Somatic mitochondrial DNA mutations in cancer escape purifying selection and high pathogenicity mutations lead to the oncocytic phenotype: pathogenicity analysis of reported somatic mtDNA mutations in tumors

• Tipo: Artigo em Revista Científica Internacional
• Data: 2012

Autores

Pereira L (Autor) FMUP; Soares, P (Autor) Outra; Maximo, V (Autor) FMUP; Samuels, DC (Autor) Outra

Revista

Título: BMC Cancer

Vol. 12

Página Final: 53

ISSN: 1471-2407

Editora: Springer Nature

Indexação

ISI Web of Knowledge - 62 Citações

Scopus - 65 Citações

Outras Informações

ID Authenticus: P-002-D3Y

DOI: 10.1186/1471-2407-12-53

Abstract (EN): Background: The presence of somatic mitochondrial DNA (mtDNA) mutations in cancer cells has been interpreted in controversial ways, ranging from random neutral accumulation of mutations, to positive selection for high pathogenicity, or conversely to purifying selection against high pathogenicity variants as occurs at the population level. Methods: Here we evaluated the predicted pathogenicity of somatic mtDNA mutations described in cancer and compare these to the distribution of variations observed in the global human population and all possible protein variations that could occur in human mtDNA. We focus on oncocytic tumors, which are clearly associated with mitochondrial dysfunction. The protein variant pathogenicity was predicted using two computational methods, MutPred and SNPs&GO. Results: The pathogenicity score of the somatic mtDNA variants were significantly higher in oncocytic tumors compared to non-oncocytic tumors. Variations in subunits of Complex I of the electron transfer chain were significantly more common in tumors with the oncocytic phenotype, while variations in Complex V subunits were significantly more common in non-oncocytic tumors. Conclusions: Our results show that the somatic mtDNA mutations reported over all tumors are indistinguishable from a random selection from the set of all possible amino acid variations, and have therefore escaped the effects of purifying selection that act strongly at the population level. We show that the pathogenicity of somatic mtDNA mutations is a determining factor for the oncocytic phenotype. The opposite associations of the Complex I and Complex V variants with the oncocytic and non-oncocytic tumors implies that low mitochondrial membrane potential may play an important role in determining the oncocytic phenotype.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 10