Long interspersed nuclear element 1 methylation in non-small cell lung cancer: implications for diagnosis, prognosis, and therapeutic targeting

Long interspersed nucleotide element 1 (LINE1), the most abundant repetitive element in the human genome, plays a crucial role in genomic instability. Aberrant LINE1 activation, primarily regulated by DNA methylation, is a hallmark of cancer. Non-small cell lung cancer (NSCLC), the most prevalent form of lung cancer worldwide, continues to pose significant challenges due to the invasiveness, high cost, and susceptibility to false positives of current diagnostic methods, as well as the emergence of treatment resistance. This review highlights the potential of LINE1 methylation as a biomarker for NSCLC, offering novel insights into its role in diagnosis, prognosis, and therapeutic strategies. Recent studies uncovered that LINE1 hypomethylation was strongly associated with poor overall survival, suggesting its utility as both a prognostic marker and a therapeutic target. However, further research is required to elucidate its precise regulatory mechanisms in LINE1 retrotransposition and to evaluate its potential as a non-invasive biomarker for improving NSCLC management.