Ribosomal Protein S6 Phosphorylation is Associated with Epithelial Dysplasia and Squamous Cell Carcinoma of the Oral Cavity

• Published in: Pathology oncology research Vol. 19; no. 2; pp. 189 - 193
• Main Authors: Chaisuparat, Risa, Rojanawatsirivej, Somsri, Yodsanga, Somchai
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01.04.2013; Springer Nature B.V
• Subjects: Adult; Aged; Aged, 80 and over; Biomarkers, Tumor - metabolism; Biomedical and Life Sciences; Biomedicine; Cancer Research; Carcinoma, Squamous Cell - metabolism; Carcinoma, Squamous Cell - pathology; Disease Progression; Early Detection of Cancer - methods; Female; Humans; Immunology; Male; Middle Aged; Mouth Mucosa - metabolism; Mouth Mucosa - pathology; Mouth Neoplasms - metabolism; Mouth Neoplasms - pathology; Oncology; Pathology; Phosphorylation; Precancerous Conditions - metabolism; Precancerous Conditions - pathology; Ribosomal Protein S6 - metabolism; Young Adult; Epithelial dysplasia; Ribosomal protein S6; Oral squamous cell carcinoma; Tumor progression
• ISSN: 1219-4956; 1532-2807
• DOI: 10.1007/s12253-012-9568-y

Ribosomal protein S6 (RPS6), a downstream effector of the mammalian target of rapamycin pathway (mTOR), is activated in many cancers including oral squamous cell carcinoma (OSCC). However, the role of RPS6 in the progression of potentially malignant disorders (or premalignant lesions) to OSCC is unknown. The purpose of this study was to examine the expression of RPS6 in epithelial dysplasia and OSCC to determine the association of RPS6 in tumor progression. In our study, an immunohistochemical analysis of RPS6 was performed on tissue microarrays containing 30 control samples, 15 epithelial dysplasia cases, and 53 OSCC cases. Correlations between the clinicopathologic features of OSCC and RPS6 expression were analyzed using the Chi-square test. We found RPS6 phosphorylation (p-RPS6) in 15/30 (50 %) control normal oral mucosa samples, 15/15 (100 %) epithelial dysplasia cases, and 47/53 (88.68 %) OSCC cases. The frequency of p-RPS6 in epithelial dysplasia or OSCC showed a statistically significant difference compared to control ( P  < 0.001). However, there were no significant correlations between p-RPS6 and the clinicopathologic features of OSCC. Our findings suggest that RPS6 activation is associated with the early events of tumor progression, suggesting p-RPS6 as a potential marker for early detection of oral cancer.