MicroRNAs 125a and 125b inhibit ovarian cancer cells through post-transcriptional inactivation of EIF4EBP1

Mechanisms of apoptosis-related non-coding RNAs in ovarian cancer: a narrative review

Ovarian cancer remains a major challenge in oncology due to its complex biology and late-stage diagnosis. Recent advances in molecular biology have highlighted the crucial role of non-coding RNAs (ncRNAs) in regulating apoptosis and cancer progression. NcRNAs, including microRNAs, long non-coding RNAs, and circular RNAs, have emerged as significant players in the molecular networks governing ovarian cancer. Despite these insights, the precise mechanisms by which ncRNAs influence ovarian cancer pathology are not fully understood. This complexity, combined with the heterogeneity of the disease and the development of treatment resistance, poses substantial obstacles to effective therapeutic development. Additionally, the lack of reliable early detection methods further complicates treatment strategies. This manuscript reviews the current state of research on ncRNAs in ovarian cancer, discusses the challenges in translating these findings into clinical applications, and outlines potential future directions. Emphasis is placed on the need for integrated approaches to unravel the intricate roles of ncRNAs, improve early detection, and develop personalized treatment strategies to address the diverse and evolving nature of ovarian cancer. While these findings provide valuable insights, it is crucial to recognize that many results are based on preclinical studies and require further validation to establish their clinical applicability.

Olaparib increases chemosensitivity by upregulating miR-125a-3p in ovarian cancer cells

OBJECTIVE

Ovarian cancer is associated with the highest mortality rate among all malignant gynecological tumors. PolyADP-ribose polymerase (PARP) inhibitor maintenance therapy is the standard treatment strategy for this type of cancer, and olaparib is a widely used oral PARP inhibitor for tumors with BRCA mutations. The present study aimed to investigate the effects of olaparib in non-BRCA-mutated ovarian cancer and the potential mechanisms involved.

METHODS

The antitumor effect of cisplatin alone or in combination with olaparib was analyzed in an ovarian cancer subcutaneous transplantation tumor model in nude mice. Furthermore, the differences in microRNA (miRNA) expression levels were analyzed using miRNA arrays. In addition, the effects of miR-125a-3p on the proliferation of non-BRCA-mutated (A2780 and OVCAR-3) ovarian cancer cells were detected using A Cell Counting Kit-8 and changes in the cell cycle were detected using flow cytometry. Furthermore, SPiDER-βGal was used to detect expression changes in cellular senescence, and the expression of DNA damage repair proteins was detected using western blot analysis.

RESULTS

The results revealed that cisplatin plus olaparib significantly reduced tumor volume in mice subjected to subcutaneous tumor transplantation, and the expression of miR-125a-3p significantly increased with this treatment combination. The overexpression of miR-125a-3p could inhibit cell migration, invasion and induces cell cycle arrest.

CONCLUSION

On the whole, the present study demonstrates that the increased expression of miR-125a-3p induces DNA damage and senescence in ovarian cancer cells, which enhances the therapeutic sensitivity.

Evolving landscape of detection and targeting miRNA/epigenetics for therapeutic strategies in ovarian cancer

Ovarian cancer (OC) accounts for the highest mortality rates among all gynecologic malignancies. The high mortality of OC is often associated with delayed detection, prolonged latency, enhanced metastatic potential, acquired drug resistance, and frequent recurrence. This review comprehensively explores key aspects of OC, including cancer diagnosis, mechanisms of disease resistance, and the pivotal role of epigenetic regulation, particularly by microRNAs (miRs) in cancer progression. We highlight the intricate regulatory mechanisms governing miR expression within the context of OC and the current status of epigenetic advancement in the therapeutic development and clinical trial progression. Through network analysis we elucidate the regulatory interactions between dysregulated miRs in OC and their targets which are involved in different signaling pathways. By exploring these interconnected facets and critical analysis, we endeavor to provide a nuanced understanding of the molecular dynamics underlying OC, its detection and shedding light on potential avenues for miRs and epigenetics-based therapeutic intervention and management strategies.

Prediction of Distant Metastases in Patients with Kidney Cancer Based on Gene Expression and Methylation Analysis

Clear cell renal cell carcinoma (ccRCC) is the most common and aggressive histological type of cancer in this location. Distant metastases are present in approximately 30% of patients at the time of first examination. Therefore, the ability to predict the occurrence of metastases in patients at early stages of the disease is an urgent task aimed at personalized treatment. Samples of tumor and paired histologically normal kidney tissue from patients with metastatic and non-metastatic ccRCC were studied. Gene expression was analyzed using real-time PCR. The level of gene methylation was evaluated using bisulfite conversion followed by quantitative methylation-specific PCR. Two groups of genes were analyzed in this study. The first group includes genes whose expression is significantly reduced during metastasis: CA9, NDUFA4L2, EGLN3, and BHLHE41 (p < 0.001, ROC analysis). The second group includes microRNA genes: MIR125B-1, MIR137, MIR375, MIR193A, and MIR34B/C, whose increased methylation levels are associated with the development of distant metastases (p = 0.002 to <0.001, ROC analysis). Based on the data obtained, a combined panel of genes was formed to identify patients whose tumors have a high metastatic potential. The panel can estimate the probability of metastasis with an accuracy of up to 92%.

Involvement of microRNA miR-125b in the control of porcine ovarian cell functions

The existing knowledge of the involvement of miR-125b in the control of ovarian functions is insufficient. To evaluate the role of miR-125b in the control of basic porcine ovarian granulosa cell functions, we examined the upregulation (using miR-125b mimics) and downregulation (using miR-125b inhibitor) of this miR-125b. Expression levels of miR-125b, viability, proliferation (expression and accumulation of PCNA and cyclin B1), the proportion of proliferative active cells, apoptosis (expression and accumulation of bax and caspase 3), the proportion of cells containing DNA fragmentation, steroid hormones, IGF-I, oxytocin, and prostaglandin E2 release were analysed by RT-qPCR, Trypan blue exclusion test, quantitative immunocytochemistry, XTT and TUNEL assays, and ELISA. Transfection of cells with miR-125b mimics decreased cell viability, proliferation, and the release of progesterone, testosterone, estradiol, and oxytocin, but stimulated apoptosis and prostaglandin E2 output. Transfection of cells with miR-125b inhibitor had the opposite effect. Moreover, it prevented the effects of miR-125b mimics. Our observations suggest that miR-125b is a potent physiological inhibitor of granulosa ovarian cell functions - cell cycle, apoptosis, and secretory activity.

The long non-coding RNA PVT1 promotes tumorigenesis of cutaneous squamous cell carcinoma via interaction with 4EBP1

The long non-coding RNA (lncRNA) plasmacytoma variant translocation 1 (PVT1) plays an oncogenic role in multiple cancers due to its high expression. However, the expression and associated regulatory mechanisms of PVT1 in cutaneous squamous cell carcinoma (cSCC) remain unclear. Our results revealed that PVT1 was highly upregulated in cSCC tissues and cSCC cell lines. To determine the functional role of PVT1 in cSCC, we constructed a stable knockdown cell model of PVT1 in the A431 and COLO16 cell lines using a lentiviral approach. Xenograft tumor experiments of nude mice in vivo, and colony formation, CCK-8, and EdU assays in vitro demonstrated that knockdown of PVT1 could widely suppress cell proliferation in vivo and in vitro. In addition, PVT1 knockdown induced cell cycle arrest and promoted apoptosis, as detected by flow cytometry analysis. Wound healing and transwell assays revealed that PVT1 knockdown significantly inhibited the migration and invasion of CSCC cell lines. To gain insight into the tumorigenic mechanism and explore the potential target molecules of PVT1, we employed label-free quantitative proteomic analysis. The GO, KEGG enrichment, and protein-protein interaction (PPI) networks suggested that 4E-binding protein 1 (4EBP1) is the possible downstream target effector of PVT1, which was validated by western blot analysis. PVT1 silencing markedly decreased 4EBP1 protein expression levels and directly bound 4EBP1 in the cytoplasm of cSCC cells. 4EBP1 overexpression counteracted the effects of PVT1 knockdown on tumorigenesis in cSCC cells, including cell proliferation, apoptosis, migration, and invasion. Our findings provide strong evidence that PVT1 is an oncogene which plays a role in tumorigenesis of cSCC, that PVT1 may interact with 4EBP1 in the cytoplasm as an underlying mechanism in cSCC carcinogenesis, and that PVT1 combined with 4EBP1 may serve as a potential new therapeutic target for cSCC.

MicroRNA miR-125b can suppress ovarian granulosa cell functions: Interrelationships with FSH

This study aimed to evaluate the involvement of miR-125b and its interrelationship with follicle-stimulating hormone (FSH) in the control of basic ovarian granulosa cell functions. The effect of miR-125b mimics on basic functions of porcine ovarian granulosa cells cultured with and without FSH, and the effect of FSH on the expression of endogenous miR-125b was examined. Expression levels of miR-125b, viability, proliferation (accumulation of PCNA and cyclin B1), apoptosis (accumulation of bax and caspase 3), the accumulation of FSH receptors (FSHR), steroid hormones, insulin-like growth factor I (IGF-I), oxytocin, and prostaglandin E2 release were analysed by reverse transcription-quantitative polymerase chain reaction, Trypan blue exclusion test, quantitative immunocytochemistry, and ELISA. Transfection of cells with miR-125b mimics inhibited cell viability, proliferation, apoptosis, the occurrence of FSHR, progesterone, testosterone, estradiol, and oxytocin release but stimulated prostaglandin E2 output. FSH promoted cell viability, proliferation, steroid hormones, IGF-I, oxytocin, and prostaglandin E2 output and reduced the expression of miR-125b and apoptosis. Furthermore, miR-125b mimics supported the effect of FSH on the release of estradiol, IGF-I, and prostaglandin E2, and inverted FSH influence on cell viability, proliferation, apoptosis, progesterone, and testosterone output. FSH supported both inhibitory and stimulatory action of miR-125b on ovarian cell functions. Present observations indicate that: miR-125b can be involved in the control of basic ovarian functions and that miR-125b and FSH are antagonists in their actions on ovarian cell functions. The ability of FSH to reduce miR-125b expression and the ability of miR-125b mimics to decrease the occurrence of FSHR and to modify FSH effects indicate the existence of the self-inhibiting FSH-miR-125b axis and that miR-125b can mediate the actions of FSH on ovarian cells.

Modulation of AKT Pathway-Targeting miRNAs for Cancer Cell Treatment with Natural Products

Many miRNAs are known to target the AKT serine-threonine kinase (AKT) pathway, which is critical for the regulation of several cell functions in cancer cell development. Many natural products exhibiting anticancer effects have been reported, but their connections to the AKT pathway (AKT and its effectors) and miRNAs have rarely been investigated. This review aimed to demarcate the relationship between miRNAs and the AKT pathway during the regulation of cancer cell functions by natural products. Identifying the connections between miRNAs and the AKT pathway and between miRNAs and natural products made it possible to establish an miRNA/AKT/natural product axis to facilitate a better understanding of their anticancer mechanisms. Moreover, the miRNA database (miRDB) was used to retrieve more AKT pathway-related target candidates for miRNAs. By evaluating the reported facts, the cell functions of these database-generated candidates were connected to natural products. Therefore, this review provides a comprehensive overview of the natural product/miRNA/AKT pathway in the modulation of cancer cell development.

METTL3-mediated m6A modification of has_circ_0007905 promotes age-related cataract progression through miR-6749-3p/EIF4EBP1

Many cases of blindness are caused by age-related cataracts (ARCs). N6-methyladenosine (m6A)-modified circRNA widely participates in disease progression. However, the role of m6A modification of circRNA in ARC is unclear. We mined and elucidated the functions and mechanisms of key circRNAs with m6A modification involved in ARC progression. The GSE153722 dataset was used to mine m6A-mediated key circRNA. Loss-of-function assays and rescue assays were used to explore the effect and mechanism of circRNA on ARC cell proliferation and apoptosis. Has_circ_0007905 was a hypermethylated and upregulated expression in the ARC group relative to the control group both in vivo and in vitro. Silencing of has_circ_0007905 promoted proliferation and inhibited the apoptosis of HLE-B3 cells. METTL3 was upregulated in HLE-B3 cells after ARC modeling and had four binding sites with has_circ_0007905 and a mediated m6A modification of has_circ_0007905. Proliferation was significantly inhibited and apoptosis of HLE-B3 cells was facilitated by METTL3 overexpression, whereas these effects were prevented by has_circ_0007905 silencing. Silencing of has_circ_0007905 led to an alteration in the transcriptome landscape. Differentially expressed genes were mainly involved in immune-related processes and pathways. EIF4EBP1 overexpression promoted apoptosis and suppressed proliferation, and also significantly reversed effects of has_circ_0007905 silencing. Moreover, miR-6749-3p significantly decreased the luciferase activities of wild type plasmids with both of has_circ_0007905 and EIF4EBP1. MiR-6749-3p inhibitor blocked elevation in proliferation and reduced EIF4EBP1 expression and apoptosis conferred by has_circ_0007905 silencing. We reveal for the first time that the commitment of ARC progression is guided by METTL3/has_circ_0007905/miR-6749-3p/EIF4EBP1 axis, and the results provide new insights into ARC pathology.

The Potential of MicroRNAs as Clinical Biomarkers to Aid Ovarian Cancer Diagnosis and Treatment

Ovarian cancer is a commonly diagnosed malignancy in women. When diagnosed at an early stage, survival outcomes are favourable for the vast majority, with up to 90% of ovarian cancer patients being free of disease at 5 years follow-up. Unfortunately, ovarian cancer is typically diagnosed at an advanced stage due to the majority of patients remaining asymptomatic until the cancer has metastasised, resulting in poor outcomes for the majority. While the molecular era has facilitated the subclassification of the disease into distinct clinical subtypes, ovarian cancer remains managed and treated as a single disease entity. MicroRNAs (miRNAs) are small (19-25 nucleotides), endogenous molecules which are integral to regulating gene expression. Aberrant miRNA expression profiles have been described in several cancers, and have been implicated to be useful biomarkers which may aid cancer diagnostics and treatment. Several preliminary studies have identified candidate tumour suppressor and oncogenic miRNAs which may be involved in the development and progression of ovarian cancer, highlighting their candidacy as oncological biomarkers; understanding the mechanisms by which these miRNAs regulate the key processes involved in oncogenesis can improve our overall understanding of cancer development and identify novel biomarkers and therapeutic targets. This review highlights the potential role of miRNAs which may be utilised to aid diagnosis, estimate prognosis and enhance therapeutic strategies in the management of primary ovarian cancer.

[MiR-125b-5 suppresses ovarian cancer cell migration and invasion by targeted downregulation of CD147]

OBJECTIVE

To investigate whether miR-125b-5p regulates biological behaviors of ovarian cancer cells by targeted regulation of CD147 expression.

METHODS

RT-qPCR was used to detect the expression of miR-125b-5p and CD147 mRNA in ovarian cancer tissues and cancer cell lines. SKOV3 cells transfected with miR-125b-5p mimic and HO8910 cells transfected with miR-125b-5p inhibitor were examined for changes in proliferation, migration and invasion using CCK-8 assay, colonyforming assay and Transwell assay. Starbase was used to predict the potential binding sites between miR-125b-5p and CD147, and double luciferase reporter gene assay was used to verify the targeting relationship. In SKOV3 cells, the effects of cotransfection with miR-125b-5p mimic and pcDNA3.1-CD147 (or pcDNA3.1) plasmid on cell proliferation, migration and invasion were assessed with CCK-8 assay and Transwell assay.

RESULTS

The expression of miR-125b-5p was significantly lowered and that of CD147 was increased in both ovarian cancer tissues and ovarian cancer cell lines (P < 0.05). Overexpression of miR-125b-5p in SKOV3 cells resulted in significantly suppressed cell proliferation, migration and invasion, while downregulation of miR-125b-5p in HO8910 cells promoted cell proliferation, migration and invasion. Bioinformatic analysis predicted that miR-125b-5p binds to CD147, which was confirmed by luciferase reporter gene assay. RT-qPCR and Western blotting showed that miR-125b-5p negatively regulated CD147 expression (P < 0.05). In SKOV3 cells, the inhibitory effects of miR-125b-5p mimic on cell proliferation, invasion and migration were significantly attenuated by co-transfection of the cells with pcDNA3.1-CD147 plasmid.

CONCLUSION

miR-125b-5p inhibits the migration and invasion of ovarian cancer cells by negatively regulating the expression of CD147.

Role of different non-coding RNAs as ovarian cancer biomarkers

Background

Among many gynecological malignancies ovarian cancer is the most prominent and leading cause of female mortality worldwide. Despite extensive research, the underlying cause of disease progression and pathology is still unknown. In the progression of ovarian cancer different non-coding RNAs have been recognized as important regulators. The biology of ovarian cancer which includes cancer initiation, progression, and dissemination is found to be regulated by different ncRNA. Clinically ncRNA shows high prognostic and diagnostic importance.

Results

In this review, we prioritize the role of different non-coding RNA and their perspective in diagnosis as potential biomarkers in the case of ovarian cancer. Summary of some of the few miRNAs involved in epithelial ovarian cancer their expression and clinical features are being provided in the table. Also, in cancer cell proliferation, apoptosis, invasion, and migration abnormal expression of piRNAs are emerging as a crucial regulator hence the role of few piRNAs is being given. Both tRFs and tiRNAs play important roles in tumorigenesis and are promising diagnostic biomarkers and therapeutic targets for cancer. lncRNA has shown a leading role in malignant transformation and potential therapeutic value in ovarian cancer therapy.

Conclusions

Hence in this review we demonstrated the role of different ncRNA that play an important role in serving strong potential as a therapeutic approach for the treatment of ovarian cancer.

EIF4EBP1 is transcriptionally upregulated by MYCN and associates with poor prognosis in neuroblastoma

Neuroblastoma (NB) accounts for 15% of cancer-related deaths in childhood despite considerable therapeutic improvements. While several risk factors, including MYCN amplification and alterations in RAS and p53 pathway genes, have been defined in NB, the clinical outcome is very variable and difficult to predict. Since genes of the mechanistic target of rapamycin (mTOR) pathway are upregulated in MYCN-amplified NB, we aimed to define the predictive value of the mTOR substrate-encoding gene eukaryotic translation initiation factor 4E-binding protein 1 (EIF4EBP1) expression in NB patients. Using publicly available data sets, we found that EIF4EBP1 mRNA expression is positively correlated with MYCN expression and elevated in stage 4 and high-risk NB patients. In addition, high EIF4EBP1 mRNA expression is associated with reduced overall and event-free survival in the entire group of NB patients in three cohorts, as well as in stage 4 and high-risk patients. This was confirmed by monitoring the clinical value of 4EBP1 protein expression, which revealed that high levels of 4EBP1 are significantly associated with prognostically unfavorable NB histology. Finally, functional analyses revealed that EIF4EBP1 expression is transcriptionally controlled by MYCN binding to the EIF4EBP1 promoter in NB cells. Our data highlight that EIF4EBP1 is a direct transcriptional target of MYCN whose high expression is associated with poor prognosis in NB patients. Therefore, EIF4EBP1 may serve to better stratify patients with NB.

Histone deacetylase HDAC2 regulates microRNA-125a expression in neuroblastoma

BACKGROUND

Neuroblastoma (NB) is an infrequent childhood malignancy of the peripheral sympathetic nervous system and is accountable for about 10% of pediatric tumors. microRNA (miR)-125a has been implicated to serve as a tumor suppressor in various cancers. Herein, we set out to ascertain whether miR-125a exerts antitumor effects in NB.

METHODS

Downregulated miRNAs were identified by miRNA microarray analysis of NB tissues and paracancerous tissues. The expression of miR-125a in NB tissues and cells was detected by reverse transcription-quantitative (RT-q) PCR, followed by prognostic analysis. Gene Ontology (GO) enrichment analysis was performed on target genes of differentially expressed miRNAs. Cell proliferation, apoptosis, and differentiation were detected by cell counting kit-8 (CCK-8), Hoechst staining, immunofluorescence, and western blot. NB cells were injected into nude mice to detect tumorigenic, apoptotic, and differentiation activities in vivo. Dual-luciferase assay and chromatin immunoprecipitation (ChIP) were carried out to verify the binding relationship between miR-125a and PHOX2B or histone deacetylases 2 (HDAC2), respectively. Finally, rescue experiments were conducted.

RESULTS

miR-125a was downregulated in NB tissues and cells, which was associated with poor prognosis. miR-125a reduced NB cell proliferation and augmented apoptosis and differentiation. NB cells with miR-125a overexpression decreased cell tumorigenesis and increased apoptosis and differentiation in xenograft tumor tissues. miR-125a targeted PHOX2B, which was highly expressed in NB tissues and cells. HDAC2, highly expressed in NB tissues and cells, repressed miR-125a transcription through histone deacetylation. Overexpression of HDAC2 or PHOX2B rescued the effects of miR-125a on NB cell proliferation, apoptosis, and differentiation.

CONCLUSION

HDAC2 inhibited miR-125a transcription through deacetylation, and miR-125a suppressed NB development through binding to PHOX2B.

circCHST15 is a novel prognostic biomarker that promotes clear cell renal cell carcinoma cell proliferation and metastasis through the miR-125a-5p/EIF4EBP1 axis

Background

Circular RNAs (circRNAs) have been indicated as potentially critical mediators in various types of tumor progression, generally acting as microRNA (miRNA) sponges to regulate downstream gene expression. However, the aberrant expression profile and dysfunction of circRNAs in human clear cell renal cell carcinoma (ccRCC) need to be further investigated. This study mined key prognostic circRNAs and elucidates the potential role and molecular mechanism of circRNAs in regulating the proliferation and metastasis of ccRCC.

Methods

circCHST15 (hsa_circ_0020303) was identified by mining two circRNA microarrays from the Gene Expression Omnibus database and comparing matched tumor versus adjacent normal epithelial tissue pairs or matched primary versus metastatic tumor tissue pairs. These results were validated by quantitative real-time polymerase chain reaction and agarose gel electrophoresis. We demonstrated the biological effect of circCHST15 in ccRCC both in vitro and in vivo. To test the interaction between circCHST15 and miRNAs, we conducted a number of experiments, including RNA pull down assay, dual-luciferase reporter assay and fluorescence in situ hybridization.

Results

The expression of circCHST15 was higher in ccRCC tissues compared to healthy adjacent kidney tissue and higher in RCC cell lines compared to normal kidney cell lines. The level of circCHST15 was positively correlated with aggressive clinicopathological characteristics, and circCHST15 served as an independent prognostic indicator for overall survival and progression-free survival in patients with ccRCC after surgical resection. Our in vivo and in vitro data indicate that circCHST15 promotes the proliferation, migration, and invasion of ccRCC cells. Mechanistically, we found that circCHST15 directly interacts with miR-125a-5p and acts as a microRNA sponge to regulate EIF4EBP1 expression.

Conclusions

We found that sponging of miR-125a-5p to promote EIF4EBP1 expression is the underlying mechanism of hsa_circ_0020303-induced ccRCC progression. This prompts further investigation of circCHST15 as a potential prognostic biomarker and therapeutic target for ccRCC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12943-021-01449-w.

Diagnostic potential of differentially regulated microRNAs among endometriosis, endometrioid ovarian cancer, and endometrial cancer

Background

There is an increased risk of developing endometrioid ovarian and endometrial cancer in patients with endometriosis and there are no definitive diagnostic biomarkers available for these three associated diseases. Therefore, we evaluated the diagnostic potential of differentially expressed microRNAs (miRNAs) from the tissue samples of endometriosis, endometrioid ovarian cancer, and endometrial cancer to establish them as biomarkers for these diseases.

Materials and Methods

Ten samples of each, i.e., endometriosis, endometrioid ovarian cancer, endometrial cancer and control healthy endometrium were enrolled after obtaining ethical clearance. Differential expression of miR-16, miR-20a, miR-99b, miR-125a, miR-143, and miR-145 and some of their target genes, i.e., vascular endothelial growth factor (VEGF), hypoxia inducible factor 1A (HIF1A), cyclooxygenase 2 (COX2), and tumor necrosis factor (TNF) were quantified using quantitative reverse transcription polymerase chain reaction. Receiver operating characteristic (ROC) curve analysis was performed to predict the diagnostic potential.

Results

miR-16 and miR-20a were significantly downregulated, whereas miR-99b, miR-125a, and miR-143 were significantly upregulated in all three diseased samples. miR-145 was significantly upregulated in endometriosis and endometrioid ovarian cancer but significantly downregulated in endometrial cancer. mRNA levels of VEGF, HIF1A, COX2, and TNF were significantly increased in all three diseased samples as compared to control samples. ROC curve analysis revealed that for endometriosis, miR-99b, and miR-125a were giving highest area under curve (AUC) (0.950 and 0.733, respectively), for endometrioid carcinoma of ovary miR-143 was giving highest AUC (0.933) and for endometrioid endometrial cancer miR-16 (AUC = 0.815), miR-99b (AUC = 0.920), and miR-145 (AUC = 0.985) were found to be best predictors.

Conclusion

These findings suggest that these miRNAs can act as good predictors and discriminators of these three diseases and might serve as potential biomarkers for them.

Interplay between DNA Methyltransferase 1 and microRNAs During Tumorigenesis

Cancer is a genetic disease resulting from genomic changes; however, epigenetic alterations act synergistically with these changes during tumorigenesis and cancer progression. Epigenetic variations are gaining more attention as an important regulator in tumor progression, metastasis and therapy resistance. Aberrant DNA methylation at CpG islands is a central event in epigeneticmediated gene silencing of various tumor suppressor genes. DNA methyltransferase 1 (DNMT1) predominately methylates at CpG islands on hemimethylated DNA substrates in proliferation of cells. DNMT1 has been shown to be overexpressed in various cancer types and exhibits tumor-promoting potential. The major drawbacks to DNMT1-targeted cancer therapy are the adverse effects arising from nucleoside and non-nucleoside based DNMT1 inhibitors. This paper focuses on the regulation of DNMT1 by various microRNAs (miRNAs), which may be assigned as future DNMT1 modulators, and highlights how DNMT1 regulates various miRNAs involved in tumor suppression. Importantly, the role of reciprocal inhibition between DNMT1 and certain miRNAs in tumorigenic potential is approached in this review. Hence, this review seeks to project an efficient and strategic approach using certain miRNAs in conjunction with conventional DNMT1 inhibitors as a novel cancer therapy. It has also been pinpointed to select miRNA candidates associated with DNMT1 regulation that may not only serve as potential biomarkers for cancer diagnosis and prognosis, but may also predict the existence of aberrant methylation activity in cancer cells.

Oleuropein reduces cisplatin resistance in ovarian cancer by targeting apoptotic pathway regulators

AIMS

Despite many attempts to treat ovarian cancer, 13,940 individuals perish annually due to this disease worldwide. Chemotherapy is the main approach to ovarian cancer treatment, but the development of drug resistance is a major obstacle to the successful treatment. Oleuropein is a phenolic ingredient with anticancer characteristics. This study was aimed at investigating the effect of oleuropein on cell viability, cisplatin resistance, and apoptosis, as well as the expression levels of miR-34a, miR-125b, miR16, miR-21, and some of their potential target genes in ovarian cancer cells.

MAIN METHODS

A2780S and A2780/CP cell lines were exposed to different concentrations of oleuropein alone or in combination with cisplatin for 48 h and 72 h. After that, the cell viability and apoptosis were evaluated using MTT assay and flow cytometry, respectively. Bioinformatics analyses were conducted using STRING database and Cytoscape software. The effect of oleuropein and/or cisplatin on the expression of miRNAs and target genes was assessed via Real-time PCR.

KEY FINDINGS

Upon treatment with oleuropein, the expression of P21, P53, and TNFRSF10B increased while that of Bcl-2 and Mcl1 decreased. Moreover, this is the 1st report of a significant decrease in the expression of miR-21 and increase in the expression of miR-34a, miR-125b, and miR16 by oleuropein and/or cisplatin in ovarian cancer cells.

SIGNIFICANCE

Altogether, these data revealed that oleuropein regulated the expression of the above-mentioned miRNAs in ovarian cancer cells, which potentially resulted in apoptosis induction, cell proliferation inhibition, and cisplatin resistance decline in ovarian cancer cells. To confirm the results of this study, it is suggested that similar experiments be performed in animal models of ovarian cancer.

Small Non-Coding-RNA in Gynecological Malignancies

Gynecologic malignancies, which include cancers of the cervix, ovary, uterus, vulva, vagina, and fallopian tube, are among the leading causes of female mortality worldwide, with the most prevalent being endometrial, ovarian, and cervical cancer. Gynecologic malignancies are complex, heterogeneous diseases, and despite extensive research efforts, the molecular mechanisms underlying their development and pathology remain largely unclear. Currently, mechanistic and therapeutic research in cancer is largely focused on protein targets that are encoded by about 1% of the human genome. Our current understanding of 99% of the genome, which includes noncoding RNA, is limited. The discovery of tens of thousands of noncoding RNAs (ncRNAs), possessing either structural or regulatory functions, has fundamentally altered our understanding of genetics, physiology, pathophysiology, and disease treatment as they relate to gynecologic malignancies. In recent years, it has become clear that ncRNAs are relatively stable, and can serve as biomarkers for cancer diagnosis and prognosis, as well as guide therapy choices. Here we discuss the role of small non-coding RNAs, i.e., microRNAs (miRs), P-Element induced wimpy testis interacting (PIWI) RNAs (piRNAs), and tRNA-derived small RNAs in gynecological malignancies, specifically focusing on ovarian, endometrial, and cervical cancer.

Integrated miRNA-mRNA Analysis Reveals Potential Biomarkers of Chemoresistance in Ovarian Cancer

The current study aimed to determine potential biomarkers related to chemoresistance in ovarian cancer and the involved signaling pathways through bioinformatics analysis. This was followed by an exploration of the related indices on the occurrence and development of chemoresistance in ovarian cancer (OC). Five miRNA/mRNA expression datasets on chemoresistance OC were obtained from the Geodatabase. The significantly different expressed miRNAs (DEMs) and differently expressed genes (DEGs) between chemoresistant OC tissues and control tissues were screened using the GEO2R online tool. Afterwards, pathway analysis was utilized to analyze the DEGs and Cytoscape with STRING 11.0 was used to visualize the protein-protein interaction (PPI) network of DEGs. Afterwards, TFmiR webserver was performed to predict the TF-miRNA-mRNA network. Finally, KM-Plotter was utilized to determine the effects of hub genes and key miRNAs on survival time. A total of 24 DEMs and 548 DEGs were screened from four different datasets on chemoresistance in OC. Seven mRNA-miRNA pairs were found. Survival analysis based on the Kaplan-Meier plotter revealed that 11 biomarkers, including hsa-miR-363, hsa-miR-125b, CDKN1N, JUN, KFL4, IGFBP3, TGFBR2, CCR5, SPP1, LOX, and MMP1, which were associated with TF-miRNA-mRNA network, were closely associated with overall survival (OS) in patients with OC (P< 0.05). The integrated genomic analysis method was successful in screening novel and important genes for the occurrence and progression of chemoresistance in OC. Moreover, this method provided valuable information for investigating chemoresistance in OC and also forms the basis for further functional research.

Essential functions of miR-125b in cancer

MicroRNAs (miRNAs) are small and highly conserved non-coding RNAs that silence target mRNAs, and compelling evidence suggests that they play an essential role in the pathogenesis of human diseases, especially cancer. miR-125b, which is the mammalian orthologue of the first discovered miRNA lin-4 in Caenorhabditis elegans, is one of the most important miRNAs that regulate various physiological and pathological processes. The role of miR-125b in many types of cancer has been well established, and so here we review the current knowledge of how miR-125b is deregulated in different types of cancer; its oncogenic and/or tumour-suppressive roles in tumourigenesis and cancer progression; and its regulation with regard to treatment response, all of which are underlined in multiple studies. The emerging information that elucidates the essential functions of miR-125b might help support its potentiality as a diagnostic and prognostic biomarker as well as an effective therapeutic tool against cancer.

Screening for functional circular RNAs using the CRISPR-Cas13 system

Circular RNAs (circRNAs) produced from back-spliced exons are widely expressed, but individual circRNA functions remain poorly understood owing to the lack of adequate methods for distinguishing circRNAs from cognate messenger RNAs with overlapping exons. Here, we report that CRISPR-RfxCas13d can effectively discriminate circRNAs from mRNAs by using guide RNAs targeting sequences spanning back-splicing junction (BSJ) sites featured in RNA circles. Using a lentiviral library that targets sequences across BSJ sites of highly expressed human circRNAs, we show that a group of circRNAs are important for cell growth mostly in a cell-type-specific manner and that a common oncogenic circRNA, circFAM120A, promotes cell proliferation by preventing the mRNA for family with sequence similarity 120A (FAM120A) from binding the translation inhibitor IGF2BP2. Further application of RfxCas13d-BSJ-gRNA screening has uncovered circMan1a2, which has regulatory potential in mouse embryo preimplantation development. Together, these results establish CRISPR-RfxCas13d as a useful tool for the discovery and functional study of circRNAs at both individual and large-scale levels.

BRDT is a novel regulator of eIF4EBP1 in renal cell carcinoma

Among all types of kidney diseases, renal cell carcinoma (RCC) has the highest mortality, recurrence and metastasis rates, which results in high numbers of tumor-associated mortalities in China. Identifying a novel therapeutic target has attracted increasing attention. Bromodomain and extraterminal domain (BET) proteins have the ability to read the epigenome, leading to regulation of gene transcription. As an important member of the BET family, bromodomain testis-specific protein (BRDT) has been well studied; however, the mechanism underlying BRDT in the regulation of RCC has not been fully investigated. Eukaryotic translation initiation factor 4E-binding protein 1 (eIF4EBP1) is a binding partner of eIF4E that is involved in affecting the progression of various cancer types via regulating gene transcription. To identify novel regulators of eIF4EBP1, an immunoprecipitation assay and mass spectrometry analysis was performed in RCC cells. It was revealed that eIF4EBP1 interacted with BRDT, a novel interacting protein. In addition, the present study further demonstrated that BRDT inhibitors PLX51107 and INCB054329 blocked the progression of RCC cells, along with suppressing eIF4EBP1 and c-myc expression. Small interfering (si) RNAs were used to knock down BRDT expression, which suppressed RCC cell proliferation and eIF4EBP1 protein expression. In addition, overexpression of eIF4EBP1 partially abolished the inhibited growth function of PLX51107 but knocking down eIF4EBP1 improved the inhibitory effects of PLX51107. Furthermore, treatment with PLX51107 or knockdown of BRDT expression decreased c-myc expression at both the mRNA and protein levels, and attenuated its promoter activity, as determined by luciferase reporter assays. PLX51107 also significantly altered the interaction between the c-myc promoter with eIF4EBP1 and significantly attenuated the increase of RCC tumors, accompanied by decreased c-myc mRNA and protein levels in vivo. Taken together, these data suggested that blocking of BRDT by PLX51107, INCB054329 or BRDT knockdown suppressed the growth of RCC via decreasing eIF4EBP1, thereby leading to decreased c-myc transcription levels. Considering the regulatory function of BET proteins in gene transcription, the present study suggested that there is a novel mechanism underlying eIF4EBP1 regulation by BRDT, and subsequently decreased c-myc in RCC, and further identified a new approach by regulating eIF4EBP1 or c-myc for enhancing BRDT-targeting RCC therapy.

Circulating and Tissue microRNAs as Biomarkers for Ovarian Cancer Prognosis

Ovarian cancer (OC) is one of the most common cancers globally with a high rate of cancer- associated mortality. OC may be classified into epithelial cell neoplasms, germ cell neoplasms and stromal cell neoplasms. The five-year survival in the early and advanced stages of disease is approximately 90% and 15%, respectively. microRNAs are short, single-stranded, non-coding ribonucleic acid (RNA). miRNAs play critical roles in post transcriptionally regulations of gene expression. miRNAs are found in different tissues and body fluids. In carcinogenesis the expression of miRNAs are altered. Recent studies have revealed that there is a relationship between alteration of miRNAs expression and the prognosis of patients with OC. The aim of this review was to summarize the findings of recent studies that have investigated the expression of circulating and tissue miRNAs as novel biomarkers in the prognosis of OC.

Roles of microRNAs in Ovarian Cancer Tumorigenesis: Two Decades Later, What Have We Learned?

Ovarian cancer is one of the top gynecological malignancies that cause deaths among females in the United States. At the molecular level, significant progress has been made in our understanding of ovarian cancer development and progression. MicroRNAs (miRNAs) are short, single-stranded, highly conserved non-coding RNA molecules (19–25 nucleotides) that negatively regulate target genes post-transcriptionally. Over the last two decades, mounting evidence has demonstrated the aberrant expression of miRNAs in different human malignancies, including ovarian carcinomas. Deregulated miRNAs can have profound impacts on various cancer hallmarks by repressing tumor suppressor genes. This review will discuss up-to-date knowledge of how the aberrant expression of miRNAs and their targeted genes drives ovarian cancer initiation, proliferation, survival, and resistance to chemotherapies. Understanding the mechanisms by which these miRNAs affect these hallmarks should allow the development of novel therapeutic strategies to treat these lethal malignancies.

The diagnostic, prognostic and therapeutic potential of circulating microRNAs in ovarian cancer

Ovarian cancer (OC) is often diagnosed at an advanced stage because of the late onset of symptoms, and this together with the lack of effective treatments, has meant it is associated with a very high mortality. The aberrant expression of MicroRNA (miRNA) contributes to the initiation and development of human tumors including OC. Several miRNAs are secreted by tumor cells and can be identified in body fluids. Serum miRNAs levels are associated with several clinical conditions, and may be used to predict prognosis and response to treatments in some cancers including OC. This review summarizes the current progresses regarding the potential applications of circulating miRNA as innovative biomarkers in OC.

The Emerging Roles of miR-125b in Cancers

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

miRNA profile in ovarian cancer

Ovarian cancer is a gynecological cancer with high mortality and a heterogeneous nature which complicates its early detection and primary prevention. Numerous studies have evaluated expression profile microRNAs (miRNAs) in tissue and serum samples of ovarian cancer patients to find appropriate biomarkers for this malignancy. Functional experiments also verified the oncogenic or suppressor effects of a number of miRNAs. miRNAs exert their role through degradation or inhibition of translation of the target mRNA. Through this regulatory function, they modulate numerous cellular processes which are ultimately associated with carcinogenesis. A number of miRNAs including miR-135a-3p, miR-200c, miR-216a and miR-340 regulate epithelial-mesenchymal transition program thus modulate invasiveness of ovarian cancer cell. Others have been shown to regulate some fundamental pathways in carcinogenesis such as mTOR and PI3K/AKT pathways. Such vast area of function of miRNAs in ovarian cancer has suggested them as putative therapeutic options for future years. In this review, we summarize the recent findings regarding the role of miRNAs in ovarian cancer pathogenesis, their application as biomarkers and the future perspectives of this research area.

Long non-coding RNA steroid receptor activator promotes the progression of endometrial cancer via Wnt/ β-catenin signaling pathway

Rationale: Steroid receptor activator (SRA), a long non-coding RNA, serves as a critical regulator of gynecologic cancer. The objective of this study was to determine biological function and clinical significance of SRA expression in endometrial cancer.

Method: We investigated whether SRA was involved in the development of endometrial cancer via binding to eukaryotic translation initiation factor 4E-binding protein 1 (EIF4E-BP1) as a transcription factor to enhance Wnt/ β-catenin signaling pathway.

Results: Expression levels of SRA were upregulated in endometrial cancer tissues compared to those in adjacent control tissues. We also found high expression of SRA in EC cells. The relationship between SRA and EIF4E-BP1 was corroborated by transfection of a luciferase reporter plasmid. In addition, SRA knockdown inhibited the expression of EIF4E-BP1 known to play a critical role in the control of protein synthesis, cell growth, and cell survival, thus promoting tumourigenesis and epithelial-mesenchymal transition (EMT) important for cell motility and metastasis. Consistently, immunostaining and western blotting analysis showed that expression levels of β-catenin and 4EBP1 in the nucleus were significantly decreased by SRA knockdown but increased by SRA over-expression.

Conclusions: These results suggest that SRA is involved in proliferation, migration, and invasion of endometrial cancer cells by increasing the expression of EIF4E-BP1 and activity of Wnt/ β-catenin signaling. These findings indicate that SRA might be a novel biomarker for predicting recurrence and prognosis. It might also serve as a promising therapeutic target in endometrial cancer.

Angioregulatory microRNAs in Colorectal Cancer

Colorectal cancer (CRC) is one of the leading causes of cancer mortality. Angiogenesis is a rate-determining step in CRC development and metastasis. The balance of angiogenic and antiangiogenic factors is crucial in this process. Angiogenesis-related genes can be regulated post-transcriptionally by microRNAs (miRNAs) and some miRNAs have been shown to shuttle between tumor cells and the tumor microenvironment (TME). MiRNAs have context-dependent actions and can promote or suppress angiogenesis dependent on the type of cancer. On the one hand, miRNAs downregulate anti-angiogenic targets and lead to angiogenesis induction. Tumor suppressor miRNAs, on the other hand, enhance anti-angiogenic response by targeting pro-angiogenic factors. Understanding the interaction between these miRNAs and their target mRNAs will help to unravel molecular mechanisms involved in CRC progression. The aim of this article is to review the current literature on angioregulatory miRNAs in CRC.

MicroRNA-125 in immunity and cancer

MicroRNAs (miRNAs) are small non-coding RNAs that play a wide variety of critical roles in different biological processes by post-transcriptionally regulating gene expression. They access diverse regulatory pathways during various stages of cellular differentiation, growth, and apoptosis, and can contribute to both normal and diseased functions. One important family of miRNAs involved in these functions is the miR-125 family (miR-125a and miR-125b). Investigations have been made to increasingly uncover the mechanisms by which the miR-125 family regulates normal homeostasis and growth in a variety of cell types including immune cells, and how dysregulation of miR-125a and miR-125b can lead to disease pathogenesis and tumorigenesis. In this review, we summarize what is currently known about miR-125a and miR-125b, mainly focusing on their roles in immune cell development and function as well as tumor suppression and promotion.

HULC functions as an oncogene in ovarian carcinoma cells by negatively modulating miR-125a-3p

The aberrant expression of highly upregulated in liver cancer (HULC) has been reported to participate in ovarian cancer development. A recent research has revealed that HULC-modulated microRNAs (miRNAs) in tumorigenesis. To confirm the functions of HULC on tumorigenesis of ovarian, we explored the effects of HULC expression on ovarian cancer cell development, as well as the underlying mechanism. We transfected SKOV3 cells with pEX-HULC, sh-HULC, and miR-125a-3p mimic as well as their corresponding negative controls (pEX-3, sh-NC, and NC) to alter the expression of HULC and miR-125a-3p, which were analyzed by quantitative reverse transcription PCR (qRT-PCR). Expression of proteins associated with cell cycle, apoptosis, and signaling pathways was determined by Western blot assay. The proliferation, apoptosis, migration, and invasion were explored by bromodeoxyuridine (BrdU) incorporation assay, Annexin V-fluorescein isothiocyanate (FITC)/propidium iodide (PI) method, and transwell migration and invasion assays, respectively. HULC overexpression promoted proliferation, migration, and invasion, while inhibited apoptosis of SKOV3 cells. In addition, HULC negatively regulated the expression of miR-125a-3p. Besides, miR-125a-3p mimic reversed the effects of HULC on proliferation, migration, and invasion as well as apoptosis of SKOV3 cells. Moreover, we found that HULC enhanced phosphorylated expression of regulatory factors in phosphatidylinositol 3 kinase/protein kinase B/mammalian targets of rapamycin (PI3K/AKT/mTOR) signaling pathway by downregulating expression of miR-125a-3p. Overexpression of HULC promoted ovarian carcinoma development by activating PI3K/AKT/mTOR signaling pathway via downregulating miR-125a-3p.

Comprehensive profiling of JMJD3 in gastric cancer and its influence on patient survival

Histone methylation is thought to control the regulation of genetic program and the dysregulation of it has been found to be closely associated with cancer. JMJD3 has been identified as an H3K27 demethylase and its role in cancer development is context specific. The role of JMJD3 in gastric cancer (GC) has not been examined. In this study, JMJD3 expression was determined. The prognostic significance of JMJD3 and its association with clinical parameters were evaluated. JMJD3 dysregulation mechanism and targets were analyzed. The effect of JMJD3 mutation was determined by functional study. Results showed that JMJD3 was overexpressed in different patient cohorts and also by bioinformatics analysis. High JMJD3 expression was correlated with shortened overall survival in patients with GC and was an independent prognosis predictor. Genetic aberration and DNA methylation might be involved in the deregulation of JMJD3 in GC. Downstream network of JMJD3 was analyzed and several novel potential targets were identified. Furthermore, functional study discovered that both demethylase-dependent and demethylase-independent mechanisms were involved in the oncogenic role of JMJD3 in GC. Importantly, histone demethylase inhibitor GSK-J4 could reverse the oncogenic effect of JMJD3 overexpression. In conclusion, our study report the oncogenic role of JMJD3 in GC for the first time. JMJD3 might serve as an important epigenetic therapeutic target and/or prognostic predictor in GC.

miR-125a/b inhibits tumor-associated macrophages mediated in cancer stem cells of hepatocellular carcinoma by targeting CD90

Cancer stem cells promote tumorigenesis and progression of hepatocellular carcinoma (HCC). Recently, emerging evidence indicates tumor-associated macrophages (TAMs) play an important role in tumor progression. However, TAMs often occurs with unknown mechanisms. As an important mediator in intercellular communications, exosomes secreted by host cells mediate the exchange of genetic materials and proteins, which involves tumor aggressiveness. The aim of the study was to investigate whether exosomes derived from TAMs mediate stem cell properties in HCC. TAMs were isolated from the tissues of HCC. microRNA (miRNA) expression profiles of TAMs were analyzed using miRNA microarray. In vitro cell coculture was further conducted to investigate the crosstalk between TAMs and tumor cells mediated by TAMs exosomes. In this study, we showed that TAMs exosomes promote HCC cell proliferation and stem cell properties. Using miRNA profiles assay, we identified significantly lower levels of miR-125a and miR-125b in exosomes and cell lysate isolated from TAMs. Functional studies revealed that the HCC cells were treated with TAM exosomes or transfected with miR-125a/b suppressed cell proliferation and stem cell properties by targeting CD90, a stem cell marker of HCC stem cells. The study indicated that miR-125a/b targeting CD90 played important roles in cancer stem cells of HCC.

Pathogenic genes related to the progression of actinic keratoses to cutaneous squamous cell carcinoma

BACKGROUND

Actinic keratosis (AK) is an incipient form of cutaneous squamous cell carcinoma (cSCC). Understanding the differentially expressed genes between AK and cSCC states would be helpful for the early prevention and treatment of cSCC. Consequently, this study aimed to screen the key genes associated with the progression of AK to cSCC.

METHODS

The microarray dataset GSE45216 was downloaded from the Gene Expression Omnibus, which included 10 AK and 30 primary cSCC skin tissue samples. Differentially expressed genes (DEGs) in cSCC samples, compared to those in AK, were identified. Gene co-expression relationships were investigated, followed by miRNA prediction. The potential functions of the co-expressed genes were predicted by gene ontology (GO) and pathway enrichment analyses. In addition, the transcription factors and drug molecules, significantly related to the co-expressed genes, were obtained.

RESULTS

A total of 320 DEGs were identified in the cSCC group, relative to the AK group. Moreover, 96 DEGs and 2,390 connecting edges were identified in the gene co-expression network. An miRNA regulatory network was constructed, including 96 DEGs and 16 miRNAs. In addition, three co-expression network modules were obtained; EIF4EBP1, SNX17, PRPF4, NXT1, and UBA5 were significant nodes in the modules.

CONCLUSIONS

EIF4EBP1, SNX17, PRPF4, NXT1, and UBA5 may be the pathogenic genes contributing to the development of cSCC from AK.

Correlation Between the Hepatic Expression of Human MicroRNA hsa-miR-125a-5p and the Progression of Fibrosis in Patients With Overt and Occult HBV Infection

AIMS

To evaluate the correlation between the hepatic expression pattern of hsa-miR-125a-5p and HBV-DNA and the progression of fibrosis in patients with overt or occult HBV infection.

METHODS

We enrolled all the HBsAg-positive treatment naive patients (overt HBV group) and all the HBsAg-negative patients with hepatocellular carcinoma and with a positive HBV-DNA in their hepatic tissue (occult HBV group), who underwent a diagnostic liver biopsy between April 2007 and April 2015. Tissue concentrations of HBV-DNA and hsa-miR-125a-5p were then analyzed by real-time quantitative PCR. Necroinflammatory activity and fibrosis were evaluated according to the Ishak score.

RESULTS

During the study period, we enrolled 64 patients with overt and 10 patients with occult HBV infection. In the overt HBV group, 35 of 64 (54.7%) showed a mild fibrosis (staging 0-2), 17 (26.6%) a moderate fibrosis (staging 3-4), while the remaining 12 (18.7%) had a cirrhosis. All patients in the occult HBV group were cirrhotic. Patients with more advanced fibrosis stage showed a higher mean age when compared with those with mild (p < 0.00001) or moderate fibrosis (p < 0.00001) and were more frequently male than patients with staging 0-2 (p = 0.04). Similarly, patients with occult B infection were older than HBsAg-positive patients. Liver concentrations of miR-125a-5p were significantly higher in patients with cirrhosis (9.75 ± 4.42 AU) when compared with patients with mild (1.39 ± 0.94, p = 0.0002) or moderate fibrosis (2.43 ± 2.18, p = 0.0006) and were moderately higher in occult than in overt HBV infection (p = 0.09). Moreover, we found an inverse correlation, although not statistically significant, between the tissue HBV-DNA levels and the staging of fibrosis.

CONCLUSION

This study suggests a correlation between the tissue expression of hsa-miR-125a-5p and the progression of liver damage in a group of patients with occult or overt HBV infection. If confirmed, these data suggest the hsa-miR-125a-5p may be a novel biomarker of hepatic damage.

Mutual suppression of miR-125a and Lin28b in human hepatocellular carcinoma cells

MicroRNA-125a exhibits an antiproliferative activity and is downregulated in several types of tumors, including hepatocellular carcinoma where it targets sirtuin-7, matrix metalloproteinase-11, and c-Raf. Another target of miR-125a is Lin28, a pluripotency factor that is generally undetectable in differentiated cells but is often upregulated/reactivated in tumors where it acts as an oncogenic factor promoting cell proliferation and tumor progression. In this study we show that downregulation of Lin28b by miR-125a partially accounts for its antiproliferative activity toward hepatocellular carcinoma cells. We also found that Lin28b is able to bind a conserved GGAG motif of pre-miR-125a and to inhibit its maturation in hepatocellular carcinoma cells. Reciprocal inhibition between miR-125a and Lin28b reasonably generates a positive feedback loop where reactivation of Lin-28b inhibits the expression of both miR-125a and let-7, reinforcing its own expression and leading to a marked overexpression of the mitogenic targets of the two miRNAs. On the other hand, perturbation of these circuits by overexpression of miR-125a suppresses Lin28b leading to a decreased cell proliferation. Overall, these data support a tumor suppressive role for miR-125a and contribute to the elucidation of its molecular targets.

Lowered expression of microRNA-125a-5p in human hepatocellular carcinoma and up-regulation of its oncogenic targets sirtuin-7, matrix metalloproteinase-11, and c-Raf

Human microRNA-125a-5p (miR-125a) is expressed in most tissues where it downregulates the expression of membrane receptors or intracellular transductors of mitogenic signals, thus limiting cell proliferation. Expression of this miRNA generally increases with cell differentiation whereas it is downregulated in several types of tumors, such as breast, lung, ovarian, gastric, colon, and cervical cancers, neuroblastoma, medulloblastoma, glioblastoma, and retinoblastoma. In this study, we focused on hepatocellular carcinoma and used real-time quantitative PCR to measure miR-125a expression in 55 tumor biopsies and in matched adjacent non-tumor liver tissues. This analysis showed a downregulation of miR-125a in 80 % of patients, with a mean decrease of 4.7-fold. Comparison of miRNA downregulation with clinicopathological parameters of patients didn't yield significant correlations except for serum bilirubin. We then evaluated the expression of known targets of miR-125a and found that sirtuin-7, matrix metalloproteinase-11, and c-Raf were up-regulated in tumor tissue by 2.2-, 3-, and 1.7-fold, respectively. Overall, these data support a tumor suppressor role for miR-125a and encourage further studies aimed at the comprehension of the molecular mechanisms governing its expression, eventually leading to treatments to restore its expression in tumor cells.

Ferritin heavy chain is a negative regulator of ovarian cancer stem cell expansion and epithelial to mesenchymal transition

Objectives

Ferritin is the major intracellular iron storage protein essential for maintaining the cellular redox status. In recent years ferritin heavy chain (FHC) has been shown to be involved also in the control of cancer cell growth. Analysis of public microarray databases in ovarian cancer revealed a correlation between low FHC expression levels and shorter survival. To better understand the role of FHC in cancer, we have silenced the FHC gene in SKOV3 cells.

Results

FHC-KO significantly enhanced cell viability and induced a more aggressive behaviour. FHC-silenced cells showed increased ability to form 3D spheroids and enhanced expression of NANOG, OCT4, ALDH and Vimentin. These features were accompanied by augmented expression of SCD1, a major lipid metabolism enzyme. FHC apparently orchestrates part of these changes by regulating a network of miRNAs.

Methods

FHC-silenced and control shScr SKOV3 cells were monitored for changes in proliferation, migration, ability to propagate as 3D spheroids and for the expression of stem cell and epithelial-to-mesenchymal-transition (EMT) markers. The expression of three miRNAs relevant to spheroid formation or EMT was assessed by q-PCR.

Conclusions

In this paper we uncover a new function of FHC in the control of cancer stem cells.

MiR-22-3p Regulates Cell Proliferation and Inhibits Cell Apoptosis through Targeting the eIF4EBP3 Gene in Human Cervical Squamous Carcinoma Cells

Background: MicroRNAs (miRNAs) are non-coding small RNAs that function as negative regulators of gene expression and are involved in tumour biology. The eIF4E-binding proteins (eIF4EBPs) play essential roles in preventing translation initiation and inhibiting protein synthesis at a global or message-specific level in a variety of tumours. Methods: According to comparative miRNA profiles of clinical cervical cancer and non-cancerous cervical tissue specimens, several miRNAs were aberrantly expressed in the cervical cancer samples. C33a and SiHa cell proliferation and apoptosis were detected using methyl thiazolyl tetrazolium (MTT) and flow cytometry assays, respectively. Results: Among the aberrantly expressed miRNAs, miR-22-3p was significantly differentially expressed in cervical cancer tissues and was highly associated with cervical cancer cell growth regulation. In addition, bioinformatic predictions and experimental validation were used to identify whether eIF4E-binding protein 3 (eIF4EBP3) was a direct target of miR-22-3p; eIF4EBP3 protein levels were generally low in the cervical cancer tissues. Furthermore, functional studies revealed that either a miR-22-3p inhibitor or eIF4EBP3 overexpression could induce apoptosis in cervical cancer cells in vitro. Importantly, we found that eIF4EBP3 accumulation could significantly attenuate cervical cancer cell proliferation triggered by a miR-22-3p mimic as well as enhance apoptosis in cervical cancer cells. Conclusion: Taken together, our data provide primary proof that miR-22-3p can induce cervical cancer cell growth at least in part by up-regulating its expression to decrease eIF4EBP3 expression levels; miR-22-3p thus holds promise as a prognostic biomarker and potential therapeutic target for treating cervical cancer.

miR-125b regulates the drug-resistance of breast cancer cells to doxorubicin by targeting HAX-1

MircroRNAs (miRNAs) are considered as essential regulators in the tumorigenesis and chemoresistance of multiple cancer types. In the present study, it was demonstrated that the expression levels of miR-125b were significantly downregulated in the tissues of patients with breast cancer (BC), as well as the BC cell lines in vitro. To study the association between chemoresistance and miR-125b in BC, doxorubicin (DOX)-resistant MCF-7 (MCF-7/R) cells were established, and gain- and loss-of-function experiments were performed. It was demonstrated that the overexpression of miR-125b increased the sensitivity of MCF-7/R cells to DOX. Furthermore, it was revealed that the sensitization of miR-125b mimics to DOX-induced cell death was regulated by the hematopoietic cell-specific protein 1-associated protein X-1 (HAX-1) vector and HAX-1 small interfering RNA. These results emphasized the notable function of miR-125b and its target of HAX-1 in regulating DOX-resistance. In addition, it was demonstrated that the miR-125b mimics promoted the loss of the mitochondrial membrane potential and the generation of reactive oxygen species induced by DOX treatment in MCF-7/R cells. These data suggest that the miR-125b-HAX-1-mitochondria pathway has a notable function in the treatment of DOX-resistant BC cells, which may provide a novel target for the chemotherapy of BC.

MicroRNAs in gynecological cancers: Small molecules with big implications

Gynecological cancers (GCs) are often diagnosed at advanced stages, limiting the efficacy of available therapeutic options. Thus, there remains an urgent and unmet need for innovative research for the efficient clinical management of GC patients. Research over past several years has revealed the enormous promise of miRNAs. These small non-coding RNAs can aid in the diagnosis, prognosis and therapy of all major GCs, viz., ovarian cancers, cervical cancers and endometrial cancers. Mechanistic details of the miRNAs-mediated regulation of multiple biological functions are under constant investigation, and a number of miRNAs are now believed to influence growth, proliferation, invasion, metastasis, chemoresistance and the relapse of different GCs. Modulation of tumor microenvironment by miRNAs can possibly explain some of their reported biological effects. miRNA signatures have been proposed as biomarkers for the early detection of GCs, even the various subtypes of individual GCs. miRNA signatures are also being pursued as predictors of response to therapies. This review catalogs the knowledge gained from collective studies, so as to assess the progress made so far. It is time to ponder over the knowledge gained, so that more meaningful pre-clinical and translational studies can be designed to better realize the potential that miRNAs have to offer.

Molecular mechanisms governing microRNA-125a expression in human hepatocellular carcinoma cells

MicroRNA-125a-5p (miR-125a) is a vertebrate homolog of lin-4, the first discovered microRNA, and plays a fundamental role in embryo development by downregulating Lin-28 protein. MiR-125a is also expressed in differentiated cells where it generally acts as an antiproliferative factor by targeting membrane receptors or intracellular transductors of mitogenic signals. MiR-125a expression is downregulated in several tumors, including hepatocellular carcinoma (HCC) where it targets sirtuin-7, matrix metalloproteinase-11, VEGF-A, Zbtb7a, and c-Raf. In this study, we have isolated the transcription promoter of human miR-125a and characterized its activity in HCC cells. It is a TATA-less Pol II promoter provided with an initiator element and a downstream promoter element, located 3939 bp upstream the genomic sequence of the miRNA. The activity of the promoter is increased by the transcription factor NF-kB, a master regulator of inflammatory response, and miR-125a itself was found to strengthen this activation through inhibition of TNFAIP3, a negative regulator of NF-kB. This finding contributes to explain the increased levels of miR-125a observed in the liver of patients with chronic hepatitis B.

MiR-200c suppresses the migration of retinoblastoma cells by reversing epithelial mesenchymal transition

AIM

To analyze the relationship between clinical features and epithelial mesenchymal transition (EMT) in retinoblastoma (RB), further to investigate whether miR-200c regulates the EMT and migration of RB cells.

METHODS

Expression of EMT-related markers and tumor-related factors were detected by immuno-histochemistry analysis in RB tissue from 29 cases. Correlations between their expression and clinical characteristics were analyzed. The regulation effects of miR-200c on EMT-related markers, tumor-related factors were observed in mRNA level and protein level by real-time polymerase chain reaction (PCR) and Western blot, respectively, in Y79 and Weri-rb1 cells. Its effects on migration force of these RB cell lines were also detected with Transwell test.

RESULTS

Lower expression of E-cadherin was present in the cases with malignant prognosis. MiR-200c promoted the expression of E-cadherin and decreased the expression of Vimentin and N-cadherin in Y79 and Weri-rb1 cells. Migration force of RB cells could be inhibited by miR-200c.

CONCLUSION

EMT might be associated with bad prognosis in RB. MiR-200c suppresses the migration of retinoblastomatous cells by reverse EMT.

miR-320 inhibited ovarian cancer oncogenicity via targeting TWIST1 expression

Ovarian cancer is the most lethal gynecological cancer in most countries. Increasing studies have demonstrated that dysregulation of microRNAs (miRNAs) can contribute to cancer progression. In this study, we showed that miR-320 was underexpressed in ovarian cancer samples compared to their non-tumor tissues. The expression of Twist homolog 1 (TWIST1) in ovarian cancer tissues was upregulated compared with that in the non-tumorous tissues. We found that the expression of TWIST1 was inversely correlated with that of miR-320 in the ovarian cancer. Overexpression of miR-320 suppressed cell proliferation, cell cycle and invasion in ovarian cancer. We identified TWIST1 as a direct target gene of miR-320 in the ovarian cancer cell. Overexpression of TWIST1 promoted the ovarian cancer cell proliferation, cell cycle and invasion. Ectopic expression of TWIST1 restored the effects of miR-320 on cell proliferation, cell cycle and invasion. These findings revealed that miR-320 was a tumor suppressive gene that supressed cell prloferation, cycle and invasion through targeting TWIST1 in ovarian cancer.

Animal Models to Study MicroRNA Function

The discovery of the microRNAs, lin-4 and let-7 as critical mediators of normal development in Caenorhabditis elegans and their conservation throughout evolution has spearheaded research toward identifying novel roles of microRNAs in other cellular processes. To accurately elucidate these fundamental functions, especially in the context of an intact organism, various microRNA transgenic models have been generated and evaluated. Transgenic C. elegans (worms), Drosophila melanogaster (flies), Danio rerio (zebrafish), and Mus musculus (mouse) have contributed immensely toward uncovering the roles of multiple microRNAs in cellular processes such as proliferation, differentiation, and apoptosis, pathways that are severely altered in human diseases such as cancer. The simple model organisms, C. elegans, D. melanogaster, and D. rerio, do not develop cancers but have proved to be convenient systesm in microRNA research, especially in characterizing the microRNA biogenesis machinery which is often dysregulated during human tumorigenesis. The microRNA-dependent events delineated via these simple in vivo systems have been further verified in vitro, and in more complex models of cancers, such as M. musculus. The focus of this review is to provide an overview of the important contributions made in the microRNA field using model organisms. The simple model systems provided the basis for the importance of microRNAs in normal cellular physiology, while the more complex animal systems provided evidence for the role of microRNAs dysregulation in cancers. Highlights include an overview of the various strategies used to generate transgenic organisms and a review of the use of transgenic mice for evaluating preclinical efficacy of microRNA-based cancer therapeutics.

miR-125b is associated with renal cell carcinoma cell migration, invasion and apoptosis

MicroRNA (miR)-125b has been identified as deregulated in a number of types of cancer. Previous studies have detected the expression of miR-125b in clear cell renal cell carcinoma (ccRCC) tissues by in situ hybridization and revealed that miR-125b was upregulated in ccRCC tissues, and was associated with recurrence and survival of patients with ccRCC. However, the function of miR-125b in RCC remains unclear. Thus, the expression of miR-125b was detected with quantitative polymerase chain reaction (qPCR) in 24 paired RCC and adjacent normal tissues. The result of qPCR showed that miR-125b was upregulated in RCC tissues. Furthermore, the function of miR-125b in RCC (786-O and ACHN) cells was detected by transfecting miR-125 mimic or inhibitor to upregulate or downregulate miR-125b expression. Cell proliferation assays (MTT and Cell Counting Kit-8), cell mobility assays (cell scratch and Transwell assay) and a cell apoptotic assay (flow cytometry assay) were performed to assess the function of miR-125b on RCC cells. Results from the assays demonstrated that overexpression of miR-125b could promote cell migration and invasion, and reduce the cell apoptotic rate. It was also revealed that downregulation of miR-125b could reduce cell migration and invasion, and induce cell apoptosis. However, the results of the cell proliferation assay revealed that miR-125b had no significant effect on cell proliferation. Not only could miR-125b predict recurrence and survival of ccRCC; the present study revealed that miR-125b could regulate RCC cell migration, invasion and apoptosis. Additional studies are required to determine the mechanism of miR-125b in RCC cells and define the target genes of miR-125b in RCC.

MicroRNAs driving invasion and metastasis in ovarian cancer: Opportunities for translational medicine (Review)

Epithelial ovarian cancer is the fifth most frequent cause of cancer death in women. In spite of the advantages in early detection and treatment options, overall survival rates have improved only slightly in the last decades. Therefore, alternative therapeutic approaches need to overcome resistance and improve the patient survival and outcome. MicroRNAs are evolutionary conserved small non-coding RNAs that function as negative regulators of gene expression by inhibiting translation or inducing degradation of messenger RNAs. In cancer, microRNAs are aberrantly expressed thus representing potential prognostic biomarkers and novel therapeutic targets. The knowledge of novel and unexpected functions of microRNAs is rapidly evolving and the advance in the elucidation of potential clinical applications deserves attention. Recently, a specific set of microRNAs dubbed as metastamiRs have been shown to initiate invasion and metastasis in diverse types of cancer. We reviewed the current status of microRNAs in development and progression of ovarian cancer with a special emphasis on tumor cells invasion and metastasis. Also, we show an update of microRNA functions in oncogenic pathways and discuss the current scenario for potential applications in clinical and translational research in ovarian cancer.

Ascites promotes cell migration through the repression of miR-125b in ovarian cancer

Interactions between ovarian cancer cells and the surrounding tumor microenvironment are not well characterized. Here, we investigated the molecular mechanisms by which malignant ascites promote the metastasis of ovarian cancer. It was found that ovarian cancer ascites promoted ovarian cancer cell migration which was attenuated by either heat inactivation or antibody blockade of TGF-β. High level (at ng/ml level) of TGF-β was detected in the ascites. In addition, ascites repressed the expression of miRNA-125b in a TGF-β-dependent manner. Mimic of miR-125b blocked ascites-induced cell migration. Furthermore, Gab2 (a target gene of miR-125b) was elevated by ascites in a TGF-β-dependent manner. And forced expression of Gab2 reversed the inhibition of migration induced by miR-125b mimic. Most importantly, the expression of miR-125b and Gab2 mRNA was negatively correlated in ovarian cancer specimens. Taken together, our finding suggested that TGF-β in ascites promoted cancer cell migration through repression of miR-125b in ovarian cancer. This might provide a novel therapeutic target for ovarian cancer in the future.