Retinoic acid receptor-related orphan receptor alpha (RORα), an essential tumor suppressor in a range of human malignancies, is classified as a member of the orphan nuclear receptor family. The most prevalent form of oral cancer, tongue squamous cell carcinoma (TSCC) is characterized by its severe malignancy and unfavorable prognosis. However, the extent to which its tumorigenesis mechanisms are associated with RORα expression levels is still not fully understood. The objective of this study was to examine the molecular mechanisms by which RORα is involved in TSCC. Through the use of immunohistochemistry (IHC), it was discovered that the expression level of RORα was significantly downregulated in TSCC tissues when compared to adjacent normal tissues in this study. To further investigate the role of RORα in TSCC, we activated the expression of RORα in human TSCC cell line (SCC9 cells) by transfecting RORα cDNA and using the selective RORα agonist SR1078. The results show that RORα can significantly inhibit the invasion, migration, proliferation, and adhesion of TSCC cells and induce cell apoptosis. In addition, xenograft models confirmed the conclusion that stable activation or treatment with SR1078 to increase RORα content significantly inhibited tumor growth and development. Taken together, this study provides solid evidence for the inhibitory role of RORα in the progression of TSCC. In addition, the preliminary application results of SR1078 in TSCC show that SR1078 is expected to be a potential therapeutic medication for TSCC. These findings provide innovative perspectives on the development of potential biomarkers and agents for TSCC therapy. The objective is to introduce novel strategy and alternatives for the prevention and treatment of TSCC.

BACKGROUND: The role of Claudin-1 in tongue squamous cell carcinoma (TSCC) metastasis needs further clarification, particularly its impact on cell migration. Herein, our study aims to investigate the role of Claudin-1 in TSCC cell migration and its underlying mechanisms.
METHODS: 36 TSCC tissue samples underwent immunohistochemical staining for Claudin-1. Western blotting and immunofluorescence analyses were conducted to evaluate Claudin-1 expression and distribution in TSCC cells. Claudin-1 knockdown cell lines were established using short hairpin RNA transfection. Migration effects were assessed through wound healing assays. Furthermore, the expression of EMT-associated molecules was measured via western blotting.
RESULTS: Claudin-1 expression decreased as TSCC malignancy increased. Adenosine monophosphate-activated protein kinase (AMPK) activation led to increased Claudin-1 expression and membrane translocation, inhibiting TSCC cell migration and epithelial-mesenchymal transition (EMT). Conversely, Claudin-1 knockdown reversed these inhibitory effects on migration and EMT caused by AMPK activation.
CONCLUSIONS: Our results indicated that AMPK activation suppresses TSCC cell migration by targeting Claudin-1 and EMT pathways.

UNASSIGNED: Chemerin, as a novel multifunctional adipokine, is proposed to be involved in high cancer risk and mortality. The present study was aimed to evaluate the prognostic value of serum Chemerin and neutrophils in patients with oral squamous cell carcinoma (OSCC).
UNASSIGNED: 120 patients with OSCC were included in this prospective cohort study. The levels of serum Chemerin were measured by enzyme-linked immunosorbent assay (ELISA). We also explored the possible effects of Chemerin on neutrophils\' chemokines in OSCC using a real-time PCR, western blotting.
UNASSIGNED: Levels of serum Chemerin, neutrophils and NLR were significantly higher among non-survivors compared to survivors of OSCC (both P < 0.05). Higher serum Chemerin levels were associated with advanced TNM stage, lymph node metastasis, differentiation and tumor recurrence (both P < 0.05). Serum Chemerin levels correlated with neutrophils and NLR levels (r = 0.708, r = 0.578, both P < 0.05). Based on ROC analysis, Chemerin + NLR predicted OSCC patient mortality with 81.54 % sensitivity and 87.27 % specificity, with an AUC of 0.8898. In a Kaplan-Meier analysis, high serum Chemerin levels, high neutrophil levels and high NLR levels were associated with shorter overall and disease-free survival (both P < 0.05). A univariate and multivariate Cox regression analysis showed that serum Chemerin and neutrophils were independent risk factors for OSCC. (both P < 0.05). QRT-PCR and western blotting results showed that Chemerin upregulated the expression of chemokines IL-17 and CXCL-5 in neutrophils (both P < 0.05).
UNASSIGNED: Our study suggests that measurement of serum Chemerin and neutrophils might be a useful diagnostic and prognostic biomarker for OSCC patients. Chemerin may promote neutrophils infiltration in OSCC through upregulation of chemokines IL17 and CXCL-5.

This study aimed to investigate the role of miR-558 in tumor angiogenesis by targeting heparinase (HPSE) in tongue squamous cell carcinoma (TSCC)-derived exosomes. In the present study, the role of exosome miR-558 in angiogenesis in vitro and in vivo was investigated by cell proliferation, migration, tube formation, subcutaneous tumor formation in mice, and in vivo Matrigel plug assay. The target genes of miR-558 were detected by means of dual luciferase assay. It was found that TSCC cells secrete miR-558 into the extracellular environment, with exosome as the carrier. Human umbilical vein endothelial cells (HUVEC) ingested exosomes, which not only increased the expression level of miR-558, but also enhanced their proliferation, migration, and tube formation functions. In vivo Matrigel plug assay demonstrated that TSCC cell-derived exosome miR-558 promoted neovascularization in vivo. Compared with negative control cells, TSCC cells overexpressing miR-558 formed subcutaneous tumors in nude mice, with larger volume, heavier mass, and more vascularization. Dual luciferase assay confirmed that HPSE was the direct target gene regulated by miR-558. HPSE promoted the proliferation, migration, and tube formation of HUVECs, and the knockout of HPSE could downregulate the pro-angiogenic effect of miR-558. In summary, miR-558 in TSCC exosomes promotes the proliferation, migration, and tube formation of HUVECs by targeting HPSE, and enhancing tumor angiogenesis.

BACKGROUND: Tongue squamous cell carcinoma (TSCC) exhibits an aggressive biological behavior of lymph node and distant metastasis, which contributes to poorer prognosis and results in tongue function loss or death. In addition to known regulators and pathways of cell migration in TSCC, it is important to uncover pivotal switches governing tumor metastasis.
METHODS: Cancer cell migration-associated transcriptional and epigenetic characteristics were profiled in TSCC, and the specific super-enhancers (SEs) were identified. Molecular function and mechanism studies were used to investigate the pivotal switches in TSCC metastasis.
RESULTS: Ameboidal-type cell migration-related genes accompanied by transcriptional and epigenetic activity were enriched in TSCC. Meanwhile, the higher-ranked SE-related genes showed significant differences between 43 paired tumor and normal samples from the TCGA TSCC cohort. In addition, key motifs were detected in SE regions, and transcription factor-related expression levels were significantly associated with TSCC survival status. Notably, BATF and ATF3 regulated the expression of ameboidal-type cell migration-related MMP14 by switching the interaction with the SE region.
CONCLUSIONS: SEs and related key motifs transcriptional regulate tumor metastasis-associated MMP14 and might be potential therapeutic targets for TSCC.

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.

The role of LRP5, a critical receptor in the Wnt signaling pathway, remains unexplored in tongue squamous cell carcinoma (TSCC). This study investigates the impact of LRP5 knockdown on the biological behaviors of TSCC cell lines both in vitro and in vivo. Our findings indicate that LRP5 knockdown significantly enhances cell proliferation, migration, and invasion in CAL27 and SCC25 cell lines. RNA-seq analysis reveals compensatory activation of the Akt pathway, with 119 genes significantly upregulated post-LRP5 knockdown. Elevated MMP1 expression suggests its potential involvement in TSCC progression. Western blot analysis demonstrates increased Akt phosphorylation, upregulated proliferation-related PCNA, and downregulated apoptosis-related caspase-3 after LRP5 knockdown. Down-regulation of E-cadherin and β-Catenin, proteins associated with cell adhesion and invasion, further elucidates the molecular mechanism underlying increased cell migration and invasion. Our study concludes that compensatory Akt pathway activation is essential for the LRP5 knockdown-induced migration and proliferation of CAL27 and SCC25 cells. These results highlight LRP5 as a potential therapeutic target for TSCC. Simultaneous inhibition of Wnt and Akt signaling emerges as a promising approach for TSCC treatment.

Cisplatin is commonly used for the chemotherapy of tongue squamous cell carcinoma (TSCC); however, adverse side effects and drug resistance impact its therapeutic efficacy. Capsaicin is an active ingredient in chili peppers that exerts antitumor effects, whether it exerts antitumor effects on cisplatin-resistant cells remains unknown. Therefore, in this study, we investigated the effect of capsaicin on cisplatin resistance in TSCC cells and explored the underlying mechanisms. A cisplatin-resistant TSCC cell line was established by treated with increasing cisplatin concentrations. Combined treatment with cisplatin and capsaicin decreased the glucose consumption and lactate dehydrogenase activity and increased the adenosine triphosphate production both in vitro and in vivo, suggesting the inhibition of the Warburg effect. Moreover, this combined treatment induced cell apoptosis and significantly upregulated the levels of proapoptotic proteins, such as Bax, cleaved caspase-3, -7, and -9, and apoptosis-inducing factor. In contrast, levels of the antiapoptotic protein, Bcl-2, were downregulated. Additionally, LKB1 and AMPK activities were stimulated, whereas those of AKT and mTOR were suppressed. Notably, AMPK knockdown abolished the inhibitory effects of capsaicin and cisplatin on the AKT/mTOR signaling pathway and Warburg effect. Overall, combined treatment with capsaicin and cisplatin reversed cisplatin resistance by inhibiting the Warburg effect and facilitating mitochondrial-dependent apoptosis via the AMPK/AKT/mTOR axis. Our findings suggest combination therapy with capsaicin and cisplatin as a potentially novel strategy and highlight capsaicin as a promising adjuvant drug for TSCC treatment.

Tongue squamous cell carcinoma (TSCC) occupies a high proportion of oral squamous cell carcinoma. TSCC features high lymph node metastasis rates and chemotherapy resistance with a poor prognosis. Therefore, an effective therapy strategy is needed to improve patient prognosis. Melatonin (MT) is a natural indole compound shown to have anti-tumor effects in several cancers. This study focused on the role and mechanism of MT in TSCC cells. The results of the study suggest that MT could inhibit cell proliferation in CRL-1623 cells. Western blot analysis showed the down-regulate of cyclin B1 and the up-regulate P21 protein by MT. MT was also shown to down-regulate the expression of Zeb1, Wnt5A/B, and β-catenin protein and up-regulate E-cadherin to inhibit the migration of CRL-1623 cells. MT also promoted the expression of ATF4, ATF6, Bip, BAP31 and CHOP in CRL-1623 cells leading to endoplasmic reticulum stress, and induced autophagy and apoptosis in CRL-1623 cells. Western blots showed that MT could promote the expression of Bax, LC3, and Beclin1 proteins and inhibit the expression of p62. We screened differentially expressed long non-coding RNAs (lncRNAs) in MT-treated cells and found that the expression of MALAT1 and H19 decreased. Moreover, MT inhibited tumor growth in nude mice inoculated with CRL-1623 cells. These results suggest that MT could induce autophagy, promote apoptosis, and provide a potential natural compound for the treatment of TSCC.

Oral squamous cell carcinoma (OSCC) is one of the most common malignant tumors in the head and neck, and among the OSCCs, tongue squamous cell carcinoma (TSCC) is one of the most common types. Although therapy strategies have recently advanced, the prognosis of TSCC has not substantially improved. Metastasis is one of the main causes of patient mortality in TSCC; therefore, it is necessary to elucidate the mechanism by which TSCC metastasis is regulated. In the present study, the early growth response 1 (Egr-1) expression in TSCC was analyzed based on GEO datasets and the effect of Egr-1 in TSCC tumor cell migration and invasion was measured using Transwell assay. By overexpressing dual-specificity protein phosphatase 1 (DUSP1) in cells with Egr-1 knockdown using lentivirus infection, the role of DUSP1 in Egr-1-regulated TSCC cell migration and invasion was determined. By using luciferase and ChIP assays, the mechanism behind how DUSP1 is regulated by Egr-1 was detected. In the present study, it was demonstrated that Egr-1 was downregulated in TSCC and the knockdown of Egr-1 increased TSCC cell migration and invasion. The expression of Egr-1 was also correlated with DUSP1. The overexpression of DUSP1 in Egr-1 knockdown cells, reduced the level of cell migration and invasion. Furthermore, it was demonstrated that knockdown of Egr-1 inhibited the promoter activity of DUSP1 and the site through which Egr-1 regulates DUSP1 transcription was identified. In conclusion, the present study demonstrated that Egr-1 regulates TSCC cell migration and invasion through modulating DUSP1, suggesting the potential of Egr-1 and DUSP1 as therapy targets for TSCC.