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UVA1 irradiation induces deoxyribonuclease dependent apoptosis in cutaneousT‐cell lymphoma in vivo
Author(s) -
Kobyletzki Gregor,
Heine Oliver,
Stephan Harald,
Pieck Carsten,
Stücker Markus,
Hoffmann Klaus,
Altmeyer Peter,
Mannherz Hans Georg
Publication year - 2000
Publication title -
photodermatology, photoimmunology and photomedicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.736
H-Index - 60
eISSN - 1600-0781
pISSN - 0905-4383
DOI - 10.1034/j.1600-0781.2000.160607.x
Subject(s) - apoptosis , staining , deoxyribonuclease , in vivo , biology , microbiology and biotechnology , programmed cell death , dna fragmentation , cutaneous t cell lymphoma , deoxyribonuclease i , pathology , lymphoma , mycosis fungoides , dna , immunology , biochemistry , medicine , genetics , base sequence
Cutaneous T‐cell lymphoma (CTCL) is a malignancy of mature T‐cells, predominantly of the helper phenotype, that primarily invade the skin. Different photo‐ and chemotherapeutic treatments are known to be beneficial in early‐stage CTCL. This observation has initiated prospective investigations into the efficacy of phototherapeutic regimens. The purpose of our study was to investigate the ability of medium‐dose UVA1 phototherapy (60 J/cm 2 ) to induce apoptosis (programmed cell death) in skin infiltrating T‐cells of CTCL in vivo . We describe the results of three different staining methods for formalin‐fixed, paraffin‐embedded tissue sections. The in situ end‐labeling (ISEL) procedure, nuclear staining using the DNA‐binding fluorochrome Hoechst 33342, and immunohistochemistry using polyclonal antibodies against recombinant mouse deoxyribonuclease I (DNase I) demonstrated that UVA1 irradiation was able to induce marked apoptosis in CTCL. Thereby, ISEL and Hoechst staining clearly revealed DNA‐condensation and nuclear fragmentation, accompanied by the formation of typical “apoptotic bodies”. The accumulation of DNase I immunoreactivity in the cytoplasm of lymphocytes in UVA1 irradiated skin indicated that DNase I or DNase I‐related endonucleases may have acted as apoptotic endonuclease(s) which were synthesized after UVA1 irradiation prior to their apoptotic elimination.