Histological features and expression of enzymes implicated in melatonin synthesis in pineal parenchymal tumours and in cultured tumoural pineal cells
| Autor: | C. Brisson, Alexandru Szathmari, François Fauchon, B. Claustrat, A. Reboul, Anne Jouvet, Michelle Fèvre-Montange, C. Mottolese, Jacques Champier |
|---|---|
| Rok vydání: | 2008 |
| Předmět: |
Acetylserotonin O-Methyltransferase
Adult Male endocrine system medicine.medical_specialty Histology AANAT Tryptophan Hydroxylase Biology Arylalkylamine N-Acetyltransferase Pineal Gland Pathology and Forensic Medicine Pinealocyte Proto-Oncogene Proteins c-myc Melatonin Pineal gland Physiology (medical) Internal medicine medicine Humans RNA Messenger Child Cells Cultured Aged Brain Neoplasms Reverse Transcriptase Polymerase Chain Reaction Infant Middle Aged Tryptophan hydroxylase Immunohistochemistry Endocrinology medicine.anatomical_structure Neurology Cell culture Child Preschool Arylalkylamine Female Neurology (clinical) Pinealoma hormones hormone substitutes and hormone antagonists medicine.drug Endocrine gland |
| Zdroj: | Neuropathology and Applied Neurobiology. 34:296-305 |
| ISSN: | 1365-2990 0305-1846 |
| DOI: | 10.1111/j.1365-2990.2007.00891.x |
| Popis: | Pineal parenchymal tumours (PPT) are rare neoplasms and there have been few in vitro studies. Their capacity for synthesizing and secreting melatonin has been only partially examined. We investigated the presence of messenger RNA (mRNA) encoding tryptophan hydroxylase (TPH), arylalkylamine N-acetyltransferase (AANAT), hydroxyindol-O-methyltransferase (HIOMT), three enzymes involved in melatonin synthesis, and c-myc, a tumoural marker, in 10 PPT, one papillary tumour of the pineal region (PTPR), cell cultures derived from four PPTs and from three other tumours of the pineal region, and in normal pineal gland. Moreover, protein expression of TPH was investigated in three PPT and PTPR. Quantitative real-time reverse transcriptase-polymerase chain reaction and immunohistochemistry were used and the melatonin production by tumoural cells in vitro was analysed by radioimmunoassay. We showed that all the tumoural tissues and cells contained c-myc mRNA. mRNAs encoding TPH, AANAT and HIOMT were detected in all PPT, suggesting that tumour cells can synthesize melatonin. Only PPT expressed TPH protein. Cultured cells lost expression of transcripts throughout passages even if ultrastructural study revealed the presence of characteristic organelles in these tumoural cells. Nevertheless, the basal secretion of melatonin observed in one PPT culture is in favour of a maintained melatonin production and secretion by tumoural pinealocytes, but melatonin production was not stimulated by a beta noradrenergic agonist. Moreover, PTPR never expressed mRNA encoding TPH, AANAT and HIOMT. Our results may contribute to a better understanding of the biology of PTT and PTPR and may help to the diagnosis of these rare tumours. |
| Databáze: | OpenAIRE |
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