Tumor-associated Macrophage-derived CXCL8 Could Induce ERα Suppression Via HOXB13 In Endometrial Cancer

Objective:To analyze the expression of TAMs and ERα in normal and EC tissue samples and the association between them.To explore the mechanism in ERα suppression by TAMs-derived CXCL8 in EC cells and the association between ERα suppression and prognosis.Content:We detect the expression of CD163 and ERα in 80 endometrial cancers and 80 normal samples.HEC-1A and Ishikawa cells were transfected with HOXB13 shRNA and shNC.Then we examine HOXB13 and ERα mRNA and protein expression in monocultured and cocultured EC cells.Next we tested CD68 and CD163 on TAMs and the migration capability of cocultured EC cells.The human cytokine antibody array was used to find cytokines secreted by macrophages.The putative cytokines were confirmed by q-PCR.Then we detect the direct binding of HOXB13 and ESR1 promoter.We also analyzed CXCL8,HOXB13,ERα and EMT marker’s expression in EC.Furthermore,we analyzed 548 endometrial cancer cases in the Cancer Genome Atlas dataset and studied the survival curves.Methods:Immunohistochemistry(IHC)was performed to detect the expression of CD163,CXCL8,HOXB13 and ERα in endometrial cancers and normal samples.qRT-PCR and Western blot were used to examine HOXB13 and ERα mRNA and protein expression in monocultured and cocultured EC cells.And cell immunofluorescence was conducted to detect CD68 and CD163.Transwell chamber was conducted to test the migration capability of cocultured EC cells.The human cytokine antibody array was used to find cytokines secreted by macrophages.The putative cytokines were confirmed by q-PCR.ChIP-qPCR was conducted to detect the direct binding of HOXB13 and ESR1 promoter.Results:The expression of TAMs positively linked to higher grade(p < 0.001)and more lymph node metastasis(p < 0.001),while ERα was opposite.TAMs-derived CXCL8 upregulated the expression of HOXB13 and suppressed ERα through direct binding of HOXB13 and ESR1 promoter.Low expression of ESR1 was associated with a poor prognosis for EC patients(log-rank p < 0.05).Conclusion:TAMs highly infiltrated in ERα-negative EC samples and indicated poor outcome.CXCL8 upregulated the expression of HOXB13 and suppressed ERα through direct binding of HOXB13 and ESR1 promoter.