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Polymerase chain reaction‐directed DNA sequencing of bleomycin‐induced “nondeletion”‐Type, 6‐thioguanine‐resistant mutants in chinese hamster ovary cell derivative AS52: Effects of an inhibitor and a mimic of superoxide dismutase
Author(s) -
An Jie,
Hsie Abraham W.
Publication year - 1994
Publication title -
environmental and molecular mutagenesis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1
H-Index - 87
eISSN - 1098-2280
pISSN - 0893-6692
DOI - 10.1002/em.2850230205
Subject(s) - chinese hamster ovary cell , mutant , biology , microbiology and biotechnology , bleomycin , mutagenesis , dna , base pair , biochemistry , genetics , gene , cell culture , chemotherapy
Bleomycin‐induced, 6‐thioguanine‐resistant, “non deletion” mutants pretreated with or without either TRIEN (triethylenetetramine), a superoxide dismutase (SOD) inhibitor, or TEMPOL (4‐hydroxy‐2,2,6,6‐tetramethylpiperidine‐1‐oxyl), a SOD mimic, were analyzed by polymerase chain reaction (PCR)‐directed DNA sequencing in a Chinese hamster ovary (CHO) cell derivative, AS52. Among the 23 bleomycin‐induced mutants, six have 3‐bp 5′‐TGA‐3′ deletions in the region of 366‐371, five have single‐base deletions, seven have base substitutions, three have insertions, and two have possible translocations. Among the 16 bleomycin‐induced mutants pretreated with TRIEN, six have the 5′‐TGA‐3′ deletion (366‐371), two have single‐base deletions, one has a 13‐bp deletion, four have single‐base substitutions, one has a double‐base substitution, and two have insertions. Among the 17 bleomycin‐induced mutants pretreated with TEMPOL, six have the same TGA deletions, two have single‐base deletions, two have single‐base insertions, four have single‐base substitutions, one mutant has a 12‐bp deletion, one has a 13‐bp deletion, and one mutant shows no detectable change in its coding region in the DNA sequence. A possible shift from a ROS‐mediated mutational spectrum to a spontaneous mutational spectrum by TRIEN further indicates that reactive oxygen species play an important role in bleomycin mutagenesis in mammalian cells. © 1994 Wiley‐Liss, Inc. This article is a US Government work and, as such, is in the public domain in the United States of America.