Human papillomavirus DNA integration and messenger RNA transcription in cervical low- and high-risk squamous intraepithelial lesions in Austrian women

Integration rates of human papilloma virus genome in a molecular survey on cervical specimens among Iranian patients

The human papilloma virus (HPV) as a major causative agent of different cancers is under investigation globally. In this study, we aim to investigate HPV infection in different cytological and pathological stages by different molecular methods, and then the viral genome integration of HPV-16 and -18 is determined by a specific real-time PCR method. The study included women who underwent liquid-based cytology. HPV PCR was conducted by MY09/11 universal primers, HPV genotyping was performed by INNO-LiPA HPV genotyping assay, and the viral genome status was defined by two real-time PCR assays. The statistics were calculated by SPSS v.22 software. In 1668 women included in the study with mean age±std. deviation of 35.6±0.7, HPV was detected in 632 (38%) participants. Following genotyping analyses, 16 HPV types and 713 strains were detected. HPV-16 and HPV-18 from high-risk types and HPV-6 and HPV-11 from low-risk types were the dominant types. We found HPV-16 strains in mixed form (58.8%), and of the HPV-18 strains, the episomal form was prevalent (92.9%). The statistics revealed significant presence of HPV-6 and within normal limits cases; HPV-16 and atypical squamous cells of undetermined significance; HPV-33 as well as HPV-39 and low-grade squamous intraepithelial lesion; HPV-6 and atypical squamous cells of undetermined significance; and HPV-35 as well as HPV-56 and squamous cell carcinoma. Our study showed high prevalence of HPV in low-grade cervical lesions, although it is associated with higher grades. The HPV molecular testing extra to cytology is recommended. HPV-16 and HPV-18 have different programs in genome integration in infected cells.

Long (27-nucleotides) small inhibitory RNAs targeting E6 protein eradicate effectively the cervical cancer cells harboring human papilloma virus

Objective

This study was to identify small inhibitory RNAs (siRNAs) that are effective in inhibiting growth of cervical cancer cell lines harboring human papilloma virus (HPV) and to examine how siRNAs interact with interferon beta (IFN-β) and thimerosal.

Methods

The HPV18-positive HeLa and C-4I cell lines were used. Four types of siRNAs were designed according to their target (both E6 and E7 vs. E6 only) and sizes (21- vs. 27-nucleotides); Ex-18E6/21, Ex-18E6/27, Sp-18E6/21, and Sp-18E6/27. Each siRNA-transfected cells were cultured with or without IFN-b and thimerosal and their viability was measured.

Results

The viabilities of HPV18-positive tumor cells were reduced by 21- and 27-nucleotide siRNAs in proportion to the siRNA concentrations. Of the two types of siRNAs, the 27-nucleotide siRNA constructs showed greater inhibitory efficacy. Sp-18E6 siRNAs, which selectively downregulates E6 protein only, were more effective than the E6- and E7-targeting Ex-18E6 siRNAs. siRNAs and IFN-β showed the synergistic effect to inhibit HeLa cell survival and the effect was proportional to both siRNA and IFN-β concentrations. Thimerosal in the presence of siRNA exerted a dose-dependent inhibition of C-4I cell survival. Finally, co-treatment with siRNA, IFN-β, and thimerosal induced the most profound decrease in the viability of both cell lines.

Conclusion

Long (27-nucleotides) siRNAs targeting E6-E7 mRNAs effectively reduce the viability of HPV18-positive cervical cancer cells and show the synergistic effect in combination with IFN-b and thimerosal. It is necessary to find the rational design of siRNAs and effective co-factors to eradicate particular cervical cancer.

HPV-Based Screening, Triage, Treatment, and Followup Strategies in the Management of Cervical Intraepithelial Neoplasia

Cervical cancer is the second most common cause of death from cancer in women worldwide, and the development of new diagnostic, prognostic, and treatment strategies merits special attention. Many efforts have been made to design new drugs and develop immunotherapy and gene therapy strategies to treat cervical cancer. HPV genotyping has potentially valuable applications in triage of low-grade abnormal cervical cytology, assessment of prognosis and followup of cervical intraepithelial neoplasia, and in treatment strategies for invasive cervical cancer. It is known that during the development of cervical cancer associated with HPV infection, a cascade of abnormal events is induced, including disruption of cellular cycle control, alteration of gene expression, and deregulation of microRNA expression. Thus, the identification and subsequent functional evaluation of host proteins associated with HPV E6 and E7 oncoproteins may provide useful information in understanding cervical carcinogenesis, identifying cervical cancer molecular markers, and developing specific targeting strategies against tumor cells. Therefore, in this paper, we discuss the main diagnostic methods, management strategies, and followup of HPV-associated cervical lesions and review clinical trials applying gene therapy strategies against the development of cervical cancer.

Human papillomavirus genotype distribution and human papillomavirus 16 and human papillomavirus 18 genomic integration in invasive and in situ cervical carcinoma in human immunodeficiency virus-infected women

BACKGROUND

Women infected with human immunodeficiency virus (HIV) are at increased risk of developing precancerous and cancerous lesions in cervix because of persistence of oncogenic human papillomavirus (HPV) infection. Scarce information about the HPV genotypes attributed to cervical cancer in the HIV-infected population is available, especially in countries with a low prevalence of this pathology.

OBJECTIVE

The objective of the study was to assess the prevalence and distribution of HPV types, and the viral integration of HPV-16 and HPV-18 in cervical squamous cell carcinoma of HIV-infected and HIV-negative women.

METHODS

A total of 140 formaldehyde-fixed paraffin-embedded specimens from 31 HIV-infected and 109 matched HIV-negative women, with a diagnosis of in situ or invasive cervical carcinoma, were identified between 1987 and 2010 from different hospitals of the Barcelona area, Spain. Human papillomavirus genotyping and integration were analyzed by standardized polymerase chain reaction.

RESULTS

Similar prevalence and distribution of HPV genotypes were detected in cervical cancers (in situ and invasive) regardless of HIV condition. The most common types were as follows: HPV-16 (58% in HIV-positive vs 72% in HIV-negative) and HPV-33 (16% vs 8%). In invasive cervical carcinoma, HPV-18 was significantly more prevalent in HIV-positive women (14% vs 1%; P = 0.014). The proportion of samples with integrated forms of HPV-16 (39% vs 45%) and HPV-18 (50% vs 50%) was similar in both groups.

CONCLUSIONS

The prevalence and distribution of principal HPV types involved in the carcinogenesis process of the cervix were similar in HIV-infected and noninfected women, although a tendency toward a lower HPV-16 and a higher HPV-18 prevalence in invasive cervical carcinoma was detected in HIV-positive women. Similar percentage of HPV-16 and HPV-18 viral integration was found in formaldehyde-fixed paraffin-embedded specimens of cervical cancer regardless of the HIV infection status.

Clinical performance of human papillomavirus E6 and E7 mRNA testing for high-grade lesions of the cervix

Infection with high-risk (HR) human papillomavirus (HPV) is the major cause of cervical cancer. However, relatively few infections progress to malignant disease. Progression to malignancy requires the overexpression of the E6 and E7 genes in the integrated HPV genome. It follows that the E6 and E7 transcripts could be useful markers of disease progression. The study presented here tests this possibility, using data from colposcopy and from cytological and histological tests to compare RNA assays for the E6 and E7 genes with DNA testing. A total of 180 women underwent colposcopy, cytology, and biopsy of suspected lesions (143 cases). Cervical brush specimens were analyzed for HPV DNA and for E6 and E7 mRNA. DNA from HR HPV was found in 57.8% of the specimens; E6 and E7 transcripts were found in 45%. The rates of detection of HPV DNA and of E6 and E7 transcripts were 33.3% and 25%, respectively, for specimens with normal findings; 51.4% and 31.9%, respectively, for specimens with cervical intraepithelial neoplasia grade 1 (CIN1); and 61.1% and 44.2% for specimens with CIN2, respectively. All specimens with CIN3 and 95.5% of specimens from patients with squamous cell carcinoma were positive by both assays. Thirty-seven patients with normal colposcopy findings did not undergo biopsy. HPV DNA and mRNA transcripts were found in 32.4% and 18.9% of these cases, respectively. Comparisons with cytological tests produced similar results. Overall, the mRNA tests showed a higher specificity than the DNA tests for high-grade lesions (72.7% and 56.2%, respectively) and a higher positive predictive value (59.3% and 49.0%, respectively). These findings suggest that mRNA assays could be more powerful than DNA testing for predicting the risk of progression and offer a strong potential as a tool for triage and patient follow-up.

RNA (E6 and E7) assays versus DNA (E6 and E7) assays for risk evaluation for women infected with human papillomavirus

In the majority of cases, high-risk human papillomavirus (HR HPV) infections regress spontaneously, with only a small percentage progressing to high-grade lesions. Current screening methods are based on DNA detection. An alternative would be to monitor expression of the E6 and E7 viral oncogenes continuously expressed by malignant phenotypes. In the work reported in this paper, we compared the two methods for a group of women with high-risk HPV infections. Cervical specimens from 400 women, previously found to be HPV DNA positive, were analyzed for HPV DNA by a liquid hybridization assay and typed by multiplex PCR (for types 16, 18, 31, and 33). Identification of HR HPV E6 and E7 RNA transcripts was performed using real-time reverse transcription-PCR and nucleic acid sequence-based amplification assays. Results were compared with concurrent cytological data. HR HPVs were found in 61.2% of patients. The most common genotype was HPV type 16 (HPV-16) (47.1%), followed by HPV-18, HPV-31, and HPV-33. Nine percent of cases involved other genotypes. Among 223 HPV DNA-positive samples, only 118 were positive in the RNA test. Among HPV DNA-positive patients with normal cytology, we detected E6 and E7 RNA transcripts in two cases (18.2%). The rate of detection increased gradually with the grade of the observed lesions, rising from 20% for patients with atypical squamous cells of undetermined significance to 48.1% for women with low-grade squamous intraepithelial lesions and 86.3% for those with high-grade squamous intraepithelial lesions. These results suggest that testing for HPV E6 and E7 transcripts could be a useful tool for screening and patient management, providing more accurate predictions of risk than those obtained by DNA testing.

Human papillomavirus type 18 DNA load and 2-year cumulative diagnoses of cervical intraepithelial neoplasia grades 2-3

BACKGROUND

The clinical relevance of the amount of human papillomavirus type 18 (HPV18) DNA in cervical tissue (ie, HPV18 DNA load) is unknown.

METHODS

Study subjects were 303 women who were HPV18 positive at enrollment into the Atypical Squamous Cells of Undetermined Significance (ASC-US) and Low-Grade Squamous Intraepithelial Lesion (LSIL) Triage Study. HPV18 DNA load, expressed as copies of HPV18 per nanogram of cellular DNA, at enrollment was quantitatively measured. Subjects were followed up semiannually for a period of 2 years for detection of cervical intraepithelial neoplasia 2-3 (CIN2-3). A linear regression model was used to examine associations of CIN2-3 with HPV18 DNA load. All statistical tests were two-sided.

RESULTS

CIN2-3 was confirmed in 92 of 303 (30.4%) HPV18-positive women. Among women without CIN2-3, HPV18 DNA load was positively associated with increasing severity of cervical cytology at enrollment (Ptrend < .001). However, among those with CIN2-3, HPV18 DNA load was not associated with severity of cervical cytology at enrollment (Ptrend = .33). The ratios of geometric means of HPV18 DNA load at enrollment among women with CIN2-3, relative to those without, were 6.06 (95% confidence interval [CI] = 0.31 to 117.92) for those with normal cytology at enrollment, 0.50 (95% CI = 0.10 to 2.44) for those with ASC-US, 0.11 (95% CI = 0.03 to 0.46) for those with LSIL, and 0.07 (95% CI = 0.01 to 0.80) for those with high-grade squamous intraepithelial lesion (HSIL). After adjusting for age and coinfection with other high-risk HPVs, a statistically significant association of lower HPV18 DNA load with CIN2-3 was observed among women with LSIL or HSIL at enrollment (P = .02). Within the 2-year period, HPV18 DNA load was unrelated to the timing of CIN2-3 diagnosis. Overall results were similar when the outcome was CIN3.

CONCLUSIONS

HPV18 DNA load was higher for women with LSIL or HSIL at enrollment with no evidence of CIN2-3 during the 2-year follow-up period than it was for women with CIN2-3. Thus, testing for high levels of HPV18 DNA does not appear to be clinically useful.

Analysis of human papillomavirus type 18 load and integration status from low-grade cervical lesion to invasive cervical cancer

The clinical value of viral load and integration testing for human papillomavirus (HPV) remains unclear. Data on HPV type 18 (HPV18) is limited. We examined the HPV18 viral load and integration status of 78 women with normal cervix or neoplasia. While the crude viral load appeared to increase with lesion severity, the association was not significant after normalization with sample cellularity. Unlike reports for HPV16, the amino-terminal 1 region of HPV18 E2 was most frequently (71.0%) disrupted, representing the best marker for integration. A substantial proportion (57.1%) of invasive cancers harbored only the episomal genome, thus jeopardizing the clinical value of integration testing. A large proportion (41.7%) of normal/low-grade lesions showed viral integration, suggesting that integration of HPV18 starts early and is unlikely to be a sole determinant for progression. Interpretation of viral load should take into account the form of HPV infection as single infections had significantly higher viral loads than coinfections (P = 0.046). More data generated from routinely collected samples are warranted to verify the clinical value of viral load and integration testing. Viral load quantitation for HPV18 is premature for clinical use at this stage.