Figure 4. Effect of ¹⁷⁷Lu-octreotate and PARPi on NCI-H727 cell monolayers.

(A) PARPi augments the ¹⁷⁷Lu-octreotate-induced reduced cell viability of NCI-H727 cells. The H727 cells were treated in six replicates for five days with ¹⁷⁷Lu-octreotate and DHQ independently and in combination as described for BON-1 cells in Figure 2. The average cell counts in each treatment groups from six independent experiments is derived and expressed as mean ± SEM exactly as described for Figure 2A. The number of cells seeded at the start of the experiment were 3.75% of the number of control cells on day of harvest. ^* indicates a significant difference from % viability of control cells. (B) PARPi potentiates the ¹⁷⁷Lu-octreotate-induced cell death and cell cycle arrest in H727 cells. The cells treated as above for panel-A were harvested at day 10 and analyzed by flow-cytometry after staining with propidium iodide. The data of each cell cycle phase (sub-G1, G1, S, and G2/M) is derived from triplicates per experimental condition and were plotted as means ± SD of fold change in the percent cell population relative to that of untreated controls. The ^* indicates a significant difference as compared to the control cells in the given cell cycle phase. (C) Analyses of DNA damage, cell cycle arrest and cell death parameters by western blotting in H727 cells. The cells treated in six replicates as indicated for panel A were harvested and pooled together for immunoblotting of various parameters. Band intensities were measured as described for Figure 2C. The panel for each immunoblot represents one of the two independent identical experiments with similar results.