Transformation of tissue-cultured xeroderma pigmentosum fibroblasts by treatment with N-methyl-N′ -nitro-N-nitrosoguanidine

Abstract

In vitro transformation by chemical carcinogens has been shown and established mainly in rodent cells¹. Attempts made to transform tissue-cultured human cells have so far failed². Only two seemingly promising reports on in vitro transformation of human cultured cells were those reported by Benedict et al.³ and Rhim et al.⁴. But the cell line used by Rhim et al. to transform by treatment with N-methyl-N′-nitro-N-nitrosoguanidine (MNNG) was derived from osteosarcoma and had itself many cytological as well as chromosomal features characteristic of malignant tumour cells. As we cannot imagine why human cells should not be transformed by the chemicals which are potent carcinogens for cells of rodent origin, we believe that successful transformation depends only on finding the optimal experimental conditions and suitable cells.