ABSTRACT
The cytotoxic activity of the non-steroidal anti-inflammatory agent ibuprofen to human promyelocytic leukemia cell line HL-60, its multidrug-resistant subline HL-60/VCR (MDR-1 gene coded P-glycoprotein), as well as myeloma U266 and B-lymphoblastoid ARH-77 cell lines was demonstrated with the aid of flow cytometric analysis. Ibuprofen inhibited proliferation and induced apoptosis (detected as sub-G0 nuclei, fluorescein diacetate staining, Annexin-V binding cells and agarose electrophoretic detection of nucleosomal DNA fragmentation) in promyelocytic cells and, to a lesser extent, in U266 and ARH-77 cells.
Subject(s)
Anti-Inflammatory Agents, Non-Steroidal/pharmacology , Anti-Inflammatory Agents, Non-Steroidal/therapeutic use , Apoptosis/drug effects , Cell Cycle/drug effects , Ibuprofen/pharmacology , Ibuprofen/therapeutic use , Leukemia, Myeloid/drug therapy , Electrophoresis, Agar Gel , Flow Cytometry , Genes, MDR/drug effects , HL-60 Cells/drug effects , Humans , Inhibitory Concentration 50 , Tumor Cells, Cultured/drug effectsABSTRACT
The differential sensitivity of examined human ovarian carcinoma cell lines (CH1, A-2780 and SKOV-3) to the IMPDH inhibitor, benzamide riboside (BR), was demonstrated with the aid of MTT assay. Present data show that all three examined ovarian carcinoma cell lines were sensitive to the cytotoxic effects of BR in the order of sensitivity CH1, SKOV-3, A-2780, (IC50 = 2.8, 4.0 and 7.4 microM, respectively). Although the IC50 of SKOV-3 cells was similar to that previously determined by others, more than 20% of SKOV-3 cells remained viable in a plateau up to 40 microM BR concentration. This relative resistance of SKOV-3 cells to BR corresponded to the absence ofBR-induced apoptosis in SKOV-3 cells, which together with clearly demonstrated sensitivity of CH1 cells to BR-induced apoptosis, established by flow cytometry (presence of nuclei with sub-G0 DNA content, Annexin V binding) and western blotting (poly-ADP-ribosyl-polymerase (PARP) cleavage), further stressed the role of drug-induced apoptosis in the over-all drug-induced cytotoxicity.
Subject(s)
Apoptosis/drug effects , Enzyme Inhibitors/toxicity , IMP Dehydrogenase/antagonists & inhibitors , Nucleosides/toxicity , Ovarian Neoplasms/pathology , Apoptosis/physiology , Cell Cycle/drug effects , Cell Survival/drug effects , DNA, Neoplasm/drug effects , Female , Humans , Poly(ADP-ribose) Polymerases/metabolism , Resting Phase, Cell Cycle , Tumor Cells, CulturedABSTRACT
BACKGROUND: The non-immunosuppressive cyclosporine analog PSC 833 has been shown to reverse multidrug-resistance of neoplastic cells including the MDR-1 gene coded P-glycoprotein (P-gp)-mediated cells resistant to paclitaxel. MATERIALS AND METHODS: Apoptosis was demonstrated in drug-sensitive HL-60 and multidrug-resistant human promyelocytic leukemia HL-60/ADR (MRP) and HL-60/VCR (MDR-1) cells in vitro with the aid of flow cytometry, DNA analysis and western blotting. RESULTS: The techniques used herein determined accumulation of paclitaxel/PSC 833 induced apoptotic cells with sub-G0 (hypodiploid) DNA content and blocked in the G2/M phase of the cell cycle, internucleosomal DNA fragmentation, poly (ADP-ribose) polymerase cleavage, Bcl-2 modulation and Bax up-regulation, without any significant alterations in the levels of Bcl-xL, CD95/Fas or Fas-L proteins. CONCLUSION: Drug resistance modulator PSC 833 abolished the P-gp-mediated multidrug-resistance to paclitaxel and paclitaxel-induced apoptosis in human myeloid leukemia (HL-60/VCR) cells in vitro. Furthermore, PSC 833 alone induced apoptosis in parental drug-sensitive leukemia cells, but not in both multidrug-resistant sublines studied.