H1417

We used 12 SCLC cell lines: SBC‐3 and SBC‐5 from the Japanese Collection of Research Bioresources Cell Bank, H69, H69AR, H719, H1048, H1105, H1417, DMS53, and H1882 from the American Type Culture Collection, and MS‐1 and Lu‐139 from the Riken Cell Bank. SBC‐3 and SBC‐5 were cultured in MEM‐EAGLE medium (Sigma‐Aldrich) with 10% fetal bovine serum (FBS; Biowest) and 1% penicillin/streptomycin (Fujifilm Wako). H69AR was maintained in RPMI‐1640 (Fujifilm) with 20% FBS and 1% penicillin/streptomycin. The other SCLC cell lines were maintained in RPMI‐1640 with 10% FBS and 1% penicillin/streptomycin. These cell lines were obtained between 2008 and 2017 and were routinely examined for the absence of mycoplasma.

The cell lines H82 (CRL-5811), H209 (HTB-172), H524 (CRL-5831), H526 (CRL-5811), H1417 (CRL-5869), and H1963 (CRL-5982) were purchased from the American Type Culture Collection. Cell line identity was confirmed via short tandem repeat profiling. Cells were maintained in RPMI 1640 (Thermo Fisher, 11875093) supplemented with 10% by volume heat inactivated fetal bovine serum (HI FBS) (Thermo Fisher, 10082147) and primocin (InvivoGen, ant-pm-2) at a final concentration of 50 μg/mL, hereafter referred to as standard RPMI. All cell lines were maintained at 37 °C in humidified chambers with 5% CO₂. All cell lines were used for no longer than 20 passages.

Cancer cell-lines (Calu-1, ChaGo-k-1, HCC70, H441, H520, H596, H661, H747, H1417, H2170, MDA-MB-468, SK-BR-3, SK-MES-1) and lung fibroblast cells (MRC-5) were obtained directly from the American Type Culture Collection (ATCC), while others (A549, BT-549, H1975, MIA-Paca-2, PANC-1) were provided by Ashok Venkitaraman (MRC Cancer Unit, Cambridge, UK). Cultures were maintained in a humidified 37 °C incubator, in culture medium (according to ATCC’s recommendation) supplemented with 10% fetal bovine serum, 2 mM l-glutamine, 100 μg mL⁻¹ streptomycin and 100 U mL⁻¹ penicillin. Paired HCT116 p53^−/− and p53^+/+ cell-lines were obtained from Bert Vogelstein (The John Hopkins Medical School, Baltimore, MD) as a gift. Isogenic Calu-1 cells stably expressing pcDNA3.1 vector, pcDNA3.1-p53wt, pcDNA3.1-p53R158G, pcDNA3.1-p53R158G(DBD, K-A), pcDNA3.1-p53R158G(CT, K-A), pcDNA3.1-p53R158G(K20A) plasmids, respectively, were generated by transfection and single-cell selection.