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

• Archives of Pharmacal Research
• /
• v.26 no.8
• /
• pp.649-652
• /
• 2003

Polymeric nanoparticles composed of polystyrene (PS) as core and poly(methacrylic acid) (PMA) as corona were prepared by the dispersion copolymerization. The potential of the nanoparticles as carriers for recombinant human epidermal growth factor (EGF) was investigated. The nanoparticles showed monodispersity and good water-dispersibility. The loading content of EGF to the nanoparticles was very high due to electrostatic interaction between EGF and nanoparticles. EGF was released as a pseudo-zero order pattern after initial burst effect. The nanoparticles were sufficient for A431 cells proliferation.

• Journal of Embryo Transfer
• /
• v.19 no.2
• /
• pp.173-183
• /
• 2004

This study was carried out to examine the effects of epidermal growth factor (EGF) and the number of cumulus-oocyte complexes (COCs) on in vitro maturation (IVM) of porcine immature oocytes, and on subsequent in vitro fertilization (IVF) and development (IVD). COCs were collected from antral follicles of porcine ovaries collected from abattoir, and were maturated in modified NCSU-23 (mNCSU-23) with 10% pFF, 0.6 mM cysteine, 50 ${\mu}mM{\beta}-mercaptoethanol$, 1 mM dbcAMP, 10 IU/mL PMSG and 10 IU/mL hCG, which was supplemented with or without 10 ng/mL EGF and into which 50 or 15 COCs per droplet was put. Oocytes matured in vitro, were fertilized in vitro in modified Tris-buffered medium (mTBM) with the final motile sperm concentration of 1${\times}$105 sperm/mL, and subsequently putative embryos were developed in vitro in NCSU- 23. The results are as follows. 1.In the result of IVM, 10 ng/mL EGF supplement duplicated the percentage of C4 group of COCs(41% vs 81%). But the rate of germinal vesicle breakdown (GVBD) and of nuclear maturation were not significantly different between control and EGF supplemented, or between the number of COCs per culture droplet, and there was not a significant interaction between the two factors, either. 2. In the result of IVF, there was not significantly different between control and EGF supplemented, or between the number of COCs per culture droplet, or was not a significant interaction between the two factors, in the rate of sperm penetration, in the percentage of oocytes with male pronucleus (MPN), and in the rate of polyspermy. 3. In the result of IVD, there was not significantly different between control and EGF supplemented, or between the number of COCs per culture droplet in the percentage of cleaved oocytes. There was not significantly different between the number of COCs per culture droplet, but between control and EGF supplemented (p<0.01) in the percentage of blastocysts, the number of inner cell mass (ICM), trophectoderm (TC) and total cells. There was no significant interaction between the two factors anywhere. These results suggested that 10 ng/mL EGF supplement into mNCSU-23 for IVM was effective in the production of more as well as better blastocysts during IVD through increasing the number of cells in those.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.15 no.4
• /
• pp.2303-2309
• /
• 2014

This study of 50's women using the Automatic Micro-needle Therapy System(AMTS) aging skin to evaluate the impact. In addition, AMTS is supplied to the EGF since the 50's women increased moisture and elasticity, pigmentation and wrinkles around the eyes to get a positive effect on the reduction of viewing purposes. In this study, 35 people who are middle-aged women October 7, 2013 from December 15, 2013 made a total of 70 days. AMTS study only the use of increased moisture(<.01) and elasticity(<.001), pigmentation(<.01) and wrinkles(<.001) were decreased. In addition, when applying active ingredients EGF better results. Thus to facilitate the regeneration of the active component, such as EGF, if used together to further increase the positive effect considered.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.14 no.8
• /
• pp.3843-3849
• /
• 2013

This study was conducted to determine the effects of fetal bovine serum (FBS), bovine serum albumin (BSA) and epidermal growth factor (EGF) on blastocoel formation, total cell number, apoptosis and apoptosis-related gene expression of porcine diploid parthenotes developing in vitro. The addition of 0.4% BSA to the culture medium enhanced the development of 2-cell stage parthenotes to the blastocysts stage (p<0.01). Treatment of FBS reduced cell numbers of blastocysts (p<0.01) and increased the percentage of apoptosis in blastocysts (p<0.001). However, BSA increased cell numbers, only in the presence of EGF reverse-transcriptase polymerase chain reaction revealed that EGF enhanced the mRNA expression of Bcl-xL in the presence of 0.4% BSA but BSA and EGF alone had no effect. However, Treatment of FBS reduced Bcl-xL mRNA expression (p<0.05) and enhanced Bak expression. This result suggests that apoptosis related gene expression is significantly affected by supplements, which may result in alteration of apoptosis and embryo viability of porcine embryos developing in vitro.

• YAKHAK HOEJI
• /
• v.40 no.4
• /
• pp.456-461
• /
• 1996

The effects of human epidermal growth factor(EGF) which was produced by recombinant DNA technique was investigated on gastric secretion, gastric lesion and ulcer models in rats. The EGF showed significant inhibition of secretion of gastric juice and total acid output, at 0.4mg/kg, id and also inhibited Shay ulceration at 0.4mg/kg, id in rats. The lesion induced by absolute ethanol was significantly reduced by oral administration of EGF at 0.4mg/kg. Likewise, EGF caused significant inhibition of indomethacin induced gastric ulcer at oral doses of 0.2 and 0.4mg/kg. The EGF produced dose-dependent inhibition of gastric ulcer induced by acidified aspirin, but showed no significant inhibition at oral doses of 0.1, 0.2 and 0.4mg/kg. The chronic gastric ulcer induced by injection of 20% acetic acid solution was significantly reduced by oral doses of 0.1 and 0.4mg/kg of EGF. Duodenal ulcer induced by mepirizole was dose-dependently inhibited by oral doses of 0.1, 0.2 and 0.4mg/kg of EGF. These data suggest that EGF possesses pronounced inhibitory action in gastric ulcer and duodenal ulcer of rats.

• Journal of Embryo Transfer
• /
• v.21 no.1
• /
• pp.29-34
• /
• 2006

본 연구는 개 체외성숙 난자를 안정적으로 생산하기 위하여 채취시기, 난구세포 부착 여부 및 배양액에 EGF와 호르몬을 첨가 후 배양했을 때 체외성숙율에 미치는 영향을 조사하였다. 1. 미성숙 난포란을 TCM-199 배양액에서 24, 45시간 배양했을 때 체외성숙율은 각각 7.93%, 8.94%로서 48시간 배양했을 때 가장 높은 체외성숙율을 나타냈다. 2. 휴지기, 난포기, 황체기에 채취한 난소로부터 회수한 난자를 20 ng/ml의 EGF가 첨가된 TCM-199 배양액에서 배양했을 때 체외성숙율은 14.3%로서 0, 10 ng/ml의 EGF 첨가군(3.1%, 7.5%)에 비해 높은 체외성숙율을 나타냈다. 3. 난구세포 부착 및 미부착 난자를 48시간 배양했을 때 체외성숙율은 각각 18.8% 및 7.5%로서 난구세포 부착 난자가 미부착 난자보다 높은 체외성숙율을 나타냈다. 4. 난자의 체외성숙 배양 시 0.5 mg/ml FSH, 5 mg/ml LH, 1 mg/ml $E_2$와 FSH+LH, $FSH+LH+E_2$를 첨가한 TCM-199 배양액에서 배양했을 때 체외성숙율은 각각 1.2%, 10.0%, 2.0%와 10.0%, 31.2%로서 호르몬의 병용처리군이 높은 체외성숙율을 나타냈다. 5. 난자의 체외성숙 배양 시 EGF와 FSH, LH, $E_2$ 및 EGF와 FSH+LH, $FSH+LH+E_2$를 첨가한 TCM-199 배양액에서 배양했을 때 체외성숙율은 32.3%, 27.0%, 3.0%와 36.2%, 69.4%로서 EGF와 호르몬 병용 처리군이 높은 체외성숙율을 나타냈다.

• Journal of Pharmaceutical Investigation
• /
• v.26 no.1
• /
• pp.29-32
• /
• 1996

In vivo and in vitro skin permeation of $recombinant^{125}$ I-EGF through normal, stripped and the first degree burn skin were studied. The in vitro skin permeation rate through the first degree burn skin $(296\;cpm/cm^2/hr)$ and the stripped skin $(1131\;cpm/cm^2/hr)$ were 3.5 times and 13 times higher, respectively, as compared with the one through normal skin. In vivo absorption study with the first degree burn skin, the peak concentration of EGF in the skin was achieved at 1-3 hr and decreased afterward up to 8 hr with an elimination constant of $1.31{\times}10^{-3}\;g/ml/hr$. To investigate the higher elimination rate of EGF in burn skin, binding and metabolism studies were conducted. No significant metabolism of EGF in burn skin $(100^{\circ}C,\;5-second\;burning)$ was observed. With the presence or unlabelled-EGF $^{125}I-EGF$ permeation through the burn skin showed higher permeation rate than the one without unlabelled-EGF. The result nay indicate that EGF-receptor binding play a role in determining the skin permeation rate.

• International Journal of Oral Biology
• /
• v.43 no.3
• /
• pp.161-169
• /
• 2018

We previously demonstrated that epidermal growth factor (EGF) enhances cell migration and invasion of breast cancer cells in a SMAD ubiquitination regulatory factor 1 (SMURF1)-dependent manner and that SMURF1 induces degradation of ${\beta}-catenin$ in C2C12 cells. However, the relationship between EGF-induced SMURF1 and ${\beta}-catenin$ expression in breast cancer cells remains unclear. So, we investigated if EGF and SMURF1 regulate ${\beta}-catenin$ expression in MDAMB231 human breast cancer cells. When MDAMB231 cells were incubated with EGF for 24, 48, and 72 hours, EGF significantly increased expression levels of SMURF1 mRNA and protein while suppressing expression levels of ${\beta}-catenin$ mRNA and protein. Overexpression of SMURF1 downregulated ${\beta}-catenin$ mRNA and protein, whereas knockdown of SMURF1 increased ${\beta}-catenin$ expression and blocked EGF-induced ${\beta}-catenin$ downregulation. Knockdown of ${\beta}-catenin$ enhanced cell migration and invasion of MDAMB231 cells, while ${\beta}-catenin$ overexpression suppressed EGF-induced cell migration and invasion. Furthermore, knockdown of ${\beta}-catenin$ enhanced vimentin expression and decreased cytokeratin expression, whereas ${\beta}-catenin$ overexpression decreased vimentin expression and increased cytokeratin expression. These results suggest that EGF downregulates ${\beta}-catenin$ in a SMURF1-dependent manner and that ${\beta}-catenin$ downregulation contributes to EGF-induced cell migration and invasion in MDAMB breast cancer cells.

• Biotechnology and Bioprocess Engineering:BBE
• /
• v.10 no.5
• /
• pp.444-450
• /
• 2005

Epidermal growth factor (EGF) activates many intracellular effector molecules, which subsequently influence the expression levels of many genes involved in cell growth, apoptosis and signal transduction, etc. In this study, the early response of gene expressions due to EGF treatment was monitored using oligonucleotide DNA microarrays in rat schwannoma cell lines. An immunoblotting experiment showed the successful activation of EGF receptors and an effector protein, STAT5, due to EGF treatment. The microarray study showed that 35 genes were significantly induced and 2 were repressed within 60 min after the treatment. The list of induced genes included early growth response 1, suppressor of cytokine signaling 3, c-fos, interferon regulatory factor 1 and early growth response 2, etc. According to the microarray data, six of these were induced by more than 10-fold, and showed at least two different induction patterns, indicating complicated regulatory mechanisms in the EGF signal transduction.