Exploring transposable elements: new horizons in cancer diagnostics and therapeutics.

Transposable elements (TE), also called transposons, are repetitive DNA sequences making up half of the human genome. Initially, TEs were described as "junk DNA" because they lack specific function. However, they have been recognized for their ability to replicate and integrate into different genomic locations; this "jumping gene" activity results in genomic instability, variation of the chromosomal architecture, and transcriptional dysregulation, all of which represent major hallmarks of cancer. In this respect, the involvement of TE in tumorigenesis was extensively studied and their role as diagnostic and therapeutic tools in cancer is now well-established. Transposons' products, including TE-derived cancer antigens, transcripts, and associated epigenetic modifications, mainly hypomethylation, were found to be promising biomarkers in several types of cancer ensuring early disease detection and prognosis. In addition, TE are currently used to design innovative approaches, with transposon-based systems, namely, Sleeping Beauty and PiggyBac, enabling precise genomic modifications and novel strategies for cancer therapy. Therefore, the aim of this review is to provide an overview on the dual application of TE as diagnostic and therapeutic tools in cancer, paving the way to improved clinical outcomes. CLINICAL TRIAL NUMBER: Not applicable.