Project description:Pheochromocytomas and paragangliomas (PPGL) are rare neuroendocrine, usually benign tumors. Currently, for these neoplasms the only reliable criterion of malignancy is the presence of metastases. The aim of the present study was to identify molecular markers that can distinguish malignant from benign PPGL. An mRNA expression array was performed on 40 benign and 11 malignant PPGL. Genes showing a significantly different expression between benign and malignant PPGL with a ratio ? 4 were selected. Differentially expressed genes were confirmed by qRT-PCR and subsequently tested in an independent validation series (4 benign and 4 malignant) by qRT-PCR. Finally, immunohistochemistry was performed for the validated genes on Tissue Micro Arrays, which included 100 PPGL (87 benign and 13 malignant). Ten genes, which were significantly differentially expressed between benign and malignant tumors (False Discovery Rates <0.05), were selected from the mRNA expression array data. Differential expression of Interleukin 13 Receptor Alpha 2 and Contactin 4 was confirmed (p<0.05) and validated by qRT-PCR. However, at the protein level, only Contactin 4 appeared to be significantly overexpressed in malignant tumors (58% in malignant versus 17% in benign; p<0.05). No difference in the immunohistochemical staining for Interleukin 13 Receptor Alpha 2 was observed between benign and malignant PPGL. Contactin 4 expression appears to be associated with malignancy in pheochromocytomas and paragangliomas, and may be predictive of malignant behavior.
Project description:SNP profiles from 78 pheochromocytomas and paragangliomas were analyzed to detect copy number changes and LOH. 78 pheochromocytomas and paragangliomas were analyzed with Illumina Human610-Quad v1.0 BeadChips.
Project description:SNP profiles from 30 pheochromocytomas and paragangliomas were analyzed to detect identical-by-descent haplotypes, highlighting a founder mutation of SDHD in two samples. 30 pheochromocytomas and paragangliomas were analyzed with Illumina Human610-Quad v1.0 BeadChips.
Project description:SNP profiles from 30 pheochromocytomas and paragangliomas were analyzed to detect identical-by-descent haplotypes, highlighting a founder mutation of SDHD in two samples.
Project description:MicroRNAs are involved in the pathogenesis of several tumors, however, there have been no data on microRNA expression in pheochromocytomas to date. In this study we have performed microRNA expression profiling in sporadic benign, hereditary benign (multiplex endocrine neoplasia type 2-related and von Hippel-Lindau syndrome-related pheochromocytomas), and sporadic recurring adrenomedullary tumors. Due to the rarity of these neoplasms, the retrieval of sufficient quantities of fresh or immediately snap frozen tumor samples is difficult, therefore the applicability of formalin-fixed paraffin-embedded tissue samples for the analysis of microRNA expression in pheochromocytomas was examined.
