Immunohistochemical Expression of BubR1 and Telomerase in Oral Squamous Cell Carcinoma

Objective: Aberrant BubR1 and Telomerase expressions are considered as important markers in tumor progression and clinical outcome. This study purposed to describe, compare, and correlate the immunohistochemical expression of BubR1 and Telomerase in oral squamous cell carcinoma (OSCC). Methods: Immunohistochemical staining was performed for 28 OSCC samples. The samples graded according to Bryne’s grading system. The reaction positivity, intracellular localization, and intensity were recorded. The expression distribution and mean-ranks of these markers were related to OSCC grades by Fisher’s exact and Kruskal Wallis tests. Finally, the correlation between them was achieved by Spearman’s rho test. Results: BubR1 was detected in 89.3% of OSCCs, equally within scores 2 and 3 (35.7%), presented with 50% faint intensity, and 64.3% cytoplasmic localization. Grade III had a significantly higher mean-rank of BubR1 scoring. Whereas Telomerase observed in 75% of OSCCs, mainly found at scores 2 and 3 (60.7%), and 42.9% was within the cytoplasm. Half of OSCCs had faint intensity. No significant differences reported in the mean-rank and stain intensity among the grades. There was no significant correlation between BubR1 and Telomerase expression. Conclusions: OSCCs had high cytoplasmic BubR1 and telomerase expression that cannot ensure proper function. Mean-rank of BubR1 expression related to OSCC grading and being more in high grade. It determines the loss of differentiation and aggressiveness of OSCC. While the mean-rank of Telomerase did not relate to histopathological grading and considered an early event in carcinogenesis, it can use for the diagnostic approach of oral carcinogenesis. These markers have an independent role in cancer progression.