In-vitro DNA synthesis of keratinocytes in normal human skin, psoriasis, seborrhoeic keratosis, Bowen's disease and basal cell carcinoma

Abstract
The DNA‐synthesizing cells in benign and malignant keratotic diseases including psoriasis, seborrhoeic keratosis, Bowen's disease and basal cell carcinoma were studied. Cells in S‐phase were labelled after small pieces of the lesions were incubated in tissue culture medium that contained 5‐bromo‐2′‐deoxyuridine (BrdU). The labelling of DNA was analysed using the labelling index and pattern. Although the malignant diseases tended to show a higher DNA labelling index, neither this nor the loss of polarity alone was associated with malignancy. However, a higher DNA labelling index together with a loss of polarity was characteristic for malignancy.