Expression of claudins-1,-3,-5,-7 and-11 on the progression of squamous cell carcinoma of the lip

Abstract

Objective: Claudins are integral transmembrane proteins of tight junctions, critical for maintenance of cell adhesion and polarity. Altered claudin expression has been detected in carcinomas and correlates with tumour progression. Actinic cheilits is a pathologic condition that affects the lower lip, caused by chronic exposure to solar radiation; it corresponds to the early phase of squamous cell carcinoma. We investigated claudin patterns in phases of actinic cheilitis, as alterations in adhesion molecules are considered important during the progression of this process. Method: Immunohistochemistry against claudins − 1, − 3, − 5, − 7and − 11 was performed in 100 cases of actinic cheilitis/squamous cell carcinoma; results were analysed qualitatively. Results: Actinic cheilitis (low grade intraepithelial squamous cell carcinoma), and the invasive front of superficially invasive squamous cell carcinoma and in situ squamous cell carcinoma were negative for claudins − 1, − 3and − 7. Claudin − 5 was present on all epithelial layers in most cases evaluated. Claudin − 11 was present in all epithelial layers in actinic cheilitis, but negative in cases of superficially invasive and deeply invasive squamous cell carcinoma. Conclusion: Altered expression of claudins is present in AC from its incipient phase throughout the progression of the disease to invasive squamous cell carcinoma.