6 research outputs found
Recommended from our members
Systematic genomic and translational efficiency studies of uveal melanoma
To further our understanding of the somatic genetic basis of uveal melanoma, we sequenced the protein-coding regions of 52 primary tumors and 3 liver metastases together with paired normal DNA. Known recurrent mutations were identified in GNAQ, GNA11, BAP1, EIF1AX, and SF3B1. The role of mutated EIF1AX was tested using loss of function approaches including viability and translational efficiency assays. Knockdown of both wild type and mutant EIF1AX was lethal to uveal melanoma cells. We probed the function of N-terminal tail EIF1AX mutations by performing RNA sequencing of polysome-associated transcripts in cells expressing endogenous wild type or mutant EIF1AX. Ribosome occupancy of the global translational apparatus was sensitive to suppression of wild type but not mutant EIF1AX. Together, these studies suggest that cells expressing mutant EIF1AX may exhibit aberrant translational regulation, which may provide clonal selective advantage in the subset of uveal melanoma that harbors this mutation
EIF1AX-regulated growth and translation in uveal melanoma.
<p><b>(A)</b> Distribution of <i>EIF1AX</i> mutations observed in cohort of 52 uveal melanomas in comparison to other cancer types (as reported by <a href="http://www.tumorportal.org" target="_blank">http://www.tumorportal.org</a>). <b>(B)</b> <i>EIF1AX</i> wild type (WT) or mutant (MUT) uveal melanoma cells were infected with <i>EIF1AX</i> or control shRNAs and cell viability was determined after 6 days using MTS. Percent growth is relative to shLuc-expressing cells. Error bars represent SD of mean from 3 independent experiments. <b>(C)</b> Immunoblot analysis of EIF1AX protein levels in shRNA-expressing cells. <b>(D)</b> Polysome profiles of cell lines expressing shRNAs against <i>EIF1AX</i> and <i>Luciferase</i>.</p
Somatic mutations in primary and metastatic uveal melanoma.
<p><b>(A)</b> The number of synonymous and nonsynonymous mutations per megabase of DNA sequence for 52 samples, arranged in columns. <b>(B)</b> Mutations in recurrently mutated genes are color-coded and ordered by significance. <b>(C)</b> Boxplots represent the distributions of allelic fractions observed per sample where the thick line represents 25-75<sup>th</sup> percentile, and thin line 5-95<sup>th</sup>. <b>(D)</b> The percentage of tumor cells (CCF) harboring a given mutation in the primary tumor in comparison to a metastatic liver sample from the same patient (UM45). <b>(E)</b> As in (D), but comparing a pre-treatment metastatic tumor sample to a post-treatment metastasis (Trio 2).</p
Decreased EIF1AX expression impairs translation of protein synthesis machinery in wildtype, but not mutated setting.
<p><b>(A)</b> Principal component analysis depicts 4 color-coded clusters of 141 genes. <b>(B)</b> The trend in translational efficiency is depicted for each cluster in cells expressing control shRNAs (CN) or <i>EIF1AX</i> shRNAs (KD). Each line represents a different gene. Ribosomal protein genes are highlighted in red. Translational efficiency was calculated as polysome CPM / total CPM. <b>(C)</b> Boxplots demonstrate the distribution of the translational efficiencies of 78 ribosomal proteins in cells as in (B).</p