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.

Expression of vascular endothelial growth factor in human adrenals

Angiogenesis is an important component in many biological processes and also in pathologic conditions including neoplastic diseases. Vascular endothelial growth factor (VEGF) is a secreted endothelial cell-specific growth factor, which is induced by tissue hypoxia and is angiogenic in vivo. Adrenal gland is a well-vascularized organ, and the roles of VEGF in normal adrenal and in adrenal tumorigenesis is not well characterized. We therefore investigated VEGF mRNA expression in normal human adrenals and in cultured adrenocortical cells. VEGF mRNA was constantly expressed in normal adrenals as well as in cultured adrenocortical cells. The mRNA levels were increased after 24h stimulation with either ACTH or cAMP. The effect of cAMP was dose-dependent. This suggests that ACTH-induced VEGF mRNA expression is mediated via protein kinase A dependent pathway.

Child rate, pregnancy outcome and ovarian function in females with classical 21-hydroxylase deficiency

BACKGROUND

Ovulatory disorders and decreased fertility rates have been found in females with classical 21-hydroxylase deficiency (21-OHD). We analyzed the pregnancies of 29 females with classical 21-hydroxylase deficiency and examined 16 of these women in a cross-sectional study.

METHODS

The child rate of the 29 patients was compared with that in the general Finnish female population with equal age distribution.The cross-sectional study of the 16 patients included a standardized questionnaire, clinical examination, ultrasonography of the internal genitalia, basal measurements of serum steroids, sex hormone binding globulin, PRL, gonadotropins and plasma ACTH.

RESULTS

The child rate was significantly lower than that in the general population (0.34 vs 0.91; p<0.001). A total of 13 pregnancies could be registered. From these pregnancies, ten healthy children were born, all for females with a simple virilizing disease. None of the nine females with salt wasting 21-OHD had any children or had sought treatment for infertility. In the cross-sectional study, females with regular menses (5/16; 31%) had well controlled adrenal androgen secretion and they had normal serum progesterone concentrations whereas the females with irregular menses (11/16; 69%) were often undersubstituted and presented with high serum progesterone concentration in the follicular phase. Polycystic ovaries could not be detected in any of these patients.

CONCLUSIONS

Females with simple virilizing 21-OHD often have irregular menses but their final prognosis for fertility seems to be better than previously reported. On the contrary, our study confirms the extremely low child rate in the salt wasting group.

Expression of low and high density lipoprotein receptor genes in human adrenals

Corticosteroids are synthesized from cholesterol which may arise from de novo synthesis or from the uptake of low or high density lipoproteins (LDL or HDL). In the present study, we compared the expression and regulation patterns of LDL receptor and CLA-1 (CD36 and LIMPII Analogous-1, an HDL receptor) genes in adult human adrenocortical tissues to shed more light on the relative contribution of LDL and HDL in human adrenal steroidogenesis. By screening 64 normal and pathological adrenal samples by Northern blotting, we found a positive correlation between LDL receptor and CLA-1 mRNA expression in the adrenal tissues (r=0.547; spearman rank correlation test P<0.01). Adrenal tissues adjacent to Cushing's adenomas contained consistently less LDL receptor and CLA-1 mRNA than normal adrenals (Mann-Whitney P<0.05). In primary cultures of normal adrenal cells, accumulation of both LDL receptor and CLA-1 mRNAs was upregulated by ACTH in a dose- and time-dependent manner, with an earlier induction of LDL receptor than CLA-1 mRNA expression. (Bu)(2)cAMP also increased the levels of these two mRNAs. Addition of LDL, but not HDL, into the culture medium increased cortisol production in untreated adrenocortical cells. Both LDL and HDL enhanced ACTH-induced cortisol production, with the effect of LDL much stronger than that of HDL. Our data show that LDL receptor and CLA-1's expression is ACTH-dependent and occurs in parallel in human adrenal tissues. LDL rather than HDL may be used as the preferential source of cholesterol for steroidogenesis in human adult adrenocortical cells.

Expression of inhibin alpha in adrenocortical tumours reflects the hormonal status of the neoplasm

Inhibins are gonadal glycoprotein hormones whose main endocrine function is to inhibit pituitary FSH secretion. In addition to testes and ovaries, other steroid-producing organs are sites of inhibin alpha subunit expression. To study the role of inhibins in human adrenal gland, we screened a panel of 150 adrenals (10 normal adrenals, 25 adrenocortical hyperplasias, 65 adrenocortical adenomas, 30 adrenocortical carcinomas and 20 phaeochromocytomas) for inhibin alpha expression. mRNA levels of inhibin alpha subunit were studied in 57 samples and all tissues were stained immunohistochemically with an inhibin alpha subunit-specific antibody. Inhibin alpha mRNA was detected in all adrenocortical tissues. Virilizing adenomas possessed a 10-fold higher median inhibin alpha mRNA expression than did normal adrenals. Bilaterally and nodularly hyperplastic adrenals and other than virilizing adrenocortical tumours had their median inhibin alpha mRNA levels close to those of normal adrenals. Immunohistochemically, inhibin alpha subunit was detectable in all normal and hyperplastic adrenals, as well as in 73% of the adrenocortical tumours. However, the percentage of inhibin alpha-positive cells varied greatly in different tumour types. The median percentage of positive cells was 10 in non-functional and Conn's adenomas, 30 in Cushing's adenomas and 75 in virilizing adenomas. In malignant adrenocortical tumours the median percentage of inhibin alpha-immunopositive cells was 20 in non-functional carcinomas, 30 in Conn's carcinomas, 65 in Cushing's carcinomas and 75 in virilizing carcinomas. All phaeochromocytomas were negative for inhibin alpha subunit both at the mRNA level and immunohistochemically. Our data show that inhibin alpha subunit is highly expressed in both normal and neoplastic androgen-producing adrenocortical cells, with less expression in cortisol-producing and hardly any in aldosterone-producing cells. This suggests a specific role for inhibins in the regulation of adrenal androgen production. We did not find any significant difference in inhibin alpha expression between benign and malignant adrenocortical tumours. Thus inhibin alpha gene does not seem to have a tumour suppressor role in human adrenal cortex.

Expression of activin A and its receptors in human pheochromocytomas

Activin A (a homodimer of two activin betaA subunits) has been shown to induce the neuronal differentiation of rat pheochromocytoma PC12 cells. We studied activin A and its receptor gene expression in human pheochromocytomas in vivo and in vitro to clarify the potential involvement of activin A in the pathophysiology of these tumors. We first screened 20 pheochromocytomas and nine normal adrenal tissues for activin betaA mRNA expression. Northern blots hybridized with specific oligonucleotide probes detected weak signals for activin betaA transcripts in pheochromocytomas. Both type I and type II activin receptor (ActR-I, ActR-IB and ActR-II) mRNA expression was also detectable in the pheochromocytoma tissues. In primary cultures of pheochromocytoma cells, expression of activin betaA mRNA was readily detectable by Northern blotting, and secretion of activin A into the conditioned medium was confirmed by an enzyme-linked immunosorbent assay. The expression of activin betaA mRNA and secretion of activin A were induced by (Bu)(2)cAMP after 1 and 3 days of treatment (all P<0.05). A protein kinase inhibitor, staurosporine, inhibited the basal and (Bu)(2)cAMP-induced accumulation of activin betaA mRNA (P<0.05). In addition, induction of chromaffin phenotype by dexamethasone also inhibited the basal and (Bu)(2)cAMP-induced expression of activin A at both mRNA and protein levels (all P<0.05). In contrast, the expression of ActR-I and ActR-IB mRNAs was not affected by these agents in cultured pheochromocytoma cells. In summary, activin betaA subunit and activin receptors are expressed in human pheochromocytomas. Production of activin A in cultured pheochromocytoma cells is induced through the protein kinase A pathway, but reduced during chromaffin differentiation. Therefore, activin A may function as a local neurotrophic factor via an auto/paracrine manner in human pheochromocytomas.

Long-term outcome of classical 21-hydroxylase deficiency: diagnosis, complications and quality of life

A nationwide search of patients with classical 21-hydroxylase deficiency (21-OHD) was performed in Finland to determine the long-term outcome of the disease. In total, 108 patients were found. Fifty-four patients (50%, 31F, 23M) had deficiency of a salt-wasting form and another 54 (50%, 29F, 25M) had a simple virilizing form of 21-OHD. A significant number of severe complications suggestive of glucocorticoid deficiency was found. There were five deaths (4.6% of all) possibly connected with cortisol deficiency. Ten additional patients (9.3% of all) had been acutely admitted 14 times in all due to symptoms of glucocorticoid deficiency. These symptoms included sudden loss of consciousness, convulsions and severe fatigue. Afterwards, permanent neurological defects were detected in two of these patients. Finally, a cross-sectional study was carried out to establish an estimate of the long-term outcome of the disease. Thirty-two (55%) of the 58 patients aged 16 y or more participated in this study. The patient group did not differ from the general Finnish population in terms of education. Three of the patients (5%) had retired prematurely. Surprisingly, the patients felt that their health-related quality of life, as reported in the RAND-36 questionnaire, was better than that of the general Finnish population (p = 0.023). However, as a significant number of all patients did not participate in this study, the quality of life evaluation results must be interpreted with caution. In conclusion, a significant number of complications was found among patients treated for classical 21-OHD. Nevertheless, the disease has a favourable outcome in terms of quality of life.

Adrenal suppression, evaluated by a low dose adrenocorticotropin test, and growth in asthmatic children treated with inhaled steroids

The aim of the present study was to evaluate the prevalence of adrenal suppression and growth retardation in children using moderate doses of budesonide or fluticasone propionate. Seventy-five asthmatic children were randomly divided into three treatment groups: 30 to the fluticasone propionate (FP), 30 to the budesonide (BUD), and 15 to the cromone (CROM) group. FP doses were 500 microg/day during the first 2 months and 200 microg/day thereafter. The respective BUD doses were 800 and 400 microg/day. A low dose ACTH (0.5 microg/1.73 m2) test was performed before treatment and 2, 4, and 6 months later. The test was considered abnormal if the stimulated serum cortisol concentration was more than 2 SD lower than the pretreatment mean (<330 nmol/L). The low dose ACTH test was abnormal after both the high and low steroid doses in 23% of the children. At the 4 month measurement there were more abnormal tests in the BUD (n = 9) than in the FP (n = 5) group (P < 0.05). At that time also the stimulated concentration of serum cortisol was lower in the BUD than in the CROM group (P < 0.01), whereas the difference between the FP and CROM groups was not significant. During the study year the mean decrease in height SD score was 0.23 in the children treated with BUD, 0.03 in the children treated with FP, and 0.09 in the children treated with CROM; the difference between the BUD and FP groups was significant (P < 0.05). In conclusion, the low dose ACTH test revealed mild adrenal suppression in a quarter of the children using moderate doses of inhaled steroids. A FP dose of 200 microg/day caused less adrenal and growth suppression than did a BUD dose of 400 microg/day.

Risk of enzyme allergy in the detergent industry

OBJECTIVES

To assess the prevalence of enzyme sensitisation in the detergent industry.

METHODS

A cross sectional study was conducted in a detergent factory. Sensitisation to enzymes was examined by skin prick and radioallergosorbent (RAST) tests. 76 Workers were tested; 40 in manufacturing, packing, and maintenance, and 36 non-exposed people in management and sales departments. The workers were interviewed for work related respiratory and skin symptoms. Total dust concentrations were measured by a gravimetric method, and the concentration of protease in air by a catalytic method.

RESULTS

Nine workers (22%) were sensitised to enzymes in the exposed group of 40, whereas none were sensitised in the non-exposed group. All the sensitised people had symptoms at work; all had rhinitis and one had asthma. Protease concentrations were generally < 20 ng/m3, but occasional peak values up to 80 ng/m3 were detected in the packing and maintenance tasks, and high values of > 1 microgram/m3 in the mixing area.

CONCLUSION

Despite the use of encapsulated enzyme preparations, high enzyme concentrations in workplace air are possible, resulting in a higher risk of sensitisation than expected.

Pituitary gonadal axis and child rate in males with classical 21-hydroxylase deficiency

Though appropriate glucocorticoid substitution therapy should abolish both cortisol deficiency and adrenal androgen excess in patients with 21-hydroxylase deficiency (21-OHD), the long-term outcome is not always satisfactory. There are several reports on low adult height in both male and female patients, and impaired fertility has been reported in females with 21-OHD. There are only few reports on gonadal function of adult male patients with 21 -OHD. In this study, we calculated the child rate of all the 29 diagnosed adult Finnish males with classical 21-OHD and compared it with the mean child rate of the whole Finnish male population with equal age distribution. Sixteen males with 21-OHD and their age-matched healthy controls were further examined in a cross-sectional study. Auxology and pituitary gonadal axis were examined in both patients and controls. Testicular ultrasonography of the patients was also performed. The mean child rate of the 29 males with 21-OHD was 0.07 which was significantly lower (p<0.001) than that in the Finnish male population of the same age (0.34). In the cross-sectional study, males with 21-OHD had serum testosterone, inhibin B, LH and FSH concentrations comparable to those of healthy controls and reference values. Serum DHEA-S concentrations were remarkably low, even in the undersubstituted males with 21-OHD (p<0.001, compared with the healthy controls). In the patient group, serum inhibin B concentration did not correlate with serum FSH concentration. Adrenal rest tumors of the testicles were found in two undersubstituted males with 21-OHD. In conclusion, our study suggests normal pituitary and gonadal function but reduced child rate in adult males with 21-OHD. This might be explained by suboptimal psychosocial adaptation to the chronic disease. However, the patients in this study were young and the final child rate may become essentially higher.

Impaired development of bone mineral density during chemotherapy: a prospective analysis of 46 children newly diagnosed with cancer

Osteopenia and osteoporosis are becoming increasingly recognized in children with cancer, though reasons for these changes are poorly understood. The purpose of the present study was to evaluate longitudinal changes in bone mineral density (BMD) and bone turnover in newly diagnosed children with a malignancy. Lumbar spine (L2-L4) and femoral neck bone mineral density (BMDareal, g/cm2) was measured by dual-energy X-ray absorptiometry in 46 children (age 2.9-16.0, median 8.0 years; 15 leukemias, 12 lymphomas, 19 solid tumors) at diagnosis, and after 6 months from the baseline. The apparent volumetric bone mineral density (BMDvol) was calculated to minimize the effect of bone size on BMD. Serum levels of osteocalcin (OC), type I collagen carboxy-terminal propeptide (PICP), and type I collagen carboxy-terminal telopeptide (ICTP) were analyzed at diagnosis, and during a 6-month follow-up. A significant decrease in lumbar BMDvol (-2.1%, p < 0.05), and in femoral BMDareal (-9.9%, p = 0.0001) and BMDvol (-8.5%, p = 0.0001) was observed after 6 months when compared with baseline measurements. The markers of bone formation (PICP, OC) were significantly decreased, and the marker of bone resorption (ICTP) was significantly increased at diagnosis as compared with normal values. By the end the follow-up, the levels of PICP and OC were normalized, whereas the level of ICTP continued to increase indicating that there was a negative balance in bone turnover. A deficient accumulation of bone mass might predispose children with a malignancy to impaired development of peak bone mass. A controlled study determining the benefits of an early intervention on bone turnover should be considered in these patients.

Disturbance in bone turnover in children with a malignancy at completion of chemotherapy

BACKGROUND

Osteoporosis and pathological fractures have been observed in children with a malignancy. The mechanisms of osteopenia in childhood malignancies have not been well established. The purpose of the present study was to evaluate changes in bone turnover and in bone hormonal metabolism in children with a malignancy at completion of their chemotherapy.

PROCEDURE

Serum levels of human intact osteocalcin, type I collagen carboxyterminal propeptide (PICP), type I collagen carboxyterminal telopeptide (ICTP), 25-hydroxyvitamin D [25-(OH)-D], 1,25-dihydroxyvitamin D [1, 25-(OH)(2)-D], intact parathyroid hormone, insulin-like growth factor I (IGF-I), IGF binding protein 3 (IGFBP-3), alkaline phosphatase, calcium, and phosphate were analyzed in 22 children with acute lymphoblastic leukemia and in 26 children with other malignancies. Results were expressed as Z-scores [mean (95% confidence intervals)] relative to healthy Caucasian-children.

RESULTS

The marker of collagen degradation (ICTP) was significantly increased [1.43 (1.10-1.76), P < 0.0001] compared to reference values, whereas the markers of bone formation (PICP, osteocalcin) were not changed [0.07 (-0.55 to 0.49), 0.35 (-0.05 to 0.74), respectively, NS]. Serum 25-(OH)-D, 1,25-(OH)(2)-D, and calcium were significantly reduced [-0.65 (-0.87 to -0.42), -0.68 (-0.92 to -0. 42), -1.42 (-1.80 to -1.04), P < 0.0001, respectively].

CONCLUSIONS

Disturbance in bone turnover with low serum 25-(OH)-D, 1, 25-(OH)(2)-D, and calcium was observed in children with a malignancy at completion of their chemotherapy. A controlled study determining the possible benefits of vitamin D and calcium supplementation on bone turnover could be considered in these patients.

Regulation of neuropeptide Y mRNA expression in cultured human pheochromocytoma cells

The expression of the neuropeptide Y (NPY) gene varies considerably in human pheochromocytomas, but the mechanisms for this variation have not been clarified. To investigate the regulation pattern of the NPY gene in human pheochromocytomas, we screened 16 pheochromocytomas and 9 normal adrenal tissues with Northern blots. The expression level of NPY mRNA in normal adrenal medulla was low and relatively constant, while the pheochromocytomas showed a very wide variation in NPY mRNA levels in both malignant and benign tumors. This indicates that NPY gene expression is not correlated with malignancy in pheochromocytomas. In primary cultures of human pheochromocytoma cells, nerve growth factor treatment (causing neuronal differentiation) increased NPY mRNA accumulation 2- to 5-fold (P < 0.05). NPY mRNA levels were also induced by protein kinase modulators (Bu)(2)cAMP and staurosporine in the cultures (P < 0.05). In contrast, treatment with dexamethasone and IGF-II (causing or linked with chromaffin differentiation) reduced NPY mRNA accumulation (P < 0.05). These data show that the regulation pattern of NPY mRNA expression in cultured human pheochromocytoma cells is different from that previously described in rat pheochromocytoma PC12 cells. Regulation of NPY mRNA expression in primary cultures by these differentiating factors suggests that the expression of NPY mRNA in pheochromocytoma tissues may be associated with the neuronal differentiation of the tumor cells affected by multiple factors.

Alterations in bone turnover and impaired development of bone mineral density in newly diagnosed children with cancer: a 1-year prospective study

In the present study, longitudinal changes in bone mineral density, bone turnover, and bone hormonal metabolism were evaluated in newly diagnosed children with cancer. Lumbar spine (L2-L4) and femoral neck bone mineral densities (grams per cm2) were measured by dual energy x-ray absorptiometry in 28 children (age, 2.9-16.0 yr; median, 8.0 yr; 10 acute lymphoblastic leukemias, 18 solid tumors) at diagnosis and after a 1-yr follow-up. Apparent volumetric density (grams per cm3) was calculated to minimize the effect of bone size on BMD. Serum levels of osteocalcin (OC), type I collagen carboxyl-terminal propeptide (PICP), and type I collagen carboxyl-terminal telopeptide were measured serially during the study. Serum 25-hydroxyvitamin D, 1,25-dihydroxyvitamin D, insulin-like growth factor I (IGF-I), and IGF-binding protein-3 were analyzed at diagnosis and at 1-yr follow-up. A significant decrease in femoral bone mineral density and apparent volumetric density was observed during the year after diagnosis [(mean (SD), -10.1% (8.8%) and -11.3% (8.1%) respectively; P < 0.01], whereas age- and sex-matched controls showed annual increments of +5.4% (7.7%; P < 0.01) and +0.7% (5.7%; P = NS) respectively. The markers of bone formation (PICP and OC) were significantly decreased at diagnosis. By the end of the follow-up, PICP and OC were normalized, whereas the marker of bone resorption (type I collagen carboxyl-terminal telopeptide) was significantly increased. Reduced levels of 25-hydroxyvitamin D, 1,25-dihydroxyvitamin D, and IGF-binding protein-3 were observed during the study. To conclude, increased bone resorption and impaired development of femoral bone density were observed in children with cancer during chemotherapy. Deficient accumulation of bone mass may lead to impaired development of peak bone mass and predispose children with cancer to increased risk of osteoporosis and diminished skeletal resistance to fractures later in life.

pG2 gene expression and its regulation in human adrenocortical and medullary tumors

The cDNA clone pG2 was originally isolated from a human pheochromocytoma. The respective gene was found to be strongly expressed in normal adrenal zona glomerulosa and medulla, as well as in Conn's adenomas and pheochromocytomas. To shed more light on the expression and regulation of the pG2 gene, we investigated its expression in a wide variety of different adrenal neoplasms and cultured adrenal cells. Northern blot analysis was used to determine the steady state level of pG2 mRNA. Besides normal adrenals, Conn's adenomas and pheochromocytomas, we found abundant expression of pG2 mRNA in Cushing's, virilizing and nonfunctional adrenocortical adenomas and carcinomas, as well as in hyperplastic adrenals. The relative levels of pG2 mRNA in various adrenocortical tumors were not significantly different from those in normal adrenals and pheochromocytomas. In primary cultures of normal adrenal cells, treatment with adrenocorticotropin induced a 3- to 15-fold increase in the expression of pG2 mRNA (P<0.01), and this effect was reproduced by incubation with (Bu)2cAMP. In cultured pheochromocytoma cells, treatment with (Bu)2cAMP and a protein kinase inhibitor, staurosporine, increased pG2 mRNA accumulation (2- to 4-fold over the control level, P<0.01, and 3- to 8-fold, P<0.01, respectively). These results indicate that pG2 is widely expressed in normal and pathological adrenal tissues from both cortical and medullary origin, which eliminates its usefulness as a specific marker for zona glomerulosa or medullary adrenal tumors. Accumulation of pG2 mRNA is regulated by multiple differentiating factors through different pathways in primary cultures of normal adrenal and pheochromocytoma cells.

Reduced bone density at completion of chemotherapy for a malignancy

OBJECTIVES

Osteoporosis and pathological fractures occur occasionally in children with malignancies. This study was performed to determine the degree of osteopenia in children with a malignancy at completion of chemotherapy.

METHODS

Lumbar spine (L2-L4) bone mineral density (BMD; g/cm2) and femoral neck BMD were measured by dual energy x ray absorptiometry in 22 children with acute lymphoblastic leukaemia (ALL), and in 26 children with other malignancies. Apparent volumetric density was calculated to minimise the effect of bone size on BMD. Results were compared with those of 113 healthy controls and expressed as age and sex standardised mean Z scores.

RESULTS

Patients with ALL had significantly reduced lumbar volumetric (-0.77) and femoral areal and volumetric BMDs (-1.02 and -0.98, respectively). In patients with other malignancies, femoral areal and apparent volumetric BMDs were significantly decreased (-0.70 and -0.78, respectively).

CONCLUSIONS

The results demonstrate that children with a malignancy are at risk of developing osteopenia. A follow up of BMD after the completion of chemotherapy should facilitate the identification of patients who might be left with impaired development of peak bone mass, and who require specific interventions to prevent any further decrease in their skeletal mass and to preserve their BMD.

Tracing past population migrations: genealogy of steroid 21-hydroxylase (CYP21) gene mutations in Finland

The genealogic origin of steroid 21-hydroxylase gene (CYP21) mutations and associated haplotypes was determined in 74 unrelated Finnish families with CYP21 deficiency (congenital adrenal hyperplasia, CAH). These families account for two thirds (85/119) of all diagnosed patients of Finnish descent found in this country. We recently demonstrated that multiple founder mutations each associated with a particular haplotype can be found in Finland. Interestingly, some of the haplotypes were identical to those observed in various European populations, whereas others have not been described elsewhere, indicating a local and perhaps a more recent origin. In the present report we show that each of the major founder haplotypes originates from a particular geographic region of Finland. Thus many local genetic isolates are to be expected in Finland. Our finding is in a clear contrast to the genetic diseases known as the 'Finnish disease heritage', in which only one mutation usually predominates. Some of the CYP21 haplotypes proved very informative for analysis of the history of the Finnish population. For example, the origin of one frequent haplotype was shown to cluster in a region assumed by archaeological data to be a major site of immigration by settlers of either Scandinavian or Baltic origin during the first centuries AD. As this haplotype is frequent in many European patient populations, we provide independent genetic evidence of this Iron Age immigration. On the other hand, another frequent haplotype found solely in Finland reflects a more recent (post 15th century) settlement expansion. Consequently, well characterised and sufficiently frequent autosomal gene markers can provide useful information on migrations both between and within populations.

Expression of insulin-like growth factor binding protein 1-6 genes in adrenocortical tumors and pheochromocytomas

The insulin-like growth factor (IGF) system appears to be important in the regulation of adrenal growth and hormone synthesis. As IGF-binding proteins (IGFBPs) modify IGF bioactivity, we investigated the expression of IGFBP 1-6 genes in different adrenal tumors and hyperplasias to further clarify the role of the IGF system in adrenal pathophysiology. IGFBP-1 mRNA levels were too low to be detected by Northern blot analysis, but could be found by RT-PCR in some tumors and hyperplastic adrenals. Other IGFBPs were detected by Northern blotting. IGFBP-3 mRNA levels were very low in normal adrenals. In adrenal tumors and hyperplastic adrenals, IGFBP-3 mRNA expression was usually higher than in normal adrenals. In hormonally active adrenocortical carcinomas, IGFBP-2, -4, -5 and -6 mRNA levels were lower than in nonfunctional carcinomas and normal adrenals. The low IGFBP mRNA expression in the hormone-producing carcinomas was associated with high IGF-II mRNA content. In adrenocortical adenomas from patients with Cushing's or Conn's syndrome, mean IGFBP mRNA levels were higher than in normal adrenals or in hormonally inactive adenomas. In nodular and bilateral hyperplasias, IGFBP-2, -3 and -4 mRNA expression was on average higher than in normal adrenals but varied substantially, as did IGFBP mRNA levels in pheochromocytomas. In comparison to normal adrenals, pheochromocytomas expressed on average higher levels of IGFBP-2 and -4 but less IGFBP-5 and -6 mRNAs. Our data show that the six IGFBPs 1-6 are expressed at variable level in adrenal tumors and hyperplasias. The low level of IGFBP mRNAs in hormonally active adrenocortical carcinomas was of particular interest.

Expression of inhibin alpha in the human adrenal gland and adrenocortical tumors

We studied the expression of inhibin alpha-subunit in normal and hyperplastic adrenal glands, as well as in various adrenocortical tumors. The protein expression of inhibin alpha was performed by immunohistochemistry. Virilizing adenomas showed strong immunoreactivity against monoclonal inhibin alpha-subunit antibody, whereas other adenomas were only weakly positive or completely negative. In the adrenal cortex no inhibin alpha immunoreactivity was detected in the zona glomerulosa. Zona fasciculata showed weak staining for inhibin alpha, however, strong immunostaining was detected in zona reticularis both in normal and hyperplastic adrenal glands. Adrenal medulla was negative for inhibin alpha. In conclusion, we show high expression of inhibin alpha subunit in zona reticularis of normal and hyperplastic adrenal glands as well as strong expression in virilizing adenomas.

Adrenocortical cells are the site of secretion and action of insulin-like growth factors and TNF-alpha

Insulin-like growth factors I and/or II are expressed in adrenal cells, and modulate their proliferation and steroid hormone synthesis suggesting that they may function as paracrine/autocrine factors. In some species, at least ACTH induces insulin-like growth factor synthesis. Thus, these peptide growth factors mediate at least some of the effects of ACTH on adrenocortical cell proliferation and differentiation. Human fetal adrenals express insulin-like growth factor II gene abundantly and ACTH-dependently, while in adult adrenals, the expression is low and no ACTH dependent regulation has been demonstrated. Hormonally active adrenocortical carcinomas and virilizing adenomas express insulin-like growth factor II gene abundantly. This phenomenon is associated with reduced expression of two putative tumor suppressor genes (H19 and p57KIP2) locating on the same genomically imprinted locus on human chromosome 11p15.5. Tumor necrosis factor-alpha belongs to the cytokines which modulate hypothalamic-pituitary-adrenal axis. It is a potent inducer of ACTH secretion but, at the adrenal level, it seems to mainly inhibit ACTH-induced steroidogenesis and also insulin-like growth factor II expression. It is produced in adrenocortical steroidogenic cells in addition to macrophages, which suggests that tumor necrosis factor-alpha may have some autocrine/paracrine functions in the adrenal cortex.

Reduced bone mineral density in long-term survivors of childhood acute lymphoblastic leukemia

PURPOSE

Osteoporosis and pathologic fractures are occasionally found in patients with childhood acute lymphoblastic leukemia (ALL). This study was performed to determine the degree of possible osteopenia in long-term survivors of childhood ALL.

PATIENTS AND METHODS

Lumbar spine (L2-L4) and femoral neck bone mineral densities (BMDs) (g/cm2) were measured in 29 survivors (aged 12 to 30 years, median 17) of childhood ALL 2 to 20 (median 8) years after discontinuation of chemotherapy. These results were compared with those from 273 healthy controls and expressed as a percentage of the age- and sex-matched control values (mean +/- standard deviation).

RESULTS

Lumbar and femoral BMDs were significantly reduced in survivors of childhood ALL. Particularly, male gender (lumbar: 91.7 +/- 10.4%, p = 0.008; femoral: 91.9 +/- 11.3%, p = 0.005) and a history of cranial irradiation (lumbar: 93.0 +/- 8.9%, p = 0.005; femoral: 94.4 +/- 13.3%, p = 0.03) were associated with low lumbar and femoral BMDs.

CONCLUSIONS

The detected deficit in bone density in survivors of childhood ALL may predispose these patients to osteoporotic fractures later in adulthood. A follow-up of BMD in survivors of childhood ALL should facilitate the identification of patients who would require specific therapeutic interventions to prevent further decrease of their skeletal mass and preserve their BMD.

Adrenomedullin gene expression and its different regulation in human adrenocortical and medullary tumors

Adrenomedullin (ADM) is a polypeptide originally discovered in a human pheochromocytoma and is also present in normal adrenal medulla. It has been proposed that ADM could be involved in the regulation of adrenal steroidogenesis via paracrine mechanisms. Our aim was to find out if ADM gene is expressed in adrenocortical tumors and how ADM gene expression is regulated in adrenal cells. ADM mRNA was detectable by Northern blotting in most normal and hyperplastic adrenals, adenomas and carcinomas. The average concentration of ADM mRNA in the hormonally active adrenocortical adenomas was about 80% and 7% of that in normal adrenal glands and separated adrenal medulla respectively. In adrenocortical carcinomas, the ADM mRNA concentration was very variable, but on average it was about six times greater than that in normal adrenal glands. In pheochromocytomas, ADM mRNA expression was about ten times greater than that in normal adrenals and three times greater than in separated adrenal medulla. In primary cultures of normal adrenal cells, a protein kinase C inhibitor, staurosporine, reduced ADM mRNA accumulation in a dose- and time-dependent fashion (P < 0.01), whereas it simultaneously increased the expression of human cholesterol side-chain cleavage enzyme (P450 scc) gene (a key gene in steroidogenesis). In cultured Cushing's adenoma cells, adrenocorticotropin, dibutyryl cAMP ((Bu)2cAMP) and staurosporine inhibited the accumulation of ADM mRNA by 40, 50 and 70% respectively (P < 0.05), whereas the protein kinase C activator, 12-O-tetradecanoyl phorbol 13-acetate (TPA), increased it by 50% (P < 0.05). In primary cultures of pheochromocytoma cells, treatment with (Bu)2cAMP for 1 and 3 days increased ADM mRNA accumulation two- to threefold (P < 0.05). Our results show that ADM mRNA is present not only in adrenal medulla and pheochromocytomas, but also in adrenocortical neoplasms. Both protein kinase A- and C-dependent mechanisms regulate ADM mRNA expression in adrenocortical and pheochromocytoma cells supporting the suggested role for ADM as an autocrine or paracrine (or both) regulator of adrenal function.

Population-wide evaluation of disease manifestation in relation to molecular genotype in steroid 21-hydroxylase (CYP21) deficiency: good correlation in a well defined population

We report a population-wide analysis of all patients with 21-hydroxylase deficiency (21-OHD) found in Finland, a country with a genetically well defined population, in which the effects of other genetic and environmental factors on the phenotype can be expected to be low. In total, 120 patients were identified, and their clinical status was evaluated. Blood samples for CYP21 genotype determination could be obtained from 78 (65%) patients, and their phenotypes were compared with their genotypes. In general, the severity of gene defects correlated well with clinical expression. All patients carrying mutations with the most drastic effects on enzymatic activity had the salt-wasting form of 21-OHD. The I2 splice mutation, which in some reports has been connected with clinical variation, was constantly associated with severe mineralocorticoid deficiency. However, patients with I172N as the determining mutation expressed a wide spectrum of phenotypes; the variation could not be attributed to additional mutations. Although genetically affected males with the nonclassical form had not been clinically diagnosed, our study suggests that nonclassical 21-OHD is substantially more rare in Finland than elsewhere, as indicated by both clinical evaluation and mutational screening.

Divergent association of apolipoprotein E polymorphism with vascular disease in patients with NIDDM and control subjects

We analysed a well-characterized group of 83 patients (43 men, 40 women; mean age +/- SEM: 65.5 +/- 0.6 years at the 10-year examination) with non-insulin-dependent (Type 2) diabetes mellitus (NIDDM) and in 123 control subjects (56 men, 67 women; mean age +/- 0.9 years) retrospectively for the relationship of apolipoprotein E (apo E) genotypes (E2/3, E3/3 vs E3/4, E4/4) to the incidence of clinical macrovascular disease and its risk factors and the incidence of microvascular complications of diabetes during the first 10 years of NIDDM, as well as carotid intima-media thickness measured by B-mode ultrasound at the 10-year examination. In patients with NIDDM, apo E4 genotype showed no relationship to clinical events or carotid intima-media thickness. However, in the control subjects with apo E4, the incidence of non-fatal myocardial infarction during the follow-up was increased (apo E4 positivity: 17.1%; apo E4 negativity 5.1%; p = 0.035) and they had higher common carotid intima-media thickness than those with apo E2/3 or apo E3/3 (1.15 +/- 0.05 mm vs 1.01 +/- 0.03 mm, p = 0.008). Apo E genotype groups showed no relationship to microvascular complications of diabetes, although control subjects with apo E4 positivity showed a higher frequency of microalbuminuria than those lacking apo E4. We conclude that apo E4 was a marker of vascular disease and increased atherosclerosis in non-diabetic subjects, whereas in the diabetic patients these relationships were absent. It is likely that NIDDM per se influences the vascular risk so overwhelmingly that the effects of other risk factors are obscured.

Ribonucleic acid expression of the CLA-1 gene, a human homolog to mouse high density lipoprotein receptor SR-BI, in human adrenal tumors and cultured adrenal cells

Human CLA-1 is homologous to the mouse SR-BI gene, which was recently identified as a high density lipoprotein receptor involved in selective cholesterol uptake in rodent adrenal cells. We screened 42 normal and pathological adrenal samples by Northern blotting and found abundant expression of CLA-1 messenger ribonucleic acid (mRNA) in normal adult and fetal adrenals, adrenocortical adenomas, and hyperplasias. Adrenocortical carcinomas and the adrenals adjacent to Cushing's adenomas contained less CLA-1 mRNA than normal adrenals. CLA-1 mRNA was also highly expressed in a Leydig cell tumor, but much less in liver, kidney, and pheochromocytomas. The accumulation of CLA-1 mRNA in primary cultures of normal adrenocortical cells was up-regulated by ACTH in a dose- and time-dependent manner. Both dibutyryl cAMP and staurosporine increased the basal expression of CLA-1 mRNA. Although there was no additive effect of ACTH and dibutyryl cAMP, staurosporine slightly enhanced the stimulatory effect of ACTH on the expression of CLA-1 mRNA. The abundant expression of CLA-1 mRNA and its regulation by the physiological hormone ACTH in human adrenal cells suggest that CLA-1 has a role in adrenal steroidogenesis, probably as a lipoprotein receptor mediating the selective cholesterol uptake in these cells.

Genetic predisposition to phaeochromocytoma: analysis of candidate genes GDNF, RET and VHL

Inherited predisposition to phaeochromocytoma (MIM No 171300) occurs in multiple endocrine neoplasia type 2 (MEN 2) (MIM No 171400), von Hippel-Lindau (VHL) disease (MIM No 199300), and neurofibromatosis type 1 (NF1) (MIM No 162200). In addition, familial phaeochromocytoma alone has also been reported and we and others have identified germline VHL mutations in five of six kindreds analysed previously. Germline mutations in the RET proto-oncogene, which encodes a receptor tyrosine kinase, and in the VHL tumour suppressor gene cause MEN 2 and VHL disease, respectively. To further investigate the genetics of phaeochromocytoma predisposition, we analysed three groups of patients with no evidence of VHL disease, MEN 2 or NF1: Group A, eight kindreds with familial phaeochromocytoma; Group B, two patients with isolated bilateral phaeochromocytoma; and Group C, six cases of multiple extra-adrenal phaeochromocytoma or adrenal phaeochromocytoma with a family history of neuroectodermal tumours. Germline missense VHL mutations were identified in three of eight kindreds with familial phaeochromocytoma. A germline VHL mutation was also characterised in one of the two patients with bilateral phaeochromocytoma. No VHL or RET mutations were detected in the final group of patients with multiple extra-adrenal phaeochromocytoma or adrenal phaeochromocytoma with a family history of neuroectodermal tumours. The absence of germline VHL and RET gene mutations in many of these families suggested that other phaeochromoeytoma susceptibility loci may exist. Glial cell line-derived neurotrophic factor (GDNF) has been recently identified as a natural ligand for RET. Thus, it seems plausible that GDNF is a good candidate gene to play a role in phaeochromocytoma susceptibility. We searched for germline mutations in GDNF in 16 cases of familial phaeochromocytoma (groups A, B and C) and looked for evidence of somatic change in GDNF in 28 sporadic phaeochromocytomas, 12 MEN 2 phaeochromocytomas and five VHL phaeochromocytomas. No GDNF mutations were identified in patients with familial phaeochromocytoma disease, but a c277C-->T (R93W) sequence variant was identified in one of 28 sporadic tumours. This candidate mutation was identified in the germline and tumour tissue but was not present in 104 control GDNF alleles. GDNF sequence variants including R93W have been suggested previously to represent low penetrance susceptibility mutations for Hirschsprung disease and the R93W was not identified in 376 control alleles studied by others. These findings suggest that although GDNF mutations do not appear to have a major role in the pathogenesis of familial or sporadic phaeochromocytomas, allelic variation at the GDNF locus may modify phaeochromocytoma susceptibility.