• Asian Pacific Journal of Cancer Prevention
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• 제13권10호
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• pp.4879-4881
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• 2012

Epidermal growth factor receptor (EGFR) overexpression is associated with resistance to chemotherapy and radiotherapy. The EGFR modulates DNA repair after radiation-induced damage through an association with the catalytic subunit of DNA protein kinase. DNA double-strand breaks (DSBs) are the most lethal type of DNA damage induced by ionizing radiation, and non-homologous end joining is the predominant pathway for repair of radiation-induced DSBs. Some cell signaling pathways that respond to normal growth factors are abnormally activated in human cancer. These pathways also invoke the cell survival mechanisms that lead to resistance to radiation. The molecular connection between the EGFR and its control over DNA repair capacity appears to be mediated by one or more signaling pathways downstream of this receptor. The purpose of this mini-review was not only to highlight the relation of the EGFR signal as a regulatory mechanism to DNA repair and radiation resistance, but also to provide clues to improving existing radiation resistance through novel therapies based on the above-mentioned mechanism.

• 대한의생명과학회지
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• 제12권3호
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• pp.249-254
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• 2006

It has been reported that liver is a very important organ to xenotransplantation. Pig is known to be a most suitable species in transplantation of human organs. However, the physiological function of pig hepatocytes is not clear elucidated. Epidermal growth factor (EGF) is known to be a mitogen in various cell systems. Thus, we examined the effect of EGF on cell proliferation and its related signal cascades in primary cultured pig hepatocytes. EGF stimulates cell proliferation in a dose (>1ng/ml) dependent manner. EGF-induced increase of $[^3H]-thymidine$ incorporation was blocked by AG 1478 ($10^{-6}M$, an EGF receptor antagonist) genistein and herbymycin A (tyrosine kinase inhibitors, $10^{-6}M$), suggesting the role of activation and tyrosine phosphorylation of EGF receptor. In addition, EGF-induced increase of $[^3H]-thymidine$ incorporation was prevented by neomycin $(10^{-4}M)$, U73122 $(10^{-5}M)$ (phospholipase C [PLC] inhibitors), staurosporine ($(10^{-8}M)$, or bisindolylmaleimide I $(10^{-6}M)$ (protein kinase C [PKC] inhibitors), suggesting the role of PLC and PKC. Moreover, EGF-induced increase of $[^3H]-thymidine$ incorporation was blocked by PD 98059 (a p44/42 mitogen activated protein kinase [MAPK] inhibitor), SB 203580 (a p38 MAPK inhibitor), and SP 600125 (a JNK inhibitor). EGF increased the translocation of PKC from cytosol to membrane fraction and activated p42/44 MAPK, p38 MAPK and JNK. In conclusion, EGF stimulates cell proliferation via PKC and MAPK in cultured pig hepatocytes.

• Asian Pacific Journal of Cancer Prevention
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• 제14권8호
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• pp.4859-4864
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• 2013

Background: The purpose of this study was to assess the effectiveness of a recombinant human epidermal growth factor (EGF)-based cream for the prevention of acute radiation dermatitis in breast cancer patients receiving radiotherapy (RT). Materials and Methods: Between December 2012 and April 2013, 40 breast cancer patients who received postoperative RT were prospectively enrolled in this study and randomly assigned to receive human recombinant EGF-based cream (intervention group) or general supportive skin care (control group). The grade of radiation dermatitis and pain score were examined at weekly intervals during RT and 6 weeks after RT completion. Results: All patients completed the planned RT and complied well with instructions for applying the study cream and general supportive skin care. In the intervention group, radiation dermatitis of maximum grade 3, 2, and 1 developed in 3 (15%), 11 (55%), and 6 patients (30%), respectively. In comparison, in the control group, radiation dermatitis of maximum grade 3, 2, and 1 developed in 8 (40%), 10 (50%), and 2 patients (10%), respectively. The intervention group showed lower incidence of grade 3 radiation dermatitis than the control group (p=0.068 in univariate analysis and p=0.035 in multivariate analysis). There was no statistically significant difference in the maximal pain score between the two groups (p=0.934). Conclusions: This single-blind randomized preliminary study showed that recombinant human EGF-based cream can have a beneficial role in preventing or minimizing radiation dermatitis in breast cancer patients. To confirm the results of our study, additional studies with a large sample size are required.

• 대한약학회:학술대회논문집
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• 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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• pp.415.3-416
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• 2002

To improve the stability of recombinant human epidermal growth factor (rhEGF) as therapeutic agent. the N-terminal PEGylated rhEGF (N-PEG-rhEGF) was prepared by site-specific bioconjugation and the stability was investigated in rat skin wound homogenates. Two different N-PEG-rhGEFs (N-PEG5K- and N-PEG20K-rhEGF) were successfully prepared with the yields of above 70%. The PEGylation site was directly confirmed by determining the molecular mass of Lys-C digested samples using MALDI- TOF MS. (omitted)

• Biotechnology and Bioprocess Engineering:BBE
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• 제2권2호
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• pp.86-89
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• 1997

Epidermal growth factor(EGF) known as a urgastrone is a powerful mitogen with a wide variety of possibilities for medical usages. A mature EGF coding region was isolated from human prepro-EGF sequence by a conventional PCR and cloned into pQE vector in which the gene product was supposed to be expressed with 6$\times$His tag for the subsequent purification. The recombinant mature EGF was expressed in M15[Rep4], an Escherichia coli host strain, in amount of 30-40% of total proteins pressent in E. coli extract by the addition of isopropylthio-$\beta$-galactopyranoside (IPTG). The recombinant EGF purified using a Ni2+-NTA affinity colume chromatography was active in its ability to induce phosphorylation on tyrosine residues of several substrate proteins when murine NH3T3 and human MRC-5 fibroblast cells were stimulated with it. This work may provide the basic technology and information for the production of recombinant EGF.

• Radiation Oncology Journal
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• 제34권1호
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• pp.1-9
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• 2016

Overexpression of human epidermal growth factor receptor 2 (HER2) is found in about 20% of breast cancer patients. With treatment using trastuzumab, an anti-HER2 monoclonal antibody, systemic control is improved. Nonetheless, the incidence of brain metastasis does not be improved, rather seems to be increased in HER2-positive breast cancer. The mainstay treatment for brain metastases is radiotherapy. According to the number of metastatic lesions and performance status of patients, radiosurgery or whole brain radiotherapy can be performed. The concurrent use of a radiosensitizer further improves intracranial control. Due to its large molecular weight, trastuzumab has a limited ability to cross the blood-brain barrier. However, small tyrosine kinase inhibitors such as lapatinib, has been noted to be a promising agent that can be used as a radiosensitizer to affect HER2-positive breast cancer. This review will outline general management of brain metastases and will focus on preclinical findings regarding the radiosensitizing effect of small molecule HER2 targeting agents.

• 약학회지
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• 제39권5호
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• pp.471-479
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• 1995

The recombinant human epidermal growth factor(DWP 401) was investigated on the pharrnacological actions. DWP 401 had no effects on the hexobarbital-induced sleeping time, locomotor activity, rotarod test, body temperature, analgesic action and anticonvulsant action in mice. It also had no influences on the isolated tracheal muscle and ileum of guinea-pig, isolated uterus and fundus strip of rats. Slight hypotensive action with effect on respiration was revealed at a dose of 8 g/kg i.v. of DWP 401 in rabbits. DWP 401 exhibited a weak inhibitory action of glucose tolerance in normal rats, significantly lowered the blood glucose contents in adrenalectomized rats at .a concentration of 160 g,/kg, and produced a significant inhibitory effect on leucocyte migration in CMC-pouch of rats at a concentration of 32 g/rat. Furthermore, DWP 401 showed a significant decrease on gastric juice volume and acidity. However. DWP 401 had no intestinal propulsion rate and influence on urine excretion.

• 폴리머
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• 제39권3호
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• pp.480-486
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• 2015

조직과 장기 유착은 외과적 수술 후 부작용으로 자주 발생된다. 이러한 조직 유착을 방지하기 위하여 유착부위에 장벽을 형성하여 장기 유착을 방지할 수 있는 온도감응성 하이드로젤 유착방지제를 제조하고자 하였다. 폴록사머, 키토산과 표피성장인자를 가지고 온도감응성 키토산 하이드로젤을 제조하였다. 제조한 키토산 하이드로젤은 인체 내 온도와 유사한 $35^{\circ}C$에서 졸-젤 전이현상을 보였고, 1분 이내에 빠르게 젤화되었다. 키토산 하이드로젤은 표피성장인자를 7일 동안 천천히 방출하였고, 마우스모델에서 평가한 결과 조직 유착 방지를 효과적으로 하는 것을 확인하였다. 온도 감응성과 항균성을 갖는 키토산 하이드로젤이 장기 부착의 증가와 표피성장인자를 천천히 방출하는 유착방지제로서 유용하게 사용될 수 있다.

• 한국동물학회:학술대회논문집
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• 한국동물학회 1997년도 한국생물과학협회 학술발표대회
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• pp.218.1-218
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• 1997

No Abstract, See Full Text

• 대한치과보철학회지
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• 제58권4호
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• pp.290-299
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• 2020

목적: 본 연구에서는 나노방출제어시스템을 이용하여 trichloroacetic acid (TCA) 및 epidermal growth factor (EGF)를 인간치은섬유아세포에 적용하였을 때, 나타나는 액틴 세포골격과 관련된 유전자 발현의 변화 양상을 확인하고자 하였다. 재료 및 방법: TCA와 EGF가 조절방출될 수 있도록 만들어진 나노방출제어시스템을 이용하였다. 인간치은섬유아세포에 TCA만 적용된 군(EXP1), TCA와 EGF가 적용된 군(EXP2), 대조군(CON)의 3가지 군으로 나누어 48시간 배양하였다. Real-time PCR을 이용하여 액틴 세포골격과 관련된 유전자 26개의 발현 양상을 분석하였다. 피어슨상관관계분석을 통해 유전자들의 상관관계와 영향요인을 확인하였다. 결과: 액틴 세포골격과 관련된 유전자 26개 중 23개가 EXP1과 EXP2에서 상향조절되었고, 이 중 14개는 EXP1에 비하여 EXP2에서 유의미한 발현량 증가를 보였다. LPAR1은 EXP1에서만 하향조절되었고, GNA13은 EXP2에서만 상향조절되었고, F2R은 EXP2에서만 하향조절되었다. 액틴 단백질의 유전자 발현에 대하여 Rac1관련 유전자 중 3개와 CDC42가 가장 큰 영향요인으로 확인되었다. 결론: 인간치은섬유아세포의 액틴 세포골격 관련 유전자들은 나노방출제어시스템을 통하여 조절 방출된 TCA와 EGF에 의해 대부분 상향조절되었다.