HLA-G in testicular germ cell tumors.
BACKGROUND
HLA-G is a non-classical major histocompatibility complex class I molecule. HLA-G expression has been found in various types of solid and hematological malignancies. It is also expressed in normal testicular and epididymal tissue. However, expression of HLA-G in testicular germ cell tumors has not been extensively studied. The aim of this study was to investigate whether HLA-G protein is present in different components of testicular germ cell tumors.


METHODS
34 testicular cancer patients, for whom tumor tissue was available, were included in the study. Immunohistochemical staining was performed on tissue sections from formalin-fixed, paraffin-embedded tissue samples.


RESULTS
7 (20.6%) patients had positive HLA-G staining in at least 1 component of the tumor sample. In 3 of 7 patients with intratubular germ cell neoplasia, staining with HLA-G was seen in this component. All of the choriocarcinoma components were strongly positive, and about 40% of teratoma components had immunopositivity. The components of seminoma and embryonal carcinoma, and most yolk sac tumors were negative. HLA-G immuno-positivity was not associated with tumor size, retroperitoneal lymph node involvement, distant metastasis, or relapse/refractory status.


CONCLUSIONS
This study demonstrated that testicular choriocarcinoma and some teratomas express HLA-G, but not seminoma, embryonal carcinoma, and yolk sac tumors.
Department of Medical Oncology, GATA Haydarpasa Training Hospital, Istanbul, Turkey.
Bülent
B
Karagöz
Abdullah
A
Haholu
Alpaslan
A
Ozgün
Oğuz
O
Bilgi
Tolga
T
Tunçel
Levent
L
Emirzeoğlu
Serkan
S
Celik
Dilaver
D
Demirel
D000293:Adolescent; D000328:Adult; D014408:Biomarkers, Tumor / Q000378:metabolism*; D002822:Choriocarcinoma / Q000378:metabolism; D059951:HLA-G Antigens / Q000378:metabolism*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009373:Neoplasms, Germ Cell and Embryonal / Q000378:metabolism*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013724:Teratoma / Q000378:metabolism; D013736:Testicular Neoplasms / Q000378:metabolism* / Q000473:pathology*; D055815:Young Adult
D014408:Biomarkers, Tumor; D059951:HLA-G Antigens