Figure 1.

Primary screen of MLH1-deficient and proficient cancer cells identifies cytarabine as MLH1-deficient selective. (A) The MLH1-deficient CRC cell line HCT116 and the MLH1-proficient comparator HCT116+Chr3 were screened in parallel. Cells were plated on day 1 and exposed to drug or control continuously from day 2. Viability was assessed using a luminescent assay on day 6. Data were analysed to obtain MLH1-deficient selective hits. (B) Scatter plot of the primary screen. Log₂ SF for HCT116 was compared with the log₂ SF for HCT116+Chr3 and plotted against screen position. (C, D) Survival curves from assays of the effects of cytarabine on (C) cell viability in HCT116+/−Chr3 cells exposed continuously to drug and (D) clonogenic survival in HCT116+/−Chr3 cells exposed to 24 h of cytarabine. Assays were performed in triplicate or quadruplicate. Error bars represent the standard error of the mean (s.e.m.).