Invasion Of Oral Squamous Cell Carcinoma Cells Research Articles

MicroRNA-134 inhibits tumor stem cell migration and invasion in oral squamous cell carcinomas via downregulation of PI3K-Akt signaling pathway by inhibiting LAMC2 expression.

Oral squamous cell carcinoma (OSCC) is the most common malignant neoplasm of the mouth. Some studies have found that multiple microRNAs (miRs) participate in OSCC physiological and pathological processes. We explored the mechanism of action of miR-134 in OSCC involving the PI3K-Akt signaling pathway. Different bioinformatics methods were used to analyze the potential genes and their related miRs in OSCC. Tumor stem cells were separated from OSCCs through magnetic cell sorting. Regulatory pattern between miR-134 and LAMC2 in OSCC was evaluated by ectopic expression, knockdown and reporter assay experiments. The expression of miR-134, LAMC2, genes in PI3K-Akt signaling pathway, and apoptosis-related genes was detected. Cell proliferation was assessed by MTT assay, cell invasion by scratch test, cell migration by Transwell assay, cell cycle and apoptosis by flow cytometry, and cell growth and migration by xenograft tumor in nude mice. LAMC2 was predicted as the crucial factor related to OSCC using different chip data, and miR-134 was predicted to specifically bind LAMC2 in all five databases. Overexpressed miR-134 or silenced LAMC2 was observed to inhibit cell proliferation, migration, invasion of OSCC cells, growth of subcutaneous xenograft in nude mice, as well as promote OSCC cell apoptosis. LAMC2, a target gene of miR-134, decreased following miR-134 promotion, while the PI3K-Akt signaling pathway was inactivated following LAMC2 knockdown. Furthermore, we also observed that the effect of overexpressed miR-134 was enhanced when LAMC2 was knocked down. Taken together, these findings suggest that miR-134-mediated direct downregulation of LAMC2 inhibits migration and invasion of tumor stem cells in OSCC by suppressing the PI3K-Akt signaling pathway.

CiRS-7 functions as a ceRNA of RAF-1/PIK3CD to promote metastatic progression of oral squamous cell carcinoma via MAPK/AKT signaling pathways

PurposeRecent findings have shown that circRNA dysregulation was involved in the development of many types of cancer. However, our knowledge of circRNA in oral squamous cell carcinoma (OSCC) remains elusive. MethodsHere, we explored whether ciRS-7 could function as a ceRNA in promoting metastasis of OSCC via regulating miR-7 activity. The expression levels of ciRS-7 and miR-7 were examined in clinical samples and cell lines by qRT-PCR, and the effects of ectopic expression of ciRS-7 and miR-7 on cell proliferation, migration and invasion were assessed in vitro and in vivo. The effects of ciRS-7 on miR-7 activity were investigated by means of luciferase reporter assay, qRT-PCR and Western blot. In addition, the effects of miR-7 mediated ciRS-7 on the levels of MAPK/AKT signaling proteins were evaluated by Western blot. ResultsWe found that ciRS-7 was highly expressed in OSCC tissues and cell lines compared with normal counterparts. Ectopic expression of ciRS-7 significantly promoted OSCC cell proliferation, migration and invasion through in vitro and in vivo. Based on bioinformatics analysis, qRT-PCR, Western blot and luciferase reporter assays, we determined that ciRS-7 functioned as a sponge for miR-7, resulting in attenuation of miR-7 targets RAF-1 and PIK3CD, which are core components of the MAPK/AKT signaling pathways. Moreover, miR-7 correlated with perineural and lymphovascular invasion in OSCC patients. Further experiments demonstrated that ciRS-7 overexpression could attenuate the anti-tumor effects of miR-7 on OSCC cells. ConclusionsOur results suggested that ciRS-7 can interact directly with miR-7, resulting in upregulation of RAF-1/PIK3CD expression and enhancing metastatic progression of OSCC.

LncRNA MALAT1 promotes cell proliferation and invasion by regulating the miR-101/EZH2 axis in oral squamous cell carcinoma.

Oral squamous cell carcinoma (OSCC) is the most common malignant tumor of the oral cavity. Emerging evidence indicates that long non-coding (lnc)RNAs play a key role in the cellular processes of tumor cells, including glycolysis, growth and movement. Here, the purpose of this study was to explore the biological functions and potential mechanism of lncRNA metastasis associated lung adenocarcinoma transcript 1 (MALAT1) in OSCC. OSCC tissues and adjacent matched paraneoplastic normal tissues were collected from 20 OSCC patients. The expression of MALAT1 and miR-101 in OSCC tissues and cell lines (HSC3, SCC9, SCC15 and SCC25) were determined by real-time-polymerase chain reaction (qPCR). Caspase-3, xaspase-8 and EZH2 protein levels were determined by western blot analysis. MALAT1-mediated miRNAs were verified by bioinformatics analysis of StarBase and Luciferase reporter assay. Cell Counting Kit-8 (CCK-8) and Transwell assays were used for investigating MALAT1 effect on cell proliferation and invasion in the OSCC cells. qPCR analysis indicated that MALAT1 expression was obviously increased, and miR-101 was decreased in the OSCC tissues and cell lines. Functional studies revealed that overexpression of MALAT1 promoted OSCC cell proliferation and invasion. Further experiments revealed that miR-101 was a target of MALAT1 and that the miR-101 inhibitor abolished the effect of MALAT1 on OSCC cell proliferation and invasion. Enhancer of zeste 2 polycomb repressive complex 2 subunit (EZH2) acted as a downstream effecter of MALAT1 in the OSCC cells. Collectively, these findings revealed that upregulation of MALAT1 facilitated OSCC proliferation and invasion by targeting the miR-101/EZH2 axis.

MiR-223 regulates oral squamous cell carcinoma metastasis through the Wnt/β-catenin signaling pathway.

Metastasis seriously affects the prognosis of patients with oral squamous cell carcinoma (OSCC); however, the precise mechanism remains poorly understood. microRNA (miRNA) array analysis of four cell lines was used to identify candidate miRNAs. The Cancer Genome Atlas (TCGA) database was used to verify the relationship between candidate miRNAs and OSCC metastasis. Transwell chambers and mouse model experiments were used to analyze OSCC cell migration and invasion abilities in vitro and in vivo. Additionally, bioinformatics and a dual luciferase reporter assay were used to identify selected miRNA target genes. A multicenter clinical cohort of 250 patients with OSCC was set up to evaluate the diagnostic and predicted value of the target genes. Finally, the molecular mechanism of a selected miRNA regulating OSCC metastasis was further explored. miR-223 expression was found to be negatively correlated with OSCC cell invasion and migration abilities. TCGA database data confirmed the relationship between miR-223 expression and OSCC metastasis. Functional experiments indicated that overexpression of miR-223 could decrease the metastasis ability of OSCC cells, while decreasing its expression level led to the enhancement of OSCC metastasis. Bioinformatics and a dual-luciferase reporter assay identified that miR-223 directly targets transcription factor 7-like 2 (TCF7L2). Additionally, TCF7L2 was shown to be negatively correlated with patient metastasis and survival. miR-223 regulates OSCC invasion and metastasis by directly targeting TCF7L2 and potentiating the Wnt/β-catenin signaling pathway. These findings demonstrate the versatile role of miR-223 in carcinogenesis. miR-223 might serve as an attractive OSCC metastasis intervention target.

PLAC8 inhibits oral squamous cell carcinogenesis and epithelial-mesenchymal transition via the Wnt/β-catenin and PI3K/Akt/GSK3β signaling pathways.

Placenta-specific 8 (PLAC8) is closely associated with the proliferation, apoptosis and autophagy of several tumor cells. However, the expression and function of PLAC8 in oral squamous cell carcinoma (OSCC) remain unknown. Therefore, the present study investigated the function and mechanism of PLAC8 in OSCC. Reverse transcription-quantitative PCR and western blot analyses were performed to quantify the expression of PLAC8 in OSCC cell lines. The function of PLAC8 in OSCC was investigated via transfection, the Transwell and Cell Counting Kit-8 assays, immunofluorescence staining and western blotting. The results demonstrated that PLAC8 exspression was downregulated in OSCC cell lines. PLAC8 inhibited the cell proliferation in OSCC. In addition, PLAC8 restrained invasion and epithelial-mesenchymal transition of OSCC cells. Furthermore, β-catenin helped to repress PLAC8 expression by regulating the Wnt/β-catenin and PI3K/Akt/GSK3β signaling pathways in OSCC cells. Collectively, the results of the present study suggest that PLAC8 acts as a tumor suppressor in OSCC by downregulating β-catenin.

Abstract 1395: Hsa_circ_005379 competitively binds to miR-182-5p to mediate PTEN expression in oral squamous cell carcinoma

Abstract Background: Oral squamous cell carcinoma (OSCC) is an oral and maxillofacial malignancy with a high incidence worldwide. Accumulating evidence indicates that circular RNAs (circRNAs) play a vital role in modulating tumor development. However, the mechanism of circRNA action in human OSCC remains largely unknown. Methods: By using high-throughput transcriptome sequencing technology, we conducted a comprehensive study of circRNAs in human OSCC. The effect of CircRNA hsa_circ_0005379 on OSCC tissues and cell lines were monitored by qRT-PCR, transwell assay and western blot analysis. Xenograft mouse models were used to assess tumor growth and animal survival. Results: CircRNA hsa_circ_0005379 was found to express significantly lower in OSCC tissue compared to paired non-cancerous matched tissue and is associated with tumor size and differentiation. Overexpression of has_circ_0005379 effectively inhibits migration, invasion, and proliferation of OSCC cells in vitro, and suppresses OSCC growth in nude mice. Mechanistic studies revealed that hsa_circ_0005379 may be involved in the regulation of epidermal growth factor receptor (EGFR) pathway. Conclusions: Our findings provide evidence that hsa_circ_0005379 exerts regulatory functions and may be a new therapeutic target for OSCC treatment. Citation Format: Yuehong Shen, Wen Su, Hongyu Yang. Hsa_circ_005379 competitively binds to miR-182-5p to mediate PTEN expression in oral squamous cell carcinoma [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 1395.

Preclinical Assessment of the Effectiveness of Magnetic Resonance Molecular Imaging of Extradomain-B Fibronectin for Detection and Characterization of Oral Cancer.

Oral squamous cell carcinoma (OSCC) has not seen a substantial improvement in patient survival despite therapeutic advances, making accurate detection and characterization of the disease a clinical priority. Here, we aim to demonstrate the effectiveness of magnetic resonance imaging (MRI) with the targeted MRI contrast agent MT218 specific to extradomain-B fibronectin (EDB-FN) in the tumor microenvironment for detection and characterization of aggressive OSCC tumors. EDB-FN expression was evaluated in human normal tongue and OSCC specimens with immunohistochemistry. Invasiveness of human CAL27, HSC3, and SCC4 OSCC cells was analyzed with spheroid formation and transwell assays. EDB-FN expression in the cells was analyzed with semiquantitative real-time PCR, western blotting, and a peptide binding study with confocal microscopy. Contrast-enhanced MRI with MT218 was performed on subcutaneous OSCC mouse models at a dose of 0.04mmol/kg, using gadoteridol (0.1mmol/kg) as a control. Strong EDB-FN expression was observed in human untreated primary and metastatic OSCC, reduced expression in treated OSCC, and little expression in normal tongue tissue. SCC4 and HSC3 cell lines demonstrated high invasive potential with high and moderate-EDB-FN expression, respectively, while CAL27 showed little invasive potential and low-EDB-FN expression. In T1-weighted MRI, MT218 produced differential contrast enhancement in the subcutaneous tumor models in correlation with EDB-FN expression in the cancer cells. Enhancement in the high-EDB-FN tumors was greater with MT218 at 0.04mmol/kg than gadoteridol at 0.1mmol/kg. The results suggest EDB-FN has strong potential as an imageable biomarker for aggressive OSCC. MRMI results demonstrate the effectiveness of MT218 and the potential for differential diagnostic imaging of oral cancer for improving the management of the disease.

Effect of circular RNA hsa_circ_0008898 on oral squamous cell carcinoma and its mechanism

Objective: To investigate the effect and molecular mechanism of hsa_circ_0008898 on the cell proliferation, migration, invasion and tumor formation of oral squamous cell carcinoma (OSCC). Methods: Quantitative real-time PCR (qPCR) and Western blotting were used to detect the expression of hsa_circ_0008898, miR-197-5p and ras homolog gene family member A (RHOA) in OSCC tissues, adjacent tissues, OSCC cells and human normal oral keratinocytes (NOK). CAL27 and SCC-25 cells were transfected with si-hsa_circ_0008898#1 (knockdown group 1), si-hsa_circ_0008898#2 (knockdown group 2), hsa_circ_0008898 (circ overexpression group) and blank plasmid (circ blank group), respectively. Then miR-197-5p inhibitor (inhibition group) and blank plasmid (inhibition control group) were transfected into hsa_circ_0008898 knockdown cells (knockdown group 1). CAL27 and SCC-25 cells were transfected with miR-197-5p mimics (miR overexpression group) and blank plasmid (miR blank group), and then transfected hsa_circ_0008898 vector (co-transfection group 1), RHOA vector (co-transfection group 2) and blank plasmid (co-transfection control group) in cells overexpressing miR-197-5p. Cell counting kit 8 (CCK-8), colony formation, Transwell and scratch test were used to detect cell proliferation, cloning ability, cell cycle distribution, cell invasion and migration ability. Ten nude mice were equally divided into two groups, with 5 mice in each group. SCC-25 cells transfected with blank plasmid (control group) and SCC-25 cells transfected with sh-hsa_circ_0008898 (knockout group) were subcutaneously injected into the armpit. The volume and mass of the tumor were measured. Results: The expressions of hsa_circ_0008898 (2.89±0.72) and RHOA (2.62±0.21) in OSCC tissues were significantly higher than those in para-carcinoma tissues (1.00±0.48, 1.00±0.11, respectively), while the expression of miR-197-5p in OSCC tissues （0.46±0.24） was significantly lower than that in para-carcinoma tissues (1.00±0.42) (P<0.05). Compared with NOK, the expression of hsa_circ_0008898 and RHOA in CAL27 and SCC-25 cells increased significantly, while the expression of miR-197-5p decreased (P<0.05). Compared with circ blank group, the cell viability, colony formation, scratch healing rate and invasive cell number of CAL27 and SCC-25 cells in knockdown group 1 and group 2 were significantly decreased, while the proportion of cells in G1 phase was significantly increased (P<0.05). Compared with inhibition control group, the cell viability, colony formation, scratch healing rate and invasive cell number of CAL27 and SCC-25 in inhibition group were significantly increased, while the proportion of cells in G1 phase was significantly decreased in inhibition group (P<0.05). Compared with miR blank group, the cell viability, colony formation, scratch healing rate and invasive cell number of CAL27 and SCC-25 in miR overexpression group were significantly decreased, while the proportion of cells in G1 phase was significantly increased in miR overexpression group (P<0.05). Compared with co-transfection control group, the cell viability, colony formation, migration area and invasive cell number of CAL27 and SCC-25 in co-transfection group2 were significantly increased, while the proportion of cells in G1 phase was significantly decreased in co-transfection group 2 (P<0.05). The volume and mass of transplanted tumor in knockout group ［(660.4±67.8) mm(3 )and (0.60±0.06) g, respectively］ were significantly lower than those in control group ［(1 210.4±198.9) mm(3) and (1.00±0.12) g, respectively］. Conclusions: Knockdown of hsa_circ_0008898 inhibited OSCC cells proliferation, cloning, migration and invasion and induced cell cycle arrest in vitro by regulating the miR-197-5p/RHOA. Additionally, Knockdown of hsa_circ_0008898 also inhibited tumor formation of OSCC cells in vivo.

The circEPSTI1/mir-942-5p/LTBP2 axis regulates the progression of OSCC in the background of OSF via EMT and the PI3K/Akt/mTOR pathway

Oral squamous cell carcinoma (OSCC) in the background of oral submucous fibrosis (OSF) caused by areca nut chewing has a high incidence in Asia-Pacific countries. However, the molecular mechanism remains unclear. Here, we performed circRNA microarray analysis to screen the circRNA expression profiles in OSCC and OSF. We identified circEPSTI1 as a circRNA with consistent, sequential upregulation from normal buccal mucosa (NBM) to OSF to OSCC. Functionally, circEPSTI1 significantly promoted OSCC cell proliferation and invasion, as evidenced by the CCK8, colony formation, wound healing, and transwell assays with circEPSTI1 overexpression and silencing. OSCC patients with circEPSTI1high status exhibited poor prognoses. CircEPSTI1 sponged miR-942-5p and accelerated epithelial-mesenchymal transition (EMT) to increase LTBP2 expression in OSCC through phosphorylation of PI3K/Akt/mTOR signaling pathway components. Blocking the PI3K/Akt/mTOR signaling pathway with the dual PI3k/mTOR inhibitor BEZ235 reversed OSCC progression induced by overexpression of circEPSTI1 and LTBP2. Collectively, these results indicate that the circEPSTI1/miR-942-5p/LTBP2 axis affects OSCC cell proliferation and invasion via the acceleration of EMT and the phosphorylation of PI3K/Akt/mTOR signaling pathway components. CircEPSTI1 may be an independent diagnostic and prognostic marker and a potential therapeutic target for OSCC patients with OSF.

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

BackgroundExosomes 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.MethodsThe 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.ResultsOur 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.ConclusionThe 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.

LncRNA MCM3AP-AS1 promotes proliferation, migration and invasion of oral squamous cell carcinoma cells via regulating miR-204-5p/FOXC1

Oral squamous cell carcinoma (OSCC) is a lethal malignancy. It is reportedly demonstrated that long non-coding RNA (lncRNA) participates in the development of OSCC. The purpose of this study was...

Gamma synuclein is a novel nicotine responsive protein in oral cancer malignancy

BackgroundThe mechanisms of neuronal protein γ-synuclein (SNCG) in the malignancy of oral squamous cell carcinoma (OSCC) are not clear. This study tested the hypothesis that SNCG is involved in nicotine-induced malignant behaviors of OSCC. The effect of nicotine on SNCG expression and epithelial-to-mesenchymal transition (EMT) markers were examined.MethodsShort hairpin RNA (shRNA) and an antagonist specific for α7-nicotine acetylcholine receptors (α7-nAChRs) were used to examine the role of α7-nAChRs in mediating the effects of nicotine. Knockdown of SNCG in nicotine-treated cells was performed to investigate the role of SNCG in cancer malignancy. The in vivo effect of nicotine was examined using a nude mouse xenotransplantation model.ResultsNicotine increased SNCG expression in a time- and dose-dependent manner. Nicotine treatment also increased E-cadherin and ZO-1 and decreased fibronectin and vimentin expression. After specific knockdown of α7-nAChRs and inhibition of the PI3/AKT signal, the effect of nicotine on SNCG expression was attenuated. Silencing of SNCG abolished nicotine-induced invasion and migration of OSCC cells. The xenotransplantation model revealed that nicotine augmented tumor growth and SNCG expression.ConclusionNicotine upregulated SNCG expression by activating the α7-nAChRs/PI3/AKT signaling that are participated in nicotine-induced oral cancer malignancy.

Activation of PGK1 under hypoxic conditions promotes glycolysis and increases stem cell‑like properties and the epithelial‑mesenchymal transition in oral squamous cell carcinoma cells via the AKT signalling pathway.

Although it has been previously documented that a hypoxic environment can promote glycolysis and the malignant progression of oral squamous cell carcinoma (OSCC) cells, the specific underlying mechanism remains unclear. Phosphoglycerate kinase 1 (PGK1) has been previously reported to serve an important role in tumor metabolism. The aim of the present study was to investigate the effects of hypoxia and PGK1 on glycolysis, stem cell-like properties and epithelial-mesenchymal transition (EMT) in OSCC cells. Cell Counting Kit-8 assays were performed to examine tumor cell viability under hypoxic conditions. Sphere formation, immunohistochemistry, western blotting, Transwell assays and mouse xenograft studies were performed to assess the biological effects of PGK1. Under hypoxic conditions, phosphoglycerate PGK1 expression was found to be upregulated, which resulted in the potentiation of stem cell-like properties and enhancement of EMT. However, PGK1 knockdown reversed hypoxia-mediated glycolysis, stem cell-like properties, EMT in addition to inhibiting OSCC cell invasion and migration. PGK1 knockdown also inhibited tumour growth, whilst the overexpression of PGK1 was demonstrated to promote tumour growth in mouse xenograft models in vivo. Downstream, activation of the AKT signalling pathway reversed the series of changes induced by PGK1 knockdown. PGK1 expression was found to be upregulated in human OSCC tissues, which was associated with the pathological differentiation of tumours and lymph node metastasis. To conclude, results from the present study demonstrate that hypoxia can increase PGK1 expression, resulting in the promotion of glycolysis, enhancing stem cell-like properties and EMT by activating AKT signalling in OSCC.

MiR‑144‑3p inhibits tumor cell growth and invasion in oral squamous cell carcinoma through thedownregulation of the oncogenic gene, EZH2.

Accumulating evidence demonstrates that microRNAs (miRNAs or miRs) play important roles in the development and progression of human malignancies, including oral squamous cell carcinoma (OSCC); however, the unique roles of miRNAs are not yet fully understood in OSCC. The present study aimed to identify novel miRNAs associated with OSCC and to elucidate their functions. Based on a micro-array analysis, miR-144-3p was found to be one of the most significantly downregulated miRNAs in OSCC tissues. Its low expression was closely associated with tumor size, differentiation and lymph node metastasis. Functionally, miR-144-3p overexpression suppressed proliferation, promoted apoptosis, and suppressed the invasion and migration of OSCC cells. In addition, enhancer of zeste homolog 2 (EZH2), a well-known oncogene, was proven to be a direct target of miR-144-3p, and its protein expression was negatively regulated by miR-144-3p. Moreover, EZH2 expression was increased, and inversely correlated with the miR-144-3p level in OSCC tissues. Notably, EZH2 knockdown inhibited cell proliferation, promoted cell apoptosis, and suppressed the invasion and migration of OSCC cells, whereas EZH2 overexpression partially reversed the anticancer effects mediated by miR-144-3p overexpression. On the whole, the findings of the present study suggest that miR-144-3p functions as a tumor suppressor by targeting the EZH2 oncogene, and may thus be considered as a potential diagnostic and therapeutic target for OSCC.

The RBP1\u2013CKAP4 axis activates oncogenic autophagy and promotes cancer progression in oral squamous cell carcinoma

Retinol-binding protein 1 (RBP1) is involved in several physiological functions, including the regulation of the metabolism and retinol transport. Studies have shown that it plays an important role in the pathogenesis of several types of cancer. However, the role of RBP1 and its correlation with autophagy in oral squamous cell carcinoma (OSCC) pathogenesis remain unknown. In this study, RBP1 was identified as the most significantly upregulated DEPs with a >2-fold change in OSCC samples when compared to normal tissues through iTRAQ-based proteomics analysis coupled with 2D LC–MS/MS. RBP1 overexpression was significantly associated with malignant phenotypes (differentiation, TNM stage, and lymphatic metastasis) of OSCC. In vitro experiments demonstrated that RBP1 was significantly increased in OSCC tissues and cell lines compared with control group. RBP1 overexpression promoted cell growth, migration, and invasion of OSCC cells. Silencing of RBP1 suppressed tumor formation in xenografted mice. We further demonstrated that the RBP1–CKAP4 axis was a critical regulator of the autophagic machinery in OSCC, inactivation of autophagy rescued the RBP1–CKAP4-mediated malignant biological behaviors of OSCC cells. Overall, a mechanistic link was provided by RBP1–CKAP4 between primary oncogenic features and the induction of autophagy, which may provide a potential therapeutic target that warrants further investigation for treatment of OSCC.

MicroRNA-367 directly targets PIK3R3 to inhibit proliferation and invasion of oral carcinoma cells.

Recently, microRNA-367 (miR-367) has been reported to function as both tumor suppressor and oncogene in several cancer types, including gastric cancer, hepatocellular cancer and lung cancer. However, the biological function of miR-367 and its precise mechanisms in oral squamous cell carcinoma (OSCC) have not been well clarified. The aim of the present study was to study the roles of miR-367/PIK3R3 axis in OSCC. The levels of PIK3R3 and miR-367 were detected by quantitative PCR assay in OSCC tissues and cell lines. Moreover, the biological roles of miR-367 and PIK3R3 in OSCC cells were assessed by cell proliferation and invasion. The mRNA and protein levels of PIK3R3 were determined by using quantitative PCR and Western blotting assays. Luciferase assays were used to confirm that PIK3R3 was one target of miR-367. In the present study, the miR-367 level was dramatically reduced in OSCC tissues and cell lines, and the PIK3R3 expression was significantly enhanced. What’s more, the PIK3R3 expression was negatively related to the miR-367 level in OSCC tissues. Furthermore, up-regulation of miR-367 obviously restrained OSCC cells proliferation and invasion. We confirmed that miR-367 could directly target PIK3R3 by luciferase reporter assay. Besides, knockdown of PIK3R3 also could markedly inhibit the proliferation and invasion of OSCC cells. Finally, overexpression of miR-367 in OSCC cells partially reversed the promoted effects of PIK3R3 up-regulation. Overexpression of miR-367 restrained OSCC cells proliferation and invasion via regulation of PIK3R3.

Overexpression of β-Adrenergic Receptors and the Suppressive Effect of β2-Adrenergic Receptor Blockade in Oral Squamous Cell Carcinoma

The purpose of this project was to investigate the expression of β-adrenergic receptors in oral squamous cell carcinoma (OSCC) and the tumor suppressive activity of β2-adrenergic receptor (β2-AR) blockade. Samples of 15 normal oral mucosal epithelial tissues, 60 surgically resected OSCC tissues, and 60 adjacent para-carcinoma tissues were collected. The expression of β1-adrenergic receptor and β2-AR was detected by real-time quantitative polymerase chain reaction and the Western blot test.SCC9 and Cal27cell lines and primary OSCC cells also were included and treated with ICI-118,551 (MedChemExpress, Monmouth Junction, NJ), a selective β2-AR blocker.In addition, the Cal27cell line was treated with propranolol (a nonselective β-adrenergic receptor blocker) to verify the suppressive effect of β2-AR blockade. For invivo assays, Cal27cells were subcutaneously injected in the tongue flank of nude mice. ICI-118,551 was orally administered to the mice in the treatment group daily. High-throughput sequencing was used to screen for changes in gene expression. Real-time quantitative polymerase chain reaction and the Western blot test both showed that β1-adrenergic receptor and β2-AR were overexpressed in OSCC tissues and cells. A relationship was found between β2-AR and a more advanced clinical stage, as well as preoperative lymphatic metastasis. After treatment with ICI-118,551 or propranolol, the capacities for proliferation, invasion, and metastasis of OSCC cells were significantly inhibited. Tumor size was significantly different between the ICI-118,551 and control groups. The survival time in the ICI-118,551 group also was prolonged significantly. Moreover, high-throughput sequencing identified 19 affected signaling pathways, including mitogen-activated protein kinase and PI3K-Akt.We confirmed a significant change to the expression of several genes closely related to the progression of cancer. This study showed that β2-AR is related to a more advanced clinical stage and preoperative lymphatic metastasis. Additionally, a β2-AR blocker has a significant suppressive effect in OSCC.

Stanniocalcin 2 contributes to aggressiveness and is a prognostic marker for oral squamous cell carcinoma

Stanniocalcin 2 (STC2), a glycoprotein that regulates calcium and phosphate homeostasis during mineral metabolism, appears to display multiple roles in tumorigenesis and cancer progression. This study aimed to access the prognostic value of STC2 in oral squamous cell carcinoma (OSCC) and its implications in oral tumorigenesis. STC2 expression was examined in 2 independent cohorts of OSCC tissues by immunohistochemistry. A loss-of-function strategy using shRNA targeting STC2 was employed to investigate STC2 in vitro effects on proliferation, apoptosis, migration, invasion, epithelial-mesenchymal transition (EMT) and possible activation of signaling pathways. Moreover, STC2 effects were assessed in vivo in a xenograft mouse cancer model. High expression of STC2 was significantly associated with poor disease-specific survival (HR: 2.67, 95% CI: 1.37–5.21, p = 0.001) and high rate of recurrence with a hazard ratio of 2.80 (95% CI: 1.07–5.71, p = 0.03). In vitro downregulation of STC2 expression in OSCC cells attenuated proliferation, migration and invasiveness while increased apoptotic rates. In addition, the STC2 downregulation controlled EMT phenotype of OSCC cells, with regulation on E-cadherin, vimentin, Snail1, Twist and Zeb2. The reactivation of STC2 was observed in the STC2 knockdown cells in the in vivo xenograft model, and no influence on tumor growth was observed. Modulation of STC2 expression levels did not alter consistently the phosphorylation status of CREB, ERK, JNK, p38, p70 S6K, STAT3, STAT5A/B and AKT. Our findings suggest that STC2 overexpression is an independent marker of OSCC outcome and may contribute to tumor progression via regulation of proliferation, survival and invasiveness of OSCC cells.

LncRNA MCM3AP-AS1 promotes the development of oral squamous cell carcinoma by inhibiting miR-363-5p.

The aim of the present study was to study the mechanism of the long non-coding (lnc)RNA MCM3AP-AS1 in the development of oral squamous cell carcinoma (OSCC). Patients with OSCC (n=36) volunteered to join the study, and their tumor/normal tissues were collected. MCM3AP-AS1 and microRNA (miR)-363-5p expression in tissues and cells was determined by reverse transcription-quantitative (RT-q)PCR. Following transfection, a CCK-8 assay and Transwell experiments were conducted to explore the effects of MCM3AP-AS1 on OSCC cell proliferation, migration and invasion. The interaction between MCM3AP-AS1 and miR-363-5p was detected by luciferase reporter gene assay. RT-qPCR analysis demonstrated significantly higher MCM3AP-AS1 expression in tumor tissues or OSCC cells compared with normal tissues or human oral keratinocytes cells (P<0.05). A high MCM3AP-AS1 level was associated with poor prognosis in OSCC patients (P<0.05 or P<0.01). Compared to the small interfering (si)-negative control (NC) group, OSCC cells of si-MCM3AP-AS1 group exhibited markedly lower optical density (at 450 nm) value and relative migration and invasion (P<0.05). miR-363-5p was directly inhibited by MCM3AP-AS1. OSCC cells of si-MCM3AP-AS1 + inhibitor-NC group exhibited clearly lower relative proliferation, migration and invasion compared with cells of si-NC + inhibitor-NC group and si-MCM3AP-AS1 + miR-363-5p inhibitor group (P<0.05). MCM3AP-AS1 promoted OSCC cells proliferation, migration and invasion by inhibiting miR-363-5p.

MiR-503-5p functions as an oncogene in oral squamous cell carcinoma by targeting Smad7.

Oral squamous cell carcinoma (OSCC) is a common oral malignancy. Previous studies indicated that the level of miR-503-5p was upregulated in OSCC tissues. However, the mechanism by which miR-503-5p regulates the proliferation and invasion of OSCC cells remains unclear. Therefore, this study aimed to investigate the role of miR-503-5p during the progression of OSCC. The level of miR-503-5p in Tca8113 cells was detected using RT-qPCR assay. In addition, CCK-8, transwell assays and flow cytometry assays were conducted to detect cell viability, migration, invasion and apoptosis, respectively. Meanwhile, the dual luciferase reporter assay was applied to explore the interaction between miR-503-5p and Smad7 in Tca8113 cells. Overexpression of miR-503-5p significantly promoted the proliferation, migration and invasion of Tca8113 cells, while downregulation of miR-503-5p markedly inhibited proliferation, migration and invasion of cells. In addition, knockdown of miR-503-5p obviously induced the apoptosis of Tca8113 cells via increasing the levels of Bax and cleaved caspase 3, and decreased the expression of Bcl-2. Moreover, SMAD family member 7 (Smad7) was identified as a direct binding target of miR-503-5p in Tca8113 cells. Overexpression of miR-503-5p significantly downregulated the levels of Smad7 and E-cadherin, but upregulated the levels of N-cadherin and MMP-9 in Tca8113 cells. These results indicated that miR-503-5p might act as an oncogene in OSCC cells by targeting Smad7. Therefore, miR-503-5p might act as a novel and potential therapeutic target for the treatment of OSCC.