Context: Oral lichen planus (OLP) is a potentially malignant disease with a prevalence rate of 0.5-2.2%. It is a T-cell-mediated autoimmune disease, in which cytotoxic CD8+ T-cells trigger apoptosis of the basal cells of oral epithelium. The reported progression of OLP to oral squamous cell carcinoma (OSCC) ranges from 0.4% to 6.5%. Apoptosis plays a major role in the maintenance of tissue homeostasis. The evasion of apoptosis in the form of dysregulation of inhibitors of apoptosis proteins (IAPs) may lead to malignant transformation. Survivin belongs to the second gene family of IAPs, which is overexpressed in many tumors such as OSCC and gastric carcinomas, and its expression is widely involved in apoptosis as well as in tumor metastasis.
Materials and methods: Sections were obtained from the paraffin-embedded archival blocks of patients diagnosed histologically as OLP, and cases with normal epithelium were used for comparison whereas cases with OSCC were used as positive control.
Results: We analyzed the expression of survivin in OLP and normal epithelium. Survivin expression with moderate intensity was seen in the cells of basal layer with nuclear positivity in cases of OLP, whereas mild to nil expression was seen in normal epithelium with nuclear and cytoplasmic positivity in different layers.
Conclusions: Survivin positivity was seen predominantly in the basal cells of OLP suggesting increased longevity of these cells which in turn might acquire dysplastic changes leading to increased risk of malignant transformation of this premalignant condition. Although the conversion rate may be low, the potential exists in the indolent course of the disease.
Keywords: Anti-apoptotic proteins; malignant transformation; oral lichen planus; oral squamous cell carcinoma; survivin.