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Biomedical subjects

Y Chardonnet

Publications and source records attributed to Y Chardonnet.

At least 37 records · Page 2Linked to original sources

Heterogeneous immunoreactivity of frozen human benign and malignant breast lesions to C-MYC and C-Ha-ras cellular oncogenes.

C-myc and c-Ha-ras oncoprotein expression was studied by immunohistochemistry and gene detection by in situ hybridization on serial frozen sections of 32 breast lesions (19 benign biopsies and 13 infiltrating carcinomas). C-myc protein was expressed in 15/19 benign and 12/13 malignant lesions; c-myc gene was detected in 17/19 benign and 13/13 malignant lesions. Although a higher proportion of benign biopsies (8/9) showed more than 50% of protein-positive cells than malignant specimens, this cannot predict the outcome of a lesion. Conversely, p21 ras protein was expressed only in 2/19 benign lesions and in most cases of grade I to III carcinomas. The c-Ha-ras gene was always detected in a small percentage of cells, in both benign and malignant lesions. The results obtained with atypical hyperplasia, a doubtful proliferating lesion, suggests that p21 c-Ha-ras protein expression is not restricted to breast carcinomas. Although Southern blot is commonly considered as a very sensitive technique for oncogene analysis, no amplification of c-myc and c-Ha-ras gene has been demonstrated either in benign or malignant lesions. The detection, on serial frozen sections, of proteins and DNA of c-myc and c-Ha-ras, showed a possible amplification of the c-myc and c-Ha-ras genes in various benign and malignant lesions.

Adult↗

Low incidence of c-Ha-ras gene mutations in benign and malignant cutaneous lesions from transplant recipients.

Transplant recipients successively develop benign, premalignant and malignant skin lesions on sun-exposed areas. It has been suggested that UV radiations might induce mutations in ras oncogenes and p53 tumour-suppressor gene, responsible for skin cancers. With PCR and oligoprobe hybridization, we investigated c-Ha-ras gene mutations at codons 12 and 61 in 120 cutaneous lesions from grafted patients, since they could represent a marker of the evolution of benign skin lesions towards malignancy in this population; 29 similar skin biopsies from non-immunosuppressed patients were also analyzed. In transplant recipients, we detected mutations at codon 12 only in 1/42 non-melanoma skin cancers and 2/29 pre-cancerous keratoses. No mutation was detected in 11 cases of cutaneous Bowen's disease from grafted patients and in pre-malignant and malignant skin samples from control patients. Benign warts exhibited an overall incidence of 18% and 15% of mutations at codon 12 of c-Ha-ras gene in grafted and control patients respectively. We detected only one mutation at codon 61 in a plantar wart. Human papillomaviruses (HPV) are thought to be involved in the malignant evolution of cutaneous disorders in transplant recipients and cooperate with a ras oncogene to induce malignancy in vitro. The presence of HPV DNA in our series of skin samples from grafted patients showed no correlation with the occurrence of c-Ha-ras mutations. Our findings indicate that c-Ha-ras-gene activation by mutations is rare in cutaneous lesions from transplant recipients, and is unlikely to play a crucial role in transformation towards malignancy in skin carcinogenesis among grafted patients.

Animals↗

Association of skin malignancies with various and multiple carcinogenic and noncarcinogenic human papillomaviruses in renal transplant recipients.

BACKGROUND: Organ transplant recipients receiving immunosuppressive treatment are prone to skin carcinomas on sun-exposed areas, and the frequency of such carcinomas in the long term reaches 40%. These carcinomas primarily are squamous cell carcinomas (SCC), which often are preceded by viral warts and premalignant keratoses. Human papillomaviruses (HPV) with other cocarcinogenic factors have been reported to play a role in the development of carcinomas in these patients. METHODS: Five hundred renal-graft recipients referred to our department were examined for the presence of warts, precancerous keratoses, Bowen disease, keratoacanthomas, and basal and squamous cell carcinomas. Adequate material for histologic and virologic examination was obtained from 24 patients. An in situ molecular hybridization technique was performed using biotinylated DNA probes for HPV types 1a, 2a, 5, 16, and 18 under stringent conditions. RESULTS: HPV DNA was detected in 44 of 86 specimens, including 14 of 17 warts, 4 of 17 premalignant keratoses, 1 of 4 Bowen disease lesions, 8 of 12 keratoacanthomas, 3 of 4 tumors in which distinction between keratoacanthomas and SCC was difficult, and 14 of 30 SCC. Twenty-six of 44 positive specimens contained several HPV types, whereas 30 specimens contained oncogenic types. Benign types 1 or 2 were detected alone in five SCC. HPV types 16 and 18 (usually detected in genital lesions) were found in 26 samples from sun-exposed areas. CONCLUSIONS: Our results show that oncogenic and benign HPV often are detected within premalignant keratoses and SCC in organ transplant recipients, which suggests that HPV may play a role in the development of cutaneous malignancies.

Adult↗

Detection of human papillomavirus DNA in CaSki and HeLa cells by fluorescent in situ hybridization. Analysis by flow cytometry and confocal laser scanning microscopy.

CaSki and HeLa cell lines, isolated from human uterine carcinomas and containing integrated human papillomavirus (HPV) DNA type 16 and 18, respectively were used to evaluate the sensitivity of HPV-DNA detection on suspended cells by fluorescent in situ hybridization using flow cytometry and on corresponding cell deposits using confocal laser scanning microscopy (CLSM). HPV DNAs were detected in cell suspensions with biotinylated DNA probes and revealed with a three-step technique: a rabbit antibiotin antibody, a biotinylated goat anti-rabbit antibody and a streptavidin-fluorescein isothiocyanate complex. By flow cytometry, HPV DNA was detectable only in CaSki cells which contained about 600 copies of HPV DNA per cell. In HeLa cells, with only 20-50 copies of HPV DNA, flow cytometry could not detect HPV DNA, whereas CLSM permitted visualization of fluorescent labelling of HPV DNA hybrids. Furthermore, CLSM showed good preservation of cellular morphology and the nucleus was clearly recognizable after fluorescent in situ hybridization and counterstaining with propidium iodide. Moreover, this examination confirmed that the fluorescent foci were specifically confined to the cell nuclei.

DNA, Viral↗

Expression of immune associated surface antigens of keratinocytes in human papillomavirus-derived lesions.

The expression of immune associated surface antigens of keratinocytes was studied in human papillomavirus (HPV) derived lesions in order to determine whether HPV types have a regulatory role in the pathogenesis of papillomas. A series of cutaneous and mucosal lesions were immunolabeled with monoclonal antibodies to the major histocompatibility complex class 1 (beta 2-microglobulin) and 2 (HLA-DR antigens), intercellular adhesion molecule (ICAM-1) and glycoprotein CD36 (OKM5) as well as CD1a (Langerhans cells), CD4, CD8 (T cells) and CD11a (LFA1 antigen). Testing for the presence of HPV was carried out by in situ hybridization with biotinylated probes for viral DNA detection and typing. We observed a drastic reduction or a loss of beta 2-microglobulin by keratinocytes from cutaneous lesions in correlation with the disappearance of Langerhans cells. Only mild alterations were observed in mucosal lesions. HLA-DR expressed by keratinocytes was only detected in condylomas and laryngeal papillomas and was usually associated with a dense inflammatory reaction. This HLA-DR expression may be correlated with an up-regulation of ICAM-1 and the presence of LFA1 positive leukocytes, mainly of CD8 phenotype, in the epithelium. CD36 was detected on differentiated keratinocytes of all lesions; its expression seems related to the proliferation state of the lesions and probably does not represent an immune marker. The different reactivity patterns observed in cutaneous and mucosal lesions may reflect: 1. different roles for mucosal and cutaneous HPV types in the induction of immunoregulatory surface antigens of keratinocytes, or 2. the changing nature of the cytokines released by mononuclear cells and infected keratinocytes in these lesions.

Adolescent↗

Detection of mucosal human papillomavirus types 6/11 in cutaneous lesions from transplant recipients.

Transplant recipient develop multiple cutaneous lesions. We have identified human papillomavirus (HPV) DNA in these lesions using three different techniques, namely polymerase chain reaction (PCR), in situ hybridization, and Southern blotting. By PCR, HPV DNA was detected in 43 of 62 samples: warts, actinic keratoses, Bowen's disease, and squamous cell carcinomas. Surprisingly, HPV 6/11, usually associated with mucosa, were frequently found in benign, premalignant, and malignant cutaneous lesions (30/43 cases). Some of these biopsies were simultaneously tested by in situ hybridization and/or Southern blotting. By in situ hybridization, HPV 6/11 were identified in two warts and one squamous cell carcinoma among 29 tissue specimens tested. Of the three samples examined by Southern blotting, HPV 6/11 were detected in one squamous cell carcinoma. In patients from a control population cutaneous biopsies did not exhibit HPV types 6/11 except in Bowen's disease; HPV types 1 or 2 were mainly found in benign warts. These findings suggest that in transplant recipients, HPV can lose their specificity towards mucosa or cutaneous epithelium. The significance of the presence of HPV 6/11 in skin lesions remains unknown.

Base Sequence↗

Epidermotropism of T cells correlates with intercellular adhesion molecule (ICAM1) expression in human papillomavirus (HPV)-induced lesions.

Adhesion molecules play an important role in inflammatory reactions. Among them, ICAM1, a ligand for the lymphocyte function-associated antigen (FLA1) of leucocytes, may be expressed by antigen-presenting cells and keratinocytes in various inflammatory disorders. As cell-mediated immune responses play a great role in HPV infections, we investigated the expression of ICAM1 and correlated it with the presence of LFA1-positive cells by immunohistochemistry on serial frozen sections of a series of non-regressing cutaneous and mucosal HPV-induced lesions. ICAM1 expression by keratinocytes was observed only in intensely infiltrated lesions of condylomas and laryngeal papillomas. Its induction was usually correlated with the presence of LFA1-positive cells (mainly CD8-positive cells) which were in close apposition to ICAM1-positive proliferative epithelial cells expressing also, in some cases, HLA-DR antigen. ICAM1 was not correlated with the presence of HPV DNA or viral antigen. In moderately infiltrated lesions, keratinocytes did not express ICAM1, and LFA1-positive cells were not observed in the epidermis. In all lesions, ICAM1 was more intense on endothelial cells than in normal skin; infiltrating cells (lymphocytes and dendritic cells) may also express this antigen but intraepithelial Langerhans cells were devoid of any labelling. These studies provide further evidence that T-lymphocyte mechanisms are important in the host response to HPV-induced lesions. ICAM1 expression correlates with a lesional infiltrate but not with HPV infection and probably results in a more efficient initiation of the immune reaction.

CD4 Antigens↗

Detection of multiple types of human papillomavirus in a giant condyloma from a grafted patient. Analysis by immunohistochemistry, in situ hybridisation, Southern blot and polymerase chain reaction.

Immunosuppressed patients such as transplant recipients are known to develop multiple lesions suggestive of human papillomavirus (HPV) infection. A giant anal condyloma was obtained from a transplant patient; several fragments taken from different areas were examined for the presence of HPV DNA using in situ hybridisation, polymerase chain reaction (PCR) and Southern blot. Typical koilocytes were seen in routinely stained tissue sections, suggesting an HPV infection; furthermore, group specific HPV antigen was detected in one of four frozen fragments. Different results were obtained by in situ hybridisation according to the fragment tested. HPV types 6/11 were detected in each of the five fragments, frozen or fixed in Bouin's or formalin solutions. However, the number of HPV DNA positive cells and the intensity of the reaction greatly varied with the specimen. HPV 16 and 18 probes also reacted positively with the sample fixed in formalin; a stronger signal was observed with HPV 18 in one large focus than with HPV 16. HPV type 5 was detected in a few isolated cells of two frozen fragments. With the Southern blot technique, the profile of an HPV 6/11 was seen only in one of two frozen fragments; in this case, the bands were intense. A slight positive reaction was also obtained in one frozen fragment with HPV 16 probe. Four frozen fragments were analyzed with PCR: HPV 6/11 was detected in each fragment; HPV 18 was detected in the four samples but with different intensities; HPV types 5 and 16 did not show any positive signal. In conclusion, the lesion is an example of infection with several HPV types, demonstrated by three different techniques. This suggests the need for careful dermatological or colposcopic follow-up of transplant recipients, in order to prevent possible malignant transformation of anogenital lesions.

Adolescent↗

c-myc and c-Ha-ras cellular oncogenes and human papillomaviruses in benign and malignant cutaneous lesions.

To analyze the role of human papillomavirus (HPV) infection and c-myc and c-Ha-ras oncogene activation in cutaneous and mucosal lesions, serial frozen sections of 47 lesions from grafted recipients and 10 biopsies from non-immunosuppressed patients were examined. HeLa, CaSki, MCF7, Colo 320 and 3T3 cells, which contain various copy numbers of HPV DNA and/or c-myc gene, were used as controls. HPV, myc and ras oncogene DNAs were not detected in normal epithelia by in situ hybridization with biotinylated DNA probes. The amplification of ras oncogene was detected in 20/57 lesions. The amplification of myc oncogene was found in 14/57 lesions, 13 of which showed both myc and ras gene amplification. c-myc and/or c-Ha-ras DNA was more frequently amplified in cutaneous squamous cell carcinomas (8/14 cases) and anogenital papillomas (4/6 cases), than in common and plantar warts (3/14 cases) or actinic keratoses (2/10 cases). HPV DNA was detected in 26/57 biopsies. Oncogene amplification was codetected with HPV DNA in 10/26 lesions, each of them containing at least one potentially oncogenic HPV type (5,16 and/or 18). The amplification was also found in 11/31 cases in the absence of HPV DNA. No significant difference was observed in the detection of HPV or oncogene DNA between the lesions of transplant recipients and those of the non-immunosuppressed population. Viral antigen was detected in 17/55 lesions by indirect immunofluorescence; 5 of the positive biopsies showed ras oncogene amplification. Myc and ras p21 oncoproteins were respectively localized in the nuclei and on the membrane of epithelial cells by indirect immunofluorescence. A good correlation was observed between the amplification of oncogenes and the expression of oncoproteins. Our results favor the hypothesis of a cooperation between HPV infection and myc and ras oncogene activation in skin carcinogenesis.

Blotting, Southern↗

Human papillomavirus DNA in cervix. In-situ hybridization with biotinylated probes on Bouin's fixed paraffin embedded specimens.

We examined retrospectively a series of 65 Bouin's fixed, paraffin-embedded tissue specimens from 8 condylomatous lesions, 16 condylomas associated with cervical intraepithelial neoplasia (CIN), and 12 neoplasia without condylomatous signs, for histological characteristics, the detection of viral structural antigen, the presence and typing of HPV DNA by molecular in situ hybridization with biotinylated probes types 6, 11, 16 and 18 under stringent conditions (Tm - 12 degrees C). HPV DNA was present in 34/65 (52%) specimens. Detection of viral structural antigen was positive in only 14% (3/22) specimens. HPV DNA were identified in 9/9 (100%) condylomatous lesions (with HPV type 6, 11, 18). Three condylomas were coinfected with both HPV type 6 or 11 and type 18; viral antigen was found in two specimens. HPV DNA were detected in 18/31 (58%) low grade and advanced CIN associated with condylomatous changes (type 6 = 5 specimens, type 11 = 3 specimens, type 16 = 4 specimens, type 18 = 6 specimens). Four of these cases were coinfected with both HPV type 6/11 and HPV type 16/18. Viral antigen was negative in all specimens. HPV DNA were detected in 7/25 (28%) advanced intra-cervical neoplasia (CIN III) without anatomopathological condylomatous changes (type 6 = 1 specimen, type 16 = 3 specimens, type 18 = 3 specimens). One of these specimens contained both HPV types 6 and 18. Viral antigen was found in one case. Our data confirm the association of HPV types 6 and 11 with condyloma and low grade neoplasia; HPV types 16 and 18 were associated with advanced cervical neoplasia.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetates↗

Influence of fixation on human papillomavirus DNA detection in frozen and embedded paraffin lesions by in situ hybridization with biotinylated probes.

Series of frozen or paraffin-embedded tissues from various body sites, taken from non-immunosuppressed or immunosuppressed patients with persistent papilloma lesions were examined for the presence of group specific antigen from human papillomavirus (HPV) by indirect immunofluorescence or HPV DNA by in situ hybridization with biotinylated probes. We have shown that it is possible to detect HPV DNA after fixation of tissues in neutral formalin, Bouin's or Baker's solution. However, the sensitivity was reduced as compared to frozen tissues. The HPV DNA was detected in nuclei of heavily infected epithelial cells such as plantar or hand warts or in dispersed cells containing high copy numbers of HPV DNA from lesions such as squamous cell carcinomas or keratoacanthomas. In premalignant or malignant lesions of both immunosuppressed or non-immunosuppressed patients, HPV DNA was rarely detected after fixation. HPV types commonly described for skin and genital samples were identified in non-immunosuppressed patients, whereas in transplant recipients oncogenic HPV type 16 was identified in benign warts as well as in premalignant or malignant lesions. Positive reactions with several HPV types were more frequent in lesions from grafted patients than from the normal population. Virus antigen was detectable more frequently in frozen sections than in fixed tissues. Our findings indicate that in situ hybridization is an appropriate and rapid technique to study the presence of HPV infection. However, numerous controls are needed to avoid misinterpretations.

Antigens, Viral↗

Langerhans cells, inflammation markers and human papillomavirus infections in benign and malignant epithelial tumors from transplant recipients.

Organ transplant recipients frequently develop warts which progress toward premalignant or malignant lesions after a rather long grafting period. The local immune responses of such lesions (warts, condyloma acuminata, actinic keratoses, Bowen, basal and squamous cell carcinomas) was studied in 32 frozen skin specimens taken from 15 male transplant recipients and compared to similar lesions from the normal population. We studied the expression of T cell subsets, Langerhans cell phenotype, HLA class 1 (beta 2-microglobulin), HLA class 2 (DR antigen), and intercellular adhesion molecule 1 (ICAM 1). The presence of HPV infection was also considered, using in situ hybridization with biotinylated probes in order to examine the correlation with immunological markers. In the dermis, the lesions from grafted patients showed a moderate to intense inflammatory reaction of HLA-DR-positive cells. Most of these cells were CD4+ and CD8+ without any predominance of a single T cell subset. In the epidermis, most lesions were characterized by a reduced number of CD1-positive cells; this was concomitant with a decrease or a loss of beta 2-microglobulin expression by epithelial cells. HLA-DR antigen was not expressed by keratinocytes or tumoral cells in any specimen; ICAM 1 antigen was observed in a few cases. The expression of these markers was similarly modified with or without the presence of HPV DNA. Conversely, most lesions from non-immunocompromised patients, except warts, showed intense inflammatory reactions, with a predominance of CD4-positive cells and large foci of ICAM 1-positive cells. Expression of activation markers by keratinocytes occurred mainly in condylomas and squamous cell carcinomas. In the normal population, HPV infection was only detected in papilloma lesions. These data indicate, in lesions from grafted patients, a lack of effective immune response with partial inhibition of activation markers expressed by keratinocytes. It is conceivable that immunosuppressive treatment with solar exposure may also be responsible for the local immune deficiency and thus for the conversion of benign warts toward malignant lesions in grafted patients.

Adult↗

Human papillomavirus detection in cervical cells by in situ hybridization with biotinylated probes.

We have investigated the applicability of human papillomavirus (HPV) DNA detection by in situ hybridization with biotinylated probes in epithelial cells obtained from the cervix using a cotton tip swab. We describe a simple procedure for obtaining homogeneous cell samples and good preservation of cellular structure. This is achieved by pretreatment of cells with L-cysteine before hybridization. Separate denaturation of cellular DNA and probe DNA is also necessary for satisfactory results. Both benign HPV DNA 6/11 and potentially oncogenic HPV DNA 16/18 could be identified in our series. In situ hybridization on cervical scrapes is a rapid, simple and very specific method for detecting patients infected with oncogenic HPV types.

Adult↗

Evaluation of human papillomavirus type 5 on frozen sections of multiple lesions from transplant recipients with in situ hybridization and non-isotopic probes.

Transplant recipients are at high risk to develop multiple cutaneous lesions after grafting. The frequency of the potentially oncogenic human papillomavirus (HPV) type 5 DNA was evaluated in cutaneous lesions taken from sun-exposed areas in transplant recipients (92 lesions and 5 samples from normal skin) and compared with a nontransplanted population (22 lesions and 7 samples from normal skin) using in situ hybridization and biotinylated probes to HPV types 1, 2, 5, 16 and 18. HPV type 5 DNA was identified in 8/92 cutaneous lesions of transplanted recipients: 3 warts, 1 case of seborrheic keratosis, 2 actinic keratoses and 2 keratoacanthomas. HPV type 5 DNA was not detected in 27 malignant tumors (8 basal cell carcinomas and 19 squamous cell carcinomas) from transplant recipients. HPV DNA type 5 was detected in only 1 case of squamous cell carcinoma from the general population. The presence of HPV DNA 5 was confirmed with Southern blotting in 2 out of 6 cases from transplant recipients. The reaction was negative with the squamous cell carcinoma from nontransplant recipients. These data indicate that the presence of HPV DNA type 5 is not very frequent; it can be detected with in situ hybridization and nonisotopic probe, which is easier to handle than Southern blot.

Biopsy↗

[Malpighian epithelia and papillomavirus infections].

Human papillomaviruses (HPV) are a large group of DNA viruses, with over 60 types identified to date, which can cause the development of benign tumors in the skin and mucosal squamous epithelia. Most of these tumors regress spontaneously but some, especially in the mucosal membranes, become malignant. HPV types with a high risk for inducing malignancies (e.g. 16 and 18) are the subject of increasing interest. HPVs are both host-specific and tissue-specific: some types preferentially infect specific epithelia, giving rise to lesions with distinct topographic characteristics. HPVs are difficult to study because they do not replicate in available in vitro models. In vivo, HPVs replicate well in epithelial cells undergoing terminal differentiation, e.g. in keratinized cells. Some 40 different types have been reported in epidermal keratinocytes, the most common being types 1 and 2 which produce large amounts of viral antigens and viral particles. In contrast, HPVs replicate poorly in the weakly keratinized squamous epithelia which line the digestive, respiratory, and genital tracts. Junctional epithelia, e.g. on the uterine cervix, are especially prone to HPV infection. The most prevalent HPV types in benign genital lesions are types 6 and 11, whose characteristic features include extrachromosomal DNA and production of only small amounts of viral antigens. The profound nuclear and cytoplasmic changes induced by HPVs lead to the formation of koïlocytes which are found mainly in the granular layer of epithelia and have been especially well described in the uterine cervix and vagina. HPV epithelial tumors are squamous cell carcinomas that often harbor HPV types 16 and 18; this is especially true of cervical intraepithelial neoplasias.(ABSTRACT TRUNCATED AT 250 WORDS)

Anus Diseases↗

[Human papillomaviruses and cellular oncogenes (c-myc, c-Ha-ras) in cutaneous and mucosal lesions in transplantation recipients].

Transplant recipients develop numerous benign and malignant cutaneous and mucosal lesions in which histological signs of human papillomavirus (HPV) infection are observed. To investigate the role of HPV and c-myc and c-Ha-ras cellular oncogenes' activation in transplanted patients lesions, we used in situ hybridization with biotinylated probes and Southern blot to detect HPV and oncogenes DNA. We analyzed 36 lesions from grafted patients: 11 common warts, 10 actinic keratoses, 13 squamous cell carcinomas and 2 anogenital papillomas. With in situ hybridization, HPV DNA was detected in 14/36 lesions, 10 of which contained several HPV types. Benign and potentially oncogenic HPV types were detected in warts as well as in squamous cell carcinomas. The Southern blot technique confirmed the distribution of HPV types. Group specific viral antigen was detected in 12 lesions, mainly warts. C-Ha-ras oncogene was amplified in 13 lesions and c-myc oncogene in 10 lesions, 9 of which showed both oncogene amplification. The results obtained with in situ hybridization for c-myc gene amplification were confirmed with the Southern blot technique in 11/14 cases. Ras and/or myc amplification was more frequent in squamous cell carcinomas and anogenital papillomas than in warts and actinic keratoses. The amplification was not always linked to the presence of HPV DNA; however, it was more frequent in lesions infected by potentially oncogenic HPV types than in lesions containing only benign HPV types. Myc and p21 oncoproteins were respectively localized in the nucleus and on the membrane of epithelial cells by immunofluorescence. Most lesions showed a good concordance between the detection of oncogene DNA and proteins. Our results suggest than c-Ha-ras and c-myc cellular oncogenes' activation and HPV infection could play a role in the cancerization of cutaneous lesions from transplant recipients.

Genes, myc↗