MicroRNA-654-5p suppresses ovarian cancer development impacting on MYC, WNT and AKT pathways

Transcription Factor 21: A Transcription Factor That Plays an Important Role in Cardiovascular Disease

BACKGROUND

According to the World Health Organisation's Health Report 2019, approximately 17.18 million people die from cardiovascular disease each year, accounting for more than 30% of all global deaths. Therefore, the occurrence of cardiovascular disease is still a global concern. The transcription factor 21 (TCF21) plays an important role in cardiovascular diseases. This article reviews the regulation mechanism of TCF21 expression and activity and focuses on its important role in atherosclerosis in order to contribute to the development of diagnosis and treatment of cardiovascular diseases.

SUMMARY

TCF21 is involved in the phenotypic regulation of vascular smooth muscle cells (VSMCs), promotes the proliferation and migration of VSMCs, and participates in the activation of inflammatory sequences. Increased proliferation and migration of VSMCs can lead to neointimal hyperplasia after vascular injury. Abnormal hyperplasia of neointima and inflammation are one of the main features of atherosclerosis. Therefore, targeting TCF21 may become a potential treatment for relieving atherosclerosis.

KEY MESSAGES

TCF21 as a member of basic helix-loop-helix transcription factors regulates cell growth and differentiation by modulating gene expression during the development of different organs and plays an important role in cardiovascular development and disease. VSMCs and cells derived from VSMCs constitute the majority of plaques in atherosclerosis. TCF21 plays a key role in regulation of VSMCs' phenotype, thus accelerating atherogenesis in the early stage. However, TCF21 enhances plaque stability in late-stage atherosclerosis. The dual role of TCF21 should be considered in the translational medicine.

Inhibiting the m6A Reader IGF2BP3 Suppresses Ovarian Cancer Cell Growth via Regulating PLAGL2 mRNA Stabilization

Background

The oncogene IGF2 mRNA binding protein 3 (IGF2BP3) could function as an m6A reader in stabilizing many tumor-associated genes' mRNAs. However, the relevant oncogenic mechanism by which IGF2BP3 promotes ovarian cancer growth is largely unknown.

Methods

The IGF2BP3 expression in ovarian cancer was identified by retrieving the datasets from The Cancer Genome Atlas (TCGA). GEO datasets evaluated the relevant signaling pathways in IGF2BP3 knockdown in ovarian cancer cells. IGF2BP3 positive correlation gene in TCGA was calculated. MTS proliferation assay was identified in IGF2BP3 knockdown and rescued by PLAG1 like zinc finger 2 (PLAGL2) overexpression in ES-2 and SKOV3 cells. Bioinformatic analysis and RIP-qPCR were predicted and identified the IGF2BP3 binding site and PLAGL2 mRNA stability. The animal experiment identified IGF2BP3 proliferation inhibition.

Results

IGF2BP3 was upregulated in ovarian cancer tissue and cells. The depletion of IGF2BP3 in ovarian cancer cells leads to an enhancement of the pathway involved in cellular proliferation and mRNA stability. IGF2BP3 positive correlation suppressed pro-proliferation gene PLAGL2. IGF2BP3 knockdown suppressed ovarian cancer cell proliferation and was rescued by PLAGL2 overexpression. Luciferase reporter assay confirmed that IGF2BP3 could bind to 3'-UTR of PLAGL2 to maintain the mRNA stability. Further, in in vivo experiments, IGF2BP3 knockdown suppressed ovarian cancer cell proliferation via inhibiting PLAGL2 expression.

Conclusion

All of these indicate that PLAGL2 mediates the main function of IGF2BP3 knockdown on ovarian cancer proliferation inhibition through mRNA stability regulation.

circCLK3 regulates colorectal cancer SW620 cell proliferation, migration, and invasion by targeting miR-654-5p

BACKGROUND

Recent studies have investigated the role of circular RNAs (circRNAs) as significant regulatory factors in the progression of multiple cancers, containing colorectal cancer (CRC). Nevertheless, the biological functions of circCLK3 in CRC and the underlying mechanisms by which it regulates CRC progression remain unclear.

AIM

To clarify the mechanism of circCLK3 regulating colorectal cancer SW620 cell proliferation, migration, and invasion.

METHODS

CRC tissues and adjacent tissues were collected, and the expression of circCLK3 and miR-654-5p was detected by qRT-PCR. SW620 cells were cultured in vitro and divided into the following groups: si-circCLK3 group, pcDNA-circCLK3 group, miR-654-5p group, si-circCLK3 + anti-miR-654-5p group, and corresponding negative control groups (si-NC group, pcDNA group, miR-NC group, and si-circCLK3 + anti-miR-NC group). CCK8 assay, colony formation test, scratch test, and Transwell test were used to detect cell proliferation, migration, and invasion. The interaction between circCLK3 and miR-654-5p was confirmed by dual-luciferase reporter assay. The protein expression of MMP-2 and MMP-9 was detected by Western blot.

RESULTS

circCLK3 expression was increased (P < 0.05), while miR-654-5p expression was decreased (P < 0.05) in CRC tissues. Cell viability, scratch healing rate, the protein levels of matrix metalloproteinase-2 (MMP-2) and MMP-9, the number of cell clones formed, and the number of invasive cells were decreased (P < 0.05) in the si-circCLK3 group. circCLK3 could negatively regulate the expression of miR-654-5p. Cell viability, scratch healing rate, the protein levels of MMP-2 and MMP-9, the number of cell clones formed and the number of invasive cells were decreased (P < 0.05) in the miR-654-5p group. Cell viability, scratch healing rate, the protein levels of MMP-2 and MMP-9, the number of cell clones formed, and the number of invasive cells were increased (P < 0.05) in the si-circCLK3 + anti-miR-654-5p group.

CONCLUSION

circCLK3 promotes CRC cell proliferation, migration, and invasion by targeting miR-654-5p.

TEAD4 predicts poor prognosis and transcriptionally targets PLAGL2 in serous ovarian cancer

The oncogenic function of TEA domain transcription factor 4 (TEAD4) has been confirmed in multiple human malignancies, while its potential role and regulatory mechanism in serous ovarian cancer progression are left unknown. By the gene expression analyses from Gene Expression Profiling Interactive Analysis (GEPIA) database, TEAD4 expression is shown to be up-regulated in serous ovarian cancer samples. Here, we confirmed the high expression of TEAD4 in clinical serous ovarian cancer specimens. In the following functional experiments, we found that TEAD4 overexpression promoted serous ovarian cancer malignant phenotypes, including proliferation, migration and invasion in serous ovarian cancer SK-OV-3 and OVCAR-3 cells, while TEAD4 knockout exerted the opposite function. The tumor growth inhibition of TEAD4 depletion was also affirmed by a Xenograft model in mice. In addition, this phenotypic deterioration induced by TEAD4 overexpression was diminished by PLAG1 like zinc finger 2 (PLAGL2) silencing. More importantly, combined with the results of the dual-luciferase assay, the transcriptional regulation of TEAD4 on PLAGL2 promoter was evidenced. Our results showed that the cancer-promoting gene TEAD4 was involved in serous ovarian cancer progression via targeting PLAGL2 at the transcriptional level.

LncRNA NEAT1 inhibits apoptosis and autophagy of ovarian granulosa cells through miR-654/STC2-mediated MAPK signaling pathway

Long non-coding RNA (lncRNA) anomalies cause early ovarian failure. LncRNA nuclear enriched abundant transcript 1 (NEAT1) was down-regulated in premature ovarian failure (POF) mice and connected to the illness, however, the mechanism remained unclear. The levels of gene and protein were measured by using quantitative real-time polymerase chain reaction, Western blot, and immunofluorescence. Follicle stimulating hormone (FSH), estradiol (E2), and luteinizing hormone (LH) levels were determined using enzyme-linked immunosorbent assay (ELISA). 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) and flow cytometry were used to determine cell viability and apoptosis. The interaction of NEAT1, miR-654, and stanniocalcin-2 (STC2) was verified by dual-luciferase reporter assay or RNA binding protein immunoprecipitation (RIP) assays. The results showed NEAT1 and STC2 down-regulated, while miR-654 up-regulated in POF mice. Overexpression of NEAT1 reduced apoptosis and autophagy in cyclophosphamide (CTX)-treated ovarian granulosa cells (OGCs), and Bax, cleaved-caspase3, LC3B, LC3II/LC3I ratio were decreased and Bcl-2 and p62 were raised. NEAT1 suppressed miR-654 expression by directly targeting miR-654. The inhibition of NEAT1 overexpression on apoptosis and autophagy in OGCs was reversed by miR-654 mimics. STC2 was a target gene of miR-654, and miR-654 inhibitor reduced the apoptosis and autophagy by regulating the STC2/MAPK axis. To sum up, NEAT1 reduced miR-654 expression and modulated the STC2/MAPK pathway to decrease apoptosis and autophagy in POF, indicating a potential therapeutic target.

Delivery of miR-654-5p via SonoVue Microbubble Ultrasound Inhibits Proliferation, Migration, and Invasion of Vascular Smooth Muscle Cells and Arterial Thrombosis and Stenosis through Targeting TCF21

Background

Abnormal proliferation of vascular smooth muscle cells (VSMCs) is an important cause of vascular stenosis. The study explored the mechanism of inhibition of vascular stenosis through the molecular mechanism of smooth muscle cell phenotype transformation.

Methods

Coronary heart disease-related genes were screened by bioinformatics, and the target genes of miR-654-5p were predicted by dual-luciferase method and immunofluorescence method. miR-654-5p mimic stimulation and transfection of TCF21 and MTAP into cells. SonoVue microbubble sonication was used to deliver miR-654-5p into cells. Cell proliferation, migration, and invasion were detected by CCK-8, wound scratch, and Transwell. HE and IHC staining were performed to study the effect of miR-654-5p delivery via SonoVue microbubble ultrasound on vessel stenosis in a model of arterial injury. Gene expression was determined by qRT-PCR and WB.

Results

TCF21 and MTAP were predicted as the target genes of miR-654-5p. Cytokines induced smooth muscle cell proliferation, migration, and invasion and promoted miR-654-5p downregulation; noticeably, downregulated miR-654-5p was positively associated with the cell proliferation and migration. Overexpression of TCF21 promoted proliferation, invasion, and migration, and mimic reversed such effects. miR-654-5p overexpression delivered by SonoVue microbubble ultrasound inhibited proliferation, migration, and invasion of cells. Moreover, in arterial injury model, we found that SonoVue microbubble ultrasound transmitted miR-654-5p into the arterial wall to inhibit arterial thrombosis and stenosis, while TCF21 was inhibited.

Conclusion

Ultrasound delivery of miR-654-5p via SonoVue microbubbles was able to inhibit arterial thrombosis and stenosis by targeting TCF21.

Extracellular Vesicles-ceRNAs as Ovarian Cancer Biomarkers: Looking into circRNA-miRNA-mRNA Code

Simple Summary

Patients with ovarian cancer have a very poor chance of long-term survival, usually due to advanced disease at the time of diagnosis. Emerging evidence suggests that extracellular vesicles contain noncoding RNAs such as microRNAs, piwiRNAs, circular RNAs, and long noncoding RNAs, with regulatory effects on ovarian cancer. In this review, we focus on ovarian cancer-associated circular RNA shuttled by extracellular vesicles as mediators of cancer progression and novel biomarkers in liquid biopsy. We propose a circular-RNA–microRNA-mRNA code that can reveal the regulatory network created by extracellular vesicles, noncoding RNAs, and mRNAs in ovarian cancer. Future research in this field will help to identify novel diagnostic biomarkers and druggable therapeutic targets, which will ultimately benefit patients.

Abstract

Ovarian cancer (OC) is one of the most lethal gynecologic malignancies in females worldwide. OC is frequently diagnosed at an advanced stage due to a lack of specific symptoms and effective screening tests, resulting in a poor prognosis for patients. Age, genetic alterations, and family history are the major risk factors for OC pathogenesis. Understanding the molecular mechanisms underlying OC progression, identifying new biomarkers for early detection, and discovering potential targets for new drugs are urgent needs. Liquid biopsy (LB), used for cancer detection and management, consists of a minimally invasive approach and practical alternative source to investigate tumor alterations by testing extracellular vesicles (EVs), circulating tumor cells, tumor-educated platelets, and cell-free nucleic acids. EVs are nanosize vesicles shuttling proteins, lipids, and nucleic acids, such as DNA, RNA, and non-coding RNAs (ncRNAs), that can induce phenotypic reprogramming of target cells. EVs are natural intercellular shuttles for ncRNAs, such as microRNAs (miRNAs) and circular-RNAs (circRNAs), known to have regulatory effects in OC. Here we focus on the involvement of circRNAs and miRNAs in OC cancer progression. The circRNA-microRNA-mRNA axis has been investigated with Circbank and miRwalk analysis, unraveling the intricate and detailed regulatory network created by EVs, ncRNAs, and mRNAs in OC.

Comprehensive Analysis of hsa-miR-654-5p's Tumor-Suppressing Functions

The pivotal roles of miRNAs in carcinogenesis, metastasis, and prognosis have been demonstrated recently in various cancers. This study intended to investigate the specific roles of hsa-miR-654-5p in lung cancer, which is, in general, rarely discussed. A series of closed-loop bioinformatic functional analyses were integrated with in vitro experimental validation to explore the overall biological functions and pan-cancer regulation pattern of miR-654-5p. We found that miR-654-5p abundance was significantly elevated in LUAD tissues and correlated with patients’ survival. A total of 275 potential targets of miR-654-5p were then identified and the miR-654-5p-RNF8 regulation axis was validated in vitro as a proof of concept. Furthermore, we revealed the tumor-suppressing roles of miR-654-5p and demonstrated that miR-654-5p inhibited the lung cancer cell epithelial-mesenchymal transition (EMT) process, cell proliferation, and migration using target-based, abundance-based, and ssGSEA-based bioinformatic methods and in vitro validation. Following the construction of a protein–protein interaction network, 11 highly interconnected hub genes were identified and a five-genes risk scoring model was developed to assess their potential prognostic ability. Our study does not only provide a basic miRNA-mRNA-phenotypes reference map for understanding the function of miR-654-5p in different cancers but also reveals the tumor-suppressing roles and prognostic values of miR-654-5p.

Analysis of circRNA-miRNA-mRNA Regulatory Network in Peripheral Blood of Radiation Workers

The health of radiation workers has always been our focus. Epidemiological investigation shows that long-term exposure to low-dose ionizing radiation can affect human health, especially cancer and cardiovascular disease, and there are many studies on it. However, up to now, there have been few reports on the research of blood and biological samples from radiation workers. In this study, radiation workers and healthy control groups were strictly screened, and the transcriptome of mRNA and circRNA was sequenced by extracting their peripheral venous blood. At the same time, appropriate data sets were selected in the GEO database for bioinformatics analysis, and circRNA-miRNA-mRNA network was constructed. We identified 9 different circular ribonucleic acids, 3 tiny ribonucleic acids, and 2 central genes (NOD 2 and IRF 7). These differentially expressed genes and non-coding RNA are closely related to ionizing radiation damage, and play an important role as biological markers. In conclusion, this study may provide new insights into the role of the circRNA-miRNA-mRNA regulatory network in the health of radiation workers, and provides a new strategy for the future study of radiation biology.

Endometrial Cancer Stem Cells: Where Do We Stand and Where Should We Go?

Endometrial cancer is one of the most common malignant diseases in women worldwide, with an incidence of 5.9%. Thus, it is the most frequent cancer of the female genital tract, with more than 34,000 women dying, in Europe and North America alone. Endometrial Cancer Stem Cells (CSC) might be drivers of carcinogenesis as well as metastatic and recurrent disease. Therefore, targeting CSCs is of high interest to improve prognosis of patients suffering of advanced or recurrent endometrial cancer. This review describes the current evidence of molecular mechanisms in endometrial CSCs with special emphasis on MYC and NF-κB signaling as well as mitochondrial metabolism. Furthermore, the current status of immunotherapy targeting PD-1 and PD-L1 in endometrial cancer cells and CSCs is elucidated. The outlined findings encourage novel therapies that target signaling pathways in endometrial CSCs as well as immunotherapy as a promising therapeutic approach in the treatment of endometrial cancer to impede cancer progression and prevent recurrence.

Disulfiram Transcends ALDH Inhibitory Activity When Targeting Ovarian Cancer Tumor-Initiating Cells

Epithelial ovarian cancer (EOC) is a global health burden and remains the fifth leading cause of cancer related death in women worldwide with the poorest five-year survival rate of the gynecological malignancies. EOC recurrence is considered to be driven by the survival of chemoresistant, stem-like tumor-initiating cells (TICs). We previously showed that disulfiram, an ALDH inhibitor, effectively targeted TICs compared to adherent EOC cells in terms of viability, spheroid formation, oxidative stress and also prevented relapse in an in vivo model of EOC. In this study we sought to determine whether specific targeting of ALDH isoenzyme ALDH1A1 would provide similar benefit to broader pathway inhibition by disulfiram. NCT-505 and NCT-506 are isoenzyme-specific ALDH1A1 inhibitors whose activity was compared to the effects of disulfiram. Following treatment with both the NCTs and disulfiram, the viability of TICs versus adherent cells, sphere formation, and cell death in our in vitro relapse model were measured and compared in EOC cell lines. We found that disulfiram decreased the viability of TICs significantly more effectively versus adherent cells, while no consistent trend was observed when the cells were treated with the NCTs. Disulfiram also affected the expression of proteins associated with NFκB signaling. Comparison of disulfiram to the direct targeting of ALDH1A1 with the NCTs suggests that the broader cellular effects of disulfiram are more suitable as a therapeutic to eradicate TICs from tumors and prevent EOC relapse. In addition to providing insight into a fitting treatment for TICs, the comparison of disulfiram to NCT-505 and -506 has increased our understanding of the mechanism of action of disulfiram. Further elucidation of the mechanism of disulfiram has the potential to reveal additional targets to treat EOC TICs and prevent disease recurrence.

LncRNA CASC15 regulates breast cancer cell stemness via the miR-654-5p/MEF2D axis

Emerging evidence has demonstrated the prognostic and diagnostic potential of long noncoding RNA (lncRNA) cancer susceptibility candidate 15 (lncRNA CASC15) for the progression and tumorigenesis of human cancer. However, how CASC15 modulates the stemness of breast cancer stem cells (BCSCs) is not well understood. In this study, high expression of CASC15 in MCF-7 CSCs was reported, relative to MCF-7 cells, and this phenomenon was associated with metastatic lymph nodes, higher TNM stage, and shorter breast cancer survival rates. Further experiments revealed that CASC15 promoted the acquisition of stemness properties of breast cancer cells (BSCCs) by competing with endogenous RNA for miR-654-5p, resulting in overexpression of MEF2D in BCSCs. Overall, breast cancer stemness and tumor development are regulated via the CASC15/miR-654-5p/MEF2D axis. Accordingly, this pathway can be explored for breast cancer therapy.

Functions of non-coding RNAs in regulating cancer drug targets

With the development of precision medicine, the efficiency of tumor treatment has been significantly improved. More attention has been paid to targeted therapy and immunotherapy as the key to precision treatment of cancer. Targeting epidermal growth factor receptor (EGFR) has become one of the most important targeted treatments for various cancers. Comparing with traditional chemotherapy drugs, targeting EGFR is highly selective in killing tumor cells with better safety, tolerability and less side effect. In addition, tumor immunotherapy has become the fourth largest tumor therapy after surgery, radiotherapy and chemotherapy, especially immune checkpoint inhibitors. However, these treatments still produce a certain degree of drug resistance. Non-coding RNAs (ncRNAs) were found to play a key role in carcinogenesis, treatment and regulation of the efficacy of anticancer drugs in the past few years. Therefore, in this review, we aim to summarize the targeted treatment of cancers and the functions of ncRNAs in cancer treatment.

Deregulated miRNA clusters in ovarian cancer: Imperative implications in personalized medicine

Ovarian cancer (OC) is one of the most common and fatal types of gynecological cancer. OC is usually detected at the advanced stages of the disease, making it highly lethal. miRNAs are single-stranded, small non-coding RNAs with an approximate size ranging around 22 nt. Interestingly, a considerable proportion of miRNAs are organized in clusters with miRNA genes placed adjacent to one another, getting transcribed together to result in miRNA clusters (MCs). MCs comprise two or more miRNAs that follow the same orientation during transcription. Abnormal expression of the miRNA cluster has been identified as one of the key drivers in OC. MC exists both as tumor-suppressive and oncogenic clusters and has a significant role in OC pathogenesis by facilitating cancer cells to acquire various hallmarks. The present review summarizes the regulation and biological function of MCs in OC. The review also highlights the utility of abnormally expressed MCs in the clinical management of OC.

Cancer Stem Cells in Ovarian Cancer-A Source of Tumor Success and a Challenging Target for Novel Therapies

Ovarian cancer is the most lethal neoplasm of the female genital organs. Despite indisputable progress in the treatment of ovarian cancer, the problems of chemo-resistance and recurrent disease are the main obstacles for successful therapy. One of the main reasons for this is the presence of a specific cell population of cancer stem cells. The aim of this review is to show the most contemporary knowledge concerning the biology of ovarian cancer stem cells (OCSCs) and their impact on chemo-resistance and prognosis in ovarian cancer patients, as well as to present the treatment options targeted exclusively on the OCSCs. The review presents data concerning the role of cancer stem cells in general and then concentrates on OCSCs. The surface and intracellular OCSCs markers and their meaning both for cancer biology and clinical prognosis, signaling pathways specifically activated in OCSCs, the genetic and epigenetic regulation of OCSCs function including the recent studies on the non-coding RNA regulation, cooperation between OCSCs and the tumor microenvironment (ovarian cancer niche) including very specific environment such as ascites fluid, the role of shear stress, autophagy and metabolic changes for the function of OCSCs, and finally mechanisms of OCSCs escape from immune surveillance, are described and discussed extensively. The possibilities of anti-OCSCs therapy both in experimental settings and in clinical trials are presented, including the recent II phase clinical trials and immunotherapy. OCSCs are a unique population of cancer cells showing a great plasticity, self-renewal potential and resistance against anti-cancer treatment. They are responsible for the progression and recurrence of the tumor. Several completed and ongoing clinical trials have tested different anti-OCSCs drugs which, however, have shown unsatisfactory efficacy in most cases. We propose a novel approach to ovarian cancer diagnosis and therapy.

PHD finger protein 20-like protein 1 (PHF20L1) in ovarian cancer: from its overexpression in tissue to its upregulation by the ascites microenvironment

Background

Ovarian cancer is the most aggressive gynecological malignancy. Transcriptional regulators impact the tumor phenotype and, consequently, clinical progression and response to therapy. PHD finger protein 20-like protein 1 (PHF20L1) is a transcriptional regulator with several isoforms, and studies on its role in ovarian cancer are limited. We previously reported that PHF20L1 is expressed as a fucosylated protein in SKOV-3 cells stimulated with ascites from patients with ovarian cancer.

Methods

We decided to analyze the expression of PHF20L1 in ovarian cancer tissues, determine whether a correlation exists between PHF20L1 expression and patient clinical data, and analyze whether ascites can modulate the different isoforms of this protein. Ovarian cancer biopsies from 29 different patients were analyzed by immunohistochemistry, and the expression of the isoforms in ovarian cancer cells with or without exposure to the tumor microenvironment, i.e., the ascitic fluid, was determined by western blotting assays.

Results

Immunohistochemical results suggest that PHF20L1 exhibits increased expression in sections of tumor tissues from patients with ovarian cancer and that higher PHF20L1 expression correlates with shorter progression-free survival and shorter overall survival. Furthermore, western blotting assays determined that protein isoforms are differentially regulated in SKOV-3 cells in response to stimulation with ascites from patients with epithelial ovarian cancer.

Conclusion

The results suggest that PHF20L1 could play a relevant role in ovarian cancer given that higher PHF20L1 protein expression is associated with lower overall patient survival.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-021-02425-6.

miR-654-5p promotes gastric cancer progression via the GPRIN1/NF-κB pathway

Background

Gastric carcinoma (GC) ranks the fifth most common cancer worldwide, with high incidence and mortality rates. Numerous microRNAs (miRNAs), including miR-654-5p, have been implicated in the pathophysiological processes of tumorigenesis. Nevertheless, the mechanism of miR-654-5p in GC is unclear.

Objectives

Our study is devoted to exploring the function and molecular mechanism of miR-654-5p on the malignant cell behaviors of GC.

Methods

The gene expression was detected by reverse transcription quantitative polymerase chain reaction. GC cell proliferation and motion were assessed by colony formation assay and transwell assay. The binding capacity between miR-654-5p and G protein-regulated inducer of neurite outgrowth 1 (GPRIN1) was explored by luciferase reporter and RNA pulldown assays. The protein levels were detected by Western blotting.

Results

miR-654-5p expression was higher in GC cells and tissues than control cells and tissues. miR-654-5p promoted GC cell growth and motion. Moreover, our findings showed that miR-654-5p was bound with GPRIN1. Importantly, downregulation of GPRIN1 rescued the inhibitory influence of miR-654-5p knockdown on GC cell malignant behaviors. Additionally, miR-654-5p activated the nuclear factor kappa-B (NF-κB) pathway by regulation of GPRIN1.

Conclusions

miR-654-5p facilitated cell proliferation, migration, and invasion in GC via targeting the GPRIN1 to activate the NF-κB pathway.

LINC02532 Contributes to Radiosensitivity in Clear Cell Renal Cell Carcinoma through the miR-654-5p/YY1 Axis

Background: Studies have shown that long non-coding RNAs (lncRNAs) play essential roles in tumor progression and can affect the response to radiotherapy, including in clear cell renal cell carcinoma (ccRCC). LINC02532 has been found to be upregulated in ccRCC. However, not much is known about this lncRNA. Hence, this study aimed to investigate the role of LINC02532 in ccRCC, especially in terms of radioresistance. Methods: Quantitative real-time PCR was used to detect the expression of LINC02532, miR-654-5p, and YY1 in ccRCC cells. Protein levels of YY1, cleaved PARP, and cleaved-Caspase-3 were detected by Western blotting. Cell survival fractions, viability, and apoptosis were determined by clonogenic survival assays, CCK-8 assays, and flow cytometry, respectively. The interplay among LINC02532, miR-654-5p, and YY1 was detected by chromatin immunoprecipitation and dual-luciferase reporter assays. In addition, in vivo xenograft models were established to investigate the effect of LINC02532 on ccRCC radioresistance in 10 nude mice. Results: LINC02532 was highly expressed in ccRCC cells and was upregulated in the cells after irradiation. Moreover, LINC02532 knockdown enhanced cell radiosensitivity both in vitro and in vivo. Furthermore, YY1 activated LINC02532 in ccRCC cells, and LINC02532 acted as a competing endogenous RNA that sponged miR-654-5p to regulate YY1 expression. Rescue experiments indicated that miR-654-5p overexpression or YY1 inhibition recovered ccRCC cell functions that had been previously impaired by LINC02532 overexpression. Conclusions: Our results revealed a positive feedback loop of LINC02532/miR-654-5p/YY1 in regulating the radiosensitivity of ccRCC, suggesting that LINC02532 might be a potential target for ccRCC radiotherapy. This study could serve as a foundation for further research on the role of LINC02532 in ccRCC and other cancers.

(In)Distinctive Role of Long Non-Coding RNAs in Common and Rare Ovarian Cancers

Rare ovarian cancers (ROCs) are OCs with an annual incidence of fewer than 6 cases per 100,000 women. They affect women of all ages, but due to their low incidence and the potential clinical inexperience in management, there can be a delay in diagnosis, leading to a poor prognosis. The underlying causes for these tumors are varied, but generally, the tumors arise due to alterations in gene/protein expression in cellular processes that regulate normal proliferation and its checkpoints. Dysregulation of the cellular processes that lead to cancer includes gene mutations, epimutations, non-coding RNA (ncRNA) regulation, posttranscriptional and posttranslational modifications. Long non-coding RNA (lncRNA) are defined as transcribed RNA molecules, more than 200 nucleotides in length which are not translated into proteins. They regulate gene expression through several mechanisms and therefore add another level of complexity to the regulatory mechanisms affecting tumor development. Since few studies have been performed on ROCs, in this review we summarize the mechanisms of action of lncRNA in OC, with an emphasis on ROCs.

ZFTA-RELA Dictates Oncogenic Transcriptional Programs to Drive Aggressive Supratentorial Ependymoma

More than 60% of supratentorial ependymomas harbor a ZFTA-RELA (ZRfus) gene fusion (formerly C11orf95-RELA). To study the biology of ZRfus, we developed an autochthonous mouse tumor model using in utero electroporation (IUE) of the embryonic mouse brain. Integrative epigenomic and transcriptomic mapping was performed on IUE-driven ZRfus tumors by CUT&RUN, chromatin immunoprecipitation sequencing, assay for transposase-accessible chromatin sequencing, and RNA sequencing and compared with human ZRfus-driven ependymoma. In addition to direct canonical NFκB pathway activation, ZRfus dictates a neoplastic transcriptional program and binds to thousands of unique sites across the genome that are enriched with PLAGL family transcription factor (TF) motifs. ZRfus activates gene expression programs through recruitment of transcriptional coactivators (Brd4, Ep300, Cbp, Pol2) that are amenable to pharmacologic inhibition. Downstream ZRfus target genes converge on developmental programs marked by PLAGL TF proteins, and activate neoplastic programs enriched in Mapk, focal adhesion, and gene imprinting networks. SIGNIFICANCE: Ependymomas are aggressive brain tumors. Although drivers of supratentorial ependymoma (ZFTA- and YAP1-associated gene fusions) have been discovered, their functions remain unclear. Our study investigates the biology of ZFTA-RELA-driven ependymoma, specifically mechanisms of transcriptional deregulation and direct downstream gene networks that may be leveraged for potential therapeutic testing.This article is highlighted in the In This Issue feature, p. 2113.

Graphene oxide-based qRT-PCR assay enables the sensitive and specific detection of miRNAs for the screening of ovarian cancer

Circulating microRNAs (miRNAs) have the potential to become reliable and noninvasive biomarkers for ovarian cancer (OC) diagnosis; however, the conventional miRNAs detection techniques exhibit enduring limitations of low sensitivity and specificity. Graphene oxide (GO), a novel nanomaterial, is at the forefront of material design for extensive biomedical applications. Owing to the excellent water affinity and single-stranded DNA (ssDNA) adsorption characteristics of GO, we designed and developed a GO-based qRT-PCR assay for the detection of miRNAs associated with OC. In the GO-based qRT-PCR system, GO could significantly improve the sensitivity and specificity of the qRT-PCR assay by noncovalently interacting with primers and ssDNA and reducing the occurrence of non-specific amplification. Moreover, the detection of miRNAs associated with OC confirmed that GO-based qRT-PCR assay could differentiate benign ovarian tumors from OC (sensitivity, 0.91; specificity, 1.00). Collectively, these findings provide robust evidence that GO-based qRT-PCR assay can be effectively used as a promising method to detect miRNAs for the screening of OC patients.

Circ_0003972 Promotes the Proliferation and Inflammation of Fibroblast-like Synovial Cells in Rheumatoid Arthritis through Regulation of the miR-654-5p/FZD4 Axis

BACKGROUND

Circular RNAs (circRNAs) have been shown to play an important role in rheumatoid arthritis (RA) progression. This study aims to explore the role and mechanism of circ_0003972 in RA progression.

METHODS

Quantitative real-time PCR was used to determine gene expression. The proliferation and apoptosis of human RA fibroblast-like synovial (HFLS-RA) cells were measured using cell counting kit 8 assay, EdU staining and flow cytometry. Western blot analysis was performed to measure protein expression, and ELISA assay was used to examine the concentrations of inflammation factors. The interaction between miR-654-5p and circ_0003972 or FZD4 was confirmed by dual-luciferase reporter assay and RIP assay.

RESULTS

Circ_0003972 was highly expressed in RA patients and HFLS-RA cells. Circ_0003972 knockdown inhibited the proliferation, inflammation, while promoted the apoptosis of TNFα-induced HFLS-RA cells. MiR-654-5p was downregulated in RA patients and HFLS-RA cells, and it could be sponged by circ_0003972. MiR-654-5p inhibitor reversed the effect of circ_0003972 silencing on the proliferation, inflammation, and apoptosis of TNFα-induced HFLS-RA cells. Frizzled-4 (FZD4) could be targeted by miR-654-5p, and its expression was positively regulated by circ_0003972. Furthermore, FZD4 overexpression also reversed the effects of miR-654-5p on proliferation, inflammation and apoptosis in TNFα-induced HFLS-RA cells.

CONCLUSION

Our data suggested that circ_0003972 might promote the proliferation and inflammation of HFLS-RA cells to accelerate RA progression via regulating miR-654-5p/FZD4.

Interference with circRNA DOCK1 inhibits hepatocellular carcinoma cell proliferation, invasion and migration by regulating the miR-654-5p/SMAD2 axis

Hepatocellular carcinoma (HCC) is the fourth most common cause of cancer-related death worldwide. The aim of the present study was to discuss the role of circular RNA (circRNA) dedicator of cytokinesis 1 (DOCK1) in HCC and whether it can affect cell proliferation, invasion and migration by regulating the microRNA (miR)-654-5p/SMAD2 axis. The expression levels of circRNA DOCK1, miR-654-5p and SMAD2 mRNA in HCC cells and transfected Hep3b cells were detected by reverse transcription-quantitative PCR analysis. SMAD2 protein expression levels in HCC cells and transfected Hep3b cells were analyzed by western blot analysis. The viability, proliferation, migration and invasion of transfected Hep3b cells was in turn detected by Cell Counting Kit-8, clone formation, wound healing and Transwell assays. The interaction of circRNA DOCK1 and miR-654-5p, miR-654-5p and SMAD2 was confirmed by the dual-luciferase reporter assay. As a result, the expression of circRNA DOCK1 and SMAD2 was increased, and miR-654-5p was decreased in HCC cells. circRNA DOCK1 directly targeted to miR-654-5p and miR-654-5p directly targeted to SMAD2. Interference with circRNA DOCK1 inhibited the proliferation, invasion and migration of HCC cells by upregulating miR-654-5p expression. The effects of circRNA DOCK1 knockdown could be partially reversed by transfection with a miR-654-5p inhibitor and SMAD2 overexpression. In conclusion, interference with circRNA DOCK1 inhibited proliferation, invasion and migration of HCC cells by regulating the miR-654-5p/SMAD2 axis.

Long noncoding RNA ILF3-AS1 aggravates papillary thyroid carcinoma progression via regulating the miR-4306/PLAGL2 axis

BACKGROUND

It have been proven that long non-coding RNAs (lncRNAs) serve as regulators in carcinogenesis. Interleukin enhancer binding factor 3 antisense RNA 1 (ILF3-AS1) has been illuminated as a prognostic factor in some cancers. Nevertheless, its expression pattern and possible functions in papillary thyroid carcinoma (PTC) have not been studied.

METHODS

The expression of ILF3-AS1 was measured by RT-qPCR and ISH. Colony formation assay and EdU assay were used to probe cell proliferation. TUNEL assay was used for analysis of cell apoptosis. Immunofluorescence and western blot were conducted to evaluate the expression change of E-cadherin and N-cadherin. The RNA interaction was demonstrated by mechanism experiments, including pull down assay and dual luciferase reporter assay.

RESULTS

ILF3-AS1 expression was evidently upregulated in PTC cell lines. ILF3-AS1 knockdown restrained the proliferation, migration and invasion of PTC cells. Mechanical investigation revealed that miR-4306 could interact with ILF3-AS1. PLAGL2 was a downstream target of miR-4306. The effects of ILF3-AS1 knockdown on the cellular processes were abrogated by miR-4306 downregulation or pleiomorphic adenoma gene-like 2 (PLAGL2) overexpression.

CONCLUSION

ILF3-AS1 plays tumor-promoting role in PTC via targeting miR-4306/PLAGL2 axis.

Long non-coding RNA Lnc-408 promotes invasion and metastasis of breast cancer cell by regulating LIMK1

Invasion and metastasis are the leading causes of death in patients with breast cancer (BC), and epithelial-mesenchymal transformation (EMT) plays an essential role in this process. Here, we found that Lnc-408, a novel long noncoding RNA (lncRNA), is significantly upregulated in BC cells undergoing EMT and in BC tumor with lymphatic metastases compared with those without lymphatic metastases. Lnc-408 can enhance BC invasion and metastasis by regulating the expression of LIMK1. Mechanistically, Lnc-408 serves as a sponge for miR-654-5p to relieve the suppression of miR-654-5p on its target LIMK1. Knockdown or knockout of Lnc-408 in invasive BC cells clearly decreased LIMK1 levels, and ectopic Lnc-408 in MCF-7 cells increased LIMK1 expression to promote cell invasion. Lnc-408-mediated enhancement of LIMK1 plays a key role in cytoskeletal stability and promotes invadopodium formation in BC cells via p-cofilin/F-actin. In addition, the increased LIMK1 also facilitates the expression of MMP2, ITGB1, and COL1A1 by phosphorylating CREB. In conclusion, our findings reveal that Lnc-408 promotes BC invasion and metastasis via the Lnc-408/miR-654-5p/LIMK1 axis, highlighting a novel promising target for the diagnosis and treatment of BC.

miR‑654‑5p inhibits autophagy by targeting ATG7 via mTOR signaling in intervertebral disc degeneration

Intervertebral disc degeneration (IDD) is a common chronic disease characterized by the loss of extracellular matrix (ECM) in the nucleus pulposus (NP). Accumulating evidence has revealed that abnormal expression of microRNAs (miRs) is closely associated with IDD development. The present study aimed to investigate the precise role and possible mechanism underlying the effects of miR‑654‑5p in the pathogenesis of IDD. NP cells were isolated from patients with IDD. Monodansylcadaverine staining was conducted to reveal cell autophagy, while western blotting was performed to detect the expression of ECM‑related proteins in NP cells. Luciferase reporter and RNA immunoprecipitation assays were conducted to identify the binding between RNAs. The results demonstrated that miR‑654‑5p was significantly upregulated in degenerated NP tissues from patients with IDD and high miR‑654‑5p expression was positively associated with disc degeneration grade. Functional assays suggested that miR‑654‑5p facilitated ECM degradation by increasing the expression levels of MMP‑3, MMP‑9 and MMP‑13, as well as decreasing collagen I, collagen II, SOX9 and aggrecan expression by inhibiting autophagy. Furthermore, autophagy‑related gene 7 (ATG7) was verified as a direct downstream target gene of miR‑654‑5p. miR‑654‑5p could bind to the 3' untranslated region of ATG7 to inhibit its mRNA expression and further reduce its translation. Notably, ATG7 knockdown abrogated the effects of the miR‑654‑5p inhibitor on ECM degradation and autophagy regulation. Furthermore, miR‑654‑5p inhibited autophagy in NP cells by increasing the protein expression levels of phosphorylated (p)‑PI3K, p‑AKT and p‑mTOR in an ATG7‑dependent manner. In conclusion, the results of the present study revealed that miR‑654‑5p may enhance ECM degradation via inhibition of autophagy by targeting ATG7 to activate the PI3K/AKT/mTOR signaling pathway. These findings may provide novel insights into the treatment of IDD.

LncRNA ARAP1-AS1 aggravates the malignant phenotypes of ovarian cancer cells through sponging miR-4735-3p to enhance PLAGL2 expression

Ovarian cancer is one of the leading lethal gynecological cancers, causing serious harm to the health of female populations. Growing studies emphasize that lncRNAs serve as significant regulators in the tumorigenesis and evolution of numerous malignancies, including ovarian cancer. Recently, the oncogenic activity of lncRNA ARAP1-AS1 has been justified in a variety of cancers. However, the potential function of ARAP1-AS1 in ovarian cancer development is still unclear. Herein, we firstly revealed the expression profile of ARAP1-AS1 in ovarian cancer. Compared to normal samples and cells, upregulation of ARAP1-AS1 was observed in tissues and cells of ovarian cancer. Therewith, it was disclosed that knockdown of ARAP1-AS1 alleviated the carcinogenicity of ovarian cancer cells. Besides, our findings delineated that ARAP1-AS1 silence inhibited the expression of oncogene PLAGL2. Considering that ARAP1-AS1 was principally expressed in the the cytoplasm of ovarian cancer cells, we speculated that ARAP1-AS1 facilitated ovarian cancer progression via functioning as a ceRNA. Further investigations indicated that ARAP1-AS1 promoted PLAGL2 expression by competitively binding with miR-4735-3p. Of note, ARAP1-AS1 contributed to the malignant phenotypes of ovarian cancer cells through modulation of miR-4735-3p/PLAGL2 axis, revealing ARAP1-AS1 as a promising therapeutic target for ovarian cancer patients.

c-MYC and Epithelial Ovarian Cancer

Ovarian cancer is the deadliest of gynecological malignancies with approximately 49% of women surviving 5 years after initial diagnosis. The standard of care for ovarian cancer consists of cytoreductive surgery followed by platinum-based combination chemotherapy. Unfortunately, despite initial response, platinum resistance remains a major clinical challenge. Therefore, the identification of effective biomarkers and therapeutic targets is crucial to guide therapy regimen, maximize clinical benefit, and improve patient outcome. Given the pivotal role of c-MYC deregulation in most tumor types, including ovarian cancer, assessment of c-MYC biological and clinical relevance is essential. Here, we briefly describe the frequency of c-MYC deregulation in ovarian cancer and the consequences of its targeting.

LINC00261 relieves the progression of sepsis-induced acute kidney injury by inhibiting NF-κB activation through targeting the miR-654-5p/SOCS3 axis

Sepsis is a life-threatening disease, which can cause the dysfunction of multiple organs, including kidney. Recently, a number of studies found that the long non-coding RNA (lncRNA) is closely associated with the development and progression of sepsis; however, the role of long intergenic non-protein coding RNA 261 (LINC00261) in sepsis-induced acute kidney injury is poorly understood. In this study, we found the expression of LINC00261 was significantly decreased in the serum of patients with sepsis than healthy controls. A similar result was also observed in the mouse model of sepsis induced by lipopolysaccharide (LPS). Further investigations revealed that overexpression of LINC00261 improved the viability, suppressed the apoptosis and reduced the generation of inflammatory cytokines in LPS-treated HK-2 cells. Mechanistically, we confirmed that LINC00261 could function as a sponge to combine with microRNA-654-5p (miR-654-5p) which inhibits nuclear factor-κB (NF-κB) activity by targeting suppressor of cytokine signaling 3 (SOCS3). In conclusion, our results demonstrate that LINC00261 may regulate the progression of sepsis-induced acute kidney injury via the miR-654-5p/SOCS3/NF-κB pathway and therefore provides a new insight into the treatment of this disease.

Long non-coding RNAs in recurrent ovarian cancer: Theranostic perspectives

Nearly 70% of ovarian cancer (OC) patients experience recurrence within the first 2 years after initial treatment. Emerging evidence indicates that long non-coding RNAs (lncRNAs) play a pivotal role in the pathogenesis of OC progression, resistance to therapy and recurrent OC (ROC). Transcriptome profiling studies have reported differential expression patterns of lncRNAs in OC which are related to increased cell invasion, metastasis and drug resistance. In this review, we highlighted the roles of lncRNAs in OC progression and outlined the potential molecular mechanisms by which lncRNAs impact on ROC. Recent advances using lncRNAs as potential biomarkers for screening, detection, prediction, response to therapy and as therapeutic targets are discussed.

MicroRNA-153-5p promotes the proliferation and metastasis of renal cell carcinoma via direct targeting of AGO1

MicroRNAs (miRNAs) have been demonstrated to affect the biological processes of cancers and showed great potential for prognostic biomarkers. In this study, we screened differentially expressed miRNAs in ccRCC based on three dimensions of metastasis, prognosis, and differential expression compared to normal tissue using bioinformatics algorithms. MiR-153-5p was identified as a candidate miRNA to promote ccRCC occurrence and progression. Clinically, we found that miR-153-5p was significantly upregulated and related to unfavorable clinical features in ccRCC. Besides, miR-153-5p served as an independent prognostic biomarker. Functionally, miR-153-5p depletion remarkably inhibited the proliferation and metastasis of ccRCC via the phosphatidylinositol 3-kinase (PI3K)/Akt signaling. Furthermore, AGO1 was proved to be a direct target of miR-153-5p. AGO1 is associated with favorable clinical features and exhibited independent prognostic value in ccRCC. Besides, we observed that AGO1 knockdown significantly promoted tumor proliferation and metastasis. Downregulation of AGO1 partly abolished the oncogenic effects of miR-153-5p knockdown. Furthermore, miR-153-5p combined with AGO1 showed more robust prognostic significance in ccRCC. In conclusion, we found that the newly identified miR-153-5p/AGO1 axis was responsible for tumor occurrence and progression via PI3K/Akt signaling, which may therefore provide promising therapeutic targets and prognostic biomarkers for patients with ccRCC.

Processing of Alu small RNAs by DICER/ADAR1 complexes and their RNAi targets

In addition to adenosine-to-inosine RNA editing activities, ADAR1 has been shown to have various RNA editing-independent activities including modulation of RNAi efficacy. We previously reported that ADAR1 forms a heterodimer complex with DICER and facilitates processing of pre-miRNAs to mature miRNAs. In addition to miRNA synthesis, DICER is involved in processing of long dsRNAs into small RNAs (endo-siRNAs). Generation of retrotransposon-derived endo-siRNAs by DICER and their functions in regulation of transcripts in mouse oocytes has been previously reported. However, the synthesis and functions of endo-siRNAs in somatic cells remain largely unknown. Here, we report that ADAR1 together with DICER generates endogenous small RNAs, Alu endo-siRNAs by cleaving long double-stranded regions of inverted Alu repeats. We identified AGO2-loaded Alu endo-siRNAs, which are highly expressed in commonly used cell lines. These Alu endo-siRNAs carrying both sense and antisense Alu sequences seem to target a set of genes containing a single Alu sequence, either antisense or sense, respectively, within their 3'UTR. In silico screening identified potential RNA silencing target genes for these Alu endo-siRNAs. We present results of a proof-of-concept experiment, in which sense Alu endo-siRNAs derived from AluSz and AluJr family elements target CUB Domain Containing Protein 1 mRNAs containing an antisense copy of AluJb in their 3'UTRs and consequently induce apoptosis in HeLa cells. Our results clearly indicate that Alu endo-siRNAs are functional also in somatic cells.

Inferences of individual differences in response to tripterysium glycosides across patients with Rheumatoid arthritis using a novel ceRNA regulatory axis

BACKGROUND

To identify biomarkers for guiding therapy and predicting clinical response of Tripterysium Glycosides Tablets (TGT) treatment is an urgent task due to individual differences in TGT response across rheumatoid arthritis (RA) patients. Competing endogenous RNA (ceRNA) regulatory system may influence drug response with involvement in diverse biological processes. Herein, we aimed to identify a TGT response-related ceRNA axis.

METHODS

A TGT response-related ceRNA axis was screened according to clinical cohort-based RNA expression profiling, lncRNA-mRNA coexpression, and ceRNA network analyses. Its clinical relevance was evaluated by computational modeling. Regulatory mechanisms of ceRNA axis were also experimentally investigated.

RESULTS

The ceRNA regulatory axis combined with lncRNA ENST00000494760, miR-654-5p, and C1QC was identified as a candidate biomarker for RA patients' response to TGT. Both ENST00000494760 and C1QC mRNA expression were significantly lower, while miR-654-5p expression was dramatically higher in TGT responders than nonresponders. Its clinical relevance was verified by computational modeling based on both independent clinical validation cohort and collagen-induced arthritis (CIA) mice. Mechanistically, miR-654-5p directly bound to the 3'-untranslated region of both ENST00000494760 and C1QC mRNA to inhibit their expression. Moreover, miR-654-5p suppressed C1QC mRNA expression, but ENST00000494760 bound to miR-654-5p and relieved its repression on C1QC mRNA, leading to RA aggressive progression and weak TGT response.

CONCLUSIONS

LncRNA ENST00000494760 overexpression may sponge miR-654-5p to promote C1QC expression in RA patients. This novel ceRNA axis may serve as a biomarker for screening the responsive RA patients to TGT treatment, which will allow improved personalized healthcare.

Back to the Future: Rethinking the Great Potential of lncRNAS for Optimizing Chemotherapeutic Response in Ovarian Cancer

Ovarian cancer (OC) is one of the most fatal cancers in women worldwide. Currently, platinum- and taxane-based chemotherapy is the mainstay for the treatment of OC. Yet, the emergence of chemoresistance results in therapeutic failure and significant relapse despite a consistent rate of primary response. Emerging evidence substantiates the potential role of lncRNAs in determining the response to standard chemotherapy in OC. The objective of this narrative review is to provide an integrated, synthesized overview of the current state of knowledge regarding the role of lncRNAs in the emergence of resistance to platinum- and taxane-based chemotherapy in OC. In addition, we sought to develop conceptual frameworks for harnessing the therapeutic potential of lncRNAs in strategies aimed at enhancing the chemotherapy response of OC. Furthermore, we offered significant new perspectives and insights on the interplay between lncRNAs and the molecular circuitries implicated in chemoresistance to determine their impacts on therapeutic response. Although this review summarizes robust data concerning the involvement of lncRNAs in the emergence of acquired resistance to platinum- and taxane-based chemotherapy in OC, effective approaches for translating these lncRNAs into clinical practice warrant further investigation.

Cancer and SOX proteins: New insight into their role in ovarian cancer progression/inhibition

Transcription factors are potential targets in disease therapy, particularly in cancer. This is due to the fact that transcription factors regulate a variety of cellular events, and their modulation has opened a new window in cancer therapy. Sex-determining region Y (SRY)-related high-mobility group (HMG) box (SOX) proteins are potential transcription factors that are involved in developmental processes such as embryogenesis. It has been reported that abnormal expression of SOX proteins is associated with development of different cancers, particularly ovarian cancer (OC). In the present review, our aim is to provide a mechanistic review of involvement of SOX members in OC. SOX members may suppress and/or promote aggressiveness and proliferation of OC cells. Clinical studies have also confirmed the potential of transcription factors as diagnostic and prognostic factors in OC. Notably, studies have demonstrated the relationship between SOX members and other molecular pathways such as ST6Ga1-I, PI3K, ERK and so on, leading to more complexity. Furthermore, SOX members can be affected by upstream mediators such as microRNAs, long non-coding RNAs, and so on. It is worth mentioning that the expression of each member of SOX proteins is corelated with different stages of OC. Furthermore, their expression determines the response of OC cells to chemotherapy. These topics are discussed in this review to shed some light on role of SOX transcription factors in OC.

miR-3609 Decelerates the Clearance of Sorafenib in Hepatocellular Carcinoma Cells by Targeting EPAS-1 and Reducing the Activation of the Pregnane X Receptor Pathway

Background

The pregnane X receptor (PXR) not only plays an important role in cellular metabolism processes but also induces the resistance of hepatocellular carcinoma (HCC) cells to molecularly targeted drugs by mediating their metabolism and clearance by these cells. Endothelial PAS domain-containing protein 1 (EPAS-1) acts as a coactivator to regulate the transcription factor activity of PXR. In the present study, a microRNA that potentially targets EPAS-1, namely miR-3609, was identified using the miRDB tool.

Methods

The expression of miR-3609 and EPAS-1 was examined by qPCR. Lentiviral particles containing the full-length sequences of miR-3609 (pri-miR-3609) were prepared. The antitumor effect of antitumor agents was examined by the in vitro and in vivo assays.

Results

The expression of miR-3609 was negatively correlated with that of EPAS-1 in both HCC clinical specimens and paired non-tumor specimens, and the effect of miR-3609 on the expression of EPAS-1 was confirmed by Western blot experiments. Overexpression of miR-3609 decreased the expression of EPAS-1 and, in turn, repressed the activation of the PXR pathway. miR-3609 decreased the transcription factor activation of PXR, repressed its recruitment to its target gene promoter regions, and decreased the expression of its target genes CYP3A4 and P-GP. In addition, miR-3609 decelerated the metabolism and clearance of sorafenib in HCC cells and enhanced the antitumor effect of sorafenib in HCC cells.

Conclusion

Therefore, the results indicate that miR-3609 decreases the expression of EPAS-1 and enhances the sensitivity of HCC cells to sorafenib.

circCELSR1 facilitates ovarian cancer proliferation and metastasis by sponging miR-598 to activate BRD4 signals

Background

Ovarian cancer is one of the most common gynecologic cancers and has high mortality rate due to the lack of early diagnosis method and efficient therapeutic agents. circCELSR1 is up-regulated in ovarian cancer, but its role and mechanisms in ovarian cancer are unclear.

Methods

Gene expression of circCELSR1, miR-598 and BRD4 in ovarian cells was examined by qRT-PCR. Protein level was determined by Western blotting. Bioinformatic analysis and luciferase assay determined the molecular binding among circCELSR1, miR-598 and BRD4 3′ UTR. Cell proliferation, migration, invasion and apoptosis were determined by colony formation, wound healing assay, transwell assay and flow cytometry analysis, respectively. An abdominal cavity metastasis nude mice model was used to determine the in vivo function of circCELSR1.

Results

circCELSR1 and BRD4 were promoted, but miR-598 was suppressed in various ovarian cancer cells. circCELSR1 bound to miR-598 and promoted expression of its downstream target BRD4. Knockdown of circCELSR1 suppressed proliferation, migration, invasion and epithelial-mesenchymal transition (EMT), but promoted apoptosis in ovarian cancer cells, and these effects were reversed by miR-598 inhibition or BRD4 overexpression. circCELSR1 inhibition decreased the expression of BRD4 and its downstream proliferation/migration related genes by targeting miR-598. Furthermore, knockdown of circCELSR1 suppressed ovarian cancer growth and metastasis in nude mice.

Conclusion

Knockdown of circCELSR1 inhibited BRD4-mediated proliferation/migration related signaling via sponging miR-598, thereby repressing ovarian cancer progression. This study provides a new regulatory mechanism of ovarian cancer may facilitate the development of therapeutic agents for ovarian cancer.

Hsa_circ_0009910: oncogenic circular RNA targets microRNA-145 in ovarian cancer cells

Circular RNAs (circRNAs) correlate with cancer cell phenotypes. Particularly, circRNAs mediate the cancer process as microRNAs (miRNAs) sponges. This study was to ascertain the roles of hsa_circ_0009910 in phenotypic aspects of ovarian cancer cells. Mantel-Cox test was performed to analyze the correlation between hsa_circ_0009910 and survival outcomes of ovarian cancer. Minigene reporter was constructed and small interfering-RNA was designed for constructing hsa_circ_0009910-dysregulated and miR-145-upregulated cells identified by qRT-PCR. Proliferative and motile activities were monitored by CCK and Transwell. Western blot was applied for quantification of cyclin D1, CDK4, CDK6, MMP-2, MMP-9, IκBα, p65, Notch1, Hes1, and Hes5. miRNAs targets were predicted using a bioinformatics tool and confirmed using qRT-PCR and Dual-Luciferase reporter assay. Hsa_circ_0009910 was correlated with the poor prognosis of ovarian cancer patients. The ovarian cancer cell phenotypes were promoted by hsa_circ_0009910 while repressed by silencing hsa_circ_0009910. Hsa_circ_0009910 silence was responsible for the upregulation of the predicted miRNAs targets. Thereinto, miR-145 was confirmed as a miRNA target and negatively regulated by hsa_circ_0009910. miR-145 nullified the biological function of hsa_circ_0009910 in the proliferative and motile phenotypes, and the active status of NF-κB and Notch. Hsa_circ_0009910, representing unfavorable prognosis, induced proliferative and motile phenotypes by suppressing miR-145 in ovarian cancer cells.

microRNAs as biomarkers of ovarian cancer

Introduction: Ovarian carcinoma (OC) is the leading cause of death in women with gynecologic cancers. Most patients are diagnosed at an advanced stage with a low five-year survival rate of 20-30%. Discovering novel biomarkers for early detection and outcome prediction of OC is an urgent medical need. miRNAs, a group of small non-coding RNAs, play critical roles in multiple biologic processes and cancer pathogenesis.Areas covered: We provide an in-depth look at the functions of miRNAs in OC, particularly focusing on their roles in chemoresistance and metastasis in OC. We also discuss the biological and clinical significance of miRNAs in exosomes and expand on long non-coding RNA which acts as ceRNA of miRNAs.Expert opinion: miRNAs participate in many biological processes including proliferation, apoptosis, chemoresistance, metastasis, epithelial-mesenchymal transition, and cancer stem cell. They will substantially contribute to our understanding of OC pathogenesis. Given their resistance to the degradation of ribonucleases and availability in plasma exosomes, miRNAs may serve as emerging biomarkers for cancer detection, therapeutic assessment, and prognostic prediction. Being a messenger, exosomal miRNAs are crucial for the crosstalk between cancer cells and stromal cells in tumor microenvironment.

Aurora Borealis (Bora), Which Promotes Plk1 Activation by Aurora A, Has an Oncogenic Role in Ovarian Cancer

Identifying novel actionable factors that critically contribute to tumorigenesis is essential in ovarian cancer, an aggressive and disseminative tumor, with limited therapeutic options available. Here we show that Aurora Borealis (BORA), a mitotic protein that plays a key role in activating the master mitotic kinase polo-like kinase 1 (PLK1), has an oncogenic role in ovarian cancer. Gain and loss of function assays on mouse models and ex vivo patient-derived ascites cultures revealed an oncogenic role of BORA in tumor development and a transcriptome-analysis in clinically representative models depicted BORA's role in survival, dissemination and inflammatory cancer related-pathways. Importantly, combinatory treatments of FDA-approved inhibitors against oncogenic downstream effectors of BORA displayed synergistic effect in ovarian cancer models, offering promising therapeutic value. Altogether, our findings uncovered for the first time a critical role of BORA in the viability of human cancer cells providing potential novel therapeutic opportunities for ovarian cancer management.

Tumor-suppressor microRNA-139-5p restrains bladder cancer cell line ECV-304 properties via targeting Connexin 43

Background:

In our previous paper, we demonstrated that Connexin 43 (CX43) was highly expressed in bladder cancer (BC) tissues. But the molecular mechanism about microRNAs (miRNAs) regulation upstream of CX43 in BC has not been well elucidated and remains to be further studied. MicroRNA-139-5p (miR-139-5p) is a tumor suppressor in progression of multifarious cancers including BC. Nevertheless, the underlying mechanisms of CX43/miR-139-5p in tumorigenesis of BC are still not well illustrated. The specific objective of our study was to inquiry the effect of CX43/miR-139-5p on BC progression and its underlying mechanism.

Methods:

The bioinformatics analysis softwares were applied to predict the miRNAs in the upstream of CX43. First, the expression levels of miR-139-5p in BC tissues (tumor) and paracancer tissues (normal) were investigated using the data from The Cancer Genome Atlas database. Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) was used to detect the mRNA expression level of miR-139-5p in three human BC cell lines 5637, T24, ECV-304 and a human bladder epithelial immortalized cell line SV-HUC-1 (normal control). Then si-CX43, si-control, miR-139-5p mimic, and its negative control (NC) were transfected into BC cell line ECV-304. The relationship of miR-139-5p and CX43 was analyzed by dual-luciferase reporter assay. The qRT-PCR and Western blotting were used to test the mRNA and protein expression level of CX43. The proliferation of ECV-304 and T24 cells were examined by cell counting kit-8. The migration and invasion of ECV-304 cells were tested by transwell assay. To determine whether miR-139-5p would affect cell proliferation, migration and invasion by targeting CX43, we executed the rescue assay. The comparison between two groups was analyzed by Student's t test, and comparisons among multiple samples were performed by one-way analysis of variance and a Bonferroni post hoc test.

Results:

The expression of miR-139-5p was remarkably down-regulated in BC tissues (tumor vs. normal, 2.286 ± 0.017 vs. 3.211 ± 0.034, t = 11.540, P < 0.0001) and cell lines (P < 0.01 in all BC cell lines). Besides, we also indicated that over-expression of miR-139-5p reduced the proliferation of ECV-304 (P = 0.001) and T24 cells (P = 0.005). Moreover, miR-139-5p over-expression weakened the invasion (P = 0.001) and migration (P = 0.001) of ECV-304 cells. Furthermore, the relative luciferase activity of CX43-wild type construct was distinctly lessened by up-regulation of miR-139-5p (miR-139-5p mimic NC vs. miR-139-5p mimic, 0.916 ± 0.063 vs. 0.356 ± 0.048, t = 7.085, P = 0.002), nevertheless the activity of CX43-mutant type construct was untouched (miR-139-5p mimic NC vs. miR-139-5p mimic, 0.918 ± 0.057 vs. 0.878 ± 0.039, t = 0.577, P = 0.595). Finally, the rescue assay revealed that CX43 deletion enhanced the depressor effect of miR-139-5p on ECV-304 cell proliferation (P < 0.01), invasion (P = 0.028), and migration (P = 0.014).

Conclusion:

MiR-139-5p, as a tumor-suppressor, repressed cell proliferation, invasion, and migration in BC, which might be achieved by regulating CX43.

miR-654-5p Targets HAX-1 to Regulate the Malignancy Behaviors of Colorectal Cancer Cells

Introduction. The biological roles of microRNA-654-5p (miR-654-5p) in cancers have been previously reported. However, its role in colorectal cancer (CRC) remains largely unknown. The purpose of this work was to investigate the roles and associated mechanisms in CRC.

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.

Wnt Signaling in Ovarian Cancer Stemness, EMT, and Therapy Resistance

Ovarian cancers represent the deadliest among gynecologic malignancies and are characterized by a hierarchical structure with cancer stem cells (CSCs) endowed with self-renewal and the capacity to differentiate. The Wnt/β-catenin signaling pathway, known to regulate stemness in a broad spectrum of stem cell niches including the ovary, is thought to play an important role in ovarian cancer. Importantly, Wnt activity was shown to correlate with grade, epithelial to mesenchymal transition, chemotherapy resistance, and poor prognosis in ovarian cancer. This review will discuss the current knowledge of the role of Wnt signaling in ovarian cancer stemness, epithelial to mesenchymal transition (EMT), and therapy resistance. In addition, the alleged role of exosomes in the paracrine activation of Wnt signaling and pre-metastatic niche formation will be reviewed. Finally, novel potential treatment options based on Wnt inhibition will be highlighted.

MicroRNA-6077 enhances the sensitivity of patients-derived lung adenocarcinoma cells to anlotinib by repressing the activation of glucose transporter 1 pathway

Anlotinib is a novel molecular targeted agent targeting the vascular endothelial growth factor receptor, which differs from the other currently available non-small cell lung cancer (NSCLC) molecular targeted drugs targeting this receptor. Although the application of anlotinib may bring new hope for patients with advanced NSCLC, the cost of treatment is high. The results of this study showed that microRNA-6077 (miR-6077) represses the expression of GLUT1 (glucose transporter 1) and enhances the sensitivity of patient-derived lung adenocarcinoma (AC) cells to anlotinib. The miR-6077, which potentially binds to the 3'untranslated region of GLUT1, was identified and screened by miRDB, an online tool; sequences of miR-6077 were prepared as lentivirus particles. A549 cells (a lung adenocarcinoma cell line) and five patient-derived AC cell lines were infected with control miRNA or miR-6077, and subsequently treated with the indicated concentration of anlotinib. The expression of proteins, such as GLUT1, was determined by western blotting. The antitumor effect of anlotinib was identified through in-vitro (e.g., MTT) or in-vivo methods (e.g., subcutaneous tumor model). Overexpression of miR-6077 repressed the expression of GLUT1 and decreased the glucose uptake, lactate production, or ATP generation in AC cells. In addition, MiR-6077 may enhance the antitumor effect of anlotinib on A549 or patient-derived AC cell lines. Therefore, our results indicated that miR-6077 represses the expression of GLUT1 and enhances the sensitivity of patients-derived lung AC cells to anlotinib.