Molecular and evolutionary analysis of HPV16 E6 and E7 genes in Greek women

Tsakogiannis, D.; Papadopoulou, Anna; Kontostathi, Georgia; Ruether, I. G. A.; Kyriakopoulou, Zaharoula; Dimitriou, Tilemachos G.; Orfanoudakis, Georges; Markoulatos, Panayotis

doi:10.1099/jmm.0.055491-0

Cited by 13 publications

(10 citation statements)

References 47 publications

(81 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Similar results in women with cervical cancer were observed in Slovenia (62.5%) (Vrtačnik Bokal et al, 2010) but a lower frequency (49%) of EUR 350G was reported across Europe in a recent meta-analysis (Tornesello et al, 2011). In our research the incidence of EUR-350G variant in the LSIL group was similar to the results of studies in Greece (64%) and in Italy (65%) but higher than in England (41%) (Tsakogiannis et al, 2013;Burroni et al, 2013;Marongiu et al, 2014). In a recent study, the International Agency for Research on Cancer (IARC) HPV Variant Study Group revealed, by examining 1121 HPV16 positive cervical cancer cases and 400 HPV16 positive controls worldwide, that E-350G is associated with an increased risk of developing cervical cancer in South and Central America but not in Europe nor Central Asia (Cornet et al, 2013a).…”

Section: Discussionsupporting

confidence: 90%

HPV16 E6 polymorphism in correlation to physical state of viral genome and risk of cervical cancer in women from the south of Poland

Szostek

Zawilińska²,

Klimek³

et al. 2017

Acta Biochim Pol

View full text Add to dashboard Cite

The aim of this study was to analyse the correlation between HPV16 E6 variants and the physical status of viral genome (integrated, mixed, episomal) among patients with cervical cancer (n=40) and low-grade squamous intraepithelial lesions - LSIL (n=40). The study was performed on 80 HPV16 positive samples. HPV16 E6 variants were identified using PCR and DNA sequencing. Nucleotide sequences of E6 were compared with the prototype sequence (EUR-350T). The physical state of HPV DNA was determined as the ratio of E2/E6 copy number per cell. Twelve different intratypic variants were identified as belonging to European (in 77 samples) and North-American 1 (in 3 samples) sublineages. The most prevalent non-synonymous variant was EUR-350G, which occurred with similar frequency in cervical cancer and LSIL. The frequencies of additional mutations in variants with EUR-350T or EUR-350G sequences differed significantly. For the first time, missense mutations G122A, C153T and G188A were discovered in EUR-350G variant. The integrated viral genome was predominant in women with cervical cancer. The EUR-350T prototype and EUR-350G without additional mutations variants were prevalent in cervical cancer samples with the HPV16 characterized by integrated DNA. In summary, European variants of HPV16 E6 dominated in both cancer and LSIL group. The presence of EUR-350G favoured the occurrence of additional nucleotide changes. We showed that nucleotide changes occur significantly more often in the mixed form of viral DNA and in LSIL group and that the variants without additional mutations may promote integration of HPV16 genome.

show abstract

Section: Discussionsupporting

confidence: 90%

HPV16 E6 polymorphism in correlation to physical state of viral genome and risk of cervical cancer in women from the south of Poland

Szostek

Zawilińska²,

Klimek³

et al. 2017

Acta Biochim Pol

View full text Add to dashboard Cite

show abstract

“…According to our findings, the most frequently disrupted site was located in the E2 hinge region (from nucleotide 3172 to 3649), while the most prevalent site of disruption within the E1 gene was located between nucleotides 1059 and 1323. Moreover, nucleotide analysis of the E1 and E2 genes in the same cervical samples, which were derived from Greek women, revealed that the region between nucleotides 3172 and 3649 (E2 gene) and the region between nucleotides 1059 and 1323 (E1 gene) are conserved among distinct HPV16 isolates that are circulating in the Greek population (Tsakogiannis et al , 2012, 2013, 2014). Taking these data into consideration, we targeted the E2 domain between nucleotides 3243 and 3539, and the E1 domain between nucleotides 1059 and 1323, through RT-PCR, in order to assign the copy numbers of the E2 and E1 genes, respectively.…”

Section: Resultsmentioning

confidence: 99%

“…In the present study, a total of 61 precancerous cervical samples and 8 cervical cancer cases associated with HPV16 infection were investigated in order to study the physical status of the HPV16 genome through quantitative RT-PCR and E2/E6 and E1/E6 ratio values analysis. However, in order to achieve more reliable results, the selection of E1, E2 and E6 targets was based on the most frequently disrupted sites of the E1 and E2 genes, and according to the most conserved E6 regions among the same HPV16 isolates, which were recently reported by our group (Tsakogiannis et al , 2012, 2013, 2014).…”

Section: Discussionmentioning

confidence: 99%

Determination of human papillomavirus 16 physical status through E1/E6 and E2/E6 ratio analysis

Tsakogiannis

Kyriakopoulou

Ruether

et al. 2014

Journal of Medical Microbiology

View full text Add to dashboard Cite

Human papillomavirus (HPV) 16 genome integration into the host chromosome is a crucial event during the life cycle of the virus and a major step towards carcinogenesis. The integration of HPV16 DNA promotes a constitutive high expression level of E6 and E7 oncoproteins, resulting in the extensive proliferation of the infected epithelial cells. In the present report the physical status of the HPV16 genome was studied, through determination of E1/E6 and E2/E6 DNA copy number ratios in 61 cervical samples of low-and high-grade malignancy and 8 cervical cancer samples, all of them associated with HPV16 infection. The selection of E1, E2 and E6 amplification target regions was performed according to the most prevalent deleted/disrupted sites of E1 and E2 genes. For this target selection we also considered the most conserved regions of E1, E2 and E6 genes among the same HPV16 isolates that were recently reported by our group. The analysis of HPV16 DNA form revealed a significant association among the mixed DNA forms in low-grade and high-grade malignancies, (x 2 , P,0.01). The comparative analysis of E1/E6 and E2/E6 in the same cervical samples provides an accurate picture of HPV16 DNA form and may reveal whether different HPV16 DNA integrants coexist in the same cervical sample or not. This study proposes that E1/E6 and E2/E6 ratios determine with accuracy the HPV16 DNA integration pattern and may predict multiple integration events in the examined sample, thus providing significant information about the progression of cervical dysplasia. INTRODUCTIONCervical cancer is the third most common type of cancer among women worldwide, with a high mortality rate. The worldwide incidence of cervical carcinoma is more than 530 000 cases per year, whereas mortality reaches 275 000 deaths annually, of which approximately 85 % occur in developing countries (Jemal et al., 2011;Forman et al., 2012). The aetiological agents for the development of highgrade precancerous cervical lesions and invasive cervical cancer are the oncogenic human papillomavirus (HPV) types present as persistent infections (Muñoz et al., 2003).To date, more than 150 different HPV types have been characterized and about 40 of them are related with anogenital tract malignancy, grouped as high-risk (HR) or low-risk (LR) genotypes (zur Hausen, 1996;Bernard et al., 2006 Bernard et al., , 2010. Epidemiological studies revealed that HPV16 is the most commonly observed HR HPV type, followed by HPV18, 31, 33 and 45 (de Sanjose et al., 2010;Li et al., 2011).Persistent infection with HR HPV types is associated with an increasing risk of integration of the viral circular genome (episome) into the host chromosomes, leading to cancer development. The circular HPV genome is then linearized, but the long control region, and the E6 and E7 oncogenes, are always retained intact (Wentzensen et al., 2004; Xu et al., 2013;Akagi et al., 2014). Viral integration appears to coincide with the development of high-grade cervical intraepithelial neoplasia (CIN II, III) as a consequence...

show abstract

“…The E7 gene was also analyzed in order to examine sequence variations that might be associated with the E1‐1374^63nt duplication. Thus, the E6–E7 region was amplified using the primer set HPV16 41/HPV16 757 as has been recently reported [Tsakogiannis et al, ].…”

Section: Methodsmentioning

confidence: 99%

Prevalence of HPV16 E1‐1374^63nt variants in Greek women

Tsakogiannis

Kyriakopoulou

Darmis

et al. 2014

Journal of Medical Virology

Self Cite

View full text Add to dashboard Cite

Recent studies have focused on sequence variation of the HPV16 E1 gene. The present study investigates the prevalence of E1-1374^63nt duplication in the Greek population, and the sequence variation at the 5' end of the E1 and E6 genes from samples that harbored this genetic alteration. Fifty HPV16 positive cervical samples, derived from Greek patients were investigated. The 5' end of the E1 gene was amplified through PCR and the variant amplicons were cloned, sequenced, and bioinformatically analyzed for selective pressure. The E1-1374^63nt duplication was identified in 24% of the examined samples, with the same prevalence in both high and low-grade cervical malignancies. The E1-1374^63nt duplication was linked to the European variant lineage (x² = 5.076, P < 0.024) and it was significantly associated with the nucleotide variation A1053C (x² = 23.102, P < 0.0001). Molecular evolution analyses anticipate that the E1-1374^63nt duplication induces functional constraints on the 5' end of E1 gene, and it is proposed that this duplication might not affect negatively the function or structure of the E1 protein. The E1-1374^63nt duplication is prevalent in the Greek population, whereas the A1053C variation might constitute a significant marker for the characterization of the E1-1374^63nt variant in the Greek population, thus providing significant information about viral pathogenicity.

show abstract

Molecular and evolutionary analysis of HPV16 E6 and E7 genes in Greek women

Cited by 13 publications

References 47 publications

HPV16 E6 polymorphism in correlation to physical state of viral genome and risk of cervical cancer in women from the south of Poland

HPV16 E6 polymorphism in correlation to physical state of viral genome and risk of cervical cancer in women from the south of Poland

Determination of human papillomavirus 16 physical status through E1/E6 and E2/E6 ratio analysis

Prevalence of HPV16 E1‐1374^63nt variants in Greek women

Contact Info

Product

Resources

About