Predominant expression of fibroblast growth factor (FGF) 8, FGF4, and FGF receptor 1 in nonseminomatous and highly proliferative components of testicular germ cell tumors.
Nonseminomatous components within testicular germ cell tumors affect patient prognosis to varying degrees. These components are well known to mimic early embryonic totipotential tissues. Prompted by the recent observation that fibroblast growth factor (FGF) 8, FGF4, and FGF receptor (FGFR) 1 are required for the growth of early postimplantational embryonic tissues, we investigated the expressions of FGF8, FGF4, and FGFRI in surgically resected specimens of primary testicular germ cell tumors using an immunohistochemical method. All cases of embryonal carcinoma (14 cases), yolk sac tumor (3 cases), and choriocarcinoma (3 cases) showed positive immunostaining for FGF8, FGF4, and FGFR1. In contrast, out of 13 cases of seminoma, immunostaining was negative for FGF8, FGF4, and FGFR1 in 8 cases (61.5%), 6 cases (46.1%), and 7 cases (53.8%), respectively. In 7 cases of mature and immature teratoma, most areas showed negative immunostaining. In addition, the Ki-67 labeling index showed extremely high mitogenic activity in embryonal carcinoma, yolk sac tumor, and choriocarcinoma, which are precisely the carcinomas with the highest expressions of FGF8, FGF4, and FGFR1. It is in keeping with the immunohistochemical result that murine teratocarcinoma P19 cells were shown to express FGF8, FGF4, and FGFRI only under undifferentiated growth conditions. Taken together, these findings confirm the involvement of FGF8, FGF4, and FGFR1 in highly proliferative conditions of nonseminomatous germ cell tumors.
Suzuki
K
K
Department of Urology, Jichi Medical School, Tochigi, Japan.
Tokue
A
A
Kamiakito
T
T
Kuriki
K
K
Saito
K
K
Tanaka
A
A
D000293:Adolescent; D000328:Adult; D002455:Cell Division; D002648:Child; D002675:Child, Preschool; D051519:Fibroblast Growth Factor 4; D051524:Fibroblast Growth Factor 8; D005346:Fibroblast Growth Factors / Q000096:biosynthesis* / Q000235:genetics; D019084:Fluorescent Antibody Technique, Indirect; D018237:Germinoma / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D007124:Immunoenzyme Techniques; D007223:Infant; D019394:Ki-67 Antigen / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011518:Proto-Oncogene Proteins / Q000096:biosynthesis* / Q000235:genetics; D012333:RNA, Messenger / Q000378:metabolism; D012334:RNA, Neoplasm / Q000032:analysis; D020794:Receptor Protein-Tyrosine Kinases / Q000096:biosynthesis*; D051496:Receptor, Fibroblast Growth Factor, Type 1; D017468:Receptors, Fibroblast Growth Factor / Q000096:biosynthesis*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D018243:Teratocarcinoma / Q000235:genetics / Q000378:metabolism; D013736:Testicular Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D014407:Tumor Cells, Cultured
C496445:FGF4 protein, human; C496456:FGF8 protein, human; D051519:Fibroblast Growth Factor 4; D019394:Ki-67 Antigen; D011518:Proto-Oncogene Proteins; D012333:RNA, Messenger; D012334:RNA, Neoplasm; D017468:Receptors, Fibroblast Growth Factor; D051524:Fibroblast Growth Factor 8; D005346:Fibroblast Growth Factors; C496348:FGFR1 protein, human; D020794:Receptor Protein-Tyrosine Kinases; D051496:Receptor, Fibroblast Growth Factor, Type 1