Fig. 5: INPP4B promotes late endosome-dependent cell proliferation and tumor growth.

a, b MCF-7 cells co-expressing GFP-INPP4B or GFP-vector, and NT or Hrs shRNA, were fixed and immunostained using CD63 antibodies, and co-stained with DAPI and phalloidin (a). Data represent the number of CD63 + puncta per cell ± SD (n = 3 experiments, >50 cells per experiment) (b). c, d MCF-7 cells co-expressing GFP-INPP4B or GFP-vector, and NT or Hrs shRNA, were suspended in 0.3% soft agar and cultured for 4 weeks to allow anchorage-independent colony growth (c). Data represent the relative colony size ± SD (n = 3 experiments in triplicate, n > 50 colonies/experiment) (d). e–g 1 × 10⁶ MCF-7 cells co-expressing GFP-vector;NT shRNA (n = 8 mice), GFP-vector:Hrs shRNA (n = 8 mice), GFP-INPP4B;NT shRNA (n = 7 mice), or GFP-INPP4B;Hrs shRNA (n = 7 mice) were mixed with Matrigel and injected into the fourth mammary fat pad of female BALB/c nude mice. From 2 weeks postinjection, tumor size was measured using callipers three times a week. Data represent tumor size measured from 2 weeks postinjection over the course of the experiment ±SD (e). Data represent extracted mammary tumor weight ex vivo at 42 days postinjection ±SD (f). Comparison of six representative extracted mammary tumors ex vivo at 42 days postinjection (g). Scale bar 10 µm (a), 1 mm (c), 1 cm (g). p values determined by one-way ANOVA with Tukey post hoc test are indicated in b, d, by two-way ANOVA with Tukey post hoc test in e, or by one-way ANOVA in f.