title: p53 expression is decreased in primary breast carcinomas with microsatellite instability.
abstract: p53 and p185 expression in primary breast cancer with microsatellite instability (MSI) is still largely unexplored. To investigate the relationship between these oncoproteins and the pathways of genomic instability, we examined 52 primary invasive breast cancers stratified by the presence and absence of MSI. We determined the status of eight microsatellite loci using radioactive and silver staining methods, and evaluated the immunohistochemical expression of p53 and p185 in a consecutive series of Italian cancer patients characterized by clinical-pathological and biological parameters. Nineteen cases (36.5%) were MSI-positive in at least two loci. p53 was expressed in 15 cases (28.8%) and p185 in eight (15.4%). MSI-positive tumors were inversely correlated with p53 expression (p = 0.0007); in addition, the percent of p53-expressing cells decreased as the number of MSI-positive loci increased. MSI-positive tumors were correlated with a larger tumor size (p = 0.04), lymph-node metastasis (p = 0.001), and advanced clinical stage (p = 0.0006). These data demonstrate the existence of two subsets of primary breast cancers: one characterized by MSI, the other by p53 expression. MSI-positive patients had a more advanced and/or aggressive disease.
authors.affiliation: Dipartimento di Endocrinologia e Oncologia Molecolare e Clinica, Facoltà di Medicina, Università Federico II, Napoli, Italy.
authors.forename: Claudia
authors.initials: C
authors.lastname: Pizzi
authors.forename: Luigi
authors.initials: L
authors.lastname: Panico
authors.forename: Laura
authors.initials: L
authors.lastname: De Marchis
authors.forename: Paolo
authors.initials: P
authors.lastname: Mastranzo
authors.forename: Massimo
authors.initials: M
authors.lastname: Di Maio
authors.forename: Cristina
authors.initials: C
authors.lastname: D'Amico
authors.forename: Gennaro
authors.initials: G
authors.lastname: Limite
authors.forename: Guido
authors.initials: G
authors.lastname: Pettinato
authors.forename: Sergio
authors.initials: S
authors.lastname: Cocozza
authors.forename: Angelo Raffaele
authors.initials: AR
authors.lastname: Bianco
authors.forename: Alma
authors.initials: A
authors.lastname: Contegiacomo
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000235:genetics* / Q000473:pathology*; D002277:Carcinoma / Q000235:genetics* / Q000473:pathology*; D018450:Disease Progression; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007150:Immunohistochemistry; D018895:Microsatellite Repeats / Q000235:genetics*; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D010641:Phenotype; D011379:Prognosis; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000096:biosynthesis* / Q000235:genetics; D016159:Tumor Suppressor Protein p53 / Q000096:biosynthesis* / Q000235:genetics
chemical_list: D018719:Erb-b2 Receptor Tyrosine Kinases; D016159:Tumor Suppressor Protein p53