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Unique LCR variations among lineages of HPV16, 18 and 45 isolates from women with normal cervical cytology in Ghana.

ABSTRACT: BACKGROUND:In addition to being useful for classification, sequence variations of human Papillomavirus (HPV) genotypes have been implicated in differential oncogenic potential and a differential association with the different histological forms of invasive cervical cancer. These associations have also been indicated for HPV genotype lineages and sub-lineages. In order to better understand the potential implications of lineage variation in the occurrence of cervical cancers in Ghana, we studied the lineages of the three most prevalent HPV genotypes among women with normal cytology as baseline to further studies. METHODS:Of previously collected self- and health personnel-collected cervical specimen, 54, which were positive for HPV16, 18 and 45, were selected and the long control region (LCR) of each HPV genotype was separately amplified by a nested PCR. DNA sequences of 41 isolates obtained with the forward and reverse primers by Sanger sequencing were analysed. RESULTS:Nucleotide sequence variations of the HPV16 genotypes were observed at 30 positions within the LCR (7460 - 7840). Of these, 19 were the known variations for the lineages B and C (African lineages), while the other 11 positions had variations unique to the HPV16 isolates of this study. For the HPV18 isolates, the variations were at 35 positions, 22 of which were known variations of Africa lineages and the other 13 were unique variations observed for the isolates obtained in this study (at positions 7799 and 7813). HPV45 isolates had variations at 35 positions and 2 (positions 7114 and 97) were unique to the isolates of this study. CONCLUSION:This study provides the first data on the lineages of HPV 16, 18 and 45 isolates from Ghana. Although the study did not obtain full genome sequence data for a comprehensive comparison with known lineages, these genotypes were predominately of the Africa lineages and had some unique sequence variations at positions that suggest potential oncogenic implications. These data will be useful for comparison with lineages of these genotypes from women with cervical lesion and all the forms of invasive cervical cancers.

SUBMITTER: Awua AK

PROVIDER: S-EPMC5401561 | biostudies-literature | 2017 Apr

REPOSITORIES: biostudies-literature

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Unique LCR variations among lineages of HPV16, 18 and 45 isolates from women with normal cervical cytology in Ghana.

Awua Adolf K AK Adanu Richard M K RMK Wiredu Edwin K EK Afari Edwin A EA Zubuch Vanessa A VA Asmah Richard H RH Severini Alberto A

Virology journal 20170421 1

<h4>Background</h4>In addition to being useful for classification, sequence variations of human Papillomavirus (HPV) genotypes have been implicated in differential oncogenic potential and a differential association with the different histological forms of invasive cervical cancer. These associations have also been indicated for HPV genotype lineages and sub-lineages. In order to better understand the potential implications of lineage variation in the occurrence of cervical cancers in Ghana, we s ...[more]

PMID: 28431571

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Project description:BackgroundHuman papillomavirus 16 (HPV16) is an oncogenic virus responsible for the majority of invasive cervical cancer cases worldwide. Due to genetic modifications, some variants are more oncogenic than others. We analysed the HPV16 phylogeny in HPV16-positive cervical Desoxyribonucleic Acid (DNA) samples collected from South African and Mozambican women to detect the circulating lineages.MethodsPolymerase chain reaction (PCR) amplification of the long control region (LCR) and 300 nucleotides of the E6 region was performed using HPV16-specific primers on HPV16-positive cervical samples collected in women from South Africa and Mozambique. HPV16 sequences were obtained through Next Generation Sequencing (NGS) methods. Geneious prime and MEGA 11 software were used to align the sequences to 16 HPV16 reference sequences, gathering the A, B, C, and D lineages and generating the phylogenetic tree. Single nucleotide polymorphisms (SNPs) in the LCR and E6 regions were analysed and the phylogenetic tree was generated using Geneious Prime software.ResultsFifty-eight sequences were analysed. Of these sequences, 79% (46/58) were from women who had abnormal cervical cytology. Fifteen SNPs in the LCR and eight in the E6 region were found to be the most common in all sequences. The phylogenetic analysis determined that 45% of the isolates belonged to the A1 sublineage (European variant), 34% belonged to the C1 sublineage (African 1 variant), 16% belonged to the B1 and B2 sublineage (African 2 variant), two isolates belonged to the D1-3 sublineages (Asian-American variant), and one to the North American variant.ConclusionsThe African and European HPV16 variants were the most common circulating lineages in South African and Mozambican women. A high-grade squamous intraepithelial lesion (HSIL) was the most common cervical abnormality observed and linked to European and African lineages. These findings may contribute to understanding molecular HPV16 epidemiology in South Africa and Mozambique.

Project description:This study was undertaken to decipher the interdependent roles of (i) methylation within E2 binding site I and II (E2BS-I/II) and replication origin (nt 7862) in the long control region (LCR), (ii) expression of viral oncogene E7, (iii) expression of the transcript (E7-E1/E4) that encodes E2 repressor protein and (iv) viral load, in human papillomavirus 16 (HPV16) related cervical cancer (CaCx) pathogenesis. The results revealed over-representation (p<0.001) of methylation at nucleotide 58 of E2BS-I among E2-intact CaCx cases compared to E2-disrupted cases. Bisulphite sequencing of LCR revealed overrepresentation of methylation at nucleotide 58 or other CpGs in E2BS-I/II, among E2-intact cases than E2-disrupted cases and lack of methylation at replication origin in case of both. The viral transcript (E7-E1/E4) that produces the repressor E2 was analyzed by APOT (amplification of papillomavirus oncogenic transcript)-coupled-quantitative-RT-PCR (of E7 and E4 genes) to distinguish episomal (pure or concomitant with integrated) from purely integrated viral genomes based on the ratio, E7 C(T)/E4 C(T). Relative quantification based on comparative C(T) (threshold cycle) method revealed 75.087 folds higher E7 mRNA expression in episomal cases over purely integrated cases. Viral load and E2 gene copy numbers were negatively correlated with E7 C(T) (p = 0.007) and E2 C(T) (p<0.0001), respectively, each normalized with ACTB C(T), among episomal cases only. The k-means clustering analysis considering E7 C(T) from APOT-coupled-quantitative-RT-PCR assay, in conjunction with viral load, revealed immense heterogeneity among the HPV16 positive CaCx cases portraying integrated viral genomes. The findings provide novel insights into HPV16 related CaCx pathogenesis and highlight that CaCx cases that harbour episomal HPV16 genomes with intact E2 are likely to be distinct biologically, from the purely integrated viral genomes in terms of host genes and/or pathways involved in cervical carcinogenesis.

Project description:BackgroundVigilant management of women with high-risk human papillomavirus (hrHPV) is necessary in cancer screening programs. To this end, we evaluated the performance of S5 (targeting DNA methylation in HPV16, HPV18, HPV31, HPV33, and human gene EPB41L3) to predict cervical intraepithelial neoplasia grade 2 or higher (CIN2+) in a sample of hrHPV-infected women referred to colposcopy in the FRIDA Study, a large screening trial in Mexico. A nested case-control sample with women referred to colposcopy either by atypical squamous cells of undetermined significance or higher (ASCUS+) in cytology and/or positive for HPV types 16 or 18 was tested by S5. Seventy-nine cases of CIN2+ were age-matched to 237 controls without a diagnosis of CIN2+ (<CIN2). DNA from exfoliated cervical cells was bisulfite converted and PCR amplified for S5 targets, and methylation was quantified at specific cytosines by pyrosequencing.ResultsThe S5 classifier separated women with CIN2+ from <CIN2 with a highly significant area under the curve (AUC) of 0.75 (95% CI 0.69-0.82), while AUC for CIN3+ was 0.81 (95% CI 0.74-0.89). To optimize sensitivity and specificity for Mexico, an alternative S5 cutoff of 3.7 was implemented to account for overall higher methylation seen in our already triaged women. All three invasive cancers were detected by methylation or HPV16/18 but none by cytology. Sensitivity of S5 for CIN2+ was 62% (95% CI 50.4-72.7%), specificity was 73% (95% CI 66.9-78.5%), and adjusted PPV was 15.1% (95% CI 12.0-18.3%). In contrast, the crude sensitivity of HPV16/18 detection and cytology were 63.3% (95% CI 51.7-73.9%) and 57.0% (95% CI 45.3-68.1%) respectively; specificity was 29.1% (95% CI 23.4-35.3%) and 62.4% (95% CI 55.9-68.6%) respectively, while adjusted PPV was 6.4% (95% CI 4.9-8.1%) and 10.5% (95% CI 8.0-13.1%), respectively. Methylation testing could reduce colposcopy referrals by 30 to 50% with virtually no loss of sensitivity for CIN2+ and CIN3+.ConclusionsS5 testing on hrHPV-positive women significantly increased diagnostic information compared to triage by HPV16/18 plus cytology and appears to have clinical utility as an additional test to substantially lessen burdens on colposcopy.Trial registrationThe FRIDA Study is registered in ClinicalTrials.gov , number NCT02510027.

Project description:We tested the hypothesis that (i) synonymous variations within the coding regions, and (ii) variations within the non-coding regions of HPV, influence cervical cancer (CaCx) pathogenesis under the impact of intact HPV16 genomes. Whole genome sequence analysis of HPV16 isolates within 70 CaCx cases and 25 non-malignant samples revealed that synonymous variations were significantly higher within the E6 (p = 0.014), E5 (p = 0.001) and L2 (p = 0.0002) genes of HPV16 isolates within cases, compared to isolates within non-malignant samples. All of the 25 (100%) humanized codons identified within L2 ORF of the samples analyzed, were harbored by CaCx cases, while 8 out of 25 (32%) were harbored by HPV16 positive non-malignant samples (p = 3.87105E-07). L2 (mRNA and protein) expression was evident only among cases with episomal viral genomes and L2 mRNA expression correlated significantly with E2 gene copy numbers suggesting expression from all episomal genomes. Among such cases, Asian American (AA) isolates portrayed all of the humanized codons (100%; 4-6/sample) recorded within L2, which was significantly higher (p = 2.02E-7) compared to the European (E) isolates (22.8%; none or 1-2/sample). Additionally, majority of E variant isolates within cases (54/57; 94.7%) portrayed a variation (T4228C) within the short non-coding region (NCR2) between E5 and L2 genes, which portrays a weak promoter activity specific for L2 mRNA expression. This resulted in loss of 9 out of 14 miRNA binding sites (hsa-miR-548 family), despite the significant overexpression of miR548a-5p and miR548d-5p among such cases (28.64 and 36.25 folds, respectively), in comparison to HPV negative control samples. The findings exemplify the biological relevance of sequence variations in HPV16 genomes and highlight that episomal HPV16 in CaCx cases employ multiple mechanisms to sustain L2 expression, thereby justifying the potential role of L2 in such cancers, as opposed to those harboring viral integration.

Project description:IntroductionMany countries have adopted active surveillance in women with cervical intraepithelial neoplasia grade 2 (CIN2), leaving the lesion untreated. However, there is a lack of consensus on the eligibility criteria for active surveillance across countries, with some abstaining from active surveillance in women with human papilloma virus 16 (HPV16) or a high-grade cytology. Here, we aimed to describe the distribution of HPV genotypes, age, and cytology in women undergoing active surveillance for CIN2.Material and methodsWe conducted a single-center cross-sectional study on women aged 23-40 undergoing active surveillance for CIN2 during 2000-2010. Women were identified through the Danish Pathology Data Bank (DPDB) at Aarhus University Hospital, Denmark. We collected information on basic characteristics and results of histopathological examinations via DPDB. Women were deemed eligible for inclusion if they had a subsequent biopsy after index CIN2, and had no prior record of CIN2+, hysterectomy, or cone biopsy. Archived biopsies underwent HPV genotyping using the HPV SPF10 - DEIA-LiPA25 system, and the diagnosis was re-evaluated by three expert pathologists. We used the Chi squared-test (p-value) for comparison across groups.ResultsWe identified 3623 women with CIN2 of whom 455 (12.6%) were included. Most women were 30 years or younger (73.8%), and half (48.8%) had a high-grade index cytology. The prevalence of any high-risk HPV was 87.0%, with HPV16 being the most prevalent genotype (35.6%). The prevalence of HPV16 was significantly higher in women aged 30 or younger (39.3%) compared to women older than 30 years (25.2%) (p = 0.006). Upon expert review, 261 (57.4%) had CIN2 confirmed, whereas 56 (12.3%) were upgraded to CIN3 and 121 (26.6%) were downgraded to CIN1/normal. While the HPV16 prevalence was similar between community and expert confirmed CIN2, the prevalence of HPV16 was significantly higher in women with expert CIN3 compared to women with expert CIN1/normal (64.3% vs. 19.0%, p = 0.001).ConclusionsThe high prevalence of HPV16 and high-grade cytology imply that these women may be perceived as a high-risk population and non-eligible for active surveillance in countries outside Denmark. Future studies should investigate the importance of HPV, age, cytology, and expert review on risk of progression to help refine criteria for active surveillance.

Project description:BackgroundPersistent infection with oncogenic Human Papillomavirus (HPV) is associated with the development of cervical cancer with each genotype differing in their relative contribution to the prevalence of cervical disease. HPV DNA testing offers improved sensitivity over cytology testing alone but is accompanied by a generally low specificity. Potential molecular markers of cervical disease include type-specific viral load (VL), integration of HPV DNA into the host genome and methylation of the HPV genome. The aim of this study was to evaluate the relationship between HPV type-specific viral load, integration and methylation status and cervical disease stage in samples harboring HPV16, HPV18, HPV31 or HPV45.MethodsSamples singly infected with HPV16 (n=226), HPV18 (n=32), HPV31 (n=75) or HPV45 (n=29) were selected from a cohort of 4,719 women attending cervical screening in England. Viral load and integration status were determined by real-time PCR while 3'L1-URR methylation status was determined by pyrosequencing or sequencing of multiple clones derived from each sample.ResultsViral load could differentiate between normal and abnormal cytology with a sensitivity of 75% and a specificity of 80% (odds ratio [OR] 12.4, 95% CI 6.2-26.1; p<0.001) with some variation between genotypes. Viral integration was poorly associated with cervical disease. Few samples had fully integrated genomes and these could be found throughout the course of disease. Overall, integration status could distinguish between normal and abnormal cytology with a sensitivity of 72% and a specificity of 50% (OR 2.6, 95% CI 1.0-6.8; p=0.054). Methylation levels were able to differentiate normal and low grade cytology from high grade cytology with a sensitivity of 64% and a specificity of 82% (OR 8.2, 95% CI 3.8-18.0; p<0.001). However, methylation varied widely between genotypes with HPV18 and HPV45 exhibiting a broader degree and higher magnitude of methylated CpG sites than HPV16 and HPV31.ConclusionsThis study lends support for HPV viral load and CpG methylation status, but not integration status, to be considered as potential biomarkers of cervical disease.

Dataset Information

Unique LCR variations among lineages of HPV16, 18 and 45 isolates from women with normal cervical cytology in Ghana.

Publications

Unique LCR variations among lineages of HPV16, 18 and 45 isolates from women with normal cervical cytology in Ghana.

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