Autocrine parathyroid hormone-like hormone promotes intrahepatic cholangiocarcinoma cell proliferation via increased ERK/JNK-ATF2-cyclinD1 signaling.

BACKGROUND AND AIMS: Intrahepatic cholangiocarcinoma (ICC) is an aggressive tumor with a high fatality rate. It was recently found that parathyroid hormone-like hormone (PTHLH) was frequently overexpressed in ICC compared with non-tumor tissue. This study aimed to elucidate the underlying mechanisms of PTHLH in ICC development. METHODS: The CCK-8 assay, colony formation assays, flow cytometry and a xenograft model were used to examine the role of PTHLH in ICC cells proliferation. Immunohistochemistry (IHC) and western blot assays were used to detect target proteins. Luciferase reporter, chromatin immunoprecipitation (ChIP) and DNA pull-down assays were used to verify the transcription regulation of activating transcription factor-2 (ATF2). RESULTS: PTHLH was significantly upregulated in ICC compared with adjacent and normal tissues. Upregulation of PTHLH indicated a poor pathological differentiation and intrahepatic metastasis. Functional study demonstrated that PTHLH silencing markedly suppressed ICC cells growth, while specific overexpression of PTHLH has the opposite effect. Mechanistically, secreted PTHLH could promote ICC cell growth by activating extracellular signal-related kinase (ERK) and c-Jun N-terminal kinase (JNK) signaling pathways, and subsequently upregulated ATF2 and cyclinD1 expression. Further study found that the promoter activity of PTHLH were negatively regulated by ATF2, indicating that a negative feedback loop exists. CONCLUSIONS: Our findings demonstrated that the ICC-secreted PTHLH plays a characteristic growth-promoting role through activating the canonical ERK/JNK-ATF2-cyclinD1 signaling pathways in ICC development. We identified a negative feedback loop formed by ATF2 and PTHLH. In this study, we explored the therapeutic implication for ICC patients.

An update on novel mechanisms of primary aldosteronism.

Primary aldosteronism (PA) is the most common and curable form of secondary hypertension. It is caused in the majority of cases by either unilateral aldosterone overproduction due to an aldosterone-producing adenoma (APA) or by bilateral adrenal hyperplasia. Recent advances in genome technology have allowed researchers to unravel part of the genetic abnormalities underlying the development of APA and familial hyperaldosteronism. Recurrent somatic mutations in genes coding for ion channels (KCNJ5 and CACNA1D) and ATPases (ATP1A1 and ATP2B3) regulating intracellular ionic homeostasis and cell membrane potential have been identified in APA. Similar germline mutations of KCNJ5 were identified in a severe familial form of PA, familial hyperaldosteronism type 3 (FH3), whereas de novo germline CACNA1D mutations were found in two cases of hyperaldosteronism associated with a complex neurological disorder. These results have allowed a pathophysiological model of APA development to be established. This model involves modifications in intracellular ionic homeostasis and membrane potential, accounting for ∼50% of all tumors, associated with specific gender differences and severity of PA. In this review, we describe the different genetic abnormalities associated with PA and discuss the mechanisms whereby they lead to increased aldosterone production and cell proliferation. We also address some of the foreseeable consequences that genetic knowledge may contribute to improve diagnosis and patient care.

Lower expression of the TWIK-related acid-sensitive K+ channel 2 (TASK-2) gene is a hallmark of aldosterone-producing adenoma causing human primary aldosteronism.

CONTEXT: The molecular mechanisms of primary aldosteronism, a common cause of human hypertension, are unknown, but alterations of K(+) channels can play a key role. OBJECTIVE: The objective of the study was to investigate the following: 1) the expression of the Twik-related acid-sensitive K(+) channels (TASK) in aldosterone producing adenomas (APAs); 2) the role of TASK-2 in aldosterone synthesis; and 3) the determinants of TASK-2-blunted expression in APAs. DESIGN: We analyzed the transcriptome and the microRNA profiles of 32 consecutive APAs and investigated the protein expression and localization of TASK-2 in APA and adrenocortical cell lines (H295R and HAC15) using immunoblotting and confocal microscopy. The functional effect of TASK-2 blunted activity caused by a dominant-negative mutation on steroidogenic enzymes, and aldosterone production was also assessed. TASK-2 regulation by selected microRNA was studied by a luciferase assay. RESULTS: TASK-2 was consistently less expressed at the transcript and protein levels in APAs than in the normal human adrenal cortex. H295R cell transfection with a TASK-2 dominant-negative mutant construct significantly increased the aldosterone production by 153% and the gene expression of aldosterone synthase (CYP11B2, gene expression fold change 3.1 vs control, P < .05) and the steroidogenic acute regulatory protein (gene expression fold change 1.8 vs control, P < .05). Two microRNAs, hsa-miR-23 and hsa-miR-34, were found to decrease the TASK-2 expression by binding to the 3' untranslated region of the TASK-2 gene. CONCLUSIONS: The TASK-2 channel lower expression represents a hallmark of APA and is associated with a higher expression of hsa-miR-23 and hsa-miR-34. The ensuing blunted TASK-2 activity increased the production of aldosterone in vitro and the expression of steroidogenic acute regulatory protein and CYP11B2. Hence, the lower expression of TASK-2 channel in APA cells can explain high aldosterone secretion in human primary aldosteronism despite the suppression of angiotensin II, hypertension, and hypokalemia.

Actualización diagnóstica y terapéutica de los tumores neuroendocrinos bien diferenciados / Updates on well-differentiated neuroendocrine tumors

Los tumores neuroendocrinos bien diferenciados (TNE) son neoplasias malignas poco frecuentes que incluyen tanto los carcinoides como los tumores neuroendocrinos pancreáticos (TNEP). Estos tumores se asocian en general con metástasis en el momento del diagnóstico. Si bien la supervivencia prolongada es frecuente, la supervivencia global se reduce de manera acentuada cuando los pacientes presentan síntomas, así como cuando el tumor progresa pese a la terapia con análogos de la somatostatina. Aunque estos fármacos pueden contribuir a tratar la sintomatología y ralentizar el crecimiento tumoral, en especial en neoplasias de bajo grado, no se ha demostrado que el tratamiento a largo plazo sea eficaz en estos pacientes. Recientemente, los ensayos preclínicos y dos estudios de fase III han brindado avances promisorios, sobre todo en el tratamiento de los TNEP. La aparición de terapias dirigidas contra el factor de crecimiento vascular endotelial (VEGF), los inhibidores de la diana de la rapamicina (mTOR) y el tratamiento con receptores de péptidos radiomarcados se ha asociado con eficacia moderada, pero pueden vincularse con toxicidad relevante. En esta revisión, discutiremos los ensayos recientes y las terapias actuales de los TNE bien diferenciados.

Actualización diagnóstica y terapéutica de los tumores neuroendocrinos bien diferenciados / Updates on well-differentiated neuroendocrine tumors

Los tumores neuroendocrinos bien diferenciados (TNE) son neoplasias malignas poco frecuentes que incluyen tanto los carcinoides como los tumores neuroendocrinos pancreáticos (TNEP). Estos tumores se asocian en general con metástasis en el momento del diagnóstico. Si bien la supervivencia prolongada es frecuente, la supervivencia global se reduce de manera acentuada cuando los pacientes presentan síntomas, así como cuando el tumor progresa pese a la terapia con análogos de la somatostatina. Aunque estos fármacos pueden contribuir a tratar la sintomatología y ralentizar el crecimiento tumoral, en especial en neoplasias de bajo grado, no se ha demostrado que el tratamiento a largo plazo sea eficaz en estos pacientes. Recientemente, los ensayos preclínicos y dos estudios de fase III han brindado avances promisorios, sobre todo en el tratamiento de los TNEP. La aparición de terapias dirigidas contra el factor de crecimiento vascular endotelial (VEGF), los inhibidores de la diana de la rapamicina (mTOR) y el tratamiento con receptores de péptidos radiomarcados se ha asociado con eficacia moderada, pero pueden vincularse con toxicidad relevante. En esta revisión, discutiremos los ensayos recientes y las terapias actuales de los TNE bien diferenciados.(AU)

Guanosine nucleotides inhibit different syndromes of PTHrP excess caused by human cancers in vivo.

There are two well-described syndromes caused by tumor production of parathyroid hormone-related peptide (PTHrP), namely osteolytic bone disease associated with breast cancer and humoral hypercalcemia of malignancy (HHM) that occurs with or without bone metastasis. Both syndromes have been shown experimentally to be inhibited by neutralizing antibodies to PTHrP. In a search for small-molecule inhibitors of PTHrP production or effects, we have identified guanine-nucleotide analogs as compounds that inhibit PTHrP expression by human tumor cells associated with these syndromes. We show in nude athymic murine models that these compounds reduce PTHrP-mediated osteolytic lesions associated with metastatic human breast-cancer cells as well as the degree of hypercalcemia caused by excessive PTHrP production by a squamous-cell carcinoma of the lung. These results suggest that the PTHrP gene promoter may be a suitable target for treating the skeletal effects of malignancy.

Analysis of numerical chromosomal aberrations in adrenal cortical neoplasms by fluorescence in situ hybridization.

PURPOSE: We identified numerical chromosomal aberrations in adrenal cortical neoplasms using interphase fluorescence in situ hybridization (FISH) and correlated these aberrations with DNA ploidy and endocrine dysfunction. MATERIALS AND METHODS: Our study included 25 adenomas and 2 carcinomas associated with primary aldosteronism or Cushing's syndrome. Eight normal adrenal tissue samples served as controls. Isolated nuclei from frozen samples were used for FISH and formalin fixed, paraffin embedded tissues from the same materials were analyzed by flow cytometry for DNA ploidy. For FISH we used centromere specific probes for chromosomes 3, 7, 8, 11 and 12. RESULTS: None of the normal adrenal tissues had any numerical chromosomal aberrations in any chromosome analyzed or any abnormal findings on DNA ploidy analysis. Tetrasomy of chromosomes 3, 7, 8, 11 and 12 was detected in 8, 13, 14, 11 and 12 of the 17 adenomas associated with primary aldosteronism, and in 2, 0, 0, 0 and 0 of the 8 associated with Cushing's syndrome, respectively. DNA flow cytometry revealed tetraploidy in 11 of the 17 cases of primary aldosteronism and in 1 of the 8 of Cushing's syndrome. Five diploid adenomas associated with primary aldosteronism also showed tetrasomy in 2 or more chromosomes. One of the 2 carcinomas showed aneuploidy and aneusomy of chromosomes 8, 11 and 12 but the other showed no abnormal peaks on DNA histography and no numerical chromosomal aberrations. CONCLUSIONS: All chromosomes analyzed in adenomas associated with primary aldosteronism frequently showed tetrasomy, whereas few chromosomal abnormalities were detected in adenomas associated with Cushing's syndrome. Our results indicate that DNA tetraploidy is common in adrenal cortical adenomas associated with primary aldosteronism. Interphase FISH strongly supported flow cytometry findings and could provide further information on individual chromosomes.

[Manifestation of Cushing syndrome and osteoporotic fractures in pregnancy in a patient with Carney complex]. / Manifestation eines Cushing-Syndroms und osteoporotischer Frakturen in der Schwangerschaft einer Patientin mit Carney-Komplex.

HISTORY AND CLINICAL FINDINGS: In a 31-year-old patient a conventional X-ray was performed due to persistent pain at the lumbar spine level after a cesarean section. It revealed compression fractures of L2 and L3. Besides very clear clinical signs of hypercortisolism, multiple hyperpigmentations and naevi in the patient's face including the lips and the conjunctiva of the right eye were visible, suggesting a Carney complex. INVESTIGATIONS: Insuppressible cortisol levels confirmed an adrenal origin of hypercortisolism. A selective catheterization of adrenal veins supported the presence of bilateral adrenal cortisol production. The computed tomography showed nodular lesions in the right and a hyperplasia of the left adrenal gland. TREATMENT AND COURSE: A bilateral adrenalectomy was performed and a primary pigmented nodular adrenal hyperplasia was confirmed histologically. Clinical signs of hypercortisolism rapidly resolved after adrenalectomy. CONCLUSIONS: The diagnosis of Cushing's syndrome as a part of Carney complex was diagnosed at the end of a pregnancy although signs of hypercortisolism were present a long time before. The rare diagnosis of Carney complex should be considered in patients exhibiting symptoms of hypercortisolim and the typical clinical signs (hyperpigmentations).

[Genetic aspects of primary hyperparathyroidism]. / Aspekty genetyczne pierwotnej nadczynnosci przytarczyc.

The results of the last decade genetic research in the field of oncogenesis of sporadic and familiar parathyroid tumors are summarised. The review of studied focuses on two main topics: multiple endocrine neoplasis syndromes as well as sporadic parathyroid adenomas and carcinomas. The current knowledge of genetic factors associated with the development of these lesions is presented.

[Molecular biology of incidentally diagnosed adrenal gland space-occupying lesion]. / Molekularbiologie der zufällig diagnostizierten Nebennierenraumforderung.

The incidentally detected adrenal mass is with a prevalence of 1% in the general population the most common pathological process of the adrenal gland. In more than 85% of the cases it is caused by benign adenomas of the adrenal cortex. These tumors have a monoclonal composition and are, therefore, caused by oncogenic mutations with consecutive clonal expansion of this cell clone. In contrast to adrenocortical carcinoma, in which mutations of the IGF II gene locus and the p53 tumor suppressor gene has been found, the oncogenes involved in the tumorigenesis of adrenal adenomas have not been identified yet. However, opposite to other endocrine tumors the receptor-cAMP-proteinkinase A signaling pathway is not involved in the pathogenesis of these tumors. Insulin may be an important growth factor of incidentally detected adrenal tumors. Heterozygote 21-hydroxylase deficiency, however, does not seem to play a major role in the tumorigenesis of adrenal incidentalomas.

Peptide receptors in gut endocrine tumours.

A great number of gut endocrine tumours show high expression of receptors for neuropeptides, such as SRIF and VIP. The expression of ssts is essential for the control of hormonal hypersecretion and tumour growth by octapeptide somatostatin analogues. Five different sst subtypes, named sst1-5, have been cloned and characterized. The therapeutic efficacy of the octapeptide analogues is determined by the expression of sst2 (sst3) and sst5 on the tumour. In general, there is a predominant expression of sst1 and sst2 mRNA in gut endocrine tumours. In vivo sst scintigraphy, after injection of [111In]pentetreotide, provides a useful tool for the diagnostic work-up of patients with these tumours. This technique can be used for the localization of the primary tumour(s), for the determination of the extent of metastatic spread and for the selection of potential candidates for therapy with (radiolabelled) octapeptide analogues. Differentiated gut endocrine tumours also show a high expression of VIP-Rs. However, undifferentiated tumours show VIP-R expression to a smaller degree. In vivo scintigraphy with 123I-labelled VIP is a sensitive technique for the in vivo identification of gut endocrine tumours and their metastases. The functional role of the tumoral VIP-Rs is still unclear and at present there are no known therapeutic applications for VIP-R agonists or antagonists in humans.

Expression in human lung cancer cell lines of genes of prohormone processing and the neuroendocrine phenotype.

Lung tumor cells and cell lines, principally the histologically classified small cell lung cancer, are characterized by the expression of neuroendocrine (NE) features including AADC (aromatic amino acid decarboxylase, previously called DOPA decarboxylase) and the production of many peptide hormones. The general mechanisms by which most aspects of the NE phenotype affect the clinical behavior of lung tumor cells are unknown, but it is well recognized that peptide hormones can have systemic effects (paraneoplastic syndromes) and several have been shown to be autocrine growth factors for cancer cells. In order to determine the relationship between expression of different aspects of the NE phenotype in lung cancer cell lines, we have compared expression of a gene required for biosynthesis of some active peptide hormones (PAM, peptidylglycine alpha-amidating monooxygenase) to the gene for AADC in 32 lung cancer cell lines. Expression of these genes was quantified by both steady state Northern blot analysis and radiochemical enzymatic activity measurements. To ensure a range of expression of NE markers, non-small cell lung cancer (NSCLC) cell lines were chosen to include several which had previously been shown to express NE markers, and several small cell lung cancer (SCLC) cell lines with previous low levels of AADC were included. PAM enzyme activity and Northern blot analysis showed a two to three log variation in levels of expression in both the small cell and non-small cell lines. A smaller range was found for AADC expression. Using the highly sensitive PAM enzyme assays, all cell lines were found to express detectable PAM. PAM activities were secreted into the growth medium of all cell lines. There was no simple correlation apparent between AADC and PAM gene expression in the lung cancer cell lines. However, classic small cell lines demonstrated high levels of expression of both PAM and AADC genes, as did the carcinoid subset of the NSCLC lines. NSCLC lines expressed levels of PAM mRNA and enzyme activities equivalent to those of SCLC but had infrequent expression of AADC (principally only carcinoid NSCLC expressed AADC). These data demonstrate that separate aspects of the NE phenotype can be differentially expressed in lung cancer histological sub-types. Expression of PAM enzymes in all sub-types of lung cancer suggests that peptide prohormone activation may be a common mechanism for autocrine growth stimulation even in non-Ne NSCLC cell lines, or may reflect maintenance in cell lines of a common pathway of lung tumor promotion.

Molecular biological research in pituitary adenomas from the pathologists' view.

Some recent findings related to pituitary adenoma pathology achieved by molecular biological methods are briefly reviewed. It is increasingly obvious that the application of the molecular pathology approach can provide a deeper insight into the causation, histogenesis, cellular derivation and differentiation as well as progression of pituitary adenomas and can help to understand better structure-function correlations.

The value of cytometric DNA analysis as a prognostic tool in neuroendocrine neoplastic diseases.

In several traditionally non-endocrine, common, human, neoplastic diseases, it has become well established during the last few years, that cytometric analyses of the DNA distribution pattern of the nuclei of tumour cells can be an excellent supplement to the conventional prognostic tools, (such as clinical staging and histopathologic malignancy assessments). When analogous studies of the value of DNA analysis by means of flow cytometry and/or image cytometry are made in neuroendocrine (NE) neoplastic diseases, the ensuing results often become rather disappointing. Thus, clear-cut aneuploid DNA histograms can be found in the neoplastic cell nuclei of clinically and histopathologically completely benign NE adenomas (and even hyperplastic nodules). In contrast, highly aggressive NE carcinomas not seldom reveal themselves to be composed of tumour cells with nuclei, displaying an euploid, i.e. normal, DNA pattern. Statements of this kind have been based on the results of comprehensive investigations in several laboratories, analysing such NE tumours as insulomas/insular carcinomas, bronchial/gastrointestinal carcinoids, phaeochromocytomas, paragangliomas, neuroblastomas, adenomas of the anterior pituitary gland, parathyroid adenomas, medullary carcinoma of the thyroid and Merkel-cell tumours of the skin. Thus, the prognostic value of the cytometric DNA ploidy pattern of the nuclei of neoplastic parenchymal cells is definitely lower in NE tumours than in most of the traditionally non-endocrine carcinomas and sarcomas. Data from published and unpublished series of these kinds of NE tumours, and those of prostatic and breast carcinomas with NE differentiation, are given. By means of a new, consecutive double staining technique, it was shown that in idiopathic nesidioblastosis, the hyperinsulinism is caused by beta cells with a nuclear DNA ploidy pattern of euploid type. By the same technique, it can be shown that in the pathogenesis of the hypergastrinaemia-induced ECL-cell carcinoids of the stomach, a switch from an euploid to an aneuploid nuclear DNA distribution pattern occurs in the ECL-cells when they pass from a state of hyperplasia to that of a genuine neoplasia. In neuroblastomas, a triploid (i.e. aneuploid) DNA pattern is part of an algorithm capable of predicting a 96% survival rate, whereas a diploid/tetraploid (i.e. euploid) DNA pattern predicts a 0% survival.

Familial non-multiple endocrine neoplasia medullary thyroid carcinoma: report of a case confirming a new clinical entity in Japan.

Most hereditary medullary thyroid carcinomas (MTC) occur in association with multiple endocrine neoplasia (MEN) type 2 syndromes. Since Farndon et al. reported two kindreds, that is collections of relatives, with familial non-MEN MTC in 1986, only five kindreds with this disorder have been reported in the English literature. In this paper, we describe a rare Japanese kindred with familial non-MEN MTC, confirming the existence of this distinct clinical entity in Japan. A 42-year-old woman underwent a left hemithyroidectomy with modified neck dissection (MND) under a diagnosis of sporadic MTC at 28 years of age. She developed lymph node metastasis in the right neck region 7 years after the initial surgery, and underwent MND and right hemithyroidectomy. Although no findings of MTC were histologically confirmed in the resected right thyroid lobe, C-cell hyperplasia was observed. Hereditary MTC was strongly suspected, but we could not confirm specific manifestations associated with MEN type 2 in any family members. However, 7 years later, a paternal aunt and cousin were diagnosed with MTC. Other family members were evaluated by ultrasonography and calcium-pentagastrin provocation testing, and three additional patients with MTC across two generations were found. None of these patients had any extrathyroidal manifestations associated with MEN type 2, and the entity of familial non-MEN MTC was confirmed.

Chromosomal aberrations in two adrenocortical tumors, one with a rearrangement at 11p15.

Adrenocortical tumors are detected with increasing frequency, but symptomatic cases with excessive hormone production are rare. We investigated cytogenetically one benign aldosterone-producing tumor (Conn Syndrome)(case 1) and one malignant cortisol-producing tumor (Cushing Syndrome)(case 2). Radioimmunoassay of cell culture supernatant of case 2 detected cortisol secretion during 2 months in culture. Flow cytometry of spill-out cells from case 2 showed a bimodal pattern (DNA Index 1.0, 1.4). Case 1 revealed a marker chromosome in 4/25 cells analyzed; the marker was a long acrocentric partially derived from chromosome 2,der(2q). In case 2, a cytogenetic harvest was achieved after prolonged culture time (6 weeks) and a marker chromosome, add(11)(p15), was detected in 16/22 cells. A breakpoint of 11p13, as well as loss of heterozygosity of alleles on 11p15, has been reported in the literature for other malignant adrenocortical cancers.