Polyunsaturated fatty acids in the treatment of weight-losing patients with pancreatic cancer

Myeloid derived suppressor cells are reduced and T regulatory cells stabilised in patients with advanced pancreatic cancer treated with gemcitabine and intravenous omega 3

Background

Pancreatic adenocarcinoma (PAC) is a devastating condition, with the majority of patients presenting with metastatic or locally advanced disease. In these patients their disease is classified as advanced pancreatic cancer (APC), which is incurable and associated with survivals generally of a few months. The overall survival (OS) for pancreatic cancer has not changed significantly in the past forty years with multiple trials demonstrating disappointing results. Immune modulatory cells particularly myeloid derived suppressor cells (MDSCs) and T regulatory cells (Tregs) are important mediators in PAC. Omega 3 fatty acids (ω-3FAs) have been shown to have anti-inflammatory properties and there is now evidence demonstrating the benefit of ω-3FAs in PAC.

Methods

This was a single-center cohort study investigating intravenous ω-3FAs and gemcitabine chemotherapy versus gemcitabine therapy only in patients with APC. Here, we investigated levels of MDSCs and Tregs and examined how these changes correlated with survival.

Results

Eighteen trial and nine control patients were recruited. There was a significant benefit in progression-free survival (PFS) in trial compared to control patients (P=0.0003). Median survival in trial patients was 5.65 months compared to 1.8 months in control patients. There was no significant benefit in OS in trial compared to control patients (P=0.13). Median survival in trial patients was 7 months compared to 2.9 months in control patients. MDSCs were significantly decreased in trial patients (P=0.0001) but not control patients. Conversely Tregs were significantly increased in control patients (P=0.005) but not in trial patients.

Conclusions

Administration of ω-3FAs with gemcitabine chemotherapy in APC results in a significant decrease of MDSCs and stability of Tregs. This may be secondary to the reduction of pro-inflammatory mediators. A phase three randomized trial is justified to further examine these effects.

Inhibition of Proliferation by Omega-3 Fatty Acids in Chemoresistant Pancreatic Cancer Cells

BACKGROUND

Pancreatic cancer-gemcitabine (GEM) chemoresistance has been demonstrated to be associated with enhanced NF-kB activation and antiapoptotic protein synthesis. The well-known capacity of omega-3 fatty acids (n-3 FAs) to inhibit NF-kB activation and promote cellular apoptosis has the potential to restore or facilitate gemcitabine chemosensitivity.

METHODS

Four pancreatic cancer cell lines (MIA PaCa-2, BxPC-3, PANC-1, and L3.6), each with distinct basal NF-kB and differing GEM sensitivity profiles, were administered: 100 uM of (1) n-3FA, (2) n-6FA, (3) GEM, (4) n-3FA + GEM, or (5) n-6FA + GEM for 24 and 48 hours. Proliferation was assessed using the WST-1 assay. To define the mechanism(s) of altered proliferation, electron mobility shift assay for NF-kB activity, western blots of phoshoStat3, phosphoIkappaB, and poly(ADP-ribose) polymerase (PARP) cleavage were performed in the MIA PaCa-2 cell line.

RESULTS

All cell lines demonstrated a time/dose-dependent inhibition of proliferation in response to n-3FA. For MIA PaCa-2 cells, n-3FA and n-3FA + GEM treatment resulted in reduction of I-kB phosphorylation and NF-kB activation when compared with n-6FA control. n-3FA and combination treatment also significantly decreased Stat3 phosphorylation, whereas GEM alone had no effect. n-3FAs and n-3FA + GEM groups demonstrated increased PARP cleavage, mirroring NF-kB activity and Stat3 phosphorylation.

CONCLUSIONS

n-3 FA treatment is specifically associated with inhibition of proliferation in these four pancreatic cell lines irrespective of varied gemcitabine resistance. An experimental paradigm to screen for potential contributory mechanism(s) in altered pancreatic cancer cellular proliferation was defined, and using this approach the co-administration of n-3 FA with GEM inhibited GEM-induced NF-kB activation and restored apoptosis in the MIA PaCa-2 cell-line.

G2/M cell-cycle arrest and apoptosis by n-3 fatty acids in a pancreatic cancer model

BACKGROUND

n-3 fatty acids (n-3FA) have anti-inflammatory and anti-proliferative effects including modulation of pro-inflammatory cascade mediators and cytokine elaboration (i.e., TNF-alpha, IL-10 and PGE(2)) in many cell lines. However, mechanisms of anti-proliferative effects have not been clearly defined.

MATERIALS AND METHODS

MIA PaCa-2 pancreatic cancer cells were treated either with n-3FA (treatment), media (control), or n-6FA (control) for all experiments. Cellular proliferation was evaluated with WST-1 reagent. Cells were stained with propidium iodide and analyzed by flow cytometry for cell-cycle arrest, which was further analyzed by cdc2 expression. Membrane and media lipid concentrations were analyzed by high-performance liquid chromatography. Apoptosis was evaluated by AnnexinV-FITC flow cytometry and reconfirmed by poly (ADP-ribose) polymerase (PARP) cleavage and B(cl)-2 expression.

RESULTS

Propidium iodide flow cytometry of MIA PaCa-2 dosed with n-3FA showed a decrease in cells in G1 phase (11-17%) and an increase cells in G2 phase (7-13%) from controls. cdc2 expression was also decreased at 24 h compared to controls. Annexin-V staining of n-3FA-treated cells demonstrated time-dependent increased apoptosis and PARP cleavage was present only in the n-3FA treatment group. Phospho-B(cl)-2 was also decreased in the n-3FA-treated cells compared to controls.

CONCLUSIONS

Co-incubation of MIA PaCa-2 cells with n-3FA results in both dose- and time-dependent cell-cycle arrest. Cells also progress to cell death via apoptosis. These data support the potential applicability for n-3FA as an antiproliferative and pro-apoptotic strategy.

Eicosapentaenoic acid (EPA, an omega-3 fatty acid from fish oils) for the treatment of cancer cachexia

BACKGROUND

Cancer cachexia is a distressing weight loss syndrome commonly seen in advanced cancer patients. It is associated with reduced quality of life and shorter survival time. Eicosapentaenoic acid (EPA) is a long chain polyunsaturated fatty acid found naturally in some fish which has been used to decrease weight loss, promote weight gain and increase survival times in patients affected with cancer cachexia.

OBJECTIVES

To evaluate the effectiveness and safety of EPA in relieving symptoms associated with the cachexia syndrome in patients with advanced cancer.

SEARCH STRATEGY

Studies were sought through an extensive search of a range of electronic databases. Hand searching was conducted on selected journals and reference lists as well as contact made with investigators, manufacturers and experts. The most recent electronic search was conducted in February 2005.

SELECTION CRITERIA

Studies were included in the review if they assessed oral EPA compared with placebo or control in randomised controlled trials of patients with advanced cancer and either a clinical diagnosis of cachexia or self-reported weight loss of 5% or more.

DATA COLLECTION AND ANALYSIS

Both methodological quality evaluation of potential trials and data extraction were conducted by two independent review authors.

MAIN RESULTS

Five trials (involving 587 patients) met the inclusion criteria. Three trials compared EPA at different doses with placebo with two outcomes, nutritional status and adverse events comparable across two of the three included trials. In addition, two trials compared different doses of EPA with an active matched control. It was possible to compare the outcomes of weight, quality of life and adverse events across these two trials. There were insufficient data to define the optimal dose of EPA.

AUTHORS' CONCLUSIONS

There were insufficient data to establish whether oral EPA was better than placebo. Comparisons of EPA combined with a protein energy supplementation versus a protein energy supplementation (without EPA) in the presence of an appetite stimulant (Megestrol Acetate) provided no evidence that EPA improves symptoms associated with the cachexia syndrome often seen in patients with advanced cancer.

Evidence for symptom management in the child with cancer

The use of complementary/alternative medicine (CAM) has been well documented among children with cancer. This report summarizes the research evidence on the role of CAM therapies for prevention and treatment of the most commonly reported cancer-related symptoms and late effects among children with cancer. Small clinical trials document evidence of effectiveness for select therapies, such as acupuncture or ginger for nausea and vomiting, TRAUMEEL S for mucositis, and hypnosis and imagery for pain and anxiety. Several relatively small clinical trials of varying quality have been conducted on these CAM therapies in children with cancer. Some herbs have demonstrated efficacy in adults, but few studies of herbs have been conducted in children. Larger randomized clinical trials are warranted for each of these promising therapies. Until the evidence is more conclusive, the providers' role is to assess and document the child's use of CAM, critically evaluate the evidence or lack of evidence, balance the potential risks with possible benefits, and assist the family in their choices and decisions regarding use of CAM for their child with cancer.