Figure 7.

Cytotoxic stress induces FGF10 secretion by damaged bone marrow stromal cells through β-catenin.A and B, HS-5 cells were respectively treated with 200 μg/l ADR, 10 μg/l IDA, and 400 μg/l for 24 h, and protein levels of β-catenin and p-mTOR in cytoplasm and nuclei lysates were assessed by Western blotting. Western blots from (A and B) were quantified, and data are shown normalized to cells treated with NS. C, HS-5 cells were exposed to β-catenin activator (LiCl) at the indicated concentrations for 24 h. Western blotting was used to detect protein levels of FGF10, β-catenin, and downstream target CyclinD1, CD44. Quantitative analysis of three replicate experiments was performed and shown relativized to β-actin. ∗p < 0.05, ∗∗p < 0.01, and ∗∗∗p< 0.001. D, the mRNA levels of FGF10 and β-catenin downstream target c-Myc, CyclinD1, and Trib2 in LiCl-treated HS-5 cells were assessed by qRT–PCR. ∗∗p < 0.01 and ∗∗∗p< 0.001 versus control. E, LiCl-treated HS-5 cells were probed with antibodies recognizing β-catenin (red and pink signals) by immunofluorescence, and nuclei were counterstained with DAPI (blue). The scale bar represents 20 μm. F, HS-5 cells were treated with Wnt signaling inhibitor XAV-939 at the indicated concentration for 1 h, and levels of β-catenin and FGF10 protein were quantified by Western blotting. G, CM was collected from HS-5 cells after treatment with 200 μg/l ADR or 1 μM XAV-939 combined with 200 μg/l ADR, and percent viable THP-1 cells in the CM after treated with 100 μg/l ADR, 5 μg/l IDA, and 200 μg/l Ara-C for 72 h were determined by CCK-8 analysis. ADR, adriamycin; Ara-C, cytarabine; CCK-8, Cell Counting Kit-8; CM, conditioned media; DAPI, 4′, 6-diamidino-2-phenylindole; FGF10, fibroblast growth factor-10; IDA, idarubicin; LiCl, lithium chloride; mTOR, mammalian target of rapamycin; NS, normal saline; qRT–PCR, quantitative RT–PCR.