Fatty acids for treating pancreatic cancer

Dietary supplementation with n-3-fatty acids in patients with pancreatic cancer and cachexia: marine phospholipids versus fish oil - a randomized controlled double-blind trial

BACKGROUND

Like many other cancer patients, most pancreatic carcinoma patients suffer from severe weight loss. As shown in numerous studies with fish oil (FO) supplementation, a minimum daily intake of 1.5 g n-3-fatty acids (n-3-FA) contributes to weight stabilization and improvement of quality of life (QoL) of cancer patients. Given n-3-FA not as triglycerides (FO), but mainly bound to marine phospholipids (MPL), weight stabilization and improvement of QoL has already been seen at much lower doses of n-3-FA (0,3 g), and MPL were much better tolerated. The objective of this double-blind randomized controlled trial was to compare low dose MPL and FO formulations, which had the same n-3-FA amount and composition, on weight and appetite stabilization, global health enhancement (QoL), and plasma FA-profiles in patients suffering from pancreatic cancer.

METHODS

Sixty pancreatic cancer patients were included into the study and randomized to take either FO- or MPL supplementation. Patients were treated with 0.3 g of n-3-fatty acids per day over six weeks. Since the n-3-FA content of FO is usually higher than that of MPL, FO was diluted with 40% of medium chain triglycerides (MCT) to achieve the same capsule size in both intervention groups and therefore assure blinding. Routine blood parameters, lipid profiles, body weight, and appetite were measured before and after intervention. Patient compliance was assessed through a patient diary. Quality of life and nutritional habits were assessed with validated questionnaires (EORTC-QLQ-C30, PAN26). Thirty one patients finalized the study protocol and were analyzed (per-protocol-analysis).

RESULTS

Intervention with low dose n-3-FAs, either as FO or MPL supplementation, resulted in similar and promising weight and appetite stabilization in pancreatic cancer patients. MPL capsules were slightly better tolerated and showed fewer side effects, when compared to FO supplementation.

CONCLUSION

The similar effects between both interventions were unexpected but reliable, since the MPL and FO formulations caused identical increases of n-3-FAs in plasma lipids of included patients after supplementation. The effects of FO with very low n-3-FA content might be explained by the addition of MCT. The results of this study suggest the need for further investigations of marine phospholipids for the improvement of QoL of cancer patients, optionally in combination with MCT.

Apoptotic death of pancreatic cancer cells induced by polyunsaturated fatty acids varies with double bond number and involves an oxidative mechanism

Polyunsaturated fatty acids (PUFAs), reported to be cytotoxic at micromolar concentrations for cancer cells in vitro and in vivo, are currently being tested in clinical trials as anti-cancer agents. This study has shown that seven PUFAs all inhibited the growth in vitro of three pancreatic cancer cell lines and the HL-60 leukaemic cell line. Five PUFAs induced cell death within 20-30 h, but two less potent PUFAs induced death between 50 and 75 h. Apoptosis was demonstrated to be the mode of cell death by light, UV fluorescence, and electron microscopy, together with studies of DNA fragmentation. In a time-course study of PUFA-treated Mia-Pa-Ca-2 cells, apoptosis accounted for an average of 80 per cent of the loss of viability, with 'secondary necrosis', a feature of late apoptosis, apparently accounting for the remainder. Correlations were found between the number of fatty acid double bonds and the proportion of cells undergoing apoptosis induced in both Mia-Pa-Ca-2 cells (R = 0.88, P = 0.0001) and HL-60 cells (R = 0.85, P = 0.0001) and inversely with the micromolar concentrations of PUFAs required for 50 per cent inhibition of growth (IC50) of Mia-Pa-Ca-2 cells (R = -0.73, P = 0.05). Cell death was preceded by progressively increasing lipid peroxidation. The extent of PUFA-induced lipid peroxidation, measured as malondialdehyde (MDA), also correlated with the proportion of apoptosis induced in Mia-Pa-Ca-2 cells (R = 0.69, P = 0.025) or HL-60 cells (R = 0.64, P = 0.043), as well as with the number of fatty acid double bonds (R = 0.82, P = 0.0015). PUFA-induced apoptosis was oxidative, being blocked by both vitamin E acetate and sodium selenite, the latter in a critically time-dependent manner. The cytotoxic effects of exposure to a PUFA and to gamma-irradiation simultaneously with, or prior to, the addition of PUFA.

Modulation of human hepatocyte acute phase protein production in vitro by n-3 and n-6 polyunsaturated fatty acids

OBJECTIVE

The authors investigate the role of a variety of essential polyunsaturated fatty acids on the spontaneous and interleukin-6 stimulated production of acute phase proteins by isolated human hepatocytes.

SUMMARY BACKGROUND DATA

The altered production of acute phase proteins by the liver is one of the principal effects of the systemic inflammatory response in human disease. It has been shown that polyunsaturated fatty acids have certain anti-inflammatory properties that potentially are mediated through altered prostaglandin or proinflammatory cytokine production. However, the effect of polyunsaturated fatty acids on the responsiveness of the human hepatocyte to proinflammatory cytokines has not been studied in detail.

METHODS

Hepatocytes isolated from human livers were maintained in primary culture in the presence of a variety of bovine serum albumin-complexed fatty acids. The influence of these fatty acids on hepatocyte acute phase protein production was assessed, in the presence and absence of recombinant interleukin-6, by measurement of acute phase proteins by enzyme-linked immunosorbent assay.

RESULTS

Eicosapentaenoic and gammalinolenic acid increased spontaneous production of alpha 1-antichymotrypsin and prealbumin but decreased spontaneous production of transferrin and haptoglobin from isolated human hepatocytes. Eicosapentaenoic and gammalinolenic significantly increased interleukin-6-stimulated production of C-reactive protein and alpha 1-antichymotrypsin but reversed the stimulatory effect of interleukin-6 on haptoglobin production. These fatty acids also reversed the inhibitory effect of interleukin-6 on prealbumin production.

CONCLUSIONS

These results show that certain fatty acids have the potential to modulate spontaneous and cytokine-induced alterations in human hepatic acute phase protein metabolism. These data indicate the presence of complex mechanisms of regulation of human hepatic protein metabolism by fatty acids, and further study will be required to establish the nature of their influence in vivo.