PARENT SESSION
1:30 PM to 3:30 PM
Tuesday, April 23, 2002
Poster Session 25 Tumor Physiology and Microenvironments
Room: Nevada Exhibition Center

(P30-297) Mouse window chamber analysis of tumor neovascularization and cell migration after irradiation.

Armour, Elwood^*,1, Stewart, Kimberly¹, McEachern, Donna¹, ¹ Department of Radiation Oncology, Royal Oak, MI

ABSTRACT-
Over the years our understanding of the consequences of radiation therapy on tumors has evolved from a simple view that radiation independently kills individual cells, to the realization of a multistep complex process of interactions involving both tumor cells and normal tissues. It is well established that the viability, radiosensitivity, and recovery capacity of tumor cells during a course of radiation depend upon tumor environmental factors that can be altered during therapy, such as oxygen tension and nutrient state. Tumor microcirculation and tumor cell migration are critical in determining a tumor's growth capacity and invasiveness. A mouse dorsal skin flap window chamber technique has been used to analyze these effects. A mammary tumor cell line (4T1) stably transfected with green fluorescent protein were used to grow multicell spheroids that were implanted into each window chamber. This technique provided a uniform, compact, reproducible cell mass that was observed for neovascularization and cell migration. Conditions of irradiated spheroids, irradiated normal tissues, irradiated tumors, and appropriate controls have been analyzed. Early irradiation inhibited neovascularization, and tumor cell proliferation and migration. The future goal of this project is to determine the role of irradiation at the tumor/normal-tissue boundary and to analyze the molecular mechanisms controlling angiogenesis and tumor cell invasion in this region. Understanding radiation effects on microcirculation, neovascularization, and tumor cell invasion at the tumor-normal tissue boundary will aid in optimizing current cancer therapeutic strategies and suggest new approaches. This work was supported by William Beaumont Hospital Research Institute grant RI-01-14. We wish to thank Dr. Mark Dewhirst for his scientific and technical advice.

KEYWORDS: neovascularization, migration, mouse, tumor