Immunohistochemical characterization of a steroid-secreting oncocytic adrenal carcinoma responsible for paraneoplastic hyperparathyroidism.

We report a unique case of a 44-year-old man with paraneoplastic hyperparathyroidism due to an oncocytic adrenocortical carcinoma (stage pT3N0R0M0, ENSAT 2 with a 4% Ki-67). Paraneoplastic hyperparathyroidism was associated with mild adrenocorticotropic hormone (ACTH)-independent hypercortisolism and increased estradiol secretion responsible for gynecomastia and hypogonadism. Biological investigations performed in blood samples from peripheral and adrenal veins revealed that the tumor secreted parathyroid hormone (PTH) and estradiol. Ectopic PTH secretion was confirmed by abnormally high expression of PTH mRNA and clusters of PTH immunoreactive cells in the tumor tissue. Double-immunochemistry studies and analysis of contiguous slides for the expression of PTH and steroidogenic markers (scavenger receptor class B type 1 [SRB1], 3ß-hydroxysteroid dehydrogenase [3ß-HSD], and aromatase) were performed. The results suggested the presence of two tumor cells subtypes with large cells with voluminous nuclei producing only PTH and that were distinct from steroid-producing cells.

Presentation, Management, and Outcomes of Urinary Bladder Paraganglioma: Results From a Multicenter Study.

CONTEXT: Urinary bladder paraganglioma (UBPGL) is rare. OBJECTIVE: We aimed to characterize the presentation and outcomes of patients diagnosed with UBPGL. METHODS: We conducted a multicenter study of consecutive patients with pathologically confirmed UBPGL evaluated between 1971 and 2021. Outcomes included repeat bladder surgery, metastases, and disease-specific mortality. RESULTS: Patients (n=110 total; n=56 [51%] women) were diagnosed with UBPGL at a median age of 50 years (interquartile range [IQR], 36-61 years). Median tumor size was 2 cm (IQR, 1-4 cm). UBPGL was diagnosed prior to biopsy in only 37 (34%), and only 69 (63%) patients had evaluation for catecholamine excess. In addition to the initial bladder surgery, 26 (25%) required multiple therapies, including repeat surgery in 10 (9%). Synchronous metastases were present in 9 (8%) patients, and 24 (22%) other patients with UBPGL developed metachronous metastases at a median of 4 years (IQR, 2-10 years) after the initial diagnosis. Development of metachronous metastases was associated with younger age (hazard ratio [HR] 0.97; 95% CI, 0.94-0.99), UBPGL size (HR 1.69; 95% CI, 1.31-2.17), and a higher degree of catecholamine excess (HR 5.48; 95% CI, 1.40-21.39). Disease-specific mortality was higher in patients with synchronous metastases (HR 20.80; 95% CI, 1.30-332.91). Choice of initial surgery, genetic association, sex, or presence of muscular involvement on pathology were not associated with development of metastases or mortality. CONCLUSIONS: Only a minority of patients were diagnosed before biopsy/surgery, reflecting need for better diagnostic strategies. All patients with UBPGL should have lifelong monitoring for development of recurrence and metastases.

Assessment of NORE1A as a putative tumor suppressor in human neuroblastoma.

The putative tumor suppressor NORE1A (RASSF5) is a member of the Ras association domain family and is commonly inactivated in human cancer. The closely related gene family member and functional collaborator RASSF1A is a bona fide tumor suppressor and is frequently involved in neuroblastoma. In the present study, we sought to investigate the role of NORE1A in human neuroblastoma. A panel of tumors (36 neuroblastomas and 4 ganglioneuromas) and neuroblastoma cell lines was assessed for NORE1A gene expression by Taqman quantitative RT-PCR. Promoter methylation was quantitatively determined by methylation sensitive pyrosequencing. The antitumourigenic role was functionally investigated in Nore1a transfected SK-N-BE (2) cells by fluorescent inhibition of caspase activity and BrdU incorporation assays. Neuroblastoma cells showed very low or absent NORE1A mRNA expression, which could not be reversed by trichostatin A or 5-aza-cytidine treatments. Neuroblastoma tumors showed suppressed NORE1A gene expression that was particularly pronounced in cases without MYCN amplification or 1p loss. Methylation of the NORE1A promoter was not observed in primary tumors and only one out of seven neuroblastoma cell lines displayed weak partial methylation. Transient expression of Nore1a resulted in enhanced apoptosis and delayed cell cycle progression. In conclusion NORE1A appears to be strongly suppressed in neuroblastic tumors and reconstitution of its expression diminishes the tumorigenic phenotype. Promotor methylation is not a common mechanism responsible for NORE1A transcriptional suppression in this tumor type.

Heterogeneous expression of SNARE proteins SNAP-23, SNAP-25, Syntaxin1 and VAMP in human parathyroid tissue.

In regulated exocytosis synaptosomal-associated protein of 25kDa (SNAP-25) is one of the key-players in the formation of SNARE (soluble N-ethylmaleimide-sensitive fusion attachment protein receptor) complex and membrane fusion. SNARE proteins are essentially expressed in neurons, neuroendocrine and endocrine cells. Whether parathyroid cells express these proteins is not known. In this study, we have examined the expression of the SNARE protein SNAP-25 and its cellular homologue SNAP-23, as well as syntaxin1 and VAMP (vesicle-associated membrane protein) in samples of normal parathyroid tissue, chief cell adenoma, and parathyroid carcinoma, using immunohistochemistry and Western blot analysis. SNAP-23 and VAMP were evenly expressed in all studied parathyroid tissues using immunohistochemistry and/or Western blot analysis. SNAP-25 (and Syntaxin1) was not expressed in normal parathyroid tissue, but in approximately 20% of chief cell adenomas, and in approximately 45% of parathyroid carcinoma samples. It is likely that the SNARE proteins SNAP-23 and VAMP play a role in the stimulus-secretion coupling and exocytosis of parathyroid hormone as these proteins were expressed in all of the parathyroid samples we studied. In particular, preferential expression of SNAP-23 rather than SNAP-25 provides an explanation of the high level of PTH secretion that occurs under conditions of low cytoplasmic free Ca(2+) concentration (around 0.1micromol/l). SNAP-25 (and Syntaxin1) appears to be a tumour-specific protein(s) in parathyroid tissues since its expression was restricted to pathological tissues.

Transcriptional profiling enables molecular classification of adrenocortical tumours.

OBJECTIVE: Tumours in the adrenocortex are common human tumours. Malignancy is however, rare, the yearly incidence being 0.5-2 per million inhabitants, but associated with a very aggressive behaviour. Adrenocortical tumours are often associated with altered hormone production with a variety of clinical symptoms. The aggressiveness of carcinomas together with the high frequency of adenomas calls for a deeper understanding of the underlying biological mechanisms and an improvement of the diagnostic possibilities. METHODS: Microarray gene expression analysis was performed in tumours of adrenocortex with emphasis on malignancy as well as hormonal activity. The sample set consisted of 17 adenomas, 11 carcinomas and 4 histological normal adrenocortexes. RNA from these was hybridised according to a reference design on microarrays harbouring 29 760 human cDNA clones. Confirmation was performed with quantitative real time-PCR and western blot analysis. RESULTS: Unsupervised clustering to reveal relationships between samples based on the entire gene expression profile resulted in two subclusters; carcinomas and non-cancer specimens. A large number of genes were accordingly found to be differentially expressed comparing carcinomas to adenomas. Among these were IGF2, FGFR1 and FGFR4 in growth factor signalling the most predominant and also the USP4, UBE2C and UFD1L in the ubiquitin-proteasome pathway. Moreover, two subgroups of carcinomas were identified with different survival outcome, suggesting that survival prediction can be made on the basis of gene expression profiles. Regarding adenomas with aldosterone overproduction, OSBP and VEGFB were among the most up-regulated genes compared with the other samples. CONCLUSIONS: Adrenocortical carcinomas are associated with a distinct molecular signature apparent in their gene expression profiles. Differentially expressed genes were identified associated with malignancy, survival as well as hormonal activity providing a resource of candidate genes for an exploration of possible drug targets and diagnostic and prognostic markers.

Allelic loss in clinically and screening-detected primary hyperparathyroidism.

OBJECTIVE: Parathyroid adenomas frequently harbour deletions of genomic DNA at chromosome regions 1p, 6q and 11q. In this study we related clinical characteristics in 56 patients with primary hyperparathyroidism (pHPT) to loss of heterozygosity (LOH) in these chromosome regions. DESIGN: LOH analysis was performed on 56 sporadic parathyroid tumours using a total of 18 microsatellite markers for chromosome regions 1p, 6q and 11q. LOH was identified, for either radioactive or fluorescent labelled markers, as total absence or reduction of > or = 50% of the signal intensity of an allele in the tumour DNA vs. constitutional DNA. PATIENTS: Twenty-one of the patients were recruited by a population-based screening for pHPT and the remaining pHPT patients were gathered from routine clinical practice. RESULTS: In total, 27%, 23% and 23% of the tumours showed LOH at 1p, 6q and 11q, respectively. LOH at both 1p and 11q was more common in the screening-detected pHPT patients compared to those recruited from clinical practice (38% vs. 20%; P = 0.02 and 43% vs. 11%; P = 0.001, respectively), while allelic loss at 6q was more prevalent in the latter group (11% vs. 31%; P = 0.001). No apparent relationships between LOH at 1p, 6q, and 11q and clinical characteristics, such as glandular weight, serum levels of PTH or calcium, were demonstrated. Moreover, additional LOH analysis of chromosome 1p suggested a putative parathyroid tumour suppressor gene(s) in the region between markers DS214 and D1S503, spanning approximately 6 cM. CONCLUSION: A high frequency of LOH at 1p and 11q in tumours of screening-detected pHPT patients is intriguing, and may suggest that inactivation of known (the MEN1 gene) and putative tumour suppressor genes at these chromosomal regions is associated with a more benign disease.