Radioresistance in cells with high content of metallothionein.
An endogenous cytoplasmic protein, metallothionein (MT) apparently gave rise to radioresistance in 2 different cell lines. A dose reduction factor of 1.9 was achieved in MT-containing cells. MT accounted for a 3-4 fold increase of total sulfhydryl groups in the resistant cell strains, compared to the non-resistant lines from which they were derived. The protein is rich in cysteine (30%), an amino acid known to give radioprotection when administered exogenously. Glutathione levels and cell-cycle phase distribution showed no marked difference between resistant and corresponding non-resistant cells.
D000818:Animals; D002455:Cell Division / Q000528:radiation effects; D002460:Cell Line; D004307:Dose-Response Relationship, Radiation; D004848:Epithelium; D005978:Glutathione / Q000032:analysis; D006801:Humans; D007739:L Cells / Q000528:radiation effects; D008667:Metalloproteins / Q000502:physiology*; D008668:Metallothionein / Q000502:physiology*; D051379:Mice; D011836:Radiation Tolerance; D012867:Skin
D008667:Metalloproteins; D008668:Metallothionein; D005978:Glutathione