Genetic Heterogeneity in Mouse Mammary Tumors

ABSTRACT: Human cancers result from a complex series of genetic alterations resulting in heterogeneous disease states. Dissecting this heterogeneity is critical for understanding underlying mechanisms and providing opportunities for therapeutics matching the complexity. Mouse models of cancer have generally been employed to reduce this complexity and focus on the role of single genes. Nevertheless, our analysis of tumors arising in the MMTV-Myc model of mammary carcinogenesis reveals substantial heterogeneity, seen in both histological and expression phenotypes. One contribution to this heterogeneity is the substantial frequency of activating Ras mutations, the frequency of which can be changed by alterations in Myc. Additionally, we show that these Myc-induced mammary tumors exhibit even greater heterogeneity, revealed by distinct histological subtypes as well as distinct patterns of gene expression, than many other mouse models of tumorigenesis. Two of the major histological subtypes are characterized by differential patterns of cellular signaling pathways, including B-Catenin and Stat3 activities. We also demonstrate the predictive nature of this approach though examining metastatic potential. Together, these data reveal that a combination of histological and genomic analyses can uncover substantial heterogeneity in mammary tumor formation and therefore highlight aspects of tumor phenotype not evident in the population as a whole. Keywords: Transcription factor expression analysis 20 MMTV-Neu Tumors, 25 Papillary MMTV-Myc T58A and 81 MMTV-Myc tumors of various histological subtypes were arrayed.

ORGANISM(S): Mus musculus

SUBMITTER: Anil Potti 

PROVIDER: E-GEOD-15904 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress