bcl-2 Expression in Cutaneous T Cell Lymphoma

Jang, Jun Gyu; Chae, Young Soo; Suh, Kee Suck; Kim, Sang Tae

Abstract

BACKGROUND: The bcl-2 is an oncogene involved in tumorigenesis by blocking apoptosis, or programmed cell death and over-expression of bcl-2 protein has been reported in several malignant tumors such as lung cancer, basal cell carcinoma, breast cancer and malignant melanoma. However, there have been only a few studies about bcl-2 expression of cutaneous T cell lymphoma.
OBJECTIVE
The purpose of this study was to examine whether there is any difference in expression of bcl-2 between mycosis fungoides(MF), angiocentric T cell lymphoma, angioimmunoblastic T cell lymphoma, subcutaneous T cell lymphoma and anaplastic large cell lymphoma. We also evaluated the statistical significance between expression of bcl-2 and the prognosis of the diseases.
METHODS
Routine paraffin sections of formalin-fixed 36 tissues (14 MF, 7 angiocentric T cell lymphoma, 5 subcutaneous panniculitic T cell lymphoma, 2 anaplastic large cell lymphoma, 1 angioimmunoblastic T cell lymphoma, 1 unspecified peripheral T cell lymphoma, 2 small plaque parapsoriasis, 2 psoriasis and 2 lichen planus) were labelled with anti-bcl-2 monoclonal antibody using an avidin- biotin-peroxidase complex. Normal skin for bcl-2 served as negative controls.
RESULTS
The results were as follows. l. All cases of benign inflammatory diseases, small plaque parapsoriasis and patch stages of MF showed positive staining for bcl-2. Therefore, there were no differences in expression of bcl-2 among these diseases. 2. In the plaque and tumor stages of mycosis fungoides, statistically significancant differences in bcl-2 expression were not found during disease progression. 3. bcl-2 expression in peripheral T cell lymphoma (five in seven cases of angiocentric T cell lymphoma showed positive staining but all other peripheral T cell lymphoma was negative) decreased significantly (p<0.05) than that of MF. 4. No statistical significance was found between bcl-2 expression and prognosis of cutaneous lymphoma (p>0.05).
CONCLUSION
These results suggest that the loss of bcl-2 expression may play a significant role in progression of cutaneous T cell lymphoma except in MF and angiocentric T cell lymphoma.