PMID- 18773878
OWN - NLM
STAT- MEDLINE
DCOM- 20081118
LR  - 20220310
IS  - 1873-2968 (Electronic)
IS  - 0006-2952 (Print)
IS  - 0006-2952 (Linking)
VI  - 76
IP  - 8
DP  - 2008 Oct 15
TI  - DNA damage and homologous recombination signaling induced by thymidylate 
      deprivation.
PG  - 987-96
LID - 10.1016/j.bcp.2008.08.010 [doi]
AB  - DNA damage is accepted as a consequence of thymidylate deprivation induced by 
      chemotherapeutic inhibitors of thymidylate synthase (TS), but the types of damage 
      and signaling responses remain incompletely understood. Thymidylate deprivation 
      increases dUTP and uracil in DNA, which is removed by base excision repair (BER). 
      Because BER requires a synthesis step, strand break intermediates presumably 
      accumulate. Thymidylate deprivation also induces cell cycle arrest during 
      replication. Homologous recombination (HR) is a means of repairing persistent BER 
      intermediates and collapsed replication forks. There are also intimate links 
      between HR and S-phase checkpoint pathways. In this study, the goals were to 
      determine the involvement of HR-associated proteins and DNA damage signaling 
      responses to thymidylate deprivation. When RAD51, which is a central component of 
      HR, was depleted by siRNA cells were sensitized to raltitrexed (RTX), which 
      specifically inhibits TS. To our knowledge, this is the first demonstration in 
      mammalian cells that depletion of RAD51 causes sensitivity to thymidylate 
      deprivation. Activation of DNA damage signaling responses was examined following 
      treatment with RTX. Phosphorylation of replication protein A (RPA2 subunit) and 
      formation of damage-induced foci were strikingly evident following IC(50) doses 
      of RTX. Induction was much more striking following RTX treatment than with 
      hydroxyurea, which is commonly used to inhibit replication. RTX treatment also 
      induced foci of RAD51, gamma-H2AX, phospho-Chk1, and phospho-NBS1, although the 
      extent of co-localization with RPA2 foci varied. Collectively, the results 
      suggest that HR and S-phase checkpoint signaling processes are invoked by 
      thymidylate deprivation and influence cellular resistance to thymidylate 
      deprivation.
FAU - Yang, Zhengguan
AU  - Yang Z
AD  - Department of Pharmaceutical and Biomedical Sciences, South Carolina College of 
      Pharmacy, University of South Carolina, 715 Sumter Street, Columbia, SC 29208, 
      USA.
FAU - Waldman, Alan S
AU  - Waldman AS
FAU - Wyatt, Michael D
AU  - Wyatt MD
LA  - eng
GR  - P20 RR017698-040002/RR/NCRR NIH HHS/United States
GR  - P20 RR017698/RR/NCRR NIH HHS/United States
GR  - R01 CA100450-04/CA/NCI NIH HHS/United States
GR  - R01 CA100450-05/CA/NCI NIH HHS/United States
GR  - R01 CA100450-02/CA/NCI NIH HHS/United States
GR  - 1 R01 CA100450/CA/NCI NIH HHS/United States
GR  - R01 CA100450/CA/NCI NIH HHS/United States
GR  - R01 CA100450-03/CA/NCI NIH HHS/United States
GR  - R01 CA100450-01A2/CA/NCI NIH HHS/United States
PT  - Journal Article
PT  - Research Support, N.I.H., Extramural
DEP - 20080819
PL  - England
TA  - Biochem Pharmacol
JT  - Biochemical pharmacology
JID - 0101032
RN  - 0 (DNA, Neoplasm)
RN  - 0 (Folic Acid Antagonists)
RN  - 0 (Nucleotides)
RN  - 0 (Quinazolines)
RN  - 0 (Replication Protein A)
RN  - 0 (Thiophenes)
RN  - 365-07-1 (Thymidine Monophosphate)
RN  - 935E97BOY8 (Folic Acid)
RN  - EC 2.1.1.45 (Thymidylate Synthase)
RN  - EC 2.7.7.- (Rad51 Recombinase)
RN  - FCB9EGG971 (raltitrexed)
SB  - IM
MH  - Cell Line, Tumor
MH  - Cell Survival/*drug effects
MH  - Colonic Neoplasms
MH  - *DNA Damage
MH  - DNA, Neoplasm/drug effects
MH  - Flow Cytometry
MH  - Folic Acid/pharmacology
MH  - Folic Acid Antagonists/pharmacology
MH  - HeLa Cells/drug effects
MH  - Humans
MH  - Nucleotides/pharmacology
MH  - Phosphorylation
MH  - Quinazolines/pharmacology
MH  - Rad51 Recombinase/drug effects/genetics
MH  - Recombination, Genetic/*drug effects
MH  - Replication Protein A/drug effects/metabolism
MH  - Thiophenes/pharmacology
MH  - Thymidine Monophosphate/*deficiency
MH  - Thymidylate Synthase/antagonists & inhibitors
PMC - PMC2574569
MID - NIHMS74021
EDAT- 2008/09/09 09:00
MHDA- 2008/11/19 09:00
PMCR- 2009/10/15
CRDT- 2008/09/09 09:00
PHST- 2008/06/16 00:00 [received]
PHST- 2008/08/05 00:00 [revised]
PHST- 2008/08/07 00:00 [accepted]
PHST- 2008/09/09 09:00 [pubmed]
PHST- 2008/11/19 09:00 [medline]
PHST- 2008/09/09 09:00 [entrez]
PHST- 2009/10/15 00:00 [pmc-release]
AID - S0006-2952(08)00557-1 [pii]
AID - 10.1016/j.bcp.2008.08.010 [doi]
PST - ppublish
SO  - Biochem Pharmacol. 2008 Oct 15;76(8):987-96. doi: 10.1016/j.bcp.2008.08.010. Epub 
      2008 Aug 19.