Aneuploidy, centrosome alteration and securin overexpression as features of pituitary somatotroph and lactotroph adenomas.
OBJECTIVE
To verify the presence of numerical chromosomal aberrations (NCAs) in different types of pituitary adenomas (PAs) and to investigate 2 of the mechanisms that are possibly related to aneuploidies in PAs: securin overexpression and centrosome alterations.


METHODS
Twenty-one PAs of different types were analyzed with interphase fluorescence in situ hybridization (FISH) on paraffin sections with centromeric probes for chromosomes 2, 3, 8, 11 and 12. In all cases, the immunohistochemical expression of securin was evaluated and the number of cells with abnormal nuclear shape recorded. The ultrastructural study of centrosomes was performed in a subset of 12 tumors.


RESULTS
At interphase FISH analysis, growth hormone (GH)-cell and prolactin (PRL)-cell PAs showed multiple chromosome gains and a low frequency of chromosome losses, suggesting a hyperdiploid chromosome assessment. In contrast, in the other types of PAs a lower frequency of NCAs was observed. In addition, when compared to other types of PAs, GH-cell and PRL-cell adenomas showed overexpression of securin and a higher number of both cells with abnormal nuclear shape and cells with centrosomes.


CONCLUSIONS
Somatotroph and lactotroph adenomas are characterized by aneuploidy, abnormal nuclear shape and centrosome amplification, which are possibly related to securin overexpression.
Uccella
Silvia
S
Department of Human Morphology, University of Insubria and Ospedale di Circolo, Varese, Italy. silvia.uccella@uninsubria.it
Tibiletti
Maria Grazia
MG
Bernasconi
Barbara
B
Finzi
Giovanna
G
Oldrini
Rita
R
Capella
Carlo
C
D000328:Adult; D000368:Aged; D000782:Aneuploidy; D002467:Cell Nucleus / Q000235:genetics / Q000378:metabolism; D049109:Cell Proliferation; D002503:Centromere / Q000235:genetics / Q000473:pathology*; D005260:Female; D015972:Gene Expression Regulation, Neoplastic / Q000235:genetics; D049912:Growth Hormone-Secreting Pituitary Adenoma / Q000235:genetics* / Q000378:metabolism / Q000473:pathology* / Q000648:ultrastructure; D006801:Humans; D007150:Immunohistochemistry; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D008854:Microscopy, Electron; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000235:genetics / Q000378:metabolism*; D015175:Prolactinoma / Q000235:genetics* / Q000378:metabolism / Q000473:pathology*; D064249:Securin
D009363:Neoplasm Proteins; D064249:Securin; C578002:pituitary tumor-transforming protein 1, human