Interleukin-6 (IL-6) Functions as an Autocrine Growth Factor in Cervical Carcinomas in Vitro

Many factors have been implicated in the etiology of cervical neoplasia, with human papilloma virus being the latest in a long line of agents that may on their own or in combination exert various initiating and promoting effects on cervical cells, resulting in their transformation. However, for such altered cells to become invasive, it is clear that they must undergo alterations in their rate of turnover, state of differentiation, and motility. We have investigated the production of the multifunctional cytokine interleukin-6 (IL-6) by five new cervical carcinoma cell lines (XH1, EH2, DE3, JE6, and SM7) and the commercially available CaSki cell line, and have studied the effects of this cytokine on the growth of the cells in vitro. All the cell lines produce biologically active IL-6 in amounts varying between 0.35 to 2.0 ng/ml. In the presence of goat anti-sera to IL-6 all the tumor cell lines showed inhibition of growth. IL-6 acts as an autocrine growth factor for in vitro cervical tumor cell growth.