Cdc6 expression as a marker of proliferative activity in brain tumors.

Antibodies against human proteins that regulate DNA replication such as Cdc6 and Mcm5 became available as a new marker of proliferation. We performed immunohistochemical analysis with MIB-1 and antibody against Cdc6 on 35 brain tumors, including tumors of neuroepithelial tissue, vestibular schwannomas, meningiomas, and pituitary adenomas. Median reactivity for MIB-1 was 8.8%, and that for Cdc6 was 55%. Reactivity in most brain tumors was significantly higher for Cdc6 than for MIB-1, but reactivity of Cdc6 was independent of tumor grade. Detection of Cdc6 expression might be useful for the estimation of proliferative activity in brain tumors.