Dolichol biosynthesis in human malignant cells

Cholesterol, ubiquinone and dolichol biosynthesis from mevalonic acid was measured in non-malignant and malignant cultured human lymphocytes, freshly isolated human mononuclear leucocytes and in cultured human hepatoma cells. The relative flux of mevalonate into ubiquinone, dilichol and cholesterol was not significantly different between malignant and non-malignant cells, although the extent of labelling of each product was an order of magnitude greater in the malignant cultured cells. The most prominent dolichol isolated from total cellular lipid and synthesized in short-term labelling of cultured leukaemic cells had a chain length one isoprene unit shorter than that observed in normal human cells. Cultured human hepatoma cells and mononuclear leucocytes isolated from the peripheral blood of individuals with lymphoblastic and myelogenic leukaemia similarly synthesized shorter-chain dolichols. The dolichols made in cultured non-tumorigenic cells, freshly isolated mononuclear leucocytes from a normal individual or a patient with non-haematological malignancy had normal chain length.