Invasion Of Tongue Squamous Cell Carcinoma Cells Research Articles

LncRNA CCAT1 knockdown suppresses tongue squamous cell carcinoma progression by inhibiting the ubiquitination of PHLPP2.

Tongue squamous cell carcinoma (TSCC) is prevailing malignancy in the oral and maxillofacial region, characterized by its high frequency. LncRNA CCAT1 can promote tumorigenesis and progression in many cancers. Here, we investigated the regulatory mechanism by which CCAT1 influences growth and metastasis of TSCC. Levels of CCAT1, WTAP, TRIM46, PHLPP2, AKT, p-AKT, and Ki67 in TSCC tissues and cells were assessed utilizing qRT-PCR, Western blot and IHC. Cell proliferation, migration, and invasion were evaluated utilizing CCK8, colony formation, wound healing and transwell assays. Subcellular localization of CCAT1 was detected utilizing FISH assay. m6A level of CCAT1 was assessed using MeRIP. RNA immunoprecipitation (RIP), Co-immunoprecipitation (Co-IP) and RNA pull down elucidated binding relationship between molecules. Nude mouse tumorigenesis experiments were used to verify the TSCC regulatory function of CCAT1 in vivo. Metastatic pulmonary nodules were observed utilizing hematoxylin and eosin (HE) staining. CCAT1 silencing repressed TSCC cell proliferation, migration and invasion. Expression of CCAT1 was enhanced through N6-methyladenosine (m6A) modification of its RNA, facilitated by WTAP. Moreover, IGF2BP1 up-regulated CCAT1 expression by stabilizing its RNA transcript. CCAT1 bond to PHLPP2, inducing its ubiquitination and activating AKT signaling. CCAT1 mediated the ubiquitination and degradation of PHLPP2 by TRIM46, thereby promoting TSCC growth and metastasis. CCAT1/TRIM46/PHLPP2 axis regulated proliferation and invasion of TSCC cells, implying that CCAT1 would be a novel therapeutic target for TSCC patients.

Integrated bioinformatics analysis of SEMA3C in tongue squamous cell carcinoma using machine-learning strategies

Tongue squamous cell carcinoma (TSCC) is an aggressive oral cancer with a high incidence of metastasis and poor prognosis. We aim to identify and verify potential biomarkers for TSCC using bioinformatics analysis. To begin with, we examined clinical and RNA expression information of individuals with TSCC from the Gene Expression Omnibus (GEO) database. Differential expression analysis and functional analysis were conducted. Multiple machine-learning strategies were next employed to screen and determine the hub gene, and receiver operating characteristic (ROC) analysis was used to assess diagnostic value. Semaphorin3C (SEMA3C) was identified as a critical biomarker, presenting high diagnostic accuracy for TSCC. In the validation cohorts, SEMA3C exhibited high expression levels in TSCC. The high expression of SEMA3C was a poor prognostic factor in TSCC by the Kaplan–Meier curve. Based on the Gene Ontology (GO) analysis, SEMA3C was mapped in terms related to cell adhesion, positive regulation of JAK-STAT, positive regulation of stem cell maintenance, and positive regulation of NF-κB activity. Single-cell RNA sequencing (ScRNA-seq) analysis showed cells expressing SEMA3C were predominantly tumor cells. Then, we further verified that SEMA3C had high expression in TSCC clinical samples. In addition, the knockdown of SEMA3C suppressed the proliferation, migration, and invasion of TSCC cells in vitro. This study is the first to report the involvement of SEMA3C in TSCC, suggesting that upregulated SEMA3C could be a novel and critical potential biomarker for future predictive diagnostics, prevention, prognostic assessment, and personalized medical services in TSCC.

Microfibril-associated protein 2 is activated by POU class 2 homeobox 1 and promotes tumor growth and metastasis in tongue squamous cell carcinoma

Tongue squamous cell carcinoma (TSCC) represents the most frequent malignancy of the oral cavity, characterized by a high metastasis rate and poor prognosis. Microfibril-associated protein 2 (MFAP2), as an extracellular matrix protein, has been found to drive tumor progression. The function and underlying mechanism of MFAP2 in TSCC remain unknown. The expression levels of MFAP2 were analyzed in tissue samples from 30 TSCC patients by real time-polymerase chain reaction and western blot assays. Our results revealed that the expression of MFAP2 mRNA and protein was upregulated in TSCC tissue samples compared with that in the matched para-carcinoma tissue samples. By performing in vitro gain-of-function or loss-of-function experiments and in vivo mouse xenograft experiments, we found that overexpression of MFAP2 induced proliferation and promoted transition from G1 to S phase of TSCC cells. Stronger invasive and migratory capabilities were observed in MFAP2-overexpressing TSCC cells. In contrast, knockdown of MFAP2 exhibited anti-proliferative, apoptosis-promoting and pro-migratory roles in TSCC cells. Knockdown of MFAP2 significantly inhibited xenograft tumor growth. Mechanistically, POU class 2 homeobox 1 (POU2F1) was recruited to the region of MFAP2 promoter and upregulates the expression of MFAP2. Silencing of MFAP2 effectively blocked the proliferation, migration, and invasion of TSCC cells caused by POU2F1 overexpression. Our results indicate that the role of MFAP2 in TSCC may attribute to transcriptional regulation of POU2F1.

Hsa_circ_0081069 facilitates tongue squamous cell carcinoma progression by modulating MAP2K4 expression via miR-634.

It has been demonstrated that circular RNA (circRNA) is involved in the progression of tongue squamous cell carcinoma (TSCC). The aim of this study was to investigate the intrinsic mechanism of circ_0081069 in TSCC progression. The expression levels of circ_00081069, miR-634, and mitogen-activated protein kinase kinase 4 (MAP2K4) in TSCC tissues and cells were detected by quantitative real-time PCR (qRT-PCR). Cell counting kit 8 assay, Edu assay, and flow cytometry assay were used to detect cell proliferation and cell cycle distribution. Transwell assay was used to detect cell migration and invasion abilities. Western blot analysis was performed to detect theprotein expression. Dual-luciferase reporter assay was used to detect the targeting relationships of circ_0081069, miR-634 and MAP2K4. Immunohistochemical staining was used to measure MAP2K4-positive cells in tissues. The effect of circ_0081069 silencing on tumor formation in TSCC in vivo was explored by xenograft tumor assay. Circ_0081069 was highly expressed in TSCC tissues and cells. Silencing ofcirc_0081069 inhibited cell proliferation, cellcycle progress, cellmigration and invasionin vitro, as well as hindered tumor growth in vivo. Mechanistically, circ_0081069 targeted miR-634 to negatively regulate miR-634 expression, and inhibition of miR-634 was able to weaken the inhibitory effect of circ_0081069 knockdown on proliferation, migration, and invasion of TSCC cells. MiR-634 targeted MAP2K4 and negatively regulated MAP2K4 expression, and overexpression of miR-634 inhibited TSCC cell proliferation, migration, and invasion, while co-overexpression of MAP2K4 was able to reverse the effects of miR-634 in TSCC cells. Circ_0081069 is involved in the regulation of proliferation, cycle progress, migration, and invasion of TSCC cells through the miR-634/MAP2K4 axis and has the potential to serve as a diagnostic biomarker and therapeutic target.

Carbon Monoxide-Releasing Molecule-3 Suppresses the Malignant Biological Behavior of Tongue Squamous Cell Carcinoma via Regulating Keap1/Nrf2/HO-1 Signaling Pathway.

Carbon monoxide-releasing molecule-3 (CORM-3) is a water-soluble complex which has the ability to release carbon monoxide (CO). The study is aimed at investigating the epidemiological characters and effects of CORM-3 on tongue squamous cell carcinoma (TSCC) cells and the mechanisms involved. Firstly, CAL27 and SCC4 were treated with CORM-3 or iCORM-3. The proliferation, migration, and invasion of cells were separately evaluated by CCK-8, scratch assay, and transwell assay. We found that the optimal concentration of CORM-3 on the proliferation of CAL27 and SCC4 cells was 400 μM, and CORM-3 was significantly inhibited the proliferation, migration, and invasion of TSCC cells. Meanwhile, CORM-3 increased the protein expression of HO-1 detected by western blot. Short-hairpin RNAs (shRNAs) were constructed to manipulate the expression of HO-1 in CAL27 and SCC4 cells. Then, rescue assays were conducted to explore the reversion effect of shHO-1 on the CORM-3 function. Mechanistically, CORM-3 decreased the protein of Keap1 expression as well as increased Nrf2 expression. Upregulation of E-cadherin was observed, as well as the downregulation of N-cadherin expression significantly. The antitumor effect of CORM-3 was used to xenograft tumor in nude mice for further investigation in vivo, and the result showed that CORM-3 significantly suppressed tumor growth in xenograft nude mice. These data suggest that CORM-3 acts as a tumor suppressor by regulating the Keap1/Nrf2/HO-1 signaling pathway in TSCC, which provides a potential chemotherapeutic strategy for TSCC.

Cyclin-dependent kinase 5 promotes the growth of tongue squamous cell carcinoma through the microRNA 513c-5p/cell division cycle 25B pathway and is associated with a poor prognosis.

BackgroundThe objective of this study was to investigate the role and molecular mechanism of cyclin‐dependent kinase 5 (CDK5) in regulating the growth of tongue squamous cell carcinoma (TSCC).MethodsThe authors used multiple methods to detect the levels of CDK5 expression in samples of TSCC and to explore the relation between CDK5 expression and various clinicopathologic factors. In vivo and in vitro cell experiments were performed to detect the proliferation, invasion, and migration of TSCC cells with CDK5 knockdown or overexpression. These studies verified that CDK5 regulates the occurrence and development of TSCC cells through the microRNA 513c‐5p/cell division cycle 25B pathway.ResultsAn elevated level of CDK5 expression in TSCC tissues was identified as an independent risk factor affecting TSCC growth and patient prognosis. Patients who had TSCC with low levels of CDK5 expression had a higher survival rate than those with high levels. Knockdown of CDK5 reduced the proliferation, migration, and invasion of TSCC cells both in vitro and in vivo. In addition, the authors observed that CDK5 regulated the growth of TSCC through the microRNA 513c‐5p/cell division cycle C25B pathway.ConclusionsCDK5 functions as an oncogene in TSCC and might serve as a molecular marker for use in the diagnosis and treatment of TSCC.Lay Summary Tongue squamous cell carcinoma (TSCC) is 1 of the most common malignant tumors of the head and neck, and the survival rate of patients with tongue cancer has been very low.Therefore, it is important to study the molecular mechanism of TSCC progression to identify biomarkers that can be used to improve its clinical diagnosis and treatment.Cyclin‐dependent kinase 5 (CDK5) is an atypical member of the cyclin‐dependent kinase family and is involved in regulating the cell cycle.Changes in the cell cycle are of great significance for the occurrence and development of tumor cells; and, in recent years, increasing evidence has suggested that CDK5 exists in a disordered state in cancer cells.In this study, the authors demonstrate that CDK5 functions as an oncogene in TSCC and might serve as a molecular marker for use in the diagnosis and treatment of TSCC.

SNHG1/miR-194-5p/MTFR1 Axis Promotes TGFβ1-Induced EMT, Migration and Invasion of Tongue Squamous Cell Carcinoma Cells.

Tongue squamous cell carcinoma (TSCC) is a common malignancy with aggressive biological behaviors. Mitochondrial fission regulator 1 (MTFR1), is aberrantly expressed in head and neck squamous cell carcinoma (HNSC), but its role in TSCC remains unclear. We aimed to explore the role of MTFR1 in TSCC. The expression of long non-coding RNA small nucleolar RNA host gene 1 (SNHG1), microRNA-194-5p and MTFR1 in TSCC cells was measured by RT-qPCR. Luciferase reporter assay and RNA pull down assay were applied to confirm the binding capacity between miR-194-5p and SNHG1 (or MTFR1). TSCC cell invasion and migration were accessed by Transwell assays. The protein levels of MTFR1 and epithelial-mesenchymal transition (EMT) markers were examined by western blot. MTFR1 had high expression level in TSCC. MTFR1 knockdown inhibited transforming growth factor β1 (TGFβ1)-induced EMT, migration and invasion of TSCC cells in vitro. MiR-194-5p targeted MTFR1 and negatively regulated its expression. In addition, SNHG1 upregulated the expression of MTFR1 by binding with miR-194-5p. Importantly, SNHG1 promoted EMT, invasion and migration of TSCC cells by upregulating MTFR1. SNHG1/miR-194-5p/MTFR1 axis promotes TGFβ1-induced EMT, migration and invasion of cells in TSCC, which could be potential targets for treating TSCC patients.

Effect of miR-384-targeting LINC00491 on proliferation, migration and invasion of tongue squamous cell carcinoma cells


 
 
 
 Purpose: To investigate the effect of long-chain non-coding RNA LINC00491 (LncRNA LINC00491) on the proliferation, migration and invasion of tongue squamous cell carcinoma (TSCC) cells, and the underlying mechanism.
 Methods: Real-time quantitative polymerase chain reaction (qRT-PCR) was applied to determine the expressions of LINC00491 and micro-RNA-384 (miR-384). Furthermore, LINC00491 and miR-384 were transfected into CAL-27 cells, while cell cycle was analyzed using flow cytometry. Cell proliferation was determined by methyl thiazolyl diphenyl-tetrazolium (MTT) assay. Cell migration and invasion were evaluated using Transwell experiments. The relationship between LINC00491 and miR-384 was confirmed using double luciferase reporting assay, while protein expression levels of P21, Ki67, E- cadherin, N-cadherin, and vimentin were assayed with Western blotting.
 Results: The expression of LINC00491 increased in TSCC tissues (p < 0.05). The proportion of cells in G1-phase increased, while the proportion of cells in S-phase decreased (p < 0.05). There was decrease in cell survival, cell migration and cell invasion (p < 0.05). The protein expression levels of Ki67, N- cadherin, and vimentin were lowered, while those of P21, E-cadherin protein were increased (p < 0.05). Transfection of LINC00491 and miR- 384 reduced the proportion of cells in G1 phase, but increased the proportion of cells in S-phase (p < 0.05). Moreover, cell survival, migration and invasion were increased. The protein expressions of Ki67, N-cadherin, and vimentin rose, while those of P21 and E-cadherin decreased (p < 0.05).
 Conclusion: LINC00491 promotes the proliferation, migration and invasion of TSCC cells by inhibiting miR-384. This finding provides a potential target for the treatment of TSCC.
 
 
 

Circ_0000003 regulates glutamine metabolism and tumor progression of tongue squamous cell carcinoma via the miR‑330‑3p/GLS axis.

Various circular RNAs (circRNAs) have been shown to exert vital functions in tongue squamous cell carcinoma (TSCC). However, their roles in TSCC progression remain to be elucidated. This research aimed to investigate the role and mechanism of hsa_circ_0000003 (circ_0000003) in TSCC progression. Here, we found that circ_0000003 expression was upregulated in TSCC tissues and cell lines, and high circ_0000003 expression was correlated with advanced TNM stage, increased tumor size and poor patient survival. Circ_0000003 was revealed to facilitate cell proliferation, migration and invasion of TSCC cells. Mechanistically, we found that circ_0000003 acted as a competing endogenous RNA (ceRNA) that sponged miR-330-3p, thereby elevating glutaminase (GLS) expression. Accordingly, cell invasion, migration, glutamine consumption, α-ketoglutarate (α-KG) production and ATP production were significantly decreased by circ_0000003 knockdown in TSCC cells, and these effects were reversed by miR-330-3p inhibition. In conclusion, circ_0000003 facilitates TSCC cell proliferation, migration, invasion and glutamine catabolism by regulating the miR-330-3p/GLS pathway.

The effects of HBXIP on the biological functions of tongue squamous cell carcinoma cells and correlation with PI3K/Akt.

BackgroundTongue squamous cell carcinoma (TSCC) is the most malignant oral cancer, having a high mortality rate.MethodsThe effects of hepatitis B X-interacting protein (HBXIP) overexpression on the proliferation, migration, and invasion of TSCC cells were measured by micro-culture tetrazolium assay (MTT) assay, transwell assay and scratch test, respectively, and the effects of HBXIP mRNA overexpression on the protein expression levels of AKT, p-AKT, PI3K, p-PI3K and S100A4 were detected by western blotting.ResultsMTT assay showed that there were significantly more proliferating cells than in the experimental group. In the scratch test and transwell assay, the migration rate and the number of invading cells were remarkably greater in the experimental group. The expression levels of p-AKT, p-PI3K and S100A4 were increased in the experimental group after HBXIP overexpression.ConclusionsHBXIP mRNA overexpression can influence the proliferation, invasion, and migration of TSCC cells and promote their proliferation and migration by increasing the protein expression levels of p-AKT, p-PI3K and S100A4.

Elevated matrix metalloproteinase 7 expression promotes the proliferation, motility and metastasis of tongue squamous cell carcinoma

BackgroundMatrix metalloproteinase 7 (MMP7), as the smallest member of the matrix metalloproteinase family, has been verified to be implicated in cancer progression, especially metastasis. However, its expression pattern and function in tongue cancer is not clear.MethodsThe expression of MMP7 in human tongue squamous cell carcinoma (TSCC) specimens compared with their respective paired nontumour tissues by real-time PCR and immunohistochemical staining. The effect of MMP7 on the proliferation, apoptosis, migration, invasion of tongue cancer cells was tested in appropriate ways after MMP7 siRNA knockdown or overexpression. The effect of MMP7 on lymph node metastasis in vivo was analyzed using a high-metastasis orthotopic nude mouse tongue transplanted tumour model.ResultsWe found markedly elevated expression of MMP7 in human TSCC specimens compared with their respective paired nontumour tissues, and this high expression was correlated with the patients’ lymph node metastasis. Furthermore, the results of molecular functional assays confirmed that MMP7 promotes cell proliferation, migration and invasion of TSCC cells. Knockdown of MMP7 inhibited lymph nodes metastasis in vivo.ConclusionsMMP7 plays an oncogenic role in carcinogenesis and metastasis of tongue cancer, and may serve as a potential therapeutic target for tongue cancer.

MiR-222 targets VGLL4 to promote growth of tongue squamous cell carcinoma

We investigated whether regulation of VGLL4 by miR-222 affects proliferation, migration, invasion, and apoptosis in human tongue squamous cell carcinoma (TSCC) cells. Nanometer Magnetic beads were prepared to extract RNA in CAL27/human oral keratinocytes (HOK). Correlation between expression of miR-222 and VGLL4 in CAL27/human oral keratinocytes (HOK) was analyzed using RT-PCR and western blot. The cellular effects of miR-222/VGLL4 interactions were detected by cck8, transwell, and cell scratch assays, and flow cytometry after miR-222 was silenced or overexpressed in CAL27 cells. We assessed tumor growth in vivo, in a subcutaneous tumor model in mice, and assessed VGLL4 protein expression in tumors by immunohistochemistry. We found that miR-222 expression is higher in CAL27 cells than that in HOK cells. VGLL4 was highly expressed in HOK cells relative to CAL27 cells. When miR-222 was overexpressed, VGLL4 mRNA expression was reduced in CAL27 cells, and protein expression was reduced in the in vivo tumor model. Thus, miR-222 may down-regulate VGLL4 to promote proliferation, migration, and invasion of TSCC cells.

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

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

IRX5 promotes NF-κB signalling to increase proliferation, migration and invasion via OPN in tongue squamous cell carcinoma.

Iroquois homeobox gene 5 (Irx5) is a highly conserved member of the Iroquois homeobox gene family. Members of this family play distinct and overlapping roles in normal embryonic cell patterning and development of malignancies. In this study, we observed that IRX5 was abnormally abundant in tongue squamous cell carcinoma (TSCC) tissues and cell lines. We used gain‐ and loss‐of‐function methods to overexpress and knockdown IRX5 expression in the TSCC cell line CAL27. Our results elucidated that elevated levels of IRX5 promoted proliferation, migration and invasion of TSCC cells, whereas stable or transient knockdown of IRX5 expression suppressed TSCC cell proliferation, migration and invasion. As a transcription factor, IRX5 performed this function by targeting osteopontin (OPN) promoter and activating the NF‐κB pathway. Finally, studies in xenograft tumour model showed that IRX5 significantly enhanced OPN expression and promoted tumour growth. Taken together, our study elucidates a promotive effect of IRX5 in TSCC through the connection with OPN. These findings reveal the new molecular mechanism of TSCC, which may potentiate its use as a novel molecular therapy target for TSCC.

LINC00511 interacts with miR-765 and modulates tongue squamous cell carcinoma progression by targeting LAMC2.

Aimed at underlying the molecular regulatory mechanism and overall biological functions of LINC00511 in tongue squamous cell carcinoma (TSCC). The expression level of LINC00511 was examined by QRT-PCR. In particular, Tca-8113 cell line was selected for subsequent experiments, in which the expression level of LINC00511 was the most significant. Meanwhile, the effects of LINC00511 on cells proliferation, cell cycle distribution, and invasion of TSCC cells were explored using RNA knockdown tools with CCK-8, flow cytometry analysis, colony formation, and transwell assay. Further, bioinformatic analysis and the dual-luciferase reporter assay both were conducted to invalidate the ceRNAs regulatory mechanism of LINC00511 in TSCC. LINC00511 was obviously upregulated in TSCC tissues and cell lines. Moreover, it was found that LINC00511 served as a competing endogenous RNA (ceRNA) through sponging miR-765 and ultimately modulated the derepression of laminin subunit gamma 2 (LAMC2). The inhibitory effects of miR-765 on TSCC cells proliferation, invasion as well as cell cycle distribution can be restored by the ectopic overexpression of LINC00511. Additionally, the restored capacity of LINC00511 promoted the expression of LAMC2, which was a downstream target of miR-765 and can be negatively regulated by miR-765. A novel molecular axis of LINC00511/miR-765/LAMC2 was investigated to regulate the tumor development of TSCC. LINC00511 promoted the expression of LAMC2 via the ceRNA mechanism of sponging miR-765. The ceRNA regulatory network provided a novel understanding of TSCC pathogenesis and also shed light on exploiting the new field of lncRNA-directed therapy against TSCC.

MicroRNA‑509 acts as a tumor suppressor in tongue squamous cell carcinoma by targeting epidermal growth factor receptor.

Tongue squamous cell carcinoma (TSCC) is the most frequent type of oral carcinoma, and is characterized by high metastatic and growth capabilities. Previous studies have demonstrated that aberrantly expressed cancer-associated microRNAs (miRs) may be associated with tumorigenesis and tumor development in various types of cancer, including TSCC. miR-509 has been identified as a critical regulator in tumorigenesis and tumor development, via its tumor-suppressing actions in several types of human cancer. In the present study, miR-509 expression in TSCC tissues and cell lines was determined by reverse transcription-quantitative polymerase chain reaction. The effects of miR-509 on TSCC cell proliferation and invasion were evaluated via MTT and invasion assays, respectively. In addition, the direct target of miR-509 in TSCC was investigated. The present study demonstrated that miR-509 expression was downregulated in TSCC tissue samples and cell lines, whereas its ectopic expression suppressed TSCC cell proliferation and invasion in vitro. In addition, epidermal growth factor receptor (EGFR) was identified as a direct target gene of miR-509 in TSCC cells. EGFR downregulation was demonstrated to suppress the proliferation and invasion of TSCC cells, similar to miR-509 overexpression. Furthermore, EGFR was significantly upregulated in TSCC tissues, and the levels of miR-509 were revealed to be negatively correlated with EGFR expression in TSCC tissues. Following transfection with miR-509 mimics, signaling pathways downstream of EGFR appeared to be suppressed, as phosphorylated (p)-extracellular signal-regulated kinase and p-Akt were downregulated in TSCC cells. In conclusion, the results of the present study suggested that miR-509 may inhibit the proliferation and invasion of TSCC cells via directly targeting EGFR, thus suggesting that the miR-509/EGFR axis may have potential as a novel therapeutic target for the development of a treatment for patients with TSCC.

Mesenchymal stem cell-derived CCN2 promotes the proliferation, migration and invasion of human tongue squamous cell carcinoma cells.

Recent studies have demonstrated that mesenchymal stem cells (MSC) exhibit a tropism to tumors and form the tumor stroma. In addition, we found that MSC can secrete different types of factors. However, the involvement of MSC‐derived factors in human tongue squamous cell carcinoma (TSCC) growth has not been clearly addressed. The CCN family includes multifunctional signaling molecules that affect the initiation and development events of various tumors. In our study, we report that CCN2/connective tissue growth factor (CTGF) was the most highly induced among the CCN family members in MSC that were co‐cultured with TSCC cells. To evaluate the relationship between CCN2 and TSCC growth, we downregulated MSC‐derived CCN2 expression with shRNA targeting CCN2 and found that MSC‐secreted CCN2 promotes TSCC cell proliferation, migration and invasion. We also confirmed that MSC‐derived CCN2 partially accelerated tumor growth in vitro. Taken together, these results suggest that MSC‐derived CCN2 contributes to the promotion of proliferation, migration and invasion of TSCC cells and may be a possible therapy target in the future.

Nicotine may promote tongue squamous cell carcinoma progression by activating the Wnt/β-catenin and Wnt/PCP signaling pathways.

To investigate the effects and the possible underlying mechanisms of nicotine stimulation on tongue squamous cell carcinoma (TSCC) progression, a TSCC cell line Cal27 and 34 samples of paraffin-embedded TSCC were examined. Immunofluorescence, western blot analysis, and TOP/FOP flash, CCK-8, wound healing and Transwell invasion assays were used to evaluate Cal27 in response to nicotine stimulation. We also investigated expression levels of related proteins of Wnt/β-catenin and Wnt/PCP pathways in paraffin-embedded TSCC samples with or without a history of smoking by immunohistochemistry. Nicotine stimulation can promote proliferation, migration, and invasion of TSCC cells in vitro, downregulate E-cadherin, and activate the Wnt/β-catenin and Wnt/PCP pathways, which could be antagonized by the α7 nicotine acetylcholine receptor (α7 nAChR) inhibitor α-BTX. Moreover, the expression levels of β-catenin, Wnt5a and Ror2 were higher in TSCC patients with a history of smoking than those without a history of smoking. Our results suggest nicotine may promote tongue squamous carcinoma cells progression by activating the Wnt/β-catenin and Wnt/PCP signaling pathways and may play a significant role in the progression and metastasis of smoking-related TSCC.

Interleukin-17A promotes tongue squamous cell carcinoma metastasis through activating miR-23b/versican pathway

Interleukin-17A (IL-17A), a proinflammatory cytokine mainly produced by T helper 17 cells, exerts protumor or antitumor effects in different cancer entities. However, the exact role of IL-17A in carcinogenesis and progression of tongue squamous cell carcinoma (TSCC) remains unclear. Here, we found that the levels of IL-17A in serum and tumor samples were significantly increased in TSCC patients and positively correlated with tumor metastasis and clinical stage. Besides, IL-17A enhanced cell migration and invasion in SCC15, a TSCC cell line. Furthermore, IL-17A inversely correlated with miR-23b expression in TSCC specimens. In vitro, NF-κB inhibited miR-23b transcription by directly binding to its promoter region. IL-17A downregulated miR-23b expression via activating NF-κB signaling pathway characterized by increasing p65 expression in the nuclear and elevating the levels of p-IKKα and p-IκBα. Overexpression of miR-23b inhibited, whereas knockdown of miR-23b promoted migration and invasion abilities of SCC15 cells. Moreover, extracellular matrix protein versican was proved to be the direct target of miR-23b through luciferase assay. IL-17A increased versican levels in vitro and knockdown of versican by siRNA inhibited SCC15 cell migration and invasion. Taken together, these results reveal a novel mechanism that IL-17A in TSCC microenvironment promotes the migration and invasion of TSCC cells through targeting miR-23b/versican pathway.

MiR-24 promotes the proliferation, migration and invasion in human tongue squamous cell carcinoma by targeting FBXW7

Recent studies suggest that aberrant expression of miR-24 is linked to various human cancers, including tongue squamous cell carcinoma (TSCC). F-box and WD-40 domain protein7 (FBXW7), a tumor-suppressor gene, is responsible for the degradation of several proto-oncogenes. However, the function and mechanism of miR-24 and FBXW7 in TSCC remains unclear. In the present study, we found that miR-24 was increased in TSCC tissues and cell lines, and that upregulation of miR-24 was associated with advanced clinical stage and a shorter overall survival of TSCC patients. Inhibition of miR-24 significantly suppressed the proliferation, migration and invasion of TSCC cells invitro. Furthermore, miR-24 repressed FBXW7 expression by directly binding to the 3-untranslated region of FBXW7. Moreover, the suppression of FBXW7 increased the proliferation, migration and invasion of TSCC cells, and the restoration of FBXW7 substantially attenuated the oncogenic effects of miR-24. In conclusion, our results demonstrated that upregulation of miR-24 was associated with tumor progression and poor prognosis in TSCC patients, and that overexpression of miR-24 was correlated with the proliferation, migration and invasion of TSCC cells invitro, at least partially through regulation of its functional target FBXW7. Thus, miR-24 may serve as a novel potential biomarker for the prognosis of TSCC patients.