Essential fatty acids, especially gamma linolenic (GLA) and eicosapentaenoic
acids, have been proposed as potential anticancer drugs. Our aim was to study the effect of the
lithium salt of
gamma linolenic acid (
LiGLA) on the growth of two human
pancreatic cancer cell lines (MIA PaCa2 and Panc 1) and primary human fibroblasts (HFF 5) in vitro. Cell growth was assessed by a microculture tetrazolium (MTT) assay.
LiGLA had a selective growth inhibitory effect on
pancreatic cancer cell lines with 50% growth inhibition (IC50) at approximately 6-16 mumol/l compared with approximately 111 mumol/l for the fibroblasts. The degree of growth inhibition increased with the time of exposure to
LiGLA. Special attention was paid to the influence of
albumin and
iron on
LiGLA-mediated growth inhibition.
Albumin incorporated into essentially serum-free culture medium inhibited the effect of
LiGLA in a dose-dependent manner, associated with reduced GLA uptake by
cancer cells. Ferric
ions were confirmed as potentiators of the growth inhibitory effect of
LiGLA but more physiologically relevant
transferrin-bound
iron was ineffective. With further improvements in the
fatty acid delivery mechanism,
LiGLA may become a useful adjunct in the management of
pancreatic cancer patients.