Human fetal colon cells and colon cancer cells respond differently to butyrate and PUFAs
We verified the hypothesis suggesting modulation of the effects of sodium butyrate (NaBt) by omega-3 or omega-6 PUFAs. Comparing the response of human colon epithelial cell lines of fetal (FHC) and adenocarcinoma (HT-29, HCT-116) origin, we detected significant differences in proliferation, differentiation and apoptotic response to the treatment of NaBt, arachidonic or docosahexaenoic acids and their combination. While in FHC and HT-29 cells NaBt induced G0/G1 arrest, differentiation and low level of apoptosis, in HCT-116 cells G2/M arrest, no differentiation and high degree of apoptosis were detected. Moreover, in FHC cells significant potentiation of apoptosis accompanied by increased arrest in the cell cycle, cell detachment and decrease in differentiation were detected after combined treatment with NaBt and both PUFAs. Changes in cytokinetics induced by fatty acids were accompanied by membrane lipid unpacking, reactive oxygen species (ROS) production, and decrease in mitochondrial membrane potential (MMP). Detection of caspase-3 activation and dynamic modulation of Mcl-1 protein expression imply their possible role in both cell differentiation and apoptotic response. Our results support the concept of modulation of NaBt effects by PUFAs, especially of omega-3 type, in colonic cells in vitro with diverse impact in cell lines derived from normal or neoplastic epithelium.