Application of a multiplex PCR to cervical cells collected by a paper smear for the simultaneous detection of all mucosal human papillomaviruses (HPVs) and typing of high-risk HPV types 16 and 18

Detection of human papillomavirus infection in oral cancers reported at dental facility: assessing the utility of FFPE tissues

Incidence of human papillomavirus (HPV)-associated oral cancers is on the rise. However, epidemiological data of this subset of cancers are limited. Dental hospital poses a unique advantage in detection of HPV-positive oral malignancies. We assessed the utility of formalin-fixed paraffin-embedded (FFPE) tissues, which are readily available, for evaluation of high-risk HPV infection in oral cancer. For protocol standardization, we used 20 prospectively collected paired FFPE and fresh tissues of histopathologically confirmed oral cancer cases reported in Oral Medicine department of a dental hospital for comparative study. Only short PCRs (~ 200 bp) of DNA isolated using a modified xylene-free method displayed a concordant HPV result. For HPV analysis, we used additional 30 retrospectively collected FFPE tissues. DNA isolated from these specimens showed an overall 23.4% (11/47) HPV positivity with detection of HPV18. Comparison of HPV positivity from dental hospital FFPE specimens with overall HPV positivity of freshly collected oral cancer specimens (n = 55) from three cancer care hospitals of the same region showed notable difference (12.7%; 7/55). Further, cancer hospital specimens showed HPV16 positivity and displayed a characteristic difference in reported sub-sites and patient spectrum. Overall, using a xylene-free FFPE DNA isolation method clubbed with short amplicon PCR, we showed detection of HPV-positive oral cancer in dental hospitals.

High frequency of HPV16 European variant E350G among Mexican women from Sinaloa

Background & objectives:

Human papillomavirus (HPV) infections play a crucial role in the aetiology of cervical cancer (CC), and HPV16 is the primary viral genotype associated with CC. A number of variants of the HPV16 E6 gene are involved in the progression of CC, differing in their prevalence and biological and biochemical properties. This study was designed to determine the frequency of HPV types 16/18 and to identify the presence of HPV16 E6-variants in asymptomatic Mexican women.

Methods:

A total of 189 cervical Pap smears were collected from women attending public health services in three different cities in Sinaloa, Mexico. Viral DNA was identified by amplification of E6 viral gene fragments using polymerase chain reaction (PCR). Identification of variants was done by sequencing a DNA fragment (321bp) of the HPV16 E6 gene.

Results:

More than half of the women tested were HPV-positive (52.38%), with HPV16 being the most frequent genotype (21.16%), followed by HPV18 (8.99%). Sequence analysis of the E6-HPV16 PCR products showed that in all cases, the viruses corresponded to European variants. It was further observed that the E350G intra-variant was the most common (>76%).

Interpretation & conclusions:

This study showed a predominance of European lineage variants of HPV16 among asymptomatic women from Sinaloa, Mexico, predominantly with of the E350G variant. This variant has been shown to be associated with an increased risk of early development of CC. The use of molecular identification of carcinogenic HPV and Pap test screening may be a good strategy for monitoring women to prevent CC.

Multiplex polymerase chain reaction for the detection of high-risk-human papillomavirus types in formalin-fixed paraffin-embedded cervical tissues

Detecting high-risk-human papillomavirus (HPV) types has become an integral part of the cervical cancer screening programmes. This study aimed to develop a multiplex polymerase chain reaction (PCR) for identification of HPV types 16 and 18 along with the beta globin gene in formalin-fixed and paraffin-embedded cervical biopsy specimens. A total of 59 samples from patients with cervical abnormalities were tested. HPV 16 positivity was 50% in cervical cancers and 52.9% in cervical intraepithelial neoplasia. Our multiplex PCR protocol can be used as a simple and cost-effective tool for high-risk-HPV detection in cervical cancer screening programmes.

Prevalence of high-risk human papilloma virus types and cervical smear abnormalities in female sex workers in Chandigarh, India

PURPOSE

Cervical cancer is the most common cancer among women in developing nations. Nearly 90% of the cases have been linked to the presence of high-risk human papillomavirus (hrHPV) types 16 and 18. The risk of cervical cancer may be high in female sex workers (FSWs) due to multiple sexual partners. This study aimed to determine the prevalence of cytological abnormalities and hrHPV types 16 and 18 in FSWs in Chandigarh, North India using the liquid-based cytology (LBC) approach.

MATERIALS AND METHODS

The cervical brush samples were collected from 120 FSW and 98 age-matched healthy controls (HCs). These were subjected to pap smear using conventional method, LBC and the detection of hrHPV types 16 and 18 was carried out using polymerase chain reaction.

RESULTS

The LBC samples showed better cytological details and also reduced the number of unsatisfactory smears from 11% in Pap to 1.5% in the LBC. A significantly higher number of inflammatory smears were reported in FSWs (51.7% vs. 34.7%, P = 0.01). The hrHPV types 16/18 were detected in 33/120 (27.5%) FSW versus 23/98 (23.5%) HCs. The risk of acquiring hrHPV was higher in FSWs, who had age at first sex ≤25 years, higher income and the habit of smoking.

CONCLUSION

The high prevalence of hrHPV among FSWs and HCs suggests the need for the implementation of effective National Screening Programme for early detection of hrHPV types to decrease the burden of cervical cancer, especially in high-risk population.

HPV16 oncogenes E6 or/and E7 may influence the methylation status of RASSFIA gene promoter region in cervical cancer cell line HT-3

Both human papillomavirus (HPV) infection and the aberrant Ras associated domain family gene 1A (RASSF1A) promoter methylation status participate in the pathogenesis of cervical cancer. Some studies suggest that E6, and E7 are involved in the pathogenetic mechanisms of RASSF1A. We mainly explored a possible involvement of HPV16 oncogenes E6 or/and E7 in RASSF1A promoter methylation status and possible roles of RASSF1A gene methylation in cervical cancer. Bisulfite genomic sequencing (BGS) PCR combined with TA clone, methylation-specific PCR (MSP) were used to analyze methylation status of the RASSF1A gene promoter in HPV16/18-positive and HPV-negative cervical cancer cell lines; ectopically expressed HPV16 E6, E7 and E6/E7 cervical cancer cell lines; normal cervical and cervical cancer tissues. The mRNA and protein expression of RASSF1A was detected by RT-PCR and western blotting. Re-expression and downregulated promoter methylation status were detected in the ectopically expressed HPV16 E6 and E7 cervical cancer cell line HT-3. The methylation status and expression of RASSF1A could be downregulated or reactivated by 5-Aza-dc in HT-3 and C33A cells. Additionally, statistics showed significant hypermethylation of RASSF1A in cervical cancer samples compared to that in normal cervical samples (P<0.05). The false negative rate (FNR) was 6.25% by HC2 method, when reconfirmed by HPV detection combining the MY09/11, GP5+/6+ and SPF1/2 methods. The ectopic expression of HPV16 E6 and/or E7 may be involved in aberrant methylation and expression of the RASSF1A gene. RASSF1A gene expression could be regulated by its promoter methylation status. Additionally, the false negativity of the HPV detection may contribute to the uncertain relationship between HPV infection and aberrant RASSF1A promoter methylation.

miR-3156-3p is downregulated in HPV-positive cervical cancer and performs as a tumor-suppressive miRNA

Background

Cervical cancer (CC) is the second most common cancer in females in developing countries. The two viral oncoproteins E6 and E7 mediate the oncogenic activities of high-risk human papillomavirus (HR-HPV), and HR-HPV, especially HPV16 or/and HPV18 (HPV16/18) play critical roles in CC through different pathways. microRNAs (miRNAs) may be associated with CC pathogenesis. Researches have indicated that human papillomavirus (HPV) may regulate cellular miRNA expression through viral E6 and E7. Herein, the purposes of this study were to identify the relationship between HPV infection and aberrantly expressed miRNAs and to investigate their pathogenic roles in CC.

Methods

miRNA expression was assessed using a microRNAs microarray in HPV16 E6- and E7-integrated HPV-negative HT-3 cell lines and mock vector-transfected HT-3 cells. The microarray results were validated, and the expression of miR-3156-3p was identified in HPV-positive and -negative CC cell lines as well as primary CC and normal cervical epithelium tissues using quantitative reverse-transcription polymerase chain reaction (qRT-PCR). Cell Counting Kit-8 (CCK8), flow cytometry, transwell analysis, tube formation, and Western blotting were used to identify the functional role of miR-3156-3p in CaSki, SiHa, and HeLa cell lines.

Results

Six underexpressed microRNAs (miR-3156-3p, 6779-3p, 4779-3p, 6841-3p, 454-5p and 656-5p) were consistently identified in HPV16 E6- and E7-integrated HT-3 cells. Further investigation confirmed a significant decrease of miR-3156-3p in HPV16/18 positive CC lesions. CCK8, flow cytometry, transwell analysis, tube formation assays, and Western blotting of the CC cell lines with miR-3156-3p over/under-expression in vitro showed that miR-3156-3p was involved in cell proliferation, apoptosis, migration, neovascularization, and SLC6A6 regulation.

Conclusions

Our findings indicate that miR-3156-3p plays a suppressor-miRNA role in CC and that its expression is associated with HR-HPV infection.

Distribution of human papilloma virus infections of uterine cervix among women of reproductive age--a cross sectional hospital-based study from North East India

Infection of the uterine cervix by human papilloma viruses (HPV) may be associated with cervical pre-cancer and invasive cervical carcinoma if left untreated. With advance in molecular techniques, it has become easier to detect the resence of HPV DNA long before the appearance of any lesion. This study concerned cervical scrape samples of 310 married non-pregnant women attending a gynecology outpatient department for both Pap and PCR testing to detect HPV DNA. Nested PCR using primers for L1 consensus gene with My9/My11 and GP6+/ GP5+followed by multiplex PCR were carried out to detect HPV 16 and HPV18.

RESULT

HPV prevalence was 11.9% out of which 3.67% cases of negative for intra-epithelial lesion or malignancy (NILM) and in 71.1% (27/38) of atypical cervical smears were HPV positive. There was increasing trend of high-risk-HPV positivity (HR HPV 16 and 18), from 20% in benign cytology (NILM) to 42.9 % in LSIL, 71.41% in HSIL and 100% in SCC. There was highly significant association of HPV infection with cervical lesion (x2=144.0, p<0.01) and also with type specific HPV prevalence (x2=7.761*(p<0.05).

HPV-type-specific response of cervical cancer cells to cisplatin after silencing replication licensing factor MCM4

Minichoromosome maintenance (MCM) proteins play key role in cell cycle progression by licensing DNA replication only once per cell cycle. These proteins are found to be overexpressed in cervical cancer cells. In this study, we depleted MCM4, one of the MCM 2-7 complex components by RNA interference (RNAi) in four cervical cancer cell lines. The four cell lines were selected on the basis of their human papillomavirus (HPV) infection: HPV16-positive SiHa, HPV18-positive ME-180, HPV16- and HPV18-positive CaSki, and HPV-negative C-33A. The MCM4-deficient cells irrespective of their HPV status grow for several generations and maintain regular cell cycle. We did not find any evidence of augmented response to a short-term (48 h) cisplatin treatment in these MCM4-deficient cells. However, MCM4-/HPV16+ SiHa cells cannot withstand a prolonged treatment (up to 5 days) of even a sublethal dosage of cisplatin. They show increased chromosomal instability compared to their control counterparts. On the other hand, MCM4-deficient CaSki cells (both HPV16+ and 18+) remain resistant to a prolonged exposure to cisplatin. Our study indicates that cervical cancer cells may be using excess MCMs as a backup for replicative stress; however, its regulatory mechanism is dependent on the HPV status of the cells.

Detection of human papillomavirus in women attending Pap cervical screening camp at a peripheral hospital of North-Eastern India

Human papillomavirus (HPV) associated cervical cancer is the leading cause of deaths in India. However, cytological/HPV screening may result in early detection of cervical cancer, resulting in early treatment and reduced mortality. Although reports related to general population is available, data on HPV prevalence among women attending AFMS health care facilities is scarce. Cervical samples were collected for cytological staining by Pap test and molecular detection by PCR, genotyping by HPV specific primers and sequencing. Apart from finding of atypical cells of undetermined significance (ASCUS) in one subject, no evidence of malignancy was observed. A high prevalence of HPV was found in this study group, which was intermediate between previous reports from general population and cervical cancer patients. All the subjects had infection of high risk HPV type16. HPV prevalence was found similar between different age groups. Although, none of the study subjects had malignant changes, but due to high prevalence of high risk HPV infection and other associated risk factors, these subjects might be at an elevated risk of developing cervical cancer. Regular follow-up of these patients who were detected HPV positive are required to screen for cervical malignancy.

Evaluation of dry and wet transport of at-home self-collected vaginal swabs for human papillomavirus testing

Our objective was to compare human papillomavirus (HPV) detection in paired self-collected vaginal samples transported by overnight mail in liquid specimen transport medium (STM) (wet) or in dry tubes (dry). Women aged 18-24 years were recruited online to self-collect vaginal swab samples at home for HPV testing and 159 women returned paired wet and dry samples. Dry samples were rehydrated with STM upon arrival at the laboratory. HPV was detected by the Roche Linear Array HPV genotyping test (37 genotypes) and Kappa and McNemar statistics were used to compare wet versus dry samples for detecting HPV. Of the subjects tested in this study, 51 % were HPV-positive (in either sample) and 40 % were positive for high-risk HPV. A total of 216 type-specific infections were detected among the 80 HPV-positive women. Almost perfect agreement was observed between paired samples for detecting any HPV (subject-level positive agreement: 91.9 %, κ: 0.85) or type-specific HPV (positive agreement across types: 90.1 %, κ: 0.90). Similar agreement between sample types was seen when testing for high-risk types and 81.9 % of all type-specific infections were detected in both samples. Among discordant pairs, wet samples were 3.3 times more likely to be positive for type-specific HPV than dry samples (P = 0.02). However, in 63.6 % of wet-positive/dry-negative discordant pairs analysed for viral load, type-specific HPV was either undetectable or detected at a low level (<100 copies) in the wet samples, suggesting that the majority of infections missed by using dry samples are less likely to be clinically relevant. Our results indicate that dry transport is a feasible option for transporting at-home self-collected vaginal samples for HPV DNA testing.

Correlation between physical status of human papilloma virus and cervical carcinogenesis

The prevalence of human papilloma virus (HPV)-16 in patients with cervical cancer, the physical status of HPV-16 in patients with cervical lesions, and the role of HPV-16 integration in cervical carcinogenesis were investigated. HPV genotyping was performed by using PCR approach with the primer GP5+/GP6+ and type-specific primer on biopsy specimens taken operatively from 198 women. Multiple PCR was done to detect physical status of HPV-16 in a series of cervical liquid-based cytology samples and biopsy specimens obtained from different cervical lesions with HPV-16 infection, including 112 specimens with cervical cancer, 151 specimens with CIN I, 246 specimens with CIN and 120 specimens with CINIII. The results showed that there were 112 cervical cancer samples (56.57% of total cervical cancer patients) with HPV-16 infection. The frequency of HPV-16 pure integration was 65.18% (73/112), 56.57% (47/120), 23.58% (58/246) and 7.95% (12/151) in cervical cancer, CINIII, CINII and CINI patients respectively. In situ hybridization was performed on some paraffin-embedded sections of CINII, CINIII and cervical cancer to verify the physical status of HPV-16 infection. Significant difference was observed between cervical cancer and CIN I, CINII, CINIII in the frequency of HPV-16 integration (P<0.01). It is suggested that HPV-16 is the most prevalent type and is associated with cervical cancer. In the case of HPV-16 infection there are close associations between the severity of cervical lesions and the frequency of HPV-16 integration. The application of testing HPV genotyping and physical status based on detection of HC-II HPV DNA would be in favor of predicting the prognosis of cervical precancerosis and enhancing the screening accuracy of cervical cancer.

A Simple and Robust Method for Semi-Quantitative Detection of Human Papillomavirus Nucleic Acids (HPV) Helps Oncological Clinicians to Assess the Severeness of HPV Cellular Changing

A simple and robust method for the detection of nucleic acids of human papilloma virus (HPV) has been developed. The assay exploits the excellent sensitivity and specificity of “nested” polymerase chain reaction (nPCR) that is designed in the original single tube configuration to effectively prevent the carry-over contamination. This approach theoretically covers the amplification of all cancer developing genotypes currently known. The nPCR, paired with very simple nucleic acids isolation steps, is a real alternative to the standard method. This manuscript shows its capacity for routine use under clinical conditions. It is shown that the strategy is at least as sensitive as the standard two tube nPCR and the data are acceptably reproducible.