Vascular expression of glucose transporter in and around hematogenous metastases of the human brain. Immunohistochemical observations.

The expression of the glucose transporter protein, GLUT 1, in endothelial cells of microvessels within and around hematogenous metastases of the human brain was investigated by immunohistochemistry using a polyclonal antibody raised against the carboxyl terminus of the transporter molecule. The metastases were obtained from 18 autopsy cases with pulmonary carcinomas. Endothelial cells of controls without evidence of brain pathology showed a strong immunoreactivity, indicating that the antigenic sites of the glucose transporter remained in the postmortem material. The endothelial cells of microvessels around the metastases did not show any changes with regard to expression of the glucose transporter. However, in 14 of the 18 tumor cases, microvessels located in the metastases did not express the transporter. Our results indicate that in human cases of brain metastases functional changes with regard to glucose transport occur within the metastases rather than in the peritumoral region.