Analysis of Fusobacterium nucleatum Driven Modulation of c-Myc Pathways in Oral Carcinogenesis

<ns3:p> Objective To evaluate the association between <ns3:italic>Fusobacterium nucleatum</ns3:italic> and c-Myc expression in Oral Potentially Malignant Disorders (OPMDs) and Oral Squamous Cell Carcinoma (OSCC) and to explore its potential role in oral carcinogenesis. Materials and Methods A total of 32 histopathologically confirmed cases (18 OPMDs and 14 OSCC) were analyzed. Anaerobic cultures and polymerase chain reaction (PCR) were used to detect <ns3:italic>F. nucleatum.</ns3:italic> Immunohistochemistry (IHC) was performed to assess c-Myc expression. Statistical analysis was conducted using Mann-Whitney and Chi-square tests, with p < 0.05 considered significant. Results <ns3:italic>F. nucleatum</ns3:italic> was detected in eight OSCC and two OPMD cases, with higher colony counts in OSCC. All samples were positive for c-Myc, but their expression levels varied. In OPMDs, positivity was mainly observed in the basal and suprabasal epithelial layers, whereas OSCC showed both peripheral and central tumor cell localization. <ns3:italic>F. nucleatum</ns3:italic> –positive OSCC cases demonstrated strong nuclear c-Myc staining (50–75% positive cells). Tobacco habits, particularly combined smoking and smokeless use, were more common in <ns3:italic>F. nucleatum</ns3:italic> –positive OSCC cases. Conclusion <ns3:italic>F. nucleatum</ns3:italic> colonization correlates with increased c-Myc expression in OPMDs and OSCC, supporting its possible role in microbially driven oral carcinogenesis. These findings suggest its potential as a prognostic biomarker and a therapeutic target. </ns3:p>