Te buffer

Template‐wrapped lentivirus was synthesized by Fubio Biological Technology (China). Plasmid, primers, probes, and template‐encapsulated E. coli were synthesized by Sangon Biotech (China). oligo(dT)₂₀ and synthetic RNA were synthesized by Hongxun Bio (China). RevertAid reverse transcriptase was purchased from Thermo Fisher Scientific (US). RNase inhibitor, Trizol, RIPA, TE buffer, NP‐40, TritonX‐100, PBS, dithiothreitol (DTT), and DEPC treated water were purchased from Beyotime (China). TwistAmp kit was purchased from TwistDx Limited (UK). The binding disc was made of the GE Whatman FTA card, and the FTA purification reagent was purchased from Whatman (UK). BSA was purchased from Solarbio (China). F127 was purchased from Sigma–Aldrich (China). Anhydrous ethanol was purchased from Titan (China).

All oligonucleotides designed in our research were provided by Sangon Biotech Co., Ltd. (Shanghai, China), and the detailed sequences information can be observed in Additional file 1: Table S1. All single-strand DNA (ssDNA) were dissolved in TE buffer and stored at 4 °C for subsequent experiments. The 10 × TM buffer (pH = 8.0) were prepared using Tris–HCl (10 mM) and MgCl₂·6H₂O (50 mM). Doxorubicin was purchased from Aladdin (Shanghai, China). Tris–HCl, MgCl₂·6H₂O, and SYBR Green I nucleic acid dyestuff was obtained from Solarbio Science & Technology Co., Ltd (Beijing, China). TE buffer, DAPI solution, DNase I enzyme, and LysoTracker Green were obtained from Beyotime Biotechnology (Shanghai, China).

The 4 × 10⁶ cells were incubated with 1% fresh formaldehyde (Sigma-Aldrich, St. Louis, MO, USA) for 10 min at room temperature and with 2 mL glycine solution (Cell Signaling Technology) for 5 min at room temperature. After the centrifugation at 2000× g for 5 min at 4 °C, cell pellets were incubated with micrococcal nuclease for 20 min at 37 °C to obtain DNA. After the purification procedure, DNA was incubated with protein A/G beads (Beyotime) binding to anti-FOXO3 (ab70315, 2.5 μg/mg, Abcam) or anti-IgG (ab172730, 0.5 μg, Abcam) overnight at 4 °C. Beads were collected to be washed by low salt immune complex wash buffer (Beyotime), high salt immune complex wash buffer (Beyotime), LiCl immune complex wash buffer (Beyotime) and TE buffer (Beyotime), successively. The enrichment and purification of DNA was performed by a PCR clean up kit (Beyotime). DNA expression was quantified by qPCR.