• Asian Pacific Journal of Cancer Prevention
• /
• v.16 no.10
• /
• pp.4203-4209
• /
• 2015

Exosomes, membranous nanovesicles, naturally carry bio-macromolecules or miRNA and play impoetant roles in tumor pathogenesis. Here, we showed that macrophages cell-derived exosomes can function as vehicles to deliver exogenous miR-21 inhibitor into BGC-823 gastric cancer cells. Exosomes loaded with miR-21inhibitor significantly increased miR-21 levels in BGC-823, but miR-21inhibitor loaded in exosomes exerted an opposite effect. miRNA transfected with exosomes had less cellular toxicity to host cells compared to conventional transfection methods. The miR-21inhibitor loaded exosomes promoted the migration ability and reduced apoptosis of BGC-823 gastric cancer cells. These observations indicate that miR-21 acts as a tumor promoter by targeting the PDCD4 gene and preventing apoptosis of gastric cancer cells through inhibition of PDCD4 expression. Furthermore, exosome -mediated miR-21 inhibitor delivery resulted in functionally more efficient inhibition and less cellular toxicity compared to conventional transfection methods. Similar approaches could be useful in modification of target biomolecules in vitro and in vivo. These findings contribute to our understanding of the functions of miR-21 and exosomes as a carrier for therapy of gastric cancer.

• Asian Pacific Journal of Cancer Prevention
• /
• v.16 no.6
• /
• pp.2129-2144
• /
• 2015

Programmed cell death (PCD) or apoptosis is a mechanism which is crucial for all multicellular organisms to control cell proliferation and maintain tissue homeostasis as well as eliminate harmful or unnecessary cells from an organism. Defects in the physiological mechanisms of apoptosis may contribute to different human diseases like cancer. Identification of the mechanisms of apoptosis and its effector proteins as well as the genes responsible for apoptosis has provided a new opportunity to discover and develop novel agents that can increase the sensitivity of cancer cells to undergo apoptosis or reset their apoptotic threshold. These novel targeted therapies include those targeting anti-apoptotic Bcl-2 family members, p53, the extrinsic pathway, FLICE-inhibitory protein (c-FLIP), inhibitor of apoptosis (IAP) proteins, and the caspases. In recent years a number of these novel agents have been assessed in preclinical and clinical trials. In this review, we introduce some of the key regulatory molecules that control the apoptotic pathways, extrinsic and intrinsic death receptors, discuss how defects in apoptotic pathways contribute to cancer, and list several agents being developed to target apoptosis.

• Journal of Life Science
• /
• v.25 no.9
• /
• pp.984-992
• /
• 2015

Sanguinarine is a benzophenanthridine alkaloid originally isolated from the roots of Sanguinaria canadensis. It has multiple biological activities (e.g., antioxidant and antiproliferative) and immune-enhancing potential. In this study, we explored the proapoptotic properties and modes of action of sanguinarine in human hepatocellular carcinoma HepG2 cells. Our results revealed that sanguinarine inhibited HepG2 cell growth and induced apoptosis in a dose-dependent manner. The induction of apoptosis by sanguinarine was associated with the up-regulation of Fas and Bax, the release of cytochrome c from the mitochondria to the cytosol, and the loss of the mitochondrial membrane potential. In addition, sanguinarine activated caspase-9 and -8, initiator caspases of the intrinsic and death extrinsic pathways, respectively, and caspase-3, accompanied by proteolytic degradation of poly (ADP-ribose) polymerase. Sanguinarine also triggered the generation of reactive oxygen species (ROS). The elimination of ROS by N-acetylcysteine reversed sanguinarine-induced apoptosis. Furthermore, sanguinarine induced the dephosphorylation of Akt and the phosphorylation of mitogen-activated protein kinases, including extracellular signal-regulated kinase (ERK), c-jun N-terminal kinase (JNK), and p38. The growth inhibition was enhanced by the combined treatment of sanguinarine with a phosphatidylinositol 3'-kinase (PI3K) inhibitor and an ERK inhibitor but not JNK and p38 inhibitors. Overall, our data indicate that the proapoptotic effects of sanguinarine in HepG2 cells depend on ROS production and the activation of both intrinsic and extrinsic signaling pathways, which is mediated by blocking PI3K/Akt and activating the ERK pathway. Thus, our data suggest that sanguinarine may be a natural compound with potential for use as an antitumor agent in liver cancer.

• Biomedical Science Letters
• /
• v.22 no.4
• /
• pp.211-214
• /
• 2016

House dust mite is an essential allergen in the pathogenesis of allergic diseases. Abnormal regulation of neutrophil apoptosis is an important pathogenic process in allergic diseases. In the present study, we investigated the effects of house dust mites on spontaneous apoptosis of neutrophils and its associated mechanisms. Extract of Dermatophagoides pteronissinus (DP) inhibited neutrophil apoptosis in a time-dependent manner. Cycloheximide (CHX), an inhibitor of translation, increased apoptosis of DP-treated neutrophils as well as control cells. The pro-apoptotic effect of CHX was blocked by DP in neutrophils. In addition, DP increased the phosphorylation of Bad in a time-dependent manner, indicating that it exerted an inhibitory effect on the function of Bad. These results suggest that DP has anti-apoptotic effects of neutrophils and may regulate protein synthesis and activation of Bad. Moreover, these findings may shed light on elucidation of allergy pathogenesis due to house dust mites.

• 한국생물공학회:학술대회논문집
• /
• 2000.11a
• /
• pp.151-154
• /
• 2000

The effect of silkworm hemolymph on insect cell apoptosis was investigated. The addition of silkworm hemolymph into the culture medium either before or during the baculovirus infection increased the host cell longevity. Silkworm hemolymph also inhibits apoptosis induced by actinomycin D, the RNA synthesis inhibitor. In this study, a flow cytometry was used for the quantitative analysis of apoptosis inhibition by silkworm hemolymph.

• Korean Journal of Pharmacognosy
• /
• v.39 no.2
• /
• pp.150-154
• /
• 2008

Butein is a one of polyphenolic compound widely available in numerous plants. It has broad biological activities including antioxidant and anti-inflammatory activities, which contributed to its protective effects against cancer. Evidences that butein influence proliferation of tumor cells make it important to determine how butein affects cell death of various cancers. In this study, we show that butein, a phenolic compound, induces apoptosis in human T lymphoma jurkat cells. We found that treatment of cells with butein increased apoptosis in a dose- and time- dependent manner as determined by staining cells with Annexin V and 7AAD. There was no significant apoptotic cell death when normal lymphocytes and monocytes from healthy donor were treated with butein. We also found caspase-3 activity was increased during butein-induced apoptosis. The buteininduced apoptotic cell death was blocked by the treatment of cells with caspase-3 inhibitor. These results indicate that butein has the potential to provide an effective strategy against cancer with the advantage of being widely avalible.

• Asian Pacific Journal of Cancer Prevention
• /
• v.17 no.4
• /
• pp.1655-1659
• /
• 2016

Celecoxib, a selective inhibitor of COX-2, showed cytotoxic effects in many cancer cell lines including cervical cancer cells. This study investigated the effect of celecoxib on cell cycle arrest in HeLa cervical cancer cells through p53 expression. In vitro anticancer activity was determined with the 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) method. A double staining method was applied to investigate the mechanism of cell death, cell cycling was analyzed by flow cytometryand immunocytochemistry was employed to stain p53 expression in cells. Celecoxib showed strong cytotoxic effects and induced apoptosis with an $IC_{50}$ value of $40{\mu}M$. It induced cell cycle arrest at G2/M phase by increasing level of p53 expression on HeLa cells.

• Proceedings of the Korean Society of Toxicology Conference
• /
• 2001.10a
• /
• pp.151-152
• /
• 2001

MCS-5A, novel Cdk inhibitor, has been reported that it has exerted cell cycle arrest action and apoptotic effect to the human promyelocytic leukemias cell. The purpose of this study is to verify these effects of MCS-5A on human promyelocytic leukemia (HL-60) cells and to clarify the action of mechanism on MCS-5A-inducing apoptosis.(omitted)

• Proceedings of the Korean Society of Toxicology Conference
• /
• 2003.10b
• /
• pp.139-140
• /
• 2003

Inflammatory as well as oxidative tissue damage has been implicated in pathophysiology of Alzheimer's disease (AD), and non-steroidal anti-inflammatory drugs have been reported to have beneficial effects in the treatment or prevention of AD. In the present study, we investigated the effect of celecoxib, a selective cyclooxygenase-2 (COX-2) inhibitor, on inflammatory cell death induced by beta-amyloid, a neurotoxic peptide associated with senile plaques formed in the brains of patients with AD.(omitted)

• Proceedings of the PSK Conference
• /
• 2003.10b
• /
• pp.91.2-91.2
• /
• 2003

Cyclin-dependent kinases (CDKs) regulate the cell division cycle, apoptosis, transcription and differentiation. Inhibition of CDK is a promising target in development of anti-cancer agents. An indirubin analog (AGM01l), a CDK inhibitor, is a synthetic compound that inhibits human cancer cell growth in vitro. AGM01l showed a potent cytotoxicity in cultured human cancer cell lines (IC$\sub$50/ = 5.43 ${\mu}$M for A549, human colon cancer cell; IC$\sub$50/ = 1.21 ${\mu}$M for SNU-638, human stomach cancer cell; IC$\sub$50/ 9.23 ${\mu}$M for HL-60, human leukemia cell). (omitted)