Immunonegative "null cell" adenomas and gonadotropin (Gn) subunit (SUs) immunopositive adenomas share frequent expression of multiple transcription factors.
The differentiation of pituitary cells and human pituitary adenomas follow three cell lineages: GH-PRL-TSH, ACTH, and FSH/LH, which are regulated by a combination of various transcription factors and co-factors. We have used RT-PCR and immunohistochemistry to show that immunonegative, "null cell" adenomas are equipped with multiple transcription factors and co-factors. The "null cell" adenomas showed similar frequencies of transcription factors as did the gonadotropin subunit (GnSU)-positive adenomas, with the exception that there were fewer instances of SF1 in the former. We speculate, therefore, that null cell adenomas and GnSU-positive adenomas share common molecular mechanisms in functional differentiation, even though the former do not produce hormones. From the high frequency of various transcription factors, we also speculate that both null cell adenomas and GnSU-positive adenomas are derived from "committed" pituitary progenitor stem cells. The questions, why a certain proportion of these pituitary tumor groups lack hormone production and why they are molecularly more committed to Gn transcription, remain to be further investigated.
Ishii
Yudo
Y
Department of Neurosurgery, Nippon Medical School, Tokai University School of Medicine, Japan.
Suzuki
Masanori
M
Takekoshi
Susumu
S
Egashira
Noboru
N
Yamazaki
Michio
M
Miyai
Shunsuke
S
Sanno
Naoko
N
Teramoto
Akira
A
Osamura
Robert Yoshiyuki
RY
D000236:Adenoma / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D000328:Adult; D000368:Aged; D019070:Cell Lineage; D002471:Cell Transformation, Neoplastic; D017931:DNA Primers / Q000737:chemistry; D005260:Female; D015870:Gene Expression; D006065:Gonadotropins, Pituitary / Q000235:genetics / Q000378:metabolism*; D006728:Hormones / Q000378:metabolism; D006801:Humans; D007124:Immunoenzyme Techniques; D008297:Male; D008875:Middle Aged; D010911:Pituitary Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D012333:RNA, Messenger / Q000378:metabolism; D012334:RNA, Neoplasm / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014157:Transcription Factors / Q000096:biosynthesis* / Q000235:genetics
D017931:DNA Primers; D006065:Gonadotropins, Pituitary; D006728:Hormones; D012333:RNA, Messenger; D012334:RNA, Neoplasm; D014157:Transcription Factors