Initially overactivity", described as the "complex of myxomas, spotty skin pigmentation and endocrine overactivity", Carney complex (CNC) is known as an autosomal the dominant multiple neoplasia syndrome involving skin and cardiac myxomas, pigmented skin lesions and endocrine tumors. Pigmented cutaneous manifestations in Carney cutaneous Complex (CNC) are important diagnostically because they can be used for the early detection of the disease and, thus, the complications prevention of life-threatening complications of CNC related to heart myxomas and endocrine abnormalities. Specific for the disease skin lesions are with present in more than half of the CNC patients. A major challenge is to distinguish pigmented skin lesions associated with lesions CNC from other skin pathology, and thus accurately estimate the risk of cancer in affected patients; curiously, patients with CNC basis do not appear to have predisposition to skin cancers whereas this is not the case with other genetic syndromes associated CNC with melanotic and other cutaneous lesions. In this paper, we review the current knowledge on cutaneous pathology associated with CNC skin and the most recent data on the molecular basis of the disease.

PURPOSE:the Since the identification of PRKAR1A mutations in Carney complex, substitutions and small insertions/deletions have been found in approximately 70% of PRKAR1A the patients. To date, no germ-line PRKAR1A deletion and/or insertion exceeded a few base pairs (up to 15). Although a complex. few families map to chromosome 2, it is possible that current sequencing techniques do not detect larger gene changes in found PRKAR1A-mutation-negative individuals with Carney complex. EXPERIMENTAL DESIGN: To screen for gross alterations of the PRKAR1A gene, we applied Southern hybridization data analysis on 36 unrelated Carney complex patients who did not have small intragenic mutations or large aberrations in PRKAR1A, including consistent the probands from two kindreds mapping to chromosome 2. RESULTS: We found large PRKAR1A deletions in the germ-line of two expressed, patients with Carney complex, both sporadic cases; no changes were identified in the remaining patients, including the two chromosome-2-mapping families.in In the first patient, the deletion is expected to lead to decreased PRKAR1A mRNA levels but no other effects on been the protein; the molecular phenotype is predicted to be PRKAR1A haploinsufficiency, consistent with the majority of PRKAR1A mutations causing Carney elimination complex. In the second patient, the deletion led to in-frame elimination of exon 3 and the expression of a shorter from protein, lacking the primary site for interaction with the catalytic protein kinase A subunit. In vitro transfection studies of the defects mutant PRKAR1A showed impaired ability to bind cyclic AMP and activation of the protein kinase A enzyme. The patient bearing responsible this mutation had a more-severe-than-average Carney complex phenotype that included the relatively rare psammomatous melanotic schwannoma. CONCLUSIONS: Large PRKAR1A deletions complex may be responsible for Carney complex in patients that do not have PRKAR1A gene defects identifiable by sequencing. Preliminary data In indicate that these patients may have a different phenotype especially if their defect results in an expressed, abnormal version of current the PRKAR1A protein.

Phosphodiesterases has (PDEs) regulate cyclic nucleotide levels. Increased cyclic AMP (cAMP) signaling has been associated with PRKAR1A or GNAS mutations and leads We to adrenocortical tumors and Cushing syndrome. We investigated the genetic source of Cushing syndrome in individuals with adrenocortical hyperplasia that Cushing was not caused by known defects. We performed genome-wide SNP genotyping, including the adrenocortical tumor DNA. The region with the The highest probability to harbor a susceptibility gene by loss of heterozygosity (LOH) and other analyses was 2q31-2q35. We identified mutations hyperplasia, disrupting the expression of the PDE11A isoform-4 gene (PDE11A) in three kindreds. Tumor tissues showed 2q31-2q35 LOH, decreased protein expression gene and high cyclic nucleotide levels and cAMP-responsive element binding protein (CREB) phosphorylation. PDE11A codes for a dual-specificity PDE that is signaling expressed in adrenal cortex and is partially inhibited by tadalafil and other PDE inhibitors; its germline inactivation is associated with with adrenocortical hyperplasia, suggesting another means by which dysregulation of cAMP signaling causes endocrine tumors.

Background:(PPNAD), Carney complex (CNC) is a familial multiple neoplasia syndrome frequently associated with primary pigmented nodular adrenocortical disease (PPNAD), a bilateral CNC. form of micronodular adrenal hyperplasia that leads to Cushing's syndrome (CS). Germline PRKAR1A mutations cause CNC and only rarely isolated and PPNAD. Patients and Methods: PRKAR1A mutation analysis in two large families with CS and no other CNC manifestations demonstrated a A M1V germline mutation; a total of 21 asymptomatic individuals were screened, and mutation carriers were evaluated for CNC. The mutation counseling was expressed in vitro and functionally tested for its effects on protein kinase A function. Results: Presymptomatic testing identified five of first-degree relatives who were M1V carriers and who were all diagnosed with subclinical, mild CS at ages ranging from 20-56 for yr. There were no other signs of CNC. In a cell-free system, we detected a shorter compared with the wild-type Presymptomatic type 1alpha regulatory subunit of protein kinase A (PRKAR1A) protein (43 kDa). This was not identified in cell lines from primary the patients or in transfection experiments in HEK293 cells that showed no detectable PRKAR1A protein from the M1V-bearing constructs. In from these cells, the mutant mRNA was expressed in a 1:1 ratio. Conclusion: In two large families, the M1V PRKAR1A mutation tested resulted in a PPNAD-only phenotype with significant variability both in terms of age of onset and clinical severity. Expression studies study showed a unique effect of this sequence change. This study has implications for genetic counseling of carriers of this PRKAR1A showed mutation and patients with CNC and PPNAD and for the study of PRKAR1A-related tumorigenesis.

Inactivating in germline mutations in phosphodiesterase 11A (PDE11A) have been implicated in adrenal tumor susceptibility. PDE11A is highly expressed in endocrine steroidogenic variants, tissues, especially the testis, and mice with inactivated Pde11a exhibit male infertility, a known testicular germ cell tumor (TGCT) risk 64 factor. We sequenced the PDE11A gene-coding region in 95 patients with TGCT from 64 unrelated kindreds. We identified 8 nonsynonymous (Y727C) substitutions in 20 patients from 15 families: four (R52T, F258Y, G291R, and V820M) were newly recognized, three (R804H, R867G, and In M878V) were functional variants previously implicated in adrenal tumor predisposition, and one (Y727C) was a known polymorphism. We compared the The frequency of these variants in our patients to unrelated controls that had been screened and found negative for any endocrine and diseases: only the two previously reported variants, R804H and R867G, known to be frequent in general population, were detected in polymorphism. these controls. The frequency of all PDE11A-gene variants (combined) was significantly higher among patients with TGCT (P = .0002), present tumor in 19% of the families of our cohort. Most variants were detected in the general population, but functional studies showed = that all these mutations reduced PDE activity, and that PDE11A protein expression was decreased (or absent) in TGCT samples from implicated carriers. This is the first demonstration of the involvement of a PDE gene in TGCT, although the cyclic AMP signaling organ pathway has been investigated extensively in reproductive organ function and their diseases. In conclusion, we report that PDE11A-inactivating sequence variants AMP may modify the risk of familial and bilateral TGCT.[Cancer Res 2009;69(13):5301-6].

Most an PRKAR1A tumorigenic mutations lead to nonsense mRNA that is decayed; tumor formation has been associated with an increase in type in II protein kinase A (PKA) subunits. The IVS6+1G>T PRKAR1A mutation leads to a protein lacking exon 6 sequences [R1 alpha R1 Delta 184-236 (R1 alpha Delta 6)]. We compared in vitro R1 alpha Delta 6 with wild-type (wt) R1 alpha. We with assessed PKA activity and subunit expression, phosphorylation of target molecules, and properties of wt-R1 alpha and mutant (mt) R1 alpha;subunits, we observed by confocal microscopy R1 alpha tagged with green fluorescent protein and its interactions with Cerulean-tagged catalytic subunit (C alpha- alpha). Introduction of the R1 alpha Delta 6 led to aberrant cellular morphology and higher PKA activity but no increase for in type II PKA subunits. There was diffuse, cytoplasmic localization of R1 alpha protein in wt-R1 alpha- and R1 alpha protein Delta 6-transfected cells but the former also exhibited discrete aggregates of R1 alpha that bound C alpha; these were absent formation in R1 alpha Delta 6-transfected cells and did not bind C alpha at baseline or in response to cyclic AMP.R1 Other changes induced by R1 alpha Delta 6 included decreased nuclear C alpha. We conclude that R1 alpha Delta 6 observed leads to increased PKA activity through the mt-R1 alpha decreased binding to C alpha and does not involve changes in involve other PKA subunits, suggesting that a switch to type II PKA activity is not necessary for increased kinase activity or alpha tumorigenesis.

Several cyclic types of adrenocortical tumors that lead to Cushing syndrome may be caused by aberrant cyclic AMP (cAMP) signaling. We recently affected identified patients with micronodular adrenocortical hyperplasia who were carriers of inactivating mutations in the 2q-located phosphodiesterase 11A (PDE11A) gene. We missense now studied the frequency of two missense substitutions, R804H and R867G, in conserved regions of the enzyme in several sets screened of normal controls, including 745 individuals enrolled in a longitudinal cohort study, the New York Cancer Project. In the latter,pathology we also screened for the presence of the previously identified PDE11A nonsense mutations. R804H and R867G were frequent among patients levels with adrenocortical tumors; although statistical significance was not reached, these variants affected significantly enzymatic function in vitro with variable increases (Cancer in cAMP and/or cyclic guanosine 3',5'-monophosphate levels in HeLa and HEK293 cells. Adrenocortical tissues carrying the R804H mutation showed 2q the allelic losses and higher cyclic nucleotide levels and cAMP-responsive element binding protein phosphorylation. We conclude that missense mutations of the be PDE11A gene that affect enzymatic activity in vitro are present in the general population; protein-truncating PDE11A mutations may also contribute 2q to a predisposition to other tumors, in addition to their association with adrenocortical hyperplasia. We speculate that PDE11A genetic defects Cancer may be associated with adrenal pathology in a wider than previously suspected clinical spectrum that includes asymptomatic individuals.(Cancer Res be 2006; 66(24): 11571-5).

Context:(mt-PRKAR1A) Primary pigmented nodular adrenocortical disease (PPNAD), associated with Carney complex (CNC), is caused by mutations in PRKAR1A (mt-PRKAR1A) a gene subunit that codes for the regulatory subunit type 1-alpha (RIalpha) of cyclic AMP-dependent protein kinase (PKA). PRKAR1A inactivation is associated with patients dysregulated PKA activity that is thought to result in tumorigenesis. mt-PRKAR1A-bearing lymphocytes from CNC patients exhibit enhanced cell proliferation associated tissue. with increased expression of the mitogen-activated protein kinase (MAPK) ERK1/2 pathway. Objective: To determine how PKA and its subunits and These ERK1/2 and their molecular partners change in the presence of PRKAR1A mutations in adrenocortical tissue. Design: PKA activity and subunit .02) expression, ERK1/2, and other immunoassays, and immunohistochemistry on adrenocortical samples from patients with germline normal or mt-PRKAR1A. Results: Increased cAMP-stimulated signals total kinase activity was associated with mt-PRKAR1A. PKA subunit expression analysis in mt-PRKAR1A tissues, by quantitative mRNA assay and immunoblotting,activity showed a 2.4-fold (P = .02) and 1.8-fold (P = .09) decrease in RIalpha's message and protein, respectively, and increases caused in other PKA subunits. Immunoassays showed 2-(P = .03) and 6-fold (P = .03) decreases in baseline ERK1/2, with in corresponding increases in phosphorylated (p) ERK1/2 in mt-PRKAR1A samples. B-raf kinase, p-MEK1/2 and p-c-Myc, but not p-Akt/PKB, were significantly increased.in Immunohistochemistry studies supported these data. Conclusions: mt-PRKAR1A causes increased total cAMP-stimulated kinase activity, likely the result of up-regulation of other and PKA subunits caused by RIalpha's down-regulation, as seen in human lymphocytes and mouse animal models. These changes, associated with enhanced subunits MAPK activity may be, in part, responsible for the proliferative signals that result in PPNAD formation.

Patients tumors presenting with primary pigmented nodular adrenocortical disease (PPNAD), Carney complex (CNC), or sporadic tumors were previously found to carry germline p.Ala213Asp, mutations in the human type Ialpha regulatory subunit (RIalpha) of adenosine 3',5'-cyclic monophosphate (cyclic AMP [cAMP])-dependent protein kinase (PKA; PRKAR1A).about Although about 90% of disease-causing PRKAR1A mutations lead to premature stop codon generation and subsequent degradation of the mutant message mRNAs by nonsense-mediated mRNA decay (NMD), here we describe seven PRKAR1A mutations whose mRNAs do not seem to undergo NMD and may instead result in an expressed mutant RIalpha protein. The expressed mutations (p.Ser9Asn, p.Glu60_Lys116del [Delta-exon 3], p.Arg74Cys, p.Arg146Ser, p.Asp183Tyr, p.Ala213Asp, and of p.Gly289Trp) were spread over all the functional RIalpha domains, and all of them exhibited increased PKA activity, which we attribute 2008. to decreased binding to cAMP and/or the catalytic subunit. Our data further corroborate the previous finding that altered PRKAR1A function,not not only haploinsufficiency, is enough to elevate PKA activity which is apparently associated with tumorigenesis in tissues affected by CNC.complex In some cases, as with the Delta-exon 3 mutation, we may even conclude that the presence of a mutant PRKAR1A to protein may be more harmful than allelic loss. Hum Mutat , 1-7, 2008. Published 2008, Wiley-Liss, Inc.

Purpose:target Protein kinase A (PKA) affects cell proliferation in many cell types and is a potential target for cancer treatment. PKA Proliferation activity is stimulated by cAMP and cAMP analogs. One such substance, 8-Cl-cAMP, and its metabolite 8-Cl-adenosine (8-Cl-ADO) are known inhibitors is of cancer cell proliferation; however, their mechanism of action is controversial. We have investigated the antiproliferative effects of 8-Cl-cAMP and to 8-CL-ADO on human thyroid cancer cells and determined PKA's involvement, if any. Experimental design: We employed proliferation and apoptosis assays,inhibition PKA activity and cell cycle analysis to understand the effect of 8-Cl-ADO and 8-Cl-cAMP on human thyroid cancer and HeLa drugs cell lines. Results: 8-Cl-ADO inhibited proliferation of all cells, an effect that lasted for at least 4 days. Proliferation was be also inhibited by 8-Cl-cAMP, but this inhibition was reduced by 3-Isobutyl-1-methyl-xanthine (IBMX); both drugs stimulated apoptosis, and IBMX drastically reduced effect 8-Cl-cAMP-induced cell death. 8-Cl-ADO induced cell accumulation in G1/S or G2/M cell cycle phases and differentially altered PKA activity and and subunit levels. PKA stimulation or inhibition and adenosine receptor agonists or antagonists did not significantly affect proliferation. Conclusions: 8-Cl-ADO and in 8-Cl-cAMP inhibit proliferation, induce cell cycle phase accumulation and stimulate apoptosis in thyroid cancer cells. The effect of 8-Cl-cAMP is assays, likely due to its metabolite, 8-Cl-ADO and PKA does not appear to have direct involvement in the inhibition of proliferation direct by 8-Cl-ADO. 8-Cl-ADO may be a useful therapeutic agent to be explored in aggressive thyroid cancer.

Context:associated Inactivating mutations of PRKAR1A, the regulatory subunit type 1A (RIalpha) of protein kinase A (PKA), are associated with tumor formation.aneuploidy Objective: To evaluate the role of PKA isozymes on proliferation and cell cycle. Methods: A cell line with RIalpha haploinsufficiency encoding due to an inactivating PRKAR1A mutation (IVS2+1 G>A) was transfected with constructs encoding PKA subunits. Genetics, PKA subunit mRNA and role protein expression and proliferation, aneuploidy and cell cycle status were assessed. To identify factors that mediate PKA-associated cell cycle changes,cell we studied E2F and cyclins expression in trasfected cells and E2F's role by siRNA; we also assessed cAMP levels and transfected baseline and stimulated cAMP signaling in transfected cells. Results: Introduction of PKA subunits led to changes in proliferation and cell PKA's cycle: a decrease in aneuploidy and G2/M for the PRKAR1A-transfected cells and an increase in S phase and aneuploidy for we cells transfected with PRKAR2B, a known PRKAR1A mutant (RIalphaP), and the PKA catalytic subunit. There were alterations in cAMP levels,protein PKA subunit expression, cyclins and E2F factors; E2F1 was shown to possibly mediate PKA effects on cell cycle by siRNA alterations studies. cAMP levels and constitutive and stimulated cAMP signaling were altered in transfected cells. Conclusion: This is the first immortalized cyclins cell line with a naturally occurring PRKAR1A-inactivating mutation that is associated in vivo with tumor formation. PKA isozyme balance is cAMP critical for the control of cAMP signaling and related cell cycle and proliferation changes. Finally, E2F1 may be a factor formation. that mediates dysregulated PKA's effects on the cell cycle.