A novel homospermidine conjugate inhibits growth and induces apoptosis in human hepatoma cells

NPC-16, a novel naphthalimide-polyamine conjugate, induced apoptosis and autophagy in human hepatoma HepG2 cells and Bel-7402 cells

The antitumor effects and molecular mechanism of NPC-16, a novel naphthalimide-polyamine conjugate, were evaluated in HepG2 cells and Bel-7402 cells. Apoptosis and necrosis were evaluated by Annexin V-FITC detection kit, and autophagy by acridine orange and Lyso-Tracker Red staining. The change of mitochondrial transmembrane potential was measured using rhodamine 123 staining. The protein expression of Beclin 1, LC3 II and mTOR, p70S6 K, 14-3-3, caspase, and Bcl-2 family members was detected by immunofluorescence assays and Western Blot. Here, we elucidated the nature of cellular response of HepG2 cells and Bel-7402 cells to NPC-16 at IC(50). NPC-16 induced caspase-dependent apoptosis via the mitochondrial pathway and death receptor pathway in Bel-7402 cells. Differently, NPC-16 triggered HepG2 cells both apoptosis and autophagy, further autophagy facilitated cellular apoptosis. Furthermore, mTOR signal pathway was involved in NPC-16-mediated autophagy in HepG2 cells. Thus, NPC-16 may be useful as a potential template for investigation the molecular mechanism of naphthalimide-polyamine conjugate against hepatocellular carcinoma.

Pseudomonas aeruginosa: mannose sensitive hemagglutinin inhibits the growth of human hepatocarcinoma cells via mannose-mediated apoptosis

A vaccine derived from the outer membrane proteins of the Gram-negative bacterium Pseudomonas aeruginosa has been shown to have immune modulatory properties. An inactivated mutant strain of P. aeruginosa with mannose sensitive hemagglutinin fimbria (PA-MSHA) has been used for adjuvant therapy for malignant cancer. In this study, the growth of human hepatocellular carcinoma Hep G2 and BEL-7402 cells is inhibited by PA-MSHA, but not by mannose-cleaved PA-MSHA. PA-MSHA-treated cells arrested in the S phase of the cell cycle and underwent apoptosis. We hypothesize that apoptosis induced by treatment of Hep G2 and BEL-7402 cells with PA-MSHA is mediated by the mannose residues of PA-MSHA and is propagated through the extrinsic apoptosis pathway directly through caspase-8. These data provide mechanistic details for the potential application of PA-MSHA-based treatment of hepatocellular carcinoma.

HL-37, a novel anthracene derivative, induces Ca(2+)-mediated apoptosis in human breast cancer cells

HL-37, a novel anthracene derivative, exhibited potent anticancer activity in many kinds of cancer cells. However, the exact mechanism and signaling pathway involved in HL-37-induced apoptosis have not been fully elucidated. Therefore, we explored the mechanisms of HL-37-mediated apoptosis in MCF-7 and MDA-MB-435 human breast cancer cells. When MCF-7 cells or MDA-MB-435 cells were co-incubated with HL-37, the percentage of apoptotic cell and S phase of cell cycle was markedly increased. In addition, a rise in intracellular calcium levels, ROS production, phosphorylation of JNK and activation of calpain were found in both MCF-7 cells and MDA-MB-435 cells after exposure to HL-37. With the HL-37-mediated reduction of mitochondrial membrane potential, cytochrome c was released from mitochondria to cytosol. Moreover, HL-37 strongly induced cleavage of caspase-4, caspase-9, as well as caspase-3 in MDA-MB-435 cells, whereas, activation of caspase-4, caspase-9 and caspase-7 but not caspase-3 was detected in MCF-7 cells. These results suggested that HL-37 induced MDA-MB-435 and MCF-7 cells apoptosis via oxidative stress and Ca(2+)/calpain/caspase-4 pathway.