Identification of conserved gene expression features between murine mammary carcinoma models and human breast tumors

Background Although numerous mouse models of breast carcinomas have been developed, we do not know the extent to which any faithfully represent clinically significant human phenotypes. To address this need, we characterized mammary tumor gene expression profiles from thirteen different murine models using DNA microarrays and compared the resulting data to that of human breast tumors. Results Unsupervised hierarchical clustering analysis showed that six models ( TgWAP-Myc, TgMMTV-Neu, TgMMTV-PyMT, TgWAP-Int., TgWAP9 Tag, and TgC3( 1)9 Tag) yielded tumors with distinctive and homogeneous expression patterns within each strain. However, in each of four other models ( TgWAP-T-181, TgMMTV-Wnt1, Brca1(Co/Co); TgMMTV-Cre; p53(+/-) and DMBA-induced), tumors with a variety of histologies and expression profiles developed. In many models, similarities to human breast tumors were recognized including proliferation and human breast tumor subtype signatures. Significantly, tumors of several models displayed characteristics of human basal-like breast tumors including two models with induced Brca1 deficiencies. Tumors of other murine models shared features and trended towards significance of gene enrichment with human luminal tumors, however, these murine tumors lacked expression of ER and ER-regulated genes. TgMMTV-Neu tumors did not have a significant gene overlap with the human HER2+/ER-subtype and were more similar to human luminal tumors. Conclusions Many of the defining characteristics of human subtypes were conserved among mouse models. Although no single mouse model recapitulated all the expression features of a given human subtype, these shared expression features provide a common framework for an improved integration of murine mammary tumor models with human breast tumors.