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A R Teyssie

Publications and source records attributed to A R Teyssie.

11 recordsLinked to original sources
PubMed2001

Physical status of the E2 human papilloma virus 16 viral gene in cervical preneoplastic and neoplastic lesions.

BACKGROUND: Integration of human papilloma virus (HPV) 16 DNA is considered an important genetic change in cervical lesion progression towards ICC. The viral E2 gene is often disrupted by this process, releasing suppression of viral E6/E7 oncogenes, a key factor for oncogenic progression. OBJECTIVES: To evaluate the physical status of HPV 16 E2 gene in cervical preneoplastic and neoplastic lesions and its relation with lesion severity. STUDY DESIGN: A sensitive PCR approach for the detection of an intact E2 HPV 16 gene in infected epithelial cells from the cervix with low grade squamous intraepithelial lesion (LGSIL), high grade squamous intraepithelial lesion (HGSIL) and invasive cervical carcinoma (ICC) diagnosis was applied. The correlation between gene disruption and lesion stage was examined. RESULTS: Sixty-two LGSIL, 39 HGSIL and 24 ICC samples were analyzed. Fifty-seven LGSIL [92%], 13 HGSIL [33%] and 4 ICC [17%] showed results compatible with an intact E2 gene, while 5 LGSIL [8%], 26 HGSIL [67%] and 20 ICC [83%] samples gave no signal. CONCLUSIONS: HPV 16 E2 gene disruption showed a positive correlation with cervical lesion progression, particularly from LGSIL to HGSIL. Although additional genetic events are very likely to be needed for HGSIL to ICC progression, the E2 gene disruption is a putative early marker to consider in the prognostic analysis of HPV 16 chronically infected women.

Adult↗
PubMed2000

[Molecular variants of human papillomavirus (HPV) types 16 and 18 in adenocarcinomas of the cervix].

Human Papillomavirus (HPV), placebo clinical trial particularly types 16 and 18, are considered human carcinogens since an etiological association has been demonstrated between these viruses and the development of cervical cancer. While the viral role in squamous carcinoma has been largely studied, the information available on adenocarcinoma is scarce, partly because of its lower frequency. In this paper we investigated the presence of HPV types and intratype variants in adenocarcinomas of the cervix. A total of 23 archive samples, fixed and paraffin embedded biopsies, were included. The detection and viral typing was performed by generic PCR and subsequent single stranded conformational polymorphism analysis (SSCP). Genetic variability was investigated in a 450 bp-fragment corresponding to L1 gene by post-PCR direct sequencing. We detected 11 HPV 16 positive samples (9 prototypes and 2 variants: 1 European and 1 Asiatic-American), 10 HPV 18 (9 prototypes and 1 European variant), 1 HPV 31 and 1 negative. The high risk HPV association with this neoplasia was confirmed with a high prevalence (43%) of HPV 18, (but) without predominance over the other types as previously published. The demonstrated variability in L1 protein epitopes originated aminoacidic changes which could have implications on the immune response and therefore should be considered in a vaccine design.

Adenocarcinoma↗
PubMed2000

[Ha-ras and p53 gene mutations scanned by PCR-SSCP in premalignant and malignant lesions of the uterine cervix associated with human papillomavirus].

The aim of this study w trial randomized as to investigate the frequencies of human papillomavirus (HPV) and mutation in Ha-ras oncogene and tumour suppressor p53 gene in cervical cancer and precursor lesions. A total of 30 invasive carcinomas (IC), 36 cervical intraepithelial neoplasia grade III (CIN III) and 12 normal tissues adjacent to the tumor (NT) were included. HPV typification and scanning of possible mutations in Ha-ras and p 53 genes were made by SSCP-PCR. The IC cases showed 93% HPV positivity, 41% having mobility shifts for Ha-ras mutations and 17% for p53 mutations while in CIN III, these percentages were 80%, 18% and 11%, respectively. In normal tissues HPV frequency was 17%. All Ha-ras mutated samples were HPV positive but 33% of p53 mutated cases were HPV negative. All mutations were heterozygous. HPV 16 was more prevalent (44%) than HPV 18 (15%) and the high rate of undetermined HPV types (18%) would indicate the circulation in our country of other types different from the assayed HPV controls (6, 11, 16, 18, 31 and 33), being variants or mixed infections. The low frequency of p53 mutations (17%) strengthens the view that wild type p53 inactivation by HPV probably plays a major role in the pathogenesis of cervical cancer. Because mutated Ha-ras was found in HPV associated premalignant lesions, we speculate that it represents an early marker for progression. Our findings provide additional evidence for an interactive effect between high risk types of HPV and oncogene activation in the development of uterine cervical cancer.

DNA, Viral↗
PubMed1975

Interferon induction by a tumoral DNA in an homologous culture system.

The interferon induction by Rous sarcoma DNA in an homologous culture system and a further insight of its kinetics and antimetabolites action were the principal aim of the present study. There was a direct relation between the dose of the inducer and the protection against the cytoplathogenic effect of the challenging virus (VSV) reaching the highest activity (68-75% CPE inhibition) with 100 mug RS-DNA. The kinetics of the induction revealed a peak inhibition by 18 hours after the inducer. Treatment with Actinomycin D evidenced that both interferon production and activity are modified. Its early addition resulted in a poor protection; but an accentuated interferon release was observed when antimetabolite was added 18 hours after the inducer. Similar results were obtained when its effect was studied on the activity of exogenous interferon. Interferon induction by Rous sarcoma DNA in an homologous system, allows the detection of a difference between tumoral and normal DNA at a biological level.

Animals↗