Malignant pheochromocytomas/paragangliomas harbor mutations in transport and cell adhesion genes.
Journal article, 2016

One out of ten patients with pheochromocytoma (PCC) and paraganglioma (PGL) develop malignant disease. Today there are no reliable pathological methods to predict malignancy at the time of diagnosis. Tumors harboring mutations in the succinate dehydrogenase subunit B (SDHB) gene often metastasize but the sequential genetic events resulting in malignant progression are not fully understood. The aim of this study was to identify somatic mutations that contribute to the malignant transformation of PCC/PGL. We performed pair-wise (tumor-normal) whole-exome sequencing to analyze the somatic mutational landscape in five malignant and four benign primary PCC/sympathetic PGL (sPGL), including two biological replicates from each specimen. In total, 225 unique somatic mutations were identified in 215 genes, with an average mutation rate of 0.54 mutations/megabase. Malignant tumors had a significantly higher number of mutations compared to benign tumors (p < 0.001). Three novel genes were identified as recurrently mutated; MYCN, MYO5B and VCL, and mutations in these genes were exclusively found in malignant sPGL tumors. Mutations in the MYO5B gene could be verified in two publicly available data sets. A gene ontology analysis of mutated genes showed enrichment of cellular functions related to cytoskeletal protein binding, myosin complex and motor activity, many of which had functions in Rab and Rac/Rho GTPase pathways. In conclusion, we have identified recurrent mutations in genes related to intracellular transport and cell adhesion, and we have confirmed MYO5B to be recurrently mutated in PCC/PGL cases with malignant potential. Our study suggests that deregulated Rab and Rac/Rho pathways may be important in PCC/PGL tumorigenesis.

massively parallel sequencing

HRAS

neuroendocrine tumor

Author

Annica Wilzén

University of Gothenburg

Anna Rehammar

Chalmers, Mathematical Sciences, Mathematical Statistics

University of Gothenburg

Andreas Muth

University of Gothenburg

Ola Nilsson

University of Gothenburg

Tajana Tešan Tomić

University of Gothenburg

Bo Wängberg

University of Gothenburg

Erik Kristiansson

University of Gothenburg

Chalmers, Mathematical Sciences, Mathematical Statistics

Frida Abel

University of Gothenburg

International Journal of Cancer

0020-7136 (ISSN) 1097-0215 (eISSN)

Vol. 138 9 2201-11

Subject Categories

Surgery

DOI

10.1002/ijc.29957

PubMed

26650627

More information

Created

10/8/2017