The interaction between steroid hormones, human papillomavirus type 16, E6 oncogene expression, and cervical cancer

2003 ◽  
Vol 13 (6) ◽  
pp. 834-842 ◽  
Author(s):  
M. Moodley ◽  
S. Sewart ◽  
C. S. Herrington ◽  
R. Chetty ◽  
R. Pegoraro ◽  
...  

Various risk factors have been implicated in the causation of cervical cancer including human papillomavirus (HPV), the early genes (E6 and E7) of which encode the main transforming proteins. Studies have suggested that steroid hormones may enhance the expression of these genes leading to loss of p53 gene-mediated cell apoptosis. A total of 120 cervical tissue samples were obtained from patients with proven cervical cancer. Patients who used depo-medroxyprogesterone acetate steroid contraception were recruited as part of the steroid arm. Only HPV DNA type 16 samples were used for the study. Controls included three cell lines (CaSki, SiHa, & C33A) and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) was used as an internal housekeeping gene. Of 120 patients, there were 111 patients with HPV type 16 identified. Of this number, RNA was present in 63 samples. There were 30 women (30/63) who used steroid contraception. In relation to patients who used contraception, HPV 16 E6 gene expression was present in 79% (n = 23) and 88% (n = 30) of steroid users compared to nonusers, respectively. In total there were 25 patients (40%) with expression of the HPV 16 E6*I gene and 30 patients with expression of the E6*II gene. There were 57% of steroid users (n = 17) who had expression of the E6*I/E6*II gene, compared to 52% (n = 17) of nonusers (P = 0.800). From a molecular level, this study does not confirm the role of injectable progesterones in cervical carcinogenesis.

2003 ◽  
Vol 13 (2) ◽  
pp. 103-110 ◽  
Author(s):  
M. Moodley ◽  
J. Moodley ◽  
R. Chetty ◽  
C. S. Herrington

Invasive cervical cancer remains a leading cause of morbidity and mortality, especially among women in the developing world where screening is either deficient or absent. Of all agents linked to the causation of this disease, high-risk human papillomavirus (HPV) appears to be the strongest factor. However, not all women with HPV develop cervical cancer. Steroid contraception has been postulated to be one mechanism whereby HPV exerts its tumorigenic effect on cervical tissue. Steroids are thought to bind to specific DNA sequences within transcriptional regulatory regions on the HPV DNA to either increase or suppress transcription of various genes. Although some earlier studies were reassuring as no increased incidence of cervical cancer was observed, subsequent research has shown a causative association, especially among long-term users. The role of steroids was further enhanced by the discovery of hormone receptors in cervical tissue. Some earlier studies of oral contraceptive steroids found no increased risk, even after controlling for other risk factors, including smoking and number of partners. However, prospective studies have shown a greater progression of dysplasia to carcinoma-in-situ with more than 6 years of oral steroid contraceptive use. Similar findings were also evident from other work, including the Royal College of General Practitioners Oral Contraception Study. The WHO Collaborative Study of Neoplasia and Steroid Contraceptives showed a relative risk of 1.2 for invasive cancer in users of the long-acting progestational contraceptive, depo-medroxyprogesterone acetate. However, in users of more than 5 years duration, an estimate of 2.4 was reported. The upstream regulatory region (URR) of the HPV type 16 viral genome, mediates transcriptional control of the HPV genome and is thought to contain enhancer elements that are activated by steroid hormones. It has been shown that steroid hormones bind to specific glucorticoid-response elements within HPV-DNA. Experimental evidence has revealed that high–risk type HPV 16 are able to stimulate the development of vaginal and cervical squamous cell carcinomas in transgenic mice exposed to slow-release pellets of 17 β-estradiol in the presence of human keratin-14 promoter. Squamous cell carcinomas developed in a multi-stage pathway only in transgenic mice and not in nontransgenic mice. The E6 oncoprotein of HPV 16 has been shown to bind to the p53 tumor suppressor gene and stimulate its degradation by a ubiquitin-dependent protease system. Steroid hormones are thought to increase the expression of the E6 and E7 HPV 16 oncogenes, which in turn bind to and degrade the p53 gene product, leading to apoptotic failure and carcinogenesis. However, the molecular basis of this remains to be proven.


2010 ◽  
Vol 84 (16) ◽  
pp. 8219-8230 ◽  
Author(s):  
Monika Somberg ◽  
Stefan Schwartz

ABSTRACT Our results presented here demonstrate that the most abundant human papillomavirus type 16 (HPV-16) mRNAs expressing the viral oncogenes E6 and E7 are regulated by cellular ASF/SF2, itself defined as a proto-oncogene and overexpressed in cervical cancer cells. We show that the most frequently used 3′-splice site on the HPV-16 genome, site SA3358, which is used to produce primarily E4, E6, and E7 mRNAs, is regulated by ASF/SF2. Splice site SA3358 is immediately followed by 15 potential binding sites for the splicing factor ASF/SF2. Recombinant ASF/SF2 binds to the cluster of ASF/SF2 sites. Mutational inactivation of all 15 sites abolished splicing to SA3358 and redirected splicing to the downstream-located, late 3′-splice site SA5639. Overexpression of a mutant ASF/SF2 protein that lacks the RS domain, also totally inhibited the usage of SA3358 and redirected splicing to the late 3′-splice site SA5639. The 15 ASF/SF2 binding sites could be replaced by an ASF/SF2-dependent, HIV-1-derived splicing enhancer named GAR. This enhancer was also inhibited by the mutant ASF/SF2 protein that lacks the RS domain. Finally, silencer RNA (siRNA)-mediated knockdown of ASF/SF2 caused a reduction in spliced HPV-16 mRNA levels. Taken together, our results demonstrate that the major HPV-16 3′-splice site SA3358 is dependent on ASF/SF2. SA3358 is used by the most abundantly expressed HPV-16 mRNAs, including those encoding E6 and E7. High levels of ASF/SF2 may therefore be a requirement for progression to cervical cancer. This is supported by our earlier findings that ASF/SF2 is overexpressed in high-grade cervical lesions and cervical cancer.


2004 ◽  
Vol 78 (13) ◽  
pp. 7199-7207 ◽  
Author(s):  
Kenneth Raj ◽  
Samuel Berguerand ◽  
Shirley Southern ◽  
John Doorbar ◽  
Peter Beard

ABSTRACT The human papillomavirus (HPV) E1∧E4 protein is the most abundantly expressed viral protein in HPV-infected epithelia. It possesses diverse activities, including the ability to bind to the cytokeratin network and to DEAD-box proteins, and in some cases induces the collapse of the former. E1∧E4 is also able to prevent the progression of cells into mitosis by arresting them in the G2 phase of the cell cycle. In spite of these intriguing properties, the role of this protein in the life cycle of the virus is not clear. Here we report that after binding to and collapsing the cytokeratin network, the HPV type 16 E1∧E4 protein binds to mitochondria. When cytokeratin is not present in the cell, E1∧E4 appears associated with mitochondria soon after its synthesis. The leucine cluster within the N-terminal portion of the E1∧E4 protein is pivotal in mediating this association. After the initial binding to mitochondria, the E1∧E4 protein induces the detachment of mitochondria from microtubules, causing the organelles to form a single large cluster adjacent to the nucleus. This is followed by a severe reduction in the mitochondrial membrane potential and an induction of apoptosis. HPV DNA replication and virion production occur in terminally differentiating cells which are keratin-rich, rigid squamae that exfoliate after completion of the differentiation process. Perturbation of the cytokeratin network and the eventual induction of apoptotic properties are processes that could render these unyielding cells more fragile and ease the exit of newly synthesized HPVs for subsequent rounds of infection.


2016 ◽  
Vol 19 (1) ◽  
pp. 160-166 ◽  
Author(s):  
Gustavo David García Muentes ◽  
Lindsay Karen García Rodríguez ◽  
Ramiro Israel Burgos Galarraga ◽  
Franklin Almeida Carpio ◽  
Juan Carlos Ruiz Cabezas

ABSTRACT: Introduction: Human papillomavirus (HPV) is considered a necessary causative agent for developing oropharyngeal, anal and cervical cancer. Among women in Ecuadorian population, cervical cancer ranks as the second most common gynecological cancer. Not many studies about HPV burden have been published in Ecuador, and genotypes distribution has not been established yet. The little data available suggest the presence of other genotypes different than 16 and 18. Objectives: In the present study, we attempt to estimate the prevalence of HPV 16, HPV 18 and other 35 genotypes among Ecuadorian women undergoing cervical cancer screening. The overall prevalence of HPV infection was also estimated. Methods: Routine cervical samples were analyzed using Linear Array(r) HPV Genotyping test (Roche). Results: A total of 1,581 cervical samples obtained from Ecuadorian women undergoing cervical cancer screening were included in this study. HPV DNA was detected in 689 cervical samples (43.58%). Of these samples, 604 (38.20%) were positive for a single HPV genotype, while another 85 (5.37%) samples were positive for multiple HPV types. Genotype 16 (5.50%) resulted in the most frequently detected type in both single and multiple infections. HPV 33 (4.55%) and HPV 11 (3.80%) occupied the second and the third place in frequency among all detected genotypes. Conclusions: Viral genotypes different from HPV 16 and HPV 18 are frequently detected among Ecuadorian women. The overall prevalence of HPV resulted higher than the one reported in other South American countries with a greater burden in the second and third decades of life.


2007 ◽  
Vol 81 (6) ◽  
pp. 2869-2879 ◽  
Author(s):  
Dai-Wei Liu ◽  
Yuh-Cheng Yang ◽  
Ho-Fan Lin ◽  
Mei-Fang Lin ◽  
Ya-Wen Cheng ◽  
...  

ABSTRACT Previously, we found that human papillomavirus type 16 (HPV-16) E5 protein is a tumor rejection antigen and can induce cytotoxic T-lymphocyte (CTL) activity. Therefore, in this study, human leukocyte antigen A*0201 (HLA-A*0201)-restricted human CTL epitopes of HPV-16 E5 protein were identified using a bioinformatics approach, and the abilities of these predicted peptides to induce an immune response in HLA-A*0201 transgenic mice were confirmed by assaying E5-specific CTLs and in vitro-generated CTLs from normal peripheral blood T lymphocytes of HLA-A2-positive human donors. Second, the CTL responses to HLA-A*0201 CTL epitopes (E5 63-71 and E7 11-20) were examined in HPV-16-infected patients with HLA-A2. Third, the effect of HLA-A-type alleles on CTL activities in response to the entire E5 and E7 proteins was examined in cervical cancer patients. E5 and E7 peptides (but not the whole proteins) stimulated E5- and E7-specific CTL recall responses in HPV-16- and HLA-A2-positive cervical cancer patients, and HPV-16 E5 and E7 proteins stimulated naïve T cells in HPV-16-negative cervical cancer patients with HLA-A11 and -A24 haplotypes. In summary, this is the first demonstration that E5 63-71 is an HLA-A*0201-restricted T-cell epitope of HPV-16 E5.


1997 ◽  
Vol 15 (2) ◽  
pp. 610-619 ◽  
Author(s):  
P Viladiu ◽  
F X Bosch ◽  
X Castellsagué ◽  
N Muñoz ◽  
J M Escribà ◽  
...  

PURPOSE To assess whether human papillomavirus (HPV) DNA detection in cervical cancer specimens, or antibodies to selected HPV 16 peptides are predictors of tumor recurrence and long-term survival in patients with squamous cell invasive cervical cancer. SUBJECTS AND METHODS Four hundred seventy-one cases included in two population-based case-control studies underwent follow-up evaluation. The survival and cause of death were ascertained for 410 cases (87%), with a median follow-up time of 4.6 years after diagnosis. HPV DNA was assessed using an L1 polymerase chain reaction (PCR)-based system and Southern hybridization (SH) on scraped cytologic specimens or biopsies. HPV 16 antibodies to E2, L2, and E7 peptides were detected with enzyme-linked immunosorbent assay (ELISA). RESULTS Clinical stage was the only independent prognostic factor for recurrence or survival. Although seropositivity to HPV 16 E7/3 peptide predicted a twofold excess risk of mortality (adjusted hazards ratio [HRa] = 2.0; 95% confidence interval [CI], 1.2 to 3.3), the association was restricted to stage I (HRa = 6.6; 95% CI, 1.2 to 37.6) and II (HRa = 5.9; 95% CI, 2.1 to 16.5) patients. The presence of HPV DNA (HRa = 0.9; 95% CI, 0.5 to 1.5), different estimates of the HPV viral load and the HPV type identified were not predictors of tumor recurrence or survival. CONCLUSION The presence of antibodies to HPV 16 E7 proteins is of prognostic value in early-stage cervical cancer. Our results provide strong evidence that detection and typing of HPV DNA in cervical cells or tissues is not a prognostic factor for recurrence or survival.


2012 ◽  
Vol 2012 ◽  
pp. 1-4 ◽  
Author(s):  
Hannah N. Coleman ◽  
Anna-Barbara Moscicki ◽  
Sepideh N. Farhat ◽  
Sushil K. Gupta ◽  
Xuelian Wang ◽  
...  

CD8 T-cell responses were examined in subjects with incident (new following negative visits) or prevalent (lasting ≥ 4 months) human papillomavirus type 16 (HPV16) or human papillomavirus (HPV18) infection. The groups were chosen from a cohort of women being followed every 4 months with cervical cytology and HPV-DNA testing. Enzyme-linked immunospot (ELISPOT) assay was performed at enrollment (time zero) and one year later. At time zero, 1 (6%) of 17 subjects with incident HPV 16/18 infections had positive ELISPOT results which increased to 6 (35%) at one year. For the subjects with prevalent HPV 16/18 infections, the ELISPOT results were similar at time zero (2 (15%) of 15 subjects positive) and at one year (3 (20%)). While all of the 11 women with prevalent HPV16 infection showed clearance one year later, unexpectedly only 1 (25%) of 4 women with prevalent HPV18 infection demonstrated clearance one year later (P=.009).


Microbiology ◽  
2000 ◽  
Vol 81 (7) ◽  
pp. 1825-1832 ◽  
Author(s):  
Mark Stevenson ◽  
Lucy C. Hudson ◽  
Julie E. Burns ◽  
Roy L. Stewart ◽  
Michael Wells ◽  
...  

The human papillomavirus type 16 (HPV-16) status of 43 cervical biopsies, which had been characterized histologically as normal, various grades of cervical intraepithelial neoplasia (CIN) and invasive squamous cell carcinoma, was examined by using (i) a novel antibody against the HPV-16 E2 protein, (ii) sensitive HPV-16 DNA in situ hybridization and (iii) microdissection/PCR for the E2 ORF. The data indicate that E2 protein expression is highest in koilocytes in lower-grade CIN (I), but decreases with increasing grade, whereas the detection of HPV DNA is delayed until CIN I/II, rising to the highest levels in carcinoma cells. Co-localization of E2 with HPV-16 DNA-positive cells was most commonly observed in koilocytes in CIN II lesions. PCR analyses of microdissected epithelium from the same or serial sections indicated that E2 ORFs were retained in an intact form in a number of higher-grade CIN lesions and invasive carcinomas.


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