Silencing microRNA-27a inhibits proliferation and invasion of human osteosarcoma cells through the SFRP1-dependent Wnt/β-catenin signaling pathway

MTF2 facilitates the advancement of osteosarcoma through mediating EZH2/SFRP1/Wnt signaling

BACKGROUND

Osteosarcoma is a soft tissue neoplasm with elevated recurrence risk and highly metastatic potential. Metal response element binding transcriptional factor 2 (MTF2) has been revealed to exert multiple activities in human tissues. The present research was conducted to explore the functions and related response mechanism of MTF2 in osteosarcoma which have not been introduced yet.

METHODS

Bioinformatics tools identified the differential MTF2 expression in osteosarcoma tissues. MTF2 expression in osteosarcoma cells was examined with Western blot. Cell Counting Kit-8 (CCK-8) assay, 5-Ethynyl-2'-deoxyuridine (EDU) staining, wound healing as well as transwell assays measured cell proliferation, migration and invasion, respectively. Flow cytometry assay detected the cellular apoptotic level. Western blot also measured the expressions of proteins associated with epithelial mesenchymal transition (EMT), apoptosis and enhancer of zeste homolog 2 (EZH2)/secreted frizzled-related protein 1 (SFRP1)/Wnt signaling. Co-immunoprecipitation (Co-IP) assay confirmed MTF2-EZH2 interaction.

RESULTS

MTF2 expression was increased in osteosarcoma tissues and cells. MTF2 interference effectively inhibited the proliferation, migration and invasion of osteosarcoma cells and promoted the cellular apoptotic rate. MTF2 directly bound to EZH2 and MTF2 silence reduced EZH2 expression, activated SFRP1 expression and blocked Wnt signaling in osteosarcoma cells. EZH2 upregulation or SFRP1 antagonist WAY-316606 partly counteracted the impacts of MTF2 down-regulation on the SFRP1/Wnt signaling and the biological phenotypes of osteosarcoma cells.

CONCLUSIONS

MTF2 might down-regulate SFRP1 to activate Wnt signaling and drive the progression of osteosarcoma via interaction with EZH2 protein.

Targeting the Wnt/β-catenin cascade in osteosarcoma: The potential of ncRNAs as biomarkers and therapeutics

Osteosarcoma (OS) is a bone cancer which stems from several sources and presents with diverse clinical features, making evaluation and treatment difficult. Chemotherapy tolerance and restricted treatment regimens hinder progress in survival rates, requiring new and creative therapeutic strategies. The Wnt/β-catenin system has been recognised as an essential driver of OS development, providing potential avenues for therapy. Non-coding RNAs (ncRNAs), such as circular RNAs (circRNAs), long non-coding RNAs (lncRNAs), and microRNAs (miRNAs), are essential in modulating the Wnt/β-catenin cascade in OS. MiRNAs control the system by targeting vital elements, while lncRNAs and circRNAs interact with system genes, impacting OS growth and advancement. This paper thoroughly analyses the intricate interplay between ncRNAs and the Wnt/β-catenin cascade in OS. We examine how uncontrolled levels of miRNAs, lncRNAs, and circRNAs lead to an abnormal Wnt/β-catenin network, which elevates the development, spread, and susceptibility to the treatment of OS. We emphasise the potential of ncRNAs as diagnostic indicators and avenues for treatment in OS care. The review offers valuable insights for academics and clinicians studying OS aetiology and creating new treatment techniques for the ncRNA-Wnt/β-catenin cascade. Utilising the oversight roles of ncRNAs in the Wnt/β-catenin system shows potential for enhancing the outcomes of patients and progressing precision medicine in OS therapy.

LncRNA MEG3 inhibits the proliferation and migration abilities of colorectal cancer cells by competitively suppressing MiR-31 and reducing the binding of MiR-31 to target gene SFRP1

To explore the potential mechanism of long-chain non-coding ribonucleic acid (lncRNA) maternal expression gene 3 (MEG3) in colorectal cancer (CRC). The relationship between MEG3 and miR-31 was detected by dual-luciferase assay. Quantitative polymerase chain reaction was utilized to determine the expression of MEG3 in CRC cell lines. Cell Counting Kit-8 assay was performed to detect cell proliferation. Transwell, cell scratch wound assay, and monoclonal proliferation assay were used to detect the proliferation, migration, and invasion of cells. In addition, cell motility was evaluated by detecting the expression of cellular pseudopodia protein α-actinin via immunofluorescence assay, and cell proliferation and motility were judged by determining the expressions of Ki-67, MMP2 and MMP9 via Western blotting. The effect of MEG3 and miR-31 on the development of colorectal cancer was verified by nude mouse tumor-bearing assay and HE staining. Transient transfection with MEG3 overexpression plasmid revealed that MEG3 inhibited the proliferation and motility of cells. The results of dual-luciferase assay showed that MEG3 could specifically inhibit the expression of miR-31, which inhibits the development of colorectal cancer. Transwell, cell scratch wound assay, and monoclonal proliferation experiment showed that miR-31 enhanced cell proliferation, migration and invasion. MEG3 overexpression plasmid was capable of reversing the proliferation and motility of CRC cells enhanced by miR-31. MEG3 can inhibit the proliferation and motility of CRC cells by competitively suppressing the binding of miR-31 to the target gene SFRP1, thus playing an inhibitory role in the pathogenesis of CRC.

A spotlight on the interplay of signaling pathways and the role of miRNAs in osteosarcoma pathogenesis and therapeutic resistance

Osteosarcoma (OS) is one of the most common bone cancers that constantly affects children, teenagers, and young adults. Numerous epigenetic elements, such as miRNAs, have been shown to influence OS features like progression, initiation, angiogenesis, and treatment resistance. The expression of numerous genes implicated in OS pathogenesis might be regulated by miRNAs. This effect is ascribed to miRNAs' roles in the invasion, angiogenesis, metastasis, proliferation, cell cycle, and apoptosis. Important OS-related mechanistic networks like the WNT/b-catenin signaling, PTEN/AKT/mTOR axis, and KRAS mutations are also affected by miRNAs. In addition to pathophysiology, miRNAs may influence how the OS reacts to therapies like radiotherapy and chemotherapy. With a focus on how miRNAs affect OS signaling pathways, this review seeks to show how miRNAs and OS are related.

Non-Coding RNA-Dependent Regulation of Mitochondrial Dynamics in Cancer Pathophysiology

Mitochondria are essential organelles which dynamically change their shape and number to adapt to various environmental signals in diverse physio-pathological contexts. Mitochondrial dynamics refers to the delicate balance between mitochondrial fission (or fragmentation) and fusion, that plays a pivotal role in maintaining mitochondrial homeostasis and quality control, impinging on other mitochondrial processes such as metabolism, apoptosis, mitophagy, and autophagy. In this review, we will discuss how dysregulated mitochondrial dynamics can affect different cancer hallmarks, significantly impacting tumor growth, survival, invasion, and chemoresistance. Special emphasis will be given to emerging non-coding RNA molecules targeting the main fusion/fission effectors, acting as novel relevant upstream regulators of the mitochondrial dynamics rheostat in a wide range of tumors.

Marsdenia tenacissima extract prevents the malignant progression of glioma through upregulating lncRNA MEG3 and SFRP1-dependent inhibition of Wnt/β-catenin pathway

BACKGROUND/AIM

Recent studies have highlighted the tumor-suppressive effect of Marsdenia tenacissima extract (MTE) on human cancers. This research unveils the potential impact of MTE on glioma and ascertains the relevant molecular mechanisms.

METHODS

Glioma cells were treated with MTE, with normal human astrocytes (NHAs) as controls. A battery of function experiments, including the CCK-8 viability test, colony formation assay, scratch migration assay, and Transwell invasion assay, was executed to address the responses of glioma cells to MTE treatment and gain or loss of function of lncMEG3, miR-542-3p, and SFRP1. FISH, RIP, and dual-luciferase reporter assays were adopted for assessing gene interactions. U251-GFP-Luc cells were delivered into nude mice through intracranial injection to develop an orthotopic glioma model for in vivo validation.

RESULTS

200 mg/mL MTE could suppress the proliferating, migrating, and invading properties of glioma cells but not affect those of NHAs. MTE treatment enhanced the expression of lncMEG3, which competes with SFRP1 for binding miR-542-3p. SFRP1 could inactivate the Wnt/β-catenin pathway. Animal experimentation substantiated the antitumor activity and mechanism of MTE in nude mice.

CONCLUSIONS

MTE suppresses glioma via the lncMEG3/miR-542-3p/SFRP1/Wnt/β-catenin axis. These findings contribute to a theoretical basis for the use of MTE for glioma patients.

Evaluation of osteogenic induction potency of miR-27a-3p in adipose tissue-derived human mesenchymal stem cells (AD-hMSCs)

BACKGROUND

Bone tissue as a dynamic tissue is able to repair its minor injuries, however, sometimes the repair cannot be completed by itself due to the size of lesion. In such cases, the best treatment could be bone tissue engineering. The use of stem cells in skeletal disorders to repair bone defects has created bright prospects. On the other hand, changes in the expression level of microRNAs (miRs) can lead to the commitment of mesenchymal stem cells (MSCs) to cell lineage. Many studies reported that post-transcriptional regulations by miRNAs are involved in all stages of osteoblast differentiation.

METHOD

After the preparing adipose tissue-derived mesenchymal stem cells, the target cells from the third passage were cultured in two groups, transfected MSCs with miR-27a-3p (DM.C + P) and control group. In different times, 7 and 14 days after culture, differentiation of these cells into osteoblast were measured using various techniques including the ALP test and calcium content test, Alizarin Red staining, Immunocytochemistry technique (ICC). Also, the relative expression of bone differentiation marker genes including Osteonectin (ON), Osteocalcin (OC), RUNX Family Transcription Factor 2 (RUNX2), Collagen type I alpha 1 (COL1) was investigated by real-time RT PCR.

RESULTS

In comparison with control groups, overexpression of miR-27a-3p in transfected cells resulted in a significant increase in the expression of bone markers genes (ON, OC, RUNX2, COL1), alkaline phosphatase (ALP) activity, and calcium content (p < 0.05). In addition, the results obtained from ICC technique showed that osteocalcin protein is expressed at the surface of bone cells. Furthermore, the expression of APC, as a target of miR-27a-3p, decreased in transfected cells.

CONCLUSION

Our data suggest that miR-27a-3p may positively regulates adipose tissue-derived mesenchymal stem cell differentiation into bone by targeting APC and activating the Wnt/b-catenin pathway.

MicroRNAs and osteosarcoma: Potential targets for inhibiting metastasis and increasing chemosensitivity

Osteosarcoma (OS) is the third most common cancer in young adults after lymphoma and brain cancer. Metastasis, like other cellular events, is dependent on signaling pathways; a series of changes in some proteins and signaling pathways pave the way for OS cells to invade and migrate. Ezrin, TGF-β, Notch, RUNX2, matrix metalloproteinases (MMPs), Wnt/β-catenin, and phosphoinositide 3-kinase (PI3K)/AKT are among the most important of these proteins and signaling pathways. Despite the improvements in treating OS, the overall survival of patients suffering from the metastatic disease has not experienced any significant change after surgical treatments and chemotherapy and 5-years overall survival in patients with metastatic OS is about 20%. Studies have shown that overexpression or inhibition of some microRNAs (miRNAs) has significant effects in limiting the invasion and migration of OS cells. The results of these studies highlight the potential of the clinical application of some miRNA mimics and miRNA inhibitors (antagomiRs) to inhibit OS metastasis in the future. In addition, some studies have shown that miRNAs are associated with the most important drug resistance mechanisms in OS, and some miRNAs are highly effective targets to increase chemosensitivity. The results of these studies suggest that miRNA mimics and antagomiRs may be helpful to increase the efficacy of conventional chemotherapy drugs in the treatment of metastatic OS. In this article, we discussed the role of various signaling pathways and the involved miRNAs in the metastasis of OS, attempting to provide a comprehensive review of the literature on OS metastasis and chemosensitivity.

Quercetin potentiates 5-fluorouracil effects in human colon cancer cells through targeting the Wnt/β-catenin signalling pathway: the role of miR-27a

INTRODUCTION

5-fluorouracil (5-FU) is the most widely used chemotherapeutic drug in treating colorectal cancer. However, its toxicity to normal tissues and tumour resistance are the main hurdles to efficient cancer treatment. MiR27-a promotes the proliferation of colon cancer cells by stimulating the Wnt/β-catenin pathway. The present study was conducted to examine whether quercetin (Q) combined with 5-FU improves the anti-proliferative effect of 5-FU on HCT-116 and Caco-2 cell lines through detection of the miR-27a/Wnt/β-catenin signalling pathway.

MATERIAL AND METHODS

Cell viability in HCT-116 and Caco-2 cell lines following quercetin and 5-FU treatment alone and in combination for 48 hours was determined using the MTT assay. The flow cytometry, quantitative real-time polymerase chain reaction, and ELISA techniques were used.

RESULTS

Our results showed that combination of quercetin and 5-FU exhibited greater cytotoxic efficacy than did 5-FU alone. Co-administration of both drugs either in combination 1 (1 : 1 Q: 5-FU) or in combination 2 (1 : 0.5 Q: 5-FU) enhanced apoptosis in HCT-116 and Caco-2 cells compared with 5-FU alone and significantly inhibited the expression of miR-27a, leading to upregulation of secreted frizzled-related protein 1 and suppression of Wnt/β-catenin signalling, which was confirmed by a significant decrease in cyclin D1 expression.

CONCLUSIONS

Quercetin strongly enhanced 5-FU sensitivity via suppression of the miR-27a/Wnt/β-catenin signalling pathway in CRC, which advocates further research of this combination with the lower dose of 5-FU.

Mesenchymal Stem Cell-Derived Extracellular Vesicles Inhibit Osteoporosis via MicroRNA-27a-Induced Inhibition of DKK2-Mediated Wnt/β-Catenin Pathway

Osteoporosis (OP) is a systemic skeletal disease that promotes bone fragility and the risk of fractures. Recent studies have shown the relevance of microRNAs (miRNAs) in the development of OP. This study aimed to evaluate the possible mechanisms of action underlying miR-27a loaded by mesenchymal stem cell (MSC)-derived extracellular vesicles (MSC-EVs) in OP. Serum samples from OP patients and normal controls were collected for miRNA microarray analysis. The expression of filtered miRNA was upregulated in osteoblasts (OB) and osteoclasts (OCs) for biological activity assessment. After developing OP mice using ovariectomy (OVX) and confirming OP, the miR-27a expression level was upregulated in mice by MSC-EV application. Dual-luciferase assays were conducted to validate the relationship between miR-27a and DKK2 expression. The poor expression of miR-27a was observed in patients with OP. miR-27a increased the expression of OB markers, the number of ALP-positive cells, and the number of calcium nodules in OCs. In OVX mice, miR-27a increased bone density, improved bone structure damage recovery, decreased the levels of bone resorption markers, and decreased OC number. miR-27a transmitted by MSC-EVs interacted with DKK2. MSC-EVs exerted the same protective effects as miR-27a on OP, whereas miR-27a inhibitor abolished the attenuating effects of MSC-EVs. In contrast, DKK2 depletion reversed the stimulatory effects of the miR-27a inhibitor on OP. The Wnt/β-catenin pathway was activated upon MSC-EV application and DKK2 silencing and was impaired upon the downregulation of the expression of miR-27a. MSC-EVs are effective in preventing mouse OP. This mechanism is mediated by the miR-27a/DKK2/Wnt/β-catenin signaling pathway.

Targeting Wnt/β-catenin signaling by microRNAs as a therapeutic approach in chemoresistant osteosarcoma

Osteosarcoma (OS) is an adolescent and young adult malignancy that mostly occurs in long bones. The treatment of OS is still a big challenge for clinicians due to increasing chemoresistance, and many efforts are being made today to find more beneficial treatments. In this regard, the use of microRNAs has shown a high capacity to develop promising therapies. By targeting cancer-involved signaling pathways, microRNAs reduce the cellular level of these protein pathways; thereby reducing the growth and invasion of tumors, and even leading cancer cells to apoptosis. One of these oncogenic pathways that play an important role in OS development and can be targeted by microRNAs is the Wnt/β-catenin signaling pathway. Hence, the first goal of this review article is to explain the cross-talk of microRNAs and the Wnt/β-catenin signaling in OS and then discussing recent findings of the use of microRNAs as a therapeutic approach in OS.

Damage-Associated Molecular Patterns Modulation by microRNA: Relevance on Immunogenic Cell Death and Cancer Treatment Outcome

Simple Summary

Inside the cell, damage-associated molecular pattern molecules (DAMPs) play several physiological functions, but when they are released or translocated to the extracellular space, they gain additional immunogenic roles. Thus, DAMPs are considered key hallmarks of immunogenic cell death (ICD) in cancer, a functionally unique regulated form of stress-mediated cell death that activates the immune system response against tumor cells. Several epigenetic modulators of DAMPs have been reported. In this review, we aimed to provide an overview of the effects of microRNAs (miRNAs) on the expression of DAMPs and the putative link between miRNA, DAMPs, and cell death, focused on ICD. Overall, we propose that miRNAs, by targeting DAMPs, play critical roles in the regulation of both cell death and immune-associated mechanisms in cancer, while evidence of their potential involvement in ICD is limited. Finally, we discuss emerging data regarding the impact of miRNAs’ modulation on cancer treatment outcome.

Abstract

Immunogenic cell death (ICD) in cancer is a functionally unique regulated form of stress-mediated cell death that activates both the innate and adaptive immune response against tumor cells. ICD makes dying cancer cells immunogenic by improving both antigenicity and adjuvanticity. The latter relies on the spatiotemporally coordinated release or exposure of danger signals (DAMPs) that drive robust antigen-presenting cell activation. The expression of DAMPs is often constitutive in tumor cells, but it is the initiating stressor, called ICD-inducer, which finally triggers the intracellular response that determines the kinetics and intensity of their release. However, the contribution of cell-autonomous features, such as the epigenetic background, to the development of ICD has not been addressed in sufficient depth. In this context, it has been revealed that several microRNAs (miRNAs), besides acting as tumor promoters or suppressors, can control the ICD-associated exposure of some DAMPs and their basal expression in cancer. Here, we provide a general overview of the dysregulation of cancer-associated miRNAs whose targets are DAMPs, through which new molecular mediators that underlie the immunogenicity of ICD were identified. The current status of miRNA-targeted therapeutics combined with ICD inducers is discussed. A solid comprehension of these processes will provide a framework to evaluate miRNA targets for cancer immunotherapy.

miR-1260b Activates Wnt Signaling by Targeting Secreted Frizzled-Related Protein 1 to Regulate Taxane Resistance in Lung Adenocarcinoma

Objectives: MicroRNAs (miRNAs) have been demonstrated to contribute to carcinogenesis; however, their association with tumor chemoresistance is not fully understood. In this study we aimed to investigate the molecular mechanisms involved in resistance to taxane-based chemotherapy in lung adenocarcinoma (LAD).

Methods: We established paclitaxel-resistant A549 cells (A549/PTX) and docetaxel-resistant H1299 cells (H1299/DTX). In order to hit the mark, we employed multiple methods including qRT-PCR, western blotting analysis, loss/gain-of-function analysis, luciferase assays, drug sensitivity assays, animal experiment, wound-healing assay, and invasion assay.

Results: Bioinformatics analysis and a luciferase reporter assay revealed that secreted frizzled-related protein 1 (SFRP1) is a direct target of miR-1260b. By qRT-PCR analysis, we found that miR-1260b was significantly upregulated in taxane-resistant cells as compared to parental cells. Suppression of miR-1260b reversed the chemoresistance of human LAD cells to taxanes both in vitro and in vivo, whereas ectopic miR-1260b expression decreased the sensitivity of parental LAD cell lines to taxanes. Downregulation of miR-1260b expression inactivated the Wnt signaling pathway and reversed the epithelial-mesenchymal transition (EMT) phenotype of taxane-resistant LAD cells. In clinical tumor tissue samples, high miR-1260b expression was detected in tumors of non-responding patients treated with taxane-based chemotherapy and was associated with low SFRP1 expression and poor prognosis.

Conclusions: Our findings reveal that targeting of the miR-1260b/SFRP1/Wnt signaling axis might provide a novel strategy for overcoming chemotherapy resistance in LAD.

LINC01089 Inhibits Tumorigenesis and Epithelial-Mesenchymal Transition of Non-small Cell Lung Cancer via the miR-27a/SFRP1/Wnt/β-catenin Axis

Long noncoding RNAs (lncRNAs) have emerged as regulators of gene expression and play critical regulatory roles in diverse biological functions and diseases, including cancer. In this study, we report the downregulation of LINC01089 in non-small cell lung cancer (NSCLC) samples, relative to adjacent non-tumor tissues, and demonstrate its role in the inhibition of proliferation, migration, and epithelial–mesenchymal transition (EMT) of NSCLC cells. Mechanistic analysis indicates that LINC01089 acts as a sponge for miR-27a, regulating its expression in NSCLC. Interestingly, LINC01089 mediated the upregulation of SFRP1 expression by inhibiting the Wnt/β-catenin–EMT pathway and inhibiting the epithelial–mesenchymal transition of NSCLC via sponging miR-27a. Overall, our findings highlight LINC01089’s tumorigenic role and regulatory mechanism in NSCLC, thereby suggesting its potential as a therapeutic target for managing NSCLC.

MicroRNA-1236-3p inhibits human osteosarcoma growth

Osteosarcoma (OS) is a common bone tumor with high mortality worldwide. The long-term survival rate of patients with metastatic or recurrent disease is <20%. The present study explored the biological role of microRNA (miRNA/miR)-1236-3p in OS. miRNA and mRNA expression levels were measured via reverse transcription-quantitative PCR. Fluorescence in situ hybridization was performed to determine miR-1236-3p expression levels in clinical specimens. Protein expression was measured via western blotting. Immunohistochemical analysis was used to detect Wnt target gene expression in tumor tissues. The interaction between the Wnt3a 3′untranslated region and miR-1236-3p was assessed via dual-luciferase reporter assays. Cell cycle, Transwell, Cell Counting Kit-8 and wound healing assays were conducted to evaluate the function of the miR-1236-3p/Wnt3a axis. Human OS (HOS) cells stably transfected with vector or miR-1236-3p sponge were injected subcutaneously into nude mice to assess the role of miR-1236-3p in vivo. miR-1236-3p expression was downregulated in OS tissues compared with chondroma tissues, and miR-1236-3p overexpression inhibited OS cell migration and proliferation compared with the negative control group. Furthermore, in vivo xenograft assays displayed enhanced tumour growth rates in the miR-1236-3p sponge group compared with the vector control group. In the present study, the results indicated that miR-1236-3p inhibited OS progression and Wnt3a was identified as a target of miR-1236-3p.

MicroRNA-27a-3p Reverses Adriamycin Resistance by Targeting BTG2 and Activating PI3K/Akt Pathway in Breast Cancer Cells

Aim

This study aimed to explore the regulative mechanisms of miR-27a-3p in chemo-resistance of breast cancer cells.

Materials and Methods

qRT-PCR was employed to determine miR-27a-3p expression in two breast cancer cell lines, MCF-7 and MCF-7/adriamycin-resistant cell line (MCF-7/ADR). The two cell lines were treated with miR-27a-3p mimics or inhibitors or corresponding negative control (NC), respectively. The changes were investigated by qRT-PCR, CCK-8 assay, Western blot (WB), colony formation assay, and flow cytometry assay. Moreover, luciferase reporter assay was analyzed to verify the downstream target gene of miR-27a-3p. Further investigation in the correlation between miR-27a-3p and BTG2 was launched by WB, flow cytometry assay, and CCK-8 assay. The expression of Akt and p-Akt was detected by WB.

Key Findings

Significantly higher miR-27a-3p expression was confirmed in MCF-7/ADR as compared with sensitive cell line MCF-7 (P<0.05). The down-regulation of miR-27a-3p in MCF-7/ADR enhanced the sensitivity of cancer cells to adriamycin treatment, decreased multidrug resistance gene 1/P-glycoprotein (MDR1/P-gp) expression, enhanced the apoptosis-related proteins expression, increased adriamycin-induced apoptosis, and inhibited cell proliferation as compared to NC groups (P<0.05). The up-regulation of miR-27a-3p in MCF-7 showed the opposite results. BTG2 is identified as a direct target of miR-27a-3p and its down-regulation reversed ADR-resistance. BTG2 treatment exhibited inhibitory effect on PI3K/Akt pathway in MCF-7/ADR cells.

Significance

miR-27a-3p might be associated with resistance of breast cancer cells to adriamycin treatments, modulating cell proliferation and apoptosis by targeting BTG2 and promoting the PI3K/Akt pathway in breast cancer cells. miR-27a-3p/BTG2 axis might be a potential therapeutic target for clinical BC resistance.

Circular RNA hsa_circ_0002052 promotes osteosarcoma via modulating miR-382/STX6 axis

Circular RNAs (circRNAs) exert pivotal effects on regulating the progression of osteosarcoma (OS). It was found through microarray analysis that circ-0002052 is abnormally expressed in OS, but the role of circ-0002052 in OS remains obscure. The results of this research manifested that relative to that in non-tumor controls, circ-0002052 level was raised in OS tissues. Up-regulated circ-0002052 was associated with advanced stage, tumor size, and metastasis. Additionally, circ-0002052 elevation indicated a low survival rate in OS patients and silencing of circ-0002052 suppressed proliferation, migration, and invasion of OS cells. It was proved that circ-0002052 sponged miR-382 and stimulated STX6 expression, thus activating Wnt/β-catenin. The function of circ-0002052 reduction in OS cells was effectively reversed by miR-382 suppression. To sum up, it can be concluded that circ-0002052, functioning as a sponge for miR-382, enhances the activation of Wnt/β-catenin mediated by STX6 to stimulate the progression of OS, and circ-0002052 may be an underlying treatment target and a biomarker for prognosis of osteosarcoma.

Epigenetics of SFRP1: The Dual Roles in Human Cancers

Secreted frizzled-related protein 1 (SFRP1) is a gene that belongs to the secreted glycoprotein SFRP family. SFRP1 has been classified as a tumor suppressor gene due to the loss of expression in various human cancers, which is mainly attributed by epigenetic inactivation via DNA methylation or transcriptional silencing by microRNAs. Epigenetic silencing of SFRP1 may cause dysregulation of cell proliferation, migration, and invasion, which lead to cancer cells formation, disease progression, poor prognosis, and treatment resistance. Hence, restoration of SFRP1 expression via demethylating drugs or over-expression experiments opens the possibility for new cancer therapy approach. While the role of SFRP1 as a tumor suppressor gene is well-established, some studies also reported the possible oncogenic properties of SFRP1 in cancers. In this review, we discussed in great detail the dual roles of SFRP1 in cancers-as tumor suppressor and tumor promoter. The epigenetic regulation of SFRP1 expression will also be underscored with additional emphasis on the potentials of SFRP1 in modulating responses toward chemotherapeutic and epigenetic-modifying drugs, which may encourage the development of novel drugs for cancer treatment. We also present findings from clinical trials and patents involving SFRP1 to illustrate its clinical utility, extensiveness of each research area, and progression toward commercialization. Lastly, this review provides directions for future research to advance SFRP1 as a promising cancer biomarker.

Bioinformatic screening and experimental analysis identify SFRP1 as a prognostic biomarker for tongue squamous cell carcinomas

OBJECTIVE

To provide a prognostic biomarker and a potential therapeutic target for tongue squamous cell carcinoma (TSCC).

DESIGN

Screening the prognostic genes of TSCC by bioinformatics, and verifying the correlation between the above genes and the prognosis of TSCC by experiments.

RESULTS

Twenty-four common differentially expressed genes (DEGs) between TSCC and the corresponding normal tissues were screened from four sets of TSCC functional gene expression series in Gene Expression Omnibus (GEO) datasets. Further bioinformatics research based on the data from The Cancer Genome Atlas (TCGA), Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) indicate that the low expression of SFRP1 might be correlated with poor prognosis of TSCC patients. By colony formation assay, reverse transcription polymerase chain reaction (RT-PCR), western blotting, immunohistochemical staining, flowcytometry, lentivirus transfection and animal experiments, it was confirmed that the low level of SFRP1 expression correlated with poor prognosis of TSCC patients.

CONCLUSION

This study identified SFRP1 as a novel prognostic biomarker and a potential therapeutic target for TSCC.

PTHR1 May Be Involved in Progression of Osteosarcoma by Regulating miR-124-3p-AR-Tgfb1i1, miR-27a-3p-PPARG-Abca1, and miR-103/590-3p-AXIN2 Axes

Our previous study has indicated that the parathyroid hormone type 1 receptor (PTHR1) may play important roles in development and progression of osteosarcoma (OS) by regulating Wnt, angiogenesis, and inflammation pathway genes. The goal of this study was to further illuminate the roles of PTHR1 in OS by investigating upstream regulation mechanisms (including microRNA [miRNA] and transcription factors [TFs]) of crucial genes. The microarray dataset GSE46861 was downloaded from the Gene Expression Omnibus database, in which six tumors with short hairpin RNA (shRNA) PTHR1 knockdown (PTHR1.358) and six tumors with shRNA control knockdown (Ren.1309) were collected from mice. Differentially expressed genes (DEGs) between PTHR1.358 and Ren.1309 were identified using the linear models for microarray data (LIMMA) method, and then the miRNA-TF-mRNA regulatory network was constructed using data from corresponding databases, followed by module analysis, to screen crucial regulatory relationships. OS-related human miRNAs were extracted from the curated Osteosarcoma Database. Gene ontology (GO) terms and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways were enriched using the Database for Annotation, Visualization, and Integrated Discovery (DAVID) tool. As a result, the miRNA-TF-mRNA regulatory network, including 1049 nodes (516 miRNA, 25 TFs, and 508 DEGs) and 15942 edges (interaction relationships, such as Pparg-Abca1 and miR-590-3p-AXIN2), was constructed, from which three significant modules were extracted and modules 2 and 3 contained interactions between miRNAs/TFs and DEGs such as miR-103-3p-AXIN2, miR-124-3p-AR-Tgfb1i1, and miR-27a-3p-PPARG-Abca1. miR-27a-3p was a known miRNA associated with OS. Abca1, AR, and miR-124-3p were hub genes in the miRNA-TF-mRNA network. Tgfb1i1 was involved in cell proliferation, Abca1 participated in the cholesterol metabolic process, and AXIN2 was associated with the canonical Wnt signaling pathway. Furthermore, we also confirmed upregulation of miR-590-3p and downregulation of AXIN2 in the mouse OS cell line K7M2-WT transfected with PTHR1 shRNA. In conclusion, PTHR1 may play important roles in progression of OS by activating miR-124-3p-AR-Tgfb1i1, miR-27a-3p-PPARG-Abca1, and miR-103/590-3p-AXIN2 axes.