• Preventive Nutrition and Food Science
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• v.3 no.1
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• pp.85-91
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• 1998

To investigate the effects of antioxidative vitamins in combination with various fatty acids on breast cancer cell proliferation, MDA-MB231 human breast cancer cells were cultured for 3 days in the serum-free Iscove's modified Dulbecco's medium (IMDM) supplemented with 1.25mg/ml delipidized bovine serum albumin and 10㎍/ml insulin. Alpha-tocopherol, ascorbic acid or both vitamins were added to the medium at the concentrations of 10 and 50μM in the presence of 3μg/ml of oletic(Oa), linoleic(LA) α-linoleinic(LNA) and docosahexaenoic acid(DHA). Cell growth was reduced significantly by α-tocopherol in a dose-dependent manner, but not affected by ascorbic aicd. The four different fatty acids did not have significant effects on cell growth, although DHA exerted inhibitory effect on the growth after 1 day. However, the each fatty acid was well incorporated into celluar lipid as such or elongated forms. Addition of α-tocopherol remarkably increased its celluar contents and reduced cellular levels of thiobarbituric acid substances (TBARS) that were elevated notably in the presence of DHA in the culture media. But ascorbic acid addition did not change much of either cellular α-tocopherol or TBARS contents. northern blot hybridization showed that tumor supressor gene ρ53 was most highly expressed by the combination of ρ-tocopherol and DHA in 8 hours of cell culture. In conclusion , the growth inhibitory effect of vitamin E suggests that breast cancer cell proliferation is reduced by the mechanism other than cytotoxicity of lipid peroxide and it is related to expressionof tumor supprosser gene p53, that can be increased by both vitamin E and n-3 fatty acid, DHA.

• Molecules and Cells
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• v.44 no.1
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• pp.13-25
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• 2021

Apoptosis and compensatory proliferation, two intertwined cellular processes essential for both development and adult homeostasis, are often initiated by the mis-regulation of centrosomal proteins, damaged DNA, and defects in mitosis. Fly Anastral spindle 3 (Ana3) is a member of the pericentriolar matrix proteins and known as a key component of centriolar cohesion and basal body formation. We report here that ana3m19 is a suppressor of lethality induced by the overexpression of Sol narae (Sona), a metalloprotease in a disintegrin and metalloprotease with thrombospondin motif (ADAMTS) family. ana3m19 has a nonsense mutation that truncates the highly conserved carboxyl terminal region containing multiple Armadillo repeats. Lethality induced by Sona overexpression was completely rescued by knockdown of Ana3, and the small and malformed wing and hinge phenotype induced by the knockdown of Ana3 was also normalized by Sona overexpression, establishing a mutually positive genetic interaction between ana3 and sona. p35 inhibited apoptosis and rescued the small wing and hinge phenotype induced by knockdown of ana3. Furthermore, overexpression of Ana3 increased the survival rate of irradiated flies and reduced the number of dying cells, demonstrating that Ana3 actively promotes cell survival. Knockdown of Ana3 decreased the levels of both intra- and extracellular Sona in wing discs, while overexpression of Ana3 in S2 cells dramatically increased the levels of both cytoplasmic and exosomal Sona due to the stabilization of Sona in the lysosomal degradation pathway. We propose that one of the main functions of Ana3 is to stabilize Sona for cell survival and proliferation.

• YAKHAK HOEJI
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• v.44 no.4
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• pp.340-346
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• 2000

Cervical cancer is one of the leading causes of female death from cancer worldwide with about 500,000 deaths per year. A strong association between certain human papilloma viruses (HPV types 16 and 18) and cervical cancer has been well known. An extract of natural products, named as Somatid, has been used to investigate whether this agent has the ability of inhibiting the oncogenes E6 and E7 of HPV type 16. This Somatid inhibited the proliferation of human cervical cancer cell lines (C-33A, SiHa, CaSki) and HaCaT keratinocytes in a dose response manner, In vitro binding assay and ELISA showed that Somatid inhibited the in vitro biding of E6 and E6AP which are essential for the binding and degradation of the tumor suppressor p53. In addition, Somatid inhibited the in vitro binding of E7 and Rb which is essential tumor suppressor for the control of cell cycle. The levels of mRNA for E6 and E7 were also decreased by Somatid. Our data suggested that Somatid inhibited the oncogenecity of E6 and E7 of HPV 16 type, thus can be used as a putative anti-HPV agent for the treatment of cervical carcinomas caused by HPV.

• Biomolecules & Therapeutics
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• v.27 no.5
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• pp.474-483
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• 2019

Vascular endothelial growth factor (VEGF) plays a pivotal role in pathologic ocular neovascularization and vascular leakage via activation of VEGF receptor 2 (VEGFR2). This study was undertaken to evaluate the therapeutic mechanisms and effects of the tetrapeptide Arg-Leu-Tyr-Glu (RLYE), a VEGFR2 inhibitor, in the development of vascular permeability and choroidal neovascularization (CNV). In cultured human retinal microvascular endothelial cells (HRMECs), treatment with RLYE blocked VEGF-A-induced phosphorylation of VEGFR2, Akt, ERK, and endothelial nitric oxide synthase (eNOS), leading to suppression of VEGF-A-mediated hyper-production of NO. Treatment with RLYE also inhibited VEGF-A-stimulated angiogenic processes (migration, proliferation, and tube formation) and the hyperpermeability of HRMECs, in addition to attenuating VEGF-A-induced angiogenesis and vascular permeability in mice. The anti-vascular permeability activity of RLYE was correlated with enhanced stability and positioning of the junction proteins VE-cadherin, ${\beta}$-catenin, claudin-5, and ZO-1, critical components of the cortical actin ring structure and retinal endothelial barrier, at the boundary between HRMECs stimulated with VEGF-A. Furthermore, intravitreally injected RLYE bound to retinal microvascular endothelium and inhibited laser-induced CNV in mice. These findings suggest that RLYE has potential as a therapeutic drug for the treatment of CNV by preventing VEGFR2-mediated vascular leakage and angiogenesis.

• Molecules and Cells
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• v.26 no.5
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• pp.468-473
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• 2008

Low-density lipoprotein (LDL) induces cell proliferation in human aortic smooth muscle cells (hAoSMCs), which may be involved in atherogenesis and intimal hyperplasia. Recent studies have demonstrated that $Cl^-$ channels are related to vessel cell proliferation induced by a variety of stimuli. In this study, we investigated a potential role of $Cl^-$ channels in the signaling pathway of LDL effects on hAoSMC proliferation with a focus on the activation of Erk1/2-PI3K/Akt and the subsequent upregulation of Egr-1. $Cl^-$ channel blockers, DIDS, but neither NPPB nor Furosemide, completely abolished the LDL-induced DNA synthesis and cell proliferation. Moreover, DIDS, but not NPPB, significantly decreased LDL-stimulated $Cl^-$ concentration, as judged by flow cytometry analysis using MQAE as a $Cl^-$-detection dye. DIDS pretreatment completely abolished the activation of Erk1/2 and PI3K/Akt in a dose-dependent manner that is the hallmark of LDL activation, as judged by Western blot and proliferation assays. Moreover, pretreatment with DIDS ($Cl^-$ channel blockers) but not LY294002 (PI3K inhibitors) completely abolished the LDL-induced upregulation of Egr-1 to the same extent as PD98059 (MEK inhibitors to inhibit Erk), as judged by Western blot and luciferase reporter assays. This is the first report, to our knowledge, that DIDS-sensitive $Cl^-$-channels play a key role in the LDL-induced cell proliferation of hAoSMCs via the activation of Erk1/2 and PI3K/Akt and the upregulation of Egr-1.

• Journal of Life Science
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• v.25 no.4
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• pp.397-405
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• 2015

S-allylcysteine (SAC) is a water-soluble organosulfur compound abundant in the aged garlic extract and has been drawing attention as a diet-derived alternative agent not only for the effects of anti-oxidation and anti-inflammation but also for the prevention and treatment of various types of cancer. However, there is no report about the anticancer effects of SAC on cervical cancer cells. The aim of this study was to analyze the inhibitory effects of SAC on cell proliferation of cervical cancer cell line, HeLa and to examine its effects on the apoptosis and cell cycle as the cellular mechanisms of anti-proliferation. For this, we examined effects of different concentrations of SAC on cell proliferation according to treatment periods. Treatment with SAC not only induced morphological changes but also resulted in the reduction of cell viability and the inhibition of concentration- and time-dependant cell proliferation of HeLa. Furthermore, SAC also induced fragmentation of DNA in both DNA fragmentation and TUNEL assays, and induced cell cycle arrest at the G₂/M phase in cell cycle analysis. These results suggest that SAC inhibits proliferation of HeLa at least in part through the induction of apoptosis and the cell cycle arrest.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.10a
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• pp.628-631
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• 2014

Recently, the proliferation of new applications, e.g., mobile TV, Internet gaming, large file transfer, and the various of user terminals, e.g., smart phones and notebooks, has dramatically increased user traffic and network load. In order to meet this traffic growth, vendors and cellular operators are working on the development of new technologies and cellular standards. Within them, small cell deployment has been heralded as one of most promising way to increase both coverage and capacity of future cellular network. Small cell technology enables to improve capacity of cellular radio network by tight cooperation between small cell and macro cell in multi-tier network where small cells are densely deployed within macro cell coverage. In this paper, we describe the deployment scenarios for cooperation between macro cell and small cells and state-of-the-art technologies related to dense small cell deployment. Then, we also provide design principles and standardization trends for small cell enhancement in 3GPP.

• BMB Reports
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• v.52 no.3
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• pp.220-225
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• 2019

We have identified a mechanism to diminish the proliferative capacity of cells during cell expansion using human adipose-derived stromal cells (hAD-SCs) as a model of replicative senescence. hAD-SCs of high-passage numbers exhibited a reduced proliferative capacity with accelerated cellular senescence. Levels of key bioactive sphingolipids were significantly increased in these senescent hAD-SCs. Notably, the transcription of sphingosine kinase 1 (SPHK1) was down-regulated in hAD-SCs at high-passage numbers. SPHK1 knockdown as well as inhibition of its enzymatic activity impeded the proliferation of hAD-SCs, with concomitant induction of cellular senescence and accumulation of sphingolipids, as seen in high-passage cells. SPHK1 knockdown-accelerated cellular senescence was attenuated by co-treatment with sphingosine-1-phosphate and an inhibitor of ceramide synthesis, fumonisin $B_1$, but not by treatment with either one alone. Together, these results suggest that transcriptional down-regulation of SPHK1 is a critical inducer of altered sphingolipid profiles and enhances replicative senescence during multiple rounds of cell division.

• Biomolecules & Therapeutics
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• v.31 no.6
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• pp.629-639
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• 2023

Cardiovascular diseases (CVDs) are the most common cardiovascular system disorders. Cellular senescence is a key mechanism associated with dysfunction of aged vascular endothelium. Hyaluronic acid and proteoglycan link protein 1 (HAPLN1) has been known to non-covalently link hyaluronic acid (HA) and proteoglycans (PGs), and forms and stabilizes HAPLN1-containing aggregates as a major component of extracellular matrix. Our previous study showed that serum levels of HAPLN1 decrease with aging. Here, we found that the HAPLN1 gene expression was reduced in senescent human umbilical vein endothelial cells (HUVECs). Moreover, a recombinant human HAPLN1 (rhHAPLN1) decreased the activity of senescence-associated β-gal and inhibited the production of senescence-associated secretory phenotypes, including IL-1β, CCL2, and IL-6. rhHAPLN1 also downregulated IL-17A levels, which is known to play a key role in vascular endothelial senescence. In addition, rhHAPLN1 protected senescent HUVECs from oxidative stress by reducing cellular reactive oxygen species levels, thus promoting the function and survival of HUVECs and leading to cellular proliferation, migration, and angiogenesis. We also found that rhHAPLN1 not only increases the sirtuin 1 (SIRT1) levels, but also reduces the cellular senescence markers levels, such as p53, p21, and p16. Taken together, our data indicate that rhHAPLN1 delays or inhibits the endothelial senescence induced by various aging factors, such as replicative, IL-17A, and oxidative stress-induced senescence, thus suggesting that rhHAPLN1 may be a promising therapeutic for CVD and atherosclerosis.

• Journal of The Korean Society of Clinical Toxicology
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• v.21 no.2
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• pp.81-91
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• 2023

Purpose: Edible insect extracts have been used as an alternative source for medicinal supplements due to their significant antioxidative and anti-inflammatory activity. Recent studies have reported that anti-microbial peptides from insects have neuroprotective effects on dopamine toxins. The purpose of this study was to investigate the protective functions of mealworm (Tenebrio molitor) extract (MWE) on N-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced cellular toxicity in SH-SY5Y neuroblastoma cells. Methods: Cellular toxicity induced by the MPTP toxin and the impact of MWE on cell survival were analyzed using MTT assays. DAPI staining was performed to observe apoptotic phenomena caused by MPTP. Changes in caspase-3 activity and protein expression were observed using enzyme activity assays and western blot assays, respectively. Results: MWE exerted significant antioxidant activity, which was measured by both DPPH and ABTS radical assays, with a dose-dependent relationship. Furthermore, MWE resulted in cellular proliferation in SHSY5Y cells in a dose-dependent manner. Furthermore, MWE pretreatment significantly inhibited MPTP-induced cytotoxicity, with a dose-dependent relationship. The morphological characteristics of apoptosis and increased reactive oxygen species induced by MPTP were also significantly reduced by MWE pretreatment. Conclusion: MWE treatment significantly attenuated MPTP-induced changes in the levels of proteins associated with apoptosis, such as caspase-3 and PARP. These findings suggest that MWE exerts neuroprotective effects on human neuroblastoma SH-SY5Y cells subject to MPTP-induced dopaminergic neurodegeneration.