Colony-stimulating factor 3 and its receptor promote leukocyte immunoglobulin-like receptor B2 expression and ligands in gastric

BACKGROUND Colony-stimulating factor 3(CSF3)and its receptor(CSF3R)are known to promote gastric cancer(GC)growth and metastasis.However,their effects on the immune microenvironment remain unclear.Our analysis indicated a potential link between CSF3R expression and the immunosuppressive receptor leukocyte immunoglobulin-like receptor B2(LILRB2)in GC.We hypothesized that CSF3/CSF3R may regulate LILRB2 and its ligands,angiopoietin-like protein 2(ANGPTL2)and human leukocyte antigen-G(HLA-G),contributing to immunosuppression.AIM To investigate the relationship between CSF3/CSF3R and LILRB2,as well as its ligands ANGPTL2 and HLA-G,in GC.METHODS Transcriptome sequencing data from The Cancer Genome Atlas were analyzed,stratifying patients by CSF3R expression.Differentially expressed genes and immune checkpoints were evaluated.Immunohistochemistry(IHC)was performed on GC tissues.Correlation analyses of CSF3R,LILRB2,ANGPTL2,and HLA-G were conducted using The Cancer Genome Atlas data and IHC results.GC cells were treated with CSF3,and expression levels of LILRB2,ANGPTL2,and HLA-G were measured by quantitative reverse transcriptase-polymerase chain reaction and western blotting.RESULTS Among 122 upregulated genes in high CSF3R expression groups,LILRB2 showed the most significant increase.IHC results indicated high expression of LILRB2(63.0%),ANGPTL2(56.5%),and HLA-G(73.9%)in GC tissues.Strong positive correlations existed between CSF3R and LILRB2,ANGPTL2,and HLA-G mRNA levels(P<0.001).IHC confirmed positive correlations between CSF3R and LILRB2(P<0.001),and HLA-G(P=0.010),but not ANGPTL2(P>0.05).CSF3 increased LILRB2,ANGPTL2,and HLA-G expression in GC cells.Heterogeneous nuclear ribonucleoprotein H1 modulation significantly altered their expression,impacting CSF3’s regulatory effects.CONCLUSION The CSF3/CSF3R pathway may contribute to immunosuppression in GC by upregulating LILRB2 and its ligands,with heterogeneous nuclear ribonucleoprotein H1 playing a regulatory role.