Fig. 5: PreNeu enhance PARP inhibition in vivo and synergize with standard endocrine therapy.

a Experimental scheme created in BioRender. Garda, c. (2025) https://BioRender.com/uueypah. Female NRG mice were implanted with estrogen pellets 2 weeks before of the injection of 1 × 10⁶ FP-MCF7-Luc+ cells. Starting from this point, every week mice received ^cbPreNeu (i.p.) and the radiance of the tumors was monitored by luminescence. When the total flux of the tumor was >10⁶, mice were treated as indicated: untreated (Ø, n = 5); Tamoxifen (n = 5), Olaparib (n = 5), neutrophil precursors (PreNeu; n = 9); PreNeu + tamoxifen (n = 6); PreNeu + Olaparib (n = 14); PreNeu + Olaparib + Tamoxifen (n = 16). After 12 weeks of treatment, mice were sacrificed. b Graph showing tumor area (mm²) of mice belonging to the different groups: untreated (Ø, n = 5); Tamoxifen (n = 5), Olaparib (n = 5), PreNeu (n = 9); PreNeu + tamoxifen (n = 6); PreNeu + Olaparib (n = 14); PreNeu + Olaparib + Tamoxifen (n = 16). Synergism was calculated with the coefficient of drug interaction (CDI). CDI (cm-PreNeu + Olaparib + Tamoxifen) = 0.59. Statistical analyses (two-tailed unpaired Student t test). c Quantifications and representative images of immunohistochemistry analysis (H&E, Ki67, γH2AX) of mice treated in the different conditions listed in a. Aggregated data from one tumor per mouse, mean of three sections per mouse, ≥3 fields per section. Statistical analyses (unpaired Student t test). d Experimental scheme created in BioRender. Garda, c. (2025) https://BioRender.com/6n3mu0w. Female NRG mice were injected with either HCC1937 BRCA^wt or HCC1937 BRCA^mut cells in the mammary fat pad. Starting from when tumors were palpable, mice were injected either with olaparib or PreNeu or PreNeu + olaparib or vehicle (Ø). e, f Tumor growth from mice injected either with e HCC1937 BRCA^mut or f HCC1937 BRCA^wt and treated as described in d (n = 5 mice for each group). Data are represented as mean ± SEM. Statistical analysis (two-way ANOVA). g, h Quantifications and representative images of immunohistochemistry analysis (H&E, Ki67, γH2AX) of mice injected either with g HCC1937 BRCA^mut or h HCC1937 BRCA^wt and treated as described in d. g Ki67: n = 10 for each groups, for γH2AX n = 11 for PreNeu and Olaparib groups, n = 10 for Ø and PreNeu + Olaparib. f Ki67: n = 12 for PreNeu, n = 8 for Ø and PreNeu + Olaparib, n = 10 for Olaparib. γH2AX: n = 10 for PreNeu and Ø, n = 9 for Olaparib, n = 8 for PreNeu+Olaparib. Mean of three sections per mouse, ≥3 fields per section. Statistical analyses (one-way ANOVA). Source data are provided as a Source data file.