miR-3156-3p is downregulated in HPV-positive cervical cancer and performs as a tumor-suppressive miRNA

A comprehensive overview on the crosstalk between microRNAs and viral pathogenesis and infection

Infections caused by viruses as the smallest infectious agents, pose a major threat to global public health. Viral infections utilize different host mechanisms to facilitate their own propagation and pathogenesis. MicroRNAs (miRNAs), as small noncoding RNA molecules, play important regulatory roles in different diseases, including viral infections. They can promote or inhibit viral infection and have a pro-viral or antiviral role. Also, viral infections can modulate the expression of host miRNAs. Furthermore, viruses from different families evade the host immune response by producing their own miRNAs called viral miRNAs (v-miRNAs). Understanding the replication cycle of viruses and their relation with host miRNAs and v-miRNAs can help to find new treatments against viral infections. In this review, we aim to outline the structure, genome, and replication cycle of various viruses including hepatitis B, hepatitis C, influenza A virus, coronavirus, human immunodeficiency virus, human papillomavirus, herpes simplex virus, Epstein-Barr virus, Dengue virus, Zika virus, and Ebola virus. We also discuss the role of different host miRNAs and v-miRNAs and their role in the pathogenesis of these viral infections.

Structural Studies of the Taurine Transporter: A Potential Biological Target from the GABA Transporter Subfamily in Cancer Therapy

The taurine transporter (TauT, SLC6A6) is a member of the solute carrier 6 (SLC6) family, which plays multiple physiological roles. The SLC6 family is divided into four subfamilies: GABA (γ-aminobutyric acid), monoamine, glycine and neutral amino acid transporters. Proteins from the GABA group, including the taurine transporter, are primarily considered therapeutic targets for treating central nervous system disorders. However, recent studies have suggested that inhibitors of SLC6A6 could also serve as anticancer agents. Overexpression of TauT has been associated with the progression of colon and gastric cancer. The pool of known ligands of this transporter is limited and the exact spatial structure of taurine transporter remains unsolved. Understanding its structure could aid in the development of novel inhibitors. Therefore, we utilized homology modelling techniques to create models of TauT. Docking studies and molecular dynamics simulations were conducted to describe protein-ligand interactions. We compared the obtained information for TauT with literature data on other members of the GABA transporter group. Our in silico analysis allowed us to characterize the transporter structure and point out amino acids crucial for ligand binding: Glu406, Gly62 and Tyr138. The significance of selected residues was confirmed through structural studies of mutants. These results will aid in the development of novel taurine transporter inhibitors, which can be explored as anticancer agents.

circ_0006789 promotes cervical cancer development via the miR-615-5p/HSF1 axis

OBJECTIVE

Circular RNAs (circRNAs) are involved in the development of human cancers, including cervical cancer (CC). However, the role and mechanism of circ_0006789 (circSLC25A43) in CC are unclear. The purpose of this study was to investigate the functional role of circ_0006789 in CC.

METHODS

The expression of circ_0006789 in CC tissues and cell lines was examined by RT-qPCR. The characterization of circ_0006789 in CC cells was verified by subcellular localisation, actinomycin D assay, and RNase R assay. After circ_0006789 was knocked down in CC cell lines, the proliferation, apoptosis, migration and invasion of CC cells were assessed by CCK-8 method, flow cytometry, and Transwell assay. RIP assay, FISH assay, dual luciferase reporter gene assay and Western blot were used to investigate the regulatory mechanism between circ_0006789, miR-615-5p and heat shock factor 1 (HSF1).

RESULTS

circ_0006789 was upregulated in CC tissues and cell lines. CC cells were inhibited in their proliferation, migration, and invasion, as well as promoted to apoptosis when circ_0006789 was knocked down. It was found that circ_0006789 targeted miR-615-5p, and miR-615-5p expression was inversely correlated with circ_0006789 expression. Furthermore, HSF1 was a target gene of miR-615-5p. Furthermore, the suppressive effects on HeLa cells mediated by circ_0006789 knockdown were counter-balanced when miR-615-5p was knocked down and HSF1 was overexpressed. Mechanistically, circ_0006789 was found to promote CC development by reducing miR-615-5p and increasing HSF1 expressions.

CONCLUSION

circ_0006789 accelerates CC development via the miR-615-5p/HSF1 axis.

A systematic review and meta-analysis of miRNAs for the detection of cervical cancer

Aim: This study aimed to critically appraise the evidence of the diagnostic effectiveness of miRNAs for the detection of cervical cancer. Methods & materials: A systematic review and meta-analysis was performed, searching PubMed, EMBASE and Web of Science. An umbrella meta-analysis of meta-analyses of individual biomarkers was performed. A Grading of Recommendations, Assessment, Development and Evaluations (GRADE) assessment of evidence was also performed. Results: A total of 52 miRNAs were included. Umbrella meta-analysis revealed significant heterogeneity in terms of sensitivity, specificity, receiver operating characteristic (ROC), positive predictive value and/or negative predictive value. Umbrella effects were 0.76 (95% CI: 0.73-0.78), 0.78 (95% CI: 0.75-0.81), 0.77 (95% CI: 0.75-0.80), 0.75 (95% CI: 0.71-0.79) and 0.76 (95% CI: 0.74-0.79), respectively. Conclusion: Moderate quality evidence suggested miR199a-5p, miR21-5p and miR-141a had excellent diagnostic performance.

Taurine and Creatine Transporters as Potential Drug Targets in Cancer Therapy

Cancer cells are characterized by uncontrolled growth, proliferation, and impaired apoptosis. Tumour progression could be related to poor prognosis and due to this fact, researchers have been working on novel therapeutic strategies and antineoplastic agents. It is known that altered expression and function of solute carrier proteins from the SLC6 family could be associated with severe diseases, including cancers. These proteins were noticed to play important physiological roles through transferring nutrient amino acids, osmolytes, neurotransmitters, and ions, and many of them are necessary for survival of the cells. Herein, we present the potential role of taurine (SLC6A6) and creatine (SLC6A8) transporters in cancer development as well as therapeutic potential of their inhibitors. Experimental data indicate that overexpression of analyzed proteins could be connected with colon or breast cancers, which are the most common types of cancers. The pool of known inhibitors of these transporters is limited; however, one ligand of SLC6A8 protein is currently tested in the first phase of clinical trials. Therefore, we also highlight structural aspects useful for ligand development. In this review, we discuss SLC6A6 and SLC6A8 transporters as potential biological targets for anticancer agents.

Overexpression of miR-3653 is Associated with HPV Infection and Serves as a Biomarker in Patients with Cervical Cancer

Background

Human papillomavirus (HPV) is a major cause of cervical cancer (CC) occurrence. This study aimed to explore whether abnormal microRNA (miR)-3653 is associated with HPV infection and to investigate the clinical value of miR-3653 in the diagnosis and prognosis of CC.

Methods

Tumor tissues and adjacent non-cancerous tissues were collected from 136 patients with CC. Cervical tissues from 101 patients with uterine fibroids were collected as controls. The expression of miR-3653 was measured by quantitative real-time PCR. The ability of miR-3653 to discriminate between HPV positive (HPV+) and HPV negative (HPV-) CC patients, and to discriminate patients from controls was assessed by receiver operating characteristic analysis. Kaplan–Meier curves and Log rank tests were used to evaluate the relationship of miR-3653 with survival of CC patient. Whether miR-3653 could function as a prognostic indicator was evaluated by univariate and multivariate Cox analyses.

Results

miR-3653, highly expressed in CC tissues, was associated with HPV infection, tumor diameter, International Federation of Gynecology and Obstetrics (FIGO) stage and lymph node metastasis in CC patients. Additionally, miR-3653 was increased in HPV+ controls, CC patients and CC cells. Moreover, miR-3653 could screen HPV+ controls, screen HPV+ patients and screen CC patients. Furthermore, miR-3653 was associated with the survival of CC patients (log-rank P < 0.001) and could serve as an independent prognostic indicator for CC patients.

Conclusion

miR-3653, increased in CC, is related to HPV infection and may serve as a diagnostic and prognostic biomarker for CC patients.

MicroRNAs in the Regulation of Solute Carrier Proteins Behind Xenobiotic and Nutrient Transport in Cells

Altered metabolism, such as aerobic glycolysis or the Warburg effect, has been recognized as characteristics of tumor cells for almost a century. Since then, there is accumulating evidence to demonstrate the metabolic reprogramming of tumor cells, addiction to excessive uptake and metabolism of key nutrients, to support rapid proliferation and invasion under tumor microenvironment. The solute carrier (SLC) superfamily transporters are responsible for influx or efflux of a wide variety of xenobiotic and metabolites that are needed for the cells to function, as well as some medications. To meet the increased demand for nutrients and energy, SLC transporters are frequently dysregulated in cancer cells. The SLCs responsible for the transport of key nutrients for cancer metabolism and energetics, such as glucose and amino acids, are of particular interest for their roles in tumor progression and metastasis. Meanwhile, rewired metabolism is accompanied by the dysregulation of microRNAs (miRNAs or miRs) that are small, noncoding RNAs governing posttranscriptional gene regulation. Studies have shown that many miRNAs directly regulate the expression of specific SLC transporters in normal or diseased cells. Changes of SLC transporter expression and function can subsequently alter the uptake of nutrients or therapeutics. Given the important role for miRNAs in regulating disease progression, there is growing interest in developing miRNA-based therapies, beyond serving as potential diagnostic or prognostic biomarkers. In this article, we discuss how miRNAs regulate the expression of SLC transporters and highlight potential influence on the supply of essential nutrients for cell metabolism and drug exposure toward desired efficacy.

Cervical Cancer, Papillomavirus, and miRNA Dysfunction

Cervical cancer is the leading cause of death by cancer in women from developing countries. Persistent infection with high-risk human papillomavirus (HPV) types 16 and 18 is a major risk factor for cervical carcinogenesis. Nevertheless, only a few women with morphologic expression of HPV infection progress into invasive disease suggesting the involvement of other factors in cervical carcinogenesis. MicroRNAs (miRNAs) are conserved small non-coding RNAs that negatively regulate gene expression including genes involved in fundamental biological processes and human cancer. Dysregulation of miRNAs has been widely reported in cervical cancer. This work focuses on reviewing the miRNAs affected during the HPV infection process, as well relevant miRNAs that contribute to the development and maintenance of malignant cervical tumor cells. Finally, we recapitulate on miRNAs that may be used to distinguish between healthy individuals from patients with precancerous lesions or cervical tumors.

HPV16-LINC00393 Integration Alters Local 3D Genome Architecture in Cervical Cancer Cells

High-risk human papillomavirus (hrHPV) infection and integration were considered as essential onset factors for the development of cervical cancer. However, the mechanism on how hrHPV integration influences the host genome structure remains not fully understood. In this study, we performed in situ high-throughput chromosome conformation capture (Hi-C) sequencing, chromatin immunoprecipitation and sequencing (ChIP-seq), and RNA-sequencing (RNA-seq) in two cervical cells, 1) NHEK normal human epidermal keratinocyte; and 2) HPV16-integrated SiHa tumorigenic cervical cancer cells. Our results reveal that the HPV-LINC00393 integrated chromosome 13 exhibited significant genomic variation and differential gene expression, which was verified by calibrated CTCF and H3K27ac ChIP-Seq chromatin restructuring. Importantly, HPV16 integration led to differential responses in topologically associated domain (TAD) boundaries, with a decrease in the tumor suppressor KLF12 expression downstream of LINC00393. Overall, this study provides significant insight into the understanding of HPV16 integration induced 3D structural changes and their contributions on tumorigenesis, which supplements the theory basis for the cervical carcinogenic mechanism of HPV16 integration.

LINC01133 promotes the progression of cervical cancer via regulating miR-30a-5p/FOXD1

BACKGROUND

The prognosis of patients with recurrent or metastatic cervical cancer (CC) remains poor, and its incidence is especially high in developing countries. Multiple long noncoding RNAs are recently identified as crucial oncogenic factors or tumor suppressors. In this study, we explored the function and mechanism of LINC01133 during the progression of CC.

METHODS

Expression levels of LINC01133 and miR-30a-5p in 50 CC tissue samples were measured using quantitative real-time polymerase chain reaction. Immunohistochemistry and Western blot analysis were used to detect the expression of oncogene forkhead box D1 (FOXD1). The association between pathological indices and the expression level of LINC01133 was also analyzed. Human CC cell lines HeLa and SiHa were used as cell models. CCK-8 and bromodeoxyuridine assays were used to assess the effect of LINC01133 on CC cell line proliferation. Flow cytometry was used to study the effect of LINC01133 on CC apoptosis. Transwell assay was conducted to detect the effect of LINC01133 on migration and invasion. Furthermore, luciferase reporter assay was used to confirm the targeting relationship between miR-30a-5p to LINC01133.

RESULTS

We observed that LINC01133 expression in CC clinical samples was significantly increased, with high expression associated with higher T stage and negative HPV infection of the patients. Its overexpression remarkably accelerated proliferation and metastasis of CC cells, with reduced apoptosis. LINC01133 knockdown suppressed the malignant phenotypes of CC cells. Overexpression of LINC01133 significantly reduced the expression of miR-30a-5p by sponging it and enhanced the expression of FOXD1.

CONCLUSIONS

We report the overexpression of LINC01133 in CC sample and cell lines, which correlated with unfavorable pathological indices. LINC01133 was a sponge of tumor suppressor miR-30a-5p, and it enhanced the expression of FOXD1 indirectly and functioned as an oncogenic lncRNA in CC.

LINC01089 inhibits the progression of cervical cancer via inhibiting miR-27a-3p and increasing BTG2

BACKGROUND

Increasing evidence confirms that long non-coding RNA (lncRNA) has a vital impact on the procession of cervical cancer (CC). The present study aimed to investigate the clinical significance of LINC01089 in CC, as well as explore its biological functions and potential molecular mechanisms.

METHODS

A quantitative real-time polymerase chain reaction (qRT-PCR) was utilized to investigate the expression of LINC01089 and miR-27a-3p in CC cells and tissues. Analysis of the correlation between the expression level of LINC01089 and the clinical pathological parameters of CC was then conducted. The human CC cell lines HeLa and SiHa were utilized for transfection to establish a gain-of-function model and loss-of-function models. Western blotting and a qRT-PCR were performed to detect B-cell translocation gene-2 (BTG2) expression in CC cells. Cell counting kit (CCK)-8 and 5-bromo-2-deoxyuridine (BrdU) assays were performed to detect the proliferation of CC cells. The transwell method was employed to evaluate the migration and invasion of CC cells. The interactions between LINC01089 and miR-27a-3p were verified by bioinformatics, a dual luciferase reporter gene experiment and a RNA immunoprecipitation experiment, respectively.

RESULTS

The expression of LINC01089 in CC was markedly down-regulated. The low expression of LINC01089 in CC was closely associated with a larger tumor size and positive lymph node metastasis. Moreover, overexpression of LINC01089 impeded the proliferation and metastasis of CC cells, whereas knockdown of LINC01089 had the opposite biological functions. In terms of mechanism, LINC01089 could sponge miR-27a-3p and indirectly up-regulate BTG2 expression.

CONCLUSIONS

LINC01089, as a tumor suppressor, impedes the development of CC by targeting miR-27a-3p to up-regulate BTG2 expression.

A novel lncRNA-miRNA-mRNA competitive endogenous RNA network for uveal melanoma prognosis constructed by weighted gene co-expression network analysis

AIMS

Uveal melanoma (UM) is the most common and aggressive intraocular tumor in adults, and long-term survival of UM patients remains poor. Abnormal competitive endogenous RNA (ceRNA) networks promote the initiation and progression of many tumors and may thus serve as useful prognostic indicators. Here, we do a comprehensive analysis of long non-coding RNA (lncRNA)-microRNA (miRNA)-mRNA ceRNA networks as prognostic markers for UM.

MATERIALS AND METHODS

The Cancer Genome Atlas UM dataset was used to identify survival-related mRNA and lncRNA modules through weighted gene co-expression network analysis (WGCNA). Prognostic miRNAs were identified using univariate Cox proportional hazard regression. We then used Cox and least absolute shrinkage and selection operator regression to screen for prognostic hub mRNAs and establish a hub ceRNA network. A nomogram of five hub mRNAs was constructed and Kaplan-Meier survival analysis performed.

KEY FINDINGS

Six mRNA modules were constructed, two of which involved 1490 mRNAs that significantly correlated with survival. Among the three lncRNA modules constructed, one involved 199 survival-related lncRNAs. Five hub prognostic mRNAs were identified and a hub ceRNA network constructed, consisting of six lncRNAs, four miRNAs, and five mRNAs, with high prognostic value.

SIGNIFICANCE

We describe a hub ceRNA network of survival-associated lncRNAs, miRNAs, and mRNA that may underlie a critical post-translational regulatory mechanism determining UM aggression. These hub RNAs may be valuable prognostic markers and therapeutic targets in UM.

Soybean-derived miRNAs specifically inhibit proliferation and stimulate apoptosis of human colonic Caco-2 cancer cells but not normal mucosal cells in culture

MicroRNAs (miRNAs) are important regulators of gene expression in eukaryotes. Studies have shown that plant-derived miRNAs can be absorbed through diets and regulate gene expression in mammals. Although soybean-derived miRNAs have been reported, their biological functions are still unclear. In this study, we found that soybean-derived small RNAs (sRNAs) significantly inhibited the proliferation and stimulated the apoptosis of Caco-2 cells. Bioinformatics analysis indicated that the target gene set of soybean miRNAs was extensively enriched in cancer pathways. Besides, we obtained 8 target genes, including Transcription factor 7 (TCF7), associated with colon cancer through prediction. Further studies showed that gma-miR159a inhibited the proliferation of Caco-2 cells and played an important role in the inhibitory effect of sRNAs by inhibiting TCF7 protein, which are upregulated in colon cancer cells but not normal mucosal cells in culture. These findings provide a novel molecular mechanism of soybean-derived miRNAs for potential application in tumor prevention.

Changes of miRNA Expression Profiles from Cervical-Vaginal Fluid-Derived Exosomes in Response to HPV16 Infection

As an oncogenic virus, HPV16 can lead to the dysfunction of cervical epithelial cells and contribute to the progression of cervical cancer. Components from the cervical-vaginal fluid (CVF) could be used as the basis for cervical cancer screening. Exosomes are widely present in various body fluids and participate in intercellular communication via its cargos of proteins, mRNAs, and miRNAs. This study was conducted to explore the changes of miRNAs in exosomes isolated form the cervical-vaginal fluid during HPV16 infection and to predict the potential effects of exosomal miRNAs on the development of cervical cancer. CVF was collected from volunteers with or without HPV16 infection. The exosomes in CVF were identified by electron microscopy. Microarray analysis was subjected to find the differentially expressed miRNAs in CVF exosomes. To confirm the results, 16 miRNAs were randomly selected to go through real-time quantitative polymerase chain reaction. In addition, GO and pathway analyses were conducted to reveal potential functions of differentially expressed miRNAs. A total of 2548 conserved miRNAs were identified in the cervical-vaginal fluid-derived exosomes. In response to HPV16 infection, 45 miRNAs are significantly upregulated and 55 miRNAs are significantly downregulated (P < 0.05). The GO and KEGG pathway analyses revealed that these differentially expressed miRNAs are tightly associated with cervical cancer tumorigenesis, through interaction with the Notch signaling pathway, TNF signaling pathway, and TGF-β signaling pathway. These results suggest that exosomal miRNAs in CVF are differentially expressed in HPV16 infection patients and HPV16-free volunteers. It provided a novel insight to understand the underlying mechanism of HPV16 infection in regulating cervical cancer progression.

Interfering Human Papillomavirus E6/E7 Oncogenes in Cervical Cancer Cells Inhibits the Angiogenesis of Vascular Endothelial Cells via Increasing miR-377 in Cervical Cancer Cell-Derived Microvesicles

Background

The dysregulation of the human papillomavirus 18 E6 and E7 oncogenes plays a critical role in the angiogenesis of cervical cancer (CC), including the proliferation, migration, and tube formation of vascular endothelial cells. Interfering E6/E7 increases the number of CC cell-derived microvesicles (CC-MVs). Additionally, microRNAs (miRNAs) can modulate CC angiogenesis and can be encapsulated in MVs.

Objective

We aim to investigate whether E6/E7 affects CC angiogenesis via regulating miRNAs in CC-MVs.

Methods

CC-MVs were isolated from a CC cell line (HeLa) which were transfected with small interfering RNAs (siRNAs) against E6/E7 or co-transfected with miR-377 mimics/inhibitors. The expression of several miRNAs in CC-MVs was detected using quantitative real-time PCR. After co-incubating CC-MVs with human umbilical vein endothelial cells (HUVECs), cell proliferation, migration, and tube formation of HUVECs were determined using cell counting kit-8, transwell, and tube formation assays, respectively.

Results

MiR-377 was increased in E6/E7-interfering CC-MVs. Overexpressing miR-377 in CC-MVs suppressed HUVEC proliferation, migration, and tube formation. LPAR2, the cell surface G protein-coupled receptor, was the downstream target of miR-377 in HUVECs. The co-transfection of E6/E7 siRNAs and miR-377 inhibitors in CCs negated the effect of E6/E7 siRNAs on the elevation of miR-377 in CC-MVs. In HUVECs, the co-transfection of E6/E7 siRNAs and miR-377 inhibitors restored the LPAR2 expression which was reduced by the E6/E7 siRNA transfection. Meanwhile, miR-377 mimic reduced LPAR2 expression and inhibited HUVEC proliferation, migration, and tube formation, while such response was negated by LPAR2 overexpression.

Conclusion

Interfering E6/E7 increased miR-377 in CC-MVs, and overexpressing miR-377 in CC-MVs inhibited angiogenesis of HUVECs via reducing LPAR2.

MiR-4458/human antigen R (HuR) modulates PBX3 mRNA stability in melanoma tumorigenesis

Melanoma, a malignancy of the melanocyte, is characterized as the most fatal skin cancer with an increasing incidence. Of note, in spite of great attempts made for better treatment, the therapeutic outcome is barely satisfactory. Abnormal expression of microRNAs (miRNAs) acting as oncogenes or tumor suppressor genes, is frequently implicated in multiple human cancers, including melanoma. Here, we found that miRNA-4458, a reportedly tumor-suppressive miRNA in several cancers, was downregulated in melanoma cells. Besides, our findings indicated that microRNA-4458 (miR-4458) hindered cell proliferation and migration, yet induced apoptosis in melanoma. Mechanical interaction of miR-4458 and PBX3 mRNA, thereby inhibiting PBX3 expression in melanoma cells, was also presented in this work. Human antigen R (HuR) was reported to be greatly upregulated in diverse cancers and HuR-dependent stabilization of target gene contributed a lot to tumor progression. In this study, it revealed the stabilization of PBX3 mRNA by HuR, thereby boosting PBX3 expression. Lastly, we concluded that miR-4458 and HuR modulated the expression of PBX3 in a competitive manner in melanoma tumorigenesis, which might yield a novel insight into the molecular pathogenesis of melanoma.

circ-BIRC6, a circular RNA, promotes hepatocellular carcinoma progression by targeting the miR-3918/Bcl2 axis

Circular (circ)RNA is a special type of endogenous RNA consisting of a covalently closed loop structure without 5' to 3' polarity and a polyadenylated tail. Accumulating evidence suggests that circRNAs play important roles in the development and progression of human cancers. However, the role of circRNAs in the progression of hepatocellular carcinoma (HCC) is largely unknown. This was addressed in the present study using high-throughput sequencing to identify aberrantly expressed circRNAs in HCC patient tissue and cell lines. We found that circ-baculoviral IAP repeat-containing (BIRC)6 was upregulated in HCC tissue samples and cells; this was associated with the overall survival of HCC patients. circ-BIRC6 knockdown reduced HCC cell proliferation, migration, and invasion and enhanced their apoptosis. Additionally, circ-BIRC6 overexpression negatively regulated the expression of microRNA miR-3918, which was identified as an inhibitor of B cell lymphoma (Bcl)2. The tumor-suppressive effect of circ-BIRC6 deletion was abrogated by inhibiting miR-3918. These results indicate that circ-BIRC6 functions as a competing endogenous RNA that regulates Bcl2 expression by sponging miR-3918, and may serve as a prognostic biomarker and therapeutic target for the treatment of HCC.

microRNAs: New prognostic, diagnostic, and therapeutic biomarkers in cervical cancer

Cervical cancer is as a kind of cancer beginning from the cervix. Given that cervical cancer could be observed in women who infected with papillomavirus, regular oral contraceptives, and multiple pregnancies. Early detection of cervical cancer is one of the most important aspects of the therapy of this malignancy. Despite several efforts, finding and developing new biomarkers for cervical cancer diagnosis are required. Among various prognostic, diagnostic, and therapeutic biomarkers, miRNA have been emerged as powerful biomarkers for detection, treatment, and monitoring of response to therapy in cervical cancer. Here, we summarized various miRNAs as an employable platform for prognostic, diagnostic, and therapeutic biomarkers in the treatment of cervical cancer.

Elevated SLC6A6 expression drives tumorigenesis and affects clinical outcomes in gastric cancer

AIM

To assess SLC6A6 expression in gastric cancer, its correlation with patients' clinicopathological features and survival, and the possible epigenetic regulation mechanism.

METHODS

Expression profiles and methylation data were obtained from the Gene Expression Omnibus database and the Cancer Genome Atlas. The SLC6A6's protein level were obtained from the Human Protein Atlas. Correlations between SLC6A6 expression and clinicopathological features were assessed using the χ² test, and survival by the Kaplan-Meier analysis. By analyzing methylation data, the mechanisms of SLC6A6 dysregulation were investigated.

RESULTS

SLC6A6 expression was higher in gastric cancer, and indicated poor prognosis. Low-methylation levels were significantly related to high SLC6A6 expression.

CONCLUSION

SLC6A6 may be a potential prognostic marker and therapeutic target. Hypomethylation contributes to SLC6A6 upregulation in gastric cancer.

[Over-expression of miR-519d alters gene expression profiles of cervical cancer SiHa cells]

OBJECTIVE

To investigate the alterations in gene expression profiles of cervical cancer cell line SiHa over-expressing miR-519d.

METHODS

SiHa cells were transfected with a miR-519d mimic or a negative control (NC) and the changes in gene expression profiles were examined using NimbleGen human gene expression microarray. Bioinformatics approaches based on the microarray data were used to identify the targeted genes of miR-519d. Real-time quantitative PCR was employed to confirm the expression of the potential target genes.

RESULTS

A total of 5172 genes were found to be differentially expressed in SiHa cells over-expressing miR-519d, including 2476 up-regulated and 2796 down-regulated genes. We identified 164 potential target genes of miR-519d, and their functions were predicted using Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) biological pathway analysis, and STRING database and pSTIING were used to search the key nodes in the protein-protein interactions and transcriptional regulatory networks in cancer. Real-time quantitative PCR confirmed the differential expressions of several candidate target genes.

CONCLUSIONS

Over-expression of miR-519d alters gene expression profiles in SiHa cells. The 164 target genes of miR-519d we identified may provide insights into the role of miR-519d in cervical tumorigenesis.

Screening of exosomal miRNAs derived from subcutaneous and visceral adipose tissues: Determination of targets for the treatment of obesity and associated metabolic disorders

Exosomal micro (mi)RNAs have been suggested to have important roles in abdominal obesity, and to be associated with metabolic alterations via posttranscriptional regulation of target genes. However, exosomal miRNA profiles in subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) have rarely been investigated. In the present study, microarray data were obtained from the Gene Expression Omnibus database with the following accession numbers: GSE68885 (exosomal miRNAs in SAT obtained from seven patients with obesity and five lean patients), GSE50574 (exosomal miRNAs in VAT obtained from seven patients with obesity and five lean patients) and GSE29718 [mRNAs in SAT (obtained from seven patients with obesity and eight lean patients) and VAT (obtained from three patients with obesity and two lean patients)]. Differentially expressed (DE)‑miRNAs and differentially expressed genes (DEGs) were identified using the Linear Models for Microarray Data method, and mRNA targets of DE‑miRNAs were predicted using the miRWalk2.0 database. Potential functions of DE‑miRNA target genes were determined using the Database for Annotation, Visualization and Integrated Discovery. As a result, 10 exosomal DE‑miRNAs were identified in SAT between patients with obesity and lean patients, while 58 DE‑miRNAs were identified in VAT between patients with obesity and lean patients. miRNA (miR)‑4517 was revealed to be a downregulated exosomal miRNA between SAT and VAT, while the other DE‑miRNAs were SAT‑(e.g. hsa‑miR‑3156‑5p and hsa‑miR‑4460) or VAT‑(e.g. hsa‑miR‑582‑5p, hsa‑miR‑566 and miR‑548) specific. Following overlapping with the target genes of DE‑miRNAs, only one DEG [cluster of differentiation 86 (CD86)] was identified in SAT samples, whereas 25 DEGs (e.g. fibroblast growth factor 2 (FGF2), FOS like 2, AP‑1 transcription factor subunit (FOSL2); and adenosine monophosphate deaminase 3 (AMPD3)] were identified in VAT samples. CD86 was revealed to be regulated by hsa‑miR‑3156‑5p; whereas FGF2, FOSL2 and AMPD3 were revealed to be regulated by hsa‑miR‑582‑5p, hsa‑miR‑566 and miR‑548, respectively. Functional enrichment analysis demonstrated that these target genes may be associated with inflammation. In conclusion, exosomal miRNAs may represent underlying therapeutic targets for the treatment of abdominal obesity and metabolic disorders via regulation of inflammatory genes.

Long non-coding RNA BCYRN1 promotes the proliferation and metastasis of cervical cancer via targeting microRNA-138 in vitro and in vivo

Cervical cancer is one of the most malignant types of tumor and the fourth leading cause of cancer-associated mortality in females worldwide. High expression of brain cytoplasmic RNA 1 (BCYRN1) has been detected in various tumors. The present study aimed to investigate the effect of BCYRN1 in the viability and motility of cervical cancer, and the relevant mechanism. The results demonstrated that BCYRN1 was upregulated in cervical cancer tissues compared with normal tissues. Elevated levels of BCYRN1 were also detected in three human cervical cancer cell lines (SiHa, HeLa and CaSki) compared with non-cancerous ectocervical epithelial cell line (Ect1/E6E7). The expression of BCYRN1 was suppressed following transfection with small interfering RNA (siRNA) in HeLa cells. The silence of BCYRN1 significantly reduced cell viability and motility. Furthermore, microRNA (miR)-138 was predicted as a direct target of BCYRN1 and the expression of miR-138 was elevated in HeLa cells transfected with BCYRN1 siRNA. Subsequently, elevated levels of miR-138 were suppressed by transfection with miR-138 inhibitor in HeLa cells pretreated with BCYRN1 siRNA. The targeting association between BCYRN1 and miR-138 was supported by luciferase reporter assays. Additionally, BCYRN1 siRNA partially counteracted the effect of miR-138 inhibitor on promoting cell viability and mobility in HeLa cells. Finally, the in vivo experiment verified that BCYRN1 siRNA was able to prevent tumor growth, and reduced the expression of migration marker proteins metalloproteinase 2 and vascular endothelial cell growth factor, with enhanced expression levels of miR-138. These results suggest that lncRNA BCYRN1 promotes the proliferation and invasion of cervical cancer via targeting miR-138.

MicroRNA Expression Profile in the Prenatal Amniotic Fluid Samples of Pregnant Women with Down Syndrome

Background:

Down syndrome, which is the most common human chromosomal anomaly that can affect people of any race and age, can be diagnosed prenatally in most cases. Prenatal diagnosis via culture method is time-consuming; thus, genetic analysis has thus been introduced and is continually being developed for rapid prenatal diagnosis. For this reason, the effective use of microRNA profiling for the rapid analysis of prenatal amniotic fluid samples for the diagnosis of Down syndrome was investigated.

Aims:

To evaluate the expression levels of 14 microRNAs encoded by chromosome 21 in amniotic fluid samples and their utility for prenatal diagnosis of Down syndrome.

Study Design:

Case-control study.

Methods:

We performed invasive prenatal testing for 56 pregnant women; 23 carried fetuses with Down syndrome, and 33 carried fetuses with a normal karyotype. Advanced maternal age and increased risk for Down syndrome in the screening tests were indications for invasive prenatal testing. The age of gestation in the study and control groups ranged between 17 and 18 weeks. The expression levels of microRNA were measured by real-time polymerase chain reaction.

Results:

The expression levels of microRNA-125b-2, microRNA-155, and microRNA-3156 were significantly higher in the study group than in the control group.

Conclusion:

The presence of significantly dysregulated microRNAs may be associated with either the phenotype or the result of abnormal development. Further large-scale comparative studies conducted in a variety of conditions may bring novel insights in the field of abnormal prenatal conditions.

Upregulation of MicroRNA-4262 Targets Kaiso (ZBTB33) to Inhibit the Proliferation and EMT of Cervical Cancer Cells

More and more studies have reported that dysregulation of microRNAs (miRNAs) leads to the proliferation and EMT of multiple cancers. Recently, several reports have demonstrated that dysregulation of miR-4262 occurs in numerous cancers. However, its role and precise mechanism in human cervical cancer (CC) have not been well clarified. Hence, this study aimed to explore the biological roles and precise mechanisms of miR-4262 in CC cell lines. The level of miR-4262 was found to be significantly decreased in CC tissues and cell lines. Moreover, decreased expression of miR-4262 was closely related to increased expression of Kaiso (ZBTB33), which belongs to the BTB/POZ family, in CC tissues and cell lines. The proliferation and EMT of CC cells were inhibited by a miR-4262 mimic. However, downregulation of miR-4262 enhanced the proliferation and EMT of CC cells. Next, bioinformatics analysis predicted that miR-4262 might directly target the Kaiso gene. Besides, luciferase reporter assay had confirmed this result. Moreover, introduction of Kaiso in CC cells partially blocked the effects of miR-4262 mimic. In conclusion, miR-4262 suppressed the proliferation and EMT of CC cells by directly downregulating Kaiso.

MiR-218 suppresses the metastasis and EMT of HCC cells via targeting SERBP1

Hepatocellular carcinoma (HCC) is the leading cause of cancer-related deaths worldwide. Although many efforts for treating HCC have been made, the survival rate remains unsatisfied. Accumulating evidence indicates that microRNA-218 (miR-218) functions as a tumor suppressor and involves in many biological processes such as tumor initiation, development, and metastasis in certain types of human cancers. However, the potential function and underlying molecular mechanism of miR-218 in HCC still remains to be elucidated. Since HCC is a genetic disease, exploring the mechanisms of the pathogeny and integration are essential for the discovery of novel treatment targets for HCC. Therefore, the aim of the present study was to investigate the abnormal expression level of miR-218 in clinical HCC tissues and HCC cells, and to evaluate its function and underlying mechanisms in HCC. Our results revealed that miR-218 expression was significantly downregulated in HCC tissues and cell lines. Gain-of-function and loss-of-function assays indicated that forced expression of miR-218 in HCC cells inhibited cell migration/invasion and reversed epithelial-mesenchymal transition (EMT) to mesenchymal-epithelial transition (MET), while deletion of miR-218 promoted cell migration/invasion and contributed to the EMT phenotype formation. Bioinformatics analysis and luciferase reporter assay confirmed that serpine mRNA binding protein 1 (SERBP1) was a target gene of miR-218 and rescue assay further confirmed that SERBP1 involved in the function of miR-218 in HCC. All these results suggested that miR-218/SERBP1 signal pathway could inhibit the malignant phenotype formation and that targeting this pathway may be a potential novel way for HCC therapeutics.