Ovise

Serous adenocarcinoma cell lines, PEO1 and PEO4 (from Fergus Couch, USA) were grown in RPMI-1640 (GE Healthcare) containing Pen/Strep (ThermoFisher Scientific) and 10% Fetal Bovine Serum (FBS) (ThermoFisher Scientific). Lines were validated by short tandem repeat profiling and BRCA2 mutation sequencing. The CCOC lines OVMANA, OVISE (both from David Huntsman, Canada), OVTOKO, JHOC9, JHOC5 (all three from Tian-Li Wang, USA), ES2, and TOV21G (both from American Type Culture Collection) were grown in RPMI-1640 containing Pen/Strep and 10% FBS. JHOC5 and OVTOKO were confirmed mycoplasma-free prior to downstream experiments. Genomic profiles of CCOC cells were compiled from previous studies (20 (link)–22 (link)) and summarized in Supplementary Table S4.
The APOBEC3B-specific (shA3B-1) and control shRNA constructs have been described (18 (link)). The second APOBEC3B-specific (shA3B-2) construct was purchased from Open Biosystems (5’-TGGTACAAATTCGATGAAA). UGI and empty lentiviral expression vectors were also described (23 (link)) and transductions were done with established protocols (24 (link)).

Human ovarian CCC cell lines RMG1, RMG2, KOC7C, and HAC2 were kindly provided by Dr. H. Itamochi (Tottori University, Tottori, Japan). Human ovarian CCC cell line OVISE, human SAC cell lines SKOV-3 and A2780 were purchased from the American Type Culture Collection. Human ovarian adenocarcinoma cell lines OVCAR4 and OVCAR5 were kindly provided by Cell Culture Facility at Fox Chase Cancer Center (Fox Chase Cancer center, PA, USA). We tested these cells lines in our laboratory for their authentication by morphologic observation. No further cell line authentication was conducted by the authors. Each cell line was never continuously passaged in culture for more than 3 months, and after that, a new vial of frozen cells was thawed. Cells were cultured in DMEM/Ham's F-12, (Gibco, Carlsbad, CA) with 10% fetal bovine serum, as reported previously (15 (link)).