Bioluminescence imaging correlates with tumor progression in an orthotopic mouse model of lung cancer.

Background And Objectives: To determine whether bioluminescence imaging of human lung cancer cells growing in an orthotopic murine model provides a sensitive tool for monitoring tumor progression in athymic nude mice.

Methods: Human lung cancer (A549) cells were stably transfected with the firefly luciferase gene and inoculated into the right lung of athymic nude mice. Seven days after inoculation tumor growth was evaluated using the Kodak in-vivo Imaging System FX and continued to be monitored on a weekly basis.

Results: In duplicate experiments, human lung cancer tumors formed in 90% of animal's injected orthotopically. The mean intensity of the bioluminescence signal emitted from the lung cancer cells increased logarithmically during the course of study. Mice with positive bioluminescence signaling had confirmed tumors by microscopic histological analysis. Bioluminescence activity had a strong correlation with the tumor volume as determined histologically.

Conclusions: Bioluminescence intensity directly correlates with tumor volume and therefore offers a reliable approach for detecting and monitoring the growth of human lung cancer cells in orthotopic murine models.