Fusion of human keratinocytes with mouse fibroblasts: a model for keratinization study.
Explore the source record for details and available documents.
Biomedical subjects
Publications and source records attributed to G Lizard.
Explore the source record for details and available documents.
Interspecific somatic hybrids were obtained by fusion of adult human epidermal cells with Mouse fibroblasts 3T3-4E, deficient in thymidine kinase. These hybrids were identified by their morphology and by the presence of markers from the parental cells. Some characters of keratinocytes such as keratin subunits 50 and 51 K were present in primary cultures and disappeared after serial passages, whereas bullous pemphigoid basement membrane zone antigens persisted for at least 20 passages. At the 7th passage, a metacentric chromosome, and more often a submetacentric chromosome, presumably of human origin, were observed in some cells.
A fetal antigen, expressed on all fetal erythrocytes during normal ontogeny, was detected on Friend erythroleukemic cells but not on circulating erythrocytes from leukemic mice. Friend cells were shown to express the fetal antigen both by immunofluorescence and antiserum absorption. The fetal antigen thus allows a clearcut distinction between the tumoral step from which emerge the Friend and erythro-proliferative cells.
Various agents have been shown to enhance drug sensitivity of multidrug resistant (MDR) cells and are thus of interest when the MDR phenotype is identified. Detection of MDR cells is of importance and can be carried out either by immunofluorescence with monoclonal antibodies or by functional tests using fluorescent dyes uptake. MDR has been analysed by flow cytometry on three sensitive and resistant cell lines, with MRK16 and C219 monoclonal antibodies directed against P-glycoprotein (P-gp) and with rhodamine 123, Hoechst 33342 and daunorubicin. Resistant cells were revealed by MRK16 and C219 but the results obtained with MRK16 gave higher both percentages of fluorescent cells and mean fluorescence. Fluorescence intensity observed with daunorubicin was lower than with rhodamine 123. With Hoechst 33342, mean fluorescence was quite identical on sensitive and on resistant cells. It was concluded that MRK16 and rhodamine 123 were well adapted to detect P-gp and evaluate its functional ability.
In humans, cyclosporin A (CsA) avoids organ allograft rejection but induces skin carcinomas after long term immunosuppressive treatment; some of these lesions contain human papillomavirus (HPV) DNA. Interferon-gamma (IFN-gamma) is sometimes used in local treatment of persistent or recurrent lesions in normal population. In vivo, both drugs have an effect on keratinocytes which remains unclear. Therefore, their effect was studied on in vitro models of normal or HPV-transformed epithelial cell cultures. After exposure of proliferating cells for 1-3 days to 0.5-16 micrograms/ml CsA and 5-160 U/ml IFN-gamma, no cytotoxicity was observed; cell growth was inhibited; cell morphology was altered with CsA and cytoplasmic vacuoles were seen in some cells. Changes in the cell cycle were mainly obtained after treatment with 8 micrograms/ml CsA or 160 U/ml IFN-gamma, with an accumulation in S-phase especially in HPV-transformed cells. Thus, CsA and IFN-gamma affected, normal and HPV-transformed epithelial cells, differently.