Format

Send to

Choose Destination
Curr Biol. 2002 Oct 29;12(21):1797-806.

DNA damage during mitosis in human cells delays the metaphase/anaphase transition via the spindle-assembly checkpoint.

Author information

1
Division of Molecular Medicine, Laboratory of Cell Regulation, Wadsworth Center, New York State Department of Health, PO Box 509, Albany, NY 12201, USA.

Abstract

BACKGROUND:

DNA damage during mitosis triggers an ATM kinase-mediated cell cycle checkpoint pathway in yeast and fly embryos that delays progression through division. Recent data suggest that this is also true for mammals. Here we used laser microsurgery and inhibitors of topoisomerase IIalpha to break DNA in various mammalian cells after they became committed to mitosis. We then followed the fate of these cells and emphasized the timing of mitotic progression, spindle structure, and chromosome behavior.

RESULTS:

We find that DNA breaks generated during late prophase do not impede entry into prometaphase. If the damage is minor, cells complete mitosis on time. However, more significant damage substantially delays exit from mitosis in many cell types. In human (HeLa, CFPAC-1, and hTERT-RPE) cells, this delay occurs during metaphase, after the formation of a bipolar spindle and the destruction of cyclin A, and it is not dependent on a functional p53 pathway. Pretreating cells with ATM kinase inhibitors does not abrogate the metaphase delay due to chromosome damage. Immunofluorescence studies reveal that cells blocked in metaphase by chromosome damage contain one or more Mad2-positive kinetochores, and the block is rapidly overridden when the cells are microinjected with a dominant-negative construct of Mad2 (Mad2deltaC).

CONCLUSIONS:

We conclude that the delay in mitosis induced by DNA damage is not due to an ATM-mediated DNA damage checkpoint pathway. Rather, the damage leads to defects in kinetochore attachment and function that, in turn, maintain the intrinsic Mad-2-based spindle assembly checkpoint.

PMID:
12419179
DOI:
10.1016/s0960-9822(02)01226-5
[Indexed for MEDLINE]
Free full text

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center