Morphologic manifestations of gene-specific molecular alterations ("genetic addictions") in mouse models of disease

Basal-like Breast Cancers: From Pathology to Biology and Back Again

Human breast cancers referred to as "basal-like" are of interest because they lack effective therapies and their biology is poorly understood. The term basal-like derives from studies demonstrating tumor gene expression profiles that include some transcripts characteristic of the basal cells of the normal adult human mammary gland and others associated with a subset of normal luminal cells. Elucidating the mechanisms responsible for the profiles of basal-like tumors is an active area of investigation. More refined molecular analysis of patients' samples and genetic strategies to produce breast cancers de novo from defined populations of normal mouse mammary cells have served as complementary approaches to identify relevant pathway alterations. However, both also have limitations. Here, we review some of the underlying reasons, including the unifying concept that some normal luminal cells have both luminal and basal features, as well as some emerging new avenues of investigation.

Analysis of mouse model pathology: a primer for studying the anatomic pathology of genetically engineered mice

This primer of pathology is intended to introduce investigators to the structure (morphology) of cancer with an emphasis on genetically engineered mouse (GEM) models (GEMMs). We emphasize the necessity of using the entire biological context for the interpretation of anatomic pathology. Because the primary investigator is responsible for almost all of the information and procedures leading up to microscopic examination, they should also be responsible for documentation of experiments so that the microscopic interpretation can be rendered in context of the biology. The steps involved in this process are outlined, discussed, and illustrated. Because GEMMs are unique experimental subjects, some of the more common pitfalls are discussed. Many of these errors can be avoided with attention to detail and continuous quality assurance.

Pathogenesis and molecular biology of a transmissible tumor in the Tasmanian devil

The emergence of a fatal transmissible cancer known as devil facial tumor disease (DFTD) is threatening the iconic Tasmanian devil with extinction in the wild within the next few decades. Since the first report of the disease in 1996, DFTD has spread to over 85% of the devils' distribution and dramatically reduced devil numbers. Research into DFTD has focused on gaining a deeper understanding of the disease on multiple levels, including an accurate assessment of the tissue origin of the tumor, elucidation of how the tumor evades immune detection, and determination of how the tumor is transmitted between individuals and how it is evolving as it spreads through the population. Knowledge gained from these studies has important implications for DFTD management and devil conservation.