p63, a p53 homologue, is a selective nuclear marker of myoepithelial cells of the human breast.

摘要: Myoepithelial cells (MCs) constitute the basal cell layer of normal mammary epithelia, and their identification is particular diagnostic value because they are retained in most benign lesions while being lost malignancy. Several MC immunocytochemical markers currently available for purposes, with special reference to smooth muscle-related antigens. p63 a member p53 gene family, its germline mutations associated severe developmental defects both rodents humans. Different isoforms have been identified, some which (DeltaNp63) preferentially expressed epithelial different organs considered as possible stem cells/reserve cells. We investigated immunohistochemically 384 samples diseased human breast, including 300 invasive carcinomas, using four antibodies recognizing all isoforms, or DeltaNp63 isoforms. Twenty cytologic specimens were also investigated. Furthermore, snap-frozen tissue from three fibroadenomas 10 ductal carcinomas paired non-neoplastic tissues corresponding lymph node metastases evaluated expression mRNA by RT-PCR. In breast immunoreactivity was confined nuclei MCs. p63-immunoreactive formed continuous rim along structures. Stromal cells, myofibroblasts, consistently unreactive. Adenomyoepitheliomas showed nuclear staining neoplastic A peripheral surrounding lobular carcinoma situ, although it discontinuous opposed Invasive devoid staining, exception two adenoid-cystic squamous metaplasia, 11 (4.6%) not otherwise specified, showing minor fraction (5-15%) comparison other markers, specific, restricted exclusively MCs, whereas muscle actin and, lesser extent, calponin decorated stromal myofibroblasts. preparations consistent feature "naked nuclei" subset clusters. RT-PCR experiments primers specific documented that Our study demonstrates pathologic MCs express suggest reliable, highly sensitive marker histologic preparations. adult epithelia normally progenitor can be speculated might clue still elusive