Single-Cell and Bulk RNA Sequencing Reveal the Potential Immune Suppressive Role of PODXL in Cervical Cancer Treated with Radiochemotherapy

Abstract

Our previous study identified the tumor-promoting role of PODXL in cervical cancer (CC), but it remains largely unknown for its impact on immune response and survival in CC patients received radiochemotherapy. Here, we investigated this issue using single-cell RNA-sequencing (scRNA-seq) and Bulk RNA-sequencing data. We performed scRNA-seq on 29,453 cells in five tumor tissues from CC patients, employed 141 bulk RNA-seq data from TCGA, and included a cohort of 168 CC patients treated with radiochemotherapy for immunostaining of PODXL protein. Gene Ontology (GO) and Gene set enrichment analysis (GSEA) analysis were performed for functional annotation. Immune cell infiltration analysis by single sample GSEA. Immunostaining validation was performed on tumor tissues from 168 CC patients treated with radiochemotherapy. Single-cell analyses revealed the specific expression of PODXL on endothelial cells and divided these cells into PODXLhigh and PODXLlow cells. GO and GSEA analyses showed that PODXLhigh cells had lower levels of leukocyte cell-cell adhesion, immunoglobulin mediated immune response and cytokine production than PODXLlow cells. We further found that PODXLhigh cells could reduce macrophage recruitment through PODXL-ACKR1 and ultimately shape the immune suppressive tumor microenvironment. Analyses of bulk RNA-seq data showed that PODXL expression was negatively correlated with survival of CC patients; moreover, compared to the PODXLlow group, the infiltration of CD8+ T cells, B cells, Th1, and follicular helper T cells were lower in the PODXLhigh group (all P values < 0.05). Furthermore, in the immunostaining validation cohort, multivariate Cox analysis showed that PODXL expression was negatively correlated with the survival for CC patients who underwent radiochemotherapy (all P values < 0.05). We revealed the potential immune suppressive role of PODXL in CC patients treated with radiochemotherapy, which may provide a candidate therapy target combined with radiochemotherapy.