Oral squamous cell carcinoma (OSCC) accounts for over 90% of oral malignancies, with more than 370 000 new cases and approximately 188 000 deaths annually worldwide. In China, there are roughly 65 000 new cases and 35 000 deaths each year, showing a significant upward trend compared with 2015 statistics. Despite continuous advancements in treatment modalities, the 5-year survival rate remains stagnant at 50%-60%, where tumor heterogeneity and therapy resistance persist as fundamental barriers to precision oncology. To address these critical challenges, this study established a standardized bioban-king protocol for OSCC patient-derived organoids (PDOs) (Patent: Method for constructing an oral squamous cell carcinoma organoid bank, ZL202311378598.3). Through groundbreaking optimization of culture media, enzymatic digestion kinetics, and stepwise cryopreservation, we achieved a biobanking success rate exceeding 95% and pioneered synchronous cultivation of matched primary tumors, lymph node metastases, and adjacent normal mucosa from individual patients, preserving spatial heterogeneity and stromal interactions. Leveraging this platform, we developed high-throughput drug screening: Quantified heterogeneity-driven differential chemoresponse using adenosine triphosphate (ATP)-based viability assays; We discovered resistance mechanisms: Identified sialylated cancer IgG (SIA-cIgG)-mediated cis-platin resistance (primary/secondary) through PTPN13 suppression, with anti-SIA-cIgG combination therapy demonstrating synergistic efficacy. Besides, we elucidated metastatic drivers: CRISPR-Cas9-edited organoids revealed WDR54 promoted metastasis via H3K4me3/H4K16ac epigenetic reprogramming, activating epithelial-mesenchymal plasticity (EMP) and inducing partial epithelial-mesenchymal transition (pEMT). This "holographic patient-mirroring" platform provided unprecedented resolution for OSCC precision therapy and had been formally incorporated into the Chinese Stomatological Association Technical Guidelines (Technical guideline for establishing patient-derived oral squamous cell carcinoma organoid banks, CHSA 2024-08). Future integration of immune-competent organoids, 3D-bioprinted vasculature, and multi-omics-AI systems will accelerate personalized oncology. These innovations will accelerate clinical translation of personalized therapeutic regimens, ultimately bridging the gap between bench research and bedside application.
Humans ; Organoids/pathology* ; Mouth Neoplasms/genetics* ; Carcinoma, Squamous Cell/pathology* ; Tissue Banks ; Biological Specimen Banks

Perineural invasion (PNI) by tumor cells is a key phenotype of highly-invasive oral squamous cell carcinoma (OSCC). Since Schwann cells (SCs) and fibroblasts maintain the physiological homeostasis of the peripheral nervous system, and we have focused on cancer-associated fibroblasts (CAFs) for decades, it's imperative to elucidate the impact of CAFs on SCs in PNI⁺ OSCCs. We describe a disease progression-driven shift of PNI^- towards PNI⁺ during the progression of early-stage OSCC (31%, n = 125) to late-stage OSCC (53%, n = 97), characterized by abundant CAFs and nerve demyelination. CAFs inhibited SC proliferation/migration and reduced neurotrophic factors and myelin in vitro, and this involved up-regulated ER stress and decreased MAPK signals. Moreover, CAFs also aggravated the paralysis of the hind limb and PNI in vivo. Unexpectedly, leukemia inhibitory factor (LIF) was exclusively expressed on CAFs and up-regulated in metastatic OSCC. The LIF inhibitor EC330 restored CAF-induced SC inactivation. Thus, OSCC-derived CAFs inactivate SCs to aggravate nerve injury and PNI development.
Schwann Cells/metabolism* ; Mouth Neoplasms/metabolism* ; Humans ; Cancer-Associated Fibroblasts/metabolism* ; Animals ; Carcinoma, Squamous Cell/metabolism* ; Neoplasm Invasiveness/pathology* ; Male ; Female ; Mice ; Cell Movement/physiology* ; Cell Proliferation/physiology* ; Cell Line, Tumor ; Leukemia Inhibitory Factor/metabolism* ; Middle Aged

Cancer stem cells (CSCs) are widely acknowledged as primary mediators to the initiation and progression of tumors. The association between microbial infection and cancer stemness has garnered considerable scholarly interest in recent years. Porphyromonas gingivalis (P. gingivalis) is increasingly considered to be closely related to the development of oral squamous cell carcinoma (OSCC). Nevertheless, the role of P. gingivalis in the stemness of OSCC cells remains uncertain. Herein, we showed that P. gingivalis was positively correlated with CSC markers expression in human OSCC specimens, promoted the stemness and tumorigenicity of OSCC cells, and enhanced tumor formation in nude mice. Mechanistically, P. gingivalis increased lipid synthesis in OSCC cells by upregulating the expression of stearoyl-CoA desaturase 1 (SCD1) expression, a key enzyme involved in lipid metabolism, which ultimately resulted in enhanced acquisition of stemness. Moreover, SCD1 suppression attenuated P. gingivalis-induced stemness of OSCC cells, including CSCs markers expression, sphere formation ability, chemoresistance, and tumor growth, in OSCC cells both in vitro and in vivo. Additionally, upregulation of SCD1 in P. gingivalis-infected OSCC cells was associated with the expression of KLF5, and that was modulated by P. gingivalis-activated NOD1 signaling. Taken together, these findings highlight the importance of SCD1-dependent lipid synthesis in P. gingivalis-induced stemness acquisition in OSCC cells, suggest that the NOD1/KLF5 axis may play a key role in regulating SCD1 expression and provide a molecular basis for targeting SCD1 as a new option for attenuating OSCC cells stemness.
Porphyromonas gingivalis/pathogenicity* ; Stearoyl-CoA Desaturase/metabolism* ; Humans ; Carcinoma, Squamous Cell/pathology* ; Mouth Neoplasms/metabolism* ; Animals ; Neoplastic Stem Cells/microbiology* ; Mice, Nude ; Mice ; Nod1 Signaling Adaptor Protein/metabolism* ; Kruppel-Like Transcription Factors/metabolism* ; Cell Line, Tumor

Hypoxia and aberrant activation of epidermal growth factor receptor (EGFR) are considered important features of various malignancies. However, whether hypoxia can directly trigger EGFR activation and its clinical implications remain unclear. In this study, we demonstrated that in oral cancer, a typical hypoxic tumor, hypoxia can induce chronic but constitutive phosphorylation of wild-type EGFR in the absence of ligands. Oral cancer cell lines exhibit different EGFR phosphorylation responses to hypoxia. In hypoxic HN4 and HN6 cells, ubiquitination-mediated endocytosis, lysosomal sorting, and degradation lead to low levels of EGFR phosphorylation. However, in CAL-27 and HN30 cells, a novel HIF-1α-induced long noncoding RNA (lncRNA), EUDAL, can compete with the E3 ligase/adaptor complex c-Cbl/Grb2 for binding to EGFR, stabilizing phosphorylated EGFR (pEGFR) and resulting in sustained activation of EGFR and its downstream STAT3/BNIP3 signaling. STAT3/BNIP3-mediated autophagy leads to antitumor drug resistance. A high EUDAL/EGFR/STAT3/autophagy pathway activation predicts poor response to chemotherapy in oral cancer patients. Collectively, hypoxia can induce noncanonical ligand-independent EGFR phosphorylation. High EUDAL expression facilitates sustained EGFR phosphorylation in hypoxic tumor cells and leads to autophagy-related drug resistance.
Humans ; ErbB Receptors/metabolism* ; Mouth Neoplasms/pathology* ; RNA, Long Noncoding/genetics* ; Drug Resistance, Neoplasm/genetics* ; Cell Line, Tumor ; Phosphorylation ; Signal Transduction ; STAT3 Transcription Factor/metabolism* ; Cell Hypoxia ; Autophagy ; Proto-Oncogene Proteins c-cbl/metabolism*

As the field of oral pathology has evolved, the nomenclature and classification of oral mucosal diseases with a remarkable risk of malignant transformation have undergone several modifications. In 2005, the World Health Organization (WHO) introduced the concept of oral potentially malignant disorders (OPMDs) as an alternative to the terms for oral precancerous lesions and precancerous conditions. In the consensus report by the WHO Collaborating Center for Oral Cancer of 2021, OPMD is defined as "any oral mucosal abnormality that is associated with a statistically increased risk of developing oral cancer."This definition encompasses a range of conditions, in-cluding oral leukoplakia, oral submucous fibrosis, proliferative verrucous leukoplakia, oral lichen planus, and other lesions. In light of the complex etiology, unclear pathogenesis, and carcinogenesis of OPMDs, early and precise diagnosis and treatment can contribute to the secondary prevention of oral cancer. For this reason, this review, which aims to provide a basis for the precise clinical diagnosis of OPMDs, was performed. Its aim was achieved by reviewing the historical evolution and research progress of the nomenclature, classification, and histopathological diagnostic criteria of OPMDs.
Humans ; Mouth Neoplasms/diagnosis* ; Precancerous Conditions/diagnosis* ; Leukoplakia, Oral/diagnosis* ; Lichen Planus, Oral/pathology* ; Oral Submucous Fibrosis/pathology* ; Mouth Mucosa/pathology* ; World Health Organization

OBJECTIVES: To investigate the mechanism of PHPS1 for promoting apoptosis of oral squamous cell carcinoma cells and the role of AMPK in regulating tumor angiogenesis under hypoxic conditions. METHODS: Human oral squamous cell carcinoma Ca9-22 cells cultured in hypoxic conditions (1% O₂) were inoculated subcutaneously in 16 nude mice, which were divided into control group and PHPS1 group (n=8) for treatment with 10% DMSO and 10% PHPS1 respectively. Tumor growth in the mice was monitored till 14 days after the treatment, and the xenografts were examined pathologically using HE staining. In Ca9-22 cells cultured in 1% O₂, the effect of PHPS1, compound C (an AMPK inhibitor), and their combination on expressions of SHP-2, AMPK, HIF-1α, PD-L1, caspase-8, caspase-3 and BAX were evaluated using Western blotting. RESULTS: In the tumor-bearing nude mice, PHPS1 treatment significantly inhibited tumor growth and neovascularization. HE staining showed significantly reduced tumor angiogenesis in PHPS1-treated mice. In Ca9-22 cells in hypoxic cultures, PHPS1 treatment significantly decreased the expression levels of SHP-2, HIF-1α, PD-L1, ERK2, STAT3 and VEGF and increased the expression of AMPK. The inhibitory effects of PHPS1 on HIF-1α and PD-L1 were obviously attenuated by the addition of compound C. PHPS1 also enhanced the expressions of caspase-3, caspase-8 and Bax proteins and increased the phosphorylation levels of PD-L1 and S195 in Ca9-22 cells, and these effects were effectively attenuated by compound C. CONCLUSIONS PHPS1 can enhance PD-L1 serine phosphorylation by regulating SHP-2/AMPK activity to promote apoptosis of oral squamous cell carcinoma cells under hypoxic conditions.
Animals ; B7-H1 Antigen/metabolism* ; Apoptosis/drug effects* ; Mice ; Carcinoma, Squamous Cell/pathology* ; Cell Line, Tumor ; Mouth Neoplasms/pathology* ; Mice, Nude ; Humans ; AMP-Activated Protein Kinases/metabolism* ; Phosphorylation ; Protein Tyrosine Phosphatase, Non-Receptor Type 11/metabolism* ; Reactive Oxygen Species/metabolism* ; Neovascularization, Pathologic/metabolism* ; Hypoxia-Inducible Factor 1, alpha Subunit/metabolism*

Oral squamous cell carcinoma (OSCC) is a prevalent malignant tumor affecting the head and neck region (Leemans et al., 2018). It is often diagnosed at a later stage, leading to a poor prognosis (Muzaffar et al., 2021; Li et al., 2023). Despite advances in OSCC treatment, the overall 5-year survival rate of OSCC patients remains alarmingly low, falling below 50% (Jehn et al., 2019; Johnson et al., 2020). According to statistics, only 50% of patients with oral cancer can be treated with surgery. Once discovered, it is more frequently at an advanced stage. In addition, owing to the aggressively invasive and metastatic characteristics of OSCC, most patients die within one year of diagnosis. Hence, the pursuit of novel therapeutic drugs and treatments to improve the response of oral cancer to medication, along with a deeper understanding of their effects, remains crucial objectives in oral cancer research (Johnson et al., 2020; Bhat et al., 2021; Chen et al., 2023; Ruffin et al., 2023).
Humans ; Mouth Neoplasms/pathology* ; Carcinoma, Squamous Cell/metabolism* ; Luteolin/therapeutic use* ; Squamous Cell Carcinoma of Head and Neck/drug therapy* ; Head and Neck Neoplasms/drug therapy* ; Cell Line, Tumor

Carcinoma-associated fibroblasts (CAFs) are the main cellular components of the tumor microenvironment and promote cancer progression by modifying the extracellular matrix (ECM). The tumor-associated ECM is characterized by collagen crosslinking catalyzed by lysyl oxidase (LOX). Small extracellular vesicles (sEVs) mediate cell-cell communication. However, the interactions between sEVs and the ECM remain unclear. Here, we demonstrated that sEVs released from oral squamous cell carcinoma (OSCC)-derived CAFs induce collagen crosslinking, thereby promoting epithelial-mesenchymal transition (EMT). CAF sEVs preferably bound to the ECM rather than being taken up by fibroblasts and induced collagen crosslinking, and a LOX inhibitor or blocking antibody suppressed this effect. Active LOX (αLOX), but not the LOX precursor, was enriched in CAF sEVs and interacted with periostin, fibronectin, and bone morphogenetic protein-1 on the surface of sEVs. CAF sEV-associated integrin α2β1 mediated the binding of CAF sEVs to collagen I, and blocking integrin α2β1 inhibited collagen crosslinking by interfering with CAF sEV binding to collagen I. CAF sEV-induced collagen crosslinking promoted the EMT of OSCC through FAK/paxillin/YAP pathway. Taken together, these findings reveal a novel role of CAF sEVs in tumor ECM remodeling, suggesting a critical mechanism for CAF-induced EMT of cancer cells.
Humans ; Paxillin/metabolism* ; Protein-Lysine 6-Oxidase/metabolism* ; Carcinoma, Squamous Cell/pathology* ; Epithelial-Mesenchymal Transition ; Integrin alpha2beta1/metabolism* ; Mouth Neoplasms/pathology* ; Collagen/metabolism* ; Fibroblasts ; Extracellular Vesicles/metabolism* ; Cell Line, Tumor ; Tumor Microenvironment

Oral squamous cell carcinoma (OSCC) escape from the immune system is mediated through several immunosuppressive phenotypes that are critical to the initiation and progression of tumors. As a hallmark of cancer, DNA damage repair is closely related to changes in the immunophenotypes of tumor cells. Although flap endonuclease-1 (FEN1), a pivotal DNA-related enzyme is involved in DNA base excision repair to maintain the stability of the cell genome, the correlation between FEN1 and tumor immunity has been unexplored. In the current study, by analyzing the clinicopathological characteristics of FEN1, we demonstrated that FEN1 overexpressed and that an inhibitory immune microenvironment was established in OSCC. In addition, we found that downregulating FEN1 inhibited the growth of OSCC tumors. In vitro studies provided evidence that FEN1 knockdown inhibited the biological behaviors of OSCC and caused DNA damage. Performing multiplex immunohistochemistry (mIHC), we directly observed that the acquisition of critical immunosuppressive phenotypes was correlated with the expression of FEN1. More importantly, FEN1 directly or indirectly regulated two typical immunosuppressive phenotype-related proteins human leukocyte antigen (HLA-DR) and programmed death receptor ligand 1 (PD-L1), through the interferon-gamma (IFN-γ)/janus kinase (JAK)/signal transducer and activator transcription 1 (STAT1) pathway. Our study highlights a new perspective on FEN1 action for the first time, providing theoretical evidence that it may be a potential immunotherapy target for OSCC.
Humans ; Carcinoma, Squamous Cell/pathology* ; DNA ; Down-Regulation ; Flap Endonucleases/metabolism* ; Head and Neck Neoplasms ; Interferon-gamma/metabolism* ; Mouth Neoplasms/pathology* ; Phenotype ; Squamous Cell Carcinoma of Head and Neck ; Tumor Microenvironment ; Janus Kinases/metabolism*

Poly Adenylate Binding Protein Interacting protein 1 (PAIP1) plays a critical role in translation initiation and is associated with the several cancer types. However, its function and clinical significance have not yet been described in oral squamous cell carcinoma (OSCC) and its associated features like lymph node metastasis (LNM). Here, we used the data available from Gene Expression Omnibus (GEO), The Cancer Genome Atlas (TCGA), and Clinical Proteomic Tumor Analysis Consortium (CPTAC) to analyze PAIP1 expression in oral cancer. The publicly available data suggests that PAIP1 mRNA and protein levels were increased in OSCC. The high PAIP1 expression was more evident in samples with advanced stage, LNM, and worse pattern of invasion. Moreover, the in vitro experiments revealed that PAIP1 knockdown attenuated colony forming, the aggressiveness of OSCC cell lines, decreasing MMP9 activity and SRC phosphorylation. Importantly, we found a correlation between PAIP1 and pSRC through the analysis of the IHC scores and CPTAC data in patient samples. Our findings suggest that PAIP1 could be an independent prognostic factor in OSCC with LNM and a suitable therapeutic target to improve OSCC patient outcomes.
Carcinoma, Squamous Cell/genetics* ; Head and Neck Neoplasms ; Humans ; Lymphatic Metastasis ; Mouth Neoplasms/pathology* ; Peptide Initiation Factors/metabolism* ; Prognosis ; Proteomics ; RNA-Binding Proteins/metabolism* ; Squamous Cell Carcinoma of Head and Neck