Somatic mosaicism has been implicated as a causative mechanism in a number of genetic and genomic disorders. X-linked acrogigantism (XLAG) syndrome is a recently characterized genomic form of pediatric gigantism due to aggressive pituitary tumors that is caused by submicroscopic chromosome Xq26.3 duplications that include GPR101. We studied XLAG syndrome patients (n = 18) to determine if somatic mosaicism contributed to the genomic pathophysiology. Eighteen subjects with XLAG syndrome caused by Xq26.3 duplications were identified using high-definition array comparative genomic hybridization (HD-aCGH). We noted that males with XLAG had a decreased log2 ratio (LR) compared with expected values, suggesting potential mosaicism, whereas females showed no such decrease. Compared with familial male XLAG cases, sporadic males had more marked evidence for mosaicism, with levels of Xq26.3 duplication between 16.1 and 53.8%. These characteristics were replicated using a novel, personalized breakpoint junction-specific quantification droplet digital polymerase chain reaction (ddPCR) technique. Using a separate ddPCR technique, we studied the feasibility of identifying XLAG syndrome cases in a distinct patient population of 64 unrelated subjects with acromegaly/gigantism, and identified one female gigantism patient who had had increased copy number variation (CNV) threshold for GPR101 that was subsequently diagnosed as having XLAG syndrome on HD-aCGH. Employing a combination of HD-aCGH and novel ddPCR approaches, we have demonstrated, for the first time, that XLAG syndrome can be caused by variable degrees of somatic mosaicism for duplications at chromosome Xq26.3. Somatic mosaicism was shown to occur in sporadic males but not in females with XLAG syndrome, although the clinical characteristics of the disease were similarly severe in both sexes.
Adrian F Daly, Bo Yuan, Frederic Fina, Jean-Hubert Caberg, Giampaolo Trivellin, Liliya Rostomyan, Wouter W de Herder, Luciana A Naves, Daniel Metzger, Thomas Cuny, Wolfgang Rabl, Nalini Shah, Marie-Lise Jaffrain-Rea, Maria Chiara Zatelli, Fabio R Faucz, Emilie Castermans, Isabelle Nanni-Metellus, Maya Lodish, Ammar Muhammad, Leonor Palmeira, Iulia Potorac, Giovanna Mantovani, Sebastian J Neggers, Marc Klein, Anne Barlier, Pengfei Liu, L’Houcine Ouafik, Vincent Bours, James R Lupski, Constantine A Stratakis, and Albert Beckers
Massimo Terzolo, Giuseppe Reimondo, Paola Berchialla, Emanuele Ferrante, Elena Malchiodi, Laura De Marinis, Rosario Pivonello, Silvia Grottoli, Marco Losa, Salvatore Cannavo, Diego Ferone, Marcella Montini, Marta Bondanelli, Ernesto De Menis, Chiara Martini, Efisio Puxeddu, Antonino Velardo, Alessandro Peri, Marco Faustini-Fustini, Patrizia Tita, Francesca Pigliaru, Giulia Peraga, Giorgio Borretta, Carla Scaroni, Nicoletta Bazzoni, Antonio Bianchi, Alessandro Berton, Andreea Liliana Serban, Roberto Baldelli, Letizia Maria Fatti, Annamaria Colao, Maura Arosio, and for the Italian Study Group of Acromegaly
It is debated if acromegalic patients have an increased risk to develop malignancies. The aim of the present study was to assess the standardized incidence ratios (SIRs) of different types of cancer in acromegaly on a large series of acromegalic patients managed in the somatostatin analogs era. It was evaluated the incidence of cancer in an Italian nationwide multicenter cohort study of 1512 acromegalic patients, 624 men and 888 women, mean age at diagnosis 45 ± 13 years, followed up for a mean of 10 years (12573 person-years) in respect to the general Italian population. Cancer was diagnosed in 124 patients, 72 women and 52 men. The SIRs for all cancers was significantly increased compared to the general Italian population (expected: 88, SIR 1.41; 95% CI, 1.18–1.68, P < 0.001). In the whole series, we found a significantly increased incidence of colorectal cancer (SIR 1.67; 95% CI, 1.07–2.58, P = 0.022), kidney cancer (SIR 2.87; 95% CI, 1.55–5.34, P < 0.001) and thyroid cancer (SIR 3.99; 95% CI, 2.32–6.87, P < 0.001). The exclusion of 11 cancers occurring before diagnosis of acromegaly (all in women) did not change remarkably the study outcome. In multivariate analysis, the factors significantly associated with an increased risk of malignancy were age and family history of cancer, with a non-significant trend for the estimated duration of acromegaly before diagnosis. In conclusion, we found evidence that acromegaly in Italy is associated with a moderate increase in cancer risk.
Albert Beckers, Maya Beth Lodish, Giampaolo Trivellin, Liliya Rostomyan, Misu Lee, Fabio R Faucz, Bo Yuan, Catherine S Choong, Jean-Hubert Caberg, Elisa Verrua, Luciana Ansaneli Naves, Tim D Cheetham, Jacques Young, Philippe A Lysy, Patrick Petrossians, Andrew Cotterill, Nalini Samir Shah, Daniel Metzger, Emilie Castermans, Maria Rosaria Ambrosio, Chiara Villa, Natalia Strebkova, Nadia Mazerkina, Stéphan Gaillard, Gustavo Barcelos Barra, Luis Augusto Casulari, Sebastian J Neggers, Roberto Salvatori, Marie-Lise Jaffrain-Rea, Margaret Zacharin, Beatriz Lecumberri Santamaria, Sabina Zacharieva, Ee Mun Lim, Giovanna Mantovani, Maria Chaira Zatelli, Michael T Collins, Jean-François Bonneville, Martha Quezado, Prashant Chittiboina, Edward H Oldfield, Vincent Bours, Pengfei Liu, Wouter W de Herder, Natalia Pellegata, James R Lupski, Adrian F Daly, and Constantine A Stratakis
X-linked acrogigantism (X-LAG) is a new syndrome of pituitary gigantism, caused by microduplications on chromosome Xq26.3, encompassing the gene GPR101, which is highly upregulated in pituitary tumors. We conducted this study to explore the clinical, radiological, and hormonal phenotype and responses to therapy in patients with X-LAG syndrome. The study included 18 patients (13 sporadic) with X-LAG and microduplication of chromosome Xq26.3. All sporadic cases had unique duplications and the inheritance pattern in two families was dominant, with all Xq26.3 duplication carriers being affected. Patients began to grow rapidly as early as 2–3 months of age (median 12 months). At diagnosis (median delay 27 months), patients had a median height and weight standard deviation scores (SDS) of >+3.9 SDS. Apart from the increased overall body size, the children had acromegalic symptoms including acral enlargement and facial coarsening. More than a third of cases had increased appetite. Patients had marked hypersecretion of GH/IGF1 and usually prolactin, due to a pituitary macroadenoma or hyperplasia. Primary neurosurgical control was achieved with extensive anterior pituitary resection, but postoperative hypopituitarism was frequent. Control with somatostatin analogs was not readily achieved despite moderate to high levels of expression of somatostatin receptor subtype-2 in tumor tissue. Postoperative use of adjuvant pegvisomant resulted in control of IGF1 in all five cases where it was employed. X-LAG is a new infant-onset gigantism syndrome that has a severe clinical phenotype leading to challenging disease management.
Annamaria Colao, Carolina Di Somma, Rosario Pivonello, Antongiulio Faggiano, Gaetano Lombardi, and Silvia Savastano
Surgery is the first-line treatment of patients with clinically non-functioning pituitary adenomas (NFAs). Because of lack of clinical syndrome these tumours are diagnosed with a variable delay, when patients suffer from compression symptoms (hypopituitarism, headache and visual field defects) due to the extension of the tumour outside the pituitary fossa. Surgery is followed by residual tumour tissue in most patients. In these cases, radiotherapy is generally used to prevent tumour regrowth. However, NFA cell membranes, in analogy with GH- and PRL-secreting adenomas, express somatostatin and dopamine receptors. Treatment with somatostatin analogues (SSA) and dopamine agonists (DA) induced some beneficial effects on visual field defects and was also followed by tumour shrinkage in a minority of cases. DA seem to be more effective on tumour shrinkage than SSA. More recently, a combination treatment with both SSA and DA have been tested in a few patients with interesting results. Lack of randomized, placebo-controlled trials prevents any conclusion on the efficacy of these drugs. By contrast, use of gonatotrophin-releasing hormone analogues has been abandoned.
Manel Puig-Domingo, Joan Gil, Miguel Sampedro-Nuñez, Mireia Jordà, Susan M Webb, Guillermo Serra, Laura Pons, Isabel Salinas, Alberto Blanco, Montserrat Marques-Pamies, Elena Valassi, Antonio Picó, Araceli García-Martínez, Cristina Carrato, Raquel Buj, Carlos del Pozo, Gabriel Obiols, Carles Villabona, Rosa Cámara, Carmen Fajardo-Montañana, Clara V Alvarez, Ignacio Bernabéu, and Mónica Marazuela
Pharmacologic treatment of acromegaly is currently based upon assay-error strategy, the first-generation somatostatin receptor ligands (SRL) being the first-line treatment. However, about 50% of patients do not respond adequately to SRL. Our objective was to evaluate the potential usefulness of different molecular markers as predictors of response to SRL. We used somatotropinoma tissue obtained after surgery from a national cohort of 100 acromegalic patients. Seventy-one patients were treated with SRL during at least 6 months under maximal therapeutic doses according to IGF1 values. We analyzed the expression of SSTR2, SSTR5, AIP, CDH1 (E-cadherin), MKI67 (Ki-67), KLK10, DRD2, ARRB1, GHRL, In1-Ghrelin, PLAGL1 and PEBP1 (RKIP) by RT-qPCR and mutations in GNAS gene by Sanger sequencing. The response to SRL was categorized as complete response (CR), partial (PR) or non-response (NR) if IGF1 was normal, between >2<3 SDS or >3 SDS IGF1 at 6 months of follow-up, respectively. From the 71 patients treated, there were 27 CR (38%), 18 PR (25%) and 26 NR (37%). SSTR2, Ki-67 and E-cadherin were associated with SRL response (P < 0.03, P < 0.01 and P < 0.003, respectively). E-cadherin was the best discriminator for response prediction (AUC = 0.74, P < 0.02, PPV of 83.7%, NPV of 72.6%), which was validated at protein level. SSTR5 expression was higher in patients pre-treated with SRL before surgery. We conclude that somatotropinomas showed heterogeneity in the expression of genes associated with SRL response. E-cadherin was the best molecular predictor of response to SRL. Thus, the inclusion of E-cadherin in subsequent treatment-decision after surgical failure may be useful in acromegaly.
Iulia Potorac, Patrick Petrossians, Adrian F Daly, Franck Schillo, Claude Ben Slama, Sonia Nagi, Mouna Sahnoun, Thierry Brue, Nadine Girard, Philippe Chanson, Ghaidaa Nasser, Philippe Caron, Fabrice Bonneville, Gérald Raverot, Véronique Lapras, François Cotton, Brigitte Delemer, Brigitte Higel, Anne Boulin, Stéphan Gaillard, Florina Luca, Bernard Goichot, Jean-Louis Dietemann, Albert Beckers, and Jean-François Bonneville
Responses of GH-secreting adenomas to multimodal management of acromegaly vary widely between patients. Understanding the behavioral patterns of GH-secreting adenomas by identifying factors predictive of their evolution is a research priority. The aim of this study was to clarify the relationship between the T2-weighted adenoma signal on diagnostic magnetic resonance imaging (MRI) in acromegaly and clinical and biological features at diagnosis. An international, multicenter, retrospective analysis was performed using a large population of 297 acromegalic patients recently diagnosed with available diagnostic MRI evaluations. The study was conducted at ten endocrine tertiary referral centers. Clinical and biochemical characteristics, and MRI signal findings were evaluated. T2-hypointense adenomas represented 52.9% of the series, were smaller than their T2-hyperintense and isointense counterparts (P<0.0001), were associated with higher IGF1 levels (P=0.0001), invaded the cavernous sinus less frequently (P=0.0002), and rarely caused optic chiasm compression (P<0.0001). Acromegalic men tended to be younger at diagnosis than women (P=0.067) and presented higher IGF1 values (P=0.01). Although in total, adenomas had a predominantly inferior extension in 45.8% of cases, in men this was more frequent (P<0.0001), whereas in women optic chiasm compression of macroadenomas occurred more often (P=0.0067). Most adenomas (45.1%) measured between 11 and 20 mm in maximal diameter and bigger adenomas were diagnosed at younger ages (P=0.0001). The T2-weighted signal differentiates GH-secreting adenomas into subgroups with particular behaviors. This raises the question of whether the T2-weighted signal could represent a factor in the classification of acromegalic patients in future studies.
Ines Donangelo, Song-Guang Ren, Tamar Eigler, Clive Svendsen, and Shlomo Melmed
The role of tumor stem cells in benign tumors such as pituitary adenomas remains unclear. In this study, we investigated whether the cells within pituitary adenomas that spontaneously develop in Rb + /− mice are hierarchically distributed with a subset being responsible for tumor growth. Cells derived directly from such tumors grew as spheres in serum-free culture medium supplemented with epidermal growth factor and basic fibroblast growth factor. Some cells within growing pituitary tumor spheres (PTS) expressed common stem cell markers (Sca1, Sox2, Nestin, and CD133), but were devoid of hormone-positive differentiated cells. Under subsequent differentiating conditions (matrigel-coated growth surface), PTS expressed all six pituitary hormones. We next searched for specific markers of the stem cell population and isolated a Sca1+ cell population that showed increased sphere formation potential, lower mRNA hormone expression, higher expression of stem cell markers (Notch1, Sox2, and Nestin), and increased proliferation rates. When transplanted into non-obese diabetic-severe combined immunodeficiency gamma mice brains, Sca1+ pituitary tumor cells exhibited higher rates of tumor formation (brain tumors observed in 11/11 (100%) vs 7/12 (54%) of mice transplanted with Sca1+ and Sca1− cells respectively). Magnetic resonance imaging and histological analysis of brain tumors showed that tumors derived from Sca1+ pituitary tumor cells were also larger and plurihormonal. Our findings show that Sca1+ cells derived from benign pituitary tumors exhibit an undifferentiated expression profile and tumor-proliferative advantages, and we propose that they could represent putative pituitary tumor stem/progenitor cells.
Cristina L Ronchi, Silviu Sbiera, Barbara Altieri, Sonja Steinhauer, Vanessa Wild, Michaela Bekteshi, Matthias Kroiss, Martin Fassnacht, and Bruno Allolio
Previous SNP array analyses have revealed genomic alterations of the Notch pathway as being the most frequent abnormality in adrenocortical tumors (ACTs). The aim of the present study was to evaluate the expression of components of Notch signaling in ACTs and to correlate them with clinical outcome. The mRNA expression of JAG1, NOTCH1, and selected target genes of NOTCH1 (HES1, HES5, and HEY2) was evaluated in 80 fresh frozen samples (28 normal adrenal glands (NAGs), 24 adenomas (ACAs), and 28 carcinomas (ACCs)) by quantitative RT-PCR. Immunohistochemistry was performed in 221 tissues on paraffin slides (16 NAGs, 27 ACAs, and 178 ACCs) for JAG1, activated NOTCH1 (aNOTCH1), and HEY2. An independent ACC validation cohort (n=77) was then also investigated. HEY2 mRNA expression was higher in ACCs than it was in ACAs (P<0.05). The protein expression of all of the factors was high (H-score 2–3) in a larger proportion of ACCs as compared to ACAs and NAGs (JAG1 in 27, 15, and 10%; aNOTCH1 in 13, 8, and 0%; HEY2 in 66, 61, and 33% respectively, all P<0.001). High JAG1 expression was associated with earlier tumor stages and lower numbers of metastases in ACCs (both P=0.08) and favorably impacted overall and progression-free survival (PFS) (131 vs 30 months, hazard ratio (HR) 0.45, and 37 vs 9 months, HR 0.51, both P<0.005). This impact on overall survival (OS) was confirmed in the validation cohort. No such association was observed for aNOTCH1 or HEY2. In conclusion, different components of the Notch1 signaling pathway are overexpressed in ACCs, which suggests a role for the pathway in malignant transformation. However, JAG1 is overexpressed in a subgroup of ACCs with a better clinical outcome.
E Ferrante, C Pellegrini, S Bondioni, E Peverelli, M Locatelli, P Gelmini, P Luciani, A Peri, G Mantovani, S Bosari, P Beck-Peccoz, A Spada, and A Lania
Somatostatin analogs currently used in the treatment of acromegaly and other neuroendocrine tumors inhibit hormone secretion and cell proliferation by binding to somatostatin receptor type (SST) 2 and 5. The antiproliferative pathways coupled to these receptors have been only partially characterized. The aim of this study was to evaluate the effect of octreotide and super selective SST2 (BIM23120) and SST5 (BIM23206) analogs on apoptotic activity and apoptotic gene expression in human somatotroph tumor cells. Eight somatotroph tumors expressing similar levels of SST2 and SST5 evaluated by real-time PCR and western blot analyses were included in the study. In cultured cells obtained from these tumors, octreotide induced a dose-dependent increase of caspase-3 activity (160 ± 20% vs basal at 10 nM) and cleaved cytokeratin 18 levels (172 ± 25% vs basal) at concentrations higher than 0.1 nM. This effect was due to SST2 activation since BIM23120 elicited comparable responses, while BIM23206 was ineffective. BIM23120-stimulated apoptosis was dependent on phosphatases, since it was abrogated by the inhibitor orthovanadate, and independent from the induction of apoptosis-related genes, such as p53, p63, p73, Bcl-2, Bax, BID, BIK, TNFSF8, and FADD. In somatotroph tumors, both BIM23120 and BIM2306 caused growth arrest as indicated by the increase in p27 and decrease in cyclin D1 expression. In conclusion, the present study showed that octreotide-induced apoptosis in human somatotroph tumor cells by activating SST2. This effect, together with the cytostatic action exerted by both SST2 and SST5 analogs, might account for the tumor shrinkage observed in acromegalic patients treated with long-acting somatostatin analogs.
Hongyu Chen, Dan Liu, Zhengyan Yang, Limin Sun, Que Deng, Shuo Yang, Lu Qian, Liang Guo, Ming Yu, Meiru Hu, Ming Shi, and Ning Guo
Angiogenesis is an important factor in invasive tumor growth, progression, and metastasis. Multiple proangiogenic mechanisms are involved in tumor angiogenesis. In this study, we showed that the neurotransmitter norepinephrine upregulated VEGF (VEGFA) expression in breast cancer cells and that the culture supernatant from norepinephrine-treated breast cancer cells promoted the formation of the capillary-like network of endothelial cells. However, the effects of norepinephrine were further enhanced when the endothelial cells were cocultured with breast cancer cells, indicating a critical role of tumor cell–endothelial cell contacts in norepinephrine-induced tumor angiogenesis. Interestingly, norepinephrine dramatically induced the activation of the Notch pathway, which is a cell-contact-mediated intercellular signaling pathway and tightly linked to tumor cell–stromal cell interaction and angiogenesis, in the endothelial cells that had been cocultured with breast cancer cells. Furthermore, the expression of the Notch ligand Jagged 1 was significantly upregulated by norepinephrine at both mRNA and protein levels in breast cancer cells. Inhibitors of β2-adrenergic receptor (β2-AR), protein kinase A (PKA), and mTOR could reverse norepinephrine-induced Jagged 1 upregulation, indicating that the β2-AR–PKA–mTOR pathway participates in this process. Knockdown of Jagged 1 expression in breast cancer cells not only repressed norepinephrine-induced activation of the Notch pathway in cocultured endothelial cells but also evidently impaired the effects of norepinephrine on capillary-like sprout formation. These data demonstrate that tumor angiogenesis mediated by the Jagged 1/Notch intercellular signaling is governed by the norepinephrine-activated β2-AR–PKA–mTOR pathway.