Dataset Information

HPV DNA methylation at the early promoter and E1/E2 integrity: A comparison between HPV16, HPV18 and HPV45 in cervical cancer.

ABSTRACT: OBJECTIVES:To compare and describe type-specific characteristics of HPV16, HPV18 and HPV45 in cervical cancer with respect to 3'LCR methylation and disruption of E1/E2. METHODS:The methylation level of 137 cervical cancer samples (70 with HPV16, 37 with HPV18, and 30 with HPV45) of Brazilian patients was analyzed by pyrosequencing. PCR amplifications were performed to characterize E1 and E2 disruption as an episomal surrogate. RESULTS:The 3'LCR of HPV16 showed a higher methylation at all CpG sites (7%, 9%, 11%, 10% and 10%) than homologous HPV18 regions (4%, 5%. 6%, 9% and 5%) and HPV45 regions (7%, 7% and 5%). Presence of intact E1/E2 was associated with higher HPV16 and HPV18 methylation levels at all CpG sites (p?

SUBMITTER: Amaro-Filho SM

PROVIDER: S-EPMC6046686 | biostudies-literature | 2018 Jun

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

HPV DNA methylation at the early promoter and E1/E2 integrity: A comparison between HPV16, HPV18 and HPV45 in cervical cancer.

Amaro-Filho Sérgio Menezes SM Pereira Chaves Cláudia Bessa CB Felix Shayany Pinto SP Basto Diogo Lisbôa DL de Almeida Liz Maria LM Moreira Miguel Angelo Martins MAM

Papillomavirus research (Amsterdam, Netherlands) 20180409

<h4>Objectives</h4>To compare and describe type-specific characteristics of HPV16, HPV18 and HPV45 in cervical cancer with respect to 3'LCR methylation and disruption of E1/E2.<h4>Methods</h4>The methylation level of 137 cervical cancer samples (70 with HPV16, 37 with HPV18, and 30 with HPV45) of Brazilian patients was analyzed by pyrosequencing. PCR amplifications were performed to characterize E1 and E2 disruption as an episomal surrogate.<h4>Results</h4>The 3'LCR of HPV16 showed a higher meth ...[more]

PMID: 29649654

Similar Datasets

Project description:BACKGROUND:Human papillomavirus (HPV) vaccines confer protection against the oncogenic genotypes HPV16 and HPV18 through the generation of type-specific neutralizing antibodies raised against virus-like particles (VLP) representing these genotypes. The vaccines also confer a degree of cross-protection against HPV31 and HPV45, which are genetically-related to the vaccine types HPV16 and HPV18, respectively, although the mechanism is less certain. There are a number of humoral immune measures that have been examined in relation to the HPV vaccines, including VLP binding, pseudovirus neutralization and the enumeration of memory B cells. While the specificity of responses generated against the vaccine genotypes are fairly well studied, the relationship between these measures in relation to non-vaccine genotypes is less certain. METHODS:We carried out a comparative study of these immune measures against vaccine and non-vaccine genotypes using samples collected from 12-15 year old girls following immunization with three doses of either Cervarix® or Gardasil® HPV vaccine. RESULTS:The relationship between neutralizing and binding antibody titers and HPV-specific memory B cell levels for the vaccine genotypes, HPV16 and HPV18, were very good. The proportion of responders approached 100% for both vaccines while the magnitude of these responses induced by Cervarix® were generally higher than those following Gardasil® immunization. A similar pattern was found for the non-vaccine genotype HPV31, albeit at a lower magnitude compared to its genetically-related vaccine genotype, HPV16. However, both the enumeration of memory B cells and VLP binding responses against HPV45 were poorly related to its neutralizing antibody responses. Purified IgG derived from memory B cells demonstrated specificities similar to those found in the serum, including the capacity to neutralize HPV pseudoviruses. CONCLUSIONS:These data suggest that pseudovirus neutralization should be used as the preferred humoral immune measure for studying HPV vaccine responses, particularly for non-vaccine genotypes.

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.

Dataset Information

HPV DNA methylation at the early promoter and E1/E2 integrity: A comparison between HPV16, HPV18 and HPV45 in cervical cancer.

Publications

HPV DNA methylation at the early promoter and E1/E2 integrity: A comparison between HPV16, HPV18 and HPV45 in cervical cancer.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets