Spontaneous transformation of human skin fibroblasts derived from neoplastic patients

In the past 15 years a considerable amount of data has been published showing that normal human fibroblasts have a finite division potential when cultured in vitro. The authors have described the spontaneous establishment in vitro of stromal fibroblasts derived from human lung cancers, but it was difficult to know whether the proliferating fibroblasts were normal stromal cells or tumor cells. Therefore it was decided to culture the fibroblasts from the skin of patients with lung tumors to see whether they had the same fate in vitro. Here, a description is given of the spontaneous transformation of skin fibroblasts derived from 4 neoplastic patients. The results show that it is possible to obtain spontaneous transformation in these cultures. Transformation is characterised by an abnormal ploidy, a capacity to form colonies in a semi solid agar medium, the formation of foci of piling up cells among the monolayers and the acquisition of an infinite life span. For the moment it is impossible to know if the transformed cells originated from skin fibroblasts or from tumor cells disseminated in the skin of the patients.