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Biomedical subjects

E M de Villiers

Publications and source records attributed to E M de Villiers.

At least 19 recordsLinked to original sources
PubMed2006

Intravenous cidofovir treatment for recalcitrant warts in the setting of a patient with myelodysplastic syndrome.

Cidofovir is an acyclic nucleoside phosphonate with broad-spectrum activity against DNA viruses, including human papilloma virus (HPV). However, data on the efficacy of cidofovir in an immunosuppressive setting remain contradictory. We report for the first time on the promotion of the healing of recalcitrant warts in a patient with myelodysplastic syndrome with intravenous cidofovir treatment.

Adult↗
PubMed2001

Opposite regulation of the HPV 20-URR and HPV 27-URR promoters by ultraviolet irradiation and cytokines.

Epidemiological evidence implicates ultraviolet radiation and genetic changes (e.g., p53 mutations) as important factors in the etiology of nonmelanoma skin cancer. Little is known about a possible role of cutaneous papillomaviruses in these tumors. We previously reported both positive and negative regulation of the promoter activity of a number of HPV types by UV irradiation. To determine the underlying mechanism, we examined the influence of pro-inflammatory cytokines and MAP-kinases induced by UV irradiation by transfecting the HPV 20-URR and the HPV 27-URR into the RKO, HaCaT and H1299 cell lines expressing wild-type or mutated p53 or lacking p53, respectively. IL-1alpha, IL-1beta, IL-6, IL-17, TNF-alpha, as well as interferon-alpha, -beta and -gamma activated the promoter in the HPV 20-URR but inhibited the HPV 27-URR promoter. The effect of IL-1alpha and UV light was abolished by the addition of IL-1 receptor antagonist. UV irradiation induced a prolonged activation of JNK in HaCaT and H1299 but not in RKO cells, and its dephosphorylation was enhanced in the presence of p53 and the HPV-URRs.

Androstadienes↗
PubMed2000

Human papillomavirus E7 proteins stimulate proliferation independently of their ability to associate with retinoblastoma protein.

Studies on human papillomavirus type 16 have demonstrated that the product of the early gene, E7, plays a key role in the immortalization and malignant transformation of the host cell. Several of the biological activities of HPV16 E7 are mediated by inactivation of the members of the pocket protein family, pRb, p107 and p130. In this study, we have characterized the in vitro properties of five E7 proteins from benign and malignant HPV types (10, 32, 48, 54, 77). We show that these E7 proteins associate with pRb and p107 with different efficiencies. All E7s increased the proliferative rate of immortalized rodent fibroblasts cultured in 10% calf serum containing medium. This property is completely independent of their ability to associate with the pocket proteins. Furthermore, all E7s, except HPV10 E7, stimulate G1/S progression and activated the cyclin E and cyclin A promoter in the absence of growth factors. This activity also does not correlate with the E7-efficiency of binding the pocket proteins. Together these data provide evidence that different E7s alter the regulation of the cell cycle by diverse mechanism(s). Finally, this comparative analysis of the different E7 proteins demonstrates that the oncogenicity of a HPV type is not determined by the ability of E7 to associate with the pocket proteins.

3T3 Cells↗
PubMed2000

Clinical course and treatment of haemorrhagic cystitis associated with BK type of human polyomavirus in nine paediatric recipients of allogeneic bone marrow transplants.

UNLABELLED: Of a total of 117 bone marrow transplant (BMT) recipients in the period from August 1988 to November 1995, 9 (7.7%) developed haemorrhagic cystitis. This condition was characterized in all nine patients by late onset (day +24 to +50 post-BMT), long duration (1 to 7 weeks), and the excretion of BK virus in the urine, as confirmed by electron microscopy, DNA hybridization and PCR analysis. Adenovirus was not involved. The serological assessment of BK virus-specific IgM and IgG pre- and post-BMT is consistent with viral reactivation in all patients, although a primary infection cannot be absolutely excluded in a single patient. A significant correlation between the use of high-dose busulphan (16 mg/kg) in the preparative regimen and development of haemorrhagic cystitis (P = 0. 0003) was evident. The severe course of the disease in two patients resulted in bladder tamponade; bleeding could not be inhibited with coagulation and laser treatment. Deterioration was prevented by bladder irrigation via a suprapubic catheter. Remission occurred spontaneously in all patients. CONCLUSION: BK virus induced haemorrhagic cystitis in a paediatric bone marrow transplantation recipients is characterized by late onset, long duration, viral reactivation and correlates to high-dose busulphan. Severe bleeding could not be influenced by surgical intervention.

Adolescent↗
PubMed2000

Detection of HPV-20, HPV-23, and HPV-DL332 in a solitary eyelid syringoma.

PURPOSE: To report evidence of many human papillomavirus types occurring in a solitary syringoma clinically appearing as a papilloma. METHODS: A 57-year-old man presented with a 10-year history of an upper eyelid tumor. Histopathology, human papillomavirus-nested polymerase chain reaction, human papillomavirus-DNA cloning into vector pCR2.1, sequencing, and computer-assisted evaluation were performed. RESULTS: Histopathology demonstrated a solitary benign syringoma. HPV-20 and HPV-23 were present in one clone each, and HPV-5-related HPV-DL332 was present in 9 clones. CONCLUSION: Many human papillomavirus types may be detected in an ocular syringoma.

DNA Primers↗
PubMed1999

The promoter of a novel human papillomavirus (HPV77) associated with skin cancer displays UV responsiveness, which is mediated through a consensus p53 binding sequence.

An aetiological role has been proposed for human papillomavirus (HPV) in skin carcinogenesis within the immunosuppressed patient population. To examine this possibility, we have focused on an HPV type that, to date, has been identified only in the cutaneous lesions of renal transplant recipients despite a high degree of sequence homology with other HPVs commonly found in warts in the general population. We report that the non-coding region of this virus, HPV type 77, contains a consensus binding site for the tumour suppressor protein p53, and we show by gel-retardation analysis that this sequence does indeed bind p53. Furthermore, using reporter gene assays, we demonstrate that HPV77 promoter activity is stimulated by UV radiation and that this response is mediated through the p53 binding site. This is the first report of a p53-dependent positive response element within a viral genome. Our results suggest a possible novel mechanism by which specific types of HPV might act as cofactors with UV radiation in cutaneous transformation.

Adult↗
PubMed1999

An interlaboratory study to determine the presence of human papillomavirus DNA in esophageal carcinoma from China.

Esophageal-carcinoma samples originating from the high-incidence area of China were tested in 2 different laboratories, each using a different degenerate PCR approach. Results confirmed the notion that none of the PCR approaches available for HPV-DNA detection today, is optimal for detecting all known HPV types at equal sensitivity and specificity. In combining results obtained in both laboratories, HPV DNA was demonstrated in 20/117 (17.1%) esophageal-carcinoma samples analyzed. HPV DNA was detected in 3/70 (4.3%) diagnostic biopsies, 7/23 (30.4%) surgical specimen and 10/24 (41.6%) cytological scrapings originating from the entire surface of the esophagus. Mucosotropic HPV types were present in 7/117 (6%) samples, only 3 being of the high-risk types (HPV 16, 18, 33). Other mucosal types found were HPV 6, 11, 13, 53 and 54. Cutaneous HPV types were present in 14/117 (12.0%) samples. HPVs 20 and 38 were present in 3 (2.6%) of the total samples and, in each case, together with another HPV type within one lesion. Two putative new HPV types, DL347 and DL 369, were identified.

Adult↗
PubMed1999

Papillomavirus in esophageal papillomas and carcinomas.

Human papillomavirus (HPV) has been implicated as a possible etiological factor in the development of squamous-cell carcinoma of the esophagus. Published data demonstrating HPV DNA in these lesions have been conflicting, varying between failure to detect HPV DNA to detection of up to 60% to 70% of the biopsies harboring HPV DNA, mainly HPV 16 and HPV 18. We have analyzed esophageal carcinoma samples from 2 high-risk areas, China and South Africa, using a degenerate PCR approach. All amplified products were cloned and sequenced. A broad spectrum of HPV types was demonstrated in 10/29 samples from China and 9/34 samples from South Africa. HPV types detected included mucosal types HPV 6, 18, 51, 52 and 57; cutaneous types HPV 9, 20, 24 and 25; and the putative new HPV types DL231, DL428 and DL436, with HPV 6/51, 6/57, 20/9 and 20/DL231 occurring as double infections. HPV 6 predominated (4 samples) in 11 esophageal papillomas originating from patients in Europe and tested for HPV DNA. Other HPV types present included HPV 20, DL284 and DL436. Another putative new HPV type, DL416, was identified in a dysplastic lesion of the esophagus.

Adult↗
PubMed1999

Human papillomaviruses in non-melanoma skin cancer.

Recent data suggest that additional factors, other than UV radiation, are involved in the etiology of non-melanoma skin cancer. These include alterations in the tumor suppressor genes, p53, p16$L*I*U$LINK4a$L*I$L/CDKN2A, p21$L*I*U$LWAF1/CIP1$L*I$L and the PTCH gene, as well as cytokines. Papillomavirus infections have been implicated in the etiology of non-melanoma skin cancer. The interaction of tumor suppressor genes and cytokines with the oncoproteins of high-risk mucosal HPV types have been studied in detail, but very little is known about the cutaneous HPV types. We have studied the effect of UV radiation on the URRs of HPV 1, 2, 3, 5, 7, 20, 23, 27, 38, 41, and 77. Neither the CAT-expression and promoter activity of these HPV types, nor presence or absence of wild-type or mutated p53 in the cell lines used, could be related to the DNA sequence homology between the different HPV types or their biological behavior.

Cyclin-Dependent Kinase Inhibitor p21↗
PubMed1999

[Detection of human papillomavirus types in tumors and inflammations of the eye].

BACKGROUND: Infections by the human papillomavirus occur in the skin and in the mucosa. They may play a significant role in the neoplastic transformation of cells. At least half of all the epithelial tumours of the ocular surface and the lacrimal drainage system have been shown to be HPV associated. However, in ca. 50% of these tumors only a limited number of mucosal HPV types could be detected by commercially available test systems. This study reports of HPV specific sequences in putatively HPV associated tumorous and inflamed tissues of the eye. MATERIALS AND METHODS: 32 biopsies of 26 patients suffering from chronic hyperplastic lesions of the lid, conjunctiva and lacrimal drainage system were examined using DNA extraction, amplification of HPV specific sequences by nested polymerase chain reaction (PCR), cloning and sequencing of the PCR products. RESULTS: Ten HPV types could be detected in 11 biopsies of 8 patients with papillo-mas, seborrheic and actinic keratosis, dacryocystitis and syringoma. In 5 of 9 histologically verified papillomas HPV 6, 20, 23, DL 332 (HPV 5b-related), DL 284 (HPV 20-related) and NN-AA44 were detected, HPV 5b, 38 and DL 284 in seborrheic keratoses, HPV 36 in actinic keratosis, NN-AA44 und NN-AA45 in dacryocystitis and HPV 20, 23 and DL 332 in syringoma. CONCLUSIONS: The DNA techniques used in this study represent important methods for the detection of HPV types and allow an association of HPV types with defined tumours and inflammations of the eye. In two of the biopsies putatively new HPV types could be identified.

Adolescent↗
PubMed1999

Degenerate and nested PCR: a highly sensitive and specific method for detection of human papillomavirus infection in cutaneous warts.

The role of human papillomavirus (HPV) in anogenital carcinogenesis is firmly established, but evidence that supports a similar role in skin remains speculative. Immunosuppressed renal transplant recipients have an increased incidence of viral warts and nonmelanoma skin cancer, and the presence of HPV DNA in these lesions, especially types associated with the condition epidermodysplasia verruciformis (EV), has led to suggestions that HPV may play a pathogenic role. However, differences in the specificities and sensitivities of techniques used to detect HPV in skin have led to wide discrepancies in the spectrum of HPV types reported. We describe a degenerate nested PCR technique with the capacity to detect a broad spectrum of cutaneous, mucosal, and EV HPV types. In a series of 51 warts from 23 renal transplant recipients, this method detected HPV DNA in all lesions, representing a significant improvement over many previously published studies. Cutaneous types were found in 84.3% of warts and EV types were found in 80.4% of warts, whereas mucosal types were detected in 27.4% of warts. In addition, the method allowed codetection of two or more distinct HPV types in 94.1% of lesions. In contrast, single HPV types were detected in all but 1 of 20 warts from 15 immunocompetent individuals. In summary, we have established a highly sensitive and comprehensive degenerate PCR methodology for detection and genotyping of HPV from the skin and have demonstrated a diverse spectrum of multiple HPV types in cutaneous warts from transplant recipients. Studies designed to assess the significance of these findings to cutaneous carcinogenesis are under way.

Base Sequence↗
PubMed1998

The genomes of three of four novel HPV types, defined by differences of their L1 genes, show high conservation of the E7 gene and the URR.

The DNA genomes of four new human papillomaviruses, HPV 75, HPV 76, HPV 77, and HPV 80, have been cloned, sequenced, and characterized. HPV 75, HPV 76 (both HPV 49-related), and HPV 77 (HPV 29-related) were isolated from benign cutaneous warts and HPV 80 (HPV 15-related) from histologically normal skin. HPV 77 has also been demonstrated in dysplastic warts and squamous cell carcinomas of the skin. The sequence data presented in this study led to a proposed modification of the definition of a new HPV type. The high degree of DNA sequence similarity between the E7 ORF of HPV 77 and HPV 29 (97.7%), as opposed to the E6 (82.8%) and L1 (85.3%) ORFs, might suggest conservation of a specific function or a possible recombinational event. Only the E6 and L1 ORFs of HPV 75 and HPV 76 have a similarity lower than 90%, whereas the DNA sequences of their upstream regulatory regions (URRs) share a similarity of 93%. The E7, E1, and E4 ORFs, as well as the URR of HPV 15 and HPV 80, share sequence similarities higher than 90%. Such a divergence in the similarity between different segments of the virus genomes of closely related HPV types has not been noted to date. A detailed comparative sequence analysis was performed. HPV 75, HPV 76, and HPV 80 revealed features characteristic of truly cutaneous HPV types, whereas HPV 77 shared several characteristics with the mucosal HPV types, some of which may have functional consequences.

Amino Acid Sequence↗
PubMed1998

Human papillomavirus infections in skin cancers.

Non-melanoma skin cancer (NMSC) is the most frequent cancer among Caucasians worldwide. The lesions occur preferentially on sun-exposed sites of the body. The role of human papillomavirus (HPV) in the etiology of carcinoma of the genital tract is well established. Epidermodysplasia verruciformis (EV) has been regarded as a model for NMSC developing on sun-exposed sites. Infection with a specific group of HPV types has been associated with the benign and malignant lesions occurring in these patients. Recent studies using improved detection methods, as well as re-examining material used in previously published studies, reported the presence of HPV DNA in NMSC from immunocompetent patients, as well as more than 90% of NMSC occurring in organ transplant recipients. Five HPV types were identified as the most prevalent in these tumors, i.e., HPV 20, HPV 23, HPV 38 and two newly identified HPV types, DL40 and DL267. These and other HPV types were also demonstrated in normal skin biopsies (35%) and a small number of melanomas. The frequent presence of more than one HPV type within a lesion was noticeable, with at least one type belonging to the EV-associated HPV types. Present data indicate that the primary infection with the majority of, if not all, HPV types, apparently occurs early in life, after which it remains latent. Prolonged ultraviolet (UV) radiation is needed either to activate viral gene functions, and/or to inactivate cellular genes responsible for controlled cell growth. Further studies are clearly needed to determine the molecular mechanisms by which these HPV infections in combination with UV-radiation may contribute to this carcinogenic process.

Cell Transformation, Neoplastic↗
PubMed1998

Human papillomaviruses are commonly found in normal skin of immunocompetent hosts.

We have previously demonstrated, by the combined application of two degenerate polymerase chain reaction primer sets, the presence of human papillomavirus (HPV) DNA in 91% of cutaneous squamous cell cancers from renal allograft recipients, with multiple types being present in one-third of these tumors. Five HPV types--HPV 20, HPV 23, HPV 38, DL40, and DL267--accounted for 73% of positive results. These HPV types are all related to the epidermodysplasia verruciformis group, and HPV 38 was originally isolated from a melanoma. The aims of this study were to determine: (i) whether HPV DNA could readily be demonstrated in skin tumors, as well as in perilesional skin, of immunocompetent patients using two polymerase chain reaction primer sets; (ii) the prevalence of infections in normal skin; and (iii) the prevalence of HPV 38 or HPV 38 related viruses in melanoma. The HPV types detected in lesions from renal allograft recipient were present not only in the perilesional skin and tumors of immunocompetent patients, but also in 35% of normal skin biopsies. HPV DNA was present in 13% of the melanoma samples, but none harbored HPV 38 DNA. We identified four putatively new HPV types. Infections with different types of human papillomavirus are widespread and often occur in clinically normal skin. In vitro studies are required to determine the specific molecular mechanisms by which these HPV types may be involved in the etiology of nonmelanoma skin cancer.

Adult↗
PubMed1998

A broad spectrum PCR method for the detection of polyomaviruses and avoidance of contamination by cloning vectors.

Polyomaviruses induce tumours of different histological types when inoculated into experimental animals, but their aetiological role in the development of malignant tumours in humans remains questionable. We developed a degenerate PCR assay in an attempt to identify additional, presently unknown human polyomavirus types which may be involved in the malignant transformation of human tissues. Degenerate oligonucleotide primers were deduced from four different conserved amino acid motifs in the highly conserved viral capsid protein, VP1. Three different sets of primers were included for the each test. Bladder carcinomas, Hodgkin's lymphomas, meningiomas, Kaposi-tumours and -cell lines were analysed. No polyomavirus DNA sequences could be detected. A comparative analysis led to the recognition of the presence of SV40 DNA sequences in more than 200 vectors available in the EMBL and Genbank Databanks and commonly used in laboratories worldwide. The majority of primers used to detect polyomavirus sequences in human tumours are distributed throughout these regions also present in the vectors. Only a small stretch of 286bp in the overlapping region of the VP1, VP2 and VP3 genes is not present in the vector sequences. We propose to use this region for the design of additional non-contamination primers.

Cloning, Molecular↗