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TNM 8th edition introduces changes in the staging of patients with differentiated thyroid carcinoma (DTC). This study aims at assessing the value of TNM 8th edition in predicting response to therapy and structural recurrence of DTC. Four hundred and eighty DTC patients were retrospectively evaluated by 7th and 8th editions of TNM staging system in relationship with risk stratification, response to therapy and recurrence of disease as defined by 2015 ATA guidelines. As compared to the 7th edition, TNM 8th led to downstage 136 patients (28.3%), with 97.5% of patients falling into lower stages (I–II) and only 2.5% remaining in higher stages (III–IV) (P th were classified more frequently at intermediate-high risk (P P = 0.009) and had higher risk of structural recurrence (P = 0.002) as compared to patients who were in the same TNM stages but were not downstaged. Specifically, the risk of structural recurrence was significantly higher in patients in whom the downstaging was induced by changes in tumour classification (hazard ratio (HR) 6.18, 95% CI 2.20–17.40; P = 0.001) but not in those who were downstaged for the increase in age cut-off (HR 2.80, 95% CI 0.86–9.19; P = 0.09). In conclusion, TNM 8th edition did not show reliability in predicting aggressiveness of DTC. In fact, the downstaging of DTC patients especially when performed due to changes in tumour classification may overlook patients predisposed to structural recurrence, potentially causing uncertainty in the therapeutic decision-making at the time of disease’s diagnosis.

Context Coronavirus disease 2019 (COVID-19) represents a global health emergency, and infected patients with chronic diseases often present with a severe impairment. Adrenal insufficiency (AI) is supposed to be associated with an increased infection risk, which could trigger an adrenal crisis. Objective Our primary aim was to evaluate the incidence of COVID-19 symptoms and complications in AI patients. Design and Setting We conducted a retrospective case-control study. All patients were on active follow-up and lived in Lombardy, Italy, one of the most affected areas. Patients We enrolled 279 patients with primary and secondary AI and 112 controls (patients with benign pituitary lesions without hormonal alterations). All AI patients had been previously trained to modify their replacement therapy on stress doses. Intervention By administering a standardized questionnaire by phone, we collected data on COVID-19 suggestive symptoms and consequences. Results In February through April 2020, the prevalence of symptomatic patients (complaining at least 1 symptom of viral infection) was similar between the 2 groups (24% in AI and 22.3% in controls, P = 0.79). Highly suggestive COVID-19 symptoms (at least 2 including fever and/or cough) also occurred equally in AI and controls (12.5% in both groups). No patient required hospitalization and no adrenal crisis was reported. Few nasopharyngeal swabs were performed (n = 12), as indicated by sanitary regulations, limiting conclusions on the exact infection rate (2 positive results in AI and none in controls, P = 0.52). Conclusions AI patients who are adequately treated and trained seem to display the same incidence of COVID-19-suggestive symptoms and disease severity as controls.

Adrenocortical carcinomas (ACCs) overexpress insulin-like growth factor 2 (IGF2), that drives a proliferative autocrine loop by binding to IGF1R and IR, but IGF1R/IR-targeted therapies failed in ACC patients. The cytoskeleton actin-binding protein filamin A (FLNA) impairs IR signalling in melanoma cells. Aims of this study were to test FLNA involvement in regulating IGF1R and IR responsiveness to both IGF2 and inhibitors in ACC. In ACC cells H295R and SW13 and primary cultures (1ACC, 4 adenomas) we found that IGF1R and IR interacted with FLNA, and FLNA silencing increased IGF1R and reduced IR expression, with a downstream effect of increased cell proliferation and ERK phosphorylation. In addition, FLNA knockdown potentiated antiproliferative effects of IGF1R/IR inhibitor Linsitinib and IGF1R inhibitor NVP-ADW742 in H295R. Finally, Western blot showed lower FLNA expression in ACCs (n = 10) than in ACAs (n = 10) and an inverse correlation of FLNA/IGF1R ratio with ERK phosphorylation in ACCs only. In conclusion, we demonstrated that low FLNA levels enhance both IGF2 proliferative effects and IGF1R/IR inhibitors efficacy in ACC cells, suggesting FLNA as a new factor influencing tumor clinical behavior and the response to the therapy with IGF1R/IR-targeted drugs.

Adrenocortical carcinomas (ACCs) are rare endocrine tumors with poor prognosis. They overexpress insulin-like growth factor 2 (IGF2), that drives a proliferative autocrine loop by binding to IGF1R and IR, with molecular dynamics still poorly identified. Although promising, IGF1R/IR-targeted therapies have demonstrated a limited efficacy in clinical trials in ACC patients. The cytoskeleton actin-binding protein filamin A (FLNA) was shown to impair IR and IGF1R signalling in melanoma and neural progenitor cells, respectively. The aims of this study were to test in ACC cells: 1) FLNA involvement in regulating IGF1R and IR expression and signalling; 2) FLNA role in modulating responsiveness to IGF1R and IGFR/IR inhibitors; 3) FLNA expression in ACCs and correlation with IGF system. In ACC cells we found by immunoprecipitation that both IGF1R and IR interacted with FLNA in basal condition, with an increased or decreased FLNA recruitment to IGF1R and to IR, respectively, after IGF2 stimulation. Genetic silencing of FLNA in ACC cell lines H295R and SW13 induced a significant increase of IGF1R expression (1.4- and 2.3-fold, respectively) and a reduction of IR (-85.5±9.1%, p

Dopamine receptor type 2 (DRD2) agonists are the first-choice treatment for PRL-secreting pituitary tumors but are poorly effective in non-functioning pituitary neuroendocrine tumors (NF-PitNETs). DRD2 reduces AKT phosphorylation in lactotrophs, but no data are available in NF-PitNETs. DRD2 effects on AKT are mediated by a β-arrestin 2-dependent mechanism in mouse striatum. The aim of this study was to investigate DRD2 effects on AKT phosphorylation and cell proliferation in human primary cultured NF-PitNET cells and in rat tumoral lactotroph cells MMQ, and to test β-arrestin 2 involvement. We found that DRD2 agonist BIM53097 induced a reduction of p- AKT /total-AKT ratio in MMQ (-32.8±17.6%, p In MMQ, β-arrestin 2 silencing prevented DRD2 inhibitory effects on p-AKT and cell proliferation. Accordingly, β-arrestin 2 transfection in subgroup 2 NF-PitNETs conferred to BIM53097 the ability to inhibit both p-AKT and cell growth. In conclusion, we demonstrated that β-arrestin 2 is required for DRD2 inhibitory effects on AKT phosphorylation and cell proliferation in MMQ and NF-PitNETs, paving the way for a potential role of β-arrestin 2 as a biomarker predicting NF-PitNETs responsiveness to treatment with dopamine agonists.

Background Vertebral fractures (VFs) are a frequent complication of acromegaly, but no studies have been so far published on effectiveness of antiosteoporotic drugs in this clinical setting. Objective To evaluate whether in real-life clinical practice bone active drugs may reduce the risk of VFs in patients with active or controlled acromegaly. Study design Retrospective, longitudinal study including 9 tertiary care endocrine units. Patients and Methods Two hundred and forty-eight patients with acromegaly (104 males; mean age 56.00 ± 13.60 years) were evaluated for prevalent and incident VFs by quantitative morphometric approach. Bone active agents were used in 52 patients (20.97%) and the median period of follow-up was 48 months (range 12-132). Results During the follow-up, 65 patients (26.21%) developed incident VFs in relationship with pre-existing VFs (odds ratio [OR] 3.75; P Conclusions Bone active drugs may prevent VFs in patients with active acromegaly.

During the COVID-19 outbreak, the European Reference Network on Rare Bone Diseases (ERN BOND) coordination team and Italian rare bone diseases healthcare professionals created the “COVID-19 Helpline for Rare Bone Diseases” in an attempt to provide high-quality information and expertise on rare bone diseases remotely to patients and healthcare professionals. The present position statement describes the key characteristics of the Helpline initiative, along with the main aspects and topics that recurrently emerged as central for rare bone diseases patients and professionals. The main topics highlighted are general recommendations, pulmonary complications, drug treatment, trauma, pregnancy, children and elderly people, and patient associations role. The successful experience of the “COVID-19 Helpline for Rare Bone Diseases” launched in Italy could serve as a primer of gold-standard remote care for rare bone diseases for the other European countries and globally. Furthermore, similar COVID-19 helplines could be considered and applied for other rare diseases in order to implement remote patients’ care.

Introduction: Acromegaly is commonly complicated by arthropathy and skeletal fragility with high risk of vertebral fractures (VFs). Objective: This study aimed to assess whether VFs may be associated with sagittal spine deformities, arthropathy, impaired quality of life (QoL), pain, and disability. Methods: Thirty-eight patients with acromegaly (median age: 55 years, 20 males) and 38 matched control subjects were evaluated by a low-dose sagittal and coronal planes, X-ray imaging system (EOS®-2D/3D) for morphometric VFs, radiological signs of spine arthropathy, and spine deformities (Cobb thoracic index ≥40°, pelvic incidence minus lumbar lordosis ≥10°, pelvic tilt >20°, and sagittal vertical axis ≥4 cm) determining sagittal spine imbalance. Acromegalic patients were also evaluated by questionnaires for QoL (Acromegaly QoL Questionnaire [AcroQoL] and Short Form-36 [SF-36]) and pain and disability (Western Ontario and McMaster University [WOMAC]). Results: Acromegalic patients showed higher prevalence of thoracic hyperkyphosis (i.e., Cobb thoracic index ≥40°; p = 0.04) and pelvic tilt >20° (p = 0.02) than control subjects. VFs were found in 34.2% of acromegalic patients (p = 0.003 vs. control subjects), in relationship with higher prevalence of hyperkyphosis (p = 0.03), pelvic tilt >20° (p = 0.04), sagittal vertical axis ≥4 cm (p = 0.03), and moderate/severe subchondral degeneration (p = 0.01). Moreover, patients with VFs had lower AcroQoL general health (p = 0.007) and SF-36 general health (p = 0.002) scores and higher WOMAC pain (p = 0.003) and global (p = 0.009) scores than patients who did not fracture. Conclusions: In acromegaly, VFs may be associated with spine deformities and sagittal imbalance, spine arthropathy, impaired QoL, and disability.

Circulating platelets (PLTs) are able to affect glioblastoma (GBM) microenvironment by supplying oncopromoter and pro-angiogenic factors. Among these mediators, sphingosine-1-phophate (S1P) has emerged as a potent bioactive lipid enhancing cell proliferation and survival. Here, we investigated the effect of “tumor education”, characterizing PLTs from GBM patients in terms of activation state, protein content, and pro-angiogenic potential. PLTs from healthy donors (HD-PLTs) and GBM patients (GBM-PLTs) were collected, activated, and analyzed by flow cytometry, immunofluorescence, and Western blotting. To assess the pro-angiogenic contribution of GBM-PLTs, a functional cord formation assay was performed on GBM endothelial cells (GECs) with PLT-releasate. GBM-PLTs expressed higher positivity for P-selectin compared to HD-PLTs, both in basal conditions and after stimulation with adenosine triphosphate (ADP) and thrombin receptor activating peptide (TRAP). PLTs showed higher expression of VEGFR-1, VEGFR-2, VWF, S1P, S1PR1, SphK1, and SPNS. Interestingly, increased concentrations of VEGF and its receptors VEGFR1 and VEGFR2, VWF, and S1P were found in GBM-PLT-releasate with respect to HD-PLTs. Finally, GBM-PLT-releasate showed a pro-angiogenic effect on GECs, increasing the vascular network’s complexity. Overall, our results demonstrated the contribution of PLTs to GBM angiogenesis and aggressiveness, advancing the potential of an anti-PLT therapy and the usefulness of PLT cargo as predictive and monitoring biomarkers.

Pseudohypoparathyroidism type 1A (PHP1A), pseudoPHP (PPHP), and PHP type 1B (PHP1B) are caused by maternal and paternal GNAS mutations and abnormal methylation at maternal GNAS promoter(s), respectively. Adult PHP1A patients are reportedly obese and short, whereas most PPHP patients are born small. In addition to parathyroid hormone (PTH) resistance, PHP1A and PHP1B patients may display early-onset obesity. Because early-onset and severe obesity and short stature are daily burdens for PHP1A patients, we aimed at improving knowledge on the contribution of the GNAS transcripts to fetal and postnatal growth and fat storage. Through an international collaboration, we collected growth and weight data from birth until adulthood for 306 PHP1A/PPHP and 220 PHP1B patients. PHP1A/PPHP patients were smaller at birth than healthy controls, especially PPHP (length Z-score: PHP1A -1.1 ± 1.8; PPHP -3.0 ± 1.5). Short stature is observed in 64% and 59% of adult PHP1A and PPHP patients. PHP1B patients displayed early postnatal overgrowth (height Z-score at 1 year: 2.2 ± 1.3 and 1.3 ± 1.5 in autosomal dominant and sporadic PHP1B) followed by a gradual decrease in growth velocity resulting in normal adult height (Z-score for both: -0.4 ± 1.1). Early-onset obesity characterizes GNAS alterations and is associated with significant overweight and obesity in adults (bodey mass index [BMI] Z-score: 1.4 ± 2.6, 2.1 ± 2.0, and 1.4 ± 1.9 in PPHP, PHP1A, and PHP1B, respectively), indicating that reduced Gsα expression is a contributing factor. The growth impairment in PHP1A/PPHP may be due to Gsα haploinsufficiency in the growth plates; the paternal XLαs transcript likely contributes to prenatal growth; for all disease variants, a reduced pubertal growth spurt may be due to accelerated growth plate closure. Consequently, early diagnosis and close follow-up is needed in patients with GNAS defects to screen and intervene in case of early-onset obesity and decreased growth velocity. © 2018 The Authors. Journal of Bone and Mineral Research Published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research (ASBMR).

Metabolic disorders deriving from the non-responsiveness of target organs to hormones, which manifest clinically similar to the deficiency of a given hormone itself, derive from molecular alterations affecting specific hormone receptors. Pseudohypoparathyroidism (PHP) and related disorders exemplify an unusual form of hormone resistance as the underlying molecular defect is a partial deficiency of the α subunit of the stimulatory G protein (Gsα), a key regulator of cAMP signaling pathway, or, as more recently described, of downstream effector proteins of the same pathway, such as PKA regulatory subunit 1A (R1A) and phosphodyestarase type 4D (PDE4D). In this group of diseases, resistance to hormones such as PTH, TSH, gonadotropins and GHRH may be variably present, so that the clinical and molecular overlap among these different but related disorders represents a challenge for endocrinologists as to differential diagnosis and genetic counseling. This review will describe the presenting features of multiple resistance in PHP and related disorders, focusing on both our current understanding and future challenges.

Background Pseudohypoparathyroidism type 1B (PHP1B; MIM#603233) is a rare imprinting disorder (ID), associated with the GNAS locus, characterized by parathyroid hormone (PTH) resistance in the absence of other endocrine or physical abnormalities. Sporadic PHP1B cases, with no known underlying primary genetic lesions, could represent true stochastic errors in early embryonic maintenance of methylation. Previous data confirmed the existence of different degrees of methylation defects associated with PHP1B and suggested the presence of mosaicism, a phenomenon already described in the context of other IDs. Results With respect to mosaic conditions, the study of multiple tissues is a necessary approach; thus, we investigated somatic cell lines (peripheral blood and buccal epithelium and cells from the urine sediment) descending from different germ layers from 19 PHP patients (11 spor-PHP1B, 4 GNAS mutated PHP1A, and 4 PHP with no GNAS (epi)genetic defects) and 5 healthy controls. We identified 11 patients with epigenetic defects, further subdivided in groups with complete or partial methylation defects. The recurrence of specific patterns of partial methylation defects limited to specific CpGs was confirmed by checking methylation profiles of spor-PHP1B patients diagnosed in our lab (n = 56). Underlying primary genetic defects, such as uniparental disomy or deletion, potentially causative for the detected partial methylation were excluded in all samples. Conclusions Our data showed no differences of methylation levels between organs and tissues from the same patient, so we concluded that the epimutation occurred in early post-zygotic phases and that the partial defects were mosaics. The number of patients with no detectable (epi)genetic GNAS defects was too small to exclude epimutations occurring in later post-zygotic phases, affecting only selected tissues different from blood, thus leading to underdiagnosis during routine molecular diagnosis. Finally, we found no correlation between methylation ratios, representing the proportion of epimutated cells, and the clinical presentation, further confirming the hypothesis of a threshold effect of the GNAS loss of imprinting leading to an “all-or-none” phenotype. Electronic supplementary material The online version of this article (10.1186/s13148-018-0449-4) contains supplementary material, which is available to authorized users.

The authors present an unusual case of a patient suffering from visual deficit due to pituitary granulomatosis with polyangiitis (GPA) associated with Rathke's cleft cyst (RCC). The patient was referred to our Neurosurgery Department presenting right eye amaurosis, third cranial nerve palsy, and left temporal hemianopsia. Magnetic resonance imaging documented a sellar or suprasellar lesion with solid and cystic components. The dura mater of the skull base was also strongly enhanced. The patient underwent surgery. Histologic examination revealed RCC associated with pituitary GPA. To our knowledge, this is the first reported case of concomitant pituitary GPA and RCC. Pituitary involvement in GPA is rare, usually diagnosed in hormonal dysfunctions. The patient in case first presented optic chiasm compression, probably due to inflammation of both the pituitary gland and the previously asymptomatic RCC. We focus on the symptoms that led us to diagnose GPA pituitary involvement and on the peculiar and unusual Magnetic resonance imaging of the case presented.

The pharmacological therapy of GH-secreting pituitary tumors is based on somatostatin (SS) analogs that reduce GH secretion and cell proliferation by binding mainly SS receptors type 2 (SST2). Antimigratory effects of SS have been demonstrated in different cell models, but no data on pituitary tumors are available. Aims of our study were to evaluate SST2 effects on migration and invasion of human and rat tumoral somatotrophs, and to elucidate the molecular mechanism involved focusing on the role of cofilin and filamin A (FLNA). Our data revealed that SST2 agonist BIM23120 significantly reduced GH3 cells migration (-22% ± 3.6%, p

Pulmonary neuroendocrine tumors (PNTs) comprise different neoplasms, ranging from low grade carcinoids to the highly malignant small cell lung cancers. Several studies identified the cytoskeleton protein Filamin A (FLNA) as determinant in cancer progression and metastasis, but the role of FLNA in PNT aggressiveness and progression is still unknown. We evaluated FLNA expression in PNTs with different grade of differentiation, the role of FLNA in cell proliferation, colony formation, angiogenesis, cell adhesion and migration in PNT cell line (H727 cells) and primary cultures and the possible interaction between FLNA and Rap1-GTPase. FLNA is highly expressed in PNTs with high malignant grade. FLNA silencing reduces cyclin D1 levels (-51±5, p

Background The transsphenoidal approach is considered the gold standard for resection of pituitary adenomas and other sellar region lesions. This approach is guided by a few fundamental anatomic landmarks that conduct the surgeon toward the sellar floor. Some anatomic structures may vary a lot (e.g., intrasphenoidal septa, intercarotid distance) and may be difficult to identify. Pneumatization and conformation of the sphenoidal sinus (SS) plays a key role in accessing the floor of the sella and other skull base structures. A poorly pneumatized SS may be a relative contraindication to the transsphenoidal approach. We analyzed outcome and complications in transsphenoidal surgery for sellar lesions with a difficult SS. Methods We analyzed 243 consecutive patients who underwent a transsphenoidal approach for sellar lesions. Patients with poor pneumatization of the SS were included. Neurosurgical and endocrinologic outcomes were reported. Results Successful treatment using a transsphenoidal approach with neuronavigation and Doppler ultrasound was achieved in 15 patients with a low degree of pneumatization of the SS. A pituitary adenoma was present in 13 of 15 patients. Endocrinologic and neurosurgical outcomes were similar to patients with normal pneumatization of the SS, showing a cure of disease in 6 of 9 patients with functioning adenomas and an improvement of symptoms in cases of nonfunctioning adenomas. Conclusions Patients with a poorly pneumatized SS can be treated safely with a transsphenoidal approach using image guidance techniques to avoid major neurovascular complications.

The role of progenitor/stem cells in pituitary tumorigenesis, resistance to pharmacological treatments and tumor recurrence is still unclear. This study investigated the presence of progenitor/stem cells in non-functioning pituitary tumors (NFPTs) and tested the efficacy of dopamine receptor type 2 (DRD2) and somatostatin receptor type 2 (SSTR2) agonists to inhibit their in vitro proliferation. We found that 70% of 46 NFPTs formed spheres co-expressing stem cell markers, transcription factors (DAX1, SF1, ERG1) and gonadotropins. Analysis of tumor behavior showed that spheres formation was associated with tumor invasiveness (OR= 3,96; IC: 1.05-14.88, p=0.036). The in vitro reduction of cell proliferation by DRD2 and SSTR2 agonists (31±17% and 35±13% inhibition, respectively, p

Dopamine receptor type 2 (DRD2) agonists are the first-choice treatment for prolactin-secreting pituitary tumors but are poorly effective in nonfunctioning pituitary neuroendocrine tumors (NF-PitNETs). DRD2 reduces AKT phosphorylation in lactotrophs, but no data are available in NF-PitNETs. DRD2 effects on AKT are mediated by a β-arrestin 2-dependent mechanism in mouse striatum. The aim of this study was to investigate DRD2 effects on AKT phosphorylation and cell proliferation in human primary cultured NF-PitNET cells and in rat tumoral lactotroph cells MMQ, and to test β-arrestin 2 involvement. We found that the DRD2 agonist BIM53097 induced a reduction of the p-AKT/total-AKT ratio in MMQ (–32.8 ± 17.6%, p < 0.001 vs. basal) and in a subset (n = 15/41, 36.6%) of NF-PitNETs (subgroup 1). In the remaining NF-PitNETs (subgroup 2), BIM53097 induced an increase in p-AKT. The ability of BIM53097 to reduce p-AKT correlated with its antimitotic effect, since the majority of subgroup 1 NF-PitNETs was responsive to BIM53097, and nearly all subgroup 2 NF-PitNETs were resistant. β-Arrestin 2 was expressed in MMQ and in 80% of subgroup 1 NF-PitNETs, whereas it was undetectable in 77% of subgroup 2 NF-PitNETs. In MMQ, β-arrestin 2 silencing prevented DRD2 inhibitory effects on p-AKT and cell proliferation. Accordingly, β-arrestin 2 transfection in subgroup 2 NF-PitNETs conferred to BIM53097 the ability to inhibit both p-AKT and cell growth. In conclusion, we demonstrated that β-arrestin 2 is required for DRD2 inhibitory effects on AKT phosphorylation and cell proliferation in MMQ and NF-PitNETs, paving the way for a potential role of β-arrestin 2 as a biomarker predicting NF-PitNETs’ responsiveness to treatment with dopamine agonists.

Although generally benign, pituitary tumors frequently show local invasiveness and resistance to pharmacological therapy. After the demonstration of the existence of pituitary gland stem cells, over the past decade, the presence of a stem cell subpopulation in pituitary tumors has been investigated, analogous to the cancer stem cell model developed for malignant tumors. This review recapitulates the experimental evidence supporting the existence of a population of stem-like cells in pituitary tumors, focusing on their potential role in tumor initiation, progression, recurrence and resistance to pharmacological therapy.

Pseudohypoparathyroidism (PHP) is a rare endocrine disorder derived from the defective activation of the cAMP pathway by the parathyroid hormone secondary to GNAS molecular defects. PHP subtypes are defined by the presence/absence of specific clinical/biochemical features. PHP1A is characterized by resistance to multiple hormones with features of Albright hereditary osteodystrophy (AHO), while pseudopseudohypoparathyroidism (PPHP) is characterized by AHO in the absence of PTH resistance. Small subsets of PHP and PPHP patients without known molecular defects have been re-diagnosed as being affected by the brachydactyly-mental retardation syndrome (BDMR), also known as the AHO-like syndrome. This study aimed to analyse 24 PHP1A and 51 PPHP patients without a molecular diagnosis for the presence of BDMR-associated 2q37 deletions to improve the differential diagnosis and to identify features that might help to avoid a misdiagnosis. Molecular investigations identified 4 deletions in 4 unrelated patients. The affected patients showed a combination of the most pathognomonic AHO features. Of note, 3 of the patients also displayed mild PTH resistance, and none of the patients developed ectopic ossifications. Our work confirmed the rarity of the misdiagnosis of BDMR in PHP patients through the identification of 4 patients bearing a 2q37 deletion in a cohort of 73 PHP patients (5.3%). Three patients with the deletion presented a PHP1A phenotype in the absence of any BDMR-specific findings. Further studies on larger case series are needed to elucidate the overlap between these clinical entities and to allow the early identification of patients.

The high expression of somatostatin receptor 2 (SST2) in growth hormone (GH)-secreting tumors represents the rationale for the clinical use of somatostatin analogs (SSAs) in acromegaly. Recently, the cytoskeletal protein Filamin A (FLNA) has emerged as key modulator of the responsiveness of GH-secreting pituitary tumors to SSAs by regulating SST2 signaling and expression. The aim of this study was to explore FLNA involvement in SST2 intracellular trafficking in tumor somatotroph cells. By biotinylation assay, we found that FLNA silencing abolished octreotide-mediated SST2 internalization in rat GH3 cell line (28.0 ± 2.7 vs. 4 ± 4.3% SST2 internalization, control versus FLNA small interfering RNAs (siRNA) cells, respectively, p < 0.001) and human GH-secreting primary cultured cells (70.3 ± 21.1 vs. 24 ± 19.2% SST2 internalization, control versus FLNA siRNA cells, respectively, p < 0.05). In addition, confocal imaging revealed impaired SST2 recycling to the plasma membrane in FLNA silenced GH3 cells. Coimmunoprecipitation and immunofluorescence experiments showed that FLNA, as well as β-arrestin2, is timely dependent recruited to octreotide-stimulated SST2 receptors both in rat and human tumor somatotroph cells. Although FLNA expression knock down did not prevent the formation of β-arrestin2-SST2 complex in GH3 cells, it significantly impaired efficient SST2 loading into cytosolic vesicles positive for the early endocytic and recycling markers Rab5 and 4, respectively (33.7 ± 8.9% down to 25.9 ± 6.9%, p < 0.05, and 28.4 ± 7.4% down to 17.6 ± 5.7%, p < 0.01, for SST2-Rab5 and SST2-Rab4 colocalization, respectively, in control versus FLNA siRNA cells). Altogether these data support an important role for FLNA in the mediation of octreotide-induced SST2 trafficking in GH-secreting pituitary tumor cells through Rab5 and 4 sorting endosomes.

Purpose: Arthropathy is a common and disabling complication of acromegaly. Since in this condition radiological findings rarely correspond to functional impairment, we elected to quantify in a large cohort of acromegalic patients: the degree of motor disability compared with data from general population, the impact of joint involvement on quality of life and work productivity, and to look for associated factors. Methods: In 211 acromegalic patients, 131 with controlled disease and 80 with active disease, eight validated scales were used to evaluate the (i) prevalence and distribution of arthropathy, (ii) degree of motor disability and joint symptoms (VAS, AIMS symptoms and WOMAC), (iii) quality of life (AcroQoL and PASQ) and work capability (WPAI:GH) as consequences of joint complications. Results: Using the WOMAC questionnaire, for which population based normative values are available, a significantly higher prevalence and severity of motor disability was detected in acromegalics compared to the general population from literature. The results provided by the different questionnaires turned out to be highly concordant. All measures of motor disability correlated both with impaired quality of life and motor disability and were worse in females and in patients with higher BMI. Conclusions: The questionnaires VAS, AIMS symptoms, and WOMAC (this latter both as a whole and with its functionality subscale), with their scores, proved to be the most adequate tools to evaluate motor disability and its consequences on both quality of life and work productivity in acromegaly. Female gender and higher BMI are associated with worse articular symptoms.

Medullary thyroid carcinoma (MTC) is a rare neuroendocrine tumor that originates from parafollicular thyroid C cells, accounting for 5% -10% of thyroid cancers. In all inherited cases of MTC, and in about 40% of sporadic cases, activating mutations of the receptor tyrosine kinase proto-oncogene RET are found. Constitutively active RET triggers signaling pathways involved in cell motility, proliferation and survival, but the mechanisms underlying malignant transformation of C-cells have been only partially elucidated. Cofilin is a key regulator of actin cytoskeleton dynamics. A crucial role of cofilin in tumor development, progression, invasion and metastasis has been demonstrated in different human cancers, but no data are available in MTC. Interestingly, RET activation upregulates cofilin gene expression. The aim of this study was to investigate cofilin contribution in invasiveness and growth of MTC cells, and its relevance in the context of mutant RET signaling. We found that cofilin transfection in human MTC cell line TT significantly increased migration (178.5±44%, p