miR-135b Stimulates Osteosarcoma Recurrence and Lung Metastasis via Notch and Wnt/β-Catenin Signaling

LncRNA GAS5 Modulates the Progression of Glioma Through Repressing miR-135b-5p and Upregulating APC

Purpose

The main purpose of this paper is to explore the interaction between GAS5 and miR-135b-5p to understand their function in the metastasis, invasion, and proliferation of glioma. This may provide new ideas for the pathogenesis and treatment of glioma.

Patients and Methods

Western blotting assays and RT‑qPCR were employed to investigate the expression of related genes in glioma tissues or cell lines. CCK-8 was used to examine the impact of GAS5 on cell viability. Motile activities were adopted by the transwell and wound healing experiments. A double luciferase experiment was performed to elucidate transcriptional regulation.

Results

GAS5 showed low expression in glioma cells and tissues, and up-regulation of GAS5 could depress the invasion, proliferation, and metastasis of glioma. GAS5 negatively regulates miR-135b-5p, which can counteract the cellular effects caused by GAS5. APC was the target of miR-135b-5p, and GAS5 can regulate the expression of APC by sponging miR-135b-5p. APC overexpression reversed the effects of miR-135b-5p promotion on glioma cells, while miR-135b-5p has the opposite function. As a downstream target gene of GAS5, miR-135b-5p was negatively regulated by GAS5. The restoration of miR-135b-5p can remarkably reverse the impact of GAS5 on glioma cells. In addition, GAS5 increased the expression of APC in glioma cells by inhibiting miR-135b-5p.

Conclusion

GAS5 increased APC expression by restraining miR-135b-5p and partially blocked the progression of glioma, suggesting that it could be an advantageous therapeutic target for glioma intervention.

Dishevelled-associated antagonist of β-catenin homolog 3 (DACT3) suppresses glioma progression though Notch1 signaling pathway in β-catenin-dependent manner

The disheveled-associated antagonist of β-catenin homolog 3 (DACT3) has been recognized as a tumor suppressor in various cancers. However, the function of DACT3 on glioma malignant progression along with potential molecular mechanisms is poorly clarified. This research aimed to investigate how DACT3 contributes to suppressing the progression of glioma. In our investigation, a pronounced decrease in DACT3 expression was observed in glioma tissues. Through the overexpression of DACT3, we noted a significant suppression in the proliferation, invasion, and migration of glioma cells, while concurrently observing an increase in cell adhesion. Our exploration into the molecular mechanisms revealed that DACT3 executes its tumor-suppressive role by impeding the expression of notch 1 intracellular domain (NICD) and translocating into the nucleus by downregulating the expression of β-catenin. Consequently, this process leads to the suppression of Notch1 signaling. To summarize, our findings reveal the function of DACT3 to inhibit glioma progression via the Notch1 signaling pathway in β-catenin dependent manner. This study stands as the pioneer in examining the role of DACT3 in glioma progression and comprehensively elucidating its molecular mechanisms in glioma development. Therefore, our results suggest that DACT3 holds promise as both a prognostic factor and a potential biomarker for guiding treatment strategies in glioma patients (Graphical Abstract).

Significance of NotchScore and JAG1 in predicting prognosis and immune response of low-grade glioma

Introduction

Low-grade glioma (LGG) is a prevalent malignant tumor in the intracranial region. Despite the advancements in treatment methods for this malignancy over the past decade, significant challenges still persist in the form of drug resistance and tumor recurrence. The Notch signaling pathway plays essential roles in many physiological processes as well as in cancer development. However, the significance of the pathway and family genes in LGG are poorly understood.

Methods

We conducted gene expression profiling analysis using the TCGA dataset to investigate the gene set associated with the Notch signaling pathway. we have proposed a metric called "NotchScore" that quantifies the strength of the Notch signaling pathway and enables us to assess its significance in predicting prognosis and immune response in LGG. We downregulated JAG1 in low-grade gliomas to assess its influence on the proliferation and migration of these tumors. Ultimately, we determined the impact of the transcription factor VDR on the transcription of PDL1 through chip-seq data analysis.

Results

Our findings indicate that tumors with a higher NotchScore, exhibit poorer prognosis, potentially due to their ability to evade the anti-tumor effects of immune cells by expressing immune checkpoints. Among the genes involved in the Notch signaling pathway, JAG1 has emerged as the most representative in terms of capturing the characteristics of both NotchScore and Notch pathways. The experimental results demonstrate that silencing JAG1 yielded a significant decrease in tumor cell proliferation in LGG cell lines. Our study revealed mechanisms by which tumors evade the immune system through the modulation of PDL1 transcription levels via the PI3K-Akt signaling pathway. Additionally, JAG1 potentially influences PDL1 in LGG by regulating the PI3K-Akt signaling pathway and the expression of the transcription factor VDR.

Discussion

These findings contribute to our understanding of immune evasion by tumors in LGG. The insights gained from this research may have implications for the development of therapeutic interventions for LGG.

Research progress in the mechanism and treatment of osteosarcoma

ABSTRACT

Osteosarcoma (OS) is the most common primary malignant bone tumor that more commonly occurs in children and adolescents. The most commonly used treatment for OS is surgery combined with chemotherapy, but the treatment outcomes are typically unsatisfactory. High rates of metastasis and post-treatment recurrence rates are major challenges in the treatment of OS. This underlines the need for studying the in-depth characterization of the pathogenetic mechanisms of OS and development of more effective therapeutic modalities. Previous studies have demonstrated the important role of the bone microenvironment and the regulation of signaling pathways in the occurrence and development of OS. In this review, we discussed the available evidence pertaining to the mechanisms of OS development and identified therapeutic targets for OS. We also summarized the available treatment modalities for OS and identified future priorities for therapeutics research.

Deciphering the Signaling Mechanisms of Osteosarcoma Tumorigenesis

Osteosarcoma (OS) is the predominant primary bone tumor in the pediatric and adolescent populations. It has high metastatic potential, with the lungs being the most common site of metastasis. In contrast to many other sarcomas, OS lacks conserved translocations or genetic mutations; instead, it has heterogeneous abnormalities, including somatic DNA copy number alteration, ploidy, chromosomal amplification, and chromosomal loss and gain. Unfortunately, clinical outcomes have not significantly improved in over 30 years. Currently, no effective molecularly targeted therapies are available for this disease. Several genomic studies showed inactivation in the tumor suppressor genes, including p53, RB, and ATRX, and hyperactivation of the tumor promoter genes, including MYC and MDM2, in OS. Alterations in the major signaling pathways, including the PI3K/AKT/mTOR, JAK/STAT, Wnt/β-catenin, NOTCH, Hedgehog/Gli, TGF-β, RTKs, RANK/RANKL, and NF-κB signaling pathways, have been identified in OS development and metastasis. Although OS treatment is currently based on surgical excision and systematic multiagent therapies, several potential targeted therapies are in development. This review focuses on the major signaling pathways of OS, and we propose a biological rationale to consider novel and targeted therapies in the future.

Non-coding RNA-based therapeutics in cancer therapy: An emphasis on Wnt/β-catenin control

Non-coding RNA transcripts are RNA molecules that have mainly regulatory functions and they do not encode proteins. microRNAs (miRNAs), lncRNAs and circRNAs are major types of this family and these epigenetic factors participate in disease pathogenesis, especially cancer that their abnormal expression may lead to cancer progression. miRNAs and lncRNAs possess a linear structure, whereas circRNAs possess ring structures and high stability. Wnt/β-catenin is an important factor in cancer with oncogenic function and it can increase growth, invasion and therapy resistance in tumors. Wnt upregulation occurs upon transfer of β-catenin to nucleus. Interaction of ncRNAs with Wnt/β-catenin signaling can determine tumorigenesis. Wnt upregulation is observed in cancers and miRNAs are able to bind to 3'-UTR of Wnt to reduce its level. LncRNAs can directly/indirectly regulate Wnt and in indirect manner, lncRNAs sponge miRNAs. CircRNAs are new emerging regulators of Wnt and by its stimulation, they increase tumor progression. CircRNA/miRNA axis can affect Wnt and carcinogenesis. Overall, interaction of ncRNAs with Wnt can determine proliferation rate, migration ability and therapy response of cancers. Furthermore, ncRNA/Wnt/β-catenin axis can be utilized as biomarker in cancer and for prognostic applications in patients.

Self-Renewal and Pluripotency in Osteosarcoma Stem Cells' Chemoresistance: Notch, Hedgehog, and Wnt/β-Catenin Interplay with Embryonic Markers

Osteosarcoma is a highly malignant bone tumor derived from mesenchymal cells that contains self-renewing cancer stem cells (CSCs), which are responsible for tumor progression and chemotherapy resistance. Understanding the signaling pathways that regulate CSC self-renewal and survival is crucial for developing effective therapies. The Notch, Hedgehog, and Wnt/β-Catenin developmental pathways, which are essential for self-renewal and differentiation of normal stem cells, have been identified as important regulators of osteosarcoma CSCs and also in the resistance to anticancer therapies. Targeting these pathways and their interactions with embryonic markers and the tumor microenvironment may be a promising therapeutic strategy to overcome chemoresistance and improve the prognosis for osteosarcoma patients. This review focuses on the role of Notch, Hedgehog, and Wnt/β-Catenin signaling in regulating CSC self-renewal, pluripotency, and chemoresistance, and their potential as targets for anti-cancer therapies. We also discuss the relevance of embryonic markers, including SOX-2, Oct-4, NANOG, and KLF4, in osteosarcoma CSCs and their association with the aforementioned signaling pathways in overcoming drug resistance.

NOTCH Signaling in Osteosarcoma

The combination of neoadjuvant chemotherapy and surgery has been promoted for the treatment of osteosarcoma; however, the local recurrence and lung metastasis rates remain high. Therefore, it is crucial to explore new therapeutic targets and strategies that are more effective. The NOTCH pathway is not only involved in normal embryonic development but also plays an important role in the development of cancers. The expression level and signaling functional status of the NOTCH pathway vary in different histological types of cancer as well as in the same type of cancer from different patients, reflecting the distinct roles of the Notch pathway in tumorigenesis. Studies have reported abnormal activation of the NOTCH signaling pathway in most clinical specimens of osteosarcoma, which is closely related to a poor prognosis. Similarly, studies have reported that NOTCH signaling affected the biological behavior of osteosarcoma through various molecular mechanisms. NOTCH-targeted therapy has shown potential for the treatment of osteosarcoma in clinical research. After the introduction of the composition and biological functions of the NOTCH signaling pathway, the review paper discussed the clinical significance of dysfunction in osteosarcoma. Then the paper reviewed the recent relevant research progress made both in the cell lines and in the animal models of osteosarcoma. Finally, the paper explored the potential of the clinical application of NOTCH-targeted therapy for the treatment of osteosarcoma.

ETC-159, an Upstream Wnt inhibitor, Induces Tumour Necrosis via Modulation of Angiogenesis in Osteosarcoma

There is an increasing urgency in the search for new drugs to target high-grade cancers such as osteosarcomas (OS), as these have limited therapeutic options and poor prognostic outlook. Even though key molecular events leading to tumorigenesis are not well understood, it is widely agreed that OS tumours are Wnt-driven. ETC-159, a PORCN inhibitor that inhibits the extracellular secretion of Wnt, has recently progressed on to clinical trials. In vitro and in vivo murine and chick chorioallantoic membrane xenograft models were established to examine the effect of ETC-159 on OS. Consistent with our hypothesis, we noted that ETC-159 treatment not only resulted in markedly decreased β-catenin staining in xenografts, but also increased tumour necrosis and a significant reduction in vascularity-a hereby yet undescribed phenotype following ETC-159 treatment. Through further understanding the mechanism of this new window of vulnerability, therapies can be developed to potentiate and maximize the effectiveness of ETC-159, further increasing its clinical utility for the treatment of OS.

Comprehensive analysis of potential cellular communication networks in advanced osteosarcoma using single-cell RNA sequencing data

Osteosarcoma (OS) is a common bone cancer in children and adolescents, and metastasis and recurrence are the major causes of poor treatment outcomes. A better understanding of the tumor microenvironment is required to develop an effective treatment for OS. In this paper, a single-cell RNA sequencing dataset was taken to a systematic genetic analysis, and potential signaling pathways linked with osteosarcoma development were explored. Our findings revealed 25 clusters across 11 osteosarcoma tissues, with 11 cell types including “Chondroblastic cells”, “Osteoblastic cells”, “Myeloid cells”, “Pericytes”, “Fibroblasts”, “Proliferating osteoblastic cells”, “Osteoclasts”, “TILs”, “Endothelial cells”, “Mesenchymal stem cells”, and “Myoblasts”. The results of Cell communication analysis showed 17 potential cellular communication networks including “COLLAGEN signaling pathway network”, “CD99 signaling pathway network”, “PTN signaling pathway network”, “MIF signaling pathway network”, “SPP1 signaling pathway network”, “FN1 signaling pathway network”, “LAMININ signaling pathway network”, “FGF signaling pathway network”, “VEGF signaling pathway network”, “GALECTIN signaling pathway network”, “PERIOSTIN signaling pathway network”, “VISFATIN signaling pathway network”, “ITGB2 signaling pathway network”, “NOTCH signaling pathway network”, “IGF signaling pathway network”, “VWF signaling pathway network”, “PDGF signaling pathway network”. This research may provide novel insights into the pathophysiology of OS’s molecular processes.

A review on the importance of miRNA-135 in human diseases

MicroRNA-135 (miR-135) is a microRNA which is involved in the pathoetiology of several neoplastic and non-neoplastic conditions. Both tumor suppressor and oncogenic roles have been reported for this miRNA. Studies in prostate, renal, gallbladder and nasopharyngeal cancers as well as glioma have shown down-regulation of miR-135 in cancerous tissues compared with controls. These studies have also shown the impact of miR-135 down-regulation on enhancement of cell proliferation and aggressive behavior. Meanwhile, miR-135 has been shown to be up-regulated in bladder, oral, colorectal and liver cancers. Studies in breast, gastric, lung and pancreatic cancers as well as head and neck squamous cell carcinoma have reported dual roles for miR-135. Dysregulation of miR-135 has also been noted in various non-neoplastic conditions such as Alzheimer’s disease, atherosclerosis, depression, diabetes, Parkinson, pulmonary arterial hypertension, nephrotic syndrome, endometriosis, epilepsy and allergic conditions. In the current review, we summarize the role of miR-135 in the carcinogenesis as well as development of other disorders.

CEMIP Promotes Osteosarcoma Progression and Metastasis Through Activating Notch Signaling Pathway

Cell migration inducing protein (CEMIP) has been linked to carcinogenesis in several types of cancers. However, the role and mechanism of CEMIP in osteosarcoma remain unclear. This study investigated the role of CEMIP in the progression and metastasis of osteosarcoma, CEMIP was found to be overexpressed in osteosarcoma tissues when compared to adjacent non-tumor tissues, and its expression was positively associated with a poor prognosis in osteosarcoma patients. Silencing CEMIP decreased osteosarcoma cells proliferation, migration, and invasion, but enhanced apoptosis in vitro, and suppressed tumor growth and metastasis in vivo. Mechanistically, CEMIP promoted osteosarcoma cells growth and metastasis through activating Notch signaling pathway, silencing CEMIP would reduce the protein expression and activation of Notch/Jagged1/Hes1 signaling pathway in vitro and in vivo, activation of Notch signaling pathway could partially reversed cell proliferation and migration in shCEMIP osteosarcoma cells. In conclusion, our study demonstrated that CEMIP plays a substantial role in the progression of osteosarcoma via Notch signaling pathway, providing a promising therapeutic target in osteosarcoma.

Long noncoding RNAs (lncRNAs) in human lymphomas

Lymphomas are a diverse group of haematologic malignancies, which occur in infection-fighting cells of the lymphatic system. Long non-coding RNAs (lncRNAs) are non-coding RNAs, which have recently received significant attention as the main mediators of gene expression. In this review, we summarize the current knowledge on lncRNAs involved in lymphomas, their molecular functions, as well as their potential clinical value. Relevant literature was identified by a PubMed search of English language papers using the following terms: Lymphoma, LncRNA, leukemia, proliferation, apoptosis, and prognosis. LncRNAs are imperative for lymphoma carcinogenesis through affecting apoptosis, cell proliferation, invasion, and response to chemotherapy. The expression level of lncRNAs can affect chemotherapy-induced apoptosis. Taken together, lncRNA dysregulation in lymphoma cells is not only an epiphenomenon but also lncRNA transcription is critically related to the initiation and progression of lymphomas. Aberrant expression of lncRNAs can lead to the transformation of normal lymphocytes into lymphoma cells.

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.

Advances in the Research of Osteosarcoma Stem Cells and its Related Genes

Osteosarcoma is a malignant tumor that often occurs in adolescents. There is an urgent need of new treatment options for osteosarcoma due to its poor prognosis after metastasis. Cancer stem cell theory states that cancer stem cells represent a small proportion of cancer cells. These cancer stem cells have self-renewal ability and are closely associated with cancer growth and metastasis as well as chemotherapy resistance. Similarly, osteosarcoma stem cells (OSCs) play an important role in the growth, metastasis, and chemotherapy resistance of osteosarcoma cells. Targeting OSCs may represent a future treatment of osteosarcoma. Furthermore, some genes have shown to regulate the growth, metastasis, and chemotherapy resistance of osteosarcoma cells by altering the stemness of OSCs. Targeting these genes may help in the treatment of osteosarcoma. This review mainly discusses recent advances in the research of OSCs and its related genes. This article is protected by copyright. All rights reserved.

Human umbilical vein endothelial cells derived-exosomes promote osteosarcoma cell stemness by activating Notch signaling pathway

Osteosarcoma is one of the most common primary malignant tumors of bone in adolescents. Human umbilical vein endothelial cells (HUVECs) derived exosomes are associated with osteosarcoma cell stemness. Little is known about the function of HUVECs-exosomes in osteosarcoma cell stemness. This work aimed to investigate the mechanism of action of HUVECs-exosomes in regulating stem cell-like phenotypes of osteosarcoma cells. HUVECs were treated with GW4869 (exosome inhibitor). Human osteosarcoma cells (U2OS and 143B) were treated with HUVECs supernatant, HUVECs-exosomes with or without RO4929097 (γ secretase inhibitor, used to block Notch signaling pathway). We found that HUVECs supernatant and HUVECs-exosomes enhanced the proportions of STRO-1⁺CD117⁺ cells and the expression of stem cell-related proteins Oct4 and Sox2. Both HUVECs supernatant and HUVECs-exosomes promoted the sarcosphere formation efficiency of U2OS and 143B cells. These stem-like phenotypes of U2OS and 143B cells conferred by HUVECs-exosomes were repressed by GW4869. Moreover, HUVECs-exosomes promoted the expression of Notch1, Hes1 and Hey1 in the U2OS and 143B cells. RO4929097 treatment reversed the impact of HUVECs-exosomes on Notch1, Hes1, and Hey1 expression by inhibiting Notch1 signaling pathway. In conclusion, this work demonstrated that HUVECs-exosomes promoted cell stemness in osteosarcoma through activating Notch signaling pathway. Thus, our data reveal the mechanism of HUVECs-exosomes in regulating cell stemness of osteosarcoma, and provide a theoretical basis for osteosarcoma treatment by exosomes.

Overexpression of Long Non-Coding RNA MIR22HG Represses Proliferation and Enhances Apoptosis via miR-629-5p/TET3 Axis in Osteosarcoma Cells

In this study, we evaluated the mechanism of long non-coding RNA MIR22 host gene (LncRNA MIR22HG) in osteosarcoma cells. Forty-eight paired osteosarcoma and adjacent tissues samples were collected and the bioinformatic analyses were performed. Target genes and potential binding sites of MIR22HG, microRNA (miR)-629-5p and tet methylcytosine dioxygenase 3 (TET3) were predicted by Starbase and TargetScan V7.2 and confirmed by dual-luciferase reporter assay. Cell Counting Kit-8, colony formation and flow cytometry assays were utilized to determine the viability, proliferation and apoptosis of transfected osteosarcoma cells. Pearson's analysis was introduced for the correlation analysis between MIR22HG and miR-629-5p in osteosarcoma tissue. Relative expressions of MIR22HG, miR-629-5p and TET3 were measured by quantitative real-time polymerase chain reaction or Western blot. MiR-629-5p could competitively bind with and was negatively correlated with MIR22HG, the latter of which was evidenced by the high expression of miR-629-5p and low expression of MIR22HG in osteosarcoma tissues. Overexpressed MIR22HG repressed the viability and proliferation but enhanced apoptosis of osteosarcoma cells, which was reversed by miR-629-5p upregulation. TET3 was the target gene of miR-629-5p, and the promotive effects of upregulated miR-629-5p on the viability and proliferation as well as its repressive effect on apoptosis were abrogated via overexpressed TET3. To sum up, overexpressed MIR22HG inhibits the viability and proliferation of osteosarcoma cells, which was achieved via regulation of the miR-629-5p/TET3 axis.

Epigenetic Regulation of the Wnt/β-Catenin Signaling Pathway in Cancer

Studies over the past four decades have elucidated the role of Wnt/β-catenin mediated regulation in cell proliferation, differentiation and migration. These processes are fundamental to embryonic development, regeneration potential of tissues, as well as cancer initiation and progression. In this review, we focus on the epigenetic players which influence the Wnt/β-catenin pathway via modulation of its components and coordinated regulation of the Wnt target genes. The role played by crosstalk with other signaling pathways mediating tumorigenesis is also elaborated. The Hippo/YAP pathway is particularly emphasized due to its extensive crosstalk via the Wnt destruction complex. Further, we highlight the recent advances in developing potential therapeutic interventions targeting the epigenetic machinery based on the characterization of these regulatory networks for effective treatment of various cancers and also for regenerative therapies.

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.

NOTCH signaling: Journey of an evolutionarily conserved pathway in driving tumor progression and its modulation as a therapeutic target

Notch signaling, an evolutionarily conserved signaling cascade, is critical for normal biological processes of cell differentiation, development, and homeostasis. Deregulation of the Notch signaling pathway has been associated with tumor progression. Thus, Notch presents as an interesting target for a variety of cancer subtypes and its signaling mechanisms have been actively explored from the therapeutic viewpoint. However, besides acting as an oncogene, Notch pathway can possess also tumor suppressive functions, being implicated in inhibition of cancer development. Given such interesting dual and dynamic role of Notch, in this review, we discuss how the evolutionarily conserved Notch signaling pathway drives hallmarks of tumor progression and how it could be targeted for a promising treatment and management of cancer. In addition, the up-to-date information on the inhibitors currently under clinical trials for Notch targets is presented along with how NOTCH inhibitors can be used in conjunction with established chemotherapy/radiotherapy regimes.

Cancer Stem Cells as a Source of Drug Resistance in Bone Sarcomas

Bone sarcomas are commonly characterized by a high degree of intra-tumor heterogeneity, which in part is due to the presence of subpopulations of tumor cells presenting stem cell properties. Similar to normal stem cells, these cancer stem cells (CSCs) display a drug resistant phenotype and therefore are responsible for relapses and tumor dissemination. Drug resistance in bone sarcomas could be enhanced/modulated during tumor evolution though the acquisition of (epi)-genetic alterations and the adaptation to changing microenvironments, including drug treatments. Here we summarize findings supporting the involvement of pro-stemness signaling in the development of drug resistance in bone sarcomas. This include the activation of well-known pro-stemness pathways (Wnt/β-Cat, NOTCH or JAT/STAT pathways), changes in the metabolic and autophagic activities, the alteration of epigenetic pathways, the upregulation of specific non-coding RNAs and the crosstalk with different microenvironmental factors. This altered signaling is expected to be translated to the clinic in the form of biomarkers of response and new therapies able to overcome drug resistance.

STAT3/miR-135b/NF-κB axis confers aggressiveness and unfavorable prognosis in non-small-cell lung cancer

Non-small-cell lung cancer (NSCLC) is one of the most commonly diagnosed cancers worldwide but has limited effective therapies. Uncovering the underlying pathological and molecular changes, as well as mechanisms, will improve the treatment. Dysregulated microRNAs (miRNAs) have been proven to play important roles in the initiation and progression of various cancers, including NSCLC. In this manuscript, we identified microRNA-135b (miR-135b) as a tumor-promoting miRNA in NSCLC. We found that miR-135b was significantly upregulated and that its upregulation was associated with poor prognosis in NSCLC patients. miR-135b was an independent prognostic factor in NSCLC. Overexpressing miR-135b significantly promoted the aggressiveness of NSCLC, as evidenced by enhanced cell proliferation, migration, invasion, anti-apoptosis, and angiogenesis in vitro and in vivo, and knockdown of miR-135b had the opposite effects. Mechanistically, our results reveal that miR-135b directly targets the 3'-untranslated region (UTR) of the deubiquitinase CYLD, thereby modulating ubiquitination and activation of NF-κB signaling. Moreover, we found that interleukin-6 (IL-6)/STAT3 could elevate miR-135b levels and that STAT3 directly bound the promoter of miR-135b; thus, these findings highlight a new positive feedback loop of the IL-6/STAT3/miR-135b/NF-κB signaling in NSCLC and suggest that miR-135b could be a potential therapeutic target for NSCLC.

MicroRNA-135b/CAMK2D Axis Contribute to Malignant Progression of Gastric Cancer through EMT Process Remodeling

There is a continued need for investigating the roles of microRNAs (miRNAs) and their targets on the progression of gastric cancer (GC), especially metastasis. Here, we performed an integrated study to identify dysregulated miRNAs critical for GC development and progression. miR-135b was determined as a promising biomarker for GC. The expression level of miR-135b was increased among GC cell lines, patient tumor tissues, serum samples, and correlation with aggravation of the GC patients. The in vitro functional assays demonstrated overexpression of miR-135b promoted cell proliferation, migration and invasion in GC, while miR-135b inhibition led to the opposite results. CAMK2D was found to be the direct target of miR-135b, serving as a tumor suppressor in GC cells. Based on our and public datasets, we confirmed the attenuation of CAMK2D expression in GC tissues. And, the expression levels of miR-135b and CAMK2D were closely associated with prognosis of GC patients. Ectopic expression of miR-135b resulted in the down-regulation of CAMK2D. Additionally, CAMK2D was a prerequisite for miR-135b to promote GC cells proliferation and migration by regulating the EMT process, which was confirmed by the in vivo experiments. Importantly, in vivo injection of miR-135b antagomir significantly repressed the tumor growth and metastasis of xenograft models, which suggested that the miR-135b antagomir were promising for clinical applications. Taken together, these results indicate that miR-135b/CAMK2D axis drives GC progression by EMT process remodeling, suggesting that miR-135b may be utilized as a new therapeutic target and prognostic marker for GC patients.

Current Status of MicroRNAs that Target the Wnt Signaling Pathway in Regulation of Osteogenesis and Bone Metabolism: A Review

The directional differentiation of bone mesenchymal stem cells (BMSCs) is regulated by a variety of transcription factors and intracellular signaling pathways. In the past, it was thought that the directional differentiation of BMSCs was related to transforming growth factors, such as bone morphogenetic protein (BMP) and MAPK pathway. However, in recent years, some scholars have pointed out that the Wnt signaling pathway, which is a necessary complex network of protein interactions for biological growth and development, takes a significant role in this process and plays a major part in regulating the development of osteoblasts by exerting signal transduction into cells. Also, they have proved the Wnt protein therapeutic truly have positive effects on the viability and osteogenic capacity of bone graft. Recent studies have shown that microRNAs (miRNAs) play an important regulatory role in this process. MiRNAs such as miRNA-218, miRNA-335, miRNA-29, microRNA-30 and other miRNAs exert negative or positive effects on some crucial molecules in the Wnt/β-catenin pathway, which in turn affect bone metabolism and osteopathy. Thus, miRNAs have been suggested as therapeutic targets for some metabolic bone diseases. This article aims to provide an update on the current status of microRNAs that target the Wnt signaling pathway in the regulation of osteogenesis and bone metabolism and includes a discussion of future areas of research, which can be a theoretical basis for bone metabolism-related diseases.

lncRNA‑CASC15 promotes osteosarcoma proliferation and metastasis by regulating epithelial‑mesenchymal transition via the Wnt/β‑catenin signaling pathway

Osteosarcoma (OS) is a rare type of tumor and mostly occurs in children and adolescents. Approximately 10–25% of patients with OS have lung metastases, and lung damage caused by lung metastasis is the main cause of mortality. Therefore, studying the growth and metastasis of OS is key in reducing OS mortality and improving prognosis. The expression of long non-coding RNA (lncRNA) cancer susceptibility 15 (CASC15) in OS patients or OS cell lines were quantified by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The expression of vimentin, E-cadherin, N-cadherin, and cyclin D were detected by RT-qPCR and western blotting. Mice were injected with OS cell lines via the tail vein to observe tumor formation in the lung. CCK-8 and EdU assays were utilized to evaluate cell proliferation. Both Ttranswell assay and cell scratch test detected cell migration. The results revealed that lncRNA-CASC15 was highly expressed in clinical samples and OS cells. In vitro verification experiments revealed that CASC15 promoted the growth of OS cells. Rescue experiments demonstrated that CASC15 affected the cell cycle by activating the Wnt/β-catenin pathway, thereby promoting cell proliferation. Furthermore, the transfection dose test indicated that lentiviruses expressing various doses of CASC15-overexpression (oe-CASC15) altered the proliferation and migration status of OS cells. CASC15 promoted OS cell metastasis both in vivo and in vitro. The overexpression of CASC15 revealed that the occurrence of metastasis was also related to the Wnt/β-catenin pathway. The western blotting results revealed that CASC15 could lead to β-catenin entering the nucleus via the Wnt pathway to promote the epithelial-mesenchymal transition (EMT) of OS cells. To sum up, CASC15 promoted the proliferation of OS cells in vitro and the growth of OS xenograft tumors in vivo. Moreover, CASC15 promoted the entry of β-catenin into the nucleus, thus activating the Wnt pathway and subsequently promoting the EMT of OS cells.

Promoting effects of MiR-135b on human multiple myeloma cells via regulation of the Wnt/β-catenin/Versican signaling pathway

MicroRNA (MiR)-135b and its mediated Wnt/β-catenin signaling pathway are involved in human malignancies. However, their roles in multiple myeloma (MM) remained poorly understood. Our study aimed to uncover their roles in MM. MiR-135b and Versican expressions were measured using quantitative real-time polymerase chain reaction (qRT-PCR). MM cell proliferation, apoptosis, migration and invasion were detected by cell counting kit-8 (CCK-8) assay, flow cytometry, wound healing assay and transwell assay, respectively. Relative expression of Wnt/β-catenin signaling pathway-related protein was quantified by Western blot. MiR-135b was upregulated in the serum of MM patients, and miR-135b upregulation promoted MM cell proliferation, migration and invasion but suppressed apoptosis. Also, miR-135b upregulation promoted activation of Wnt/β-catenin signaling pathway. However, downregulation of miR-135b caused an opposite effect. After incubating cells with miR-135b inhibitor and Wnt/β-catenin signaling pathway agonist Lithium chloride (LiCl), which reversed the effects of downregulating miR-135b. Versican is the downstream effector of the Wnt/β-catenin signaling pathway, and its silencing reversed the effects of LiCl on MM cells. In conclusion, miR-135b and its mediated Wnt/β-catenin signaling pathway promoted proliferation, migration and invasion but suppressed apoptosis of MM cells through regulating Versican, providing a possible treatment for MM.

Construction of a MicroRNA-Based Nomogram for Prediction of Lung Metastasis in Breast Cancer Patients

The lung is one of the most common sites of distant metastasis in breast cancer (BC). Identifying ideal biomarkers to construct a more accurate prediction model than conventional clinical parameters is crucial. MicroRNAs (miRNAs) data and clinicopathological data were acquired from the Molecular Taxonomy of Breast Cancer International Consortium (METABRIC) database. miR-663, miR-210, miR-17, miR-301a, miR-135b, miR-451, miR-30a, and miR-199a-5p were screened to be highly relevant to lung metastasis (LM) of BC patients. The miRNA-based risk score was developed based on the logistic coefficient of the individual miRNA. Univariate and multivariate logistic regression selected tumor node metastasis (TNM) stage, age at diagnosis, and miRNA-risk score as independent predictive parameters, which were used to construct a nomogram. The Cancer Genome Atlas (TCGA) database was used to validate the signature and nomogram. The predictive performance of the nomogram was compared to that of the TNM stage. The area under the receiver operating characteristics curve (AUC) of the nomogram was higher than that of the TNM stage in all three cohorts (training cohort: 0.774 vs. 0.727; internal validation cohort: 0.763 vs. 0.583; external validation cohort: 0.925 vs. 0.840). The calibration plot of the nomogram showed good agreement between predicted and observed outcomes. The net reclassification improvement (NRI), integrated discrimination improvement (IDI), and decision-curve analysis (DCA) of the nomogram showed that its performances were better than that of the TNM classification system. Functional enrichment analyses suggested several terms with a specific focus on LM. Subgroup analysis showed that miR-30a, miR-135b, and miR-17 have unique roles in lung metastasis of BC. Pan-cancer analysis indicated the significant importance of eight predictive miRNAs in lung metastasis. This study is the first to establish and validate a comprehensive lung metastasis predictive nomogram based on the METABRIC and TCGA databases, which provides a reliable assessment tool for clinicians and aids in appropriate treatment selection.

Notch-1 promotes the malignant progression of osteosarcoma through the activation of cell division cycle 20

The molecular mechanism of osteosarcoma (OS) pathogenesis is poorly understood. The Notch signaling pathway has been shown to be critically involved in tumorigenesis, including OS. Therefore, we explored the molecular mechanism by which the Notch-1 signaling pathway is involved in OS progression. Several approaches were carried out to determine the biological function of Notch-1 in OS cells. The MTT results revealed that Notch-1 overexpression increased the viability of OS cells, whereas Notch-1 downregulation reduced cell viability. Consistently, modulation of Notch-1 regulated apoptosis and the migratory and invasive abilities of OS cells. Mechanistic studies showed that Notch-1 overexpression augmented cell division cycle 20 (Cdc20) expression in OS cells. Moreover, overexpression of Cdc20 alleviated the inhibitory effects of Notch-1 downregulation on the viability, migration and invasion of OS cells. Our study offers a promising OS treatment strategy by inhibiting Notch-1.

Long intergenic non-coding RNA 1939 eliminates proliferation and migration of human renal cell carcinoma (RCC) cells by down-regulation of miR-154

Renal carcinoma (RCC) is widely accepted as a malignant tumour of urinary system. Long intergenic non-coding RNA 1939 (LINC01939) is a novel lncRNA which was found to be down-regulated in RCC. Thus, we set out to explore the effect and regulation mechanism of LINC01939 in RCC. LINC01939 and miR-154 in RCC tissues and cell lines were detected using qRT-PCR assay. To examine cellular viability of ACHN and CAKI-1 cells, cell counting kit-8 (CCK-8) assay was exploited here. Flow cytometric analysis was conducted to examine apoptosis. Cell mobility was valued through wound healing assays. Western blotting was applied for examination of proteins related to proliferation, apoptosis, migration and Wnt/β-catenin/Notch. LINC01939 was down-regulated in RCC tissues. LINC01939 overexpression impeded proliferation and migration, and induced apoptosis. Further study found that the overexpression of LINC01939 strongly suppressed miR-154 expression. Then, the inhibiting effect of overexpressed LINC01939 on proliferation and mobility and the promoting role of LINC01939 in apoptosis were abolished by the combination of miR-154 mimic. Finally, we found that overexpressed LINC01939 inactivated Wnt/β-catenin and Notch through suppressing miR-154. Up-regulation of LINC01939 inhibited proliferation and migration of RCC cells by down-regulating miR-154.

Gamabufotalin suppressed osteosarcoma stem cells through the TGF-β/periostin/PI3K/AKT pathway

AIMS

To investigate the effect of gamabufotalin (GBT) on metastasis and modulation of stemness features in osteosarcoma, and the molecular mechanisms underlying such effects.

METHODS

Human osteosarcoma U2OS/MG-63 cell lines were used in this study. Cell proliferation, migration, and invasion were determined by MTT assay, wound healing assay, and cell invasion assay, respectively. The inhibitive effect of GBT on stemness was assessed by flow cytometry and mammosphere formation. The protein levels of related proteins were detected by western blotting analysis. The effect of GBT on tumorigenicity and metastasis was determined by immunofluorescence staining and immunohistochemistry in vivo experiments.

RESULTS

We found that GBT suppressed the viability of U2OS/MG-63 cells in a time- and dose-dependent manner. Notably, GBT had no effect on the viability of human fetal osteoblastic (hFOB) 1.19 cells. Moreover, GBT increased the width of wounds, reduced the number of invasive osteosarcoma cells and reversed the epithelial-mesenchymal transition phenotype. Notably, we found that, compared with hFOB1.19 cells, the levels of transforming growth factor-β (TGF-β), periostin, phosphorylated-AKT (p-AKT), and phosphorylated-PI3K (p-PI3K) were higher in spheroids group than in parent cells. In addition, GBT reduced the ratio of CD133+ cells, the size of spheroids and Nanog, as well as the protein levels of SRY-box transcription factor 2 (SOX2), and octamer-binding protein 3/4 (OCT3/4). Our in vivo experiments showed that GBT consistently reduced lung metastasis lesions, the expression levels of matrix metalloproteinase 2 (MMP2), TGF-β, periostin, p-AKT, and p-PI3K (immunohistochemistry staining), as well as that of CD133 in tumor tissues (immunofluorescence analysis). From a mechanistic point of view, exogenous TGF-β/periostin/PI3K/AKT overexpression neutralized the reduction of GBT-decreased invasion/migration and the suppression of stemness properties.

CONCLUSION

Collectively, our data demonstrated that GBT inhibited the viability and tumorigenesis capability of osteosarcoma cells by blocking the TGF-β/periostin/PI3K/AKT signaling pathway. Therefore, GBT may represent a promising therapeutic agent for the management of osteosarcoma.

Bone Microenvironment and Osteosarcoma Metastasis

The bone microenvironment is an ideal fertile soil for both primary and secondary tumors to seed. The occurrence and development of osteosarcoma, as a primary bone tumor, is closely related to the bone microenvironment. Especially, the metastasis of osteosarcoma is the remaining challenge of therapy and poor prognosis. Increasing evidence focuses on the relationship between the bone microenvironment and osteosarcoma metastasis. Many elements exist in the bone microenvironment, such as acids, hypoxia, and chemokines, which have been verified to affect the progression and malignance of osteosarcoma through various signaling pathways. We thoroughly summarized all these regulators in the bone microenvironment and the transmission cascades, accordingly, attempting to furnish hints for inhibiting osteosarcoma metastasis via the amelioration of the bone microenvironment. In addition, analysis of the cross-talk between the bone microenvironment and osteosarcoma will help us to deeply understand the development of osteosarcoma. The cellular and molecular protagonists presented in the bone microenvironment promoting osteosarcoma metastasis will accelerate the exploration of novel therapeutic strategies towards osteosarcoma.

Lycorine inhibits tumor growth of human osteosarcoma cells by blocking Wnt/β-catenin, ERK1/2/MAPK and PI3K/AKT signaling pathway

Osteosarcoma (OS) is the most common type of primary bone cancer. Even with advances in early diagnosis and aggressive treatment, the overall prognosis for OS remains to be further elevated. Lycorine was an isoquinoline alkaloid mainly existed in the bulb of lyco salvia miltiorrhiza and was shown to inhibit several types of cancer. In the present study, we investigated the anti-OS activity of lycorine and the possible underlying mechanism. We found that lycorine inhibited cell proliferation of human OS cells while had lower cytotoxcity against normal cells, and triggered cell cycle arrest at the G1/S transition. Moreover, we validated that lycorine promoted apoptosis via death receptor pathway and mitochondrial pathway, suppressed migration and invasion by reversing epithelial mesenchymal transition (EMT) and suppressing the degradation of extracellular matrix (ECM) in vitro. In addition, orthotopic implantation model of 143B OS cells further confirmed that lycorine suppressed OS growth and lung metastasis in vivo. Mechanically, lycorine reduced the protein level of β-catenin and its' downstream molecule c-Myc. Furthermore, lycorine also decreased the phosphorylation of ERK1/2 and AKT. Together, our results reveal that lycorine may inhibit tumor growth of OS cells possibly through suppressing Wnt/β-catenin, ERK1/2 and PI3K/AKT signaling pathway.

Silencing hsa_circRNA_0008035 exerted repressive function on osteosarcoma cell growth and migration by upregulating microRNA-375

Traditionally, circular RAN hsa_circ_0008035 was proven to function as a tumor inhibitor in gastric cancer. Nevertheless, much less was known about hsa_circ_0008035 in osteosarcoma (OSA). This project was undertaken to assess the role of hsa_circ_0008035 in OSA. Hsa_circ_0008035 level in serum of OSA patients, OSA tissues and cell lines were measured by reverse transcription-quantitative PCR. After downregulation or overexpression of hsa_circ_0008035, cell proliferation, apoptosis and migration were tested in MG63, SAOS-2 or hFOB1.19 cells. Meanwhile, the expression level of miR-375 was analyzed. The binding between hsa_circ_0008035 and miR-375 was confirmed using bioinformatics and luciferase assay. Subsequently, the effects of miR-375 inhibition on MG63 cell growth and migratory potential were reevaluated. Eventually, the activating status of Notch pathway was assessed by Western blot. Our results demonstrated that hsa_circ_0008035 was overexpressed in serum of OSA patients, OSA tissues and cells. Silencing hsa_circRNA_0008035 impeded OSA cell growth and migration, while hsa_circ_0008035 facilitated cell behaviors of hFOB1.19 cells. Additionally, hsa_circ_0008035 negatively modulated miR-375 expression. Meanwhile, miR-375 inhibition overturned the suppressive effects of silencing hsa_circRNA_0008035 on OSA cell behaviors. Furthermore, silencing hsa_circ_0008035 perturbed Notch pathway by adjusting miR-375 expression. In conclusion, silencing hsa_circRNA_0008035 exerted repressive function on OSA cell growth and migration and Notch pathway by accelerating miR-375.

MiR-135b Induces Osteosarcoma Invasion by the Modulation of FOXO-1 and c-Myc

Background: Osteosarcoma (OS) is the most common type of bone malignancy. Many studies have attempted to find the association between microRNAs and cancer-associated processes. Alterations in miRNA expression through genetic or epigenetic changes, impairment of transcription factors, and ectopic expression of miRNAs induce the development and progression of cancer. Although miR-135b has been thoroughly documented as an oncogene in the majority of studies, some controversies remain about the conflicting role of miR-135b as a tumor-suppressor. Objectives: The present study aimed at investigating the oncogenic and/or tumor-suppressing role of miR-135b in human OS. Methods: In this study, 21 OS tissue samples, along with 21 adjacent bone tissues (normal) as control specimens were collected to analyze the expression of miR-135b. The Saos2 cell-line was transiently transfected with the miR-135b mimic and inhibitor to assess its effect on two critical transcription factors, namely FOXO-1 and c-Myc. qRT-PCR was performed to quantify the expression of miR-135b in both OS tissues and the Saos2 cell-line. The MTT, cell migration, and cell invasion assays were used to characterize the miR-135b function. The western blot analysis was carried out to monitor the targets of miR-135b. Finally, the changes in cellular functions such as migration and invasion, following the transfection of miR-135b mimic and inhibitor, were verified. Results: The results showed that in comparison with the adjacent normal bone tissues, the expression of miR-135b was higher in OS tissue samples, which inversely correlated with the expression rate of FOXO-1, whereas the expression of c-Myc had a direct relationship to miR-135b expression. Functionally, the miR-135b mimic led to an increase in cell proliferation, invasion, and migration of OS cancer cells. Conclusions: MiR-135b induces the proliferation and invasion of OS cells by the degradation of FOXO-1 and upregulation of c-Myc.

Identification of miR-135b as a novel regulator of TGFβ pathway in gastric cancer

Gastric cancer (GC) is a common malignant tumor worldwide, with a high incidence and low survival rate. The transforming growth factor-beta (TGFβ) signaling pathway usually plays a tumor-suppressive role and is normally quietened in GC. The downregulation of transforming growth factor-beta receptor II (TGFBR2) affects TGFβ signaling pathway, which exerts an immense effect on tumor cell proliferation and metastasis. Although the effect of the TGFβ signaling pathway on cancer cells is well studied, little is known about the mechanism by which TGFBR2 expression is downregulated. Here, we showed that TGFBR2 protein, but not TGFBR2 mRNA, was consistently downregulated in GC, suggesting that post-transcriptional mechanism is involved in the regulation of TGFBR2. Bioinformatics analysis and luciferase reporter analysis proved that miR-135b combines precisely with the 3'-UTR of TGFBR2 mRNA. EdU assays and cell migration assays respectively showed that miR-135b overexpression induced the growth and invasion of GC cells. However, the overexpression of TGFBR2 had the opposite effect. TGFBR2 acted as the direct target for miR-135b and was downregulated in gastric cancer cells. Therefore, miR-135b promotes proliferation and migration of GC cells by negatively regulating TGFBR2 expression, displaying an oncomiR effect. Altogether, this conclusive evidence supported that miR-135b mediates the progression of GC by targeting TGFBR2 and miR-135b/TGFBR2 axis can be used in future targeted therapy for GC.

Tegavivint and the β-Catenin/ALDH Axis in Chemotherapy-Resistant and Metastatic Osteosarcoma

BACKGROUND

The Wnt/β-catenin pathway is closely associated with osteosarcoma (OS) development and metastatic progression. We investigated the antitumor activity of Tegavivint, a novel β-catenin/transducin β-like protein 1 (TBL1) inhibitor, against OS employing in vitro, ex vivo, and in vivo cell line and patient-derived xenograft (PDX) models that recapitulate high risk disease.

METHODS

The antitumor efficacy of Tegavivint was evaluated in vitro using established OS and PDX-derived cell lines. Use of an ex vivo three-dimensional pulmonary metastasis assay assessed targeting of β-catenin activity during micro- and macrometastatic development. The in vivo activity of Tegavivint was evaluated using chemoresistant and metastatic OS PDX models. Gene and protein expression were quantified by quantitative Reverse transcription polymerase chain reaction or immunoblot analysis. Bone integrity was determined via microCT. All statistical tests were two-sided.

RESULTS

Tegavivint exhibited antiproliferative activity against OS cells in vitro and actively reduced micro- and macrometastatic development ex vivo. Multiple OS PDX tumors (n = 3), including paired patient primary and lung metastatic tumors with inherent chemoresistance, were suppressed by Tegavivint in vivo. We identified that metastatic lung OS cell lines (n = 2) exhibited increased stem cell signatures, including enhanced concomitant aldehyde dehydrogenase (ALDH1) and β-catenin expression and downstream activity, which were suppressed by Tegavivint (ALDH1: control group, mean relative mRNA expression = 1.00, 95% confidence interval [CI] = 0.68 to 1.22 vs Tegavivint group, mean = 0.011, 95% CI = 0.0012 to 0.056, P < .001; β-catenin: control group, mean relative mRNA expression = 1.00, 95% CI = 0.71 to 1.36 vs Tegavivint group, mean = 0.45, 95% CI = 0.36 to 0.52, P < .001). ALDH1high PDX-derived lung OS cells, which demonstrated enhanced metastatic potential compared with ALDHlow cells in vivo, were sensitive to Tegavivint. Toxicity studies revealed decreased bone density in male Tegavivint-treated mice (n = 4 mice per group).

CONCLUSIONS

Tegavivint is a promising therapeutic agent for advanced stages of OS via its targeting of the β-catenin/ALDH1 axis.

miR-492 promotes chemoresistance to CDDP and metastasis by targeting inhibiting DNMT3B and induces stemness in gastric cancer

OBJECTIVE

Metastasis and chemoresistance indicate treatment fail and progresses in gastric cancer (GC) patients. However, the molecular mechanisms of chemoresistance and metastasis remain unclear in GC. Thus, identifying the biological indicators of chemoresistance and metastasis is particularly important.

MATERIALS AND METHODS

We establish a role for miR-492 in GC metastasis and chemoresistance through experiments in vitro and in vivo.

RESULTS

We identified miR-492 overexpression in GC specimens and cell lines, the miR-492 expression level was inversely correlated with the prognosis of GC patients. The inhibition of miR-492 suppressed GC cell invasion and enhanced the sensitivity of gastric cancer cells to CDDP treatment. In contrast, miR-492 overexpression significantly stimulated GC cell invasion and contributed to chemoresistance development. In addition, our research results indicated that the inhibition of miR-492 stimulates GC stemness, and the overexpression of miR-492 induces GC stemness. Importantly, our experiments demonstrated that miR-492 inhibitor suppressed tumor formation, and the combination treatment of miR-492 inhibitor and CDDP significantly inhibited tumor growth in vivo. Furthermore, we demonstrated that miR-492 exerts its anticancer role by targeting DNMT3B in GC.

CONCLUSIONS

Our results suggested that inhibiting miR-492 is a novel strategy to control tumor metastasis and chemoresistance in GC.

MicroRNA-1296-5p suppresses the proliferation, migration, and invasion of human osteosarcoma cells by targeting NOTCH2

Osteosarcoma (OS) is a highly aggressive bone tumor with a poor prognosis. MicroRNAs are revealed to exerts essential roles in the carcinogenesis and tumor invasion of OS. But, the function of miR-1296-5p and its related mechanism in OS progression have not yet been studied. This study discovered the levels of miR-1296-5p in OS and corresponding noncancerous tissues, and we demonstrated that miR-1296-5p level was markedly downregulated in tumor specimens as compared with nontumor tissues. In addition, we discovered that miR-1296-5p was also underexpressed in OS cells compared with the hFOB1.19 osteoblast cells. Interestingly, the reduced expression of miR-1296-5p was confirmed to associated with large tumor size, advanced tumor stages, and distance metastasis, respectively. Patients with OS low-expressing miR-1296-5p showed a prominent shorter survival. In addition, gain-of-function assays verified that miR-1296-5p overexpression remarkably repressed OS cell proliferation, migration, and invasion. Conversely, depletion of miR-1296-5p facilitated the growth and mobility of OS cells. Notably, miR-1296-5p inversely modulated notch receptor 2 (NOTCH2) in OS cells. The level of NOTCH2 messenger RNA was negatively correlated with miR-1296-5p level in OS samples. NOTCH2 knockdown markedly suppressed the abilities of MG-63 cell proliferation and mobility. More importantly, the restoration of NOTCH2 prominently rescued miR-1296-5p-induced tumor-suppressive effects on MG-63 cells. In conclusion, our study identified the reduced expression of miR-1296-5p, which contributed to OS progression. miR-1296-5p might be a promising prognostic marker and therapeutic target in OS.

High Expression of PQBP1 and Low Expression of PCK2 are Associated with Metastasis and Recurrence of Osteosarcoma and Unfavorable Survival Outcomes of the Patients

Osteosarcoma (OS) is the most common primary bone malignancy, predominately affecting children and adolescents. Due to the introduction of chemotherapy, the 5-year survival rate of OS patients has dramatically improved to 60-70%. Unfortunately, OS patients with recurrence or metastatic disease have less than a 20% chance of long-term survival, despite aggressive therapies. In this study, we aimed to identify gene expression patterns associated with metastasis and recurrence in order to identify potential biomarkers with prognostic power. We found that high expression of polyglutamine tract-binding protein 1 (PQBP1) and low expression of phosphoenolpyruvate carboxykinase 2 (PCK2) were related to a high probability of recurrence and metastasis in OS patients and also predicted shorter recurrence-free survival (RFS) and metastasis-free survival (MFS) after adjustment for other clinical variables. Prediction models based on the combination of PQBP1 and PCK2 expression had good and robust predictive power for recurrence and metastasis. A PQBP1 and PCK2-centered protein interaction network was built, and the hypothetical regulatory path between them was identified and termed the PQBP1-SF3A2-UBA52-PCK2 axis. Gene enrichment analysis indicated that aberrations of metabolism might play an important role in recurrence and metastasis in OS patients. Accordingly, PQBP1 and PCK2 are crucial for recurrence and metastasis in OS, and these findings provide a molecular basis for the exploitation of diagnostic and therapeutic strategies for overcoming recurrence and metastasis in OS.

miR-150-5p Inhibits Non-Small-Cell Lung Cancer Metastasis and Recurrence by Targeting HMGA2 and β-Catenin Signaling

Dysregulated microRNAs (miRNAs) play crucial roles in the regulation of cancer stem cells (CSCs), and CSCs are closely associated with tumor initiation, metastasis, and recurrence. Here we found that miR-150-5p was significantly downregulated in CSCs of non-small-cell lung cancer (NSCLC) and its expression level was negatively correlated with disease progression and poor survival in patients with NSCLC. Inhibition of miR-150-5p increased the CSC population and sphere formation of NSCLC cells in vitro and stimulated NSCLC cell tumorigenicity and metastatic colonization in vivo. In contrast, miR-150-5p overexpression potently inhibited sphere-formed NSCLC cell tumor formation, metastatic colonization, and recurrence in xenograft models. Furthermore, we identified that miR-150-5p significantly inhibited wingless (Wnt)-β-catenin signaling by simultaneously targeting glycogen synthase kinase 3 beta interacting protein (GSKIP) and β-catenin in NSCLC cells. miR-150-5p also targeted high mobility group AT-hook 2 (HMGA2), another regulator of CSCs, and Wnt-β-catenin signaling. The restoration of HMGA2 and β-catenin blocked miR-150-5p overexpression-induced inhibition of CSC traits in NSCLC cells. These findings suggest that miR-150-5p functions as a CSC suppressor and that overexpression of miR-150-5p may be a novel strategy to inhibit CSC-induced metastasis and recurrence in NSCLC.

MicroRNA-Based Diagnosis and Treatment of Metastatic Human Osteosarcoma

Osteosarcoma is a malignant tumor of the bones that commonly occurs in young individuals. The 5-year survival rate of osteosarcoma patients is 60-70%. Metastasis to the lungs leads to death in 30-40% of osteosarcoma patients. Therefore, the development of effective strategies for early detection and treatment of this disease are important to improve the survival of osteosarcoma patients. However, metastatic markers for osteosarcoma and molecules that might be targeted for the treatment of metastatic osteosarcoma have not been identified yet. Therefore, the mechanism of metastasis to the lungs needs to be explored from a novel viewpoint. Recently, the aberrant expression of microRNAs (miRNAs) has been reported to be involved in the carcinogenesis and cancer progression of many cancers. Furthermore, miRNAs in the blood have been reported to show an aberrant expression unique to several cancers. Therefore, miRNAs are gaining attention as potential diagnostic markers for cancers. On the other hand, normalizing the dysregulated expression of miRNAs in cancer cells has been shown to alter the phenotype of cancer cells, and thus treatment strategies targeting miRNAs are also being considered. This review summarizes the abnormality of miRNA expression associated with the metastasis of osteosarcoma and describes the present situation and issues regarding the early diagnosis and development of treatment strategies for metastatic osteosarcoma based on the current understanding of this disease.

Lnc SMAD5-AS1 as ceRNA inhibit proliferation of diffuse large B cell lymphoma via Wnt/β-catenin pathway by sponging miR-135b-5p to elevate expression of APC

Diffuse large B cell lymphoma (DLBCL) is a common and fatal hematological malignancy. Long noncoding RNAs (lncRNAs) have emerged as crucial biomarkers and regulators in many cancers. Novel lncRNA biomarker in DLBCL needs to be investigated badly, as well as its function and molecular mechanism. To further explore, microarray analysis was performed to identify the differentially expressed lncRNAs in DLBCL tissues. To investigate the biological functions of SMAD5-AS1, we performed gain- and loss-of-function experiments in vitro and in vivo. Furthermore, bioinformatics analysis, dual-luciferase reporter assays, Argonaute 2-RNA immunoprecipitation (AGO2-RIP), RNA pull-down assay, quantitative PCR arrays, western blot assay, TOPFlash/FOPFlash reporter assay, and rescue experiments were conducted to explore the underlying mechanisms of competitive endogenous RNAs (ceRNAs). We found that SMAD5-AS1 was down-regulated in DLBCL tissues and cell lines. Functionally, SMAD5-AS1 downregulation promoted cell proliferation in vitro and in vivo, whereas SMAD5-AS1 overexpression could lead to the opposite effects in vitro and in vivo. Bioinformatics analysis and luciferase assays revealed that miR-135b-5p was a direct target of SMAD5-AS1, which was validated by dual-luciferase reporter assays, AGO2-RIP, RNA pull-down assay, and rescue experiments. Also, dual-luciferase reporter assays and rescue experiments demonstrated that miR-135b-5p targeted the adenomatous polyposis coli (APC) gene directly. SMAD5-AS1/miR-135b-5p inhibits the cell proliferation via inactivating the classic Wnt/β-catenin pathway in the form of APC dependency. Our results indicated that SMAD5-AS1 inhibits DLBCL proliferation by sponging miR-135b-5p to up-regulate APC expression and inactivate classic Wnt/β-catenin pathway, suggesting that SMAD5-AS1 may act as a potential biomarker and therapeutic target for DLBCL.

Effect of miR-135b inhibitor on biological characteristics of osteosarcoma cells through up-regulating PPM1A

miR-135b is expressed abnormally in various tumors and plays an important role in the occurrence and development of tumors bydifferent pathways. The role of miR-135b in osteosarcoma (OS) and its mechanisms were uncertain. The study aimed to clarify the role of miR-135b in osteosarcoma (OS) cells and explore the effect of miR-135b inhibitor on the biological characteristics of OS cells. Firstly, Compared with adjacent bone tissues, the expression of miR-135b was increased and inversely correlated with potential target-PPM1A mRNA, while the expression of PPM1A was decreased in OS tissues. Dual luciferase reporter assay was used to verify that PPM1A was a target gene of miR-135b and RT-PCR and western blot were used to detect that miR-135b negatively regulated expression of PPM1A in MG63 and U2OS cell lines. After transfection, miR-135b inhibitor significantly inhibited cell proliferation and invasion both in MG63 and U2OS cells and blocked cell cycle in the G2/M phase and induced cells apoptosis, while PPM1A knockdown abolished the inhibition of miR-135b inhibitor on the proliferation and invasion of OS cells. In conclusion, miR-135b is up-regulated in OS cells and down regulating miR-135b expression could inhibit the proliferation and invasion of OS cells by up-regulating PPM1A. miR-135b might be a new therapeutic target of OS.

GAS5 Regulates RECK Expression and Inhibits Invasion Potential of HCC Cells by Sponging miR-135b

Objectives

Long noncoding RNA (LncRNA) growth arrest-specific 5 (GAS5) has been characterized as a tumor suppressor in numerous kinds of human cancers. Its anticancer function in hepatocellular carcinoma (HCC) includes repression of cell proliferation and metastasis, leaving the internal mechanisms unclear. In this study, we intended to examine the anti-invasion effects of GAS5 on HCC and explore the downstream regulatory mechanisms.

Methods

Expression of GAS5 and microRNA-135b (miR-135b) was analyzed by qRT-PCR in paired HCC tissue samples. Their correlation with HCC patients' survival was determined. Transwell assays were done to evaluate in vitro invasion ability. Targeting of GAS5 and RECK by miR-135b was confirmed by qRT-PCR, western blot, and luciferase reporter assays.

Results

Decreased GAS5 and increased miR-135b in HCC inversely correlate with each other and both correlate with poor prognosis of HCC patients. Functionally, GAS5 suppresses while miR-135b promotes HCC cell invasion capacities in vitro. Mechanistically, GAS5 is a target of miR-135b. Furthermore, GAS5 positively regulates expression of RECK, also a target of miR-135b, which further inhibits MMP-2 expression and contributes to invasion repression.

Conclusion

GAS5 acted as a tumor suppressor in HCC invasion in a competing endogenous RNA manner. Our findings indicate that GAS5 is a promising therapeutic target for HCC treatment.

miR-125a Promotes the Progression of Giant Cell Tumors of Bone by Stimulating IL-17A and β-Catenin Expression

Giant cell tumors of bone (GCTBs) exhibit high recurrence and aggressive bone lytic behavior; but, the mechanism of GCTB progression is largely unknown. In GCTB, we detected abundant levels of miR-125a, which were associated with tumor extension, grade, and recurrence. miR-125a stimulates stromal cell tumorigenicity and growth in vivo by promoting the expression of interleukin-17A (IL-17A) and β-catenin. In contrast, inhibition of miR-125a suppressed stromal cell tumorigenicity and growth. Then, we found that miR-125a stimulates IL-17A by targeting TET2 and Foxp3, and it stimulates β-catenin expression by targeting APC and GSK3β in stromal cells. Furthermore, we identified that IL-17A stimulates miR-125a by activating nuclear factor κB (NF-κB) signaling in stromal cells. Finally, our data show that simultaneous inhibition of IL-17A signaling and miR-125a more significantly inhibits stromal cell growth than miR-125a inhibition alone. miR-125a stimulates the progression of GCTB, and it might represent a useful candidate marker for progression. Simultaneously blocking miR-125a and IL-17A might represent a new therapeutic strategy for GCTB.

MiR-139-5p suppresses osteosarcoma cell growth and invasion through regulating DNMT1

BACKGROUND

Accumulating evidence has suggested the crucial roles of differentially expressed miRNAs in osteosarcoma progression. MiR-139-5p was decreased in various cancers. However, the role of miR-139-5p in the development of osteosarcoma and the underlying mechanism remain to be addressed.

METHODS

MiR-139-5p and DNA methyltransferase-1 (DNMT1) mRNA expressions in osteosarcoma tissues and cells were detected by qRT-PCR and western blot analysis. The effects of miR-139-5p and DNMT1 on osteosarcoma cell migration, invasion and epithelial-mesenchymal transition (EMT) were investigated through cell migration and invasion assays, and western blot analysis. The relationship between miR-139-5p and DNMT1was explored using luciferase reporter analysis and western blot. A xenograft tumor model was employed to verify the effects of miR-139-5p on osteosarcoma.

RESULTS

We found that miR-139-5p was strikingly decreased in osteosarcoma tissues and cell lines. MiR-139-5p over-expression suppressed osteosarcoma cell growth, migration and invasion, while loss of miR-139-5p promoted osteosarcoma cell proliferation, migration and invasion. Following, we characterized that DNMT1 was a direct target of miR-139-5p that interacted with the 3'-untranslated region of DNMT1. MiR-139-5p regulated a down-regulation in DNMT1 protein expression levels. We also found that DNMT1 expression was increased and negatively correlated with miR-139-5p expression in osteosarcoma tissues clinically. Xenograft tumor analysis suggested that miR-139-5p over-expression reduced tumor growth in osteosarcoma in vivo through decreasing DNMT1 expressions.

CONCLUSION

MiR-139-5p suppressed the osteosarcoma progression by reducing DNMT1, supplying new insight into the molecular mechanism uncovering osteosarcoma growth.

Construction and analysis of a ceRNA‑ceRNA network reveals two potential prognostic modules regulated by hsa‑miR‑335‑5p in osteosarcoma

Osteosarcoma is an aggressive cancer of the skeletal system, which is associated with a poor prognosis due to the high recurrence rate. Although previous studies have revealed that competitive endogenous RNAs (ceRNAs) are involved in various biological processes in the physiology and development of osteosarcoma, the roles of ceRNAs in osteosarcoma recurrence remain largely unexplored. The present study constructed a ceRNA-ceRNA network for osteosarcoma by systematically integrating matched expression profiles for microRNAs (miRNAs/miRs) and mRNAs, and identified two ceRNA-mediated modules that were associated with recurrence in patients with osteosarcoma. A multivariate Cox regression analysis demonstrated that the recurrence-free prognosis associated with the expression of the two modules was independent of other clinical factors. In addition, hsa-miR-335-3p was identified as an upstream regulating factor for both modules. In conclusion, the results of the present study suggested that ceRNAs may act as potential therapeutic biomarkers for predicting the recurrence of osteosarcoma, and may help to identify patients with osteosarcoma at a high risk of recurrence, who may benefit from adjuvant therapy.

miR-223-3p Inhibits Human Osteosarcoma Metastasis and Progression by Directly Targeting CDH6

Cadherin-6 (CDH6) is aberrantly expressed in cancer and closely associated with tumor progression. However, the functions of CDH6 in human osteosarcoma and the molecular mechanisms underlying CDH6 in osteosarcoma oncogenesis remain poorly understood. In this work, we assessed the role of CDH6 in human osteosarcoma and identified that the expression of CDH6 was closely related with the overall survival and poor prognosis of osteosarcoma patients. MicroRNAs (miRNAs) have been implicated as important epigenetic regulators during the progression of osteosarcoma. Using dual-luciferase reporter assays, we showed that miR-223-3p suppresses CDH6 expression by directly binding to the 3' UTR of CDH6. miR-223-3p overexpression significantly inhibited cell invasion, migration, growth, and proliferation by suppressing the CDH6 expression in vivo and in vitro. Besides, CDH6 overexpression in the miR-223-3p-transfected osteosarcoma cells effectively rescued the inhibition of cell invasion, migration, growth, and proliferation mediated by miR-223-3p. Additionally, Kaplan-Meier analysis suggests that the expression of miR-223-3p predicts favorable clinical outcomes for osteosarcoma patients. Moreover, the expression of miR-223-3p was downregulated in osteosarcoma patients and was negatively associated with the expression of CDH6. Collectively, these data highlight that miR-223-3p/CDH6 axis is an important novel pleiotropic regulator and could early predict the metastatic potential in human osteosarcoma treatments.