The E7 Oncoprotein Is Translated from Spliced E6*I Transcripts in High-Risk Human Papillomavirus Type 16- or Type 18-Positive Cervical Cancer Cell Lines via Translation Reinitiation

ABSTRACT High-risk human papillomaviruses (HPVs) encode two viral oncoproteins, E6 and E7, from a single bicistronic pre-mRNA containing three exons and two introns. Retention of intron 1 in the E6 coding region is essential for production of the full-length E6 oncoprotein. However, splicing of intron 1 is extremely efficient in cervical cancer cells, leading to the production of a spliced transcript, E6*I, of E6. Here, we investigated whether this splicing of intron 1 might benefit E7 production. Using RNA interference as a tool, we targeted the intron 1 region using small interfering RNAs (siRNAs) in HPV-positive cell lines. At an effective low dose, the siRNAs specifically suppressed E6 expression but not E7 expression, as demonstrated by the stabilization of p53. However, at high doses the HPV18 intron 1-specific siRNA substantially and specifically reduced the level of the 18E6*I mRNA lacking the intron region in HeLa cells, implying its nuclear silencing on the pre-mRNA before RNA splicing. Two other siRNAs targeting the exon 2 regions of HPV16 and -18, which encode the E7 oncoprotein, reduced the E6*I mRNAs to a remarkable extent and preferentially suppressed expression of E7, leading to accumulation of hypophosphorylated p105Rb and cell cycle arrest, indicating that the majority of E7 proteins are the translational products of E6*I mRNAs. This was confirmed by transient transfection in 293 cells: E7 could be translated only from the E7 open reading frame (ORF) on E6*I mRNA in a distance-dependent matter of upstream E6*I ORF by translation reinitiation. The data thus provide direct evidence that the E6*I mRNAs of high-risk HPVs are responsible for E7 production.

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High-Risk Human Papillomavirus E7 Proteins Target PTPN14 for Degradation

mBio ◽

10.1128/mbio.01530-16 ◽

2016 ◽

Vol 7 (5) ◽

Cited By ~ 37

Author(s):

Elizabeth A. White ◽

Karl Münger ◽

Peter M. Howley

Keyword(s):

Cervical Cancer ◽

High Risk ◽

Protein Tyrosine Phosphatase ◽

Tyrosine Phosphatase ◽

Human Papillomaviruses ◽

E7 Oncoprotein ◽

Hpv E7 ◽

Transforming Activity ◽

E7 Proteins ◽

High Risk Hpv

ABSTRACTThe major transformation activity of the high-risk human papillomaviruses (HPV) is associated with the E7 oncoprotein. The interaction of HPV E7 with retinoblastoma family proteins is important for several E7 activities; however, this interaction does not fully account for the high-risk E7-specific cellular immortalization and transformation activities. We have determined that the cellular non-receptor protein tyrosine phosphatase PTPN14 interacts with HPV E7 from many genus alpha and beta HPV types. We find that high-risk genus alpha HPV E7, but not low-risk genus alpha or beta HPV E7, is necessary and sufficient to reduce the steady-state level of PTPN14 in cells. High-risk E7 proteins target PTPN14 for proteasome-mediated degradation, which requires the ubiquitin ligase UBR4, and PTPN14 is degraded by the proteasome in HPV-positive cervical cancer cell lines. Residues in the C terminus of E7 interact with the C-terminal phosphatase domain of PTPN14, and interference with the E7-PTPN14 interaction restores PTPN14 levels in cells. Finally, PTPN14 degradation correlates with the retinoblastoma-independent transforming activity of high-risk HPV E7.IMPORTANCEHigh-risk human papillomaviruses (HPV) are the cause of cervical cancer, some other anogenital cancers, and a growing fraction of oropharyngeal carcinomas. The high-risk HPV E6 and E7 oncoproteins enable these viruses to cause cancer, and the mechanistic basis of their carcinogenic activity has been the subject of intense study. The high-risk E7 oncoprotein is especially important in the immortalization and transformation of human cells, which makes it a central component of HPV-associated cancer development. E7 oncoproteins interact with retinoblastoma family proteins, but for several decades, it has been recognized that high-risk HPV E7 oncoproteins have additional cancer-associated activities. We have determined that high-risk E7 proteins target the proteolysis of the cellular protein tyrosine phosphatase PTPN14 and find that this activity is correlated with the retinoblastoma-independent transforming activity of E7.

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Cigarette Smoking Promotes Infection of Cervical Cells by High-Risk Human Papillomaviruses, but not Subsequent E7 Oncoprotein Expression

10.20944/preprints201801.0034.v1 ◽

2018 ◽

Author(s):

Kimon Chatzistamatiou ◽

Theodoros Moysiadis ◽

Dimos Vryzas ◽

Ekaterini Chatzaki ◽

Andreas M. Kaufmann ◽

...

Keyword(s):

Cervical Cancer ◽

High Risk ◽

Sandwich Elisa ◽

Protein Detection ◽

Human Papillomaviruses ◽

Smoking Intensity ◽

Hpv Dna ◽

E7 Oncoprotein ◽

Detection Assay ◽

Cervical Cells

Persistent cervical infection with high-risk Human papillomaviruses (hrHPVs) is a necessary, but not sufficient, condition for the development of cervical cancer. Therefore, there are other co-factors facilitating the hrHPV carcinogenic process, one of which is smoking. In order to assess the effect of smoking on high-risk (hr) HPV DNA positivity and on the expression of HPV E7 oncoprotein, as a surrogate of persistent hrHPV infection, we used data from women recruited for the PIPAVIR project, which examined the role of E7 protein detection in cervical cancer screening. Women were tested for hrHPV DNA, using Multiplex Genotyping and E7 protein, using a novel sandwich ELISA method, and gave information on their smoking habits. Among 1473 women, hrHPV prevalence was 19.1%. The odds ratio (OR) for hrHPV positivity of smokers compared to non-smokers was 1.785 (95%CI: 1.365-2.332, p<0.001). The ORs for E7 positivity, concerning hrHPV positive women, ranged from 0.720 to 1.360 depending on the E7 detection assay used, but this was not statistically significant. Smoking increases the probability of hrHPV infection, and smoking intensity is positively associated to this increase. Smoking is not related to an increased probability of E7 protein positivity for hrHPV positive women.

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Adenoviral Vectors Armed with PAPILLOMAVIRUs Oncogene Specific CRISPR/Cas9 Kill Human-Papillomavirus-Induced Cervical Cancer Cells

Cancers ◽

10.3390/cancers12071934 ◽

2020 ◽

Vol 12 (7) ◽

pp. 1934 ◽

Cited By ~ 1

Author(s):

Eric Ehrke-Schulz ◽

Sonja Heinemann ◽

Lukas Schulte ◽

Maren Schiwon ◽

Anja Ehrhardt

Keyword(s):

Cervical Cancer ◽

Cancer Cells ◽

Cell Lines ◽

Cancer Cell ◽

Cancer Cell Lines ◽

Adenoviral Vectors ◽

Human Papillomaviruses ◽

Cervical Cancer Cell ◽

Adenoviral Delivery ◽

Cervical Cancer Cells

Human papillomaviruses (HPV) cause malignant epithelial cancers including cervical carcinoma, non-melanoma skin and head and neck cancer. They drive tumor development through the expression of their oncoproteins E6 and E7. Designer nucleases were shown to be efficient to specifically destroy HPV16 and HPV18 oncogenes to induce cell cycle arrest and apoptosis. Here, we used high-capacity adenoviral vectors (HCAdVs) expressing the complete CRISPR/Cas9 machinery specific for HPV18-E6 or HPV16-E6. Cervical cancer cell lines SiHa and CaSki containing HPV16 and HeLa cells containing HPV18 genomes integrated into the cellular genome, as well as HPV-negative cancer cells were transduced with HPV-type-specific CRISPR-HCAdV. Upon adenoviral delivery, the expression of HPV-type-specific CRISPR/Cas9 resulted in decreased cell viability of HPV-positive cervical cancer cell lines, whereas HPV-negative cells were unaffected. Transduced cervical cancer cells showed increased apoptosis induction and decreased proliferation compared to untreated or HPV negative control cells. This suggests that HCAdV can serve as HPV-specific cancer gene therapeutic agents when armed with HPV-type-specific CRISPR/Cas9. Based on the versatility of the CRISPR/Cas9 system, we anticipate that our approach can contribute to personalized treatment options specific for the respective HPV type present in each individual tumor.

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HPV and Other Microbiota; Who’s Good and Who’s Bad: Effects of the Microbial Environment on the Development of Cervical Cancer—A Non-Systematic Review

Cells ◽

10.3390/cells10030714 ◽

2021 ◽

Vol 10 (3) ◽

pp. 714

Author(s):

Matthias Läsche ◽

Horst Urban ◽

Julia Gallwas ◽

Carsten Gründker

Keyword(s):

Systematic Review ◽

Cervical Cancer ◽

High Risk ◽

Cervical Carcinoma ◽

Hpv Infection ◽

Human Papillomaviruses ◽

Inflammatory Reactions ◽

Metabolic Signalling ◽

Microbial Environment ◽

High Risk Hpv

Cervical cancer is responsible for around 5% of all human cancers worldwide. It develops almost exclusively from an unsolved, persistent infection of the squamocolumnar transformation zone between the endo- and ecto-cervix with various high-risk (HR) human papillomaviruses (HPVs). The decisive turning point on the way to persistent HPV infection and malignant transformation is an immune system weakened by pathobionts and oxidative stress and an injury to the cervical mucosa, often caused by sexual activities. Through these injury and healing processes, HPV viruses, hijacking activated keratinocytes, move into the basal layers of the cervical epithelium and then continue their development towards the distal prickle cell layer (Stratum spinosum). The microbial microenvironment of the cervical tissue determines the tissue homeostasis and the integrity of the protective mucous layer through the maintenance of a healthy immune and metabolic signalling. Pathological microorganisms and the resulting dysbiosis disturb this signalling. Thus, pathological inflammatory reactions occur, which manifest the HPV infection. About 90% of all women contract an HPV infection in the course of their lives. In about 10% of cases, the virus persists and cervical intra-epithelial neoplasia (CIN) develops. Approximately 1% of women with a high-risk HPV infection incur a cervical carcinoma after 10 to 20 years. In this non-systematic review article, we summarise how the sexually and microbial mediated pathogenesis of the cervix proceeds through aberrant immune and metabolism signalling via CIN to cervical carcinoma. We show how both the virus and the cancer benefit from the same changes in the immune and metabolic environment.

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The application of CRISPR/Cas9 system in cervical carcinogenesis

Cancer Gene Therapy ◽

10.1038/s41417-021-00366-w ◽

2021 ◽

Author(s):

Chun Gao ◽

Ping Wu ◽

Lan Yu ◽

Liting Liu ◽

Hong Liu ◽

...

Keyword(s):

Cervical Cancer ◽

High Risk ◽

Transgenic Mice ◽

Cell Line ◽

Cell Lines ◽

Cancer Cell ◽

Precancerous Lesions ◽

Cancer Cell Lines ◽

Cervical Carcinogenesis ◽

Cervical Precancerous Lesions

AbstractIntegration of high-risk HPV genomes into cellular chromatin has been confirmed to promote cervical carcinogenesis, with HPV16 being the most prevalent high-risk type. Herein, we evaluated the therapeutic effect of the CRISPR/Cas9 system in cervical carcinogenesis, especially for cervical precancerous lesions. In cervical cancer/pre-cancer cell lines, we transfected the HPV16 E7 targeted CRISPR/Cas9, TALEN, ZFN plasmids, respectively. Compared to previous established ZFN and TALEN systems, CRISPR/Cas9 has shown comparable efficiency and specificity in inhibiting cell growth and colony formation and inducing apoptosis in cervical cancer/pre-cancer cell lines, which seemed to be more pronounced in the S12 cell line derived from the low-grade cervical lesion. Furthermore, in xenograft formation assays, CRISPR/Cas9 inhibited tumor formation of the S12 cell line in vivo and affected the corresponding protein expression. In the K14-HPV16 transgenic mice model of HPV-driven spontaneous cervical carcinogenesis, cervical application of CRISPR/Cas9 treatment caused mutations of the E7 gene and restored the expression of RB, E2F1, and CDK2, thereby reversing the cervical carcinogenesis phenotype. In this study, we have demonstrated that CRISPR/Cas9 targeting HPV16 E7 could effectively revert the HPV-related cervical carcinogenesis in vitro, as well as in K14-HPV16 transgenic mice, which has shown great potential in clinical treatment for cervical precancerous lesions.

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Acceptability and feasibility of human papillomavirus vaccination for adolescents in school environments in Libreville

International Journal of Reproduction Contraception Obstetrics and Gynecology ◽

10.18203/2320-1770.ijrcog20203825 ◽

2020 ◽

Vol 9 (9) ◽

pp. 3541

Author(s):

Nathalie L. Ambounda ◽

Sylvain H. Woromogo ◽

Olive M. Kenmogne ◽

Felicite E. Yagata Moussa ◽

Vicky N. Simo Tekem ◽

...

Keyword(s):

Cervical Cancer ◽

Human Papillomavirus ◽

High Risk ◽

Precancerous Lesions ◽

Hpv Vaccination ◽

Immunization Coverage ◽

Human Papillomaviruses ◽

Professional Status ◽

Human Papillomavirus Vaccination ◽

Cross Sectional

Background: High-risk oncogenic human papillomaviruses (HPV) are the cause of sexually transmitted viral infection. Its persistence is a risk factor for precancerous lesions of the cervix, which will constitute the base of cervical cancer. In the world, the prevalence of high-risk oncogenic HPV is 66.7%, which is higher among women starting their sexual activity.Methods: An analytical cross-sectional study was conducted in high schools in Gabon regarding parents. The variables selected were the socio-cultural and demographic characteristics of the parents, their knowledge of human papillomavirus vaccination and their acceptability of HPV vaccination and finally the feasibility of HPV vaccination. The statistical test used was Pearson's Chi-square, and a difference was considered significant for p<0.05.Results: The majority of parents, 89%, were informed of the existence of cervical cancer. However, 73.4% of them were unaware of the existence of vaccination against cervical cancer. Only 2.4% of parents had vaccinated their daughters against cervical cancer at the time of the study. These parents only 53.4% expressed an interest in vaccinating their daughters in 53.4% of cases. The ability to vaccinate children is associated with the socio-professional status of parents (p˂0.000).Conclusions: The majority of parents approved school-based vaccination against human papillomavirus infections despite its reported cost and lack of information. The integration of anti-HPV vaccination into the expanded programme on immunization in Gabon will improve immunization coverage.

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Prevalence and Subtype Distribution of High-Risk Human Papillomavirus Among Women Presenting for Cervical Cancer Screening at Karanda Mission Hospital

JCO Global Oncology ◽

10.1200/go.20.00286 ◽

2020 ◽

pp. 1276-1281 ◽

Cited By ~ 1

Author(s):

Paul Thistle ◽

Rabea Parpia ◽

Debanjan Pain ◽

Hang Lee ◽

Justen Manasa ◽

...

Keyword(s):

Cervical Cancer ◽

Human Papillomavirus ◽

Cancer Screening ◽

High Risk ◽

Cervical Cancer Screening ◽

Screening Program ◽

Large Fraction ◽

Human Papillomaviruses ◽

Mission Hospital ◽

Dna Types

PURPOSE High-risk human papillomaviruses (hrHPV) are the primary cause of cervical cancer. Human papillomavirus (HPV) vaccination is expected to prevent cervical cancers caused by the HPV types included in vaccines and possibly by cross-protection from other types. This study sought to determine the hrHPV type distribution in women at a rural Zimbabwe hospital. METHODS We implemented a cross-sectional study at the Karanda Mission Hospital. Using the Visual Inspection with Acetic Acid Cervicography technique, clinicians collected cervical swabs from 400 women presenting for screening for cervical cancer. Samples were initially analyzed by Cepheid GeneXpert; candidate hrHPV genotypes were further characterized using the Anyplex II HPV28 Detection Kit. RESULTS Twenty-one percent of the 400 women were positive for a high-risk genotype when using the GeneXpert analyzer; 17% were positive when using the multiplex analysis. Almost two thirds of the hrHPV women had a single DNA type identified, whereas one third had multiple genotypes, ranging from 2 to 5. hrHPV was observed more frequently in HIV-positive than in HIV-negative women (27% v 15%). Of the 113 isolates obtained, 77% were hrHPV genotypes not included in the bivalent or quadrivalent vaccines, and 47% represented DNA types not covered in the nonavalent vaccine. Forty-seven percent of the women with hrHPV harbored a single genotype that was not covered by the nonavalent vaccine. CONCLUSION A large fraction of hrHPV isolates from women participating in a cervical cancer screening program in northern Zimbabwe are DNA types not covered by the bivalent, quadrivalent, or nonavalent vaccines. These findings suggest the importance of characterizing the hrHPV DNA types isolated from cervical neoplasia in this population and determining whether cross-immunization against these genotypes develops after administration of the vaccines in current use.

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Cervical Human Papillomavirus Prevalence, Genotypes, and Associated Risk Factors among Female Sex Workers in Greater Accra, Ghana

Journal of Oncology ◽

10.1155/2019/8062176 ◽

2019 ◽

Vol 2019 ◽

pp. 1-7 ◽

Cited By ~ 2

Author(s):

Abdul Rashid Adams ◽

Priscillia Awo Nortey ◽

Benjamin Ansah Dortey ◽

Richard Harry Asmah ◽

Edwin Kwame Wiredu

Keyword(s):

Cervical Cancer ◽

High Risk ◽

Cancer Prevention ◽

Sex Workers ◽

Female Sex Workers ◽

Cervical Cancer Prevention ◽

Human Papillomaviruses ◽

Female Sex ◽

Hpv Prevalence ◽

Hpv Genotypes

Cervical cancer is a largely preventable disease mediated by persistent infection with high-risk Human Papillomaviruses (Hr-HPV). There are now three approved vaccines against the most common HPV genotypes. In Ghana, mortality due to cervical cancer is on the rise, due to the absence of an organized and effective cervical cancer prevention and control program. Data on circulating HPV genotypes is important for studying the likely impact of mass introduction of HPV vaccination of the female population before sexual debut. High HPV prevalence has been reported in Female Sex Workers (FSWs), who constitute an important active group for maintenance of HPV in the population. This study was conducted to determine the size of HPV prevalence in this group and to provide information for future assessment of the impact of vaccine introduction in the country. We conducted a cross-sectional study where the snowballing technique was used to identify and select FSW’s ≥18 years, operating within suburbs of Greater Accra Region (GAR). A risk factor assessment interview was conducted and cervical swabs were collected for HPV-DNA detection and genotyping by Nested Multiplex PCR. Hundred participants, age ranging from 18 to 45 years, median 24 years, were studied. The prevalence of Cervical HPV was 26%. Eleven genotypes were detected comprising 9 high-risk in order of decreasing prevalence HPV-16 (8%), HPV-35 (5%), HPV-33/39/-68 (3%), HPV-52/51/59 (2%) and HPV-18 (1%) and 2 Low-risk types, HPV-42(3%), and HPV-43 (1%). Three women had HPV types that could not be genotyped by our method. Oral contraceptives use was associated with a reduced chance of HPV infection (P=0.002; OR=0.19, 95% CI 0.07-0.54). This study found a high HPV prevalence among FSWs in the GAR. A high number of Hr-HPV genotypes seen are vaccine preventable, providing additional compelling argument for implementing a national cervical cancer prevention plan including vaccination.

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Clinical Significance of the Interaction between Human Papillomavirus (HPV) Type 16 and Other High-Risk Human Papillomaviruses in Women with Cervical Intraepithelial Neoplasia (CIN) and Invasive Cervical Cancer

Journal of Oncology ◽

10.1155/2020/6508180 ◽

2020 ◽

Vol 2020 ◽

pp. 1-9

Author(s):

Arsenio A. Spinillo ◽

Mattia M. Dominoni ◽

Anna A. C. Boschi ◽

Cecilia C. Sosso ◽

Giacomo G. Fiandrino ◽

...

Keyword(s):

Cervical Cancer ◽

High Risk ◽

Residual Disease ◽

Invasive Cervical Cancer ◽

Intraepithelial Neoplasia ◽

Human Papillomaviruses ◽

Multiple Infections ◽

Cervical Lesions ◽

Hpv 16 ◽

The Impact

The aim is to evaluate the clinical consequences of coinfection between HPV 16 and other high-risk HPVs among women with a histological diagnosis of CIN or invasive cervical cancer. A total of 2985 women, with a diagnosis of either CIN or cancer (<IB) on cervical or cone biopsy, were included. HPV genotypes were identified using the INNO-LiPA HPV genotyping assay, version EXTRA, on cervical scraping, before the colposcopic evaluation and the colposcopic biopsies or conization. In the overall population, HPV16 interacted positively with HPV18 (RR = 2, 95% CI 1.5–2.6) and negatively with HPV33, 51, 52, and 66, in log-linear analysis. There was an excess of CIN3 diagnoses among subjects coinfected with HPV16 and HPV18 or HPV52, although the absolute number of cases was relatively small. In a logistic model, the odds ratio of CIN3+ associated with coinfection of HPV16 and HPV18 (OR = 3.8, 95% CI 2.5–5.7, p = 0.004 compared to single HPV16) or HPV52 (OR = 3.6, 95% CI 2.6–5.1, p = 0.009 compared to single HPV) was higher than that associated with single HPV 16 infections. Finally, multiple infections had no effect on residual disease and did not influence the recurrence of high-grade CIN during a median follow-up of 25 months (IR 17–41). HPV16 interacted positively with HPV18 and negatively with HPV33, 51, 52, and 66 supporting the notion that HPV16 interacts mostly negatively with other HR-HPVs in CIN lesions. Among specimens coinfected with HPV16 and 18 or 52, there was an excess of CIN3+ although the impact on the prevalence of severe cervical lesions was limited.

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