Leukaemia inhibitory factor and interleukin-8 expression in nonmelanoma skin cancers

Leukaemia inhibitory factor (LIF) and interleukin (IL)-8 possess activities which may contribute to the development of carcinomas. LIF can stimulate proliferation of some tumour cell lines and IL-8 is angiogenic. Using semiquantitative reverse-transcription polymerase chain reaction (RT-PCR), we measured the expression of LIF and IL-8 mRNA in cultured normal keratinocytes (NKC) and the malignant carcinoma cells lines A431, SiHa, HeLa, and in biopsies of basal cell carcinoma (BCC), squamous cell carcinoma (SCC) and normal skin. Protein expression for LIF was assessed by immunohistochemistry in the biopsies. LIF mRNA expression was increased significantly (P < 0.01) in all carcinoma lines, except SiHa, compared with NKC but the IL-8 mRNA expression in carcinoma cell lines was similar to that in NKC. Expression of LIF mRNA was elevated in BCC and SCC compared with normal skin, but a significant difference was observed only between SCC and normal skin (P < 0.01). Both BCC and SCC showed significantly greater expression of IL-8 compared with normal skin (P < 0.01). There was no correlation between LIF and IL-8 mRNA expression either in BCCs or in SCCs. Immunoreactivity for LIF was absent throughout BCC and SCC, however, normal epidermis surrounding the tumour stained positive, as in normal skin. These data may suggest a role for LIF and IL-8 in the development of skin carcinomas, but without co-ordinate regulation of these two cytokines in this process.