alpha-chymotrypsin and Leukemia--Myelogenous--Chronic--BCR-ABL-Positive

To determine the safety, target inhibition, and signals of clinical activity of tipifarnib in combination with bortezomib in patients with advanced acute leukemias.. In a "3 + 3" design, patients received escalating doses of tipifarnib (days 1-14) and bortezomib (days 1, 4, 8, 11) every 3 weeks until maximum tolerated dose was reached. Peripheral blood mononuclear cells (PBMC) were collected at days 1, 8, and 22 for measurement of chymotrypsin-like and farnesyltransferase activity. Purified bone marrow leukemic blasts were collected at baseline and at day 8 for measurement of NF-κB activity.. The combination was well-tolerated, and maximum tolerated dose was not reached. Dose-limiting toxicities included diarrhea, fatigue, and sensorimotor neuropathy. Chymotrypsin-like and farnesyltransferase activity within PBMCs were decreased in a majority of patients at day 8. NF-κB activity within leukemic blasts was decreased in a majority of patients at day 8. Complete response with incomplete count recovery was observed in 2 patients, and additional 5 patients had stable disease.. Tipifarnib and bortezomib combination in patients with advanced leukemias was well-tolerated, demonstrated relevant target inhibition, and was associated with signals of clinical activity in patients with advanced and refractory acute leukemias. Future studies of this combination may be warranted in more selected groups of patients in whom these molecular targets are of particular importance.

Topics: Aged; Aged, 80 and over; Antineoplastic Combined Chemotherapy Protocols; Boronic Acids; Bortezomib; Chymotrypsin; Farnesyltranstransferase; Female; Humans; Leukemia, Myelogenous, Chronic, BCR-ABL Positive; Leukemia, Myeloid, Acute; Leukocytes, Mononuclear; Male; Maximum Tolerated Dose; Middle Aged; NF-kappa B; Precursor Cell Lymphoblastic Leukemia-Lymphoma; Proteasome Inhibitors; Pyrazines; Quinolones

We have previously shown by reverse transcriptase-PCR (rtPCR) that CML CD34+ HLA-DR- cells are enriched for BCR/ABL(-) hematopoietic progenitor cells (HPC) while leukemic HPC reside predominately within CML CD34+ HLA-DR+ cells. We investigated whether the 30/35 kDa fragment of fibronectin (FN) could be used to enhance retroviral-mediated gene transfer (RMGT) in chronic phase CML marrow HPC. CML CD34+ HLA-DR- and CD34+ HLA-DR+ cells were transduced with vector supernate containing the neomycin resistance gene on plates coated with either FN or bovine serum albumin (BSA) as control, then assayed for transduced HPC in progenitor cell assays in the presence or absence of G418. Transduction efficiency of CML CD34+ HLA-DR- cells over BSA ranged from 0.09 to 7.2% (mean 3.3 +/- 1.5%), while that over FN plates ranged from 3.8 to 23% (mean 11.0 +/- 4.5%) (n = 4). Transduction efficiencies of CML CD34+ HLA-DR+ cells ranged from 0.4 to 9.8% (mean 3.7 +/- 1.7%) and 6.0 to 26% (mean 17.3 +/- 4.5%) (n = 5) over BSA and FN, respectively. rtPCR analysis for BCR/ABL mRNA of individual G418-resistant HPC generated from CD34+ HLA-DR- cells revealed that normal BCR/ABL(-) HPC were successfully transduced under these experimental conditions. These results demonstrate the feasibility of transducing normal CML primitive HPC, and illustrate the potential clinical use of FN in the setting of gene therapy for CML, as well as other diseases.

Topics: Adult; Antigens, CD34; Chymotrypsin; Drug Resistance; Fibronectins; Fusion Proteins, bcr-abl; Gene Transfer Techniques; Genes, Reporter; Genetic Vectors; Hematopoietic Stem Cell Transplantation; Hematopoietic Stem Cells; Humans; Immunomagnetic Separation; Interleukin-2; Leukemia, Myelogenous, Chronic, BCR-ABL Positive; Middle Aged; Neomycin; Peptide Fragments; Polymerase Chain Reaction; Retroviridae; RNA; Serum Albumin, Bovine

After exposure to 12-O-tetradecanoylphorbol-13-acetate (TPA), cells of the promyelocytic leukemia cell line, HL-60, differentiate into macrophage-like cells. Within 24 h the cells adhere to the surface of the culture flask and increase production of nonspecific esterases. The intracellular concentration of the serine proteases increases two- to threefold within 4 days and continues to increase as the cells develop into mature macrophages. The acid hydrolases, lysozyme and beta-glucuronidase, were secreted by the differentiated cells. Both the intracellular and extracellular concentrations of these enzymes continued to increase as the cells matured. The fully differentiated cells readily phagocytized opsonized yeast cells. Phagocytosis had little effect on the secretion of acid hydrolases, while intracellular proteases increased significantly. The fully differentiated HL-60 cells resembled normal macrophages regarding all parameters studied. Viability of the differentiated cells exceeded 50% when cultured for 30 days. Therefore, these cells should prove to be a useful tool for the study of macrophage function with respect to microorganisms that are resistant to destruction by phagocytic cells.

Topics: Candida albicans; Cell Differentiation; Cell Line; Chymotrypsin; Glucuronidase; Humans; Hydrolases; Leukemia, Myelogenous, Chronic, BCR-ABL Positive; Muramidase; Pancreatic Elastase; Phagocytosis; Serine Endopeptidases; Tetradecanoylphorbol Acetate; Tumor Cells, Cultured