• Preventive Nutrition and Food Science
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• v.11 no.3
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• pp.177-183
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• 2006

Methanolic and aqueous extracts of 26 red algae species collected from Jeju Island coast were prepared at a high $(70^{\circ}C)$ and a room temperature $(20^{\circ}C)$ and were examined for their cytotoxic activity against 4 tumor cell lines: U-937 (human monoblastoid leukemia cell line), HL-60 (human promyelocytic leukemia cell line), B-16 (murine melanoma cell line) and HeLa (woman cervical carcinoma cell line). $20^{\circ}C$ methanolic extract of Polysiphonia japonica showed cytotoxic activity of over 50% against U-937, HL-60 and B-16 cells. On the other hand, the $20^{\circ}C$ aqueous extract of Scinaia okamurae and $70^{\circ}C$ aqueous extract of Chondrus crispus showed cell growth inhibition activity of more than 50% against HL-60 and B-16 cells. The highest cytotoxic activity was observed in the $20^{\circ}C$ aqueous extract of Scinaia okamurae against B-16 cells (80.55%).

• Archives of Pharmacal Research
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• v.26 no.5
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• pp.405-410
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• 2003

Vitamin K-related analogs induce growth inhibition in various cancer cell lines. A naphthoquinone analog, termed 2,3-dichloro-5, 8-dihydroxy-1,4-naphthoquinone (DDN), induces apoptosis in human promyeloid leukemic HL-60 cells, and shows antitumor activity in vivo. Following treatment with DDN, evidence of apoptosis, including DNA fragmentation and cleavage of poly ADP ribose polymerase (PARP), was observed. DDN induced an upregulation of proapoptotic Bax protein, and Bid cleavage. Antiapoptotic Bcl-2 protein levels were not changed by DDN, but the expression of Bcl-xL was decreased. In addition, DDN reduced the mass of solid tumor in the Sarcoma 180 tumor-bearing mouse model. These results indicate that DDN exerts antitumor activity, which appears to be related to the induction of apoptosis by regulating Bcl-2 family proteins.

• Biomolecules & Therapeutics
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• v.19 no.4
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• pp.411-418
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• 2011

Ginsenoside Rp1 (G-Rp1) is a novel ginseng saponin derivative with anti-tumor activity. However, the biochemical and molecular mechanisms of G-Rp1 on anti-tumor activity are not fully understood. In the present study, we report that G-Rp1 inhibits lung cancer cell proliferation, migration and adhesion in p53 wild-type A549 and p53-defi cient H1299 cells. Anti-proliferative activity of G-Rp1 in lung cancer cells is mediated by enhanced nuclear localization of cyclin-dependent kinase inhibitors including $p27^{Kip1}$ and $p21^{WAF1/Cip1}$, and subsequent inhibition of pRb phosphorylation. We also show that these anti-tumor activities of G-Rp1 in both A549 and H1299 cells appear to be mediated by suppression of mitogenic signaling pathways such as ERK, Akt and $p70^{S6K}$. Taken together, these findings suggest further development and evaluation of G-Rp1 for the treatment of lung cancers with mutated p53 as well as wild-type p53.

• Biomolecules & Therapeutics
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• v.27 no.5
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• pp.484-491
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• 2019

Glioblastoma is the most aggressive common brain tumor in adults. Curcumin, from Curcuma longa, is an effective antitumor agent. Although the same proteins control both autophagy and cell death, the molecular connections between them are complicated and autophagy may promote or inhibit cell death. We investigated whether curcumin affects autophagy, which regulates curcumin-mediated tumor cell death in A172 human glioblastoma cells. When A172 cells were incubated with $10{\mu}M$ curcumin, autophagy increased in a time-dependent manner. Curcumin-induced cell death was reduced by co-incubation with the autophagy inhibitors 3-methyladenine (3-MA), hydroxychloroquine (HCQ), and LY294002. Curcumin-induced cell death was also inhibited by co-incubation with rapamycin, an autophagy inducer. When cells were incubated under serum-deprived medium, LC3-II amount was increased but the basal level of cell viability was reduced, leading to the inhibition of curcumin-induced cell death. Cell death was decreased by inhibiting curcumin-induced autophagy using small interference RNA (siRNA) of Atg5 or Beclin1. Therefore, curcumin-mediated tumor cell death is promoted by curcumin-induced autophagy, but not by an increase in the basal level of autophagy in rapamycin-treated or serum-deprived conditions. This suggests that the antitumor effects of curcumin are influenced differently by curcumin-induced autophagy and the prerequisite basal level of autophagy in cancer cells.

• BMB Reports
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• v.57 no.4
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• pp.194-199
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• 2024

Overexpression of mitofusin-2 (MFN2), a mitochondrial fusion protein, is frequently associated with poor prognosis in cervical cancer patients. Here, I aimed to investigate the involvement of MFN2 in cervical cancer progression and determine the effect of MFN2 on prognosis in cervical cancer patients. After generating MFN2-knockdown SiHa cells derived from squamous cell carcinoma, I investigated the effect of MFN2 on SiHa cell proliferation using the Cell Counting Kit-8 assay and determined the mRNA levels of proliferation markers. Colony-forming ability and tumorigenesis were evaluated using a colony-formation assay and tumor xenograft mouse models. The migratory and invasive abilities associated with MFN2 were measured using wound-healing and invasion assays. Wnt/β-catenin-mediated epithelial-mesenchymal transition (EMT) markers related to MFN2 were assessed through quantitative RT-PCR. MFN2-knockdown SiHa cells exhibited reduced proliferation, colony formation, migration, invasion, and tumor formation in vivo. The motility of SiHa cells with MFN2 knockdown was reduced through Wnt/β-catenin-mediated EMT inhibition. MFN2 promoted cancer progression and tumorigenesis in SiHa cells. Overall, MFN2 could serve as a therapeutic target and a novel biomarker for cervical cancer.

• BMB Reports
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• v.57 no.7
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• pp.318-323
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• 2024

Regulation of cell fate and lung cell differentiation is associated with Aminoacyl-tRNA synthetases (ARS)-interacting multifunctional protein 2 (AIMP2), which acts as a non-enzymatic component required for the multi-tRNA synthetase complex. In response to DNA damage, a component of AIMP2 separates from the multi-tRNA synthetase complex, binds to p53, and prevents its degradation by MDM2, inducing apoptosis. Additionally, AIMP2 reduces proliferation in TGF-β and Wnt pathways, while enhancing apoptotic signaling induced by tumor necrosis factor-α. Given the crucial role of these pathways in tumorigenesis, AIMP2 is expected to function as a broad-spectrum tumor suppressor. The full-length AIMP2 transcript consists of four exons, with a small section of the pre-mRNA undergoing alternative splicing to produce a variant (AIMP2-DX2) lacking the second exon. AIMP2-DX2 binds to FBP, TRAF2, and p53 similarly to AIMP2, but competes with AIMP2 for binding to these target proteins, thereby impairing its tumor-suppressive activity. AIMP2-DX2 is specifically expressed in a diverse range of cancer cells, including breast cancer, liver cancer, bone cancer, and stomach cancer. There is growing interest in AIMP2-DX2 as a promising biomarker for prognosis and diagnosis, with AIMP2-DX2 inhibition attracting significant interest as a potentially effective therapeutic approach for the treatment of lung, ovarian, prostate, and nasopharyngeal cancers.

• Journal of Applied Biological Chemistry
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• v.53 no.3
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• pp.139-146
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• 2010

The inhibitory effects of 25 polyphenols against in vitro allergic reactions were compared using biochemical and cell assays. Three polyphenols including curcumin, gallic acid, and quercetin suppressed the release of $\beta$-hexosaminidase from ionophore A23187-stimulated RBL-2H3 cells more effectively (>50% inhibition at $100{\mu}M$ concentration). They were found to have potencies in suppressing the release of histamine not only from ionophore A23187-, but also from immunoglobulin E (IgE)-stimulated RBL-2H3 cells. Moreover, such suppressive effects of the three polyphenols were also observed in A23187 plus PMA-costimulated rat peritoneal mast cells. The extent of inhibition were quantified as the respective polyphenol concentration that inhibit 50% ($IC_{50}$) of $\beta$-hexosaminidase or histamine release, showing an inhibition tendency with decreasing order of curcumin>gallic acid>quercetin. Down-regulation of $Ca^{2+}$ influx was suggested as the cause of the inhibition of $\beta$-hexosaminidase and histamine releases in these cells. The immune process inhibition was confirmed by the observed reduction in the gene expressions and release of pro-inflammatory cytokine tumor necrosis factor (TNF)-$\alpha$, interleukin (IL)-$1\beta$, and IL-4, due probably to antioxidant activity of the polyphenols. These findings illustrate that curcumin, gallic acid, and quercetin may be beneficial against allergic inflammatory diseases.

• The Korean Journal of Physiology and Pharmacology
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• v.16 no.2
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• pp.145-151
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• 2012

In the present work, we studied the structure-activity relationship (SAR) of tautomycetin (TMC) and its derivatives. Further, we demonstrated the correlation between the immunosuppressive fuction, anticancer activity and protein phosphatase type 1 (PP1) inhibition of TMC and its derivatives. We have prepared some TMC derivatives via combinatorial biosynthesis, isolation from fermentation broth or chemical degradation of TMC. We found that the immunosuppressive activity was correlated with anticancer activity for TMC and its analog compounds, indicating that TMC may home at the same targets for its immunosuppressive and anticancer activities. Interestingly, TMC-F1, TMC-D1 and TMC-D2 all retained significant, albeit reduced PP1 inhibitory activity compared to TMC. However, only TMC-D2 showed immunosuppressive and anticancer activities in studies carried out in cell lines. Moreover, TMC-Chain did not show any significant inhibitory activity towards PP1 but showed strong growth inhibitory effect. This observation implicates that the maleic anhydride moiety of TMC is critical for its phosphatase inhibitory activity whereas the C1-C18 moiety of TMC is essential for the inhibition of tumor cell proliferation. Furthermore, we measured $in$ $vivo$ phosphatase activities of PP1 in MCF-7 cell extracts treated with TMC and its related compounds, and the results indicate that the cytotoxicity of TMC doesn't correlate with its $in$ $vivo$ PP1 inhibition activity. Taken together, our study suggests that the immunosuppressive and anticancer activities of TMC are not due to the inhibition of PP1. Our results provide a novel insight for the elucidation of the underlying molecular mechanisms of TMC's important biological functions.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1998.11a
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• pp.128-128
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• 1998

Matrix metalloproteinases (MMPs) are a family of zinc-dependent proteases that degrade extracellular matrix and basement membrane. These enzymes are play important roles in tumor cell invasion and metastasis, as well as angiogenesis and other connective tissue diseases. In our screening program for inhibitors of MMP-2 from fungal metabolites, we have isolated novel non-peptidic inhibitors of MMPs, designated gelastatin A and B from the culture broth of Westerdykella multispora F50733. The structures of gelastatin A and B were determined to be 3-(5E-hexa-2E,4E-dienylidene-2-oxo-5,6-dihydro-2H-pyran-3yl)-propanoic acid and 3-(5Z-hexa-2E,4E-dienylidene-2-oxo-5,6-dihydro-2H-pyran-3yl)-propanoic acid, respectively. Gelastatin A and B exist as a mixture of two stereoisomers in a ratio of 2: 1. The 2: 1 mixture of gelastatin A and B inhibited activated MMP-2 and MMP-9 with an IC$\sub$50/ value of 0.63, 5.29 ${\mu}$M, respectively. They inhibited the invasion of B16F10 melanoma cells through basement membrane Matrigel with dose dependent.

• The Korea Journal of Herbology
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• v.34 no.6
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• pp.117-124
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• 2019

Objective : Broccoli is edible green plant that has a wide variety of health benefits including cancer prevention and cholesterol reduction. However, leaves of broccoli are not eaten and are mostly left as waste. This study was conducted to evaluate the effects of the broccoli leaf extract (BLE) on prostaglandin E₂ (PGE₂) production related to nuclear factor kappa B (NF-κB) signaling in lipopolysaccharide (LPS)-activated macrophages. Methods : BLE was prepared by extracting dried leaf with ethanol. Cell viability was determined by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. PGE₂ and inflammatory cytokines were detected by enzyme-linked immunosorbent assay (ELISA). Expression level of each protein was monitored by Western blot analysis. Results : In LPS-activated Raw264.7 cells, PGE₂ release into culture medium was dramatically enhanced compared to control cells. However, increased PGE₂ was attenuated dose-dependently by treatment with BLE. Inhibition of PGE₂ production by BLE was due to the suppression of cyclooxygenase-2 (COX-2) expression determined by Western blot analysis. BLE also inhibited the production of inflammatory cytokines such as interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α). Inhibition at PGE₂ and cytokine was mediated from inhibition of nuclear translocation of NF-κB due to the repression of inhibitory kappa B alpha (IκBα) phosphorylation and degradation. Conclusion : This study showed that BLE exerted inhibitory activities against PGE₂, which is critical for the initiation and resolution of inflammatory responses, and that inhibition of PGE₂ was mediated by suppression of NF-κB signaling. These results suggest that the waste broccoli leaves could be used for controlling inflammation.