Figure 2.

Genotoxicity mechanisms. (i) Promoter insertion upstream and in sense to cellular transcription units can lead to read-through transcription into adjacent cellular genes, either from the internal promoter or from the long terminal repeat (LTR) as indicated by the arrows. If splice acceptor (SA) and donor (SD) sites are present, promoter insertion can be accompanied by splice events; (ii) promoter activation is mediated by enhancer-interactions by respective elements in the internal promoter or in the LTR with cellular promoters; (iii) gene transcript truncation can lead to shortened cellular transcripts, either lacking 3' (left example) or 5' sequences (right example).