• Journal of Korean Dental Science
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• v.16 no.2
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• pp.172-181
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• 2023

Purpose: To investigate the effect of epidermal growth factor (EGF) with collagen matrix (CM) for increasing gingival thickness. Materials and Methods: In five mongrel dogs, bilateral gingival defects were surgically made on the maxillary canines. After two months, either a subepithelial connective tissue graft (group SCTG) or CM with EGF (0.1 ug/ml, group EGF) was grafted, and the flap was coronally positioned to cover the graft materials. The animals were sacrificed after three months. Intraoral scanning was performed for soft tissue analysis. Histologic and histomorphometric analyses were performed. Result: Two animals exhibited wound dehiscence during the healing phase, leaving three for analysis. No statistically significant difference was found in soft tissue changes (P>0.05). The level of gingival margin (GM) increased in both groups (1.02±0.74 mm in group SCTG vs. 1.24±0.83 mm in group EGF). Linear increases at the GM pre-augmentation in the soft tissue profile were 1.08±0.58 mm in group SCTG and 0.96±0.73 mm in group EGF. Histomorphometric parameters (keratinized tissue height, tissue thickness, and rete peg density) were not significantly different between the groups (P>0.05). Conclusion: EGF loaded onto CM led to comparable gingival phenotype enhancement to SCTG.

• Clinical and Experimental Reproductive Medicine
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• v.22 no.2
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• pp.163-170
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• 1995

Growth factors (GFs) produced by the embryo or by the maternal reproductive tract have been reported to regulate the embryonic development and differentiation. Among GFs, EGF as a mitogen plays a role in mitosis and functional differentiation of trophectoderm cells in mouse. The present study was carried out to investigate the effect of EGF on development of mouse embryos and to localize EGF in the mouse oocytes and embryos, which has been reported to be detected in the reproductive tract in mammals. To investigate the effect of EGF on the development of the embryo, mouse 2-cell embryos were cultured to blastocysts stage in Ham's F10 medium, treated with EGF(10-50 ng/ml) for 72 hrs. Immunocytochemistry was performed from oocyte to blastocyst stage with anti-EGF and anti-Mouse IgG, in order to determine the stage which EGF would be expressed in mouse. Exogenous EGF (more than 10 ng/ml) in the culture medium improved the developmental and hatching rates in the mouse embryos. As a result of immunocytochemistry, the embryonic EGF was expressed after the late 4-cell stage. EGF is thought to enhance preimplantation embryonic development and hatching. Exogenous EGF in the culture medium is thought to activate EGF receptor in the late 4-cell embryos and to enhance blastulation and hatching in mouse embryos. It is concluded that EGF enhances the developmental and hatching rates in the mouse embryos.

• Archives of Pharmacal Research
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• v.19 no.6
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• pp.490-496
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• 1996

Naphtodianthrone hypericin produced a potent antitumor activity in vitro against several tumor cells. However, it did not show any cytotoxicity on normal cells such as Macaccus rheus monkey kidney cells (MA-104) and primary cultured rat hepatocytes up to $500{\mu}M$ concentration. Hypericin added to A431 human epidermoid carcinoma cell membrane inhibited the autophosphorylation of the epidermal growth factor (EGF) receptor and the tyrosine phosphorylation of RR-SRC peptide catalyzed by an EGF-receptor. Similarly, treatment of the A431 cells with hypericin inhibited the tyrosine phosphorylation of EGF-dependent endogenous EGF-receptor by western blotting analysis. Hypericin also inhibited the T cell PTK, $P56^{lck}$, in a dose-dependent fashion with an $IC_{50}=5{\mu}M$. The tyrosine phosphorylation, on RR-SRC peptide and EGF-induced receptor autophosphorylation, either in vitro or in intact cells was inhibited by hypericin at the same concentration as that in A431 cell proliferation. These data suggest that hypericin directly inhibits EGF-receptor and $P56^{lck}$ PTK activity in vitro and can mediate such action in vivo.

• Journal of Life Science
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• v.17 no.2 s.82
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• pp.185-191
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• 2007

Akt/PKB plays pivotal roles in many physiological responses such as proliferation, differentiation, apoptosis, and angiogenesis. Here we show that tyrosine phosphorylation of Akt/PKB is essential for the subsequent phosphorylation at $Thr^{\308}$. Tyrosine phosphorylation of Akt/PKB was induced by stimulation of COS-7 cells with epidermal growth factor receptor (EGF) and its phosphorylation was significantly enhanced by constitutive targeting of Akt/PKB to the plasma membrane by myristoylation. Interestingly, incubation of affinity purified Myc-tagged Akt/PKB with purified EGF receptor resulted in tyrosine phosphorylation as well as $Ser^{\473}$ phosphorylation of Akt/PKB. In addition, tyrosine-phosphorylated Akt/PKB could directly associate with activated EGF receptor in vitro. Finally, alanine mutation at putative tyrosine phosphorylation site $(Tyr^{\326})$ abolished EGF induced $Thr^{\308}$ phosphorylation of wild type as well as constitutively active form of Akt/PKB. Given these results we suggest here that direct tyrosine phosphorylation of Akt/PKB by EGF receptor could be another mechanism of EGF-induced control of many physiological responses.

• Reproductive and Developmental Biology
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• v.30 no.3
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• pp.163-167
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• 2006

The purpose of the present study was to establish culture conditions for the in vitro study of the neonatal piglet Sertoli cell. Isolation for the culture of Sertoli cell was established using collagenase and pancreatin digestion of testicular tissues. The effects of various culture media, fetal bovine serum(FBS), follicular stimulating hormone(FSH), epidermal growth factor(EGF) and insulin-transferrin-sodium selenite(ITS) on growth of neonatal piglet Sertoli cells were investigated. The mitogenic effects of Dulbecco's modified Eagle's medium+Ham's F-12 medium was higher than other media used in this experiment. The addition of 1% FBS in cultures was necessary for attachment of Sertoli cell clusters. However, except FBS and EGF, FSH and ITS did not stimulate Sertoli cell proliferation. When Sertoli cells isolated from neonatal piglets were cultured in Dulbecco's modified Eagle's medium+Ham's F-12 medium supplemented with 1% FBS, FSH EGF and ITS, the yield and plating efficiency of Sertoli cells were largely increased. Confluency of Sertoli cells was reached as early as 4 days of culture. The method described here reduces or eliminates many of the drawbacks of the conventional procedures used to isolate and culture of Sertoli cells, thus providing a useful tool in studies of growth kinetics and regulation of cell proliferation in vitro.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.6
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• pp.793-798
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• 2006

The quality characteristics of semen are important indicators of the fertility of a boar. Development of genetic markers for the semen quality in boars will be beneficial to the improvement of porcine fertility. We investigated the relationship between the polymorphisms of epidermal growth factor (EGF), prostaglandin-endoperoxide synthase 2 (PTGS2) and prolactin receptor (PRLR) genes, and semen quality traits in boars. The genomic DNA of 233 boars (157 Duroc and 86 Landrace) from a central testing station was subjected to genotyping for surveying gene frequency. The EGF, PTGS2 and PRLR genotypes were determined using the restriction fragment length polymorphism method. Thirty-seven normal, mature Duroc boars from an AI center were also genotyped and their semen quality traits were collected. The effect of genotype on semen quality traits was analyzed by the least-squares means method using data corrected for season. The frequencies of the AA genotype of EGF, PTGS2 and PRLR in Duroc boars were 0.14, 0.01 and 0.66, respectively. In Landrace, the frequencies of the AA genotype were 0.03, 0.09 and 0.62, respectively. Boars with the BB genotype in EGF, with the AB genotype in PTGS2 and with the AA genotype in PRLR had significantly better semen quality with a higher percentage of normal sperm and a lower percentage of immature sperm than those with other genotypes. These findings imply that polymorphisms of EGF, PTGS2 and PRLR genes might be used as markers for improving the semen quality of boars.

• Annals of Pediatric Endocrinology and Metabolism
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• v.23 no.4
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• pp.204-209
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• 2018

Purpose: Growth hormone transduction defect (GHTD) is characterized by severe short stature, impaired STAT3 (signal transducer and activator of transcription-3) phosphorylation and overexpression of the cytokine inducible SH2 containing protein (CIS) and p21/CIP1/WAF1. To investigate the role of p21/CIP1/WAF1 in the negative regulation of the growth hormone (GH)/GH receptor and Epidermal Growth Factor (EGF)/EGF Receptor pathways in GHTD. Methods: Fibroblast cultures were developed from gingival biopsies of 1 GHTD patient and 1 control. The protein expression and the cellular localization of p21/CIP1/WAF1 was studied by Western immunoblotting and immunofluorescence, respectively: at the basal state and after induction with $200-{\mu}g/L$ human GH (hGH) (GH200), either with or without siRNA CIS (siCIS); at the basal state and after inductions with $200-{\mu}g/L$ hGH (GH200), $1,000-{\mu}g/L$ hGH (GH1000) or 50-ng/mL EGF. Results: After GH200/siCIS, the protein expression and nuclear localization of p21 were reduced in the patient. After successful induction of GH signaling (control, GH200; patient, GH1000), the protein expression and nuclear localization of p21 were reduced. After induction with EGF, p21 translocated to the cytoplasm in the control, whereas in the GHTD patient it remained located in the nucleus. Conclusion: In the GHTD fibroblasts, when CIS is reduced, either after siCIS or after a higher dose of hGH (GH1000), p21's antiproliferative effect (nuclear localization) is also reduced and GH signaling is activated. There also appears to be a positive relationship between the 2 inhibitors of GH signaling, CIS and p21. Finally, in GHTD, p21 seems to participate in the regulation of both the GH and EGF/EGFR pathways, depending upon its cellular location.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.6
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• pp.542-549
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• 2021

The purpose of this study was to provide an economical and easy preparation method for recombinant human epidermal growth factor (rhEGF) without the need for an expensive enzyme to cleave the fusion part. However, the N-terminal fusion part is still useful for affinity chromatography. The hEGF is an important hormone in cell growth and proliferation in humans, and many studies on the expression and purification of this protein have been reported. In the present study, the hEGF gene was designed to be optimized with the E. coli codon usage preference and to contain Asn-Gly at the N-terminus of the protein. The gene was inserted into pRSET_A, an E. coli expression vector, and transformed into E. coli BL21 (DE3). The recombinant fusion protein was successfully co-expressed with pG-Tf2, a chaperone vector, in E. coli and purified by Ni-NTA column chromatography. The rhEGF was then released by hydroxylamine treatment and confirmed by SDS-PAGE. ELISA analysis showed that the activity of the free rhEGF was more than 92% similar to that of commercial EGF. The biological activity of the rhEGF was confirmed by a cell proliferation test with human skin fibroblasts.

• Korean Journal of Veterinary Research
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• v.43 no.2
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• pp.211-218
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• 2003

Human ovarian cancerous cells survive in a way that they trigger the nucleotide excision repair (NER) or double-strand DNA repair (dsDNA) repair mechanism to show resistance to anticancer drugs and activate many kinds of repair protein, thus removing damaged DNAs. Two experiments on the PA-1 human ovarian teratocareinoma cell line that hardly has any expression of epidermal growth factor receptor (EGFR) were conducted in the study; first, EGF-R was transfected and its receptor was obtained. The receptor was investigated in terms of its mutual relations with many kinds of protein concerning NER or dsDNA repair. Second, it was examined what kind impact cisplatin and adriamycin had on the effects of EGF-R over the PA-1 cell line lacking EGF-R. When being administered with cisplatin and adriamycin, Hey and Hey C2 cell lines showed a high level of resistance while PA-1 cell line a high level of sensitivity. Hey and Hey C2 cell lines that are resistant against anticancer drugs exhibited a high level of EGF-R expression while PA-1 cell line that is sensitive to them did a much lower level of the expression. When PA-1 cell line was transfected for the expression of DNA adduct and EGF-R, it showed a higher level of resistance compared to the control group. There was no difference in the expression of DNA repair proteins (DNA- dependent protein kinase, Ku70, and Ku80) between Hey and the PA-1 cell lines. The results indicate that the Hey cell line that is resistant against cisplatin and adriamycin works along the signaling system responding to the changes of EGF-R while the PA-1 cell line that is sensitive to both of them does to the lack of EGF-R.

• Microbiology and Biotechnology Letters
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• v.26 no.1
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• pp.61-67
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• 1998

Recombinant human epidermal growth factor (rhEGF) was produced by E. coli BL2l (DE3) harboring a plasmid pYHB101. The production of rhEGF was 44.5 mg/L when the E. coli BL2l (pYHB101) was cultured at 27$^{\circ}C$ for 48 hr in the modified MBL medium containing 10 $\mu\textrm{g}$/L glucose with 10 $\mu\textrm{m}$ IPTG/lactose induction at 2 hr after inoculation. It was shown that lactose is able to induce the rhEGF expression of E. coli BL2l (pYHB101) with the same efficiency as IPTG. In the batch culture system, when induced with 10 $\mu\textrm{m}$ lactose, E. coli BL2l (pYHB101) produced maximum 45 mg/L of the rhEGF at 28 hr culture in the modified MBL medium containing 10 g/L glucose. In the semi-fed batch culture system, the volumetric yield was 160 mg/L when the culture was added with 0.5% (w/v) lactose and 0.25% (w/v) yeast extract in the late logarithmic phase and 94.3% of rhEGF was secreted as soluble form. However, when the culture was added with them in the early logarithmic phase, the volumetric yield was 120 mg/L and 20.9% of rhEGF was found in cytoplasmic insoluble aggregates. It was found that the addition time of lactose was important for production of soluble rhEGF from E. coli BL21 (pYHB101).