Wild-type U2AF1 antagonizes the splicing program characteristic of U2AF1-mutant tumors and is required for cell survival
| Autor: | Harold E. Varmus, Jovian Yu, Sameer Prasad, Robert K. Bradley, Hayley Motowski, Dennis Liang Fei, Rakesh Chatrikhi, Clara L. Kielkopf, Shaojian Gao |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2016 |
| Předmět: |
0301 basic medicine
Cancer Research Lung Neoplasms RNA splicing Mutant Exonic splicing enhancer QH426-470 medicine.disease_cause Biochemistry Lung and Intrathoracic Tumors Mice 0302 clinical medicine Mutant protein Adenocarcinomas Splicing Factor U2AF Medicine and Health Sciences Genetics (clinical) 0303 health sciences Mutation Splice site mutation Adenocarcinoma of the Lung Messenger RNA Genomics Cell biology 3. Good health Nucleic acids Gene Expression Regulation Neoplastic Oncology 030220 oncology & carcinogenesis Sequence Analysis Transcriptome Analysis Research Article Cell Survival Adenocarcinoma of Lung Adenocarcinoma Biology Research and Analysis Methods Carcinomas 03 medical and health sciences Splicing factor Sequence Motif Analysis Cell Line Tumor medicine Genetics Animals Humans RNA Messenger Nucleotide Motifs Molecular Biology Techniques Sequencing Techniques Gene Molecular Biology Ecology Evolution Behavior and Systematics Cell Proliferation 030304 developmental biology Biology and life sciences Alternative splicing Wild type Computational Biology Cancers and Neoplasms Genome Analysis Xenograft Model Antitumor Assays Molecular biology Alternative Splicing 030104 developmental biology RNA processing RNA Mutant Proteins Gene expression Transcriptome Cloning |
| Zdroj: | PLoS Genetics, Vol 12, Iss 10, p e1006384 (2016) PLoS Genetics |
| DOI: | 10.1101/048553 |
| Popis: | We have asked how the common S34F mutation in the splicing factor U2AF1 regulates alternative splicing in lung cancer, and why wild-type U2AF1 is retained in cancers with this mutation. A human lung epithelial cell line was genetically modified so that U2AF1S34F is expressed from one of the two endogenous U2AF1 loci. By altering levels of mutant or wild-type U2AF1 in this cell line and by analyzing published data on human lung adenocarcinomas, we show that S34F-associated changes in alternative splicing are proportional to the ratio of S34F:wild-type gene products and not to absolute levels of either the mutant or wild-type factor. Preferential recognition of specific 3′ splice sites in S34F-expressing cells is largely explained by differential in vitro RNA-binding affinities of mutant versus wild-type U2AF1 for those same 3′ splice sites. Finally, we show that lung adenocarcinoma cell lines bearing U2AF1 mutations do not require the mutant protein for growth in vitro or in vivo. In contrast, wild-type U2AF1 is required for survival, regardless of whether cells carry the U2AF1S34F allele. Our results provide mechanistic explanations of the magnitude of splicing changes observed in U2AF1-mutant cells and why tumors harboring U2AF1 mutations always retain an expressed copy of the wild-type allele. Author Summary Large-scale genomics studies have identified recurrent mutations in many genes that fall outside the conventional domain of proto-oncogenes. They include genes encoding factors that mediate RNA splicing; mutations affecting four of these genes are present in up to half of proliferative myeloid disorders and in a significant number of solid tumors, including lung adenocarcinoma. Here we have characterized several properties of a common mutant version of the U2AF1 splicing factor, a component of the U2 auxiliary factor complex, in lung cells. We have found that mutant-associated changes in splice site selection are primarily influenced by the ratio of mutant and wild-type U2AF1 gene products; thus increasing wild-type U2AF1 levels represses the mutant-induced splicing program. We show that the altered splice site preferences of mutant U2AF1 can be attributed to changes in its binding to relevant 3′ splice sites. We also show that mutant U2AF1 is different from some oncogenes: the growth properties of lung cancer cell lines carrying the mutant allele are unaffected by loss of the mutant gene, while the wild-type allele is absolutely required for survival. These results advance our understanding of the molecular determinants of the mutant-associated splicing program, and they highlight previously unappreciated roles of wild-type U2AF1 in the presence of the recurrent U2AF1S34F mutation. |
| Databáze: | OpenAIRE |
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