Migration Of Oral Squamous Cell Carcinoma Cells Research Articles

Ephrin A4-ephrin receptor A10 signaling promotes cell migration and spheroid formation by upregulating NANOG expression in oral squamous cell carcinoma cells

Ephrin type-A receptor 10 (EPHA10) has been implicated as a potential target for breast and prostate cancer therapy. However, its involvement in oral squamous cell carcinoma (OSCC) remains unclear. We demonstrated that EPHA10 supports in vivo tumor growth and lymphatic metastasis of OSCC cells. OSCC cell migration, epithelial mesenchymal transition (EMT), and sphere formation were found to be regulated by EPHA10, and EPHA10 was found to drive expression of some EMT- and stemness-associated transcription factors. Among EPHA10 ligands, exogenous ephrin A4 (EFNA4) induced the most OSCC cell migration and sphere formation, as well as up-regulation of SNAIL, NANOG, and OCT4. These effects were abolished by extracellular signal-regulated kinase (ERK) inhibition and NANOG knockdown. Also, EPHA10 was required for EFNA4-induced cell migration, sphere formation, and expression of NANOG and OCT4 mRNA. Our microarray dataset revealed that EFNA4 mRNA expression was associated with expression of NANOG and OCT4 mRNA, and OSCC patients showing high co-expression of EFNA4 with NANOG or OCT4 mRNA demonstrated poor recurrence-free survival rates. Targeting forward signaling of the EFNA4-EPHA10 axis may be a promising therapeutic approach for oral malignancies, and the combination of EFNA4 mRNA and downstream gene expression may be a useful prognostic biomarker for OSCC.

Knockdown of RABL3 suppresses the proliferation and invasion of oral squamous cell carcinoma through inactivating the FAK/AKT pathway.

Rab-like 3 (RABL3) is a member of Rab family that is related with several kinds of cancers. However, the functional roles of RABL3 in oral squamous cell carcinoma (OSCC) remain largely unknown. In the current study, we examined the expression levels of RABL3 in OSCC tissues and cell lines. The results showed that RABL3 expression was markedly increased in OSCC tissues and cell lines. Knockdown of RABL3 significantly suppressed the proliferation, migration and invasion of OSCC cells. Overexpression of RABL3 exhibited opposite effects with RABL3 knockdown. In vivo assay demonstrated that knockdown of RABL3 suppressed the tumorigenesis of OSCC. Moreover, RABL3 regulated the activation of focal adhesion kinase (FAK)/protein kinase B (Akt) signaling pathway in OSCC cells. Inhibition of FAK reversed the effects of RABL3 overexpression on cell proliferation, migration and invasion of OSCC cells. In conclusion, these findings demonstrated that RABL3 acted as an oncogene in OSCC, which was attributed to the regulation of FAK/Akt pathway. Thus, RABL3 may be potential therapeutic target for the treatment of OSCC.

Knockdown of RhoC Inhibits Oral Squamous Cell Carcinoma Cell Invasion and Metastasis via Regulation of HMGA2.

Ras homolog family member C (RhoC) is an important component of intracellular signal transduction and its overexpression has been reported to be involved in regulating tumor proliferation, invasion, and metastasis in various malignant tumors. However, its role and underlying mechanism in oral squamous cell carcinoma (OSCC) still remain obscure. In our study, RhoC expression, its relation with clinical stages, and survival rate in OSCC were analyzed using datasets from The Cancer Genome Atlas (TCGA). Next, a RhoC knockdown cell model was established in vitro, and the effects of RhoC knockdown in OSCC cells were detected by the MTT assay, colony formation assay, transwell invasion assay, scratch assay, and F-actin phalloidin staining. An in vivo tongue-xenografted nude mouse model was established to measure the effects of knockdown of RhoC on tumor cell growth and lymph node metastasis. A mechanism study was conducted by real-time PCR and immunocytochemistry. The results of TCGA analysis showed that RhoC was overexpressed in OSCC tumor tissues. In vitro assays indicated that knockdown of RhoC did not have much effect on OSCC cell growth but significantly suppressed cell colony formation, invasion, and migration abilities, and F-actin polymerization was also reduced. The tongue-xenografted in vivo model demonstrated that knockdown of RhoC suppressed OSCC cell growth and inhibited metastasis to the superficial cervical lymph nodes. Further mechanism studies showed that knockdown of RhoC downregulated HMGA2 expression, and HMGA2 expression was highly correlated with RhoC expression in OSCC tumor tissues via the analysis of TCGA datasets. Overall, our study showed that knockdown of RhoC inhibited OSCC cells invasion and migration in vitro and OSCC cell growth and lymph node metastasis in vivo. Moreover, the potential mechanisms involved in these activities may be related to the regulation of HMGA2 expression. The RhoC gene could serve as a promising therapeutic target for OSCCs in the future.

Semaphorin 4A restricts tumor progression by inhibiting angiogenesis of oral squamous cell carcinoma cells

ObjectiveTo investigate the effects of Semaphorin 4A (Sema4A) on the angiogenesis, migration and invasion of oral squamous cell carcinoma (OSCC) cells. MethodsSema4A expression in OSCC patients was detected by Immunohistochemistry, and its relationship with clinicopathological features and prognosis of patients was analyzed. The mRNA and protein expression of Sema4A in primary human oral keratinocytes (HOKs) and OSCC cells (SCC-25, HSC-3, CAL-27) were determined by Western blotting and qRT-PCR. After HOKs, HSC-3 cells and SCC-25 cells transfected with Control/Sema4A CRISPR activation plasmid, the migration and invasion abilities were detected by Wound healing and Transwell invasion. Tube formation assay was also performed on endothelial cells and the contents of VEGF and bFGF were quantified using qRT-PCR and ELISA. ResultsCytoplasmic Sema4A expression was related to T classification, clinical stage and nodal metastasis of OSCC patients. Patients with low cytoplasmic Sema4A expression showed the higher microvessel density (MVD) and the poorer prognosis in OSCC. Compared with HOK, OSCC cells (SCC-25, HSC-3, CAL-27) declined apparently in Sema4A expression, which was much more significant in metastatic HSC-3 and SCC-25 cells. After HOKs, HSC-3 cells and SCC-25 cells transfected with Sema4A over-expression plasmid, the invasion and migration abilities were decreased. Besides, overexpression of Sema4A could significantly inhibit the tube formation of HUVEC induced by OSCC cells with reductions of angiogenic factors (VEGF and bFGF). ConclusionOver-expression of Sema4A could restrict tumor progression through inhibiting the angiogenesis, invasion and migration of OSCC cells.

Long non-coding RNA CASC9 promotes tumor progression in oral squamous cell carcinoma by regulating microRNA-545-3p/laminin subunit gamma 2

ABSTRACT Long non-coding RNA (lncRNA) CASC9 is reported to be a tumor promoter in oral cancer, but its mechanism in oral squamous cell carcinoma (OSCC) has not been fully explored. Our study aimed to identify the interaction between lncRNA CASC9, microRNA-545-3p (miR-545-3p), and laminin subunit gamma 2 (LAMC2) in OSCC cells. Our study confirmed that lncRNA CASC9 and LAMC2 were upregulated in OSCC, whereas miR-545-3p expression was reduced. After performing a series of cell functional experiments, it was found that knockdown of lncRNA CASC9 or LAMC2 resulted in the inhibition of proliferation, colony formation, and migration of OSCC cells, but their negative effects could be partly impaired by the miR-545-3p inhibitor. In addition, we proved for the first time that lncRNA CASC9 can sponge miR-545-3p to upregulate LAMC2. In conclusion, our study revealed that lncRNA CASC9 promotes the malignancy of OSCC cells by sponging miR-545-3p to enhance LAMC2 expression, implying that lncRNA CASC9/miR-545-3p/LAMC2 may be an intervention approach in OSCC therapy.

Downregulated hsa_circ_0036988 promotes proliferation and metastasis in oral squamous cell carcinoma.

As a novel class of endogenous ncRNAs, Circular RNAs (circRNAs) have been verified to be involved in the carcinogenesis and tumor progression. This study aimed to investigate the potential function of a candidate circRNA hsa_circ_0036988 in oral squamous cell carcinoma (OSCC). The altered expression of hsa_circ_0036988 was validated by quantitative real-time polymerase chain reaction (qRT-PCR) in OSCC samples and OSCC cell lines. The associations between the levels of hsa_circ_0036988 and the clinicopathological features were statistically analysed. The function of hsa_circ_0036988 in OSCC were evaluated via a series of in vitro experiments by using constructed plasmids or siRNA. Western blotting assays were conducted to evaluate changes in protein expression levels. Hsa_circ_0036988 was significantly downregulated in OSCC tissues compared with adjacent normal tissues. While low expression of hsa_circ_0036988 was highly correlated with lymph nodes metastasis. Overexpression or knockdown of hsa_circ_0036988 significantly affected the proliferation, migration and invasion of OSCC cells. Furthermore, the altered expression of hsa_circ_0036988 have an impact on the epithelial-to-mesenchymal transition (EMT)-related protein expression levels. Our findings indicated that hsa_circ_0036988 may affect cell proliferation, migration and invasion by regulating EMT progress, which might provide a therapeutic strategy for the treatment of OSCC.

Long non-coding RNA LINC01207 promotes cell proliferation and migration but suppresses apoptosis and autophagy in oral squamous cell carcinoma by the microRNA-1301-3p/lactate dehydrogenase isoform A axis

ABSTRACT Long noncoding RNAs (lncRNAs) have been reported to participate in the progression of various cancers, including oral squamous cell carcinoma (OSCC). This study aims to find out whether lncRNA LINC01207 regulates the progression of OSCC. Reverse transcription quantitative polymerase chain reaction (RT-qPCR) was conducted to evaluate gene expression in OSCC cells and tissues. Cell viability, proliferation, migration, apoptosis, and autophagy were detected using Cell Counting Kit-8 (CCK-8), colony formation, Transwell assays, flow cytometry, and western blot analysis. Luciferase reporter and RNA immunoprecipitation (RIP) assays were conducted to assess the interactions among genes. We found that LINC01207 was overexpressed in OSCC cells and tissues. LINC01207 silencing inhibited OSCC cell proliferation and migration but promoted apoptosis and autophagy, and LINC01207 overexpression had an opposite result. LINC01207 interacted with microRNA-1301-3p (miR-1301-3p) while lactate dehydrogenase isoform A (LHDA) was targeted by miR1301-3p. Effects caused by LINC01207 downregulation on OSCC cells were reversed by overexpression of LDHA. Overall, LINC01207 promotes OSCC progression via the miR-1301-3p/LDHA axis

LINC00662 Promotes Oral Squamous Cell Carcinoma Cell Growth and Metastasis through miR-144-3p/EZH2 Axis.

PurposeLong non-coding RNA (lncRNA) is identified as an important regulator involved in oral squamous cell carcinoma (OSCC) tumorigenesis. This study aimed to investigate the functional role and underlying mechanism of LINC00662 in OSCC.Materials and MethodsThe expression levels of LINC00662, miR-144-3p, and enhancer of zeste homolog 2 (EZH2) mRNA were quantified with quantitative real-time polymerase chain reaction in OSCC tissues and cell lines. Western blot analysis was used to assay the expression levels of E-cadherin, Vimentin, and EZH2. Cell proliferation, migration, and invasion were monitored by cell counting kit-8 and Transwell assays. Dual-luciferase reporter and RNA immunoprecipitation assays were employed to verify the regulatory relationship between LINC00662 and miR-144-3p.ResultsThe expression of LINC00662, positively associated with the increased TNM stage and lymph node metastasis of the patients, was up-regulated in OSCC tissues and cells. The overexpression of LINC00662 facilitated the proliferation, migration, and invasion of OSCC cells. MiR-144-3p could bind to LINC00662, and the promoting effect of LINC00662 overexpression was counteracted by miR-144-3p mimic. Moreover, EZH2 expression was negatively regulated by miR-144-3p and positively regulated by LINC00662. The silencing of EZH2 attenuated the promoting effects of overexpression of LINC00662 on cell proliferation, migration, invasion, and epithelial-mesenchymal transition.ConclusionLINC00662, as an oncogenic lncRNA of OSCC, accelerates OSCC progression by repressing miR-144-3p expression and increasing EZH2 expression.

Exosome-derived long non-coding RNA ADAMTS9-AS2 suppresses progression of oral submucous fibrosis via AKT signalling pathway.

Oral submucosal fibrosis (OSF) is one of the pre‐cancerous lesions of oral squamous cell carcinoma (OSCC). Its malignant rate is increasing, but the mechanism of malignancy is not clear. We previously have elucidated the long non‐coding RNA (lncRNA) expression profile during OSF progression at the genome‐wide level. However, the role of lncRNA ADAMTS9‐AS2 in OSF progression via extracellular communication remains unclear. lncRNA ADAMTS9‐AS2 is down‐regulated in OSCC tissues compared with OSF and normal mucous tissues. Low ADAMTS9‐AS2 expression is associated with poor overall survival. ADAMTS9‐AS2 is frequently methylated in OSCC tissues, but not in normal oral mucous and OSF tissues, suggesting tumour‐specific methylation. Functional studies reveal that exosomal ADAMTS9‐AS2 suppresses OSCC cell growth, migration and invasion in vitro. Mechanistically, exosomal ADAMTS9‐AS2 inhibits AKT signalling pathway and regulates epithelial‐mesenchymal transition markers. Through profiling miRNA expression profile regulated by exosomal ADAMTS9‐AS2, significantly enriched pathways include metabolic pathway, PI3K‐Akt signalling pathway and pathways in cancer, indicating that exosomal ADAMTS9‐AS2 exerts its functions through interacting with miRNAs during OSF progression. Thus, our findings highlight the crucial role of ADAMTS9‐AS2 in the cell microenvironment during OSF carcinogenesis, which is expected to become a marker for early diagnosis of OSCC.

Palbociclib induces DNA damage and inhibits DNA repair to induce cellular senescence and apoptosis in oral squamous cell carcinoma

Palbociclib is an FDA-approved cyclin-dependent kinase (CDK) 4/6 inhibitor that has been clinically proven to be effective in breast cancer. However, its use in oral cancer is not well researched. In this study, we investigated the inhibitory activity of palbociclib against oral squamous cell carcinoma (OSCC) cells and explored the mechanism of inhibition. The effects of palbociclib on the cytotoxicity of OSCC cells were determined by MTT and colony formation assays. β-Galactosidase staining and cell-cycle analysis were used to determine palbociclib-induced cellular senescence and apoptosis of OSCC cells. Wound healing and transwell assays were performed to assess the effects of palbociclib treatment on migration and invasion ability of OSCC cells. Whole transcriptome sequencing was conducted to show the relationship between DNA damage repair of OSCC cells and palbociclib treatment. Palbociclib-induced DNA damage and repair capacity of OSCC cells were confirmed by comet assay and immunofluorescence confocal microscopy. Western blotting was used to verify the palbociclib-mediated changes in the CDK/pRB/c-Myc/CDC25A pathway. Finally, invitro findings were tested in a mouse xenograft model. Our results showed that palbociclib can significantly inhibit the growth, migration, and invasive ability of OSCC cells and can accelerate cellular senescence and apoptosis. We found that palbociclib induced DNA damage and p21 expression through the p53-independent pathway, thereby downregulating c-Myc and CDC25A expression to inhibit cell cycle progression. In addition, palbociclib downregulated RAD51 expression to inhibit DNA damage repair ability of OSCC cell. Palbociclib was found to have anti-oral squamous cell carcinoma activity and to simultaneously induce DNA damage and inhibit its repair, and to accelerated cellular senescence and apoptosis.

MiR-770 promotes oral squamous cell carcinoma migration and invasion by regulating the Sirt7/Smad4 pathway.

Oral squamous cell carcinoma (OSCC) is a common malignant cancer with unfavorable prognosis, and the epithelial-to-mesenchymal transition (EMT) is a critical contributor to OSCC metastasis. Recently, we have shown that sirtuin 7 (Sirt7) is associated with EMT and OSCC metastasis by acetylating small mother against decapentaplegic 4 (Smad4). Nonetheless, the mechanism of Sirt7 downregulation in OSCC cells remains unknown. This study analyzed the potential microRNAs that were predicted to regulate Sirt7 expression by online databases. We identified miR-770 as an upstream regulator of Sirt7 that targets its 3'-untranslated region. The expression of miR-770 was observed to be negatively correlated with the mRNA expression of Sirt7 in metastatic OSCC tumors, and higher miR-770 expression was correlated with poorer OSCC patient survival. Our in vitro data indicated that miR-770 promoted OSCC cell migration and invasion, and this process was dependent on Sirt7/Smad4 signaling. Furthermore, in vivo metastasis experiments indicated that miR-770 overexpression led to more prominent OSCC metastasis and downregulated Sirt7 expression. Collectively, our results revealed a new role of Sirt7 downregulation in metastatic OSCC and suggested that miR-770 is a potential target in counteracting OSCC metastasis.

Suppression of miR-886-3p mediated by arecoline (ARE) contributes to the progression of oral squamous cell carcinoma

Previous studies have reported that as the main extract of areca nut, arecoline (ARE) causes DNA damage and in turn contributes to the carcinogenesis of oral epithelial cells. It has...

Melatonin Inhibits the Progression of Oral Squamous Cell Carcinoma via Inducing miR-25-5p Expression by Directly Targeting NEDD9.

Melatonin exerts anti-cancer roles in various types of cancers. However, to the best of our knowledge, its role in oral squamous cell carcinoma (OSCC) is unknown. The present study aimed to investigate the role of melatonin and its underlying mechanism in OSCC. MTT, colony formation, wound healing, and transwell invasion assays proved that melatonin played anti-tumor effects in OSCC cells by inhibiting cell viability, proliferation, migration, and invasion in a concentration-dependent manner. The RT-qPCR analysis showed that miR-25-5p was significantly upregulated after melatonin treatment. Further, miR-25-5p might be involved in melatonin-induced inhibitory effects on the biological behavior of OSCC. The expression of miR-25-5p was decreased in tumor tissues and OSCC cells detected by RT-qPCR. MTT assay, colony formation assay, and TUNEL staining indicated miR-25-5p overexpression inhibited OSCC cell viability, proliferation, and induced OSCC cell apoptosis. Furthermore, wound healing, transwell invasion assay, and animal experiments suggested that miR-25-5p might exert suppressive effects on the migration, invasion, and tumor formation of OSCC cells, while miR-25-5p knockdown exhibited the opposite effects in OSCC cells. Bioinformatics analysis, western blot analysis, and luciferase reporter assay suggested that neural precursor cell expressed developmentally downregulated protein 9 (NEDD9) was proved to be a putative target for miR-25-5p. The role of NEDD9 in inhibiting OSCC cell proliferation, invasion, and migration was verified with NEDD9 siRNA transfection. Thus, melatonin exerted anti-proliferative, anti-invasive, and anti-migrative effects on OSCC via miR-25-5p/NEDD9 pathway. Melatonin could be applied as a potential novel drug on treating OSCC.

PRKD3 promotes malignant progression of OSCC by downregulating KLF16 expression.

We aimed to clarify the molecular mechanism of how PRKD3 promotes the malignant progression of oral squamous cell carcinoma (OSCC). 62 cases of OSCC tissues and normal adjacent ones which were further confirmed by a qualified pathologist were collected from patients in the Department of Pathology and Stomatology of our hospital. PRKD3 expression in the above tissue samples was studied by quantitative real-time polymerase chain reaction (qRT-PCR) analysis, and its relationship with clinicopathological characteristics of these OSCC patients was analyzed. Meanwhile, a PRKD3 knockdown expression model was constructed in OSCC cell lines for cell functional experiments. The relationship between PRKD3 and KLF16 was elucidated through bioinformatics and Luciferase reporter gene experiments. Our data showed that PRKD3 expression in OSCC specimens was remarkably higher than that in adjacent ones. PRKD3 expression showed positive association with the incidence of distant metastasis, but not with other clinical indicators such as gender, age, tumor stage or lymph node metastasis incidence. Patients with high PRKD3 expression had lower overall survival compared to those with low expression. In addition, OSCC cells migration ability and invasiveness were remarkably attenuated after PRKD3 was knocked down. Bioinformatics and Luciferase assay revealed that PRKD3 could directly bind to KLF16 and Western blot suggested that KLF16 was upregulated after PRKD3 was knocked down. In addition, knocking down KLF16 reversed the inhibitory effect of PRKD3 knockdown on invasiveness and metastasis of OSCC cells. The highly-expressed PRKD3, remarkably associated with metastasis incidence and poor prognosis of OSCC patients, may accelerate the malignant progression of OSCC through modulating KLF16 expression.

LncRNA JPX overexpressed in oral squamous cell carcinoma drives malignancy via miR-944/CDH2 axis.

Oral squamous cell carcinoma (OSCC) is a common head and neck cancer with high incidence. Numerous reports have elucidated that long non-coding RNAs (lncRNAs) serve as crucial regulatory factors in various diseases including cancer. Nonetheless, the role of lncRNA JPX in OSCC is still not elaborated. In our research, we detected the expression of lncRNA JPX through qRT-PCR. Colony formation, EdU staining, Transwell, TUNEL, and caspase-3 activity assays were applied for estimating the function of lncRNA JPX in OSCC. RIP, pull-down, and luciferase reporter experiments were adopted to examine the interrelations between lncRNA JPX, miR-944, and CDH2. LncRNA JPX was discovered as highly expressed in OSCC cells. Silencing lncRNA JPX restrained OSCC cell proliferation, migration, and invasion. Interestingly, lncRNA JPX bound with miR-944 and then augmented CDH2 via a competing endogenous RNA (ceRNA) mechanism. Importantly, overexpressed CDH2 recovered the suppression of silenced lncRNA JPX on the oncogenic behaviors of OSCC cells. In short, lncRNA JPX contributes to OSCC cell proliferation, migration, and invasion via miR-944/CDH2 axis, which offers a new direction for potential targeted treatment of OSCC.

MiR-146a Overexpression in Oral Squamous Cell Carcinoma Potentiates Cancer Cell Migration and Invasion Possibly via Targeting HTT

Huntingtin (HTT) is one of the target genes of miR-146-a and regulates various cancer cell activities. This study aims to explore the miR-146a expression pattern in oral squamous cell carcinoma (OSCC) and its role and mechanism in OSCC progression and metastasis via targeting the HTT gene. OSCC tissue and non-cancerous matched tissue (NCMT) were obtained from 14 patients. OSCC cell lines and normal HOK cells were used to analyze migration and invasion assay. OSCC-induced miR-146a knockout mice (B6.Cg-Mir146tm1.1Bal) model was developed. Transwell cell migration/invasion and scratch wound assays were used to investigate the OSCC cell migration and invasion in vitro. Kaplan-Meier survival analysis was used to investigate the association of HTT expression patterns in cancer tissue with patient survival percentage and duration. Pearson’s correlation analysis tested the association between miR-146a and HTT expression in OSCC tissues. miR-146a mimic and inhibitor transfection were performed to overexpress and knockdown the miR-146a in OSCC cells, respectively. miR-146a expression was highly upregulated in OSCC tissues and OSCC cell lines. Cancer cell migration/invasion was enhanced in miR-146a overexpressed cells and reduced in mi-R146a knockdowned cells. HTT expression was reduced in OSCC tissues and cell lines compared to NCMT and HOK cells, respectively. HTT expression was downregulated in miR-146a overexpressed OSCC cells and upregulated in miR-146a knockdowned OSCC cells. The expression pattern of miR-146a in OSCC cell lines and tissues was inversely correlated with HTT expression. Prediction of miRNA target analysis showed that HTT possesses the binding sites for miR-146a. HTT overexpression in OSCC tissues was associated with patients’ higher survival percentage and duration. HTT knockdown in OSCC cells enhanced miR-146a expression and cell migration/invasion. Inducing OSCC in miR-146a knockout mice increased the HTT expression in tongue tissue and alleviated the cancer aggressiveness and epithelial damage. Overexpressed miR-146a in OSCC targets the HTT gene and enhances cancer cell migration/invasion unraveling the possible role of HTT in miR146a-mediated OSCC cell migration and invasion.

Deregulation of lysophosphatidic acid metabolism in oral cancer promotes cell migration via the up-regulation of COX-2.

Oral squamous cell carcinoma (OSCC) is the sixth most common cancer worldwide and accounts for 300,000 new cases yearly. The five-year survival rate is approximately 50% and the major challenges to improving patient prognosis include late presentation, treatment resistance, second primary tumours and the lack of targeted therapies. Therefore, there is a compelling need to develop novel therapeutic strategies. In this study, we have examined the effect of lysophosphatidic acid (LPA) on OSCC cell migration, invasion and response to radiation, and investigated the contribution of cyclooxygenase-2 (COX-2) in mediating the tumour promoting effects of LPA. Using the TCGA data set, we show that the expression of the lipid phosphate phosphatases (LPP), LPP1 and LPP3, was significantly down-regulated in OSCC tissues. There was no significant difference in the expression of the ENPP2 gene, which encodes for the enzyme autotaxin (ATX) that produces LPA, between OSCCs and control tissues but ENPP2 levels were elevated in a subgroup of OSCCs. To explore the phenotypic effects of LPA, we treated OSCC cell lines with LPA and showed that the lipid enhanced migration and invasion as well as suppressed the response of the cells to irradiation. We also show that LPA increased COX-2 mRNA and protein levels in OSCC cell lines and inhibition of COX-2 activity with the COX-2 inhibitor, NS398, attenuated LPA-induced OSCC cell migration. Collectively, our data show for the first time that COX-2 mediates some of the pro-tumorigenic effects of LPA in OSCC and identifies the ATX-LPP-LPA-COX-2 pathway as a potential therapeutic target for this disease.

LncRNA XIST Inhibits the Progression of Oral Squamous Cell Carcinoma via Sponging miR-455-3p/BTG2 Axis.

ObjectiveOral squamous cell carcinoma (OSCC) is one of the most common cancers, accounting for over 90% of malignant lesions in the oral cavity. Long non-coding RNAs play an important role in the development of OSCC. This study aimed to investigate the effects of lncRNA XIST on the malignant behaviors of OSCC cells and its possible molecular mechanisms.MethodsReal-time quantitative PCR and Western blot were used to detect the RNA and protein level, respectively. CAL27 and SCC25 cells with the lowest expression level of XIST were used for further study. MTT, transwell assay, colony formation, and xenograft model were applied to examine the effect of XIST on the progression of OSCC. FISH assay was performed to investigate the co-location of XIST and miR-455-3p in OSCC cells. The bioinformatics analysis, luciferase, and RNA pull down assay were utilized to predict and verify the target genes of miR-455-3p.ResultsXIST was downregulated in OSCC tissues and cell lines. Overexpression of XIST inhibited the proliferation, migration, and invasion ability of OSCC cells. Bioinformatics analysis and luciferase reporter assay confirmed XIST could bind to miR-455-3p. Besides, miR-455-3p directly targeted BTG2 in OSCC cells. Rescue experiments further confirmed the positive interaction between miR-455-3p and XIST as well as between miR-455-3p and BTG2.ConclusionXIST was down-regulated in OSCC. XIST regulated the expression of BTG2 via sponging miR-455-3p. XIST/miR-455-3p/BTG2 signal axis inhibited the malignant progression of OSCC.

Role of miR-218-GREM1 axis in epithelial-mesenchymal transition of oral squamous cell carcinoma: An in vivo and vitro study based on microarray data.

Oral squamous cell carcinoma (OSCC) is a prevalent cancer that develops in the head and neck area and has high annual mortality despite optimal treatment. microRNA‐218 (miR‐218) is a tumour inhibiting non‐coding RNA that has been reported to suppress the cell proliferation and invasion in various cancers. Thus, our study aims to determine the mechanism underlying the inhibitory role of miR‐218 in OSCC. We conducted a bioinformatics analysis to screen differentially expressed genes in OSCC and their potential upstream miRNAs. After collection of surgical OSCC tissues, we detected GREM1 expression by immunohistochemistry, RT‐qPCR and Western blot analysis, and miR‐218 expression by RT‐qPCR. The target relationship between miR‐218 and GREM1 was assessed by dual‐luciferase reporter gene assay. After loss‐ and gain‐of‐function experiments, OSCC cell proliferation, migration and invasion were determined by MTT assay, scratch test and Transwell assay, respectively. Expression of TGF‐β1, Smad4, p21, E‐cadherin, Vimentin and Snail was measured by RT‐qPCR and Western blot analysis. Finally, effects of miR‐218 and GREM1 on tumour formation and liver metastasis were evaluated in xenograft tumour‐bearing nude mice. GREM1 was up‐regulated, and miR‐218 was down‐regulated in OSCC tissues, and GREM1 was confirmed to be the target gene of miR‐218. Furthermore, after up‐regulating miR‐218 or silencing GREM1, OSCC cell proliferation, migration and invasion were reduced. In addition, expression of TGF‐β signalling pathway‐related genes was diminished by overexpressing miR‐218 or down‐regulating GREM1. Finally, up‐regulated miR‐218 or down‐regulated GREM1 reduced tumour growth and liver metastasis in vivo. Taken together, our findings suggest that the overexpression of miR‐218 may inhibit OSCC progression by inactivating the GREM1‐dependent TGF‐β signalling pathway.

SNHG3/miR-2682-5p/HOXB8 promotes cell proliferation and migration in oral squamous cell carcinoma.

The potential molecular mechanism underlying the disease progression of oral squamous cell carcinoma (OSCC) remains largely elusive. The purpose of the study is to figure out the role and molecular mechanism of homeobox B8 (HOXB8) in OSCC. The expression level of HOXB8 in OSCC was validated by RT-qPCR. The functions of HOXB8 in OSCC cells were identified through loss-of-function assays, including CCK-8 assay, colony formation assay, transwell assay, and immunofluorescence (IF). The upstream miRNA that could directly target HOXB8 was searched out through bioinformatics analysis and luciferase reporter assay. Mechanism experiments were further conducted to predict the long non-coding RNA (lncRNA) that could positively regulate HOXB8 and compete for miR-2682-5p with HOXB8. HOXB8 was markedly upregulated in OSCC tissues and cell lines. Furthermore, cell proliferation and migration were inhibited due to the shortage of HOXB8. HOXB8 was targeted by miR-2682-5p that negatively regulated cell proliferation and migration. Small nucleolar RNA host gene 3 (SNHG3) acted as a sponge for miR-2682-5p. Inhibition of miR-2682-5p or the overexpression of HOXB8 rescued the effects of SNHG3 silencing on the proliferation and migration. HOXB8 is regulated by SNHG3/miR-2682-5p axis to promote OSCC cell proliferation and migration.