CSChighE-cadherinlow immunohistochemistry panel predicts poor prognosis in oral squamous cell carcinoma.

Identifying marker combinations for robust prognostic validation in primary tumour compartments remains challenging. We aimed to assess the prognostic significance of CSC markers (ALDH1, CD44, p75NTR, BMI-1) and E-cadherin biomarkers in OSCC. We analysed 94 primary OSCC and 67 metastatic lymph node samples, including central and invasive tumour fronts (ITF), along with clinicopathological data. We observed an increase in ALDH1+/CD44+/BMI-1- tumour cells in metastatic lesions compared to primary tumours. Multivariate analysis highlighted that elevated p75NTR levels (at ITF) and reduced E-cadherin expression (at the tumour centre) independently predicted metastasis, whilst ALDH1high exhibited independent predictive lower survival at the ITF, surpassing the efficacy of traditional tumour staging. Then, specifically at the ITF, profiles characterized by CSChighE-cadherinlow (ALDH1highp75NTRhighE-cadherinlow) and CSCintermediateE-cadherinlow (ALDH1 or p75NTRhighE-cadherinlow) were significantly associated with worsened overall survival and increased likelihood of metastasis in OSCC patients. In summary, our study revealed diverse tumour cell profiles in OSCC tissues, with varying CSC and E-cadherin marker patterns across primary tumours and metastatic sites. Given the pivotal role of reduced survival rates as an indicator of unfavourable prognosis, the immunohistochemistry profile identified as CSChighE-cadherinlow at the ITF of primary tumours, emerges as a preferred prognostic marker closely linked to adverse outcomes in OSCC.

Chaga mushroom extract suppresses oral cancer cell growth via inhibition of energy metabolism.

Oral cancer stands as a prevalent maligancy worldwide; however, its therapeutic potential is limited by undesired effects and complications. As a medicinal edible fungus, Chaga mushroom (Inonotus obliquus) exhibits anticancer effects across diverse cancers. Yet, the precise mechanisms underlying its efficacy remain unclear. We explored the detailed mechanisms underlying the anticancer action of Chaga mushroom extract in oral cancer cells (HSC-4). Following treatment with Chaga mushroom extracts, we analyzed cell viability, proliferation capacity, glycolysis, mitochondrial respiration, and apoptosis. Our findings revealed that the extract reduced cell viability and proliferation of HSC-4 cells while arresting their cell cycle via suppression of STAT3 activity. Regarding energy metabolism, Chaga mushroom extract inhibited glycolysis and mitochondrial membrane potential in HSC-4 cells, thereby triggering autophagy-mediated apoptotic cell death through activation of the p38 MAPK and NF-κB signaling pathways. Our results indicate that Chaga mushroom extract impedes oral cancer cell progression, by inhibiting cell cycle and proliferation, suppressing cancer cell energy metabolism, and promoting autophagy-mediated apoptotic cell death. These findings suggest that this extract is a promising supplementary medicine for the treatment of patients with oral cancer.

An Update on the Use of Artificial Intelligence in Digital Pathology for Oral Epithelial Dysplasia Research.

INTRODUCTION: Oral epithelial dysplasia (OED) is a precancerous histopathological finding which is considered the most important prognostic indicator for determining the risk of malignant transformation into oral squamous cell carcinoma (OSCC). The gold standard for diagnosis and grading of OED is through histopathological examination, which is subject to inter- and intra-observer variability, impacting accurate diagnosis and prognosis. The aim of this review article is to examine the current advances in digital pathology for artificial intelligence (AI) applications used for OED diagnosis. MATERIALS AND METHODS: We included studies that used AI for diagnosis, grading, or prognosis of OED on histopathology images or intraoral clinical images. Studies utilizing imaging modalities other than routine light microscopy (e.g., scanning electron microscopy), or immunohistochemistry-stained histology slides, or immunofluorescence were excluded from the study. Studies not focusing on oral dysplasia grading and diagnosis, e.g., to discriminate OSCC from normal epithelial tissue were also excluded. RESULTS: A total of 24 studies were included in this review. Nineteen studies utilized deep learning (DL) convolutional neural networks for histopathological OED analysis, and 4 used machine learning (ML) models. Studies were summarized by AI method, main study outcomes, predictive value for malignant transformation, strengths, and limitations. CONCLUSION: ML/DL studies for OED grading and prediction of malignant transformation are emerging as promising adjunctive tools in the field of digital pathology. These adjunctive objective tools can ultimately aid the pathologist in more accurate diagnosis and prognosis prediction. However, further supportive studies that focus on generalization, explainable decisions, and prognosis prediction are needed.

Challenges in the Assessment of Medullary Bone Invasion in Oral Cavity Cancers and Its Prognostic Significance.

BACKGROUND: As per AJCC 8th edition TNM staging system, bone invasion is a poor prognostic marker that upstages oral cavity squamous carcinoma (OSCC) to pT4a. Cortical erosion alone of bone or tooth socket by a gingival primary is not sufficient to upstage a tumour. The differentiation of cortical erosion from invasion through the cortical bone into the medulla is often challenging, limiting accurate staging. This review aims to assess the difficulties in differentiating cortical erosion from medullary invasion and evaluate the prognostic significance of different patterns of bone involvement. METHODS: A retrospective review of OSCC with primary curative surgery and bone resection treated at a single-center over 10 years, was performed to assess the prognostic significance of bone invasion. Hematoxylin-eosin stained slides of a subset of cases were re-reviewed in a planned manner to assess difficulties in precise categorization (no invasion/erosion/cortical invasion and medullary invasion), evaluate interobserver agreement, and correlate with clinical outcome. RESULTS: Five hundred and ninety patients were included, with a median follow-up of 28 months. On univariate analysis, the 3-year local, nodal and distant metastasis control were not significantly different in the 3 groups of no invasion, erosion, and invasion (p = 0.43, 0.47, and 0.47, respectively). Overall survival (OS) at 3 years was 78.1% and disease-free-survival(DFS) was 63.7% in the entire cohort. On univariate analysis, there was significant difference in OS and DFS based on these groups. This did not translate into independent prognostic benefit on multivariable analysis (p = 0.75 and 0.19, respectively). The independent prognostic factors were margin positivity, tumor differentiation, perineural invasion and pathological nodal involvement. Planned re-review of a subset of 202 cases resulted in a change in bone involvement category in 26/202 cases, which was mainly due to difficulty in assessing cortico-medullary junction near the tooth socket and bone fragmentation. The assessment showed moderate to near complete agreement (kappa 0.59-0.82) between 2 observers. CONCLUSION: Our study shows that bone involvement is not an independent prognostic marker and there is no specific correlation of medullary invasion with outcome over those that showed cortical erosion. Several factors contribute to difficulties and interobserver variability in assessing bone involvement.

WNT3 promotes chemoresistance to 5-Fluorouracil in oral squamous cell carcinoma via activating the canonical ß-catenin pathway.

BACKGROUND: 5-Fluorouracil (5FU) is a primary chemotherapeutic agent used to treat oral squamous cell carcinoma (OSCC). However, the development of drug resistance has significantly limited its clinical application. Therefore, there is an urgent need to determine the mechanisms underlying drug resistance and identify effective targets. In recent years, the Wingless and Int-1 (WNT) signaling pathway has been increasingly studied in cancer drug resistance; however, the role of WNT3, a ligand of the canonical WNT signaling pathway, in OSCC 5FU-resistance is not clear. This study delved into this potential connection. METHODS: 5FU-resistant cell lines were established by gradually elevating the drug concentration in the culture medium. Differential gene expressions between parental and resistant cells underwent RNA sequencing analysis, which was then substantiated via Real-time quantitative PCR (RT-qPCR) and western blot tests. The influence of the WNT signaling on OSCC chemoresistance was ascertained through WNT3 knockdown or overexpression. The WNT inhibitor methyl 3-benzoate (MSAB) was probed for its capacity to boost 5FU efficacy. RESULTS: In this study, the WNT/ß-catenin signaling pathway was notably activated in 5FU-resistant OSCC cell lines, which was confirmed through transcriptome sequencing analysis, RT-qPCR, and western blot verification. Additionally, the key ligand responsible for pathway activation, WNT3, was identified. By knocking down WNT3 in resistant cells or overexpressing WNT3 in parental cells, we found that WNT3 promoted 5FU-resistance in OSCC. In addition, the WNT inhibitor MSAB reversed 5FU-resistance in OSCC cells. CONCLUSIONS: These data underscored the activation of the WNT/ß-catenin signaling pathway in resistant cells and identified the promoting effect of WNT3 upregulation on 5FU-resistance in oral squamous carcinoma. This may provide a new therapeutic strategy for reversing 5FU-resistance in OSCC cells.

Diagnostic accuracy of contrast-enhanced computed tomography in assessing bone invasion in patients with oral squamous cell carcinoma.

OBJECTIVES: This study aimed to evaluate the diagnostic accuracy of contrast-enhanced computed tomography (CT) in detecting bone invasion in oral squamous cell carcinoma (OSCC) patients and to explore clinicopathological factors associated with its reliability. MATERIALS AND METHODS: 417 patients underwent preoperative contrast-enhanced CT followed by radical surgery. The presence or absence of bone invasion served as the outcome variable, with histopathologic examination of the resection specimen considered the gold standard. Statistical analyses, comprising correlation analyses and the determination of sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV), were conducted. RESULTS: CT exhibited 76.85% sensitivity, 82.20% specificity, 47.14% PPV, and 89.67% NPV. False-positive and false-negative rates were 11.27% and 5.99%, respectively. Artifacts affected assessment in 44 patients, but not in those with bone invasion. Tumor size, depth of invasion (DOI), tumor localization at the upper jaw, lymphatic invasion, and perineural invasion correlated with incorrect identification of bone invasion (Chi-square, p < 0.05). CONCLUSIONS: Despite utilizing thin-section CT, notable false-positive and false-negative results persisted. Patients with T3 tumors, DOI ≥ 10 mm, or upper jaw tumors are at higher risk for misidentification of bone invasion. Combining multiple methods may enhance diagnostic accuracy, and the integration of artificial intelligence or tracking electrolyte disturbances by tumor depth profiling shows promise for further assessment of bone invasion before histopathology. CLINICAL RELEVANCE: Surgeons should consider these insights when planning tumor resection. Supplementary imaging may be warranted in cases with high risk factors for misidentification. Further methodological advancements are crucial for enhancing diagnostic precision.

EP4-induced mitochondrial localization and cell migration mediated by CALML6 in human oral squamous cell carcinoma.

Lymph node metastasis, primarily caused by the migration of oral squamous cell carcinoma (OSCC) cells, stands as a crucial prognostic marker. We have previously demonstrated that EP4, a subtype of the prostaglandin E2 (PGE2) receptor, orchestrates OSCC cell migration via Ca2+ signaling. The exact mechanisms by which EP4 influences cell migration through Ca2+ signaling, however, is unclear. Our study aims to clarify how EP4 controls OSCC cell migration through this pathway. We find that activating EP4 with an agonist (ONO-AE1-473) increased intracellular Ca2+ levels and the migration of human oral cancer cells (HSC-3), but not human gingival fibroblasts (HGnF). Further RNA sequencing linked EP4 to calmodulin-like protein 6 (CALML6), whose role remains undefined in OSCC. Through protein-protein interaction network analysis, a strong connection is identified between CALML6 and calcium/calmodulin-dependent protein kinase kinase 2 (CaMKK2), with EP4 activation also boosting mitochondrial function. Overexpressing EP4 in HSC-3 cells increases experimental lung metastasis in mice, whereas inhibiting CaMKK2 with STO-609 markedly lowers these metastases. This positions CaMKK2 as a potential new target for treating OSCC metastasis. Our findings highlight CALML6 as a pivotal regulator in EP4-driven mitochondrial respiration, affecting cell migration and metastasis via the CaMKK2 pathway.

The involvement of epidermal growth factor receptor/protein kinase B signaling in the tumor intrinsic PD-L1-induced malignant potential of oral squamous cell carcinoma.

BACKGROUND: Various antigen-presenting cells and tumor cells-expressing PD-L1 inhibits antitumor immune responses in the tumor microenvironment. Recently, numerous studies have shown that tumor cell intrinsic PD-L1 also plays important roles in tumor growth and progression. On the other hand, oral squamous cell carcinoma (OSCC) cells overexpress epidermal growth factor receptor (EGFR) and EGFR signal pathway exacerbates tumor progression. Therefore, this study assessed whether tumor-intrinsic PD-L1 facilitates malignant potential of OSCC cells through regulation of EGFR signaling. METHODS: Two OSCC cell lines, SAS and HSC-3, were transfected with PD-L1 and EGFR-specific small interfering RNA (siRNA). Influences of PD-L1 knockdown on malignant potentials of OSCC cells were examined by Cell Counting kit-8 assay, transwell assay, sphere formation assay, flow cytometry, and Western blot. Effects of PD-L1 and EGFR knockdown on each expression were examined by quantitative real-time PCR (qRT-PCR), Western blot, and flow cytometry. RESULTS: Transfection of an PD-L1-siRNA into OSCC cells decreased the abilities of proliferation, stemness, and mobility of these cells significantly. PD-L1 knockdown also decreased EGFR expression through the promotion of proteasome- and lysosome-mediated degradation and following activation of the EGFR/protekin kinase B (AKT) signal pathway. Meanwhile, EGFR knockdown did not influence PD-L1 expression in SAS and HSC-3 cells, but treatment with a recombinant human EGF induced its expression. Treatment with erlotinib and cetuximab suppressed rhEGF-induced PD-L1 expression and localization in the cellular membrane of both OSCC cells. CONCLUSION: OSCC cells-expressing PD-L1 induced by EGF stimulation may promote malignancy intrinsically via the activation of the EGFR/AKT signaling cascade.

Survival estimation of oral cancer using fuzzy deep learning.

BACKGROUND: Oral cancer is a deadly disease and a major cause of morbidity and mortality worldwide. The purpose of this study was to develop a fuzzy deep learning (FDL)-based model to estimate the survival time based on clinicopathologic data of oral cancer. METHODS: Electronic medical records of 581 oral squamous cell carcinoma (OSCC) patients, treated with surgery with or without radiochemotherapy, were collected retrospectively from the Oral and Maxillofacial Surgery Clinic and the Regional Cancer Center from 2011 to 2019. The deep learning (DL) model was trained to classify survival time classes based on clinicopathologic data. Fuzzy logic was integrated into the DL model and trained to create FDL-based models to estimate the survival time classes. RESULTS: The performance of the models was evaluated on a test dataset. The performance of the DL and FDL models for estimation of survival time achieved an accuracy of 0.74 and 0.97 and an area under the receiver operating characteristic (AUC) curve of 0.84 to 1.00 and 1.00, respectively. CONCLUSIONS: The integration of fuzzy logic into DL models could improve the accuracy to estimate survival time based on clinicopathologic data of oral cancer.

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

BACKGROUND: Fusobacterium 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. METHODS: In this study, we investigated F. nucleatum effect on OSCC cell proliferation using in vitro and in vivo experiments. RESULTS: Our 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 ß-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 ß-catenin and cycle-related genes. In vivo BALB/c nude experiments showed increased tumor volume and Ki-67 proliferation index after F. nucleatum intervention. CONCLUSION: Our study suggests that F. nucleatum promotes OSCC cell proliferation through the CDH1/ß-catenin pathway, advancing our understanding of its role in OSCC progression and highlighting its potential as a therapeutic target.

Extracellular vesicles from Aggregatibacter actinomycetemcomitans exhibit potential antitumorigenic effects in oral cancer: a comparative in vitro study.

Aggregatibacter actinomycetemcomitans is an opportunistic Gram-negative periodontopathogen strongly associated with periodontitis and infective endocarditis. Recent evidence suggests that periodontopathogens can influence the initiation and progression of oral squamous cell carcinoma (OSCC). Herein we aimed to investigate the effect of A. actinomycetemcomitans-derived extracellular vesicles (EVs) on OSCC cell behavior compared with EVs from periodontopathogens known to associate with carcinogenesis. EVs were isolated from: A. actinomycetemcomitans and its mutant strains lacking the cytolethal distending toxin (CDT) or lipopolysaccharide (LPS) O-antigen; Porphyromonas gingivalis; Fusobacterium nucleatum; and Parvimonas micra. The effect of EVs on primary and metastatic OSCC cells was assessed using cell proliferation, apoptosis, migration, invasion, and tubulogenesis assays. A. actinomycetemcomitans-derived EVs reduced the metastatic cancer cell proliferation, invasion, tubulogenesis, and increased apoptosis, mostly in CDT- and LPS O-antigen-dependent manner. EVs from F. nucleatum impaired the metastatic cancer cell proliferation and induced the apoptosis rates in all OSCC cell lines. EVs enhanced cancer cell migration regardless of bacterial species. In sum, this is the first study demonstrating the influence of A. actinomycetemcomitans-derived EVs on oral cancer in comparison with other periodontopathogens. Our findings revealed a potential antitumorigenic effect of these EVs on metastatic OSCC cells, which warrants further in vivo investigations.

Metastatic sarcomas of the oral cavity: A systematic review.

Oral metastatic sarcomas (OMSs) occur only occasionally, and information about their characteristics is based on the restricted number of cases reported in the literature. This study aims to systematically review the English literature to recognize the clinicopathologic characteristics of OMSs. An electronic search was performed in PubMed Central and Scopus databases. The search included all the published articles (human case reports and case series) up till April 2023, with no time restrictions. OMSs were slightly more prevalent in males in their fifth to seventh decades of life. However, a high percentage of OMSs has been reported in the second decade of life. Lower extremities, breasts and uterus are the most common primary origin of metastatic sarcoma. Gingiva and mandible were common locations in the oral cavity for metastatic deposits. Generally, they demonstrated widespread affliction. The mean time interval between primary tumor detection and diagnosis of the oral metastasis was about 33.54 ± 36.19 months. Death was reported in 83 patients (67.48 %) with a mean survival rate of 7.98 ± 10.30 months. The most common microscopic tumor types were leiomyosarcoma (n = 21, 17 %), followed by angiosarcoma (n = 20, 16.26 %) and osteosarcoma (n = 18, 14.63 %). In conclusion, while oral metastases of sarcomas are not common, those should be considered in the differential diagnosis of the oral lesions. Although OMSs show a high occurrence in the 7th decade of the life, the average age of patients with oral involvement is lower than the overall metastatic lesions. OMSs may present as widespread disease with poor prognosis.

[Precancers of the oral mucosa: clinic, diagnostics]. / Predraki slizistoi obolochki rta: klinika i diagnostika.

OBJECTIVE: The aim of the study. Improving the efficiency of diagnosis and detailing the features of the clinic of «potentially malignant¼ diseases of the oral mucosa. MATERIALS AND METHODS: Clinical and laboratory examination of 124 patients of the department of oral mucosa diseases aged 35 to 80 years, among whom there were 75 women and 49 men, with diseases such as erythroplakia - 12 patients, verrucous leukoplakia - 52 patients, erosive form of leukoplakia - 35 patients, cheilitis Manganotti - 25 patients. Histological and immunohistochemical methods of investigation were used as diagnostics. To assess the proliferative activity of epithelial cells, the determination of the Ki-67 index was used. The synthesis of keratin 15 (K15) in epithelial layers was determined as a diagnostic criterion for the severity of neoplasia. The expression of human papillomavirus type 16 (HPV 16) antigens and p16INK4a protein in epithelial cells was studied, as well as the expression of p53 protein. RESULTS: A high prevalence of p53 mutations was observed in patients with erythroplakia. In leukoplakia, the expression of the Ki-67 protein was detected in the cell nuclei in both the basal and parabasal layers of the multilayer squamous epithelium, in 77% of cases, the expression of the p16INK4a protein in the epithelial nuclei with varying degrees of dysplastic changes was noted, and a positive reaction to HPV16 was also observed in the cell nuclei and cytoplasm of epithelial cells in the basal, parabasal and spiny epithelial layers. The appearance of K15 in the cytoplasm of cells above the basal layer with abrasive precancerous cheilitis was found in 48% of cases. CONCLUSION: To diagnose early manifestations of neoplastic processes in «potentially malignant¼ diseases of the oral mucosa, it is necessary to use both classical histological and immunohistochemical methods of investigation with various markers.

Differences in the response of normal oral mucosa, oral leukoplakia, oral squamous cell carcinoma-derived mesenchymal stem cells, and epithelial cells to photodynamic therapy.

OBJECTIVE: The objective of this study is to investigate the variances in transcriptome gene expression of normal oral mucosa-derived mesenchymal stem cell (OM-MSC), oral leukoplakia-derived MSC (OLK-MSC) and oral squamous cell carcinoma-derived MSC(OSCC-MSC). as Additionally, the study aims to compare the in vitro proliferation, migration, invasion ability, and response to photodynamic therapy (PDT) of these three MSC, HOK, DOK, leuk1, and Cal27 cell lines. METHODS: HOK, DOK, leuk1, Cal27 cells were cultured in vitro. 3 MSC cells were obtained from OM, OLK, OSCC tissue (n = 3) and identified through flow cytometry. They were also cultured in vitro for osteogenic and lipogenic-induced differentiation. Based on the Illumina HiSeq high-throughput sequencing platform, OM-MSC, OLK-MSC, OSCC-MSC (n = 3) were subjected to transcriptome sequencing, functional annotation, and enrichment analysis of differentially expressed genes and related genes. CCK8 assay, wound healing assay, and transwell assay were performed to compare the proliferation, migration, and invasion of the seven types of cells. The 7 cells were incubated with 0, 0.125 mM, 0.25 mM, 0.5 mM, 1 mM, and 2 mM of the photosensitizer (5-aminolevulinic acid, 5-ALA) in vitro. Subsequently, they were irradiated with a 150 mM, 635 nm laser for 1 min, and the cell activity was detected using the CCK8 assay after 24 h. The mitochondrial changes in the 7 cells before and after the treatment of PDT were detected using the JC-10 probe, and the changes in ATP content were measured before and after the PDT treatment. RESULTS: OM-MSC, OLK-MSC, and OSCC-MSC expressed positive MSC surface markers. After osteogenic and lipogenic-induced differentiation culture, stained calcium nodules and lipid droplets were visible, meeting the identification criteria of MSC. Pathway enrichment analysis revealed that the differentially expressed genes (DEGs) of OSCC-MSC compared to OLK-MSC were primarily associated with the PI3K-Akt signaling pathway and tumor-related pathways. OSCC-MSC exhibited stronger migratory and invasive abilities compared to Cal27. The IC50 values required for OM, OLK, and OSCC-derived MSC were lower than those required for epithelial cells treated with PDT, which were 1.396 mM, 0.9063 mM, and 2.924 mM, respectively. Cell membrane and mitochondrial disruption were observed in seven types of cells after 24 h of PDT treatment. However, HOK, DOK, leuk1, and Cal27 cells had an ATP content increased. CONCLUSIONS: OLK, OSCC epithelial cells require higher concentrations of 5-ALA for PDT treatment than MSC of the same tissue origin. The concentration of 5-ALA required increases with increasing cell malignancy. Differences in the response of epithelial cells and MSC to PDT treatment may have varying impacts on OLK recurrence and malignancy.

Pleckstrin Homology Domain Leucine-rich Repeat Protein Phosphatase Acts as a Tumor Suppressor in Oral Squamous Cell Carcinoma.

The pleckstrin homology domain leucine-rich repeat protein phosphatase (PHLPP) family has been found to have both tumor-suppressor and oncogenic properties across various types and locations of cancer. Given that PHLPP has not been previously studied in oral squamous cell carcinoma (SCC), we conducted an assessment of the expression of both its isoforms in oral SCC tissues and cell lines and compared these findings to their corresponding normal counterparts. In addition, we assessed the relationship between PHLPP and clinicopathological factors and patient survival. Quantitative real-time polymerase chain reaction was used to detect the mRNA levels of PHLPP1 and PHLPP2 in cancerous and normal cell lines in addition to 124 oral SCC and noncancerous adjacent epithelia (N = 62, each). Correlations between their expression rate and clinicopathological parameters were further evaluated in 57 patients. Data were statistically analyzed with t test and paired t test, analysis of variance, Mann-Whitney U , and Cox Regression tests ( P < 0.05). We found significantly lower levels of both PHLPP isoforms in oral SCC tissues compared with noncancerous epithelia ( P < 0.001, for both). However, in the cell lines, this difference was significant only for PHLPP1 ( P = 0.027). The correlation between the two isoforms was significant only in cancerous tissues ( P < 0.001). None of the clinicopathologic factors showed significant associations with either of the isoforms and there was no correlation with survival. We showed for the first time that PHLPP1 and PHLPP2 act as tumor suppressors in oral SCC at the mRNA level. The regulation of their mRNA appears to be different between normal and cancerous tissues.

Prevotella intermedia boosts OSCC progression through ISG15 upregulation: a new target for intervention.

PURPOSE: Periodontitis-associated bacteria, such as Porphyromonas gingivalis and Fusobacterium nucleatum, are closely linked to the risk of oral squamous cell carcinoma (OSCC). Emerging studies have indicated that another common periodontal pathogen, Prevotella intermedia (P. intermedia), is enriched in OSCC and could affect the occurrence and progression of OSCC. Our aim is to determine the effects of P. intermedia on the progression of OSCC and the role of antibiotics in reversing these effects. METHODS: In this study, a murine xenograft model of OSCC was established, and the mice were injected intratumorally with PBS (control group), P. intermedia (P.i group), or P. intermedia combined with an antibiotic cocktail administration (P.i + ABX group), respectively. The effects of P. intermedia and ABX administration on xenograft tumor growth, invasion, angiogenesis, and metastasis were investigated by tumor volume measurement and histopathological examination. Enzyme-linked immunosorbent assay (ELISA) was used to investigate the changes in serum cytokine levels. Immunohistochemistry (IHC) was adopted to analyze the alterations in the levels of inflammatory cytokines and infiltrated immune cells in OSCC tissues of xenograft tumors. Transcriptome sequencing and analysis were conducted to determine differential expression genes among various groups. RESULTS: Compared with the control treatment, P. intermedia treatment significantly promoted tumor growth, invasion, angiogenesis, and metastasis, markedly affected the levels of inflammatory cytokines, and markedly altered M2 macrophages and regulatory T cells (Tregs) infiltration in the tumor microenvironment. However, ABX administration clearly abolished these effects of P. intermedia. Transcriptome and immunohistochemical analyses revealed that P. intermedia infection increased the expression of interferon-stimulated gene 15 (ISG15). Correlation analysis indicated that the expression level of ISG15 was positively correlated with the Ki67 expression level, microvessel density, serum concentrations and tissue expression levels of inflammatory cytokines, and quantities of infiltrated M2 macrophages and Tregs. However, it is negatively correlated with the quantities of infiltrated CD4+ and CD8+ T cells. CONCLUSION: In conclusion, intratumoral P. intermedia infection aggravated OSCC progression, which may be achieved through upregulation of ISG15. This study sheds new light on the possible pathogenic mechanism of intratumoral P. intermedia in OSCC progression, which could be a prospective target for OSCC prevention and treatment.

Prevalence and implications of bilateral and solely contralateral lymph node metastases in oral squamous cell carcinoma.

OBJECTIVES: Effective management of neck in oral squamous cell carcinoma (OSCC) is pivotal for oncological outcomes. Although consensus exists for ipsilateral neck dissection (ND), the necessity for contralateral ND remains controversial. This study aimed to assess the prevalence and implications of bilateral/solely contralateral (B/SC) lymph node metastases (LNMs) to determine the need for contralateral elective ND. Additionally, it examined the prevalence and implications of occult B/SC metastases. MATERIALS AND METHODS: In a retrospective cohort study, 420 OSCC patients underwent primary surgical treatment following German guidelines at a tertiary center. Preoperative contrast-enhanced computed tomography was conducted, and ND adhered to a standardized approach. RESULTS: Solely contralateral metastases occurred in 0.95% of patients, with bilateral metastases observed in 7.13%. Occult B/SC metastases occurred in 3.81% of the cases. Correlation analysis revealed a statistically significant association between B/SC metastases and higher tumor stages, tumor localization at the upper jaw or floor of the mouth, proximity to the midline, ipsilateral LNMs, and lymphatic invasion (all p < 0.05). Patients with B/SC metastases showed poorer disease-free survival, with statistical significance reached in the bilateral LNMs group (p = 0.010). Similarly, a significant difference was noted in overall survival between patients with bilateral and solely ipsilateral metastases (p = 0.044). CONCLUSIONS: B/SC LNMs are rare in patients with OSCC, especially in those who present with clinico-radiologically negative ipsilateral necks. Higher rates of B/SC metastases occur in case of advanced tumors and those localized at the upper jaw or floor of the mouth. Ipsilateral LNMs significantly elevate the risk of contralateral LNMs, tripling the associated risk. CLINICAL RELEVANCE: These findings provide valuable insights for surgeons considering contralateral ND or extended adjuvant treatment for OSCC patients. However, the absence of high-level evidence from randomized controlled trials impedes the establishment of a definitive standard of care.

Oral mucosa - an examination map for confocal laser endomicroscopy within the oral cavity: an experimental clinical study.

OBJECTIVES: Confocal laser endomicroscopy (CLE) is an optical method that enables microscopic visualization of oral mucosa. Previous studies have shown that it is possible to differentiate between physiological and malignant oral mucosa. However, differences in mucosal architecture were not taken into account. The objective was to map the different oral mucosal morphologies and to establish a "CLE map" of physiological mucosa as baseline for further application of this powerful technology. MATERIALS AND METHODS: The CLE database consisted of 27 patients. The following spots were examined: (1) upper lip (intraoral) (2) alveolar ridge (3) lateral tongue (4) floor of the mouth (5) hard palate (6) intercalary line. All sequences were examined by two CLE experts for morphological differences and video quality. RESULTS: Analysis revealed clear differences in image quality and possibility of depicting tissue morphologies between the various localizations of oral mucosa: imaging of the alveolar ridge and hard palate showed visually most discriminative tissue morphology. Labial mucosa was also visualized well using CLE. Here, typical morphological features such as uniform cells with regular intercellular gaps and vessels could be clearly depicted. Image generation and evaluation was particularly difficult in the area of the buccal mucosa, the lateral tongue and the floor of the mouth. CONCLUSION: A physiological "CLE map" for the entire oral cavity could be created for the first time. CLINICAL RELEVANCE: This will make it possible to take into account the existing physiological morphological features when differentiating between normal mucosa and oral squamous cell carcinoma in future work.

Nutritional Status and Quality of Life in Patients with Oral Squamous Cell Carcinoma Before and After Surgical Oncological Treatment: A Single-Center Retrospective Study.

BACKGROUND Oral squamous cell carcinoma (OSCC) is the most common of head and neck malignancies in well-developed countries. In most cases, patients with OSCC experience a degree of nutritional status disturbances and decreased quality of life (QoL). This study aimed to compare nutritional status and QoL in 51 patients before and after surgery for OSCC. MATERIAL AND METHODS Fifty-one eligible patients with OSCC were followed during a 3-year period (2019-2022). For all patients, we determined body mass index (BMI), serum albumin (ALB), prognostic nutritional index, and nutritional risk index before and after treatment. Also, all patients completed a standardized QoL questionnaire before and after treatment. The obtained data were compared between the groups by using the t test and multivariate Cox regression. RESULTS The values of BMI and NRI were statistically significantly different between the preoperative and postoperative measurements (24.1 kg/m² vs 21.1 kg/m², and 103 vs 100.1, respectively, P=0.001), while values of ALB and prognostic nutritional index did not differ significantly (41.35 g/L vs 39.1 g/L, and 48.5 vs 46.2, respectively). Dysphagia (P=0.03) and chewing problems (P=0.04) were found to be the 2 most important factors decreasing the QoL of patients. CONCLUSIONS Based on our results, BMI and NRI were the most sensitive parameters of nutritional status. Dysphagia and chewing problems were the 2 most important factors affecting the QoL in patients with OSCC.

Genomic Engineering of Oral Keratinocytes to Establish In Vitro Oral Potentially Malignant Disease Models as a Platform for Treatment Investigation.

Precancerous cells in the oral cavity may appear as oral potentially malignant disorders, but they may also present as dysplasia without visual manifestation in tumor-adjacent tissue. As it is currently not possible to prevent the malignant transformation of these oral precancers, new treatments are urgently awaited. Here, we generated precancer culture models using a previously established method for the generation of oral keratinocyte cultures and incorporated CRISPR/Cas9 editing. The generated cell lines were used to investigate the efficacy of a set of small molecule inhibitors. Tumor-adjacent mucosa and oral leukoplakia biopsies were cultured and genetically characterized. Mutations were introduced in CDKN2A and TP53 using CRISPR/Cas9 and combined with the ectopic activation of telomerase to generate cell lines with prolonged proliferation. The method was tested in normal oral keratinocytes and tumor-adjacent biopsies and subsequently applied to a large set of oral leukoplakia biopsies. Finally, a subset of the immortalized cell lines was used to assess the efficacy of a set of small molecule inhibitors. Culturing and genomic engineering was highly efficient for normal and tumor-adjacent oral keratinocytes, but success rates in oral leukoplakia were remarkably low. Knock-out of CDKN2A in combination with either the activation of telomerase or knock-out of TP53 seemed a prerequisite for immortalization. Prolonged culturing was accompanied by additional genetic aberrations in these cultures. The generated cell lines were more sensitive than normal keratinocytes to small molecule inhibitors of previously identified targets. In conclusion, while very effective for normal keratinocytes and tumor-adjacent biopsies, the success rate of oral leukoplakia cell culturing methods was very low. Genomic engineering enabled the prolonged culturing of OL-derived keratinocytes but was associated with acquired genetic changes. Further studies are required to assess to what extent the immortalized cultures faithfully represent characteristics of the cells in vivo.