Evidence of a functional estrogen receptor in parathyroid adenomas

Unraveling the molecular and immunological landscape: Exploring signaling pathways in osteoporosis

Osteoporosis, characterized by compromised bone density and microarchitecture, represents a significant global health challenge, particularly in aging populations. This comprehensive review delves into the intricate signaling pathways implicated in the pathogenesis of osteoporosis, providing valuable insights into the pivotal role of signal transduction in maintaining bone homeostasis. The exploration encompasses cellular signaling pathways such as Wnt, Notch, JAK/STAT, NF-κB, and TGF-β, all of which play crucial roles in bone remodeling. The dysregulation of these pathways is a contributing factor to osteoporosis, necessitating a profound understanding of their complexities to unveil the molecular mechanisms underlying bone loss. The review highlights the pathological significance of disrupted signaling in osteoporosis, emphasizing how these deviations impact the functionality of osteoblasts and osteoclasts, ultimately resulting in heightened bone resorption and compromised bone formation. A nuanced analysis of the intricate crosstalk between these pathways is provided to underscore their relevance in the pathophysiology of osteoporosis. Furthermore, the study addresses some of the most crucial long non-coding RNAs (lncRNAs) associated with osteoporosis, adding an additional layer of academic depth to the exploration of immune system involvement in various types of osteoporosis. Finally, we propose that SKP1 can serve as a potential biomarker in osteoporosis.

[Hyperparathyroidism of different genesis in young patients with Turner syndrome: case series and brief review]

Hyperparathyroidism is a syndrome characterized by an excessive secretion of parathyroid hormone. Etiologically, hyperparathyroidism is subdivided into primary hyperparathyroidism, which develops as a result of parathyroid adenoma, carcinoma or hyperplasia, and secondary hyperparathyroidism, which happens as a compensatory response to a hypocalcemia caused by condition outside the parathyroid glands. Turner syndrome may also be accompanied by mineral metabolism disorders of various etiology. An association of hyperparathyroidism and Turner syndrome is interesting because of multifactorial impact on bone mineral density, but only few cases of such coexistence have been previously described in the literature. This article describes two patients with Turner syndrome and hyperparathyroidism of different etiology. Hyperparathyroidism, normocalcemia, vitamin D deficiency, osteoporosis, parathyroid tumors were found in both cases. In one case a number of assays was performed to confirm the patient's normocalcemic primary hyperparathyroidism, and surgery was performed to achieve remission. In the second case, treatment of vitamin D deficiency resulted in normalization of serum concentration of parathormone, after which the patient was prescribed antiresorptive therapy. The pathogenetic association between Turner syndrome and hyperparathyroidism requires further investigation. Comprehensive approach to the diagnosis and treatment of mineral metabolism disorders are essential for patients with coexistence of these two diseases.

Molecular Genetic Aspects of Sporadic Multiglandular Primary Hyperparathyroidism

Multiglandular primary hyperparathyroidism (MGD) represents a rare form of primary hyperparathyroidism (PHPT). MGD is associated with hereditary PHPT, but the sporadic MGD is more common and affects a similar patient profile as single gland parathyroid disease (SGD). The distinction between SGD and MGD is of great clinical importance, especially for the strategy of parathyroidectomy. Based on the limited knowledge available, MGD is likely to be a genetically heterogeneous disease resulting from the interaction of germline and somatic DNA mutations together with epigenetic alterations. Furthermore, these events may combine and occur independently in parathyroid tumors within the same individual with MGD. Gene expression profiling has shown that SGD and MGD may represent distinct entities in parathyroid tumorigenesis. We are waiting for studies to analyze exactly which genes are different in SGD and MGD in order to identify potential biomarkers that can distinguish between the two forms of the disease.

Molecular and Cellular Mechanisms of Osteoporosis

Osteoporosis is a widespread systemic disease characterized by a decrease in bone mass and an imbalance of the microarchitecture of bone tissue. Experimental and clinical studies devoted to investigating the main pathogenetic mechanisms of osteoporosis revealed the important role of estrogen deficiency, inflammation, oxidative stress, cellular senescence, and epigenetic factors in the development of bone resorption due to osteoclastogenesis, and decreased mineralization of bone tissue and bone formation due to reduced function of osteoblasts caused by apoptosis and age-depended differentiation of osteoblast precursors into adipocytes. The current review was conducted to describe the basic mechanisms of the development of osteoporosis at molecular and cellular levels and to elucidate the most promising therapeutic strategies of pathogenetic therapy of osteoporosis based on articles cited in PubMed up to September 2023.

Molecular and Clinical Spectrum of Primary Hyperparathyroidism

Recent data suggest an increase in the overall incidence of parathyroid disorders, with primary hyperparathyroidism (PHPT) being the most prevalent parathyroid disorder. PHPT is associated with morbidities (fractures, kidney stones, chronic kidney disease) and increased risk of death. The symptoms of PHPT can be nonspecific, potentially delaying the diagnosis. Approximately 15% of patients with PHPT have an underlying heritable form of PHPT that may be associated with extraparathyroidal manifestations, requiring active surveillance for these manifestations as seen in multiple endocrine neoplasia type 1 and 2A. Genetic testing for heritable forms should be offered to patients with multiglandular disease, recurrent PHPT, young onset PHPT (age ≤40 years), and those with a family history of parathyroid tumors. However, the underlying genetic cause for the majority of patients with heritable forms of PHPT remains unknown. Distinction between sporadic and heritable forms of PHPT is useful in surgical planning for parathyroidectomy and has implications for the family. The genes currently known to be associated with heritable forms of PHPT account for approximately half of sporadic parathyroid tumors. But the genetic cause in approximately half of the sporadic parathyroid tumors remains unknown. Furthermore, there is no systemic therapy for parathyroid carcinoma, a rare but potentially fatal cause of PHPT. Improved understanding of the molecular characteristics of parathyroid tumors will allow us to identify biomarkers for diagnosis and novel targets for therapy.

Germline Mutations Related to Primary Hyperparathyroidism Identified by Next-Generation Sequencing

Primary hyperparathyroidism (PHPT) is characterized by overproduction of parathyroid hormone and subsequent hypercalcemia. Approximately 10% of PHPT cases are hereditary, and several genes, such as MEN1, RET, CASR, and CDC73, are responsible for the familial forms of PHPT. However, other genetic mutations involved in the etiology of PHPT are largely unknown. In this study, we identified genetic variants that might be responsible for PHPT, including familial PHPT, benign sporadic PHPT, and sporadic parathyroid cancer, using next-generation sequencing (NGS). A total of 107 patients with PHPT who underwent NGS from 2017 to 2021 at Severance Hospital were enrolled. We reviewed the pathogenic variants, likely pathogenic variants, and variants of uncertain significance (VUS) according to the American College of Medical Genetics and Genomics and the Association for Molecular Pathology criteria. Of the 107 patients (mean age: 47.6 ± 16.1 years, women 73.8%), 12 patients were diagnosed with familial PHPT, 13 with parathyroid cancer, and 82 with benign sporadic PHPT. Using NGS, we identified three pathogenic variants in two genes (CDC73 and MEN1), 10 likely pathogenic variants in six genes (CASR, CDC73, LRP5, MEN1, SDHA, and VHL), and 39 non-synonymous VUS variants that could be related to parathyroid disease. Interestingly, we identified one GCM2 variant (c.1162A>G [p.Lys388Glu]) and five APC variants that were previously reported in familial isolated hyperparathyroidism, benign sporadic PHPT, and parathyroid cancer. We also analyzed the characteristics of subjects with positive genetic test results (pathogenic or likely pathogenic variants), and 76.9% of them had at least one of the following features: 1) age < 40 years, 2) family history of PHPT, 3) multiglandular PHPT, or 4) recurrent PHPT. In this study, we analyzed the NGS data of patients with PHPT and observed variants that could possibly be related to PHPT pathogenesis. NGS screening for selected patients with PHPT might help in the diagnosis and management of the disease.

Hyperparathyroidism presenting as hyperemesis and acute pancreatitis in pregnancy: A case report

RATIONALE

Nausea and vomiting are common in the early period of pregnancy and rarely seen as an overture to pancreatitis.

PATIENT CONCERNS

Here, we describe a 31-year-old pregnant woman who presented with progressive nausea and vomiting followed by severe epigastric pain. Biochemical data and sonographic features confirmed the occurrence of acute pancreatitis. Accompanying electrolyte abnormalities included hypercalcemia and hypokalemia. Her condition stabilized following medical treatment, but hypercalcemia persisted despite intravenous fluids and furosemide administration.

DIAGNOSES

A diagnosis of primary hyperparathyroidism was made based on the elevated parathyroid hormone level and urinary calcium-to-creatinine clearance ratio.

INTERVENTIONS

Localization study with neck ultrasonography indicated left inferior parathyroid adenoma. She underwent parathyroidectomy successfully and made an uneventful recovery.

OUTCOMES

At 37 weeks of gestation, she had a serum calcium level of 8.8 mg/dL and normal parathyroid hormone of 28.55 pg/mL. A healthy baby weighing 3180 g was delivered smoothly with no clinical nor biochemical evidence of hypocalcemia.

LESSONS

Although primary hyperparathyroidism during pregnancy is usually asymptomatic, patients may present with atypical manifestations such as hyperemesis and pancreatitis. Proper diagnosis and timely intervention are crucial to minimizing potential hazards to both mother and fetus.

Molecular Choreography and Structure of Ca2+ Release-Activated Ca2+ (CRAC) and KCa2+ Channels and Their Relevance in Disease with Special Focus on Cancer

Ca²⁺ ions play a variety of roles in the human body as well as within a single cell. Cellular Ca²⁺ signal transduction processes are governed by Ca²⁺ sensing and Ca²⁺ transporting proteins. In this review, we discuss the Ca²⁺ and the Ca²⁺-sensing ion channels with particular focus on the structure-function relationship of the Ca²⁺ release-activated Ca²⁺ (CRAC) ion channel, the Ca²⁺-activated K⁺ (K_Ca2+) ion channels, and their modulation via other cellular components. Moreover, we highlight their roles in healthy signaling processes as well as in disease with a special focus on cancer. As K_Ca2+ channels are activated via elevations of intracellular Ca²⁺ levels, we summarize the current knowledge on the action mechanisms of the interplay of CRAC and K_Ca2+ ion channels and their role in cancer cell development.

ORAI2 Promotes Gastric Cancer Tumorigenicity and Metastasis through PI3K/Akt Signaling and MAPK-Dependent Focal Adhesion Disassembly

The ubiquitous second messenger Ca²⁺ has long been recognized as a key regulator in cell migration. Locally confined Ca²⁺, in particular, is essential for building front-to-rear Ca²⁺ gradient, which serves to maintain the morphologic polarity required in directionally migrating cells. However, little is known about the source of the Ca²⁺ and the mechanism by which they crosstalk between different signaling pathways in cancer cells. Here, we report that calcium release-activated calcium modulator 2 (ORAI2), a poorly characterized store-operated calcium (SOC) channel subunit, predominantly upregulated in the lymph node metastasis of gastric cancer, supports cell proliferation and migration. Clinical data reveal that a high frequency of ORAI2-positive cells in gastric cancer tissues significantly correlated with poor differentiation, invasion, lymph node metastasis, and worse prognosis. Gain- and loss-of-function showed that ORAI2 promotes cell motility, tumor formation, and metastasis in both gastric cancer cell lines and mice. Mechanistically, ORAI2 mediated SOC activity and regulated tumorigenic properties through the activation of the PI3K/Akt signaling pathways. Moreover, ORAI2 enhanced the metastatic ability of gastric cancer cells by inducing FAK-mediated MAPK/ERK activation and promoted focal adhesion disassembly at rear-edge of the cell. Collectively, our results demonstrate that ORAI2 is a novel gene that plays an important role in the tumorigenicity and metastasis of gastric cancer. SIGNIFICANCE: These findings describe the critical role of ORAI2 in gastric cancer cell migration and tumor metastasis and uncover the translational potential to advance drug discovery along the ORAI2 signaling pathway.

Naught all zeros in sequence count data are the same

Genomic studies feature multivariate count data from high-throughput DNA sequencing experiments, which often contain many zero values. These zeros can cause artifacts for statistical analyses and multiple modeling approaches have been developed in response. Here, we apply different zero-handling models to gene-expression and microbiome datasets and show models can disagree substantially in terms of identifying the most differentially expressed sequences. Next, to rationally examine how different zero handling models behave, we developed a conceptual framework outlining four types of processes that may give rise to zero values in sequence count data. Last, we performed simulations to test how zero handling models behave in the presence of these different zero generating processes. Our simulations showed that simple count models are sufficient across multiple processes, even when the true underlying process is unknown. On the other hand, a common zero handling technique known as "zero-inflation" was only suitable under a zero generating process associated with an unlikely set of biological and experimental conditions. In concert, our work here suggests several specific guidelines for developing and choosing state-of-the-art models for analyzing sparse sequence count data.

Intratumor heterogeneity in human parathyroid tumors

Parathyroid tumors are the second most common endocrine neoplasia after thyroid neoplasia. They are mostly associated with impaired parathormone (PTH) synthesis and release determining the metabolic and clinical condition of primary hyperparathyroidism (PHPT). PHPT is the third most prevalent endocrine disorder, mainly affecting postmenopausal women. Parathyroid benign tumors, both adenomas of a single gland or hyperplasia involving all the glands, are the main histotypes, occurring in more than 95% of PHPT cases. The differential diagnosis between benign and malignant parathyroid lesions is a challenge for clinicians. It relies on histologic features, which display significant overlap between the histotypes with different clinical outcomes. Parathyroid adenomas and hyperplasia have been considered so far as a unique monoclonal/polyclonal entity, while accumulating evidence suggest great heterogeneity. Intratumor parathyroid heterogeneity involves tumor cell type, as well as tumor cell function, in terms of PTH synthesis and secretion, and of expression patterns of membrane and nuclear receptors (calcium sensing receptor, vitamin D receptor, α-klotho receptor and others). Intratumor heterogeneity can also interfere with cell molecular biology, in regard to clonality, oncosuppressor gene expression (such as MEN1 and HRPT2/CDC73), transcription factors (GCM2, TBX1) and microRNA expression. Such heterogeneity is likely involved in the phenotypic variability of the parathyroid tumors, and it should be considered in the clinical management, though at present target therapies are not available, with the exception of the calcium sensing receptor agonists.

Gender Predilection in Sporadic Parathyroid Adenomas

Primary hyperparathyroidism is a common endocrinopathy that is mainly caused by benign parathyroid adenomas. The frequency, clinical presentation and complications of the disease show significant differences between genders, with the majority of cases being reported in postmenopausal women. Due to this gender predilection, several studies have investigated the role of sex hormones in the pathogenesis of the disease and their potential use as targets for optimal and gender-specific management. Epigenetic mechanisms that regulate gene transcription may also contribute to these differences between genders. In this review, we outline what is currently known regarding the role of sex hormones and the recent data on the role of non-coding RNAs in the differences between genders in primary hyperparathyroidism due to sporadic parathyroid adenomas.

Primary hyperparathyroidism: should surgery be performed on all patients? Current evidence and residual uncertainties

Primary hyperparathyroidism (pHPT) is the third most common endocrine disease and is characterized by hypercalcaemia and elevated or inappropriately 'normal' levels of the parathyroid hormone (PTH). The main target organs of PTH are the skeletal system and the kidneys. Before the 1970s, pHPT was a rarely detected disease associated with notable morbidity and premature mortality. Introduction of biochemical screening, allowing for a wide range of indications, has contributed to the detection of the full spectrum of the disease. A new entity with an isolated elevation of PTH, normocalcaemic HP, has emerged and is currently being explored. The highest incidence of pHPT, 3-5%, is observed amongst women, and the prevalence increases with age. The female-to-male ratio is 3-4 : 1 except in younger patients where distribution is equal and known hereditary causes account for approximately 10% of the cases. In the last few decades, it has become evident that fewer patients than previously believed are truly asymptomatic. The cause of pHPT is often a benign tumour, a parathyroid adenoma, and the only definite treatment is parathyroidectomy (PTX). No medical treatment, single or combined, can achieve a curing of pHPT. Recent data indicate that PTX, despite being proven to be cost-effective compared to conservative treatment, is underutilized, especially in elderly pHPT patients. The decision of PTX should always be based on a safe diagnosis, and the potential benefits of curative treatment should not be outweighed by the risks of surgery or anaesthesia.

A Role for Circular Non-Coding RNAs in the Pathogenesis of Sporadic Parathyroid Adenomas and the Impact of Gender-Specific Epigenetic Regulation

Epigenetic changes, including altered small non-coding RNAs, appear to be implicated in the pathogenesis of sporadic parathyroid adenomas (PAs). In this study, we investigated the circular RNAs (circRNAs) expression profile in sporadic PAs. Sixteen tissue samples of sporadic PAs, and four samples of normal parathyroid tissue (NPT) were investigated. Sample preparation and microarray hybridization were performed based on the Arraystar’s standard protocols, and circRNAs sequences were predicted by bioinformatics tools. We identified 35 circRNAs that were differentially expressed in sporadic PAs compared to NPT; 22 were upregulated, and 13 were downregulated, according to the pre-defined thresholds of fold-change > 2.0 and p< 0.05. In the subgroup analysis of PAs from male patients (n = 7) compared to PAs from female patients (n = 9), we also find a different expression profile. In particular, 19 circRNAs were significantly upregulated, and four circRNAs were significantly downregulated in male patients, compared to female counterparts. We show here for the first time a differential circRNA expression pattern in sporadic PAs compared to NPT, and a different expression profile in PA samples from male compared to female patients, suggesting an epigenetic role in the PA pathogenesis, and also an effect of gender in the epigenetic regulation of PAs.

TRPC6 Channels Are Required for Proliferation, Migration and Invasion of Breast Cancer Cell Lines by Modulation of Orai1 and Orai3 Surface Exposure

Transient receptor potential channels convey signaling information from a number of stimuli to a wide variety of cellular functions, mainly by inducing changes in cytosolic Ca²⁺ concentration. Different members of the TRPC, TRPM and TRPV subfamilies have been reported to play a role in tumorigenesis. Here we show that the estrogen receptor positive and triple negative breast cancer cell lines, MCF7 and MDA-MB-231, respectively, exhibit enhanced expression of the TRPC6 channel as compared to the non-tumoral MCF10A cell line. In vitro TRPC6 knockdown using shRNA impaired MCF7 and MDA-MB-231 cell proliferation, migration and invasion detected by BrdU incorporation, wound healing and Boyden chamber assays, respectively. Using RNAi-mediated TRPC6 silencing as well as overexpression of the pore-dead dominant-negative TRPC6 mutant we have found that TRPC6 plays a relevant role in the activation of store-operated Ca²⁺ entry in the breast cancer cell lines but not in non-tumoral breast cells. Finally, we have found that TRPC6 interacts with Orai1 and Orai3 in MCF7 and MDA-MB-231 cells and is required for the translocation of Orai1 and Orai3 to the plasma membrane in MDA-MB-231 and MCF7 cells, respectively, upon Ca²⁺ store depletion. These findings introduce a novel mechanism for the modulation of Ca²⁺ influx and the development of different cancer hallmarks in breast cancer cells.

Inflammatory infiltrates in parathyroid tumors

CONTEXT

Inflammatory infiltrates are sometimes present in solid tumors and may be coupled to clinical behavior or etiology. Infectious viruses contribute to tumorigenesis in a significant fraction of human neoplasias.

OBJECTIVE

Characterize inflammatory infiltrates and possible viral transcription in primary hyperparathyroidism.

DESIGN

From the period 2007 to 2016, a total of 55 parathyroid tumors (51 adenomas and 4 hyperplasias) with prominent inflammatory infiltrates were identified from more than 2000 parathyroid tumors in the pathology archives, and investigated by immunohistochemistry for CD4, CD8, CD20 and CD45 and scored as +0, +1 or +2. Clinicopathological data were compared to 142 parathyroid adenomas without histological evidence of inflammation. Transcriptome sequencing was performed for 13 parathyroid tumors (four inflammatory, 9 non-inflammatory) to identify potential viral transcripts.

RESULTS

Tumors had prominent germinal center-like nodular (+2) lymphocytic infiltrates consisting of T and B lymphocytes (31%) and/or diffuse (+1-2) infiltrates of predominantly CD8+ T lymphocytes (84%). In the majority of cases with adjacent normal parathyroid tissue, the normal rim was unaffected by the inflammatory infiltrates (96%). Presence of inflammatory infiltrates was associated with higher levels of serum-PTH (P = 0.007) and oxyphilic differentiation (P = 0.002). Co-existent autoimmune disease was observed in 27% of patients with inflammatory infiltrates, which in turn was associated with oxyphilic differentiation (P = 0.041). Additionally, prescription of anti-inflammatory drugs was associated with lower serum ionized calcium (P = 0.037).

CONCLUSIONS

No evidence of virus-like sequences in the parathyroid tumors could be found by transcriptome sequencing, suggesting that other factors may contribute to attract the immune system to the parathyroid tumor tissue.

Cinacalcet corrects hypercalcemia in mice with an inactivating Gα11 mutation

Loss-of-function mutations of GNA11, which encodes G-protein subunit α₁₁ (Gα₁₁), a signaling partner for the calcium-sensing receptor (CaSR), result in familial hypocalciuric hypercalcemia type 2 (FHH2). FHH2 is characterized by hypercalcemia, inappropriately normal or raised parathyroid hormone (PTH) concentrations, and normal or low urinary calcium excretion. A mouse model for FHH2 that would facilitate investigations of the in vivo role of Gα₁₁ and the evaluation of calcimimetic drugs, which are CaSR allosteric activators, is not available. We therefore screened DNA from > 10,000 mice treated with the chemical mutagen N-ethyl-N-nitrosourea (ENU) for GNA11 mutations and identified a Gα₁₁ variant, Asp195Gly (D195G), which downregulated CaSR-mediated intracellular calcium signaling in vitro, consistent with it being a loss-of-function mutation. Treatment with the calcimimetic cinacalcet rectified these signaling responses. In vivo studies showed mutant heterozygous (Gna11^+/195G) and homozygous (Gna11^195G/195G) mice to be hypercalcemic with normal or increased plasma PTH concentrations and normal urinary calcium excretion. Cinacalcet (30mg/kg orally) significantly reduced plasma albumin–adjusted calcium and PTH concentrations in Gna11^+/195G and Gna11^195G/195G mice. Thus, our studies have established a mouse model with a germline loss-of-function Gα₁₁ mutation that is representative for FHH2 in humans and demonstrated that cinacalcet can correct the associated abnormalities of plasma calcium and PTH.

Cinacalcet corrects hypercalcemia in a mouse model for familial hypocalciuric hypercalcemia type 2 (FHH2) caused by a germline loss-of-function G-protein subunit α11 (Gα11) mutation, Asp195Gly.

Next-generation sequencing for endocrine cancers: Recent advances and challenges

Contemporary molecular biology research tools have enriched numerous areas of biomedical research that address challenging diseases, including endocrine cancers (pituitary, thyroid, parathyroid, adrenal, testicular, ovarian, and neuroendocrine cancers). These tools have placed several intriguing clues before the scientific community. Endocrine cancers pose a major challenge in health care and research despite considerable attempts by researchers to understand their etiology. Microarray analyses have provided gene signatures from many cells, tissues, and organs that can differentiate healthy states from diseased ones, and even show patterns that correlate with stages of a disease. Microarray data can also elucidate the responses of endocrine tumors to therapeutic treatments. The rapid progress in next-generation sequencing methods has overcome many of the initial challenges of these technologies, and their advantages over microarray techniques have enabled them to emerge as valuable aids for clinical research applications (prognosis, identification of drug targets, etc.). A comprehensive review describing the recent advances in next-generation sequencing methods and their application in the evaluation of endocrine and endocrine-related cancers is lacking. The main purpose of this review is to illustrate the concepts that collectively constitute our current view of the possibilities offered by next-generation sequencing technological platforms, challenges to relevant applications, and perspectives on the future of clinical genetic testing of patients with endocrine tumors. We focus on recent discoveries in the use of next-generation sequencing methods for clinical diagnosis of endocrine tumors in patients and conclude with a discussion on persisting challenges and future objectives.

A pregnant dilemma: primary hyperparathyroidism due to parathyromatosis in pregnancy

OBJECTIVE

To describe an exceedingly rare case of parathyromatosis in pregnancy and the limited medical treatment options available for such cases that are refractory to surgery.

METHODS

Case presentation and description of clinical course with brief review of the literature.

RESULTS

A 21-year-old woman with a history of 3.5 gland parathyroidectomy presented with severe hyperemesis during her first trimester of pregnancy and was found to have primary hyperparathyroidism attributable to parathyromatosis. We describe the diagnostic and management dilemmas associated with this case, which included localization of the culprit lesions, a technically challenging surgical resection and subsequent medical management with cinacalcet when symptomatic hypercalcemia recurred during the third trimester. To our knowledge, this is only the third report of the successful use of cinacalcet during pregnancy, and the first case report of parathyromatosis presenting during pregnancy.

CONCLUSION

Cinacalcet was used safely and effectively during the third trimester of pregnancy to treat symptomatic hypercalcemia due to parathyromatosis.

Diffuse parathyroid hormone expression in parathyroid tumors argues against important functional tumor subclones

OBJECTIVE

Primary hyperparathyroidism is usually characterized by a monoclonal parathyroid tumor secreting excess parathyroid hormone (PTH). The main regulator of PTH secretion is calcium and the calcium-PTH set point is shifted in parathyroid tumor cells. We sought to investigate the relationship between tumor PTH and PTH mRNA expression and clinical presentation as well as the regulatory factors including phosphate, vitamin D, and fibroblast growth factor 23.

DESIGN

A total of 154 parathyroid tumors were analyzed by PTH immunohistochemistry and chromogenic in situ hybridization of PTH mRNA. A subset of samples (n = 34) was analyzed using quantitative real-time PCR.

RESULTS

Low tumor PTH mRNA level was significantly associated with low tumor PTH immunoreactivity (P = 0.026), but the two did not correlate with regard to histological distribution within individual tumors. Tumors displaying reduced PTH mRNA levels as compared with normal rim were significantly larger (P = 0.013) and showed higher expression of the calcium-sensing receptor (CASR) (P = 0.046). Weaker tumor PTH mRNA level was significantly associated with higher concentration of circulating 25-hydroxyvitamin D (P = 0.005). No significant correlation was seen between PTH immunoreactivity and patient biochemistry. Tumor weight was strongly associated with circulatory concentrations of calcium and PTH.

CONCLUSIONS

No areas with apparently higher PTH expression were identified, perhaps suggesting that hyper functioning parathyroid tumor subclones should be rare. Circulating 25-hydroxyvitamin D levels may influence tumor PTH expression in vivo. If PTH immunoreactivity reflects the tumor calcium-PTH set point, our data imply that the main determinant of disease severity should be tumor weight.

Metastatic ductal carcinoma of the breast to the thyroid gland diagnosed with fine needle aspiration: A case report with emphasis on morphologic and immunophenotypic features

Metastases to the thyroid are uncommon [<0.2% of thyroid fine needle aspirations (FNA)]. Of metastases to the thyroid, breast carcinoma is relatively common. The diagnosis of metastasis to the thyroid has important therapeutic and prognostic implications. To our knowledge, a morphologic and immunophenotypic comparison of metastatic ductal carcinoma of the breast and primary thyroid carcinomas has not been reported. Here, we report the case of a 37-year-old female with a history of metastatic ductal carcinoma of the breast (modified Bloom-Richardson grade 2; ER+, PgR+, HER2+) diagnosed 6 years prior. She developed hoarseness, prompting a CT scan. Multiple thyroid nodules were found, including a 1.5 cm hypoechoic, solid, irregularly-shaped nodule. On FNA, cells were arranged singly and in crowded groups, varied in size and degree of pleomorphism, and exhibited rare nuclear grooves, inconspicuous nucleoli, and rare intracytoplasmic lumina with no nuclear pseudoinclusions or colloid (Figs. 1A and B). These findings raised the differential of papillary thyroid carcinoma (Fig. 1C), follicular neoplasm (Fig. 1D), medullary carcinoma (Fig. 1E), parathyroid (Fig. 1F), and metastatic breast carcinoma. Immunostaining for GATA-3 (+), ER (+), PAX-8 (-), and TTF-1 (-) was consistent with metastatic breast carcinoma (Fig. 2). We conclude that metastatic breast carcinoma to the thyroid may morphologically mimic primary thyroid carcinoma on FNA; a panel of immunomarkers, such as GATA-3, hormonal marker(s), PAX-8, and TTF-1, may be useful in some cases. GATA-3 immunostaining for metastatic breast carcinoma was helpful in our case and has not been previously reported in a thyroid metastasis sampled by FNA. Diagn. Cytopathol. 2016;44:530-534. © 2016 Wiley Periodicals, Inc.

CRAC channels, calcium, and cancer in light of the driver and passenger concept

Advances in next-generation sequencing allow very comprehensive analyses of large numbers of cancer genomes leading to an increasingly better characterization and classification of cancers. Comparing genomic data predicts candidate genes driving development, growth, or metastasis of cancer. Cancer driver genes are defined as genes whose mutations are causally implicated in oncogenesis whereas passenger mutations are defined as not being oncogenic. Currently, a list of several hundred cancer driver mutations is discussed including prominent members like TP53, BRAF, NRAS, or NF1. According to the vast literature on Ca(2+) and cancer, Ca(2+) signals and the underlying Ca(2+) channels and transporters certainly influence the development, growth, and metastasis of many cancers. In this review, I focus on the calcium release-activated calcium (CRAC) channel genes STIM and Orai and their role for cancer development, growth, and metastasis. STIM and Orai genes are being discussed in the context of current cancer concepts with a focus on the driver-passenger hypothesis. One result of this discussion is the hypothesis that a driver analysis of Ca(2+) homeostasis-related genes should not be carried out by looking at isolated genes. Rather a pool of “Ca(2+) genes” might be considered to act as one potential cancer driver. This article is part of a Special Issue entitled: Calcium and Cell Fate. Guest Editors: Jacques Haiech, Claus Heizmann, Joachim Krebs, Thierry Capiod and Olivier Mignen.

Comprehensive evaluation of fusion transcript detection algorithms and a meta-caller to combine top performing methods in paired-end RNA-seq data

Background: Fusion transcripts are formed by either fusion genes (DNA level) or trans-splicing events (RNA level). They have been recognized as a promising tool for diagnosing, subtyping and treating cancers. RNA-seq has become a precise and efficient standard for genome-wide screening of such aberration events. Many fusion transcript detection algorithms have been developed for paired-end RNA-seq data but their performance has not been comprehensively evaluated to guide practitioners. In this paper, we evaluated 15 popular algorithms by their precision and recall trade-off, accuracy of supporting reads and computational cost. We further combine top-performing methods for improved ensemble detection.

Results: Fifteen fusion transcript detection tools were compared using three synthetic data sets under different coverage, read length, insert size and background noise, and three real data sets with selected experimental validations. No single method dominantly performed the best but SOAPfuse generally performed well, followed by FusionCatcher and JAFFA. We further demonstrated the potential of a meta-caller algorithm by combining top performing methods to re-prioritize candidate fusion transcripts with high confidence that can be followed by experimental validation.

Conclusion: Our result provides insightful recommendations when applying individual tool or combining top performers to identify fusion transcript candidates.

Clinicopathological correlates of hyperparathyroidism

Hyperparathyroidism is a common endocrine disorder with potential complications on the skeletal, renal, neurocognitive and cardiovascular systems. While most cases (95%) occur sporadically, about 5% are associated with a hereditary syndrome: multiple endocrine neoplasia syndromes (MEN-1, MEN-2A, MEN-4), hyperparathyroidism-jaw tumour syndrome (HPT-JT), familial hypocalciuric hypercalcaemia (FHH-1, FHH-2, FHH-3), familial hypercalciuric hypercalcaemia, neonatal severe hyperparathyroidism and isolated familial hyperparathyroidism. Recently, molecular mechanisms underlying possible tumour suppressor genes (MEN1, CDC73/HRPT2, CDKIs, APC, SFRPs, GSK3β, RASSF1A, HIC1, RIZ1, WT1, CaSR, GNA11, AP2S1) and proto-oncogenes (CCND1/PRAD1, RET, ZFX, CTNNB1, EZH2) have been uncovered in the pathogenesis of hyperparathyroidism. While bi-allelic inactivation of CDC73/HRPT2 seems unique to parathyroid malignancy, aberrant activation of cyclin D1 and Wnt/β-catenin signalling has been reported in benign and malignant parathyroid tumours. Clinicopathological correlates of primary hyperparathyroidism include parathyroid adenoma (80-85%), hyperplasia (10-15%) and carcinoma (<1-5%). Secondary hyperparathyroidism generally presents with diffuse parathyroid hyperplasia, whereas tertiary hyperparathyroidism reflects the emergence of autonomous parathyroid hormone (PTH)-producing neoplasm(s) from secondary parathyroid hyperplasia. Surgical resection of abnormal parathyroid tissue remains the only curative treatment in primary hyperparathyroidism, and parathyroidectomy specimens are frequently encountered in this setting. Clinical and biochemical features, including intraoperative PTH levels, number, weight and size of the affected parathyroid gland(s), are crucial parameters to consider when rendering an accurate diagnosis of parathyroid proliferations. This review provides an update on the expanding knowledge of hyperparathyroidism and highlights the clinicopathological correlations of this prevalent disease.

Tumour nuclear oestrogen receptor beta 1 correlates inversely with parathyroid tumour weight

Primary hyperparathyroidism (PHPT) is a common endocrinopathy, frequently caused by a parathyroid adenoma, rarely by a parathyroid carcinoma that lacks effective oncological treatment. As the majority of cases are present in postmenopausal women, oestrogen signalling has been implicated in the tumourigenesis. Oestrogen receptor beta 1 (ERB1) and ERB2 have been recently identified in parathyroid adenomas, the former inducing genes coupled to tumour apoptosis. We applied immunohistochemistry and slide digitalisation to quantify nuclear ERB1 and ERB2 in 172 parathyroid adenomas, atypical adenomas and carcinomas, and ten normal parathyroid glands. All the normal parathyroid glands expressed ERB1 and ERB2. The majority of tumours expressed ERB1 (70.6%) at varying intensities, and ERB2 (96.5%) at strong intensities. Parathyroid carcinomas expressed ERB1 in three out of six cases and ERB2 in five out of six cases. The intensity of tumour nuclear ERB1 staining significantly correlated inversely with tumour weight (P=0.011), and patients whose tumours were classified as ERB1-negative had significantly greater tumour weight as well as higher serum calcium (P=0.002) and parathyroid hormone levels (P=0.003). Additionally, tumour nuclear ERB1 was not expressed differentially with respect to sex or age of the patient. Levels of tumour nuclear ERB2 did not correlate with clinical characteristics. In conclusion, decreased ERB1 immunoreactivity is associated with increased tumour weight in parathyroid adenomas. Given the previously reported correlation with tumour-suppressive signalling, selective oestrogen receptor modulation (SERMs) may play a role in the treatment of parathyroid carcinomas. Future studies of SERMs and oestrogen treatment in PHPT should consider tumour weight as a potential factor in pharmacological responsiveness.

The neglected CRAC proteins: Orai2, Orai3, and STIM2

Plasma-membrane-localized Orai1 ion channel subunits interacting with ER-localized STIM1 molecules comprise the major subunit composition responsible for calcium release-activated calcium channels. STIM1 "translates" the Ca(2+) store content into Orai1 activity, making it a store-operated channel. Surprisingly, in addition to being the physical activator, STIM1 also modulates Orai1 properties, including its inactivation and permeation (see Chapter 1). STIM1 is thus more than a pure Orai1 activator. Within the past 7 years following the discovery of STIM and Orai proteins, the molecular mechanisms of STIM1/Orai1 activity and their functional importance have been studied in great detail. Much less is currently known about the other isoforms STIM2, Orai2, and Orai3. In this chapter, we summarize the current knowledge about STIM2, Orai2, and Orai3 properties and function. Are these homologues mainly modulators of predominantly STIM1/Orai1-mediated complexes or do store-dependent or -independent functions such as regulation of basal Ca(2+) concentration and activation of Orai3-containing complexes by arachidonic acid or by estrogen receptors point toward their "true" physiological function? Is Orai2 the Orai1 of neurons? A major focus of the review is on the functional relevance of STIM2, Orai2, and Orai3, some of which still remains speculative.

When would I use medical therapies for the treatment of primary hyperparathyroidism?

Although there may be controversy surrounding the indications for parathyroidectomy in primary hyperparathyroidism, it remains the only accepted definitive therapy. However, even if parathyroidectomy is indicated, some patients refuse surgery, are medically unfit or have residual or recurrent disease inaccessible to further surgery. Some of these patients may be suitable for long-term observation but others require intervention for management of symptomatic or moderate to severe hypercalcaemia, loss of bone mineral density or renal calculi. The selection of a suitable therapy for each patient should be individualized.