• KSBB Journal
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• v.7 no.3
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• pp.209-215
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• 1992

The aims of this sutdy was to investgate the action mechanism of polycation on the $\beta$-glucan synthetase II (GS II) related to cell wall synthesis in suspension cultured carrot cells. In the suspension cultured cells treated with poly-L-Iysine($12{\mu}M$) and poly-L-ornithine ($12{\mu}M$) having ploycationic nature, GS II activity increased about 40% and 50% than that of the control respectively. And similar response was observed when ATP and NaF were treated. On the other hand, ploy-L-lysine and ploy-L-ornithine did nor affect the membrane permeability. Phorbol-12-myrlstate-13-acetate (TPA), activator of protein klnase, increased about 35% and 1-(5-isoquinolinyl sulfonyl)-2-methyl-piperrazine (H-7), inhibitor of protein kinase, decreased about 30% of GSII activity than that of control. These results suggest that polycation plays a role in the cell wall synthesis by increasing GS II activity through phosphorylation.

• BMB Reports
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• v.43 no.3
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• pp.199-204
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• 2010

The protein p104 was first isolated as a binding partner of the Src homology domain of phospholipase C$\gamma$1, and has been shown to associate with p85$\alpha$, Grb2. The ectopic expression of p104 reduced cellular growth rate, which was also achieved with the overexpression of only the proline-rich region of p104. The proline-rich region of p104 has been found to inhibit the colony formation of platelet-derived growth factor BB-stimulated NIH3T3 cells and MCF7 cancer cells on soft agar. Mutagenesis analysis showed that the second and third proline-rich regions are essential for growth control, as well as for interaction with p85$\alpha$. Overexpression of p104 increased the level of the cyclin-dependent kinase inhibitor, $p27^{Kip1}$, and inhibited the activity of phosphoinositide 3-kinase (PI3K). In summary, p104 interacts with p85$\alpha$ and is involved in the regulation of $p27^{Kip1}$ expression for the reduction of cellular proliferation.

• Molecules and Cells
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• v.25 no.4
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• pp.504-509
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• 2008

Three G-protein-linked acetylcholine receptors (GARs) exist in the nematode C. elegans. GAR-3 is pharmacologically most similar to mammalian muscarinic acetylcholine receptors (mAChRs). We observed that carbachol stimulated ERK1/2 activation in Chinese hamster ovary (CHO) cells stably expressing GAR-3b, the predominant alternatively spliced isoform of GAR-3. This effect was substantially reduced by the phospholipase C (PLC) inhibitor U73122 and the protein kinase C (PKC) inhibitor GF109203X, implying that PLC and PKC are involved in this process. On the other hand, GAR-3b-mediated ERK1/2 activation was inhibited by treatment with forskolin, an adenylate cyclase (AC) activator. This inhibitory effect was blocked by H89, an inhibitor of cAMP-dependent protein kinase A (PKA). These results suggest that GAR-3b-mediated ERK1/2 activation is negatively regulated by cAMP through PKA. Together our data show that GAR-3b mediates ERK1/2 activation in CHO cells and that GAR-3b can couple to both stimulatory and inhibitory pathways to modulate ERK1/2.

• BMB Reports
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• v.46 no.4
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• pp.213-218
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• 2013

Members of the colony stimulating factor cytokine family play important roles in macrophage activation and recruitment to inflammatory lesions. Among them, granulocyte-macrophage colony stimulating factor (GM-CSF) is known to be associated with immune response to mycobacterial infection. However, the mechanism through which Mycobacterium tuberculosis (MTB) affects the expression of GM-CSF is poorly understood. Using PMA-differentiated THP-1 cells, we found that MTB infection increased GM-CSF mRNA expression in a dose-dependent manner. Induction of GM-CSF mRNA expression peaked 6 h after infection, declining gradually thereafter and returning to its basal levels at 72 h. Secretion of GM-CSF protein was also elevated by MTB infection. The increase in mRNA expression and protein secretion of GM-CSF caused by MTB was inhibited in cells treated with inhibitors of p38 MAPK, mitogen-activated protein kinase kinase (MEK-1), and PI3-K. These results suggest that up-regulation of GM-CSF by MTB is mediated via the PI3-K/MEK1/p38 MAPK-associated signaling pathway.

• Journal of Life Science
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• v.17 no.3 s.83
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• pp.356-361
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• 2007

To investigate the region of ErbB2 for the $ErbB2-{\beta}-catenin$ interaction, a proteasome $resistant-{\beta}-catenin$ and various ErbB2 constructs were transfected in COS7 cells. ErbB2 proteins were immunoprecipitated, and coimmunoprecipitated ${\beta}-catenin$ was examined by Western blotting. ${\beta}-catenin$ coimmunoprecipitated with full length ErbB2. Of the truncated ErbB2 proteins DT (1-1123), DHC (1-1031) and DK (1-750), the ErbB2 constructs containing the kinase domain, DT and DHC, precipitated together with ${\beta}-catenin$ but DK containing no kinase domain did not. To further test the requirement of the kinase domain for ${\beta}-catenin-ErbB2$ interaction, the presence of ${\beta}-catenin$ in the immunocomplex was examined following transfection with an ErbB2 mutant (${\triangle}750-971$) whose kinase domain is internally deleted and subsequent immunoprecipitation of the ErbB2 mutant. ${\beta}-catenin$ was not detected in the immunocomplex. These results suggest that the ErbB2 kinase domain comprises a potential site for ${\beta}-catenin$ binding to the receptor tyrosine kinase.

• Journal of Microbiology and Biotechnology
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• v.32 no.5
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• pp.645-656
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• 2022

Gossypol, a natural phenolic aldehyde present in cotton plants, was originally used as a means of contraception, but is currently being studied for its anti-proliferative and anti-metastatic effects on various cancers. However, the intracellular mechanism of action regarding the effects of gossypol on pancreatic cancer cells remains unclear. Here, we investigated the anti-cancer effects of gossypol on human pancreatic cancer cells (BxPC-3 and MIA PaCa-2). Cell counting kit-8 assays, annexin V/propidium iodide staining assays, and transmission electron microscopy showed that gossypol induced apoptotic cell death and apoptotic body formation in both cell lines. RNA sequencing analysis also showed that gossypol increased the mRNA levels of CCAAT/enhancer-binding protein homologous protein (CHOP) and activating transcription factor 3 (ATF3) in pancreatic cancer cell lines. In addition, gossypol facilitated the cleavage of caspase-3 via protein kinase RNA-like ER kinase (PERK), CHOP, and Bax/Bcl-2 upregulation in both cells, whereas the upregulation of ATF was limited to BxPC-3 cells. Finally, a three-dimensional culture experiment confirmed the successful suppression of cancer cell spheroids via gossypol treatment. Taken together, our data suggest that gossypol may trigger apoptosis in pancreatic cancer cells via the PERK-CHOP signaling pathway. These findings propose a promising therapeutic approach to pancreatic cancer treatment using gossypol.

• Journal of Nutrition and Health
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• v.53 no.5
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• pp.452-463
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• 2020

Purpose: Aster tataricus (AT) is one of the Asteraceae perennial herbs used in traditional Chinese medicine. The herb contains various bioactive substances, such as flavonoids, isoflavonoids, and phenolic compounds in the roots, and exhibits a range of effects including anti-bacterial, anti-oxidant, and anti-inflammatory activities. This study compared the immunomodulatory effects of ethanol and water extracts of whole AT, except the roots, and analyzed the molecular mechanisms for the regulatory effects on cytokine secretion from THP-1 cells. Methods: The effects of AT extract on the cell viability and proliferation of THP-1 cells were analyzed using the Cell Counting Kit-8 method. The concentrations of interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) in the cell culture supernatant of the AT-treated THP-1 cells were measured using an enzyme-linked immunosorbent assay. The protein levels of cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), inhibitor of nuclear factor kappa B (IκBα), and mitogen-activated protein kinase (MAPK) phosphorylation in the cell lysates were determined by western blotting. Results: The water extract and the ethanol extract of AT did not affect the cell viability, and increased the proliferation of THP-1 cells significantly compared to the vehicle. The water extract increased the secretion of IL-1β from THP-1 cells in a dose-dependent manner, but the ethanol extract had no effect. The expression of COX-2 and iNOS protein and the phosphorylation of MAPK and Akt were induced in AT-treated cells. In addition, IκBα was degraded by AT in a concentration-dependent manner. IL-1β secretion by AT was reduced by extracellular-signal-regulated kinase (ERK) and c-Jun N-terminal kinase (JNK) inhibitors, while TNF-α secretion was decreased by inhibitors of ERK, p38 MAPK, and JNK. Interestingly, the p38 MAPK inhibitor increased the production of IL-1β by AT further. Conclusion: The water extract of the above-ground parts of AT contains immunomodulatory bioactive substances that stimulate immune cells through the MAPK signaling pathway.

• Nutrition Research and Practice
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• v.11 no.2
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• pp.90-96
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• 2017

BACKGROUND/OBJECTIVES: Although the antioxidative effects of lycopene are generally known, the molecular mechanisms underlying the anti-inflammatory properties of lycopene are not fully elucidated. This study aimed to examine the role and mechanism of lycopene as an inhibitor of inflammation. METHODS/MATERIALS: Lipopolysaccharide (LPS)-stimulated SW 480 human colorectal cancer cells were treated with 0, 10, 20, and $30{\mu}M$ lycopene. The MTT assay was performed to determine the effects of lycopene on cell proliferation. Western blotting was performed to observe the expression of inflammation-related proteins, including nuclear factor-kappa B ($NF-{\kappa}B$), inhibitor kappa B ($I{\kappa}B$), mitogen-activated protein kinase (MAPK), extracellular signal-related kinase (ERK), c-jun NH2-terminal kinase (JNK), and p38 (p38 MAP kinase). Real-time polymerase chain reaction was performed to investigate the mRNA expression of tumor necrosis factor ${\alpha}$ ($TNF-{\alpha}$), interleukin-1 beta ($IL-1{\beta}$), interleukin-6 (IL-6), inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2). Concentrations of nitric oxide (NO) and prostaglandin $E_2$ ($PGE_2$) were determined via enzyme-linked immunosorbent assays. RESULTS: In cells treated with lycopene and LPS, the mRNA expression of $TNF-{\alpha}$, $IL-1{\beta}$, IL-6, iNOS, and COX-2 were decreased significantly in a dose-dependent manner (P < 0.05). The concentrations of $PGE_2$ and NO decreased according to the lycopene concentration (P < 0.05). The protein expressions of $NF-{\kappa}B$ and JNK were decreased significantly according to lycopene concertation (P < 0.05). CONCLUSIONS: Lycopene restrains $NF-{\kappa}B$ and JNK activation, which causes inflammation, and suppresses the expression of $TNF-{\alpha}$, $IL-1{\beta}$, IL-6, COX-2, and iNOS in SW480 human colorectal cancer cells.

• Journal of Cancer Prevention
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• v.23 no.4
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• pp.170-175
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• 2018

Background: Human hepatocellular carcinoma (HCC) is a common liver tumor and the main cause of cancer-related death. Tyrosine kinase inhibitors, such as imatinib and GNF5 which were developed to treat chronic myelogenous leukemia, regulate the progression of various cancers. The aim of this study was to confirm the anti-tumor activity of tyrosine kinase inhibitors through regulation of S-phase kinase-associated protein 2 (Skp2), an important oncogenic factor in various cancer cells, in human hepatocarcinoma SK-HEP1 cells. Methods: Cell viability and colony formation assays were conducted to evaluate the effects of imatinib, GNF5 and GNF2 on the growth of SK-HEP1 cells. Using immunoblot analysis, we assessed change of the activation of caspases, PARP, Akt, mitogen-activated protein kinases, and Skp2/p27/p21 pathway by imatinib and GNF5 in SK-HEP1 cells. Using sh-Skp2 HCC cells, the role of Skp2 in the effects of imatinib and GNF5 was evaluated. Results: Imatinib and GNF5 significantly inhibited the growth of SK-HEP1 cells. Treatment of imatinib and GNF5 decreased Skp2 expression and Akt phosphorylation, and increased the expression of p27, p21, and active-caspases in SK-HEP1 cells. In sh-Skp2 HCC cells, cell growth and the expression of Skp2 were inhibited by more than in the mock group treated with imatinib and GNF5. Conclusions: These results suggest that the anti-growth activity of tyrosine kinase inhibitors may be associated with the regulation of p27/p21 and caspases through Skp2 blockage in HCC cells.

• Journal of Ginseng Research
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• v.33 no.1
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• pp.26-32
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• 2009

Diabetic nephropathy is associated with the dysfunction of proximal tubule cells. Insulin-like growth factor 1(IGF-I) has also been considered to play an important role in the development of diabetic nephropathy. Ginsenosides have been used as a remedy for diabetes in Asian countries. Therefore, we examined the preventive effect of ginsenosides against high glucose-induced alteration of IGF-I secretion in the primary cultured proximal tubule cells. In present study, Ginseng saponin (GS) completely blocked high glucose-induced stimulation of IGF-I secretion in proximal tubule cells, whereas panaxatriol (PI) and panaxadiol (PD) partially suppressed. In addition, high glucose stimulated cAMP formation and protein kinase C(PKC) activity from cytosolic to membrane fraction. GS completely prevented high glucose-induced stimulation of cAMP and PKC activity while PT and PD partially did. Furthermore, high glucose-induced stimulation of IGF-I was blocked by the treatment of PKI (protein kinase A inhibitor) and bisindolylmaleimide I (protein kinase C inhibitor). In conclusion, GS prevented high glucose-induced dysfunction of proximal tubule cells.