MiR-888 regulates side population properties and cancer metastasis in breast cancer cells

miR-888 and E-Cadherin Levels in Ductal Carcinoma Breast Cancer as Possible Cancer-Related Markers

Background: Cancer occurs due to genetic or epigenetic factors. Breast cancer (BC) is the most common cancer among females and is considered one of the leading causes of cancer death worldwide. Epigenetic biomarkers have proven to be important in cancer management. Methods: E-cadherin gene expression and its associated regulatory microRNA, miR-888, were studied in 60 ductal carcinoma BC patients compared with normal controls using real-time Reverse Transcription Polymerase Chain Reaction. In addition, the association of the gene and microRNA expression with hormone receptors and other clinicopathologic characteristics were assessed. The correlation between plasma and tumor miR-888 expression was studied to evaluate its potential as a marker of noninvasiveness. Results: The results showed a significant increase in expression of miR-888, and a decrease in E-cadherin expression in tumor tissues compared with normal controls. The miR-888 and E-cadherin mRNA levels showed an inverse correlation. The overexpression of miR-888 in both tumor and plasma and downregulation of E-cadherin were particularly prominent when there was nodal involvement and distant metastasis status as we well as being significantly associated with higher disease stages and triple-negative tumor hormone receptor status. The Kaplan-Meier survival curves indicated that overall survival was significantly poor in BC patients with higher miR-888 and lower E-cadherin expression. Conclusions: Our study indicated that elevated eXpression of miR-888 may be a negative prognostic factor in breast cancer.

Mi-RNA-888-5p Is Involved in S-Adenosylmethionine Antitumor Effects in Laryngeal Squamous Cancer Cells

Simple Summary

Laryngeal Squamous Cell Carcinoma (LSCC) is a leading cause of cancer-related death with a strong interest in identifying and developing new treatments. MicroRNAs (miRNAs) have emerged as one of the most important determinants of neoplastic transformation and progression. miRNA modulation causes significant antitumor effects both in vitro and in vivo and miRNA regulation by natural compounds, represents a promising approach in the field of cancer research. S-Adenosylmethionine (AdoMet), a natural compound and a nutritional supplement, is well known for its antiproliferative and pro-apoptotic effects in many kinds of human tumors. Here, we report that AdoMet induces ER-stress and autophagy paralleled by miR-888-5p downregulation and MYCBP and CDH1 increased expression in Laryngeal Squamous Cancer Cells (LSCC). This study contributes to understanding the mechanisms by which AdoMet exerts its effects in LSCC, suggesting the use of AdoMet as an attractive miRNA-mediated chemopreventive and therapeutic strategy against cancer.

Abstract

(1) Purpose: The methyl donor S-Adenosylmethionine (AdoMet) has been widely explored as a therapeutic compound, and its application-alone or in combination with other molecules-is emerging as a potential effective strategy for the treatment and chemoprevention of tumours. In this study, we investigated the antitumor activity of AdoMet in Laryngeal Squamous Cell Carcinoma (LSCC), exploring the underlying mechanisms. (2) Results: We demonstrated that AdoMet induced ROS generation and triggered autophagy with a consistent increase in LC3B-II autophagy-marker in JHU-SCC-011 and HNO210 LSCC cells. AdoMet induced ER-stress and activated UPR signaling through the upregulation of the spliced form of XBP1 and CHOP. To gain new insights into the molecular mechanisms underlying the antitumor activity of AdoMet, we evaluated the regulation of miRNA expression profile and we found a downregulation of miR-888-5p. We transfected LSCC cells with miR-888-5p inhibitor and exposed the cells to AdoMet for 48 and 72 h. The combination of AdoMet with miR-888-5p inhibitor synergistically induced both apoptosis and inhibited cell migration paralleled by the up-regulation of MYCBP and CDH1 genes and of their targets. (3) Conclusion: Overall, these data highlighted that epigenetic reprogramming of miRNAs by AdoMet play an important role in inhibiting apoptosis and migration in LSCC cell lines.

Expressions of miR-302a, miR-105, and miR-888 Play Critical Roles in Pathogenesis, Radiotherapy, and Prognosis on Rectal Cancer Patients: A Study From Rectal Cancer Patients in a Swedish Rectal Cancer Trial of Preoperative Radiotherapy to Big Database Analyses

Differential expressions and functions of various micoRNAs (miRNAs) have been intensively studied in both colon and rectal cancers. However, the importance of miRNAs on radiotherapy (RT) response and clinical outcome in rectal cancer patients remains unclear. In this study, we used real-time polymerase chain reaction to examine the expressions of miR-302a, miR-105, and miR-888 in normal mucosa and cancer tissue from rectal cancer patients with and without preoperative RT. The biological function of miR-302a, miR-105, and miR-888 expression was further analyzed and identified through the public databases: TCGA (The Cancer Genome Atlas) and GEPIA (Gene Expression Profiling Interactive Analysis). The results showed that the expression of miR-105 in rectal cancer was higher than that in normal mucosa in RT (P = 0.042) and non-RT patients (P = 0.003) and was associated with mucinous histological type (P = 0.004), COX-2 (P = 0.042), and p73 expression (P = 0.030). The expression of miR-302a was shown more frequently in cancers with necrosis (P = 0.033) and with WRAP53 expression (P = 0.015), whereas miR-888 expression occurred more frequently in tumors with protein the expression of survivin (P = 0.015), AEG-1 (astrocyte elevated gene-1) (P = 0.003), and SATB1 (special AT-rich sequence binding protein 1) (P = 0.036). Moreover, TargetScan also predicted AEG-1 and SATB1 as putative targets for miR-888. The miRNA-gene network analysis showed that ABI2 was associated with all the three miRNAs, with lower expression and good diagnostic value in rectal cancers. The TCGA database demonstrated the association of miR-105 expression with high carcinoembryonic antigen level (P = 0.048). RT reduced the expressions of miR-302a, miR-105, and miR-888. Prognostic analysis showed that miR-888 expression was independently associated with worse survival of patients without RT [overall survival, P = 0.001; disease-free survival, P = 0.009]. Analysis of biological function revealed that the protein serine/threonine kinase activity and PI3K-AKT signaling pathway were the most significantly enriched functions and pathways, respectively. Our findings suggest that miR-105 is involved in rectal cancer pathogenesis and miR-888 is associated with prognosis. MiR-302a, miR-105, and miR-888 have potential influence on the pathogenesis, RT, and prognosis of rectal cancer.

Potential miRNAs for miRNA-Based Therapeutics in Breast Cancer

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

Clinical significance of serum miR-888-5p in patients with primary hepatocellular carcinoma

BACKGROUND

MiR-888-5p is highly expressed in hepatocellular carcinoma (HCC) tissues and cell lines, and it can promote tumor invasion and metastasis and is related to disease stage and poor prognosis. However, the clinical value of serum miR-888-5p levels in the diagnosis and prognosis of HCC remains unclear.

AIM

To detect serum miR-888-5p in patients with HCC and investigate its diagnostic value and correlation with clinical characteristics of HCC.

METHODS

A total of 197 subjects were enrolled, consisting of 68 HCC patients, 46 chronic hepatitis B (CHB) patients, 43 liver cirrhosis (LC) patients, and 40 healthy volunteers. Serum miR-888-5p levels were measured by quantitative real-time polymerase chain reaction (qRT-PCR). The diagnostic value of miR-888-5p and its correlation with clinical features were assessed.

RESULTS

Compared with CHB patients, LC patients, and healthy controls, serum miR-888-5p increased significantly in HCC patients (P < 0.05). Receiver operating characteristic curve (ROC) analysis demonstrated that the area under the ROC curve (AUC) of miR-888-5p combined with alpha-fetoprotein (AFP) in discriminating HCC patients from healthy controls was 0.907 (sensitivity: 91.18%; specificity: 72.50%), higher than that of either AFP (AUC = 0.819; sensitivity: 73.53%; specificity: 97.50%) or miR-888-5p alone (AUC = 0.737; sensitivity: 79.41%; specificity: 62.50%). Serum miR-888-5p maintained its diagnostic efficiency in AFP negative HCC patients with an AUC of 0.793 (sensitivity: 90.90%; specificity: 62.50%). Serum miR-888-5p levels were significantly associated with pulmonary metastasis (P = 0.01) of HCC.

CONCLUSION

Serum miR-888-5p has high diagnostic value for HCC, and combined detection of serum miR-888-5p and AFP could improve the diagnostic efficiency. MiR-888-5p also has good diagnostic value for AFP negative HCC, and it is closely related to lung metastasis of HCC. MiR-888-5p is expected to become a new serum marker for early diagnosis and prognosis evaluation of HCC.

Rewiring E2F1 with classical NHEJ via APLF suppression promotes bladder cancer invasiveness

Background

Bladder cancer progression has been associated with dysfunctional repair of double-strand breaks (DSB), a deleterious type of DNA lesions that fuel genomic instability. Accurate DSB repair relies on two distinct pathways, homologous recombination (HR) and classical non-homologous end-joining (c-NHEJ). The transcription factor E2F1 supports HR-mediated DSB repair and protects genomic stability. However, invasive bladder cancers (BC) display, in contrast to non-invasive stages, genomic instability despite their high E2F1 levels. Hence, E2F1 is either inefficient in controlling DSB repair in this setting, or rewires the repair apparatus towards alternative, error-prone DSB processing pathways.

Methods

RT-PCR and immunoblotting, in combination with bioinformatics tools were applied to monitor c-NHEJ factors status in high-E2F1-expressing, invasive BC versus low-E2F1-expressing, non-invasive BC. In vivo binding of E2F1 on target gene promoters was demonstrated by ChIP assays and E2F1 CRISPR-Cas9 knockdown. MIR888-dependent inhibition of APLF by E2F1 was demonstrated using overexpression and knockdown experiments, in combination with luciferase assays. Methylation status of MIR888 promoter was monitored by methylation-specific PCR. The changes in invasion potential and the DSB repair efficiency were estimated by Boyden chamber assays and pulse field electrophoresis, correspondingly.

Results

Herein, we show that E2F1 directly transactivates the c-NHEJ core factors Artemis, DNA-PKcs, ligase IV, NHEJ1, Ku70/Ku80 and XRCC4, but indirectly inhibits APLF, a chromatin modifier regulating c-NHEJ. Inhibition is achieved by miR-888-5p, a testis-specific, X-linked miRNA which, in normal tissues, is often silenced via promoter methylation. Upon hypomethylation in invasive BC cells, MIR888 is transactivated by E2F1 and represses APLF. Consequently, E2F1/miR-888/APLF rewiring is established, generating conditions of APLF scarcity that compromise proper c-NHEJ function. Perturbation of the E2F1/miR-888/APLF axis restores c-NHEJ and ameliorates cell invasiveness. Depletion of miR-888 can establish a ‘high E2F1/APLF/DCLRE1C’ signature, which was found to be particularly favorable for BC patient survival.

Conclusion

Suppression of the ‘out-of-context’ activity of miR-888 improves DSB repair and impedes invasiveness by restoring APLF.

Electronic supplementary material

The online version of this article (10.1186/s13046-019-1286-9) contains supplementary material, which is available to authorized users.

MicroRNA-192-5p Promote the Proliferation and Metastasis of Hepatocellular Carcinoma Cell by Targeting SEMA3A

Side population (SP) cells are a small subset of cells isolated from a cultured cancer cell line with characteristics similar to those of cancer stem cells, such as high metastatic and tumorigenic potentials. However, the molecular mechanisms remain unclear for the malignant properties of SP cells. In this study, SP cells were isolated by staining cultured HCCLM3 cells with fluorescent DNA-binding dye Hoechst 33342 and sorted by flow cytometry. The proportion of SP cells was 2.79%±0.19% in the HCCLM3 cell line. Compared with non-SP cells, SP cells possessed stronger capability of sphere formation and tumorigenicity, and expressed higher levels of CD133 and CD90. Then, we found that SP cells possessed 25 upregulated and 34 downregulated microRNAs with differences of >3-fold. As one of the upregulated microRNAs, miR-192-5p was computationally predicted to target semaphorin 3A (SEMA3A), a potent suppressor of tumor angiogenesis in various cancer models. Luciferase reporter assay showed that SEMA3A was a direct target of miR-192-5p. Overexpression of miR-192-5p promoted cell proliferation and metastasis targeting SEMA3A in HCCLM3 cells. Immunohistochemical staining revealed that SEMA3A expression was significantly reverse associated with metastasis in hepatocellular carcinoma tissues. The results indicate that miR-192-5p contributes to targeting SEMA3A in HCCLM3 cells, and this may be used as a target in targeted therapy and a marker for cancer behavior and prognosis.

Non-coding RNAs as potential therapeutic targets in breast cancer

Paradigm shifting studies especially involving non-coding RNAs (ncRNAs) during last few decades have significantly changed the scientific perspectives regarding the complexity of cellular signalling pathways. Several studies have shown that the non-coding RNAs, initially ignored as transcriptional noise or products of erroneous transcription; actually regulate plethora of biological phenomena ranging from developmental processes to various diseases including cancer. Current strategies that are employed for the management of various cancers including that of breast fall short when their undesired side effects like Cancer Stem Cells (CSC) enrichment, low recurrence-free survival and development of drug resistance are taken into consideration. This review aims at exploring the potential role of ncRNAs as therapeutics in breast cancer, by providing a comprehensive understanding of their mechanism of action and function and their crucial contribution in regulating various aspects of breast cancer progression such as cell proliferation, angiogenesis, EMT, CSCs, drug resistance and metastasis. In addition, we also provide information about various strategies that can be employed or are under development to explore them as potential moieties that may be used for therapeutic intervention in breast cancer.

Joint testing and false discovery rate control in high-dimensional multivariate regression

Multivariate regression with high-dimensional covariates has many applications in genomic and genetic research, in which some covariates are expected to be associated with multiple responses. This paper considers joint testing for regression coefficients over multiple responses and develops simultaneous testing methods with false discovery rate control. The test statistic is based on inverse regression and bias-corrected group lasso estimates of the regression coefficients and is shown to have an asymptotic chi-squared null distribution. A row-wise multiple testing procedure is developed to identify the covariates associated with the responses. The procedure is shown to control the false discovery proportion and false discovery rate at a prespecified level asymptotically. Simulations demonstrate the gain in power, relative to entrywise testing, in detecting the covariates associated with the responses. The test is applied to an ovarian cancer dataset to identify the microRNA regulators that regulate protein expression.

miR-888 functions as an oncogene and predicts poor prognosis in colorectal cancer

MicroRNAs (miRNAs) are important regulators of tumor formation, progression and metastasis. The present study characterized a novel miRNA (miR)-888, as a potent oncomiR in human colorectal cancer (CRC). The clinicopathological investigation on 126 cases of CRC patients demonstrated that the expression level of miR-888 was significantly upregulated in tumors compared with adjacent healthy tissue, and was associated with tumor stage and histological differentiation. A Kaplan-Meier analysis and log-rank test demonstrated that CRC patients with increased miR-888 expression exhibited a decreased overall survival (OS) and disease-free survival (DFS) compared with patients with low miR-888 expression. Further univariate and multivariate analyses identified miR-888 as an independent prognostic factor for poor survival outcome in CRC patients. To determine the biological role of miR-888 in human CRC, in vitro Cell Counting kit-8, wound healing and transwell assays were performed and demonstrated that miR-888 contributed greatly to CRC cell proliferation, invasion and metastasis. Furthermore, potential targets of miR-888 were investigated using a luciferase reporter assay, followed by polymerase chain reaction and western blot analysis. The findings revealed that miR-888 directly bound to the 3′-untranslated region of mothers against decapentaplegic-4 and thus inhibited its expression and promoted the tumor growth factor-1-induced cancer metastasis signaling. The results of the present study identified miR-888 as an oncogenic miRNA in CRC and provide a foundation for promising research in the future regarding this predictive and prognostic biomarker.

Characterization and Evidence of the miR-888 Cluster as a Novel Cancer Network in Prostate

Prostate cancer afflicts 1 in 7 men and is the second leading cause of male cancer-related deaths in the United States. MicroRNAs (miRNAs), an extensive class of approximately 22 nucleotide noncoding RNAs, are often aberrantly expressed in tissues and fluids from prostate cancer patients, but the mechanisms of how specific miRNAs regulate prostate tumorigenesis and metastasis are poorly understood. Here, miR-888 was identified as a novel prostate factor that promotes proliferation and migration. miR-888 resides within a genomic cluster of 7 miRNA genes (mir-892c, mir-890, mir-888, mir-892a, mir-892b, mir-891b, mir-891a) on human chromosome Xq27.3. Moreover, as miR-888 maps within HPCX1, a locus associated with susceptibility and/or hereditary prostate cancer, it was hypothesized that additional miRNA cluster members also play functional roles in the prostate. Expression analysis determined that cluster members were similarly elevated in metastatic PC3-ML prostate cells and their secreted exosomes, as well as enriched in expressed prostatic secretions urine-derived exosomes obtained from clinical patients with high-grade prostate cancer. In vitro assays revealed that miR-888 cluster members selectively modulated PC3-derived and LNCaP cell proliferation, migration, invasion, and colony formation. Mouse xenograft studies verified miR-888 and miR-891a as pro-oncogenic factors that increased prostate tumor growth in vivo Further analysis validated RBL1, KLF5, SMAD4, and TIMP2 as direct miR-888 targets and that TIMP2 is also coregulated by miR-891a. This study provides the first comprehensive analysis of the entire miR-888 cluster and reveals biological insight.Implications: This work reveals a complex noncoding RNA network in the prostate that could be developed as effective diagnostic and therapeutic tools for advanced prostate cancer. Mol Cancer Res; 16(4); 669-81. ©2018 AACR.

miRNA therapy targeting cancer stem cells: a new paradigm for cancer treatment and prevention of tumor recurrence

Cancer stem cells (CSCs) are a small subpopulation of cells within tumors that retain the properties of self-renewal and tumorigenicity in vivo. Although CSCs have been reported in multiple cancers, the regulation of CSCs has not been described at the molecular level. miRNAs are endogenous small noncoding RNAs that post-transcriptionally regulate the expression of their target genes via RNA interference and are involved in almost all cellular processes. Since aberrant miRNA expression occurs in CSCs, such dysregulated miRNAs may be promising therapeutic targets. In this review, we summarize the current knowledge regarding miRNAs that regulate CSC properties and discuss an in vivo delivery system for synthetic miRNA mimics and miRNA inhibitors for the development of innovative miRNA therapy against CSCs.