TY - JOUR
T1 - CNDAC-induced DNA double-strand breaks cause aberrant mitosis prior to cell death
AU - Liu, Xiaojun
AU - Jiang, Yingjun
AU - Takata, Kei ichi
AU - Nowak, Billie
AU - Liu, Chaomei
AU - Wood, Richard D.
AU - Hittelman, Walter N.
AU - Plunkett, William
N1 - Funding Information:
This work was supported by grant R01 CA28596 (to W. Plunkett) and Cancer Center Support grant P30 CA16672 from the NCI, Department of Health and Human Services. R.D. Wood was supported by NIH P01 grant CA193124 and theGradyF.Saunders,PhDDistinguishedResearchProfessorship.K.Takatawas supported by an Institutional Research Grant (IRG) from The University of Texas MD Anderson Cancer Center and by the Center for Radiation Oncology Research (CROR). We thank Drs. Simona Colla and Andrea Santoni for their assistance with Comet Assay IV software.
Publisher Copyright:
© 2019 American Association for Cancer Research.
PY - 2019
Y1 - 2019
N2 - Incorporation of the clinically active deoxycytidine analogue 20-C-cyano-20-deoxy-1-b-D-arabino-pentofuranosyl-cytosine (CNDAC) into DNA generates single-strand breaks that are subsequently converted to double-strand breaks (DSB). Here, we investigated the cellular manifestations of these breaks that link these mechanisms to cell death, and we further tested the relevance of DNA repair pathways in protection of cells against CNDAC damage. The present investigations demonstrate that following exposure to CNDAC and a wash into drug-free medium, chromosomal aberrations, DNA strand breaks, and multinucleate cells arose. These portended loss of viability and were dependent upon exposure time, CNDAC concentration, and passage through mitosis. Following a pulse incubation with CNDAC, live cell imaging using GFP-tagged histone H2B as a marker demonstrated a normal rate of progression to mitosis, but a concentration-dependent delay in passage to a second mitosis. Progression through mitosis was also delayed and accompanied by formation of multinucleate cells. CNDAC-treated cells lacking XPF-ERCC1 nuclease function showed a 16-fold increase in chromosome aberrations. Chromosomal damage in Rad51D-mutant cells (homologous recombination repair deficient) were even more severely affected with extensive aberrations. Rodent or human Polq (POLQ) mutant cells, defective in Pol q–mediated alternative end joining, did not show enhanced cellular sensitivity to CNDAC. These findings are consistent with formation of DSBs in the second S-phase following exposure, resulting in chromosome aberrations, aberrant mitoses, and subsequent apoptosis.
AB - Incorporation of the clinically active deoxycytidine analogue 20-C-cyano-20-deoxy-1-b-D-arabino-pentofuranosyl-cytosine (CNDAC) into DNA generates single-strand breaks that are subsequently converted to double-strand breaks (DSB). Here, we investigated the cellular manifestations of these breaks that link these mechanisms to cell death, and we further tested the relevance of DNA repair pathways in protection of cells against CNDAC damage. The present investigations demonstrate that following exposure to CNDAC and a wash into drug-free medium, chromosomal aberrations, DNA strand breaks, and multinucleate cells arose. These portended loss of viability and were dependent upon exposure time, CNDAC concentration, and passage through mitosis. Following a pulse incubation with CNDAC, live cell imaging using GFP-tagged histone H2B as a marker demonstrated a normal rate of progression to mitosis, but a concentration-dependent delay in passage to a second mitosis. Progression through mitosis was also delayed and accompanied by formation of multinucleate cells. CNDAC-treated cells lacking XPF-ERCC1 nuclease function showed a 16-fold increase in chromosome aberrations. Chromosomal damage in Rad51D-mutant cells (homologous recombination repair deficient) were even more severely affected with extensive aberrations. Rodent or human Polq (POLQ) mutant cells, defective in Pol q–mediated alternative end joining, did not show enhanced cellular sensitivity to CNDAC. These findings are consistent with formation of DSBs in the second S-phase following exposure, resulting in chromosome aberrations, aberrant mitoses, and subsequent apoptosis.
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U2 - 10.1158/1535-7163.MCT-18-1380
DO - 10.1158/1535-7163.MCT-18-1380
M3 - Article
C2 - 31501277
AN - SCOPUS:85075960770
SN - 1535-7163
VL - 18
SP - 2283
EP - 2295
JO - Molecular cancer therapeutics
JF - Molecular cancer therapeutics
IS - 12
ER -