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 where 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 right frontal lobe of mice, and then secured in place in the skull with cement. Experiments evaluating the usefulness, reproducibility and morbidity of the 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 precisely delivered into the same area following injections at different times. Repeat injections were performed without a stereotaxic frame and without 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 treatment strategies on established brain tumors in a mouse model which more closely simulates the clinical situation. It obviates the need for time consuming stereotaxic procedures or repeat invasive intracerebral injections.