TY - JOUR
T1 - Decreased resistance to gemcitabine (2',2'-difluorodeoxycitidine) of cytosine arabinoside-resistant myeloblastic murine and rat leukemia cell lines
T2 - Role of altered activity and substrate specificity of deoxycytidine kinase
AU - Bergman, Andries M.
AU - Pinedo, Herbert M.
AU - Jongsma, Ans P M
AU - Brouwer, Marjoleine
AU - Ruiz Van Haperen, Veronique W T
AU - Veerman, Gijsbert
AU - Leyva, Albert
AU - Eriksson, Steffan
AU - Peters, Godefridus J.
PY - 1999/2/15
Y1 - 1999/2/15
N2 - We determined the potential activity of 2',2'-difluorodeoxycytidine (gemcitabine, dFdC) in 1-β-d-arabinofuranosylcytidine (ara-C)-sensitive and-resistant leukemia cell lines. Both drugs are phosphorylated by deoxycytidine kinase (dCK); the triphosphates, dFdCTP and ara-CTP, respectively, are incorporated into DNA. In the murine leukemia cell line L1210, induction of resistance to ara-C resulted in the 2200-fold resistant subline L4A6. The Brown Norway rat myelocytic leukemia ara-C-sensitive cell line (BCLO) was >300-fold more sensitive to ara-C than its variant Bara-C. In L1210 cells, gemcitabine was 8-fold more active than ara-C; in L4A6, BCLO, and Bara-C cells, gemcitabine was 16-, 28-, and more than 3-fold more active than ara-C, respectively. A partial explanation for these differences may be the higher dCK activity in the parental cell lines L1210 and BCLO with gemcitabine compared to ara-C as a substrate. DCK activity was not or hardly detectable in the resistant L4A6 and Bara-C cell. In the rat leukemia cell lines, deoxycytidine (dCyd) phosphorylation activity showed an aberrant pattern, since the activity with dCyd was 1.5-fold higher in the Bara-C cell line compared with BCLO, possibly due to thymidine kinase 2. The wild-type L1210 cells accumulated at least 3-fold more ara-CTP and dFdCTP than the rat leukemia cell line BCLO. The ara-C-resistant variants L4A6 and Bara-C did not accumulate dFdCTP or ara-CTP. In conclusion, gemcitabine was more active than ara-C in all leukemia cell lines tested. The sensitivity of the wild-type cell lines correlates with the accumulation of dFdCTP and ara-CTP, but is independent of dCK. However, both resistant variants had decreased dCK activities, but were relatively more sensitive to dFdC than to ara-C. Copyright (C) 1999 Elsevier Science Inc.
AB - We determined the potential activity of 2',2'-difluorodeoxycytidine (gemcitabine, dFdC) in 1-β-d-arabinofuranosylcytidine (ara-C)-sensitive and-resistant leukemia cell lines. Both drugs are phosphorylated by deoxycytidine kinase (dCK); the triphosphates, dFdCTP and ara-CTP, respectively, are incorporated into DNA. In the murine leukemia cell line L1210, induction of resistance to ara-C resulted in the 2200-fold resistant subline L4A6. The Brown Norway rat myelocytic leukemia ara-C-sensitive cell line (BCLO) was >300-fold more sensitive to ara-C than its variant Bara-C. In L1210 cells, gemcitabine was 8-fold more active than ara-C; in L4A6, BCLO, and Bara-C cells, gemcitabine was 16-, 28-, and more than 3-fold more active than ara-C, respectively. A partial explanation for these differences may be the higher dCK activity in the parental cell lines L1210 and BCLO with gemcitabine compared to ara-C as a substrate. DCK activity was not or hardly detectable in the resistant L4A6 and Bara-C cell. In the rat leukemia cell lines, deoxycytidine (dCyd) phosphorylation activity showed an aberrant pattern, since the activity with dCyd was 1.5-fold higher in the Bara-C cell line compared with BCLO, possibly due to thymidine kinase 2. The wild-type L1210 cells accumulated at least 3-fold more ara-CTP and dFdCTP than the rat leukemia cell line BCLO. The ara-C-resistant variants L4A6 and Bara-C did not accumulate dFdCTP or ara-CTP. In conclusion, gemcitabine was more active than ara-C in all leukemia cell lines tested. The sensitivity of the wild-type cell lines correlates with the accumulation of dFdCTP and ara-CTP, but is independent of dCK. However, both resistant variants had decreased dCK activities, but were relatively more sensitive to dFdC than to ara-C. Copyright (C) 1999 Elsevier Science Inc.
KW - ara-C
KW - Cytogenetic alterations
KW - Deoxycytidine kinase activity
KW - Drug accumulation
KW - Drug resistance
KW - Gemcitabine
KW - Thymidine kinase activity
UR - http://www.scopus.com/inward/record.url?scp=0032898341&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0032898341&partnerID=8YFLogxK
U2 - 10.1016/S0006-2952(98)00318-9
DO - 10.1016/S0006-2952(98)00318-9
M3 - Article
C2 - 9933028
AN - SCOPUS:0032898341
SN - 0006-2952
VL - 57
SP - 397
EP - 406
JO - Biochemical Pharmacology
JF - Biochemical Pharmacology
IS - 4
ER -