Multiple endocrine neoplasia (MEN) refers to a group of autosomal dominant disorders with generally high penetrance that lead to the development of a wide spectrum of endocrine and non-endocrine manifestations. The most frequent among these conditions is MEN type 1 (MEN1), which is caused by germline heterozygous loss-of-function mutations in the tumor suppressor gene MEN1. MEN1 is characterized by primary hyperparathyroidism (PHPT) and functional or nonfunctional pancreatic neuroendocrine tumors and pituitary adenomas. Approximately 10% of patients with familial or sporadic MEN1-like phenotype do not have MEN1 mutations or deletions. A novel MEN syndrome was discovered, initially in rats (MENX), and later in humans (MEN4), which is caused by germline mutations in the putative tumor suppressor CDKN1B. The most common phenotype of the 19 established cases of MEN4 that have been described to date is PHPT followed by pituitary adenomas. Recently, somatic or germline mutations in CDKN1B were also identified in patients with sporadic PHPT, small intestinal neuroendocrine tumors, lymphoma and breast cancer, demonstrating a novel role for CDKN1B as a tumor susceptibility gene for other neoplasms. In this review, we report on the genetic characterization and clinical features of MEN4.
Rami Alrezk, Fady Hannah-Shmouni, and Constantine A Stratakis
Stephen J Marx
Five syndromes share predominantly hyperplastic glands with a primary excess of hormones: neonatal severe primary hyperparathyroidism, from homozygous mutated CASR, begins severely in utero; congenital non-autoimmune thyrotoxicosis, from mutated TSHR, varies from severe with fetal onset to mild with adult onset; familial male-limited precocious puberty, from mutated LHR, expresses testosterone oversecretion in young boys; hereditary ovarian hyperstimulation syndrome, from mutated FSHR, expresses symptomatic systemic vascular permeabilities during pregnancy; and familial hyperaldosteronism type IIIA, from mutated KCNJ5, presents in young children with hypertension and hypokalemia. The grouping of these five syndromes highlights predominant hyperplasia as a stable tissue endpoint and as their tissue stage for all of the hormone excess. Comparisons were made among this and two other groups of syndromes, forming a continuum of gland staging: predominant oversecretions express little or no hyperplasia; predominant hyperplasias express little or no neoplasia; and predominant neoplasias express nodules, adenomas, or cancers. Hyperplasias may progress (5 of 5) to neoplastic stages while predominant oversecretions rarely do (1 of 6; frequencies differ P<0.02). Hyperplasias do not show tumor multiplicity (0 of 5) unlike neoplasias that do (13 of 19; P<0.02). Hyperplasias express mutation of a plasma membrane-bound sensor (5 of 5), while neoplasias rarely do (3 of 14; P<0.002). In conclusion, the multiple distinguishing themes within the hyperplasias establish a robust pathophysiology. It has the shared and novel feature of mutant sensors in the plasma membrane, suggesting that these are major contributors to hyperplasia.
F Lumachi, M Ermani, F Marino, A Poletti, SMM Basso, M Iacobone, and G Favia
The aim of this study was to evaluate the usefulness of DNA flow cytometry to determine tumor nuclear DNA index (DI), and nucleolar organizer region protein counts visualized by the argyrophil (AgNOR) technique, in confirming diagnosis and predicting clinical outcome of patients with parathyroid carcinoma (PC). We reviewed paraffin-embedded tissue sections, from 15 patients (median age 63 years, range 30–68 years) with PC who died of the disease, which were randomly compared with tissue sections from 15 age- and sex-matched patients with parathyroid adenoma (PA). The proliferative activity in parathyroid tumours as detected by DI and AgNOR counts was evaluated in all specimens. Both DI (1.37 ± 0.33 vs 1.0 ± 0.1) and AgNOR (3.01 ± 0.31 vs 1.54 ± 0.35) counts were higher (P < 0.001) (Student’s t-test) in patients with PC than in those with PA. Diploid (DI = 1), aneuploid (DI>1) and hypoploid (DI<1) neoplasms were found in 11 (PC = 4, PA = 7), 14 (PC = 11, PA = 3) and five (PC = 0, PA = 5) patients respectively. The average postoperative survival in patients with PC was 46.9 ± 37.4 months (range 21–146 months). The survivals of patients with aneuploid (n = 11) and diploid (n = 4) PC were 74.0 ± 58.1 and 34.1 ± 18.4 months (P=0.21) respectively. There was a significant relationship between DI and AgNOR counts (R=0.69, P < 0.01), but no correlation was found between survival and both DI (Rho = 0.17, P = 0.55) and AgNOR counts (Rho = 0.26, P = 0.35). Moreover, there was no correlation (P = NS) between the main preoperative biochemical parameters and survival. In conclusion, DI and AgNOR are useful in confirming the diagnosis of PC, but they are of little value in predicting the clinical outcome of patients with PC.
F Cetani, E Pardi, C Banti, P Collecchi, P Viacava, S Borsari, G Fanelli, A G Naccarato, F Saponaro, P Berti, P Miccoli, A Pinchera, and C Marcocci
Aberrant accumulation of β-catenin has been found in various types of human tumors. The aim of this study was to evaluate whether Wnt/β-catenin signaling is activated in parathyroid carcinomas and adenomas. We studied 154 parathyroid tumors (18 carcinomas (13 with distant metastases), six atypical adenomas, and 130 adenomas). Three normal parathyroid tissues were used as control. Direct sequencing of exon 3 of the CTNNB1 gene showed absence of stabilizing mutations in all the tumors. Immunostaining of β-catenin was performed in all carcinomas and in 66 adenomas (including three atypical). Normal parathyroid showed a homogeneous distinct outer cell membrane staining in the majority of cells and no nuclear staining. A weak cytoplasmic staining was observed in one case. All tumors showed negative nuclear staining. With the exception of one carcinoma, which had a negative membrane staining, all other samples showed a membrane staining which was similar to that of the normal parathyroid. β-Catenin expression was heterogeneous with a range of positive cells between 5 and 80%, independently of tumor type. Our results suggest that the Wnt/β-catenin signaling pathway is not involved in the development of parathyroid carcinomas and adenomas.
H-C Jennifer Shen, Jennifer E Rosen, Lauren M Yang, Sharon A Savage, A Lee Burns, Carmen M Mateo, Sunita K Agarwal, Settara C Chandrasekharappa, Allen M Spiegel, Francis S Collins, Stephen J Marx, and Steven K Libutti
Multiple endocrine neoplasia type 1 (MEN1) is an autosomal dominant syndrome caused by mutations in the MEN1 tumor suppressor gene. Loss of the functional second copy of the MEN1 gene causes individuals to develop multiple endocrine tumors, primarily affecting the parathyroid, pituitary, and pancreas. While it is clear that the protein encoded by MEN1, menin, suppresses endocrine tumors, its biochemical functions and direct downstream targets remain unclear. Recent studies have suggested that menin may act as a scaffold protein to coordinate gene transcription, and that menin is an oncogenic cofactor for homeobox (HOX) gene expression in hematopoietic cancer. The role of HOX genes in adult cell differentiation is still obscure, but growing evidence suggests that they may play important roles in the development of cancer. Therefore, we hypothesized that specific HOX genes were regulated by menin in parathyroid tumor development. Utilizing quantitative TaqMan RT-PCR, we compared expression profiles of the 39 HOX genes in human familial MEN1 (fMEN1) parathyroid tumors and sporadic parathyroid adenomas with normal samples. We identified a large set of 23 HOX genes whose deregulation is specific for fMEN1 parathyroid tumors, and only 5 HOX genes whose misexpression are specific for sporadic parathyroid tumor development. These findings provide the first evidence that loss of the MEN1 tumor suppressor gene is associated with deregulation of specific HOX gene expression in the development of familial human parathyroid tumors. Our results strongly reinforce the idea that abnormal expression of developmental HOX genes can be critical in human cancer progression.
Chiara Verdelli, Irene Forno, Annamaria Morotti, Riccardo Maggiore, Gilberto Mari, Leonardo Vicentini, Stefano Ferrero, Elisabetta Kuhn, Valentina Alessandra Vaira, and Sabrina Corbetta
Tumors of the parathyroid glands are highly vascularized and display a microRNAs (miRNAs) profile divergent from normal parathyroid glands (PaNs). Angiogenic miRNAs, namely miR-126-3p, miR-126-5p, and miR-296-5p, have been found downregulated in parathyroid tumors. Here, we show that miR-126-3p expression levels are reduced in parathyroid adenomas (PAds; n=12) compared with PaNs (n=4). In situ hybridization (ISH) of miR-126-3p and miR-296-5p in 10 PAds show that miR-126-3p is expressed by endothelial cells lining the walls of great vessels and by cells within the thin stroma surrounding acinar structures. At variance, miR-296-5p was detectable in most PAd epithelial cells. Combining ISH for miR-126-3p with immunohistochemistry for the endothelial and mesenchymal markers CD34, CD31 and α-smooth-muscle-actin (αSMA), we could identify that miR-126-3p is localized in the αSMA-positive thin stroma. Further, miR-126-3p-expressing cells are enriched in the CD34-positive stromal cells surrounding epithelial cell acinar structures, a cellular pattern consistent with tumor-associated myofibroblasts (TAMs). In line with this, CD34-positive cells, sorted by FACS from PAds tissues, express miR-126-3p at higher levels than CD34-negative cells, suggesting that miR-126-3p downregulation promotes the endothelial-to-αSMA+ mesenchymal transition. In human mesenchymal stem cells derived from bone marrow (hBM-MSCs), a model of TAMs, the co-culture with PAds-derived cells for 5 days decreases miR-126-3p, while it increases VEGFA expression. At variance, adrenomedullin (ADM) expression is unaffected. Finally, overexpression of the miR-126-3p mimic in both hBM-MSCs and PAds-derived explants downregulates VEGFA expression levels. In conclusion, miR-126-3p is expressed by both endothelial cells and TAMs in PAds, and its downregulation promotes neoangiogenesis, possibly through VEGFA over-expression.
Derek Raghavan, Antoinette R Tan, E Shannon Story, Earle F Burgess, Laura Musselwhite, Edward S Kim, and Peter E Clark
Substantial management changes in endocrine-related malignancies have been required as a response to the COVID-19 pandemic, including a draconian reduction in the screening of asymptomatic subjects, delay in planned surgery and radiotherapy for primary tumors deemed to be indolent, and dose reductions and/or delays in initiation of some systemic therapies. An added key factor has been a patient-initiated delay in the presentation because of the fear of viral infection. Patterns of clinical consultation have changed, including a greater level of virtual visits, physical spacing, masking, staffing changes to ensure a COVID-free population and significant changes in patterns of family involvement. While this has occurred to improve safety from COVID-19 infection, the implications for cancer outcomes have not yet been defined. Based on prior epidemics and financial recessions, it is likely that delayed presentation and treatment of high-grade malignancy will be associated with worse cancer outcomes. Cancer patients are also at increased risk from COVID-19 infection compared to the general population. Pandemic management strategies for patients with tumors of breast, prostate, thyroid, parathyroid and adrenal gland are reviewed.
Simona Grozinsky-Glasberg, Ilan Shimon, Márta Korbonits, and Ashley B Grossman
Neuroendocrine tumours (NETs) represent a heterogeneous family of neoplasms, which may develop from different endocrine glands (such as the pituitary, the parathyroid or the neuroendocrine adrenal glands), endocrine islets (within the thyroid or pancreas) as well as from endocrine cells dispersed between exocrine cells throughout the digestive and respiratory tracts. The development of somatostatin analogues (SSA) as important diagnostic and treatment tools has revolutionised the clinical management of patients with NETs. However, although symptomatic relief and stabilisation of tumour growth for various periods of time are observed in many patients treated with SSA, tumour regression is rare. Possible mechanisms when this does occur include antagonism of local growth factor release and effects, probably including activation of tyrosine and serine–threonine phosphatases, and indirect effects via anti-angiogenesis. The development of new SSA, new drug combination therapies and chimaeric molecules should further improve the clinical management of these patients, as should a more complete understanding of their mode of action.
Anna Angelousi, Krystallenia I Alexandraki, George Kyriakopoulos, Marina Tsoli, Dimitrios Thomas, Gregory Kaltsas, and Ashley Grossman
Endocrine organs are metastatic targets for several primary cancers, either through direct extension from nearby tumour cells or dissemination via the venous, arterial and lymphatic routes. Although any endocrine tissue can be affected, most clinically relevant metastases involve the pituitary and adrenal glands with the commonest manifestations being diabetes insipidus and adrenal insufficiency respectively. The most common primary tumours metastasing to the adrenals include melanomas, breast and lung carcinomas, which may lead to adrenal insufficiency in the presence of bilateral adrenal involvement. Breast and lung cancers are the most common primaries metastasing to the pituitary, leading to pituitary dysfunction in approximately 30% of cases. The thyroid gland can be affected by renal, colorectal, lung and breast carcinomas, and melanomas, but has rarely been associated with thyroid dysfunction. Pancreatic metastasis can lead to exo-/endocrine insufficiency with renal carcinoma being the most common primary. Most parathyroid metastases originate from breast and lung carcinomas and melanoma. Breast and colorectal cancers are the most frequent ovarian metastases; prostate cancer commonly affects the testes. In the presence of endocrine deficiencies, glucocorticoid replacement for adrenal and pituitary involvement can be life saving. As most metastases to endocrine organs develop in the context of disseminated disease, surgical resection or other local therapies should only be considered to ameliorate symptoms and reduce tumour volume. Although few consensus statements can be made regarding the management of metastases to endocrine tissues because of the heterogeneity of the variable therapies, it is important that clinicians are aware of their presence in diagnosis.
Xiang Zhang, Ya Hu, Mengyi Wang, Ronghua Zhang, PeiPei Wang, Ming Cui, Zhe Su, Xiang Gao, Quan Liao, and Yupei Zhao
Parathyroid carcinoma (PCa) is a rare endocrine neoplasia that typically has unfavourable outcomes. The contribution of long non-coding RNAs (lncRNAs) to the development of malignant and benign parathyroid tumours remains largely unknown. In this study, we explored transcriptomic profiling of lncRNA and mRNA expression in 6 PCa, 6 parathyroid adenoma (PAd) and 4 normal parathyroid (PaN) tissues. In total, 2641 lncRNA transcripts and 2165 mRNA transcripts were differentially expressed between PCa and PAd. Enrichment analysis demonstrated that dysregulated transcripts were involved mainly in the extracellular matrix (ECM)–receptor interaction and energy metabolism pathways. Bioinformatics analysis suggested that ATF3, ID1, FOXM1, EZH2 and MITF may be crucial to parathyroid carcinogenesis. Series test of cluster analysis segregated differentially expressed lncRNAs and mRNAs into several expression profile models, among which the ‘plateau’ profile representing components specific to parathyroid carcinogenesis was selected to build a co-expression network. Seven lncRNAs and three mRNAs were selected for quantitative RT-PCR validation in 16 PCa, 41 PAd and 4 PaN samples. Receiver-operator characteristic curves analysis showed that lncRNA PVT1 and GLIS2-AS1 yielded the area under the curve values of 0.871 and 0.860, respectively. Higher hybridization signals were observed in PCa for PVT1 and PAd for GLIS2-AS1. In conclusion, the current evidence indicates that PAd and PCa partially share common signalling molecules and pathways, but have independent transcriptional events. Differentially expressed lncRNAs and mRNAs have intricate interactions and are involved in parathyroid tumourigenesis. The lncRNA PVT1 and GLIS2-AS1 may be new potential markers for the diagnosis of PCa.