Suppression of lipogenesis by siRNA-mediated silencing of SREBP-1

Suppression of lipogenesis by siRNA-mediated silencing of SREBP-1 and SREBP-2, led to reduction of Hep3B (Fig. 4A) and HLE (not shown) cell proliferation and induction of apoptosis (Supporting Fig. 5). A significant reduction in cell proliferation and induction of apoptosis was also detected after treatment with fatty oxidation inducers (e.g., 5-aminoimidazole-4-carboxamide 1-beta-D-ribofuranoside [AICAR] and metformin), glycolysis inhibitors (e.g., 2-deoxy-D-glucose [2-DG] and 3-bromopyruvate [3-BrPA]), and with the G6PD

inhibitor, 6-aminonicotinamide (6-AN), in Hep3B (Fig. 4B; Supporting Fig. 5) and HLE (not shown) cell lines. Noticeably, combined treatment with SREBP-1/2 siRNA, metformin, 2-DG, and 6-AN resulted in a much more pronounced growth restraint of Hep3B (Fig. 4C; Supporting Fig. 5) and HLE (not shown) cells, when compared with treatment using SREBP-1/2 siRNA, 2-DG, or 6-AN alone, implying Rucaparib in vivo https://www.selleckchem.com/products/Fulvestrant.html a synergistic, antineoplastic function of the four treatments when used combinatorially. Because mTORC1 is a major effector of AKT metabolic properties,25 we determined whether mTORC1 is responsible

for the observed effect on metabolism induced by insulin. For this purpose, Hep3B and HLE cell lines were subjected to insulin treatment concomitant with inhibition of either mTORC1 or AKT. In the Hep3B cell line, a rise in the AKT pathway was detectable as early as 10 minutes after insulin administration (data not shown). Levels of the AKT cascade remained elevated 24 and 36 hours after insulin supplementation (Fig. 5A,B) and were associated with a significant

increase in HCC cell proliferation and survival (Fig. 5C,D). Hep3B cell growth was considerably inhibited by a decrease in cell proliferation and induction of apoptosis when insulin administration was associated with rapamycin (an mTORC1 inhibitor) treatment (Fig. 5C,D). Of Anidulafungin (LY303366) note, treatment of Hep3B cells with the AKT1/2 inhibitor or the PI3K/mTOR dual inhibitor, NVP-BEZ235, led to a much more pronounced growth inhibition (Fig. 5C,D). At the molecular level, rapamycin treatment induced a down-regulation of the proteins involved in de novo lipogenesis, glycolysis, and the pentose 6-phosphate pathway and an up-regulation of ACADM and ECHS1 (Fig. 5A,B). However, the expression of AKR1B10, USP2a, chREBP, and PRKCλ/ι remained unaffected after rapamycin administration (Fig. 5A). Also, levels of the negative regulators of lipogenesis, INSIG2 and AMPKα2, were not rescued by rapamycin (Fig. 5A). Furthermore, levels of proteins involved in gluconeogenesis, including G6Pase, PGC-1α, MKP-3, and phosphorylated/inactivated FOXO1, were unmodified in rapamycin-treated cells (Fig. 5B). In contrast, the use of either AKT1/2 inhibitor or NVP-BEZ235 had a remarkable effect on the levels of all the proteins involved in lipogenesis, glycolysis, pentose phosphate, and gluconeogenesis in Hep3B cells (Fig. 5A,B).

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