Methionine Deprivation Induced Changes in Genome Methylation of mTORC Nutrient Sensing Genes

Objective. This study was conducted to determine changes in methylation of mTORC1 nutrient sensing pathway genes. Background. Methionine is a conditional essential amino acid required for cell growth and development. Through complex molecular steps, intracellular levels of methionine is sensed by the mammalian target of rapamycin complex 1 (mTORC1). mTORC1 is a serine/threonine protein kinase that regulates cellular growth and proliferation. Methionine deprivation promotes the association of the intracellular SAMTOR-GATOR1 complex, which in turn inhibits mTORC1. Methionine deprivation in cancer cell lines with cloned mgld gene plasmid transfection results in cell death. Thus, Mgld could serve as a gene therapeutic agent for cancers. Furthermore, studying genomic methylation changes of the mTORC1 nutrient sensing genes could unveil details of molecular modifications and control. Methods. The methylome (whole genome methylation) for two different prostate cancer cell lines (DU145 & PC3) was obtained through Bisulfite DNA sequencing (Illumina). Both cell lines were treated with MEGLcyt (MEGL with a cytoplasmic localization signal vector), MEGLnls (MEGL with a nuclear localization signal vector), empty plasmid vector (VTR), or no vector (CTRL). A total of 16 different conditions were generated. The methylome of 20 genes from the mTORC1 pathway was analyzed. The mean difference for each condition, p value, and p value adjusted false discovery rate were recorded for each gene and promoter. A mean methylation difference >5% (>0.05) in any condition was considered significant. Results. Significant methylation changes observed. Conclusion. Global genome methylation changes upon methionine deprivation affect’s genes of mTORC1 nutrient sensing signaling pathway. Grants. NSU-PFRDG