Rare forms of genetic paediatric adrenal insufficiency: Excluding congenital adrenal hyperplasia.

Adrenal insufficiency (AI) is a severe endocrine disorder characterized by insufficient glucocorticoid (GC) and/or mineralocorticoid (MC) secretion by the adrenal glands, due to impaired adrenal function (primary adrenal insufficiency, PAI) or to insufficient adrenal stimulation by pituitary ACTH (secondary adrenal insufficiency, SAI) or tertiary adrenal insufficiency due to hypothalamic dysfunction. In this review, we describe rare genetic causes of PAI with isolated GC or combined GC and MC deficiencies and we also describe rare syndromes of isolated MC deficiency. In children, the most frequent cause of PAI is congenital adrenal hyperplasia (CAH), a group of adrenal disorders related to steroidogenic enzyme deficiencies, which will not be included in this review. Less frequently, several rare diseases can cause PAI, either affecting exclusively the adrenal glands or with systemic involvement. The diagnosis of these diseases is often challenging, due to the heterogeneity of their clinical presentation and to their rarity. Therefore, the current review aims to provide an overview on these rare genetic forms of paediatric PAI, offering a review of genetic and clinical features and a summary of diagnostic and therapeutic approaches, promoting awareness among practitioners, and favoring early diagnosis and optimal clinical management in suspect cases.

Paediatric Cushing's disease: Epidemiology, pathogenesis, clinical management and outcome.

Cushing's disease (CD) is rare in paediatric practice but requires prompt investigation, diagnosis and therapy to prevent long-term complications. Key presenting features are a change in facial appearance, weight gain, growth failure, virilization, disturbed puberty and psychological disturbance. Close consultation with an adult endocrinology department is recommended regarding diagnosis and therapy. The incidence of CD, a form of ACTH-dependent Cushing's syndrome (CS), is equal to approximately 5% of that seen in adults. The majority of ACTH-secreting adenomas are monoclonal and sporadic, although recent studies of pituitary tumours have shown links to several deubiquitination gene defects. Diagnosis requires confirmation of hypercortisolism followed by demonstration of ACTH-dependence. Identification of the corticotroph adenoma by pituitary MRI and/or bilateral inferior petrosal sampling for ACTH may contribute to localisation before pituitary surgery. Transsphenoidal surgery (TSS) with selective microadenomectomy is first-line therapy, followed by external pituitary irradiation if surgery is not curative. Medical therapy to suppress adrenal steroid synthesis is effective in the short-term and bilateral adrenalectomy should be considered in cases unfit for TSS or radiotherapy or when urgent remission is needed after unsuccessful surgery. TSS induces remission of hypercortisolism and improvement of symptoms in 70-100% of cases, particularly when performed by a surgeon with experience in children. Post-TSS complications include pituitary hormone deficiencies, sub-optimal catch-up growth, and persisting excess of BMI. Recurrence of hypercortisolism following remission is recognised but infrequent, being less common than in adult CD patients. With experienced specialist medical and surgical care, the overall prognosis is good. Early referral to an experienced endocrine centre is advised.

Cortisol Circadian Rhythm and Insulin Resistance in Muscle: Effect of Dosing and Timing of Hydrocortisone Exposure on Insulin Sensitivity in Synchronized Muscle Cells.

INTRODUCTION/AIM: Circadian clock disruption is emerging as a risk factor for metabolic disorders, and particularly, alterations in clock genes circadian expression have been shown to influence insulin sensitivity. Recently, the reciprocal interplay between the circadian clock machinery and hypothal-amus-pituitary-adrenal axis has been largely demonstrated: the circadian clock may control the physiological circadian endogenous glucocorticoid (GC) secretion and action; GCs, in turn, are potent regulators of the circadian clock and their inappropriate replacement has been associated with metabolic impairment. The aim of the current study was to investigate in vitro the interaction between the timing-of-the-day exposure to different hydrocortisone (HC) concentrations and muscle insulin sensitivity. METHODS: Serum-shock synchronized mouse skeletal muscle C2C12 cells were exposed to different HC concentrations resembling the circulating daily physiological cortisol profile (standard cortisol profile) and the circulating daily cortisol profile that reached in adrenal insufficient (AI) patients treated with once-daily modified-release HC (flat cortisol profile) and treated with thrice-daily conventional immediate-release HC (steep cortisol profile). The 24 h spontaneous oscillation of the clock genes in synchronized C2C12 cells was used to align the timing for in vitro HC exposure (Bmal1 acrophase, midphase, and bathyphase) with the reference times of cortisol peaks in AI patients treated with IR-HC (8 a.m., 1 p.m., and 6 p.m.). A panel of 84 insulin sensitivity-related genes and intracellular insulin signaling proteins were analyzed by RT-qPCR and Western blot, respectively. RESULTS: The steep profile, characterized by a higher HC exposure during Bmal1bathyphase, produced significant downregulation in 21 insulin sensitivity-related genes including Insr, Irs1, Irs2, Pi3kca, and Adipor2, compared to the flat and standard profile. Reduced intracellular IRS1 Tyr608, AKT Ser473, AMPK Thr172, and ACC Ser79 phosphorylations were also observed. CONCLUSIONS: The current study demonstrated that late-in-the-day cortisol exposure modulates insulin sensitivity-related gene expression and intracellular insulin signaling in skeletal muscle cells.

Abnormal linear growth in paediatric adrenal diseases: Pathogenesis, prevalence and management.

Abnormal adrenal function can interfere with linear growth, potentially causing either acceleration or impairment of growth in paediatric patients. These abnormalities can be caused by direct effects of adrenal hormones, particularly glucocorticoids and sex steroids, or be mediated by indirect mechanisms such as the disturbance of the growth hormone-insulin-like growth factor-1 axis and aromatization of androgens to oestrogens. The early diagnosis and optimal treatment of adrenal disorders can prevent or minimize growth disturbance and facilitate improved height gain. Mechanisms of growth disturbance in the following abnormal states will be discussed; hypercortisolaemia, hyperandrogenaemia and obesity. Prevalence and features of growth disturbance will be discussed in ACTH-dependent and ACTH-independent Cushing's syndrome, adrenocortical tumours, premature adrenarche, congenital adrenal hyperplasia and adrenal insufficiency disorders. Recommendations for management have been included.

Pituitary tumors and pregnancy: the interplay between a pathologic condition and a physiologic status.

Pregnancy is becoming a relatively common event in patients with pituitary tumors (PT), due to the increasing availability of medical treatments, which control pituitary diseases associated with the development of PT. However, the presence of PT and its treatment may be a disturbing factor for pregnancy, and pregnancy significantly influences the course and the management of PT. This review summarizes the knowledge about the management of PT during pregnancy and the occurrence of pregnancy in patients with pre-existent PT, focusing on secreting PT characterized by hormonal excess and on clinically non-functioning PT often associated to hormone deficiency, which configure the hypopituitaric syndrome.

Machine learning-based algorithms applied to drug prescriptions and other healthcare services in the Sicilian claims database to identify acromegaly as a model for the earlier diagnosis of rare diseases.

Acromegaly is a rare disease characterized by a diagnostic delay ranging from 5 to 10 years from the symptoms' onset. The aim of this study was to develop and internally validate machine-learning algorithms to identify a combination of variables for the early diagnosis of acromegaly. This retrospective population-based study was conducted between 2011 and 2018 using data from the claims databases of Sicily Region, in Southern Italy. To identify combinations of potential predictors of acromegaly diagnosis, conditional and unconditional penalized multivariable logistic regression models and three machine learning algorithms (i.e., the Recursive Partitioning and Regression Tree, the Random Forest and the Support Vector Machine) were used, and their performance was evaluated. The random forest (RF) algorithm achieved the highest Area under the ROC Curve value of 0.83 (95% CI 0.79-0.87). The sensitivity in the test set, computed at the optimal threshold of predicted probabilities, ranged from 28% for the unconditional logistic regression model to 69% for the RF. Overall, the only diagnosis predictor selected by all five models and algorithms was the number of immunosuppressants-related pharmacy claims. The other predictors selected by at least two models were eventually combined in an unconditional logistic regression to develop a meta-score that achieved an acceptable discrimination accuracy (AUC = 0.71, 95% CI 0.66-0.75). Findings of this study showed that data-driven machine learning algorithms may play a role in supporting the early diagnosis of rare diseases such as acromegaly.

Development and testing of diagnostic algorithms to identify patients with acromegaly in Southern Italian claims databases.

Acromegaly is a rare disease characterized by an excessive production of growth-hormone and insulin-like growth factor 1, typically resulting from a GH-secreting pituitary adenoma. This study was aimed at comparing and measuring accuracy of newly and previously developed coding algorithms for the identification of acromegaly using Italian claims databases. This study was conducted between January 2015 and December 2018, using data from the claims databases of Caserta Local Health Unit (LHU) and Sicily Region in Southern Italy. To detect acromegaly cases from the general target population, four algorithms were developed using combinations of diagnostic, surgical procedure and co-payment exemption codes, pharmacy claims and specialist's visits. Algorithm accuracy was assessed by measuring the Youden Index, sensitivity, specificity, positive and negative predictive values. The percentage of positive cases for each algorithm ranged from 7.9 (95% CI 6.4-9.8) to 13.8 (95% CI 11.7-16.2) per 100,000 inhabitants in Caserta LHU and from 7.8 (95% CI 7.1-8.6) to 16.4 (95% CI 15.3-17.5) in Sicily Region. Sensitivity of the different algorithms ranged from 71.1% (95% CI 54.1-84.6%) to 84.2% (95% CI 68.8-94.0%), while specificity was always higher than 99.9%. The algorithm based on the presence of claims suggestive of acromegaly in ≥ 2 different databases (i.e., hospital discharge records, copayment exemptions registry, pharmacy claims and specialist visits registry) achieved the highest Youden Index (84.2) and the highest positive predictive value (34.8; 95% CI 28.6-41.6). We tested four algorithms to identify acromegaly cases using claims databases with high sensitivity and Youden Index. Despite identifying rare diseases using real-world data is challenging, this study showed that robust validity testing may yield the identification of accurate coding algorithms.

MicroRNAs and Long Non-Coding RNAs in Adrenocortical Carcinoma.

Non-coding RNAs (ncRNAs) are a type of genetic material that do not encode proteins but regulate the gene expression at an epigenetic level, such as microRNAs (miRNAs) and long non-coding RNAs (lncRNAs). The role played by ncRNAs in many physiological and pathological processes has gained attention during the last few decades, as they might be useful in the diagnosis, treatment and management of several human disorders, including endocrine and oncological diseases. Adrenocortical carcinoma (ACC) is a rare and aggressive endocrine cancer, still characterized by high mortality and morbidity due to both endocrine and oncological complications. Despite the rarity of this disease, recently, the role of ncRNA has been quite extensively evaluated in ACC. In order to better explore the role of the ncRNA in human ACC, this review summarizes the current knowledge on ncRNA dysregulation in ACC and its potential role in the diagnosis, treatment, and management of this tumor.

ENSAT registry-based randomized clinical trials for adrenocortical carcinoma.

Adrenocortical carcinoma (ACC) is an orphan disease lacking effective systemic treatment options. The low incidence of the disease and high cost of clinical trials are major obstacles in the search for improved treatment strategies. As a novel approach, registry-based clinical trials have been introduced in clinical research, so allowing for significant cost reduction, but without compromising scientific benefit. Herein, we describe how the European Network for the Study of Adrenal Tumours (ENSAT) could transform its current registry into one fit for a clinical trial infrastructure. The rationale to perform randomized registry-based trials in ACC is outlined including an analysis of relevant limitations and challenges. We summarize a survey on this concept among ENSAT members who expressed a strong interest in the concept and rated its scientific potential as high. Legal aspects, including ethical approval of registry-based randomization were identified as potential obstacles. Finally, we describe three potential randomized registry-based clinical trials in an adjuvant setting and for advanced disease with a high potential to be executed within the framework of an advanced ENSAT registry. Thus we, therefore, provide the basis for future registry-based trials for ACC patients. This could ultimately provide proof-of-principle of how to perform more effective randomized trials for an orphan disease.

Pathophysiology of diabetes mellitus in Cushing's syndrome.

Cushing's syndrome is commonly complicated with an impairment of glucose metabolism, which is often clinically manifested as diabetes mellitus. The development of diabetes mellitus in Cushing's syndrome is both a direct and indirect consequence of glucocorticoid excess. Indeed, glucocorticoid excess induces a stimulation of gluconeogenesis in the liver as well as an inhibition of insulin sensitivity both in the liver and in the skeletal muscles, which represent the most important sites responsible for glucose metabolism. In particular, glucocorticoid excess stimulates the expression of several key enzymes involved in the process of gluconeogenesis, with a consequent increase of glucose production, and induces an impairment of insulin sensitivity either directly by interfering with the insulin receptor signaling pathway or indirectly, through the stimulation of lipolysis and proteolysis and the consequent increase of fatty acids and amino acids, which contribute to the development of insulin resistance. Moreover, the peculiar distribution of adipose tissue throughout the body, with the predominance of visceral adipose tissue, significantly contributes to the worsening of insulin resistance and the development of a metabolic syndrome, which participates in the occurrence and maintenance of the impairment of glucose tolerance. Finally, glucocorticoid excess is able to impair insulin secretion as well as act at the level of the pancreatic beta cells, where it inhibits different steps of the insulin secretion process. This phenomenon is probably responsible for the passage from an impairment of glucose tolerance to an overt diabetes mellitus in susceptible patients with Cushing's syndrome.

Cardiovascular disease in Cushing's syndrome: heart versus vasculature.

Cushing's syndrome (CS) causes metabolic abnormalities that determine an increased cardiovascular risk not only during the active phase of the disease but also for a long time after cure. Cardiovascular complications, such as premature atherosclerosis, coronary artery disease, heart failure, and stroke, in patients with CS cause a mortality rate higher than that observed in a normal population. The increased cardiovascular risk is mainly due to metabolic complications, such as metabolic syndrome, but also to vascular and cardiac alterations such as atherosclerosis and cardiac structural and functional changes. In the clinical management of patients with CS the focus should be on identifying the global cardiovascular risk and the aim should be to control not only hypertension but also other correlated risk factors, such as obesity, glucose intolerance, insulin resistance, dyslipidemia, endothelial dysfunction and the prothrombotic state. Considering that remission from hypercortisolism is often difficult to achieve and that the cardiovascular risk can persist even during disease remission, care and control of all cardiovascular risk factors should be one of the primary goals during the follow-up of these patients.

Medical Treatment of Cushing's Disease: An Overview of the Current and Recent Clinical Trials.

Cushing's disease (CD) is a serious endocrine disorder characterized by chronic hypercortisolism, or Cushing's syndrome (CS), caused by a corticotroph pituitary tumor, which induces an excessive adrenocorticotropic hormone (ACTH) and consequently cortisol secretion. CD presents a severe clinical burden, with impairment of the quality of life and increase in mortality. Pituitary surgery represents the first-line therapy, but it is non-curative in one third of patients, requiring additional treatments. Among second-line treatments, medical therapy is gradually gaining importance, although the current medical treatments are unable to reach optimal efficacy and safety profile. Therefore, new drugs and new formulations of presently available drugs are currently under clinical investigation in international clinical trials, in order to assess their efficacy and safety in CD, or in the general population of CS. Among pituitary-directed agents, pasireotide, in the twice-daily subcutaneous formulation, has been demonstrated to be an effective treatment both in clinical trials and in real-world studies, and extension studies of the phase II and III clinical trials reported evidence of long-term efficacy with general good safety profile, although associated with frequent hyperglycemia, which requires monitoring of glucose metabolism. Moreover, the most recent once-monthly intramuscular formulation, pasireotide long-acting release (LAR), showed similar efficacy and safety, but associated with potential better compliance profile in CD. Roscovitine is an experimental drug currently under investigation. Among adrenal-directed agents, metyrapone is the only historical agent currently under investigation in a prospective, multicenter, international clinical trial, that would likely clarify its efficacy and safety in a large population of patients with CS. Osilodrostat, a novel agent with a mechanism of action similar to metyrapone, seems to offer a rapid, sustained, and effective disease control of CD, according to recently completed clinical trials, whereas levoketoconazole, a different chemical formulation of the historical agent ketoconazole, is still under investigation in clinical trials, with preliminary evidences showing an effective and safe control of CS. ATR-101 is an experimental drug currently under investigation. Among glucocorticoid receptor-directed drugs, mifepristone has been demonstrated to improve clinical syndrome and comorbidities, especially hypertension and impairment of glucose metabolism, but the occurrence of hypokalemia and in women uterine disorders, due to the concomitant action on progestin receptor, requires caution, whereas the preliminary evidence on relacorilant, characterized by high selectivity for glucocorticoid receptor, suggested good efficacy in the control of hypertension and impairment of glucose metabolism, as well as a good safety profile, in CS. Finally, a limited experience has demonstrated that combination therapy might be an interesting approach in the management of CD. The current review provides a summary of the available evidences from current and recent clinical trials on CD, with a specific focus on preliminary data.

Mitotane Concentrations Influence Outcome in Patients with Advanced Adrenocortical Carcinoma.

Mitotane is the main option of treatment for advanced adrenocortical carcinoma (ACC). However, limited evidence is available regarding the impact of plasma mitotane levels on patient outcome. To address this question, we retrospectively analyzed patients with advanced ACC treated with mitotane for ≥3 months, with ≥3 measurements of plasma mitotane reported in the Lysosafe Online® database (HRA Pharma, France), followed at 12 tertiary centers in Italy from 2005 to 2017. We identified 80 patients, initially treated with mitotane alone (56.2%) or plus chemotherapy (43.8%). The preference toward combination therapy was given to de novo stage IV ACC and younger patients. After the first line of treatment, 25% of valid cases experienced clinical benefit (14.5% objective response, 10.5% stabilization of disease) and 75% progression, without differences between the groups of treatment. Patients with progression had a lower time in the target range (TTR) of plasma mitotane and an unfavorable outcome. Death occurred in 76.2% of cases and multivariate analysis showed that clinical benefit after first treatment and longer TTR were favorable predictors of overall survival (OS). In conclusion, the present findings support the importance of mitotane monitoring and strengthen the concept of a therapeutic window for mitotane.

The medical treatment of Cushing's disease: effectiveness of chronic treatment with the dopamine agonist cabergoline in patients unsuccessfully treated by surgery.

BACKGROUND: The role of dopamine agonists in the treatment of Cushing's disease (CD) has been previously debated. AIM: The aim of this study was to evaluate the effectiveness of short-term (3 months) and long-term (12-24 months) treatment with cabergoline in patients with CD. PATIENTS AND METHODS: 20 patients with CD unsuccessfully treated by surgery entered the study. Cabergoline was administered at an initial dose of 1 mg/wk, with a monthly increase of 1 mg, until urinary cortisol levels normalized or the maximal dose of 7 mg/wk was achieved. The responsiveness to treatment was evaluated according to changes in urinary cortisol excretion. A decrease greater than 25% was considered as a partial response, whereas complete normalization was considered as a full response at short-term evaluation; persistence of normal cortisol excretion was the only criterion to evaluate the response at long-term evaluation. RESULTS: After short-term treatment, 15 (75%) patients were responsive to cabergoline treatment. Among these, normalization of cortisol excretion was maintained in 10, whereas treatment escape was observed in five patients after 6-18 months. Among the 10 long-term responsive patients, eight were followed for 24 months, whereas the remaining two were followed for 12-18 months, due to cabergoline withdrawal for intolerance. A sustained control of cortisol secretion for 24 month cabergoline treatment at the maximal dose ranging from 1-7 mg/wk (median: 3.5) without significant side effects, was obtained in eight of 20 (40%) patients. CONCLUSIONS: The results of this study demonstrated that cabergoline treatment is effective in controlling cortisol secretion for at least 1-2 yr in more than one third of a limited population of patients with CD. If this evidence is confirmed by additional studies, this agent may be considered as a useful treatment option in patients with CD who are unsuccessfully treated by neurosurgery.

The role of mTOR pathway as target for treatment in adrenocortical cancer.

Adrenocortical carcinomas (ACCs) are rare tumors with scant treatment options for which new treatments are required. The mTOR pathway mediates the intracellular signals of several growth factors, including the insulin-like growth factors (IGFs), and therefore represents a potential attractive pathway for the treatment of several malignancies including ACCs. Several mTOR inhibitors, including sirolimus, temsirolimus and everolimus, have been clinically developed. This review summarizes the results of the studies evaluating the expression of the mTOR pathway components in ACCs, the effects of the mTOR inhibitors alone or in combination with other drugs in preclinical models of ACCs and the early experience with the use of these compounds in the clinical setting. The mTOR pathway seems a potential target for treatment of patients with ACC, but further investigation is still required to define the potential role of mTOR inhibitors alone or in combination with other drugs in the treatment of ACC patients.

Vitamin D reverts resistance to the mTOR inhibitor everolimus in hepatocellular carcinoma through the activation of a miR-375/oncogenes circuit.

Primary or acquired resistant mechanisms prevent the employment of individualized therapy with target drugs like the mTOR inhibitor everolimus (EVE) in hepatocellular carcinoma (HCC). The current study evaluated the effect of 1,25(OH)2Vitamin D (VitD) treatment on EVE sensitivity in established models of HCC cell lines resistant to everolimus (EveR). DNA content and colony formation assays, which measure the proliferative index, revealed that VitD pre-treatment re-sensitizes EveR cells to EVE treatment. The evaluation of epithelial and mesenchymal markers by western blot and immunofluorescence showed that VitD restored an epithelial phenotype in EveR cells, in which prolonged EVE treatment induced transition to mesenchymal phenotype. Moreover, VitD treatment prompted hepatic miRNAs regulation, evaluated by liver miRNA finder qPCR array. In particular, miR-375 expression was up-regulated by VitD in EveR cells, in which miR-375 was down-regulated compared to parental cells, with consequent inhibition of oncogenes involved in drug resistance and epithelial-mesenchymal transition (EMT) such as MTDH, YAP-1 and c-MYC. In conclusion, the results of the current study demonstrated that VitD can re-sensitize HCC cells resistant to EVE treatment triggering miR-375 up-regulation and consequently down-regulating several oncogenes responsible of EMT and drug resistance.

IGF and mTOR pathway expression and in vitro effects of linsitinib and mTOR inhibitors in adrenocortical cancer.

PURPOSE: The IGF and mTOR-pathways are considered as potential targets for therapy in patients with adrenocortical carcinoma (ACC). This study aims to describe the IGF pathway in ACC and to explore the response to the combined treatment with the IGF1R/IR inhibitor linsitinib, and mTOR inhibitors (sirolimus and everolimus) in in vitro models of ACC. METHODS: The protein expression level of IGF2, IGF1R and IGF2R was evaluated by immunohistochemistry in 17 human ACCs and the mRNA expression level of IGF1, IGF2, IGF1R, IR isoforms A and B, IGF2R, IGF-Binding-Proteins[IGFBP]-1, 2, 3 and 6 was evaluated by RT-qPCR in 12 samples. In H295R and HAC15 ACC cell lines the combined effects of linsitinib and sirolimus or everolimus on cell survival were evaluated. RESULTS: A high protein expression of IGF2, IGF1R and IGF2R was observed in 82, 65 and 100% of samples, respectively. A high relative expression of IGF2 mRNA was found in the majority of samples. The mRNA levels of the IRA were higher than that of IRB and IGF1R in the majority of samples (75%). Linsitinib inhibits cell growth in the H295R and HAC15 cell lines and, combined with sirolimus or everolimus, linsitinib showed a significant additive effect. CONCLUSIONS: In addition to IGF2 and IGF1R, ACC express IGF2R, IRA and several IGFBPs, suggesting that the interplay between the different components of the IGF pathway in ACC could be more complex than previously considered. The addition of mTOR inhibitors to linsitinib may have stronger antiproliferative effects than linsitinib alone.

Cushing's Syndrome.

Cushing's syndrome is a rare endocrine disease characterized by cortisol hypersecretion, induced mainly by a pituitary tumor (Cushing's disease) or, rarely, by an adrenal or an ectopic neuroendocine tumor. Cushing's syndrome is associated with severe morbidities and an increased mortality. The major systemic complications and the main cause of death are represented by cardiovascular disease. The prognosis of the disease is mainly affected by the difficulties in the diagnosis and treatment of the disease, which remain a considerable challenge.

Effect of combined treatment with a pan-PI3K inhibitor or an isoform-specific PI3K inhibitor and everolimus on cell proliferation in GH-secreting pituitary tumour in an experimental setting.

PURPOSE: PI3K/Akt/mTOR pathway activation is common in GH-secreting pituitary tumours, and a target for treatment with mTOR inhibitors, including everolimus (EVE). The current study aimed to evaluate the efficacy of two PI3K inhibitors (PI3Ki), NVP-BKM120 and NVP-BYL719, alone and in combination with EVE in rat GH-secreting pituitary tumour cell line (GH3) and human GH-secreting pituitary tumour cell cultures. METHODS: In GH3 cell line and in six GH-secreting tumour cell cultures, the effects of PI3Ki and EVE, as single agents and in combination, were tested on cell viability and colony survival, by MTT and clonogenic assay, respectively, whereas western blot was performed to evaluate the underlying intracellular signalling pathways. RESULTS: PI3Ki and EVE showed a dose-dependent inhibition of cell viability in GH3 cell line, with PI3Ki displaying a synergistic effect when combined with EVE. PI3Ki and EVE inhibited colony survival in GH3 cell line with no further improvement in combination. In GH-secreting pituitary tumour cell cultures PI3Ki are effective in inhibiting cell viability increasing the slight and non significant inhibition induced by EVE as single agent, generally showing a synergistic effect. Despite in both GH3 cell line and GH-secreting pituitary tumour cell cultures combination of PI3Ki enhanced EVE effect, the study of intracellular signalling pathways revealed a different regulation of PI3K/Akt/mTOR and MAPK between the two models. CONCLUSIONS: The results of the current study demonstrated that PI3Ki, especially in combination with EVE, are effective in inhibiting cell proliferation, therefore representing a promising therapeutic tool for the treatment of aggressive GH-secreting pituitary tumours, not responsive to standard medical therapies.

Treatment with growth hormone receptor antagonist in acromegaly: effect on cardiac structure and performance.

AIM: The aim of the current study was to evaluate the effect of short-term (6 months) and long-term (18 months) treatment with pegvisomant on cardiac structure and performance in patients with acromegaly. PATIENTS: Seventeen patients (nine women, eight men, 27-61 yr) with active acromegaly entered and 12 completed the long-term study. After a baseline evaluation, including measurement of hemodynamic, biochemical, and hormonal parameters, and a standard Doppler echocardiography, treatment with pegvisomant was started at the initial dose of 10 mg/d, increasing by 5 mg/d every 6 wk on the basis of IGF-I levels until normalization or the achievement of a maximal dose of 40 mg/d. RESULTS: After short-term treatment, IGF-I levels were normalized in 10 of the 17 (59%) patients. Left ventricular mass index (LVMi) was significantly decreased without changes in diastolic and systolic performance. After long-term treatment, IGF-I levels were normalized in 10 of the 12 (83%) patients. Blood glucose and serum insulin levels were decreased compared with baseline. LVMi was further decreased compared with short-term treatment, so that the prevalence of left ventricle hypertrophy decreased from 50% at baseline to 17% after 18 months of treatment. Moreover, ejection fraction as well as early to late (atrial) peak velocity ratio (E/A) were significantly increased, whereas isovolumic relaxation time was significantly decreased compared with baseline, demonstrating an improvement of both diastolic and systolic function. A significant correlation was found between the change in IGF-I levels and that of left ventricular ejection fraction. In general, the prevalence of cardiac insufficiency was present in 13 of the 17 (76%) patients at baseline and in one (8%) patient after 18 months of treatment. CONCLUSIONS: Long-term treatment with the GH receptor antagonist improves acromegalic cardiomyopathy by decreasing cardiac hypertrophy and enhancing diastolic and systolic function, and consequently partially or completely reverting the cardiac insufficiency.