Generation of induced pluripotent stem cell line (MIPTi002-A) derived from a patient with a heterozygous type mutation in the CDC73 gene

CDC73-related disorders are inherited in an autosomal dominant manner. An individual with a CDC73-related disorder may have inherited the disorder from an affected parent or developed it as the result of a de novo pathogenic variant of CDC73. The iPSC line was obtained by reprogramming the PBMCs of a patient with a heterozygous type mutation of the CDC73 gene. This cell line could be useful to scrutinize and study the development of CDC73-associated parathyroid carcinoma.

Multiple Metastases of Parathyroid and Papillary Thyroid Carcinoma in a Female Patient Treated with Long-Term Hemodialysis

Parathyroid cancer is a rare, clinically aggressive malignancy with a prevalence of approximately 0.005% relative to all carcinoma cases and 1-5% among patients with primary hyperparathyroidism. Prognosis largely depends on the extent of the primary surgery. Non-radical surgical treatment increases the risk of local and distant metastases of the parathyroid cancer associated with limited treatment options. The combination of thyroid and parathyroid disorders has been described rather well for the general population; however, cases of parathyroid and thyroid carcinoma in the same patient are extremely rare (1 case per 3000 patients with parathyroid disorders). We present a rare clinical case of combination of parathyroid and thyroid cancers with metastases of both tumors to the neck lymph nodes in a woman with a mutation in the MEN1 gene (NM_130799.2): c.658T > C p.Trp220Arg (W220R), who has been exposed to radiation for 20 years before diagnosis of thyroid cancer and received renal replacement therapy with long-term hemodialysis before the diagnosis of parathyroid cancer. The patient underwent several surgeries because of metastases of the parathyroid cancer in the neck lymph nodes. Surgeons used intraoperative navigation methods (single-channel gamma detection probe, Gamma Probe 2, and fluorescence angiography with indocyanine green (ICG)) to clarify the volume of surgery. Currently, the patient is still in laboratory remission, despite the structural recurrence of tumors.

Different treatment strategies in primary hyperparathyroidism during pregnancy

PURPOSE

Primary hyperparathyroidism (PHPT) in pregnancy is rare enough and can be unrecognized because of nonspecific symptoms in most cases, but life-threatening complications for mother, fetus and neonate also occurs. PHPT requires frequent monitoring of the mother and fetus by a multidisciplinary team. Diagnostics and treatment approaches are limited and require individual risk-benefit assessment.

METHODS

In this paper we describe 3 cases of PHPT in pregnant women with different managing approaches (surveillance, drug therapy and surgical treatment) and successful outcomes. Additionally, the most actual literature data on this problem is reviewed.

RESULTS

The management of PHPT in pregnancy should be based on the clinical features, severity of hypercalcemia, gestational age and patient's preference. In the first case a conservative approach with low-calcium diet and oral hydration resulted in mother's reduced serum calcium level before delivery. The second patient had severe hypercalcemia and absolute indications for surgery that was successfully performed at 25 week of gestation. The third woman received cinacalcet because of severe hypercalcemia and potential perioperative risks in the third trimester with an improvement in well-being.

CONCLUSION

Nowadays parathyroidectomy is the best choice for patients with symptomatic PHPT and severe hypercalcemia. This intervention should be carried out preferably in the second trimester to avoid maternal and fetal complications. Mild forms of the disease can require just a conservative management. The drug treatment of PHPT during pregnancy is still controversial.

The role of menin in bone pathology

Multiple endocrine neoplasia type 1 (MEN1) is the most common cause of hereditary primary hyperparathyroidism (PHPT). Bone disorders are considered one of the key symptoms in PHPT present with the significant reduction in bone mineral density and low-energy fractures. Previously, these bone disorders were believed to be caused solely by the increase in the level of parathyroid hormone and its subsequent effect on bone resorption. The current paradigm, however, states that the mutations in the menin gene, which cause the development of MEN1, can also affect the metabolism of the cells of the osteoid lineage. This review analyzes both the proven and the potential intracellular mechanisms through which menin can affect bone metabolism.

A Novel Isogenic Human Cell-Based System for MEN1 Syndrome Generated by CRISPR/Cas9 Genome Editing

Multiple endocrine neoplasia type 1 (MEN1) is a rare tumor syndrome that manifests differently among various patients. Despite the mutations in the MEN1 gene that commonly predispose tumor development, there are no obvious phenotype-genotype correlations. The existing animal and in vitro models do not allow for studies of the molecular genetics of the disease in a human-specific context. We aimed to create a new human cell-based model, which would consider the variability in genetic or environmental factors that cause the complexity of MEN1 syndrome. Here, we generated patient-specific induced pluripotent stem cell lines carrying the mutation c.1252G>T, D418Y in the MEN1 gene. To reduce the genetically determined variability of the existing cellular models, we created an isogenic cell system by modifying the target allele through CRISPR/Cas9 editing with great specificity and efficiency. The high potential of these cell lines to differentiate into the endodermal lineage in defined conditions ensures the next steps in the development of more specialized cells that are commonly affected in MEN1 patients, such as parathyroid or pancreatic islet cells. We anticipate that this isogenic system will be broadly useful to comprehensively study MEN1 gene function across different contexts, including in vitro modeling of MEN1 syndrome.

Serum circulating miRNA-342-3p as a potential diagnostic biomarker in parathyroid carcinomas: A pilot study

Objective

To compare the serum miRNA expression profiles between patients with benign and malignant parathyroid tumours.

Background

Despite recent advances in molecular biology, a histological tissue biopsy is still the method of choice used to diagnose most cancers. The preoperative cytology is not an applicable method for diagnosis of parathyroid cancer (PC); therefore, huge interest exists in terms of finding alternative methodologies to seek specific cancer biomarkers.

Design

A retrospective cross‐sectional study.

Patients and Methods

Serum samples of patients with PC (n = 13) and parathyroid adenoma (PA) (n = 11), age (p = .999) and sex (p = .999) were matched and examined via the simultaneous comparative expression analysis of 754 microRNAs (miRNAs). The «TaqMan OpenArray Human MicroRNA Panel» (Applied Biosystems) was used to conduct real‐time PCRs using the «QuantStudio 12К Flex» station (Life Technologies).

Results

According to the results of a pilot study, significant changes in expression levels between the PC group and the PA group (control) (p < .05) were observed for 17 miRNAs. Among them, the downregulation of miRNA‐342‐3p met the Benjamini‐Hochberg adjustment criteria for multiple comparisons (p = .02).

Conclusions

Serum miRNA‐342‐3p could be a promising biomarker for PC to improve diagnosis and prognosis.

Denosumab for management of severe hypercalcemia in primary hyperparathyroidism

Hypercalcemic crisis is a severe but rare complication of primary hyperparathyroidism (PHPT), and data on denosumab treatment of patients with this disease is still very limited. The aim of this paper is to investigate the hypocalcemic effect of denosumab in PHPT patients with severe hypercalcemia when surgery should be delayed or is impossible for some reasons. We performed a retrospective study of 10 patients. The analysis included the use of biochemical markers of calcium-phosphorus metabolism, which were followed after the administration of 60 mg of denosumab. The trend to calcium reduction was already determined on the 3rd day after denosumab administration. In most cases the decrease in serum calcium level to the range of 2.8 mmol/L on average or lower was observed on the 7th day (P = 0.002). In addition to a significant increase in calcium levels we confirmed a significant increase in the estimated glomerular filtration rate on 7th day (P = 0.012). After that, seven patients underwent successful parathyroidectomy and achieved eucalcemia or hypocalcemia, one patient developed the recurrence of parathyroid cancer after initial surgery, while two patients with severe cardiovascular pathology refused surgery. Our study shows that denosumab is a useful tool in PHPT-associated hypercalcemia before surgery or if surgery is contraindicated.

Diagnosis and treatment challenges of parathyroid carcinoma in a 27-year-old woman with multiple lung metastases

SUMMARY

Parathyroid carcinoma is an extremely rare disorder with little treatment options. It could be misdiagnosed in medical centers with little experience in management of such cases. Our clinical case shows that the initial misdiagnosis of a parathyroid carcinoma in a young woman has led to the development of multiple lung metastases, thus making its treatment hardly possible. Initiation of treatment with sorafenib - a multi-kinase inhibitor approved for treatment of different types of cancer but not parathyroid carcinoma - has led to a significant decrease in the size of lung metastases and has prevented the progression of hyperparathyroidism, which is usually severe in cases of parathyroid carcinoma. The detection of a germline CDC73 mutation in this patient has raised additional concerns about the necessity of periodic screening for early detection of renal, jaw and uterine lesions.

LEARNING POINTS

Diagnosis of parathyroid carcinoma may be challenging due to the absence of reliable diagnostic criteria. Thus, thorough histological examination is needed using immunohistochemical staining of resected tissue in suspicious cases. CDC73 genetic testing should be considered in patients with parathyroid carcinoma.Sorafenib may be a promising treatment of patients with parathyroid carcinoma with distant metastases.