Assessment of laminin-5 in oral dysplasia and squamous cell carcinoma.

PURPOSE

Laminin-5 is an important protein in the establishment of an intact basement membrane. The aims of this study were to assess the expression of laminin-5 (γ2 chain) using cyclin D1 and Ki-67 in hyperplastic oral mucosal lesions, oral dysplasia, and squamous cell carcinoma (SCC).

MATERIALS AND METHODS

Paraffin-embedded tissue blocks of 134 patients were stained for laminin-5, cyclin D1, and Ki-67 using immunohistochemistry and assessed by virtual microscopy. Statistical analysis was performed using Kruskal-Wallis tests and Mann-Whitney U tests for post hoc assessment.

RESULTS

Laminin-5, cyclin D1, and Ki-67 were found to have significant differences in expression for the different categories of dysplasia, SCC, and hyperplasia (P < .001). Cyclin D1 and Ki-67 expression levels were significantly increased in moderate and severe dysplasia and SCC, with no significant difference in expression between hyperplasia and mild dysplasia or between biopsies of severe dysplasia and SCC. Laminin-5 expression was only significantly increased in SCC, confirming it as a marker of malignant transformation and invasion.

CONCLUSIONS

The results of this study indicate that overexpression of laminin-5 is found only in SCC and not dysplastic lesions. Therefore, laminin-5 has potential as a marker for the intraoperative assessment of cancer excision margins and could be used as a target for chemotherapeutic agents.