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PubMed1994

[Local factors in bone remodeling. II. Factors stimulating bone resorption].

In this article, author gives a surveillance of factors, locally produced in bone tissue, which stimulate bone resorption. Production of local factors in bone tissue cells is initiated by various hormones, including some systemic hormones. Some new hypothesis about relation of systemic hormones activity and local bone tissue factors production are described including hypothesis about function of estrogens on bone.

Animals↗

PubMed2004

Insulin-like growth factor-II regulates the expression of vascular endothelial growth factor by the human keratinocyte cell line HaCaT.

Psoriasis is a chronic, relapsing skin disease characterized by enhanced angiogenesis. The pathogenetic process resulting in hypervascularity remains to be further investigated. It has been reported that a potent angiogenic factor, vascular endothelial growth factor (VEGF) is overexpressed in psoriatic epidermis and that the level of insulin-like growth factor II (IGF-II) is significantly elevated in the tissue fluid and serum of the psoriatic lesion. We considered the possibility that IGF-II might function as a paracrine inducer of VEGF. Here, we demonstrated that exposure of HaCaT keratinocytes to IGF-II induced both mRNA and protein expression of VEGF through the MAP kinase (extracellular signal-regulated kinase (ERK2) pathway. Particularly, we determined that phosphorylation of ERK2 but not p38 and JNK1/2 was activated by IGF-II in a time-dependent manner. Additionally, we found that IGF-II treatment induced the expression of MDM2 through the MAP kinase pathway. Moreover, the increase of MDM2 resulted in decreased levels of p53 followed by increased expression of HIF-1alpha and VEGF. Taken together, these results suggest that IGF-II enhances the expression of VEGF in HaCaT cells by increasing HIF-1alpha levels.

Cell Line↗

PubMed1994

Expression of insulin-like growth factor II in hepatitis B, cirrhosis and hepatocellular carcinoma: its relationship with hepatitis B virus antigen expression.

Expression of insulin-like growth factor II in two human hepatocellular carcinoma cell lines and in hepatitis B, cirrhosis and hepatocellular carcinoma in 419 cases were investigated, and its relationship with the expression of hepatitis B virus X gene was studied by means of immunohistochemical and electron microscopic techniques. The results demonstrated that hepatocellular carcinoma cells (SMMC 7721 and QGY 7703) in culture could express insulin-like growth factor II. Expression seemed to be regulated by cell density, which was suggested as the molecular basis of the contact inhibition of cell proliferation. In tissue sections, cells with high expression of insulin-like growth factor II were observed not only in hepatocellular carcinoma (93%) but also in 95% of the pericancerous liver tissues, 72% of cirrhotic livers, 64% of chronic active hepatitis and 37% of chronic persistent hepatitis. In most cases of hepatocellular carcinoma, insulin-like growth factor II was localized in the cytoplasm of the cancer cells. In the benign liver disorders, four types of cells that highly expressed insulin-like growth factor II were observed: (a) a kind of small liver cell we named the small polygonal liver cell; (b) multinuclear giant hepatocytes; (c) hepatocytes in most of hyperplastic and neoplastic nodules, small hepatocyte nodules and some of regenerative nodules; and (d) some proliferating ductular cells. Even more interestingly, insulin-like growth factor II expression was shown to be closely related to the expression of hepatitis B virus X gene product. We suggest that the activation of insulin-like growth factor II gene and its overexpression may be a crucial step in the processes of hepatitis B virus-associated hepatocarcinogenesis and that the X gene product may activate the insulin-like growth factor II gene through a transactivation mechanism. In addition, we studied the characteristics of small polygonal liver cells, and the roles they may play in the regeneration and carcinogenesis of hepatitis B virus-infected liver are discussed.

Carcinoma, Hepatocellular↗

PubMed1997

Insulin-like growth factor II signaling through the insulin-like growth factor II/mannose-6-phosphate receptor promotes exocytosis in insulin-secreting cells.

The insulin-like growth factor II (IGF-II)/mannose-6-phosphate (M-6-P) receptor is known to participate in endocytosis as well as sorting of lysosomal enzymes and is involved in membrane trafficking through rapid cycling between cytosolic membrane compartments and the plasma membrane. Here we demonstrate that IGF-II, acting through the IGF-II/M-6-P receptor, promotes exocytosis of insulin in the pancreatic beta cell. The effect of IGF-II was evoked at nonstimulatory concentrations of glucose, was mediated by a pertussis toxin sensitive GTP-binding protein, was dependent on protein kinase C-induced phosphorylation, and was independent of changes in cytoplasmic free Ca2+ concentration. Since the applied concentration of IGF-II is within the range normally found free in circulation in humans, this novel signaling pathway for the IGF-II/M-6-P receptor is likely to be involved in modulation of insulin exocytosis under physiological conditions.

Adenosine Triphosphate↗

PubMed2006

Influence of tumor necrosis factor-alpha on estradiol, progesterone, insulin-like growth factor-II, and insulin-like growth factor binding protein-1, 2, and 3 in cultured human luteinized granulosa cells.

OBJECTIVE: The objective was to investigate the influence of tumor necrosis factor (TNF)-alpha on estradiol, progesterone, insulin-like growth factor (IGF)-II, and insulin-like growth factor binding protein (IGFBP)-1, 2, and 3 in cultured human luteinized granulosa cells. STUDY DESIGN: Human luteinized granulosa cells were obtained from follicular fluid by transvaginal oocyte aspiration from infertile patients undergoing controlled ovarian hyperstimulation (COH) for in vitro fertilization (IVF). The cells were cultured for 72 h with TNF-alpha at concentrations of 1.0, 10.0, and 100.0 ng/ml. The cells not treated with TNF-alpha served as controls. Radioimmunoassay (RIA) and reverse transcription-polymerase chain reaction (RT-PCR) were used to examine the influence of TNF-alpha on estradiol, progesterone, IGF-II, and IGFBP-1, 2, and 3. Results were analyzed using the Kolmogorov-Smirnov test and analysis of variance (ANOVA). Statistical significance was defined as p<0.05. RESULTS: The concentrations of progesterone seemed to decrease as the concentrations of TNF-alpha increased and the concentration of progesterone in the 100.0 ng/ml TNF-alpha group was significantly lower than that in the control and other TNF-alpha groups. The expressions of IGF-II mRNA in the 10.0 and 100.0 ng/ml TNF-alpha groups were significantly lower than that in the control group. The expressions of IGFBP-2 mRNA seemed to be decreased in the 10.0 and 100.0 ng/ml TNF-alpha groups compared with that in the control group, but there were no statistical significances. CONCLUSION: TNF-alpha may play a role as a regulator of human ovarian physiology by modulating the IGF systems in luteinized granulosa cells.

Adult↗

PubMed1995

Insulin-like growth factor II mediates epidermal growth factor-induced mitogenesis in cervical cancer cells.

There is increasing evidence that activation of the insulin-like growth factor I (IGF-I) receptor plays a major role in the control of cellular proliferation of many cell types. We studied the mitogenic effects of IGF-I, IGF-II, and epidermal growth factor (EGF) on growth-arrested HT-3 cells, a human cervical cancer cell line. All three growth factors promoted dose-dependent increases in cell proliferation. In untransformed cells, EGF usually requires stimulation by a "progression" factor such as IGF-I, IGF-II, or insulin (in supraphysiologic concentrations) in order to exert a mitogenic effect. Accordingly, we investigated whether an autocrine pathway involving IGF-I or IGF-II participated in the EGF-induced mitogenesis of HT-3 cells. With the RNase protection assay, IGF-I mRNA was not detected. However, IGF-II mRNA increased in a time-dependent manner following EGF stimulation. The EGF-induced mitogenesis was abrogated in a dose-dependent manner by IGF-binding protein 5 (IGFBP-5), which binds to IGF-II and neutralizes it. An antisense oligonucleotide to IGF-II also inhibited the proliferative response to EGF. In addition, prolonged, but not short-term, stimulation with EGF resulted in autophosphorylation of the IGF-I receptor, and coincubations with both EGF and IGFBP-5 attenuated this effect. These data demonstrate that autocrine secretion of IGF-II in HT-3 cervical cancer cells can participate in EGF-induced mitogenesis and suggest that autocrine signals involving the IGF-I receptor occur "downstream" of competence growth factor receptors such as the EGF receptor.

Base Sequence↗

PubMed1995

Differential expression of transforming growth factor alpha and insulin-like growth factor II in chronic active hepatitis B, cirrhosis and hepatocellular carcinoma.

In the present study we investigated the expression of transforming growth factor alpha and insulin-like growth factor II to explain the role of these growth factors in the development of hepatocellular carcinoma from chronic active hepatitis B and cirrhosis. The expression of transforming growth factor alpha and insulin-like growth factor II was tested in 38 tissue samples from patients with chronic active hepatitis B, 32 cirrhosis and 31 hepatocellular carcinoma, by immunohistochemical staining using monoclonal anti-transforming growth factor alpha and anti-insulin-like growth factor II. All patients were seropositive for HBsAg. Transforming growth factor alpha was expressed in 26 (68.4%) of 38 chronic active hepatitis B, 18 (56.3%) of 32 cirrhosis and 16 (51.6%) of 31 hepatocellular carcinoma tissue samples. Transforming growth factor alpha was found in the periportal hepatocytes of chronic active hepatitis B and in regenerating hepatocytes of cirrhotic nodules. In hepatocellular carcinoma tissues, transforming growth factor alpha-containing tumor cells were evenly distributed within the tumor tissues but focal distribution limited to a part of tumor tissues was also observed. The expression of insulin-like growth factor II was observed in 30 (93.8%) of 32 cirrhosis and all the 31 hepatocellular carcinoma tissue samples tested, but not in chronic active hepatitis B samples. Insulin-like growth factor II was expressed in most hepatocytes of regenerating nodules and in tumorous as well as non-tumorous hepatocytes of hepatocellular carcinoma tissues.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1985

Association of hereditary heparin co-factor II deficiency with thrombosis.

A family was investigated for heparin co-factor II deficiency. Three of the five members examined had had thrombosis and their levels of heparin co-factor II were reduced to 50%. All five members had antithrombin III levels within the normal range. Analysis on crossed immunoelectrophoresis showed no qualitative abnormality of patient heparin co-factor II antigen. Since heparin co-factor II activity and concentration were reduced to the same extent, the deficiency was due to reduced protein synthesis.

Adult↗

PubMed1987

Vitamin K in the newborn: influence of nutritional factors on acarboxy-prothrombin detectability and factor II and VII clotting activity.

The incidence of acarboxy-prothrombin and the clotting activity of factors II and VII were evaluated on the fifth day of life in 183 healthy newborns, who had received no vitamin K prophylaxis. Acarboxy-prothrombin was detected in 93/183 newborns. All acarboxy-prothrombin-negative babies had factors II and VII clotting activities above 25% whereas a great variability was observed in acarboxy-prothrombin-positive babies: 21/93 had factor II and 14/93 had factor VII activities below 25%. Seventy-two of the acarboxy-prothrombin-positive babies had normal factor II and VII clotting times on the fifth day of life. These babies must be suspected to have had vitamin K deficiency on one of the first 4 days, as acarboxy-prothrombin has a 50% disappearance rate of 50 h. Acarboxy-prothrombin was mainly observed in breast-fed infants (84/122) and only rarely detectable in infants receiving supplementary (7/44) or exclusive formula feeding (2/17). The type of milk feeding however might be less important for the babies' vitamin K supply than the actual milk intake. All acarboxy-prothrombin-positive babies had received small amounts of milk on the first 4 days of life. In those with low factor II and VII clotting activities the milk intake was low throughout the first 4 days of life, whereas babies with acarboxy-prothrombin and and normal clotting activities had increased their milk intake to more than 100 ml on the third and fourth day of life. Recommendations for vitamin K prophylaxis in newborns should be given with regard to the feeding on the first days of life.

Biomarkers↗

PubMed1990

Insulin-like growth factor II and nonsuppressible insulin-like activity levels in newborns.

We measured insulin-like growth factor II and nonsuppressible insulin-like activity levels in the sera of newborn infants with different birth weights and gestational ages to determine the significance of these peptides in fetal growth. Our results obtained by use of one-way analysis of variance showed that the insulin-like growth factor II and nonsuppressible insulin-like activity levels in premature, average-weight-for-gestational-age, large-for-gestational-age, and small-for-gestational-age newborns were significantly different (p less than 0.01). Although levels in the premature neonates were less than the other three groups and large-for-gestational-age neonates had a higher insulin-like growth factor II level than the other three groups, maternal insulin-like growth factor II levels in all groups were similar. These results suggest that insulin-like growth factor II may play a major role in fetal growth.

Analysis of Variance↗

PubMed2003

Evaluation of electronic microarrays for genotyping factor V, factor II, and MTHFR.

BACKGROUND: Genetic risk factors associated with venous thrombosis include mutations in the factor V (Leiden), factor II (prothrombin), and methylenetetrahydrofolate reductase (MTHFR) genes. We evaluated a method using electronically addressable microarrays for the detection of mutations in these genes that have been associated with vascular disease. METHODS: The NanoChip Molecular Biology Workstation (Nanogen) uses electronic microarrays for mutation detection. Factor V, factor II, and MTHFR genotypes identified in the NanoChip system on 225 samples were compared with genotypes from LightCycler assays (Roche). We determined within- and between-cartridge signal and ratio variation and analyzed the effect of additional mutations at or near the detection area used for the NanoChip assays. RESULTS: Genotypes determined for all three mutations on the NanoChip platform were in complete concordance with LightCycler results. Within-cartridge signal variation as measured by the CV of fluorescence signals was <10% for each allele when present. The within-cartridge CV for heterozygous mutant/wild-type ratios was <8.5%, and between-cartridge CV was <18%. A dilution study showed that results could be obtained in this assay with 6 ng of nucleic acid per PCR, the lowest input tested. The presence of additional sequence variations near the expected mutations can produce equivocal or discrepant results. CONCLUSIONS: Mutation detection using the NanoChip Molecular Biology Workstation was accurate and reproducible for the three assays evaluated.

Electronics↗

PubMed1997

Plasma levels of factors II, VII and X and their relationship to the international normalized ratio during chronic warfarin therapy.

Monitoring of oral anticoagulant therapy is usually undertaken with the prothrombin time (PT), which is influenced by factors II, X, and VII. A number of studies have suggested that the prothrombin (factor II) level may be the most important determinant of the therapeutic efficacy of these drugs. Although some studies suggest that oral anticoagulants induce a similar residual level of plasma vitamin K-dependent proteins, others have called this into question. We therefore measured plasma levels of factors II, X, and VII in 50 patients undergoing chronic Warfarin therapy. The plasma levels of factors II, X, and VII were significantly different. Although the factor X levels of all plasmas were < 30%, levels of factors II and VII were > 30% in 14% and 50% of the samples, respectively. Multivariable analysis showed factor II levels to be the least significant of the three factors measured in determining the international normalized ratio of plasma or whole blood. Thus, plasma levels of the vitamin K-dependent coagulation factors are not equal in patients on chronic Warfarin therapy. If factor II (prothrombin) levels are indeed the major determinants of the therapeutic efficacy of Warfarin, alternative means of monitoring that more accurately reflects prothrombin levels should be evaluated.

Administration, Oral↗

PubMed2004

Interplay of insulin-like growth factor-II, insulin-like growth factor-I, insulin-like growth factor-I receptor, COX-2, and matrix metalloproteinase-7, play key roles in the early stage of colorectal carcinogenesis.

PURPOSE: The aim of this study was to characterize the relationship of insulin-like growth factor (IGF)-II expression with IGF-I, IGF-I receptor (IGF-IR), cyclooxygenase-2 (COX-2), and matrix metalloproteinase (MMP)-7 in early colorectal carcinogenesis. EXPERIMENTAL DESIGN: With the semiquantitative reverse transcriptase-PCR, 90 human colorectal tumor tissues (63 adenomas and 27 submucosal pT1 cancers) were analyzed for IGF-II, IGF-IR, IGF-I, COX-2, and MMP-7 expression. Ninety-nine adenoma tissues and 60 pT1 cancer tissues were also analyzed immunohistochemically for IGF-II expression. Loss of imprinting of the IGF-II gene was analyzed. Paired carcinoma and adenoma tissues obtained from a carcinoma in adenoma lesion was analyzed by a cDNA array. RESULTS: IGF-II mRNA expression was detected in 37.8% of the 90 colorectal tumor tissues. The frequency of IGF-II mRNA expression was significantly higher in pT1 cancer (70.4%) than in adenoma (23.8%). Immunohistochemical IGF-II expression was also more frequently detected in pT1 cancer (58.3%) than in adenoma (25.3%). Loss of imprinting of the IGF-II gene was observed in 15 (44.1%) of the 34 colorectal tumors in which IGF-II was overexpressed. IGF-II expression was positively correlated with the expression of IGF-IR and IGF-I. COX-2 and MMP-7 mRNA expression was detected in 42.2% and 77.8% of the tumor tissues, respectively, and both were positively correlated with IGF-I, IGF-II, and IGF-IR expression. IGF-II was the most differentially expressed gene between carcinoma and adenoma lesions. CONCLUSIONS: IGF-II, in conjunction with IGF-IR, IGF-I, COX-2, and MMP-7, seems to play a key role in the early stage of colorectal carcinogenesis.

Adenocarcinoma↗

PubMed1990

Radioimmunoassay for insulin-like growth factor II (IGF-II).

Insulin-like growth factor II (IGF-II) levels in human plasma were measured in physiological and pathological conditions by radioimmunoassay (RIA) with biosynthetic IGF-II. This RIA was specific for IGF-II and cross-reactivity with IGF-I was 1%. The sensitivity was 15 pg/tube with 50% displacement at 50 pg/tube. The intra- and inter-assay coefficients of variation for IGF-II were 6.3 and 9.3%, respectively. The plasma IGF-II levels in normal adults, patients with hypopituitarism and patients with active acromegaly were 589.6 +/- 15.8, 800.9 +/- 45.6 and 330.3 +/- 24.3 ng/ml, respectively. After human growth hormone (hGH) treatment in hypopituitarism, IGF-II slightly increased, but not significantly. After adenomectomy in patients with acromegaly, IGF-II significantly decreased. These data indicate that IGF-II concentrations in plasma were partially GH dependent. This GH dependency was less than that of IGF-I. IGF-II was low in patients with anorexia nervosa and with liver cirrhosis and high in patients with renal failure. In two cases with extrapancreatic tumor-associated hypoglycemia, plasma IGF-II was increased to 1123.8 and 843.5 ng/ml, and returned to normal after tumor resection. These data showed that IGF-II was partly dependent on GH and nutritional conditions and that IGF-II was the most likely cause of some cases of hypoglycemia with extrapancreatic tumor. This specific and sensitive RIA of IGF-II would be useful in evaluating its physiological and pathological role in plasma and tissue.

Acromegaly↗

PubMed1998

Insulin-like growth factor II (IGF-II).

Insulin-like growth factor II (IGF-II) plays a key role in mammalian growth, influencing foetal cell division and differentiation and possibly metabolic regulation. The mature 67 amino acid peptide shares sequence homology with both insulin and IGF-I. The liver is the main endocrine source of IGFs, but autocrine/paracrine activity is found in most tissues. The type 1 receptor mediates most of the biological effects of IGF-I and IGF-II; the type 2 receptor is involved with IGF-II degradation. Binding proteins may both localise IGFs to the receptors and regulate their activities. The IGF2 gene is maternally imprinted in mouse and human. Relaxation of IGF2 imprinting occurs in the Beckwith-Wiedemann syndrome of somatic overgrowth, sporadic Wilms' tumour and a number of other cancers. In the general adult population, the IGF2-INS gene cluster may also influence body weight, in which case IGF-II function could become a target for therapeutic intervention in obesity.

Adult↗

PubMed1986

Coordinate developmental regulation of high and low molecular weight mRNAs for rat insulin-like growth factor II.

Insulin-like growth factor II (IGF-II) is a mitogenic polypeptide that is thought to play a role in fetal growth and development. To study the hormonal and developmental regulation of IGF-II gene expression, we have isolated a cDNA clone for rat IGF-II (rIGF-II) from a 12S [1.2-kilobase-pair (kbp)] fraction of mRNA from a rat liver cell line (BRL-3A) that directs the cell-free synthesis of pre-pro-rIGF-II. In the present study, the rIGF-II probe was used to determine the size of IGF-II RNA. Surprisingly, in BRL-3A cells and in neonatal liver, the probe hybridized under stringent conditions 10-20 times more strongly to a larger (4 kbp) RNA than to 1.2-kbp RNA. The 4-kbp RNA is almost exclusively cytoplasmic and is colinear with a 551-base fragment of the rIGF-II cDNA insert containing coding and 3' noncoding regions. The 4-kbp and 1.2-kbp RNA species are regulated coordinately with developmental age, being high in liver from neonatal rats but not detectable in liver from older animals, suggesting that both IGF-II mRNA species arise from a single primary transcript by alternative RNA processing. Although oligodeoxynucleotide hybridization and S1 nuclease protection experiments suggest that the 4-kbp RNA contains an intact protein-coding region, fractions enriched in 4-kbp RNA do not direct the translation of pre-pro-rIGF-II in vitro. This may indicate that the 4-kbp RNA specifies an altered protein product that has not yet been recognized, or alternatively that it contains a normal protein-coding region but requires further RNA processing to be activated for translation.

Animals↗

PubMed1995

Skeletal growth of transgenic mice with elevated levels of circulating insulin-like growth factor-II.

Insulin-like growth factor-II (IGF-II) is a major factor produced by skeletal tissues. To evaluate endocrine effects of IGF-II on bone growth, we measured skeletal dimensions of 12-week-old transgenic mice harbouring fusion genes where a human IGF-II cDNA is transcriptionally controlled by rat phospheonolpyruvate carboxykinase (PEPCK) promoter sequences. Transgene expression in liver, kidney and intestine resulted in circulating IGF-II levels in transgenic mice which were 2-3-fold higher than in controls. Serum IGF-I concentrations of transgenic mice were lower than in controls. Body weight was not influenced by the expression of the IGF-II transgene. Only 1 out of 5 measurements taken from the radius was significantly affected by the presence of the transgene, while in 60 measurements taken from eight other bones there was no difference between transgenic mice and controls. Furthermore, serum levels of calcium and phosphate as well as alkaline phosphatase activity were not significantly altered in PEPCK-IGF-II transgenic mice. Our findings demonstrate that moderately increased levels of circulating IGF-II do not cause major changes in skeletal growth and turnover in mice. This may be due to a lack of activity of circulating IGF-II on bone growth or to physiological consequences of elevated IGF-II, like a reduction of circulating IGF-I or an increase in IGF binding proteins.

Animals↗

PubMed1991

Differential expression of insulin-like growth factor II in human meningiomas.

Two glioma tumor lines and brain tumor specimens from 10 patients were analyzed to determine genic expression of insulin-like growth factor II. Messenger ribonucleic acid encoding insulin-like growth factor II was found to be expressed in significant amounts in two of two meningiomas but not in any of the gliomas. Immunofluorescence studies on these tumors and normal brain confirmed the presence of insulin-like growth factor II in both meningiomas, but not in any of the gliomas or in normal brain. Within the meningiomas, only a small number of cells highly expressed insulin-like growth factor II immunoreactive material, and this could be evidence for a paracrine mechanism in these tumors. These data suggest that the enhanced expression of insulin-like growth factor II may be a characteristic of meningiomas.

Adult↗