INTERLEUKIN-6 (IL-6) PRODUCTION IN CARCINOMA OF THE CERVIX

Interleukin-6 (IL-6) is a pleiotropic cytokine that is not only a medi ator in major immunologic reactions but also a growth factor of kerati nocytes. We studied the IL-6 secretion in vitro of 15 human cell lines derived from both squamous cell carcinoma (SCC) and adenocarcinoma of the uterine cervix. Four of the eight well differentiated SCC secrete d a large amount (>1500 pg/48 h/10(6) cells) of IL-6 in nude mice. In contrast, poorly differentiated SCC cell lines and all of the 7 adenoc arcinoma cell lines secreted a small amount (<500 pg/48 h/10(6) cells of IL-6). The expression of IL-6 mRNA of the cell lines correlated wel l with their IL-6 secretion potential. However, the expression of IL-6 receptor did not correlate with the IL-6 secretory potential. We also studied the IL-6 secretion of freshly isolated normal squamous epithe lium and of dysplastic epithelium. In culture, two normal squamous epi thelia secreted a large amount (>2000 pg/48 h/10(6) cells), whereas 8 dysplasia epithelia secreted an extremely small amount (<10 pg/48 h/10 (6) cells). About one-third of patients with SCC had a raised serum IL -6 value. IL-6 production may help to differentiate between SCC and ad enocarcinoma of the uterine cervix. IL-6 regulation seems to change in the course of SCC carcinogenesis.