Topoisomerase II α is encoded by TOP2A gene, which is located on 17q21.2 in the human chromosome. It is essential for controlling the topological state of DNA by reversibly breaking the DNA strands during replication, recombination and transcription. TOP2A expression increases at late S phase and during G2/M of the cell cycle and decreases after mitosis. Polymorphism with TOP2A causes chromosome instability and tumorigenesis. TOP2A causes tumor proliferation and invasiveness in various cancer types like breast cancer, ovarian cancer and prostate cancer.
