Gomisin G Suppresses the Growth of Colon Cancer Cells by Attenuation of AKT Phosphorylation and Arrest of Cell Cycle Progression

Colorectal cancer is one of the leading causes of cancer related death due to a poor prognosis. In this study, we investigated the effect of Gomisin G on colon cancer growth and examined the underlying mechanism of action. We found that Gomisin G significantly suppressed the viability and colony formation of LoVo cells. Gomisin G reduced the phosphorylation level of AKT implying that Gomisin G suppressed the PI3K-AKT signaling pathway. Gomisin G also induced apoptosis shown by Annexin V staining and an increased level of cleaved poly-ADP ribose polymerase (PARP) and Caspase-3 proteins. Furthermore, Gomisin G remarkably triggered the accumulation of cells at the sub-G1 phase which represents apoptotic cells. In addition, the level of cyclin D1 and phosphorylated retinoblastoma tumor suppressor protein (Rb) was also reduced by the treatment with Gomisin G thus curtailing cell cycle progression. These findings show the suppressive effect of Gomisin G by inhibiting proliferation and inducing apoptosis in LoVo cells. Taken together, these results suggest Gomisin G could be developed as a potential therapeutic compound against colon cancer.

Erratum to “Gomisin G Inhibits the Growth of Triple-Negative Breast Cancer Cells by Suppressing AKT Phosphorylation and Decreasing Cyclin D1” Biomol.Ther. 26 (2018) 322–327

The authors request to correct the author name from Yoonho Lim to Yoongho Lim page 322.

TMF and glycitin act synergistically on keratinocytes and fibroblasts to promote wound healing and anti-scarring activity

Keratinocyte-fibroblast interactions are critical for skin repair after injury. During the proliferative phase of wound healing, proliferation, migration and differentiation of these cells are the major mechanisms leading to tissue remodeling. We have previously reported that glycitin, a major soy isoflavone, stimulates dermal fibroblast proliferation; and the phytochemical, 4′,6,7-trimethoxyisoflavone (TMF), induces migration of HaCaT keratinocyte cells. We therefore investigated whether these compounds display synergistic effects on skin cells during wound healing in vitro and in vivo. Co-treatment with TMF and glycitin synergistically promotes the proliferation and migration of both keratinocytes and dermal fibroblasts, with a 1:1 ratio of these compounds showing the greatest efficacy in our co-culture system. This keratinocyte-fibroblast interaction occurred via the secretion of TGF-β, and the induction of differentiation and proliferation was confirmed in both indirect and direct co-culture assays. In an excisional and burn wound animal model, mice treated with a 1:1 ratio of TMF and glycitin showed faster wound closure, regeneration and scar reduction than even the positive control drug. These data indicate that two isoflavones, TMF and glycitin, act synergistically to promote wound healing and anti-scarring and could potentially be developed together as a bioactive therapeutic for wound treatment.

A new synthetic chalcone derivative, 2-hydroxy-3',5,5'-trimethoxychalcone (DK-139), suppresses the Toll-like receptor 4-mediated inflammatory response through inhibition of the Akt/NF-kappaB pathway in BV2 microglial cells

Microglial cells are the resident innate immune cells that sense pathogens and tissue injury in the central nervous system (CNS). Microglial activation is critical for neuroinflammatory responses. The synthetic compound 2-hydroxy-3',5,5'-trimethoxychalcone (DK-139) is a novel chalcone-derived compound. In this study, we investigated the effects of DK-139 on Toll-like receptor 4 (TLR4)-mediated inflammatory responses in BV2 microglial cells. DK-139 inhibited lipopolysaccharide (LPS)-induced TLR4 activity, as determined using a cell-based assay. DK-139 blocked LPS-induced phosphorylation of IkappaB and p65/RelA NF-kappaB, resulting in inhibition of the nuclear translocation and trans-acting activity of NF-kappaB in BV2 microglial cells. We also found that DK-139 reduced the expression of NF-kappaB target genes, such as those for COX-2, iNOS, and IL-1beta, in LPS-stimulated BV2 microglial cells. Interestingly, DK-139 blocked LPS-induced Akt phosphorylation. Inhibition of Akt abrogated LPS-induced phosphorylation of p65/RelA, while overexpression of dominant-active p110CAAX enhanced p65/RelA phosphorylation as well as iNOS and COX2 expression. These results suggest that DK-139 exerts an anti-inflammatory effect on microglial cells by inhibiting the Akt/IkappaB kinase (IKK)/NF-kappaB signaling pathway.

Chlorpromazine activates p21(Waf1/Cip1) gene transcription via early growth response-1 (Egr-1) in C6 glioma cells

2-Chloro-10-[3(-dimethylamino)propyl]phenothiazinemonohydrochloride (chlorpromazine) is a phenothiazine derivative used clinically to control psychotic disorders. It also exhibits an anticancer activity. Treatment with chlorpromazine (CPZ) results in cell-cycle arrest at the G2/M phase in rat C6 glioma cells. CPZ reduces the expression of cell cycle-related proteins, such as cyclin D1, cyclin A, and cyclin B1, but causes an increase in the p21(Waf1/Cip1) level. The molecular mechanism by which CPZ regulates p21(Waf1/Cip1) expression is unknown. Here, we provide evidence that CPZ activates the p21(Waf1/Cip1) gene promoter via induction of the transcription factor early growth response-1 (Egr-1) independently of p53 in C6 cells. A point mutation in the Egr-1-binding motif within the p21(Waf1/Cip1) promoter abrogated promoter inducibility due to CPZ. Forced expression of Egr-1 enhanced p21(Waf1/Cip1) promoter activity. In contrast, knockdown of endogenous Egr-1 by small interference RNA attenuated CPZ-induced p21(Waf1/Cip1) promoter activity. A chromatin immunoprecipitation assay demonstrated that Egr-1 binds to the p21(Waf1/Cip1) gene promoter. Further analysis showed that the ERK and JNK MAP kinases are required for induction of Egr-1 by CPZ. Finally, stable silencing of Egr-1 expression lead to attenuated CPZ-inducible p21(Waf1/Cip1) expression and inhibited G2/M phase cell-cycle arrest. These results demonstrate that a functional link between ERK and JNK MAP kinase pathways and p21(Waf1/Cip1) induction via Egr-1 contributes to CPZ-induced anticancer activity in C6 glioma cells.

Transcription of the protein kinase C-delta gene is activated by JNK through c-Jun and ATF2 in response to the anticancer agent doxorubicin

Expression of protein kinase C-delta (PKC delta) is up-regulated by apoptosis-inducing stimuli. However, very little is known about the signaling pathways that control PKC delta gene transcription. In the present study, we demonstrate that JNK stimulates PKC delta gene expression via c-Jun and ATF2 in response to the anticancer agent doxorubicin (DXR) in mouse lymphocytic leukemia L1210 cells. Luciferase reporter assays showed that DXR-induced activation of the PKC delta promoter was enhanced by ectopic expression of JNK1, c-Jun, or ATF2, whereas it was strongly reduced by expression of dominant negative JNK1 or by treatment with the JNK inhibitor SP600125. Furthermore, point mutations in the core sequence of the c-Jun/ATF2 binding site suppressed DXR-induced activation of the PKC delta promoter. Our results suggest an additional role for a JNK signaling cascade in DXR-induced PKC delta gene expression.

The Effects of Monacolin-Inoculated Rice Embryo on the Body Fat and Serum Lipid Profiles of Obese Elementary School Students / 대한지역사회영양학회지

The purpose of this study was to investigate the effect of Monacolin-inoculated rice embryo on the body fat and serum lipid profiles in 61 obese elementary school students. The subjects divided into two groups 31 obese children had the experimental diet (rice embryo inoculated Monacolin) and 30 obese children had the control diet three times a day after meals. The mean age, height, weight, and BMI of 61 subjects were 10.5 +/- 0.5 years, 143.6 +/- 6.8 cm, 55.0 +/- 8.9 kg, and 26.1 +/- 3.9, respectively. The changes of body fat mass (kg) in experimental group and control group after 6 weeks were -0.60 kg and -0.03 kg, respectively. The changes of body fat (%) in experimental group and control group after 6 weeks were -1.44% and -0.25%, respectively. These changes of body fat in experimental group were significantly higher than in control group (p < 0.05). The change of total-cholesterol in experimental group and control group during 6 weeks were -17.52 mg/dL and -1.70 mg/dL, respectively. The change of LDL-cholesterol in experimental group and control group during 6 weeks were -17.06 mg/dL and -2.80 mg/dL, respectively. The change of triglyceride in experimental group and control group after 6 weeks were -9.58 mg/dL and 11.67 mg/dL. Total-cholesterol, LDL- cholesterol and triglyceride of experimental group after 6 weeks significantly decreased compared to control group (p < 0.05). After experimental diet (6 weeks), total-cholesterol was negatively correlated with body water contents, soft lean mass and fat free mass (p < 0.05). Triglyceride showed a significantly positive correlation with body weight and body fat mass, however, it was negatively correlated with fat free mass (p < 0.05). HDL-cholesterol showed a significantly positive correlation with fat free mass (p < 0.05). These results show that Monacolin-inoculated rice embryo is effective in decreasing body fat and blood lipid in obese children.