POSTREPLICATION REPAIR IN 3 MURINE MELANOMAS, A MAMMARY-CARCINOMA, AND A NORMAL MOUSE LUNG FIBROBLAST LINE

  • 1 January 1980
    • journal article
    • research article
    • Vol. 40  (6) , 1867-1872
Abstract
Repair of UV light-induced damage to DNA was studied in 3 melanoma lines, a mammary carcinoma line, EMT6, and a normal lung fibroblast line, MLF, all from the mouse. The melanomas were B16CL4, a .gamma.-ray-resistant clonal line derived from B16; S91H-, and auxotrophic line derived from Cloudman S91; and HP, a freshly isolated line from s.c. grown Harding-Passey melanoma. The melanomas and MLF performed minimal excision repair and photoreactivation. Postreplication repair, was an active process in all 5 of the lines. All 3 melanomas exhibited postreplication repair rates that were about twice that of MLF. The freshly isolated HP line evolved during subcultivation, and its postreplication repair rate dropped after 3 mo. to a rate comparable to EMT6, which was 1.5 times that of MLF. Postreplication repair is an important process in melanomas and may be related to radiation response.