miR-19a and miR-424 target TGFBR3 to promote epithelial-to-mesenchymal transition and migration of tongue squamous cell carcinoma cells

The biomarkers for maintenance Cancer stem cell features can be applicable in precision medicine of head and neck squamous cell carcinoma

Cancer stem cells (CSCs) play a crucial role in tumor relapse, proliferation, invasion, and drug resistance in head and neck squamous cell carcinoma (HNSCC). This narrative review aims to synthesize data from articles published between 2019 and 2023 on biomarkers for detecting CSCs in HNSCC and changes in molecular pathways, genetics, epigenetics, and non-coding RNAs (ncRNAs) in CSCs relevant to precision medicine approaches in HNSCC management. The search encompassed 41 in vitro studies and 22 clinical studies. CSCs exhibit diverse molecular profiles and unique biomarker expression patterns, offering significant potential for HNSCC diagnosis, treatment, and prognosis, thereby enhancing patient survival. Their remarkable self-renewal ability and adaptability are closely linked to tumorigenicity development and maintenance. Assessing biomarkers before and after therapy can aid in identifying various cell types associated with cancer progression and relapse. Screening for CSCs, senescent tumor cells, and cells correlated with the senescence process post-treatment has proven highly beneficial. However, the clinical application of precision medicine in HNSCC management is hindered by the lack of specific and definitive CSC biomarkers. Furthermore, our limited understanding of CSC plasticity, governed by genomic, transcriptomic, and epigenomic alterations during tumorigenesis, as well as the bidirectional interaction of CSCs with the tumor microenvironment, underscores the need for further research. Well-designed studies involving large patient cohorts are, therefore, essential to establish a standardized protocol and address these unresolved queries.

Role of miR-424 in the carcinogenesis

Recent studies have revealed the impact of microRNAs (miRNAs) in the carcinogenic process. miR-424 is a miRNA whose role in this process is being to be identified. Experiments in the ovarian cancer, cervical cancer, hepatocellular carcinoma, neuroblastoma, breast cancer, osteosarcoma, intrahepatic cholangiocarcinoma, prostate cancer, endometrial cancer, non-small cell lung cancer, hemangioma and gastric cancer have reported down-regulation of miR-424. On the other hand, this miRNA has been found to be up-regulated in melanoma, laryngeal and esophageal squamous cell carcinomas, glioma, multiple myeloma and thyroid cancer. Expression of this miRNA is regulated by methylation status of its promoter. Besides, LINC00641, CCAT2, PVT1, LIN00657, LINC00511 and NNT-AS1 are among lncRNAs that act as molecular sponges for miR-424, thus regulating its expression. Moreover, several members of SNHG family of lncRNAs have been found to regulate expression of miR-424. This miRNA is also involved in the regulation of E2F transcription factors. The current review aims at summarization of the role of miR-424 in the process of cancer evolution and its impact on clinical outcome of patients in order to find appropriate markers for malignancies.

Decoding the interaction between miR-19a and CBX7 focusing on the implications for tumor suppression in cancer therapy

Cancer is a complex and multifaceted disease characterized by uncontrolled cell growth, genetic alterations, and disruption of normal cellular processes, leading to the formation of malignant tumors with potentially devastating consequences for patients. Molecular research is important in the diagnosis and treatment, one of the molecular mechanisms involved in various cancers is the fluctuation of gene expression. Non-coding RNAs, especially microRNAs, are involved in different stages of cancer. MicroRNAs are small RNA molecules that are naturally produced within cells and bind to the 3'-UTR of target mRNA, repressing gene expression by regulating translation. Overexpression of miR-19a has been reported in human malignancies. Upregulation of miR-19a as a member of the miR-17-92 cluster is key to tumor formation, cell proliferation, survival, invasion, metastasis, and drug resistance. Furthermore. bioinformatics and in vitro data reveal that the miR-19a-3p isoform binds to the 3'UTR of CBX7 and was identified as the miR-19a-3p target gene. CBX7 is known as a tumor suppressor. This review initially describes the regulation of mir-19a in multiple cancers. Accordingly, the roles of miR-19 in affecting its target gene expression CBX7 in carcinoma also be discussed.

miR-19a may function as a biomarker of oral squamous cell carcinoma (OSCC) by regulating the signaling pathway of miR-19a/GRK6/GPCRs/PKC in a Chinese population

BACKGROUND

In this study, we aimed to investigate the potential of miR-19a as a biomarker of OSCC and its underlying molecular mechanisms.

METHODS

We collected serum and saliva samples from 66 OSCC patients and 66 healthy control subjects. Real-time PCR analysis, bioinformatic analysis and luciferase assays were performed to establish a potential signaling pathway of miR-19a/GRK6/GPCRs/PKC. Flowcytometry and Transwell assays were performed to observe the changes in cell apoptosis, metastasis and invasion.

RESULTS

We found that miR-19a, GPR39 mRNA and PKC mRNA were upregulated while GRK6 mRNA was downregulated in the serum and saliva samples collected from OSCC patients. Moreover, in silico analysis confirmed a potential binding site of miR-19a on the 3'UTR of GRK6 mRNA, and the subsequent luciferase assays confirmed the molecular binding between GRK6 and miR-19a. We further identified that the over-expression of miR-19a could regulate the signaling between GRK6, GPR39 and PKC via the signaling pathway of miR-19a/GRK6/GPR39/PKC, which accordingly resulted in suppressed cell apoptosis and promoted cell migration and invasion.

CONCLUSION

Collectively, the findings of our study propose that miR-19a is a crucial mediator in the advancement of OSCC, offering a potential avenue for the development of innovative therapeutic interventions aimed at regulating GRK6 and its downstream signaling pathways.

MiRNA-related metastasis in oral cancer: moving and shaking

Across the world, oral cancer is a prevalent tumor. Over the years, both its mortality and incidence have grown. Oral cancer metastasis is a complex process involving cell invasion, migration, proliferation, and egress from cancer tissue either by lymphatic vessels or blood vessels. MicroRNAs (miRNAs) are essential short non-coding RNAs, which can act either as tumor suppressors or as oncogenes to control cancer development. Cancer metastasis is a multi-step process, in which miRNAs can inhibit or stimulate metastasis at all stages, including epithelial-mesenchymal transition, migration, invasion, and colonization, by targeting critical genes in these pathways. On the other hand, long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs), two different types of non-coding RNAs, can regulate cancer metastasis by affecting gene expression through cross-talk with miRNAs. We reviewed the scientific literature (Google Scholar, Scopus, and PubMed) for the period 2000-2023 to find reports concerning miRNAs and lncRNA/circRNA-miRNA-mRNA networks, which control the spread of oral cancer cells by affecting invasion, migration, and metastasis. According to these reports, miRNAs are involved in the regulation of metastasis pathways either by directly or indirectly targeting genes associated with metastasis. Moreover, circRNAs and lncRNAs can induce or suppress oral cancer metastasis by acting as competing endogenous RNAs to inhibit the effect of miRNA suppression on specific mRNAs. Overall, non-coding RNAs (especially miRNAs) could help to create innovative therapeutic methods for the control of oral cancer metastases.

miRNAs as potential game-changers in head and neck cancer: Future clinical and medicinal uses

Head and neck cancers (HNCs) are a group of heterogeneous tumors formed most frequently from epithelial cells of the larynx, lips, oropharynx, nasopharynx, and mouth. Numerous epigenetic components, including miRNAs, have been demonstrated to have an impact on HNCs characteristics like progression, angiogenesis, initiation, and resistance to therapeutic interventions. The miRNAs may control the production of numerous genes linked to HNCs pathogenesis. The roles that miRNAs play in angiogenesis, invasion, metastasis, cell cycle, proliferation, and apoptosis are responsible for this impact. The miRNAs also have an impact on crucial HNCs-related mechanistic networks like the WNT/β-catenin signaling, PTEN/Akt/mTOR pathway, TGFβ, and KRAS mutations. miRNAs may affect how the HNCs respond to treatments like radiation and chemotherapy in addition to pathophysiology. This review aims to demonstrate the relationship between miRNAs and HNCs with a particular emphasis on how miRNAs impact HNCs signaling networks.

Proteoglycans Determine the Dynamic Landscape of EMT and Cancer Cell Stemness

Proteoglycans (PGs) are pivotal components of extracellular matrices, involved in a variety of processes such as migration, invasion, morphogenesis, differentiation, drug resistance, and epithelial-to-mesenchymal transition (EMT). Cellular plasticity is a crucial intermediate phenotypic state acquired by cancer cells, which can modulate EMT and the generation of cancer stem cells (CSCs). PGs affect cell plasticity, stemness, and EMT, altering the cellular shape and functions. PGs control these functions, either by direct activation of signaling cascades, acting as co-receptors, or through regulation of the availability of biological compounds such as growth factors and cytokines. Differential expression of microRNAs is also associated with the expression of PGs and their interplay is implicated in the fine tuning of cancer cell phenotype and potential. This review summarizes the involvement of PGs in the regulation of EMT and stemness of cancer cells and highlights the molecular mechanisms.

Promising Biomarkers in Head and Neck Cancer: The Most Clinically Important miRNAs

Head and neck cancers (HNCs) comprise a heterogeneous group of tumors that extend from the oral cavity to the upper gastrointestinal tract. The principal etiologic factors for oral tumors include tobacco smoking and alcohol consumption, while human papillomavirus (HPV) infections have been accused of a high incidence of pharyngeal tumors. Accordingly, HPV detection has been extensively used to categorize carcinomas of the head and neck. The diverse nature of HNC highlights the necessity for novel, sensitive, and precise biomarkers for the prompt diagnosis of the disease, its successful monitoring, and the timely prognosis of patient clinical outcomes. In this context, the identification of certain microRNAs (miRNAs) and/or the detection of alterations in their expression patterns, in a variety of somatic fluids and tissues, could serve as valuable biomarkers for precision oncology. In the present review, we summarize some of the most frequently studied miRNAs (including miR-21, -375, -99, -34a, -200, -31, -125a/b, -196a/b, -9, -181a, -155, -146a, -23a, -16, -29, and let-7), their role as biomarkers, and their implication in HNC pathogenesis. Moreover, we designate the potential of given miRNAs and miRNA signatures as novel diagnostic and prognostic tools for successful patient stratification. Finally, we discuss the currently ongoing clinical trials that aim to identify the diagnostic, prognostic, or therapeutic utility of miRNAs in HNC.

Exosomal microRNAs shuttling between tumor cells and macrophages: cellular interactions and novel therapeutic strategies

Extracellular vesicles secreted by tumor microenvironment (TME) cells are vital players in tumor progression through transferring nucleic acids and proteins. Macrophages are the main immune cells in TME and tumor associated macrophages (TAM) express M2 phenotype, which induce tumor proliferation, angiogenesis, invasion, metastasis and immune elimination, resulting in the subsequent evolution of malignancies. There are a high number of studies confirmed that tumor cells and TAM interact with each other through extracellular vesicles in various cancers, like pancreatic ductal adenocarcinoma, gastric cancer, breast cancer, ovarian cancer, colon cancer, glioblastoma, hepatocellular cancer, and lung cancer. Herein, this review summarizes the current knowledge on mechanisms of communications between tumor cells and TAM via extracellular vesicles, mainly about microRNAs, and targeting these events might represent a novel approach in the clinical implications of this knowledge into successful anti-cancer strategies.

Triclosan induced zebrafish immunotoxicity by targeting miR-19a and its gene socs3b to activate IL-6/STAT3 signaling pathway

As a broad-spectrum antibacterial agent, triclosan (TCS) has been confirmed to possess potential immunotoxicity to organisms, but the underlying mechanisms remains unclear. Herein, with the aid of transgenic zebrafish strains Tg (coro1A: EGFP) and Tg (rag2: DsRed), we intuitively observed acute TCS exposure caused the drastic differentiation, abnormal development and distribution of innate immune cells, as well as barriers to formation of adaptive immune T cells. These abnormalities implied occurrence of the cytokine storm, which was further evidenced by expression changes of immune-related genes, and functional biomarkers. Based on transcriptome deep sequencing, target gene prediction and dual luciferase validation, the highly conservative and up-regulated miR-19a was chosen as the research target. Under TCS exposure, miR-19a up-regulation triggered down-regulation of its target gene socs3b, and simultaneously activated the downstream IL-6/STAT3 signaling pathway. Artificial over-expression and knock-down of miR-19a was realized by microinjecting agomir and antagomir, respectively, in 1-2-cell embryos. The miR-19a up-regulation inhibited socs3b expression to activate IL-6/STAT3 pathway, and yielded abnormal changes in the functional cytokine biomarkers, along with the sharp activation of immune responses. These findings disclose the molecular mechanisms regarding TCS-induced immunotoxicity, and offer important theoretical guidance for healthy safety evaluation and disease early warning from TCS pollution.

Regulation of Ferroptosis by Non-Coding RNAs in Head and Neck Cancers

Ferroptosis is a newly identified mode of programmed cell death characterized by iron-associated accumulation of lipid peroxides. Emerging research on ferroptosis has suggested its implication in tumorigenesis and stemness of cancer. On the other hand, non-coding RNAs have been shown to play a pivotal role in the modulation of various genes that affect the progression of cancer cells and ferroptosis. In this review, we summarize recent advances in the theoretical modeling of ferroptosis and its relationship between non-coding RNAs and head and neck cancers. Aside from the significance of ferroptosis-related non-coding RNAs in prognostic relevance, we also review how these non-coding RNAs participate in the regulation of iron, lipid metabolism, and reactive oxygen species accumulation. We aim to provide a thorough grounding in the function of ferroptosis-related non-coding RNAs based on current knowledge in an effort to develop effective therapeutic strategies for head and neck cancers.

KLF16 Downregulates the Expression of Tumor Suppressor Gene TGFBR3 to Promote Bladder Cancer Proliferation and Migration

Introduction

Krüppel-like factors (KLFs), which comprise 17 family members, exert important functions during the development of cancer. The role of KLF16 seems controversial in carcinogenesis because both tumor suppressive and promoting effects have been reported.

Methods

The expression level of KLF16 was analyzed based on public data sets from The Cancer Genome Atlas (TCGA) and evaluated by immunohistochemical (IHC) staining. CCK8 assay, colony formation analysis, transwell assays and the PI/Annexin V-APC assay kit were performed to detect cell growth, colony formation, cell migration and apoptosis of BC cells. Xenograft tumorigenesis assay was performed to detect the KLF16 expression on BC growth in vivo. Dual-luciferase reporter assay and chromatin immunoprecipitation (ChIP)-qPCR assay were performed to analyze the interaction between KLF16 and its target.

Results

In this study, we explored the role of KLF16 in bladder cancer (BC). We demonstrated that KLF16 was overexpressed in human BC tissues. The high expression of KLF16 was a potential predictor of a poor prognosis in patients with BC. Interference with KLF16 expression in 563 cells, having relatively higher levels of KLF16, repressed cell proliferation and migration. In contrast, upregulation of KLF16 in T24 cells enhanced cellular function, including cell growth and migration. KLF16 also suppressed the apoptosis of BC cells. Additionally, KLF16 inhibited the expression of the TGF-type III receptor (TGFBR3) by binding to its promoter sequence and reducing transcriptional activity. There was a negative correlation between KLF16 and TGFBR3 in human BC tissues. Furthermore, TGFBR3 was revealed to be a negative regulator of BC cell proliferation and migration. KLF16 also supported BC tumorigenesis by downregulating TGFBR3 expression in vivo.

Discussion

These results suggested that KLF16 acts as an oncogene in BC through transcriptional inactivation of TGFBR3. This study provides evidence that targeting the KLF16/TGFBR3 axis may be beneficial for BC patients.

TGF-β superfamily co-receptors in cancer

Transforming growth factor-β (TGF-β) superfamily signaling via their cognate receptors is frequently modified by TGF-β superfamily co-receptors. Signaling through SMAD-mediated pathways may be enhanced or depressed depending on the specific co-receptor and cell context. This dynamic effect on signaling is further modified by the release of many of the co-receptors from the membrane to generate soluble forms that are often antagonistic to the membrane-bound receptors. The co-receptors discussed here include TβRIII (betaglycan), endoglin, BAMBI, CD109, SCUBE proteins, neuropilins, Cripto-1, MuSK, and RGMs. Dysregulation of these co-receptors can lead to altered TGF-β superfamily signaling that contributes to the pathophysiology of many cancers through regulation of growth, metastatic potential, and the tumor microenvironment. Here we describe the role of several TGF-β superfamily co-receptors on TGF-β superfamily signaling and the impact on cellular and physiological functions with a particular focus on cancer, including a discussion on recent pharmacological advances and potential clinical applications targeting these co-receptors.

Inhibiting microRNA-424 in bone marrow mesenchymal stem cells-derived exosomes suppresses tumor growth in colorectal cancer by upregulating TGFBR3

OBJECTIVE

MicroRNAs (miRNAs) have been demonstrated to be differently expressed in colorectal cancer (CRC) and were identified as biomarkers and therapeutic targets for CRC. We aimed to identify the effect of microRNA-424 (miR-424) on process of CRC.

METHODS

Exosomes were obtained from bone marrow mesenchymal stem cells (BMSCs). MiR-424, transforming growth factor-β receptor 3 (TGFBR3) vimentin, S100A4, p-Smad1 expression in tissues and cells was measured. After treated with miR-424 inhibitor or TGFBR3 overexpression plasmid, the migration, invasion, cell cycle distribution and apoptosis of Lovo cells and exosomes-transfected Lovo cells were determined. The subcutaneous tumor models were established and the tumor growth was observed. The target relation between miR-424 and TGFBR3 was confirmed.

RESULTS

MiR-424 was upregulated while TGFBR3 was downregulated in CRC tissues. TGFBR3 was targeted by miR-424. Inhibited miR-424 or elevated TGFBR3 upregulated p-Smad1, indicating that TGFBR3 mediated the Smad1 pathway, thus regulating CRC progression. MiR-424 inhibition or TGFBR3 restoration also suppressed migration and invasion of CRC cells, arrested the CRC cells at G0/G1 phase, and promoted CRC cell apoptosis. Moreover, exosomal miR-424 from BMSCs promoted CRC development.

CONCLUSION

Inhibited exosomal miR-424 from BMSCs inhibited malignant behaviors of CRC cells by targeting TGFBR3, thus suppressing the progression of CRC.

Role of miRNA-19a in Cancer Diagnosis and Poor Prognosis

Cancer is a multifactorial disease that affects millions of people every year and is one of the most common causes of death in the world. The high mortality rate is very often linked to late diagnosis; in fact, nowadays there are a lack of efficient and specific markers for the early diagnosis and prognosis of cancer. In recent years, the discovery of new diagnostic markers, including microRNAs (miRNAs), has been an important turning point for cancer research. miRNAs are small, endogenous, non-coding RNAs that regulate gene expression. Compelling evidence has showed that many miRNAs are aberrantly expressed in human carcinomas and can act with either tumor-promoting or tumor-suppressing functions. miR-19a is one of the most investigated miRNAs, whose dysregulated expression is involved in different types of tumors and has been potentially associated with the prognosis of cancer patients. The aim of this review is to investigate the role of miR-19a in cancer, highlighting its involvement in cell proliferation, cell growth, cell death, tissue invasion and migration, as well as in angiogenesis. On these bases, miR-19a could prove to be truly useful as a potential diagnostic, prognostic, and therapeutic marker.

Roles of microRNAs in Regulating Cancer Stemness in Head and Neck Cancers

Head and neck squamous cell carcinomas (HNSCCs) are epithelial malignancies with 5-year overall survival rates of approximately 40-50%. Emerging evidence indicates that a small population of cells in HNSCC patients, named cancer stem cells (CSCs), play vital roles in the processes of tumor initiation, progression, metastasis, immune evasion, chemo-/radioresistance, and recurrence. The acquisition of stem-like properties of cancer cells further provides cellular plasticity for stress adaptation and contributes to therapeutic resistance, resulting in a worse clinical outcome. Thus, targeting cancer stemness is fundamental for cancer treatment. MicroRNAs (miRNAs) are known to regulate stem cell features in the development and tissue regeneration through a miRNA-target interactive network. In HNSCCs, miRNAs act as tumor suppressors and/or oncogenes to modulate cancer stemness and therapeutic efficacy by regulating the CSC-specific tumor microenvironment (TME) and signaling pathways, such as epithelial-to-mesenchymal transition (EMT), Wnt/β-catenin signaling, and epidermal growth factor receptor (EGFR) or insulin-like growth factor 1 receptor (IGF1R) signaling pathways. Owing to a deeper understanding of disease-relevant miRNAs and advances in in vivo delivery systems, the administration of miRNA-based therapeutics is feasible and safe in humans, with encouraging efficacy results in early-phase clinical trials. In this review, we summarize the present findings to better understand the mechanical actions of miRNAs in maintaining CSCs and acquiring the stem-like features of cancer cells during HNSCC pathogenesis.

Circulating microRNA Panel as a Potential Novel Biomarker for Oral Squamous Cell Carcinoma Diagnosis

Simple Summary

Although early detection of oral squamous cell carcinoma (OSCC) is considered vital, classical biomarkers have shown poor sensitivity and specificity for early detection and monitoring of OSCC. Therefore, identification of reliable and sensitive biomarkers allowing for early detection and monitoring of OSCC is of the utmost importance. In this study, we successfully identified significantly upregulated or downregulated microRNAs in OSCC patients, and reported that a combination of six microRNAs could distinguish between OSCC and the control group with a higher degree of accuracy. Furthermore, compared with serum squamous cell carcinoma (SCC) antigen, the miRNA panel reflected the presence of OSCC accurately. The present results suggest that the combined microRNA panel based on serum microRNA levels shows potential as a novel diagnostic biomarker of OSCC.

Abstract

A lack of reliable biomarkers for oral squamous cell carcinoma (OSCC) poses a major clinical issue. The sensitivity and specificity of classical serum tumor markers, such as the squamous cell carcinoma antigen (SCC-Ag), are quite poor, especially for early detection. This study aimed to identify specific serum miRNAs potentially serving as OSCC biomarkers. The expression levels of candidate miRNAs in serum samples from 40 OSCC patients and 40 healthy controls were quantitatively analyzed via microarray and reverse transcription PCR (RT-PCR) analyses. To enhance the accuracy of detection, we used Fisher’s linear discriminant analysis to establish a diagnostic model that incorporated a combination of selected miRNAs. Consequently, miR-19a and miR-20a were significantly upregulated in the patient group (p = 0.014 and 0.036, respectively), whereas miR-5100 was downregulated (p = 0.001). We found that a combination of six miRNAs (miR-24, miR-20a, miR-122, miR-150, miR-4419a, and miR-5100) could distinguish between OSCC and the control group with a higher degree of accuracy (Area Under the Curve, AUC: 0.844, sensitivity: 55%, and specificity: 92.5%). Furthermore, compared to serum SCC antigen, the 6-miRNA panel could accurately detect the presence of OSCC. The present specific miRNAs panel may serve as a novel candidate biomarker of oral cancer.

Epithelial-to-mesenchymal transition in oral squamous cell carcinoma: Challenges and opportunities

Oral squamous cell carcinoma (OSCC) is the most common malignancy representing 90% of all forms of oral cancer worldwide. Although great efforts have been made in the past decades, the 5-year survival rate of OSCC patients is no more than 60% due to tumor metastasis and subsequent recurrence. The metastasis from the primary site is due to a complex process known as epithelial-to-mesenchymal transition (EMT). During the EMT, epithelial cells gradually acquire the structural and functional characteristics of mesenchymal cells, leading to the upregulation of cell migration and the promotion of tumor cell dissemination. Therefore, EMT attracted broad attention due to its close relationship with cancer invasion and metastasis. Therefore, in the present review, an extensive description of the current research on OSCC and the role of EMT in this cancer type is provided, including diverse EMT markers, regulatory networks and crucial EMT-inducing transcription factors in OSCC. Moreover, a brief summary was made regarding the current application of EMT-correlated indexes in the prognostic analysis of OSCC patients, and the potential therapeutic approaches against OSCC and difficulties in the development of an effective anti-EMT treatment are discussed. Our aim is to provide novel insights to develop new strategies to combat OSCC by targeting EMT.

microRNA-18a from M2 Macrophages Inhibits TGFBR3 to Promote Nasopharyngeal Carcinoma Progression and Tumor Growth via TGF-β Signaling Pathway

OBJECTIVES

Nasopharyngeal carcinoma (NPC) is a type of nasopharyngeal disease with high metastasis and invasion properties. Tumor-associated alternative activated (M2) macrophages are evidenced to connect with NPC. Based on this, this study purposes to explore the mechanism and participation of microRNA-18a (miR-18a) from M2 macrophages in NPC.

METHODS

Peripheral blood mononuclear cells were differentiated to macrophages and macrophages were polarized to M2 type by interleukin-4. SUNE-1 and CNE2 cells were transfected with restored or depleted miR-18a or transforming growth factor-beta III receptor (TGFBR3) to explore their roles in NPC progression with the involvement of the TGF-β signaling pathway. Next, SUNE-1 and CNE2 cells were co-cultured with M2 macrophages that had been treated with restored or depleted miR-18a or TGFBR3 to comprehend their combined roles in NPC with the involvement of the TGF-β signaling pathway.

RESULTS

MiR-18a was highly expressed and TGFBR3 was lowly expressed in NPC cells. MiR-18a restoration, TGFBR3 knockdown or co-culture with miR-18a mimics, or si-TGFBR3-transfected M2 macrophages promoted SUNE-1 cell progression, tumor growth in mice, decreased p-Smad1/t-Smad1, and elevated p-Smad3/t-Smad3. miR-18a downregulation, TGFBR3 overexpression, or co-culture with miR-18a inhibitors or OE-TGFBR3-transfected M2 macrophages depressed CNE2 cell progression, tumor growth in mice, increased p-Smad1/t-Smad1, and decreased p-Smad3/t-Smad3.

CONCLUSION

Our study elucidates that miR-18a from M2 macrophages results in promoted NPC cell progression and tumor growth in nude mice via TGFBR3 repression, along with the Smad1 inactivation and Smad3 activation.

Role of miRNA-424 in Cancers

microRNA (miRNA) is an important part of non-coding RNA that regulates gene expression at a posttranscriptional level. miRNA has gained increasing interest in recent years, both in research and clinical fields. miRNAs have been found to play an important role in various diseases, particularly cancer. Aberrant miR-424 expression is found in several tumors where they can function as either oncogenes or tumor-suppressor genes. Meanwhile, miR-424 is also affected by the reorganization of many other non-coding RNAs such as lncRNA and cirRNA. Several studies have found that miR-424 participates in proliferation, differentiation, apoptosis, invasion, angiogenesis, and drug resistance, and plays an important role in the tumorigenesis and progression of tumors. This review will focus on the recent progress of research on miR-424 in tumors.

Exosomal CircGDI2 Suppresses Oral Squamous Cell Carcinoma Progression Through the Regulation of MiR-424-5p/SCAI Axis

Background

Exosomes are small membrane vesicles that are secreted by most cell types. Circular RNAs (circRNAs) have recently been identified in exosomes, and exosomal circRNAs exert important biological activities in human cancers, including oral squamous cell carcinoma (OSCC). The purpose of this study was to investigate whether circRNA GDP dissociation inhibitor 2 (circGDI2) was transferred by exosomes and how exosomal circGDI2 regulated OSCC cell malignant behaviors.

Methods

The levels of circGDI2, miR-424-5p and suppressor of cancer cell invasion (SCAI) were detected by quantitative real-time polymerase chain reaction (qRT-PCR) or Western blot. Cell proliferation was evaluated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay. Transwell assays were performed to detect cell migration and invasion. Measurement of glucose consumption and lactate production were conducted using a corresponding assay kit. Targeted correlations among circGDI2, miR-424-5p and SCAI were confirmed by dual-luciferase reporter assays. Xenograft assays were used to observe the role of circGDI2 in tumor growth in vivo.

Results

Our data indicated that circGDI2 was down-regulated in OSCC, and it could be transferred by the exosomes in OSCC cells. The up-regulation of exosomal circGDI2 weakened OSCC cell proliferation, migration, invasion and glycolysis. CircGDI2 functioned as a molecular sponge of miR-424-5p, and SCAI was a direct target of miR-424-5p. MiR-424-5p mediated the repression of exosomal circGDI2 overexpression on OSCC cell malignant behaviors, and miR-424-5p silencing mitigated OSCC cell progression by up-regulating SCAI. Moreover, exosomal circGDI2 regulated SCAI expression through sponging miR-424-5p. Additionally, the overexpression of exosomal circGDI2 inhibited tumor growth in vivo.

Conclusion

The present study had led to the identification of exosomal circGDI2 that regulated OSCC cell malignant behaviors through targeting the miR-424-5p/SCAI axis, highlighting circGDI2 as a novel exosome-based cancer biomarker and therapeutic agent for OSCC treatment.

The roles of microRNAs in the stemness of oral cancer cells

Oral cancer (OC), which is the most common form of head and neck cancers, has one of the lowest (~50%) overall 5-year survival rates. The main reasons for this high mortality rate are diagnosis of OC in advanced stages in most patients and spread to distant organs via lymph node metastasis. Many studies have shown that a small population of cells within the tumor plays vital roles in the initiation, progression, and metastasis of the tumor, resistance to chemotherapeutic agents, and recurrence. These cells, identified as cancer stem cells (CSCs), are the main reasons for the failure of current treatment modalities. Deregulated expressions of microRNAs are closely related to tumor prognosis, metastasis and drug resistance. In addition, microRNAs play important roles in regulating the functions of CSCs. Until now, the roles of microRNAs in the acquisition and maintenance of OC stemness have not been elucidated in detail yet. Here in this review, we summarized significant findings and the latest literature to better understand the involvement of CSCs in association with dysregulated microRNAs in oral carcinogenesis. Possible roles of these microRNAs in acquisition and maintenance of CSCs features during OC pathogenesis were summarized.

Cyto-biological effects of microRNA-424-5p on human colorectal cancer cells

MicroRNA (miR)-424-5p is overexpressed in colorectal cancer (CRC); however, its role, clinical significance and underlying molecular mechanism have remained to be fully elucidated. The aim of the present study was to investigate the roles of miR-424-5p in CRC and the underlying mechanisms. It was demonstrated that miR-424-5p is overexpressed in CRC, based on bioinformatics analysis using The Cancer Genome Atlas TCGA and analysis of tissue samples from patients with CRC from The First Hospital of Hebei Medical University, and the expression of miR-424-5p was associated with the depth of invasion and Dukes' staging. In CRC cells, the oncogenic roles of miR-424-5p were also verified by Cell Counting Kit-8, wound healing and Transwell assays. To identify target genes, all transcripts were compared between miR-424-5p mimic-transfected SW480 cells and mimic control cells by transcriptome sequencing. Subsequently, the differentially expressed genes (DEGs) were subjected to Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses. The DEGs were revealed to be significantly enriched in the GO terms 'serine hydrolase activity,' 'serine-type peptidase activity' and 'serine-type endopeptidase activity'. KEGG signaling pathway analysis indicated that the DEGs were significantly enriched in 'endocytosis', 'regulation of actin cytoskeleton', 'Wnt signaling pathway' and 'ubiquitin-mediated proteolysis signaling pathway'. These results suggested that miR-424-5p is a potential target in the treatment of CRC.

TRG-AS1 is a potent driver of oncogenicity of tongue squamous cell carcinoma through microRNA-543/Yes-associated protein 1 axis regulation

The long noncoding RNA T cell receptor gamma locus antisense RNA 1 (TRG-AS1) plays an important role in glioblastoma progression. The objective of this study was to determine the expression status of TRG-AS1 in tongue squamous cell carcinoma (TSCC). The regulatory effects of TRG-AS1 depletion on the malignant processes of TSCC cells were illustrated both in vitro and in vivo. Additionally, the precise molecular mechanisms through which TRG-AS promotes TSCC oncogenicity were investigated. TRG-AS1 expression in TSCC tissues and cell lines was detected using reverse transcription-quantitative PCR. Functional experiments including Cell Counting Kit-8 assay, flow cytometric apoptotic assay, migration and invasion assays, and xenograft tumor model analysis were conducted to severally determine the effects of TRG-AS1 on TSCC cell proliferation, apoptosis, migration, and invasion in vitro and tumor growth in vivo. Herein, TRG-AS1 was highly expressed in TSCC and closely associated with advanced TNM stage, high lymph node metastasis, and poor overall survival. Functionally, TRG-AS1 depletion suppressed TSCC cell proliferation, migration, and invasion in vitro; promoted cell apoptosis; and attenuated tumor growth in vivo. Mechanistically, TRG-AS1 served as a molecular sponge for microRNA-543 (miR-543), thereby contributing to the increased expression of Yes-associated protein 1 (YAP1) - a miR-543 target. Rescue experiments confirmed that miR-543 inhibition or YAP1 overexpression abrogated the anticancer effects of TRG-AS1 silencing in TSCC cells. In conclusion, TRG-AS1 aggravates TSCC malignancy by regulating the miR-543/YAP1 axis. Identification of the TRG-AS1/miR-543/YAP1 regulatory pathway may provide novel insights into TSCC diagnosis, prognosis, and therapy.

The STAT3-miR-223-TGFBR3/HMGCS1 axis modulates the progression of cervical carcinoma

Cervical cancer is induced by persistent infections with high-risk human papillomaviruses (HPVs), which produce the early protein 6 of HPVs (E6)/E7 protein that is involved in cell transformation by interacting with several oncoproteins or tumor suppressors. However, the role of noncoding RNA in mediating the pathogenesis of cervical cancer remains unclear. Here, we report that the novel signal transducer and activator of transcription 3 (STAT3)-microRNA-223-3p (miR-223)-TGFBR3/HMGCS1 axis regulated by the E6 protein controls cervical carcinogenesis. miR-223 was highly expressed in cervical tumor tissues, whereas TGFBR3 or HMGCS1 was significantly downregulated. miR-223 targeted the 3'-UTRs of TGFBR3 and HMGCS1 and suppressed their expression, leading to increased anchorage-independent growth and cervical squamous cell carcinoma (CSCC) tumor growth in vitro and in vivo. The increased expression of miR-223 was mediated by the transcription factor STAT3, whose activity was enhanced by E6 in the context of interleukin (IL)-6 stimulation. In addition, exosomal miR-223 derived from CSCC cells induced IL-6 secretion by monocyte/macrophage in a coculture system in vitro, and IL-6 secretion, in turn, led to enhanced STAT3 activity in CSSC cells, forming a positive feedback loop. Furthermore, modified miR-223 inhibitor effectively suppressed tumor growth in cell line-derived xenograft model, suggesting that miR-223 is a potential promising therapeutic target in CSCC. In conclusion, our results demonstrate that the STAT3-miR-223-HMGCS1/TGFBR3 axis functions as a key signaling pathway in cervical cancer progression and provides a new therapeutic target.

MiR-26a/miR-26b represses tongue squamous cell carcinoma progression by targeting PAK1

Background

Tongue squamous cell carcinoma (TSCC) is the most common oral malignancy. Previous studies found that microRNA (miR)-26a and miR-26b were downregulated in TSCC tissues. The current study was designed to explore the effects of miR-26a/miR-26b on TSCC progression and the potential mechanism.

Methods

Expression of miR-26a, miR-26b and p21 Activated Kinase 1 (PAK1) in TSCC tissues and cell lines was detected by reverse transcription- quantitative polymerase chain reaction (RT-qPCR). Flow cytometry analysis was performed to examine cell cycle and apoptosis. Transwell assay was conducted to evaluate the migrated and invasive abilities of SCC4 and Cal27 cells. In addition, western blot assay was employed to analyze the protein level. Glucose assay kit and lactate assay kit were utilized to analyze glycolysis. Dual-luciferase reporter and RNA immunoprecipitation (RIP) assays were applied to explore the relationship between miR-26a/miR-26b and PAK1. Xenograft tumor model was constructed to explore the role of miR-26a/miR-26b in vivo.

Results

Both miR-26a and miR-26b were underexpressed, while PAK1 was highly enriched in TSCC. Overexpression of miR-26a and miR-26b inhibited TSCC cell cycle, migration invasion and glycolysis, while promoted cell apoptosis. Both miR-26a and miR-26b directly targeted and negatively regulated PAK1 expression. Introduction of PAK1 partially reversed miR-26a/miR-26b upregulation-mediated cellular behaviors in TSCC cells. Gain of miR-26a/miR-26b blocked TSCC tumor growth in vivo.

Conclusion

MiR-26a/miR-26b repressed TSCC progression via targeting PAK1 in vitro and in vivo, which enriched our understanding about TSCC development and provided new insights into the its treatment.

lncRNA CCAT2 Enhanced Resistance of Glioma Cells Against Chemodrugs by Disturbing the Normal Function of miR-424

Background

Aggressive metastasis of tumor cells assumed a constructive role in strengthening chemoresistance of tumors, so this investigation was intended to elucidate if lncRNA CCAT2 sponging downstream miR-424 regulated chemotolerance of glioma cells by boosting metastasis of glioma cells.

Methods

One hundred and twenty-eight pairs of glioma tissues and corresponding adjacent tissues were resected from glioma patients during their operation, and we also purchased a series of glioma cell lines, including U251, U87, A172 and SHG44. Furthermore, pcDNA3.1-CCAT2, si-CCAT2, miR-424 mimic and miR-424 inhibitor were transfected into SHG44 and U251 cell lines, so as to evaluate impacts of CCAT2 and miR-424 on chemosensitivity of the glioma cells. Besides, proliferation, invasion and metastasis of the cells were determined through the implementation of colony formation assay, transwell assay and scratch assay.

Results

Glioma tissues and cells were monitored with higher CCAT2 expression and lower miR-424 expression than adjacent normal tissues and NHA cell line (P<0.05). Among the glioma cell lines, the SHG44 cell line showed the strongest resistance against teniposide, temozolomide and cisplatin (P<0.05), whereas the U251 cell line was more sensitive to teniposide, temozolomide, vincristine and cisplatin than any other cell line (P<0.05). Besides, pcDNA3.1-CCAT2 and miR-424 inhibitor could enhance tolerance of glioma cell lines against drugs (P<0.05). Moreover, in-vitro transfection of si-CCAT2 and miR-424 mimic could significantly retard proliferation, invasion and migration of SHG44 and U251 cells (P<0.05), and CCAT2 was found to negatively regulate miR-424 expression by sponging it (P<0.05). In addition, CHK1 was deemed as the molecule targeted by upstream miR-424, and its overexpression can changeover the effects of miR-424 mimic on proliferation and metastasis of SHG44 and U251 cells.

Conclusion

lncRNA CCAT2/miR-424/Chk1 axis might serve as a promising target for improving chemotherapeutic efficacies in glioma treatment.

Circular RNA LARP4 correlates with decreased Enneking stage, better histological response, and prolonged survival profiles, and it elevates chemosensitivity to cisplatin and doxorubicin via sponging microRNA-424 in osteosarcoma

BACKGROUND

This study aimed to evaluate the association of circular RNA La-related RNA-binding protein 4 (circ-LARP4) with clinical features and prognosis in osteosarcoma patients, and further explore its effect on chemosensitivity in osteosarcoma cells.

METHODS

Seventy-two osteosarcoma patients with Enneking stage IIA-IIB who underwent resection were consecutively enrolled, and then, tumor tissues and non-tumor tissues were obtained. Circ-LARP4 in tumor tissue/non-tumor tissue was detected by quantitative polymerase chain reaction. After circ-LARP4 overexpression and negative control overexpression plasmid transfection, relative cell viability (%) was evaluated by Cell Counting Kit-8 in MG63 cells treated by different concentrations of cisplatin, methotrexate, and doxorubicin, and IC50 was calculated.

RESULTS

Circ-LARP4 was downregulated in tumor tissue compared with non-tumor tissue and had a good value in distinguishing tumor tissue from non-tumor tissue with an area under curve of 0.829 (95% CI: 0.762-0.859). Meanwhile, tumor circ-LARP4 was negatively correlated with the Enneking stage. After resection, circ-LARP4 high expression patients showed an increased tumor cell necrosis rate to adjuvant chemotherapy compared to circ-LARP4 low expression patients, and circ-LARP4 high expression correlated with prolonged disease-free survival and overall survival. In vitro experiments revealed that circ-LARP4 overexpression elevated the chemosensitivity of MG63 cells to cisplatin and doxorubicin but not methotrexate, with decreased cisplatin IC50 and doxorubicin IC50 concentrations than negative control. Besides, miR-424 overexpression attenuated the chemosensitivity in circ-LARP4 overexpression-treated MG63 cells.

CONCLUSION

Circ-LARP4 high expression correlates with decreased Enneking stage and prolonged survival profiles, and it elevates chemosensitivity to cisplatin and doxorubicin via sponging miR-424 in osteosarcoma.

Hsa_circ_0042666 inhibits proliferation and invasion via regulating miR-223/TGFBR3 axis in laryngeal squamous cell carcinoma

Circular RNAs (circRNAs) have been reported to play critical roles in tumorigenesis. However, the roles of circRNAs in laryngeal squamous cell carcinoma (LSCC) are still largely unknown. In our present study, we identified a novel circRNA hsa_circ_0042666, which was poorly expressed in LSCC. Low hsa_circ_0042666 expression was closely associated with advanced tumor stage, lymph-node metastasis, and poor overall survival. In vitro function assays, we showed that hsa_circ_0042666 dramatically reduced LSCC cells proliferation and invasion in vitro. In mechanism, our data indicated that hsa_circ_0042666 could competitively bind to miR-223 as a miRNA sponge to regulate TGFBR3 expression in LSCC progression. Altogether, these findings elucidated that hsa_circ_0042666 regulated LSCC cells proliferation and invasion by miR-223/TGFBR3 axis, which might provide a therapeutic strategy for the treatment of LSCC.

miR-611 promotes the proliferation, migration and invasion of tongue squamous cell carcinoma cells by targeting FOXN3

OBJECTIVES

The function of miR-611 has not yet been reported. We aimed to investigate the effects of miR-611 on tongue squamous cell carcinoma (TSCC) and the underlying mechanism.

MATERIALS AND METHODS

The expression level of miR-611 in TSCC tissues was measured using quantitative reverse transcriptase-polymerase chain reaction (RT-qPCR). Cell proliferation, migration and invasion were examined by performing CCK-8, IncuCyte and Transwell assays. Bioinformatics analyses and microarrays were used to screen for target genes, which were verified using a luciferase reporter assay, RT-qPCR and Western blotting. The xenograft model was used to assess the effects of miR-611 in vivo.

RESULTS

miR-611 was upregulated in TSCC tissues, which was significantly correlated with TNM stage and negatively associated with the overall survival of patients. In addition, upregulation of miR-611 not only potentiated the proliferation, migration, invasion and epithelial-mesenchymal transition (EMT) of TSCC cells in vitro, but also promoted tumour growth in vivo. FOXN3 was identified as a candidate target gene of miR-611 and subsequently verified. Finally, miR-611 induced a malignant phenotype of TSCC, which was rescued by overexpression of FOXN3.

CONCLUSIONS

Our findings suggest that miR-611 is a novel therapeutic target for TSCC.

Macrophage-derived exosomal microRNA-501-3p promotes progression of pancreatic ductal adenocarcinoma through the TGFBR3-mediated TGF-β signaling pathway

Background

Exosomes from cancer cells or immune cells, carrying bio-macromolecules or microRNAs (miRNAs), participate in tumor pathogenesis and progression by modulating microenvironment. Our study aims to investigate the role of these microRNA-501-3p (miR-501-3p) containing exosomes derived from tumor-associated macrophage (TAM) in the progression of pancreatic ductal adenocarcinoma (PDAC).

Methods

Firstly, the function of TAM recruitment in PDAC tissues was assessed, followed by identification of the effects of M2 macrophage-derived exosomes on PDAC cell activities and tumor formation and metastasis in mice. In silico analysis was conducted to predict differentially expressed genes and regulatory miRNAs related to PDAC treated with macrophages, which determined miR-501-3p and TGFBR3 for subsequent experiments. Next, gain- and loss-of-function experiments were performed to examine their role in PDAC progression with the involvement of the TGF-β signaling pathway.

Results

TAM recruitment in PDAC tissues was associated with metastasis. Highly expressed miR-501-3p was observed in PDAC tissues and TAM-derived exosomes. Both M2 macrophage-derived exosomes and miR-501-3p promoted PDAC cell migration and invasion, as well as tumor formation and metastasis in nude mice. MiR-501-3p was verified to target TGFBR3. PDAC cells presented with down-regulated TGFBR3, which was further decreased in response to M2 macrophage treatment. TGF-β signaling pathway activation was implicated in the promotion of miR-501-3p in PDAC development. The suppression of macrophage-derived exosomal miR-501-3p resulted in the inhibition of tumor formation and metastasis in vivo.

Conclusion

M2 macrophage-derived exosomal miR-501-3p inhibits tumor suppressor TGFBR3 gene and facilitates the development of PDAC by activating the TGF-β signaling pathway, which provides novel targets for the molecular treatment of PDAC.

Electronic supplementary material

The online version of this article (10.1186/s13046-019-1313-x) contains supplementary material, which is available to authorized users.

MicroRNA‑758 inhibits tumorous behavior in tongue squamous cell carcinoma by directly targeting metadherin

Numerous microRNAs (miRNAs) are dysregulated in tongue squamous cell carcinoma (TSCC), and their dysregulation has been demonstrated to have a strong correlation with TSCC progression via regulation of their targets. Therefore, miRNAs have potential use in the diagnosis and treatment of patients with TSCC. In the present study, miRNA‑758 (miR‑758) expression in TSCC tissues and cell lines was detected through reverse transcription‑quantitative polymerase chain reaction, and the effects of miR‑758 on TSCC cell proliferation and invasion were investigated by using Cell Counting kit‑8 and Transwell invasion assays. A luciferase reporter assay was performed to determine the target interaction between miR‑758 and metadherin (MTDH) in TSCC cells. The results revealed that miR‑758 was downregulated in TSCC tissues and cell lines. miR‑758 overexpression restricted the proliferation and invasion of TSCC cells. Additionally, MTDH was verified as a direct target gene of miR‑758 in TSCC cells. Furthermore, MTDH was observed to be upregulated in TSCC tissues, and the upregulation of MTDH was inversely correlated with miR‑758 expression. Moreover, restored MTDH expression significantly counteracted the suppressive effects of miR‑758 overexpression on TSCC cells. These results suggested that miR‑758 may prevent TSCC progression and development by directly targeting MTDH, thereby providing evidence that miR‑758 is a novel therapeutic target for the treatment of patients with TSCC.

H19X-encoded miR-424(322)/-503 cluster: emerging roles in cell differentiation, proliferation, plasticity and metabolism

miR-424(322)/-503 are mammal-specific members of the extended miR-15/107 microRNA family. They form a co-expression network with the imprinted lncRNA H19 in tetrapods. miR-424(322)/-503 regulate fundamental cellular processes including cell cycle, epithelial-to-mesenchymal transition, hypoxia and other stress response. They control tissue differentiation (cardiomyocyte, skeletal muscle, monocyte) and remodeling (mammary gland involution), and paradoxically participate in tumor initiation and progression. Expression of miR-424(322)/-503 is governed by unique mechanisms involving sex hormones. Here, we summarize current literature and provide a primer for future endeavors.

miR-424-5p regulates cell proliferation, migration and invasion by targeting doublecortin-like kinase 1 in basal-like breast cancer

Our previous study has showed doublecortin like kinase 1 (DCLK1) serves as an oncogene to regulate basal-like breast cancer cell proliferation, migration and invasion, and is associated with malignant status and poor prognosis. The aim of this study is to identify microRNAs (miRNAs), which target DCLK1 to regulate basal-like breast cancer cell proliferation, migration and invasion. In our results, we observed that miR-424-5p expression was decreased in basal-like breast cancer tissues and cell lines. Furthermore, we found 3'-UTR of DCLK1 had binding site of miR-424-5p based on microRNA target databases, and there was an inverse correlation between miR-424-5p and DCLK1 in basal-like breast cancer tissues. Moreover, we confirmed miR-424-5p directly targeted to 3'-UTR of DCLK1 through luciferase reporter assay, and miR-424-5p negatively regulated DCLK1 mRNA and protein expressions through qRT-PCR and western blot. The gain-of-function studies showed that miR-424-5p suppressed basal-like breast cancer cell proliferation, migration and invasion. The rescued-function studies suggested up-regulation of DCLK1 could rescue inhibition of miR-424-5p mimics in the regulation of basal-like breast cancer cell proliferation, migration and invasion. Finally, low-expression of miR-424-5p was associated with advanced clinical stage, large tumor size, more metastatic lymph nodes, present distant metastasis and poor histological grade in basal-like breast cancer patients. In conclusion, miR-424-5p is a tumor suppressive microRNA to regulate tumor cell proliferation, migration and invasion via binding to the functional target DCLK1, and associated with malignant status in basal-like breast cancer.