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Hereditas(Beijing) ›› 2026, Vol. 48 ›› Issue (7): 671-689.doi: 10.16288/j.yczz.25-289

• Review • Previous Articles     Next Articles

The retrotransposon LINE-1: a double-edged sword in tumorigenesis

Lu Tian(), Qian Liu(), Shan Cen(), Xiaoyu Li()   

  1. Department of Immunology, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, China
  • Received:2025-11-05 Revised:2026-01-16 Online:2026-02-09 Published:2026-02-09
  • Contact: Qian Liu, Shan Cen, Xiaoyu Li E-mail:s2023010039@pumc.edu.cn;j2024080001@pumc.edu.cn;shancen@imb.pumc.edu.cn;xiaoyulik@hotmail.com
  • Supported by:
    National Natural Science Foundation of China(31870164);Chinese Academy of Medical Sciences Innovation Fund for Medical Sciences(2021-I2M-1-043);National Key R&D Program of China(2023YFC2306701)

Abstract:

Transposons, also known as jumping genes, are DNA sequences capable of relocating within or between chromosomes. Long interspersed element-1 (LINE-1), the only autonomously active retrotransposon in the human genome, plays a critical role in maintaining genomic stability through its dynamic regulation. Under normal physiological conditions, the host employs epigenetic and other mechanisms to maintain LINE-1 in a silenced state. However, when this precise regulatory control is disrupted, aberrant LINE-1 activation can lead to insertional mutations, resulting in genomic instability and the development of various genetic disorders and malignant tumors. Recent evidence has demonstrated elevated LINE-1 expression in multiple cancers, such as breast, esophageal, lung, and colorectal cancer, suggesting a close association between LINE-1 dysregulation and tumorigenesis. This review summarizes the multi-layered regulatory network governing LINE-1, encompassing epigenetic modifications, non-coding RNAs, and various host restriction factors. It also explores the molecular mechanisms underlying LINE-1 aberrant activation in the tumor microenvironment and outlines the diverse pathways through which LINE-1 influences tumor development, such as compromising genomic stability, triggering inflammation and immune responses, and participating in cellular immortalization. This review not only provides a theoretical foundation for utilizing LINE-1 as a molecular biomarker in cancer diagnosis but also offers new perspectives for developing novel anti-tumor therapeutic strategies based on LINE-1 regulation.

Key words: LINE-1, retrotransposons, cancer, genomic instability, epigenetic regulation