RT Journal Article T1 L1 Retrotransposon Heterogeneity in Ovarian Tumor Cell Evolution. A1 Nguyen, Thu H M A1 Carreira, Patricia E A1 Sanchez-Luque, Francisco J A1 Schauer, Stephanie N A1 Fagg, Allister C A1 Richardson, Sandra R A1 Davies, Claire M A1 Jesuadian, J Samuel A1 Kempen, Marie-Jeanne H C A1 Troskie, Robin-Lee A1 James, Cini A1 Beaven, Elizabeth A A1 Wallis, Tristan P A1 Coward, Jermaine I G A1 Chetty, Naven P A1 Crandon, Alexander J A1 Venter, Deon J A1 Armes, Jane E A1 Perrin, Lewis C A1 Hooper, John D A1 Ewing, Adam D A1 Upton, Kyle R A1 Faulkner, Geoffrey J K1 L1 K1 LINE-1 K1 chemoresistance K1 ovarian cancer K1 retrotransposon AB LINE-1 (L1) retrotransposons are a source of insertional mutagenesis in tumor cells. However, the clinical significance of L1 mobilization during tumorigenesis remains unclear. Here, we applied retrotransposon capture sequencing (RC-seq) to multiple single-cell clones isolated from five ovarian cancer cell lines and HeLa cells and detected endogenous L1 retrotransposition in vitro. We then applied RC-seq to ovarian tumor and matched blood samples from 19 patients and identified 88 tumor-specific L1 insertions. In one tumor, an intronic de novo L1 insertion supplied a novel cis-enhancer to the putative chemoresistance gene STC1. Notably, the tumor subclone carrying the STC1 L1 mutation increased in prevalence after chemotherapy, further increasing STC1 expression. We also identified hypomethylated donor L1s responsible for new L1 insertions in tumors and cultivated cancer cells. These congruent in vitro and in vivo results highlight L1 insertional mutagenesis as a common component of ovarian tumorigenesis and cancer genome heterogeneity. YR 2018 FD 2018 LK http://hdl.handle.net/10668/12650 UL http://hdl.handle.net/10668/12650 LA en DS RISalud RD Apr 7, 2025