Abnormal expression of MDM2 in prostate carcinoma

Abnormal expression of MDM2 in prostate carcinoma

Author Leite, Katia Ramos Moreira Autor UNIFESP Google Scholar
Franco, Marcello Fabiano de Autor UNIFESP Google Scholar
Srougi, Miguel Autor UNIFESP Google Scholar
Nesrallah, Luciano J. Google Scholar
Nesrallah, Adriano Google Scholar
Bevilacqua, Ruy G. Google Scholar
Darini, Elaine Google Scholar
Carvalho, Claudia M. Google Scholar
Meirelles, Maria Ines Google Scholar
Santana, Isaque Google Scholar
Camara-Lopes, L. H. Google Scholar
Institution Hosp Sirio Libanes
Universidade Federal de São Paulo (UNIFESP)
Universidade de São Paulo (USP)
Abstract Mutation of p53 is rare in localized prostate carcinoma the oncoprotein MDM2, whose gene has a response element for p53, promotes the degradation of p53 protein and inhibits its transcriptional activation of genes related to cell cycle arrest and apoptosis, constituting a negative feedback control. We studied p53 and MDM2 expression by immunohistochemistry and looked for mutations in p53 exons 5 to 8 by polymerase chain reaction-single strand conformational polymorphism in 118 patients submitted to radical prostatectomy for localized prostate cancer. in 28 cases, we studied cell proliferation by immunohistochemistry, using antibody for Ki-67, and apoptosis by the deoxynucleotidyl transferase mediated dUTP biotin nick end labeling technique. Although no p53 mutations were found, p53 protein was detected in 31.4% of the cases, and these cases had higher Gleason scores (P = .03) and more advanced tumor stages (P = .02). MDM2 was overexpressed in 40.7% of the cases, and these: cases had greater tumor volumes (P = .001). Tumors that were positive for both p53 and MDM2 were larger (P = .003) and of more advanced stage (P = .03). Within the 28-case subset, the proliferative index was higher among MDM2-positive tumors (P = .046), and the apoptotic index was lower among p53-positive tumors (P = .01). We conclude that, although p53 mutation is a rare event in prostate carcinogenesis, the detection of p53 protein by immunohistochemistry is common and is associated with decreased apoptosis and increased histologic grade and tumor stage. We also conclude that the overexpression of MDM2 has a role in prostate carcinogenesis, being frequently detected and associated with increased cell proliferation and tumor volume. Finally, we propose that the MDM2-positive/53-positive phenotype identifies prostate cancers with aggressive behavior.
Keywords prostate cancer
MDM2 prognosis
polymerase chain reaction
single strand conformation polymorphism
gene mutation
cell proliferation
Language English
Date 2001-05-01
Published in Modern Pathology. Philadelphia: Lippincott Williams & Wilkins, v. 14, n. 5, p. 428-436, 2001.
ISSN 0893-3952 (Sherpa/Romeo, impact factor)
Publisher Lippincott Williams & Wilkins
Extent 428-436
Origin http://dx.doi.org/10.1038/modpathol.3880330
Access rights Open access Open Access
Type Article
Web of Science ID WOS:000168791800010
URI http://repositorio.unifesp.br/handle/11600/26534

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