Development of a new mouse brain tumor model using implantable micro-cannulas

The objective of this study was to develop a brain tumor model in a mouse w here gene therapy could be delivered either directly into a pre-established tumor bed or prophylacticly prior to tumor delivery (protective treatment) . Micro-cannulas were constructed from metal tubing, implanted into the rig ht frontal lobe of mice, and then secured in place in the skull with cement . Experiments evaluating the usefulness, reproducibility and morbidity of t he system were performed. It was found that tumor cells could reproducibly be delivered into the right frontal lobe of the mice. Two tumors could be p recisely delivered into the same area following injections at different tim es. Repeat injections were performed without a stereotaxic frame and withou t the need for repeat intracerebral needle tracts. There were no noticeable side effects of maintaining the cannulas in place for long periods of time . In summary, this system is useful for studying the effects of various tre atment strategies on established brain tumors in a mouse model which more c losely simulates the clinical situation. It obviates the need for time cons uming stereotaxic procedures or repeat invasive intracerebral injections.