beta-Ionone enhances TRAIL-induced apoptosis in hepatocellular carcinoma cells through Sp1-dependent upregulation of DR5 and downregulation of NF-kappaB activity.

beta-Ionone (ION), an end-ring analogue of beta-carotenoid, has been known to inhibit tumor cell growth and induce apoptosis in various types of cancer cells. Nevertheless, its apoptosis-related molecular mechanisms remain unclear. Here, we first investigated the molecular mechanisms by which ION sensitizes cancer cells to the therapeutic potential of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL).

Induction of p53-independent apoptosis by a novel synthetic hexahydrocannabinol analog is mediated via Sp1-dependent NSAID-activated gene-1 in colon cancer cells.

Nonsteroidal anti-inflammatory drug (NSAID)-activated gene-1 (NAG-1) has received greater attention as a novel molecular target for anti-cancer therapeutics in recent years. We identified a novel synthetic hexahydrocannabinol analog, LYR-8 [(1-((9S)-1-hydroxy-6,6,9-trimethyl-6a,7,8,9,10,10a-hexahydro-6H-benzo[c]chromen-2-yl)ethanone)], as a potent NAG-1 and apoptosis inducer in a panel of human cancer cells. LYR-8 did not possess any affinity for cannabinoid receptor CB(1) or CB(2), which eliminates the concern about potential psychoactive side effects.

A novel cyclin-dependent kinase inhibitor down-regulates tumor necrosis factor-alpha (TNF-alpha)-induced expression of cell adhesion molecules by inhibition of NF-kappaB activation in human pulmonary epithelial cells.

BAI (a novel cyclin-dependent kinase (CDK) inhibitor, 2-[1,1'-biphenyl]-4-yl-N-[5-(1,1-dioxo-1lambda(6)-isothiazolidin-2-yl)-1H-indazol-3-yl] acetamide) is known to have anti-proliferative activity, but the mechanism responsible for it remains unclear. We here investigated the functional effect of BAI on airway inflammation and its action mechanism. BAI down-regulated the expression of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) in human lung epithelial A549 cells stimulated with tumor necrosis factor-alpha: (TNF-alpha), resulting in the suppression of leukocyte adhesion to lung epithelial A549 cells.

Overexpression of Par-4 sensitizes TRAIL-induced apoptosis via inactivation of NF-kappaB and Akt signaling pathways in renal cancer cells.

The prostate-apoptosis-response-gene-4 (Par-4) is up-regulated in prostate cells undergoing programmed cell death. Furthermore, Par-4 protein has been shown to function as an effector of cell death in response to various apoptotic stimuli that trigger mitochondria and membrane receptor-mediated cell death pathways. In this study, we investigated how Par-4 modulates TRAIL-mediated apoptosis in TRAIL-resistant Caki cells.

Quercetin enhances TRAIL-induced apoptosis in prostate cancer cells via increased protein stability of death receptor 5.

Aims: Quercetin has been shown to enhance tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-induced apoptosis of prostate cancer cells via mechanisms that include upregulation of death receptor (DR) 5, a protein reported to play an important role in sensitizing cancer cells to apoptosis. We aimed to determine the specific mechanisms underlying quercetin-induced DR5 expression.

Main Methods: Human prostate cancer cells were exposed to quercetin and TRAIL.

Gangliosides induce autophagic cell death in astrocytes.

Background And Purpose: Gangliosides, sialic acid-containing glycosphingolipids, abundant in brain, are involved in neuronal function and disease, but the precise molecular mechanisms underlying their physiological or pathological activities are poorly understood. In this study, the pathological role of gangliosides in the extracellular milieu with respect to glial cell death and lipid raft/membrane disruption was investigated.

Experimental Approach: We determined the effect of gangliosides on astrocyte death or survival using primary astrocyte cultures and astrocytoma/glioma cell lines as a model.

Superoxide anion and proteasomal dysfunction contribute to curcumin-induced paraptosis of malignant breast cancer cells.

Curcumin is considered a pharmacologically safe agent that may be useful in cancer chemoprevention and therapy. Here, we show for the first time that curcumin effectively induces paraptosis in malignant breast cancer cell lines, including MDA-MB-435S, MDA-MB-231, and Hs578T cells, by promoting vacuolation that results from swelling and fusion of mitochondria and/or the endoplasmic reticulum (ER). Inhibition of protein synthesis by cycloheximide blocked curcumin-induced vacuolation and subsequent cell death, indicating that protein synthesis is required for this process.

Capsaicin sensitizes malignant glioma cells to TRAIL-mediated apoptosis via DR5 upregulation and survivin downregulation.

Capsaicin, a pungent ingredient of red chili peppers, has been reported to possess antitumor activities. Here, we show that subtoxic doses of capsaicin effectively sensitize multiple malignant glioma cell lines to tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-induced apoptosis. Although TRAIL alone mediated partial proteolytic processing of procaspase-3 in glioma cells, cotreatment with capsaicin and TRAIL efficiently restored complete activation of caspases.

A novel resveratrol analogue HS-1793 treatment overcomes the resistance conferred by Bcl-2 and is associated with the formation of mature PML nuclear bodies in renal clear cell carcinoma Caki-1 cells.

Bcl-2 protects cancer cells from the apoptotic effects of various chemotherapeutic agents. Inhibition or downregulation of Bcl-2 represents a new therapeutic approach to bypass chemoresistance in cancer cells. Previously we designed and synthesized the resveratrol analogue HS-1793 displaying stronger antitumor efficacy than resveratrol and further demonstrated the HS-1793 resistance conferred by Bcl-2 in human leukemic U937 cells.

Anti-invasive activity of histone deacetylase inhibitors via the induction of Egr-1 and the modulation of tight junction-related proteins in human hepatocarcinoma cells.

The potential anti-metastasis and anti-invasion activities of early growth response gene-1 (Egr-1) and claudin-3, a tight junction (TJ)-related protein, were evaluated using histone deacetylase (HDAC) inhibitors in human hepatocarcinoma cells. The results of wound healing and Transwell assays showed that HDAC inhibitors such as trichostatin A and sodium butyrate inhibited cell migration and invasion. HDAC inhibitors markedly induced Egr-1 expression during the early period, after which expression levels decreased.

Rottlerin induces heme oxygenase-1 (HO-1) up-regulation through reactive oxygen species (ROS) dependent and PKC delta-independent pathway in human colon cancer HT29 cells.

Heme oxygenase-1 (HO-1) is a cytoprotective enzyme activated by its substrate heme and diverse stimuli. The induction of HO-1 gene expression is one of the important events in cellular response to pro-oxidative and pro-inflammatory insults. In this study, the effect of rottlerin, a putative PKC delta inhibitor, on HO-1 expression in HT29 human colon cancer cells was investigated.

Induction of apoptosis by esculetin in human leukemia U937 cells: roles of Bcl-2 and extracellular-regulated kinase signaling.

In the present study, we reported that apoptosis induced by esculetin, a phenolic compound with apoptotic activity in cancer cells, was markedly blocked by Bcl-2-overexpression, but restored by HA14-1, a small-molecule Bcl-2 inhibitor, in human leukemic U937 cells. The combined use of esculetin and HA14-1 effectively induced Bid cleavage and loss of mitochondrial membrane potential (MMP, Deltapsi(m)) leading to the activation of caspases and cleavage of poly(ADP-ribose) polymerase (PARP) in Bcl-2-overexpressing (U937/Bcl-2) cells. Combined treatment with esculetin and HA14-1 upregulated the expression of death receptor 4 (DR4), and activation of extracellular-regulated kinase (ERK) in a time-dependent manner.

The coffee diterpene kahweol induces apoptosis in human leukemia U937 cells through down-regulation of Akt phosphorylation and activation of JNK.

Kahweol, the coffee-specific diterpene, has been reported for its tumor cell growth inhibitory activity and anti-carcinogenic activity. The mechanism by which kahweol initiates apoptosis remains poorly understood. In the present study, we investigated the effect of kahweol on the apoptotic pathway in U937 human promonocytic cells.

Curcumin inhibits phorbol myristate acetate (PMA)-induced MCP-1 expression by inhibiting ERK and NF-kappaB transcriptional activity.

Monocyte chemoattractant protein-1 (MCP-1) is a potent mediator of macrophage migration and therefore, plays an essential role in early events of inflammation. In the present study, we show the protein kinase C activator, phorbol myristate acetate (PMA), potently induced mRNA expression and secretion of the C-C chemokine MCP-1 in U937 cells. We found that curcumin, a natural biologically active compound extracted from rhizomes of Curcuma species, significantly inhibited the PMA-induced increase in MCP-1 expression and secretion.

Clinical and molecular characterizations of novel POU3F4 mutations reveal that DFN3 is due to null function of POU3F4 protein.

X-linked deafness type 3 (DFN3), the most prevalent X-linked form of hereditary deafness, is caused by mutations in the POU3F4 locus, which encodes a member of the POU family of transcription factors. Despite numerous reports on clinical evaluations and genetic analyses describing novel POU3F4 mutations, little is known about how such mutations affect normal functions of the POU3F4 protein and cause inner ear malformations and deafness. Here we describe three novel mutations of the POU3F4 gene and their clinical characterizations in three Korean families carrying deafness segregating at the DFN3 locus.

Anticancer activity and differentially expressed genes in head and neck cancer cells treated with a novel cyclin-dependent kinase inhibitor.

Background: Cyclin-dependent kinases (CDKs) are involved in the regulation of the cell cycle and the growth of tumor cells. In this study, we investigated the antitumor effect and differentially expressed genes (DEGs) in head and neck cancer cells treated by a novel CDK inhibitor, 2-[1,1'-biphenyl]- 4-yl-N-[5-(1,1-dioxo-1lambda(6)-isothiazolidin-2-yl)-1H-indazol-3-yl] acetamide (BAI).

Methods: Cell growth was measured by XTT assay.

Transglutaminase 2 expression levels regulate sensitivity to cystamine plus TRAIL-mediated apoptosis.

In this study, we demonstrate for the first time that cystamine, an inhibitor of transglutaminase 2 (TG2), enhanced tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-mediated apoptosis in Caki cells, but not in normal human mesangial cells. Cystamine plus TRAIL-induced down-regulation of c-FLIP was recovered to basal levels by addition of the pancaspase inhibitor, z-VAD. The forced expression of c-FLIP attenuated cystamine plus TRAIL-mediated apoptosis in Caki cells.

SAHA treatment overcomes the anti-apoptotic effects of Bcl-2 and is associated with the formation of mature PML nuclear bodies in human leukemic U937 cells.

Bcl-2 protects tumor cells from the apoptotic effects of various antineoplastic agents. Increased expression of Bcl-2 has been associated with poor response to chemotherapy in various malignancies, including leukemia. Therefore, bypassing the resistance conferred by anti-apoptotic factors such as Bcl-2 represents an attractive therapeutic strategy against cancer cells, including leukemic cells.

Genistein sensitizes human hepatocellular carcinoma cells to TRAIL-mediated apoptosis by enhancing Bid cleavage.

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a member of the tumor necrosis factor superfamily, and it has been shown that many human cancer cell lines are refractory to TRAIL-induced cell death. However, the molecular mechanisms underlying resistance are unclear. In this study, we show that TRAIL resistance is reversed in human hepatoma cells by genistein, an isoflavone found in soy products.

Interleukin-1beta promotes the expression of monocyte chemoattractant protein-1 in human aorta smooth muscle cells via multiple signaling pathways.

Monocyte chemoattractant protein-1 (MCP1) plays a key role in monocyte/macrophage infiltration to the sub-endothelial space of the blood vessel wall, which is a critical initial step in atherosclerosis. In this study, we examined the intracellular signaling pathway of IL-1beta-induced MCP1 expression using various chemical inhibitors. The pretreatment of a phosphatidylcholine (PC)-specific PLC (PC-PLC) inhibitor (D609), PKC inhibitors, or an NF-kapaB inhibitor completely suppressed the IL-1beta-induced MCP1 expression through blocking NF-gammaB translocation to the nucleus.

A novel resveratrol derivative, HS1793, overcomes the resistance conferred by Bcl-2 in human leukemic U937 cells.

The chemopreventive and chemotherapeutic properties associated with resveratrol offer promise for the design of new chemotherapeutic agents. However, resveratrol is not a potent cytotoxic compound when compared with other chemotherapeutic drugs. Thus, several studies were undertaken to obtain synthetic analogues of resveratrol with potent activity.

Se-methylselenocysteine sensitized TRAIL-mediated apoptosis via down-regulation of Bcl-2 expression.

Recent studies establish a critical role of selenium in cancer prevention in vitro and in vivo. Selenium may sensitize TRAIL-mediated apoptosis in human renal cancer cells and increase therapeutic efficacy. In this study, we demonstrate that concomitant administration of TRAIL and Se-methylselenocysteine (Se-MSC) produces synergistic effects on the induction of apoptosis in Caki cells.

Withaferin A sensitizes TRAIL-induced apoptosis through reactive oxygen species-mediated up-regulation of death receptor 5 and down-regulation of c-FLIP.

Withaferin A (Wit A) has reportedly shown cytotoxicity in a variety of tumor cell lines. Here, we show that cotreatment with subtoxic doses of Wit A and tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) induces apoptosis in human renal cancer cells, Caki cells, but not in human normal mesangial cells. Moreover, the combined treatment with Wit A and TRAIL dramatically induces apoptosis in various cancer cell types, suggesting that this combined treatment might offer an attractive strategy for safely treating human cancers.

Over-expression of Reticulon 3 (RTN3) enhances TRAIL-mediated apoptosis via up-regulation of death receptor 5 (DR5) and down-regulation of c-FLIP.

Reticulons (RTNs) are a group of integral membrane proteins that have no homology to other known apoptosis-related domains. Herein, we found that RTN3 overexpressing Caki cells were sensitive to TRAIL-mediated apoptosis. RTN3-induced down-regulation of c-FLIP was recovered by pan-caspase inhibitor, z-VAD to basal levels in TRAIL-treated cells.