Endocrine Abstracts

Background: Hypophosphatasia is a rare genetic disease with low serum alkaline phosphatase (ALP) activity and hypophosphatasemia. It is caused by loss-of-function mutations and deletions of the tissue-nonspecific isoenzyme of alkaline phosphatase (TNSALP) gene; it has a wide range of severity in its phenotype, from death in utero to asymptomatic disease accidentally diagnosed in adult life. Furthermore, some diseases and drugs may induce hypophosphatasemia. Thus, the ...

Background: Hypophosphatasia (HPP) is a rare metabolic, inherited disease of bone metabolism, caused by loss-of-function mutations within the gene coding for TNSALP, that result in a decrease in serum ALP concentrations and consequent accumulation of ALP substrates outside of the cell, including inorganic pyrophosphate which inhibits bone mineralization. HPP leads to a variety of clinical manifestations across all ages and its prognosis is conditioned principally by the skelet...

Epigenetic deregulation is emerging as a component of the parathyroid tumorigenesis. We identified a long non-coding RNA (LNCRNA) signature clearly distinguishing parathyroid adenomas (PAds) and carcinomas from normal glands. Among the deregulated LncRNAS, HAR1B was upregulated in PAds harboring the common chromosome 11q loss of heterozygosity (Chr11q-LOH; n=10) compared with PAds harboring normal chromosome 11 haplotype (Chr11q-WT; n=12; P&...

We previously described aberrant expression of microRNAs belonging to the chromosome 19 cluster (C19MC) and the close miR-371-373 cluster in two-thirds of parathyroid carcinomas (PCas). Therefore, we investigated the involvement of the miR-371-373 cluster in parathyroid tumours, where miR-372 was the most consistently upregulated. miR-372 is known to be highly expressed in human embryonic stem cells and definitely downregulated upon differentiation. Moreover, miR-372 promotes ...

Though there is no evidence of a constitutive nuclear accumulation of β-catenin, the Wnt/β-catenin pathway might be deregulated in parathyroid tumours. We investigated unphosphorylated active β-catenin distribution by western blot in 16 typical parathyroid adenomas (PAds): β-catenin accumulation in the nuclear protein fractions varied from the levels detected in Caco-2 cells with constitutively active Wnt signalling (three PAds) to the levels measured in HE...

Parathyroid carcinomas (PCas) are rare endocrine malignant neoplasia characterized by an abnormal PTH secretion and, consequently, severe and uncontrolled hypercalcemia. Clinically, the preoperative diagnosis can be misleading, because PCas share some molecular and clinical similarities with benign lesions and are often indolent. The histological diagnosis of carcinoma is achieved based on the presence of mitotic nuclear figures, capsular invasion, parenchyma infiltration, vas...

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Embryonic transcription factors have been involved in tumourigenesis. The transcription factor TBX1 regulates the embryonic parathyroid cells fate. Indeed, it has never been investigated in human adult parathyroids. Here, expression, function and regulation of the TBX1 gene were analyzed in adult normal and tumour parathyroid tissues. Immunohistochemistry identified 30–70% (mean±S.E.M, 52.0±7.3%) of cells expressing TBX1 at nuclear levels...

An embryonic gene signature has been suggested in parathyroid tumours. We investigated the expression of early embryonic stem cell (ESC) genes in parathyroid tumours. POU5F1/OCT4, SOX2 and NANOG transcripts were detected in almost all parathyroid adenomas (PAds; n=22) and atypical PAds (n=3), besides the variable expression of ESC genes KLF4, EGR1, and REX1/ZFP42. OCT4, SOX2 and NANOG proteins expression w...

Cancer cells and embryonic stem cells share many key biological properties and have common genetic signature: transcription factors regulating self-renewal and differentiation have been found expressed in human cancer cells. We focused our attention on TBX1, the gene involved in 22q11.2 microdeletion/DiGeorge syndrome, which is involved in heart, thymic and parathyroid cells differentiation.Real-time PCR, western blot and immunohistochemistry de...