This case report deals with multiple intracranial metastatic
tumors and studies of expression and regulation characteristics of
aquaporins (AQPs) of cerebellar metastatic
tumor and brain tissue surrounding
tumor. In this work, we try to understand the role of abnormal expression of AQPs in formation and elimination of
brain edema and provide new ideas for the treatment of
brain edema induced by
tumor. The work involves resection of intracranial occupying lesions to get cerebellar metastatic
tumor organization. Total
RNA was extracted, RT-PCR was done, and immunohistochemical staining was done to study the expression and regulation characteristics of AQPs. We found that AQP4 had a high expression in the peritumoral brain tissue and no expression in the center of brain
metastasis tumor organization. Around the
tumor tissue, the AQP4 staining was junior in the more distant region from
tumor and it added significantly in close to the
tumor tissue region. It demonstrated that the AQP4 expression was upregulated, obviously with the distance drawing near gradually to
tumor tissue. In addition, stained AQP1 was not observed on cerebellar metastatic
tumor and peritumoral brain microvascular endothelial cells. The phenomenon that AQP4 had an increased expression in the surrounding region of cerebellar metastatic
tumor and, moreover, increased significantly in the region next to the cerebellar metastatic
tumor tightly is probably related to the formation of peritumoral
brain edema and plays an important role in
cytotoxic brain edema mechanism. AQP1 was not expressed on cerebellar metastatic
tumor and peritumoral brain tissue microvascular endothelial cells, and this may be an important factor that the peritumoral interstitial
brain edema is removed ineffectively to cause 'small
tumor, big
edema.'