The role of regulatory B cells during the progression of human hepatocellular carcinoma

Abstract

Hong Kong Human regulatory B cells (hBregs) have been shown to play an important role in autoimmune diseases, but their function during human cancer progression remains elusive. In this study, we aim to unveil the underlying mechanism of hBregs regulating human hepatocellular carcinoma (HCC) growth. B cells in HCC liver tumor were examined by immunohistochemistry. We found a tendency that the amount of B cells increased with HCC progression (p=0.001), and it’s in the marginal region of HCC increased (P<0.001) more dramatically. In vitro, human HCC cell line MHCC-97L cells were cocultured with hBregs. hBregs promoted HCC cells proliferation (P=0.011) and migration (p=0.006) and decreased HCC cells apoptosis (p=0.078). HCC cells also promoted hBregs proliferation and migration (p=0.003). hBregs could interact with HCC cells directly through CD40-CD154 signaling. Tail vein injection of hBreg cells into SCID mice increased the size of HCC xenograft tumor (4 weeks, p=0.0221). In vivo imagining showed that hBreg cells could migrate into tumor. Our findings indicate that hBregs could promote HCC progression.