title: P53 protein expression in lymphomas and reactive lymphoid tissue.
abstract: P53 is a tumour suppressor gene, located in the short arm of chromosome 17, which encodes for a nuclear protein involved in the control of cellular growth, regulating the entry of the cell into the S-phase. P53 mutations have been identified in a progressively increasing number of human malignancies. Nuclear p53 protein is usually present in non-tumour cells in minute concentrations, due to its short half-life. In contrast, tumours with p53 mRNA mutations show a higher nuclear protein concentration, detectable by immunohistological techniques, due to stabilization by complexing with other proteins such as heat-shock protein or wild-type p53 protein. Levels of nuclear p53 protein detected by immunohistochemistry with the monoclonal antibody PAb 1801 were measured with the aid of an image analysis system in 83 non-Hodgkin's lymphomas (NHLs) and 13 cases of Hodgkin's disease, as well as in 14 cases of normal thymus, reactive tonsils, and lymphadenitis. High levels of p53 protein (greater than 5 per cent of the cells) were present only in high-grade lymphomas (in the proportion 13/55), with a peak incidence in Burkitt's lymphoma (5/8 cases). Lower levels (less than 5 per cent) of p53 protein were detected in low-grade B- and T-cell lymphomas, as well as in most of the cases of Hodgkin's disease, where p53 protein was selectively present in Hodgkin and Reed-Sternberg cells. In 5/14 reactive tonsils or lymph nodes, occasional p53-positive cells were identified. These results suggest a relationship between levels of p53 protein and the aggressiveness of NHL.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Pathology, Hospital Virgen de la Salud, Toledo, Spain.
authors.forename: R
authors.initials: R
authors.lastname: Villuendas
authors.forename: M A
authors.initials: MA
authors.lastname: Piris
authors.forename: J L
authors.initials: JL
authors.lastname: Orradre
authors.forename: M
authors.initials: M
authors.lastname: Mollejo
authors.forename: P
authors.initials: P
authors.lastname: Algara
authors.forename: L
authors.initials: L
authors.lastname: Sanchez
authors.forename: J C
authors.initials: JC
authors.lastname: Martinez
authors.forename: P
authors.initials: P
authors.lastname: Martinez
mesh_terms: D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D008198:Lymph Nodes / Q000378:metabolism; D008199:Lymphadenitis / Q000378:metabolism / Q000473:pathology; D008221:Lymphoid Tissue / Q000378:metabolism* / Q000473:pathology; D008223:Lymphoma / Q000378:metabolism* / Q000473:pathology; D014066:Palatine Tonsil / Q000378:metabolism; D013194:Staining and Labeling; D013950:Thymus Gland / Q000378:metabolism; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism*
chemical_list: D016159:Tumor Suppressor Protein p53