Anti-Müllerian hormone and letrozole levels in boys with constitutional delay of growth and puberty treated with letrozole or testosterone

STUDY QUESTION

Does treatment of constitutional delay of growth and puberty (CDGP) in boys with aromatase inhibitor letrozole (Lz) or conventional low-dose testosterone (T) have differing effects on developing seminiferous epithelium?

SUMMARY ANSWER

Anti-Müllerian hormone (AMH) declined similarly in both treatment groups, and the two Sertoli cell-derived markers (AMH and inhibin B (iB)) exhibited differing responses to changes in gonadotrophin milieu.

WHAT IS KNOWN ALREADY

Boys with CDGP may benefit from puberty-inducing medication. Peroral Lz activates gonadotrophin secretion, whereas intramuscular low-dose T may transiently suppress gonadotrophins and iB.

STUDY DESIGN, SIZE, DURATION

Sera of 28 boys with CDGP who participated in a randomised, controlled, open-label trial at four paediatric centres in Finland between August 2013 and January 2017 were analysed. The patients were randomly assigned to receive either Lz (2.5 mg/day) (n = 15) or T (1 mg/kg/month) (n = 13) for 6 months.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The 28 patients were at least 14 years of age, showed first signs of puberty, wanted medical attention for CDGP and were evaluated at 0, 3, 6 and 12 months of visits. AMH levels were measured with an electrochemiluminescence immunoassay and Lz levels with liquid chromatography coupled with tandem mass spectrometry.

MAIN RESULTS AND THE ROLE OF CHANCE

AMH levels decreased in both treatment groups during the 12-month follow-up (P < 0.0001). Between 0 and 3 months, the changes in gonadotrophin levels (increase in the Lz group, decrease in the T group) correlated strongly with the changes in levels of iB (FSH vs iB, r = 0.55, P = 0.002; LH vs iB, r = 0.72, P < 0.0001), but not with the changes in AMH (P = NS). At 12 months, AMH levels did not differ between the groups (P = NS). Serum Lz levels (range, 124-1262 nmol/L) were largely explained by the Lz dose per weight (at 3 months r = 0.62, P = 0.01; at 6 months r = 0.52, P = 0.05). Lz levels did not associate with changes in indices of hypothalamic-pituitary-gonadal axis activity or Sertoli cell markers (in all, P = NS).

LIMITATIONS, REASONS FOR CAUTION

The original trial was not blinded for practical reasons and included a limited number of participants.

WIDER IMPLICATIONS OF THE FINDINGS

In early puberty, treatment-induced gonadotrophin stimulus was unable to counteract the androgen-mediated decrease in AMH, while changes in iB levels were associated with changes in gonadotrophin levels. AMH decreased similarly in both groups during the treatment, reassuring safety of developing seminiferous epithelium in both treatment approaches. Since a fixed dose of Lz induced variable serum Lz levels with a desired puberty-promoting effect in all boys, more research is needed to aim at a minimal efficient dose per weight.

STUDY FUNDING/COMPETING INTEREST(S)

This study was supported by the Academy of Finland, the Foundation for Pediatric Research, the Emil Aaltonen Foundation, Sigrid Juselius Foundation and Helsinki University Hospital Research Funds. The authors have nothing to disclose.

TRIAL REGISTRATION NUMBER

NCT01797718.

Serum glucocorticoids and adiponectin associate with insulin resistance in children born small for gestational age

OBJECTIVES

Altered glucocorticoid activity is one possible mechanism linking fetal growth restriction with later insulin resistance (IR) and type 2 diabetes. We aimed to investigate whether serum glucocorticoid parameters are related to IR in children born small for gestational age (SGA).

DESIGN

A total of 110 children (55 age- and gender-matched pairs born SGA or appropriate for gestational age (AGA) in a case-control setting) were studied at the mean age of 12.2 (s.d. 0.2) years.

METHODS

Serum cortisol, corticosteroid-binding globulin (CBG), free cortisol index (FCI=cortisol/CBG), and glucocorticoid bioactivity (GBA, transactivation assay) were analyzed and related to serum adiponectin and insulin-like growth factor-binding protein 1 (IGFBP1) concentrations and homeostasis model assessment for IR (HOMA-IR) and QUICKI indices.

RESULTS

In the pooled study population, GBA correlated well with cortisol and FCI (r=0.681 and 0.586 respectively; P<0.001 for both). Serum cortisol, CBG, FCI, GBA, HOMA-IR, or QUICKI did not differ between the SGA and AGA subjects, but the SGA children had lower body mass index (P=0.005) and waist circumference (WC) (P=0.001). The mean GBA in the highest GBA quartile was higher among the SGA subjects than among the AGA subjects (138.6 vs 96.4 nmol/l cortisol equivalents, P<0.001). In the SGA children, GBA correlated positively with HOMA-IR (r=0.522, P<0.001) and inversely with adiponectin (r=-0.278, P=0.042) (WC/height ratio adjustments), and in logistic regression analysis, higher GBA (odds ratio (OR) 1.3; P=0.013), lower adiponectin (OR 1.4; P=0.038), and lower IGFBP1 (OR 1.9; P=0.010) associated independently with higher HOMA-IR.

CONCLUSIONS

These findings suggest that increased glucocorticoid activity and low serum adiponectin concentrations associate with IR in SGA children.

WNT-4 mRNA expression in human adrenocortical tumors and cultured adrenal cells

The members of the Wnt glycoprotein family are important in embryogenesis and adult tissue homeostasis, and deletion of WNT-4 gene in mice leads to improper development of many organs including the adrenals. The objective of this study was to investigate the expression of WNT-4 gene in human adrenals and adrenocortical tumors. The WNT-4 mRNA expression (analyzed by quantitative real-time RT-PCR) was significantly higher in Conn's adenomas (p<0.01) and lower in Cushing's adenomas, virilizing carcinomas and fetal adrenals (p<0.05) compared with normal adult adrenals. WNT-4 mRNA expression was clearly upregulated by ACTH and 8-bromo-cAMP (8-BrcAMP) in primary cultures of normal adult adrenocortical cells, but downregulated by 8-BrcAMP and 12- O-tetradecanoylphorbol-13-acetate (TPA) in human NCI-H295R adrenocortical carcinoma cells. Angiotensin II tended to increase WNT-4 mRNA expression at 24 hours and decreased it at 48 hours time point in both cell culture types. The abundant WNT-4 mRNA expression in Conn's adenomas and its hormonal regulation in adrenocortical cells suggest a role for WNT-4 in human adrenocortical function.

Investigation of the role of SDHB inactivation in sporadic phaeochromocytoma and neuroblastoma

Germline mutations in the succinate dehydrogenase (SDH) (mitochondrial respiratory chain complex II) subunit B gene, SDHB, cause susceptibility to head and neck paraganglioma and phaeochromocytoma. Previously, we did not identify somatic SDHB mutations in sporadic phaeochromocytoma, but SDHB maps to 1p36, a region of frequent loss of heterozygosity (LOH) in neuroblastoma as well. Hence, to evaluate SDHB as a candidate neuroblastoma tumour suppressor gene (TSG) we performed mutation analysis in 46 primary neuroblastomas by direct sequencing, but did not identify germline or somatic SDHB mutations. As TSGs such as RASSF1A are frequently inactivated by promoter region hypermethylation, we designed a methylation-sensitive PCR-based assay to detect SDHB promoter region methylation. In 21% of primary neuroblastomas and 32% of phaeochromocytomas (32%) methylated (and unmethylated) alleles were detected. Although promoter region methylation was also detected in two neuroblastoma cell lines, this was not associated with silencing of SDHB expression, and treatment with a demethylating agent (5-azacytidine) did not increase SDH activity. These findings suggest that although germline SDHB mutations are an important cause of phaeochromocytoma susceptibility, somatic inactivation of SDHB does not have a major role in sporadic neural crest tumours and SDHB is not the target of 1p36 allele loss in neuroblastoma and phaeochromocytoma.

DNA methylation affects cell proliferation, cortisol secretion and steroidogenic gene expression in human adrenocortical NCI-H295R cells

Aberrant DNA methylation may be involved in human adrenocortical tumorigenesis, which is often accompanied by abnormal hormone production. In this study, we aimed to clarify the effects of DNA methylation on steroidogenesis using the human adrenocortical NCI-H295R cell line as a model. Treatment with the DNA methylation inhibitor 5-aza-2'-deoxycytidine (Azad; 10 microM for 7 days) decreased the proliferation rate to approximately 20% and the cell number to 60% of the control, with a simultaneous increase in the expression of the cyclin-dependent kinase inhibitor p57(KIP2) gene. In addition, Azad treatment increased cortisol secretion dose and time dependently, whereas dehydroepiandrosterone sulfate secretion was not affected. Azad treatment decreased basal and (Bu)2cAMP-induced expression of low- and high-density lipoprotein receptor, steroidogenic acute regulatory protein (StAR), cholesterol side-chain cleavage enzyme, steroid 17alpha-hydroxylase/17,20-lyase and steroid 21-hydroxylase mRNA, as well as the StAR protein level. In contrast, Azad treatment increased the basal expression of steroid 11beta-hydroxylase and 3beta-hydroxysteroid dehydrogenase/Delta5-Delta4-isomerase genes, although it inhibited the (Bu)2cAMP-induced expression of these two genes. The expression of steroidogenic factor-1 (SF-1) and DAX-1 (dosage-sensitive sex reversal-adrenal hypoplasia congenita critical region on the X-chromosome 1) genes (both harboring putative CpG islands in their promoters) and the methylation degree of the HpaII recognition site(s) in the SF-1 gene promoter region were reduced by Azad treatment. The immunostaining pattern of the methyl-CpG-binding protein MeCP2 was also modified by Azad treatment. These results suggest that DNA methylation may be implicated in the regulation of cell proliferation and steroidogenesis in human adrenocortical cells.

Transcription factors GATA-4 and GATA-6 in human adrenocortical tumors

Transcription factors GATA-4 and GATA-6 are expressed during normal adrenocortical development in mice and humans, and in vitro studies have linked them to adrenal steroidogenesis. GATA-4 is highly expressed in the adrenocortical tumors of gonadectomized mice, whereas GATA-6 is down-regulated in the tumor area. Based on these findings we studied GATA-4 and GATA-6 expression in 39 human adrenocortical tumors using RT-PCR, Northern analysis and immunohistochemistry. 6/18 adenomas and 4/11 carcinomas were positive for GATA-4 mRNA. GATA-6 mRNA was expressed in 19/19 adenomas and 9/10 carcinomas, and GATA-6 immunoreactivity was remarkably lower in adrenocortical carcinomas than in adenomas (p < 0.05). Some of the steroidogenically active human adrenocortical cells (NCI-H295R) were weakly positive for GATA-4, whereas steroidogenically inactive cells (ACT-1) were totally GATA-4 negative. In contrast, both cell lines expressed GATA-6. GATA expression patterns similar to the animal models can thus be observed in human adrenocortical tumors, but the pathophysiological significance of these findings remains to be elucidated.

cAMP-dependent protein kinase activation inhibits proliferation and enhances apoptotic effect of tumor necrosis factor-alpha in NCI-H295R adrenocortical cells

Adrenocorticotropin is the major regulator of adrenocortical development and function. It acts mainly through the cAMP-dependent protein kinase A (PKA) pathway. Our aim was to study the interaction of tumor necrosis factor-alpha (TNFalpha) and the PKA pathway in adrenocortical cell proliferation and apoptosis. The PKA activator Dibutyryl cAMP ((Bu)2cAMP) strongly induced differentiation and inhibited proliferation in the human adrenocortical cell line NCI-H295R (H295R). TNFalpha induced apoptosis of H295R cells. Interestingly, (Bu)2cAMP treatment clearly enhanced TNFalpha-induced apoptosis in H295R cells, but not in another human adrenocortical cell line SW-13, the mouse adrenocortical Y-1 cell line or the human HeLa cell line. This synergistic effect was not due to the (Bu)2cAMP-induced glucocorticoid secretion since dexamethasone had no significant effect on the TNFalpha-induced apoptosis. (Bu)2cAMP treatment rapidly increased the expression of the proto-oncogene c-myc in H295R cells, but not in SW-13, Y-1 or HeLa cells. In transient c-myc transfection assay, c-myc expression associated with decreased expression of the proliferation marker Ki-67 in H295R cells. In conclusion, cAMP-dependent protein kinase activation reduced proliferation and augmented TNFalpha-induced apoptosis in adrenocortical H295R cells, and these effects were associated with increased c-myc expression.

Expression of activin/inhibin signaling components in the human adrenal gland and the effects of activins and inhibins on adrenocortical steroidogenesis and apoptosis

Activins and inhibins are structurally related glycoprotein hormones modulating pituitary FSH secretion and gonadal steroidogenesis. Activins and inhibins are also produced in the adrenal cortex where their physiological role is poorly known. Hormonally active human adrenocortical tumors express and secrete inhibins, while in mice adrenal inhibins may function as tumor suppressors. To clarify the significance of adrenal activins and inhibins we investigated the localization of activin/inhibin signaling components in the adrenal gland, and the effects of activins and inhibins on adrenocortical steroidogenesis and apoptosis. Activin receptor type II/IIB and IB, activin signal transduction proteins Smad2/3, and inhibin receptor betaglycan were expressed throughout the adrenal cortex, whereas Smad4 expression was seen mainly in the zona reticularis and the innermost zona fasciculata as evaluated by immunohistochemistry. Treatment of cultured adrenocortical carcinoma NCI-H295R cells with activin A inhibited steroidogenic acute regulatory protein and 17alpha-hydroxylase/17,20-lyase mRNA accumulation as evaluated by the Northern blot technique, and decreased cortisol, androstenedione, dehydroepiandrosterone and dehydroepiandrosterone sulfate secretion as determined by specific enzyme immunoassays. Activin A increased apoptosis as measured by a terminal deoxynucleotidyl transferase in situ apoptosis detection method. Inhibins had no effect on steroidogenesis or apoptosis. In summary, activin/inhibin signaling components are coexpressed in the zona reticularis and the innermost zona fasciculata indicating full signaling potential for adrenal activins and inhibins in these layers. Activin inhibits steroidogenic enzyme gene expression and steroid secretion, and increases apoptosis in human adrenocortical cells. Thus, the activin-inhibin system may have a significant role in the regulation of glucocorticoid and androgen production and apoptotic cell death in the human adrenal cortex.

Lumbar bone mineral density in normal subjects aged 3-6 years: a prospective study

Longitudinal studies on bone mineral density (BMD) accrual in young children are scarce. The purpose of the present study was to evaluate prospectively the development of spinal BMD in healthy Finnish children aged 3-6 y by dual-energy x-ray absorptiometry (DXA). Lumbar spine (L2-L4) areal BMD (g/cm2) was measured by DXA (Lunar DPX) in 20 children (10M, 10F) aged 3.3-6.9 y (median 4.8 y) at baseline and after a median follow-up of 1.0y (range 0.8-1.1 y). Apparent volumetric BMD (BMDvol, g/cm3) was calculated to minimize the effect of bone size on BMD in growing spine. At baseline, lumbar areal and volumetric BMDs (mean +/- SD) for males were 0.623+/-0.087 g/cm2 and 0.270+/-0.034 g/cm3, respectively, and for females 0.620+/-0.082 g/cm2 and 0.254+/-0.035 g/cm3, respectively. During the median follow-up of 1 y, lumbar areal and volumetric BMDs (mean +/- SD) increased in males by 4.7+/-2.7% (p < 0.01) and 3.5+/-3.5% (p <0.05), respectively, and in females by 7.2+/-5.3% (p <0.01) and 3.1+/-3.1% (p <0.05), respectively. No statistically significant difference in the BMD values was observed between the sexes.

CONCLUSION

A significant increase in both areal and apparent volumetric BMD was observed in children aged 3-6 y during a follow-up of I y. The increase in volumetric BMD indicated that there was a real accrual of BMD in growing spine measured by DXA. The present study provides prospective data on BMD accrual in young children for the evaluation of bone mass development in early childhood.

Transcription factors GATA-4 and GATA-6 during mouse and human adrenocortical development

Our earlier work implicates transcription factors GATA-4 and GATA-6 in the murine adrenal. We have now studied their expression during mouse and human adrenal development in detail. GATA-4 and GATA-6 mRNAs are readily detectable from embryonic day 15 in mouse and gestational week 19 in human adrenal cortex. In postnatal adrenal, GATA-4 expression is down-regulated, whereas GATA-6 mRNA and protein continue to be abundantly present. In a human adrenocortical cell line NCI-H295R, GATA-6 mRNA is up-regulated by cAMP. This cell line does not express GATA-4. Our findings suggest that GATA-6 expression is hormonally controlled, and required throughout adrenal development from fetal to adult age. GATA-4, on the other hand, may serve a role in fetal adrenal gene regulation.

Regulation of follistatin-related gene (FLRG) expression by protein kinase C and prostaglandin E(2) in cultured granulosa-luteal cells

Activin and its binding protein follistatin may act as local regulators of cell growth and steroidogenesis in the human ovary. The recently identified follistatin-related gene (FLRG) is expressed abundantly in the human ovary, has high affinity for activin, and is able to inhibit activin-induced transcriptional responses. However, little is known about the regulation of FLRG expression in specific cell types in the ovary, while it is known that gonadotrophins induce follistatin gene expression in human granulosa-luteal cells. In this study, we investigated the expression of FLRG mRNA in granulosa-luteal cells of preovulatory follicles obtained from women undergoing IVF. FLRG mRNA was detected by RT-PCR in fresh and cultured granulosa-luteal cells, as well as in normal ovarian stroma, theca and granulosa cells. Northern blot analysis revealed a 2.5 kb transcript of the FLRG in cultured granulosa-luteal cells. The protein kinase C activator, 12-O-tetradecanoyl phorbol 13-acetate (TPA, 160 nmol/l), and prostaglandin E(2) (PGE(2), 1 micromol/l) increased FLRG mRNA accumulation up to 3-8 fold over the control level after 24 h of treatment, and these stimulatory effects were dose-dependent. Co-treatment with the protein kinase C inhibitor, Ro-31-8220 (3 micromol/l), blocked the stimulatory effect of TPA. Although short term treatment with the protein kinase A activator, (Bu)(2)cAMP (1 mmol/l), slightly reduced FLRG mRNA expression in most experiments, long term treatment with FSH (100 IU/l), LH (100 IU/l), or (Bu)(2)cAMP had no significant effect on the FLRG mRNA levels. As expected, gonadotrophins, protein kinase A and C activators and PGE(2) increased granulosa-luteal cell progesterone secretion into the culture media. Taken together, previous and our present data suggest that protein kinase C and A signal transduction pathways differently regulate the expression of FLRG and follistatin genes in human ovarian granulosa-luteal cells.

Acute insulin response tests for the differential diagnosis of congenital hyperinsulinism

Mutations in genes encoding the two subunits of the beta-cell ATP-sensitive potassium channel (K(ATP)) channel (SUR1 and Kir6.2) are the major cause of congenital hyperinsulinism (CHI). In this study, the K(ATP) channel genes were screened in a population-based study that included all verified Finnish CHI patients (n = 43) in a 27-yr period. Seven different mutations were identified, which accounted for 60% of all cases. The functional consequences of the major missense mutations were studied in vivo by determining acute (1-3 min) plasma insulin and C-peptide responses to calcium (n = 18), glucose (n = 12), and tolbutamide (n = 11) in those CHI patients who were able to take part in these studies. C-peptide and insulin responses to calcium were significantly higher in the patients with SUR1-E1506K mutation, compared with patients without K(ATP) channel mutations. The patients with SUR1-V187D mutation showed a reduced response to tolbutamide but unexpectedly did not show any response to calcium stimulation. A compound heterozygous patient with Kir6.2-(-54)/K67N mutations responded to calcium but also to tolbutamide. In conclusion, our results show that a positive response in the calcium test is indicative of a K(ATP) channel mutation, but all mutations cannot be identified with this method. The insulin response to tolbutamide in patients with SUR1 mutations is impaired to different extents, depending on the genotype. The combination of calcium and tolbutamide tests is a useful tool for the detection of CHI patients with K(ATP) channel dysfunction. Our results, however, also demonstrate the complexity of these responses and the difficulties in their interpretation.

Sexual function and fertility in adult females and males with congenital adrenal hyperplasia

Female patients with classic 21-hydroxylase deficiency (21-OHD) present with decreased fertility and low childbirth rates, women with a salt-wasting form of 21-OHD being most severely affected. In cases of undersubstitution with glucocorticoids, tonic androgen secretion disturbs ovulation. However, even adequately substituted females may present with apparent infertility. Despite adrenal androgen suppression, adrenal progesterone secretion can prevent thickening of the endometrium in the follicular phase. Furthermore, functional ovarian hyperandrogenism is a common finding even in women with well-controlled classic 21-OHD. Psychosexual factors may also contribute significantly to decreased childbirth rates found in these patients. Genital ambiguity may lead to a disturbed body image and the patients have been found to feel less feminine than healthy control women. The repeated psychological insult caused by frequent genital examinations and operations is also important, though its exact impact has been difficult to determine. Finally, prenatal androgen excess can cause masculinization of the central nervous system leading to boyish behavior in childhood and decreased heterosexual activity in adulthood. Some recent reports show a high rate of infertility also in men with 21-OHD. They are at risk of benign testicular tumors, adrenal rests, which can lead to permanent infertility. Also, raised adrenal androgen production leading to increased estrogen concentrations can suppress gonadotropin secretion and may lead to a hypogonadotropic state.

Biphasic regulation of activin A secretion by gonadotropins in cultured human ovarian granulosa-luteal cells leads to decreasing activin:inhibin ratios during continuing gonadotropin stimulation

Pituitary gonadotropins mediate part of their effects on ovarian function via local hormones and growth factors produced by granulosa cells. Activins and inhibins are among these factors, and they have often opposite effects on various components of the reproductive system. The purpose of this study was to investigate the regulation of ovarian activin A secretion using cultured human ovarian granulosa-luteal cells as a model. The granulosa-luteal cells, obtained from women taking part in an in vitro fertilization program, were cultured and treated with FSH, LH, 8-bromo cAMP (8-BrcAMP, a protein kinase A activator) and 12-O-tetradecanoyl phorbol-13-acetate (TPA, a protein kinase C activator). Conditioned cell culture media were analyzed for activin A, inhibin A and progesterone concentrations with specific enzyme immunoassays. FSH and LH (1-100 IU/l) increased activin A secretion with 24 h of treatment (to 132% and 253% of control respectively; P<0.05 for both), but their effects were inhibitory in 48-h treatments (26% and 16% decreases respectively; P<0.05 for both). In the same experiments, FSH and LH increased inhibin A and progesterone secretion after both 24 and 48 h of treatment. 8-BrcAMP (0.1-100 muM) increased activin A in 24- and 48-h experiments (to 206% and 148% of control respectively; P<0.01 for both). Inhibin A and progesterone secretion were stimulated by 8-BrcAMP time- and dose-dependently. TPA increased activin A secretion dose-dependently (0.1-100 ng/ml) in both 24- and 48-h experiments. At 100 ng/ml concentration, it increased activin A up to 61-fold and inhibin A up to 16-fold of control in 24-h experiments. We conclude that gonadotropins regulate immunoreactive activin A secretion biphasically in cultured human granulosa-luteal cells: initial stimulation is followed by inhibition. In contrast, gonadotropins increase inhibin A and progesterone secretion continuously. Consequently, continuing gonadotropin stimulation leads to a decreasing activin:inhibin ratio, which may have a significant role in the local fine-tuning of ovarian steroidogenesis.

RASSF1A promoter region CpG island hypermethylation in phaeochromocytomas and neuroblastoma tumours

Deletions of chromosome 3p are frequent in many types of neoplasia including neural crest tumours such as neuroblastoma (NB) and phaeochromocytoma. Recently we isolated several candidate tumour suppressor genes (TSGs) from a 120 kb critical interval at 3p21.3 defined by overlapping homozygous deletions in lung and breast tumour lines. Although mutation analysis of candidate TSGs in lung and breast cancers revealed only rare mutations, expression of one of the genes (RASSF1A) was absent in the majority of lung tumour cell lines analysed. Subsequently methylation of a CpG island in the promoter region of RASSF1A was demonstrated in a majority of small cell lung carcinomas and to a lesser extent in non-small cell lung carcinomas. To investigate the role of 3p TSGs in neural crest tumours, we (a) analysed phaeochromocytomas for 3p allele loss (n=41) and RASSF1A methylation (n=23) and (b) investigated 67 neuroblastomas for RASSF1A inactivation. 46% of phaeochromocytomas showed 3p allele loss (38.5% at 3p21.3). RASSF1A promoter region hypermethylation was found in 22% (5/23) of sporadic phaeochromocytomas and in 55% (37/67) of neuroblastomas analysed but RASSF1A mutations were not identified. In two neuroblastoma cell lines, methylation of RASSF1A correlated with loss of RASSF1A expression and RASSF1A expression was restored after treatment with the demethylating agent 5-azacytidine. As frequent methylation of the CASP8 gene has also been reported in neuroblastoma, we investigated whether RASSF1A and CASP8 methylation were independent or related events. CASP8 methylation was detected in 56% of neuroblastomas with RASSF1A methylation and 17% without RASSF1A methylation (P=0.0031). These results indicate that (a) RASSF1A inactivation by hypermethylation is a frequent event in neural crest tumorigenesis, particularly neuroblastoma, and that RASSF1A is a candidate 3p21.3 neuroblastoma TSG and (b) a subset of neuroblastomas may be characterized by a CpG island methylator phenotype.

Serum dehydroepiandrosterone sulfate concentration as an indicator of adrenocortical suppression in asthmatic children treated with inhaled steroids

ACTH regulates adrenal androgen production, which may thus be reduced during glucocorticosteroid therapy. Dehydroepiandrosterone sulfate is the most abundant androgen secreted by the adrenals. We wished to evaluate whether serum levels of dehydroepiandrosterone sulfate can be used as an indicator of adrenal suppression during inhaled steroid treatment in children. Sixty school-aged children with newly diagnosed asthma were randomly divided into budesonide (n = 30) and fluticasone propionate (n = 30) groups. Fifteen cromone-treated children served as a control group. The budesonide dose was 800 microg/d during the first 2 months and 400 microg/d thereafter. The respective fluticasone propionate doses were 500 and 200 microg/d. Serum dehydroepiandrosterone sulfate concentrations were measured before and after 2 and 4 months of treatment. In the budesonide group, serum dehydroepiandrosterone sulfate decreased from the baseline by a mean of 21% (95% confidence interval, 13-29%; P < 0.001) after 2 months of high dose treatment and by 16% (95% confidence interval, 8-25%; P < 0.001) after 4 months of treatment. In the fluticasone propionate group, the respective figures were 10% (95% confidence interval, 4-16%; P < 0.01) and 6% (95% confidence interval, 16% decrease-3% increase; P = NS). A low dose ACTH test indicated adrenocortical suppression at 4 months in 14 (23%) steroid-treated children. In these children, dehydroepiandrosterone sulfate decreased by a mean of 21% (95% confidence interval, 14-28%), whereas in those 46 steroid-treated children with normal ACTH test results, dehydroepiandrosterone sulfate decreased by 8% (95% confidence interval, 0-16%; P < 0.05 between these groups). In the control group, dehydroepiandrosterone sulfate levels tended to increase (by a mean of 26%), reflecting the normal physiological change at this age. In conclusion, inhaled steroid treatment suppresses dehydroepiandrosterone sulfate production in a dose-dependent manner. Monitoring of serum dehydroepiandrosterone sulfate concentrations can be used as a practical method to follow adrenocortical function and to detect its suppression during inhaled steroid treatment in children.

Inhibin/activin betaB-subunit expression in pheochromocytomas favors benign diagnosis

Malignancy of pheochromocytomas is difficult to estimate on the basis of histopathological features. Good prognostic markers are not available. In our search for new markers to differentiate malignant pheochromocytomas from benign ones we tested the value of inhibin/activin subunit expression. Inhibins are heterodimeric glycoproteins consisting of an alpha-subunit and either a betaA- or a betaB-subunit. Activins are composed of beta-subunits only. Immunohistochemically inhibin/activin betaB-subunit was strongly positive in the normal adrenal medulla, but the cortex was negative. A striking difference was found in inhibin/activin betaB expression between benign and malignant pheochromocytomas. The majority of benign adrenal tumors (27 of 30) showed strong or moderate immunoreactivity, whereas all seven malignant tumors were negative or only weakly positive for inhibin/activin betaB-subunit. The percentage of positively staining cells varied greatly in extraadrenal pheochromocytomas and in those benign tumors that showed over 5 mitoses/10 high power fields, necrosis, or capsular or vascular invasion, here called borderline tumors. Inhibin/activin betaB messenger ribonucleic acid was also found in pheochromocytomas. However, no significant differences in messenger ribonucleic acid levels were found in various types of tumors. Weak immunohistochemical positivity for inhibin/activin betaA-subunit was detected in the adrenal cortex, but the medulla and most of the pheochromocytomas were negative. Our data show that inhibin/activin betaB-subunit is expressed in normal adrenal medullary cells. Strong staining is found in most benign adrenal pheochromocytomas, whereas malignant tumors are almost negative. This suggests that loss of inhibin/activin betaB-subunit expression in pheochromocytomas may be used as an indicator of malignant potential.

Gonadotrophins inhibit and activin induces expression of inhibin/activin beta(B) subunit mRNA in cultured human granulosa-luteal cells

During the human menstrual cycle, serum inhibin concentrations fluctuate in a cyclic fashion. To examine the regulation of inhibin/activin beta(B) subunit gene expression in ovarian granulosa-luteal cells, the levels of beta(B) subunit mRNA were determined in primary cultures of human granulosa-luteal cells treated with gonadotrophins and protein kinase modulators. Granulosa cells were obtained from women undergoing an IVF programme. The cells were enzymatically dispersed, separated from red blood cells, and maintained in culture for 5--10 days before addition of different agents. Northern blot analysis with specific oligonucleotide probes was performed to study inhibin/activin beta(B) subunit mRNA levels. Both LH and FSH reduced the accumulation of beta(B) subunit mRNA in a dose-dependent manner. The protein kinase A activator, (Bu)(2)cAMP, and the protein kinase inhibitor staurosporine also inhibited beta(B) subunit mRNA expression dose-dependently. Activin A increased dose-dependently beta(B) subunit mRNA expression. Our study suggests that activin-induced and gonadotrophin-inhibited beta(B) subunit expression in granulosa cells might be key factors in the transition from inhibin B to inhibin A dominance during the menstrual cycle.

Comparison between low- and standard-dose ACTH tests in premature infants at risk for chronic lung disease

In order to find a sensitive method to evaluate adrenocortical function in premature infants, we compared low- (0.5 microg/1.73 m(2)) and standard-dose (250 microg/1.73 m(2)) adrenocorticotropin tests (LD- and SD-ACTH) in 12 very-low-birth-weight infants before and 2 days after the end of dexamethasone therapy (duration 9-14 days) for chronic lung disease. Basal serum cortisol levels were inappropriately low in several infants already before dexamethasone therapy (median 190, range 60-357 nmol/l). The 95% confidence intervals of mean serum cortisol levels at 20 min were equal in LD- and SD-ACTH, while at 60 min, the low-dose gave a clearly lower response than the standard-dose test. The LD-ACTH can be used in premature infants as in older children and adults, but the criteria for adrenocortical insufficiency need to be defined.

Serum lipid concentrations and growth characteristics in 12-year-old children born small for gestational age

According to Barker's hypothesis, children born small for gestational age (SGA) are at increased risk for cardiovascular diseases in adulthood. The aim of our study was to determine whether retarded fetal growth is associated with dyslipidemia in childhood and, if so, to find predictive factors in the growth characteristics of SGA children. We studied the serum lipid concentrations of 55 SGA children and their 55 appropriate for gestational age control subjects at the age of 12 y. Growth variables were recorded at birth, 5 y, and 12 y of age. The study group consisted of all full-term SGA children born at our university hospital during a 22-mo period in 1984-1986. Nearly half of the SGA children (47.3%) were in the highest quartile for serum total cholesterol of the appropriate for gestational age children (p = 0.038). In multiple logistic regression analysis, poor catch-up growth in height (odds ratio, 13. 8; 95% confidence interval, 2.0-97.5), female sex (odds ratio, 8.1; 95% confidence interval, 1.3-48.9), and early stage of puberty (odds ratio, 7.5; 95% confidence interval, 1.2-46.5) predicted high cholesterol level in the SGA children. By the age of 5 y, 20 (36.4%) SGA children showed catch-up growth of > or =2 SD scores in height, and 21 (38.2%) SGA children showed catch-up growth of > or =2 SD scores in weight from birth. At the age of 12 y, the SGA children were still significantly shorter (p<0.001) and lighter (p< 0.05) than the appropriate for gestational age children, even though their pubertal development was similarly advanced. In conclusion, to be born SGA has long-term consequences for later growth and may already influence the level of serum total cholesterol before the teens. SGA children with poor catch-up growth in height may be at the highest risk for hypercholesterolemia.

Regulation of immunoreactive inhibin A and B secretion in cultured human granulosa-luteal cells by gonadotropins, activin A and insulin-like growth factor type-1 receptor

Inhibins are gonadal glycoproteins with endocrine effects on pituitary FSH secretion and para/autocrine effects on ovarian and testicular function. The purpose of this study was to investigate the endocrine and para/autocrine regulation of inhibin A and inhibin B secretion in human ovarian granulosa-luteal cells. The cells were obtained from women undergoing in vitro fertilization, and the primary cultures were treated with FSH, LH, human chorionic gonadotropin (hCG), activin A, 8-bromo cyclic AMP (8-BrcAMP), staurosporine (a protein kinase C inhibitor) and an antagonist of IGF action (type-1 IGF receptor antibody alpha IR3). The secretion of inhibins was measured by ELISA assays capable of reliably distinguishing between inhibin A and B. FSH, LH, hCG and 8-BrcAMP increased inhibin A secretion on average up to 180% (P<0.01), 192% (P<0.05), 210% (P<0.01) and 243% (P<0.01) respectively of the control level, while their stimulatory effect on inhibin B secretion was less pronounced (up to 167%, P<0.01; 139%, P<0.05; 127%, P>0.05; 133%, P>0.05 of the controls respectively). alpha IR3 decreased inhibin A and B secretion down to 70% (P<0.01) and 50% (P<0.01) respectively of the control. Staurosporine decreased inhibin B secretion down to 49% (P<0.01) of the control; its effect on inhibin A secretion was not significant. Activin A increased inhibin B secretion up to fourfold of the control (P<0.05) while its effect on inhibin A secretion was insignificant. We conclude that gonadotropins via the protein kinase A signal transduction pathway are the main positive regulators of inhibin A and B secretion in human granulosa-luteal cells. The protein kinase C signal transduction pathway seems to be important especially for inhibin B secretion. Locally produced IGFs are probably important inducers of the production of both forms of inhibin in human ovaries while activins seem to upregulate inhibin B secretion.