• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.3
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• pp.437-443
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• 2003

Epidemiological data suggest that lycopene has anticancer activities in humans. Insulin-like growth factor-I receptor (IGF-IR) is a transmembrane tyrosine kinase that mediates the biological actions of IGFs and may play an active role in cancer progression. Because our previous in vitro studies have indicated lycopene inhibits HT-29 cell growth, the aim of this study was to determine whether lycopene induces apoptotic cell death and the inhibitory effect of lycopene on HT-29 cell growth is related to changes in IGF-IR levels and the receptor's intracellular signalling pathways. HT-29 cells were incubated for 4 days in serum-free medium in the presence of 0, 25, 50, or 100 $\mu$M lycopene, and the DNA fragmentation assay was performed. Cells treated with lycopene produced a distinct oligonucleosomal ladder with different sizes of DNA fragments, a typical characteristic of cells undergoing apoptosis. HT-29 cells were cultured for 4 days in serum-free medium in the presence of 0~100 $\mu$M lycopene and IGF-I (10nM) was added for 0~60 minutes immediately prior to lysate preparations. Western blot analysis of total lysates revealed that lycopene decreased the levels of IRS-1, Akt, phosphatidylinositol 3-kinase (PI3K), and IGF-IR $\beta$-subunit, and increased the levels of the IGF-IR precursor dose dependently. Lycopene also decreased IGF-I-induced phosphorylation of IGF-IR$\beta$, IRS-1 and Akt, which were, at least in part, due to decreased expression of these proteins. These results suggest that lycopene induces apoptosis of HT-29 cells by inhibiting IGF-IR signaling thereby interfering with an IGF-II-driven autocrine growth loop, which is known to exist in this cell line.

• Journal of Embryo Transfer
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• v.12 no.3
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• pp.229-246
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• 1997

Implantation is a most important biological process during pregnancy whereby conceptus establishes its survival as well as maintenance of pregnancy. During the periimplantation period, both uterine endometriurn and conceptus synthesize and secrete a host of growth factors and cytokines which mediate the actions of estrogen and /or progesterone and also exert their steroid-independent actions. Growth factors expressed by the materno-conceptal unit en masse have important roles in cell migration, stimulation or inhibition of cell proliferation, cellular differentiation, maintenance of pregnancy and materno-conceptal communications in an autorcrine /paracrine manner. The present review focuses on the role of the intrauterine IGF system during periimplantation conceptus development. The IGF system comprises of IGF- I and IGF- II ligands, types I and II IGF receptors and six or more IGF-binding proteins(IGFBPs). IGFs and IGFBPs are expressed and secreted by uterine endometrium with tissue, pregnancy stage and species specificities under the influence of estrogen, progesterone and other growth factor(s). Conceptus also synthesizes components of the IGF system beginning from a period between 2-cell and blastocyst stages. Maternal IGFs are utilized by both maternal and conceptal tissues; conceptus-derived growth factors are believed to be taken up primarily by conceptus. IGFs enhance the development of both maternal and conceptal compartments in a wide range of biological processes. They stimulate proliferation and differentiation of endometrial cells and placental precursor cells including decidual transformation from stromal cells, placental formation and the synthesis of some steroid and protein hormones by differentiated endometrial cells or placenta. It is also well-documented in a number of experimental settings that both IGFs stimulate preimplantation embryo development. In slight contrast to these, prenatal mice carrying a null mutation of IGF and /or IGF receptor gene do not exhibit any apparent growth retardation until after implantation. Reason (s) for this discrepancy between the knock-out result and the in vitro ones, however, is not known. IGFBPs, in general, are believed to inhibit IGF action within the materno-conceptal unit, thereby allowing endometrial stromal cell differentiation as well as dampening ex cessive placental invasion into maternal tissue. There is evidence, however, indicating that IGFBP can enhance IGF action depending on environrnental conditions perhaps by directioning IGF ligand to the target cell. There is also a third possibility that certain IGFBPs and their proteolytic fragments may have their own biological activities independent of the IGF. In addition to IGFBPs, IGFBP proteases including those found within the uterine tissue or lumen are thought to enhance IGF bioavailability by degrading their substrates without affecting their bound ligand. In this regard, preliminary results in early pregnant pigs suggest that a partially characterized IGFBP protease activity in uterine luminal fluid enhances intrauterine IGF bioavailability during conceptus morphological development. In summary, a number of in vitro results indicate that IGFs stimulates the development of the rnaterno-conceptal unit during the periimplantation period. IGFBPs appear to inhibit IGF action by sequestering their ligands, whereas IGFBP proteases are thought to enhance intrauterine bioavailability of IGFs. Much is remaining to be clarified, however, regarding the roles of the individual IGF system components. These include in vivo evidence for the role of IGFs in early conceptus development, identification of IGF-regulated genes and their functions, specific roles for individual IGFBPs, identification and characterization of IGFBP proteases. The intrauterine IGF club house thus will be paying a lot of attention to forthcoming results in above and other areas, with its door wide-open!

• Clinical and Experimental Pediatrics
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• v.49 no.12
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• pp.1340-1347
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• 2006

Purpose : The aim of the present study was to investigate the role of polymorphic cytosine adenine (CA) repeat of the IGF-I gene in the age-related alterations of serum IGF-I levels in healthy children. Methods : Two hundred and forty three normal healthy children (136 boys; 107 girls) aged between 7 and 15 years were enrolled in the present study. The primers were designed to cover the promoter regions containing the polymorphic CA repeat. Data were analyzed using GeneMapper software, version 3.7. All analyses were performed using MEDCALC software packages. Results: Deletion of 2 bp (G, A) following 3' of CA repeat were observed in all Korean children. The CA repeat sequences ranged from 17 to 23, and 19 CA repeat were the most common with an alleles frequency of 39.3 percent. Considering genotypes, 63.8 percent of subjects were homozygote or heterozygote for 19 CA repeat (192 bp allele), suggesting that this is wild type allele from which all other alleles originated in Korean children. Homozygote for 19 CA repeat were 14.7 percent, heterozygote for 19 CA repeat was 49.1 percent and 19 CA noncarriers totalled 36.2 percent. In 19 CA repeat noncarriers, the mean height, weight and serum IGF-I level were lower compared with those of 19 CA homozygous carriers, but statistically not significant. Correlations between serum IGF-I level and age according to the IGF-I genotypes revealed statistically significant relationships in the all groups, in the 19 CA repeat carrier group and, even in the noncarrier group. Conclusions : There were no significant differences of the mean height, weight and serum IGF-I levels among three different genotype groups. Also, there were no significantly different correlations between 19 CA repeat polymorphisms and serum IGF-I levels, according to genotype. Our results suggest that the IGF-I 19 CA repeat gene polymorphism is not associated with circulating IGF-I levels in healthy children.

• Tuberculosis and Respiratory Diseases
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• v.63 no.1
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• pp.42-51
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• 2007

Background: TRAIL is a cytokine that selectively induces apoptosis in various cancer cell lines. Gefitinib is new targeted drug applied in lung cancer that selectively inhibits EGFR tyrosine kinase. However, lung cancers have shown an initial or acquired resistance to these drugs. This study examined the effect of IGF-1R and its blockade on enhancing the sensitivity of lung cancer cell lines to TRAIL and gefitinib. Methods: Two lung cancer cell lines were used in this study. NCI H460 is very sensitive to TRAIL and gefitinib. On the other hand, A549 shows moderate resistance to TRAIL and gefitinib. The IGF-1R blockade was performed using adenoviruses expressing the dominant negative IGF-1R and shRNA to IGF-1R and AG1024 (IGF-1R tyrosine kinase inhibitor). Results: The adenovirus expressing dominant negative IGF-1R(950st) induced the increased expression of defective IGF-1R on the lung cancer cell surface, and the adenovirus-shIGF-1R effectively decreased the level of IGF-1R expression on cell surface. The genetic blockade of IGF-1R by the adenovirus-dnIGF-1R and AG1024 increased the sensitivity of A549 cells to TRAIL. The reduction of IGF-1R by transduction with ad-shIGF-1R also increased the sensitivity of the A549 cells to gefitinib. Conclusion: The blockade of IGF-1R through various mechanisms increased the sensitivity of the lung cancer cell line that was resistant to TRAIL and gefitinib. However, further studies using other cell lines showing acquired resistance as well as in vivo animal experiments will be needed.

• Clinical and Experimental Pediatrics
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• v.51 no.7
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• pp.722-728
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• 2008

Purpose : This study was designed to examine the effects of adiponectin, leptin, insulin, insulin-like growth factor (IGF)-I and IGF binding protein (BP)-3 levels in cord blood on weight, length, and adiposity at birth in healthy term infants. In addition, we evaluated the mechanism to change the hormone levels in appropriate for gestational age (AGA) during the first month. Methods : We collected cord blood from 200 term neonates (109 males, 91 females) with no perinatal problems, and measured the hormone levels and anthropometric parameters including weight, length, and skin-fold thickness. Term neonates were divided into 3 groups as follows: birth weight appropriate for gestational age (AGA) (n=132), birth weight less for gestational age (SGA) (n=29), and birth weight more for gestational age (LGA) (n=39). Venous blood samples of 15 fullterm healthy neonates were obtained at 3, 7, and 30 d after birth. Results : The adiponectin, insulin, and IGF-I levels were significantly lower in the SGA group than in the AGA and LGA groups. The leptin levels were significantly higher in the LGA group than in the AGA and SGA groups. Cord blood adiponectin, leptin, insulin, IGF-I, and IGFBP-3 levels correlated significantly and positively with birth weight and the sum of the skin-fold thickness. A significant positive correlation was observed between adiponectin, leptin, and IGF-I levels and birth weight. Adiponectin level correlated significantly with that leptin level (r=0.191, P=0.038), but not with insulin, IGF-I and IGFBP-3 levels. IGF-I levels were higher in females than in males. At 7 d after birth, the leptin level decreased along with physiologic weight loss, and then increased. IGF-I, also decreased at 3 d, significantly increased 1 month later. Conclusion : We suggest that adiponectin, leptin, insulin, IGF-I, and IGFBP-3 play an important role in regulating fetal growth. Adiponectin may be involved in regulating fetal growth through mechanisms different from those mediated by insulin or IGF-I. High levels of IGF-I in female neonates indicates a gender difference which serves as evidence for in utero sexual dimorphism. It is likely that IGF-I has a more important role than that of hormones in postnatal growth.

• Clinical and Experimental Pediatrics
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• v.52 no.2
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• pp.176-180
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• 2009

Purpose : The objective of this study was to establish the serum IGF-1 level in newborn infants, and investigate its association with growth and diseases. Methods : In a retrospective study, serum IGF-1 levels were measured for newborn infants admitted to NICU at Kyungpook University Hospital from March 2007 to July 2007. Birth data, disease history, and hospital course were obtained from medical records. Results : Of 52 blood samples obtained at birth, serum IGF-l levels in 30 preterm infants ($31.6{\pm}27.3$ ng/mL) were lower than in 22 full-term infants ($53.4{\pm}40.0$ ng/mL; P<0.05). In sick full-term infants, serum IGF-1 levels ($46.0{\pm}40.2$ ng/mL) were lower than in healthy full-term infants ($64.1{\pm}39.5$ ng/mL; P<0.05). In preterm infants, there were no differences in IGF-1 levels between healthy ($33.2{\pm}23.3$ ng/mL) and sick infants ($30.6{\pm}30.4$ ng/mL); however, IGF-1 levels in both sick and healthy preterm infants were lower than in healthy full-term infants. Among infants admitted after 8 days of life, serum IGF-1 levels were higher in infants who gained weight ($70.8{\pm}36.2$ ng/mL) than in infants who lost weight ($13.3{\pm}19.9$ ng/mL; P<0.01); however IGF-1 levels showed no difference between gender or method of delivery. Conclusion : The study showed lower IGF-l levels in preterm infants than in full-term infants. Additionally, the IGF-l level in infants with weight loss was lower than in infants with weight gain. These results indicate that serum IGF-1 is associated with gestational age and postnatal growth.

• Korean Journal of Animal Reproduction
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• v.23 no.3
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• pp.213-220
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• 1999

The litter size has been the primary interest of economic traits in pig reproduction. It has been recently shown that insulin-like growth factor-Ⅰ(IGF-Ⅰ) plays roles in establishing pregnancy and in supporting fetal growth and development. But, the effect of serum IGF-Ⅰ on litter size has not been studied. Therefore, this study was conducted to relate serum IGF-Ⅰ concentration with porcine litter size and to investigate the possible connection with estrogen receptor(ER) as a candidate gene for the litter size. Sera during day 45 to 105 of pregnancy were collected from two groups showing high and low litter size and serum IGF-Ⅰ concentration was measured by radioimmunoassay (RIA). IGF-Ⅰ levels in both groups decreased gradually as pregnancy stage proceeded but were not significantly different. Secondly, DNA was extracted from blood and PCR-RFLP was utilized to analyze ER genotypes of pigs in each group, which produced three polymorphic patterns. Based on the ER genotypes analyzed, low litter size group showed higher IGF-Ⅰ concentration than high litter size group. Taken together, the results indicate that the serum IGF system was correlated with steroid system but not with the litter size in pigs. Thus, this study implies that porcine litter size could be determined locally at the ovary level.

• Journal of Periodontal and Implant Science
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• v.30 no.2
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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.

• Food Science of Animal Resources
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• v.26 no.1
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• pp.113-120
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• 2006

Insulin-like growth factor-I(IGF-I) rich fraction, which was obtained molecules ranged between 30 and 1 kDa, was fractionated by ultrafiltration from bovine colostral whey. IGF-I rich fraction was confirmed by SDS-PACE and western blotting and then the quantity of IGF-I was measured by sandwich ELISA. ICF-I concentration in IGF-I rich fraction was 10 ng/mg proteins. IGF-I rich fraction, standard IGF-I and colostral whey weie treated to murine peritoneal macrophages. And then we experimented that effect of immune activity on macrophage and splenocyte. As a result, in group treated with IGF-I rich fraction $1{mu}g/mL$, production of interleukin-6 and nitric oxide were 9.85 ng and $17.17{\mu}M$ and production of phagocytosis, tumor necrosis factor-${\alpha}\;and\;H_{2}O_{2}$ were 78.3, 34.5 and 6% compared to the control group. In splenocyte immune response, B cell and T cell proliferation and NK cell activity were 103, 126 and 22.2% in group treated with IGF-I rich fraction $1{\mu}g/mL$ to compared to the control, respectively.

• Journal of Genetic Medicine
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• v.2 no.1
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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.