Line-1 Retrotransposons and Their Role in Cancer Publisher



Rahbari R¹ ; Habibi L² ; Garciapuche JL³ ; Badge RM⁴ ; Garciaperez J³ Show Affiliations
Source: Epigenetics Territory and Cancer Published:2015

Abstract

Retrotransposons comprise over 40 % of the human genome and are a major contributor to genome diversity and evolution. They contribute to human genome variation through both germline and somatic retrotransposition. Over recent years, studies on the biology of cancer have revealed that somatic retrotransposition is a feature of many cancer genomes. The most recent comparison between 200 pairs of tumours and normal tissue, across 11 tumour types, has revealed frequent somatic retrotransposition in particular cancers; lung squamous cell, head and neck squamous cell, colorectal and endometrial carcinomas. Importantly some of these insertions occur in cancer-related genes underlining retrotransposition's role as a mutagen. It is now clear that retrotransposons contribute to genome instability during cancer progression. However, the exact role of retrotransposons in tumuorigenesis, tumour progression and prognosis still remains a subject of an active discussion in the field of cancer biology. In this chapter, we have attempted to explain the biology of retrotransposons in the human genome, with the main focus on LINE-1 elements. We then have discussed how LINE-1 causes genome instability in the genome and the host defence mechanisms deployed to supress their retrotransposition. Next, we discuss the role of LINE-1 activity during tumourigenesis and consider the recent findings concerning their activity in different types of cancers. Finally, we explore how retrotransposons can be used as diagnostic tools in cancer.