Isolation of cell cycle-dependent gamma ray-sensitive Chinese hamster ovary cell

Stamato, Thomas D.; Weinstein, Ronald S.; Giaccia, Amato J.; MacKenzie, Laurie

doi:10.1007/bf01543175

Cited by 166 publications

(56 citation statements)

References 25 publications

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“…This correlation of drug sensitivity under hypoxia with the rate of drug metabolism did not hold for the two CHO mutants, XR-1 and V-3, which are sensitive to ionising radiation due to a deficiency in DNA double strand break rejoining (Stamato et al, 1983;Whitmore et al, 1989). Complementation studies showed that both these cell lines represent separate DNA repair deficient mutants.…”

Section: Discussionmentioning

confidence: 94%

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SR 4233 cytotoxicity and metabolism in DNA repair-competent and repair-deficient cell cultures

Biedermann

Wang²,

Graham³

et al. 1991

Br J Cancer

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Summary In order to understand in more detail the mechanism underlying the preferential hypoxic cytotoxicity of the benzotriazine N-oxide SR 4233, we have compared the hypoxic cytotoxicity of this drug to the rates of hypoxic metabolism in both DNA double strand break repair-competent and repair-deficient cell cultures. Rodent SCCVII cells and repair deficient, radiation sensitive cells (rodent XR-1, V-3, and human AT5BI) were most sensitive to SR 4233 under hypoxia with a lethal dose needed to kill 50% of cells (LDm0)

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Section: Discussionmentioning

confidence: 94%

“…CHO V-3 cells (Whitmore et al, 1989) were obtained courtesy of G.F. Whitmore, U. of Toronto. XR-1, a cell cycle specific gammaray sensitive CHO cell mutant (Stamato et al, 1983) (Figure 7b). The cell lines SCCVII and AT5BI displaying the highest sensitivity to SR 4233 under hypoxia also metabolised the drug to the greatest extent.…”

mentioning

confidence: 99%

SR 4233 cytotoxicity and metabolism in DNA repair-competent and repair-deficient cell cultures

Biedermann

Wang²,

Graham³

et al. 1991

Br J Cancer

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“…An XRCC3 gene knockout in the human colon cancer cell line HCT116 has been reported recently, and the XRCC3-deficient cells showed ϳ2-fold excess sensitivity to MMC (58 (59,60) that is associated primarily with the late S/G 2 phase (49). By contrast, the NHEJ-defective Chinese hamster ovary mutants for XRCC4, Ku86, and DNA-PKcs (the XR-1, xrs5/6, and V3 cell lines, respectively) are highly sensitive to IR in G 1 and early S phases compared with the wild type but are more IR-resistant in late S/G 2 (61)(62)(63)(64). A similar pattern was reported for murine pre-B cells carrying the scid mutation (65).…”

Section: Rad51c Dynamically Influences the Protein Levels Of Other Rad51mentioning

confidence: 99%

Human Rad51C Deficiency Destabilizes XRCC3, Impairs Recombination, and Radiosensitizes S/G2-phase Cells

Lio

Schild

Brenneman

et al. 2004

Journal of Biological Chemistry

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The highly conserved Rad51 protein plays an essential role in repairing DNA damage through homologous recombination. In vertebrates, five Rad51 paralogs (Rad51B, Rad51C, Rad51D, XRCC2, and XRCC3) are expressed in mitotically growing cells and are thought to play mediating roles in homologous recombination, although their precise functions remain unclear. Among the five paralogs, Rad51C was found to be a central component present in two complexes, Rad51C-XRCC3 and Rad51B-Rad51C-Rad51D-XRCC2. We have shown previously that the human Rad51C protein exhibits three biochemical activities, including DNA binding, ATPase, and DNA duplex separation. Here we report the use of RNA interference to deplete expression of Rad51C protein in human HT1080 and HeLa cells. In HT1080 cells, depletion of Rad51C by small interfering RNA caused a significant reduction of frequency in homologous recombination. The level of XRCC3 protein was also sharply reduced in Rad51C-depleted HeLa cells, suggesting that XRCC3 is dependent for its stability upon heterodimerization with Rad51C. In addition, Rad51C-depleted HeLa cells showed hypersensitivity to the DNA-cross-linking agent mitomycin C and moderately increased sensitivity to ionizing radiation. Importantly, the radiosensitivity of Rad51C-deficient HeLa cells was evident in S and G 2 /M phases of the cell cycle but not in G 1 phase. Together, these results provide direct cellular evidence for the function of human Rad51C in homologous recombinational repair.In mammalian cells, DNA double strand breaks (DSBs) 1 are repaired primarily by two distinct mechanisms, non-homologous end joining (NHEJ), a non-templated, potentially errorprone process in which nucleotide alternations are tolerated at the site of rejoining, and homologous recombination (HR), a largely error-free process in which a sister chromatid or homologous chromosome is used as a template for repair (for review, see Refs. 1 and 2). Homologous recombinational repair (HRR) provides high fidelity in repairing DNA damage and is therefore essential and critical for the maintenance of genome stability and tumor avoidance (for review, see Refs. 3 and 4). The Rad51 protein plays a key role in HR, functioning to mediate homologous DNA pairing and strand exchange (5, 6). Five vertebrate Rad51 paralogs are expressed in mitotically growing cells: Rad51B (7-9), Rad51C (10), Rad51D (9, 11, 12), XRCC2 (13-15), and XRCC3 (13,16,17). These proteins share 20 -30% sequence identity with Rad51 and with each other. Only vertebrates appear to contain all five of these Rad51 paralogs. In human cells, Rad51C participates in various paralog complexes, including Rad51B-Rad51C, Rad51C-XRCC3, and Rad51B-Rad51C-Rad51D-XRCC2 (18 -22). In terms of proteinprotein interactions, Rad51C apparently has a central role, interacting directly with Rad51B, Rad51D, and XRCC3 and also weakly with Rad51 (23,24). However, the functional significance of these complexes is not yet clear.Mutant studies provide a direct means for identifying the function of genes. A knock-out ...

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“…CHOK1 (a glycine auxotroph of CHO cells), 4364A (a proline and glycine auxotroph of CHOK1 [17]), xrs 5 (18) and XR-1 (7,9,34,35) (hamster DNA double-strand break repair-deficient mutant cell lines), and A x W-1 (a hybrid of XR-1 and a wild-type human line [8]) were obtained from A. J. Giaccia (Stanford University) and were cultured in RPMI 1640 medium. V-G8 and V-E5 (hamster ataxia telangiectasia-like mutants), the wild-type parental line V79 (39), and V79B and XR-V9B (40) were maintained in Ham's F-10 medium.…”

mentioning

confidence: 99%

“…It is the parental line from which XR-1 was originally derived by mutagenesis (35). Recombination in 4364A was 0.3% for signal joint formation, as determined with substrate pJH200.…”

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confidence: 99%

DNA Double-Strand Break Repair

Encyclopedia of Cancer

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V(D)J recombination has been examined in several X-ray-sensitive and double-strand break repair-deficient Chinese hamster cell mutants. Signal joint formation was affected in four mutants (xrs 5, XR-1, V-3, and XR-V9B cells, representing complementation groups 1 through 4, respectively) defective in DNA double-strand break rejoining. Among these four, V-3 and XR-V9B were the most severely affected. Only in V-3 was coding joint formation also affected. Ataxia telangiectasia-like hamster cell mutants (V-E5 and V-G8), which are normal for double-strand break repair but are X ray sensitive, were normal for all aspects of the V(D)J recombination reaction, indicating that X-ray sensitivity is not the common denominator but that the deficiency in double-strand break repair appears to be. The abnormality at the signal joints consisted of an elevated incidence of nucleotide loss from each of the two signal ends. Interestingly, in complementation groups 1 (xrs 5) and 2 (XR-1), signal joint formation was within the normal range under some transfection conditions. This suggests that the affected gene products in these two complementation groups are not catalytic components. Instead, they may be either secondary or stochiometric components involved in the later stages of both the V(D)J recombination reaction and double-strand break repair. The fact that such factors can affect the precision of the signal joint has mechanistic implications for V(D)J recombination.The exons encoding the immunoglobulin and T-cell receptor variable-region domains are assembled during lymphocyte development by V(D)J recombination. This site-specific reaction is directed by a pair of joining signals recognized by components of the recombination activity. The consensus sequence of each signal consists of a palindromic heptamer and an AT-rich nonamer. These two elements are separated by a 12-base spacer at one signal and a 23-base spacer at the other. The recombination site for each signal is at the end of the heptamer on the side distal from the nonamer. During recombination, coding ends and signal ends are generated by recombinase-mediated cleavage at the crossover sites. The two coding ends are joined to form what is termed a coding joint, and the two signal ends are joined to form a signal joint (reviewed in reference 20). Modification can occur at the two coding ends (20,25) in ways that are similar in some respects to modifications of chromosomal ends left after transposon excisions in eukaryotes (4, 21, 36).Murine scid (3) has been shown to be defective in V(D)J recombination, defective in the repair of double-strand breaks, and sensitive to X-irradiation (la, 2, 4a, 10, lOa, 28, 31, 32). The scid defect in double-strand break repair implies that the processing of coding ends in the V(D)J recombination reaction is similar to the processing of chromosomal breaks. Both processes can involve nucleotide loss, and both processes can involve nucleotide addition (22, 27).The complexity of mechanisms involved in cellular responses to ionizing radiati...

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Isolation of cell cycle-dependent gamma ray-sensitive Chinese hamster ovary cell

Cited by 166 publications

References 25 publications

SR 4233 cytotoxicity and metabolism in DNA repair-competent and repair-deficient cell cultures

SR 4233 cytotoxicity and metabolism in DNA repair-competent and repair-deficient cell cultures

Human Rad51C Deficiency Destabilizes XRCC3, Impairs Recombination, and Radiosensitizes S/G2-phase Cells

DNA Double-Strand Break Repair

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