Genetically defined mouse models offer an important tool to identify critical secondary genetic alterations with relevance to human cancer pathogenesis. We used newly generated MMTV-Cre105Ayn mice to inactivate p53 and/or Rb strictly in the mammary epithelium, and to determine recurrent genomic changes associated with deficiencies of these genes. p53 inactivation led to formation of estrogen receptor-positive raloxifene-responsive mammary carcinomas with features of luminal subtype B. Rb deficiency was insufficient to initiate carcinogenesis but promoted genomic instability and growth rate of neoplasms associated with p53 inactivation. Genome-wide analysis of mammary carcinomas identified a recurrent amplification at chromosome band 9A1, a locus orthologous to human 11q22, which contains protooncogenes cIAP1 (Birc2), cIAP2 (Birc3) and Yap1. It is interesting that this amplicon was preferentially detected in carcinomas carrying wild-type Rb. However, all three genes were overexpressed in carcinomas with p53 and Rb inactivation, likely due to E2F-mediated transactivation, and cooperated in carcinogenesis according to gene knockdown experiments. These findings establish a model of luminal subtype B mammary carcinoma, identify critical role of cIAP1, cIAP2 and Yap1 co-expression in mammary carcinogenesis and provide an explanation for the lack of recurrent amplifications of cIAP1, cIAP2 and Yap1 in some tumors with frequent Rb deficiency, such as mammary carcinoma.
We have not found any resources mentioned in this publication.
SciCrunch is a data sharing and display platform. Anyone can create a custom portal where they can select searchable subsets of hundreds of data sources, brand their web pages and create their community. SciCrunch will push data updates automatically to all portals on a weekly basis. User communities can also add their own data to SciCrunch, however this is not currently a free service.