region.

CONCLUSIONS

We speculate that E2 regulates HAS2 expression by targeting miRNA-101-3p in synovial fibroblasts of patients with ICR. Thus, the E2-miRNA-101-3p-HAS2 pathway might play an important role in the pathogenesis of ICR.

Med19 is targeted by miR-101-3p/miR-422a and promotes breast cancer progression by regulating the EGFR/MEK/ERK signaling pathway

Our previous study found that mediator complex subunit 19 (Med19) is upregulated and involved in breast cancer tumorigenesis; however, the detailed effects and mechanism of Med19 in breast cancer require further study. In this study, we found that Med19 was obviously elevated in human breast cancer tissues, which was significantly associated with larger tumors, high-grade malignant features and poor prognosis. Furthermore, Med19 enhanced breast cancer cell proliferation, epithelial-mesenchymal transition, invasion and migration in vitro and in vivo. Med19 interacted with epidermal growth factor receptor (EGFR) and increased EGFR expression. Moreover, Med19 activated the EGFR/mitogen-activated protein kinase (MEK)/extracellular signal-regulated kinase (ERK) pathway and exerted its oncogenic activity in an EGFR signaling-mediated manner. In addition, Med19 expression was regulated by miR-101-3p and miR-422a. Med19 expression positively correlated with EGFR expression and negatively correlated with miR-101-3p and miR-422a expression in human breast cancer tissues. Med19 mediated the crosstalk between miR-101-3p/miR-422a and the EGFR/MEK/ERK signaling pathway. This study revealed a new miR-101-3p/miR-422a-Med19-EGFR/MEK/ERK axis that plays a significant role in breast cancer progression. These results help elucidate the potential mechanisms of Med19 in human breast cancer progression.

Construction of an miRNA‑gene regulatory network in colorectal cancer through integrated analysis of mRNA and miRNA microarrays

The aim of the present study was to identify potential biomarkers associated with colorectal cancer (CRC). The GSE32323 and GSE53592 mRNA and microRNA (miRNA) expression profiles were selected from the Gene Expression Omnibus database. The differentially expressed genes (DEGs) and differentially expressed miRNAs (DEMs) in CRC tissue samples compared with surrounding control tissue samples (DEGs‑CC), and DEGs in cells treated with 5‑aza‑2'‑deoxycitidine compared with untreated cells (DEGs‑TC) were identified with the Limma package. The Database for Annotation, Visualization and Integrated Discovery was used to conduct the functional and pathways enrichment analysis. Differential co‑regulation networks were constructed using the DCGL package of R. The targets of DEMs were identified using TargetScan. The overlaps between DEGs and the targets were selected. The miRNA‑gene regulatory network of the overlaps was established. There were 145 DEMs, and 1,284 DEGs in DEGs‑CC, and 101 DEGs in DEGs‑TC. DEGs‑CC were enriched in 196 Gene Ontology (GO) terms and 23 Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. DEGs‑TC were enriched in 46 GO terms and two KEGG pathways. A differential co‑regulation network of the DEGs and a miRNA‑gene regulatory network between DEMs and overlapped DEGs were respectively constructed. miR‑124‑3p, miR‑145‑5p and miR‑320a may be critical in CRC, and serum/glucocorticoid regulated kinase 1 and SRY‑box 9 may be potential biomarkers for CRC tumor progression.

Identification of potential prognostic microRNA biomarkers for predicting survival in patients with hepatocellular carcinoma

Background

The aim of the present study was to identify potential prognostic microRNA (miRNA) biomarkers for hepatocellular carcinoma (HCC) prognosis prediction based on a dataset from The Cancer Genome Atlas (TCGA).

Materials and methods

A miRNA sequencing dataset and corresponding clinical parameters of HCC were obtained from TCGA. Genome-wide univariate Cox regression analysis was used to screen prognostic differentially expressed miRNAs (DEMs), and multivariable Cox regression analysis was used for prognostic signature construction. Comprehensive survival analysis was performed to evaluate the prognostic value of the prognostic signature.

Results

Five miRNAs were regarded as prognostic DEMs and used for prognostic signature construction. The five-DEM prognostic signature performed well in prognosis prediction (adjusted P < 0.0001, adjusted hazard ratio = 2.249, 95% confidence interval =1.491-3.394), and time-dependent receiver-operating characteristic (ROC) analysis showed an area under the curve (AUC) of 0.765, 0.745, 0.725, and 0.687 for 1-, 2-, 3-, and 5-year HCC overall survival (OS) prediction, respectively. Comprehensive survival analysis of the prognostic signature suggests that the risk score model could serve as an independent factor of HCC and perform better in prognosis prediction than other traditional clinical indicators. Functional assessment of the target genes of hsa-mir-139 and hsa-mir-5003 indicates that they were significantly enriched in multiple biological processes and pathways, including cell proliferation and cell migration regulation, pathways in cancer, and the cyclic adenosine monophosphate (cAMP) signaling pathway.

Conclusion

Our study indicates that the novel miRNA expression signature may be a potential prognostic biomarker for HCC patients.

High expression of SLC6A10P contributes to poor prognosis in lung adenocarcinoma

PURPOSE

To investigate the expression profile and prognostic value of SLC6A10P in patients with non-small cell lung cancer (NSCLC).

PATIENTS AND METHODS

TCGA datasets were used to investigate the differential expression of SLC6A10P in NSCLC, lung adenocarcinoma (LUAD), and lung squamous cell carcinoma (LUSC). Expression of SLC6A10P was measured by in situ hybridization in tissue microarrays containing 136 NSCLC (51 LUAD and 85 LUSC) patients. The prognostic value of SLC6A10P was then evaluated.

RESULTS

SLC6A10P was highly expressed in tumor tissues compared with normal lung tissues. High SLC6A10P expression was associated with lymph node metastasis (NSCLC, P = 0.0054; LUAD, P = 0.0149), more advanced tumor stage (NSCLC, P = 0.0126; LUAD, P = 0.0416) and poor overall survival (NSCLC, P = 0.0248; LUAD, P = 0.0316) in NSCLC and LUAD. Multivariate analysis revealed that SLC6A10P was an independent prognostic factor in LUAD patients (P = 0.017). SLC6A10P showed no association with clinicopathological parameters and no prognostic value in LUSC.

CONCLUSION

SLC6A10P is highly expressed in tumor tissues and its high expression predictspoor survival in patients with LUAD. SLC6A10P might serve as a novel therapeutic target and prognostic biomarker in LUAD patients in the future.

Long non-coding RNA NEAT1 regulates epithelial membrane protein 2 expression to repress nasopharyngeal carcinoma migration and irradiation-resistance through miR-101-3p as a competing endogenous RNA mechanism

The altered expression of long non-coding RNAs (lncRNAs) is often related to carcinogenesis, metastasis and resistance to radiation or chemotherapy. In the current study, cDNA microarray analysis found that NEAT1 expression was reduced in nasopharyngeal carcinoma (NPC) patients and that it regulated NPC progression. However, the detailed mechanisms of NEAT1 in NPC were unclear. NEAT1 repressed NPC cell growth, invasion and radiation resistance in vitro and tumor metastasis in vivo. In addition, the results of an approach integrating bioinformatics, luciferase reporter assays and RNA immunoprecipitation indicated that NEAT1 antagonized miR-101-3p through a competing endogenous RNA (ceRNA) mechanism and that the interaction between NEAT1 and EMP2 was miR-101-3p dependent. Our results showed a novel connection of NEAT1, miR-101-3p and EMP2 in NPC migration and radiation resistance.