Tumour-suppressive microRNA-29s inhibit cancer cell migration and invasion by targeting laminin-integrin signalling in head and neck squamous cell carcinoma

Salivary miRNAs as a novel therapeutic marker in a patient with advanced oral squamous cell carcinoma: A case report

The global prevalence of oral squamous cell carcinoma (OSCC) has been increasing. OSCC at the advanced stage tends to resist conventional treatment and causes local recurrence and distant metastasis, resulting in poor prognosis. Therefore, detecting this cancer at an early stage and performing early intervention are important. Promising biomarkers to detect OSCC have yet to be established; however, microRNAs (miRNAs/miRs) serve a crucial role in OSCC tumorigenesis and may be potential biomarkers. In the present case report, the availability of salivary miRNAs as a therapeutic and prognostic marker for patients with OSCC was assessed. The patient was a 33-year-old woman who was diagnosed with advanced OSCC of the tongue, and their miRNA profile isolated from a saliva sample at each clinical course was evaluated. Microarray analysis of the salivary samples revealed changes in the levels of four miRNAs (hsa-miR-6798-5p, miR-6803-5p, miR-6805-5p and miR-6845-5p) in accordance with the clinical course. Neoadjuvant chemotherapy and surgical procedure decreased the levels, whereas the levels increased when the patient was diagnosed with lung metastasis. Furthermore, tongue and lung metastatic lesion specimens exhibited expression of the vascular endothelial growth factor receptor-2, which is regulated by the four miRNAs. Accordingly, the present report proposed that salivary miRNAs could be a therapeutic and prognostic biomarker for OSCC.

Exosomal microRNA as a key regulator of PI3K/AKT pathways in human tumors

MicroRNAs (miRNAs) are conserved non-protein-coding RNAs that are naturally present in organisms and can control gene expression by suppressing the translation of mRNA or causing the degradation of mRNA. MicroRNAs are highly concentrated in the PI3K/AKT pathway, and abnormal activation of the PI3K/AKT pathway plays a role in cancer progression. The AKT/PI3K pathway is critical for cellular functions and can be stimulated by cytokines and in normal situations. It is involved in regulating various intracellular signal transduction, including development, differentiation, transcriptional regulation, protein, and synthesis. There is a growing body of evidence indicating that miRNAs, which are abundant in exosomes released by different cells, can control cellular biological activities via modulating the PI3K/AKT pathway, hence influencing cancer progression and drug resistance. This article provides an overview of the latest research progress regarding the function and medical use of the PI3K/AKT pathway and exosomal miRNA/AKT/PI3K axis in the behaviors of cancer cells.

Matricellular proteins: Potential biomarkers in head and neck cancer

The extracellular matrix (ECM) is a complex network of diverse multidomain macromolecules, including collagen, proteoglycans, and fibronectin, that significantly contribute to the mechanical properties of tissues. Matricellular proteins (MCPs), as a family of non-structural proteins, play a crucial role in regulating various ECM functions. They exert their biological effects by interacting with matrix proteins, cell surface receptors, cytokines, and proteases. These interactions govern essential cellular processes such as differentiation, proliferation, adhesion, migration as well as multiple signal transduction pathways. Consequently, MCPs are pivotal in maintaining tissue homeostasis while orchestrating intricate molecular mechanisms within the ECM framework. The expression level of MCPs in adult steady-state tissues is significantly low; however, under pathological conditions such as inflammation and cancer, there is a substantial increase in their expression. In recent years, an increasing number of studies have focused on elucidating the role and significance of MCPs in the development and progression of head and neck cancer (HNC). During HNC progression, there is a remarkable upregulation in MCP expression. Through their distinctive structure and function, they actively promote tumor growth, invasion, epithelial-mesenchymal transition, and lymphatic metastasis of HNC cells. Moreover, by binding to integrins and modulating various signaling pathways, they effectively execute their biological functions. Furthermore, MCPs also hold potential as prognostic indicators. Although the star proteins of various MCPs have been extensively investigated, there remains a plethora of MCP family members that necessitate further scrutiny. This article comprehensively examines the functionalities of each MCP and highlights the research advancements in the context of HNC, with an aim to identify novel biomarkers for HNC and propose promising avenues for future investigations.

Release of miR-29 Target Laminin C2 Improves Skin Repair

miRNAs are small noncoding RNAs that regulate mRNA targets in a cell-specific manner. miR-29 is expressed in murine and human skin, where it may regulate functions in skin repair. Cutaneous wound healing model in miR-29a/b1 gene knockout mice was used to identify miR-29 targets in the wound matrix, where angiogenesis and maturation of provisional granulation tissue was enhanced in response to genetic deletion of miR-29. Consistently, antisense-mediated inhibition of miR-29 promoted angiogenesis in vitro by autocrine and paracrine mechanisms. These processes are likely mediated by miR-29 target mRNAs released upon removal of miR-29 to improve cell-matrix adhesion. One of these, laminin (Lam)-c2 (also known as laminin γ2), was strongly up-regulated during skin repair in the wound matrix of knockout mice. Unexpectedly, Lamc2 was deposited in the basal membrane of endothelial cells in blood vessels forming in the granulation tissue of knockout mice. New blood vessels showed punctate interactions between Lamc2 and integrin α6 (Itga6) along the length of the proto-vessels, suggesting that greater levels of Lamc2 may contribute to the adhesion of endothelial cells, thus assisting angiogenesis within the wound. These findings may be of translational relevance, as LAMC2 was deposited at the leading edge in human wounds, where it formed a basal membrane for endothelial cells and assisted neovascularization. These results suggest a link between LAMC2, improved angiogenesis, and re-epithelialization.

The tumor ecosystem in head and neck squamous cell carcinoma and advances in ecotherapy

The development of head and neck squamous cell carcinoma (HNSCC) is a multi-step process, and its survival depends on a complex tumor ecosystem, which not only promotes tumor growth but also helps to protect tumor cells from immune surveillance. With the advances of existing technologies and emerging models for ecosystem research, the evidence for cell-cell interplay is increasing. Herein, we discuss the recent advances in understanding the interaction between tumor cells, the major components of the HNSCC tumor ecosystem, and summarize the mechanisms of how biological and abiotic factors affect the tumor ecosystem. In addition, we review the emerging ecological treatment strategy for HNSCC based on existing studies.

In silico analysis reveals hypoxia-induced miR-210-3p specifically targets SARS-CoV-2 RNA

Human coronaviruses (HCoVs) until the emergence of SARS in 2003 were associated with mild cold and upper respiratory tract infections. The ongoing pandemic caused by SARS-CoV-2 has enhanced the potential for infection and transmission as compared to other known members of this family. MicroRNAs (miRNA) are 21-25 nucleotides long non-coding RNA that bind to 3' UTR of genes and regulate almost every aspect of cellular function. Several human miRNAs have been known to target viral genomes, mostly to downregulate their expression and sometimes to upregulate also. In some cases, host miRNAs could be sequestered by the viral genome to create a condition for favourable virus existence. The ongoing SARS CoV-2 pandemic is unique based on its transmissibility and severity and we hypothesised that there could be a unique mechanism for its pathogenesis. In this study, we exploited in silico approach to identify human respiratory system-specific miRNAs targeting the viral genome of three highly pathogenic HCoVs (SARS-CoV-2 Wuhan strain, SARS-CoV, and MERS-CoV) and three low pathogenic HCoVs (OC43, NL63, and HKU1). We identified ten common microRNAs that target all HCoVs studied here. In addition, we identified unique miRNAs which targeted specifically one particular HCoV. miR-210-3p was the single unique lung-specific miRNA, which was found to target the NSP3, NSP4, and NSP13 genes of SARS-CoV-2. Further miR-210-NSP3, miR-210-NSP4, and miR-210-NSP13 SARS-CoV-2 duplexes were docked with the hAGO2 protein (PDB ID 4F3T) which showed Z-score values of -1.9, -1.7, and -1.6, respectively. The role of miR-210-3p as master hypoxia regulator and inflammation regulation may be important for SARS-CoV-2 pathogenesis. Overall, this analysis advocates that miR-210-3p be investigated experimentally in SARS-CoV-2 infection.Communicated by Ramaswamy H. Sarma.

Revisiting laminin and extracellular matrix remodeling in metastatic squamous cell carcinoma: What have we learned after more than four decades of research?

Patients with squamous cell carcinoma (SCC) have significantly lower survival upon the development of distant metastases. The extracellular matrix (ECM) is a consistent yet dynamic influence on the metastatic capacity of SCCs. The ECM encompasses a milieu of structural proteins, signaling molecules, and enzymes. Just over 40 years ago, the fibrous ECM glycoprotein laminin was identified. Roughly four decades of research have revealed a pivotal role of laminins in metastasis. However, trends in ECM alterations in some cancers have been applied broadly to all metastatic diseases, despite evidence that these characteristics vary by tumor type. We will summarize how laminins influence the SCC metastatic process exclusively. Enhanced laminin protein deposition occurs at the invasive edge of SCC tumors, which correlates with elevated levels of laminin-binding β1 integrins on SCC cells, increased MMP-3 presence, worse prognosis, and lymphatic dissemination. Although these findings are significant, gaps in knowledge of the formation of a premetastatic niche, the processes of intra- and extravasation, and the contributions of the ECM to SCC metastatic cell dormancy persist. Bridging these gaps requires novel in vitro systems and animal models that reproduce tumor-stromal interactions and spontaneous metastasis seen in the clinic. These advances will allow accurate assessment of laminins to predict responders to transforming growth factor-β inhibitors and immunotherapy, as well as potential combinatorial therapies with the standard of care. Such clinical interventions may drastically improve quality of life and patient survival by explicitly targeting SCC metastasis.

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.

Celecoxib Reverse Invasion and Metastasis of Gastric Cancer through Lnc_AC006548.28-miR-223-LAMC2 Pathway

Celecoxib, a specific cyclooxygenase-2 (COX-2) inhibitor, is a traditional nonsteroidal antipyretic analgesic and anti-inflammatory drug commonly used in clinic, which has inhibitory effect on colorectal cancer, gastric cancer, and other malignant tumors. This study showed that Celecoxib could significantly reverse the invasion and metastasis of gastric cancer and improved the pathological changes due to GC. We collected the clinical specimens to analyze the correlation between the expression of Lnc_AC006548.28, miR-223, and LAMC2. In the mouse model, Celecoxib can slowdown the growth of GC tumor and the occurrence of this effect may depend on Lnc_AC006548.28-miR-223-LAMC2 pathway, in vitro transfection, RT-PCR, western blot, CCK8, small chamber assay, flow cytometry, and immunohistochemistry to retest the protective effect of celecoxib. Our results showed that Celecoxib could reverse invasion and metastasis of gastric cancer through Lnc_AC006548.28-miR-223-LAMC2 pathway.

Unraveling diverse roles of noncoding RNAs in various human papillomavirus negative cancers

Human papillomavirus (HPV)-negative tumors distinguish from cancers associated with HPV infection. Due to its high rate of lymph node metastasis and difficulty in inchoate discover and diagnosis, the treatment efficacy of HPV-negative cancers is unsatisfactory. Epidemiological evidence suggests that HPV-negative tumor patients have a poor prognosis, and the mortality is higher than that of cancer patients caused by HPV infection. Evidence has demonstrated that noncoding RNAs (ncRNAs) play a crucial role in regulation of physiological and developmental processes. Therefore, dysregulated ncRNAs are involved in the occurrence of diversified diseases, including cancer. In cumulative studies, ncRNAs are concerned with pathogenetic mechanisms of HPV-negative tumors via regulating gene expression and signal transduction. It is important to decipher the functions of ncRNAs in HPV-negative cancers and identify the potential biomarkers, which will bring new treatment strategies for improving outcome of cancer therapy. In this review, we demonstrated the effects of ncRNAs via regulating the development and progression of HPV- negative tumors by directly or indirectly acting on target molecules, which provide a basis for future tumor targeted therapy by targeting ncRNAs for HPV-negative cancers.

Exosomal-microRNA transcriptome profiling of Parental and CSC-like MDA-MB-231 cells in response to cisplatin treatment

Triple negative breast cancer (TNBC) is the most aggressive breast cancer subtype with higher risk of metastasis and cancer reoccurrence. Cisplatin is one of the potential anticancer drugs for treating TNBC, where its effectiveness remains challenged by frequent occurrence of cisplatin resistance. Since acquirement of drug resistance often being associated with presence of cancer stem cells (CSCs), investigation has been conducted, suggesting CSC-like subpopulation to be more resistant to cisplatin than their parental counterpart. On the other hand, plethora evidences showed the transmission of exosomal-miRNAs are capable of promoting drug resistance in breast cancers. In this study, we aim to elucidate the differential expression of exosomal-microRNAs profile and reveal the potential target genes in correlation to cisplatin resistance associated with CSC-like subpopulation by using TNBC cell line (MDA-MB-231). Utilizing next generation sequencing and Nanostring techniques, cisplatin-induced dysregulation of exosomal-miRNAs were evaluated in maximal for CSC-like subpopulation as compared to parental cells. Intriguingly, more oncogenic exosomal-miRNAs profile was detected from treated CSC-like subpopulation, which may correlate to enhancement of drug resistance and maintenance of CSCs. In treated CSC-like subpopulation, unique clusters of exosomal-miRNAs namely miR-221-3p, miR-196a-5p, miR-17-5p and miR-126-3p were predicted to target on six genes (ATXN1, LATS1, GSK3β, ITGA6, JAG1 and MYC), aligned with previous finding which demonstrated dysregulation of these genes in treated CSC-like subpopulation. Our results highlight the potential correlation of exosomal-miRNAs and their target genes as well as novel perspectives of the corresponding pathways that may be essential to contribute to the attenuated cytotoxicity of cisplatin in CSC-like subpopulation.

The Role of MicroRNA in Head and Neck Cancer

Head and neck squamous cell carcinoma (HNSCC) include epithelial tumors arising in the structures of aerodigestive tract such as oral and nasal cavity, pharynx, larynx, paranasal sinuses, and local lymph nodes. HNSCC is the sixth most common cancer worldwide, and its prognosis is very poor. MicroRNAs (miRNAs) are small single stranded noncoding RNAs which are about 19-25 nucleotides involved in cell proliferation, development, differentiation and metastasis. It is believed that miRNA alterations correlate with initiation and progression of cancer cell proliferation or inhibition of tumorigenesis especially in development, progression, and metastasis of HNSCC. Altered expression of miRNAs could be novel molecular biomarkers for the diagnosis and prognosis of HNSCC. Despite the advances in cancer treatment, the mortality rate of HNSCC is still high. The potential application of miRNAs for cancer therapy has been demonstrated in many studies. In this review, we discuss the very recent studies on different aspects of miRNA dysregulation with their clinical significance and miRNA-based therapy.

Integrin α6 overexpression promotes lymphangiogenesis and lymphatic metastasis via activating the NF-κB signaling pathway in lung adenocarcinoma

OBJECTIVE

It has been reported that tumor-associated lymphangiogenesis plays an important role in lymph node metastasis and contributes to the poor survival of lung adenocarcinoma (LUAD) patients. As yet, however, the molecular mechanism underlying LUAD-associated lymphangiogenesis has remained elusive.

METHODS

Immunohistochemistry (IHC) was used to determine the expression of integrin subunit alpha 6 (ITGA6) and the lymphatic vessel endothelial hyaluronan receptor 1 (Lyve1) in clinicopathologically characterized LUAD specimens. The effect of ITGA6 overexpression on lymphangiogenesis and lymphatic metastasis was examined by tube formation, scratch wound-healing, and cell migration assays in vitro and a popliteal lymph node metastasis model in vivo. Mechanistically, overexpression of ITGA6 and activation of NF-κB signaling were examined by real-time PCR, ubiquitination and dual-luciferase reporter assays. Finally, high ITGA6 expression in LUAD tissue samples was related to copy number variation (CNV) using the TCGA database.

RESULTS

We found that ITGA6 overexpression correlated with microlymphatic vessel density in LUAD specimens (p < 0.01). Importantly, by using a popliteal lymph node metastasis model, we found that ITGA6 upregulation significantly enhanced lymphangiogenesis and lymphatic metastasis in vivo (p < 0.05). In addition, we found that ITGA6 overexpression enhanced the capability of A549 and H1299 LUAD cells to induce tube formation and migration in human lymphatic endothelial cells (HLECs). Mechanistically, we found that ITGA6 sustained NF-κB activity via binding and promoting K63 polyubiquitination of TNF receptor-associated factor 2 (TRAF2). Finally, CNV analysis revealed ITGA6 amplification of 27.5% in the LUAD tissue samples in the TCGA database.

CONCLUSIONS

Taken together, our results uncover a plausible role for ITGA6 in mediating lymphangiogenesis and lymphatic metastasis and may provide a basis for targeting ITGA6 to treat LUAD lymphatic metastasis.

microRNA Profile Associated with Positive Lymph Node Metastasis in Early-Stage Cervical Cancer

Lymph node metastasis (LNM) is an important prognostic factor in cervical cancer (CC). In early stages, the risk of LNM is approximately 3.7 to 21.7%, and the 5-year overall survival decreases from 80% to 53% when metastatic disease is identified in the lymph nodes. Few reports have analyzed the relationship between miRNA expression and the presence of LNM. The aim of this study was to identify a subset of miRNAs related to LNM in early-stage CC patients. Formalin-fixed paraffin-embedded tissue blocks were collected from patients with early-stage CC treated by radical hysterectomy with lymphadenectomy. We analyzed samples from two groups of patients—one group with LNM and the other without LNM. Global miRNA expression was identified by microarray analysis, and cluster analysis was used to determine a subset of miRNAs associated with LNM. Microarray expression profiling identified a subset of 36 differentially expressed miRNAs in the two groups (fold change (FC) ≥ 1.5 and p < 0.01). We validated the expression of seven miRNAs; miR-487b, miR-29b-2-5p, and miR-195 were underexpressed, and miR-92b-5p, miR-483-5p, miR-4534, and miR-548ac were overexpressed according to the microarray experiments. This signature exhibited prognostic value for identifying early-stage CC patients with LNM. These findings may help detect LNM that cannot be observed in imaging studies.

The Secretome of Human Neonatal Mesenchymal Stem Cells Modulates Doxorubicin-Induced Cytotoxicity: Impact in Non-Tumor Cells

Doxorubicin (Dox) is one of the most widely used treatments for breast cancer, although limited by the well-documented cardiotoxicity and other off-target effects. Mesenchymal stem cell (MSC) secretome has shown immunomodulatory and regenerative properties, further potentiated under 3D conditions. This work aimed to uncover the effect of the MSC-derived secretome from 3D (CM3D) or 2D (CM2D) cultures, in human malignant breast cells (MDA-MB-231), non-tumor breast epithelial cells (MCF10A) and differentiated AC16 cardiomyocytes, co-treated with Dox. A comprehensive proteomic analysis of CM3D/CM2D was also performed to unravel the underlying mechanism. CM3D/CM2D co-incubation with Dox revealed no significant differences in MDA-MB-231 viability when compared to Dox alone, whereas MCF10A and AC16 viability was consistently improved in Dox+CM3D-treated cells. Moreover, neither CM2D nor CM3D affected Dox anti-migratory and anti-invasive effects in MDA-MB-231. Notably, Ge-LC-MS/MS proteomic analysis revealed that CM3D displayed protective features that might be linked to the regulation of cell proliferation (CAPN1, CST1, LAMC2, RANBP3), migration (CCN3, MMP8, PDCD5), invasion (TIMP1/2), oxidative stress (COX6B1, AIFM1, CD9, GSR) and inflammation (CCN3, ANXA5, CDH13, GDF15). Overall, CM3D decreased Dox-induced cytotoxicity in non-tumor cells, without compromising Dox chemotherapeutic profile in malignant cells, suggesting its potential use as a chemotherapy adjuvant to reduce off-target side effects.

Role of Salivary MicroRNA and Cytokines in the Diagnosis and Prognosis of Oral Squamous Cell Carcinoma

Oral squamous cell carcinoma (OSCC) is the most prevalent oral malignant tumor worldwide. An early diagnosis can have a major positive impact on its prognosis. Human saliva contains cytokines, DNA and RNA molecules, circulating cells, and derivatives of tissues and extracellular vesicles, among other factors that can serve as biomarkers. Hence, the analysis of saliva may provide useful information for the early diagnosis of OSCC for its prognosis. The objective of this review was to determine the potential usefulness of salivary biomarkers (cytokines and microRNA) to diagnose OSCC and improve its prognosis. A combination of salivary miRNA and proteomic data could allow a definitive and early diagnosis to be obtained. However, there remains a need to optimize and standardize the protocols used to quantify miRNAs.

Fibulin 2 Is Hypermethylated and Suppresses Tumor Cell Proliferation through Inhibition of Cell Adhesion and Extracellular Matrix Genes in Non-Small Cell Lung Cancer

Fibulins (FBLNs), interacting with cell adhesion receptors and extracellular matrix (ECM) components, play multiple roles in ECM structures and tissue functions. Abnormal expression of FBLN2, one of the fibulin family members, contributes to tumor initiation and development. However, the function of FBLN2 in human non-small cell lung cancer (NSCLC) has not yet been elucidated. In this study, we found that FBLN2 was downregulated in 9 out of 11 lung cancer cell lines compared to normal bronchial epithelial cells, which was associated with DNA hypermethylation. Primary lung squamous cell carcinoma expressed significantly more FBLN2 protein compared to adenocarcinoma (p = 0.047). Ectopic expression of FBLN2 led to decreased cell proliferation, migration and invasion, accompanied by inactivated MAPK/ERK and AKT/mTOR pathways, while FBLN2 siRNA knockdown resulted in an opposite biological behaviour in NSCLC cells. Additionally, overexpression of FBLN2 led to dysregulation of cell adhesion molecules, ECM markers and a panel of lysate/exosome-derived-microRNAs, which are involved in cell adhesion and ECM remodelling. Taken together, our data indicate that FBLN2 is methylated and exerts a tumor suppressor function through modulation of MAPK/ERK and AKT pathways and regulation of cell adhesion and ECM genes. Moreover, FBLN2 might be a potential biomarker for the sub-classification of NSCLC.

miR-29b-3p Increases Radiosensitivity in Stemness Cancer Cells via Modulating Oncogenes Axis

Radioresistance conferred by cancer stem cells (CSCs) is the principal cause of the failure of cancer radiotherapy. Eradication of CSCs is a prime therapeutic target and a requirement for effective radiotherapy. Three dimensional (3D) cell-cultured model could mimic the morphology of cells in vivo and induce CSC properties. Emerging evidence suggests that microRNAs (miRNAs) play crucial roles in the regulation of radiosensitivity in cancers. In this study, we aim to investigate the effects of miRNAs on the radiosensitivity of 3D cultured stem-like cells. Using miRNA microarray analysis in 2D and 3D cell culture models, we found that the expression of miR-29b-3p was downregulated in 3D cultured A549 and MCF7 cells compared with monolayer (2D) cells. Clinic data analysis from The Cancer Genome Atlas database exhibited that miR-29b-3p high expression showed significant advantages in lung adenocarcinoma and breast invasive carcinoma patients’ prognosis. The subsequent experiments proved that miR-29b-3p overexpression decreased the radioresistance of cells in 3D culture and tumors in vivo through interfering kinetics process of DNA damage repair and inhibiting oncogenes RBL1, PIK3R1, AKT2, and Bcl-2. In addition, miR-29b-3p knockdown enhanced cancer cells invasion and migration capability. MiR-29b-3p overexpression decreased the stemness of 3D cultured cells. In conclusion, our results demonstrate that miR-29b-3p could be a sensitizer of radiation killing in CSC-like cells via inhibiting oncogenes expression. MiR-29b-3p could be a novel therapeutic candidate target for radiotherapy.

Molecular Pathogenesis and Regulation of the miR-29-3p-Family: Involvement of ITGA6 and ITGB1 in Intra-Hepatic Cholangiocarcinoma

Simple Summary

Even today, there are no effective targeted therapies for intrahepatic cholangiocarcinoma (ICC) patients. Clarifying the molecular pathogenesis of ICC will contribute to the development of treatment strategies for this disease. In this study, we searched for the role of the miR-29-3p-family and its association with oncogenic pathway. Interestingly, aberrant expression of ITGA6 and ITGB1 was directly regulated by the miR-29-3p-family which are involved in multiple oncogenic pathways in ICC, and enhanced malignant transformation of ICC cells. Furthermore, SP1 which is a transcriptional activator of ITGA6/ITGB1, is regulated by the miR-29-3p-family. These molecules may be novel therapeutic targets for ICC.

Abstract

The aggressive nature of intrahepatic cholangiocarcinoma (ICC) renders it a particularly lethal solid tumor. Searching for therapeutic targets for ICC is an essential challenge in the development of an effective treatment strategy. Our previous studies showed that the miR-29-3p-family members (miR-29a-3p, miR-29b-3p and miR-29c-3p) are key tumor-suppressive microRNAs that control many oncogenic genes/pathways in several cancers. In this study, we searched for therapeutic targets for ICC using the miR-29-3p-family as a starting point. Our functional studies of cell proliferation, migration and invasion confirmed that the miR-29-3p-family act as tumor-suppressors in ICC cells. Moreover, in silico analysis revealed that “focal adhesion”, “ECM-receptor”, “endocytosis”, “PI3K-Akt signaling” and “Hippo signaling” were involved in oncogenic pathways in ICC cells. Our analysis focused on the genes for integrin-α6 (ITGA6) and integrin-β1 (ITGB1), which are involved in multiple pathways. Overexpression of ITGA6 and ITGB1 enhanced malignant transformation of ICC cells. Both ITGA6 and ITGB1 were directly regulated by the miR-29-3p-family in ICC cells. Interestingly, expression of ITGA6/ITGB1 was positively controlled by the transcription factor SP1, and SP1 was negatively controlled by the miR-29-3p-family. Downregulation of the miR-29-3p-family enhanced SP1-mediated ITGA6/ITGB1 expression in ICC cells. MicroRNA-based exploration is an attractive strategy for identifying therapeutic targets for ICC.

ECM Remodeling in Squamous Cell Carcinoma of the Aerodigestive Tract: Pathways for Cancer Dissemination and Emerging Biomarkers

Squamous cell carcinomas (SCC) include a number of different types of tumors developing in the skin, in hollow organs, as well as the upper aerodigestive tract (UADT) including the head and neck region and the esophagus which will be dealt with in this review. These tumors are often refractory to current therapeutic approaches with poor patient outcome. The most important prognostic determinant of SCC tumors is the presence of distant metastasis, significantly correlating with low patient survival rates. Rapidly emerging evidence indicate that the extracellular matrix (ECM) composition and remodeling profoundly affect SSC metastatic dissemination. In this review, we will summarize the current knowledge on the role of ECM and its remodeling enzymes in affecting the growth and dissemination of UADT SCC. Taken together, these published evidence suggest that a thorough analysis of the ECM composition in the UADT SCC microenvironment may help disclosing the mechanism of resistance to the treatments and help defining possible targets for clinical intervention.

ECM Remodeling in Squamous Cell Carcinoma of the Aerodigestive Tract: Pathways for Cancer Dissemination and Emerging Biomarkers

Simple Summary

Local and distant metastasis of patients affected by squamous cell carcinoma of the upper aerodigestive tract predicts poor prognosis. In the latest years, the introduction of new therapeutic approaches, including targeted and immune therapies, has improved the overall survival. However, a large number of these patients do not benefit from these treatments. Thus, the identification of suitable prognostic and predictive biomarkers, as well as the discovery of new therapeutic targets have emerged as a crucial clinical need. In this context, the extracellular matrix represents a suitable target for the development of such therapeutic tools. In fact, the extracellular matrix is composed by complex molecules able to interact with a plethora of receptors and growth factors, thus modulating the dynamic crosstalk between cancer cells and the tumor microenvironment. In this review, we summarize the current knowledge of the role of the extracellular matrix in affecting squamous cell carcinoma growth and dissemination. Despite extracellular matrix is known to affect the development of many cancer types, only a restricted number of these molecules have been recognized to impact on squamous cell carcinoma progression. Thus, we consider that a thorough analysis of these molecules may be key to develop new potential therapeutic targets/biomarkers.

Abstract

Squamous cell carcinomas (SCC) include a number of different types of tumors developing in the skin, in hollow organs, as well as the upper aerodigestive tract (UADT) including the head and neck region and the esophagus which will be dealt with in this review. These tumors are often refractory to current therapeutic approaches with poor patient outcome. The most important prognostic determinant of SCC tumors is the presence of distant metastasis, significantly correlating with low patient survival rates. Rapidly emerging evidence indicate that the extracellular matrix (ECM) composition and remodeling profoundly affect SSC metastatic dissemination. In this review, we will summarize the current knowledge on the role of ECM and its remodeling enzymes in affecting the growth and dissemination of UADT SCC. Taken together, these published evidence suggest that a thorough analysis of the ECM composition in the UADT SCC microenvironment may help disclosing the mechanism of resistance to the treatments and help defining possible targets for clinical intervention.

Lack of Conserved miRNA Deregulation in HPV-Induced Squamous Cell Carcinomas

Squamous cell carcinomas (SCCs) in the anogenital and head and neck regions are associated with high-risk types of human papillomaviruses (HR-HPV). Deregulation of miRNA expression is an important contributor to carcinogenesis. This study aimed to pinpoint commonly and uniquely deregulated miRNAs in cervical, anal, vulvar, and tonsillar tumors of viral or non-viral etiology, searching for a common set of deregulated miRNAs linked to HPV-induced carcinogenesis. RNA was extracted from tumors and nonmalignant tissues from the same locations. The miRNA expression level was determined by next-generation sequencing. Differential expression of miRNAs was calculated, and the patterns of miRNA deregulation were compared between tumors. The total of deregulated miRNAs varied between tumors of different locations by two orders of magnitude, ranging from 1 to 282. The deregulated miRNA pool was largely tumor-specific. In tumors of the same location, a low proportion of miRNAs were exclusively deregulated and no deregulated miRNA was shared by all four types of HPV-positive tumors. The most significant overlap of deregulated miRNAs was found between tumors which differed in location and HPV status (HPV-positive cervical tumors vs. HPV-negative vulvar tumors). Our results imply that HPV infection does not elicit a conserved miRNA deregulation in SCCs.

hsa‑miR‑5580‑3p inhibits oral cancer cell viability, proliferation and migration by suppressing LAMC2

The present study aimed to explore whether and how microRNA-5580-3p (miR-5580-3p) affected oral cancer (OC) cell phenotypes via regulation of laminin subunit γ2 (LAMC2). Bioinformatics analysis was used to identify miR-5580-3p/LAMC2, a novel interactome that, to the best of our knowledge, has not been studied previously in OC. In the present study, the expression levels of miR-5580-3p and LAMC2 were detected by reverse transcription-quantitative PCR, while the protein expression levels of LAMC2 were identified using western blotting. To determine the effects of miR-5580-3p and LAMC2 in OC, a number of experiments, including Cell Counting Kit-8, 5-bromo-2′-deoxyuridine cell proliferation and wound healing migration assays, were performed using OC SCC-4 and Cal-27 cell lines. Additionally, luciferase reporter assays were employed to examine the interaction between miR-5580-3p and LAMC2 mRNA. The results demonstrated that miR-5580-3p expression was downregulated, while LAMC2 expression was upregulated in OC tissues and cell lines. In addition to the observation that miR-5580-3p promoted the malignant phenotypes of OC, it was also revealed that miR-5580-3p inhibited OC cell viability, proliferation and migration by suppressing LAMC2. Therefore, the present study suggested that miR-5580-3p and LAMC2 may be potential biomarkers and therapeutic targets for OC diagnosis and therapies in the future.

Potential Therapeutic Significance of Laminin in Head and Neck Squamous Carcinomas

Simple Summary

Head and neck cancers (HNC) account for approximately 500,000 new cases of tumors annually worldwide and are represented by upper aerodigestive tract malignant neoplasms, which particularly arise in oral cavity, larynx, and pharynx tissues. Thus, due to the biological diversity between the upper aerodigestive organs, and to the heterogeneity of risk factors associated with their malignant transformation, HNC behavior, and prognosis seem to strongly vary according to the tumor site. However, despite to the heterogeneity which characterizes head and neck tumors, squamous cell carcinomas (SCC) represent the predominant histopathologic HNC subtype. In this sense, it has been reported that SCC tumor biology is strongly associated with deregulations within the extracellular matrix compartment. Accordingly, it has been shown that laminin plays a remarkable role in the regulation of crucial events associated with head and neck squamous cell carcinomas (HNSCC) progression, which opens the possibility that laminin may represent a convergence point in HNSCC natural history.

Abstract

Head and neck squamous cell carcinomas (HNSCC) are among the most common and lethal tumors worldwide, occurring mostly in oral cavity, pharynx, and larynx tissues. The squamous epithelia homeostasis is supported by the extracellular matrix (ECM), and alterations in this compartment are crucial for cancer development and progression. Laminin is a fundamental component of ECM, where it represents one of the main components of basement membrane (BM), and data supporting its contribution to HNSCC genesis and progression has been vastly explored in oral cavity squamous cell carcinoma. Laminin subtypes 111 (LN-111) and 332 (LN-332) are the main isoforms associated with malignant transformation, contributing to proliferation, adhesion, migration, invasion, and metastasis, due to its involvement in the regulation of several pathways associated with HNSCC carcinogenesis, including the activation of the EGFR/MAPK signaling pathway. Therefore, it draws attention to the possibility that laminin may represent a convergence point in HNSCC natural history, and an attractive potential therapeutic target for these tumors.

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.

Genetic Drivers of Head and Neck Squamous Cell Carcinoma: Aberrant Splicing Events, Mutational Burden, HPV Infection and Future Targets

Head and neck cancers include cancers that originate from a variety of locations. These include the mouth, nasal cavity, throat, sinuses, and salivary glands. These cancers are the sixth most diagnosed cancers worldwide. Due to the tissues they arise from, they are collectively named head and neck squamous cell carcinomas (HNSCC). The most important risk factors for head and neck cancers are infection with human papillomavirus (HPV), tobacco use and alcohol consumption. The genetic basis behind the development and progression of HNSCC includes aberrant non-coding RNA levels. However, one of the most important differences between healthy tissue and HNSCC tissue is changes in the alternative splicing of genes that play a vital role in processes that can be described as the hallmarks of cancer. These changes in the expression profile of alternately spliced mRNA give rise to various protein isoforms. These protein isoforms, alternate methylation of proteins, and changes in the transcription of non-coding RNAs (ncRNA) can be used as diagnostic or prognostic markers and as targets for the development of new therapeutic agents. This review aims to describe changes in alternative splicing and ncRNA patterns that contribute to the development and progression of HNSCC. It will also review the use of the changes in gene expression as biomarkers or as the basis for the development of new therapies.

LncRNA EBLN3P promotes the progression of osteosarcoma through modifying the miR-224-5p/Rab10 signaling axis

The treatment of patients with advanced-stage osteosarcoma represents a major challenge, with very few treatments currently approved. Although accumulating evidence has demonstrated the importance of lncRNAs in osteosarcoma, the current knowledge on the functional roles and molecular mechanisms of lncRNA endogenous born avirus-like nucleoprotein (EBLN3P) is limited. At present, the expressions of EBLN3P and miR-224-5p in osteosarcoma tissues were quantified by reverse transcription-quantitative PCR assay, and the expression of Ras-related protein 10 (Rab10) in osteosarcoma tissues was quantified by immunohistochemistry and western-blotting. The bioinformatics prediction software ENCORI was used to predict the putative binding sites of EBLN3P, Rab10 and miR-224-5p. The regulatory role of EBLN3P or miR-224-5p on cell proliferation, migration and invasion ability were verified by Cell Counting Kit-8, wound healing and Transwell assays, respectively. The interaction among EBLN3P, miR-224-5p and Rab10 were testified by luciferase. The increased expression of EBLN3P and Rab10 and decreased expression of miR-224-5p were observed in osteosarcoma tissues and cell lines. Besides, the overexpression of EBLN3P or knockdown of miR-224-5p were revealed to promote the proliferation, migration and invasion of osteosarcoma cells. Bioinformatics analysis and luciferase assay revealed that EBLN3P could directly interacted with miR-224-5p to attenuate miR-224-5p binding to the Rab10 3'-untranslated region. Furthermore, the mechanistic investigations revealed activation of the miR-224-5p/Rab10 regulatory loop by knockdown of miR-372-3p or overexpression of Rab10, thereby confirming the in vitro role of EBLN3P in promoting osteosarcoma cell proliferation, migration and invasion. To the best of our knowledge, the present study is the first to demonstrate that EBLN3P may act as a competitive endogenous RNA to modulate Rab10 expression by competitive sponging to miR-224-5p, leading to the regulation of osteosarcoma progression, which indicates a possible new approach to osteosarcoma diagnosis and treatment.

Regulators at Every Step-How microRNAs Drive Tumor Cell Invasiveness and Metastasis

Tumor cell invasiveness and metastasis are the main causes of mortality in cancer. Tumor progression is composed of many steps, including primary tumor growth, local invasion, intravasation, survival in the circulation, pre-metastatic niche formation, and metastasis. All these steps are strictly controlled by microRNAs (miRNAs), small non-coding RNA that regulate gene expression at the post-transcriptional level. miRNAs can act as oncomiRs that promote tumor cell invasion and metastasis or as tumor suppressor miRNAs that inhibit tumor progression. These miRNAs regulate the actin cytoskeleton, the expression of extracellular matrix (ECM) receptors including integrins and ECM-remodeling enzymes comprising matrix metalloproteinases (MMPs), and regulate epithelial-mesenchymal transition (EMT), hence modulating cell migration and invasiveness. Moreover, miRNAs regulate angiogenesis, the formation of a pre-metastatic niche, and metastasis. Thus, miRNAs are biomarkers of metastases as well as promising targets of therapy. In this review, we comprehensively describe the role of various miRNAs in tumor cell migration, invasion, and metastasis.

Expressions of microRNA-29a and microRNA-34a in pleomorphic adenomas of salivary glands

Background

The most common type of salivary gland tumor is pleomorphic adenoma. The genetic area of focus in the diagnosis of salivary gland tumors is a study of the role of miRNA.

Methods

Twenty-two patients with pleomorphic adenomas of the salivary glands were used for the examinations. The histological typing of the salivary gland tumors was performed when using routine staining with hematoxylin and eosin, as well as with immunohistochemistry. The expressions of miR-34a and miR-29a were evaluated by using reverse transcription and the quantitative polymerase chain reaction in a real-time setting. In addition, the study also calculated the levels of expression of miR-29a and miR-34a in the venous blood.

Results

The majority of patients-15 (68.18%) and 22 (100.00%) had a positive response to human papillomavirus (HPV) and pleomorphic adenoma gene 1 (PLAG1), respectively. The conducted analyses of the expressions of miR-34a and miR-29a showed that the highest expression was observed in the salivary gland tissue adjacent to the tumor (1,052.02±367.20 and 111.93±56.97, versus 47.72±28.93 and 8.12±4.40 in the intact salivary gland tissue, respectively).

Conclusions

There was a sufficiently high level of miR-34a and miR-29a expressions in the tissues of the tumor of pleomorphic adenomas of the salivary glands when compared with the intact salivary gland tissue.

MicroRNA profile in the squamous cell carcinoma: prognostic and diagnostic roles

Head and neck squamous cell carcinomas (HNSCCs) are human malignancies associated with both genetic and environmental factors. MicroRNAs (miRNAs) as a group of small non-coding RNAs have prominent roles in the development of this kind of cancer. Expressions of several miRNAs have been demonstrated to be increased in HNSCC samples vs. non-malignant tissues. In silico prediction tools and functional analyses have confirmed the function of some miRNAs in the modulation of cancer-associated targets, thus indicating these miRNAs as onco-miRs. Moreover, numerous miRNAs have been down-regulated in HNSCC samples. Their targets mostly enhance cell proliferation or inhibit apoptosis. miRNAs signature has practical implications in the diagnosis, staging, and management of HNSC. Most notably, numerous miRNAs have been shown to alter response of tumor cells to anti-cancer drugs such as cisplatin and doxorubicin. Circulating levels of these small transcripts have been suggested as promising biomarkers for diagnosis of HNSCC. In the present manuscript, we sum up the available literature regarding the miRNAs signature in HNSCC and their role as diagnostic/prognostic biomarkers.

Long Noncoding RNA EBLN3P Promotes the Progression of Liver Cancer via Alteration of microRNA-144-3p/DOCK4 Signal

BACKGROUND

Therapy for patients with liver cancer in the advanced stage remains a great challenge, and there are very few approved treatments. Although accumulated evidence demonstrates the importance of lncRNAs in liver cancer, data on the functional roles and molecular mechanisms of endogenous bornavirus-like nucleoprotein (EBLN3P) have been rarely reported.

MATERIALS AND METHODS

The bioinformatics prediction software ENCORI was used to predict the putative binding sites of EBLN3P. The regulatory roles of EBLN3P and miR-144-3p in cell proliferation, migration and invasion ability were verified by the Cell Counting Kit-8, wound healing and Transwell assays, respectively. The interactions among EBLN3P, miR-144-3p and DOCK4 were explored by a luciferase assay and Western blotting. The expression of EBLN3P and microRNA (miR)-144-3p in liver cancer tissues was quantified by reverse transcription-quantitative PCR, and the expression of dedicator of cytokinesis 4 (DOCK4) was quantified by immunohistochemical analysis.

RESULTS

The present results revealed that overexpression of EBLN3P or knockdown of miR-144-3p promoted liver cancer cell proliferation, migration and invasion. Bioinformatics analysis and a luciferase assay demonstrated that EBLN3P directly interacts with miR-144-3p to attenuate miR-144-3p binding to the 3'-untranslated region of DOCK4. Furthermore, the mechanistic investigations showing that the miR-144-3p/DOCK4 regulatory loop was activated by knockdown of miR-144-3p or overexpression of DOCK4 validate the roles of EBLN3P in promoting liver cancer cell proliferation, migration and invasion in vitro. Elevated levels of EBLN3P and DOCK4 and decreased miR-144-3p expression were observed in both liver cancer tissues and cell lines.

CONCLUSION

The present study is the first to demonstrate that EBLN3P may act as a ceRNA to modulate DOCK4 expression by competitively sponging miR-144-3p, leading to the regulation of liver cancer progression, which provides new insights for liver cancer diagnosis and treatment.

Screening key lncRNAs with diagnostic and prognostic value for head and neck squamous cell carcinoma based on machine learning and mRNA-lncRNA co-expression network analysis

BACKGROUND

Head and neck squamous cell carcinoma (HNSCC) is the seventh most common type of cancer around the world. The aim of this study was to seek the long non-coding RNAs (lncRNAs) acting as diagnostic and prognostic biomarker of HNSCC.

METHODS

Base on TCGA dataset, the differentially expressed mRNAs (DEmRNAs) and lncRNAs (DElncRNAs) were identified between HNSCC and normal tissue. The machine learning and survival analysis were performed to estimate the potential diagnostic and prognostic value of lncRNAs for HNSCC. We also build the co-expression network and functional annotation. The expression of selected candidate mRNAs and lncRNAs were validated by Quantitative real time polymerase chain reaction (qRT-PCR).

RESULTS

A total of 3363 DEmRNAs (1822 down-regulated and 1541 up-regulated mRNAs) and 32 DElncRNAs (13 down-regulated and 19 up-regulated lncRNAs) between HNSCC and normal tissue were obtained. A total of 13 lncRNAs (IL12A.AS1, RP11.159F24.6, RP11.863P13.3, LINC00941, FOXCUT, RNF144A.AS1, RP11.218E20.3, HCG22, HAGLROS, LINC01615, RP11.351J23.1, AC024592.9 and MIR9.3HG) were defined as optimal diagnostic lncRNAs biomarkers for HNSCC. The area under curve (AUC) of the support vector machine (SVM) model, decision tree model and random forests model and were 0.983, 0.842 and 0.983, and the specificity and sensitivity of the three model were 95.5% and 96.2%, 77.3% and 97.6% and 93.2% and 97.8%, respectively. Among them, AC024592.9, LINC00941, LINC01615 and MIR9-3HG was not only an optimal diagnostic lncRNAs biomarkers, but also related to survival time. The focal adhesion, ECM-receptor interaction, pathways in cancer and cytokine-cytokine receptor interaction were four significantly enriched pathways in DEmRNAs co-expressed with the identified optimal diagnostic lncRNAs. But for most of the selected DEmRNAs and DElncRNAs, the expression was consistent with our integrated analysis results, including LINC00941, LINC01615, FOXCUT, TGA6 and MMP13.

CONCLUSION

AC024592.9, LINC00941, LINC01615 and MIR9-3HG was not only an optimal diagnostic lncRNAs biomarkers, but also were a prognostic lncRNAs biomarkers.

Functional Landscape of Dysregulated MicroRNAs in Oral Squamous Cell Carcinoma: Clinical Implications

MicroRNA (miRNA) dysregulation is associated with the pathogenesis of oral squamous cell carcinoma (OSCC), and its elucidation could potentially provide information on patient outcome. A growing body of translational research on miRNA biology is focusing on precision oncology, aiming to decode the miRNA regulatory network in the development and progression of cancer. Tissue-specific expression and stable presence in all body fluids are unique features of miRNAs, which could be potentially exploited in the clinical setting. Recent understanding of miRNA properties has led them to be useful, attractive, and potential tools either as biomarkers (distinct miRNA expression signature) for diagnosis and prognostic outcomes or as targets for novel therapeutic entities, enabling personalized treatment for OSCC. In this review, we discuss recent research on different aspects of alterations in miRNA profiles along with their clinical significance and strive to identify probable potential miRNA biomarkers for diagnosis and prognosis of OSCC. We also discuss the current understanding and scope of development of miRNA-based therapeutics against OSCC.

miR-23a-3p/SIX1 regulates glucose uptake and proliferation through GLUT3 in head and neck squamous cell carcinomas

SIX1 overexpression has been reported in several cancers. However, its involvement in head and neck squamous cell carcinoma (HNSCC) remains unclear. In this study we investigated the clinical significance and biological roles of SIX1 in HNSCC. SIX1 expression was upregulated in HNSCC and correlated with TNM stage and nodal metastasis. Analysis of TCGA dataset demonstrated that high SIX1 expression correlated with poor patient prognosis. Overexpression of SIX1 in the Fadu cell line upregulated cell proliferation, colony formation, glucose uptake and ATP production. In contrast, SIX1 depletion in the Detroit562 cell line downregulated cell proliferation, colony formation, glucose uptake and ATP production. We analyzed a series of genes involved in glucose metabolism and found that SIX1 overexpression upregulated GLUT3, an important glucose transporter, at both mRNA and protein levels. Using the TRANSFAC database, we found that SIX1 had potential binding sites on the GLUT3 promoter, which was validated by chromatin immunoprecipitation (ChIP) assays. Next, we focused on miR-23a-3p, which could target SIX1 in HNSCC cells. The miR-23a-3p mimic downregulated SIX1 expression while the miR-23a-3p inhibitor upregulated SIX1 expression. The binding of miR-23a-3p to the 3'-UTR of SIX1 was confirmed using the luciferase reporter assay. Analysis of TCGA dataset showed a negative correlation between the miR-23a-3p and SIX1. Furthermore, the miR-23a-3p mimic inhibited cell proliferation, ATP production and glucose uptake, which could be rescued by transfection with the SIX1 plasmid. In summary, our study demonstrated that SIX1 facilitated HNSCC cell growth through regulation of GLUT3 and glucose uptake. miR-23a-3p targeted the SIX1/GLUT3 axis and suppressed glucose uptake and proliferation in HNSCC.

LncRNA HULC induces the progression of osteosarcoma by regulating the miR-372-3p/HMGB1 signalling axis

Background

Osteosarcoma is a malignancy that normally affects children, adolescents, and young adults. Although accumulating evidence has demonstrated the importance of HULC in osteosarcoma, little is reported about its functional roles and molecular mechanisms.

Methods

The expression of HULC and miR-372-3p in osteosarcoma tissues was quantified by qRT-PCR. The regulatory roles of HULC and miR-372-3p on cell proliferation, apoptosis, migration and invasion were determined by CCK-8, colony formation, flow cytometry, wound healing, and transwell assays, respectively. The bioinformatics prediction software RAID v2.0 was used to predict the putative binding sites. The interactions among HULC, miR-372-3p and HMGB1 were explored by luciferase assay and western blot assay.

Results

Our results revealed elevated HULC and decreased miR-372-3p expression in both osteosarcoma tissues and cell lines. Overexpression of HULC or knockdown of miR-372-3p promoted osteosarcoma cell proliferation, migration and invasion and induced cell apoptosis. Bioinformatics and luciferase assays verified that HULC directly interacted with miR-372-3p to attenuate miR-372-3p binding to the HMGB1 3′-UTR. Furthermore, mechanistic investigations confirmed that activation of the miR-372-3p/HMGB1 regulatory loop by knockdown of miR-372-3p or overexpression of HMGB1 reversed the in vitro roles of HULC in promoting osteosarcoma cell proliferation, migration and invasion.

Conclusion

Our study is the first to demonstrate that HULC may act as a ceRNA to modulate HMGB1 expression by competitively sponging miR-372-3p, leading to the regulation of osteosarcoma progression, which provides new insight into osteosarcoma diagnosis and treatment.

MicroRNAs and Metastasis

Metastasis, the development of secondary malignant growths at a distance from the primary site of a cancer, is associated with almost 90% of all cancer deaths, and half of all cancer patients present with some form of metastasis at the time of diagnosis. Consequently, there is a clear clinical need for a better understanding of metastasis. The role of miRNAs in the metastatic process is beginning to be explored. However, much is still to be understood. In this review, we present the accumulating evidence for the importance of miRNAs in metastasis as key regulators of this hallmark of cancer.

Regulation of Oncogenic Targets by miR-99a-3p (Passenger Strand of miR-99a-Duplex) in Head and Neck Squamous Cell Carcinoma

To identify novel oncogenic targets in head and neck squamous cell carcinoma (HNSCC), we have analyzed antitumor microRNAs (miRNAs) and their controlled molecular networks in HNSCC cells. Based on our miRNA signature in HNSCC, both strands of the miR-99a-duplex (miR-99a-5p: the guide strand, and miR-99a-3p: the passenger strand) are downregulated in cancer tissues. Moreover, low expression of miR-99a-5p and miR-99a-3p significantly predicts poor prognosis in HNSCC, and these miRNAs regulate cancer cell migration and invasion. We previously showed that passenger strands of miRNAs have antitumor functions. Here, we screened miR-99a-3p-controlled oncogenes involved in HNSCC pathogenesis. Thirty-two genes were identified as miR-99a-3p-regulated genes, and 10 genes (STAMBP, TIMP4, TMEM14C, CANX, SUV420H1, HSP90B1, PDIA3, MTHFD2, BCAT1, and SLC22A15) significantly predicted 5-year overall survival. Notably, among these genes, STAMBP, TIMP4, TMEM14C, CANX, and SUV420H1 were independent prognostic markers of HNSCC by multivariate analyses. We further investigated the oncogenic function of STAMBP in HNSCC cells using knockdown assays. Our data demonstrated that the aggressiveness of phenotypes in HNSCC cells was attenuated by siSTAMBP transfection. Moreover, aberrant STAMBP expression was detected in HNSCC clinical specimens by immunohistochemistry. This strategy may contribute to the clarification of the molecular pathogenesis of this disease.

A High-Content Screening Approach to Identify MicroRNAs Against Head and Neck Cancer Cell Survival and EMT in an Inflammatory Microenvironment

Head and neck squamous cell carcinoma (HNSCC) is among the most common cancer types. Metastasis, the main cause of death by cancer, can be promoted by an inflammatory microenvironment, which induces epithelial-mesenchymal transition (EMT) through a NF-κB-mediated stabilization of Snail. Here, we aimed to explore how microRNAs (miRs) can affect cell survival and EMT in HNSCC cells under an inflammatory microenvironment. By using a high-content screening (HCS) approach, we evaluated alterations in morphometric parameters, as well as expression/localization of Snail/Slug, in HNSCC cells primed with TNF-α. Based on those quantitation, we established the optimal experimental conditions of EMT induction driven by TNF-α. Those conditions were applied to cells transfected with distinct miRs (N = 31), followed by clusterization of miRs based on alterations related to cell survival and EMT. The signaling pathways enriched with molecular targets from each group of miRs were identified by in silico analyses. Finally, cells were transfected with siRNAs against signaling pathways targeted by miRs with anti-survival/EMT effect and evaluated for alterations in cell survival and EMT. Overall, we observed that TNF-α, at 20 ng/ml, induced EMT-related changes in cell morphology, Snail/Slug expression, and cell migration. Predicted targets of miRs with anti-survival/EMT effect were enriched with targets of NF-κB, PI3K/ATK, and Wnt/beta catenin pathways. Strikingly, individual gene silencing of elements from those pathways, namely RELA (NF-kB), AKT1 (PI3K/AKT), and CTNNB1 (Wnt/beta catenin) reduced cell survival and/or expression of Snail/Slug in cells stimulated with TNF-α. As a whole, our HCS approach allowed for the identification of miRs capable of inhibiting cell survival and EMT considering the presence of an inflammatory microenvironment, also indicating the common signaling pathways and molecular targets most likely to underlie those alterations. These findings may contribute to the development of targeted therapies against HNSCC.

Identification of potential hub genes associated with the pathogenesis and prognosis of pancreatic duct adenocarcinoma using bioinformatics meta-analysis of multi-platform datasets

Pancreatic duct adenocarcinoma (PDAC) is a highly malignant type of cancer with a low five-year survival rate. Gene alterations are crucial to the molecular pathogenesis of PDAC. Therefore, the present study analyzed gene expression profiles to reveal genes involved in the tumorigenesis of PDAC. A total of eight gene expression profiles (GSE15471, GSE16515, GSE41368, GSE62165, GSE62452, GSE71729, GSE71989 and GSE91035) and a PDAC dataset were acquired from the Gene Expression Omnibus and The Cancer Genome Atlas (TCGA) database, respectively. Differentially expressed genes (DEGs) were screened using functional annotation, Gene Ontology (GO) enrichment analysis, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis and protein-protein interaction (PPI) network construction. A Cox proportional hazards model was then constructed and used to analyze the data. A total of 136 DEGs (67 up- and 69 downregulated genes) were identified between PDAC tissues and normal tissues. The ‘extracellular matrix-related’ genes were the most enriched in the GO term analysis. ‘Pancreatic secretion’, ‘phosphoinositide-3-kinase–protein kinase B/Akt (PI3K-Akt) signaling pathway’, ‘protein digestion and absorption’ and ‘ECM-receptor interaction’ were the most enriched categories in KEGG pathway analysis. Following PPI network construction, the 10 most significant genes [albumin, epidermal growth factor, matrix metalloproteinase (MMP) 9, epidermal growth factor receptor, fibronectin 1, MMP1, plasminogen activator inhibitor-1, tissue inhibitor of metalloproteinase 1, plasminogen activator urokinase (PLAU) and PLAU receptor) exhibiting a high degree of connectivity, were identified as the hub genes likely to be associated with the pathogenesis of PDAC. In addition, a prognostic predictive system for PDAC, composed of five genes (laminin subunit γ 2, laminin subunit β 3, serpin family B member 5, amphiregulin and secreted frizzled related protein 4), was constructed. This was validated in the GSE62452 dataset (using 66 PDAC samples with outcome data) and TCGA PDAC dataset (using 146 PDAC samples with outcome data). In conclusion, the present study revealed potential hub genes involved in PDAC progression, providing directive significance for individualized clinical decision-making and molecular-targeting therapy in patients with PDAC.

Germinal Centre B Cell Functions and Lymphomagenesis: Circuits Involving MYC and MicroRNAs

BACKGROUND

The transcription factor MYC regulates several biological cellular processes, and its target gene network comprises approximately 15% of all human genes, including microRNAs (miRNAs), that also contribute to MYC regulatory activity. Although miRNAs are emerging as key regulators of immune functions, the specific roles of miRNAs in the regulation/dysregulation of germinal centre B-cells and B-cell lymphomas are still being uncovered. The regulatory network that integrates MYC, target genes and miRNAs is a field of intense study, highlighting potential pathways to be explored in the context of future clinical approaches.

METHODS

The scientific literature that is indexed in PUBMED was consulted for publications involving MYC and miRNAs with validated bioinformatics analyses or experimental protocols. Additionally, seminal studies on germinal centre B-cell functions and lymphomagenesis were reported.

CONCLUSIONS

This review summarizes the interactions between MYC and miRNAs through regulatory loops and circuits involving target genes in germinal centre B-cell lymphomas with MYC alterations. Moreover, we provide an overview of the understanding of the regulatory networks between MYC and miRNAs, highlighting the potential implication of this approach for the comprehension of germinal centre B-cell lymphoma pathogenesis. Therefore, circuits involving MYC, target genes and miRNAs provide novel insight into lymphomagenesis that could be useful for new improved therapeutic strategies.

Differential gene expression analysis of HNSCC tumors deciphered tobacco dependent and independent molecular signatures

Head and neck cancer is the sixth most common cancer worldwide, with tobacco as the leading cause. However, it is increasing in non-tobacco users also, hence limiting our understanding of its underlying molecular mechanisms. RNA-seq analysis of cancers has proven as effective tool in understanding disease etiology. In the present study, RNA-Seq of 86 matched Tumor/Normal pairs, of tobacco smoking (TOB) and non-smokers (N-TOB) HNSCC samples analyzed, followed by validation on 375 similar datasets. Total 2194 and 2073 differentially expressed genes were identified in TOB and N-TOB tumors, respectively. GO analysis found muscle contraction as the most enriched biological process in both TOB and N-TOB tumors. Pathway analysis identified muscle contraction and salivary secretion pathways enriched in both categories, whereas calcium signaling and neuroactive ligand-receptor pathway was more enriched in TOB and N-TOB tumors respectively. Network analysis identified muscle development related genes as hub node i. e. ACTN2, MYL2 and TTN in both TOB and N-TOB tumors, whereas EGFR and MYH6, depicts specific role in TOB and N-TOB tumors. Additionally, we found enriched gene networks possibly be regulated by tumor suppressor miRNAs such as hsa-miR-29/a/b/c, hsa-miR-26b-5p etc., suggestive to be key riboswitches in regulatory cascade of HNSCC. Interestingly, three genes PKLR, CST1 and C17orf77 found to show opposite regulation in each category, hence suggested to be key genes in separating TOB from N-TOB tumors. Our investigation identified key genes involved in important pathways implicated in tobacco dependent and independent carcinogenesis hence may help in designing precise HNSCC diagnostics and therapeutics strategies.

Downregulation of miR-29c-3p is associated with a poor prognosis in patients with laryngeal squamous cell carcinoma

Background

Laryngeal squamous cell carcinoma (LSCC) is considered to be a common malignancy of the head and neck with poor prognosis for its late diagnosis, metastasis and recurrence. Growing evidence demonstrates that the dysregulation of miR-29c-3p (microRNA-29c-3p) plays an important role in various tumor processes. Our study investigates the expression of miR-29c-3p in LSCC and analyzes the correlation of its dysregulation with clinicopathologic parameters and prognosis.

Methods

The expression of hsa-miR-29c-3p in LSCC tissues and the adjacent normal laryngeal tissues was detected in 96 LSCC formalin-fixed paraffin-embedded tissues by quantitative real-time PCR (qRT-PCR). The SPSS statistical software package (17.0) was used to analyze the associations between miR-29c-3p expressions and various clinicopathological characteristics. The overall survival (OS) was analyzed by the Kaplan-Meier method and log-rank test, and we analyzed the independent factor of prognosis by Cox proportional hazard analysis.

Results

A downregulation of miR-29c-3p expression in LSCC was significantly correlated with smoking index, tumor size, tumor site, differentiation, T classification, TNM stage, and lymph node metastasis (P < 0.05), but there was no correlation with age and alcohol consumption (P > 0.05). In the multivariate survival analysis, low miR-29c-3p expression was associated with shorter overall survival (P < 0.05). Furthermore, miR-29c expression was an independent prognostic factor for laryngeal cancer patients.

Conclusions

MiR-29c-3p has different expression levels at different stages of tumor progression, suggesting that miR-29c-3p may be a promising biomarker for evaluating the progression of LSCC and the prognosis of patients with LSCC. MiR-29c-3p can also be a novel molecular target for anti-laryngeal cancer therapy.

Evaluation of circulating serum 3 types of microRNA as biomarkers of oral squamous cell carcinoma; A pilot study

INTRODUCTION

The microRNAs are molecules which have important biologic role and play key point in cancers. The aim of present study was to determine the miR-21, miR-24, and miR-29a expression in serum of patients with oral squamous cell carcinoma.

MATERIALS AND METHODS

Blood samples were obtained from 40 patients (20 in cases and 20 in control group) to determine the miR-21, miR-24, and miR-29a expressions by using real-time PCR and ΔCT.

RESULTS

Mean miR-29a was -2.28 ± 2.15 and 5.61 ± 2.38 in case and control groups, respectively. The miR-21 was 6.90 ± 3.86 and -0.88 ± 2.31 in case and control groups, respectively. According to the results, miR-24 was 2.13 ± 2.89 and -0.35 ± 2.44 in case and control, respectively. A significant difference was observed on miR-21, miR-24, and miR-29a between two groups (P < .05). The results obtained by t test showed miR-21 and miR-24 were higher and miR-29a was lower in plasma of oral squamous cell carcinoma patients and this differences were significant (P < .05).

CONCLUSION

These results suggested miR-21, miR-24, and miR-29a in serum of patients with oral squamous cell carcinoma comparing with normal group can be used as potent markers for carcinoma detection and also may be a potentially therapeutic approach in the future. More longitudinal studies with larger samples are necessary to confirm these findings.

Rapamycin-upregulated miR-29b promotes mTORC1-hyperactive cell growth in TSC2-deficient cells by downregulating tumor suppressor retinoic acid receptor β (RARβ)

miR-29b has been identified as a rapamycin-induced microRNA (miRNA) in Tsc2-deficient, mTORC1-hyperactive cells. The biological significance of this induction of miR-29b is unknown. We have found that miR-29b acts as an oncogenic miRNA in Tsc2-deficient cells: inhibition of miR-29b suppressed cell proliferation, anchorage-independent cell growth, cell migration, invasion, and the growth of Tsc2-deficient tumors in vivo. Importantly, the combination of miR-29b inhibition with rapamycin treatment further inhibited these tumor-associated cellular processes. To gain insight into the molecular mechanisms by which miR-29b promotes tumorigenesis, we used RNA sequencing to identify the tumor suppressor retinoid receptor beta (RARβ) as a target gene of miR-29b. We found that miR-29b directly targeted the 3'UTR of RARβ. Forced expression of RARβ reversed the effects of miR-29b overexpression in proliferation, migration, and invasion, indicating that it is a critical target. miR-29b expression correlated with low RARβ expression in renal clear cell carcinomas and bladder urothelial carcinomas, tumors associated with TSC gene mutations. We further identified growth family member 4 (ING4) as a novel interacting partner of RARβ. Overexpression of ING4 inhibited the migration and invasion of Tsc2-deficient cells while silencing of ING4 reversed the RARβ-mediated suppression of cell migration and invasion. Taken together, our findings reveal a novel miR-29b/RARβ/ING4 pathway that regulates tumorigenic properties of Tsc2-deficient cells, and that may serve as a potential therapeutic target for TSC, lymphangioleiomyomatosis (LAM), and other mTORC1-hyperactive tumors.

N6-methyladenosine modification of ITGA6 mRNA promotes the development and progression of bladder cancer

Background

Accumulating evidence has revealed the critical roles of N⁶-methyladenosine (m⁶A) modification of mRNA in various cancers. However, the biological function and regulation of m⁶A in bladder cancer (BC) are not yet fully understood.

Methods

We performed cell phenotype analysis and established in vivo mouse xenograft models to assess the effects of m⁶A-modified ITGA6 on BC growth and progression. Methylated RNA immunoprecipitation (MeRIP), RNA immunoprecipitation and luciferase reporter and mutagenesis assays were used to define the mechanism of m⁶A-modified ITGA6. Immunohistochemical analysis was performed to assess the correlation between METTL3 and ITGA6 expression in bladder cancer patients.

Findings

We show that the m⁶A writer METTL3 and eraser ALKBH5 altered cell adhesion by regulating ITGA6 expression in bladder cancer cells. Moreover, upregulation of ITGA6 is correlated with the increase in METTL3 expression in human BC tissues, and higher expression of ITGA6 in patients indicates a lower survival rate. Mechanistically, m⁶A is highly enriched within the ITGA6 transcripts, and increased m⁶A methylations of the ITGA6 mRNA 3’UTR promotes the translation of ITGA6 mRNA via binding of the m⁶A readers YTHDF1 and YTHDF3. Inhibition of ITGA6 results in decreased growth and progression of bladder cancer cells in vitro and in vivo. Furthermore, overexpression of ITGA6 in METTL3-depleted cells partially restores the BC adhesion, migration and invasion phenotypes.

Interpretation

Our results demonstrate an oncogenic role of m⁶A-modified ITGA6 and show its regulatory mechanisms in BC development and progression, thus identifying a potential therapeutic target for BC.

Fund

This work was supported by National Natural Science Foundation of China (81772699, 81472999).

MiR-302a-5p suppresses cell proliferation and invasion in non-small cell lung carcinoma by targeting ITGA6

MicroRNA-302a-5p (miR-302a-5p) has been implicated in several cancers; however, its role in human non-small cell lung carcinoma (NSCLC) remains unknown. In this study, we showed that miR-302a-5p is downregulated in NSCLC tissues and cell lines. Cell Counting Kit-8 and 5-ethynyl-2'-deoxyuridine assays showed that overexpression of a miR-302a-5p mimic suppressed NSCLC cell proliferation, which was confirmed by the results of a cell cycle assay. Overexpression of miR-302a-5p also reduced the migration and invasion of NSCLC cells. Additionally, miR-302a-5p overexpression significantly inhibited NSCLC growth and metastasis in a mouse xenograft model. With regard to the underlying mechanism, integrin α6 (ITGA6) mRNA was shown to be a novel target of miR-302a-5p, and overexpression of ITGA6 attenuated the inhibitory effects of miR-302a-5p on the proliferation and migration of NSCLC cells. In clinical NSCLC samples, miR-302a-5p expression was negatively correlated with ITGA6 expression, which was high in the samples. Collectively, these results indicate that miR-302a-5p acts as a tumor suppressor in NSCLC by directly targeting ITGA6 mRNA and may be useful as a theranostic biomarker of NSCLC.

Multilayer network analysis of miRNA and protein expression profiles in breast cancer patients

MiRNAs and proteins play important roles in different stages of breast tumor development and serve as biomarkers for the early diagnosis of breast cancer. A new algorithm that combines machine learning algorithms and multilayer complex network analysis is hereby proposed to explore the potential diagnostic values of miRNAs and proteins. XGBoost and random forest algorithms were employed to screen the most important miRNAs and proteins. Maximal information coefficient was applied to assess intralayer and interlayer connection. A multilayer complex network was constructed to identify miRNAs and proteins that could serve as biomarkers for breast cancer. Proteins and miRNAs that are nodes in the network were subsequently categorized into two network layers considering their distinct functions. The betweenness centrality was used as the first measurement of the importance of the nodes within each single layer. The degree of the nodes was chosen as the second measurement to map their signalling pathways. By combining these two measurements into one score and comparing the difference of the same candidate between normal tissue and cancer tissue, this novel multilayer network analysis could be applied to successfully identify molecules associated with breast cancer.

The Role of MicroRNAs in Recurrence and Metastasis of Head and Neck Squamous Cell Carcinoma

Head and neck squamous cell carcinoma (HNSCC) affects 650,000 people worldwide and has a dismal 50% 5-year survival rate. Recurrence and metastasis are believed the two most important factors causing this high mortality. Understanding the biological process and the underlying mechanisms of recurrence and metastasis is critical to develop novel and effective treatment, which is expected to improve patients' survival of HNSCC. MicroRNAs are small, non-coding nucleotides that regulate gene expression at the transcriptional and post-transcriptional level. Oncogenic and tumor-suppressive microRNAs have shown to regulate nearly every step of recurrence and metastasis, ranging from migration and invasion, epithelial-mesenchymal transition (EMT), anoikis, to gain of cancer stem cell property. This review encompasses an overview of microRNAs involved in these processes. The recent advances of utilizing microRNA as biomarkers and targets for treatment, particularly on controlling recurrence and metastasis are also reviewed.