Doxorubicin induces the DNA damage response in cultured human mesenchymal stem cells.
Anthracyclines, including doxorubicin, are widely used in the treatment of leukemia. While the effects of doxorubicin on hematopoietic cells have been characterized, less is known about the response of human mesenchymal stem cells (hMSCs) in the bone marrow stroma to anthracyclines. We characterized the effect of doxorubicin on key DNA damage responses in hMSCs, and compared doxorubicin sensitivity and DNA damage response activation between isolated hMSCs and the chronic myelogenous leukemia cell line, K562. Phosphorylation of H2AX, Chk1, and RPA2 was more strongly activated in K562 cells than in hMSCs, at equivalent doses of doxorubicin. hMSCs were relatively resistant to doxorubicin such that, following exposure to 15 μM doxorubicin, the level of cleaved caspase-3 detected by western blotting was lower in hMSCs compared to K562 cells. Flow cytometric analysis of cell cycle progression demonstrated that exposure to doxorubicin induced G2/M phase arrest in hMSCs, while 48 h after exposure, 15.6 % of cells were apoptotic, as determined from the percentage of cells having sub-G1 DNA content. We also show that the doxorubicin sensitivity of hMSCs isolated from a healthy donor was comparable to that of hMSCs isolated from a chronic lymphocytic leukemia patient. Overall, our results demonstrate that high doses of doxorubicin induce the DNA damage response in hMSCs, and that cultured hMSCs are relatively resistant to doxorubicin.
DNA Damage Response Laboratory, Centre for Chromosome Biology and School of Natural Sciences, National University of Ireland Galway, Galway, Ireland. severine.hennequart@unicaen.fr
Séverine
S
Cruet-Hennequart
Áine M
ÁM
Prendergast
Georgina
G
Shaw
Frank P
FP
Barry
Michael P
MP
Carty
D000903:Antibiotics, Antineoplastic / Q000009:adverse effects* / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects; D000071877:Checkpoint Kinase 1; D004249:DNA Damage; D004317:Doxorubicin / Q000009:adverse effects* / Q000494:pharmacology; D005260:Female; D059565:G2 Phase Cell Cycle Checkpoints / Q000187:drug effects; D006657:Histones / Q000378:metabolism; D006801:Humans; D043564:Inorganic Pyrophosphatase / Q000378:metabolism; D020014:K562 Cells; D059566:M Phase Cell Cycle Checkpoints / Q000187:drug effects; D008297:Male; D059630:Mesenchymal Stem Cells / Q000378:metabolism* / Q000473:pathology; D024101:Mitochondrial Proteins / Q000378:metabolism; D010766:Phosphorylation / Q000187:drug effects; D011494:Protein Kinases / Q000378:metabolism
D000903:Antibiotics, Antineoplastic; C468783:H2AX protein, human; D006657:Histones; D024101:Mitochondrial Proteins; D004317:Doxorubicin; D011494:Protein Kinases; C000605867:CHEK1 protein, human; D000071877:Checkpoint Kinase 1; D043564:Inorganic Pyrophosphatase; C509848:PPA2 protein, human