Comparative uptake of adriamycin and daunorubicin in sensitive and resistant friend leukemia cells measured by flow cytometry

Abstract

Based on the fluorescence properties of adriamycin (ADM) and daunorubicin (DNR), uptake in sensitive and resistant Friend leukemia cells (FLC) was studied with the aid of the fluorescence activated cell sorter (FACS II). A quantitative cell by cell fluorescence intensity analysis showed a differential affinity of FLC to ADM and DNR. The cellular uptake of these two drugs was temperature dependent and was not hindered by sodium azide treatment; incorporation into isolated nuclei was not temperature dependent, nor hindered by sodium azide. Friend leukemia cell variants resistant to adriamycin (ADM-RFLC) and to daunorubicin (DNR-RFLC) were developed. The rate of uptake of ADM and DNR across the plasma membrane of these two cell variants was lower than in sensitive cells. Although these cells were crossresistant to both ADM and DNR, the drug-induced fluorescence intensity was distributed differently in the corresponding resistant cell variants. We suggest therefore that resistance is the consequence of changes induced in the plasma membrane components. These changes may differ according to which drug is used.Key terms: Cell sorter, adriamycin, daunorubicin, resistant cells Adriamycin (ADM) and daunorubicin (DNR) are glycosidic anthracycline anticancer antibiotics (3, 7, 23, 28) with bifunctional molecules containing a hydrophobic and a hydrophilic region. The hydrophobic region is composed of a resonating ring system introducing an intrinsic fluorescence property to the molecule. When this molecule is excited with an appropriate light wavelength, a fluorescence signal is obtained. It has been previously observed that anthracgclines are incorporated in cells and distributed mainly in nuclei (2, 11). Since the cytotoxic effect is correlated with an interaction with DNA, altering the DNA dependent DNA and RNA polymerase activities (1,16,21, 27), cellular uptake could be a decisive factor for the biological and therapeutic effect of drugs belonging to this group. The exact mode of cellular '

Mechanism-Based Epigenetic Chemosensitization Therapy of Diffuse Large B-Cell Lymphoma

“…Cellular uptake of doxorubicin (hydroxy-daunorubicin) was determined by uptake of daunorubicin as previously published(65). Briefly, cell lines OCI-Ly1, OCI-Ly10, OCI-Ly18, Karpas231, Karpas422, SC1, RL, VAL1, CCRF-CEM/VBL100 (MDR+)(66) and CCRF-CEM (MDR−) were incubated with vehicle, daunorubicin 500 nM and 2.5 μM in complete medium at 37 C for 1 h and washed 3 times with PBS.…”

Synthesis of a Dual Functional Anti-MDR Tumor Agent PH II-7 with Elucidations of Anti-Tumor Effects and Mechanisms

“…Adriamycin can be activated by 500–566 nm wavelength green excitation laser, and emits 620 nm wavelength red fluorescence [70]–[72], we used 544 nm wavelength excitation laser in this experiment. 488 nm/522 nm were set as the excitation and emission wavelengths of FITC labeled PH II-7 respectively.…”