Epstein- Barr viral load in exfoliated cells of oral squamous cell carcinoma and oral potentially malignant disorders - A cross-sectional study

Oral Squamous Cell Carcinoma (OSCC) has varied etiology. Among the etiological factors, genetic predisposition or the presence of oncogenic viruses can cause impairment in the physiological mechanisms of cellular proliferation control. The present study was chosen to determine the association of Epstein- Barr virus (EBV) with oral squamous cell carcinoma and oral potentially malignant disorders (OPMD). Oral exfoliated cells were collected from the subjects diagnosed with OSCC (n = 19), OPMD (n = 23) and healthy subjects without any deleterious condition (n = 39). The DNA extraction was performed with DNeasy Blood & Tissue Kits (Qiagen, Germany). Quantitative Real-Time PCR was then carried out with QuantiNova® SYBR® Green PCR Kit (Qiagen, Germany). Statistical analysis was performed using Chi-square test. EBV DNA was detected in all samples of all the three groups. Compared to healthy subjects, very high EBV load was observed in the oral exfoliated cells of OSCC and OPMD patients. The presence of EBV DNA in all the subjects of all the three groups reveals that EBV is an oral resident. Besides its presence, the abundance of EBV DNA among OSCC and OPMD suggests it's association to these pathologies. The high odds and risk ratio obtained for EBV copy number further supports a strong association of this virus to OSCC and OPMD. This may be the first study to quantify EBV DNA in oral exfoliated epithelial cells of OSCC and OPMD.