TY - JOUR
T1 - Attenuation of phosphorylation by deoxycytidine kinase is key to acquired gemcitabine resistance in a pancreatic cancer cell line
T2 - Targeted proteomic and metabolomic analyses in PK9 cells
AU - Ohmine, Ken
AU - Kawaguchi, Kei
AU - Ohtsuki, Sumio
AU - Motoi, Fuyuhiko
AU - Egawa, Shinichi
AU - Unno, Michiaki
AU - Terasaki, Tetsuya
PY - 2012/7
Y1 - 2012/7
N2 - Purpose: Multiple proteins are involved in activation and inactivation of 2′,2′-difluorodeoxycytidine (gemcitabine, dFdC). We aimed to clarify the mechanism of dFdC resistance in a pancreatic cancer cell line by applying a combination of targeted proteomic and metabolomic analyses. Methods: Twenty-five enzyme and transporter proteins and 6 metabolites were quantified in sensitive and resistant pancreatic cancer cell lines, PK9 and RPK9, respectively. Results: The protein concentration of deoxycytidine kinase (dCK) in RPK9 cells was less than 0.02-fold (2%) compared with that in PK9 cells, whereas the differences (fold) were within a factor of 3 for other proteins. Targeted metabolomic analysis revealed that phosphorylated forms of dFdC were reduced to less than 0.2% in RPK9 cells. The extracellular concentration of 2′,2′-difluorodeoxyuridine (dFdU), an inactive metabolite of dFdC, reached the same level as the initial dFdC concentration in RPK9 cells. However, tetrahydrouridine treatment did not increase phosphorylated forms of dFdC and did not reverse dFdC resistance in RPK9 cells, though this treatment inhibits production of dFdU. Conclusions: Combining targeted proteomics and metabolomics suggests that acquisition of resistance in RPK9 cells is due to attenuation of dFdC phosphorylation via suppression of dCK.
AB - Purpose: Multiple proteins are involved in activation and inactivation of 2′,2′-difluorodeoxycytidine (gemcitabine, dFdC). We aimed to clarify the mechanism of dFdC resistance in a pancreatic cancer cell line by applying a combination of targeted proteomic and metabolomic analyses. Methods: Twenty-five enzyme and transporter proteins and 6 metabolites were quantified in sensitive and resistant pancreatic cancer cell lines, PK9 and RPK9, respectively. Results: The protein concentration of deoxycytidine kinase (dCK) in RPK9 cells was less than 0.02-fold (2%) compared with that in PK9 cells, whereas the differences (fold) were within a factor of 3 for other proteins. Targeted metabolomic analysis revealed that phosphorylated forms of dFdC were reduced to less than 0.2% in RPK9 cells. The extracellular concentration of 2′,2′-difluorodeoxyuridine (dFdU), an inactive metabolite of dFdC, reached the same level as the initial dFdC concentration in RPK9 cells. However, tetrahydrouridine treatment did not increase phosphorylated forms of dFdC and did not reverse dFdC resistance in RPK9 cells, though this treatment inhibits production of dFdU. Conclusions: Combining targeted proteomics and metabolomics suggests that acquisition of resistance in RPK9 cells is due to attenuation of dFdC phosphorylation via suppression of dCK.
KW - drug resistance
KW - gemcitabine
KW - metabolomics
KW - pancreatic cancer
KW - proteomics
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U2 - 10.1007/s11095-012-0728-2
DO - 10.1007/s11095-012-0728-2
M3 - Article
C2 - 22419259
AN - SCOPUS:84862608491
VL - 29
SP - 2006
EP - 2016
JO - Pharmaceutical Research
JF - Pharmaceutical Research
SN - 0724-8741
IS - 7
ER -