• BMB Reports
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• v.30 no.2
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• pp.119-124
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• 1997

Transforming growth $factor-{\beta}\;(TGF-{\beta})$ is a multifunctional polypeptide that exerts biological roles including cell proliferation, differentiation, extracellular matrix deposition and apoptosis in many different cell types. $TGF-{\beta}$, although known as a negative growth regulator, has not been tested in human embryo lung (HEll cells. This study attempts to understand the role of $TGF-{\beta}$ on growth control of HEL cells in relationship to tyrosine phosphorylation pattern of cellular proteins. In density-arrested HEL cells treated with $TGF-{\beta}$, analysis of Western immunoblot showed induction of tyrosine phosphorylation of two major cellular proteins (15 kDa and 45 kDa). In normal proliferating HEL cells with different concentrations of serum, further analysis indicated that the increase in tyrosine phosphorylation of a 45 kDa protein was regulated in serum concentration-dependent manner. However, in proliferating HEL cells treated with $TGF-{\beta}$, tyrosine phosphorylation of 45 kDa was down-regulated. Calcium involvement in the regulation of tyrosine phosphorylation of 45 kDa and 15 kDa proteins was also examined. Tyrosine phosphorylation of 15 kDa protein but not of 45 kDa protein was regulated by exogenous calcium. The level of tyrosine phosphorylation of 15 kDa protein was low at reduced caclium concentration and high at elevated caclium concentration. $TGF-{\beta}$ reversed the pattern of tyrosine phosphorylation of 15 kDa protein. These results suggest that tyrosine phosphorylation of 45 and 15 kDa proteins in HEL cells may be controlled depending on the physiological status of the cells, i.e., low in arrested cells and high in proliferating cells. And the tyrosine phosphorylation of the two proteins appears to be down- or up-regulated by $TGF-{\beta}$.

• The Journal of Korean Society of Virology
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• v.26 no.1
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• pp.1-8
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• 1996

Human cytomegalovirus (HCMV) replication and $Ca^{2+}$ response in human cell lines of neuronal origin were investigated. SK-N-SH (neuroblastoma cells) and A172 cells (glioblastoma cells) were used. SK-N-SH cells were permissive for HCMV multiplication with a delay of one day compared to virus multiplication in human embryo lung (HEL) cells. The delay of HCMV multiplication in SK-N-SH cells appeared to be correlated with a delay in the $Ca^{2+}$ response. The cytoplasmic free $Ca^{2+}$ concentration ($[Ca^{2+}]_i$) began to increase at 12 h p.i. in HCMV-infected SK-N-SH cells, while $[Ca^{2+}]_i$ increase in HCMV-infected HEL cells was observed as early as 3 h p.i. On the whole, the level of the increase in $[Ca^{2+}]_i$ in SK-N-SH cells was about 30% of that in HEL cells. On the other hand, in A172 cells infected with HCMV, neither production of infectious virus nor detectable increase in $[Ca^{2+}]_i$ was observed. Treatment with TPA of HCMV-infected SK-N-SH cells resulted in $[Ca^{2+}]_i$ increase at 6 h p.i. The stimulatory effect of TPA on HCMV- induced $[Ca^{2+}]_i$ increase continued until 12 h p.i., but TPA failed to stimulate the $Ca^{2+}$ response in SK-N-SH cells at 24 h p.i., suggesting that the effect of TPA had disappeared in SK-N-SH cells at that time point. In conclusion, SK-N-SH cells are permissive for HCMV replication and the delay in $Ca^{2+}$ response may be a consequence of the lower responsiveness of SK-N-SH cells than HEL cells to HCMV infection.

• Korean Journal of Microbiology
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• v.31 no.1
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• pp.72-78
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• 1993

Since the 'promoter/enhancer region of the major immediate early (IE) ~ene of human cytomegalovirus (HCMV) contains the cyclic AMP (cAMP) response element (CRE) consensus sequence, it was reasonable to hypothesize that cAMP might affect HCMV replication. Cyclic AMP modulating drugs such as 8-bromoadenosine 3',5'-cyclic monophosphate (BrA), and papaverine were used to affect the intracellular levels of cAMP, and the effects of the drugs on HCMV replication were studied. While papaverine effectively inhibited HCMV multiplication and DNA synthesis, BrA exerted little effect on the production of infectious HCMV yields. The synthesis of DNA in HCMV-infected cells appeared to be stimulated by BrA In order to understand the effect of cAMP on the expression of HCMV major IE gene, plasmid (pCMVIE/CAT) containing a reporter gene driven by HCMV IE promoter was transfected into either permissive human embryo lung (HEL) cells or nonpermissive cells. PL,Javerine, which has been reported to block the HCMV-induced increase in cAMP, reduced the expression of pCMVIE/CA T in permissive HEL cells. Treatment of transfected cells with BrA increased the expression of HCMV major IE promoter not only in HEL cells, but also in nonpermissive HeLa and Vero cells. Therefore, it seems that the expression of HCMV major IE gene is regulated by cAMP.

• KSBB Journal
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• v.22 no.2
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• pp.67-72
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• 2007

This study investigates the optimal method of administrating 5-aminolevulinic acid (5-ALA) in the context of fluorescence detection by analyzing protoporphyrin IX (PpIX) fluorescence in the cultured normal and cancer cells. 5-ALA was injected as a photosensitizer to the lung cancer cells (A549, NCI-H460) and normal lung cells (HeI299). Hel299, A549, and NCI-H460 cells were incubated with various concentrations of 5-ALA ($0\sim800{\mu}g/mL$). The accumulation of PpIX induced by 5-ALA was observed in A549, NCI-H460 and Hel299 cells. The cell viability was estimated by means of the MTT assay. Formation of PpIX was measured by fluorescence spectroscopy. Especially, formation of PpIX in cancer cells was higher than normal cells. This study suggests that the difference of PpIX induced in normal and cancer cells treated with 5-ALA may use by means of fluorescence diagnosis for cancer.

• IMMUNE NETWORK
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• v.20 no.4
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• pp.35.1-35.13
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• 2020

Antigen delivery systems play critical roles in determining the quality and quantity of Ab responses in vivo. Induction of protective antibodies by B cells is essential in the development of vaccines against infectious pathogens, whereas production of IgE antibodies is prerequisite for investigation of allergic responses, or type 1 hypersensitivity reactions. Virus-like particles (VLPs) are efficient platforms for expression of proteins of interest in highly repetitive manners, which grants strong Ab responses to target antigens. Here, we report that delivery of hen egg lysozyme (HEL), a model allergen, through VLP could provoke strong HEL specific IgE Ab responses in mice. Moreover, acute allergic responses were robustly induced in the mice sensitized with VLPs that express HEL, when challenged with recombinant HEL protein. Our data show that antigen delivery in the context of VLPs could function as a platform for sensitization of mice and for subsequent examination of allergic reactions to molecules of interest.

• Natural Product Sciences
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• v.3 no.1
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• pp.19-28
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• 1997

Constitutive cyclooxygenase (COX-I) is present in cells under physiological conditions, whereas inducible cyclooxygenase (COX-II) is induced by some cytokines, mitogens, and endotoxin presumably in pathological conditions such as inflammation. We have evaluated the inhibitory effects of solvent fractionated extracts of natural products on the activities of COX-I and COX-II. Oxygen uptake COX assay was performed, as a primary screening from the tissue extracts of bovine seminal vesicles (BSV), by monitoring the initial rate of oxygen uptake using an oxygen electrode. Additionally, we evaluated plant extracts for the inhibitory effects of COX-I (in HEL cells) and COX-II (in lipopolysaccharide activated J774A.1 macrophages) using thin layer chromatography of prostanoids produced from $^{14}C-labelled$ arachidonic acid (AA). The use of such models of COX-I and COX-II assay will lead to the identification of specific inhibitors of cyclooxygenases with presumably less side effects than present therapies. Inhibitory effects of 50 kinds of plant extracts on the COX-I and COX-II activities were determined and the active fractions were found in the ethyl acetate fractions of Dryopteris crassirhizoma (roots), Amomum cardamomum (roots), Triticum aestivum (seeds), Perilla sikokiana (leaves), Anemarrhena asphodeloides (roots). Especially, the ethyl acetate fraction of Dryopteris crassirhizoma (roots), which exhibited the strong inhibition against BSV COX $(IC_{50},\;65.4\;{\mu}g/ml)$, COX-I $(IC_{50},\;8.5\;{\mu}g/ml)$, and COX-II $(IC_{50},\;17.2\;{\mu}g/ml)$, is under investigation to isolate active principles using activity-guided fractionation method.

• BMB Reports
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• v.48 no.12
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• pp.691-695
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• 2015

We report that phytosphingosine, a sphingolipid found in many organisms and implicated in cellular signaling, promotes megakaryocytic differentiation of myeloid leukemia cells. Specifically, phytosphingosine induced several hallmark changes associated with megakaryopoiesis from K562 and HEL cells including cell cycle arrest, cell size increase and polyploidization. We also confirmed that cell type specific markers of megakaryocytes, CD41a and CD42b are induced by phytosphingosine. Phospholipids with highly similar structures were unable to induce similar changes, indicating that the activity of phytosphingosine is highly specific. Although phytosphingosine is known to activate p38 mitogen-activated protein kinase (MAPK)-mediated apoptosis, the signaling mechanisms involved in megakaryopoiesis appear to be distinct. In sum, we present another model for dissecting molecular details of megakaryocytic differentiation which in large part remains obscure.

• Proceedings of the Korean Society of Applied Pharmacology
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• 2003.11a
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• pp.81-81
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• 2003

The present study was taken to examine the inhibitory effect of extracts of Scytosiphon lomentaria, a marine alga growing in Jeju Island, on the growth of cancer cells and to develop an anti-cancer agent using components of S. lomemtaria. The effect was observed by the measurement of metabolic activity using colorimetric 3-(4,5-dimethylthiazol)-2,5-diphenyltetrazolium bromide (MTT) assay. In results, crude extract of this alga markedly inhibited the growth of leukemia cell lines such as HL-60 and KG-1, but could scarcely inhibit the growth of normal cells (HEL299) and adenocarcinoma cells (SNU-16 and HCT-I5). When HL-60 cells were treated with the extract, DNA fragmentation and the increase of proportion of sub-G1 hypodiploid cells were observed. Therefore, the inhibitory effect of S. lomemtaria on the growth of HL-60 cells seems to arise from the induction of apoptosis. In order to understand the mechanism of apoptosis inducton by S. lomemtaria, we examined the changes of Bcl-2 and Bax expression. The extract reduced Bcl-2, an anti-apoptotic protein, but increased Bax, a pro-apoptotic protein in a dose-dependent manner. When we examined the activation of caspase-3, an effector of apoptosis, the expression of active form(19 kDa) of caspase-3 was increased and the increase of their activities was demonstrated by the cleavage of poly(ADP-ribose)polymerase, a substrate of caspase-3, to 85 kDa. The results indicate that extract of S. lomentaria induces the apoptosis of HL-60 cells via the down-regulation of Bc1-2 and the activation of caspases.

• Korean Journal of Medicinal Crop Science
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• v.12 no.1
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• pp.36-42
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• 2004

The immune activation and anticancer activities of the water and ethanol extracts from Artemisia capillaris Thunb. were studied. The growth of human hepatocarcinoma and human gastric cancer cell was inhibited by the addition of $1.0\;mg/m{\ell}$ of the water extract, by about 77% and 95%, respectively. The growth of human breast cancer cells was also inhibited by addition of $0.5\;mg/m{\ell}$ of both water and ethanol extracts by 88%. The growth of human normal lung cell, HEL299 was inhibited by 15% indicating very low cytotoxicity of both extracts. Overall selectivity of the both extracts on several human cancer cell line was over 2.5. The growth of both human B and T cells was enhanced up to 1.6 to 2.1 times by adding the ethanol extracts. The secretion of cytokines, $TNF-{\alpha}$ and IL-6, from human B cells was also increased showing $68\;pg/m{\ell}$ and $67\;pg/m{\ell}$, respectively, compared to $35{\sim}40\;pg/m{\ell}$ of the control. In terms of the immune activity, there was not much difference between water and ethanol extracts of Artemisia capillaris Thunb. It implies that the extraction solvent could not differ the biological activities of the extracts. Based on these results, Artemisia capillaris Thunb. can be developed into a potentially useful cancer chemoprentive agent.

• YAKHAK HOEJI
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• v.52 no.1
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• pp.1-6
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• 2008

The present study investigated the antiproliferative effects of Crnum asiaticum var. japonicum against HL-60 human leukemia cells. The 80% MeOH extract or several solvent fractions from the C. asiaticum inhibited the growth of HL-60 cells, whereas the growth of HEL-299 cells, human embryonic lung fibroblast, was scarcely inhibited. When the HL-60 cells were treated with the $CHCl_3$ fraction, the BuOH fraction, the EtOAc fraction and the $H_2O$ fraction, DNA ladder, chromatin condensation and increase of sub-G1 hypodiploid cells were observed. Furthermore, the $CHCl_3$ fraction and the BuOH fraction reduced Bc1-2 mRNA level, whereas Bax mRNA level was increased. These results suggest that the inhibitory effect of C. asiaticum on the growth of the HL-60 cell might be mediated through the induction of apoptosis via the down-regulation of Bc1-2. Taken together, components of C. asiaticum might have a therapeutic potential for the treatment of human leukemia.