Interleukin‐6 functions as an autocrine growth factor in a cholangiocarcinoma cell line

Abstract

The tumour cells of a human cholangiocarcinoma cell line, HuCC‐T1, were found to express mRNA of interleukin‐6 (IL‐6) and to secrete a large amount of biologically active IL‐6 in the culture medium at the concentration of 22.6 ng/mL. Interleukin‐6 was demonstrated in the cytoplasm of the cells by immunohistochemical staining. Furthermore, these cells showed the presence of receptors for IL‐6 on the surface, and DNA synthesis of the cells was stimulated by the exogenous addition of recombinant human IL‐6 into the culture medium. The cell growth was significantly inhibited in the presence of anti‐human IL‐6 antibody in the culture medium. These findings indicate that IL‐6 is one of the autocrine growth factors of this cell line in vitro.