title: Placental alkaline phosphatase in pediatric adrenocortical cancer.
abstract: The germline R337H mutation in the TP53 gene is considered to be responsible for the increased incidence of adrenocortical tumors (ACTs) in children from Brazil. High level production of hormones in ACTs (>95%) cause virilization alone (60%), Cushing syndrome (<5%), the mixed type (30%), or other rarer manifestations. ACT probably develops owing to events occurring during the final stages of intrauterine life based on the very common early onset of signs and symptoms shortly after birth. In this study, we determined by immunohistochemistry and enzyme assays whether placental alkaline phosphatase (PLAP) is expressed in pediatric ACTs. Immunohistochemical analysis revealed positive p53 expression in 88% of the tested ACTs (29 of 33). PLAP was detected at a slightly lower frequency based on immunohistochemical (17 of 33, 51%) and enzyme activity analyses (9 of 16, 56%). In conclusion, probably at a certain time point during adrenocortical development (end of gestation to early postnatal period), some fetal zone cells survive owing to defective apoptosis and develop into childhood ACT, maintaining some characteristics of the embryonal period, such as PLAP expression. Further studies of PLAP should investigate the functional role, if any, of PLAP in such tumors.
authors.affiliation: Center for Molecular Genetics and Cancer Research in Children (CEGEMPAC), Agostinho Leão Júnior, Brazil.
authors.forename: Giovanna Assis Pereira
authors.initials: GA
authors.lastname: Boechat
authors.forename: Sérvio Túlio
authors.initials: ST
authors.lastname: Stinghen
authors.forename: Gislaine
authors.initials: G
authors.lastname: Custódio
authors.forename: Mara Albonei Dudeque
authors.initials: MA
authors.lastname: Pianovski
authors.forename: Francisco Ricardo de Oliveira
authors.initials: FR
authors.lastname: Figueiredo
authors.forename: Jesse
authors.initials: J
authors.lastname: Jenkins
authors.forename: Gerard P
authors.initials: GP
authors.lastname: Zambetti
authors.forename: Raul C
authors.initials: RC
authors.lastname: Ribeiro
authors.forename: Bonald C
authors.initials: BC
authors.lastname: Figueiredo
mesh_terms: D000302:Adrenal Cortex / Q000196:embryology* / Q000378:metabolism*; D000306:Adrenal Cortex Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology*; D000469:Alkaline Phosphatase / Q000378:metabolism*; D017209:Apoptosis / Q000502:physiology; D002648:Child; D005260:Female; D058851:GPI-Linked Proteins / Q000378:metabolism; D018095:Germ-Line Mutation; D006801:Humans; D007150:Immunohistochemistry; D007527:Isoenzymes / Q000378:metabolism*; D008297:Male; D016159:Tumor Suppressor Protein p53 / Q000235:genetics
chemical_list: D058851:GPI-Linked Proteins; D007527:Isoenzymes; C495901:TP53 protein, human; D016159:Tumor Suppressor Protein p53; D000469:Alkaline Phosphatase; C019839:alkaline phosphatase, placental