TY - JOUR
T1 - Immunodetection of chorionic gonadotropin and its subunits in human nonfunctioning pituitary adenomas
AU - Saccomanno, Katia
AU - Spada, Anna
AU - Bassetti, Monique
AU - Gil-Del-Alamo, Paloma
AU - Faglia, Giovanni
PY - 1994/5
Y1 - 1994/5
N2 - Human nonfunctioning pituitary adenomas (NFPA) may produce CG in addition to the classical glycoprotein hormones (LH, FSH, and TSH). The aim of the present study was to localize LHβ, FSHβ, TSHβ, α-subunit (αSU), CG, and its β-subunit (βSU) in NFPA using a highly specific immunohistochemical technique. Nine NFPA, obtained at surgery, were processed for both electron microscopy and immunohistochemistry. Three tumors resulted oncocytomas, and six were null cell. Using an immunofluorescence technique, all tumors were positive for at least one glycoprotein; in particular, seven adenomas were markedly positive for CGβ, whereas only two were positive for the intact CG. No association among LHβ, FSHβ, and CGβ positivity could be demonstrated in the different adenomas. In the seven tumors positive for both CGβ and αSU, double fluorescence labeling demonstrated that six cases localized CGβ and αSU in different cells, but only one tumor showed the two subunits colocalized in the same cells. These data confirm that pituitary tumors synthesize both αSU and βSU of glycoprotein hormones; in particular, the present study indicates that the majority of NFPA is able to synthesize CG, particularly its βSU. Moreover, the localization of CGβ and αSU in different tumoral cells might account for the preferential expression of βSU and αSU instead of the intact hormonal molecules in NFPA.
AB - Human nonfunctioning pituitary adenomas (NFPA) may produce CG in addition to the classical glycoprotein hormones (LH, FSH, and TSH). The aim of the present study was to localize LHβ, FSHβ, TSHβ, α-subunit (αSU), CG, and its β-subunit (βSU) in NFPA using a highly specific immunohistochemical technique. Nine NFPA, obtained at surgery, were processed for both electron microscopy and immunohistochemistry. Three tumors resulted oncocytomas, and six were null cell. Using an immunofluorescence technique, all tumors were positive for at least one glycoprotein; in particular, seven adenomas were markedly positive for CGβ, whereas only two were positive for the intact CG. No association among LHβ, FSHβ, and CGβ positivity could be demonstrated in the different adenomas. In the seven tumors positive for both CGβ and αSU, double fluorescence labeling demonstrated that six cases localized CGβ and αSU in different cells, but only one tumor showed the two subunits colocalized in the same cells. These data confirm that pituitary tumors synthesize both αSU and βSU of glycoprotein hormones; in particular, the present study indicates that the majority of NFPA is able to synthesize CG, particularly its βSU. Moreover, the localization of CGβ and αSU in different tumoral cells might account for the preferential expression of βSU and αSU instead of the intact hormonal molecules in NFPA.
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U2 - 10.1210/jc.78.5.1103
DO - 10.1210/jc.78.5.1103
M3 - Article
C2 - 7513714
AN - SCOPUS:0028256457
VL - 78
SP - 1103
EP - 1107
JO - Journal of Clinical Endocrinology and Metabolism
JF - Journal of Clinical Endocrinology and Metabolism
SN - 0021-972X
IS - 5
ER -