title: Identification of p53 and its isoforms in human breast carcinoma cells.
abstract: In breast carcinoma, disruption of the p53 pathway is one of the most common genetic alterations. The observation that the p53 can express multiple protein isoforms adds a novel level of complexity to the outcome of p53 mutations. p53 expression was analysed by Western immunoblotting and immunohistochemistry using monoclonal antibodies DO-7, Pab240, and polyclonal antiserum CM-1. The more frequently p53-positive nuclear staining has been found in the invasive breast tumors. One of the most intriguing findings is that mutant p53 appears as discrete dot-shaped regions within the nucleus of breast cancer cells. In many malignant cells, the nucleolar sequestration of p53 is evident. These observations support the view that the nucleolus is involved directly in the mediation of p53 function or indirectly by the control of the localization of p53 interplayers. p53 expressed in the nuclear fraction of breast cancer cells revealed a wide spectrum of isoforms. p53 isoforms ΔNp53 (47 kDa) and Δ133p53 β (35 kDa), known as dominant-negative repressors of p53 function, were detected as the most predominant variants in nuclei of invasive breast carcinoma cells. The isoforms expressed also varied between individual tumors, indicating potential roles of these p53 variants in human breast cancer.
authors: Laboratory of Molecular Biology and Endocrinology, "Vinča" Institute of Nuclear Sciences, University of Belgrade, Mihaila Petrovića Alasa 12-14, P.O. Box 522, 11 001 Belgrade, Serbia.
authors: Zorka
authors: Z
authors: Milićević
authors: Biomedical Department, Institute for Pharmaceutical Research and Development, Galenika a.d., Pasterova 2, 11 000 Belgrade, Serbia.
authors: Vladan
authors: V
authors: Bajić
authors: Department of Biology and Human Genetics, Institute of Physiology, Faculty of Pharmacy, University of Belgrade, Vojvode Stepe 450, 11 000 Belgrade, Serbia.
authors: Lada
authors: L
authors: Živković
authors: Laboratory of Molecular Biology and Endocrinology, "Vinča" Institute of Nuclear Sciences, University of Belgrade, Mihaila Petrovića Alasa 12-14, P.O. Box 522, 11 001 Belgrade, Serbia.
authors: Jelena
authors: J
authors: Kasapović
authors: Department of Chemistry, Institute for Chemistry, Technology and Metallurgy, University of Belgrade, Studentski trg 12-16, 11000 Belgrade, Serbia.
authors: Uroš
authors: U
authors: Andjelković
authors: Department of Biology and Human Genetics, Institute of Physiology, Faculty of Pharmacy, University of Belgrade, Vojvode Stepe 450, 11 000 Belgrade, Serbia.
authors: Biljana
authors: B
authors: Spremo-Potparević
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008875:Middle Aged; D009154:Mutation; D020033:Protein Isoforms; D021381:Protein Transport; D016159:Tumor Suppressor Protein p53 / Q000235:genetics / Q000378:metabolism*
chemical_list: D020033:Protein Isoforms; D016159:Tumor Suppressor Protein p53