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J Cason

Publications and source records attributed to J Cason.

At least 19 recordsLinked to original sources
PubMed2006

Differential regulation of different human papilloma virus variants by the POU family transcription factor Brn-3a.

The Brn-3a POU family transcription factor is overexpressed in human cervical carcinoma biopsies and is able to activate expression of the human papilloma virus type 16 (HPV-16) upstream regulatory region (URR), which drives the expression of the E6 and E7 oncoproteins. Inhibition of Brn-3a expression in human cervical cancer cells inhibits HPV gene expression and reduces cellular growth and anchorage independence in vitro as well as the ability to form tumours in vivo. Here, we show that Brn-3a differentially regulates different HPV-16 variants that have previously been shown to be associated with different risks of progression to cervical carcinoma. In human cervical material, Brn-3a levels correlate directly with HPV E6 levels in individuals infected with a high risk variant of HPV-16, whereas this is not the case for a low-risk variant. Moreover, the URRs of high- and intermediate-risk variants are activated by Brn-3a in transfection assays, whereas the URR of a low-risk variant is not. The change of one or two bases in a low-risk variant URR to their equivalent in a higher-risk URR can render the URR responsive to Brn-3a and vice versa. These results help explain why the specific interplay between viral and cellular factors necessary for the progression to cervical carcinoma only occurs in a minority of those infected with HPV-16.

Adolescent↗
PubMed2000

High prevalence of human papillomavirus type 16 infection among children.

Infection with high-risk human papillomaviruses (HPV), is the most significant risk factor for cervical cancer and it may be possible to prevent this malignancy by immunisation. Before immunisation programmes can be designed, however, it is necessary to know the age of acquisition and all routes of infection for these viruses. Sexual transmission is well documented and vertical transmission has also been demonstrated, although the frequency of transmission remains controversial. We previously showed that vertical transmission frequently results in persistent infection, and now present data on the prevalence of HPV-16 DNA (the most prevalent high-risk HPV type) in healthy children. Buccal samples from 267 healthy children aged 3-11 years were tested for HPV DNA by generic PCR (MY09/MY11), and a HPV-16 specific nested PCR. Reverse transcriptase (RT)-PCR was used to determine the prevalence of transcriptionally active HPV-16 infection in a subset of children. HPV-16 DNA was detected by nested PCR in 138 of 267 (51.7%) samples, whereas HPV DNA was detected in only 45 (16.8%) specimens by generic PCR, that has a lower analytical sensitivity. There were no significant differences in prevalence according to age or sex. Early region mRNA was detected by RT-PCR in six (11.3%) of 53 HPV-16 E5 DNA positive samples. HPV-16 E5 DNA sequences from 10 children confirmed the identity of the sequences detected and identified 13 HPV-16 variants.

Child↗
PubMed2000

Lipopolysaccharide and silica-stimulated mononuclear cell prostaglandin production in ulcerative colitis.

Basal, lipopolysaccharide (LPS) and silica-stimulated prostaglandin (PG) production were compared between peripheral blood mononuclear cells (PBMNC) from UC patients and healthy subjects (HS). Basal and LPS-stimulated PBMNC PGI2, but not PGE2, production was greater in UC. LPS stimulated both PGE2 and PGI2 by PBMNC from HS and UC patients. Silica stimulated production of both PGs by cells from HS but only PGE2 by cells from UC patients. The differences in responses to silica and LPS may result from differences in activation of NFkappaB or, alternatively, prior sensitisation to one of these agents. That PBMNC PGE2 production is not increased in UC, as it is in Crohn's disease, suggests that there are differences in PBMNC behaviour between these two diseases.

Adult↗
PubMed2000

Cervical lesions are associated with human papillomavirus type 16 intratypic variants that have high transcriptional activity and increased usage of common mammalian codons.

Human papillomavirus type 16 (HPV-16) is a major cause of cervical neoplasia, but only a minority of HPV-16 infections result in cancer. Whether particular HPV-16 variants are associated with cervical disease has not yet been clearly established. An investigation of whether cervical neoplasia is associated with infection with HPV-16 intratypic variants was undertaken by using RFLP analyses in a study of 100 HPV-16 DNA-positive women with or without neoplasia. RFLP variant 2 was positively associated [odds ratio (OR)=2.57] and variant 5 was negatively associated with disease (OR=0.2). Variant 1, which resembles the reference isolate of HPV-16, was found at a similar prevalence among those with and without neoplasia. Variants 1 and 2 were also more likely to be associated with detectable viral mRNA than variant 5 (respectively P=0.03 and P=0.00). When HPV-16 E5 ORFs in 50 clones from 36 clinical samples were sequenced, 19 variant HPV-16 E5 DNA sequences were identified. Twelve of these DNA sequences encoded variant E5 amino acid sequences, 10 of which were novel. Whilst the associations between HPV-16 E5 RFLP variants and neoplasia could not be attributed to differences in amino acid sequences, correlation was observed in codon usage. DNA sequences of RFLP variant 2 (associated with greatest OR for neoplasia) had a significantly greater usage of common mammalian codons compared with RFLP pattern 1 variants.

Amino Acid Sequence↗
PubMed2000

HPV16 E6 oncogene variants in women with cervical intraepithelial neoplasia.

Human papillomaviruses (HPVs) are strongly associated with the development of high grade cervical intraepithelial neoplasia (CIN) and cervical carcinoma, with between 40-80% of patients with cervical carcinoma being attributed to a single HPV type, HPV16 depending on the methods used and geographical location of the particular study [van den Brule et al., 1996]. An HPV16 E6 variant has been described which is strongly associated with high grade CIN [Ellis et al., 1997] and with the human leukocyte antigen (HLA)-B7 genotype in women with cervical carcinoma where HLA-B7 positive patients were demonstrated to have a significantly poorer clinical outcome [Ellis et al., 1995]. To determine whether this HPV16 E6 variant might play a significant role in the pathogenesis of cervical disease, 174 HPV16 positive women were selected from those attending the colposcopy clinics of Guy's and St Thomas' Hospital Trust following polymerase chain reaction (PCR) amplification of HPV16 L1 or E5 DNAs from cervical brush swabs or fixed biopsy tissue. HPV16 E6 DNA was amplified by PCR and the variant sequence was identified by Msp 1 restriction enzyme digestion, as the nucleotide substitution creates an additional unique Msp 1 site. The study group comprised 29 normal controls, 7 women with borderline cytology, 123 women with cervical dysplasia and 12 women with cervical cancer. 101/174 (58%) of these women had amplifiable E6 DNA and restriction enzyme digestion was performed on 95 of these. The variant E6 sequence was identified in 3/95 (3%) individuals, two of whom had normal histology and one had a CIN II lesion. Wild type E6 sequence was identified in the remaining 92/95 (97%) individuals. These data suggest that this particular E6 variant does not play a major role in the pathogenesis of HPV16 related cervical disease in women living in the South London area.

DNA, Viral↗
PubMed1998

Proliferative T-cell responses to human papillomavirus type 16 E5 are decreased amongst women with high-grade neoplasia.

Proliferative responses to human papillomavirus type 16 (HPV-16) E5 peptides were determined for short-term cell lines derived from peripheral blood mononuclear cells of 75 women. Cell lines from 16 of the 75 women proliferated in response to stimulation with pooled E5 peptides; this was most common for patients with low-grade squamous cervical intraepithelial lesions (LSIL; 6 of 15 patients, 40%) and less frequent for asymptomatic women with no cervical lesions (4 of 20, 20%), those with high-grade squamous intraepithelial lesions(HSIL; 5 of 33, 15%) and others with cervical cancer (1 of 7, 14%, P = 0.027). Amongst these patients, proliferative responses were exclusive to those that were positive for HPV-16 DNA (12 of 41, 29%; c.f. none of 13 HPV-16 DNA-negative subjects exhibited a proliferative response; P= 0023) and were again most prevalent amongst HPV-16 DNA-positive LSIL (6 of 14, 43%), as compared with HPV-16 DNA-positive HSIL (5 of 23, 22%) or HPV-16 DNA-positive cervical cancer patients (1 of 4, 25%, P > 0.05). In contrast, for asymptomatic women, responsiveness was statistically independent of HPV-16 DNA status, i.e. responsiveness in HPV-16 DNA-positive and DNA-negative subjects was observed in 3 of 15 (20%) and 1 of 5 (20%) cases, respectively (P > 0.05). There were no associations between detection of HPV-16 mRNA and proliferative responses (P> 0.05). These data suggest that HPV-16 E5-specific T-helper activity is depressed amongst women with HSIL lesions.

Adolescent↗
PubMed1998

Transmission of cervical cancer-associated human papilloma viruses from mother to child.

There is now compelling evidence that persistent infection with certain types of human genital papillomaviruses (HPV) may, after many years, lead to cervical cancer. However, HPV have been detected in asymptomatic women, infants and children. Several studies have demonstrated that infants can acquire high-risk HPV infections from their mothers at birth. Thus, the traditional view that cervical-cancer associated HPV infections are primarily sexually transmitted needs to be re-assessed. Accordingly, the role of mother to child transmission of cancer-associated HPVs may need to be investigated further. These facts are pertinent to those developing prophylactic vaccines to prevent high-risk HPV infections and cervical carcinoma.

Child↗
PubMed1997

Polymerase chain reaction protocols for the detection of DNA from mucosal human papillomavirus types -6, -11, -16, -18, -31 and -33.

Individual types of human papillomaviruses (HPV) which infect mucosal surfaces have been implicated as the causative agents for carcinomas of the cervix, anus, penis, larynx and the buccal cavity, occasional periungal carcinomas, as well as benign anogenital warts. The identification of particular HPV types is thus important for: identifying patients with premalignant lesions who are at risk of progression to malignancy; epidemiological studies; studies of the natural history of these viruses; and even medico-legal cases of suspected sexual abuse of children. In this protocol we describe PCR assays for: the identification of DNA from the mucosal HPVs types -6, -11, -16, -18, -31 and -33; a consensus HPV PCR for detecting DNA from 20 characterised mucosal HPVs, as well as more than 25 novel HPVs; and, for a control PCR for beta-globin.

DNA, Viral↗
PubMed1997

Detection of human papillomavirus type 16 early-gene transcription by reverse transcription-PCR is associated with abnormal cervical cytology.

Human papillomavirus type 16 (HPV-16) is associated with abnormal Papanicolou smears, indicative of cervical intraepithelial neoplasia. HPV-16 is the most common genital HPV and is found in up to 40% of young women with normal cervical cytology. In order to investigate whether transcriptionally active HPV-16 infection is associated with abnormal cervical smears, a reverse transcription-nested PCR assay with primers from the E5 open reading frame was developed to detect all HPV-16 early-region mRNA (E-mRNA) transcripts. It was used to study HPV-16-infected women with normal and abnormal cervical cytologies to obtain evidence of active infection. Among HPV-16 DNA-positive women, HPV-16 E-mRNA was detected in 15 of 37 (40.5%) women with abnormal cervical cytology but in only 4 of 35 (11.4%) women with normal cytology (P = 0.007). Thus, HPV-16 E-mRNA transcription is associated with abnormal cervical smears and may have value as a prognostic marker of progressive disease.

Adult↗
PubMed1997

Relationship between human papillomavirus infection and overexpression of p53 protein in cervical carcinomas and lymph node metastases.

Overexpression of p53 protein is common in cervical carcinoma. We investigated archival biopsies from 26 cervical cancer patients (24 with available lymph nodes) to determine the relationship between p53 overexpression and HPV infection at the cervix and lymph nodes. Twelve cervical carcinoma patients had p53 protein in cervical biopsies detectable by immunohistochemistry using monoclonal antibody DO-1, and 22 were positive for HPV DNA in polymerase chain reaction assays (16, contained HPV-16; 3, HPV-18; and, 3 HPV-X). Seven cervical cancer patients had one or more lymph nodes positive for p53 protein, and all but one of these were concordantly p53 positive at the cervix. However, detection of p53 protein in cervical biopsies was predictive neither of the expression of p53 at draining lymph nodes (P > 0.1) nor of the occurrence of metastases (P > 0.1). Fourteen patients were positive at one or more lymph nodes for HPV DNA. Cervical positivity for HPV DNA was associated significantly with concordant HPV positivity at the lymph nodes (P = 0.039) and was predictive of metastases (P = 0.019). There was no association between positivity for p53 and for HPV DNA at primary cervical carcinomas or at the lymph nodes (all P > 0.1). We conclude that, although detectable p53 protein is a common feature of cervical carcinomas, it is not predictive of metastases and is independent of HPV infection.

Adolescent↗
PubMed1996

Detection of human papillomavirus type-16 DNA utilising microtitre-plate based amplification reactions and a solid-phase enzyme-immunoassay detection system.

The development of a nested polymerase chain reaction (PCR) assay to detect low concentrations of human papillomavirus type-16 (HPV-16) DNA for epidemiological studies is described. The PCR utilises primers located in the E5 open reading frame, has an analytical sensitivity of 4 HPV-16 genomes and does not produce amplicons from other common genital HPVs (types-6, -11, -18, -31 and 33). This assay was carried out in 96-well plates utilising internal primers labelled with dinitrophenol (DNP) and biotin so that amplicons can be captured onto streptavidincoated plates and detected using an alkaline phosphatase-labelled monoclonal antibody to DNP. The assay was effective for detecting HPV-16 DNA in plasmids, cell-lines and, both freshly collected or archival (formalin-fixed/paraffin embedded) clinical specimens. This system is therefore suitable for epidemiological studies to identify individuals infected with HPV-16 DNA in episomal form who may be at increased risk of developing anogenital carcinomas.

DNA Primers↗
PubMed1996

Analytic sensitivities of hybrid-capture, consensus and type-specific polymerase chain reactions for the detection of human papillomavirus type 16 DNA.

Human papillomavirus type 16 (HPV-16) DNA is detected commonly in cervical carcinomas; in this study, we have determined the analytical sensitivities of Hybrid Capture, HPV-consensus PCR, and three HPV-16-specific polymerase chain reactions (PCRs) for the detection of HPV-16 DNA. Samples investigated included a cervical cancer cell line, cervical scrapes from 20 patients attending colposcopy clinics, and buccal swabs from eight immunosuppressed children. HPV-16 E7 and E5-nested PCRs [Cavuslu et al. (1996): Journal of Virological Methods, in press] produced positive signals from samples containing fewer than ten HPV-16 genomes per reaction. HPV-consensus PCR [Manos et al. (1989): Cancer Cells 7:209-214] and HPV-16 PCR using primers of van den Brule et al. [(1990): Journal of Clinical Microbiology 25:2739-2743] were of intermediate sensitivity (i.e., produced positive signals from samples containing 250 and 2,500 HPV-16 genoms/reaction, respectively) and Hybrid Capture could detect just 50,000 HPV-16 genomes/reaction. Highest rates of positivity for cervical samples were detected with HPV-16 E7 or E5-nested PCRs [50% (10 of 20 samples) and 60% (12 of 20 samples) positive, respectively], intermediate rates with HPV-consensus PCR and PCRs using the primers of van den Brule et al. [both 35% (7 of 20 samples)], and lowest rates of positivity [25% (5 of 20 samples)] with Hybrid Capture. None of eight buccal swab samples from immunosuppressed children were positive by Hybrid Capture, yet three (37.5%) were positive by HPV-16 E5-nested PCR. These data indicate that HPV-16 type-specific PCRs should be used for the investigation of specimens that may contain low amounts of HPV-16 DNA.

Adolescent↗
PubMed1996

Detection of human papillomavirus type 16 in microtitre plate based immuno-enzymatic assays: use to determine E5 gene expression in cervical carcinomas.

BACKGROUND: E5-based nested polymerase chain reaction (PCR) assays and a PCR-enzyme immunoassay (EIA) to detect human papillomavirus type 16 (HPV-16) DNA have been developed. These assays were designed to detect small amounts of HPV-16 DNA for epidemiological studies of subclinical infection. OBJECTIVES: The E5 gene of HPV-16 may be lost in some cell lines derived from cervical carcinomas. The aim of this study was to determine if, and how frequently, E5 gene loss occurs in biopsy samples from patients with cervical lesions. STUDY DESIGN: Sixteen HPV-16 (E7) DNA positive and five HPV-16 DNA negative cervical lesions (nineteen cervical carcinomas, two cervical intraepithelial neoplasias) were investigated by E5 nested PCR and EIA. RESULTS: Overall, 15 of the 16 (93.75%) HPV-16 E7 positive samples were positive for HPV-16 E5 DNA: 14 of 16 (87.5%) were positive by E5 PCR and 15 of 16 (93.75%) were positive by E5 PCR, nested PCR and by PCR-EIA. One of 14 HPV-16 (E7) DNA positive cervical carcinomas was negative for E5 DNA in all three assays. CONCLUSION: Loss of the HPV-16 E5 open reading frame (ORF) is a rare event in HPV-16 positive cervical carcinomas and was detected in just one of 14 (7.1%) cases.

Journal Article↗
PubMed1996

Human papillomavirus type 16 in infants: use of DNA sequence analyses to determine the source of infection.

Perinatal transmission of human papillomavirus type 16 (HPV-16) and persistence of virus DNA in infants until 6 months of age has been described. To confirm the origin of infant infections as maternal, we determined the nucleotide sequence of the upstream regulatory region (URR; bp 7540 to 157) of HPV-16 in samples from 13 HPV-16 DNA-positive mothers and their infants at 6 weeks and 2 years of age. Identical HPV-16 variant URR sequences were found in two mother/infant samples and similar variants were found in three sets. Four mothers with samples which contained prototypic HPV-16 sequences delivered infants who also had the prototypic sequence. Four mothers with variant URRs delivered infants who harboured either prototypic or different URR variants. Thus, concordant variants or prototypic sequences were detected in nine of 13 mother/infant samples, indicating that up to 69.2% of HPV-16-positive infants acquire virus from their mothers.

Base Sequence↗