title: In vitro activity of bortezomib in cultures of patient tumour cells--potential utility in haematological malignancies.
abstract: Bortezomib represents a new class of anti-cancer drugs, the proteasome inhibitors. We evaluated the in vitro activity of bortezomib with regard to tumour-type specificity and possible mechanisms of drug resistance in 115 samples of tumour cells from patients and in a cell-line panel, using the short-term fluorometric microculture cytotoxicity assay. Bortezomib generally showed dose-response curves with a steep slope. In patient cells, bortezomib was more active in haematological than in solid tumour samples. Myeloma and chronic myeloid leukaemia were the most sensitive tumour types although with great variability in drug response between the individual samples. Colorectal and kidney cancer samples were the least sensitive. In the cell-line panel, only small differences in response were seen between the different cell lines, and the proteasome inhibitors, lactacystin and MG 262, showed an activity pattern similar to that of bortezomib. The cell-line data suggest that resistance to bortezomib was not mediated by MRP-, PgP, GSH-; tubulin and topo II-associated MDR. Combination experiments indicated synergy between bortezomib and arsenic trioxide or irinotecan. The data support the current use of bortezomib but also points to its potential utility in other tumour types and in combination with cytotoxic drugs.
authors.affiliation: Division of Clinical Pharmacology, Department of Medical Sciences, Uppsala University Hospital, entr 61, 4th floor, SE-751 85, Uppsala, Sweden.
authors.forename: Kristina
authors.initials: K
authors.lastname: Wiberg
authors.forename: Kristina
authors.initials: K
authors.lastname: Carlson
authors.forename: Anna
authors.initials: A
authors.lastname: Aleskog
authors.forename: Rolf
authors.initials: R
authors.lastname: Larsson
authors.forename: Peter
authors.initials: P
authors.lastname: Nygren
authors.forename: Elin
authors.initials: E
authors.lastname: Lindhagen
mesh_terms: D000970:Antineoplastic Agents / Q000627:therapeutic use*; D001897:Boronic Acids / Q000627:therapeutic use*; D000069286:Bortezomib; D045744:Cell Line, Tumor; D003603:Cytotoxins / Q000627:therapeutic use; D004347:Drug Interactions; D019008:Drug Resistance, Neoplasm; D019337:Hematologic Neoplasms / Q000188:drug therapy*; D006801:Humans; D011480:Protease Inhibitors / Q000627:therapeutic use*; D061988:Proteasome Inhibitors; D011719:Pyrazines / Q000627:therapeutic use*; D014407:Tumor Cells, Cultured
chemical_list: D000970:Antineoplastic Agents; D001897:Boronic Acids; D003603:Cytotoxins; D011480:Protease Inhibitors; D061988:Proteasome Inhibitors; D011719:Pyrazines; D000069286:Bortezomib