mTORC1 and mTORC2 Expression Levels in Oral Squamous Cell Carcinoma: An Immunohistochemical and Clinicopathological Study

Abstract

Background/aim: Mammalian target of rapamycin (mTOR) plays a critical role in the regulation of tumor cell motility, invasion and cancer cell metastasis. mTOR consists of two separate multi-protein complexes, mTOR complex (mTORC) 1 and mTORC2.

Materials and methods: We investigated the expression levels of mTORC1 and mTORC2 immunohistochemically in oral squamous cell carcinoma (OSCC).

Results: mTORC1 and mTORC2 were more highly expressed in tumors than in normal oral mucosa. mTORC1 expression was correlated with T classification, N classification, and survival rate (p<0.05), whereas mTORC2 expression was only correlated with T classification (p<0.05). Histologically, the expression levels of mTORC1 and mTORC2 correlated with cancer cell invasion and the expression of proliferating cell nuclear antigen (p<0.05), respectively. Expression levels of vascular endothelial growth factors and hypoxia-inducible factor 1 in the mTORC1 (-)/ mTORC2 (+) group were significantly lower than those in other groups.

Conclusion: These findings suggested that mTORC1 and mTORC2 could be promising anti-tumor targets in OSCC, and mTORC1 (-)/mTORC2 (+) may have a correlation with the malignant potential of OSCC.

Keywords: mTORC1; mTORC2; oral cancer.