DNA Cross-Linker–Induced G2/M Arrest in Group C Fanconi Anemia Lymphoblasts Reflects Normal Checkpoint Function

作者：Michael Charles Heinrich, Maureen E. Hoatlin, Amy J. Zigler, Kirsten V. Silvey, Antony C. Bakke, Winifred W. Keeble, Yu Zhi, Carol A. Reifsteck, Markus Grompe, Michael G. Brown, R. Ellen Magenis, Susan B. Olson, Grover C. Bagby · 发表于：Blood · 年份：1998 · DOI：10.1182/blood.v91.1.275 · 被引用次数：82 · 研究领域：DNA Repair Mechanisms、CRISPR and Genetic Engineering、Carcinogens and Genotoxicity Assessment

Cells from individuals with Fanconi anemia (FA) arrest excessively in the G2/M cell cycle compartment after exposure to low doses of DNA cross-linking agents. The relationship of this abnormality to the fundamental genetic defect in such cells is unknown, but many investigators have speculated that the various FA genes directly regulate cell cycle checkpoints. We tested the hypothesis that the protein encoded by the FA group C complementing gene (FAC) functions to control a cell cycle checkpoint and that cells from group C patients (FA[C]) have abnormalities of cell cycle regulation directly related to the genetic mutation. We found that retroviral transduction of FA(C) lymphoblasts with wild-type FAC cDNA resulted in normalization of the cell cycle response to low-dose mitomycin C (MMC). However, when DNA damage was quantified in terms of cytogenetic damage or cellular cytotoxicity, we found similar degrees of G2/M arrest in response to equitoxic amounts of MMC in FA(C) cells as well as in normal lymphoblasts. Similar results were obtained using isogenic pairs of uncorrected, FAC- or mock-corrected (neo only) FA(C) cell lines. To test the function of other checkpoints we examined the effects of hydroxyurea (HU) and ionizing radiation on cell cycle kinetics of FA(C) and normal lymphoblasts as well as with isogenic pairs of uncorrected, FAC-corrected, or mock-corrected FA(C) cell lines. In all cases the cell cycle response of FA(C) and normal lymphoblasts to these two agents w...