Figure 2.

CD22-expressing cells that survive Inotuzumab Ozogamicin are blocked in the G2/M phase of the cell cycle. (A) Representative dot plots showing the apoptotic rates observed in BL-2, SUP-B15 and Namalwa cells. The indicated CD22-positive cell lines were either left untreated (UNT) or treated with calicheamicin equivalents corresponding to their IO IC₅₀ values for 48 h. Apoptotic rates were evaluated using flow cytometry after Annexin V-FITC/7AAD double staining. The indicated percentage values show the distribution of viable and necrotic/apoptotic cells for each condition. (B) Histograms representing the average percentage of Annexin V and 7 AAD positive cells in the untreated (white columns) or IO treated (with their respective IC₅₀ values; black columns) conditions. Columns represent average ± standard deviation of three independent experiments performed in triplicates. ^***p < 0.001 (C) Representative experiment displaying the cell cycle distribution of BL-2, SUP-B15 and Namalwa cells. Each line was treated for 12, 24, and 48 h with it's respective IO IC₅₀ value and surviving cells were then analyzed for cell cycle distribution by flow cytometry using propidium iodide (PI). The percentage of cells blocked in G2/M is indicated for each panel.