Development Of Tongue Squamous Cell Carcinoma Research Articles

Overexpression of circFNDC3B promotes the progression of oral tongue squamous cell carcinoma through the miR‐1322/MED1 axis

The potential role of circFNDC3B in regulating oral tongue squamous cell carcinoma development (OTSCC) remains unknown. The level of circFNDC3B in OTSCC tissues or cell lines was measured and its function in vitro and in vivo was analyzed. Interactions among circFNDC3B, miR-1322, and MED1 were verified by luciferase reporter and RNA pull-down assays. The level of circFNDC3B in tissues or cell lines of OTSCC was higher than that in control groups. siRNA-mediated circFNDC3B inhibition resulted in weakened proliferation, migration, and invasion, which was reversed by miR-1322. Overexpression of MED1 in OTSCC cells partially reversed the tumor suppression functions of si-circFNDC3B or miR-1322 mimics in vitro. circFNDC3B overexpression dramatically promoted tumor growth in vivo. circFNDC3B directly bound with miR-1322 and consequently promoted the MED1 expression in OTSCC cells. The circFNDC3B/miR-1322/MED1 axis participates in OTSCC progression, which may provide novel therapeutic targets for OTSCC.

Microbial community alteration in tongue squamous cell carcinoma.

Tongue squamous cell carcinoma (TSCC) is the most common oral cavity malignancy. The role of the microbial community in TSCC development and progression is unclear. In the present study, 23 patients with TSCC were recruited. Tissue DNA was extracted from cancer and paracancerous normal tissues from all participants. Next-generation 16S rDNA amplicon sequencing and functional prediction were applied for taxonomic analysis. Alpha diversity measurements using the Shannon and Simpson diversity indexes indicated a significant increase in the microbiotic diversity of cancer samples (Shannon index: P = 0.001, Simpson index: P = 0.015); otherwise, no differences were found when using observed operational taxonomic units (OTUs) and Chao1 index (observed OTUs: P = 0.261, Chao1 index: P = 0.054). The dominant phyla of the microbiota included Bacteroidetes, Proteobacteria, Firmicutes, Actinobacteria, and Fusobacteria. Multivariate analysis of variance (Adonis) and nonparametric analysis of similarities (ANOSIM) based on unweighted unifrac distances demonstrated differences in the bacterial community structure between the two groups (P = 0.001 for Adonis, P = 0.001 for ANOSIM). Compared with the normal samples, Neisseria, Streptococcus, and Actinomyces levels decreased significantly in cancer samples. Co-occurrence network analysis implied that the bacterial community in cancer was more conserved than that in normal tissue. Matched-pair analysis of cancer and control samples revealed a significant alteration in the relative abundance of specific taxa. These findings will enrich our knowledge of the association between the oral microbial community and TSCC. Further experiments should investigate the potential carcinogenic mechanism of microbial community alterations in TSCC. KEY POINTS: • Microbial community role in tongue squamous cell carcinoma. • Significant alteration of microbiome found between cancer and normal tissues. • Microbial community alteration and potential carcinogenic mechanism.

MicroRNA-27a promotes tumorigenesis in tongue squamous cell carcinoma by enhancing proliferation, migration and suppressing apoptosis.

Tongue squamous cell carcinoma (TSCC) is a major subtype of head and neck squamous cell carcinoma (HNSCC), which is an intractable cancer with a poor prognosis. Studies have shown that microRNAs (miRNAs) play an important role in TSCC biology. However, the expression and functions of miRNAs in TSCC remain unclear. The non-coding RNA profiles of TSCC were downloaded from the GEO database. WGCNA (Weighted gene co-expression network analysis) and differential expression miRNA (DE-miRNA) analyses were employed to identify key candidate miRNAs. miRNA expression was detected using RT-qPCR analysis. The target genes of key miRNAs were predicted. Gene ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses were performed to explore the potential functions and pathways of key miRNA. miRNA inhibitor was transfected to detect the function of miRNA. The effect of miRNA deregulation on TSCC cell proliferation and apoptosis was investigated using MTS, Annexin V-FITC/PI double staining, and flow cytometry assays. miR-27a was a key miRNA in TSCC, which was significantly up-regulated in both Cal-27 cells and malignant tissues from the TSCC patients. In addition, functional analysis showed that miR-27a was involved in the regulation of the MAPK, ERBB, and Jak-STAT signaling pathways. Moreover, RHOA and PRKACA were potential target genes of miR-27a, suggesting them as possible mediators of the tumor-promoting effect of miR-27a. Moreover, downregulation of miR-27a inhibited cell proliferation and facilitated cell apoptosis in Cal-27 cells. Our findings strongly suggest that miR-27a could promote the tumorigenesis and development of TSCC, which makes it a potential new diagnostic marker and therapeutic target for TSCC.

LncRNA PART1 Exerts Tumor-Suppressive Functions in Tongue Squamous Cell Carcinoma via miR-503-5p.

BackgroundTongue squamous cell carcinoma (TSCC) accounts for one-third of oral cancers. Previous studies had reported that lncRNA/miRNA regulated the biological behaviors of different cancer cells. However, the mechanisms of PART1 in regulating tumorigenesis and TSCC development via targeting miR-503-5p had not been studied.MethodsThe expressions of PART1 and miR-503-5p in tissues and cultured cell lines were detected by qRT-PCR. StarBase 3.0 was used to predict the binding sites of PART1, then dual-luciferase assay and RNA pull-down assay were executed to confirm whether miR-503-5p was a target of PART1. TSCC cells were co-transfected with PART1-overexpressed plasmid or miR-503-5p mimics in vitro, and the transfection efficiency was evaluated through qRT-PCR. Western blot was performed to assess the expressions of EMT-related proteins. CCK-8 and clone formation assays were conducted to detect cell proliferation, TUNEL assay was used to detect apoptosis, and transwell assay was executed to test migration and invasion.ResultsThe low PART1 expression and high miR-503-5p expression were found in TSCC tissues and cell lines (CAL-27 and SCC9). PART1 expression was positively correlated with patients’ prognosis. The targeting and binding relationship between PART1 and miR-503-5p was confirmed, and overexpressed PART1 diminished the expression of miR-503-5p as well. Moreover, PART1 facilitated apoptosis, inhibited proliferation, invasion and migration of TSCC cells, and these influences were impeded by miR-503-5p overexpression.ConclusionLncRNA PART1 played a cancer-suppressing role in TSCC by targeting miR-503-5p, which provided a potential target for TSCC treatment.

High SOX8 expression promotes tumor growth and predicts poor prognosis through GOLPH3 signaling in tongue squamous cell carcinoma.

According to our previous study, GOLPH3 is markedly up‐expressed in tongue squamous cell carcinoma (TSCC), which is also associated with poor survival. However, it remains unclear about key upstream and downstream mechanisms of GOLPH3. This study aimed to illuminate new mechanisms modulating GOLPH3 upregulation and promoting TSCC development at the molecular level. Using mass spectrometry and agarose‐streptavidin‐biotin pull‐down analyses, SOX8 (SRY‐Box 8) was identified to be the new protein to bind the GOLPH3 promoter within TSCC cells, which was further verified to be the regulator of GOLPH3 upregulation. The knockdown of SOX8 suppressed the promoter activity of GOLPH3, while secondarily inhibiting TSCC cell proliferation both in vivo and in vitro. Interestingly, GOLPH3 overexpression rescued the SOX8 knockdown‐mediated suppression on TSCC proliferation. Additionally, exogenous over‐expression of SOX8 also activated the activity of promoter as well as GOLPH3 expression, in the meantime of promoting TSCC development. Moreover it was discovered that SOX8 regulated GOLPH3 expression through interacting with TFAP2A. Moreover our results suggested that the SOX8 level was increased within tumor tissue compared with that in para‐cancer normal counterpart, which showed positive correlation with the GOLPH3 level. According to Kaplan‐Meier analyses, TSCC cases having higher SOX8 and GOLPH3 expression were associated with poorer prognostic outcomes. Taken together, this study reveals that SOX8 enhances the TSCC cell growth via the direct transcriptional activation of GOLPH3, which also indicates the potential to use SOX8/GOLPH3 pathway as the treatment target among TSCC patients.

Circular RNA expression profiling identifies specific circular RNAs in tongue squamous cell carcinoma.

Tongue squamous cell carcinoma (TSCC) is the most frequent type of oral cancer associated with high malignancy. Circular RNAs (circRNAs) are a form of non-coding RNA with stable and conserved expression in mammalian cells. The aim of the present study was to investigate circRNAs expression profiles in TSCC, and examine the roles and potential mechanisms of circRNA-081069 (circ_081069). A high-throughput circRNA microarray analysis of tumor samples and adjacent normal tissues from four patients with TSCC was performed. Bioinformatic analysis was conducted to screen the differentially expressed circRNAs. Reverse transcription-quantitative PCR was performed to confirm the microarray results. A migration assay and proliferation assay were performed to detect the migratory and proliferative ability of TSCC cells. A luciferase assay was conducted to investigate the interaction between circ_081069 and microRNA (miRNA/miR)-665. In total, 335 circRNAs were found to be differentially expressed in tumor tissues. Among them, 59 were upregulated and 276 were downregulated (P<0.05; fold change ≥2 or ≤0.5). A total of seven circRNAs, including two upregulated and five downregulated circRNAs, were further confirmed using quantitative PCR analysis in the ten paired TSCC tissues and adjacent normal tissues. The present study showed that circRNA_081069 promoted the migratory and proliferative ability of TSCC cells in vitro. Furthermore, the potential circRNA-miRNA interactions were predicted, and the present results identified miR-665 as a miRNA target of circ_081069. The present results suggested that circRNAs may be involved in TSCC development, and understanding the interaction between circ_081069 and miR-665 may facilitate the development of novel diagnostic and therapeutic targets for TSCC.

Expression and significance of microRNA-125b in tongue squamous cell carcinoma

The expression of microRNA-125b in tongue squamous cell carcinoma (TSCC) was detected and analyzed for its relationship with the clinicopathological features of TSCC. Real time fluorescence-quantitative polymerase chain reaction (RT-qPCR) was used to detect the expression of microRNA-125b in 35 TSCC tissues and adjacent normal tissues from 35 TSCC cases. The relationship between the expression of microRNA-125b in TSCC tissues and the clinicopathological features of patients with TSCC was analyzed. In situ hybridization (ISH) was used to detect the expression level of microRNA-125b gene in the TSCC tissues and adjacent normal tissues. RT-qPCR results showed that the relative expression levels of microRNA-125b in the TSCC issues was 2.32±0.69, and that of normal tissues was 0.87±0.32. The statistical results showed that the expression level of microRNA-125b was significantly higher in the TSCC tissues than in the normal tissues (P<0.001). The expression level of microRNA-125b in the TSCC tissues was not significantly correlated with age, gender, pathological grade, and lymph node metastasis but was positively correlated with TNM stage. Patients with high TNM stage had high microRNA-125b expression levels (P<0.05). The ISH results showed that the expression levels of microRNA-125b in the TSCC tissues were 0.010±0.003, and that of normal tissues was 0.004±0.001. The expression levels of microRNA-125b in the 35 TSCC tissues were significantly higher than those in the normal tissues (P<0.05). MicroRNA-125b is highly expressed in TSCC and associated with TNM stage, suggesting that high microRNA-125b expression may be involved in the development of TSCC.

NIT2 overexpression predicts poor prognosis in tongue squamous cell carcinoma patients

There is disputable on the role of nitrilase-like 2 (NIT2) in cancer. Its expression and its relationship with clinicopathological features in tongue squamous cell carcinoma (TSCC) are not yet clear. The purpose of this study is to investigate the expression of NIT2 in TSCC and its correlation with clinicopathological characteristics in TSCC patients. Through proteomic identification, we found that the protein NIT2 was related to the development of TSCC. q-PCR, western blot and immunohistochemistry techniques were applied to detect the expression of NIT2 in TSCC. The relationship between the expression of NIT2 and clinicopathological features was analyzed by Chi square tests. The results showed the expression of NIT2 in TSCC was significantly higher than that in normal tongue tissues (p < 0.05). Univariate and multivariate analysis showed that the positive expression of NIT2 and N classification were associated with decreased disease-free survival rate (DFS) and overall survival (OS) (p < 0.05). The results suggested that NIT2 is overexpressed in TSCC and NIT2 may be a potential therapeutic target for TSCC.

Long noncoding RNA LINC00961 inhibited cell proliferation and invasion through regulating the Wnt/β-catenin signaling pathway in tongue squamous cell carcinoma.

Tongue squamous cell carcinoma (TSCC) is the most frequent style of oral squamous cell carcinoma. However, the molecular mechanisms and function of LINC00961 in the TSCC progression remain unknown. In this study, we proved that LINC00961 expression was downregulated in TSCC cells (Tca8113, SCC1, SCC-4, and SCC-15) compared with normal tissue. In addition, we showed that LINC00961 expression was downregulated in TSCC samples compared with matched normal tissues. Moreover, ectopic expression of LINC00961 decreased TSCC cell growth and invasion and suppressed epithelial-mesenchymal transition in TSCC cell. Furthermore, we indicated that overexpression of LINC00961 decreased β-catenin expression. Knockdown of LINC00961 promoted cell proliferation and invasion partly via promoting the Wnt/β-catenin signaling pathway. These results suggested that LINC00961 was downregulated in TSCC tissues and acted as a tumor suppressor gene in the development of TSCC.

Mitochondrial DNA variations in tongue squamous cell carcinoma.

Tongue squamous cell carcinoma (TSCC) is the most common type of oral carcinoma. Mitochondrial DNA (mtDNA) is a circular DNA molecule of 16,569 bp, which functionally encompasses a regulatory non-coding region (D-loop) and 37 encoding genes that correspond to 13 subunits of respiratory chain complexes (I, III, IV and V), 22 transfer RNAs and 2 ribosomal (r)RNAs. Recently, mtDNA has been implicated as a mutation hotspot in various tumors. However, to our knowledge mtDNA alteration in TSCC has not been investigated to date. In the present study, the mitochondrial genomes of tongue carcinoma, adjacent non-cancerous tissue and peripheral blood samples from 8 patients with TSCC were sequenced and aligned with the revised Cambridge Reference Sequence. Overall, only one synonymous mutation, which mapped to the NADH:ubiquinone oxidoreductase core subunit 5 gene, was observed in the tongue carcinoma sample from a single patient. A further 21 polymorphisms were identified, including six in the non-coding region (D-loop), five in Complex I, three in Complex III, two in Complex IV, two in Complex V and three in rRNA. In addition, mitochondrial microsatellite instability (mtMSI) was detected in 2/8 tongue carcinoma samples, and localized in the D310 region. These variations, particularly the polymorphisms and mtMSI, imply that the mitochondrial genome may be a hotspot of genome alteration in tongue cancer. Further investigation is expected to reveal the role of mtDNA alteration in TSCC development, as well as its clinical implications.

CRNDE promotes cell tongue squamous cell carcinoma cell growth and invasion through suppressing miR-384.

Tongue squamous cell carcinoma (TSCC) is the most common type of oral cancer and is an aggressive head and neck malignancy. Increasing studies have demonstrated that long noncoding RNAs (lncRNAs) play important roles in diverse biological cell processes, such as cell development, fate decisions, cell differentiation, cell migration, and invasion. In our study, we showed that long noncoding RNA colorectal neoplasia differentially expressed (CRNDE) expression was upregulated in TSCC cell lines and tissues. Overexpression of CRNDE increased the TSCC cell proliferation, cell cycle, and cell invasion. Moreover, ectopic expression of CRNDE inhibited the miR-384 expression in the SCC1 cell and increased the Kirsten Ras (KRAS), cell division cycle 42, and insulin receptor substrate 1 expression, which were the direct target genes of miR-384. We demonstrated that the miR-384 expression was downregulated in the TSCC samples compared withthe paired adjacent nontumor samples. The expression of CRNDE was negatively correlated with the expression of miR-384 in the TSCC samples. Overexpression of miR-384 suppressed TSCC cell proliferation, cell cycle, and invasion. Furthermore, we demonstrated that CRNDE promoted TSCC cell proliferation and invasion through inhibiting miR-384 expression. These results suggested that CRNDE acts as an oncogene in the development of TSCC, which partially occurs through inhibiting miR-384 expression.

Safflower polysaccharide inhibits the development of tongue squamous cell carcinoma

BackgroundSafflower polysaccharide (SPS) is one of the most important active components of safflower (Carthamus tinctorius L.), which has been confirmed to have the immune-regulatory function and antitumor effect. This study aimed to explore the effects of safflower polysaccharide (SPS) on tongue squamous cell carcinoma (TSCC).MethodsHN-6 cells were treated with 5 μg/mL cisplatin and various concentrations of SPS (0, 0.02, 0.04, 0.08, 0.16, 0.32, 0.64, and 1.28 mg/mL), and cell proliferation was measured. After treatment with 5 μg/mL cisplatin and 0.64 mg/mL SPS, the induction of apoptosis and the protein and mRNA expression of Bax, Bcl-2, COX-2, and cleaved caspase-3 in HN-6 cells were quantified. In addition, HN-6 cells were implanted into mice to establish an in vivo tumor xenograft model. Animals were randomly assigned to three groups: SPS treatment, cisplatin treatment, and the model group (no treatment). The body weight, tumor volume, and tumor weight were measured, and the expression of the above molecules was determined.ResultsSPS treatment (0.02–0.64 mg/mL) for 24–72 h inhibited HN-6 cell proliferation. In addition, 0.64 mg/mL SFP markedly induced apoptosis in HN-6 cells and arrested the cell cycle at the G0/G1 phase. Compared with the control group, the expression of Bcl-2 and COX-2 was markedly reduced by SPS treatment, whereas the expression of Bax and cleaved caspase-3 was increased. Moreover, SPS significantly inhibited the growth of the tumor xenograft, with similar changes in the expression of Bcl-2, COX-2, Bax, and cleaved caspase-3 in the tumor xenograft to the in vitro analysis.ConclusionsOur results indicated that SPS may inhibit TSCC development through regulation of Bcl-2, COX-2, Bax, and cleaved caspase-3 expression.

Prognostic implications of CD44, NANOG, OCT4, and BMI1 expression in tongue squamous cell carcinoma.

Tongue squamous cell carcinoma (SCC) contains a cell subpopulation referred to as cancer stem cells (CSCs), which are responsible for tumor growth, metastasis, and resistance to chemotherapy and radiotherapy. The CSC markers have been used to isolate these cells and as biomarkers to predict overall survival. The CSC markers CD44, NANOG, OCT4, and BMI1 were investigated using reverse transcriptase-quantitative polymerase chain reaction (RT-qPCR) and immunohistochemistry and correlated with clinicopathological parameters. The CD44 overexpression was associated with disease-related death (P = 0.02) and worst prognosis. NANOG was upregulated in nontumoral margins and associated with T1/T2 classification, lymph node metastasis, and worst prognosis. OCT4 was associated with lymph node metastasis and worst overall survival. BMI1 and CD44v3 were overexpressed in tongue SCC. Coexpression of CD44++ /NANOG++ was associated with worst overall survival when compared with patients with CD44-/+ /NANOG-/+ . The CSC markers might play an important role not only in CSC trait acquisition but also in tongue SCC development and progression.

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.

C-reactive protein is associated with the development of tongue squamous cell carcinoma.

C-reactive protein (CRP) acts as a biomarker reflecting different degrees of inflammation. Accumulating reports have suggested that there is a close relationship between CRP and various cancers. However, the influence of CRP on the development of tongue squamous cell carcinoma (TSCC) remains unclear. The purpose of this study was to investigate the role of CRP in TSCC. The results of immunohistochemical staining and statistical analyses showed that CRP expression was associated with TSCC tumor size, lymph node metastasis and pathological differentiation. Cell Counting Kit-8 (CCK-8) assay revealed that CRP could enhance TSCC cell proliferation in a dose- and time-dependent manner. Moreover, with CRP stimulation, proliferating cell nuclear antigen (PCNA) expression patterns presented a notable time-dependent up-regulation. In addition, CRP could enhance the invasion and migration of TSCC cells, as revealed by transwell and wound-healing assays, respectively. Annexin V-FITC/PI staining showed that CRP could protect TSCC cells from starvation- and drug-induced apoptosis. With CRP stimulation, the protein expression levels of phosphorylated protein kinase B (pAkt), phosphorylated mammalian target of rapamycin (pmTOR) and phosphorylated S6 ribosomal protein (pS6) were significantly increased, as demonstrated by western blot analysis. Our data suggest that CRP may play an important role in the development of TSCC. Moreover, the biological effects of CRP on TSCC cells might be related to Akt, mTOR, and S6.

FoxM1 promotes epithelial-mesenchymal transition, invasion, and migration of tongue squamous cell carcinoma cells through a c-Met/AKT-dependent positive feedback loop.

Forkhead box protein M1 (FoxM1) has been associated with cancer progression and metastasis. However, the function of FoxM1 in tongue squamous cell carcinoma (TSCC) remains largely unknown. The purpose of this study was to determine the role of FoxM1 in regulation of epithelial-mesenchymal transition (EMT) and migration of TSCC cells. We found that FoxM1 induced EMT and increased invasion/migration capacity in SCC9 and SCC25 cells. FoxM1 stimulation increased c-Met, pAKT, and vimentin levels but decreased E-cadherin level. Chromatin immunoprecipitation assay established that FoxM1 is bound to the promoter of c-Met to activate its transcription. In turn, c-Met promoted the expression of FoxM1 and pAKT. Blocking AKT signaling attenuated the invasion and migration of SCC9 and SCC25 cells stimulated by FoxM1 or c-Met. These results indicate that a positive feedback loop controls the EMT and migration of TSCC cells induced by FoxM1 and c-Met through AKT. Furthermore, the expression levels of FoxM1, pAKT, and c-Met were found to significantly increase in TSCC tissues compared with normal tissues, and these three biomarkers were concomitantly expressed in TSCC tissues. Clinical association analyses indicated that the expression of FoxM1, c-Met, and pAKT was associated with clinicopathological characteristics of patients with TSCC including tumor stage, tumor size, and lymph node metastasis. Taken together, our findings suggest that FoxM1 promotes the EMT, invasion and migration of TSCC cells, and cross-talks with c-Met/AKT signaling to form a positive feedback loop to promote TSCC development.

Inhibiting MT2-TFE3-dependent autophagy enhances melatonin-induced apoptosis in tongue squamous cell carcinoma.

Autophagy modulation is a potential therapeutic strategy for tongue squamous cell carcinoma (TSCC). Melatonin possesses significant anticarcinogenic activity. However, whether melatonin induces autophagy and its roles in cell death in TSCC are unclear. Herein, we show that melatonin induced significant apoptosis in the TSCC cell line Cal27. Apart from the induction of apoptosis, we demonstrated that melatonin-induced autophagic flux in Cal27 cells as evidenced by the formation of GFP-LC3 puncta, and the upregulation of LC3-II and downregulation of SQSTM1/P62. Moreover, pharmacological or genetic blockage of autophagy enhanced melatonin-induced apoptosis, indicating a cytoprotective role of autophagy in melatonin-treated Cal27 cells. Mechanistically, melatonin induced TFE3(Ser321) dephosphorylation, subsequently activated TFE3 nuclear translocation, and increased TFE3 reporter activity, which contributed to the expression of autophagy-related genes and lysosomal biogenesis. Luzindole, a melatonin membrane receptor blocker, or MT2-siRNA partially blocked the ability of melatonin to promote mTORC1/TFE3 signaling. Furthermore, we verified in a xenograft mouse model that melatonin with hydroxychloroquine or TFE3-siRNA exerted a synergistic antitumor effect by inhibiting autophagy. Importantly, TFE3 expression positively correlated with TSCC development and poor prognosis in patients. Collectively, we demonstrated that the melatonin-induced increase in TFE3-dependent autophagy is mediated through the melatonin membrane receptor in TSCC. These data also suggest that blocking melatonin membrane receptor-TFE3-dependent autophagy to enhance the activity of melatonin warrants further attention as a treatment strategy for TSCC.

High glucose enhances the metastatic potential of tongue squamous cell carcinoma via the PKM2 pathway.

Previous evidence has indicated an increased cancer risk in individuals with diabetes mellitus (DM). The aim of this study was to investigate the relationship between DM (high glucose) and tongue squamous cell carcinoma (TSCC) and how high glucose mediated the metastatic potential of TSCC. The relationship between DM and TSCC was assessed in a retrospective study. The role and its mechanism of high glucose on the proliferation, metastatic potential of TSCC were investigated in vitro and in vivo. The prevalence rate of DM in patients with TSCC was 12.84%, which was significantly higher than that (9.7%) in the general population in China. Although no significant difference was observed in the overall survival (OS) rate, TSCC patients with DM have a 1.38-fold increase in relative risk affecting 5-year OS compared to patients without DM. High glucose enhanced the TSCC cell proliferation, migration, invasion and upregulated PKM2 (pyruvate kinase M2) expression. Whereas, these effect was abolished after knockdown of PKM2 in TSCC cells. High glucose promoted tumour growth and lung metastasis of TSCC in a DM animal model. Our results confirm DM as a risk factor for the development of TSCC. High glucose enhances the metastatic potential of TSCC through stimulation of the PKM2 pathway.

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

ABSTRACTPrevious studies indicate that TGFBR3 (transforming growth factor type III receptor, also known as betaglycan), a novel suppressor of progression in certain cancers, is down-regulated in tongue squamous cell carcinoma (TSCC). However, the role of this factor as an upstream regulator in TSCC cells remains to be elucidated. The present study was designed to elucidate whether TGFBR3 gene expression is regulated by two microRNA molecules, miR-19a and miR-424. The study also aimed to determine if these microRNAs promote migration of CAL-27 human oral squamous cells. Immunohistochemistry (IHC) and western blot analyses demonstrated that TGFBR3 protein levels were dramatically down-regulated in clinical TSCC specimens. Conversely, bioinformatics analyses and qRT-PCR results confirmed that both miR-19a and miR-424 were markedly up-regulated in clinical TSCC specimens. In this study, we observed that transfection of a TGFBR3-containing plasmid dramatically inhibited epithelial-to-mesenchymal transition (EMT) and migration in CAL-27 cells. Co-immunoprecipitation analyses also revealed that TGFBR3 forms a complex with the β-arrestin 2 scaffolding protein and IκBα. Furthermore, overexpression of TGFBR3 decreased p-p65 expression and increased IκBα expression; these effects were subsequently abolished following knockdown of β-arrestin 2. Moreover, over-expression of miR-19a and miR-424 promoted migration and EMT in CAL-27 cells. We also observed that the promotion of EMT by miR-19a and miR-424 was mediated by the inhibition of TGFBR3. Our study provides evidence that miR-19a and miR-424 play important roles in the development of TSCC. These results expand our understanding of TGFBR3 gene expression and regulatory mechanisms pertaining to miRNAs.

Tumor-Associated Macrophages in the Development of 4-Nitroquinoline-1-Oxide-Induced Tongue Squamous Cell Carcinoma in a Mouse Model

Objective: We aimed to determine the distribution of tumor-associated macrophages (TAMs) in the development of tongue squamous cell carcinoma (SCC) and to elucidate the role of TAMs in the progression of tongue SCC. Methods: The expression of the macrophage markers nitric oxide synthase, Retnla, and mannose receptor 1 in the development of tongue SCC was longitudinally observed using real-time quantitative polymerase chain reaction. Additionally, an immunohistochemical study using an anti-mannose receptor (MR) antibody was performed. Results: The numbers of both of M1 and M2 macrophages in the tongues of mice treated with 4-nitroquinoline-1-oxide (4NQO) were significantly lower compared with those of normal tongues. The cyclooxygenase-2 (COX-2) inhibitor did not prevent cancer progression and did not affect the total number of macrophages in the tongues of 4NQO-treated mice. In the immunohistochemical studies, MR staining was observed in lymphangioendothelium in the subepithelial area of the tongues. The staining intensity of the MR was significantly stronger in the 4NQO-treated mice compared with that in control mice and 4NQO-treated mice treated with the COX-2 inhibitor. Conclusion: TAMs may not contribute to the development of 4NQO-induced tongue SCC. MR expression is associated with the progression of 4NQO-induced tongue SCC.