• Journal of Periodontal and Implant Science
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• v.26 no.4
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• pp.841-858
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• 1996

Epidermal growth factor(EGF) is one of polypeptide growth factors. EGF has been reported as a biological mediator which regulates activities of wound healing process including the cell proliferation, migration and metabolism. The purposes of this study is to evaluate the effects of EGF on the human periodontal ligament cells and human gingival fibroblast cells that promote regeneration of periodntal tissue. The mitogenic effects of epidermal growth factor on human periodontal ligament cells and human gingival fibroblasts were evaluated by determining the incorporation of 5-Bromo-2'-deoxy-uridine into DNA of the cells in a dose dependent manner. The prepared cells were the primary cultured gingival fibroblast and periodontal ligament cells from humans, the fourth or sixth subpassages were used in the experiments. Cells were seeded in DMEM containing 10% FBS. 1, 10, 50, 100, $200{\eta}g/ml$ and epidermal growth factor were added to the quiescent cells for 24 hours, 48 hours and 72 hours. They were labeled with $10\{mu}l/200{\mu}l$ 5-Bromo-2'-deoxy-uridine for the last 6 hours of each culture. The results of the five determinants were presented as mean and S.D.. The results were as follows : The DNA synthetic activity of human gingival fibroblasts were increased dose dependently by epidermal growth factor at 24 hours, 48 hours and 72 hours. The mitogenic effects were similar at the 24 and 48 hours of epidermal growth factor, but the DNA synthetic activity of human gingival fibroblasts generally decreased at 72 hours. The DNA synthetic activity of human periodontal ligament cells were increased dose dependently by epidermal growth factor at 24 hours but the DNA synthetic activity decreased at $200{\eta}g/ml$ of each hour. Generally the maximum mitogenic effects were observed at the 48 hours application of epidermal growth factor. The DNA synthetic activity of human periodontal ligament cells generally decreased lower at 24, 72 hours than at 48 hours the application of epidermal growth factor. In the comparison of DNA synthetic activity between human gingival fibroblasts and human periodontal ligament cells, human periodontal ligament cells had slightly higher proliferation activity than human gingival fibroblasts for a longer time at the high dosage of the epidermal growth factor. In conclusion, epidermal growth factor have important roles in the stimulation of DNA synthesis in human periodontal ligament cells and human gingival fibroblasts, and thus may be useful for clinical applications in periodontal regenerative procedures.

• KSBB Journal
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• v.23 no.5
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• pp.460-462
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• 2008

Pollens grains collected from fully dehisced lily (Lilium longiflorum) anthers were given wounds by means of shaking in the presence of aluminum oxide particles. They were transformed by infiltration with Agrobacterium cells harboring a synthetic DNA encoding signal peptide-fused epidermal growth factor (EGF). After incubation for 24 hr in vitro, the pollen culture showed that EGF mRNAs and proteins were successfully expressed in the analysis of cDNA blot hybridization and immuno-blotting.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.20 no.4
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• pp.334-340
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• 1998

Stimulatory effects of epidermal growth factor (EGF) and transforming growth $factor-{\alpha}$($TGF-{\alpha}$) on the growth of squamous cancer cell lines established from human oral cancer tissue with moderate differentiation were studied in vitro. After culturing in serum-free media for 24 hours, growth factors-EGF only, $TGF-{\alpha}$ only and EGF, $TGF-{\alpha}$ together-were added to the media and numbers of cells were analyzed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and compared with the control at 96, 144 hours. Each of EGF and $TGF-{\alpha}$ showed statistically significant stimulatory effects on the growth of cells respectively. Dose-dependent relationship of the stimulatory effects were not clearly demonstrated. The effects of EGF were higher than those of $TGF-{\alpha}$ and combinative administration showed higher effects than those of single uses. In conclusion, EGF may play an important and major role in differentiation and growth of human oral squamous cancer cells. $TGF-{\alpha}$, produced from cells activated by EGF, also can stimulate the cell growth and could be an alternative ligand for EGF receptor.

• Biomolecules & Therapeutics
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• v.3 no.1
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• pp.80-84
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• 1995

Effects of titrated extract of Centella asiatica (TECA) and epidermal growth factor (EGF) isolated from the urine of pregnant horse on the proliferation of human epidermal keratinocyte in culture were studied. An increase in the number of keratinocyte was observed with the treatment of TECA at the concentration ranges from 1 $\mu\textrm{g}$/mι to 100 $\mu\textrm{g}$/mι. Effects of low molecular weight EGF (LEGF) and high molecular weight EGF (HEGF) on the proliferation of keratinocyte in culture were also studied. The number of keratinocyte in culture was significantly increased with LEGF and HEGF respectively at the concentration of 10 ng/mι. Simultaneous treatment of the keratinocyte with LEGF, HEGF and TECA led to the increased proliferation of keratinocytes resulting 96% of the effect of a positive control, EGF isolated from mouse submaxillary glands.

• Biomolecules & Therapeutics
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• v.2 no.1
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• pp.77-81
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• 1994

The acute toxicity of recombinant human epidermal growth factor, DWP-401 was evaluated in ICR mice of both sexes. Six groups of mice were administered orally or subcutaneously with 0, 0.125, 0.25, 0.5, 1 and 2 mg/kg of DWP-401. Abnormal clinical signs related to the compound were not observed, and no deaths occurred. Gross findings of necropsy revealed no evidence of specific toxicity related to DWP-401. LD$_{50}$ values for both male and female mice were evaluated to be over 2 mg/kg, which is approximately 2, 000 fold of presumed clinical dose.e.

• Journal of Food Hygiene and Safety
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• v.9 no.1
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• pp.31-36
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• 1994

The acute toxicity of recombinant human epidermal growth factor, DWP-401 was evaluated in SD rats. Male and female rats aging 6 weeks were administered orally or subcutaneously with 0, 0.125, 0.25, 0.5, 1 and 2 mg/kg of DWP-401. No deaths and no toxic symptoms related to the DWP-401 were observed. The body weights of treated animals were not significantly different from the controls. The results of necropsy revealed no abnormal gross findings of the organs in treated animals. LD50 values of DWP-401 for male and female rats were estimated to be over 2 mg/kg, which is approximately 2, 000 times of expected clinical dose.

• Biomolecules & Therapeutics
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• v.4 no.2
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• pp.138-147
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• 1996

DWP401, a recombinant human epidermal growth factor, was subcutaneously administered to ICR mice at the dose levels of 0, 0.04, 0.2 and 1.0 mg/kg/day (15rats/sex/group) in order to evaluate the subchronic toxicity. General observations, examinations for food and water consumption, ophthalmoscopy and urinalysis were carried out during the study. For the complete gross and microscopic examinations, 10 mice/ sex/group were sacrificed at the ends of the dosing period, and the remaining animals were sacrificed with a 5 week recovery period. Examinations for hematology and blood biochemistry were also carried out at the time of recovery period. Based on the results, it was thought that the target tissue or organs were mesothelial cell, injection site, spleen, adrenal gland, ovary and transitional epithelial cell of urinary tract, and no observed toxic level of DWP401 was 0.04 mg/kg while definite toxic dose level might be 0.2 mg/kg.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.35 no.5
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• pp.287-293
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• 2009

Cell survival is the result of a balance between programmed cell death and cellular proliferation. Cell membrane receptors and their associated signal transducing proteins control these processes. Of the numerous receptors and signaling proteins, epidermal growth factor receptor (EGFR) is one of the most important receptors involved in signaling pathways implicated in the proliferation and survival of cancer cells. EGFR is often highly expressed in human tumors including oral squamous cell carcinomas, and there is increasing evidence that high expression of EGFR is correlated with poor clinical outcome of common human cancers. Therefore, we examined the antiproliferative activity of gefitinib, epidermal growth factor receptor tyrosine kinase inhibitor (EGFR TKI), in head and neck cancer cell lines. SCC-9, KB cells were cultured and growth inhibition activity of gefitinib was measured with MTT assay. To study influence of gefitinib in cell cycle, we performed cell cycle analysis with flow cytometry. Western blot was done to elucidate the expression of EGFR in cell lines and phosphorylation of EGFR and downstream kinase protein, Erk and Akt. Significant growth inhibition was observed in SCC-9 cells in contrast with KB cells. Also, flow cytometric analysis showed G1 phase arrest only in SCC-9 cells. In Western blot analysis for investigation of EGFR expression and downstream molecule phosphorylation, gefitinib suppressed phosphorylation of EGFR and downstream protein kinase Erk, Akt in SCC-9. However, in EGFR positive KB cells, weak expression of active form of Erk and Akt and no inhibitory activity of phosphorylation in Erk and Akt was observed. The antiproliferative activity of gefitinib was not correlated with EGFR expression and some possibility of phosphorylation of Erk and Akt as a predictive factor of gefitinib response was emerged. Further investigations on more reliable predictive factor indicating gefitinib response are awaited to be useful gefitinib treatment in head and neck cancer patients.

• Journal of the korean academy of Pediatric Dentistry
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• v.34 no.3
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• pp.438-446
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• 2007

Viable cells of periodontal ligament would be an important factor for the successful replantation of an avulsed tooth. Therefore, it is critical to choose the storage medium for the preservation of traumatically avulsed teeth. Growth factors and hormones could be considered for the therapeutic application of the maintenance of viable periodontal ligament fibroblasts (PDLFs). Epidermal growth factor (EGF) has been suggested as an important player for the regeneration and wound healing process on other tissues. Therefore, EGF was evaluated for the therapeutic application on avulsed teeth. In addition, the synergic effect of EGF with tri-iodothyronine (T3) and heparin-binding epidermal growth factor-like growth factor (HB-EGF). The cell proliferation of PDLFs was determined by MTT assay and increased dose-dependently up to 10 ng/ml in the presence of EGF. Maximum cellular growth was shown at the concentration of 10 ng/ml EGF. Also, EGF promoted the wound healing of PDLFs examined by in vitro wound healing assay. Combined effects of EGF with T3 or HB-EGF on the proliferation of PDLFs were also studied. Interestingly, EGF showed the synergic effect on the proliferation of PDLFs with T3 and HB-EGF. To find out the mechanism of the synergic effect of EGF and T3, the effect of T3 on the expression of endogenous EGF receptor was determined by RT-PCR. The result was that T3 enhanced the expression of EGF receptor in PDLFs. It suggested that EGF might be a good choice for a therapeutic application, which can be used as combination with T3 and HB-EGF.

• Tuberculosis and Respiratory Diseases
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• v.75 no.5
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• pp.188-198
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• 2013

Over the past decade, several kinase inhibitors have been approved based on their clinical benefit in cancer patients. Unfortunately, in many cases, patients develop resistance to these agents via secondary mutations and alternative mechanisms. To date, several major mechanisms of acquired resistance, such as secondary mutation of the epidermal growth factor receptor (EGFR) gene, amplification of the MET gene and overexpression of hepatocyte growth factor, have been reported. This review describes the recent findings on the mechanisms of primary and acquired resistance to EGFR tyrosine kinase inhibitors and acquired resistance to anaplastic lymphoma kinase inhibitors, primarily focusing on non-small cell lung carcinoma.