Tumor deletion mapping of chromosomal region 13q14 in 43 growth hormone secreting pituitary adenomas.
Previous studies have reported allelic loss in chromosomal region 13q14 in pituitary tumors. However, the role of RB1 in this region has not been clarified. We performed a tumor deletion map of chromosomal region 13q14 with pituitary adenomas and matched blood samples of 43 patients with acromegaly. Twenty-one patients had non-invasive tumors, 19 had invasive tumors, and in 3 this information was not available. Results showed loss of heterozygosity in at least one microsatelite marker of region 13q14 in 12% (5 of 43) of the somatotropinomas. Retention of marker D13S1325, telomeric to RB1, suggests that the putative tumor suppressor gene is located centromeric to this region, which includes RB1 locus. The participation of RB1 was excluded in four of the five cases because retinoblastoma protein was shown to be positive in these tumors in our previous study. Allelic loss occurred in similar frequency in invasive and noninvasive adenomas. In summary, we confirmed the participation of chromosomal region 13q14 in a subset of GH-secreting adenomas with no regard to tumor grade. RB1 was not implicated, suggesting the participation of another tumor suppressor gene in this region during the first steps of somatotropinoma development.
Donangelo
Ines
I
Serviço de Endocrinologia, Departmento de Clínica Médica, Hospital, Universitário Clementino Fraga Filho, Universidade Federal do Rio de Janeiro, Brazil.
Araújo
Paula Bruna
PB
Antenuzi
Daniela
D
Farage
Mariana
M
Marcondes
Jorge
J
Filho
Paulo Niemeyer
PN
Gadelha
Mônica R
MR
D000172:Acromegaly / Q000235:genetics; D000236:Adenoma / Q000235:genetics*; D002874:Chromosome Mapping; D002882:Chromosomes, Human, Pair 13 / Q000235:genetics*; D049912:Growth Hormone-Secreting Pituitary Adenoma / Q000235:genetics*; D019382:Human Growth Hormone / Q000378:metabolism; D006801:Humans; D019656:Loss of Heterozygosity; D009361:Neoplasm Invasiveness
D019382:Human Growth Hormone