Bioinformatic analysis of computational identified differentially expressed genes in tumor stoma of pregnancy‑associated breast cancer.

The present study aimed to screen the differentially expressed genes (DEGs) in tumor-associated stroma of pregnancy-associated breast cancer (PABC). By analyzing Affymetrix microarray data (GSE31192) from the Gene Expression Omnibus database, DEGs between tumor associated stromal cells and normal stromal cells in PABC were identified. Gene Ontology (GO) function and pathway enrichment analyses for the DEGs were then performed, followed by construction of a protein-protein interaction (PPI) network. A total of 94 upregulated and 386 downregulated DEGs were identified between tumor associated stromal cells and normal stromal cells in patients with PABC. The upregulated DEGs were primarily enriched in the cytokine-cytokine receptor interaction pathway and GO terms associated with the immune response, which included the DEGs of interleukin 18 (IL18) and cluster of differentiation 274 (CD274). The downregulated DEGs were primarily involved in GO terms associated with cell surface receptor linked signal transduction and pathways of focal adhesion and pathways in cancer. In the PPI network, nodes of jun proto-oncogene (JUN), FBJ murine osteosarcoma viral oncogene homolog (FOS), V-myc avian myelocytomatosis viral oncogene homolog (MYC), and alpha-smooth muscle actin (ACTA2) had higher degrees. The hub genes of JUN, FOS, MYC and ACTA2, as well as the DEGs IL18 and CD274 that were associated with the immune response in GO terms may exert important functions in the molecular mechanisms of PABC. These genes may be used as new molecular targets in the treatment of this disease.