Cell Growth & Differentiation, Vol 6, Issue 10 1245-1250, Copyright © 1995 by American Association of Cancer Research
Oral keratinocytes immortalized with the early region of human papillomavirus type 16 show elevated expression of interleukin 6, which acts as an autocrine growth factor for the derived T103C cell line
D Bryan, CJ Sexton, D Williams, IM Leigh and IA McKay
Department of Experimental Dermatology, London Hospital Medical College, United Kingdom.
Interleukin 6 (IL-6) is a pleiotropic cytokine produced by cells in
response to injurious stimuli including viral infections and UV light.
Numerous human keratinocyte-derived lines overexpress IL-6 and have been
shown to respond to IL-6 as a mitogen. In a survey of such lines, we
discovered that two lines, SiHa and Caski, which harbor human
papillomavirus (HPV) type 16 genomes, showed the highest levels of
secretion. We have, therefore, asked whether immortalization of human
keratinocytes with HPV 16 could result in elevated secretion of IL-6. Oral
keratinocytes were transfected with a plasmid expressing the entire HPV
type 16 early region under the control of the Moloney leukemia virus long
terminal repeat promoter. Three immortal lines were derived and tested for
their ability to secrete biologically active IL-6. These lines showed 2-,
3-, and 9-fold increases in detectable IL-6 when compared with parental
strains of keratinocytes. Cells from one of these lines, T103C, showed a
negative growth response to IL-6-neutralizing antisera, suggesting that the
secreted IL-6 acted as an autocrine growth stimulator.