Increased Expression Of IGF-1 Research Articles

Distinct allelic expression patterns of imprinted IGF2 in adenocarcinoma and squamous cell carcinoma of the lung.

The insulin-like growth factor 2 gene (IGF2) is an imprinting gene, which mediates cell growth and apoptosis. The loss of imprinting (LOI) of IGF2 has been associated with the development of cancer. In the present study, loss LOI of IGF2 in lung cancer was analyzed using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) in combination with DNA sequencing of samples collected by laser capture microdissection. The status of each sample was assigned as imprinting when PCR-RFLP revealed only one band or sequence with a single peak; otherwise, the case was classified as LOI. LOI was identified in eight out of 13 adenocarcinoma cases (62%), but was not detected in any of the nine squamous cell carcinoma cases (0%). These results suggest that IGF2 LOI is involved in the molecular pathogenesis of lung adenocarcinoma, but not squamous cell carcinoma, and that LOI may be detected through increased IGF2 expression levels.

Upregulation of IGF2 expression during vascular calcification

The process of vascular calcification shares many similarities with that of skeletal mineralisation and involves the deposition of hydroxyapatite crystals in arteries and cardiac valves. However, the cellular mechanisms responsible have yet to be fully elucidated. In this study, we employed microarray analysis to demonstrate the upregulation of more than >9000 genes during the calcification of murine vascular smooth muscle cells (VSMCs), of which the most significantly, differentially expressed gene was Igf2. Following the validation of increased IGF2 expression by RT-qPCR and immunoblotting in calcifying murine VSMCs, IGF2 expression was further demonstrated in the calcified aorta of the Enpp1(-/-) mouse model of medial aortic calcification. Having confirmed that IGF1R and IGF2R were expressed in cultured murine VSMCs, cell-signalling studies in these cells revealed that IGF2 (50 ng/ml) significantly stimulated the phosphorylation of Akt and Erk1/2 (P<0.05). These results potentially indicate that IGF2 may mediate VSMC calcification via the stimulation of Erk1/2 and Akt signalling. This study suggests that the increased IGF2 expression in calcifying VSMCs may reflect the well-established prenatal role of IGF2, particularly as the osteogenic phenotypic transition of VSMCs in a calcified environment recapitulates many of the events occurring during embryonic development. A full understanding of the importance of IGF2 in this pathological process will lead to a better understanding of the aetiology of vascular calcification.

Effects of adenoviral vector expressing hIGF-1 on apoptosis in nucleus pulposus cells in vitro

The excessive apoptosis of cells of the nucleus pulposus may plays an important role in intervertebral disc (IVD) degeneration. It has been shown that the pro-inflammatory cytokine tumour necrosis factor (TNF)-α can induce disc cell apoptosis. Insulin-like growth factor (IGF)-1 can promote nucleus pulposus cell proliferation; however, whether or not IGF-1 inhibits TNF-α-induced apoptosis in the nucleus pulposus has not yet been elucidated. In this study, our objective was to create a potentially therapeutic viral vector, which could be used to achieve the enforced expression of IGF-1 in rabbit nucleus pulposus cells. Furthermore, we investigated the ability of IGF-1 to reverse TNF-α-induced apoptosis in cells of the nucleus pulposus. Isolated nucleus pulposus cells were cultured to a confluent monolayer, digested with collagenase Ⅱ and purified using trypsin and differential adhesion methods. Nucleus pulposus cells were positively identified using type Ⅱ collagen immunohistochemistry. Following transfection with adenoviral vectors engineered to overexpress recombinant human IGF-1 (Ad-hIGF-1) or TNF-α, the cells were observed under a light microscope. Terminal deoxynucleotidyl transferase (TdT)-mediated dUTP-biotin nick end-labeling (TUNEL) and flow cytometry (FCM) were used to assess the rate of apoptosis. The Ad-hIGF-1 viral vector was effectively transduced into the nucleus pulposus cells and increased IGF-1 expression as confirmed by RT-PCR and western blot analysis. In the TNF-α-treated group, a large number of apoptotic cells was observed that exhibited morphological changes associated with this form of cell death. Minimal apoptosis was observed in the Ad-hIGF-1-treated group and the control group showed no obvious signs of apoptosis. TUNEL assay revealed that the rate of apoptosis in the Ad-hIGF-1 group was significantly reduced compared with the TNF-α-treated group (P<0.01). This result was confirmed using FCM. The rate of apoptosis was also significantly increased in the TNF-α-exposed cells compared with the control group (P<0.01). Our findings strongly suggest that the adenoviral vector expressing hIGF-1 can successfully infect nucleus pulposus cells in vitro and effectively enhance the expression of IGF-1. In addition, IGF-1 reversed the TNF-α -induced apoptosis of nucleus pulposus cells. Thus, Ad-hIGF-1 may be useful in the development of clinical interventions for disc degeneration.

Single Nucleotide Polymorphism Array Profiling of Adrenocortical Tumors - Evidence for an Adenoma Carcinoma Sequence?

Adrenocortical tumors consist of benign adenomas and highly malignant carcinomas with a still incompletely understood pathogenesis. A total of 46 adrenocortical tumors (24 adenomas and 22 carcinomas) were investigated aiming to identify novel genes involved in adrenocortical tumorigenesis. High-resolution single nucleotide polymorphism arrays (Affymetrix) were used to detect copy number alterations (CNAs) and copy neutral losses of heterozygosity (cnLOH). Genomic clustering showed good separation between adenomas and carcinomas, with best partition including only chromosome 5, which was highly amplified in 17/22 malignant tumors. The malignant tumors had more relevant genomic aberrations than benign tumors, such as a higher median number of recurrent CNA (2631 vs 94), CNAs >100 Kb (62.5 vs 7) and CN losses (72.5 vs 5.5), and a higher percentage of samples with cnLOH (91% vs 29%). Within the carcinoma cohort, a precise genetic pattern (i.e. large gains at chr 5, 7, 12, and 19, and losses at chr 1, 2, 13, 17, and 22) was associated with a better prognosis (overall survival: 72.2 vs 35.4 months, P=0.063). Interestingly, >70% of gains frequent in beningn were also present in malignant tumors. Notch signaling was the most frequently involved pathway in both tumor entities. Finally, a CN gain at imprinted “IGF2” locus chr 11p15.5 appeared to be an early alteration in a multi-step tumor progression, followed by the loss of one or two alleles, associated with increased IGF2 expression, only in carcinomas. Our study serves as database for the identification of genes and pathways, such as Notch signaling, which could be involved in the pathogenesis of adrenocortical tumors. Using these data, we postulate an adenoma-carcinoma sequence for these tumors.

Increasing expression of insulin-like growth factor I in masseter as protective therapy targeting the muscular apoptosis and remodeling physiology of TMD pain

The temporomandibular joint (TMJ) is a site of chronic pain problems commonly associated with overload in the muscles of mastication and the resulting stress on the joint. A potential therapy can be seen in the ability of insulin-like growth factor I (IGF-1) to enhance repair and maintain tissue health. Faster and increased growth and repair through increased IGF-1 expression in the masseter may promote muscle that is more resistant to the normal increase in apoptosis found in overloaded masseter, potentially reducing symptoms of TMJ pain.

Molecular analysis of the randomized phase II/III study of the anti-IGF-1R antibody dalotuzumab (MK-0646) in combination with cetuximab (Cx) and irinotecan (Ir) in the treatment of chemorefractory KRAS wild-type metastatic colorectal cancer (mCRC).

3531 Background: Previously reported results of this randomized study demonstrated that the addition of dalotuzumab (Dz) worsened the PFS and OS of chemofractory mCRC patients receiving Cx and Ir (Watkins et al; ASCO 2011). Comprehensive molecular analysis has been undertaken retrospectively to identify possible predictors of Cx resistance and Dz response. Methods: Quantitative RT-PCR for IGF-1, IGF-2, immunohistochemistry for IGF-1R and microarray expression profiling was conducted on archival tumor tissue. All patients had received Cx and Ir with either placebo (n=107), weekly Dz (n=112), or 2 weekly Dz (n=110). Results: Data from 292 and 206 patients was successfully obtained by RT-PCR or microarray respectively. Within the placebo arm, high IGF-1 expression was found to be associated with resistance to Cx (IGF-1-/IGF-1+; PFS 6.7/3.7 months, OS 15.5/9.6 months). High IGF-1 expression was associated with benefit from the addition of weekly Dz (placebo/weekly Dz; PFS 3.7/5.7 months, OS 9.6/18.2 months). By contrast the addition of Dz was not effective in tumors with high IGF-2 expression (placebo/weekly Dz; PFS 8.4/2.7 months). Microarray analysis revealed distinct populations that differentially correlated with Cx and Dz response. An epithelial phenotype appeared more associated with Cx response, whereas a mesenchymal phenotype more associated with Dz response. Rectal cancers showed greater association with increased IGF-1 expression, EMT gene signature and Dz response. Conclusions: These data support IGF-1 and IGF-2 as potential biomarkers for response to Dz therapy and high IGF-1 as a marker of resistance to Cx therapy. Based on these data Dz is being further evaluated in a molecularly selected population of mCRC. [Table: see text]

Wt1 ablation and Igf2 upregulation in mice result in Wilms tumors with elevated ERK1/2 phosphorylation

Wilms tumor (WT) is a genetically heterogeneous childhood kidney tumor. Several genetic alterations have been identified in WT patients, including inactivating mutations in WT1 and loss of heterozygosity or loss of imprinting at 11p15, which results in biallelic expression of IGF2. However, the mechanisms by which one or a combination of genetic alterations results in tumorigenesis has remained challenging to determine, given the lack of a mouse model of WT. Here, we engineered mice to sustain mosaic, somatic ablation of Wt1 and constitutional Igf2 upregulation, mimicking a subset of human tumors. Mice with this combination of genetic alterations developed tumors at an early age. Mechanistically, Wt1 ablation blocked mesenchyme differentiation, and increased Igf2 expression upregulated ERK1/2 phosphorylation. Importantly, a subset of human tumors similarly displayed upregulation of ERK1/2 phosphorylation, which suggests ERK signaling might contribute to WT development. Thus, we have generated a biologically relevant mouse model of WT and defined one combination of driver alterations for WT. This mouse model will provide a powerful tool to study the biology of WT initiation and progression and to investigate therapeutic strategies for cancers with IGF pathway dysregulation.

Abstract 4912: The role of long-range enhancer blocker CTCF in TGF-β/β-2 spectrin signaling: A human cancer stem cell disorder, Beckwith-Wiedemann syndrome

Abstract Hereditary cancer syndromes provide powerful insights into dysfunctional signaling pathways that lead to sporadic cancers. Beckwith-Wiedemann syndrome (BWS) is a hereditary human cancer stem cell syndrome currently linked to deregulated imprinting at chromosome 11p15 and uniparental disomy (UPD) and is characterized by overgrowth and is associated with an 800-fold increased risk of embryonal neoplasms of childhood that include Wilms’ tumors, hepatoblastomas, pancreatoblastoma, neuroblastoma, rhabdomyosarcoma, and adrenocortical carcinomas. The transcriptional insulator CTCF (CCCTC-binding factor), a highly conserved zinc finger protein, has been implicated in BWS and has diverse regulatory functions, including transcriptional activation/repression, insulation, imprinting, and X chromosome inactivation However, causal molecular defects and genetic models have remained elusive to date in the majority of cases. TGF-β employs Smad proteins as intracellular mediators of signaling to regulate the target gene expression by activating or repressing gene transcription. The non-pleckstrin homology (PH) domain β-general-spectrin (β2SP), a scaffolding protein, functions as a potent TGF-β signaling Smad3/4 adaptor in tumor suppression and development. Yet, the role of the β2SP/TGF-β pathway in human tumor syndromes remains unclear, Our previous data have shown that β2SP is an important effector of TGF-β tumor suppressor function. Deletion of β2SP results in a dramatic and spontaneous formation of liver, gastrointestinal (GI) and pancreatic cancers. Aims: In this study, we investigated the relationship between epigenetic silencing of β-2 Spectrin/TGF-β[[Unsupported Character - &amp;#61472;]] Signaling and loss of CTCF protein stabilization in a Human Cancer Stem Cell Disorder: Beckwith-Wiedemann Syndrome. Results show that: 1) β2SP is silenced at its promoter by DNA Methylation in human BWS non-tumor tissues and cell lines. 2) Loss of β2SP, mis-localization of Smad3 and disruption of TGF-β signaling are observed in human Beckwith-Wiedemann non-tumor tissues and cell lines 3) Ectopic expression of β2SP in human BWS cells rescues Smad3 localization and TGF-β target gene activation 4) Increased IGF2 expression in β2SP+/− and β2SP+/−/Smad3+/− mice is similar to that observed in human BWS. 5) CTCF protein levels are markedly decreased in β2SP+/− and β2SP+/−/Smad3+/− tissues. Conclusions: Our results suggest that epigenetic regulation of the TGF-β pathway results in the loss of β2SP and its crucial Smad3 adaptor function. The loss of an adaptor protein β2SP affecting CTCF stabilization, is causally related to the genesis and progression of human BWS. In addition, β2SP+/− and β2SP+/−/Smad3+/− mice provide an important animal model to study BWS. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 4912.

Loss of imprinting of IGF2 correlates with hypermethylation of the H19 differentially methylated region in hepatoblastoma

IGF2, a maternally imprinted foetal growth factor gene, is implicated in many childhood tumours including hepatoblastoma (HB); however, the genetic and epigenetic alterations have not comprehensively been studied. We analysed the methylation status of the H19 differentially methylated region (DMR), loss of heterozygosity (LOH) and allelic expression of IGF2 in 54 HB tumours, and found that 12 tumours (22%) with LOH, 9 (17%) with loss of imprinting (LOI) and 33 (61%) with retention of imprinting (ROI). Biallelic and monoallelic IGF2 expressions correlated with hypermethylation and normal methylation of H19 DMR, respectively, in two tumours with LOI and seven tumours with ROI. Quantitative RT–PCR analysis showed minimal expression of H19 mRNA and substantial expression of IGF2 mRNA in tumours with LOH or LOI, and substantial expression of both H19 and IGF2 mRNAs in tumours with ROI. Increased IGF2 expression with predominant embryonic P3 transcript was found in the majority of HBs with ROI and foetal livers. In contrast to the earlier reports, our findings suggest that the disruption of the enhancer competition model reported in Wilms' tumour may also occur in HB. Both frequencies of LOH and LOI seem to be lower in HB than in Wilms' tumour, reflecting the different tissue origins.

Insulin‐like growth factor‐1 gene therapy and cell transplantation in diabetic wounds

Impaired wound healing is a frequent phenomenon in diabetes mellitus. However, little is known of the fundamental cause of this pathology. The present study examined the effect of human insulin-like growth factor (hIGF)-1 overexpression in combination with autologous cell transplantation to diabetic wounds in a preclinical large-animal model. Diabetes was induced in Yorkshire pigs with streptozotocin. Keratinocytes were cultured and transfected with hIGF-1 or LacZ transgene. Plasmids were lipoplexed with either Lipofectin or Lipofectamin 2000. Transgene expression was assessed by enzyme-linked immunosorbent assay or X-gal staining. For in vivo studies, full-thickness wounds were created and dressed with a sealed chamber. Transfected cells were transplanted into the wounds. Wound contraction was monitored and biopsies were obtained for measurement of re-epithelialization. Wound fluid was collected and analysed for IGF-1 concentrations. Quantification showed up to 740 ng/ml IGF-1 in vitro and significantly higher concentrations over 14 days compared to controls for the Lipofectamin 2000 group. Lipofectin-mediated gene transfer showed peak expression on day 2 with 68.5 ng/ml. In vivo, transfected cells showed peak expression of 457 ng/ml at day 1, followed by subsequent decline to 5 ng/ml on day 12 with Lipofectamin 2000. For Lipofectin, no significant IGF-1 expression could be detected. Gene therapy caused significantly faster wound closure (83%) than both controls (native-cell therapy = 57%; control wounds = 32%). The present study demonstrates that optimized nonviral gene transfer increased IGF-1 expression in diabetic wounds by up to 900-fold. This high IGF-1 concentration in combination with cell therapy improved diabetic wound healing significantly.

Aging and Cancer-Related Loss of Insulin-like Growth Factor 2 Imprinting in the Mouse and Human Prostate

Loss of imprinting (LOI) is an epigenetic alteration involving loss of parental origin-specific expression at normally imprinted genes. A LOI for Igf2, a paracrine growth factor, is important in cancer progression. Epigenetic modifications may be altered by environmental factors. However, is not known whether changes in imprinting occur with aging in prostate and other tissues susceptible to cancer development. We found a LOI for Igf2 occurs specifically in the mouse prostate associated with increased Igf2 expression during aging. In older animals, expression of the chromatin insulator protein CTCF and its binding to the Igf2-H19 imprint control region was reduced. Forced down-regulation of CTCF leads to Igf2 LOI. We further show that Igf2 LOI occurs with aging in histologically normal human prostate tissues and that this epigenetic alteration was more extensive in men with associated cancer. This finding may contribute to a postulated field of cancer susceptibility that occurs with aging. Moreover, Igf2 LOI may serve as a marker for the presence of prostate cancer.

Blueberry polyphenols attenuate kainic acid-induced decrements in cognition and alter inflammatory gene expression in rat hippocampus

Cognitive impairment in age-related neurodegenerative diseases such as Alzheimer's disease may be partly due to long-term exposure and increased susceptibility to inflammatory insults. In the current study, we investigated whether polyphenols in blueberries can reduce the deleterious effects of inflammation induced by central administration of kainic acid by altering the expression of genes associated with inflammation. To this end, 4-month-old male Fischer-344 (F344) rats were fed a control, 0.015% piroxicam (an NSAID) or 2% blueberry diet for 8 weeks before either Ringer's buffer or kainic acid was bilaterally micro-infused into the hippocampus. Two weeks later, following behavioral evaluation, the rats were killed and total RNA from the hippocampus was extracted and used in real-time quantitative RT-PCR (qRT-PCR) to analyze the expression of inflammation-related genes. Kainic acid had deleterious effects on cognitive behavior as kainic acid-injected rats on the control diet exhibited increased latencies to find a hidden platform in the Morris water maze compared to Ringer's buffer-injected rats and utilized non-spatial strategies during probe trials. The blueberry diet, and to a lesser degree the piroxicam diet, was able to improve cognitive performance. Immunohistochemical analyses of OX-6 expression revealed that kainic acid produced an inflammatory response by increasing the OX-6 positive areas in the hippocampus of kainic acid-injected rats. Kainic acid up-regulated the expression of the inflammatory cytokines IL-1β and TNF-α, the neurotrophic factor IGF-1, and the transcription factor NF-κB. Blueberry and piroxicam supplementations were found to attenuate the kainic acid-induced increase in the expression of IL-1β, TNF-α, and NF-κB, while only blueberry was able to augment the increased IGF-1 expression. These results indicate that blueberry polyphenols attenuate learning impairments following neurotoxic insult and exert anti-inflammatory actions, perhaps via alteration of gene expression.

Creatine Supplementation Exacerbates Allergic Lung Inflammation and Airway Remodeling in Mice

Creatine supplement is the most popular nutritional supplement, and has various metabolic functions and sports medicine applications. Creatine supplementation increases muscle mass and can decrease muscular inflammation. Some studies have also suggested a beneficial role of creatine supplementation on chronic pulmonary diseases such as chronic obstructive pulmonary disease and cystic fibrosis. Among athletes, the prevalence of asthma is high, and many of these individuals may be taking creatine. However, the effects of creatine supplementation on chronic pulmonary diseases of allergic origin have not been investigated. In the present study, we analyzed the effects of creatine supplementation on a model of chronic allergic lung inflammation. Thirty-one Balb/c mice were divided into four groups: control, creatine (Cr), ovalbumin (OVA), and OVA+Cr. OVA and OVA+Cr groups were sensitized with intraperitoneal injections of OVA on Days 0, 14, 28, and 42. OVA challenge (OVA 1%) and Cr treatment (0.5 g/kg/d) were initiated on Day 21 and lasted until Day 53. We determined the index of hyperresponsiveness, the serum levels of OVA-specific immunoglobulin (Ig)E and IgG(1), and the total and differential cell counts in bronchoalveolar lavage fluid. We also quantified airway inflammation, and the airway density of IL-4+, IL-5+, IL-2+, IFN-gamma+, and insulin-like growth factor (IGF)-1+ cells, collagen and elastic fibers, and airway smooth muscle thickness. Our results showed that creatine in OVA-sensitized mice increased hyperresponsiveness; eosinophilic inflammation; airway density of IL-4+, IL-5+, and IGF-1 inflammatory cells; airway collagen and elastin content; and smooth muscle thickness. The results show that creatine supplementation exacerbates the lung allergic response to OVA through a T helper cell type 2 pathway and increased IGF-1 expression.

BCR-ABL Activates IGF-1 Expression and Signaling in Chronic Myelogenous Leukemia Blast Crisis Cell Lines.

CML blast crisis is characterized by the continued presence of the Philadelphia chromosome, which expresses the P210 BCR-ABL fusion protein, and the acquisition of additional molecular and chromosomal alterations. Evolution from CML chronic phase to blast crisis is associated with loss of heterozygosity at chromosome region 1p36, which contains the putative tumor suppressor RIZ1. We found that RIZ1 expression decreases during progression from CML chronic phase to myeloid blast crisis and that forced RIZ1 expression in CML blast crisis (CML-BC) cell lines decreases proliferation, increases apoptosis, and enhances differentiation. Furthermore, we found that RIZ1 represses IGF-1 autocrine production and blocks the activation of the IGF-1 receptor, AKT, and ERK signaling pathways in CML-BC cell lines thereby implicating RIZ1 control of the IGF-1 pathway in the regulation of these phenotypes. As BCR-ABL induces a growth factor independent phenotype due to the activation of autocrine growth factor production, we analyzed IGF-1 expression in CML-BC cell lines following exposure to imatinib. We found that imatinib treatment reduced IGF-1 mRNA and extracellular IGF-1 suggesting that RIZ1 may suppress blast crisis by counteracting the ability of BCR-ABL activate RIZ1 regulated genes. We characterized the signaling pathways used by BCR-ABL to activate IGF-1 expression and found that the HCK inhibitor PP2 and STAT5b shRNA reduced IGF-1 expression whereas the JAK2 inhibitor AG490 increased IGF-1 expression. These results suggest that BCR-ABL activates HCK, which in turn activates STAT5b and induces IGF-1 expression. To confirm the importance of BCR-ABL induced IGF-1 signaling to CML-BC cell line viability, proliferation and apoptosis, we characterized these cellular phenotypes in the presence of IGF-1 receptor blocking antibody and the IGF-1 receptor tyrosine kinase inhibitor AG1024. Blockage of autocrine IGF-1 signaling in CML-BC cell lines using an anti-IGF-1 receptor blocking antibody reduced cell viability and decreased proliferation. AG1024 treatment of CML-BC cell lines decreased proliferation and induced apoptosis. Together these results demonstrate that RIZ1 counteracts the ability of BCR-ABL to induce IGF-1 signaling in CML-BC cell lines, which influences cell proliferation, apoptosis, and differentiation. Our findings highlight RIZ-1 and IGF-1 signaling pathways as potential therapeutic targets for treating CML blast crisis.

Multi-organic endocrine disrupting activity of the UV screen benzophenone 2 (BP2) in ovariectomized adult rats after 5 days treatment.

The chemical industry has developed sun protection factor products, which contain a variety of so-called "UV screens", among others, benzophenones (BP). Based on the structure it can be assumed, that the variant BP2 may be a potent estrogenic endocrine disrupter (ED). Only very limited data are available in the literature about such action of BP2, which focussed on the uterotrophic effect in immature rats. However, determination of ED activity in the uterus is only a restricted approach with the potential risk of missing undesirable actions. Therefore, we examined a putative multiple organ ED activity of BP2 by measuring gene expression of marker genes in the uterus, liver, vagina and pituitary after 5 days oral application in adult ovariectomized (ovx) rats. An effect on lipid metabolism was assessed by determination of cholesterol, high- and low-density lipoproteins (HDL and LDL) in the blood. As control compound, estradiol (E2) was included in the study. A dose dependent E2-agonistic activity was observed in the uterus (increased weight), vagina (increased IGF1 expression), pituitary (reduced LH synthesis), liver (increased IGF1 expression) and lipid parameters (reduction). A non-E2-like action of BP2 was observed on T4- and T3-levels, which were significantly reduced. Except for the action of BP2 on thyroid hormone levels where it may inhibit thyroid peroxidase, this UV screen exerts clear E2-agonistic actions. Application of BP2 for 5 days proved to be a sufficient treatment period to unravel a multi-organic endocrine disrupting activity of this UV screen.

The expression of insulin-like growth factor 1 in follicular dermal papillae correlates with therapeutic efficacy of finasteride in androgenetic alopecia

Background: It is generally believed that dihydrotestosterone is one of the pivotal mediators of hair loss in androgenetic alopecia (AGA). Finasteride, which blocks the conversion of testosterone to dihydrotestosterone, has now become an integral part of the current treatment approaches for male AGA. Several lines of evidence support the notion that dermal papilla (DP) cells represent the androgen target within the hair follicle. The specific molecular regulators modulated by androgens within hair follicles in the balding scalp are unknown. Objective: The purpose of this study was to identify and quantify changes in expression of specific molecular hair growth regulators in DP of men with AGA treated with finasteride and correlate these findings to clinical efficacy. Methods: Biopsy specimens were collected from 9 male patients from both the balding area and nonbalding occipital area before and after 4 months of finasteride therapy. DP were microdissected and total RNA was extracted from an equal number of DP from each biopsy specimen. The expression of various cytokines, including insulin-like growth factor (IGF)-1, was determined by reverse transcription polymerase chain reaction. The signals were detected by autoradiography. All 9 patients were given finasteride for 1 year and evaluated for efficacy at month 12. Efficacy was graded on a 7-point scale on the basis of comparison with initial baseline photography. Results: IGF-1 was up-regulated by finasteride treatment in 4 of 9 patients. Among the patients with increased IGF-1 expression, 3 of them showed moderate clinical improvement after 12 months of treatment and another patient remained unchanged. In contrast, 3 patients with decreased IGF-1 expression in the balding scalp showed clinical worsening after 12 months. The other 2 patients without noticeable change in IGF-1 expression showed either slight improvement or no change in their hair condition. Conclusion: In a small uncontrolled study of 9 patients with AGA, an increased expression of IGF-1 messenger RNA levels in the DP was associated with patient response to finasteride.

In situ detection of insulin-like growth factor II (IGF2) and H19 gene expression in hepatocellular carcinoma.

To assess the relationship between insulin-like growth factor II (IGF2) and H19 gene expression at the cellular level, we have examined the distribution of IGF2 and H19 mRNA by means of an situ hybridization in hepatic malignancies consisting of hepatocellular carcinoma (HCC), cholangiocellular carcinoma (CCC), and metastatic liver cancer (MLC). In HCC, 15 of 27 tumors (56%) and 11 of 27 tumors (41%) demonstrated increased IGF2 and H19 gene expression, respectively. Of 16 HCCs with increased expression of either IGF2 or H19, 10 tumors coexpressed both transcripts at comparable levels. Moreover, the spatiotemporal distribution and the cellular localization of the two gene transcripts were almost identical, suggesting the presence of a reciprocal relation between IGF2 and H19. In addition, 5 HCCs showed increased IGF2 expression without concomitant H19 expression, whereas 1 HCC showed increased H19 expression without IGF2 transcripts. However, 11 HCCs showed no IGF2 or H19 expression. On the other hand, neither IGF2 transcripts nor H19 transcripts were detected in 2 CCCs or 10 MLCs studied. The data suggest that IGF2 and/or H19 gene expression may be characteristic of some HCCs.