The theme of this Program Project Grant is heavily based around the use of preclinical in vivo[unreadable] models to study the molecular mechanisms involved with the effects to cancer on the skeleton.[unreadable] Each project requires the use of animal models and careful assessment and monitoring of those[unreadable] animals for both skeletal and soft tissue metastases. The Small Animal Core proposed here will[unreadable] provide support for all work involving animals within each individual project. Services will include[unreadable] maintenance of tumor cell lines, management of all procedures involving small animals as well as[unreadable] state-of-the art methods for assessing the effects of cancer on the skeleton. This core builds on the[unreadable] previously existing laboratory core by incorporating new techniques such as optical imaging of[unreadable] green fluorescent protein expressing tumor cells, MicroSPECT, MicroPET and microCT for the[unreadable] assessment of tumor effects of the skeleton and tumor burden. An additional strength of the Small[unreadable] Animal Core is the participation of recognized experts in these areas. Techniques such as[unreadable] MicroSPECT, Micro PET and MicroCT are used in clinical diagnostics for patients with both breast[unreadable] cancer and multiple myeloma but to our knowledge have not yet been utilized in small animal[unreadable] models of metastatic disease. Use of these techniques will allow us to make direct comparisons[unreadable] between our preclinical models and disease in patients providing for validation of our preclinical[unreadable] models of breast cancer and multiple myeloma. Furthermore, these techniques will build on those[unreadable] that we have used in the past such as radiography and histomorphometry by allowing us to obtain a[unreadable] much more thorough picture of tumor burden and distribution in the whole intact animal, while[unreadable] providing much better resolution.