RESUMO
This study aims to examine the expression profiles of the miR-183 cluster (miR-96/182/183) in pheochromocytoma. Pheochromocytoma tissues were prospectively collected from 50 patients with pheochromocytoma. Expression of miR-183 cluster members and SDHB protein expression were analyzed in these tissues by quantitative real-time polymerase chain reaction and immunohistochemistry, respectively. The expression of miR-183 cluster members in pheochromocytomas was correlated with the clinical and pathological parameters of these patients. The expression levels of miR-183 cluster members were predominantly downregulated or deleted in pheochromocytoma. Low expression or deletion of miR-96 was predominantly noted in younger patients with pheochromocytoma (<50 years, P=.01). Female patients in the study group showed marked deletion of miR-182 (P=.05). Deletion of the cluster was also associated with SDHB protein expression in pheochromocytoma. Moreover, patients with low miR-183 cluster expression had a slightly better survival rate when compared with patients with high expression. To conclude, the findings indicate a role for miR-183 cluster members in the pathogenesis and clinical progression of pheochromocytoma.
Assuntos
Neoplasias das Glândulas Suprarrenais/enzimologia , Neoplasias das Glândulas Suprarrenais/genética , Biomarcadores Tumorais , MicroRNAs/genética , Feocromocitoma/enzimologia , Feocromocitoma/genética , Succinato Desidrogenase/análise , Transcriptoma , Adolescente , Neoplasias das Glândulas Suprarrenais/mortalidade , Neoplasias das Glândulas Suprarrenais/patologia , Adulto , Idoso , Biomarcadores Tumorais/análise , Biomarcadores Tumorais/genética , Criança , Pré-Escolar , Regulação para Baixo , Feminino , Perfilação da Expressão Gênica/métodos , Regulação Neoplásica da Expressão Gênica , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Feocromocitoma/mortalidade , Feocromocitoma/patologia , Prognóstico , Estudos Prospectivos , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Adulto JovemRESUMO
AIMS: The goal of this pilot study was to develop a customized, cost-effective amplicon panel (Ampliseq) for target sequencing in a cohort of patients with sporadic phaeochromocytoma/paraganglioma. METHODS: Phaeochromocytoma/paragangliomas from 25 patients were analysed by targeted next-generation sequencing approach using an Ion Torrent PGM instrument. Primers for 15 target genes (NF1, RET, VHL, SDHA, SDHB, SDHC, SDHD, SDHAF2, TMEM127, MAX, MEN1, KIF1Bß, EPAS1, CDKN2 & PHD2) were designed using ion ampliseq designer. Ion Reporter software and Ingenuity® Variant Analysis™ software (www.ingenuity.com/variants) from Ingenuity Systems were used to analysis these results. RESULTS: Overall, 713 variants were identified. The variants identified from the Ion Reporter ranged from 64 to 161 per patient. Single nucleotide variants (SNV) were the most common. Further annotation with the help of Ingenuity variant analysis revealed 29 of these 713variants were deletions. Of these, six variants were non-pathogenic and four were likely to be pathogenic. The remaining 19 variants were of uncertain significance. The most frequently altered gene in the cohort was KIF1B followed by NF1. Novel KIF1B pathogenic variant c.3375+1G>A was identified. The mutation was noted in a patient with clinically confirmed neurofibromatosis. Chromosome 1 showed the presence of maximum number of variants. CONCLUSIONS: Use of targeted next-generation sequencing is a sensitive method for the detecting genetic changes in patients with phaeochromocytoma/paraganglioma. The precise detection of these genetic changes helps in understanding the pathogenesis of these tumours.