Understand the role of HBV infection in the development of breast cancer

Female patients with hepatitis B virus (HBV) infection have a higher incidence and poorer prognosis of breast cancer. There was a significant difference in the expression of miRNAs in serum exosomes between female patients with or without HBV infection. Whether this difference accounted for the different incidence and progression of breast cancer were not appreciated. We analysed changes in miRNAs in exosomes of HBV-infected female patients and found that miR-1237-3p and miR-363-3p were down-regulated, whereas miR-100-5p, miR-125b-5p, miR-1260a, miR-1287-5p, miR-148a-3p, miR-885-5p and miR-99a-5p were up-regulated. We overlapped the target genes of these miRNAs with the differentially altered genes in breast cancer tissues to derive the differentially expressed genes (DEGs). The biological functions of the DEGs were closely related to breast cancer development. The hub genes to the DEGs included CXCL11, CXCL12, GNG2, LPAR1, GPR17, CXCL1, ADCY5, ADCY3, CX3CL1, and S1PR1. Differential expression of the hub genes lead to worse clinicopathological types and poorer prognosis.We obtained similar results in clinical samples. In conclusion, female patients with HBV infection may affect the expression of miRNAs in serum exosomes to regulate the target genes in breast tissues, this mechanism will improve the occurrence and development of breast cancer and lead to poor prognosis.