The anti proliferative effect of tamoxifen is synergistically enhanced when used in combination with retinoids. Retinoids also show promising effects in adjuvant therapy for HCC. However, the therapeutic potentials of retin oids against HCC have not been extensively investigated. In the present study, we initiated a comprehensive screening including most http://www.selleckchem.com/products/MLN8237.html commercially available retinoids on three widely used human HCC cell lines for apoptosis induction. Agree with previous Inhibitors,Modulators,Libraries studies, we found that fenretinide induces apop tosis in Hep3B cells. In addition, we found that fenretinide also effectively induces apoptosis in Huh 7 cells. In con trast, HepG2 cells are resistant to fenretinide treatment. To elucidate the mechanisms underlying the observed differ ential susceptibility, gene expression analysis of twelve nuclear receptor genes were assessed by real time PCR.
Our data strongly suggest that the susceptibility of HCC cells to fenretinide treatment is determined by the basal and the induced expression level of RAR. Furthermore, we showed that fenretinide Inhibitors,Modulators,Libraries directly activates RAR in Huh 7 cells. Finally, the RAR deficient Huh 7 cells exhibited marked reduction of fenretinide induced apoptosis. Based on these findings, we conclude that, in Huh 7 cells, fenretinide directly activates RAR and induces apoptosis Inhibitors,Modulators,Libraries in a RAR dependent manner. Methods Reagents The retinoids used in this study are grouped into three cat egories carotenoids including carotene, lycopene, and lutein. classic retinoids including all trans retinol palmitate, retinol acetate, 9 cis retinaldehyde, 13 cis reti nol, 13 cis retinaldehyde, 13 cis retinoic acid, and fenreti nide.
receptor specific retinoids Inhibitors,Modulators,Libraries including all trans retinoic acid, 9 cis retinoic acid, and TTNPB benzoic acid. Carotene, lyco pene, all trans retinol palmitate, 9 cis retinaldehyde, 13 cis retinol, fenretinide, Inhibitors,Modulators,Libraries all trans retinoic acid, 9 cis retin oic acid, and TTNPB were purchased from Sigma Aldrich. Lutein was purchased from US Biological. Retinol acetate and 13 cis retinalde hyde were purchased from Toronto Research Chemicals. 13 cis retinoic acid was purchased from BIOMOL. Retinoids were dissolved in dimethyl sulfoxide at 10 mM as the stock solution and stored at 80 C. Retinoids were diluted with serum free medium to a 10M final concentration immediately before use. The final concentration of DMSO in the culture medium was 0.
1% in all treatments. Because retinoids are light sensitive, all retinoid treatments directly were conducted under dim light. Cell culture Huh 7 cells were cultured in Dulbeccos Modification of Eagles Medium and HepG2 and Hep3B cells were cul tured in Minimum Essential Medium. The media were supplemented with 10% fetal calf serum. Cells were cultured at 37 C in 5% CO2 atmosphere with a relative humidity of 95%. Cells were plated with approx imately 1 106 cells per T 25 flask and cultured overnight.