Increased Twist expression in advanced stage of mycosis fungoides and Sezary syndrome

Background: The mechanisms of tumor progression in mycosis fungoides (MF) and Sezary syndrome (SS) are poorly understood. Twist, a transcription factor, is thought to promote solid tumor progression by blocking p53 and inhibiting c-myc-induced apoptosis. Whether Twist expression is correlated to MF/SS stages remains unknown. Methods: Twist, c-myc and p53 proteins in 68 MF/SS lesions across all T stages were examined by immunohistochemistry, and mRNA levels in peripheral blood CD4+ T-cells from SS patients were measured by real-time quantitative polymerase chain reaction. Results: Positive staining for Twist was found in 12.5% (2/16) of T1 and 33.3% (7/21) of T2 early stage patches/plaques compared to 50.0% (9/18) of T3 tumors and 84.6% (11/13) of T4 erythroderma. Most T4 erythroderma were positive for Twist in dermal lymphocytes, with the strongest staining. Positive staining for c-myc was higher in T3/T4 lesions (29/31, 93.5%) than T1/T2 lesions (25/37, 67.6%, p < 0.05), with strongest staining in T3 tumors. Aberrant p53 expression was more common in T3/T4 lesions (8/31, 25.8%) than in T1/T2 lesions (2/37, 5.4%, p < 0.05). Twist mRNA was detected in all CD4+ T cells from SS patients but not in normal donors. Conclusions: Increased Twist protein expression in advanced MF/SS lesions suggests that Twist expression may correlate with MF/SS stages.