Fornace A J, Seres D S, Lechner J F, Harris C C
Chem Biol Interact. 1981 Sep;36(3):345-54. doi: 10.1016/0009-2797(81)90077-6.
DNA-protein cross-links were detected in several types of mammalian cells in culture when they were exposed to chromate salts. The cell types included human bronchial epithelial cells--the apparent cell type of origin of the malignancies reported in chromate workers. The level of cross-linking was proportional to the concentration of chromate used. These cross-links appeared to be persistent since no removal was seen after 12 h of repair incubation. A low level of DNA single strand breaks (SSB) were also induced after exposure of the cells to chromate but were rejoined after 4 h of repair incubation. The active form of chromium appears to be the trivalent since chromic but not chromate salts induced DNA-protein cross-links in isolated nuclei. Chromic salts also produced cross-linking between DNA and protein in solution while the hexavalent form was inactive. These data imply that chromate crosses the cell membrane, is reduced to the trivalent form and induces stable linkages of DNA to protein.
当几种培养的哺乳动物细胞暴露于铬酸盐时，可检测到DNA-蛋白质交联。细胞类型包括人支气管上皮细胞——铬酸盐工人中报告的恶性肿瘤的明显起源细胞类型。交联水平与所用铬酸盐的浓度成正比。这些交联似乎是持久的，因为在修复孵育12小时后未见去除。细胞暴露于铬酸盐后也诱导了低水平的DNA单链断裂（SSB），但在修复孵育4小时后重新连接。铬的活性形式似乎是三价的，因为亚铬酸盐而非铬酸盐在分离的细胞核中诱导DNA-蛋白质交联。亚铬酸盐还在溶液中产生DNA与蛋白质之间的交联，而六价形式则无活性。这些数据表明，铬酸盐穿过细胞膜，还原为三价形式，并诱导DNA与蛋白质的稳定连接。
