A case report including EM and DNA repair investigations in a dermatosis associated with multiple skin cancers: epidermodysplasia verruciformis

Case for diagnosis

A 27-year-old mixed-raced (pardo) female patient presented with flat ovate hypochromic plaques with a rough surface on the back and upper limbs, with an aspect resembling pityriasis versicolor. She reports family history involving a brother with similar lesions. Lab tests, including anti-HIV, showed no alterations and a histopathological examination showed enlarged keratinocytes with basophilic and microvacuolated cytoplasm occupying the upper portion of the spinous layer and the granulous layer. After anatomic-clinical correlation, the diagnosis of epidermodysplasia verruciformis pityriasis versicolor like was confirmed.

Epidermodysplasia verruciformis. Clinical and light- and electron-microscopic observations during etretinate therapy

Three patients with epidermodysplasia verruciformis (EV) were treated with etretinate for 9-13 months. The patients had lesions characteristic of EV, including flat warts, common genital warts, pityriasis-versicolor-like lesions and malignant changes such as actinic keratosis and Bowenoid cancer in situ. During etretinate treatment, some flattening of the warts was observed in all three patients, and the lesions on the chest and back became less red and scaling. However, none of the lesions disappeared completely, and when the treatment was discontinued, the lesions relapsed. No malignant changes were detected during the period of therapy. Electron microscopy revealed the presence of typical large, clear cells containing viral particles in the upper epidermis. Etretinate therapy induced the same type of fine-structural changes as those seen in keratinization disorders and genodermatoses. The clear cells and virus particles persisted throughout the treatment period. More long-term, controlled studies are necessary to make possible an estimate of the curative and cancer-inhibitory effect of etretinate treatment in patients with EV.

Unscheduled DNA synthesis induced by N-acetoxy-2-acetylaminofluorene is not sensitive to regulation by ADP-ribosyl transferase

We have directly compared in resting human mononuclear leukocytes the DNA repair effects caused by ADP-ribosyl transferase (ADPRT) activity following DNA damage induction by gamma radiation, UV radiation, ethylene oxide (EO) and N-acetoxy-2-acetylaminofluorene (NA-AAF). The presence of inhibitors of ADPRT during the quantitation of unscheduled DNA synthesis (UDS) resulted in about a 2-fold increase of UDS when induced by gamma radiation, UV radiation or EO. The stimulation of UDS by EO, UV- or gamma-radiation in the presence of an ADPRT inhibitor was equally strong whether 1 mM or 10 mM hydroxyurea was used to suppress scheduled DNA synthesis. The level of NA-AAF induced UDS was not affected by inhibitors of ADPRT. In addition, direct estimation of ADPRT activity revealed that at doses giving maximal UDS, NA-AAF damage did not induce a measurable enzymatic activity whereas gamma-radiation, UV radiation and EO all showed a significant dose response increase. We have interpreted our data to mean that NA-AAF induced UDS estimates DNA repair relating mainly to DNA lesions that are recognized with difficulty, and hence, the rate of endonuclease-induced DNA strand break accumulation is not sufficient to allow a stimulation of ADPRT and affect the quantitation of UDS.

Human papillomaviruses associated with epidermodysplasia verruciformis. II. Molecular cloning and biochemical characterization of human papillomavirus 3a, 8, 10, and 12 genomes

The DNAs of four human papillomaviruses (HPVs) that were found in the benign lesions of three patients suffering from epidermodysplasia verruciformis have been characterized. The flat wart-like lesions and the macular lesions of patient 1 contained two viruses, HPV-3a and HPV-8, respectively, whose genomes had previously been only partially characterized. The flat wart-like lesions of patient 2 and the macular lesions of patient 3 each contained a virus previously considered as belonging to types 3 and 5, respectively. These viruses are shown in the present study to be different from all of the HPV types so far characterized; they have tentatively been named HPV-10 and HPV-12. The HPV-3a, HPV-8, and HPV-12 DNAs and the two SalI fragments of HPV-10 DNA (94.1 and 5.9% of the genome length) were cloned in Escherichia coli after having been inserted in plasmid pBR322. The cloned HPV genomes have similar sizes (about 7,700 base pairs), but their guanine-plus-cytosine contents differ from 41.8% for HPV-12 DNA to 45.5% for HPV-3a DNA. The study of the sensitivity of the four HPV DNAs to 14 restriction endonucleases permitted the construction of cleavage maps. Evidence for conserved restriction sites was found only for the HPV-3a and HPV-10 genomes since 5 of the 21 restriction sites localized in the HPV-3a DNA seem to be present also in the HPV-10 DNA. Hybridization experiments, performed in liquid phase at saturation, showed a 35% sequence homology between HPV-3a and HPV-10 DNAs, 17 to 29% sequence homology among HPV-5, HPV-8, and HPV-12 DNAs, almost no sequence homology between the HPV-3a or HPV-10 DNA and the other HPV DNAs, and a weak homology between HPV-9 DNA and HPV-8 or HPV-12 DNA. Blot hybridization experiments showed no sequence homology between the HPV-3a, HPV-8, and HPV-12 DNAs and the DNAs of the HPVs associated with skin warts (HPV-1a, HPV-2, HPV-4, and HPV-7) or with mucocutaneous and mucous membrane lesions (HPV-6b and HPV-11a, respectively). One exception was a weak sequence homology between the HPV-2 prototype and HPV-3a or HPV-10 DNA.(ABSTRACT TRUNCATED AT 400 WORDS)

Direct comparison, in humans resting lymphocytes, of the inter-individual variations in unscheduled DNA synthesis induced by N-acetoxy-2-acetylaminofluorene and ultraviolet irradiation

Unscheduled DNA synthesis (UDS) in human leukocytes has become a popular tool for estimating an individual's DNA-repair capacity and sensitivity to mutagens. The physical induction of UDS by UV-irradiation, as opposed to the chemical induction of UDS by N-acetoxy-2-acetylaminofluorene (NA-AAF), has yielded contradictory reports in the literature regarding inter-individual variations relating to risk factors such as age. In an effort to resolve this anomaly, we have compared directly, in duplicate lymphocyte samples from 29 male individuals, the UDS induced by 10 microM NA-AAF and UV-irradiation of 10 J . m-2. The kinetics of UV-induced UDS was very "fast", being 50% complete within 2.5 h whereas the corresponding value for NA-AAF-induced UDS was 7 h. Consistent with our previous studies, individual variations in NA-AAF-induced UDS were positively correlated to age. However, a strong tendency toward both positive and negative correlations to an individual's age could be calculated depending on whether "fast"- or "slow"-UV-induced DNA repair was taken into consideration. These data, therefore, question the validity of previous reports establishing DNA-repair deficiencies when UV-induced UDS was used for quantitation and the "fast" UV repair was only partially estimated because of early delays in the 3H-dThd pulse. If appropriately pulsed with 3H-dThd, then the inter-individual fluctuations in NA-AAF- and UV-induced UDS correlated to each other in a highly significant linear manner (r = 0.51, p less than 0.01). Basic similarities between NA-AAF- and UV-induced UDS were also observed when both parameters correlated to the phytohemagglutinin responsiveness of the lymphocytes. A working hypothesis, based on environmentally influenced changes in chromatin structure regulating the relative accessibility of NA-AAF- and UV-induced lesions for repair, was formulated to explain the parallel inter-individual fluctuations of NA-AAF- and UV-induced UDS.

UV-induced DNA repair in hairy cell leukaemia patients

We analysed by liquid scintillation counting and by autoradiography the DNA repair synthesis induced by UV irradiation in mononucleated cells from peripheral blood of 'hairy cell leukaemia' patients. In 9 out of 12 patients the repair activity values obtained in repeated assays were found to be significantly lower than those of healthy donors.