MicroRNA-766 targeting regulation of SOX6 expression promoted cell proliferation of human colorectal cancer

A Critical Review on microRNAs as Prognostic Biomarkers in Laryngeal Carcinoma

During the past decade, a vast number of studies were dedicated to unravelling the obscurities of non-coding RNAs in all fields of the medical sciences. A great amount of data has been accumulated, and consequently a natural need for organization and classification in all subfields arises. The aim of this review is to summarize all reports on microRNAs that were delineated as prognostic biomarkers in laryngeal carcinoma. Additionally, we attempt to allocate and organize these molecules according to their association with key pathways and oncogenes affected in laryngeal carcinoma. Finally, we critically analyze the common shortcomings and biases of the methodologies in some of the published papers in this area of research. A literature search was performed using the PubMed and MEDLINE databases with the keywords "laryngeal carcinoma" OR "laryngeal cancer" AND "microRNA" OR "miRNA" AND "prognostic marker" OR "prognosis". Only research articles written in English were included, without any specific restrictions on study type. We have found 43 articles that report 39 microRNAs with prognostic value associated with laryngeal carcinoma, and all of them are summarized along with the major characteristics and methodology of the respective studies. A second layer of the review is structural analysis of the outlined microRNAs and their association with oncogenes and pathways connected with the cell cycle (p53, CCND1, CDKN2A/p16, E2F1), RTK/RAS/PI3K cascades (EGFR, PI3K, PTEN), cell differentiation (NOTCH, p63, FAT1), and cell death (FADD, TRAF3). Finally, we critically review common shortcomings in the methodology of the papers and their possible effect on their results.

Extracellular vesicles and the "six Rs" in radiotherapy

Over half of patients with cancer receive radiation therapy during the course of their disease. Decades of radiobiological research have identified 6 parameters affecting the biological response to radiation referred to as the 6 "Rs": Repair, Radiosensitivity, Repopulation, Redistribution, Reoxygenation, and Reactivation of the anti-tumour immune response. Extracellular Vesicles (EVs) are small membrane-bound particles whose multiple biological functions are increasingly documented. Here we discuss the evidence for a role of EVs in the orchestration of the response of cancer cells to radiotherapy. We highlight that EVs are involved in DNA repair mechanisms, modulation of cellular sensitivity to radiation, and facilitation of tumour repopulation. Moreover, EVs influence tumour reoxygenation dynamics, and play a pivotal role in fostering radioresistance. Last, we examine how EV-related strategies could be translated into novel strategies aimed at enhancing the efficacy of radiation therapy against cancer.

Advanced strategies of targeting circular RNAs as therapeutic approaches in colorectal cancer drug resistance

Colorectal cancer (CRC) stands second in terms of mortality and third among the highest prevalent kinds of cancer globally. CRC prevalence is rising in moderately and poorly developed regions and is greater in economically advanced regions. Despite breakthroughs in targeted therapy, resistance to chemotherapeutics remains a significant challenge in the long-term management of CRC. Circular RNAs (circRNAs) have been involved in growing cancer therapy resistance, particularly in CRC, according to an increasing number of studies in recent years. CircRNAs are one of the novel subclasses of non-coding RNAs, previously thought of as viroid. According to studies, circRNAs have been recommended as biological markers for therapeutic targets and diagnostic and prognostic purposes. That is particularly notable given that the expression of circRNAs has been linked to the hallmarks of CRC since they are responsible for drug resistance in CRC patients; thereby, circRNAs are significant for chemotherapy failure. Moreover, knowledge concerning circRNAs remains relatively unclear despite using all these advanced techniques. Here, in this study, we will go over the most recent published work to highlight the critical roles of circRNAs in CRC development and drug resistance and highlight the main strategies to overcome drug resistance to improve clinical outcomes.

circRNA ITGA7 restrains growth and enhances radiosensitivity by up-regulating SMAD4 in colorectal carcinoma

Circular RNAs have been reported to be widely involved in cancer cell tumorigenesis and drug resistance; here, the aim of this study was to investigate whether circRNA Integrin Subunit Alpha 7 (ITGA7) (circ_ITGA7) was associated with the tumor growth and radiosensitivity of colorectal cancer (CRC). We found that circ_ITGA7 expression was lower in CRC tissues and cells than those in the normal tissues and cell lines according to quantitative real-time polymerase chain reaction. As shown by cell counting kit-8 assay, flow cytometry, colony formation assay, and xenograft experiment, ectopic overexpression of circ_ITGA7 remarkably restrained CRC tumor growth and enhanced radiosensitivity in vitro and in vivo. Mechanistically, circ_ITGA7 could target microRNA (miR)-766 to prevent the degradation of its target gene mothers against decapentaplegic homolog 4 (SMAD4), the binding between miR-766 and circ_ITGA7 or SMAD4 was first verified by dual-luciferase activity assay. Additionally, miR-766 up-regulation reversed the inhibitory effects of circ_ITGA7 on CRC growth and radiosensitivity. Besides that, inhibition of miR-766 reduced CRC cell growth and sensitized cells to radiotherapy, and these effects mediated by miR-766 inhibitor were rescued by the silencing of SMAD4. In all, circ_ITGA7 suppressed CRC growth and enhanced radiosensitivity by up-regulating SMAD4 through sequestering miR-766, providing an insight for the further development of CRC treatment.

The key role of microRNA-766 in the cancer development

Cancer is caused by defects in coding and non-coding RNAs. In addition, duplicated biological pathways diminish the efficacy of mono target cancer drugs. MicroRNAs (miRNAs) are short, endogenous, non-coding RNAs that regulate many target genes and play a crucial role in physiological processes such as cell division, differentiation, cell cycle, proliferation, and apoptosis, which are frequently disrupted in diseases such as cancer. MiR-766, one of the most adaptable and highly conserved microRNAs, is notably overexpressed in several diseases, including malignant tumors. Variations in miR-766 expression are linked to various pathological and physiological processes. Additionally, miR-766 promotes therapeutic resistance pathways in various types of tumors. Here, we present and discuss evidence implicating miR-766 in the development of cancer and treatment resistance. In addition, we discuss the potential applications of miR-766 as a therapeutic cancer target, diagnostic biomarker, and prognostic indicator. This may shed light on the development of novel therapeutic strategies for cancer therapy.

Sox6, A Potential Target for MicroRNAs in Cardiometabolic Disease

PURPOSE OF REVIEW

The study aims to review recent advances in knowledge on the interplay between miRNAs and the sex-determining Region Y (SRY)-related high-mobility-group box 6 (Sox6) in physiology and pathophysiology, highlighting an important role in autoimmune and cardiometabolic conditions.

RECENT FINDINGS

The transcription factor Sox6 is an important member of the SoxD family and plays an indispensable role in adult tissue homeostasis, regeneration, and physiology. Abnormal expression of the Sox6 gene has been implicated in several disease conditions including diabetes, cardiomyopathy, autoimmune diseases, and hypertension. Expression of Sox6 is regulated by miRNAs, which are RNAs of about 22 nucleotides, and have also been implicated in several pathophysiological conditions where Sox6 plays a role. Regulation of Sox6 by miRNAs is important in diverse physiological tissues and organs. Dysregulation of the interplay between miRNAs and Sox6 is an important determinant of various disease conditions and may be actionable for therapeutic purposes.

MiR-766-3p Suppresses Malignant Behaviors and Stimulates Apoptosis of Colon Cancer Cells via Targeting TGFBI

BACKGROUND

MicroRNAs (miRNAs) can affect the progression of colon cancer cells. A variety of miRNAs, especially miR-766-3p, are proved to be abnormally expressed in colon cancer, but the molecular mechanism of miR-766-3p in this cancer has not yet been fully defined.

METHODS

Differentially expressed genes in the TCGA-COAD dataset were searched through bioinformatics analysis. MiR-766-3p and TGFBI mRNA levels were measured by qRT-PCR. TGFBI protein expression was measured via Western blot. Targeting relation between miR-766-3p and TGFBI was investigated by dual-luciferase reporter gene assay. Cell proliferation, invasion migration, and apoptosis were detected by cell functional assays.

RESULTS

MiR-766-3p was less expressed, while TGFBI was conspicuously highly expressed in colon cancer. MiR-766-3p high expression suppressed cell malignant behaviors and induced cell apoptosis in colon cancer. MiR-766-3p had a targeting relation with TGFBI verified by dual-luciferase assay. The cancer-suppressive impact of miR-766-3p overexpression was attenuated by overexpressing TGFBI.

CONCLUSIONS

MiR-766-3p/TGFBI axis suppressed malignant behaviors and facilitated apoptosis of colon cancer cells. MiR-766-3p may be an underlying target for colon cancer.

The Role of microRNAs in Pulp Inflammation

The dental pulp can be affected by thermal, physical, chemical, and bacterial phenomena that stimulate the inflammatory response. The pulp tissue produces an immunological, cellular, and vascular reaction in an attempt to defend itself and resolve the affected tissue. The expression of different microRNAs during pulp inflammation has been previously documented. MicroRNAs (miRNAs) are endogenous small molecules involved in the transcription of genes that regulate the immune system and the inflammatory response. They are present in cellular and physiological functions, as well as in the pathogenesis of human diseases, becoming potential biomarkers for diagnosis, prognosis, monitoring, and safety. Previous studies have evidenced the different roles played by miRNAs in proinflammatory, anti-inflammatory, and immunological phenomena in the dental pulp, highlighting specific key functions of pulp pathology. This systematized review aims to provide an understanding of the role of the different microRNAs detected in the pulp and their effects on the expression of the different target genes that are involved during pulp inflammation.

microRNA-19a-3p and microRNA-376c-3p Promote Hepatocellular Carcinoma Progression Through SOX6-Mediated Wnt/β-Catenin Signaling Pathway

Background

Recent researches have suggested that microRNA (miR)-19a-3p and miR-376c-3p might function as initiators in diverse cancers. Based on which, in this current study, we aimed to probe into the combined effects and mechanisms of miR-19a-3p and miR-376c-3p in hepatocellular carcinoma (HCC) cells.

Methods

Tumor tissues and adjacent normal tissues from 21 cases of HCC patients, HCC cell lines, and human normal liver cell lines were used in this study. RT-qPCR and Western blot were implemented to detect the expression of miR-19a-3p, miR-376c-3p, SOX6, and Wnt/β-catenin pathway-associated factors in HCC tissues and cells. The direct relationships between miR-19a-3p or miR-376c-3p and SOX6 were confirmed by luciferase activity assay. HCC cells were treated with miR-19a-3p inhibitor, miR-376c-3p inhibitor, or oe-SOX-6 to figure out their functions in HCC malignancy. The in vivo assays were conducted for the confirmation of in vitro results.

Results

In both HCC tissues and cells, miR-19a-3p and miR-376c-3p were highly expressed, and SOX6 was poorly expressed. Depleted miR-19a-3p or miR-376c-3p was found to result in retarded HCC development. Bioinformatics analysis and luciferase activity assay revealed that SOX6 was the common target gene of miR-19a-3p and miR-376c-3p. Overexpressed SOX6 was demonstrated to block the Wnt/β-catenin pathway, thereby slowing down HCC progression. The in vivo assays showed that suppressed miR-19a-3p or miR-376c-3p and elevated SOX6 could reduce the tumor volume and weight of nude mice.

Conclusion

This study suggests that miR-19a-3p/miR-376c-3p activates the Wnt/β-catenin pathway via targeting SOX6, contributing to promoted biological functions of HCC cells.

The Role of Noncoding RNAs in the Regulation of Anoikis and Anchorage-Independent Growth in Cancer

Cancer is a global health concern, and the prognosis of patients with cancer is associated with metastasis. Multistep processes are involved in cancer metastasis. Accumulating evidence has shown that cancer cells acquire the capacity of anoikis resistance and anchorage-independent cell growth, which are critical prerequisite features of metastatic cancer cells. Multiple cellular factors and events, such as apoptosis, survival factors, cell cycle, EMT, stemness, autophagy, and integrins influence the anoikis resistance and anchorage-independent cell growth in cancer. Noncoding RNAs (ncRNAs), such as microRNAs (miRNAs) and long noncoding RNAs (lncRNAs), are dysregulated in cancer. They regulate cellular signaling pathways and events, eventually contributing to cancer aggressiveness. This review presents the role of miRNAs and lncRNAs in modulating anoikis resistance and anchorage-independent cell growth. We also discuss the feasibility of ncRNA-based therapy and the natural features of ncRNAs that need to be contemplated for more beneficial therapeutic strategies against cancer.

Identification and Characterization of Serum microRNAs as Biomarkers for Human Disc Degeneration: An RNA Sequencing Analysis

Circulating microRNAs (miRNAs) have been associated with various degenerative diseases, including intervertebral disc (IVD) degeneration. Lumbar disc herniation (LDH) often occurs in young patients, although the underlying mechanisms are poorly understood. The aim of this work was to generate RNA deep sequencing data of peripheral blood samples from patients suffering from LDH, identify circulating miRNAs, and analyze them using bioinformatics applications. Serum was collected from 10 patients with LDH (Disc Degeneration Group); 10 patients without LDH served as the Control Group. RNA sequencing analysis identified 73 differential circulating miRNAs (p < 0.05) between the Disc Degeneration Group and Control Group. Gene ontology enrichment analysis (p < 0.05) showed that these differentially expressed miRNAs were associated with extracellular matrix, damage reactions, inflammatory reactions, and regulation of apoptosis. Kyoto Encyclopedia of Genes and Genomes analysis showed that the differentially expressed genes were involved in diverse signaling pathways. The profile of miR-766-3p, miR-6749-3p, and miR-4632-5p serum miRNAs was significantly enriched (p < 0.05) in multiple pathways associated with IVD degeneration. miR-766-3p, miR-6749-3p, and miR-4632-5p signature from serum may serve as a noninvasive diagnostic biomarker for LHD manifestation of IVD degeneration. Furthermore, several dysregulated miRNAs may be involved in the pathogenesis of IVD degeneration. Further study is needed to confirm the functional role of the identified miRNAs.

Inhibition of lncRNA MAAT Controls Multiple Types of Muscle Atrophy by cis- and trans-Regulatory Actions

Muscle atrophy is associated with negative outcomes in a variety of diseases. Identification of a common therapeutic target would address a significant unmet clinical need. Here, we identify a long non-coding RNA (lncRNA) (muscle-atrophy-associated transcript, lncMAAT) as a common regulator of skeletal muscle atrophy. lncMAAT is downregulated in multiple types of muscle-atrophy models both in vivo (denervation, Angiotensin II [AngII], fasting, immobilization, and aging-induced muscle atrophy) and in vitro (AngII, H₂O₂, and tumor necrosis factor alpha [TNF-α]-induced muscle atrophy). Gain- and loss-of-function analysis both in vitro and in vivo reveals that downregulation of lncMAAT is sufficient to induce muscle atrophy, while overexpression of lncMAAT can ameliorate multiple types of muscle atrophy. Mechanistically, lncMAAT negatively regulates the transcription of miR-29b through SOX6 by a trans-regulatory module and increases the expression of the neighboring gene Mbnl1 by a cis-regulatory module. Therefore, overexpression of lncMAAT may represent a promising therapy for muscle atrophy induced by different stimuli.

Effect of MicroRNA-766 Promotes Proliferation, Chemoresistance, Migration, and Invasion of Breast Cancer Cells

INTRODUCTION

Breast cancer (BCa) remains the most common cancer in women worldwide. It has been shown that microRNAs (miRs) play essential roles in tumorigenesis and progression in many types of cancers, including BCa. We assessed the role of miR-766 on the proliferation, chemosensitivity, migration, and invasion of BCa cells.

MATERIALS AND METHODS

The effect of miR-766 on the proliferation of MCF-7 and T47D BCa cells was evaluated using the MTT assay. The function of miR-766 on the migration and invasion of MCF-7 and T47D cells was examined using Transwell migration and Matrigel invasion assays. Protein expression was evaluated by Western blot. The role of miR-766 on 5-fluorouracil-induced apoptosis in MCF-7 and T47D cells was determined using the Caspase-Glo3/7 assay. A subcutaneous tumor xenograft was performed to examine the effect of miR-766 on tumor growth in vivo.

RESULTS

Upregulation of miR-766 improved the proliferation, invasion, and migration of BCa cells. Furthermore, miR-766 reduced the sensitivity of MCF-7 and T47D cells to 5-fluorouracil treatment. The tumor xenograft experiment showed that miR-766 promoted BCa growth in vivo. miR-766 decreased 5-flurouracil-induced apoptosis by regulation of BAX and Bcl-2 expression. miR-766 also affected the epithelial-mesenchymal transition by altering E-cadherin, N-cadherin, SNAIL, and vimentin expression in MCF-7 and T47D cells. Further study showed that the expression of phosphatase and tensin homolog and phosphorylated AKT in MCF-7 and T47D cells had changed after aberrant expression of miR-766.

CONCLUSION

miR-766 displayed important roles in tumorigenesis and progression in BCa cells and might act as a potential biomarker to predict the chemotherapy response and progression in BCa.

The Value of Serum MicroRNA Expression Signature in Predicting Refractoriness to Bortezomib-Based Therapy in Multiple Myeloma Patients

Bortezomib is the first-in-class proteasome inhibitor, commonly used in the treatment of multiple myeloma (MM). The mechanisms underlying acquired bortezomib resistance in MM are poorly understood. Several cell-free miRNAs have been found to be aberrantly regulated in MM patients. The aim of this pilot study was to identify a blood-based miRNA signature that predicts bortezomib-based therapy efficacy in MM patients. Thirty MM patients treated with bortezomib-based regimens were studied, including 19 with refractory disease and 11 who were bortezomib sensitive. Serum miRNA expression patterns were identified with miRCURY LNA miRNA miRNome PCR Panels I+II (Exiqon/Qiagen). Univariate analysis found a total of 21 miRNAs to be differentially expressed in patients with MM according to bortezomib sensitivity. Multivariate logistic regression was created and allowed us to discriminate refractory from sensitive patients with a very high AUC of 0.95 (95%CI: 0.84-1.00); sensitivity, specificity and accuracy were estimated as 0.95, 0.91, and 0.93. The model used expression of 3 miRNAs: miR-215-5p, miR-181a-5p and miR-376c-3p. This study is the first to demonstrate that serum expression of several miRNAs differs between patients who are bortezomib refractory and those who are sensitive which may prove useful in studies aimed at overcoming drug resistance in MM treatment.

Serum exosomal microRNA-766-3p expression is associated with poor prognosis of esophageal squamous cell carcinoma

The aim was to analyze the association between exosomal microRNA (miR)‐766‐3p expression levels in serum and the prognosis of esophageal squamous cell carcinoma (ESCC). The serum global exosomal miRNA expression of ESCC patients was measured by microRNA microarray. Quantitative real‐time PCR was used to analyze the expression levels of candidate miRNAs in both serum and tissues from ESCC patients. Wilcoxon tests were applied to evaluate clinical characteristics and their association with serum levels of exosomal miR‐766‐3p. A Cox regression model was used to identify prognostic factors. The effects of miR‐766‐3p expression on cell migration and invasion were examined using Transwell assays, and CCK‐8 assays were carried out to measure cell proliferation. The TNM stage was associated with high serum exosomal miR‐766‐3p levels of ESCC patients (P = .030). Higher serum exosomal miR‐766‐3p expression levels were associated with poor prognosis (for overall survival, hazard ratio [HR] [95% confidence interval (CI)], 2.21 [1.00, 4.87]; for disease‐free survival, HR [95% CI], 2.15 [1.01, 4.59]). However, we found no association between the expression of miR‐766‐3p in tissue and ESCC prognosis. In vitro results showed that miR‐766‐3p promotes cell migration and invasion, but not cell proliferation. By using dual‐luciferase reporter assay, HOXA13 was confirmed as a direct target gene of miR‐766‐3p. The ESCC patients with highly expressed serum exosomal miR‐766‐3p had a significantly worse survival. Therefore, serum exosomal miR‐766‐3p could serve as a prognostic marker for the assessment of ESCC.

Baicalin Protects Human OA Chondrocytes Against IL-1β-Induced Apoptosis and ECM Degradation by Activating Autophagy via MiR-766-3p/AIFM1 Axis

Background

Osteoarthritis (OA) is one of the most prevalent and degenerative diseases with complicated pathology including articular cartilage degradation, subchondral sclerosis and synovitis. Chondrocytes play a crucial role in maintaining cartilage integrity.

Methods

Primary chondrocytes were treated with 10 ng/mL IL-1β alone, or pre-treated with 20 μM baicalin for 5 h followed by co-treatment with 20 μM baicalin and 10 ng/mL IL-1β. CCK-8 assay was used to assess cell viability, and cell apoptosis was analyzed by both PI/FITC-Annexin V staining and quantitating apoptosis-related Bcl-2, Bax and cleaved-caspase-3 expression at both protein and mRNA level by Western blotting and qRT-PCR, respectively. Chondrocytes were transfected with miRNA-766-3p mimic and autophagy flux was examined by LC3, Beclin and p62 Western blotting and by Cyto-ID assay to quantify autophagic vacuoles.

Results

Baicalin treatment decreased the apoptosis rate and the expressions of pro-apoptotic proteins induced by IL-1β, up-regulated anti-apoptotic Bcl-2 expression, and inhibited the degradation of ECM. Baicalin increased autophagy through up-regulating the autophagy markers Beclin-1 expression and LC3 Ⅱ/LC3 Ⅰ ratio and promoting autophagic flux. Contrarily, autophagy inhibition partially alleviated the beneficial effects of baicalin on ECM synthesis and anti-apoptosis in the chondrocytes treated with L-1β. Furthermore, the differential expressional profiles of miR-766-3p and apoptosis-inducing factor mitochondria-associated 1 (AIFM1) were determined in IL-1β and IL-1β + baicalin-treated chondrocytes, and we confirmed AIFM1 was a target of miR-766-3p. MiR-766-3p overexpression suppressed apoptosis and facilitated autophagy and ECM synthesis in the chondrocytes through decreasing AIFM1. Contrarily, silencing of miR-766-3p inhibited chondrocyte autophagy and promoted apoptosis, and this effect could be reversed by AIFM1 silence.

Conclusion

Baicalin protects human OA chondrocytes against IL-1β-induced apoptosis and the degradation of ECM through activating autophagy via miR-766-3p/AIFM1 axis and serves as a potential therapeutic candidate for OA treatment.

Downregulation of microRNA-126 is inversely correlated with insulin receptor substrate-1 protein expression in colorectal cancer and is associated with advanced stages of disease

Colorectal cancer (CRC) is a common human malignant tumor, and the fourth most common cause of cancer-associated mortality in China. However, the pathogenesis of CRC is not yet fully understood. The present study aimed to investigate the expression and clinical significance of microRNA (miR)-126 and insulin receptor substrate-1 (IRS-1), as well as the role of miR-126 in the prognosis of patients with CRC. A total of 86 colorectal tissue specimens, including 40 CRC and adjacent normal tissue, 26 colorectal adenoma tissue and 20 normal colorectal tissue samples, were collected for the present study. Reverse transcription-quantitative PCR analysis was performed to determine miR-126 and IRS-1 mRNA expression levels, while western blotting and immunohistochemistry (IHC) analyses were performed to determine IRS-1 protein expression levels. The correlation between miR-126 and IRS-1 expression, as well as the association between altered miR-126 and IRS-1 expression levels and clinicopathological characteristics, and the overall survival time of patients with CRC were assessed. The results demonstrated that miR-126 expression was significantly downregulated, while IRS-1 protein expression was upregulated in CRC tissues compared with that in adjacent normal tissues, colorectal adenoma tissues and normal colorectal tissues, respectively. IHC analysis exhibited strong positive staining of IRS-1 protein in CRC tissues, while absent or weak staining of IRS-1 protein was detected in adjacent normal tissues, colorectal adenoma tissues and normal colorectal tissues. miR-126 expression was inversely correlated with IRS-1 protein expression in CRC tissues (r=−0.420; P<0.05). Furthermore, downregulated miR-126 expression was associated with advanced clinicopathological characteristics of the disease and a shorter overall survival time in patients with CRC. Taken together, the results of the present study suggest that miR-126 downregulation may be a candidate molecular marker predictive of poor prognosis of patients with CRC.

MicroRNA-766 Promotes The Proliferation, Migration And Invasion, And Inhibits The Apoptosis Of Cutaneous Squamous Cell Carcinoma Cells By Targeting PDCD5

Purpose

This study aimed to investigate the regulatory role and mechanism of microRNA-766 (miR-766) on cutaneous squamous cell carcinoma (CSCC) cells.

Methods

The expression of miR-766 and programmed cell death 5 (PDCD5) was detected in CSCC tissues and CSCC cell lines (A431, SCL-1 and DJM-1 cells) by qRT-RCR. The proliferation, colony-forming ability, apoptosis, migration and invasion of A431 and SCL-1 cells was measured by MTT, colony formation, flow cytometry, wound healing and transwell assay, respectively. The interaction between miR-766 and PDCD5 was detected by dual-luciferase reporter gene assay. The expression of matrix metalloproteinase 2 (MMP-2), MMP-9 and PDCD5 was measured by Western blot. In addition, A431 cells were subcutaneously injected into mice, and the tumor volume and weight were measured.

Results

MiR-766 was upregulated, and PDCD5 was downregulated in CSCC tissues and cells. MiR-766 significantly promoted the proliferation, migration and invasion, and inhibited the apoptosis of A431 and SCL-1 cells. MiR-766 also significantly increased the expression of MMP-2 and MMP-9 in A431 and SCL-1 cells. PDCD5 was a target gene of miR-766. PDCD5 significantly reversed the tumor-promoting effect of miR-766 on A431 and SCL-1 cells. In addition, miR-766 inhibitor inhibited the tumor growth in mice.

Conclusion

MiR-766 inhibitor inhibited the proliferation, migration and invasion, and promoted the apoptosis of CSCC cells via downregulating PDCD5.

Long Noncoding RNA RMRP Suppresses the Tumorigenesis of Hepatocellular Carcinoma Through Targeting microRNA-766

PURPOSE

This study aimed to explore the regulatory effect of long noncoding RNA (lncRNA) ribonuclease mitochondrial RNA processing gene (RMRP) on hepatocellular carcinoma (HCC).

METHODS

The expression of RMRP in HCC tissues and cell lines was assessed by qRT-PCR. Kaplan-Meier method was utilized to analyze the correlation between RMRP expression and the survival of HCC patients. MHCC97H and HuH7 cells were transfected with pcDNA3.1-RMRP or pcDNA3.1, respectively. MTT and flow cytometry assays were conducted to examine the proliferation and apoptosis of HCC cells, respectively. The migration and invasion of HCC cells were assessed using wound healing and transwell assays, respectively. StarBase3.0 and dual-luciferase reporter gene assay were used to identify the target relationship between miR-766 and RMRP. A xenografted tumor model was established in rats to evaluate the effect of RMRP in vivo.

RESULTS

RMRP was down-regulated in HCC tissues and cells. Low expression of RMRP was correlated with poor survival of HCC patients. The A495 value and colony number were significantly decreased in pcDNA3.1-RMRP-transfected MHCC97H and HuH7 cells. The apoptosis rate was significantly increased in pcDNA3.1-RMRP-transfected MHCC97H and HuH7 cells. The migration rate and the number of invasive cells were significantly decreased in pcDNA3.1-RMRP-transfected MHCC97H and HuH7 cells. MiR-766 was a target of RMRP and eliminated the anti-tumor effect of RMRP on MHCC97H cells. The up-regulation of RMRP suppressed the growth of xenograft tumors in rats.

CONCLUSION

Overexpression of RMRP suppressed the tumorigenesis of HCC by targeting miR-766.

Circular RNA circ_0001105 Inhibits Progression and Metastasis of Osteosarcoma by Sponging miR-766 and Activating YTHDF2 Expression

BACKGROUND

Circular RNAs (circRNAs) play vital roles in the modulation of tumor progression. This study explored the biological functions of circ_0001105 in the progression of osteosarcoma (OS).

METHODS

qRT-PCR and in situ hybridization (ISH) were performed to detect the expression status of circ_0001105 in cells and tissues. Bioinformatics analysis, dual-luciferase reporter gene assay, Western blot and qRT-PCR were performed to determine the relationships among RNAs. The CCK-8, colony formation, EdU, transwell and wound healing assays were conducted to evaluate the cell growth, invasion and migration of OS cells. Tumor xenografts were established to investigate the effects of circ_0001105 on tumor growth in vivo. Lastly, the protein expression of YTHDF2 in OS tissues was measured using immunohistochemical staining.

RESULTS

Data showed that circ_0001105 and YTHDF2 were significantly lower, while miR-766 was higher in OS tissues compared to adjacent tissues. Low expression of circ_0001105 or YTHDF2 was associated with poor survival of OS patients as demonstrated by the Kaplan-Meier analysis. In addition, miR-766 was identified as a direct binding target of circ_0001105 and YTHDF2. Ectopic overexpression of circ_0001105 or YTHDF2 significantly suppressed OS cell viability and invasion through regulating miR-766. Last, overexpression of circ_0001105 significantly attenuated in vivo tumor growth.

CONCLUSION

Our findings suggest that circ_0001105 inhibits OS progression, at least partially, by regulating miR-766/YTHDF2 signaling pathway.

Inhibition of Microrna-766-5p Attenuates the Development of Cervical Cancer Through Regulating SCAI

PURPOSE

MicroRNAs (miRNAs) are considered to play anti-tumor roles in cancers. This study is designed to illustrate the role and potential mechanism of miR-766-5p in cervical cancer (CC) progression.

METHODS

MiR-766-5p expression in tissues and serum of CC patients was detected by quantitative reverse-transcription PCR (qRT-PCR). Receiver operating characteristic (ROC) curve was performed to evaluate the diagnostic value of serum miR-766-5p in CC. The 5-ethynyl-2'-deoxyuridine (EdU) assay, flow cytometry, wound healing as well as transwell assay were utilized to detect the proliferation, apoptosis, migration and invasion of CC cells, respectively. The interaction between miR-766-5p and SCAI was confirmed by dual-luciferase reporter gene assay. Xenografted tumor model was established to measure the growth of tumor xenograft in vivo.

RESULTS

MiR-766-5p was significantly increased in tissues and serum of CC patients. ROC curve suggested that serum miR-766-5p could serve as a biomarker for the diagnosis of CC. Inhibition of miR-766-5p suppressed the proliferation, migration and invasion, and promoted the apoptosis of CC cells. SCAI was proved to be a target of miR-766-5p. Silencing of SCAI eliminated the inhibiting effects of miR-766-5p inhibitor on the proliferation, migration and invasion of CC cells in vitro. Additionally, down-regulation of SCAI also reversed the inhibitory effect of miR-766-5p inhibitor on the growth of tumor xenograft in vivo.

CONCLUSIONS

Inhibition of miR-766-5p restrains the cell proliferation, migration and invasion, and promotes the apoptosis in CC through negatively regulating SCAI.

A Novel Saliva-Based miRNA Signature for Colorectal Cancer Diagnosis

Salivary microRNAs (miRNAs) are of high interest as diagnostic biomarkers for non-oral cancer. However, little is known about their value for colorectal cancer (CRC) detection. Our study aims to characterize salivary miRNAs in order to identify non-invasive markers for CRC diagnosis. The screening of 754 miRNAs was performed in saliva samples from 14 CRC and 10 healthy controls. The differential expressed miRNAs were validated by RT-qPCR in 51 CRC, 19 adenomas and 37 healthy controls. Receiver operating characteristic (ROC) curves and logistic regression models were performed to analyze the clinical value of these miRNAs. Twenty-two salivary miRNAs were significantly deregulated in CRC patients vs. healthy individuals (p < 0.05) in the discovery phase. From those, five upregulated miRNAs (miR-186-5p, miR-29a-3p, miR-29c-3p, miR-766-3p, and miR-491-5p) were confirmed to be significantly higher in the CRC vs. healthy group (p < 0.05). This five-miRNA signature showed diagnostic value (72% sensitivity, 66.67% specificity, AUC = 0.754) to detect CRC, which was even higher in combination with carcinoembryonic antigen (CEA) levels. Overall, after the first global characterization of salivary miRNAs in CRC, a five-miRNA panel was identified as a promising tool to diagnose this malignancy, representing a novel approach to detect cancer-associated epigenetic alterations using a non-invasive strategy.

Novel role of the SRY-related high-mobility-group box D gene in cancer

The SRY-related high-mobility-group box (Sox) gene family encodes a set of transcription factors and is defined by the presence of highly conserved domains. The Sox gene can be divided into 10 groups (A-J). The SoxD subpopulation consists of Sox5, Sox6, Sox13 and Sox23, which are involved in the transcriptional regulation of developmental processes, including embryonic development, nerve growth and cartilage formation. Recently, the SoxD gene family was recognized as important transcriptional regulators associated with many types of cancer. In addition, Sox5 and Sox6 are representatives of the D subfamily, and there are many related studies; however, there are few reports on Sox13 and Sox23. In this review, we first introduce the structures of the SoxD genes. Next, we summarize the latest research progress on SoxD in various types of cancer. Finally, we discuss the potential direction of future SoxD research. In general, the information reviewed here may contribute to future experimental design and increase the potential of SoxD as a cancer treatment target.

Altered erythroid-related miRNA levels as a possible novel biomarker for detection of autologous blood transfusion misuse in sport

BACKGROUND

Autologous blood transfusion (ABT) is a performance-enhancing method prohibited in sport; its detection is a key issue in the field of anti-doping. Among novel markers enabling ABT detection, microRNAs (miRNAs) might be considered a promising analytical tool.

STUDY DESIGN AND METHODS

We studied the changes of erythroid-related microRNAs following ABT, to identify novel biomarkers. Fifteen healthy trained males were studied from a population of 24 subjects, enrolled and randomized into a Transfusion (T) and a Control (C) group. Seriated blood samples were obtained in the T group before and after the two ABT procedures (withdrawal, with blood refrigerated or cryopreserved, and reinfusion), and in the C group at the same time points. Traditional hematological parameters were assessed. Samples were tested by microarray analysis of a pre-identified set of erythroid-related miRNAs.

RESULTS

Hematological parameters showed moderate changes only in the T group, particularly following blood withdrawal. Among erythroid-related miRNAs tested, following ABT a pool of 7 miRNAs associated with fetal hemoglobin and regulating transcriptional repressors of gamma-globin gene was found stable in C and differently expressed in three out of six T subjects in the completed phase of ABT, independently from blood conservation. Particularly, two or more erythropoiesis-related miRNAs within the shortlist constituted of miR-126-3p, miR-144-3p, miR-191-3p, miR-197-3p, miR-486-3p, miR-486-5p, and miR-92a-3p were significantly upregulated in T subjects after reinfusion, with a person-to-person variability but with congruent changes.

CONCLUSIONS

This study describes a signature of potential interest for ABT detection in sports, based on the analysis of miRNAs associated with erythroid features.

T, Antaya R, Narayan D. MicroRNA Microarray Profiling in Infantile Hemangiomas

Objective: MicroRNAs are short, noncoding RNA molecules that negatively regulate the stability and translational efficiency of target mRNAs. They are critical regulators of growth and development. Our aim was to identify microRNAs involved in the growth and regulation of infantile hemangiomas. In addition, we searched for the presence of Piwi-interacting RNAs in hemangioma tissue as another regulator of infantile hemangiomas. Methods: RNA was extracted from hemangioma specimens from 3 clinical, age-based categories: proliferative (N = 16), quiescent (N = 8), and involuting (N = 9). RNAs from human dermal microvascular endothelial cells were used as controls. MicroRNA microarray was performed, and the expression profiles of the hemangiomas and endothelial cells were compared using the t test. 5' End-labeling of RNA of our hemangioma specimens was performed for Piwi-interacting RNA detection. Results: Analysis confirmed statistically significant downregulated (N = 18) and upregulated (N = 15) microRNAs. Piwi-interacting RNA analysis did not detect Piwi-interacting RNA transcripts in the hemangioma specimens. Conclusions: The differential expression of microRNAs found in our hemangioma specimens provides insight into the regulation of hemangioma formation and proliferation, quiescence, and fibrofatty involution. Piwi-interacting RNA transcripts were not detected in the hemangioma specimens. These novel findings will help in establishing new therapeutic and diagnostic initiatives for these tumors.

MicroRNA-765 is pregulated in multiple myeloma and serves an oncogenic role by directly targeting SOX6

Increasing evidence has revealed that microRNAs (miRNAs) are closely associated with multiple myeloma (MM) pathogenesis and progression. Therefore, an in-depth understanding of the biological functions of miRNAs in MM may be helpful for the identification of promising therapeutic techniques for patients with MM. miRNA-765 (miR-765) has been reported to be dysregulated in many types of human cancer. However, the expression pattern, specific roles and underlying mechanisms of miR-765 in MM remain largely unknown. In the present study, plasma miR-765 significantly increased in patients with MM and cell lines. The downregulation of miR-765 in MM cells attenuated proliferation and promoted apoptosis. Bioinformatics analysis predicted that SRY-Box 6 (SOX6) was a putative target of miR-765. This was experimentally verified using a luciferase reporter assay, reverse transcription-quantitative PCR and western blot analysis. Furthermore, plasma SOX6 was downregulated in patients with MM and the downregulation of SOX6 was inversely correlated with that of miR-765 expression. Furthermore, SOX6 knockdown markedly abrogated the effects of miR-765 underexpression on cell proliferation and apoptosis in MM. The current study demonstrated that miR-765 serves an oncogenic role in MM progression by directly targeting SOX6, suggesting that miR-765 may be a potential therapeutic target for MM prevention and treatment.

SOX6 blocks the proliferation of BCR-ABL1+ and JAK2V617F+ leukemic cells

SOX6 is a HMG-box transcription factor expressed in a wide range of tissues. Recent data show that SOX6 expression is altered in different cancers, in the majority of cases being downregulated. To date, no data are available about SOX6 role in hematological malignancies. Here we demonstrate that SOX6 overexpressing BCR-ABL1⁺ B-ALL cells are unable to promote leukemia in a mouse model. Starting from this observation, we extended our study to a panel of human leukemic cells carrying genetic lesions distinctive of different types of leukemias and myeloproliferative disorders (the BCR-ABL1 translocation and the JAK2V617F amino acid substitution) to dissect the cellular events induced by SOX6. The inhibition of proliferation is the invariant outcome of SOX6 overexpression but it is achieved via two different cellular responses: terminal differentiation in erythroid-biased cells, irrespectively of their mutation, and apoptosis in megakaryocytic-primed and lymphoid cells. Within this context, cells carrying the highest copy number of the JAK2V617F allele better counteract the SOX6-imposed growth arrest. The interrogation of the GEPIA (Gene Expression Profiling Interactive Analysis) human dataset reveals that SOX6 is downregulated in a cohort of AML patients, uncovering a wide anti-proliferative role of SOX6 in a variety of mutant backgrounds.

MicroRNA-766-3p Contributes to Anti-Inflammatory Responses through the Indirect Inhibition of NF-κB Signaling

MicroRNA (miRNA) is small RNA of 20 to 22 nucleotides in length and is stably present in plasma. Regulating the expression of miRNA taken into cells has been suggested as a general therapeutic approach. We identified the novel anti-inflammatory miRNA hsa-miR-766-3p and investigated its biological function in human rheumatoid arthritis (RA) fibroblast-like synoviocyte MH7A cells. To verify the function of the miRNA present in the plasma of RA patients, we performed a comprehensive analysis of the miRNA expression during abatacept treatment and identified eight miRNAs with significantly altered expression levels. Among these eight miRNAs, miR-766-3p was found to have a clear function. The expression of inflammatory genes in response to inflammatory stimuli was suppressed in MH7A transduced with miR-766-3p. We showed that miR-766-3p indirectly reduced the activation of NF-κB and clarified that this mechanism was partially involved in the reduction of the mineralocorticoid receptor expression. In addition, the inflammatory responses were suppressed in other types of cells. These results indicate the novel function of miR-766-3p, findings that may aid in the development of therapies to suppress inflammation, not only in RA but also in other diseases.

MicroRNA‑766 inhibits the malignant biological behaviours of pancreatic ductal adenocarcinoma by directly targeting ETS1

Increasing evidence indicates that numerous microRNAs (miRNAs) are altered in pancreatic ductal adenocarcinoma (PDAC), and their alterations significantly influence the malignant behaviour of PDAC. Therefore, identifying miRNAs associated with PDAC and their biological roles in the disease may provide promising therapeutic opportunities. Alteration of the expression of miRNA‑766 (miR‑766) has been previously reported in several types of human malignancy. However, to the best of our knowledge, whether miR‑766 exhibits different expression patterns in PDAC and its underlying functions in the progression of PDAC remain to be elucidated. In the present study, reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR) was used to detect miR‑766 expression levels in PDAC tissues and cell lines. The effects of miR‑766 upregulation on PDAC cell proliferation and invasion were evaluated using MTT and invasion assays, respectively. The mechanisms underlying the role of miR‑766 in PDAC cells were explored using bioinformatics analysis, luciferase reporter assay, RT‑qPCR and western blot analysis. It was found that miR‑766 was significantly downregulated in PDAC tissues and cell lines. The detailed roles of miR‑766 in the progression of PDAC were characterised using Panc‑1 and Aspc‑1 cell lines. The results revealed that the upregulation of miR‑766 restricted the proliferation and invasion of PDAC cells. Through a series of experiments, it was found that E26 transformation specific‑1 (ETS1) was a direct target of miR‑766 in PDAC cells. Furthermore, ETS1 knockdown simulated the inhibitory effects of the overexpression of miR‑766 on PDAC cells, whereas the effects of miR‑766 restoration on the PDAC cells were reversed by overexpressing ETS1. In conclusion, the findings of the present study demonstrate that miR‑766 offers potential as a therapeutic target for patients with PDAC.

microRNA-181b suppresses the metastasis of lung cancer cells by targeting sex determining region Y-related high mobility group-box 6 (Sox6)

BACKGROUND

The aim of the study was to measure the expression of microRNA (miR)-181b in patients with lung cancer, investigate its biological function and elucidate the underlying mechanisms associated with the development of lung cancer.

METHODS

miR-181b expression in tissues was measured via RT-qPCR. After A549 cells were transfected with miR-181b mimic or si-Sox6, the proliferation, migration and cell cycle distribution of A549 were evaluated using cell counting kit-8 assay, transwell assay and flow cytometry. The levels of cell cycle-related proteins and Sox6 were analyzed by western blotting. Gene targets of miR-181b were predicted via bioinformatics analysis and verified using a dual-luciferase reporter gene assay.

RESULTS

Expression of miR-181b was significantly downregulated in lung cancer tissues (P < 0.05), and was inversely correlated with the degree of cell differentiation and clinical stages of lung cancer (both P < 0.05). Additionally, the expression of miR-181b was significantly lower in adenocarcinoma compared with squamous cell carcinoma in the lungs (P < 0.05). Overexpression of miR-181b significantly decreased the protein level of Sox6 and significantly suppressed the cell proliferation and metastasis (both P < 0.05); this effect was also observed in A549 cells transfected with si-Sox6. The luciferase activity of a Sox6 3'-untranslated region-based reporter construct was significantly lower when transfected with miR-181b (P < 0.05), which suggests that Sox6 is a direct target of miR-181b.

CONCLUSION

The results of the present study suggest that miR-181b may function as a tumor inhibitor in the development of lung cancer via targeting Sox6 to decrease the proliferation and metastasis of lung cancer cells.

MicroRNA‑766 inhibits papillary thyroid cancer progression by directly targeting insulin receptor substrate 2 and regulating the PI3K/Akt pathway

MicroRNAs (miRNAs/miRs) are widely dysregulated in papillary thyroid cancer (PTC). Dysregulated miRNAs, together with their target genes, comprise a complex network that has been implicated in the regulation of PTC pathogenesis. Further knowledge of the functional roles of aberrantly expressed miRNAs in PTC, and the underlying molecular mechanisms, may assist in the identification of novel therapeutic targets. miR‑766 has been well studied in human cancer; however, the expression status, specific roles and regulatory mechanisms of miR‑766 in PTC remain unclear. The present study aimed to detect miR‑766 expression in PTC tissues and cell lines, to explore the biological roles of miR‑766 in the malignant biological behaviors of PTC cells, and to determine the underlying mechanism of action of miR‑766 in PTC cells. The results revealed that miR‑766 was downregulated in PTC tissues and cell lines, and its downregulation was strongly associated with TNM stage and lymph node metastasis. Overexpression of miR‑766 inhibited PTC cell proliferation, colony formation, migration and invasion, promoted cell apoptosis and reduced tumor growth in vivo. Mechanistically, insulin receptor substrate 2 (IRS2) was identified as a direct target of miR‑766 in PTC cells. IRS2 was upregulated in PTC tissues, and this was inversely correlated with miR‑766 expression. Inhibition of IRS2 simulated the tumor suppressor activity of miR‑766 in PTC cells. Restoration of IRS2 expression negated the tumor‑suppressing effects of miR‑766 overexpression on PTC cells. Notably, miR‑766 directly targeted IRS2 to inhibit activation of the phosphoinositide 3‑kinase (PI3K)/protein kinase B (Akt) pathway in PTC cells in vitro and in vivo. Overall, these findings indicated that miR‑766 may inhibit the malignant biological behaviors of PTC cells by directly targeting IRS2 and regulating the PI3K/Akt pathway, thus suggesting that this miRNA may be a promising therapeutic target for PTC.

MicroRNA-766-3p Inhibits Tumour Progression by Targeting Wnt3a in Hepatocellular Carcinoma

Recent studies have indicated that microRNAs (miRNAs) play an important role in hepatocellular carcinoma (HCC) progression. In this study, we showed that miR-766-3p was decreased in approximately 72% of HCC tissues and cell lines, and its low expression level was significantly correlated with tumour size, TNM stage, metastasis, and poor prognosis in HCC. Ectopic miR-766-3p expression inhibited HCC cell proliferation, colony formation, migration and invasion. In addition, we showed that miR-766-3p repressed Wnt3a expression. A luciferase reporter assay revealed that Wnt3a was a direct target of miR-766-3p, and an inverse correlation between miR-766-3p and Wnt3a expression was observed. Moreover, Wnt3a up-regulation reversed the effects of miR-766-3p on HCC progression. In addition, our study showed that miR-766-3p up-regulation decreased the nuclear β-catenin level and expression of Wnt targets (TCF1 and Survivin) and reduced the level of MAP protein regulator of cytokinesis 1 (PRC1). However, these effects of miR-766-3p were reversed by Wnt3a up-regulation. In addition, PRC1 up-regulation increased the nuclear β-catenin level and protein expression of TCF1 and Survivin. iCRT3, which disrupts the β-catenin-TCF4 interaction, repressed the TCF1, Survivin and PRC1 protein levels. Taken together, our results suggest that miR-766-3p down-regulation promotes HCC cell progression, probably by targeting the Wnt3a/PRC1 pathway, and miR-766-3p may serve as a potential therapeutic target in HCC.

MicroRNA-373 promotes cell migration via targeting salt-inducible kinase 1 expression in melanoma

It is well established that altered expression of microRNAs (miRs) is critical in numerous human cancer types. Nevertheless, the molecular mechanisms of many miRs are yet to be elucidated. In the present study, reverse transcription-quantitative polymerase chain reaction and western blot analyses, and cell migration assays were performed to verify dysregulation of miR-373 in melanoma and its biological function. The transcriptional level of miR-373 was identified to be upregulated in melanoma tissues and cell lines compared with nevus and normal melanocytes. miR-373 was identified to function as an oncomiR, promoting melanoma cell migration. Notably, miR-373 was observed to suppress its downstream gene salt-inducible kinase 1 (SIK1) through directly binding the 3'-untranslated region of SIK1 expression. Furthermore, reduced SIK1 expression was identified to be responsible for the oncogenic effect of miR-373. In conclusion, the present study indicates that miR-373 functions as an oncomiR to promote melanoma progression through targeting SIK1 expression. This may provide a new therapeutic approach for melanoma.

MicroRNA-766 promotes cancer progression by targeting NR3C2 in hepatocellular carcinoma

MicroRNAs (miRNAs) have been reported to play important roles in tumor progression of various cancers. However, the clinical significance and biologic function of miR-766 in hepatocellular carcinoma (HCC) remain unknown. In this study, we investigated the roles of miR-766 in HCC progression using HCC cell lines and a xenograft mouse model. miR-766 expression in tumor tissues and adjacent nontumorous liver tissues of patients with HCC was evaluated by quantitative RT-PCR. Our results showed that miR-766 promoted proliferation and metastasis of HCC cells in vitro and in vivo and that NR3C2 was a direct target of miR-766 and involved in miR-766-mediated proliferation and metastasis of HCC cells. We also found that miR-766 affected the β-catenin signaling pathway by targeting NR3C2. Furthermore, miR-766 was significantly up-regulated in HCC tissues and was correlated with the prognosis of patients with liver cancer. Taken together, our results show that miR-766 affects HCC progression by modulating NR3C2 expression and is a possible new therapeutic target for patients with HCC.-Yang, C., Ma, X., Guan, G., Liu, H., Yang, Y., Niu, Q., Wu, Z., Jiang, Y., Bian, C., Zang, Y., Zhuang, L. MicroRNA-766 promotes cancer progression by targeting NR3C2 in hepatocellular carcinoma.

Characterization of hepatocellular adenoma and carcinoma using microRNA profiling and targeted gene sequencing

Background

Hepatocellular adenomas (HCA) are benign liver tumors that may transform into hepatocellular carcinoma (HCC), but the molecular drivers of this transformation remain ill-defined. This study evaluates the molecular changes in HCA and HCC and in comparison to their adjacent non-neoplastic liver.

Methods

11 patients with HCA and 10 patients with HCC without underlying hepatitis or cirrhosis were included in this pilot study. Tumor and non-tumor liver tissues were selected for immunohistochemical staining, small RNA sequencing, and targeted gene sequencing. We compared microRNA expressions and mutations between HCA and HCC and non-neoplastic liver.

Results

HCA were classified as inflammatory (n = 6), steatotic (n = 4), or β-catenin activated (n = 1) subtypes. MicroRNA profile of all 3 HCA subtypes clustered between that of normal liver and HCC in principal component analysis. In both HCA and HCC, miR-200a, miR-429, and miR-490-3p were significantly downregulated compared to normal liver, whereas miR-452, miR-766, and miR-1180 were significantly upregulated. In addition, compared to HCA, HCC had significantly higher expression of members of the chromosome 19 miRNA cluster (C19MC), including miR-515-5p, miR-517a, miR-518b, and miR-520c-3p.

Conclusions

This study indicates that while there are significant differences in the molecular profile between HCA and HCC, several miRNAs are similarly deregulated in HCA and HCC compared to adjacent normal liver. These results may provide insights into the drivers of hepatocarcinogenesis and warrant further investigations.

miR-96 targets SOX6 and promotes proliferation, migration, and invasion of hepatocellular carcinoma

Recent research suggested that microRNA 96 (miR-96) might function as an oncogene in several types of cancers. Therefore, the purpose of this study was to probe into the mechanism of miR-96 in hepatocellular carcinoma (HCC) cells. HCC tissues and non-tumorous tissues, HCC cell lines, and healthy cell lines were all involved in this study. Quantitative real-time PCR (qRT-PCR) and Western blot were used to detect miR-96 and SOX6 mRNA and protein expressions. The direct regulation of miR96 on SOX6 was confirmed by luciferase reporter assays. Cell proliferation and growth were determined by MTT (3-(4,5-dimethyl–2-thiazolyl)–2,5-diphenyl–2-H-tetrazolium bromide) assay and colony formation assay. Wound healing and transwell assay were employed for migration and invasion analyses. Finally, SPSS 21.0 and GraphPad 7.0 were applied for statistical analyses. In HCC tissues, miR-96 was highly expressed while SOX6 was lowly expressed. The overexpression of miR-96 reversely inhibited the expression of SOX6, contributing to the promotion of the biological functions of HCC cells. miR-96 could promote cell proliferation, migration, and invasion in HCC by targeting SOX6.

ADAM9 enhances CDCP1 by inhibiting miR-1 through EGFR signaling activation in lung cancer metastasis

MicroRNAs (miRNAs), which are endogenous short noncoding RNAs, can regulate genes involved in important biological and pathological functions. Therefore, dysregulation of miRNAs plays a critical role in cancer progression. However, whether the aberrant expression of miRNAs is regulated by oncogenes remains unclear. We previously demonstrated that a disintegrin and metalloprotease domain 9 (ADAM9) promotes lung metastasis by enhancing the expression of a pro-migratory protein, CUB domain containing protein 1 (CDCP1). In this study, we found that this process occurred via miR-1 down-regulation. miR-1 expression was down-regulated in lung tumors, but increased in ADAM9-knockdown lung cancer cells, and was negatively correlated with CDCP1 expression as well as the migration ability of lung cancer cells. Luciferase-based reporter assays showed that miR-1 directly bound to the 3′-untranslated region of CDCP1 and inhibited its translation. Treatment with a miR-1 inhibitor restored CDCP1 protein levels and enhanced tumor cell mobility. Overexpression of miR-1 decreased tumor metastases and increased the survival rate in mice. ADAM9 knockdown reduced EGFR signaling and increased miR-1 expression. These results revealed that ADAM9 down-regulates miR-1 via activating EGFR signaling pathways, which in turn enhances CDCP1 expression to promote lung cancer progression.

MicroRNA Expression Profiling of the Armed Forces Health Surveillance Branch Cohort for Identification of "Enviro-miRs" Associated With Deployment-Based Environmental Exposure

OBJECTIVE

The aim of this study was to identify serum microRNA (miRNA) biomarkers that indicate deployment-associated exposures in service members at military installations with open burn pits. Another objective was to determine detection rates of miRNAs in Department of Defense Serum Repository (DoDSR) samples with a high-throughput methodology.

METHODS

Low-volume serum samples (n = 800) were profiled by miRNA-capture isolation, pre-amplification, and measurement by a quantitative PCR-based OpenArray platform. Normalized quantitative cycle values were used for differential expression analysis between groups.

RESULTS

Assay specificity, dynamic range, reproducibility, and detection rates by OpenArray passed target desired specifications. Serum abundant miRNAs were consistently measured in study specimens. Four miRNAs were differentially expressed in the case deployment group subjects.

CONCLUSIONS

miRNAs are suitable RNA species for biomarker discovery in the DoDSR serum specimens. Serum miRNAs are candidate biomarkers for deployment and environmental exposure in military service members.

SOX6 is downregulated in osteosarcoma and suppresses the migration, invasion and epithelial-mesenchymal transition via TWIST1 regulation

Transcription factor SOX6 (SOX6) has been reported to serve essential roles in numerous types of cancers. However, the expression and functions of SOX6 in osteosarcoma (OS) have not been analyzed. In the present study, the patterns of SOX6 expression in OS cell lines and tissues were investigated by reverse transcription‑quantitative polymerase chain reaction and western blotting. The results of the present study revealed that SOX6 was notably downregulated in OS tissues and cell lines. Subsequently, gain‑ and loss‑of‑function studies demonstrated that SOX6 inhibited OS cell migration and invasion. In addition, SOX6 may have suppressed epithelial‑mesenchymal transition via twist‑related protein 1 (TWIST1) modulation. Chromatin immunoprecipitation (ChIP), quantitative ChIP and dual luciferase activity assays were used to confirm the binding of SOX6 to the promoter region of TWIST1. Additionally, colony formation assays and Cell Counting Kit‑8 assays demonstrated that SOX6 suppressed cell proliferation. The findings of the present study indicated that SOX6 serves as a tumor suppressor in OS and may be a potential therapeutic target for OS.

MiR-766 induces p53 accumulation and G2/M arrest by directly targeting MDM4

p53, a transcription factor that participates in multiple cellular functions, is considered the most important tumor suppressor. Previous evidence suggests that post-transcriptional deregulation of p53 by microRNAs contributes to tumorigenesis, tumor progression and therapeutic resistance. In the present study, we found that the microRNA miR-766 was aberrantly expressed in breast cancer, and that over-expression of miR-766 caused accumulation of wild-type p53 protein in multiple cancer cell lines. Supporting its role in the p53 signalling pathway, miR-766 decreased cell proliferation and colony formation in several cancer cell lines, and cell cycle analyses revealed that miR-766 causes G2 arrest. At a mechanistic level, we demonstrate that miR-766 enhances p53 signalling by directly targeting MDM4, an oncogene and negative regulator of p53. Analysis of clinical genomic data from multiple cancer types supports the relevance of miR-766 in p53 signalling. Collectively, our study demonstrates that miR-766 can function as a novel tumor suppressor by enhancing p53 signalling.

Identification of Sox6 as a regulator of pancreatic cancer development

Pancreatic cancer (PC) is an aggressive malignancy associated with a poor prognosis and low responsiveness to chemotherapy and radiotherapy. Most patients with PC have metastatic disease at diagnosis, which partly accounts for the high mortality from this disease. Here, we explored the role of the transcription factor sex‐determining region Y‐box (Sox) 6 in the invasiveness of PC cells. We showed that Sox6 is down‐regulated in patients with PC in association with metastatic disease. Sox6 overexpression suppressed PC cell proliferation and migration in vitro and tumour growth and liver metastasis in vivo. Sox6 inhibited epithelial‐mesenchymal transition (EMT), and Akt signalling. Sox6 was shown to interact with the promoter of Twist1, a helix–loop–helix transcription factor involved in the induction of EMT, and to modulate the expression of Twist1 by recruiting histone deacetylase 1 to the promoter of the Twist1 gene. Twist1 overexpression reversed the effect of Sox6 on inhibiting EMT, confirming that the effect of Sox6 on suppressing tumour invasiveness is mediated by the modulation of Twist1 expression. These results suggest a novel mechanism underlying the aggressive behaviour of PC cells and identify potential therapeutic targets for the treatment of PC.

The role of miR-766-5p in cell migration and invasion in colorectal cancer

Colorectal cancer (CRC) develops from the colon or rectum and is the fourth highest inducer of cancer mortality. In the present study, cancer tissues and normal tissues were extracted from patients with CRC who were treated in the Affiliated Hospital of Shandong University of Traditional Chinese Medicine (Jinan, China). Reverse transcription-quantitative polymerase chain reaction demonstrated that the expression level of miR-766-5p was significantly higher (P<0.01) in cancer tissue than that in normal tissue. SW480 cells were used for in vitro study and randomly separated into the miR-negative control (NC) inhibitor treatment group and miR-766-5p inhibitor treatment group. SW480 cell behaviors were evaluated. Results demonstrated that in the miR-766-5p inhibitor group, there was a decreased level of cell proliferation/migration/invasion and higher cell apoptosis compared with that in the miR-NC inhibitor group. miR-766-5p was predicted and verified to target the 3' untranslated region of suppressor of cancer cell invasion (SCAI) in SW480 cells. Protein expression levels of matrix metalloproteinase-2/phosphoinositide 3-kinase/AKT were decreased and SCAI was increased following miR-766-5p inhibitor treatment. In conclusion, the present study indicated that miR-766-5p inhibitor repressed the process of CRC by targeting SCAI.

A combination of circulating miRNAs for the early detection of ovarian cancer

Ovarian cancer is the leading cause of gynecologic cancer mortality, due to the difficulty of early detection. Current screening methods lack sufficient accuracy, and it is still challenging to propose a new early detection method that improves patient outcomes with less-invasiveness. Although many studies have suggested the utility of circulating microRNAs in cancer detection, their potential for early detection remains elusive. Here, we develop novel predictive models using a combination of 8 circulating serum miRNAs. This method was able to successfully distinguish ovarian cancer patients from healthy controls (area under the curve, 0.97; sensitivity, 0.92; and specificity, 0.91) and early-stage ovarian cancer from patients with benign tumors (0.91, 0.86 and 0.83, respectively). This method also enables subtype classification in 4 types of epithelial ovarian cancer. Furthermore, it is found that most of the 8 miRNAs were packaged in extracellular vesicles, including exosomes, derived from ovarian cancer cells, and they were circulating in murine blood stream. The circulating miRNAs described in this study may serve as biomarkers for ovarian cancer patients. Early detection and subtype determination prior to surgery are crucial for clinicians to design an effective treatment strategy for each patient, as is the goal of precision medicine.

DNA-methylation-mediated repression of miR-766-3p promotes cell proliferation via targeting SF2 expression in renal cell carcinoma

Aberrant expression of microRNA (miRNA) emerges as an important role in a wide range of human malignances, and further identification as well as validation of the change of these endogenous non-protein-coding transcripts is warranted. Here, we identify a novel epigenetic regulation of miR-766-3p and investigate its biological function as well as clinical significance in renal cell carcinoma (RCC). Bisulfate analysis elucidates that the promoter of miR-766-3p is highly methylated in RCC tissues compared to non-tumorous tissues. Notably, the downregulation of miR-766-3p is obviously associated with clinical stage and worse prognosis in RCC patients. Upregulated miR-766-3p attenuates cell-cycle progression via targeting SF2 expression and additional SF2/P-AKT/P-ERK signaling pathway. Moreover, high level of SF2, as a novel oncoprotein in RCC, was significantly associated with poor survival in a large cohort of RCC specimens. Taken together, our study presents a road map for the prediction and validation of miR-766-3p/SF2 axis and thus imparts a therapeutic way for further RCC progression.

miR-938 promotes colorectal cancer cell proliferation via targeting tumor suppressor PHLPP2

Colorectal cancer (CRC) is one of the leading causes of cancer-related deaths worldwide. Although the development of therapy approaches, the outcome of CRC patients still is poor, understanding the biological mechanism of CRC progression is critical to improve the treatment strategies. miRNAs regulate CRC progression, we found miR-938 was upregulated in CRC tissues and cells, MTT assay, colony formation assay and soft agar growth assay suggested miR-938 overexpression promoted CRC cell proliferation, miR-938 knockdown inhibited CRC cell proliferation. Tumor suppressor PH domain Leucine-rich-repeats Protein Phosphatase 2 (PHLPP2) was a target of miR-938, miR-938 inhibited PHLPP2, luciferase activity assay suggested miR-938 directly bound to the 3'UTR of PHLPP2, meanwhile, we found miR-938 promoted c-Myc and Cyclin D1 expression, confirming miR-938 promoted CRC cell proliferation. Double knockdown of miR-938 and PHLPP2 promoted CRC cell proliferation, suggesting miR-938 promoted CRC cell proliferation by inhibiting PHLPP2.

Deregulation of the miR-16-KRAS axis promotes colorectal cancer

KRAS plays a significant role in the etiology and progression of colorectal cancer (CRC), but the mechanism underlying this process has not been fully elucidated. In this study, we found that the KRAS protein levels were higher in CRC tissues than in the normal adjacent tissues, whereas its mRNA levels varied irregularly, suggesting that a post-transcriptional mechanism is involved in the regulation of KRAS. Then, we performed bioinformatic analyses to search for miRNAs that potentially target KRAS. We predicted and experimentally validated that miR-16 directly recognizes the 3'-UTR of the KRAS transcript and regulates KRAS expression. Furthermore, the in vitro results showed that the repression of KRAS by miR-16 suppressed the proliferation and invasion and induced the apoptosis of CRC cells, and the in vivo results revealed that miR-16 exerted a tumor-suppressive effect by negatively regulating KRAS in xenograft mice. Taken together, our findings provide evidence supporting the role of miR-16 as a tumor suppressor in CRC by targeting KRAS.

SOX-mediated molecular crosstalk during the progression of tumorigenesis

SOX family transcription factor has emerged as a double-edged sword relating to tumorigenesis and metastasis. Multiple studies have revealed different expression patterns and contradictory roles of SOX factors in the tumor initiation and progression. The aberrant expression of SOX factors is regulated by copy number alteration, methylation modulation, microRNAs, transcription factors and post-translational modification. This review summarizes the role of SOX factors in molecular interactions and signaling pathways during different steps of carcinogenesis, such as CSCs stemness maintenance, EMT occurrence, cell invasion, cell proliferation and apoptosis. The Wnt signaling pathway is also shown to provide vital intermediate signaling transduction. We believe that SOX family proteins may be used as prognostic markers for human clinical therapy, and novel therapy strategies targeting SOX factors should be explored in future clinical applications.