Fig. 4

CBR3-AS1 recruits MDSCs through the miR-409-3p/CXCL1/CXCR2 axis. A Relative mRNA expression levels of CXCL1 in H520 cells transfected with a control empty vector (vecCtrl), miR-409-3p mimic plasmid (miR-409-3p), control shRNA (shCtrl), or specific interfering hairpin RNAs targeting miR-409-3p (shmiR-409-3p). The cells were exposed to radiation after 24 h of transfection. B Relative protein expression levels of CXCL1 in H520 cells. β-actin was used as the reference for normalization. C Relative luciferase activity of CXCL1 under miR-409-3p overexpression in the wild-type and mutant CXCL1 groups treated with radiation. D, E Relative mRNA and protein expression levels of CXCL1 in H520 cells transfected with shCtrl, shCBR3-AS1, or shmiR-409-3p. F Migration ability of MDSCs toward the conditioned medium of H520 cells transfected with CXCL1, shCXCL1, or treated with a CXCR2 inhibitor (SB265610, 10 mM) and treated with radiation. G, H Levels of interferon (IFN)-γ secreted by CD8⁺ and CD4.⁺ T cells co-cultured with H520 cells transfected with CXCL1, shCXCL1 or treated with a CXCR2 inhibitor (SB265610, 10 mM). IFN-γ expression was reported as the mean fluorescence intensity. The significance between two groups was analyzed using Student's t-test. Data are presented as mean ± SD from three independent experiments. Statistical significance was defined as *P < 0.05, **P < 0.01, and ***P < 0.001