PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “HPV integration”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources
PubMed2026

Dual-dimensional profiling of host genomic variations and HPV integration in PD-L1-stratified cervical cancer via Oxford Nanopore Technology.

BACKGROUND: The integration of human papillomavirus (HPV) DNA into the host genome is a key step in the development of HPV-associated cervical cancer (CC). However, the genomic characteristics of host genomic variations and HPV integration within the context of programmed death-ligand 1 (PD-L1) expression stratification have not been systematically investigated. METHODS: Whole-genome sequencing was performed using Oxford Nanopore Technology (ONT) on six samples (three from the high PD-L1 expression group and three from the low PD-L1 expression group). The characteristics of host genomic variations under different PD-L1 expression stratifications were explored, including structural variations (SV), copy number variations (CNV), single nucleotide polymorphisms (SNP), and insertion-deletions (Indel). Subsequently, the distribution features of HPV integration sites were analyzed, different integration types were identified, and pathway analysis was conducted. RESULTS: Whole-genome SV analysis revealed that the total number of SVs and the composition of mutation types were similar between the high and low PD-L1 expression groups, with insertions (INS) and deletions (DEL) predominating in both. These variations were primarily enriched in intergenic regions and introns. In the low PD-L1 expression group, integration events were observed at multiple chromosomal loci, with the most frequent integration occurring in the KLF5 gene region on chromosome 13. No frequently integrated loci were identified in the high PD-L1 expression group. Additionally, four distinct HPV integration breakpoint patterns were preliminarily identified and analyzed. CONCLUSION: PD-L1 expression stratification did not significantly alter the overall genomic instability of the host. However, differences were observed in the distribution patterns of HPV integration sites. These findings provide new insights into the genomic heterogeneity of CC under different PD-L1 expression backgrounds and may lay the groundwork for future research exploring stratified immunotherapy based on HPV integration features.

Humans↗
PubMed2005

HPV in situ hybridization: impact of different protocols on the detection of integrated HPV.

Although there is consensus that HPV integration is common in invasive cervical carcinomas and uncommon or absent in low-grade uterine cervical intraepithelial neoplasia (CIN I), estimates for HPV integration in CIN II/III range from 5 to 100% using different PCR-based and in situ hybridization (ISH) approaches. It has been suggested that HPV integration can be identified using ISH by scoring of punctate signals. The increased sensitivity of fluorescence ISH (FISH) methods, allowing the detection of single copies of HPV, complicates the distinction between integrated and episomal HPV. Recently it has been suggested that, in such assays, the signals originating from integrated virus can be hidden in a background of episomal HPV. We therefore compared 2 different FISH protocols for the detection of integrated HPV in a series of CIN II/III lesions: 1) a mild protocol in which episomal HPV and RNA is retained and 2) a harsh protocol that extensively extracts proteins and RNA, and which promotes the partial loss of episomal HPV but not integrated HPV. A series of 28 HPV 16/18 positive CIN II/III lesions (17 solitary lesions and 11 lesions adjacent to microinvasive carcinoma) were studied. A punctate signal pattern was identified in 7 of these lesions with both protocols. Punctate signal was also present in control samples from lesions that are known to be associated with HPV integration (invasive squamous cell carcinoma (n = 3), adenocarcinoma in situ (n = 3), and invasive adenocarcinoma (n = 1). HPV RNA contributed significantly to the intensity of punctate FISH signal, especially when applying the mild protocol, as shown by omitting DNA denaturation, including RNase pretreatment steps and measuring the fluorescence signal intensity. Also, HPV RNA was frequently detected in addition to episomal/integrated HPV DNA in the majority of the other 21 CIN II/III lesions; this resulted in intense granular/diffuse FISH signals throughout the epithelium. However, in 7 of these lesions, the harsh protocol gave a more consistent punctate pattern in cells throughout the full thickness of the epithelium. This supports the hypothesis that the harsh protocol unmasks integrated HPV more efficiently by extracting RNA and episomal HPV. Overall, with this harsh protocol, a clonally expanded population of cells containing punctate HPV signals was found in 5 of 17 (29%) solitary CIN II/III lesions and in 9 of 11 (88%) CIN II/III lesions associated with microinvasive carcinoma. Combining these data with the results from our previous study, with the harsh protocol in 7 of 40 (18%) solitary CIN II/III lesions and 19/21 (90%) CIN II/III lesions associated with microinvasive carcinoma (p < 0.001), this pattern was found. This indicates that, when robustly defined, a punctate HPV pattern in CIN II/III lesions is associated with the presence of an invasive carcinoma.

Adenocarcinoma↗
PubMed2005

Human papillomavirus (HPV) transcripts in malignant inverted papilloma are from integrated HPV DNA.

OBJECTIVES: The objectives of the study were to detect human papillomavirus (HPV) sequences in nasal inverted papilloma (IP) lesions and to determine whether HPV is involved in the progression of IP to sinonasal squamous cell carcinoma (SCC). STUDY DESIGN: A retrospective study was performed on 14 patients diagnosed with IP within the last 12 years. Three of these 14 patients developed SCC. METHODS: Eighteen formalin-fixed, paraffin-embedded tissue blocks were obtained for these 14 patients. After DNA extraction, polymerase chain reaction (PCR) was performed, followed by hybridization using HPV 6, 11, 16, 18, 31, 33, 35, 45, and 52 specific DNA probes, in an attempt to identify HPV type in each specimen. After RNA extraction, the integration status of the HPV genome was evaluated based on the relative abundance of E7 and E5 viral transcripts, assessed by quantitative real-time PCR. RESULTS: HPV sequences were detected in samples from 3 of the 14 patients with IP. Of the three patients with SCC, HPV sequences were detected in two patients, whereas one patient was negative for the oligoprobes tested. Of the 11 patients diagnosed only with IP, 1 patient was positive for HPV DNA (HPV type 11). This difference in HPV positivity between IP and SCC was not statistically significant (P = .09, Fisher's Exact test, two tailed). Viral transcripts were detected in both patients with SSC who were HPV positive. Because HPV early transcripts are polycistronic, loss of 3' transcript sequences (E5) and retention of 5' sequences (E7) indicates integration. One of the SSC containing HPV 18 sequences showed a E7/E5 ratio of 776:1. The other SSC showed E7 transcripts and an absence of E5 transcripts CONCLUSION: HPV transcripts were present in SCC positive for HPV, and the relative level of E7 to E5 transcripts indicates integration of the viral genome. These findings are suggestive of HPV having an active role in the lesion. More extensive studies are needed to determine the exact role of HPV in IP and progression to SCC.

Carcinoma, Squamous Cell↗
PubMed2003

A comprehensive analysis of HPV integration loci in anogenital lesions combining transcript and genome-based amplification techniques.

Persistent infections with high-risk human papillomaviruses (HPVs) induce dysplastic lesions of the lower genital tract. Some of these lesions eventually progress to invasive cancers, particularly of the uterine cervix. In many advanced preneoplastic cervical lesions and most derived carcinomas, HPV genomes are found to be integrated into the host cell chromosomes. Although HPV integration seems to play an important role in the progression of cervical dysplasia, the underlying mechanisms are still unclear. To investigate the pathogenic role of genomic integration of HPV genomes in greater detail, we analysed integration sites of HPV16 and 18 genomes in 21 anogenital precancerous and cancerous lesions using a ligation-mediated chain reaction (DIPS) and the recently described amplification of papilloma virus oncogene transcripts (APOT) assay. On the genomic level, only singular integration events were observed in individual neoplastic cell clones. At many integration sites, a short overlap between HPV and genomic sequences was observed, suggesting that the integration of HPV genomes is mediated by nonhomologous sequence-specific recombination. APOT analysis revealed that the majority of integrated HPV genomes was actively transcribed. These data suggest that in the progression of cervical preneoplasia to invasive carcinomas, integration of viral genomes occurs only at single or few chromosomal loci in a given cell clone. Disruption of cellular genes might support malignant transformation in rare cases; however, it is not a pathogenic prerequisite. The main function of HPV integration seems to be the stabilization of oncogene transcription.

Biopsy↗
PubMed1991

In situ human papillomavirus (HPV) genotyping of cervical intraepithelial neoplasia in South African and British patients: evidence for putative HPV integration in vivo.

In South Africa asymptomatic wart virus infection diagnosed by morphological criteria occurs in 16-20% of all ethnic groups; the incidence in black women is 66%. To identify human papillomavirus (HPV) types the prevalence of HPV in cervical intraepithelial neoplasia (CIN) in South African women (n = 72) with age matched British women (n = 73) was compared by non-isotopic in situ hybridisation (NISH) using digoxigenin labelled probes for HPV 6, 11, 16, 18, 31, 33 and 35 on archival biopsy specimens. A higher proportion of British biopsy specimens (68%) contained HPV than those from South Africa (50%) in CIN 2 and 3; this difference was due to HPV 16. Thirty six per cent of the positive biopsy specimens from South African women also contained HPV 33/35 compared with 16% in the United Kingdom. There was no difference in HPV detection with age in either group. These data indicate that HPV types vary geographically, with "minor" HPV types being more common in South Africa. Three qualitatively distinct NISH signals were observed; a diffuse (type 1) signal in superficial cells, mainly koilocytes; a punctate signal (type 2) in basal/"undifferentiated" cells in CIN 3; and combined type 1 and 2 signals in CIN with wart virus infection (type 3). The punctate signal may represent HPV integration.

Adolescent↗
PubMed2007

HPV integration begins in the tonsillar crypt and leads to the alteration of p16, EGFR and c-myc during tumor formation.

The prevalence of human papillomavirus (HPV) infection is high in the oropharyngeal mucosal regions, of which the tonsil is the most commonly affected. There may be a link between HPV and the pathogenesis of tonsillar cancer (TC), because of common anatomical characteristics between cervical and tonsillar cancer. We aimed to clarify whether HPV directly affects the oncogenesis and biologic behavior of TC by making a comparison between infection prevalence, physical status and viral loading numbers, and clinicopathologic prognostic factors. To compare HPV-related molecules between TC and tonsillitis (CFT), p16, survivin, HIF-1alpha, skp-1, cyclin A, cyclin B1, c-myc and EGFR were investigated. We observed a significant difference in HPV prevalence between 52 TCs and 69 CFTs (73.1% vs. 11.6%), and most of the HPVs were type 16 (87.2%) and nonepisomal (94.1%). Most TCs associated with HPV arose from the tonsillar crypts, and tended to be inverted and poorly differentiated. Compared with HPV-negative TC, HPV-positive TC showed a strong association with p16 overexpression (p<0.0001), and an inverse association with EGFR amplification (p=0.0478). HPV-16 integration status was strongly associated with c-myc amplification (p=0.034) and HIF-1alpha overexpression (p=0.022). HPV-16 integration could be directly related to tonsillar carcinogenesis initially in tonsillar crypts, followed by cell cycle aberration such as p16 overexpression related to the G1-S phase.

Carcinoma, Squamous Cell↗
PubMed1990

Integrated HPV 1 genomes in a human keratinocyte cell line can be transactivated by a SV40/BPV1 recombinant virus which expresses BPV1 E2 proteins.

This paper describes studies carried out on an HPV 1 carrying human keratinocyte cell line (SVD2) and two subclones of it. Although these lines contain multiple copies of HPV 1 genomes, in situ hybridization revealed that integration was restricted to band q33 on the long arms of chromosome 2. An E4 1.25-kb mRNA was specifically identified by Northern blotting and a PCR generated cDNA confirmed the presence of the E1/E4 spliced mRNA which is abundant in HPV 1 containing papillomas. Infection of an SVD2 subclone (SVD2 (cyst) sp) with a SV40/BPV1 recombinant virus which expresses the BPV1 E2 48-kb transactivator protein enhanced HPV 1 transcription at least 20-fold.

Cell Line, Transformed↗
PubMed1996

Use of the polymerase chain reaction to specifically amplify integrated HPV-16 DNA by virtue of its linkage to interspersed repetitive DNA.

A polymerase chain reaction (PCR) based technique that combines a virus specific primer and a human interspersed repetitive sequence (IRS) specific primer in order to detect integration of human papilloma virus type 16 (HPV-16) is described. Amplification of viral-host DNA junctions occurs when viral integration results in placement of the virus specific primer binding site near (less that 3-4 kb) the primer binding site within a repetitive sequence element. The method relies on enzyme labeled oligonucleotide probes to achieve rapid, specific, and nonradioisotopic detection of viral integration related PCR products since episomal forms of the viral DNA do not lead to exponential accumulation of hybridizable PCR products. The technique is demonstrated for human genomic DNA derived from clinical cervical swab specimens and archival paraffin embedded blocks. Viral integration was detected in 41% of the HPV-16 positive samples (n = 34). In this positive subset, 64% were classified as invasive neoplasias, 29% CIN III and 7% CIN II. Analyzing the positive invasive neoplasias, 6 of 9 (66%) of the fingerprint results were obtained when an HPV primer was paired with an Alu primer. Interestingly, 100% of Alu primed fingerprint results obtained were derived from samples presenting invasive neoplasia (P < 0.025 by chi square).

Base Sequence↗
PubMed2005

Analysis of p16INK4a and integrated HPV genomes as progression markers.

Most cervical cancers are preventable when the precursor lesions are detected in time. Human papilloma viruses (HPVs) are the main risk factors for cervical cancer development, but there is a high percentage of healthy women infected with HPV that never develop a lesion. Only a small percentage of low-grade dysplasias finally grow out to invasive cancer. Several biomarkers can be used to identify lesions at risk for malignant progression. Overexpression of p16INK4a is induced by the viral oncoprotein E7 and distinguishes dysplastic lesions from benign changes. Integration of human papillomavirus DNA into the host genome is mainly found in high-grade dysplastic lesions and invasive cancers, and points to an increased progression potential.

Base Sequence↗
PubMed1997

Mutated and wild-type p53 expression and HPV integration in proliferative verrucous leukoplakia and oral squamous cell carcinoma.

The frequencies of overexpression and mutation in the p53 tumor suppressor gene were examined in proliferative verrucous leukoplakia and oral squamous cell carcinoma with immunohistochemistry and single-strand conformation polymorphism analysis of DNA fragments amplified by polymerase chain reaction. Ten samples each of normal oral mucosa, proliferative verrucous leukoplakia, and squamous cell carcinoma were immunostained with antibodies against p53 protein; 8 of 10 cases of proliferative verrucous leukoplakia cases and 7 of 10 cases of oral squamous cell carcinoma were positive for p53 protein. Minimal staining was observed in normal oral tissues. The quantified labeling indexes demonstrated a range that corresponded to lesion progression. Single-strand conformation polymorphism analysis revealed p53 gene mutations within exons 5 to 8 in 40% (4 of 10) of the squamous cell carcinoma samples. Two of the 4 mutated squamous cell carcinoma samples lacked p53 expression. No p53 mutations were detected in proliferative verrucous leukoplakia tissues. Human papillomavirus 16 was identified in 2 of 7 p53 positive oral squamous cell carcinoma samples. Human papillomavirus 16 and 18 were identified in two of eight p53 positive proliferative verrucous leukoplakia samples. One p53 negative squamous cell carcinoma sample was positive for human papillomavirus 16 and had a mutation in exon 6 of the p53 gene. Human papillomavirus infection along with p53 expression plays a yet to be defined role in the pathogenesis of a limited number of cases of proliferative verrucous leukoplakia and squamous cell carcinoma. p53 immunohistochemistry, p53 gene mutations, and human papillomavirus infection prevalence do not provide a means to differentiate between leukoplakia and carcinoma and do not provide a predictive test for progression of leukoplakia to carcinoma.

Carcinoma, Squamous Cell↗
PubMed2003

A subset of head and neck squamous cell carcinomas exhibits integration of HPV 16/18 DNA and overexpression of p16INK4A and p53 in the absence of mutations in p53 exons 5-8.

Besides well-known risk factors such as tobacco use and alcohol consumption, oncogenic human papillomavirus (HPV) infection also has recently been suggested to promote head and neck tumorigenesis. HPV is known to cause cancer by inactivation of cell cycle regulators p53 and pRb via expression of viral oncoproteins E6 and E7. This indicates that p53 mutations are not a prerequisite in HPV-induced tumor development. However, discrepancy exists with respect to the frequency of head and neck squamous cell carcinomas (HNSCC) harboring DNA of oncogenic HPV and the fraction of these tumors showing p53 mutations. In our study, we examined the frequency of HNSCC demonstrating HPV 16/18 integration as identified by fluorescence in situ hybridization (FISH) and investigated their p53 (mutation) status by immunohistochemistry and single-strand conformation polymorphism (SSCP) analysis of exons 5-8. Paraffin-embedded, archival biopsy material from 27 premalignant mucosal lesions and 47 cases of HNSCC were analyzed. Ten of the 47 (21%) HNSCC unequivocally exhibited HPV 16 integration, including 8 of 12 (67%) tonsillar carcinomas. This is supported by the immunohistochemical detection of p16(INK4A) overexpression in all 10 HPV-positive tumors. Although FISH is considered to be less sensitive than PCR-based methods for HPV detection, our data clearly demonstrate clonal association of HPV with these tumors, as illustrated by the presence of integrated HPV 16 in both the primary tumor and their metastases in 2 patients. In contrast, HPV 16/18 DNA could not be detected in the premalignant lesions. In 30 of 47 (64%), HNSCC accumulation of p53 was observed, including 8 of the 10 HPV-positive carcinomas. However, in none of the latter cases could mutations in exons 5-8 be identified, except for a polymorphism in codon 213 of exon 6 in one patient. Evaluation of clinical data revealed a significant inverse relation between tobacco use with or without alcohol consumption, and HPV positivity of the tumors.

Adult↗
PubMed1999

Recurrent integration of human papillomaviruses 16, 45, and 67 near translocation breakpoints in new cervical cancer cell lines.

Progressive chromosomal changes and integration of human papillomavirus (HPV) sequences mark the development of invasive cervical cancer. Chromosomal localization of HPV integration is essential to the study of genomic regions involved in HPV-induced pathogenesis. Yet, the available information about HPV integration loci is still limited, especially with respect to different HPV types. We have established cell lines from five cervical cancers with HPV-16, HPV-45, and HPV-67. We have determined HPV integration sites and karyotype abnormalities by using the multicolor combined binary ratio-fluorescence in situ hybridization method (Tanke et al.) with 24 chromosome-specific paints in combination with full-length HPV DNA probes. All cell lines were cytogenetically abnormal, and exhibited numerical and structural chromosomal deviations. HPV sequences were integrated at various (segments of) chromosomes. Duplicate integration sites were seen in all multiploid cell lines, suggesting that viral integration had preceded chromosomal endoreduplication. HPV-16 was found near the t(3p14.1-14.3;14) breakpoint in cervical squamous cell carcinoma (CSCC)-7 and mainly in episomal form in CSCC-1. HPV-45 was integrated near 3q26-29 in cervical (adeno or adenosquamous) carcinoma (CC)-8 and near 1q21-23 as well as near the t(1q21;22q13) breakpoint in CC-10A and CC-10B variant lines. HPV-67 was localized near the breakpoint of t(3p23-26;13q22-31) in CC-11. Southern blot analysis showed that, except for CSCC-1, the physical state of HPV in the cell lines was the same as in the original tumor lesions. This set of six cervical cancer cell lines included three lines with HPV-45, a major non-Western high-risk HPV type, the first reported HPV-67-positive cell line, and two cell lines with integrated and episomal HPV-16 DNA, respectively. The novel combined binary ratio-fluorescence in situ hybridization technique enabled us to simultaneously map chromosomal rearrangements and HPV integration sites, thereby revealing recurrent integration near translocation junctions for all of these HPV types in the cell lines from three of the five primary tumors. The detection of multiple HPV integration sites at rearranged chromosomes at such high frequency in cervical cancer-derived cells may reflect events that are relevant to the development of cervical cancer.

Adult↗
PubMed2006

MYC activation associated with the integration of HPV DNA at the MYC locus in genital tumors.

To determine whether integration of human papillomavirus (HPV) DNA sequences could lead to the deregulation of genes implied in oncogenesis, we analysed the HPV integration sites in a series of nine cell lines derived from invasive genital carcinomas. Using in situ hybridization, HPV16 or 18 sequences were found at chromosome band 8q24, the localization of MYC, in IC1, IC2, IC3, IC6 and CAC-1 cells and at other sites in IC4, IC5, IC7 and IC8 cells. We then localized viral sequences at the molecular level and searched for alterations of MYC structure and expression in these cells. MYC genomic status and viral integration sites were also analysed in primary tumors from which IC1, IC2, IC3 and IC6 cells were derived. In IC1, IC2 and CAC-1 cells, HPV DNA was located within 58 kb of MYC, downstream, upstream, or within MYC. In IC3 and IC6 cells, HPV DNA was located 400-500 kb upstream of MYC. Amplification studies showed that, in IC1, IC2 and IC3, viral and MYC sequences were co-amplified in an amplicon between less than 50 and 800 kb in size. MYC amplification was also observed in primary tumors, indicating that this genetic alteration, together with viral insertion at the MYC locus, had already taken place in vivo. MYC was not amplified in the other cell lines. MYC mRNA and protein overexpression was observed in the five cell lines in which the HPV DNA was inserted close to the MYC locus, but in none of the lines where the insertion had occurred at other sites. MYC activation, triggered by the insertion of HPV DNA sequences, can be an important genetic event in cervical oncogenesis.

Carcinoma↗
PubMed2005

Integration of HPV-16 and HPV-18 DNA in vulvar intraepithelial neoplasia.

OBJECTIVE: Vulvar intraepithelial neoplasia (VIN) is a premalignant disease of the lower genital tract. The increased occurrence of high-risk human papillomavirus (HPV) infection seems to be associated with the increasing frequency of VIN. Integration of HPV DNA into host chromosome has been hypothesized to be a critical step in the carcinogenesis of cervical neoplasia resulting in altered expression of two viral transforming genes E6 and E7. METHOD: We analyzed HPV-16 and HPV-18 DNA, and integrated transcripts of HPV-16 and HPV-18 genomes in 30 VIN cases with 53 lesions using a PCR-based protocol for the amplification of papillomavirus oncogene transcripts (APOT). RESULT: 24 of 30 VIN lesions (80%) harbored HPV-16 (in 23 cases) and HPV-18 DNA. Integration of HPV-16 and HPV-18 genome was observed in eight (38.1%) of 21 HPV-16/18 positive VIN III cases. All eight VIN were multifocal and had multicentric disease (CIN/VAIN) including one case that progressed to vulvar carcinoma. Five of eight lesions were found to have E7 specific viral-cellular fusion transcripts only, two of eight showed E7-E4 viral-cellular fusion transcripts, and one of eight had both episomally derived and E7-E4 viral-cellular fusion transcripts. In 10 (83.3%) of 12 multifocal VIN III patients, all specimens derived from the same patient harbored the same HPV type and HPV transcript pattern suggesting monoclonality. CONCLUSION: HPV-16 is the most prevalent type among VIN II/III. HPV-16 and HPV-18 DNA integration into host cell genome seems to be related to the progression stage of vulvar dysplasia and, therefore, may be necessary for development of HPV-associated invasive vulvar carcinoma.

Adult↗
PubMed2002

Single copy heterozygote integration of HPV 33 in chromosomal band 5p14 is found in an epithelial cell clone with selective growth advantage.

Infection with human papillomavirus (HPV) of specific high-risk type triggers a series of events in target cells, which will eventually lead to development of genital neoplasia. The integration of high-risk HPV DNA into the cell genome has been regarded as a crucial event in tumor progression. With respect to different HPV types, the knowledge of HPV integrated loci is still limited. We have now determined the genomic variation and chromosomal location of HPV 33 DNA in the cell line UT-DEC-1, established from a vaginal mild dysplasia lesion. The viral sequence of the cell line was determined, and a variant of the prototype HPV 33 strain was identified, showing nucleotide substitutions resulting in amino acid changes in the E2, L2 and E4 open reading frames. In late passage UT-DEC-1 cells, a deletion of more than half of the 3' part of E1 and major parts of the E2 and E4 genes provided evidence for integration. The flanking sequences of the integration site were completely homologous to published sequences from chromosomal band 5p14, and remained unchanged in all subclones established from late passage cells. There were no chromosomal deletions or gross rearrangements at the integration site, and only a single heterozygotic copy of HPV 33 was detected. The karyotype of late passage cells showed only minor changes compared with early passage cells. During passaging of the cell line, there were progressive changes towards a malignant phenotype, and in parallel to this, the cells carrying episomal HPV 33 of the early passages was completely superseded by cells containing the integrated virus. Thus, our results show that this single copy heterozygote integration of HPV 33 into chromosome band 5p14 appears to be associated with emergence of cells escaping senescence, and with growth advantage compared with cells carrying episomal virus.

Base Sequence↗
PubMed1999

Mutational and functional analysis of HPV-16 URR derived from Korean cervical neoplasia.

OBJECTIVE: The YY1 mutation has been suggested as one of the indicators that explains development of cervical neoplasia by episomal-type HPV. To extend this hypothesis, we examined whether a mutation(s) in the YY1 site is functionally related to the invasiveness of cervical neoplasia and the physical status of HPV DNA. METHODS: The URR sequences were obtained by PCR amplification of HPV-16 genome from CIN and invasive cancer patients and cloned into pUC18 for sequencing and into pBLCAT8+ for functional CAT assay. RESULTS: Our previous data classified HPV-infected patients into three groups: 3 cancer cases carrying episomal HPV DNA; 12 cancer cases carrying integrated HPV DNA; 12 CIN cases carrying episomal HPV DNA. The specific variants in HPV-16 URR were found in Korean women: G-->A transition at nt 7520 (100%, 27/27), A-->C transition at nt 7729 (70%; 19/27), and G-->A transition at nt 7841 (78%; 21/27). Selective mutations were observed at the YY1 binding sites of HPV-16 URR in the 3 patients with invasive cervical cancer who have the episomal forms of HPV-16 DNA: A-->C transition at nt 7484 and G-->A transition at nt 7488 (YY1-binding site 2; from 7481 to 7489). Additionally, C-->T transition at nt 7785 (YY1-binding site 3; from 7781 to 7790) was found in 2 of 3 patients. No YY1 site mutations were detected in the 12 CIN patients and in the HPV-integrated invasive cancer patients. To determine whether these mutations have effects on the expression of HPV E6/E7 genes driven by URR, the transient transfection assay was employed using URR-CAT reporter plasmid. The relative activities of three URR mutants from episomal HPV-16 DNA of cervical cancers were two- to fourfold higher than that of the HPV-16 URR prototype. In contrast, the URRs from integrated HPV-16 DNA in cervical cancer and from episomal HPV-16 DNA in CIN, where no mutation of the YY1 binding site was detected, showed similar levels of promoter activity to that of the URR prototype. CONCLUSIONS: Our results support the hypothesis that the mutation at the YY1 binding site is functionally related to the development of cervical neoplasia caused by episomal HPV-16 DNA in Korean cervical cancer patients. Thus, mutation in the YY1 site of episomal HPV-16 URR may play a corresponding role of HPV integration in the progression of cervical cancer.

DNA Mutational Analysis↗