HLA EXPRESSION IN HEPATOCELLULAR-CARCINOMA CELL-LINES

The present study undertook to investigate the biological significance of human leucocyte antigen expression in hepatocellular carcinoma and to elucidate the role of potential modulating agents on human leucocy te antigen expression. These studies used several hepatic tumour-deriv ed cell lines as in vitro model systems. The cell lines included PLC/P RF/S (Alexander cell line), Hep3B, HepG2, TONG PHC, HA22T/VGH, HA59T/V GH and Mahlavu. The cell lines K562 and Raji were used as negative and positive controls, respectively. K562, a B lymphoid-derived cell line , was shown to express negligible amounts of human leucocyte antigens, while Raji, an erythromyeloid-derived cell line, expressed both class I and class II human leucocyte antigens as well as their respective i nvariant chains, beta(2)-microglobulin and Ii. Using an ELISA, experim ents performed on these cell lines confirmed the natural expression of class I and class II antigens by the HA22T/VGH and HA59T/VGH cell lin es, whereas PLC/PRF/S displayed class II surface antigens only. The ef fects of modulating agents such as interferon-gamma sodium butyrate an d clofazimine on human leucocyte antigen expression were investigated using the HA22T/VGH, HA59T/VGH and TONG PHC cell lines. These agents i ncreased class I and class II human leucocyte antigen expression on HA 22T/VGH and TONG PHC cells, but had no effect on the HA59T/VGH cell li ne. The results suggest a potential use for these agents as modulators of human leucocyte antigen expression by human heptocellular cell lin es.