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.

Comparative analysis of normal and psoriatic skin both in vivo and in vitro

“…This hypothesis is reinforced by the observation of a higher frequency of Ki67-positive cells in NSRE than in normal epidermis. Other groups using different culture systems have reported similar results [14,37,401 when epidermis reconstructed from normal dissociated keratinocytes developed other psoriatic features including the expression of Psi3 antigen [35] and the production of interleukin 6 [22].…”

Proliferating cells in human eccrine and apocrine sweat glands.

“…The present data showed that a few secretory cells were in S-phase in both eccrine and apocrine sweat glands; therefore, these cells could proliferate. The labeling index of BrdUrd in eccrine secretory cells was much lower than that in normal epidermis (0.09-0.14% vs 1.4 0.4%) (6). Nevertheless, we believe that the presence of proliferating cells was valid, since both the BrdUrd and the PCNA that it is unlikely that myoepithelial cells proliferate and replace lost secretory cells, a t least in normal sweat glands.…”

“…In this study, small pieces of skin were incubated in a medium containing 100 pM BrdUrd under 3 atmospheric pressures of 95% 02-5% CO2 as reported by Sasaki and colleagues (11,12). The validity and usefulness of this method have been reported in previous publications, including our own (6,11,12).…”

The relationship of Ki67 and involucrin expression in proliferative, pre-neoplastic and neoplastic skin

“…8 In addition, the onset of terminal differentiation is precocious as shown by involucrin expression, 9,10 although dysplasia is not a feature. The proliferative fraction is similarly increased in in-situ and invasive neoplasia, 11,12 while abnormal differentiation is seen as a feature of dysplasia by conventional light microscopy. These observations suggest that proliferation and differentiation are uncoupled in many skin disorders, both benign and malignant.…”