Further Consideration of a Mouse Model Malignant Pheochromocytoma for Diagnosis and Treatment

Malignant pheochromocytomas, which account for 10% of all cases of pheochromocytoma, are an extremely troublesome disease for urologists and endocrinologists. It is difficult to examine malignant pheochromocytomas using conventional histopathological methods, and the condition carries a poor prognosis and no useful treatment has yet been established. We established a mouse model for metastatic malignant pheochromocytomas and tried to identify metastatic-related genes, which can provide useful information for the diagnosis and treatment of malignant pheochromocytomas for the purpose of developing a new diagnostic method for malignant pheochromocytomas Metastasis suppressor genes affect the spread of several cancers and, therefore, may provide promise as prognostic markers or therapeutic targets for malignant pheochromocytoma. We hypothesized that the downregulation of metastasis suppressor genes in malignant pheochromocytoma may play a role in malignant behavior. Using quantitative real-time PCR, expression of five genes (Metap2, Reck, S100a4, Timp2, and Timp3) was verified as significantly lower in liver tumors than in subcutaneous tumors. Downregulation of these genes has been previously been associated with malignancy of pheochromocytomas. These findings indicate that different microenvironments can differentially affect the expression of metastasisrelated genes in pheochromocytomas, and that overexpression or underexpression of these genes need not be present when the tumor cells are initially disseminated. This model is very useful, as this cell produces tyrosine hydroxylase and has more of the pheochromocytoma phenotype than the traditional pheochromocytoma lines. However, the establishment of malignant pheochromocytoma lines in humans will be necessary for in vivo research. .