Topoisomerase IIalpha expression in breast cancer: correlation with outcome variables.

Topoisomerase IIalpha (topo IIalpha) plays a key role in DNA replication and is a target for multiple chemotherapeutic agents. In breast cancer, topo II expression has been linked to cell proliferation and HER2/neu protein overexpression. However, its relationship with outcome variables is not well established.

Prognostic significance of p34cdc2 cyclin-dependent kinase and MIB1 overexpression, and HER-2/neu gene amplification detected by fluorescence in situ hybridization in breast cancer.

The HER-2/neu oncogene, localized to chromosome 17q, shares substantial homology with the epidermal growth factor receptor. HER-2/neu gene amplification and protein overexpression have been associated with poor prognosis in breast cancer. Formalin-fixed paraffin-embedded primary invasive breast cancer tissues from 135 women were tested for HER-2/neu gene amplification by automated fluorescence in situ hybridization (FISH) using a sequence probe.