Journal Article

MYO5B mutations in pheochromocytoma/paraganglioma promote cancer progression

Nilsson, Staffan, Ejeskär, Katarina, Abel, Frida, Muth, Andreas, Tomić, Tajana Tešan, Rehammar, Anna, Kristiansson, Erik, Olausson, Josefin, Deland, Lily, Wassén, Ola Nilsson

2020

Overview

Identification of additional cancer-associated genes and secondary mutations driving the metastatic progression in pheochromocytoma and paraganglioma (PPGL) is important for subtyping, and may provide optimization of therapeutic regimens. We recently reported novel recurrent nonsynonymous mutations in the MYO5B gene in metastatic PPGL. Here, we explored the functional impact of these MYO5B mutations, and analyzed MYO5B expression in primary PPGL tumor cases in relation to mutation status. Immunohistochemistry and mRNA expression analysis in 30 PPGL tumors revealed an increased MYO5B expression in metastatic compared to non-metastatic cases. In addition, subcellular localization of MYO5B protein was altered from cytoplasmic to membranous in some metastatic tumors, and the strongest and most abnormal expression pattern was observed in a paraganglioma harboring a somatic MYO5B:p.G1611S mutation. In addition to five previously discovered MYO5B mutations, the present study of 30 PPGL (8 previous and 22 new samples) also revealed two, and hence recurrent, mutations in the gene paralog MYO5A. The three MYO5B missense mutations with the highest prediction scores (p.L587P, p.G1611S and p.R1641C) were selected and functionally validated using site directed mutagenesis and stable transfection into human neuroblastoma cells (SK-N-AS) and embryonic kidney cells (HEK293). In vitro analysis showed a significant increased proliferation rate in all three MYO5B mutated clones. The two somatically derived mutations, p.L587P and p.G1611S, were also found to increase the migration rate. Expression analysis of MYO5B mutants compared to wild type clones, demonstrated a significant enrichment of genes involved in migration, proliferation, cell adhesion, glucose metabolism, and cellular homeostasis. Our study validates the functional role of novel MYO5B mutations in proliferation and migration, and suggest the MYO5-pathway to be involved in the malignant progression in some PPGL tumors.

• Publisher: Public Library of Science,Public Library of Science (PLoS)
• Subject: adrenal-gland / Binding sites / Biology and Life Sciences / cancer growth / Cancer metastasis / Cancer research / Cell adhesion / Cell migration / Cell proliferation / cell-metabolism / cellular homeostasis / clinical-experience / Colorectal cancer / controlled study / Development and progression / expression / female / Funding / gene / Gene expression / Gene mutation / Genes / Genetic aspects / Genetic disorders / Genetics & Heredity / Glucose metabolism / growth-factor / HEK293 cell line / Homeostasis / human / human cell / human tissue / Immunohistochemistry / in vitro study / Kinases / Localization / major clinical study / male / malignant pheochromocytoma / Medical Genetics and Genomics / Medicine / Medicine and Health Sciences / Medicinsk genetik och genomik / Metastases / Metastasis / metformin / microvillus inclusion disease / Missense mutation / Mutation / MYO5A gene / MYO5B gene / myosin Va / myosin vb / Neuroblastoma / Neuroblastoma cells / Neuroblasts / Neuroendocrine tumors / Neurological disorders / Paraganglioma / paralogy / pathogenicity / Pathology / Pheochromocytoma / protein localization / Proteins / Public health / Research and Analysis Methods / Site-directed mutagenesis / SK-N-AS cell line / Software / somatic mutation / stable transfection / Surgery / Transfection / Translational Medicine TRIM / Translationell medicin TRIM / tumor gene / Tumors