A case of acral lentginous melanoma: the correlation between CD95L expression on melanoma cells and apoptosis of tumor infiltrating lymphocytes.
There is an increasing amount of evidence that melanoma cells express the ligand for CD95 (CD95L), a potent inducer of apoptosis which contributes to creating the immune privileged circumstances of tumor sites. However, it still remains to be demonstrated whether the capacity of melanoma cells to express CD95L is acquired during the progression. We addressed this question with a case of acral lentiginous melanoma by employing immunostaining using an antibody directed against CD95L as well as by in situ TUNEL staining. H&E-staining of tumor specimens revealed that there were two different growth patterns. The central part of the tumor showed a deeper invasion into the dermis (Breslow thickness >4 -mm). The horizontally growing edge of the tumor proliferated more superficially (Breslow thickness<3-mm). Relatively fewer lymphocytes were observed around the melanoma nests in central areas, which expressed detectable amounts of CD95L. In contrast, more lymphocytes were observed among the melanoma cells in the peripheral lesion, where CD95L was not detected. To evaluate the relevance of the CD95L expression, in situ TUNEL staining was performed. This indicated a significant correlation of lymphocyte apoptosis with CD95L expression on melanoma cells. Together the data suggest that expression of CD95L is turned on depending on the level of melanoma, and that it may tribute to creating immune privileged circumstances by initiating apoptosis of tumor filrating lymphocytes.
Maeda
A
A
Department of Dermatology Kinki University School of Medicine, Osaka, Japan.
Aragane
Y
Y
Kawada
A
A
Isogai
R
R
Orita
T
T
Tezuka
T
T
D017209:Apoptosis; D014408:Biomarkers, Tumor / Q000032:analysis*; D001707:Biopsy, Needle; D015870:Gene Expression; D006801:Humans; D007150:Immunohistochemistry; D020287:In Situ Nick-End Labeling; D016246:Lymphocytes, Tumor-Infiltrating / Q000473:pathology*; D008297:Male; D008545:Melanoma / Q000175:diagnosis / Q000473:pathology*; D008875:Middle Aged; D011379:Prognosis; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D012878:Skin Neoplasms / Q000175:diagnosis / Q000473:pathology*; D019014:fas Receptor / Q000235:genetics*
D014408:Biomarkers, Tumor; D019014:fas Receptor