Immunohistochemical Expression of BubR1 and Telomerase in Minor Salivary Gland Tissue Adjacent to Oral Squamous Cell Carcinoma

Abstract

Objectives: Evaluation of the expression of tissue markers in the parenchyma within the area adjacent to a primary tumor is critical in cancer progression, prevention, and identification of early changes in the field of cancerization. The present study aimed to evaluate BubR1 and telomerase activity in minor salivary gland tissue adjacent to oral squamous cell carcinoma (OSCC) with their clinicopathological features. 
 Methods: Four-micron tissue sections from 21 formalin-fixed paraffin blocks of OSCC surgical margins were prepared and stained for anti-BubR1 and anti-telomerase antigens. 
 Results: The studied sample included 71.4% males and 28.6% females, and the most prevalent site was buccal mucosa (42.9%). The total sample showed a high (71.4%) BubR1 expression, while telomerase was expressed in 42.9%. BubR1 was expressed significantly in the buccal mucosa (p=0.000) in the myoepithelial (cytoplasmic) and ductal cells (cytoplasmic and mixed). In comparison, telomerase showed significant myoepithelial mixed and cytoplasmic expression of buccal mucosa (p=0.013) and nuclear expression in ductal cells within the tongue (p=0.05). Both markers showed altered expression and predominated significantly in cases adjacent to poorly differentiated OSCC (p<0.05). Lastly, a moderate/strong correlation between the aberrant accumulation of BubR1 and telomerase was found (r=0.5-0.8, p<0.05). 
 Conclusions: Elevated expression of BubR1 and telomerase was found in the minor salivary gland adjacent to OSCC. Therefore, they represent a valuable tool to identify molecular changes in the field of cancerization. Cases of OSCC excised from buccal mucosa and tongue required a regular follow-up, especially poorly differentiated OSCCs. The elevated expression of both markers positively regulates each other.