TY - JOUR
T1 - DNA damage tolerance
T2 - A double-edged sword guarding the genome
AU - Ghosal, Gargi
AU - Chen, Junjie
N1 - Funding Information:
We apologize to those colleagues whose work has not been cited due to space limitation. This work was supported by grants from the National Institutes of Health (CA089239, CA092312, and CA100109 to J.C.). J.C is also a recipient of an Era of Hope Scholar award from the Department of Defense (W81XWH-05-1-0470) and a member of M.D. Anderson Cancer Center (CA016672).
PY - 2013/6/1
Y1 - 2013/6/1
N2 - Preservation of genome integrity is an essential process for cell homeostasis. During the course of life of a single cell, the genome is constantly damaged by endogenous and exogenous agents. To ensure genome stability, cells use a global signaling network, namely the DNA damage response (DDR) to sense and repair DNA damage. DDR senses different types of DNA damage and coordinates a response that includes activation of transcription, cell cycle control, DNA repair pathways, apoptosis, senescence, and cell death. Despite several repair mechanisms that repair different types of DNA lesions, it is likely that the replication machinery would still encounter lesions that are mis-repaired or not repaired. Replication of damaged genome would result in high frequency of fork collapse and genome instability. In this scenario, the cells employ the DNA damage tolerance (DDT) pathway that recruits a specialized low fidelity translesion synthesis (TLS) polymerase to bypass the lesions for repair at a later time point. Thus, DDT is not a repair pathway per se, but provides a mechanism to tolerate DNA lesions during replication thereby increasing survival and preventing genome instability. Paradoxically, DDT process is also associated with increased mutagenesis, which can in turn drive the cell to cancer development. Thus, DDT process functions as a double-edged sword guarding the genome. In this review, we will discuss the replication stress induced DNA damage-signaling cascade, the stabilization and rescue of stalled replication forks by the DDT pathway and the effect of the DDT pathway on cancer.
AB - Preservation of genome integrity is an essential process for cell homeostasis. During the course of life of a single cell, the genome is constantly damaged by endogenous and exogenous agents. To ensure genome stability, cells use a global signaling network, namely the DNA damage response (DDR) to sense and repair DNA damage. DDR senses different types of DNA damage and coordinates a response that includes activation of transcription, cell cycle control, DNA repair pathways, apoptosis, senescence, and cell death. Despite several repair mechanisms that repair different types of DNA lesions, it is likely that the replication machinery would still encounter lesions that are mis-repaired or not repaired. Replication of damaged genome would result in high frequency of fork collapse and genome instability. In this scenario, the cells employ the DNA damage tolerance (DDT) pathway that recruits a specialized low fidelity translesion synthesis (TLS) polymerase to bypass the lesions for repair at a later time point. Thus, DDT is not a repair pathway per se, but provides a mechanism to tolerate DNA lesions during replication thereby increasing survival and preventing genome instability. Paradoxically, DDT process is also associated with increased mutagenesis, which can in turn drive the cell to cancer development. Thus, DDT process functions as a double-edged sword guarding the genome. In this review, we will discuss the replication stress induced DNA damage-signaling cascade, the stabilization and rescue of stalled replication forks by the DDT pathway and the effect of the DDT pathway on cancer.
KW - DNA damage tolerance (DDT)
KW - Proliferating cell nuclear antigen (PCNA)
KW - Replicative DNA polymerase
KW - Stalled replication forks
KW - Translesion polymerase
KW - Translesion synthesis (TLS)
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U2 - 10.3978/j.issn.2218-676X.2013.04.01
DO - 10.3978/j.issn.2218-676X.2013.04.01
M3 - Review article
C2 - 24058901
AN - SCOPUS:84964057679
SN - 2218-676X
VL - 2
SP - 107
EP - 129
JO - Translational Cancer Research
JF - Translational Cancer Research
IS - 3
ER -