• Journal of Genetic Medicine
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• 제2권1호
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• pp.41-47
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• 1998

Human uniparental gestations such as gynogenetic ovarian teratomas provide a model to evaluate the integrity of parent-specific gene expression - i.e. imprinting - in the absence of a complementary parental genetic contribution. The few imprinted genes characterized so far include the insulin-like growth factor-2 gene (IGF2) coding for a fetal growth factor and H19 gene whose normal function is unknown but it is likely to act as an mRNA. IGF2 is expressed by the paternal allele and H19 by the maternal allele. This reciprocal expression is quite interesting because both H19 and IGF2 genes are located close to each other on chromosome 11p15.5. In situ RNA hybridization analysis has shown variable expression of the H19 and IGF2 alleles according to the tissue origin in 11 teratomas. Especially, Skin, derivative of ectoderm, is expressed conspicuously. We examined imprinting of H19 and IGF2 in teratomas using PCR and RT-PCR of exonic polymorphism. H19 and IGF2 transcript could be expressed either biallelically or monoallelically in the teratomas. Biallelic expression (i.e., loss of imprinting) of IGF2 occurred in 5 out of 6 mature teratomas and 1 out of 1 immature teratoma. Biallelic expression of H19 occurred in 4 out of 10 mature teratomas and 1 out of 1 immature teratoma. Expression levels of H19 and IGF2 transcript using the semi-quantitative RT-PCR had no relation between monoallelic and biallelic expression. Moreover, IGF2 biallelic expression did not affect allele-specificity or levels of H19 expression. These results demonstrate that both genes, H19 and IGF2, can be imprinted, expressed and regulated independently and individually of each other in ovarian teratoma.

• Asian Pacific Journal of Cancer Prevention
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• 제16권1호
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• pp.221-225
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• 2015

As metformin can inhibit endometrial carcinoma (EC) cell growth and the insulin growth factor (IGF) system is active in EC, the question of whether it can regulate endometrial carcinoma cell secretion of IGF-1 or expression of IGF-1 receptor (IGF-1R) is of interest. In this study, serum IGF-1 levels in EC patients were found to be comparable with that in the non EC patients (p>0.05). However, the IGF-1 level in the medium of cultured cells after treatment with metformin was decreased (p<0.05). IGF-1R was highly expressed in human endometrial carcinoma paraffin sections, but IGF-1R and phosphor-protein kinase B/protein kinase B (p-Akt/Akt) expression was down-regulated after metformin treatment (p<0.05). In summary, metformin can reduce the secretion of IGF-1 by Ishikawa and JEC EC cell lines and their expression of IGF-1R to deactivate downstream signaling involving the PI-3K/Akt pathway to inhibit endometrial carcinoma cell growth.

• Journal of Periodontal and Implant Science
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• 제30권2호
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• pp.375-390
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• 2000

The purpose of this study is to evaluate the expression ofIGF-I, considered as the mediator of action of estrogen, and IGF-IA and IGF-IB, alternative slicing form of IGF-I, using $17{\beta}-estradiol$ in MC3T3-E1 cells. We observed the effect on type I collagen and osteopontin gene expression and DNA synthetic activity of MC3T3-E1 cells, added by estrogen, IGF-I and combination and the interactionon proliferation and differentiation of MC3T3-E1 cells. The results were as follows :RT-PCR experiment for observing timedependantIGF-I gene expression patternshowed IGF-IA and IB gene expression in both of control and test group. In these IGF-IA gene expression was appeared predominantly. In control, IGF-I geneexpression level was maintained until 24hr and then decreased gradually. In testgroup, IGF-I gene expression level increased as time goes by. Experiment measuring DNA synthetic activity, as it is added by $17{\beta}-estradiol$, IGF-I and combination, showed that first day , there was the tendency of more increase of synthetic activity in all test group than control but no statical significance(P>0.05), and third day, there was more increase of DNA synthetic activity in $17{\beta}-estradiol$ group and combination group and it was statically significant. (P<0.005) Experiment for observing type I collagen gene expression pattern showed more increase of expression in $17{\beta}-estradiol$ group than control and no significant difference in IGF-I group and combination group. Experiment for observing osteopontin gene expression pattern showed no significant difference in control and test group. In conclusion, $17{\beta}-estradiol$ in MC3T3- E1 cells increased IGF-I gene and DNA synthetic activity simultaneously, therefore it appeared that IGF-I is related to the action of estrogen. Combination treatment of IGF-I and $17{\beta}-estradiol$ has effect on cell proliferation but this effect is lower than IGF-I or $17{\beta}-estradiol$ alone. However, combination treatment has not great effect on type I collagen or osteopontin gene expression thus little effect of cell differentiation.

• BMB Reports
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• 제52권6호
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• pp.385-390
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• 2019

Leptin, an adipokine regulating energy metabolism, appears to be associated with breast cancer progression. Insulin-like growth factor-1 (IGF-1) mediates the pathogenesis of breast cancer. The regulation of IGF-1 expression by leptin in breast cancer cells is unclear. Here, we found that leptin upregulates IGF-1 expression at the transcriptional level in breast cancer cells. Activating protein-1 (AP-1)-binding element within the proximal region of IGF-1 was necessary for leptin-induced IGF-1 promoter activation. Forced expression of AP-1 components, c-FOS or c-JUN, enhanced leptin-induced IGF-1 expression, while knockdown of c-FOS or c-JUN abrogated leptin responsiveness. All three MAPKs (ERK1/2, JNK1/2, and p38 MAPK) mediated leptin-induced IGF-1 expression. These results suggest that leptin contributes to breast cancer progression through the transcriptional upregulation of leptin via the MAPK pathway.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제31권5호
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• pp.363-369
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• 2005

Purpose: To determine the role of Insulin-like Growth Factor-I (IGF-I) in the regulation of Vascular Endothelial Growth Factor (VEGF) expression in MG-63 cells and then to find the mechanism b which this regulation occurs. Materials and methods: MG-63 cells were grown to confluence in 60-mm dishes. To determine the effects of IGF-I on expression of VEGF mRNA according to time and concentration, the cells were treated with 10 nM IGF-I, following isolation of total RNA and Northern blot analysis after 1, 2, 4, 8, 12, 24 hours and after 2 hours of treatment with 0.5, 2, 10, 25, 50 nM IGF-I respectively, isolation of total RNA and Northern blot analysis were followed. To determine the mechanism of action of IGF-I, inhibitors such as hydroxyurea $(76.1\;{\mu}g/ml)$, actinomycin D $(2.5\;{\mu}g/ml)$, cycloheximide $(10\;{\mu}g/ml)$ were added 1 hour after treatment of 10 nM IGF-I. Results: 1. the expression of VEGF mRNA was increased with treatment of IGF-I. 2. The expression of VEGF mRNA was increased according to time-and concentration dependent manner of IGF-I. 3. The effect of IGF-I was decreased by hydroxyuera, actinomycin D, but not by cycloheximide. Conclusion: IGF-I regulate the expression of VEGF mRNA in the level of DNA synthesis and transcription. These results could suggest that IGF-I plays an important role in angiogenesis in the process of new bone formation and remodeling.

• Asian-Australasian Journal of Animal Sciences
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• 제25권7호
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• pp.903-912
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• 2012

In Erhualian and Yorkshire reciprocal cross $F_1$ pig populations, we examined the mRNA expression characteristic of liver-derived IGF-1, IGF-1R, IGF-2, IGF-2R and IGFBP-3 during the embryonic and postnatal developmental periods (E50, E70, E90, D1, D20, D70, D120 and D180). Our results demonstrated that the IGF-system genes mRNA levels exhibited an ontogenetic expression pattern, which was potentially associated with the porcine embryonic development, postnatal growth, organogenesis and even the initiation and acceleration of puberty. The expression pattern of IGF-system genes showed variation in the reciprocal cross ($F_1$ YE and EY pigs). This study also involved the expression features of imprinted genes IGF-2 and IGF-2R. The parent-of-origin effect of imprinted genes was reflected by their differential expression between the reciprocal crosses populations. The correlation analysis also indicated that the regulatory network and mechanisms involved in the IGF system were a complex issue that needs to be more fully explored. A better understanding of IGF system components and their interactive mechanisms will enable researchers to gain insights not only into animal organogenesis but also into somatic growth development and even reproduction.

• Fisheries and Aquatic Sciences
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• 제22권9호
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• pp.19.1-19.10
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• 2019

We investigated the insulin-like growth factor 1 (IGF-1)/AKT signaling pathway involved in muscle formation, growth, and movement in the adductor muscle of triploid Pacific oyster, Crassostrea gigas. Large and small triploid oysters (LTs and STs) cultured under identical conditions were screened, and the signaling pathways of individuals with superior growth were compared and analyzed. mRNA and protein expression levels of actin, troponin, tropomyosin, and myosin, proteins important in muscle formation, were higher in LTs compared with STs. Expression levels of IGF-1, IGF binding protein (IGFBP), and IGFBP complex acid-labile subunit were also higher in LTs compared with STs. Phosphorylation of the IGF receptor as well as that of AKT was high in LTs. In addition, the expression of phosphomammalian target of rapamycin and phospho-glycogen synthase kinase $3{\beta}$ was increased and the expression of Forkhead box O3 was decreased in LTs. Therefore, we suggested that the IGF-1/AKT signaling pathway affects the formation, growth, and movement of the adductor muscle in triploid oysters.

• Asian Pacific Journal of Cancer Prevention
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• 제13권12호
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• pp.6139-6144
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• 2012

Aims: Mammalian target of rapamycin (mTOR) is master regulator of the PI3K/Akt/mTOR pathway and plays an important role in NSCLCs. Here we characterized mRNA and protein expression levels of mTOR and its functional associated molecules including PTEN, IGF-1R and 4EBP1 in surgically resected NSCLCs. Methods: Fifty-four patients with NSCLCs who underwent pulmonary resection were included in current study. mRNA levels of mTOR, PTEN, IGF-1R, and 4EBP1 were evaluated by RT-PCR and protein expression of mTOR, PTEN, and IGF-1R by immunohistochemistry (IHC). Association of expression of the relevant molecules with clinical characteristics, as well as correlations between mTOR and PTEN, 4EBP1 and IGF-1R were also assessed. Results: The results of RT-PCR showed that in NSCLCs, the expression level of mTOR increased, while PTEN, 4EBP1 and IGF-1R decreased. Statistical analysis indicated high IGF-1R expression was correlated with advanced clinical stage (stage III) and PTEN expression was reversely associated with tumor size (P=0.16). The results of IHC showed mTOR positive staining in 51.8% of cases, while IGF-1R positive staining was found in 83.3% and loss of PTEN in 46.3%. Protein expression of mTOR was correlated with its regulators, PTEN and IGF-1R, to some extent. Conclusions: Abnormal activation of mTOR signaling, high expression of IGF-1R, and loss of PTEN were observed in resected NSCLC specimens. The poor expression agreement of mTOR with its regulators, PTEN, and IGF-1R, implied that combination strategy of mTOR inhibitors with other targets hold significant potential for NSCLC treatment.

• 한국식품과학회지
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• 제35권4호
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• pp.702-707
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• 2003

본 연구는 가시오가피를 함유한 성장촉진용 조성물인 GSM의 성장촉진 효과를 관찰하기 위하여, 족경골 말단의 성장판 증식과 골성장인자 IGF-1 유전자 발현에 미치는 영향, 골세포와 간세포에서 골성장인자 IGF-1 유전자 발현, 그리고 족경골의 생육 효과를 관찰하였다. GSM은 세포실험을 통하여 주요 성장 인자인 IGF-1을 간에서 합성을 촉진시킬 뿐만 아니라, 골에서도 합성을 촉진시키는 효과를 나타내었다. 그리고 간과 골에서 합성이 촉진된 IGF-1은 동물실험을 통하여 장골 길이 성장의 중요한 척도가 되는 성장판 말단부의 증식층 및 비대층의 연골세포 활력을 증대시켜 성장판 두께를 증가시켰고, 또한 골무기질밀도를 증가시키는 효과를 보여주었다. 따라서 본 연구는 GSM의 지속적인 연구를 통하여 성장기 어린이에게 성장촉진 및 골강화에 응용할 수 있는 소재로 개발 가능성이 있음을 제시하였다.

• KSBB Journal
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• 제17권3호
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• pp.283-289
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• 2002

Insulin-like growth factor-I(IGF-I)은 성장호르몬의 여러 가지 성정촉진 작용을 매개하는 분열 유발성 폴리펩티드이며, 조직의 수선과 재생, 창상치유 및 골대사와 같은 과정들에서 중요한 역할을 하는 것으로 알려져 있고, 비교적 여러 조직에서 발현되고 있는 IGF-I 유전자의 전사조절에 대한 정확한 분자적 기전과 호르몬 및 대사 상태가 그것을 어떻게 조절하는지 아직 밝혀져 있지 않다. 쥐를 절삭시키므로써 대사 상태를 변조시켰을 때, 간 조직내 IGF-I mRNA의 발현에 미치는 절식의 영향을 살펴보기 위하여 solution hybridizatioon/RNase protection 방법으로 분석 하였다. IGF-I의 exon 1 및 exon 2에 의하여 encode된 tran-scripts 모두가 감소된 결과를 얻었고, 이러한 감소는 전사 수준에서 일어난 것으로 nuclear run-on 분석에 의하여 확인하였다. 또한 절식시킨 쥐에서 IGF-I mRNA의 양을 조절하는 cia-acting elements를 IGF-I 유전자의 5'-flanking 지역과 exon 1과 econ 2에서 밝히고자 절식시킨 쥐의 신선한 간조직에서 핵 추출물을 얻어 IGF-I의 여러 가지 DNA fragments와 반응시켜 DNase I protection 분석을 한 결과, IGF-I 유전자의 주요한 전사 개 시점으로부터 downstream에 있는 sequences가 절식으로 변조시킨 대사상태에서 IGF-I의 발현 조절에 중요하며 이곳에는 전사인자인 C/EBP family의 isoform들을 포함한 간조직에 풍부하게 존재하는 여러 전사인자들이 결합할 것으로 제안하였다.