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Constantine A Stratakis

Publications and source records attributed to Constantine A Stratakis.

At least 37 records · Page 2Linked to original sources
PubMed2006

Cortisol and growth hormone: clinical implications of a complex, dynamic relationship.

Children with Cushing syndrome (CS), whether CS is iatrogenic or caused by endocrine tumors, have short stature and suffer from excess adiposity and lower bone mineral density. These clinical observations are well entrenched in the minds of pediatricians and pediatric endocrinologists. It is then surprising when one discovers that patients with cortisol-secreting adrenal tumors actually do not have completely suppressed growth hormone levels unless they are obese. Adequate adrenocortical glucocorticoid secretion is necessary for normal function of the somatotropic axis, at least in rodents. Furthermore, glucocorticoids appear to play a regulatory role in skeletal bone accumulation that goes far beyond the well known suppressive effects of excess cortisol on osteoblastic function. To add to the complexity, endocrine and paracrine cortisol levels and actions depend much on the activity of metabolizing enzymes, such as 11-beta-hydroxysteroid dehydrogenase type-1 and CYP3A. The text that follows reviews the complex and dynamic state of the relationship between two of the most important hormones that regulate growth and development in childhood as revealed from clinical, physiologic, and basic science studies. The message is clear: although excess cortisol inhibits growth and the skeleton, normal cortisol levels are part of the mix that ensures both normal growth hormone secretion and bone accumulation in childhood.

Cushing Syndrome↗
PubMed2005

Serial analysis of gene expression in adrenocortical hyperplasia caused by a germline PRKAR1A mutation.

CONTEXT: Adrenocortical tumors have been studied at the molecular genetic and cytogenetic levels, but the gene expression profiles of normal and tumor adrenal tissue have not been extensively investigated. OBJECTIVE: The objective of this study was to obtain information about transcriptome differences in hyperplastic adrenal cells. DESIGN AND PATIENTS: We performed serial analysis of gene expression (SAGE) on control adrenal tissue and primary pigmented nodular adrenocortical disease (PPNAD) tissue from two adolescent female patients. MAIN OUTCOME MEASURE: The main outcome measure was to provide quantitative datasets of the vast majority of the transcripts implicated in normal and pathogenic adrenal functioning. RESULTS: The libraries of 28,705 and 31,278 tags represented 14,846 and 16,698 unique mRNAs from the control and PPNAD tissue, respectively. A total of 842 tags from the two libraries did not match any known sequences. We found 127 tags, including 70 no-match tags, to be expressed almost exclusively in control and/or PPNAD adrenals and to be absent or very rare in other human tissues. Examples of well-characterized genes expressed at significantly higher levels in PPNAD included steroidogenic acute regulator, chromogranin A, and those coding for the steroidogenic enzymes P450 cytochromes CYP17A1 and CYP21A2. Pathway analysis revealed Wnt signaling as the most up-regulated in PPNAD. These data were confirmed for selected genes by quantitative RT-PCR and/or immunohistochemistry. CONCLUSIONS: This study was the first of its kind for adrenal tissue and provides important information about the adrenal transcriptome and aberrant signaling in an inherited form of adrenocortical hyperplasia.

Adrenal Cortex Neoplasms↗
PubMed2005

An assessment of petrosal sinus sampling for localization of pituitary microadenomas in children with Cushing disease.

CONTEXT: Pituitary adenomas in Cushing disease (CD) are usually small and difficult to visualize. Bilateral inferior petrosal venous sampling (BIPSS) before and after ovine CRH stimulation is reserved for patients who have ACTH-dependent Cushing syndrome and negative magnetic resonance imaging (MRI) or positive MRI but inconsistent biochemical data. OBJECTIVE: The objective of the study was to evaluate the usefulness of BIPSS as a tool for localization of a pituitary adenoma in children with CD. DESIGN: The study was a retrospective review of the records of 141 children who were admitted for evaluation of CD from 1982 to 2004. SETTING: The study was conducted at a tertiary care center. INTERVENTIONS AND OUTCOME MEASURES: Lateralization of ACTH secretion during BIPSS was compared with MRI and surgical findings for the localization of a microadenoma. RESULTS: A total of 94 patients, 49 males and 45 females with an age range of 5.3 to 18.7 yr (13 +/- 3.2 yr), underwent BIPSS. Localization of a microadenoma by BIPSS agreed with surgical location in only 58% of the cases (95% confidence interval, 43-66). The combined use of information from the MRI and inferior petrosal venous sampling did not predict the location of the tumor more frequently than MRI alone (P > 0.1), which in this study localized a lesion in 39% of the patients (95% confidence interval, 28-50). The procedure was completed successfully in all patients, and no serious complications were recorded. CONCLUSIONS: Although BIPSS was safe and well tolerated in an experienced center, lateralization of the ACTH gradient during BIPSS was a poor predictor of the site of the adenoma in children with CD.

Adenoma↗
PubMed2005

KiSS-1/G protein-coupled receptor 54 metastasis suppressor pathway increases myocyte-enriched calcineurin interacting protein 1 expression and chronically inhibits calcineurin activity.

OBJECTIVE: Tumor metastasis is a critical determinant of death from cancer. Metastin, a product of the KiSS-1 gene, is an endogenously expressed metastasis suppressor that is the ligand for G protein-coupled receptor 54 (GPR54), a Gq/11-coupled receptor. In the present study, our goal was to define the basis of GPR54 action using thyroid cancer cells as a model. DESIGN AND RESULTS: We used GPR54-null thyroid cancer cells to create a stable GPR54 overexpression model. Cell growth and cell migration of the GPR54-expressing lines were inhibited by recombinant metastin, and metastin stimulated the protein kinase C, ERK, and phosphatidylinositol-3-kinase pathways. To identify metastin-regulated genes, we performed microarray analyses using RNA isolated from GPR54 stable transfectants before and after 1 and 24 h of metastin stimulation. Consistent increases in expression of the gene encoding myocyte-enriched calcineurin interacting protein 1 (MCIP-1), an inhibitor of calcineurin, were identified and confirmed using real-time RT-PCR and Western blot. Functionally, metastin treatment of GPR54-expressing cells initially increased calcineurin activity, followed by a prolonged reduction in calcineurin activity for 24 and 48 h, consistent with the pattern of MCIP-1 expression. In addition, treatment with cyclosporin A, a calcineurin inhibitor, blocked cell migration. Lymph node metastasis in papillary thyroid cancers demonstrated loss of MCIP-1 expression in comparison with primary tumors. CONCLUSIONS: These data suggest a role for MCIP-1 and calcineurin inhibition in GPR54-mediated metastasis suppression in human cancers.

Calcineurin Inhibitors↗
PubMed2005

Detection of adrenocorticotropin-secreting pituitary adenomas by magnetic resonance imaging in children and adolescents with cushing disease.

CONTEXT: We recently showed that pre- and postcontrast spoiled gradient-recalled acquisition in the steady-state (SPGR) was superior to conventional pre- and postcontrast T-1 weighted spin echo (SE) acquisition magnetic resonance imaging (MRI) for the diagnostic evaluation of pituitary tumors in adult patients. OBJECTIVE: The present investigation assessed the use of SPGR vs. SE-MRI in the diagnostic evaluation of ACTH-secreting tumors in children and adolescents with Cushing disease. DESIGN: Data were analyzed retrospectively from a series of patients seen over 7 yr (1997-2004). SETTING: The setting for this study was a tertiary care referral center. PATIENTS: Thirty children with Cushing disease (13 females and 17 males with a mean age of 12 +/- 3 yr) were studied. INTERVENTIONS AND OUTCOME MEASURES: Imaging results were compared with surgical and pathological findings and the clinical outcome. RESULTS: Twenty-eight patients had microadenomas, and two had macroadenomas; the latter were identified by both MRI techniques. Precontrast SE and SPGR-MRI identified four and six of the microadenomas, respectively. Postcontrast SPGR-MRI identified the location of the tumor in 18 of 28 patients, whereas postcontrast SE-MRI identified the location and accurately estimated the size of the tumor in only five patients (P < 0.001). CONCLUSIONS: We conclude that conventional MRI, even with contrast enhancement, mostly failed to identify ACTH-secreting microadenomas in children and adolescents with Cushing disease. Postcontrast SPGR-MRI was superior to SE-MRI and should be used in addition to conventional SE-MRI in the pituitary evaluation of children and adolescents with suspected Cushing disease.

Adenoma↗
PubMed2005

A mouse model for the Carney complex tumor syndrome develops neoplasia in cyclic AMP-responsive tissues.

Carney complex is an autosomal dominant neoplasia syndrome characterized by spotty skin pigmentation, myxomatosis, endocrine tumors, and schwannomas. This condition may be caused by inactivating mutations in PRKAR1A, the gene encoding the type 1A regulatory subunit of protein kinase A. To better understand the mechanism by which PRKAR1A mutations cause disease, we have developed conventional and conditional null alleles for Prkar1a in the mouse. Prkar1a(+/-) mice developed nonpigmented schwannomas and fibro-osseous bone lesions beginning at approximately 6 months of age. Although genotype-specific cardiac and adrenal lesions were not seen, benign and malignant thyroid neoplasias were observed in older mice. This spectrum of tumors overlaps that seen in Carney complex patients, confirming the validity of this mouse model. Genetic analysis indicated that allelic loss occurred in a subset of tumor cells, suggesting that complete loss of Prkar1a plays a key role in tumorigenesis. Similarly, tissue-specific ablation of Prkar1a from a subset of facial neural crest cells caused the formation of schwannomas with divergent differentiation. These observations confirm the identity of PRKAR1A as a tumor suppressor gene with specific importance to cyclic AMP-responsive tissues and suggest that these mice may be valuable tools not only for understanding endocrine tumorigenesis but also for understanding inherited predispositions for schwannoma formation.

Alleles↗
PubMed2005

Hereditary leiomyomatosis associated with bilateral, massive, macronodular adrenocortical disease and atypical cushing syndrome: a clinical and molecular genetic investigation.

Hereditary leiomyomatosis and renal cell cancer (HLRCC) is an autosomal dominant disorder caused by mutations in the fumarate hydratase (FH) gene on chromosome 1q42.3-43. Massive macronodular adrenocortical disease (MMAD) is a heterogeneous condition associated with Cushing syndrome (CS) and bilateral hyperplasia of the adrenal glands. In MMAD, cortisol secretion is often mediated by ectopic, adrenocortical expression of receptors for a variety of substances; however, to date, no consistent genetic defects have been identified. In a patient with HLRCC caused by a germline-inactivating FH mutation, we diagnosed atypical (subclinical) CS due to bilateral, ACTH-independent adrenocortical hyperplasia. A clinical protocol for the detection of ectopic expression of various hormone receptors was employed. Histology was consistent with MMAD. The tumor tissue harbored the germline FH mutation and demonstrated allelic losses of the 1q42.3-43 FH locus. We then searched the National Institutes of Health (NIH) databases of patients with MMAD or HLRCC and found at least three other cases with MMAD that had a history of tumors that could be part of HLRCC; among patients with HLRCC, there were several with some adrenal nodularity noted on computed tomography but none with imaging findings consistent with MMAD. From two of the three MMAD patients, adrenocortical tumor DNA was available and sequenced for coding FH mutations; there were none. We conclude that in a patient with HLRCC, adrenal hyperplasia and CS were due to MMAD. The latter was likely due to the FH germline mutation because in tumor cells, only the mutant allele was retained. However, other patients with MMAD and HLRCC, or HLRCC patients with adrenal imaging findings consistent with MMAD, or MMAD patients with somatic FH mutations were not found among the NIH series. Although a fortuitous association cannot be excluded, HLRCC may be added to the short list of monogenic disorders that have been reported to be associated with the development of adrenal tumors; FH may be considered a candidate gene for MMAD.

Adrenal Cortex Neoplasms↗
PubMed2005

Children experience cognitive decline despite reversal of brain atrophy one year after resolution of Cushing syndrome.

Adults with Cushing syndrome frequently develop brain atrophy, memory impairment, and depression, with partial to complete resolution after cure. The effect of excess glucocorticoid exposure on the brain of children has not been systematically studied. Eleven children (six girls, five boys; ages, 8-16 yr) with endogenous Cushing syndrome seen at the National Institutes of Health Clinical Center from 1999-2000 and 10 healthy age- and sex-matched control subjects were studied. Cognitive and psychological evaluations and magnetic resonance imaging of the brain were done before and 1 yr after cure for patients with Cushing syndrome and once for controls. The estimated duration of Cushing syndrome was 4.4 +/- 1.2 yr. When compared with control subjects, children with Cushing syndrome had significantly smaller cerebral volumes (P < 0.001), larger ventricles (P = 0.02), and smaller amygdala (P = 0.004). At baseline, there were no significant differences in IQ between the two groups, and no psychopathology was identified. Despite reversal of cerebral atrophy 1 yr after surgical cure (total cerebral volume, 947 +/- 94 vs.1050 +/- 74 ml, P < 0.001; ventricular volume, 21.4 +/- 12.5 vs. 14.5 +/- 11.6 ml, P < 0.001), children with Cushing syndrome experienced a significant (P < 0.05) decline in Wechsler IQ scores (Full Scale, 112 +/- 19 vs. 98 +/- 14) and a decline in school performance, without any associated psychopathology. The effect of glucocorticoid excess on the brain of children appears to be different from adults. Despite rapid reversibility of cerebral atrophy, children experience a significant decline in cognitive function 1 yr after correction of hypercortisolism.

Adolescent↗
PubMed2005

Common genetic changes in hereditary and sporadic pituitary adenomas detected by comparative genomic hybridization.

Twenty-four pituitary adenomas, both the sporadic type (n = 18) and the type arising in association with either multiple endocrine neoplasia, type 1 (MEN1; n = 2), or Carney complex (CNC, n = 4) were analyzed by comparative genomic hybridization. Twenty-one (88%) tumors displayed chromosomal alterations. The number of chromosomal aberrations in each tumor varied from 2 to greater than 10. Several recurrent chromosomal abnormalities were identified in this study. The most frequently detected losses of chromosomal material involved 1p (14 of 24, 58%), 11p (11 of 24, 46%), 17 (10 of 24, 42%), 16p (9 of 24, 38%), 4 (8 of 24, 33%), 10p (6 of 24, 25%), 12 (6 of 24, 25%), 20 (6 of 24, 25%), 22q (6 of 24, 25%), 13q (5 of 24, 21%), and 9p (4 of 24, 17%). Copy number increases were detected on 4q (7 of 24, 29%), 17 (8 of 24, 33%), 19 (7 of 24, 29%), 1p (6 of 24, 25%), 5 (6 of 24, 25%), 20 (6 of 24, 25%), 6q (5 of 24, 21%), 13q21-qter (5 of 24, 21%), and 16p (5 of 24, 21%). Chromosome 11 loss, which involved 11p in all cases, was the most significant finding and was common to tumors arising sporadically and in association with MEN1 and CNC. In addition, the majority of the tumors (18 of 24, 75% overall and 86% of all tumors with chromosomal abnormalities) showed involvement of chromosome 1. Tumors had either loss (14 of 24, 58%) or gain (6 of 24, 25%) in the 1p32-1pter region. Finally, changes on chromosome 17, either loss or gain, occurred in 71% (17) of all 24 patients. In summary, all the tumors with chromosomal rearrangements (21 of 24, 88%), whether sporadic pituitary adenomas or those associated with MEN1 or CNC, had alteration(s) of 1p32, 11p, or 17.

Adenoma↗
PubMed2005

Molecular and immunohistochemical investigation of protein kinase a regulatory subunit type 1A (PRKAR1A) in odontogenic myxomas.

Odontogenic myxomas are rare benign neoplasms affecting the jaw. Myxomas of bones and other sites occur as part of Carney complex (CNC), a multiple neoplasia syndrome caused by mutations in the PRKAR1A gene, which codes for the regulatory subunit of protein kinase A (PKA). In the present study, 17 odontogenic myxomas from patients without CNC were screened for PRKAR1A mutations and PRKAR1A protein expression by immunohistochemistry (IHC). Mutations of the coding region of the PRKAR1A gene were identified in 2 tumors; both these lesions showed no or significantly decreased immunostaining of PRKAR1A in the tumor compared to that in the surrounding normal tissue. One mutation (c.725C>A) led to a nonconservative amino acid substitution in a highly conserved area of the gene (A213D); the other was a single base-pair deletion that led to a frameshift (del774C) and a stop codon 11 amino acids downstream of the mutation site; both tumors were heterozygous for the respective mutations. Of the remaining tumors, 7 of the 15 without mutations showed almost no PRKAR1A in the tumor cells, whereas IHC showed that the protein was abundant in nontumorous cells. We concluded that PRKAR1A may be involved by its down-regulation in the pathogenesis of odontogenic myxomas caused by mutations and/or other genetic mechanisms. Of the sporadic, nonfamilial tumors associated with PRKAR1A mutations, the odontogenic type was the first myxomatous lesion found to harbor somatic PRKAR1A sequence changes.

Cyclic AMP-Dependent Protein Kinase RIalpha Subuni↗
PubMed2005

Rieger's anomaly and other ocular abnormalities in association with osteogenesis imperfecta and a COL1A1 mutation.

A patient with osteogenesis imperfecta (OI) and some features of Ehlers-Danlos syndrome had Rieger's anomaly and other associated ocular abnormalities. He carried a COL1A1 mutation (c.3313delA) that has only rarely been seen in OI. The association of ocular anterior chamber abnormalities with OI has not been reported previously, while OI with Ehlers-Danlos syndrome features has only been described in some kindreds. The patient had serious complications as a result of his ocular anomalies. We speculate that the course of his disease and, perhaps, its co-existence with OI could be exacerbated by his collagen type-I defect, although no causality can be established by this report of a single case.

Abnormalities, Multiple↗
PubMed2005

Allelic variation in gene expression in thyroid tissue.

Heritable allelic variation in gene expression may contribute to sporadic and familial disease, but is relatively unexplored. Papillary thyroid cancer (PTC) is characterized by strong heritability but predisposing genes have not been detected. Here we tested the hypothesis that inherited variation in allelic expression occurs in thyroid tissue and so might contribute to disease. We studied genes with a role in thyroid function, signaling, and/or tumorigenesis (PRKAR1A, DUOX1, IP3RI, ARGBP2, TPO, TG, and PEG10). We screened thyroid tissues from controls and patients with thyroid disease and lymphoblastoid cell lines from 40 healthy individuals. We demonstrated the robustness of the technique, a fluorescent dideoxy terminator-based method distinguishing the mRNA products of alleles in individuals who are heterozygous for a polymorphism in the transcript. We confirmed that the PEG10 gene transcript was derived only from one allele because of genetic imprinting. Three other genes, DUOX1, TPO, and ARGBP2 showed allelic variation in thyroid tissue and/or lymphoblastoid cells. Benign and malignant thyroid tissue from the same patient always gave concordant results. DUOX1 variation in expression was seen in 3 of 13 patients with PTC and 6 of 27 patients with benign disease. Further studies are needed to determine the significance of these and other allelic variations.

Alleles↗
PubMed2004

Down-regulation of regulatory subunit type 1A of protein kinase A leads to endocrine and other tumors.

Mutations of the human type Ialpha regulatory subunit (RIalpha) of cyclic AMP-dependent protein kinase (PKA; PRKAR1A) lead to altered kinase activity, primary pigmented nodular adrenocortical disease, and tumors of the thyroid and other tissues. To bypass the early embryonic lethality of Prkar1a(-/-) mice, we established transgenic mice carrying an antisense transgene for Prkar1a exon 2 (X2AS) under the control of a tetracycline-responsive promoter. Down-regulation of Prkar1a by up to 70% was achieved in transgenic mouse tissues and embryonic fibroblasts, with concomitant changes in kinase activity and increased cell proliferation, respectively. Mice developed thyroid follicular hyperplasia and adenomas, adrenocortical hyperplasia, and other features reminiscent of primary pigmented nodular adrenocortical disease, histiocytic and epithelial hyperplasias, lymphomas, and other mesenchymal tumors. These were associated with allelic losses of the mouse chromosome 11 Prkar1a locus, an increase in total type II PKA activity, and higher RIIbeta protein levels. This mouse provides a novel, useful tool for the investigation of cyclic AMP, RIalpha, and PKA functions and confirms the critical role of Prkar1a in tumorigenesis in endocrine and other tissues.

Adenoma↗
PubMed2004

Eyelid myxoma in Carney complex without PRKAR1A allelic loss.

Eyelid nodules were investigated in a patient with Carney complex who was heterozygous for the most commonly known PRKAR1A-inactivating mutation, c.578delTG. Immunohistochemical studies confirmed the diagnosis of myxoma. Loss of heterozygosity was not present, suggesting that haploinsufficiency alone was responsible for tumorigenesis of this eyelid lesion.

Abnormalities, Multiple↗
PubMed2004

Minireview: PRKAR1A: normal and abnormal functions.

The type 1alpha regulatory subunit (RIalpha) of cAMP-dependent protein kinase (PKA) (coded by the PRKAR1A gene) is the main component of type I PKA, which regulates most of the serine-threonine kinase activity catalyzed by the PKA holoenzyme in response to cAMP. Carney complex (CNC), or the complex of spotty skin pigmentation, myxomas, and endocrine overactivity, is a multiple endocrine (and not only) neoplasia syndrome that is due to PRKAR1A-inactivating mutations. The R1alpha protein and PRKAR1A mRNA have been found to be up-regulated in a series of cell lines and human and rodent neoplasms, suggesting this molecule's involvement in tumorigenesis and its potential role in cell cycle regulation, growth, and/or proliferation. Alterations in PKA activity elicit a variety of effects depending on the tissue, developmental stage, degree of differentiation, and cAMP levels. In addition, RIalpha may have functions independent of PKA. The presence of inactivating germline mutations and the loss of its wild-type allele in some CNC lesions indicate that PRKAR1A might function as a tumor suppressor gene in these tissues, but could PRKAR1A be a classic tumor suppressor gene? Probably not, and this review explains why.

Cyclic AMP-Dependent Protein Kinase RIalpha Subuni↗
PubMed2004

Triple-A syndrome with prominent ophthalmic features and a novel mutation in the AAAS gene: a case report.

BACKGROUND: Triple-A syndrome (Allgrove syndrome) is an autosomal recessive disorder characterized by adrenal insufficiency, alacrima, achalasia, and - occasionally - autonomic instability. Mutations have been found in the AAAS gene on 12q13. CASE PRESENTATION: We present the case of a 12 year-old boy with classic systemic features of triple-A syndrome and several prominent ophthalmic features, including: accommodative spasm, dry eye, superficial punctate keratopathy, and pupillary hypersensitivity to dilute pilocarpine. MRI showed small lacrimal glands bilaterally. DNA sequencing of PCR-amplified fragments from the 16 exons of the AAAS gene revealed compound heterozygosity for a new, out-of-frame 5-bp deletion in exon 15, c1368-1372delGCTCA, and a previously-described nonsense mutation in exon 9, c938C>T, R286X. CONCLUSIONS: In addition to known ophthalmic manifestations, triple-A syndrome can present with accommodative dysregulation and ocular signs of autonomic dysfunction.

Accommodation, Ocular↗