Characterization of methionine dependence in melanoma cells.

Autor: Garg S; Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences., Morehead LC; Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences., Bird JT; Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences., Graw S; Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences., Gies A; Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences., Storey AJ; Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences., Tackett AJ; Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences., Edmondson RD; Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences., Mackintosh SG; Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences., Byrum SD; Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences., Miousse IR; Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences.
Jazyk: angličtina
Zdroj: BioRxiv : the preprint server for biology [bioRxiv] 2023 Apr 05. Date of Electronic Publication: 2023 Apr 05.
DOI: 10.1101/2023.04.05.535723
Abstrakt: Dietary methionine restriction is associated with a reduction in tumor growth in preclinical studies and an increase in lifespan in animal models. The mechanism by which methionine restriction inhibits tumor growth while sparing normal cells is incompletely understood. We do know that normal cells can utilize methionine or homocysteine interchangeably (methionine independence) while most cancer cells are strictly dependent on methionine availability. Here, we compared a typical methionine dependent and a rare methionine independent melanoma cell line. We show that replacing methionine, a methyl donor, with its precursor homocysteine generally induced hypomethylation in gene promoters. This decrease was similar in methionine dependent and methionine independent cells. There was only a low level of pathway enrichment, suggesting that the hypomethylation is generalized rather than gene specific. Whole proteome and transcriptome were also analyzed. This analysis revealed that contrarily to the effect on methylation, the replacement of methionine with homocysteine had a much greater effect on the transcriptome and proteome of methionine dependent cells than methionine independent cells. Interestingly, methionine adenosyltransferase 2A (MAT2A), responsible for the synthesis of s-adenosylmethionine from methionine, was equally strongly upregulated in both cell lines. This suggests that the absence of methionine is equally detected but triggers different outcomes in methionine dependent versus independent cells. Our analysis reveals the importance of cell cycle control, DNA damage repair, translation, nutrient sensing, oxidative stress and immune functions in the cellular response to methionine stress in melanoma.
Databáze: MEDLINE