Mitomycin C

Mitomycin C is an antitumour antibiotic used as a chemotherapy medicine. It works as a potent DNA crosslinker: once activated inside the body it forms a reactive mitosene that alkylates guanine bases at specific DNA sequences, blocking the copying of DNA into RNA and stopping protein synthesis, which takes away a cancer cell's ability to multiply. It treats upper gastrointestinal, anal and breast cancers by intravenous injection, and is also used topically in eye surgery and instilled directly into the bladder for bladder cancer. Japanese scientists discovered it in 1955 from the soil bacterium Streptomyces caespitosus, and researchers at Kyowa Hakko Kogyo isolated the purified compound as purple crystals in 1956.