Abstract
Abstract 4607
Nuclear factor kappa B (NFkB) is a critical transcription factor involved in the growth and survival of CLL cells. NFkB is recognized as an important target for the development of novel therapies for the treatment of various malignancies. In vitro and in experimental animal models, OMEGA-3 fatty acid (O3FA) supplementation has been shown to inhibit NFkB activity.
Patients with early stage CLL (Rai stages 0-II) who required no therapy, where accrued to this phase I-II trial. O3FA supplements were given for a total of 12 months at doses ranging from 2250 mg (EPA plus DHA), escalated to 4500 mg and 6750 mg per day as tolerated. NFkB activity was measured in peripheral blood samples after separation of mononuclear cell by gradient centrifugation and expressed as luminescence units/μ g of protein. Baseline and multiple serial samples were obtained during the study period. In-vitro cytotoxicity assays to doxorubicin were conducted using standard LD50 methods. Compliance was monitored by analysis of red cell and lymphocyte membrane lipid composition by gas chromatography.
Fifteen patients have been accrued to the trial, 8 of them have currently completed the planned 12 months of the study period. No significant clinical changes in disease activity were noted. O3FA was well tolerated. Supplementation resulted in a dose-dependent increase of O3FA composition of red cell and lymphocyte membranes in a dose dependent manner. At baseline, CLL patients had NFkB above the range observed in normal controls (2.05 × 104 to 2.32 × 105 NFkB lum units/μ g). The median value in CLL patients at baseline was 11.60 × 106 NFkB lum units/μ g (range 0.9 × 105 to 23.12 × 106). Among 5 patients with the highest baseline levels of NFkB, a decrease in NFkB activity ranging from 0.02 to 0.19 of the baseline value, was noted at the 2 higher doses of O3FA supplementation. Similar results were seen in patients with relatively lower levels of baseline NFkB activity (0.9 × 105 to 2.96 × 106 lum units/μ g). In vitro, significant doxorubicin cytotoxicity (>50%) was noted in samples obtained during supplementation, at μ gM concentrations which produced no detectable cell kill in baseline samples.
O3FA supplementation resulted in significant inhibition of NFkB activity in leukemic cells from patients with CLL. In-vitro, after O3FA supplementation CLL cells became more sensitive to doxorubicin. Preliminary analysis of whole genome micro arrays revealed significant down-regulation of multiple genes associated with O3FA supplementation.
No relevant conflicts of interest to declare.
Author notes
Asterisk with author names denotes non-ASH members.
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