Fig. 1: The PLK4 inhibitor CFI-400945 causes polyploidy and cell death in lymphoma cells.
From: Synthetic lethality of drug-induced polyploidy and BCL-2 inhibition in lymphoma
a CFI half maximal inhibitory concentration (IC50) values in a panel of cell lines representing different subtypes of lymphoma treated with CFI for 72 h. Cell viability was measured by CellTiter-Glow assay. Each bar represents the mean ± SD of 3 independent experiments, each time in triplicate. Responses to CFI treatment is categorized as resistant (1), intermediate (2), and Sensitive (3) cell lines. b Western blot analysis of total STIL and Aurora B phosphorylation levels in CFI-resistant and sensitive cell lines treated with increasing concentration of CFI for 72 h. β-actin was used as a loading control. c Western blot analysis of anti- and pro-apoptotic Bcl-2 family proteins. Sensitive cell lines exhibit overexpression of pro-apoptotic proteins after treatment with CFI at the indicated doses. α-tubulin was used as a loading control. d Representative confocal images of OCI-Ly19 cells treated with dimethyl sulfoxide (DMSO) (0.1%) or with the indicated doses of CFI for 72 h. Treatment with 10–50 nM of CFI causes centrosome amplification, while 500 nM leads to complete failure in duplication. Cells were fixed and stained for pericentrin and CEP110. Insets are 4X magnified. Scale bar, 5 μm. Images are representative of two independent experiments. A minimum of three z-stack images were captured under the same condition. e Stacked bar graph of the percentage of cells with 0, 1, 2, or over 2 centrosomes per cell in OCI-Ly19 cells treated with CFI. Values represent the experiment shown in panel c. f Representative flow cytometric analyses of cell cycle distribution by propidium iodide (PI) staining in CFI sensitive (OCI-Ly19), intermediate (Daudi), and resistant (HBL-1) cell lines after 72 h of CFI treatment (25 or 250 nM) or control (DMSO 0.1%). Data represent two independent experiments (n = 2). g Stacked bar graph representing the cell-cycle distribution of PI staining in three lymphoma cell lines treated with either control (DMSO, 0.1%) or CFI (25 or 250 nM) for 72 h. CFI induced a specific G2/M arrest and polyploidy in the resistant cell lines and an increase in the sub-G1 population on the CFI-sensitive cell lines. Data were represented as mean percentage ± SD (n = 2 independent experiments). Each immunoblot results in the representative of at least three repeats. Source data for panels a–e, g are provided as a Source Data file.
