Lipid Accumulation And Apoptosis In HT-29 Cells Induced With Soybean Isoflavones

Colon cancer is the most common malignant tumor in China, it is the fourth leading cause of death in our country, and the trend appears to be on the rise year by year. And the intake of soybean and its products can show a negative relation with colon cancer incidence and mortality. Soybean isoflavones are the secondary metabolites in the process of soybean growth, it is one of the main physiological activity components in soybeans. And geni stein and daidzein are two main kinds of active substances and the biologically active forms possessing a variety of biological activity. Both genistein and daidzein have the effect of inducing tumor cell apoptosis,thus reducing the morbidity and mortality of colon cancer cells. High-fat diet can induce the accumulation of lipid droplets in the bodys, in the meantime, lipid droplets can provide energy for the growth of cancer cells, thy are also a sign of tumor proliferation. Genistein and daidzein are speculated to inhibit lipid droplets in the accumulation of the cells in the- body, in turn, inhibit cancer cell proliferation,anti-cancer effect.MTT test and flow cytometry results showed that after the culture of 48 h, 200?mol/L concentration of genistein and daidzein showed the highest inhibitory rate, so we chose 200 ?mol/L and 48 h as the optimal experiment concentration and the optimal action time, respectively. Using scanning electron microscope observation,the effect of genistein and daidzein on HT-29 cells after 24 h treatment appeared early apoptotic status; after 72 h treatment, HT-29 cells presented state of late apoptosis.Oil-Red O staining and BODIPY dyeing experiments results showed that after the culture of genistein and daidzein for 6 h, then through oleic acid induced HT-29 cells 48 h, lipid droplets volume significantly below via the HT-29 cells induced only cultured by oleic acid, that can effectively restrain the genistein and daidzein lipid drops in HT-29 after oleic acid induced the accumulation of intracellular.Immunofluorescence staining and DAPI staining proved that can make the isoflavones (genistein and daidzein after oleic acid induced apoptosis of HT-29. Semi RT-PCR results showed genistein and daidzein that can reduce gene expressions levels of PPAR-?, Fas, DGAT2, ACCI, L-FABP and GPAT3 and MTTP in HT-29 cell,improved the expression level of UCP2 gene. Western Blot results showed that genistein and daidzein can improve perilipin, Vimentin, ERK, Caspase-8 and FOX03a protein expressions level in HT-29 cells, reduce the ADRP protein expression level. Taken togegther, all results showed that genistein and daidzein can activate PPAR-y- ERK pathway in HT-29 cells, while ERK expression level increases,which promotes the FOX03a expression level increases, and trigger the Caspase family cascade reaction, which induces cell apoptosis.