Answer to Question #229858 in General Chemistry for Eugine

Question

Carcinogenesis is the process whereby cells with a growth advantage over their neighbors and are transformed by mutations in the genes that control cell division.

Relative to biochemical concepts, explain precisely why cis-Platin is used as an anti-cancer agent while trans-Platin is an inactive cancer agent?  

Answer 1

The cis-Platin is used as an anti cancer agent due to the fact that the transplatin trans-isomer is inactive. The inactivity in transplatin is due to the kinetic instability and the formation of DNA adducts. The kinetic instability promotes its deactivation while the formation of DNA adducts promotes regioselectivity. Due to the presence of the two groups, the cis-Platin undergoes substitution on the ammine ligands by the action of the aromatic N-donor and imino ligands to form compounds that leads to growth inhibition in cancer cells. The cis-Platin interacts with cancer cells by creating both intra and inter-strand DNA cross links which inhibits DNA replication.

The substitution action on the ligands reduces the kinetic instability of the trans platin and also the formation of DNA adducts leads to formation of a different compounds that have much greater reactivity leading to rapid deactivation by the cancer cells thus making it ineffective therapy.