Characterization and functional analysis of the expression of intercellular adhesion molecule-1 in human papillomavirus-related disease of cervical keratinocytes.

We have investigated the expression of intercellular adhesion molecule-1 (ICAM-1) in squamous neoplasia of the cervix and have noted a significant induction of the molecule in high-grade intra-epithelial lesions. Using monolayer and organotypic in vitro tissue culture systems, we have shown that there is no constitutive ICAM-1 expression on cervical keratinocytes immortalized but not transformed by human papillomavirus type 16, whereas two human papillomaviruses type 16 containing and fully transformed cervical keratinocyte lines do constitutively express the molecule. All cell types, including human papillomavirus-negative normal cervical keratinocytes, can be induced to up-regulate their expression of ICAM-1 by pro-inflammatory cytokines such as interferon-gamma. In addition, we have used an in vitro adhesion assay to show that ICAM-1:lymphocyte function antigen-1 interaction is functionally important in lymphocyte binding to cervical keratinocytes, suggesting a role for ICAM-1 in retaining and enabling functional activity of lymphocytes in the cervix in intraepithelial neoplasia.

In vivo and in vitro effects of v-fos and EJ-Ha-ras oncogene expression in murine epidermal keratinocytes.

Primary neonatal Balb/c keratinocyte (NEK) cultures grown, using 3T3 feeder cell support in high calcium, serum supplemented medium, were transfected with EJ-Ha-ras or v-fos DNA sequences and pSV2 neo. Several neo resistant clones were isolated and several established cell lines expressing the transfected gene products derived. Two of these lines, Ras 8 and Fos 1, have been examined in detail with respect to their self renewal capacity and differentiation potential in vitro and in vivo. In vitro, both lines (when compared to normal NEK) have an extended probably immortal phenotype, enhanced colony forming efficiency (a measure of in vitro self renewal capacity) and a reduction in growth factor and serum dependence. When grafted onto syngeneic recipients neither cell line is tumourigenic. Instead a histologically abnormal epithelium with no stratum corneum and with features specific to the oncogene expressed is formed. The extent of the histological atypia correlates with the in vitro alterations in cytoskeletal peptides as revealed by 2D PAGE. However despite the gross histological abnormality there is no alteration in the in vivo self renewal capacity (measured as the number of grafted cells required for epidermal reformation) between normal NEK and the Ras 8 or Fos 1 lines; in each case a minimum of 10(5) cells/1.14 cm2 is required before a full thickness epithelium forms.