[Dietary fatty acids and cancer: potential cellular and molecular mechanisms].

Experimental evidence indicates that n-3 fatty acids, especially the long-chain polyunsaturated fatty acids, unlike n-6 fatty acids could prevent cancer development. This survey shows that fatty acids could act through several mechanisms including the production of reactive oxygen species, the modulation of gene expression and signal transduction pathways, or the eicosanoid biosynthesis. Human genetics has underlined several polymorphisms in genes identified as possible targets of fatty acids which suggests that the link between nutritional intake and cancer prevention, especially the eventual anti-carcinogenic effects of n-3 fatty acids, depends on the genetic background.

Control of molecular orientation in electrostatically stabilized ferroelectric liquid crystals.

The continuously reorientable (XY-like) ferroelectric polarization density of a chiral smectic liquid crystal is shown experimentally to produce nearly complete screening of the applied electric field in an appropriate cell geometry. This screening, combined with the expulsion of polarization charge for large polarization materials, is shown to produce electrostatic control of the orientation of a uniform optic axis or polarization field.

Liquid-crystal-solid interface structure at the antiferroelectric-ferroelectric phase transition.

Total internal reflection is used to probe the molecular organization at the surface of a tilted chiral smectic liquid crystal at temperatures in the vicinity of the bulk antiferroelectric-ferroelectric phase transition. Data are interpreted using an exact analytical solution of a real model for ferroelectric order at the surface. In the mixture T3, ferroelectric surface order is expelled with the bulk ferroelectric-antiferroelectric transition.

Immunolocalization of a new intestinal antiproliferative factor in human intestinal epithelial cells.

A new intestinal antiproliferative factor (IAF) with an approximate molecular weight of 120 kDa has been purified from the human small intestine. This factor blocks the progression of human colon adenocarcinoma cells HT-29 from the G1 to the S phase. IAF, specific of the lower part of the digestive tract, was detected rather late in mouse embryonic development.

Monoterpenes inhibit proliferation of human colon cancer cells by modulating cell cycle-related protein expression.

The monoterpene perillyl alcohol (POH) is a naturally occurring anti-cancer compound which is effective against a variety of rodent organ-specific tumor models. To establish the molecular mechanisms of POH and its major metabolite perillic acid (PA) as anti-proliferative agents, their effects on cell proliferation, cell cycle and cell cycle regulatory proteins were studied in HCT 116 human colon cancer cells. POH, and to a lesser extent, PA, exerted a dose-dependent inhibitory effect on cell growth correlated with a G1 arrest.