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It is suggested that HPV-18 variants from the A lineage have higher oncogenic potential compared to B variants. Some studies show uneven distribution of HPV-18 variants in cervical adenocarcinomas and squamous cell carcinomas. Regarding HPV-18 variants’ functions, the few studies reported focus on E6, and none were performed using natural host cells. Here, we immortalized primary human keratinocytes (PHKs) with E6/E7 of HPV-18 A1 and B1 sublineages and functionally characterized these cells. PHK18A1 reached immortalization significantly faster than PHK18B1 and formed a higher number of colonies in monolayer and 3D cultures. Moreover, PHK18A1 showed greater invasion ability and higher resistance to apoptosis induced by actinomycin-D. Nevertheless, no differences were observed regarding morphology, proliferation after immortalization, migration, or epithelial development in raft cultures. Noteworthy, our study highlights qualitative differences among HPV-18 A1 and B1 immortalized PHKs: in contrast to PHK18A1, which formed more compact colonies and spheroids of firmly grouped cells and tended to invade and migrate as clustered cells, morphologically, PHK18B1 colonies and spheroids were looser, and migration and invasion of single cells were observed. Although these observations may be relevant for the association of these variants with cervical cancer of different histological subtypes, further studies are warranted to elucidate the mechanisms behind these findings.

As funcoes das oncoproteinas E6 e E7 do Papilomavirus Humano tipo 16 (HPV-16) na progressao de celulas epiteliais imortalizadas para tumores invasivos nao sao totalmente compreendidas. Aqui, estabelecemos uma nova ligacao entre E6 e E7 de duas variantes moleculares de HPV-16 (AA e E-350G) e c-MYC, em relacao a cooperacao na promocao da transformacao maligna de queratinocitos humano primarios de prepucio de recem-nascido (PHK). Nosso objetivo foi estudar os efeitos sinergicos de E6/E7 e c-MYC na proliferacao e no potencial de transformacao in vitro de PHKs. Avaliou-se a proliferacao celular atraves da expressao proteica do Antigeno Nuclear de Celulas Proliferantes (PCNA). Tambem avaliamos a capacidade de transformacao, in vitro, dos PHKs atraves de dois ensaios complementares. Observamos que E-350G-c-MYC PHKs exibiram um aumento discreto na expressao de PCNA e formaram significativamente mais colonias tanto nos ensaios de soft-agar quanto nos ensaios em placas de cultura de baixa adesao. No geral, concluimos que a variante E-350G co-transfectada com c-MYC pode promover a transformacao celular maligna com eficiencia maior do que a variante AA-c-MYC. As propriedades oncogenicas exibidas pela variante E-350G permitem entender em maior detalhe os mecanismos que podem levar a neoplasia cervical humana, dada a maior frequencia de sua ocorrencia na progressao de lesoes precursoras de alto grau para carcinomas invasivos.

Asian-American (AA) HPV-16 variants are associated with higher risk of cancer. Abnormal activation of intracellular signaling play a critical role in cancer development and progression. Our aim was to elucidate mechanisms underlying the higher oncogenic potential attributed to AA variant. We evaluated activation of MAPK and PI3K/AKT pathways in primary human keratinocytes (PHKs) transduced with E6/E7 of three HPV-16 variants: E-P, AA, E-350G. Phenotypes examined included migration, anchorage independent growth and invasion. AA PHKs presented the highest levels of active proteins involved in all cascades analyzed: MAPK-ERK, MAPK-p38 and PI3K-AKT. AA PHKs were more efficient in promoting anchorage independent growth, and in stimulating cell migration and invasion. MEK1 inhibition decreased migration. The mesenchymal phenotype marker vimentin was increased in AA PHKs. Our results suggest that MEK1, ERK2, AKT2 hyperactivation influence cellular behavior by means of GSK-3b inactivation and EMT induction prompting AA immortalized PHKs to more efficiently surpass carcinogenesis steps.

Human papillomavirus (HPV) infections are associated with the development of anogenital lesions in men. There are no reports describing the distribution of non-α HPV types in the anal canal of a sexually diverse group of men. The HPV Infection in Men (HIM) Study is a multicentre study on the natural history of HPV infection in Brazil, Mexico, and the USA. At baseline, 12% of anal canal PCR HPV-positive specimens were not typed by the Roche Linear Array, and were considered to be unclassified. Our goals were to characterize HPVs among these unclassified specimens at baseline, and to assess associations with participant socio-demographic and behavioural characteristics. Unclassified HPVs were typed by sequencing of amplified PGMY09/11 products or cloning of PGMY/GP + nested amplicons followed by sequencing. Further analysis was conducted with FAP primers. Of men with unclassified HPV in the anal canal, most (89.1%) were men who have sex with women. Readable sequences were produced for 62.8% of unclassified specimens, of which 75.2% were characterized HPV types. Eighteen, 26 and three different α-HPV, β-HPV and γ-HPV types were detected, respectively. α-HPVs were more commonly detected among young men (18–30 years) than among older men (45–70 years), whereas β-HPVs were more frequent among mid-adult men (31–44 years). β-HPVs were more common among heterosexual men (85.0%) than among non-heterosexual men. All β-HPVs detected among non-heterosexual men were β2-HPV types. The high prevalence of β-HPV in the anal canal of men who do not report receptive anal sex is suggestive of other forms of transmission that do not involve penile–anal intercourse.

Background Human papillomavirus (HPV) prevalence in head and neck squamous cell carcinomas (HNSCC) diverges geographically. The reliability of using p16INK4a expression as a marker of viral infection is controversial in HNSCC. We evaluated HPV types and HPV-16 variants prevalence, and p16INK4a expression in HNSCC specimens provided by two different Institutions in São Paulo. Methods HPV DNA from formalin-fixed specimens was accessed by Inno-LiPA, HPV-16 variants by PCR-sequencing, and p16INK4a protein levels by immunohistochemistry. Results Overall, HPV DNA was detected among 19.4 % of the specimens (36/186). Viral prevalence was higher in the oral cavity (25.0 %, 23/92) then in other anatomical sites (oropharynx 14,3 %, larynx 13.7 %) when samples from both Institutions were analyzed together. HPV prevalence was also higher in the oral cavity when samples from both Institutions were analyzed separately. HPV-16 was the most prevalent type identified in 69.5 % of the HPV positive smaples and specimens were assigned into Asian-American (57.2 %) or European (42.8 %) phylogenetic branches. High expression of p16INK4a was more common among HPV positive tumors. Conclusion Our results support a role for HPV-16 in a subset of HNSCC.

We compared E6/E7 protein properties of three different HPV-16 variants: AA, E-P and E-350G. Primary human foreskin keratinocytes (PHFK) were transduced with HPV-16 E6 and E7 and evaluated for proliferation and ability to grow in soft agar. E-P infected keratinocytes presented the lowest efficiency in colony formation. AA and E-350G keratinocytes attained higher capacity for in vitro transformation. We observed similar degradation of TP53 among HPV-16 variants. Furthermore, we accessed the expression profile in early (p5) and late passage (p30) transduced cells of 84 genes commonly involved in carcinogenesis. Most differences could be attributed to HPV-16 E6/E7 expression. In particular, we detected different expression of ITGA2 and CHEK2 in keratinocytes infected with AA and AA/E-350G late passage cells, respectively, and higher expression of MAP2K1 in E-350G transduced keratinocytes. Our results indicate differences among HPV-16 variants that could explain, at least in part, differences in oncogenic potential attributed to these variants.

Background The long control region (LCR) of human papillomavirus (HPV) regulates early gene transcription by interaction with several viral and cellular transcription factors (TFs). Methods To identify novel TFs that could influence early expression of HPV type 18 (HPV-18) and HPV type 16 (HPV-16), a high-throughput transfection array was used. Results Among the 704 TFs tested, 28 activated and 36 inhibited the LCR of HPV-18 by more than 2-fold. For validation, C33 cells were cotransfected with increasing amounts of selected TF expression plasmids in addition to LCR-luciferase vectors of different molecular variants of HPV-18 and HPV-16. Among the TFs identified, only GATA3, FOXA1, and MYC have putative binding sites within the LCR sequence, as indicated using the TRANSFAC database. Furthermore, we demonstrated FOXA1 and MYC in vivo binding to the LCR of both HPV types using chromatin immunoprecipitation assay. Conclusions We identified new TFs implicated in the regulation of the LCR of HPV-18 and HPV-16. Many of these factors are mutated in cancer or are putative cancer biomarkers and could potentially be involved in the regulation of HPV early gene expression.

Background Understanding the duration of human papillomavirus (HPV) infection may help find suitable end points for vaccine trials and testing intervals in screening studies. We studied genotype-specific infection duration among 2462 women enrolled in the Ludwig-McGill cohort study. Methods Cervical specimens collected every 4-6 months were tested by a polymerase chain reaction protocol. Actuarial techniques were used to estimate the duration of HPV infection and to investigate the influence of age, number of sexual partners, and coinfection with multiple HPV types. Results At enrollment, the prevalence of infection with high-risk HPV types was 10.6%, and the prevalence of infection with low-risk HPV types was 6.1%; incidence rates were 6.1 and 5.0 infections per 1000 women-months, respectively. Prevalent infections took longer to clear than incident infections (mean time to clearance, 18.6 months vs. 13.5 months). The mean duration of incident infection with high- and low-risk HPV varied according to the analytic approach used to measure this variable and showed considerable variation by HPV type (range, 5.1-15.4 months). Age and number of partners did not influence infection duration, whereas coinfection was associated with increased infection duration. The mean duration of HPV-16 monoinfection was 11.0 months, and the mean duration of HPV-16 coinfection was 15.4 months. Conclusion There was considerable variation among HPV types with regard to the duration of infection. Coinfection with multiple types contributed to an increased infection duration.

Made available in DSpace on 2015-12-07T15:35:13Z (GMT). No. of bitstreams: 0 Previous issue date: 2015. Added 1 bitstream(s) on 2015-12-07T15:54:20Z : No. of bitstreams: 1 PMC4494706.pdf: 414997 bytes, checksum: 4e8d783045d88f6196d51134beb364da (MD5) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tencnológico (CNPq) A significant proportion of recurrent respiratory papillomatosis (RRP) is caused by human papillomavirus type 6 (HPV-6). The long control region (LCR) contains cis-elements for regulation of transcription. Our aim was to characterize LCR HPV-6 variants in RRP cases, compare promoter activity of these isolates and search for cellular transcription factors (TFs) that could explain the differences observed. The complete LCR from 13 RRP was analyzed. Transcriptional activity of 5 variants was compared using luciferase assays. Differences in putative TFs binding sites among variants were revealed using the TRANSFAC database. Chromatin immunoprecipation (CHIP) and luciferase assays were used to evaluate TF binding and impact upon transcription, respectively. Juvenile-onset RRP cases harbored exclusively HPV-6vc related variants, whereas among adult-onset cases HPV-6a variants were more prevalent. The HPV-6vc reference was more transcriptionally active than the HPV-6a reference. Active FOXA1, ELF1 and GATA1 binding sites overlap variable nucleotide positions among isolates and influenced LCR activity. Furthermore, our results support a crucial role for ELF1 on transcriptional downregulation. We identified TFs implicated in the regulation of HPV-6 early gene expression. Many of these factors are mutated in cancer or are putative cancer biomarkers, and must be further studied. Laboratory of Genomic Studies, Universidade do Estado de São Paulo, UNESP, São José do Rio Preto, SP, Brazil Molecular Biology Laboratory, Center of Translational Oncology, Instituto do Câncer do Estado de São Paulo, ICESP, São Paulo, Brazil Department of Ophthalmology/Otorhinolaryngology and Head/Neck Surgery, Discipline Otorhinolaryngology, Faculty of Medicine of Ribeirão Preto, Universidade de São Paulo, USP, São Paulo, Brazil Laboratory of Research in Virology, Faculty of Medicine of São José do Rio Preto, FAMERP, São José do Rio Preto, Brazil Molecular Biology Laboratory, Center of Translational Oncology, Instituto do Câncer do Estado de São Paulo, ICESP, São Paulo, Brazil Department of Radiology and Oncology, School of Medicine, Universidade de São Paulo, USP, São Paulo, Brazil School of Medicine, Santa Casa de São Paulo and HPV Institute, São Paulo, Brazil Laboratory of Genomic Studies, Universidade do Estado de São Paulo, UNESP, São José do Rio Preto, SP, Brazil FAPESP: 2010/00029-0 FAPESP: 2008/57889-1 CNPq: 573799/2008-3

Background The genital skin of males hosts a diversity of HPV genotypes and uncharacterized HPV genotypes. Previously we demonstrated that a specific viral genotype was not identified in 14% of all genital specimens (i.e., HPV unclassified specimens) using the Roche Linear Array method. Our goal was to identify and assess the prevalence of individual HPV types among genital HPV unclassified specimens collected in the HIM Study population, at enrollment, and examine associations with socio-demographic and behavioral characteristics. Methods Genital skin specimens of men that were considered unclassified (HPV PCR positive, no genotype specified) at enrollment were typed by sequencing amplified PGMY09/11 products or cloning of PGMY/GP+ nested amplicons followed by sequencing. PGMY/GP+ negative specimens were further analyzed using FAP primers. HPV type classification was conducted through comparisons with sequences in the GenBank database. Results Readable nucleotide sequences were generated for the majority of previously unclassified specimens (66%), including both characterized (77%) and yet uncharacterized (23%) HPV types. Of the characterized HPV types, most (73%) were Beta [β]-HPVs, primarily from β-1 and β-2 species, followed by Alpha [α]-HPVs (20%). Smokers (current and former) were significantly more likely to have an α-HPV infection, compared with any other genus; no other factors were associated with specific HPV genera or specific β-HPV species. Conclusions Male genital skin harbor a large number of β-HPV types. Knowledge concerning the prevalence of the diverse HPV types in the men genital is important to better understand the transmission of these viruses. Electronic supplementary material The online version of this article (doi:10.1186/s12879-014-0677-y) contains supplementary material, which is available to authorized users.

Background Human papillomavirus type 6 (HPV-6) and HPV-11 are the etiological agents of approximately 90% of genital warts (GWs). The impact of HPV-6 genetic heterogeneity on persistence and progression to GWs remains undetermined. Methods HPV Infection in Men (HIM) Study participants who had HPV-6 genital swabs and/or GWs preceded by a viable normal genital swab were analyzed. Variants characterization was performed by polymerase chain reaction sequencing and samples classified within lineages (A, B) and sublineages (B1, B2, B3, B4, B5). Country- and age-specific analyses were conducted for individual variants; odds ratios and 95% confidence intervals for the risk of GWs according to HPV-6 variants were calculated. Results B3 variants were most prevalent. HPV-6 variants distribution differed between countries and case status. HPV-6 B1 variants prevalence was increased in GWs and genital swabs of cases compared to controls. There was difference in B1 and B3 variants detection in GW and the preceding genital swab. We observed significant association of HPV-6 B1 variants detection with GW development. Conclusions HPV-6 B1 variants are more prevalent in genital swabs that precede GW development, and confer an increased risk for GW. Further research is warranted to understand the possible involvement of B1 variants in the progression to clinically relevant lesions.

The HPV infection in men (HIM) study examines the natural history of genital HPV infection in men. Genotyping methods used in this study identify 37 α-HPV types; however, the viral type could not be identified in approximately 22% of male genital specimens that were HPV PCR positive. Our aim was to genotype HPV-unclassified specimens by sequencing PGMY09/11, GP5+/6+ or FAP59/64 PCR products. Using this approach we were able to detect 86 unique HPV types among 508 of 931 specimens analyzed. We report for the first time the presence of a broad range of α-, β- and γ-HPV at the male genitals.

Purpose: To investigate the presence of human papillomavirus (HPV) DNA in tumour tissue from patients with unilateral retinoblastoma. Methods: Samples of paraffin-embedded tumour tissue from 43 children with unilateral retinoblastoma were collected to investigate the presence of HPV DNA using polymerase chain reaction (PCR) and dot blot hybridization. Results: Oncogenic HPV DNA types 16 and 35 were detected in 12 (27.9%) of 43 tumour specimens. A higher frequency of differentiated tumours (63.3%) was observed among the HPV-positive tumours. Conclusions: Future studies are necessary to demonstrate an association between HPV and sporadic retinoblastoma.

Retinoblastoma is the most frequent intra-ocular malignant tumor of the childhood, occurring in 1 of 18,000-30,000 live births. Little is known about the causes of sporadic retinoblastoma and only a few authors have investigated the etiologic role of human papillomavirus (HPV), with controversial results. Formalin-fixed, paraffin-embedded tissue blocks containing retinoblastoma were retrieved from the archives of the Department of Pathology at Hospital A C Camargo, Sao Paulo, Brazil. All patients were treated with enucleation (21 children had both eyes enucleated). Retinoblastoma and, when possible, normal retina of each specimen, were micro-dissected under direct light microscopic visualization by using a PixCell II Laser Capture Micro-dissection System. The DNA quality was evaluated by polymerase chain reaction (PCR) amplification of 110 base pairs fragment of the human β-globin gene using primers PCO3+/PCO4+. All globin positive specimens were analyzed by PCR for the presence of HPV DNA using consensus primers GP5+/GP6+. A total of 154 specimens were evaluated. Forty-four patients also had normal retinal specimens available for analysis of DNA HPV. The DNA HPV prevalence among all tumor specimens was 4.6% (95% CI 2.0; 8.8) (7 positive specimens/153 adequate specimens). Among normal retinal specimens, the DNA HPV prevalence was 9.1% (95% CI 2.9; 20.5) (4 positive specimens/44 specimens). There was no statistically significant difference between these rates (P = 0.318). Excluding any experimental failure, our results indicate a low prevalence of HPV DNA in retinoblastomas. We were therefore unable to conclude about the association between these oncogenic viruses and this rare pediatric neoplasm.

The aim of this study was to investigate a possible relation between oral squamous cell carcinoma (SCC), the presence of high-risk human papillomavirus (HR-HPV) DNA and p16 expression in young patients. Paraffin-embedded tumor blocks from 47 oral SCC of young (≤40-year old) patients were evaluated. The presence of HPV DNA in tumor specimens was analyzed by polymerase chain reaction (PCR) using GP5+/GP6+ generic primers (L1 region) followed by dot blot hybridization for HPV typing. When necessary, the HPV16 positivity was confirmed by PCR HPV16 E7-specific primers. Cases involving young patients were compared with 67 oral SCC from patients ≥50-year old (controls). Demographic and clinical data were collected to analyze patient outcomes. p16(ink4) expression was evaluated by immunostaining of tissue microarrays. HPV16 was detected in 22 (19.2%) cases; 15 (68.2%) young and 7 (31.8%) control patients, a statistically significant difference (p = 0.01). In 1 (1.7%) young group specimen, HPV DNA 16 and 18 was detected. p16 expression was observed in 11 (25.6%) cases from the young group and in 11 (19.6%) controls (p = 0.48). Association between HPV and p16 was verified, and it was statistically significant (p = 0.002). The higher prevalence of high-risk HPV types, especially HPV16, may be a contributing factor to oral carcinogenesis in younger individuals.

Head and neck squamous cell carcinoma is a disease associated with tobacco and alcohol abuse. There is evidence that the oncogenic human papillomavirus (HPV) may also be a risk for upper aerodigestive tract cancers. High-risk HPVs encode two early proteins, E6 and E7, that can bind to p53 and pRb, respectively, and induce its degradation or inactivation. The TP53 gene has a single polymorphism at codon 72 of exon 4 that encodes either arginine (Arg) or proline (Pro). The purpose of this study was to evaluate the role of HPV infection and TP53 polymorphism in head and neck cancer. We analyzed 50 tumors, as well swabs of oral mucosa from 142 control individuals, with a polymerase chain reaction technique. The prevalence of HPV in controls was 10.6% and in cancer specimens 16%. The frequency distribution of genotypes in controls was 50% Arg/Arg, 43% Arg/Pro and 7% Pro/Pro; in tumors, it was 52% Arg/Arg, 32% Arg/Pro, and 16% Pro/Pro. Contrary to the results of some studies on cervical cancer, no association between any TP53 genotype or allele and the development of head and neck cancer was observed, regardless of HPV status, except for the Pro/Pro genotype, which is associated with the absence of HPV. The arginine allele appears to protect against head and neck cancers. Also, the data showed that HPV infection results in no increased risk of developing head and neck tumors.

Background Human Papillomavirus (HPV) is considered as a necessary, but not sufficient, cause of cervical cancer. In this study, we aimed to assess the prevalence of HPV in a series of pre-malignant and malignant cervical lesion cases, to identify the virus genotypes, and to assess their distribution pattern according to lesion type, age range, and other considered variables. The samples were submitted to histopathological revision examination and analysed by polymerase chain reaction (PCR) for the presence of HPV DNA, followed by HPV typing by dot blot hybridisation. Findings Of the analysed samples, 53.7% showed pre-malignant cervical lesions, and 46.3% presented with cervical cancer. Most cancer samples (84.1%) were classified as invasive carcinoma. The mean age of these cancer patients was 47.3 years. The overall HPV prevalence was 82.4% in patients with pre-malignant lesions and 92.0% in the cancer patients. HPV 16 was the most prevalent type, followed by HPV 18 and 58, including both single and double infections. Double infection was detected in 11.6% of the samples, and the most common combination was HPV 16+18. Conclusions Cervical cancer appears to occur in women in a lower age range in the studied area, compared to the situation in other Brazilian regions. Furthermore, among the patients with CIN 3 and those with cancer, we observed a higher proportion of married women, women with more than one sexual partner, smokers, and individuals with less than an elementary education, relative to their counterparts. Findings The overall HPV prevalence was 82.4% in patients with pre-malignant lesions and 92.0% in the cervical cancer patients from Northeast Brazil. HPV 16 was the most prevalent type, followed by HPV 18 and 58. The most common double infection was HPV 16+18. Cervical cancer appears to occur in women in a lower age range in the Northeast Brazil. Among the patients with CIN 3 and those with cancer, we observed a higher proportion of married women, women with more than one sexual partner, smokers, and individuals with less than an elementary education, relative to their counterparts.