Author/Editor		Kralj, Eva; Žakelj, Simon; Trontelj, Jurij; Berginc, Katja; Pajič, Tadej; Preložnik-Zupan, Irena; Černelč, Peter; Ostanek, Barbara; Podgornik, Helena; Marc, Janja; Kristl, Albin
Title		Določanje privzema imatiniba v levkocite kot napovedni dejavnik uspešnosti zdravljenja KML
Translated title		Determination of imatinib intracellular uptake in leukocytes as a prognostic factor in CML therapy
Type		članek
Source		561580
Vol. and No.		Letnik 81, št. suppl. 2
Publication year		2012
Volume		str. II-188 - II-196
Language		slv
Abstract		Izhodišča: Imatinib je prvo usmerjeno zdravilo pri zdravljenju kronične mieloične levkemije (KML). Odziv bolnikov na zdravljenje z imatinibom je odvisen tudi od vstopa učinkovine v tarčno celico z organskim kationskim prenašalcem 1 (OCT1). Na osnovi privzema radioaktivno označenega imatiniba v mononuklearne (MNC) celi - ce bolnikov pred začetkom zdravljenja je že bila dokazana povezava med aktivnostjo OCT1 prenašalcev in uspešnostjo zdravljenja. Domneva se, da bi določanje aktivnosti OCT1 pri bolnikih s KML lahko prispevalo k napovedi uspešnosti zdravljenja z imatinibom. Metode: MNC in granulocite (Gran) zdravega prostovoljca smo pred ali po ločevanju na Ficoll-u inkubirali v raztopini imatiniba s prazosinom oz. brez. Celice smolizirali s tekočim dušikom, nato pa iz lizata z mešanico organskih topil ekstrahirali imatinib. Vsebnost učinkovine v eks - traktu smo določili z metodo LC-MS/MS. Rezultati: Največji privzem imatiniba smo izmerili v predhodno ločenih Gran, v katerih je bila znotrajcelična koncentracija imatiniba skoraj 10-krat večja kot v ostalih vrstah celic. Ob dodatku prazosina (inhibitor OCT1) so bile znotrajcelične koncentracije imatiniba statistično značilno nižje tako v MNC (1,49 Ž 0,11 vs. 17,8 Ž 1,6 mg/L) kot tudi v Gran (96,2 Ž 2,2 vs. 191,2 Ž 7,7 mg/L), inkubiranih z učinkovino po ločevanju na Ficoll - -u. Absolutna aktivnost OCT1 je bila največja v Gran (6,27 Ž 0,66 ng imatiniba/200000 celic). Zaključki: Razvili smo postopek za določanje privzema imatiniba v levkocite, ki ne temelji na uporabi radioaktivno označenih spojin. Z njim želimo preveriti povezanost aktivnosti OCT1 z uspehom zdravljenja z imatinibom tudi na slovenski populaciji bolnikov s KML.Background: Imatinib is the first target therapy for chronic myelogenous leukemia (CML). Response to imatinib treatment also depends on the uptake of the drug into the target cell by organic cation transporter 1 (OCT1). OCT1 activity determined by the uptake of 14C-imatinib (IUR) in isolated mononuclear cells (MNC) has already been linked with treatment response. It has been proposed that the OCT1 activity determination could provide a valuable tool for the prediction of treatment success in patients with CML. Methods: MNC and granulocytes (Gran) of a healthy volunteer were incubated with imatinib in the presence or absence of prazosin before and after Ficoll cell sorting. The cells were lysed with liquid nitrogen and extracted with organic solvents. The intracellular concentration (c i ) of imatinib wasdetermined by LC-MS/MS method. Results: We measured the highest IUR in Granisolated prior to incubation with imatinib. There the c i was 10-fold higher than in other cells. With prazosin, significantly lower imatinib c i were ob - served in MNC (1.49 Ž 0.11 vs. 17.8 Ž 1.6 mg/L) and Gran (96.2 Ž 2.2vs. 191.2 Ž 7.7 mg/L) incubated after cell sorting. We measured the highest absolute OCT1 activity in Gran (6.27 Ž 0.66 ng imatinib/200000 cells).Conclusions: We developed a procedure for the measurement of imatinib uptake into the white blood cells, which is not based on the use of radi - oactively labelled compounds. By means of this test, we also hope to determinethe correlation of OCT1 activity with treatment success in the population of Slovenian CML patients.
Keywords		imatinib kronična mieloična levkemija levkociti