RESUMO
DNA is double helical macromolecule which carries all the genetic information and it is usually found enveloped inside a nucleus. The DNA helix relaxes and supercoils itself frequently in order to derive information from the genes during processes like transcription, condensation, replication and recombination, which require mutable or immutable alterations to cause the separation of the two DNA strands. Due to problems caused by the helical structure of DNA, these topoisomerase enzymes perform the required DNA uncoiling. Their role in cell cycle is also significant as their mutation leads to failure of anaphase separation (1, 2). In the present review, the important roles of DNA topoisomerases and their inevitable role in cell growth and cell cycle are discussed viz. how they function in cell proliferation and what are the results when different inhibitors are added to the cells, affecting cell cycle at various checkpoints .