Abstract
Objective. To evaluate the anti-tumor potential of β-lapachone in multiple myeloma (MM) cell lines (U266, RPMI8226, and MM.1S); MM cell lines resistant to dexamethasone (MM.1R), melphalan (RPMI8226/LR5), doxorubicin (RPMI8226/DOX40), and mitoxantrone (RPMI8226/ MR20); and MM cells from patients (MM1-MM4). Materials and Methods. Cytotoxicity of β-lapachone was assessed by MTT and [ 3H]-thymidine uptake assays. Apoptosis was analyzed using propidium iodide staining, DNA fragmentation, TUNEL assay, caspase-9 colorimetric assay, and immunoblotting for caspase-3, poly (ADP-ribose) polymerase (PARP), and caspase-8 cleavage products. Paracrine growth of MM cells was assessed by [ 3H]-thymidine uptake in cultures of bone marrow stromal cells (BMSCs) and MM cells. Interleukin-6 (IL-6) and vascular endothelial growth factor (VEGF) secretion in the culture supernatants was measured by specific enzyme-linked immunosorbent assays (ELISAs). Results. β-lapachone showed significant cytotoxicity in MM cells (IC 50: 4-8 μM). In contrast, normal peripheral blood mononuclear cells (PBMCs) and BMSCs from MM patients were relatively resistant (IC 50: 8-16 μM). IL-6 did not protect against β-lapachone-induced apoptosis in MM.1S cells, and dexamethasone showed additive cytotoxicity. β-lapachone also decreased binding of MM.1S cells to BMSCs; abrogated IL-6 and VEGF secretion triggered by adhesion of BMSCs to MM.1S cells; reduced proliferation of MM.1S cells adherent to BMSCs; and decreased intracellular adhesion molecule-1 (ICAM-1) expression on MM.1S cells. Furthermore, β-lapachone induced typical PARP cleavage, increased caspase-9 proteolytic activity, and activation of caspase-3, without activation of caspase-8 in U266 cells. Conclusion. These studies provide a framework for clinical evaluation of β-lapachone to improve the outcome for patients with MM.
Original language | English |
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Pages (from-to) | 711-720 |
Number of pages | 10 |
Journal | Experimental Hematology |
Volume | 30 |
Issue number | 7 |
DOIs | |
Publication status | Published - Jul 2002 |
Externally published | Yes |
Keywords
- Antibiotics, Antineoplastic/pharmacology
- Antineoplastic Agents, Phytogenic/pharmacology
- Apoptosis/drug effects
- Bone Marrow Cells/cytology
- Caspases/metabolism
- Cell Adhesion/drug effects
- Cell Division/drug effects
- Dexamethasone/pharmacology
- Doxorubicin/pharmacology
- Drug Resistance, Neoplasm
- Drug Screening Assays, Antitumor
- Enzyme Activation/drug effects
- Enzyme Inhibitors/pharmacology
- Enzyme Precursors/metabolism
- Humans
- Intercellular Adhesion Molecule-1/biosynthesis
- Interleukin-6/pharmacology
- Leukocytes, Mononuclear/drug effects
- Melphalan/pharmacology
- Mitoxantrone/pharmacology
- Multiple Myeloma/pathology
- Naphthoquinones/pharmacology
- Neoplasm Proteins/antagonists & inhibitors
- Paracrine Communication
- Poly(ADP-ribose) Polymerases/metabolism
- Stromal Cells/cytology
- Topoisomerase I Inhibitors
- Topoisomerase II Inhibitors
- Tumor Cells, Cultured/drug effects
ASJC Scopus subject areas
- Genetics
- Molecular Biology
- Hematology
- Cancer Research
- Cell Biology