Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.30.2 (endonuclease)
 18,621 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A new type-specific, sensitive, non-radioactive assay is described for the detection of human papillomavirus (HPV) DNA in tissues. Sequences within the E6 gene were amplified by the polymerase chain reaction (PCR), using primer pairs which clearly distinguish HPV types, including those with close sequence homology such as 6b and 11. The amplified DNA products were identified by non-radioactive oligonucleotide hybridization and restriction endonuclease mapping, and the method was sufficiently sensitive to detect between 3 and 5 SiHa cells (each containing 1-2 copies of HPV 16 DNA) amongst 10,000 non-HPV-containing cells. Frozen and archival paraffin sections were equally acceptable substrates for the reaction. The assay was applied to frozen sections of full thickness cervical epithelium from 60 cases of cervical intraepithelial neoplasia (CIN) and 24 normal cervical controls. HPV DNA was detected in 60 per cent of cases of CIN 3 and CIN 2, in 25 per cent of cases of CIN 1, and in none of the normal controls. Prevalence of HPV 16 was similar (approximately 50 per cent) in both CIN 2 and CIN 3, and in the whole series HPV 16 was almost five-fold more common than HPV 18. Low-risk HPV types were present in 5 per cent of CIN 1, but 0 per cent of CIN 2 and CIN 3 biopsies. The data emphasize the biological similarity of CIN 2 and CIN 3 lesions, and their divergence from CIN 1.
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PMID:HPV in full thickness cervical biopsies: high prevalence in CIN 2 and CIN 3 detected by a sensitive PCR method. 166 60

It was postulated that non-isotopic in situ hybridisation (NISH) signal types 1-3 for human papillomavirus in cervical biopsy specimens represent episomal or integrated virus. The aim of this study was to validate this hypothesis by independent molecular techniques. Fresh cervical intraepithelial neoplasia (CIN) and squamous cell cancer (SCC) tissue were examined for NISH signal pattern by hybridising with digoxigenin labelled HPV 16. DNA was extracted from the same samples and analysed by restriction endonuclease digestion and Southern blotting to determine the physical state of the viral genome. Six CIN biopsy specimens showed a type 1 NISH signal for HPV 16. On Southern analysis these biopsy specimens contained only episomal HPV 16. Three SCC with a type 2 NISH signal contained integrated HPV 16 by Southern analysis. Two specimens, a CIN 3 and an SCC with a type 3 NISH signal for HPV 16, showed the presence of both episomal and integrated HPV 16 with conventional Southern analysis and two dimensional gel electrophoresis. These results show that episomal HPV can be reliably determined by NISH type 1 signal, integrated HPV by type 2, and a combination of both episomal and integrated HPV, by a type 3 signal in archival paraffin wax embedded cervical biopsy specimens. This will add another variable to the epidemiological studies of HPV infection. In particular, it will now allow retrospective studies to be done to define the role of episomal and integrated HPV in the evolution of cervical intraepithelial neoplasia and other cervical disease associated with this virus.
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PMID:Episomal and integrated human papillomavirus in cervical neoplasia shown by non-isotopic in situ hybridisation. 166 53

A novel human papillomavirus type (HPV) was cloned from an invasive cervical carcinoma. The viral clone showed no homology with other known prototypes of HPV (HPV-1 through HPV-57), except HPV-33 by Southern blot analysis under stringent conditions. It showed less than 20% homology to HPV-33 by reassociation kinetic analysis. The restriction endonuclease map of the clone was different from those of other HPV types and its predicted genome organization surmised by hybridization with subgenomic fragment probes of HPV-33 DNA showed the typical HPV genome organization. The results indicate that this clone is a new type of HPV, designated as HPV-58, distinct from the other known types of HPV. HPV-58 was detected in none of 6 specimens of cervical condylomata acuminata, in 7 of 58 specimens of cervical intraepithelial neoplasia, and in 4 of 50 specimens of invasive cervical carcinoma studied in Nagano prefecture, Japan.
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PMID:Molecular cloning of a novel human papillomarvirus (type 58) from an invasive cervical carcinoma. 216 40

The fragile histidine triad (FHIT) gene encompasses the common chromosomal fragile site FRA3B. Human papilloma virus (HPV), which is the main aetiological agent in cervical cancers, has been found to be able to integrate its genes into the chromosome 3 fragile site of cultured cells, deleting a piece of DNA which includes the FHIT gene. Eighty-six microdissected archival cervical LLETZ biopsies comprising cases of cervical intraepithelial neoplasia (CIN) 1 (n=27), CIN3 (n=30) and microinvasive carcinoma (n=29) were evaluated for HPV infection and FHIT gene loss of heterozygosity (LOH). FHIT gene LOH was detected by polymerase chain reaction (PCR) using fluorescently labelled intragenic microsatellite markers D3S1300 and D3S4103. PCR products were analysed on a semi-automated DNA sequencer using Fragment Manager(trade mark) software to determine allele loss. The HPV status of the lesions was determined by PCR using generic and type-specific primers in conjunction with restriction endonuclease digestion. The results were analysed using Epi-Info and SPSS-PC statistical analysis software. Haematoxylin and eosin-stained sections from the 86 cases were profiled for six histopathological features, some of which have been previously shown to be associated with microinvasive cancer. FHIT gene LOH was found in 36% of CIN1 cases, 52% of CIN3 cases and 73% of microinvasive cases (p=0.029). HPV 16 DNA was found in 68% of CIN3 cases and 93% of microinvasive cases (p<0.001). The second most prevalent HPV type found was HPV 31, which was present in only four lesions, three of which had FHIT gene LOH. When FHIT gene LOH was evaluated versus HPV 16 and 31 infection using the chi-square test, a statistically significant relationship was found (p=0.014). FHIT gene LOH was found to be independent of the histopathological features evaluated. The finding of a statistically significant relationship between FHIT gene LOH and oncogenic HPV infection suggests a link between the integration of viral DNA and subsequent gene deletion in the progression of cervical cancer. FHIT gene anomalies may prove to be excellent markers of progression in early uterine cervical cancers.
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PMID:Deletion of the FHIT gene in neoplastic and invasive cervical lesions is related to high-risk HPV infection but is independent of histopathological features. 1111 68

The diagnosis of cervical intraepithelial neoplasia (CIN) has low interobserver reproducibility. The pathogenesis of human papillomavirus (HPV) from infection to high-grade CIN is well understood. In benign lesions, HPV-DNA is often packaged into virions, whereas malignant transformation disrupts virion assembly. It is conceivable that if cervical lesions were exposed to endonuclease digestion, HPV virions would alter nuclear susceptibility to DNA degradation. We propose that susceptibility to endonuclease digestion can serve as a simple marker to identify CIN grade. From paraffin-embedded tissue blocks, condyloma accuminata, CIN I-III, and cervical carcinoma cases were identified. Sections were placed in a bath containing DNAse I for DNA digestion. Residual DNA was stained by a Feulgen process. Endonuclease-resistant DNA (erDNA) staining was correlated to disease grade. In addition, 10 HPV (+) patients whose infection regressed and 8 whose infection progressed to CIN II or above had their initial HPV lesions stained for erDNA. erDNA was observed in 81% condylomas and 80% CIN I cases. All CIN II, III, and cancer cases were endonuclease sensitive with 100% of lesions showing no staining. Eighty percent of HPV lesions that regressed had erDNA staining, whereas 75% lesions that progressed had no erDNA staining. The spectrum of cervical disease caused by HPV has different susceptibilities to endonuclease digestion, which may aid in the diagnosis of CIN. Furthermore, in our small pilot study, erDNA status was associated with the clinical outcomes. Prospective studies are needed to confirm this observation. erDNA status is a promising novel biomarker.
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PMID:Endonuclease-resistant DNA: a novel histochemical marker for cervical intraepithelial neoplasia and cervical carcinoma. 2212 17

Oncogene-induced DNA replication stress has been implicated as a driver of tumorigenesis. Many chromosomal rearrangements characteristic of human cancers originate from specific regions of the genome called common fragile sites (CFSs). CFSs are difficult-to-replicate loci that manifest as gaps or breaks on metaphase chromosomes (termed CFS 'expression'), particularly when cells have been exposed to replicative stress. The MUS81-EME1 structure-specific endonuclease promotes the appearance of chromosome gaps or breaks at CFSs following replicative stress. Here we show that entry of cells into mitotic prophase triggers the recruitment of MUS81 to CFSs. The nuclease activity of MUS81 then promotes POLD3-dependent DNA synthesis at CFSs, which serves to minimize chromosome mis-segregation and non-disjunction. We propose that the attempted condensation of incompletely duplicated loci in early mitosis serves as the trigger for completion of DNA replication at CFS loci in human cells. Given that this POLD3-dependent mitotic DNA synthesis is enhanced in aneuploid cancer cells that exhibit intrinsically high levels of chromosomal instability (CIN(+)) and replicative stress, we suggest that targeting this pathway could represent a new therapeutic approach.
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PMID:Replication stress activates DNA repair synthesis in mitosis. 2672 56