Chios Gum Mastic Induces Cell Cycle Arrest and Apoptosis in Human Osteosarcoma Cells / 대한해부학회지

Chios gum mastic (CGM) is a resin produced from the stem and leaves of Pistiacia lentiscus L var chia, a plant which grows only on Chios Island in Greece. CGM has been used for many centuries as a dietary supplement and folk medicine for stomach and duodenal ulcers in many Mediterranean countries and is also known to induce cell cycle arrest and apoptosis in some cancer cells. This study was undertaken to investigate the alteration of the cell cycle and induction of apoptosis by CGM treatment on human osteosarcoma (HOS) cells. The viability and the growth inhibition of HOS cells were assessed by the MTT assay and clonogenic assay respectively. The hoechst staining, TUNEL assay and DNA electrophoresis were conducted to observe the HOS cells undergoing apoptosis. HOS cells were treated with CGM, and Western blotting, immunocytochemistry, confocal microscopy, FACScan flow cytometry, mitochondrial membrane potential change and proteasome activity were conducted. CGM treatment of HOS cells was found to result in a dose- and time-dependent decrease in cell viability, a dose-dependent inhibition of cell growth, and apoptotic cell death. Tested HOS cells also showed several lines of apoptotic manifestation and G1 arrest in cell cycle progression. In summary, this study clearly demonstrated that CGM induces G1 cell cycle arrest via the modulation of cell cycle-related proteins, and apoptosis via proteasome, mitochondrial and caspase cascades in HOS cells. Therefore, our data provide the possibility that a natural product, CGM could be considered as a novel therapeutic strategy for human osteosarcoma.

Apoptotic Effect of Co-Treatment with a Natural Product, Chios Gum Mastic, and a Synthetic Chenodeoxycholic Acid Derivative, HS-1200, on Human Osteosarcoma Cells / 체질인류학회지

Chios gum mastic (CGM) is a resinous exudate obtained from the stem and the main leaves of Pistacia lenticulus tree native to Mediterranean areas. Recently it reported that CGM induced apoptosis in a few cancer cells in vitro. It has been reported that the synthetic chenodeoxycholic acid (CDCA) derivatives showed apoptosis-inducing activity on various cancer cells in vitro. This study was undertaken to investigate the synergistic apoptotic effect of co-treatment with a natural product, CGM and a CDCA derivative, HS-1200 on human osteosarcoma (HOS) cells. To investigate whether the co-treatment of CGM and HS-1200 compared with each single treatment efficiently reduced the viability of HOS cells, MTT assay was conducted. Induction and augmentation of apoptosis were confirmed by DNA electrophoresis, Hoechst staining and DNA hypoploidy, Westen blot analysis and immunofluorescent staining were performed to study the alterations of the expression level and translocation of apoptosis-related proteins in co-treatment. Furthermore, proteasome activity and mitochondrial membrane potential (MMP) change were also assayed. In this study, HOS cells co-treated with CGM and HS-1200 showed several lines of apoptotic manifestation whereas each single treated HOS cells did not. Although the single treatment of 40 microgram/mL CGM or 25 micrometer HS-1200 for 24 h did not induce apoptosis, the cotreatment of them induced prominently apoptosis. Therefore our data provide the possibility that combination therapy of CGM and HS-1200 could be considered as a novel therapeutic strategy for human osteosarcoma.

Synthetic Chenodeoxycholic Acid Derivative HS-1200-induced Apoptosis of Human Melanoma Cells / 체질인류학회지

Bile acids and their synthetic derivatives induced apoptosis in various kinds of cancer cells and anticancer effects. It has been reported that the synthetic chenodeoxycholic acid (CDCA) derivatives showed apoptosis-inducing activity on various cancer cells in vitro. It wasn't discovered those materials have apoptosis-inducing effects on G361 human melanoma cells. The present study was done to examine the synthetic bile acid derivatives, HS-1199 and HS-1200, induced apoptosis on G361 cells and such these apoptosis events. The viability of G361 cells was assessed by the MTT assay. Induction of apoptosis was confirmed by DNA electrophoresis and Hoechst staining. Westen blot analysis and immunofluorescent staining were performed to study the alterations in expression level and translocation of apoptosis-related proteins. Proteasome activity and mitochondrial membrane potential (MMP) change were also assayed. Tested G361 cells showed several lines of apoptotic manifestation such as activation of caspase-3, DFF and PARP, DNA degradation (HS-1200 only), nuclear condensation, inhibition of proteasome activity, reduction of mitochondrial membrane potential, and the release of cytochrome c and AIF to cytosol. Between two synthetic derivatives, HS-1200 showed stronger apoptosis-inducing effect than HS-1199 did. Taken collectively, we here demonstrated for the first time that synthetic CDCA dedrivatives induce apoptosis of human melanoma cells through the proteasome, mitochondria and caspase pathway. Therefore our data provide the possibility that HS-1200 could be considered as a novel therapeutic strategy for human melanoma cells from its powerful apoptosis-inducing activity.

Induction of Apoptosis in Human Oral Squamous Carcinoma Cells by Extracellular Products from Pseudomonas aeruginosa / 대한해부학회지

It was reported that cancer in humans and animals infected with microbial pathogens was regressed about 100 years ago. Bacteria are able to trigger apoptosis by a variety of mechanisms including the secretion of protein synthesis inhibitors, pore forming proteins, molecules activating the endogenous death machinery in the infected cell. This study was conducted in order to investigate whether extracellular products of Psuedomonas aeruginosa (EPPA) induce apoptosis in human oral carcinoma cells (OSC9). The EPPA showed cytotoxic effect on OSC9 cells in dose and time-dependent manner. The cell death was demonstrated to be due to apoptosis characterized by chromatin condensation and nuclear fragment. EPPA treatment induced cleavage of caspase-3 and caspase-6. The caspase substrates, PARP, DFF45 and lamin A were cleaved during EPPA-induced apoptosis. Taken together, EPPA induces apoptosis on human oral squamous carcinoma cells in caspase-dependent manner. Our data therefore provide that EPPA contains a novel antitumor agent for human oral squamous carcinoma.