Highly Reproducible and Sensitive Electrochemiluminescence Biosensors for HPV Detection Based on Bovine Serum Albumin Carrier Platforms and Hyperbranched Rolling Circle Amplification

Most DNA-based electrochemiluminescence (ECL) biosensors are established through the self-assembly of thiolated single-stranded DNA (ssDNA) probes on the Au electrode surface. Because of this random assembly process, a significant discrepancy exists in the distribution of a modified DNA film on different electrodes, which greatly affects the reproducibility of a biosensor. In this study, a porous bovine serum albumin (BSA) layer was first modified on the electrode surface, which can improve the position distribution and spatial orientation of the self-assembly ssDNA probe. It was then coupled with hyperbranched rolling circle amplification to develop the high-reproducibility-and-sensitivity ECL biosensor for human papillomavirus 16 E6 and E7 oncogene detection. In the presence of the target DNA, the surface of the electrode accumulates abundant amplified products through reaction, which contain double-stranded DNA (dsDNA) fragments of different lengths, followed by plentiful dichlorotris (1,10-phenanthroline) ruthenium(II) hydrate (Ru(phen)₃²⁺, acting as an ECL indicator) insertion into grooves of dsDNA fragments, and a strong signal can be detected. There is a linear relationship between the signal and the target concentration range from 10 fM to 15 pM, and the detection limit is 7.6 fM (S/N = 3). After the BSA modification step, the relative standard deviation was reduced from 9.20 to 3.96%, thereby achieving good reproducibility. The proposed ECL strategy provides a new method for constructing high-reproducibility-and-sensitivity ECL biosensors.

Characterization of cervical biopsies of women with HIV and HPV co-infection using p16ink4a, ki-67 and HPV E4 immunohistochemistry and DNA methylation

This study aims to characterize cervical intraepithelial neoplasia (CIN) in women living with HIV using biomarkers. Immunohistochemical (IHC) staining for human papillomavirus (HPV) E4 protein indicates CIN with productive HPV infection, whereas Ki-67 and p16ink4a indicate CIN with transforming characteristics, which may be further characterized using DNA hypermethylation, indicative for advanced transforming CIN. Cervical biopsies (n = 175) from 102 HPV positive women living with HIV were independently reviewed by three expert pathologists. The consensus CIN grade was used as reference standard. IHC staining patterns were scored for Ki-67 (0-3), p16ink4a (0-3), and E4 (0-2) and correlated to methylation levels of four cellular genes in corresponding cervical scrapes. Reference standards and immunoscores were obtained from 165 biopsies:15 no dysplasia, 91 CIN1, 31 CIN2, and 28 CIN3. Ki-67 and p16ink4a scores increased with increasing CIN grade, while E4 positivity was highest in CIN1 and CIN2 lesions. E4 positive CIN1 lesions had higher Ki-67 and p16ink4a scores and higher methylation levels compared with E4 negative CIN1 lesions. E4 positive biopsies with low cumulative Ki-67/p16 ink4a immunoscores (0-3) had significantly higher methylation levels compared with E4 negative biopsies. No significant differences in Ki-67 and p16ink4a scores and methylation levels were observed between E4 negative and positive CIN2 or CIN3 lesions. The presence of high methylation levels in scrapes of CIN lesions with IHC characteristics of both productive (E4 positive) and transforming infections (increased Ki-67/p16ink4a expression) in women living with HIV might indicate a rapid aggressive course of HPV infections towards cancer in these women.

[The value of P16/ki67 double labeling, HPV E6/E7 mRNA detection and their combined application in cytological shunt diagnosis of low-grade squamous intraepithelial lesions]

Objective To explore the value of double labeling of P16/ki67, E6/E7 mRNA of human papillomavirus (HPV) and combined detection in shunt diagnosis of low-grade squamous intraepithelial lesions (LSIL) by thin-layer cervical cytology (TCT). Methods The study enrolled 239 patients who underwent colposcopy and biopsy within 4 weeks after primary TCT diagnosis. The remaining cytological samples were double-labeled with P16/ki67 immunocytochemical staining and the HPV E6/E7 mRNA was detected by Panther automatic HPV E6/E7 mRNA detection system. Using SPSS22.0 software, the positive rates of P16/ki67 double-labeling, HPV E6/E7 mRNA and combined detection were analyzed in different cervical lesions, and the positive rates in the same cervical lesions were compared horizontally to evaluate the efficiency of double labeling of P16/ki67, HPV E6/E7 and combined detection in the diagnosis of high-grade squamous intraepithelial lesions (HSIL) and above lesions. Results The diagnostic results of HE staining for the 239 cases of LSIL were 71 cases of chronic cervicitis (29.71%), 143 cases of LSIL (59.83%), 22 cases of HSIL (9.20%) and 3 cases of cervical cancer (1.26%). There were 46 cases of P16⁺ki67⁺ lesions (19.25%), 41 cases of ki67⁺P16^- lesions (17.15%), 33 cases of ki67^-P16⁺ lesions (13.81%) and 119 cases of P16-ki67- lesions (49.79%). The positive rates of P16/ki67 double-labeling, HPV E6/E7 mRNA and combined detection increased with the severity of cervical lesions. The positive rate of combined detection was the highest in the HSIL lesions, which was higher than that of P16/ki67 double-labeling and HPV E6/E7 mRNA detection. The sensitivity of combined detection was higher than that of P16/ki67 double-labeling and HPV E6/E7 mRNA detection. The Youden index of joint detection was 0.7850. Conclusion The combined detection of P16/ki67 double labeling, HPV E6/E7 mRNA and HPV E6/E7 mRNA had a certain clinical value in the management of cell LSIL shunt diagnosis. The combined detection significantly improved the sensitivity and Youden index of HSIL and above lesions, while maintaining a high specificity and coincidence rate.

Performance of OncoE6TM Cervical Test in detecting cervical precancer lesions in HIV-positive women attending an HIV clinic in Bujumbura, Burundi: a cross-sectional study

OBJECTIVE

New rapid and low-cost molecular tests for cervical cancer screening, such as the OncoE6 Cervical Test, are emerging and could be alternatives for low-income and middle-income countries. To this end, we evaluated the clinical performance of the OncoE6 Cervical Test in detecting cervical intraepithelial neoplasia (CIN) among HIV-infected women in Bujumbura, Burundi.

METHODS

From June to December 2017, a cross-sectional study was conducted in 680 HIV-positive women at the University Hospital. Women aged 25-65 years who declared having had vaginal intercourse were consecutively recruited, and cervical specimens for OncoE6, liquid-based cytology and human papillomavirus (HPV) genotyping were obtained and visual inspection with acetic acid performed. Thereafter, participants underwent a colposcopic examination. The sensitivity, specificity, and positive and negative predictive values of the different tests were calculated with reference to 'colposcopic-histological' diagnoses, and areas under the receiver operating curves of OncoE6 and cytology tests were compared.

RESULTS

The prevalence of CIN was 4.9%, and OncoE6 positivity was 3.1%. OncoE6 sensitivity varied from poor to low with increasing disease severity (42.1%, 95% CI 19.9% to 64.3% at CIN2+ threshold; and 58.3%, 95% CI 30.4% to 86.2% at CIN3+ threshold). OncoE6 had the highest specificity compared with all other tests used together. The performance of the OncoE6 test was significantly lower compared with cytology at atypical squamous cell of undetermined significance (ASCUS+) cut-off (AUC=0.68 vs 0.85, p=0.03) and low-grade squamous intraepithelial lesion (LSIL+) cut-off (AUC=0.68 vs 0.83, p=0.04) for CIN2+ diagnoses. However, the performance of the OncoE6 test was similar to that of cytology at high-grade squamous intraepithelial lesion (HSIL+) cut-off (AUC=0.68 vs 0.76; p=0.30) for CIN2+ diagnoses and was also similar to that of cytology at all cut-offs (ASCUS+, LSIL+ and HSIL+) for CIN3+ diagnoses (p1=0.76, p2=0.95 and p3=0.50, respectively).

CONCLUSION

The current OncoE6 test proved to be a point-of-care test. However, given its poor performance for CIN2+ diagnoses, we do not recommend it for primary screening. We recommend to enrich it with more oncogenic HPV types, which may improve the performance of the test akin to that of cytology.

Distribution of HPV-16 and HPV-18 from the Patients Attending At Mymensingh Medical College Hospital by Newly Developed Oncoprotein Detection Assay

Cervical cancer is one of cause of death in women in many developing countries. Persistent infection with Human Papilloma Virus (HPV), primarily high risk types 16 and 18, is recognized as a causal and essential factor for the development of cervical cancer. The objective of this cross sectional observational study is to detect the distribution of HPV-16 and HPV-18 among Onco E6 positive cases. Following universal safety precautions a total of 180 endocervical swabs were collected from Colposcopy clinic of Obstetrics and Gynaecology Department of Mymensingh Medical College Hospital (MMCH), Mymensingh, Bangladesh from January 2016 to December 2016. Laboratory work was done in the department of Microbiology, Mymensingh Medical College. E6 strip test is an immunochromatographic test based on the detection of HPV-E6 oncoprotein in cervical swab samples. Onco E6 cervical test was done on 180cases. Among them 60% were VIA positive and 120% were VIA negative. From this VIA positive cases 12(16.25%) were On E6 cervical test positive and from VIA negative cases 3(2.5%) were positive by this On E6 cervical test. From this 12 Onco E6 cervical test positive cases 10(%) were HPV-16 and 2(%) were HPV-18 and from VIA negative cases 3 were only HPV-16 by this test. Histopathological test done on 35 suspected cases and out of 08 cervical carcinoma cases 07 were positive by this Onco E6 cervical test which was also HPV-16 type. It may be concluded that HPV-16 is most prevalent type to cause cervical cancer and by this newly developed protein detection assay will be helpful to reduce over treatment and save many lives.

[The role of HPV E6/E7 mRNA combined with P16/ki67 immunocytochemistry in the diagnosis of atypical squamous cells of undetermined significance(ASCUS)]

Objective To investigate the diagnostic value of human papillomavirus (HPV) E6/E7 mRNA combined with P16/antigen KI-67(ki67) immunocytochemical double staining in the atypical squamous cells of undetermined significance (ASCUS). Methods A total of 272 patients were selected and the results of HPV E6/E7 and P16/ki67 immunocytochemical double staining in the remaining cytological specimens were retrospectively analyzed. HPV E6/E7 gene was detected by HPV E6/E7 gene detection kit and Panther molecular diagnostic instrument. P16/ki67 was detected by immunocytochemical staining and Ventana Benchmark Ultra immunohistochemical staining instrument. Then we analyzed the difference of positive rate between the two detection methods in the same grade of cervical epithelial lesions, explored the difference of the two detection methods and their combined detection in the diagnosis of high grade squamous intraepithelial lesions (HSIL), and finally evaluated the role of different detection methods in shunt diagnosis of ASCUS. Results Histopathological findings of cervical cytology ASCUS includes chronic cervicitis, low-grade squamous intraepithelial lesions (LSIL), HSIL and cervical cancer. The positive rate of simple molecular diagnosis or immunocytochemical staining increased with the severity of cervical lesions. In cervicitis and LSIL lesion group, the difference between the positive rates of the two methods was obvious, but in HSIL and cervical cancer lesion group, there was no significant difference between the positive rates of the two methods. The sensitivity, specificity, Yoden index, coincidence rate, positive predictive value and negative predictive value were 95.65%, 85.40%, 0.81, 87.13%, 57.14% and 98.97%, respectively. Conclusion The detection of HPV E6/E7 and P16/ki67 immunocytochemical staining has certain significance in ASCUS shunt diagnosis. The combined detection of HPV E6/E7 and P16/ki67 can significantly improve the sensitivity of shunt diagnosis and maintain a good specificity.

Self-sampling coupled to the detection of HPV 16 and 18 E6 protein: A promising option for detection of cervical malignancies in remote areas

Objective

To evaluate both the performance and acceptability of a method coupling self-sampling with detection of cervical malignancy via elevated HPV 16 and 18 E6 oncoproteins (OncoE6™ Cervical Test) in remote areas in Brazil.

Methods

Women living in rural villages in proximity to Coari city, Amazonas, Brazil were invited to participate in a cervical cancer screening study. 412 subjects were enrolled; there were no refusals. In addition to E6 protein detection, DNA was extracted from the brushes and evaluated for HPV genotypes by PCR (PGMY09/11), followed by typing by the Papillocheck™ if positive. Subjects who were found to be positive for OncoE6 or HPV-DNA were referred for colposcopy.

Results

For 110 subjects (27%) this was the first cervical cancer exam. Overall the HPV-DNA prevalence was 19.1% (n = 79); 1.4% (n = 6) were positive by the OncoE6 Test. Fifty-six women attended the invitation for colposcopy where nine had an abnormal cervix and were subsequently biopsied. Histopathological analysis revealed 2 CIN3, 2 carcinomas and 5 CIN1. OncoE6 called two out of the three HPV 16 or 18 associated CIN3+ lesions.

Conclusions

The findings suggest that self-administered sample collection in combination with OncoE6 Test is feasible in this population. This could enable expanded screening coverage while ensuring a high specificity which is imperative given the remote geographic location, since women bearing abnormal test results would necessitate travel and logistical burden to access colposcopy and treatment.

A prospective study of women with ASCUS or LSIL pap smears at baseline and HPV E6/E7 mRNA positive: a 3-year follow-up

Human papillomavirus (HPV) testing is used in the triage of women with a borderline smear result. The efficiency of testing women with a low-grade squamous intraepithelial lesion (LSIL) and atypical squamous cells of undetermined significance (ASCUS) is less clear. For this reason we used a new HPV test that detects E6/E7 messenger RNA (mRNA), which might have a higher specificity. The objective of this prospective study was to assess whether HPV E6/E7 mRNA positivity in women with ASCUS and LSIL at baseline, is able to predict those women who have a high risk of developing a histological cervical intraepithelial neoplasia (CIN2) or worse lesion. We took into consideration the women's age and HPV DNA genotype and followed them up for 3 years. Cervical samples from women with high-risk HPV (HR-HPV) DNA-positive ASCUS (n = 90) or LSIL (n = 222) were tested for the presence of HR-HPV E6/E7 mRNA and the women were monitored for the development of histopathologically verified CIN2+. Thirteen patients with ASCUS and 17 with LSIL did not complete follow-up. All patients with LSIL and ASCUS, enrolled in this study, had confirmed lesions at the colposcopic examination. Follow-up was available for 312 women, 193 were positive in the HR-HPV DNA test and 93 had a HPV E6/E7 mRNA positive test. Finally, 22 women positive in the HPV DNA test for high-risk genotypes and with positive E6/E7 mRNA had a histologically confirmed CIN2+. Only two cases with negative HPV E6/E7 mRNA had CIN2+. The study shows that women positive in the HPV E6/E7 mRNA test have a greater risk of malignant progression of cervical lesions and therefore deserve greater attention and earlier check-ups.

OncoE6 Positivity among VIA Positive Suspected Cases from Colposcopy Clinic of Mymensingh Medical College Hospital, Mymensingh

Cervical cancer is a major world health problem for women. It is the fourth most leading cause of death in women around the world. High risk HPV DNA has been shown to be present in 99.7% of cervical cancers worldwide. Oncoprotein E6 and E7 play an important role in the development of cervical cancer which can be detected by OncoE6 cervical test. This Cross sectional observational study was performed to detect E6 Oncoprotein from cervical swab by OncoE6 cervical test. Following universal safety precautions a total of 47 endocervical swabs were collected from Colposcopy clinic of Obstetrics and Gynaecology department of Mymensingh Medical College Hospital (MMCH), Mymensingh, Bangladesh from January 2015 to December 2015. Laboratory work was done in the department of Microbiology, Mymensingh medical college. E6 strip test is an immunochromatographic test based on the detection of HPV-E6 oncoprotein in cervical swab samples. The swab specimen was treated with lysis solution and conditioning solution. Then the specimen solution was clarified by centrifugation. After that the sample solution was transferred into Detector mAb vial, wash solution vial and finally into developing solution vial. The test unit was then placed on a reading guide. Positive result was indicated by the appearance of purple colored test line. Out of 47 specimens 21(44.68%) were OncoE6 positive by OncoE6 cervical test. Among 21 positive cases 19(90.48%) were HPV-16 and 2 were (9.52%) HPV-18. Histopathologically out of 22 cervical carcinoma cases 20(90.90%) were positive by this test. Based on the findings of the present study, it may be concluded that screening with HPV E6 may minimize the overtreatment as well as the colposcopy referral. So it can be used as primary screening to aid colposcopy and to identify real disease. HPV based screening may help to control cervical cancer in Bangladesh. As HPV is a sexually transmitted infection; so, male screening method should be established.

Risk stratification and long-term risk prediction of E6 oncoprotein in a prospective screening cohort in China

E6 oncoprotein is a necessary agent of HPV driven oncogenic transformation. This study is aimed at evaluating the risk stratification potency of HPV 16/18 E6 oncoprotein (E6) as a triage method for HPV positivity. Moreover, it also acts as a predictor of cervical intraepithelial neoplasia grade 3 or worse (CIN3+). The screening cohort of 1,997 women was followed for a 15 year period in approximate five-year intervals. Participants were concurrently screened by HPV DNA testing (HC2), liquid based cytology (LBC), visual inspection with acetic acid (VIA) and were referred to colposcopy and biopsy if any tests reflected positive. E6 was performed on cervical samples collected from this cohort in 2005 and 2014. The ability of E6 to predict CIN3+ risk after the five- and ten-year interval was evaluated. Among HPV positive women in 2005, E6 indicated the lowest positive rate (9.9%) compared to LBC (48.4%) and VIA (28.0%), however, a higher prevalence rate (10.3%) and 10-year cumulative incidence rate (53.0%) of CIN3+ were detected among women who were E6 positive. Meanwhile, only 4.2% and 2.9% of women with abnormal LBC and positive VIA were diagnosed as prevalent CIN3+ in 2005, 23.0% and 16.5% developed to CIN3+ after year 10, respectively. Strong associations were found between precedent and subsequent HPV persistence and E6 oncoprotein expression (ORadjusted  = 40.0 and 21.2, respectively). E6 oncoprotein could serve as a low-cost, highly specific, strongly indicative point-of-care method in the triage and treatment of HPV positive women.

Immunohistochemical Evaluation of E6/E7 HPV Oncoproteins Staining in Cervical Cancer

BACKGROUND/AIM

High-risk human papillomavirus (HPV) subtypes (i.e. 16 and 18) lead to uterine cervical cancer as well as HPV-positive oropharyngeal cancer (OSCC), a form of head and neck cancer. The induction of HPV-induced cancer is driven by virus-specific oncoproteins E6 and E7. E6 protein of HPV types 16 and 18 interacts with the E3 ubiquitin protein ligase, resulting in ubiquitination and proteolysis of tumor protein p53. E7 inactivates retinoblastoma protein (Rb) by phosphorylation followed by an increase of free eukaryotic transcription factor E2F (E2F) in the cell. This leads to an increase of cyclin-dependent kinase inhibitor p16, that is used as an immunohistochemical marker of HPV-associated OSCC. Unfortunately, p16 is not exclusively increased by E7 oncoprotein in carcinogenesis. Therefore, the aim of this study was to develop an immunohistochemical approach for the direct detection of E6/E7 oncoproteins in uterine cervical cancer as well as in OSCC.

MATERIAL AND METHODS

Paraffin sections of uterine cervical cancer and 130 were analyzed. Immunohistochemical staining protocols were evaluated with tissue slides from patients with cervical dysplasia (CIN III) and squamous epithelial carcinoma tissue with HPV infection. Liver and placental tissues were used as negative controls. E6-Specific antibody (Biorbyt) was used as primary antibody. The polymer staining method and diaminobenzidine were applied for further development. Panels of E7-specific antibodies were tested. Again, the polymer staining method and diaminobenzidine were applied for further development.

RESULTS

E6-Specific antibody revealed specific and intense staining after pre-incubation of tissue slides with citrate buffer solution. Only the E7 antibody obtained from Chemicon showed intense and specific staining in patients with CIN III and squamous epithelial carcinoma tissue. Pre-incubation with proteinase K diminished non-specific reaction.

CONCLUSION

Our results revealed a useful staining protocol for the immunohistochemical evaluation of E6/E7 oncoprotein expression in uterine cervical cancer, as well as in HPV-positive oropharyngeal cancer. Advantages of this method compared to mRNA in situ hybridization of E6/E7 are the much lower costs, as well as the broader applicability in pathological practice.

Human Papilloma Virus as a Biomarker for Personalized Head and Neck Cancer Radiotherapy

A dramatic increase in the incidence of HPV-related oropharyngeal cancer has been reported in some parts of the western world over the past 30 years. They constitute a clinically distinct subgroup of cancers in terms of molecular biology, patient characteristics, and treatment outcome. This chapter describes the molecular characteristics, epidemiology, and demographics of the HPV-related head and neck cancers and discuss available methods to detect HPV-related tumours. The impact of HPV-related biomarkers in clinical studies on radiotherapy only, altered fractionation, modulation of hypoxia, and concurrent chemo- or bio-radiotherapy are reviewed as well as the perspectives of de-escalation and immune-modulation are discussed.

Type-specific detection of human papillomaviruses in Kazakh esophageal squamous cell carcinoma by genotyping both E6 and L1 genes with MALDI-TOF mass spectrometry

BACKGROUND

Many studies have suggested a relationship between human papillomavirus (HPV) infection and the risk of esophageal squamous cell carcinoma (ESCC). However, findings are inconclusive, potentially because of geographic heterogeneity and variations in detection methods.

OBJECTIVES

We sought to further investigate the prevalence of HPV with a new detection method, the MassARRAY Sequenom technique, in esophageal squamous cell carcinomas occurring in patients belonging to Kazakh populations in Xinjiang, China.

STUDY DESIGN

In the present study, a novel genotyping method for detecting 30 HPV genotypes, specifically by genotyping both the HPV E6 and L1 genes with multiplex PCR using matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) (PCR-MS) was first adopted to evaluate HPV genotypes in 89 esophageal cancer samples and 49 matched adjacent normal esophageal tissues.

RESULTS

Six HPV genotypes (HPV6, HPV16, HPV33, HPV39, HPV51, and HPV82) were present in at least 51.7% of the esophageal carcinoma tissues, which was significantly greater than 28.6% prevalence among controls (P < 0.05). HPV16 was the most common of all the genotypes investigated (HPV16 prevalence in carcinoma tissue: 49.4%; odds ratio 3.02, 95% confidence interval 1.39-6.53). HPV-positive ESCC patients were generally younger than HPV-negative patients (P = 0.04). In addition, HPV infection was more common in cases of well-differentiated and shallower invasive depth.

CONCLUSIONS

Based on this new detection method, our findings reiterate the possibility that HPV infection (especially HPV16) may be involved in the etiology of esophageal carcinoma in the Kazakh populations and that HPV E6 gene positivity may be associated with prognosis of patients.

[Semi-quantitative detection of HPV L1 capsid protein in exfoliative cytological examination facilitates the differential diagnosis of cervical lesions]

OBJECTIVE

To evaluate the association of human papilloma virus (HPV) L1 capsid protein expression levels with cervical intraepithelial neoplasia (CIN) and its clinical significance.

METHODS

Immunohistochemistry were performed to detect the expression of HPV L1 capsid protein in the cervical exfoliative cytological examination of 153 cases. The intensity (positive unit, PU) was assessed semi-quantitatively using ImagePro Plus image analysis software. The results were evaluated based on histopathologic diagnosis of cervical biopsy.

RESULTS

PU of HPV L1 capsid protein in different cytopathological groups, including normal/inflammation, atypical squamous cells of unknown significance (ASCUS), low-grade squamous intraepithelial lesion (LSIL), high-grade squamous intraepithelial lesion (HSIL), was 46.87±24.46, 27.23±24.30, 24.10±22.45, 9.36±19.82, respectively, and the differences were statistically significant (P<0.01). PU of HPV L1 capsid protein in different histopathological groups, including normal cervixes or chronic cervicitis, LSIL and HSIL, was 41.30±26.66, 24.84±22.18, 8.69±19.20, respectively, and the differences were statistically significant (P<0.01). Patients with high-risk HPV16 and HPV18 had significantly lower PU of HPV L1 capsid protein than those with other high-risk HPV (P<0.01). PU of HPV L1 capsid protein were correlated negatively with both cytopathological groups and histopathological groups of cervical diseases (r=-0.458, P<0.01 and r=-0.441, P<0.01, respectively). PU of HPV L1 capsid protein was not associated with patients' age (P>0.05).

CONCLUSION

Semi-quantitative analysis of HPV L1 capsid protein expression can directly reflect the precancerous progression of cervical cancer.

Evaluation of clinical performance of a novel urine-based HPV detection assay among women attending a colposcopy clinic

BACKGROUND

Human papillomavirus (HPV) testing in urine offers a convenient approach for cervical cancer screening but has previously suffered from limited clinical sensitivity.

OBJECTIVES

We evaluated clinical performance of the prototype Trovagene HPV test, a novel polymerase chain reaction assay that targets the E1 region of the HPV genome and detects and amplifies short fragments of cell-free HPV DNA in urine.

STUDY DESIGN

We conducted a pilot study among 72 women referred to colposcopy following abnormal screening. Participants provided a urine sample prior to clinician-collected cervical sampling and colposcopically-directed punch biopsy. Trovagene HPV test results on urine samples were compared with cervical and urine testing by Linear Array HPV Genotyping Test (LA-HPV) for detection of histologically-confirmed cervical precancerous lesions.

RESULTS

There was high concordance between urine samples tested by the Trovagene HPV test and corresponding cervical (87.5%) and urine (81.9%) samples tested by LA-HPV. The Trovagene HPV test had high sensitivity (92.3% for detecting CIN2/3, and 100% for CIN3), comparable to LA-HPV testing on cervical samples (96.0% and 100%, respectively), and higher than LA-HPV testing on urine samples (80.8% and 90.0%, respectively). In this referral population, the specificity of the Trovagene urine HPV test was non-significantly lower (29% for CIN2/3 and 25% for CIN3) than corresponding estimates of LA-HPV testing on cervical (36% and 28%, respectively) and urine (42% and 38%, respectively) samples.

CONCLUSIONS

This pilot study suggests that the Trovagene HPV test has high sensitivity for urine-based detection of cervical precancer and merits evaluation in larger studies.

[Correlation study of HPV-16 existential status with Th17/Treg cytokines]

OBJECTIVE

To explore the relationship between the presence of HPV-16 DNA and the expression Treg surface marker Foxp3(+), peripheral blood levels of Th17/Treg cell-associated cytokines and explore their roles and significance in cervical cancer progression.

METHODS

Between January 2012 and October 2012 at Shengjing Hospital of China Medical University, a total of 142 HPV16 positive patients were divided into cervical cancer (CC, n = 60), cervical intraepithelial neoplasia (CIN, n = 65) and control group (n = 17). Cervical liquid-based cytological (LBC) samples were collected to detect E2 and E6 genes of HPV type 16 using multiple real-time polymerase chain reaction (PCR). E2/E6 ratio was used to evaluate the physical status of HPV-16 DNA in host cell genome. The SP immunohistochemical method was used to detect the expressions of FOXP3 in cervical lesions. The concentrations of Th17/Treg cell-associated cytokines were detected by enzyme-linked immunosorbent assay (ELISA).

RESULTS

Under the same status of HPV16 DNA in vivo, the levels of Foxp3(+), transforming growth factor-β (TGF-β) and interleukin-10 (IL-10) were significantly higher than those of the control group (P < 0.01) while the levels of interleukin-17 (IL-17) and interleukin-21 (IL-21)were significantly lower than those of the control group (P < 0.05) . In the same disease, HPV16 DNA integration rate grew with the increases of Foxp3(+), TGF-β and IL-10 while IL-17 and IL-21 were opposite. In the different status of HPV16 type DNA, the expression of Foxp3(+) was closely correlated with Federation International of Gynecology and Obstetrics (FIGO) stage, histological grade and lymphnode metastasis (P < 0.05) except for age (P > 0.05).

CONCLUSION

Treg cytokines, HPV16 integration rate and severity of cervical lesions are positively correlated while Th17 cytokines show opposite effects. Th17/Treg cell-associated cytokines may play an important role in the occurrence and development of cervical cancer.

Association of human papillomavirus genomic sequences by polymerase chain reaction in gastric carcinomas in Brazil

OBJECTIVE

To investigate the prevalence of human papillomavirus (HPV) in patients with gastric cancer and compare with a control group.

STUDY DESIGN

Forty paraffin samples of gastric cancer and 40 endoscopic normal mucosa and peripheral blood controls were subjected to examination by polymerase chain reaction for the L1 gene of HPV. The extracted DNA was amplified in 2 reaction systems using 2 pairs of primers: MY09/MY11 and GP+5/GP+6. We used Milli-Q water as negative control and a mixture of 1 microL of human blood plus 0.25 microL of plasmid pBR322 (HPV-16) as positive control.

RESULTS

HPV was found in 4 patients with gastric cancer and 10 patients without cancer.

CONCLUSION

There was no statistically significant difference between the 2 samples (p = 0.077).

[Capsid protein L1 HPV-16 in a modified cervical epithelium]

The 58 cervical biopsies were studied by cytological, histological, immunomorphological methods, electron microscopy and PCR. Expression of L1 was observed only in the differentiated cells of squamous and metaplastic cervical epithelium. At increase of grade of cervical epithelial lesion decrease expression L1 from 75% of cases of CIN1 up to 28.5% of cases of SCC. Not all capsid structures connect with DNA HPV in case of CIN3.

B7-H1 expression model for immune evasion in human papillomavirus-related oropharyngeal squamous cell carcinoma

Human papillomavirus (HPV) is associated with oropharyngeal squamous cell carcinomas. Persistent viral infection is postulated to lead to carcinogenesis, although infection of benign adjacent epithelium is not typically observed. It is known that immune evasive tumor cells can provide an ideal niche for a virus. The B7-H1/PD-1 cosignaling pathway plays an important role in viral immune evasion by rendering CD8+ cytotoxic T cells anergic. We hypothesized that HPV-related oropharyngeal squamous cell carcinomas express B7-H1 as a mechanism for immune evasion. A tissue microarray was utilized, for which HPV E6/E7 mRNA by in situ hybridization was previously performed. Immunohistochemistry was performed to detect B7-H1 and staining was characterized by pattern, distribution, and intensity. B7-H1 was expressed by 84 of the 181 (46.4%) cases. Both tumor cell membranous and cytoplasmic expression were present and cytoplasmic expression was identified in some peritumoral lymphocytes. Expression was analyzed in several different ways and then considered binarily as positive versus negative. Tumors expressing B7-H1 were more likely to be HPV positive (49.2 vs. 34.1 %, p = 0.08). B7-H1 expression showed no correlation with disease recurrence in the entire cohort (OR = 1.09, p = 0.66), HPV positive cohort (OR = 0.80, p = 0.69) or HPV negative cohort (OR = 2.02, p = 0.22). However, B7-H1 expression intensity did correlate with the development of distant metastasis (p = 0.03), and B7-H1 intensity of 3+ (versus all other staining) showed a strong trend towards distant metastasis in the HPV positive (OR = 6.67, p = 0.13) and HPV negative (OR = 9.0, p = 0.13) cohorts. There was no correlation between B7-H1 expression and patient survival for any of the different ways in which staining was characterized, whether binarily, by distribution, intensity, or combined scores. B7-H1 is expressed in the majority of oropharyngeal squamous cell carcinomas with transcriptionally-active HPV. This suggests that B7-H1 expression by tumor cells may play a role in harboring persistent HPV infection.

A molecular beacon-based method for screening cervical cancer

The aim of this study is to develop a new screening method, molecular beacon (MB) imaging, for detection of cervical cancer and to determine its potential clinical applications by examining the sensitivity and specificity of target-specific MBs. Two target-specific molecular beacons were designed and synthesized for survivin and HPV16E6 mRNA. The two designed MBs and a random control MB were used to detect cervical cancer cell lines and a normal cell line. RT-PCR and western blot targeting survivin and HPV16E6 was done for verification. Furthermore the sensitivity and the specificity of the survivin and HPV16E6 mRNA MBs were examined in smears from 125 clinical cervical patients. The survivin and HPV16E6 mRNA MBs generated a strong fluorescence signal in cervical cancer cell lines, but not in the normal cell line, while the random control MB did not generated any signal in both cell lines. The fluorescence intensity correlated well with the gene expression levels in the cells determined by reverse transcription-PCR and Western blot analysis. The clinical sensitivity and the specificity of survivin MB-FITC were 72.5 and 77% while those of HPV16E6 MB-Cy3 were 96.1% and 71.6%, respectively. A parallel test of the two target MBs showed that the sensitivity increased to 98% and the specificity was 70.2%. The survivin and HPV16E6 mRNA MBs showed good reliability and sensitivity. They have great potential for clinical use in cervical cancer screening.

Quantitative measurement of human papillomavirus type 16 e5 oncoprotein levels in epithelial cell lines by mass spectrometry

The high-risk human papillomavirus type 16 (HPV-16) E5 protein (16E5) induces tumors in a transgenic mouse model and may contribute to early stages of cervical carcinogenesis. Although high-risk E5 expression is generally thought to be lost during the progression to cervical carcinoma following integration of HPV DNA into the host genome, episomal viral DNA has been documented in a subset of HPV-16-positive malignant lesions. Numerous studies have shown that transcripts that could potentially encode 16E5 are present in cervical biopsy specimens and cervical cancer cell lines, but the presence of E5 protein has been demonstrated in only two reports that have not been corroborated. In the present study, we show that trypsin cleavage of 16E5 generates a unique four-amino-acid C-terminal peptide (FLIT) that serves as a marker for E5 expression in transfected cells and epithelial cell lines containing integrated and episomal HPV-16 DNA. Following trypsin cleavage, reversed-phase chromatography and mass spectrometry (MS) were used to detect FLIT. Immunoprecipitation assays using a newly generated anti-16E5 antibody confirmed that 16E5 was solely responsible for the FLIT signal, and deuterated FLIT peptide provided an internal standard that enabled us to quantify the number of 16E5 molecules per cell. We show that 16E5 is expressed in the Caski but not in the SiHa cervical cancer cell line, suggesting that 16E5 may contribute to the malignant phenotype of some cervical cancers, even in cells exclusively containing an integrated HPV genome.

HPV DNA, E6*I-mRNA expression and p16INK4A immunohistochemistry in head and neck cancer - how valid is p16INK4A as surrogate marker?

It has been proposed that p16(INK4A) qualifies as a surrogate marker for viral oncogene activity in head and neck cancer (HNSCC). By analyzing 78 HNSCC we sought to validate the accuracy of p16(INK4A) as a reliable marker of active HPV infections in HNSCC. To this end we determined HPV DNA (HPVD) and E6*I mRNA (HPVR) expression status and correlated these results with p16(INK4A) staining. In tonsillar SCC 12/20 were HPVD+ and 12/12 of these showed active HPV infections whereas in non-tonsillar SCC 10/58 were HPVD+ and 5/10 showed active HPV infections. Thus, we prove about 8% of non-tonsillar SCC to be also correlated with HPV-associated carcinogenesis. Strikingly, 3/14 (21.4%) of tonsillar and non-tonsillar HPVD+/HPVR+ cases did not show p16(INK4A) overexpression and these cases would have been missed when applying initial p16(INK4A) staining only. However, in 13 cases negative for HPV, DNA p16(INK4A) was overexpressed. In conclusion, our data confirm tonsillar SCC to be predominantly but not only associated with active HPV infections. Furthermore, our data show that p16(INK4A) overexpression is not evident in a subgroup of HNSCC with active HPV infection. Definitive HPV data should therefore be utilized in diagnostics and treatment modalities of HPV positive and HPV negative HNSCC patients, resulting in a paradigm shift regarding these obviously different tumor entities.

[HPV-associated squamous cell carcinogenesis]

About 7-8% of all human cancers are thought to be related to infections with high-risk (HR) human papilloma virus (HPV). Besides cervical cancer, especially squamous cell carcinomas of the anogenital and oropharyngeal regions are associated with HR-HPV. Transmission of HPV is due to sexual activity. Harald zur Hausen was awarded in 2008 with the Nobel price in medicine for the establishment of a causal link between certain HPV infections and cervical cancer. Meanwhile potent prophylactic vaccines are available to prevent infections with HPV-16 and HPV-18, the two most frequently observed HR HPV types worldwide. On molecular grounds a persistent HPV infection is the central risk factor for the development of HPV-associated neoplasias. Continued expression of the viral E6 and E7 oncogenes disrupts cell cycle control mechanisms in infected cells, thereby gaining limitless proliferative capacity and resistance against apoptotic signals. However acquisition of mutations and genomic instability might cause malignant transformation in these cells.

[Comparative study on the HPV infection rate of different esophageal squamous cell carcinoma in Anyang China]

OBJECTIVE

Comparative and statistical analysis the HPV infection rate between fresh tissue and Paraffin-embedded Specimens of esophageal squamous cell carcinoma,and comparative the testing results with others regions.

METHODS

Extracted the total DNA from the novel fresh tissue and Paraffin-embedded Specimens; Detected the DNA by PCR with universal primer and Detected the HPV type with human papilloma virus nucleic acid amplification-based typing detection reagent kit (Hybribio); Compared the statistical result from the different specimens; analyzed the result between different region.

RESULTS

HPV infection rate of fresh tissue is 82.6% with HPV16 (34.8%) and HPV18 (34.8%), and paraffin-embedded specimens is 78.2% with HPV16 (30.4%) and HPV18 (17.4%).

CONCLUSION

The results provides the first evidence that there wasn't noticeable difference between HPV infection rate of the two specimens. So broader specimen source could be used for HPV testing.

Analysis of p53, p16(INK4a), pRb and Cyclin D1 expression and human papillomavirus in primary ovarian serous carcinomas

AIM

To evaluate the prognostic relevance of key cell cycle regulatory proteins p53, p16(INK4a), pRb and Cyclin D1 expression, the presence of high risk HPVs and their association with clinicopathological parameters and the clinical follow up in ovarian cancer patients.

METHODS

53 cases of primary ovarian serous carcinomas were immunohistochemically examined for the expression of p53, p16(INK4a), pRb and Cyclin D1 proteins. Tumor DNA was extracted from paraffin blocks and subjected to HPV 16 and 18 testing. The association between HPV 16 and 18 E6 oncoprotein and cell cycle proteins expression in ovarian carcinomas also was evaluated by immunohistochemistry.

RESULTS

We demonstrated that a majority of moderately and poorly differentiated ovarian carcinomas are characterized by strong expression of p53 and p16(INK4a) proteins. In contrast, strong staining with cyclin D1 antibody was observed in well differentiated tumors. The correlation between strong p53, pRb, Cyclin D1 and clinical stages of disease was also observed. We show that patients with high positivity for p53, p16(INK4a) and Cyclin D1 had a poor prognosis and reduced overall survival. The presence of HPV 16/18 DNA was detected in 17% of ovarian carcinomas. The tumor tissues that reacted positively to HPV E6 antibody in focal and diffuse manners had also significantly low p53 expression profile.

CONCLUSION

These findings suggest that p53, p16(INK4a) and Cyclin D1 expression and HPV infection may represent a promising tool toward the identification of ovarian cancer patients with poorer prognosis and shorter survival who might therefore need a more aggressive therapy and HPV screening.

Targeted cellular uptake and siRNA silencing by quantum-dot nanoparticles coated with β-cyclodextrin coupled to amino acids

Quantum dots (QDs) have the potential to serve as photostable beacons to track siRNA delivery, which is fast becoming an attractive approach to probe gene function in cells. In this paper, we synthesized QD nanoparticles coated with β-cyclodextrin (β-CD) coupled to amino acids with different surface charges (positive, negative, and neutral) through direct ligand-exchange reactions and used them to deliver siRNA. We found that these QDs are diffluent in biological buffer with high colloidal stability and have strong optical emission properties similar to those of tri-n-octylphosphine oxide (TOPO)-coated QDs and also have a long fluorescence lifetime (12.5 ns for L-His-β-CD-coated CdSe/ZnSe QDs). The results of in vitro cytotoxicity and internalization of these modified QDs in normal and cancer cells showed that the β-CD coupled to amino acid outlayers greatly improved the biocompatibility of QDs, and conferred with lower cytotoxicity even at very high concentration. In particular, the L-His-β-CD-coated CdSe/ZnSe QDs presented lower cytotoxicity to these cells (CC(50) value is 180.6±3.4 μg mL(-1) in ECV-304 cells for 48 h). Transmission electron microscope (TEM) images showed that the QDs were localized in vesicles in the cytoplasm of the cells. Furthermore, compared with existing transfection agents, gene-silencing efficiency of the modified QDs was slightly improved for HPV18 E6 gene in HeLa cells by gel electrophoresis analysis. Finally, the unique optical properties of QDs allow visible imaging of siRNA delivery in live cells. Taken together, our study not only provides new insights into the mechanisms of amino acid mediated delivery, but also greatly facilities the monitoring of gene-silencing studies.

Evaluation of the HPV L1 capsid protein in prognosis of mild and moderate dysplasia of the cervix uteri

Cervical intraepithelial neoplasia (CIN) can be detected in the cytologic smears years before invasive squamous cancer arises, but no reproducible morphologic criteria exist to predict behavior of cervical lesions. The possibility of predicting the clinical course of cervical lesions could be of high value in clinical practice and some women will spare of unnecessary treatment. HPV L1 capsid protein represents about 90% of the total protein on the surface of the virus and can be detected in mild to moderate dysplasia and rarely in severe dysplasia. The purpose of the study was to evaluate the use of immunodetection of HPV L1 protein on archival Pap smears with findings of mild and moderate dysplasia in predicting its clinical course. Immunochemical analyses with L1 antibody revealed positively stained nuclei of squamous epithelial cells in 56 of 114 smears (49.1%). The staining results were correlated with follow-up smears or with histologic verification. Regression (negativisation of the Pap smear for 24 months or longer) was noticed in 31 of 56 (55.4%) L1-positive cases and in 20 of 58 (34.5%) L1-negative cases. Persistent disease occured in 13 (23.2%) L1-positive cases and in 14 (24.1%) L1-negative cases. Progressive disease occured in 12 (21.4%) L1-positive cases and in 24 (41.4%) L1-negative cases. The difference in the clinical course between the L1-positive and L1-negative patients was statistically significant (p = 0.025). Also, the difference in the clinical course of the L1-negative staining in the under-30 and over-30 years age group was statistically significant (p = 0.04). For conclusion, our data confirm that immunostaining for HPV L1 capsid protein could offer prognostic information about mild and moderate intraepithelial cervical squamous lesions.

Identification of unusual E6 and E7 proteins within avian papillomaviruses: cellular localization, biophysical characterization, and phylogenetic analysis

Papillomaviruses (PVs) are a large family of small DNA viruses infecting mammals, reptiles, and birds. PV infection induces cell proliferation that may lead to the formation of orogenital or skin tumors. PV-induced cell proliferation has been related mainly to the expression of two small oncoproteins, E6 and E7. In mammalian PVs, E6 contains two 70-residue zinc-binding repeats, whereas E7 consists of a natively unfolded N-terminal region followed by a zinc-binding domain which folds as an obligate homodimer. Here, we show that both the novel francolin bird PV Francolinus leucoscepus PV type 1 (FlPV-1) and the chaffinch bird PV Fringilla coelebs PV contain unusual E6 and E7 proteins. The avian E7 proteins contain an extended unfolded N terminus and a zinc-binding domain of reduced size, whereas the avian E6 proteins consist of a single zinc-binding domain. A comparable single-domain E6 protein may have existed in a common ancestor of mammalian and avian PVs. Mammalian E6 C-terminal domains are phylogenetically related to those of single-domain avian E6, whereas mammalian E6 N-terminal domains seem to have emerged by duplication and subsequently diverged from the original ancestral domain. In avian and mammalian cells, both FlPV-1 E6 and FlPV-1 E7 were evenly expressed in the cytoplasm and the nucleus. Finally, samples of full-length FlPV-1 E6 and the FlPV-1 E7 C-terminal zinc-binding domain were prepared for biophysical analysis. Both constructs were highly soluble and well folded, according to nuclear magnetic resonance spectroscopy measurements.

[Importance of immunohistochemical studies in the diagnosis and the prognostic evaluation of cervical intraepithelial neoplasia and invasive squamous cell carcinoma of the uterine cervix. Review]

Immunohistochemical studies in cervical intraepithelial neoplasia and cervical carcinoma are evaluated in this review. A variety of proteins like p53, bcl2, C-Myc, Ki 67, Cyclines, P16 INK4a, p21, p27, beta-catenin, Wnt and MCM, have been related to the development of cervical neoplasia and human papilloma virus infection. It is described how transcriptional factors of genes induce loss of heterozygosity, numerical chromosome abnormality and inactivation of gene products or the partial loss of some membrane glycoproteins induced by oncogenic human papillomaviruses (HPV).

Variant haplotypes at XRCC1 and risk of oral leukoplakia in HPV non-infected samples

BACKGROUND

One of the mechanisms in human papillomavirus (HPV)-related carcinogenesis is inhibition of DNA repair by HPV oncoprotein. In this study, we investigated whether polymorphisms at XRCC1, one of the DNA repair loci, could modulate the risk of tobacco-related leukoplakia and cancer in HPV-infected individuals.

METHODS

Tissue DNA from 83 oral cancer, 91 leukoplakia and 100 healthy controls were screened for HPV 16/18 infection and polymorphisms at XRCC1 by PCR-RFLP to estimate the risk of diseases independently and jointly.

RESULTS

Human papillomavirus infection was significantly associated with increased risk of leukoplakia and cancer (OR = 2.8, 95% CI = 1.2-6.5 and OR = 5.5, 95% CI = 1.6-19, respectively). Independently, genotypes at three polymorphic sites on XRCC1 did not modulate the risk of diseases but pooled variant haplotypes increased the risk of leukoplakia in overall and HPV non-infected (OR = 1.8, 95% CI = 1.2-2.8; OR = 2.2, 95% CI = 1.2-4.0, respectively) samples but not that of cancer.

CONCLUSION

The association between variant haplotypes at XRCC1 and risk of leukoplakia is pronounced in non-infected individuals since HPV oncoprotein could inhibit directly the DNA repair activity of XRCC1. But more samples of leukoplakia and cancer are essential to validate these results.

Prognostic relevance of human papillomavirus L1 capsid protein detection within mild and moderate dysplastic lesions of the cervix uteri in combination with p16 biomarker

OBJECTIVE

To proof the prognostic relevance of HPV L1 capsid protein detection on colposcopically-guided punch biopsies in combination with p16.

STUDY DESIGN

Sections of colposcopically-guided punch biopsies from 191 consecutive cases with at least 5 years of follow-up were stained with HPV L1 capsid protein antibodies (Cytoactiv screening antibody) and a monoclonal anti-p16 antibody. Fifty sections were derived from a benign group, 91 from low-grade (cervical intraepithelial neoplasia [CIN 1]) lesions and 50 from high-grade (CIN 2 and 3) lesions.

RESULTS

Overall only 16.1% of the 87 L1-negative, p16-positive CIN lesions showed remission of the lesion compared to 72.4% of the double positive cases. None of the L1/p16 double negative CIN lesions progressed.

CONCLUSION

HPV L1 capsid protein detection with Cytoactiv screening antibody seems to be a promising new tool to predict the behavior of HPV-associated (p16-positive) early dysplastic lesions.

Early detection of cervical neoplasia by Raman spectroscopy

Early detection of malignant tumours, or their precursor lesions, improves patient outcome. High risk human papillomavirus (HPV), particularly HPV16, infection can lead to the development of uterine cervical neoplasia, and therefore, the identification in clinical samples of the effects of HPV infection may have clinical value. In this report, we apply Raman microspectroscopy to live and fixed cultured cells to discriminate between defined cell types. Raman spectra were acquired from primary human keratinocytes (PHK), PHK expressing the E7 gene of HPV 16 (PHK E7) and CaSki cells, an HPV16-containing cervical carcinoma-derived cell line. Averaged Raman spectra showed variations, mostly in peaks originating from DNA and proteins, consistent with HPV gene expression and cellular changes associated with neoplasia, in both live and fixed cells. Principal component analysis produced good discrimination between the cell types, with sensitivities of up to 100% for the comparison of fixed PHK and CaSki. These results demonstrate the ability of Raman spectroscopy to discriminate between cell types representing different stages of cervical neoplasia. More specifically, this technique was able to identify cells expressing the HPV 16 E7 gene accurately and objectively, suggesting that this approach may be of value in diagnosis. Moreover, the ability to detect the effects of the virus in fixed samples also demonstrates the compatibility of Raman spectroscopy with current cervical screening methods. (c) 2007 Wiley-Liss, Inc.

Myc and human papillomavirus type 16 E7 genes cooperate to immortalize human keratinocytes

The E6 protein of the oncogenic human papillomaviruses (HPVs), in combination with the E7 protein, is essential for the efficient immortalization of human foreskin keratinocytes (HFKs). Since we recently demonstrated that E6 activates the human telomerase reverse transcriptase (hTERT) promoter via a Myc-dependent mechanism, we speculated that overexpressed Myc might be able to substitute for E6 in cell immortalization. Myc (similar to E6) was unable to immortalize HFKs when transduced alone, despite inducing high levels of telomerase activity. However, when transduced with E7, Myc immortalized HFKs following a brief but detectable crisis period. In contrast to E6 + E7-immortalized cells, the Myc + E7-immortalized cells expressed high levels of p53 protein as well as two p53-regulated proteins, p21 and hdm-2. The increase in p21 and hdm-2 proteins correlated directly with their mRNA levels, suggesting transcriptional activation of the respective genes by the overexpressed p53 protein. Interestingly, a significant proportion of the p53 protein in the Myc + E7-immortalized cells was localized to the cytoplasm, potentially due to interactions with the overexpressed hdm-2 protein. Regardless, cell immortalization by the Myc + E7 genes occurred independently of p53 degradation. Since we have already observed high-efficiency cell immortalization with the hTERT + E7 or E6 mutant (p53 degradation-defective) + E7 genes (i.e., no crisis period) that proceeds in the presence of high levels of p53, we hypothesize that the crisis period in the Myc + E7 cells is due not to the levels of the p53 protein but rather to unique properties of the Myc protein. The common factor in cell immortalization by the three gene sets (E6 + E7, Myc + E7, and hTERT + E7 genes) is the induction of telomerase activity.

Inhibition of T-cell receptor signal transduction and viral expression by the linker for activation of T cells-interacting p12(I) protein of human T-cell leukemia/lymphoma virus type 1

The p12(I) protein of human T-cell leukemia/lymphoma virus type 1 (HTLV-1) is a small oncoprotein that increases calcium release following protein kinase C activation by phorbol myristate acetate, and importantly, this effect is linker for activation of T cells (LAT) independent. Here, we demonstrate that p12(I) inhibits the phosphorylation of LAT, Vav, and phospholipase C-gamma 1 and decreases NFAT (nuclear factor of activated T cells) activation upon engagement of the T-cell receptor (TCR) with anti-CD3 antibody. Furthermore, we demonstrate that p12(I) localizes to membrane lipid rafts and, upon engagement of the TCR, relocalizes to the interface between T cells and antigen-presenting cells, defined as the immunological synapse. A p12(I) knockout molecular clone of HTLV-1 expresses more virus upon antigen stimulation than the isogenic wild type, suggesting that, by decreasing T-cell responsiveness, p12(I) curtails viral expression. Thus, p12(I) has contrasting effects on TCR signaling: it down-regulates TCR in a LAT-dependent manner on one hand, and on the other, it increases calcium release in a LAT-independent manner. The negative regulation of T-cell activation by p12(I) may have evolved to minimize immune recognition of infected CD4(+) T cells, to impair the function of infected cytotoxic CD8(+) T cells, and to favor viral persistence in the infected host.

[Progress of study on anti-human cervical papilloma virus infection with Chinese and Western medicine]

Human papilloma virus (HPV) infection is closely correlated with the occurrence of cervical cancer and precancerous lesion, high risk HPV can induce cervical cancer by the corresponding protein of E6 and E7 gene expression. Earlier diagnosis and earlier prevention of HPV infection are the key points in blocking cervical cancer, and combined use of Chinese herbal preparations with Western medicine is the important way for preventing HPV infection and prohibiting cervical canceration. So, to develop anti-viral chemical compound from natural drugs has become the hotspot of research today.

Circulating human papillomavirus type 16 specific T-cells are associated with HLA Class I expression on tumor cells, but not related to the amount of viral oncogene transcripts

Human papillomavirus (HPV) is a necessary factor in the pathogenesis of cervical cancer. Circulating HPV-specific T-cells responding to the E6 and E7 HPV proteins can be detected only in half of cervical cancer patients. Potential explanations for the absence of this response are lack of sufficient amounts of antigen to activate the immune response or local immune escape mechanisms. We studied the relationship between HPV 16 E6/E7 oncogene mRNA expression, human leukocyte antigen (HLA) expression on tumor cells and the presence of circulating E6- and E7-specific T-cell responses in cervical cancer patients. The amount of antigen was assessed by HPV E6/E7 mRNA expression levels measured by quantitative polymerase chain reaction. HLA Class I and Class II expression on tumor cells was analyzed by immunohistochemistry. A proliferative HPV-specific T-cell response was detected in 15/29 patients. The amount of HPV E6/E7 mRNA was not related to the presence of immune response. HLA Class I expression was downregulated in 19 patients and completely lost in 7 patients. HLA Class II expression was upregulated in 18 patients. HLA Class I expression on tumor cells showed a strong correlation with immunity (p = 0.001). Explicitly, all patients with complete HLA loss lacked HPV specific T-cell responses. The presence of circulating HPV-specific T-cells might reflect ongoing antitumor response that is sustained by CD8+ T-cells killing HLA Class I positive cancer cells. We hypothesize that HLA Class I expression status on tumor cells might as well influence the response to HPV E6/E7 directed immunotherapy.

Relationship between HPV16/18 E6 and 53, 21WAF1, MDM2, Ki67 and cyclin D1 expression in esophageal squamous cell carcinoma: comparative study by using tissue microarray technology

AIM

To investigate the role of human papillomavirus (HPV) HPV16/18 E6 oncogene in the carcinogenesis of esophageal cell carcinoma (ESCC).

MATERIALS AND METHODS

Tissue microarray (TMA) block was constructed from 60 cases of paraffin-embedded ESCC tissues and pair-matched controls (adjacent normal epithelium). Immunohistochemistry (IHC) methods were applied to detect the expression of HPV16/18 E6, p53, p21(WAF1), MDM2, Ki67 and cyclin D1 proteins on TMA slides. In situ hybridization (ISH) targeting HPV gene was also used.

RESULTS

In ESCC samples, 18.3% (11/60) were revealed HPV16/18 E6 positive by IHC, while 40.0% (24/60) HPV positive by ISH; HPV16/18 E6 expression was significantly higher than that of control samples. In ESCC samples, the expressions of p53, p21(WAF1), Cyclin D1, MDM2 and Ki67 were recorded in 60.0% (36/60), 40.0% (24/60), 51.7% (31/60), 65.0% (39/60) and 88.3% (53/60) cases respectively, In ESCC samples, p53, MDM2 and Ki67 expression correlated with the HPV16/18 E6 expression (p less, similar 0.01), p21(WAF1) expression - with these of MDM2 and cyclin D1 (p less, similar 0.01) whilst expression of Ki67 - with ESCC grade (p less, similar 0.01).

CONCLUSION

HPV might be one of etiological factor of esophageal carcinoma in Shantou, China. p53, MDM2 proteins may play important roles in the pathogenesis of HPV-associated ESCC.

Comparative Analysis of 19 Genital Human Papillomavirus Types with Regard to p53 Degradation, Immortalization, Phylogeny, and Epidemiologic Risk Classification

We have analyzed E6 proteins of 19 papillomaviruses able to infect genital tissue with regard to their ability to degrade p53 and the thus far unknown immortalization potential of the genomes of human papillomaviruses (HPV) 53, 56, 58, 61, 66, and 82 in primary human keratinocytes. E6 proteins of HPV types 16, 18, 33, 35, 39, 45, 51, 52, 56, 58, and 66, defined as high-risk types, were able to induce p53 degradation in vitro, and HPV18-, HPV56-, and HPV58-immortalized keratinocytes revealed markedly reduced levels of p53. In contrast, the E6 proteins of HPV6 and 11 and HPV44, 54, and 61, regarded as possible carcinogenic or low-risk HPV types, respectively, did not degrade p53. Interestingly, the E6 proteins of HPV 53, 70, and 82 inconsistently risk classified in the literature were also found to induce p53 degradation. The genomes of HPV53 and 82 immortalized primary human keratinocytes that revealed almost absent nuclear levels of p53. These data suggest a strict correlation between the biological properties of certain HPV types with conserved nucleotide sequence (phylogeny), which is largely coherent with epidemiologic risk classification. HPV types 16, 18, 33, 35, 39, 45, 51, 52, 56, 58, and 66, generally accepted as high-risk types, behaved in our assays biologically different from HPV types 6, 11, 44, 54, and 61. In contrast, HPV70, regarded as low-risk type, and HPV53 or HPV82, with inconsistent described risk status, were indistinguishable with respect to p53 degradation and immortalization from prototype high-risk HPV types. This could imply that other important functional differences exist between phylogenetically highly related viruses displaying similar biological properties in tissue culture that may affect their carcinogenicity in vivo.

DMBA/TPA-Induced Tumor Formation Is Aggravated in Human Papillomavirus Type 16 E6/E7 Transgenic Mouse Skin

Human papillomavirus type 16 (HPV16) is a major causative factor in the development of uterine cervical carcinomas. We investigated the role of E6/E7 in tumor formation. Skin-specific E6/E7 transgenic mice showed approximately twice as many tumors compared with nontransgenic mice in dimethylbenz[a]anthracene (DMBA)-initiated and a 12-O-tetradecanoylphorbol-13-acetate (TPA)-promoted two-stage skin carcinogenesis. This model showed a significant increase of epidermal cell proliferation in the transgenic mice. The 8-hydroxy-2'deoxyguanosine (8OH-dG) detection assay showed that oxidative DNA damage was significantly higher in the transgenic mice after TPA treatments. The overexpression of E6/E7 in the skin in the DMBA/TPA two-stage-induced carcinogenesis model aggravated the incidence of tumor formation. HPV16 E6/E7 appears to act as an enhancer of carcinogenesis that requires initiation by DMBA and promotion by TPA.

Early integration of high copy HPV16 detectable in women with normal and low grade cervical cytology and histology

BACKGROUND

Integration of human papillomavirus (HPV) DNA has been considered a late event in cervical carcinogenesis. However, integrated forms of HPV were recently detected in cancer precursor lesions using a new real time polymerase chain reaction (PCR) to detect the deletions at the 3362-3443 region of HPV16 E2 OBJECTIVE: To study the frequency of HPV16 DNA integration in cervical lesions and compare the sensitivity of an additional upstream region of the E2 ORF (2962-3138) in detecting HPV integration.

METHODS

Using the TaqMan based PCR, HPV16 positive DNA samples were analysed in 164 cervical scrapings from women participating in a multicentre screening trial. Biopsy confirmation was available in 62 cases.

RESULTS

Primers targeting the 3362-3443 region detected the majority of E2 deletions. In only 23% of the samples was the E2 upstream region equal or better target than the 3362-3443 region. Mixed (episomal/integrated) pattern was the most prevalent physical state of HPV16, also present in PAP smears with normal morphology. Pure integrated form was most prevalent in HSIL and cancer lesions, but also detectable in low grade abnormalities (NSIL, ASC-US, LSIL). Women with only integrated HPV16 were almost 10 years older than those with episomal HPV16. Viral load of integrated HPV16 was related to cytological abnormality (p = 0.003) but not to histology.

CONCLUSIONS

Integrated HPV16 is present in low grade cervical lesions, mostly mixed with the episomal form. Women with the pure integrated form of HPV16 are older than those with the other forms.

Factors influencing subcellular localization of the human papillomavirus L2 minor structural protein

Two structural proteins form the capsids of papillomaviruses. The major structural protein L1 is the structural determinant of the capsids and is present in 360 copies arranged in 72 pentamers. The minor structural protein L2 is estimated to be present in twelve copies per capsid. Possible roles for L2 in interaction with cell surface receptors and in virion uptake have been suggested. As previously reported, L2 localizes in subnuclear domains identified as nuclear domain 10 (ND10). As it was demonstrated that L2 is able to recruit viral and cellular proteins to ND10, a possible role for L2 as a mediator in viral assembly has been proposed. In this study, we determined factors influencing the localization of L2 at ND10. Under conditions of moderate L2 expression level and in the absence of heterologous viral components, we observed that, in contrast to previous reports, L2 is mainly distributed homogeneously throughout the nucleus. L2, however, is recruited to ND10 at a higher expression level or in the presence of viral components derived from vaccinia virus or from Semliki Forest virus. We observed that translocation of L2 to ND10 is not a concentration-dependent accumulation but rather seems to be triggered by yet unidentified cellular factors. In contrast to HPV 11 and 16 L2, the HPV 18 L2 protein seems to require L1 for efficient nuclear accumulation.

Detection of cervical abnormalities in a developing country using measurement of Brn-3a in cervical smears

OBJECTIVE

We have previously shown that Brn-3a is elevated in biopsies from women in the United Kingdom with high grade cervical neoplasia, and that it specifically trans-activates the HPV URR in vitro and in vivo. The aim of this study is to establish the relationship of Brn-3a, HPV E6 and pathological diagnosis in cervical smear from women in a developing country with a high prevalence of cervical disease. This is a follow-up of our previous work in which for the first time Brn-3a and E6 levels in cervical smears from women in United Kingdom were shown to correlate with the histological diagnosis of cervical neoplasia and were even better in predicting underlying pre-malignant disease than conventional procedures.

METHOD

Cervical smears from 295 women with cervical abnormalities attending gynecological clinics in Brazil were used to make RNA. The mRNA levels of Brn-3a and HPV E6 were measured and the data obtained were used to establish the relationship between Brn-3a and the histological diagnosis.

RESULTS

The cellular transcription factor Brn-3a was readily measured in cervical smears from the Brazilian population. Its presence was shown to be frequently associated with the expression of HPV E6. The measured level of Brn-3a parallels the severity of the cervical ailment and predicts the pathological categories.

CONCLUSIONS

The ability of Brn-3a to predict for cervical ailments is independent to the geographical characteristics of the population, and hence it could be used routinely as an adjunct to colposcopy and pathological diagnosis in developing and developed countries.

Expression of the high-risk human papillomavirus type 18 and 45 E7 oncoproteins in cervical carcinoma biopsies

E7 proteins are major oncoproteins of high-risk human papillomaviruses (HPVs), which play a key role in cervical carcinogenesis. These proteins have been shown to immortalize primary human cells. Due to the absence of antibodies with suitable sensitivity and specificity, little is known about expression of the E7 oncoproteins in naturally infected tissues. Recently, high-level expression of the E7 protein of HPV-16, the most prevalent oncogenic HPV type, was demonstrated in cervical carcinomas by immunohistochemistry; however, approximately 15 additional high-risk HPV types are known to be associated with cervical carcinoma. It is unknown whether the E7 oncoproteins of HPV-18 and -45, the second and third most prevalent HPV types, are expressed in cervical cancers. Using antibodies against HPV-18 and -45 E7 proteins, it is shown here for the first time that the HPV-18 and -45 E7 proteins can be detected in cervical carcinoma biopsies. Together with anti-HPV-16 E7 antibodies, this could create the possibility of detecting E7 oncoproteins in approximately 80 % of all cervical cancers.

Value and feasibility of HPV DNA test in cervical scraping smears

To investigate the reliability and feasibility of human papillomavirus (HPV) DNA test in cervical scraping smears with polymerase chain reaction (PCR), 131 cases of cervical scraping specimens were collected, and the positive rates and accuracy of HPV infection were determined in normal subjects and cervical cancer patients. GP5+/GP6+ and E7 primer pairs designed for detecting HPV L1 and HPV type 16 E7 were tested in this study. Our results showed that positive rates of HPV DNA in normal population and cervical cancer patients were 32.99% and 73.53% respectively and there was significant difference between them (P < 0.001). In normal subjects, detection rates of HPV DNA with GP5+/GP6+ and E7 primer pairs were 27.84% and 16.49% respectively, with statistically significant difference between them (P > 0.05). However the detection rates in cervical cancer patients were 38.24% and 67.65% for the two markers, with a significant difference found between them (P < 0.05). It is concluded that HPV DNA test with PCR for cervical scraping smears was feasible. GP5+/GP6+ primer pairs may be a useful probe to screen HPV infection in normal population, but they are not sensitive enough in cervical cancer patients. It is suggested that high risk type HPV DNA test was very useful in population with high risk of cervical cancer.

[The prevalence of E6/E7 HPV type 16 in laryngeal cancer and in normal mucosa]

Many authors suggest that HPV infection can play a great role in development of benign and malignant tumours of upper respiratory tract in human. The aim of this study was to determine the prevalence of E6/E7 HPV-16 in laryngeal squamous cell carcinoma, and normal laryngeal mucosa, and to analyse their correlation with sex, lymph node status, primary tumor stage, localization, and histological differentiation. HPV 16 DNA presence was analysed using PCR technique in 72 samples of laryngeal carcinoma and in samples of 50 normal mucosa. Human papillomavirus was detected in 26 (36.1%) of the 72 patients. There was no statistically significant correlation HPV positivity and clinicopathological features of the analysed group. In 5 (10%) of 50 samples of normal mucosal. HPV 16 presence in normal mucosa and in laryngeal squamous cell carcinoma was detected in 3 patients. Our observations suggest that HPV16 can play a role in pathogenesis of laryngeal cancer.

Does HPV play a role in the etiopathogenesis of ameloblastoma? An immunohistochemical, in situ hybridization and polymerase chain reaction study of 18 cases using laser capture microdissection

Ameloblastomas are epithelial tumors of odontogenic origin, biologically characterized by local recurrence. Among different etiologic factors, HPV infection has been recently postulated to be somehow involved in ameloblastoma etiopathogenesis. To address this issue, we studied 18 ameloblastomas by means of immunohistochemistry, in situ hybridization (conventional and amplified), polymerase chain reaction and nested-polymerase chain reaction analyses using laser capture microdissection in order to detect the occurrence of HPV in this setting. No evidence of HPV infection was detected by morphological examination, immunohistochemistry, in situ hybridization and conventional polymerase chain reaction, while nested-polymerase chain reaction showed a weak positive band in two cases. However, the subsequent restriction enzyme analysis carried out from the nested-polymerase chain reaction amplification products of these two samples excluded the presence of HPV subtypes 16, 18, 31, 33, 35, 52, and 58. The search for HPV 6 and 11 in the same specimens was also negative. In conclusion, our data do not support an etiopathogenetic evidence for HPV in ameloblastoma.

[Detection of high-risk human papillomavirus (HPV) E6 and E7 oncogene transcripts increases the specificity of the detection of a cervical intraepithelial neoplasia (CIN)]

AIMS

The oncogenic potential of the high-risk human papillomavirus (HR-HPV) genotypes depends on the expression of the viral oncogenes E6 and E7. Thus, the detection of these transcripts could serve as a factor in the evaluation of a woman's risk of development of cervical intraepithelial neoplasia (CIN).

METHODS

A nested RT-PCR assay for the detection of E6/E7 oncogene transcripts of all known HR-HPV genotypes was established. Cervical scrapes of 779 HR-HPV-DNA-positive women exhibiting all grades of CIN were examined.

RESULTS

Spliced E6/E7 oncogene transcripts of all the HR-HPVs were detected in numerous samples. In 459 cases with agreement between the cytologic and histologic findings, the prevalence increased with lesion severity: CIN 0, 18%; CIN I, 58%; CIN II, 77%; CIN III, 84%. While sensitivity and negative predictive value of HR-HPV DNA-positivity for the detection of a CIN lesion were significantly (p < 0.0001) higher than those of E6/E7 mRNA positivity (90.3% vs. 65.5% and 93% vs. 83.1%), the opposite was true for the specificity and positive predictive value (72.8 % vs. 95.2%) and 65.1% vs. 88.5%, p < 0.0001). Preliminary follow-up data in 120 initially HPV-16 DNA-positive women revealed the development, persistence or progression of a CIN lesion in 33% (8/24) of HR-HPV DNA-positive and E6/E7 mRNA-negative women, compared to 93% (66/71, p < 0.0001) in women in whom transcriptional activity of the E6/E7 oncogenes was detectable.

CONCLUSIONS

Besides the identification of HPV DNA, the detection of HR-HPV E6/E7 oncogene transcripts may serve as a valuable tool in increasing the specificity of HPV testing.

Cervical human papillomavirus screening by PCR: advantages of targeting the E6/E7 region

PCR is a promising method for detection of human papillomavirus (HPV), the high-risk forms of which are responsible for cervical cancer. PCR primers that target the L1 or E1 region can be unreliable and may miss more advanced disease, whereas those directed at the E6 or E7 regions, which encode oncogenic products, are preferable because 1) the LI/E1 regions, but never the E6/E7 regions, are lost during integration of viral DNA into host genomic DNA, a process that can represent an integral component of progression from infection to tumorigenesis; and 2) the E6/E7 nucleotide sequence exhibits less nucleotide variation. The choice of region used for PCR has implications for HPV screening strategies in the clinical diagnosis and management of cervical cancer.