Enhanced incorporation of 1-beta-D-arabinofuranosylcytosine by pretreatment with etoposide.
We examined the effects of timing of administration of etoposide on cytosine arabinoside (ara-C) incorporation into DNA in L1210 ascites tumor. At 1 hr after injection of ara-C, 3-hr and 6-hr pretreatments with 15 mg/kg of etoposide increased ara-C incorporation to more than 200% as compared to that of ara-C given alone. Simultaneous administration of etoposide, however, decreased ara-C incorporation to 33% of that of ara-C alone. These results might explain the previously reported sequence dependency of the antitumor effect of etoposide and ara-C.
Ooi
K
K
Department of Pharmacy, Social Insurance Hazu Hospital, Mie-Ken, Japan.
Ohkubo
T
T
Kuwabara
H
H
Higashigawa
M
M
Kawasaki
H
H
Kakitoh
H
H
Kagawa
Y
Y
Inagaki
S
S
Sumida
K
K
Sakurai
M
M
D000818:Animals; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000494:pharmacology / Q000627:therapeutic use*; D003561:Cytarabine / Q000008:administration & dosage* / Q000494:pharmacology; D004273:DNA, Neoplasm / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D005047:Etoposide / Q000008:administration & dosage* / Q000494:pharmacology; D007939:Leukemia L1210 / Q000188:drug therapy*; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains
D004273:DNA, Neoplasm; D003561:Cytarabine; D005047:Etoposide