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Biomedical subjects

G Orth

Publications and source records attributed to G Orth.

At least 109 records · Page 6Linked to original sources
PubMed1986

Epidermodysplasia verruciformis. Skin carcinoma containing human papillomavirus type 5 DNA sequences and primary hepatocellular carcinoma associated with chronic hepatitis B virus infection in a patient.

In a case of epidermodysplasia verruciformis with impaired cell-mediated immunity and multiple skin cancers human papillomavirus type 5 (HPV5) DNA sequences were demonstrated in a cutaneous squamous cell carcinoma. HPV5 and HPV8 were detected in the benign disseminated skin lesions together with three newly characterized HPVs: HPV17, HPV19 and HPV24. A chronic infection with hepatitis B virus resulting in macronodular cirrhosis associated with a primary hepatocellular carcinoma was also acquired by this patient. This case provides an example of the circumstantial evidence which suggests that certain types of HPV are potentially oncogenic and stresses the importance of immune surveillance in the protection against virus-associated tumors.

Adult↗
PubMed1986

[Human papillomaviruses in the epithelial cells of the cervix uteri: frequency of types 16 and 18. Preliminary results of a clinical, cytologic and viral study].

Between April 1 and June 30 1984, cervical scrapes were taken from 381 women attending the Gynecology Department of the Anticancer Center René-Huguenin. The scrapes were examined for the presence of human papillomavirus (HPV) DNA, by a molecular hybridization method, at the Pasteur Institute. The four HPV types involved in genital pathology, HPV 6, HPV 11, HPV 16 and HPV 18, were studied. Twenty four specimens (6.3%) were found positive: 19 for HPV 16, 3 for HPV 18, 2 for HPV 6 or HPV 11. Results of molecular hybridization were compared with cytological findings. HPV 6 or HPV 11 were detected in cases of mild dysplasia. HPV 16 or HPV 18 were mainly detected in cases diagnosed as severe dysplasia or carcinoma in situ (9 out of 14, i.e. 64.3%), and invasive carcinoma (3 out of 5 cases). The results were further confirmed when virological data obtained with cervical scrapes were compared with the histological diagnosis on biopsies: 14 out of 15 cases of severe dysplasia or carcinoma in situ (93%) and 3 out of 6 cases of invasive squamous carcinoma had been found positive for HPV 16 or HPV 18. Interestingly, four "normal" women (1.3%) with a negative cytology were found positive for HPV 16 or HPV 18. The data obtained by this sensitive and reliable method are useful to the clinician to identify women presenting a high risk of subsequent cervical intraepithelial neoplasia or invasive carcinoma, and, thus, to adapt the treatment and the follow-up of these patients.

Adult↗
PubMed1985

A type-II DNA topoisomerase and a catenating protein from the transplantable VX2 carcinoma.

It has recently been suggested that topoisomerases could be important targets for several DNA intercalating drugs used in cancer therapy. This prompted us to purify and characterize a type II topoisomerase in a highly tumorigenic transplantable rabbit tumor isolated from a skin carcinoma associated with cottontail rabbit papillomavirus. We have found that the decatenating activity present in tumor cells was 40-100 times higher than that in the rabbit liver, while no activity could be found in skin extracts. The type II topoisomerases purified from tumor and liver cells consist of two subunits with molecular masses of about 160 kDa. The conditions of the reactions of relaxation, unknotting and decatenation catalyzed by these topoisomerases II were found to be similar to those observed with enzymes of other eukaryotic cells. In the course of the purification of the VX2 enzyme, we isolated and characterized a protein of about 30 kDa in whose presence the topoisomerase II was able to catenate very efficiently supercoiled DNA molecules. This protein has the same electrophoretic mobility as an H1-2 histone, and cross-reacts with an anti-H1 antiserum. The VX2 topoisomerase II as well as the VX2 tumor should constitute useful models for assays of antitumoral drugs.

Animals↗
PubMed1985

Increased natural killer cell activity in patients with epidermodysplasia verruciformis.

Six patients with epidermodysplasia verruciformis (EV) were studied for natural killer cell (NKC) cytotoxic response of their peripheral blood mononuclear cells against K-562 target cells in an 18-hour chromium 51-release assay. Four patients displayed higher cytotoxic responses than controls did, whereas two others did not differ from controls. Patients with EV who had increased NKC activity were found to be infected with potentially oncogenic human papillomaviruses (types 5, 8, 9, 14, 17, 19, 22, 24, and others), and they have had multiple skin carcinomas and/or Bowen's precancerous dermatosis. Two patients with EV who had normal cytotoxic response were free of skin malignancies.

Adult↗
PubMed1985

Fine structure of the cottontail rabbit papillomavirus mRNAs expressed in the transplantable VX2 carcinoma.

We analyzed the polyadenylated mRNAs transcribed from the cottontail rabbit papillomavirus genomes present in the domestic rabbit transplantable carcinoma line VX2, employing a combination of S1 nuclease mapping and primer extension techniques with vector M13-based single-stranded DNA probes. Each of the two major mRNA species (1,860 and 1,110 bases long) contained two exons which corresponded to the E6-E7 and E2-E4 open reading frames. The splice donor site for these transcripts was located at position 1371 at the beginning of the E1 open reading frame. Consequently, the splicing event did not lead to the fusion of the E region proximal (E6 and E7) and distal (E2, E4, or E5) open reading frames. The translation of the polycistronic RNA could result in the production of E6 and E7 proteins alone or of an additional E1-E4 fusion product if translation reinitiation can occur after the E7 stop codon. A heterogeneity was detected in the 5' ends of the longer transcript; E6 transcripts could thus yield a full-length or a truncated E6 protein. We also detected a minor subset of mRNAs covering the E2-E4 coding region and including at least three species with estimated sizes of 4.2, 2.8, and 1.8 kilobases. All the viral transcripts detected in the VX2 tumor cells were polyadenylated at the same site (position 4367) 20 base pairs beyond the first AATAAA signal which borders the E region.

Animals↗
PubMed1985

Two Shope papillomavirus-associated VX2 carcinoma cell lines with different levels of keratinocyte differentiation and transplantability.

Two cell lines, named VX2T and VX2R, were isolated from the transplantable VX2 carcinoma, a wholly anaplastic tumor established from a carcinoma induced by the Shope cottontail rabbit papillomavirus (CRPV) (J.G. Kidd and P. Rous, J. Exp. Med. 71:813-838, 1940). The CRPV genome was found to be maintained and transcribed in both cell lines, as in the VX2 carcinoma. The VX2T cells retained the tumor-producing capacity in the rabbit and the low expression of epidermal keratinocyte differentiation of the VX2 tumor cells. The VX2R cells, although tumorigenic for nude mice, were no longer serially transplantable in the rabbit and expressed differentiated functions of keratinocytes. These data indicate that the anaplastic characteristic and the transplantability of VX2 carcinoma cells to immune competent allogenic hosts may be lost without any detectable modification of the physical state and transcription of the CRPV genome.

Animals↗
PubMed1985

Specific cell-mediated immunity in patients with epidermodysplasia verruciformis and plane warts.

The characterization of different types of human papilloma viruses made it possible to study the specific immune responses to purified viral antigens in patients with warts. The specific cell-mediated immunity was investigated by means of a leukocyte migration inhibition factor test in 9 patients with epidermodysplasia verruciformis and 4 patients with regressing plane warts. The results show a significant increase in specific cell-mediated reactivity concomitant with the regression of the warts.

Adult↗
PubMed1984

Monoclonal antibodies to the major capsid protein of human papillomavirus type 1.

Two stable monoclonal hybridoma cell lines secreting type-specific antibodies against the human papillomavirus type 1 (HPV-1) were isolated. The monoclonal antibodies detected HPV-1 antigens in frozen sections of HPV-1-induced warts, using immunofluorescence or immunoperoxidase techniques, and they reacted with HPV-1 particles in an immunodiffusion test. The two monoclonal antibodies recognized the major structural viral polypeptide, with a molecular weight of 54 000, and a minor polypeptide, with molecular weight of 76 000, in both the dissociated viral particles and in the wart extracts.

Antibodies, Monoclonal↗
PubMed1984

The search for a culture system for papillomavirus.

Papillomaviruses induce tumors of keratinocytes. Vegetative viral DNA replication and virion assembly are seen in those cells which are in the process of keratinizing or are keratinized. To date, no cell culture system has been developed that permits expression of the complete viral life cycle. Keratinocytes infected in culture may harbor the virus as a stable, replicating episome, but they do not support vegetative viral growth, nor do they become immortalized or transformed. The major obstacle in using keratinocyte cultures may be related to a dual need for transformation and full differentiation. Some animal papillomaviruses have been shown to be capable of transforming cultured murine fibroblasts. The fibroblast model is useful for identifying the viral-transforming gene(s) and their products.

Animals↗
PubMed1984

Clinical observations, virologic studies, and treatment trials in patients with epidermodysplasia verruciformis, a disease induced by specific human papillomaviruses.

We have studied 11 patients with the papillomavirus-induced disease epidermodysplasia verruciformis (EV). Clinical diagnostic features are widespread, long-lasting, pityriasis versicolor-like macules and flat, wart-like papules, both usually occurring in early childhood, with the subsequent development in the third decade of multiple skin cancers of the Bowenoid in situ and squamous cell types, primarily in sun-exposed skin. Virologic studies using the methods of immunofluorescence microscopy, restriction endonuclease analysis, and DNA blot hybridization have shown benign lesions to be associated with one or several types of the human papillomaviruses (HPVs) specifically associated with EV (at least 15 types recognized on the basis of sequence homology studies of molecularly cloned genomes). Skin cancers in these patients were associated with the genomes of either HPV-5, HPV-8 or HPV-14, suggesting that these three viruses are potentially oncogenic. A genetic factor appears to play a role in the pathogenesis of EV, since 5 of our patients were children of consanguineous parents and 2 had siblings also suffering with EV, suggesting a recessive inheritance pattern. Treatment of 4 EV patients with an oral retinoid resulted in partial temporary improvement of benign lesions, and the treatment of 2 patients with intralesional interferon injections into multiple Bowenoid cancers in situ has resulted in the disappearance of these lesions. Finally, EV serves as a model for studying the interplay of oncogenic viruses, genetic and immunologic factors, and sunlight in the production of skin cancer in humans.

Adult↗
PubMed1984

Physical state and transcription of the cottontail rabbit papillomavirus genome in warts and transplantable VX2 and VX7 carcinomas of domestic rabbits.

The physical state and the transcription of the genome of cottontail rabbit papillomavirus (CRPV) in non-virus-producing warts and in the VX2 and VX7 transplantable carcinomas of domestic rabbits were compared. The CRPV DNA present in VX2 and VX7 carcinomas (10 to 20 and 100 to 200 genome equivalents per diploid cell, respectively) was found to be entirely integrated into the cellular DNA, most probably as head-to-tail tandem repeats, in contrast to warts, in which viral DNA (10 to 100 copies per diploid cell) was found only as free, mainly monomeric, molecules. In the VX7 tumor, ca. 50% of the viral DNA molecules were found to be longer than one genome length, indicating that viral DNA rearrangements had occurred. A major viral transcript of 1,250 bases was detected in warts and in VX2 and VX7 carcinomas. Complementary sequences were localized within the E region, the putative transforming region inferred from the nucleotide sequence of the CRPV genome (I. Giri, O. Danos, and M. Yaniv, manuscript in preparation). Analysis of heteroduplexes formed between single-stranded CRPV DNA and polyadenylated RNAs from the VX2 tumor showed that the 1,250-base RNA resulted from the splicing of the sequences corresponding to the open reading frame E6 to those corresponding to the 3' third of E2. A second viral transcript, measuring 2,000 bases, was detected in warts and, in lesser amounts than the 1,250-base species, in VX2 carcinoma, and a 2,100-base RNA was found in VX7 carcinoma. Complementary sequences to these messengers were localized to the same part of the genome as the 1,250-base species and to a contiguous fragment situated upstream. Heteroduplex analysis showed that the 2,000-base species from VX2 carcinoma resulted from the splicing of the sequences corresponding to E6 and E7 to those corresponding to the 3' third of E2. The sequences spliced out upon the maturation of the two messengers of VX2 carcinoma correspond to E1, the two-thirds of E2, and most of E4. Additional transcripts were found in VX7 carcinoma, a major 3,100-base species transcribed from the E region, and several minor species, measuring from 2,400 bases, which all hybridize with a subgenomic fragment contained in the L region encoding the viral capsid polypeptides. This could account for the antiviral antibodies found in animals bearing the VX7 carcinoma.

Animals↗
PubMed1984

Molecular cloning and characterization of the genomes of nine newly recognized human papillomavirus types associated with epidermodysplasia verruciformis.

The genomes of 11 human papillomaviruses (HPVs) found in benign lesions of eight patients suffering from epidermodysplasia verruciformis were cloned in Escherichia coli after insertion into plasmid pBR322. The study of the sensitivity of the cloned HPV DNAs to 14 restriction endonucleases permitted the construction of physical maps. DNA-DNA hybridization experiments, performed under stringent conditions, showed that these viruses represent nine new types, HPVs 14 (with subtypes a and b), 15, 17 (with subtypes a and b), 19, 20, 21, 22, 23, and 24. These HPVs were divided into three groups based on an absent or very weak cross-hybridization among the genomes of the viruses belonging to different groups.

Chromosome Mapping↗
PubMed1984

[Presence of papillomavirus genomes and amplification of the c-myc and C-Ha-ras oncogenes in invasive cancers of the uterine cervix].

Invasive squamous cell carcinomas of the uterine cervix from 12 untreated patients were examined for the presence of human papillomavirus (HPV) genomes and for the state of the oncogenes c-myc and c-Ha-ras. Blot hybridization experiments have demonstrated the presence of the genome of HPV type 16 (HPV 16) in six tumors and that of the genomes of HPV types weakly related to HPV 16 or HPV 18 in five others. In the nine tumors corresponding to advanced stages of the disease (stages 3 and 4) there was a 3-30 fold amplification of c-myc and/or c-Ha-ras. A concomitant amplification of both oncogenes was found in eight cancers. In only one of the three tumors confined to the cervix (stage 1), the oncogene c-Ha-ras was weakly amplified. Neither HPV DNA sequences, nor oncogene amplification were detected in the leukocytes of five patients. Thus, it seems likely that specific HPV types play a role in the development of carcinomas of the uterine cervix, and that cellular oncogenes, activated through an amplification process, are involved in at least some steps of tumor progression.

Adult↗