Ju-Hye Lee

Modulation of proliferation and differentiation of C2C12 skeletal muscle cells by fatty acids

AIMS This study was performed to elucidate whether mitogen-activated protein kinases (MAPKs) are involved in the modulation of the proliferation and differentiation of skeletal muscle cells by fatty acids. MAIN METHODS C2C12 myoblasts were cultured in differentiation medium containing 2% horse serum for 3 days, and treated with each fatty acid. Phosphorylation levels of MAPKs were examined by immunoblot analysis. KEY FINDINGS The mono-unsaturated fatty acids (MUFAs), oleic acid (OA) and n-6 polyunsaturated fatty acids (n-6 PUFAs), linoleic acid (LA), gamma-linoleic acid (GLA), and arachidonic acid (AA) increased the proliferation of C2C12 cells. On the other hand, n-3 polyunsaturated fatty acids (n-3 PUFAs) and saturated fatty acids (SFs) did not affect the proliferation of C2C12 cells. In addition, the treatment of cis-9, trans-11 conjugated linoleic acid (c9,t11 CLA) showed an increased cell proliferation. However, trans-10, cis-12 conjugated linoleic acid (t10,c12 CLA) significantly inhibited cell proliferation. Treatment of C2C12 cells with LA, OA, and c9,t11 CLA increased phosphorylation levels of ERK1/2 and JNK during proliferation. During cell differentiation, OA, LA, and c9,t11 CLA stimulated differentiation of C2C12 cells, whereas t10,c12 CLA inhibited differentiation. We also found that OA, LA, and c9, t11 CLA increased phosphorylation level of ERK1/2, but not JNK during differentiation. SIGNIFICANCE These results suggest that fatty acids are able to modulate the proliferation and differentiation of skeletal muscle and MAPKs may be involved in the modulation of the proliferation and differentiation of skeletal muscle cells by fatty acids.

Mechanisms of thiosulfinates from Allium tuberosum L.-induced apoptosis in HT-29 human colon cancer cells.

This study was performed to elucidate the apoptotic pathways by thiosulfinates, major biologically active components of Allium tuberosum L., in HT-29 human colon cancer cells. Thiosulfinates significantly induced cell death in dose- and time-dependent manners in HT-29 cells, which is associated with apoptosis. Thiosulfinates activated the initiator caspase-8, and -9, and the effector caspase-3. In the present study, thiosulfinates were found to stimulate Bid cleavage, indicating that the apoptotic action of caspase-8-mediated Bid cleavage leads to the activation of caspase-9. Thiosulfinates down-regulated the expression of the anti-apoptotic protein Bcl-2, and up-regulated the expression of the pro-apoptotic protein Bax. We also found that thiosulfinates increased the expression of AIF, a caspase-independent mitochondrial apoptosis factor, and induced DNA fragmentation and chromatin condensation in HT-29 cells. These results indicate that thiosulfinates from A. tuberosum L. inhibited cell proliferation and activated both the caspase-dependent and caspase-independent apoptotic pathways in HT-29 cells.

Sensitization of Tumor Necrosis Factor-Related Apoptosis-Inducing Ligand (TRAIL)-Resistant Primary Prostate Cancer Cells by Isoegomaketone from Perilla frutescens

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is currently in clinical trials as a cancer treatment due to its ability to induce apoptosis selectively in cancer cells. Nevertheless, the risk of developing resistance warrants the development of sensitizers that can overcome resistance to TRAIL. In this study, isoegomaketone (1) acted as a synergistic TRAIL sensitizer by mediating up-regulation of DR5 expression in primary prostate cancer RC-58T/h/SA#4 cells. Combined with 1, TRAIL exhibited enhanced apoptotic activity in a human prostate cancer cell line designated RC-58T/h/SA#4, as indicated by increases in annexin V-positive and sub-G1 cell populations as well as condensation of chromatin or apoptotic bodies. Combined treatment also activated caspases-8, -9, and -3; increased the protein levels of Bax, AIF, and cytosolic cytochrome c; and induced PARP cleavage while reducing Bcl-2 protein expression. Human recombinant DR5 Fc chimera efficiently attenuated 1-induced apoptosis, thereby demonstrating the critical role of DR5 in 1-mediated apoptotic cell death. Furthermore, DR5 expression induced by 1 was mediated via a ROS-independent pathway that required CHOP and p53. Overall, these findings provide evidence that 1 potentiates TRAIL-mediated apoptosis through up-regulation of DR5 via a ROS-independent pathway. This suggests that 1 has potential for increasing the effectiveness of prostate cancer therapy with TRAIL.

Cultivated Orostachys japonicus Induces Apoptosis in Human Colon Cancer Cells

This study was performed to elucidate the anticancer activities and the mechanism of chloroform fractions from cultivated Orostachys japonicus (CFCOJ) in human colon cancer cells. CFCOJ markedly decreased viable cell numbers in both a dose-dependent and time-dependent manner within SW480 cells. Cell death induced by CFCOJ increased cell populations in the sub-G1 phase, as well as the formation of apoptotic bodies, nuclear condensation, and induced DNA fragmentation. CFCOJ-induced apoptosis was associated with the activation of initiator caspase-8 and -9, as well as the effector caspase-3. CFCOJ also stimulated Bid cleavage, indicating that the apoptotic action of caspase-8-mediated Bid cleavage leads to the activation of caspase-9. CFCOJ increased the expression of the proapoptotic protein, Bax, and decreased the expression of the antiapoptotic protein, Bcl-2. These results indicate that CFCOJ exert anticancer effects on human colon cancer SW480 cells through a caspase-dependent apoptotic pathway.

Lethariella zahlbruckneri Acetone Extract-Induced Apoptosis of MCF-7 Human Breast Cancer Cells Involves Caspase Cascade and Mitochondria- Mediated Death Signaling

Lethariella zahlbruckneri has been traditionally used in tea and medicines in China. This study aimed to evaluate the anti-cancer properties of L. zahlbruckneri acetone extract (AEL) and to explore its potential mechanisms on MCF- 7 human breast cancer cells. The polyphenol and flavonoid concentrations of were 14.4 mg gallic acid equivalent/g and 6.5 mg quercetin equivalent/g, respectively. AEL inhibited the growth of MCF-7 cells in a dose- and time dependent manner. AEL significantly induced apoptotic cell death, resulting in an increase in the sub-G1 apoptotic cell population, apoptotic DNA fragmentation, and a morphological change. Pretreatment with a caspase inhibitor modestly attenuated the AEL-induced increase in the sub-G1 cell population, implying that caspases play a partial role in AEL-induced apoptosis. Moreover, AEL-induced apoptosis was associated with changes of caspase activities, up-regulation of the apoptotic protein (Bax), and down-regulation of the anti-apoptotic protein (Bcl-2). AEL also induced apoptosis-inducing factor-release from mitochondria, indicating apoptosis stimulation through a caspaseindependent pathway. These results suggest that AEL exerts its anti-cancer effects on MCF-7 human breast cancer cells through mitochondrial caspase-dependent and caspase-independent apoptotic pathways.

Sorghum Extract Enhances Caspase-dependent Apoptosis in Primary Prostate Cancer Cells and Immune Activity in Macrophages

Sorghum bicolor L. is one of the important minor cereals in Asia, Africa, and the central United States, and it is considered a rich source of polyphenols, flavonoids, and dietary fiber. However, there is a lack of data on the anti-cancer activity of Sorghum in prostate cancer cells and immune activity in macrophages. This study aims to investigate the potential effects of an ethanol extract of S. bicolor L. (SE) on inducing apoptosis in RC-58T/h/SA#4 cells and immunomodulatory activity in RAW 264.7 cells. SE significantly inhibited the viability of RC-58T/h/SA#4 primary prostate cancer cells in a dose-dependent manner. The morphology of RC-58T/h/SA#4 cells treated with SE was shrunken and involved the formation of an apoptotic body and nuclear condensation. In addition, SE markedly activated caspase-8, -9, and -3; increased the protein levels of Bax, p53, cleaved PARP, and cytosolic cytochrome c; and decreased Bcl-2 protein expression. Furthermore, the inhibition of caspases in RC-58T/h/SA#4 cells with z-VAD-fmk attenuated SE-induced cell growth inhibition. The production of nitric oxide (NO) was also elevated by SE treatment, as revealed by immune response parameters. These results suggest that SE inhibits growth and induces apoptosis in primary human prostate cancer cells in a caspase-dependent manner, and it modulates the immune functions in macrophages. Therefore, Sorghum bicolor L. may be used as a functional food to prevent prostate cancer and enhance immune activity.

Anti-proliferative Effects of Acid Extract of Gracilaria Verrucosa on Primary Human Prostate Cancer Cells

Human Prostate Cancer Cells Seong-Min Hong, Hyun-Dong Cho, Jeong-Ho Kim, Ju-Hye Lee 4 , Woo-Si Song, Sung-Tae Lee, Mi-Kyung Lee and Kwon-Il Seo* Institute of Agricultural Life Sciences, Dong-A University, Busan 49315, Korea Department of Food Science and Technology, Kyungpook National University, Daegu 41566, Korea 3 Department of Food Nutrition, Sunchon National University, Suncheon, Jeonnam 57922, Korea 4 Functional Food & Nutrition Division, National Institute of Agricultural Science, Rural Development Administration, Wanju, Jeonbuk 55365, Korea 5 Marine Service Co., Ltd. Suncheon 540-811, Korea Department of Pharmacy, Sunchon National University, Suncheon, Jeonnam 57922, Korea Department of Biotechnology, Dong-A University, Busan 49315, Korea

Extracts from the Root of Platycodon grandiflorum Modulate Induction of Inflammatory Changes in Coculture of Adipocytes and Macrophages

Obesity changes the morphology and composition of adipose tissue, leading to changes in production and secretion of the several proinflammatory mediators. This study aims to obtain in vitro evidences that extracts from the root of Platycodon grandiflorum (PGE) can inhibit inflammatory responses in obesity. We investigated the effect of PGE on the production of proinflammatory mediators in lipopolysaccharide (LPS)-stimulated macrophages and in the interaction between adipocytes and macrophages. At first, to determine whether PGE suppresses proinflammatory cytokine production in macrophages, RAW 264.7 macrophages were stimulated with LPS in the presence or absence of PGE for 24 h. PGE significantly inhibited the production of LPS-induced proinflammatory mediators as TNF-α, NO, and MCP-1 in the cells. We next examined the effect of PGE on proinflammatory mediators in coculture of adipocytes and macrophages. RAW 264.7 cells and hypertrophied 3T3-L1 cells were incubated in serum-free DMEM medium for 24 h. Then, PGE was added to the coculture at various concentrations for 24 h. The PGE treatment significantly decreased production of proinflammatory mediators in the cocultured cells. However, PGE enhanced anti-inflammatory mediator such as adiponectin expression. These data demonstrated that PGE may suppress the inflammatory responses of the adipose tissue in obesity.