Fig. 2: Orphan G protein-coupled receptor GPR132 triggers myeloid differentiation in AML.

A Gene set enrichment analysis (GSEA) of the TCGA AML dataset comparing GPR132 HIGH and GPR132 LOW. Gene set involving positive regulation of myeloid leukocyte differentiation is shown. ES, enrichment score; NES, normalized enrichment score; FDR, false discovery rate. B, C Gene expression correlation between GPR132 and CD11b (B) or CD14 (C) in TCGA-LAML dataset. A two-sided Pearson’s correlation analysis was performed. D Flow-cytometric analysis of myeloid differentiation marker CD11b expression using Tet-On AML cells (HL60 and MV4-11) with (OE) or without (Con) doxycycline treatment (1 μg/mL) for 72 h. Data are shown as means ± SEM (n = 3). Student’s t-tests were performed, ***P < 0.001. E NBT reduction analysis showing formazan formation in Tet-On AML cells (HL60 and MV4-11) with or without doxycycline exposure (1 μg/mL) for 72 h. Scale bars represent 20 μm. F Representative Wright–Giemsa staining images showing the mature myeloid cell morphology of Tet-On AML cells (HL60 and MV4-11) following doxycycline treatment (1 μg/mL, 72 h). Scale bars represent 20 μm. G Representative images of colony formation for Tet-On AML cells. Cells were cultured in a semi-solid medium and treated with 1 μg/mL doxycycline to induce GPR132 overexpression. Colonies were photographed under a microscope on day 7. Scale bars represent 100 μm. H GPR132 delays growth and promotes differentiation of AML in vivo. GPR132 Tet-On HL60 cells were injected into the mid-right flank of female athymic nude mice subcutaneously. When tumor volumes reached nearly 200 mm³, mice were treated with doxycycline (1 mg/mL in drinking water) for 2 weeks. Tet-On represents Tet-On-GPR132. Data are presented as means ± SEM (n = 6). Student’s t-tests were performed, *P < 0.05. I Expression analysis of GPR132 determined using qPCR in Tet-On HL60 xenograft mice model. Tet-On represents Tet-On-GPR132. Student’s t-tests were performed (n = 6), N.S., not significant, **P < 0.01. J Correlation analysis of GPR132 and CD11b expression in tumor tissues. H Expression levels were detected using qPCR. Student’s t-tests were performed (n = 6), N.S., not significant, ***P < 0.001.