Etoposide is an antineoplastic drug given orally or IV to treat cancers such as leukemias, lymphomas, lung, testicular, ovarian, and prostate cancers. It acts in rapidly dividing cells since this is a major property of cancer cells. This means that in addition to targeting cancers cells, it would also target other rapidly dividing cells like hair follicles. Etoposide enters the cell via the canalicular multispecific organic anion transporter 2 and goes into the nucleus where it forms a complex with DNA and topoisomerase II. DNA topoisomerase II is responsible for cutting and religating double stranded DNA. Etoposide binds to and inhibits topoisomerase II. This prevents the repair of single and double stranded breaks in the DNA, leading to errors in DNA synthesis. Etoposide is cell cycle phase specific. In the cell cycle, G1 involves cell growth, S includes DNA synthesis, G2 includes more growth, preparation for mitosis (produce new proteins) and DNA checkpoint replicated DNA is repaired and M is mitosis/cell division. Etioposide inhibits the S and G2 phases of the cell cycle. The errors during DNA synthesis eventually triggers the cell death pathway, leading to apoptosis of the cell. This prevents growth and progression of the cancer as the cancer cells are dying. Common side effects of etoposide are nausea, vomiting, myelosuppression, alopecia, abdominal pain, hypotension, stomatitis, diarrhea, fatigue, allergic reactions and constipation.

Etoposide Anti-Cancer Pathway References