Molecular classification and immunologic characteristics of immunoreactive high-grade serous ovarian cancer

Abstract

High-grade serous ovarian cancer (HGS-OvCa) is one of the most lethal gynaecological malignancies. Molecular classification identified an immunoreactive subtype of HGS-OvCa; however, the immunologic characteristics of immunoreactive HGS-OvcA remain unclear. In this study, 121 immunoreactive HGS-OvCa samples were identified from a meta-analysis of 5 large transcriptome profiling data sets using a cross-platform immunoreactive HGS-OvCa subgroup-specific classifier. By comparing the gene expression profiles of immunoreactive HGS-OvCa samples and normal tissues, 653 differentially expressed genes (DEGs) were identified. KEGG pathway analysis revealed that the leukocyte transendothelial migration pathways were significantly enriched in the immunoreactive HGS-OvCa. Protein-protein interaction analysis identified a module that showed strong involvement of the immune-related chemokine signalling pathway. Moreover, the GSEA enrichment analysis showed a T-cell subgroup and M1 macrophages were significantly enriched in immunoreactive OvCa compared with normal samples. Macrophage infiltration levels were significantly elevated in immunoreactive HGS-OvCa compared with other OvCa subtypes. In addition, expression of immune checkpoint molecules VTCN1 and IDO1 was significantly increased in immunoreactive HGS-OvCa. In summary, our results suggest that the immunoreactive HGS-OvCa has unique molecular characteristics and a tumour-associated immune microenvironment featured by increased infiltration of macrophages, rather than lymphocytes. VTCN1 could be potential targets for the treatment of immunoreactive HGS-OvCa.