Polyunsaturated fatty acids reduce fatty acid synthase and hydroxy-methyl-glutaryl CoA-reductase gene expression and promote apoptosis in HepG2 cell line.
BACKGROUND
n-3 and n-6 polyunsaturated fatty acids (PUFAs) are the two major classes of PUFAs encountered in the diet, and both classes of fatty acids are required for normal human health. Moreover, PUFAs have effects on diverse pathological processes impacting chronic disease, such as cardiovascular and immune disease, neurological disease, and cancer.


OBJECTIVE
To investigate the effects of eicosapentaenoic acid (EPA) and arachidonic acid (ARA) on the proliferation and apoptosis of human hepatoma cell line HepG2 after exposure to increasing concentrations of EPA or ARA for 48 h. Moreover, in the same cells the gene expression of Fatty Acid Synthase (FAS) and 3-Hydroxy-3-Methyl-Glutaryl Coenzyme A Reductase (HMG-CoAR) was also investigated.


METHODS
Cell growth and apoptosis were assayed by MTT and ELISA test, respectively after cell exposure to increasing concentrations of EPA and ARA. Reverse-transcription and real-time PCR was used to detect FAS and HMG-CoAR mRNA levels in treated cells.


RESULTS
Our findings show that EPA inhibits HepG2 cell growth in a dose-dependent manner, starting from 25 μM (P < 0.01, one-way ANOVA test and Dunnett's post test) and exerts a statistically significant pro-apoptotic effect already at 1 μM of EPA. Higher doses of ARA were need to obtain a statistically significant inhibition of cell proliferation and a pro-apoptotic effect in these cells (100 μM, P < 0.01, one-way ANOVA test and Dunnett's post test). Moreover, a down-regulation of FAS and HMG-CoAR gene expression was observed after EPA and ARA treatment in HepG2 cells, starting at 10 μM (P < 0.05, one-way ANOVA test and Dunnett's post test).


CONCLUSIONS
Our results demonstrate that EPA and ARA inhibit HepG2 cell proliferation and induce apoptosis. The down-regulation of FAS and HMG-CoAR gene expression by EPA and ARA might be one of the mechanisms for the anti-proliferative properties of PUFAs in an in vitro model of hepatocellular carcinoma.
Laboratory of Biochemistry, National Institute for Digestive Diseases, Castellana Grotte (BA), Italy.
Maria
M
Notarnicola
Caterina
C
Messa
Maria G
MG
Refolo
Valeria
V
Tutino
Angelica
A
Miccolis
Maria G
MG
Caruso
D017209:Apoptosis / Q000187:drug effects*; D016718:Arachidonic Acid / Q000494:pharmacology*; D049109:Cell Proliferation / Q000187:drug effects; D015536:Down-Regulation; D015118:Eicosapentaenoic Acid / Q000494:pharmacology*; D064429:Fatty Acid Synthases / Q000096:biosynthesis* / Q000235:genetics; D056945:Hep G2 Cells; D006801:Humans; D006903:Hydroxymethylglutaryl CoA Reductases / Q000096:biosynthesis* / Q000235:genetics
D016718:Arachidonic Acid; D015118:Eicosapentaenoic Acid; D006903:Hydroxymethylglutaryl CoA Reductases; D064429:Fatty Acid Synthases
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