DynamicAluMethylation during Normal Development, Aging, and Tumorigenesis

Abstract

DNA methylation primarily occurs on CpG dinucleotides and plays an important role in transcriptional regulations during tissue development and cell differentiation. Over 25% of CpG dinucleotides in the human genome reside withinAluelements, the most abundant human repeats. The methylation ofAluelements is an important mechanism to suppressAlutranscription and subsequent retrotransposition. Decades of studies revealed thatAlumethylation is highly dynamic during early development and aging. Recently, many environmental factors were shown to have a great impact onAlumethylation. In addition, aberrantAlumethylation has been documented to be an early event in many tumors andAlumethylation levels have been associated with tumor aggressiveness. The assessment of theAlumethylation has become an important approach for early diagnosis and/or prognosis of cancer. This review focuses on the dynamicAlumethylation during development, aging, and tumor genesis. The cause and consequence ofAlumethylation changes will be discussed.