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Updated: Jul 27, 2025
10:10
Retroviral Scanning: Mapping MLV Integration Sites to Define Cell-specific Regulatory Regions
Published on: May 28, 2017
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Cancer cells co-evolve with retrotransposons to mitigate viral mimicry
Biorxiv : the Preprint Server for Biology
|June 9, 2023
Summary
Pancreatic tumors evolve to control immune responses by modulating repetitive elements, specifically Short Interspersed Nuclear Elements (SINEs), to promote tumor growth and shape the tumor microenvironment.
Area of Science:
- Genomics
- Cancer Biology
- Immunology
Background:
- Overexpression of repetitive elements is a hallmark of human cancers.
- Repetitive elements can mimic viruses, activating innate immune responses.
- The role of specific repeats in tumor evolution and the tumor immune microenvironment (TME) is poorly understood.
Approach:
- Integrated whole genome and transcriptome analysis of multiregional pancreatic ductal adenocarcinoma (PDAC) samples.
- Comprehensive evolutionary analysis to understand the dynamics of repetitive elements.
- Investigated the relationship between repeat evolution, immune signaling, and cellular components within the TME.
Key Points:
- Younger Short Interspersed Nuclear Elements (SINEs) are more likely to form immunostimulatory double-strand RNAs (dsRNAs).
- Immunostimulatory SINE expression correlates with type-I interferon genes and is inversely correlated with pro-tumorigenic macrophage infiltration.
- SINE expression is regulated by Long Interspersed Nuclear Elements 1 (LINE1/L1) mobility or ADAR1 activity, dependent on TP53 mutation status.
Conclusions:
- Pancreatic tumors actively evolve to modulate SINE-induced immune stress, promoting pro-tumorigenic inflammation.
- Genomic repeats act as a mechanism for tumors to co-evolve with the TME by regulating viral mimicry.
- This study provides insights into how 'dark matter' genomic repeats contribute to cancer progression and immune evasion.
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