Expression of CD44V6 and PCNA in squamous cell carcinomas.

Objective: To investigate the expression of cluster of differentiation 44 variant 6 (CD(44V6)) and proliferating cell nuclear antigen (PCNA) in ocular squamous cell carcinomas.
Methods: Streptavidin-biotin complex (SABC) immunohistochemistry was used to explore the expression of CD(44V6) and PCNA in 35 cases of ocular squamous cell carcinomas, 20 cases of papillomas, and 11 cases of normal eyelid tissue.
Results: The CD(44V6) positive rate was 62.9% (22/35) in ocular squamous cell carcinomas, 15.0% (3/20) in papillomas, but not detectable in the 11 cases of normal eyelid tissue. The positive expression rates of CD(44V6) in ocular squamous cell carcinomas were significantly higher than in benign tumors (chi(2) = 11.57, P < 0.01) or control tissue (P = 0.001), and the positive expression rates of CD(44V6) in metastasis were significantly higher than without metastasis (P = 0.049). PCNA labeling indexes (PI) in tumors with CD(44V6) expression were significantly higher than those without (t = 20.21, P < 0.01).
Conclusions: Overexpression of CD(44V6) is correlated with the progress and metastasis of ocular squamous cell carcinomas. CD(44V6) protein positive staining is associated with high PI. CD(44V6) and PCNA are useful for evaluating prognosis.