Establishment and evaluation of a Sprague-Dawley rat model of intramedullary spinal cord glioma

Background and Aim: Intramedullary spinal cord glioma has no evident boundary with normal spinal cord tissue. The rate of successful surgical resection of intramedullary spinal cord glioma is low. Well-established animal models for intramedullary spinal cord glioma can help promote translation from related basic therapy research to clinical applications. In this study, we established a rat model of intramedullary spinal cord glioma. Materials and Methods: A total of 23 male Sprague-Dawley (SD) rats were randomized into blank control (n = 3) and experimental (n = 20) groups. The blank control group received intramedullary injection of Dulbecco's modified Eagle medium (DMEM) and the experimental group was injected with DMEM containing C6 glioma cells. The neurological states of these rats were evaluated using the Basso, Beattie, and Bresnahan scale (BBB). Tumor sizes were measured by magnetic resonance imaging. The histopathological analysis was performed to observe the growth of infiltrating tumors. All procedures involving animals were approved by the Ethics Committee of the Laboratory Animal Facility Biomedical Analysis Center, Tsinghua University (Beijing, China; approval No. 17-WGH1). Results: On postoperative 7 days, the experimental group presented with a significant progressive decrease in motor function (mean BBB score 15.00 ± 1.20) compared with the blank control group (20.67 ± 0.47, P < 0.01). All rats in the experimental group showed exponential tumor growth and had an average survival of up to 5 weeks after tumor cell implantation. The tumor sizes were 3.18 ± 0.21 mm3, 68.55 ± 3.38 mm3, and 345.28 ± 22.57 mm3 on postoperative 7, 14, and 28 days. The histopathological analysis illustrated that the growth of infiltrating tumors followed the longitudinal axis of the spinal cord. Conclusions: Thus, we have established a SD rat model of intramedullary spinal cord glioma, and we found that our findings are reproducible and homogeneous. These positive results provide solid bases for further studies of intramedullary spinal cord glioma.