Immunohistochemical Study of Laminin-332 γ2 Chain and MMP-9 in High Risk of Malignant Transformation Oral Lesions and OSCC.

Objectives: Oral squamous cell carcinoma is associated with alterations in basement membrane. Laminin-332 is present in basal lamina and performs multiple biologic effects by γ2 chain. Matrix metalloproteinase acts disrupting extracellular components and was related to poor prognosis in cancer. Here, molecular profile of laminin-332 γ2 chain and matrix metalloproteinase-9 was assessed in oral lesions.

Material and Methods: The expression of laminin-332 γ2 chain and matrix metalloproteinase-9 (MMP-9) was examined by immunohistochemistry in 10 patients with high risk of malignant transformation oral lesions and 26 cases of oral squamous cell carcinoma (OSCC). Associations between microscopic and clinicopathologic features were established.

Results: Immunostaining of laminin-332 γ2 chain in high risk oral lesions was most detected in basement membrane which is continuous, while the majority of OSCC cases showed a discontinuous membrane (P = 0.001). It was observed a positive reaction for γ2 chain in invasive fronts and a higher expression in epithelial compartment of smoking patients with OSCC (P < 0.0001). In epithelium, MMP-9 expression was presented in all layers with no difference between lesions. However, an elevated immunostaining in stromal cells was associated with male patients (P = 0.0054), older than 60 years (P = 0.0101) and with OSCC.

Conclusions: Present study results support the hypothesis of changes in molecules expression in high risk oral lesions and oral squamous cell carcinoma. A relation between clinical and molecule profile was observed. Those molecules may represent a useful tool to predict oral cancer behaviour.