Induction of Multinucleate Cells by 8-MOP and UV Treatment <i>in vitro</i> and <i>in vivo</i>

Abstract

Fibroblast cells were treated with a single dose of 8-methoxypsoralen (8-MOP) and long-wave UV irradiation in vitro and the cytotoxic effects of the treatment followed up for 5 passages. During the first passage, there was an inhibition in cell proliferation, the induction of chromosomal aberrations and the production of macrocells as well as cells with more than one nucleus. In the subsequent passages, the proliferation rate of the cells gradually normalized but there was a concomitant increase in chromosomal aberrations and in the number of macrocells and multinucleate cells. Specimens, which were taken from the uninvolved skin of psoriatic patients who had been treated between 20 and 40 times with an oral dose of 8-MOP and black light irradiation (PUVA) also revealed the presence of binucleate, tetranucleate and multinucleate epidermal cells as well as binucleate and tetranucleate dermal fibroblasts.

Polyploidization and Hemiploidization Induced by PUVA <i>in viv</i><i>o</i>

“…It appears, therefore, that most of the epidermal cells retain their mitotic ability despite the PUVA insult, and that they replicate with a distorted mitotic mechanism evolving into multinucleate cells. These results are in accordance with the histological findings of the photo-onycholytic nail bed which had revealed the highest number of multinucleate cells [2] as compared with the uninvolved skin of the PUVA-treated psoriatic patients [1], and implicate a temporal factor, namely, that cells in a tissue with a slow turnover would have ample time to germinate into multinucleate cells.…”

“…Histological sections prepared from biopsies of the uninvolved skin of PUVA-treated psoriatic patients and also the nail bed of patients who had contracted photo-onycholysis due to 8-MOP and sunlight irradiation, like wise revealed the presence of multinucleate epidermal cells and multinucleate fibroblasts [1,2]. These findings disclosed that PUVA treatment virtually had the same effect on the cells in vivo as in vitro.…”

“…For morphological studies, 5.0-6.0 x 104 fibroblasts were seeded and grown on coverslips in culture dishes. After 50 h of incubation the cells were fixed, stained and examined under the light microscope [1]. Whereas only binucleate cells could be discerned interspersed amongst the mononucleate cells in the cultures of the first biopsies, a vast number of cells possessing 2, 3, 4 and more nuclei showed up in the cultures of the second and third biopsies ( fig.…”

“…The potential of a combined treatment of and long-wave ultraviolet (UV360) irradiation (PUVA) to induce multi nucleate cells and macrocells was ascertained in long-term fibroblast cultures in vitro [1]. Binucleate cells, macrocells and multinucleate cells were produced already in the first passage of the cells following a single in vitro exposure of the cultures to PUVA and thereafter in every subsequent passage.…”

Condylomata acuminata with Pigmented Papular Lesions

“…Ultrastructural features of MPBD may also be somewhat similar to those of condylomata acuminata in the aspect of showing perinuclear vacuolization of the kératinocytes in the upper epidermis [5] and human papilloma virus like particles in the nuclei of the kératinocytes beneath the horny layer [3], although they are basically similar to the alterations observed in Bowen's disease [5], From the above findings, it seems that the pigmented papules of condylomata acuminata and of MPBD may essentially be the same kind of lesion. Multinucleated epidermal cell with clumped nuclei which is one of the histological characteristics of Bowen's disease and of MPBD has also been observed in nonneoplastic inflammatory conditions [4,6,7,10,12]. Repeated stripping of the horny layer of the epidermis also produces in creased mitotic figures and multinucleation of the kératinocytes [8].…”