pRb inactivation in mammary cells reveals common mechanisms for tumor initiation and progression in divergent epithelia.

Bibliographic Details
Title: pRb inactivation in mammary cells reveals common mechanisms for tumor initiation and progression in divergent epithelia.
Authors: Karl Simin, Hua Wu, Lucy Lu, Dan Pinkel, Donna Albertson, Robert D Cardiff, Terry Van Dyke
Source: PLoS Biology, Vol 2, Iss 2, p E22 (2004)
Publisher Information: Public Library of Science (PLoS), 2004.
Publication Year: 2004
Collection: LCC:Biology (General)
Subject Terms: Biology (General), QH301-705.5
More Details: Retinoblastoma 1 (pRb) and the related pocket proteins, retinoblastoma-like 1 (p107) and retinoblastoma-like 2 (p130) (pRb(f), collectively), play a pivotal role in regulating eukaryotic cell cycle progression, apoptosis, and terminal differentiation. While aberrations in the pRb-signaling pathway are common in human cancers, the consequence of pRb(f) loss in the mammary gland has not been directly assayed in vivo. We reported previously that inactivating these critical cell cycle regulators in divergent cell types, either brain epithelium or astrocytes, abrogates the cell cycle restriction point, leading to increased cell proliferation and apoptosis, and predisposing to cancer. Here we report that mouse mammary epithelium is similar in its requirements for pRb(f) function; Rb(f) inactivation by T(121), a fragment of SV40 T antigen that binds to and inactivates pRb(f) proteins, increases proliferation and apoptosis. Mammary adenocarcinomas form within 16 mo. Most apoptosis is regulated by p53, which has no impact on proliferation, and heterozygosity for a p53 null allele significantly shortens tumor latency. Most tumors in p53 heterozygous mice undergo loss of the wild-type p53 allele. We show that the mechanism of p53 loss of heterozygosity is not simply the consequence of Chromosome 11 aneuploidy and further that chromosomal instability subsequent to p53 loss is minimal. The mechanisms for pRb and p53 tumor suppression in the epithelia of two distinct tissues, mammary gland and brain, are indistinguishable. Further, this study has produced a highly penetrant breast cancer model based on aberrations commonly observed in the human disease.
Document Type: article
File Description: electronic resource
Language: English
ISSN: 1544-9173
1545-7885
Relation: https://doaj.org/toc/1544-9173; https://doaj.org/toc/1545-7885
DOI: 10.1371/journal.pbio.0020022
Access URL: https://doaj.org/article/368c23be1c4140f3adfd3d880e397868
Accession Number: edsdoj.368c23be1c4140f3adfd3d880e397868
Database: Directory of Open Access Journals
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More Details
ISSN:15449173
15457885
DOI:10.1371/journal.pbio.0020022
Published in:PLoS Biology
Language:English