Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0043346 (xeroderma pigmentosum)
 2,924 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

CC-1065 is an extremely potent antitumor antibiotic that forms a well-defined adduct with DNA in which the molecule lies within the minor groove and is covalently attached through N3 of adenine. Addition of CC-1065 to human fibroblast cells produced a prolonged depletion of the nicotinamide adenine dinucleotide (NAD) pool even at extremely low drug concentrations (0.01 microgram/mL). The depletion of NAD by CC-1065 was blocked by 3-aminobenzamide, which is consistent with a NAD depletion mechanism involving poly-(ADP-ribose) synthesis in response to a repair-induced DNA strand breakage event. Significantly, similar extents of NAD depletion were also evident in xeroderma pigmentosum cells of complementation groups A and D following exposure to CC-1065. Since this NAD depletion is presumably associated with repair-induced incision, the repair of CC-1065-DNA adducts can probably take place by a pathway distinct from that involved in repair of more conventional bulky DNA adducts. The prolonged depletion of NAD, even at low doses of drug, suggests that CC-1065 causes DNA damage that results in a delay or block in DNA excision repair between the excision and ligation steps.
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PMID:Depletion of nicotinamide adenine dinucleotide in normal and xeroderma pigmentosum fibroblast cells by the antitumor drug CC-1065. 379 Apr 94

Roles of poly(ADP-ribose) in repair and replication were studied in UV-irradiated normal, xeroderma pigmentosum (XP), and Cockayne syndrome (CS) fibroblasts. UV radiation reduced cellular NAD with concurrent synthesis of poly-(ADP-ribose) in a dose-dependent manner in normal and CS cells, but not in XP cells. Enzymatic incision of DNA of UV-irradiated XP cells by T4-endonuclease V activated poly(ADP-ribose) polymerase. Methyl methanesulfonate (MMS) also reduced the cellular NAD in all the above strains. However, inhibitors of poly(ADP-ribose) synthesis did not affect UV-induced unscheduled DNA synthesis (UDS) and UV and MMS survivals. Thus, poly(ADP-ribose) synthesis may have a chromatin-stabilizing effect, but not the key role in excision repair of UV damage, unlike in the repair of dimethyl sulfate alkylation. CS cells were deficient in the NAD pool and in the recovery of post-UV DNA synthesis, which were rescued by an exogenous supply of NAD. Such normalization in CS cells was inhibited by excess nicotinamide as in normal cells, suggesting that replicon reinitiation may require specific poly(ADP-ribosyl)ation in UV-irradiated human cells.
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PMID:Roles of poly(ADP-ribose) synthesis in repair and replication in normal human, Cockayne syndrome, and xeroderma pigmentosum fibroblasts after UV irradiation. 641 14