Altered expression of claudin-1, claudin-7, and tricellulin regardless of human papilloma virus infection in human tonsillar squamous cell carcinoma

Abstract

Conclusions: Altered expression of claudin-1, claudin-7, and tricellulin in early tonsillar squamous cell carcinoma (SCC) independent of human papilloma virus (HPV) infection may lead to tumor progression. Objectives: Integral tight junction proteins, the claudins and tricellulin, play a crucial role in all tissues. HPV is significantly associated with tonsillar SCC. We sought to determine the expression of claudin-1, claudin-7, and tricellulin in HPV-infected and HPV-free tonsillar SCC. Methods: Twenty-eight tonsillar SCCs were studied by immunohistochemical analysis and real-time reverse transcription polymerase chain reaction with in situ hybridization analysis. Results: Compared with normal tissues, claudin-1 was strongly expressed, whereas claudin-7 and tricellulin were weakly expressed or were absent in primary SCC and metastatic lymph nodes. Claudin-7 and tricellulin were markedly reduced at all stages of tumor development. In situ hybridization analysis showed no correlation between HPV infection and altered expression of the tight junction proteins.

Keywords::

• Tight junction proteins
• in situ hybridization

Acknowledgement

This work was supported by Grants-in Aid for Scientific Research from the Ministry of Education, Science, Sport and Culture of Japan (#21791628).

Declaration of interest: This work was supported by Grants-in-aid for Young Scientists (B) from the Japan Society of the Promotion of Science 20791208. The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.