Oral Squamous Cell Carcinoma Cell Proliferation Research Articles

Theranostic Potential of Bacteriophages against Oral Squamous Cell Carcinoma.

Oral Squamous Cell Carcinoma (OSCC) is a widespread and challenging disease that accounts for 94% of cancers of the oral cavity worldwide. Bacteriophages (phages) have shown promise as a potential theranostic agent for the treatment of OSCC. It may offer advantages in overcoming the challenges of conventional methods. Modern high-throughput pyrosequencing techniques confirm the presence of specific bacterial strains associated with OSCC. Bio-panning and filamentous phages facilitate visualization of the peptide on surfaces and show high affinity in OSCC cells. The peptide has the potential to bind integrin (αvβ6), aid in diagnosis, and inhibit the proliferation of OSCC cells. Mimotopes of tumor-associated antigens show cytotoxic and immune responses against cancer cells. Biomarker-based approaches such as transferrin enable early OSCC diagnosis. A modified temperate phage introduces CRISPR-Cas3 to target antimicrobial-resistant bacteria associated with OSCC. The research findings highlight the evolving field of phage diagnostics and therapy and represent a new avenue for non-invasive, targeted approaches to the detection and treatment of OSCC. However, extensive clinical research is required to validate the efficacy of phages in innovative cancer theranostic strategies.

Radiation-induced exosomes promote oral squamous cell carcinoma progression via enhancing SLC1A5-glutamine metabolism.

Radiotherapy (RT) can drive cancer cells to enter a state of cellular senescence in which cells can secrete senescence-associated secretory phenotype (SASP) and produce small extracellular vesicles (sEVs) to interact with cells in the tumor microenvironment (TME). Tumor-derived sEVs that are taken up by recipient cells contribute to cancer cell metabolic plasticity, resistance to anticancer therapy, and adaptation to the TME. However, how radiation-induced sEVs support oral squamous cell carcinoma (OSCC) progression remains unclear. Beta-galactosidase staining and SASP mRNA expression analysis were used to evaluate the senescence-associated activity of OSCC cells after irradiation. Nanoparticle tracking analysis was performed to identify radiation-induced sEVs. Liquid chromatography-tandem mass spectrometry (LC-MS) was used to explore changes in the levels of proteins in radiation-induced sEVs. Cell Counting Kit-8 and colony formation assays were performed to investigate the function of radiation-induced SASP and sEVs in vitro. A xenograft tumor model was established to investigate the functions of radiation-induced sEVs and V-9302 in vivo as well as the underlying mechanisms. Bioinformatics analysis was performed to determine the relationship between glutamine metabolism and OSCC recurrence. We determined that the radiation-induced SASP triggered OSCC cell proliferation. Additionally, radiation-induced sEVs exacerbated OSCC cell malignancy. LC-MS/MS and bioinformatics analyses revealed that SLC1A5, which is a cellular receptor that participates in glutamine uptake, was significantly enriched in radiation-induced sEVs. In vitro and in vivo, inhibiting SLC1A5 could block the oncogenic effects of radiation-induced sEVs in OSCC. Radiation-induced sEVs might promote the proliferation of unirradiated cancer cells by enhancing glutamine metabolism; this might be a novel molecular mechanism underlying radiation resistance in OSCC patients.

NCAPD2 promotes the malignant progression of oral squamous cell carcinoma via the Wnt/β-catenin pathway

ABSTRACT Oral squamous cell carcinoma (OSCC) is the most common type of oral cancer, with a poor prognosis, yet the underlying mechanism needs further exploration. Non-SMC condensin I complex subunit D2 (NCAPD2) is a widely expressed protein in OSCC, but its role in tumor development is unclear. This study aimed to explore NCAPD2 expression and its biological function in OSCC. NCAPD2 expression in OSCC cell lines and tissue specimens was analyzed using quantitative polymerase chain reaction, western blotting, and immunohistochemistry. Cancer cell growth was evaluated using cell proliferation, 5-Ethynyl-2’-deoxyuridine (EdU) staining, and colony formation assays. Cell migration was evaluated using wound healing and Transwell assays. Apoptosis was detected using flow cytometry. The influence of NCAPD2 on tumor growth in vivo was evaluated in a mouse xenograft model. NCAPD2 expression was significantly higher in OSCC than that in normal oral tissue. In vitro, the knockdown of NCAPD2 inhibited OSCC cell proliferation and promoted apoptosis. NCAPD2 depletion also significantly inhibited the migration of OSCC cells. Moreover, NCAPD2 overexpression induced inverse effects on OSCC cell phenotypes. In vivo, we demonstrated that downregulating NCAPD2 could inhibit the tumorigenicity of OSCC cells. Mechanically, OSCC regulation by NCAPD2 involved the Wnt/β-catenin signaling pathway. These results suggest NCAPD2 as a novel oncogene with an important role in OSCC development and a candidate therapeutic target for OSCC.

Phenformin activates ER stress to promote autophagic cell death via NIBAN1 and DDIT4 in oral squamous cell carcinoma independent of AMPK

The efficient clinical treatment of oral squamous cell carcinoma (OSCC) is still a challenge that demands the development of effective new drugs. Phenformin has been shown to produce more potent anti-tumor activities than metformin on different tumors, however, not much is known about the influence of phenformin on OSCC cells. We found that phenformin suppresses OSCC cell proliferation, and promotes OSCC cell autophagy and apoptosis to significantly inhibit OSCC cell growth both in vivo and in vitro. RNA-seq analysis revealed that autophagy pathways were the main targets of phenformin and identified two new targets DDIT4 (DNA damage inducible transcript 4) and NIBAN1 (niban apoptosis regulator 1). We found that phenformin significantly induces the expression of both DDIT4 and NIBAN1 to promote OSCC autophagy. Further, the enhanced expression of DDIT4 and NIBAN1 elicited by phenformin was not blocked by the knockdown of AMPK but was suppressed by the knockdown of transcription factor ATF4 (activation transcription factor 4), which was induced by phenformin treatment in OSCC cells. Mechanistically, these results revealed that phenformin triggers endoplasmic reticulum (ER) stress to activate PERK (protein kinase R-like ER kinase), which phosphorylates the transitional initial factor eIF2, and the increased phosphorylation of eIF2 leads to the increased translation of ATF4. In summary, we discovered that phenformin induces its new targets DDIT4 and especially NIBAN1 to promote autophagic and apoptotic cell death to suppress OSCC cell growth. Our study supports the potential clinical utility of phenformin for OSCC treatment in the future.

Crosstalk between cancer cells and macrophages promotes OSCC cell migration and invasion through a CXCL1/EGF positive feedback loop.

C-X-C motif chemokine ligand 1 (CXCL1) and epithelial growth factor (EGF) are highly secreted by oral squamous cell carcinoma (OSCC) cells and tumor-associated macrophages, respectively. Recent studies have shown that there is intricate "cross-talk" between OSCC cells and macrophages. However, the underlying mechanisms are still poorly elucidated. The expression of CXCL1 was detected by immunohistochemistry in OSCC clinical samples. CXCL1 levels were evaluatedby RT‒PCR and ELISA in an OSCC cell line and a normal epithelial cell line. The expression of EGF was determined by RT‒PCR and ELISA. The effect of EGF on the proliferation of OSCC cells was evaluated by CCK-8 and colony formation assays. The effect of EGF on the migration and invasion ability and epithelial-mesenchymal transition (EMT) of OSCC cells was determined by wound healing, Transwell, RT‒PCR, Western blot and immunofluorescence assays. The polarization of macrophages was evaluated by RT‒PCR and flow cytometry. Western blotting was used to study the molecular mechanism in OSCC. The expression of C-X-C motif chemokine ligand 1 (CXCL1) was higher in the OSCC cell line (Cal27) than in immortalized human keratinocytes (Hacat cells). CXCL1 derived from Cal27 cells upregulates the expression of epithelial growth factor (EGF) in macrophages. Paracrine stimulation mediated by EGF further facilitates the epithelial-mesenchymal transition (EMT) of Cal27 cells and initiates the upregulation of CXCL1 in a positive feedback-manner. Mechanistically, EGF signaling-induced OSCC cell invasion and migration can be ascribed to the activation of NF-κB signaling mediated by the epithelial growth factor receptor (EGFR), as determined by western blotting. OSCC cell-derived CXCL1 can stimulate the M2 polarization of macrophages and the secretion of EGF. Moreover, EGF significantly activates NF-κB signaling and promotes the migration and invasion of OSCC cells in a paracrine manner. A positive feedback loop between OSCC cells and macrophages was formed, contributing to the promotion of OSCC progression.

About a Possible Impact of Endodontic Infections by Fusobacterium nucleatum or Porphyromonas gingivalis on Oral Carcinogenesis: A Literature Overview.

Periodontitis is linked to the onset and progression of oral squamous cell carcinoma (OSCC), an epidemiologically frequent and clinically aggressive malignancy. In this context, Fusobacterium (F.) nucleatum and Porphyromonas (P.) gingivalis, two bacteria that cause periodontitis, are found in OSCC tissues as well as in oral premalignant lesions, where they exert pro-tumorigenic activities. Since the two bacteria are present also in endodontic diseases, playing a role in their pathogenesis, here we analyze the literature searching for information on the impact that endodontic infection by P. gingivalis or F. nucleatum could have on cellular and molecular events involved in oral carcinogenesis. Results from the reviewed papers indicate that infection by P. gingivalis and/or F. nucleatum triggers the production of inflammatory cytokines and growth factors in dental pulp cells or periodontal cells, affecting the survival, proliferation, invasion, and differentiation of OSCC cells. In addition, the two bacteria and the cytokines they induce halt the differentiation and stimulate the proliferation and invasion of stem cells populating the dental pulp or the periodontium. Although most of the literature confutes the possibility that bacteria-induced endodontic inflammatory diseases could impact on oral carcinogenesis, the papers we have analyzed and discussed herein recommend further investigations on this topic.

F. Nucleatum enhances oral squamous cell carcinoma proliferation via E-cadherin/β-Catenin pathway

BackgroundFusobacterium nucleatum (F. nucleatum) is a microbial risk factor whose presence increases the risk of oral squamous cell carcinoma (OSCC) progression. However, whether it can promote the proliferation of OSCC cells remains unknown.MethodsIn this study, we investigated F. nucleatum effect on OSCC cell proliferation using in vitro and in vivo experiments.ResultsOur results showed that F. nucleatum promoted OSCC cell proliferation, doubling the cell count after 72 h (CCK-8 assay). Cell cycle analysis revealed G2/M phase arrest. F. nucleatum interaction with CDH1 triggered phosphorylation, upregulating downstream protein β-catenin and activating cyclinD1 and Myc. Notably, F. nucleatum did not affect noncancerous cells, unrelated to CDH1 expression levels in CAL27 cells. Overexpression of phosphorylated CDH1 in 293T cells did not upregulate β-catenin and cycle-related genes. In vivo BALB/c nude experiments showed increased tumor volume and Ki-67 proliferation index after F. nucleatum intervention.ConclusionOur study suggests that F. nucleatum promotes OSCC cell proliferation through the CDH1/β-catenin pathway, advancing our understanding of its role in OSCC progression and highlighting its potential as a therapeutic target.

An Acid-Responsive Iron-Based Nanocomposite for OSCC Treatment

Oral squamous cell carcinoma (OSCC) is the most common type of oral cancer, characterized by invasiveness, local lymph node metastasis, and poor prognosis. Traditional treatment and medications have limitations, making the specific inhibition of OSCC growth, invasion, and metastasis a challenge. The tumor microenvironment exhibits mildly acidity and high concentrations of H2O2, and its exploitation for cancer treatment has been widely researched across various cancers, but research in the oral cancer field is relatively limited. In this study, by loading ultra-small Prussian blue nanoparticles (USPBNPs) into mesoporous calcium–silicate nanoparticles (MCSNs), we developed an acid-responsive iron-based nanocomposite, USPBNPs@MCSNs (UPM), for the OSCC treatment. UPM demonstrated excellent dual enzyme activities, generating toxic ·OH in a mildly acidic environment, effectively killing OSCC cells and producing O2 in a neutral environment to alleviate tissue hypoxia. The results showed that UPM could effectively inhibit the proliferation, migration, and invasion of OSCC cells, as well as the growth of mice solid tumors, without obvious systemic toxicity. The mechanisms may involve UPM inducing ferroptosis of OSCC cells by downregulating the xCT/GPX4/glutathione (GSH) axis, characterized by intracellular iron accumulation, reactive oxygen species accumulation, GSH depletion, lipid peroxidation, and abnormal changes in mitochondrial morphology. Therefore, this study provides empirical support for ferroptosis as an emerging therapeutic target for OSCC and offers a valuable insight for future OSCC treatment.

The role of CXCL2-mediated crosstalk between tumor cells and macrophages in Fusobacterium nucleatum-promoted oral squamous cell carcinoma progression

Dysbiosis of the oral microbiota is related to chronic inflammation and carcinogenesis. Fusobacterium nucleatum (Fn), a significant component of the oral microbiota, can perturb the immune system and form an inflammatory microenvironment for promoting the occurrence and progression of oral squamous cell carcinoma (OSCC). However, the underlying mechanisms remain elusive. Here, we investigated the impacts of Fn on OSCC cells and the crosstalk between OSCC cells and macrophages. 16 s rDNA sequencing and fluorescence in situ hybridization verified that Fn was notably enriched in clinical OSCC tissues compared to paracancerous tissues. The conditioned medium co-culture model validated that Fn and macrophages exhibited tumor-promoting properties by facilitating OSCC cell proliferation, migration, and invasion. Besides, Fn and OSCC cells can recruit macrophages and facilitate their M2 polarization. This crosstalk between OSCC cells and macrophages was further enhanced by Fn, thereby amplifying this positive feedback loop between them. The production of CXCL2 in response to Fn stimulation was a significant mediator. Suppression of CXCL2 in OSCC cells weakened Fn’s promoting effects on OSCC cell proliferation, migration, macrophage recruitment, and M2 polarization. Conversely, knocking down CXCL2 in macrophages reversed the Fn-induced feedback effect of macrophages on the highly invasive phenotype of OSCC cells. Mechanistically, Fn activated the NF-κB pathway in both OSCC cells and macrophages, leading to the upregulation of CXCL2 expression. In addition, the SCC7 subcutaneous tumor-bearing model in C3H mice also substantiated Fn’s ability to enhance tumor progression by facilitating cell proliferation, activating NF-κB signaling, up-regulating CXCL2 expression, and inducing M2 macrophage infiltration. However, these effects were reversed by the CXCL2-CXCR2 inhibitor SB225002. In summary, this study suggests that Fn contributes to OSCC progression by promoting tumor cell proliferation, macrophage recruitment, and M2 polarization. Simultaneously, the enhanced CXCL2-mediated crosstalk between OSCC cells and macrophages plays a vital role in the pro-cancer effect of Fn.

Possible Role of miR-375-3p in Cervical Lymph Node Metastasis of Oral Squamous Cell Carcinoma.

No clinically useful predictors of latent cervical lymph node metastasis (LNM) in early oral squamous cell carcinoma (OSCC) are available. In this study, we focused on the microRNAs (miRNAs) involved in the expression of numerous genes and explored those associated with latent cervical LNM in early OSCC (eOSCC). First, microarray and RT-PCR analyses revealed a significant downregulation of miR-375-3p expression in primary eOSCC tissues with latent cervical LNM. Next, we examined the effects of miR-375-3p mimics on the growth and migration of four human OSCC cell lines that do not express miR-375-3p. The overexpression of miR-375-3p significantly suppressed the cell proliferation and migration of human OSCC cells in vitro. Furthermore, miR-375-3p mimics markedly inhibited the subcutaneously xenografted human OSCC tumors. Finally, we found the genes involved in the PI3K-AKT pathway and cell migration as target gene candidates of miR-375-3p in human OSCC cells. These findings suggest that miR-375-3p functions as a tumor suppressive-miRNA in OSCC and may serve as a potential biomarker for the prediction of latent cervical LNM in eOSCC and a useful therapeutic target to suppress OSCC progression.

Combination treatment with ferroptosis and autophagy inducers significantly inhibit the proliferation and migration of oral squamous cell carcinoma

Oral squamous cell carcinoma (OSCC), a malignancy originating from mucosal epithelial cells. Currently, triggering apoptotic cell death with anticancer drugs is the main way to inhibit OSCC cells. However, the capability to trigger apoptosis in tumors is constrained by the intrinsic resistance of tumor cells to apoptosis, hampering its effectiveness. Thus, utilizing alternative modes of non-apoptotic cell death offers new therapeutic possibilities, such as using a drug combination strategy to simultaneously induce ferroptosis and autophagy has the potential to improve OSCC therapy. In this study, we found the ferroptosis inducer RSL3 has certain inhibitory effects on the proliferation and migration of OSCC cells. Interestingly, our studies showed that RSL3 is also associated with autophagy activation. Based on this finding, we tried to combine RSL3 with the autophagy inducer LYN-1604 to improve the therapeutic effect. The results demonstrated that simultaneous regulation of autophagy and ferroptosis significantly reduced the proliferation and migration of OSCC cells. Taken together, we demonstrated the therapeutic potential of RSL3 in OSCC cells and proposed that simultaneous activation of autophagy and ferroptosis have synergistic effects, which would provide valuable clues for further exploration of targeted therapy for OSCC.

Abstract 3795: Possible role of miR-375-3p in cervical lymph node metastasis of oral squamous cell carcinoma

Abstract Latent cervical lymph node metastasis (LNM) is the most important prognostic factor in early oral squamous cell carcinoma (OSCC). However, no clinically useful predictors of LNM in early OSCC are available. In this study, we focused on the microRNAs (miRNAs) involved in the expression of numerous genes and explored those associated with latent cervical LNM in OSCC. Microarray analysis of miRNA expression showed that the expression levels of miR-375-3p were significantly reduced in primary OSCC tissues with latent cervical LNM. Subsequently, we quantified the expression of miR-375-3p by RT-qPCR and digital PCR. Similar to the results of miRNA microarray analysis, miR-375-3p was significantly downregulated in primary OSCC tissues with latent cervical LNM. The results of digital PCR showed a more significant difference than those of RT-qPCR. When the reference value for predicting latent cervical LNM was set to less than 57.85 copies based on the receiver operating characteristic curve, the sensitivity, specificity, accuracy, and area under the curve were 80%, 100%, 90%, and 0.942, respectively. Next, we examined the effects of miR-375-3p mimics on the growth and migration of four human OSCC cell lines (SAS-L1, HSC2, HSC3, and Ca9-22) that do not express miR-375-3p. When an miR-375-3p mimic was introduced into these cells, cell proliferation and migration were significantly suppressed. Total RNA was extracted from these cells reverse-transfected with miR-375-3p mimic for 48 hours. Microarray analysis and Ingenuity Pathway Analysis (IPA) miRNA target filter showed that miR-375-3p overexpression reduced the expression of 266 genes, of which 37 genes had the target sequences of miR-375-3p in their 3’-untranslated region. Among these target genes, CEPT1 and TIMM8A knockdown significantly inhibited the migration of all human OSCC cells, similar to miR-375-3p mimics. Furthermore, IPA core analysis revealed a decrease in expression of genes involved in the activation of PI3K-AKT pathways by miR-375-3p overexpression. These results indicated that downregulating miR-375-3p expression could promote cervical LNM by enhancing cell proliferation and migration in OSCC. We also found that CEPT1 and TIMM8A as novel target genes of miR-375-3p regulated the migration of human OSCC cells. The expression levels of miR-375-3p in primary OSCC tissues appear to be a useful biomarker for predicting latent cervical LNM. Citation Format: Masato Saika, Koh-ichi Nakashiro, Norihiko Tokuzen, Hiroyuki Shirai, Daisuke Uchida. Possible role of miR-375-3p in cervical lymph node metastasis of oral squamous cell carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3795.

Abstract 6992: Profilin 2 (PFN2) promotes the proliferation, migration, invasion and epithelial-to-mesenchymal transition of oral squamous cell carcinoma

Abstract Background:Oral squamous cell carcinoma (OSCC) stands as a prevalent malignancy worldwide. Profilin 2 (PFN2), an actin-binding protein regulating actin polymerization dynamics and associated with cell motility, has recently gained attention as a significant regulator in various cancers. However, the clinical significance and biological function of PFN2 in OSCC remain debatable. This study aims to elucidate the role of PFN2 in OSCC. Methods:We assessed PFN2 expression in OSCC and adjacent normal oral mucosa tissues through Q-RT-PCR and immunohistochemistry analysis. Associations between PFN2 expression, clinicopathological features, and OSCC prognosis were analyzed. Cell proliferation, invasion, and migration effects were examined via MTT and Transwell assays. Western blotting assessed the protein expression related to epithelial–mesenchymal transition (EMT). Additionally, we established OSCC xenografts to determine tumorigenicity in vivo using female Nude mice. Results:PFN2 RNA and protein expression were significantly increased in OSCC compared to normal oral mucosa. PFN2 expression positively correlated with lymphovascular invasion and cervical lymph node metastasis. MTT and Transwell assays demonstrated that PFN2 promoted OSCC cell proliferation, migration, invasion, and endothelial invasion. Downregulation of PFN2 induced an EMT phenotype, including an increase in the expression of the epithelial marker E-cadherin and a decrease in the expression of mesenchymal markers Vimentin, Snail, and Slug in OSCC cells in vitro. Similarly, OSCC cells with reduced PFN2 expression exhibited weaker tumorigenicity in vivo. Conclusions:Our findings unveil a novel role for PFN2 in promoting OSCC progression and metastasis, suggesting its potential as an early biomarker for high-risk populations. Targeting PFN2 may offer a promising therapeutic strategy for OSCC treatment. Citation Format: Chung Ji LIu, Li-Han Lin, Kuo-Wei Chang, Hui-Wen Cheng. Profilin 2 (PFN2) promotes the proliferation, migration, invasion and epithelial-to-mesenchymal transition of oral squamous cell carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6992.

Enhanced lipid biosynthesis in oral squamous cell carcinoma cancer-associated fibroblasts contributes to tumor progression: Role of IL8/AKT/p-ACLY axis.

Lipid metabolic reprogramming of tumor cells has been proven to play a critical role in tumor initiation and development. However, lipid metabolism in cancer-associated fibroblasts (CAFs) has rarely been studied, particularly in CAFs of oral squamous cell carcinoma (OSCC). Additionally, the molecular mechanism by which tumor cells regulate lipid metabolism in fibroblasts is unclear. In this study, we found that phosphorylated ATP citrate lyase (p-ACLY), a key lipid metabolic enzyme, was upregulated in OSCC CAFs. Compared to paracancerous normal fibroblasts, CAFs showed enhanced lipid synthesis, such as elevated cytosolic acetyl-CoA level and accumulation of lipid droplets. Conversely, reduction of p-ACLY level blocked this biological process. In addition, blocking lipid synthesis in CAFs or inhibiting fatty acid uptake by OSCC cells reduced the promotive effects of CAFs on OSCC cell proliferation, invasion, and migration. These findings suggested that CAFs are one of lipid sources required for OSCC progression. Mechanistically, AKT signaling activation was involved in the upregulation of p-ACLY level and lipid synthesis in CAFs. Interleukin-8 (IL8), an exocrine cytokine of OSCC cells, could activate AKT and then phosphorylate ACLY in fibroblasts. This study suggested that the IL8/AKT/p-ACLY axis could be considered as a potential target for OSCC treatment.

LRRC59 promotes the progression of oral squamous cell carcinoma by interacting with SRP pathway components and enhancing the secretion of CKAP4-containing exosomes

BackgroundAs a ribosome receptor, LRRC59 was thought to regulate mRNA translation on the ER membrane. Evidence suggests that LRRC59 is overexpressed in a number of human malignancies and is associated with poor prognoses, but its primary biological function in the development of oral squamous cell carcinoma (OSCC) remains obscure. ObjectiveThe purpose of this study is to investigate at the expression changes and functional role of LRRC59 in OSCC. MethodsLRRC59 gene expression and correlation with prognosis of OSCC patients were first examined using the data from The Cancer Genome Atlas (TCGA) databases. Following that, a series of functional experiments, including cell counting kit-8, cell cycle analysis, wound healing assays, and transwell assays, were carried out to analyze the biological roles of LRRC59 in tumor cells. Mechanistically, we employed Tandem Affinity Purification-Mass Spectrometry (TAP-MS) approach to isolate and identify protein complexes of LRRC59. Downstream regulatory proteins of LRRC59 were verified through immunoprecipitation and immunofluorescence experiments. Furthermore, we isolated exosomes from OSCC cell supernatant and conducted co-culture experiments to examine the effect of LRRC59 knockdown on OSCC cells. ResultsIn samples from OSCC patients, LRRC59 was highly expressed and correlated with poor prognoses. Moreover, the gene sets analysis based on TCGA RNA-seq data indicated that LRRC59 seemed to be strongly related with protein secretory and OSCC migration. Upregulated levels of LRRC59 are more prone to lymph node metastasis in OSCC patients. LRRC59 knockdown impaired the ability of OSCC cell proliferation, migration, and invasion invitro. Mechanistically, our TAP-MS data situate LRRC59 in a functional nexus for mRNA translation regulation via interactions with SRP pathway components, translational initiation factors, CRD-mediated mRNA stabilization factors. More importantly, we found that LRRC59 interacted with cytoskeleton-associated protein 4 (CKAP4) and promoted the formation of CKAP4-containing exosomes. We also revealed that the LRRC59-CKAP4 axis was a crucial regulator of CKAP4-containing exosome secretion in OSCC cells for migration and invasion. ConclusionsTherefore, based on our findings, LRRC59 may serve as a potential biomarker for OSCC patients, and LRRC59-induced exosome secretion via the CKAP4 axis may serve as a potential therapeutic target for OSCC.

USP14 promotes the cancer stem-like cell properties of OSCC via promoting SOX2 deubiquitination.

USP14 (Ubiquitin-specific-processing protease 14) is a deubiquitinating enzyme with oncogenic effects in oral squamous cell carcinoma (OSCC). This study aims to identify new substrates of USP14 and elucidate their role in modulating cancer stem-like cells (CSCs) in OSCC. Bioinformatics prediction and docking were performed using UbiBrowser 2.0 and HDOCK, respectively. OSCC cell lines and patient-derived cells were used for experimental validation, employing co-immunoprecipitation, cycloheximide chase assays, and tumor sphere formation to evaluate the effects of USP14 on SOX2 stability, ubiquitination, and CSC phenotypes. USP14 upregulation was associated with worse overall survival and progression-free interval in OSCC. USP14 interacted with SOX2 with its ubiquitin carboxyl-terminal hydrolase domain. USP14 knockdown impaired SOX2 stability by increasing its polyubiquitination. Ectopic overexpression of wild-type USP14, but not the hydrolase-deficient-mutant USP14C114A , enhanced SOX2 stability by reducing polyubiquitination. USP14 knockdown suppressed OSCC cell proliferation, colony formation, and tumor sphere formation invitro and tumor growth invivo. However, the reduction of CSC markers following USP14 knockdown was mitigated by overexpressing SOX2. These findings were verified in OSCC patient-derived CSC cells. This study revealed a USP14-SOX2 axis regulating the CSC properties of OSCC.

IL-36 antagonism blunts the proliferation and migration of oral squamous cell carcinoma cells

IL-36 is known to mediate inflammation and fibrosis. Nevertheless, IL-36 signalling axis has also been implicated in cancer, although understanding of exact contribution of IL-36 to cancer progression is very limited, partly due to existence of multiple IL-36 ligands with agonistic and antagonistic function. Here we explored the role of IL-36 in oral squamous cell carcinoma (OSCC). Firstly, we analyzed expression of IL-36 ligands and receptor and found that the expression of IL-36γ was significantly higher in head and neck cancer (HNSCC) than that of normal tissues, and that the high expression of IL-36γ predicted poor clinical outcomes. Secondly, we investigated the direct effect of IL-36γ on OSCC cells and found that IL-36γ stimulated proliferation of OSCC cells with high expression of IL-36R expression. Interestingly, IL-36γ also promoted migration of OSCC cells with low to high IL-36R expression. Critically, both proliferation and migration of OSCC cells induced by IL-36γ were abrogated by anti-IL-36R mAb. Fittingly, RNA sequence analysis revealed that IL-36γ regulated genes involved in cell cycle and cell division. In summary, our results showed that IL-36γ can be a tumor-promoting factor, and targeting of IL-36R signalling may be a beneficial targeted therapy for patients with abnormal IL-36 signalling.

The effect of c-Fos on the prognosis, proliferation, and invasion of oral squamous cell carcinoma.

This study aimed to determine the role of c-Fos in growth and invasion of oral squamous cell carcinoma (OSCC). Immunohistochemistry was used to assess c-Fos expression in 94 OSCC tissues and 30 adjacent normal tissues, the correlation between c-Fos expression and clinicopathological characteristics was examined, and Kaplan-Meier and Cox analysis were used to investigate the role of c-Fos in predicting the prognosis of OSCC patients. The effects of c-Fos on the growth and invasion of OSCC were disclosed by overexpression and knockdown of c-Fos. Furthermore, based on bioinformatics prediction, the effect of miR-155-5p on c-Fos expression was examined, and dual-luciferase reporter assay system was used to determine whether miR-155-5p regulated the transcriptional activity of c-Fos in OSCC. c-Fos was markedly increased in OSCC tissues and cells. c-Fos upregulation indicates a poor prognosis in OSCC patients, and c-Fos promotes cell proliferation, migration, and invasion in OSCC. miR-155-5p could regulate the expression and the transcriptional activity of c-Fos by directly targeting the c-Fos 3'-UTR. This study demonstrated that c-Fos contributed to the progression of OSCC and may act as a potential target for OSCC therapy, and a potential prognostic biomarker of OSCC.

Cisplatin-based miRNA delivery strategy inspired by the circCPNE1/miR-330-3p pathway for oral squamous cell carcinoma

Circular RNAs (circRNAs) are ideal biomarkers of oral squamous cell carcinoma (OSCC) because of their highly stable closed-loop structure, and they can act as microRNA (miRNA) sponges to regulate OSCC progression. By analyzing clinical samples, we identified circCPNE1, a dysregulated circRNA in OSCC, and its expression level was negatively correlated with the clinical stage of OSCC patients. Gain-of-function assays revealed the tumor-suppressive effect of circCPNE1, which was then identified as a miR-330-3p sponge. MiR-330-3p was recognized as a tumor promoter in multiple studies, consistent with our finding that it could promote the proliferation, migration, and invasion of OSCC cells. These results indicated that selective inhibition of miR-330-3p could be an effective strategy to inhibit OSCC progression. Therefore, we designed cationic polylysine-cisplatin prodrugs to deliver antagomiR-330-3p (a miRNA inhibitory analog) via electrostatic interactions to form PP@miR nanoparticles (NPs). Paratumoral administration results revealed that PP@miR NPs effectively inhibited subcutaneous tumor progression and achieved partial tumor elimination (2/5), which confirmed the critical role of miR-330-3p in OSCC development. These findings provide a new perspective for the development of OSCC treatments.

A pH‐Sensitive Smart Monomer Prevents Oral Cancer Progression

Oral squamous cell carcinoma (OSCC) is a prevalent cancer worldwide, and the development of anti‐OSCC materials is urgent. The tumor microenvironment has been identified as a significant characteristic of cancer, with the pHe value in OSCC ranging from 6.56 to 6.97. Given the acidic nature of OSCC, the creation of pH‐sensitive antitumor materials has become a prominent area of research. A pH‐sensitive tertiary amine monomer, dodecylmethylaminoethyl methacrylate (DMAEM), has been previously synthesized. This study aims to evaluate the impact of DMAEM on OSCC. The results demonstrated that DMAEM inhibited the proliferation, migration, and invasion of OSCC cells. Furthermore, it promoted apoptosis and autophagy of OSCC cells, with its anti‐OSCC effect being strengthened in the acidic environment. In a subcutaneous transplantation tumor model, DMAEM inhibited the growth of OSCC and expression of Ki‐67. The analysis of 16S rDNA sequencing data revealed that DMAEM had no significant impact on the Alpha/Beta diversity of the gastrointestinal tract microbiota in mice and had minimal effect on its composition. Overall, this study suggests that DMAEM exhibits pH‐responsive behavior in the acidic tumor microenvironment, effectively inhibiting OSCC without disturbing the gastrointestinal microbiota. These findings highlight the potential of DMAEM for clinical applications in OSCC treatment.