Comparison of real-time PCR signal-amplified in situ hybridization and conventional PCR for detection and quantification of human papillomavirus in archival cervical cancer tissue

Human papillomavirus type-specific distribution in cervical intraepithelial neoplasia and cancer in The Gambia prior to HPV immunization programme: a baseline for monitoring the quadrivalent vaccine

BACKGROUND

Cervical cancer is the leading cause of cancer deaths in Gambian women. Current estimates indicate that 286 women are annually diagnosed with cervical cancer with a fatality rate of 70%. In an attempt to address this, in 2019 the quadrivalent HPV vaccine was incorporated into the Gambia's Expanded Programme on Immunisation. The study aims to retrospectively assess the prevalence and distribution of high-risk HPV genotype in archived, formalin fixed paraffin embedded cervical biopsy tissues diagnosed with cervical cancer in the Gambia from year 2013-2022.

METHOD

A total of 223 samples with histologically diagnosis of cervical cancer with adequate tissues were sectioned and deparaffinised, followed by HPV DNA extraction and the detection of HR-HPV by real-time multiplex PCR. The human β-globin gene was amplified in 119 samples, which were subsequently tested for HPV DNA.

RESULTS

HPV was prevalent in 87.4% (104 of 119) cervical cancer cases, 12.6% (15/119) samples tested negative. Amongst cervical cancer cases, HPV 16 genotype was the most frequent type accounting for 53.8% (56 /104), followed by other HR-HPV genotypes 17.3% (18/104), and HPV genotype 18 was 15.4% (16/104). Furthermore, multiple HPV infections involving HPV 16 and /or 18 was detected in 14 cases as follows: HPV genotypes 16 and 18 (3.8%, 4 /104), HPV 16 and other HR-HPV (6.7%, 8/104), and HPV 18 and other HR-HPV (1.9%, 2/104). A significant association between age and diagnosis with cervical cancer (p = 0.02), and HPV genotype 16 (p = 0.04) was observed.

CONCLUSION

There was no difference in the distribution of HPV 16 and 18 genotypes in cervical cancer cases in The Gambia in comparison with the global distribution. However, the high prevalence of cervical cancer cases with other HR-HPV, and combined infections of HPV 16 with other HR-HPV genotypes seen in this study, clearly shows that the nonavalent HPV vaccine could be more beneficial for The Gambia. This study provides The Gambia with a baseline data to use in policy decisions regarding future evaluation of the quadrivalent HPV vaccine in the country.

Genetic diversity, variation and recombination among the human papillomaviruses (HPVs) genomes isolated in China: a comparative genomic and phylogenetic analysis

Human papillomaviruses (HPVs) are widespread, sexually transmitted group of viruses that infect most individuals at some stage, causing genital warts and cancers. They are members of the Papillomaviridae family, which contains about 400 HPV types. China is among the high HPV burden countries with reported infections of multiple HPV types, accounting for 17.3% of global deaths and 18.2% of global new cases. Thus, understanding the genetic variation and geographic diversity characteristics of HPVs isolated in China is critical for global HPV prevention strategies. Thus, we analyzed the available HPV genome sequences isolated in China that grouped into two categories (alpha- and gamma-papillomaviruses) based on full-length genomes. The most common were HPV-16, -6, -58, and -52 respectively. In addition, four of the novel strains isolated in China, e.g. TG550, JDFY01, CH2, and L55 clustered with the HPV-mSK 159, 244, 201, and 200 respectively. Our phylogeographic network analysis indicated that the L55, TG550, and CH2 are genetically identical to the mSK 200, 046, and 201 respectively, while JDFY01 appeared separately, connected to the mSK-040 following five mutational steps. Also, we found ten recombination events among HPV-6/11 types within their E1, E2, E7, L1/L2 proteins, and Long Control Region ORFs. We achieved the consensus amino acid sequences of HPV proteins and found a conserved stretch of amino acids within E5A of all HPVs circulating in China. These findings offer valued insights into the genetic relationships, distribution, and evolution of the HPVs in China that may assist in adapting effective HPV preventive measures.

Advances in human papillomavirus detection and molecular understanding in head and neck cancers: Implications for clinical management

Head and neck cancers (HNCs), primarily head and neck squamous cell carcinoma (HNSCC), are associated with high-risk human papillomavirus (HR HPV), notably HPV16 and HPV18. HPV status guides treatment and predicts outcomes, with distinct molecular pathways in HPV-driven HNSCC influencing survival rates. HNC incidence is rising globally, with regional variations reflecting diverse risk factors, including tobacco, alcohol, and HPV infection. Oropharyngeal cancers attributed to HPV have significantly increased, particularly in regions like the United States. The HPV16 genome, characterized by oncoproteins E6 and E7, disrupts crucial cell cycle regulators, including tumor protein p53 (TP53) and retinoblastoma (Rb), contributing to HNSCC pathogenesis. P16 immunohistochemistry (IHC) is a reliable surrogate marker for HPV16 positivity, while in situ hybridization and polymerase chain reaction (PCR) techniques, notably reverse transcription-quantitative PCR (RT-qPCR), offer sensitive HPV detection. Liquid-based RT-qPCR, especially in saliva, shows promise for noninvasive HPV detection, offering simplicity, cost-effectiveness, and patient compliance. These molecular advancements enhance diagnostic accuracy, guide treatment decisions, and improve patient outcomes in HNC management. In conclusion, advances in HPV detection and molecular understanding have significant clinical management implications. Integrating these advancements into routine practice could ultimately improve patient outcomes.

Cytauxzoon felis in salivary glands of Amblyomma americanum

Cytauxzoon felis is a tick-borne piroplasmid hemoparasite that causes life-threatening disease in cats. Despite the critical role that ticks play in pathogen transmission, our knowledge regarding the C. felis life cycle remains limited to the feline hosts. Specific life stages of C. felis within the tick host have never been visualized microscopically and previous investigations have been limited to molecular detection by polymerase chain reaction (PCR). Sporozoites are the infectious stage of piroplasmids that are transmitted by ticks. In other tick-borne piroplasmids, sporozoite-based vaccines play a key role in disease prevention and management. We believe sporozoites have similar potential for cytauxzoonosis. Therefore, the objective of this study was to use different molecular and microscopic techniques to detect and evaluate C. felis sporozoites in tick salivary glands (SG). A total of 140 Amblyomma americanum adults that were fed on C. felis-infected cats as nymphs were included for this study. Specifically, dissected SGs were quartered and subjected to C. felis RT-PCR, RNAscope® in situ hybridization (ISH), histology, direct azure staining, and transmission electron microscopy (TEM). Cytauxzoon felis RT-PCR was also performed on half tick (HT) carcasses after SG dissection. Cytauxzoon felis RNA was detected in SGs of 17/140 ticks. Of these, 7/17 ticks had microscopic visualization via ISH and/or TEM. The remaining 10/17 ticks had only molecular detection of C. felis in SGs via RT-PCR without visualization. Cytauxzoon felis RNA was detected solely in HT carcasses via RT-PCR in 9/140 ticks. In ISH-positive tick SGs, hybridization signals were present in cytoplasms of SG acinar cells. TEM captured rare C. felis organisms with characteristic ultrastructural features of sporozoites. This study describes the first direct visualization of any developing stage of C. felis in ticks. Forthcoming studies should employ a combination of molecular and microscopic techniques to investigate the C. felis life cycle in A. americanum.

Small cell neuroendocrine carcinoma of vagina: Report of a unique case with literature review

Small cell carcinoma (SCC) of vagina is extremely rare. The association between this tumor and high-risk HPV infection is unclear. To our knowledge, HPV status has been reported in only 3 previous cases of SCC of vagina. Herein, we present a unique case of vaginal small cell carcinoma with discordant HPV testing results between vaginal and cervical samples. We also review and discuss findings from previously reported cases of small cell carcinoma of vagina.

Development of Quantitative Rapid Isothermal Amplification Assay for Leishmania donovani

Quantification of pathogen load, although challenging, is of paramount importance for accurate diagnosis and clinical management of a range of infectious diseases in a point-of-need testing (PONT) scenario such as in resource-limited settings. We formulated a quantification approach to test the standard-curve based absolute quantification ability of isothermal recombinase polymerase amplification (RPA) assay. As a test of principle, a 10-fold dilution series of Leishmania donovani (LD) genomic DNA prepared in nuclease-free-water (NFW), and from culture-spiked-blood (CSB) were tested, and a 15 min assay was performed. A modified algorithm was formulated to derive the detection outcome. The threshold-record times (Tr) in seconds thus obtained were plotted against the initial load of parasite genomes for log-linear regression analysis. The quantitative RPA (Q-RPA) assay was further evaluated against a LD quantitative (q)-PCR assay with DNA extracted from visceral and post-Kala-azar dermal leishmaniasis case specimens and stratified into different ranges of threshold cycle (Ct). The best-fitted regression models were found linear with mean r²/root mean square error (RMSE) values of residual points (in seconds) estimated as 0.996/8.063 and 0.992/7.46 for replicated series of NFW and CSB, respectively. In both series, the lower limit of detection reached less than 0.1 parasite genome equivalent DNA. Absolute agreement between Q-RPA and LD-qPCR was found for test positivity, and strong positive correlations were observed between the Tr and Ct values (r = 0.89; p < 0.0001) as well as between the absolute parasite loads (r = 0.87; p < 0.0001) quantified by respective assays. The findings in this very first Q-RPA assay for leishmaniasis are suggestive of its potential in monitoring LD load in clinical specimens, and the development of rapid Q-RPA assays for other infectious diseases.

Canine bocavirus-2 infection and its possible association with encephalopathy in domestic dogs

Canine bocaviruses (CBoVs) have been recognized as pathogens associated with intestinal diseases. Hematogenous spreading caused by CBoV has been documented and may potentiate the virus entry across the blood-brain barrier to initiate a brain infection. This study focused attention on CBoV detection in cases of encepahlopathy and attempted to determine its viral localization. A total of 107 dog brains that histologically exhibited encephalopathy (ED) were investigated for the presence of CBoVs using polymerase chain reaction (PCR). Thirty-three histologically normal brain samples from dogs were used as a control group (CD). CBoV-2 was detected in 15 ED dogs (14.02%) but not in CD dogs (p = 0.02), while no CBoV-1 and -3 were detected. Among the CBoV-2 positive dogs, brain histological changes were characterized by nonsuppurative encephalitis, with inclusion body-like materials in some brains. In situ hybridization (ISH) and transmission electron microscopy (TEM) confirmed the presence of CBoV-2 viral particles in glial cells, supporting neurotropism of this virus. ISH signals were also detected in the intestines, lymphoid organs, and the heart, suggesting both enteral and parenteral infections of this virus. Whole genome characterization and evolutionary analysis revealed genetic diversity of CBoV-2 sequences and it was varying among the different countries where the virus was detected. This study points to a possible association of CBoV-2 with encephalopathy in dogs. It also highlights the genetic diversity and cellular tropism of this virus.

Role of High-Risk HPV Detected by PCR in Malignant Sinonasal Inverted Papilloma: A Meta-Analysis

INTRODUCTION

Prior studies suggest that there may be a link between human papillomavirus (HPV) infection and malignant sinonasal inverted papilloma (SNIP). This systematic review and meta-analysis was performed to further evaluate this potential association.

STUDY DESIGN

Systematic review with meta-analysis.

METHODS

The Medline and Embase databases were used to identify case-control studies reporting the risk of malignant SNIP in patients with high-risk HPV subtypes identified by polymerase chain reaction (PCR). Meta-analysis was performed to determine pooled odds ratios (ORs) and 95% confidence intervals (CI).

RESULTS

Twenty-one studies were identified, including a total of 841 subjects with SNIP. Seventeen studies were included in the final analysis, as four studies did not have any HPV-positive tumors in either group. A total of 56 malignant SNIP and 551 benign SNIP were ultimately identified. The pooled log-OR was 1.80 (95% CI: 1.03-2.57) for all high-risk HPV subtypes. Stratification by high-risk HPV subtype showed a log-OR of 1.67 (95% CI: 0.88-2.46) for HPV-16 and log-OR of 2.68 (95% CI: 1.30-4.05) for HPV-18.

CONCLUSION

Infection with high-risk HPV subtypes may be associated with an increased risk of malignant SNIP. HPV-18 showed the greatest overall average effect size of the common high-risk subtypes.

LEVEL OF EVIDENCE

n/a Laryngoscope, 2021.

Incidence OF HPV and EBV in oral cancer and their clinico-pathological correlation- a pilot study of 108 cases

Introduction

Out of all non-communicable diseases, cancer is the leading cause of death in the 21st century. Oral cancer ranks in top ten cancers in the world and oncogenic viruses contribute to its development and are a major preventable risk factor for it.

Material and methods

In the present study we intend to find the incidence of HPV and EBV by PCR in 108 sporadic oral cancer patients and study the clinico-pathological variables in agreement to their presence or absence.

Results

We found that the incidence of EBV in oral cancer is much higher (30/108; 27.8%) than HPV 16 (14/108; 13%) and, a complete absence of HPV 18 (0/108) was reported by real time PCR. Co-infection by EBV and HPV was reported in 5.6% cases (6/108). However, on comparing this data with the corresponding clinico-pathological cofactors (age, gender, grade of tumour, tumour size, nodal status, metastasis, DOI, TIL, ENE) it was found that there was no statistical significance between the two.

Conclusion

Hence, we conclude that these oncogenic viruses are independent cofactors to oral cancer development and none of the clinico-morphologic variable is associated with the viral etiology.

Deep brain stimulation effects on learning, memory and glutamate and GABAA receptor subunit gene expression in kindled rats

Epileptic seizures are accompanied by learning and memory impairments. In this study, the effect of low frequency stimulation (LFS) on spatial learning and memory was assessed in kindled animals and followed for one month. Fully kindled rats received LFS at 4 times (immediately, 6 h, 24 h and 30 h following the final kindling stimulation). Applying LFS improved kindled animals' performance in the Barnes maze test. This LFS action was accompanied by a decrease in NR2B gene expression, an increase in the gene expression of the α subunit of calcineurin A and an increased NR2A/NR2B ratio in kindled animals. In addition, the gene expression of the GABA_A receptor γ₂ subunit increased at 2-3 h after applying LFS. The increase in NR2A/NR2B ratio was also observed 1 week after LFS. No significant changes were observed one month after LFS administration. Field potential recordings in the hippocampal CA1 area showed that kindling-induced potentiation of the field EPSP slope returned to near baseline when measured 2-3 h after applying LFS. Therefore, it may be postulated that applying LFS in kindled animals reduced the seizure-induced learning and memory impairments, albeit time-dependently. In tandem, LFS prevented kindling-induced alterations in gene expression of the described proteins, which are potentially important for synaptic transmission and/or potentiation. Moreover, a depotentiation-like phenomenon may be a possible mechanism underlying the LFS action.

Epileptic seizures are accompanied by learning and memory impairments. In this study, the effect of low frequency stimulation (LFS) on spatial learning and memory was assessed in kindled animals and followed for one month. Fully kindled rats received LFS at 4 times (immediately, 6 h, 24 h and 30 h following the final kindling stimulation). Applying LFS improved kindled animals’ performance in the Barnes maze test. This LFS action was accompanied by a decrease in NR2B gene expression, an increase in the gene expression of the α subunit of calcineurin A and an increased NR2A/NR2B ratio in kindled animals. In addition, the gene expression of the GABA_A receptor γ₂ subunit increased at 2–3 h after applying LFS. The increase in NR2A/NR2B ratio was also observed 1 week after LFS. No significant changes were observed one month after LFS administration. Field potential recordings in the hippocampal CA1 area showed that kindling-induced potentiation of the field EPSP slope returned to near baseline when measured 2–3 h after applying LFS. Therefore, it may be postulated that applying LFS in kindled animals reduced the seizure-induced learning and memory impairments, albeit time-dependently. In tandem, LFS prevented kindling-induced alterations in gene expression of the described proteins, which are potentially important for synaptic transmission and/or potentiation. Moreover, a depotentiation-like phenomenon may be a possible mechanism underlying the LFS action.

The Clinical Relevance of p16 and p53 Status in Patients with Squamous Cell Carcinoma of the Vulva

Objective

To investigate the prognostic significance of HPV status in vulvar squamous cell carcinomas (VSCC) and to determine whether preoperative determination of p16 or p53 status would have clinical relevance.

Methods

Patients treated for VSCC at a tertiary hospital in Sydney, Australia, from 2002 to 2014, were retrospectively evaluated (n = 119). Histological specimens were stained for p53 and p16 expression, and HPV status was determined by PCR detection of HPV DNA.

Results

HPV DNA was detected in 19%, p16 expression in 53%, and p53 expression in 37% of patients. Kaplan-Meier survival estimates indicated that p16/HPV-positive patients had superior five-year disease-free survival (76% versus 42%, resp., p = 0.004) and disease-specific survival (DSS) (89% versus 75% resp., p = 0.05) than p53-positive patients. In univariate analysis, nodal metastases (p < 0.001), tumor size >4 cm (p = 0.03), and perineural invasion (p = 0.05) were associated with an increased risk of disease progression and p16 expression with a decreased risk (p = 0.03). In multivariable analysis, only nodal metastases remained independent for risk of disease progression (p = 0.01). For DSS, lymph node metastases (p < 0.001) and tumor size (p = 0.008) remained independently prognostic.

Conclusion

The p16/HPV and p53 status of VSCC allows separation of patients into two distinct clinicopathological groups, although 10% of patients fall into a third group which is HPV, p16, and p53 negative. p16 status was not independently prognostic in multivariable analysis. Treatment decisions should continue to be based on clinical indicators rather than p16 or p53 status.

Free convective PCR: From principle study to commercial applications-A critical review

Polymerase chain reaction (PCR) is an extremely important tool for molecular diagnosis, as it can specifically amplify nucleic acid templates for sensitive detection. As another division of PCR, free convective PCR was invented in 2001, which can be performed in a capillary tube pseudo-isothermally within a significantly short time. Convective PCR thermal cycling is implemented by inducing thermal convection inside the capillary tube, which stratifies the reaction into spatially separate and stable melting, annealing, and extension zones created by the temperature gradient. Convective PCR is a promising tool that can be used for nucleic acid diagnosis as a point-of-care test (POCT) due to the significantly simplified heating strategy, reduced cost, and shortened detection time without sacrificing sensitivity and accuracy. Here, we review the history of free convective PCR from its invention to development and its commercial applications.

A fluorometric hybridization assay for detecting and genotyping high-risk human papillomavirus 16 and 18 in archival tissues of cervical specimens

Early diagnosis and genotyping of high-risk human papillomavirus (HR-HPV) in cervical tissue specimens is significant for cervical cancer prevention. A sensitive microplate fluorometric hybridization assay (MFHA) was designed for the detection of HPV DNA 16 and 18 in cervical tissue. Following optimization and validation of the method, 60 formalin-fixed and paraffin-embedded cervical samples representing different cervical intraepithelial neoplasia grades of HPV-associated lesions were tested to determine the sensitivity and specificity of the assay. Using consensus GP5+/6+ biotin-labeled primers to amplify a conserved region within the L1 gene, the amplicons were added to the microplate wells coated with specific probes for the hybridization of HPV 16 and 18 individually. Final detection was performed with streptavidin-AlexaFluor488 conjugated. The results were then compared with type-specific nested polymerase chain reaction (PCR) and colorimetric microplate assay. While the agreement between the results obtained by the type-specific nested PCR and fluorometric assay for the detection of both HR-HPV types was 100%, this agreement for the detection of HPV type 16 and 18 using microplate colorimetric assay was 94.2% and 85% respectively. Overall, the results of the fluorometric and colorimetric assays are promising for detecting both HR-HPV types in a large number of cervical tissue samples with the higher MFHA assay sensitivity.

Prevalence of human papillomavirus genotypes in cervical cancer in Maiduguri, Nigeria

INTRODUCTION

Cervical cancer is the commonest gynaecological malignancy and the second most common cancer among women worldwide. Several epidemiological, clinical and molecular studies have strongly implicated oncogenic high-risk human papillomavirus infection in the aetiopathogenesis of cervical cancer. The objectives of this study were to determine the cervical HPV prevalence and genotype distribution in cervical cancer in Maiduguri, Nigeria.

METHODS

This was a descriptive and retrospective study. Sixty-three archived paraffin-embedded tissue blocks with confirmed diagnoses of cervical cancer during the study period (2013-2015) were retrieved and examined. The procedure included deparaffinization of tissue samples, DNA extraction, PCR, gel electrophoresis, and HPV genotyping by reverse hybridization line probe assay.

RESULTS

Sixty-three cervical cancer cases were subjected to genomic DNA extraction and HPV-DNA detection by PCR. Fifty-eight samples showed PCR positivity while 5 samples were PCR negative. HPV-specific DNA was detected in 44 of the 58 PCR-positive samples and thus the prevalence was 69.8%. Ten different high-risk HPV genotypes were detected. Both single and multiple high-risk HPV infections were observed. The most prevalent type of the human papillomavirus detected was HPV16.

CONCLUSION

HPV-DNA was prevalent in majority of the examined cervical cancer tissues and that HPV16, HPV18, HPV45, HPV51 and HPV52 were the predominant HPVs detected in both single and multiple HPV infections. The results of this study and further studies will provide more detailed information about HPV and may contribute significantly to the prevention of cervical cancer through primary high-risk HPV testing and HPV vaccination against the oncogenic viruses.

Expression of AMHR2 and C-KIT in cervical lesions in Uyghur Women of Xinjiang, China

BACKGROUND

Cervical cancer is one of the most common malignant tumors in women. Anti-Müllerian hormone receptor 2 (AMHR2) and C-Kit were two members of protein kinase which were reported increased in some cancers like ovarian carcinoma and breast cancer. The present study aimed to assess the expression of AMHR2 and c-Kit in cervical cancer of different differentiated degrees as well as in cervicitis sections.

METHODS

All the lesions were collected randomly during clinical observations in hospitals located in Xinjiang, China. Polymerase chain reaction (PCR) and immunohistochemical staining were used to detect AMHR2 and c-Kit expression in cervical samples from women who had been infected with human papilloma virus (HPV)16. The expression rate was compared between cervical cancer of well, moderately and poorly differentiated and cervicitis.

RESULTS

The average age of the patients was 45 years; ranged from 23 to 80. For AMHR2, all 17 cervicitis samples ranged from (++) to (++++), while cervical cancer showed 11 (+), 9 (++), 15 (+++),9 (++++), and 8 (-), which showed AMHR2 expression was lessen with the poorer of differentiation degree of cervical cancer (P < .05). For c-Kit, 18 cervicitis samples mainly expressed as (-) with none showed (+++) or (++++), while cervical cancer samples showed 7 (-), 6 (+), 1 (++), 2 (+++), and 8 (++++), which indicated c-Kit's expression increased with the reduction of cervical cancer's differentiation degree (P < .05).

CONCLUSION

AMHR2 might have some correlation with self defense of our body, while c-Kit might link with the potential invasive capacity of cervical cancer.

High-risk and low-risk human papilloma virus in association to spontaneous preterm labor: a case-control study in a tertiary center, Egypt

INTRODUCTION

This study aimed to detect the correlation between human papillomavirus (HPV) and spontaneous preterm labor in Egyptian women and its association to the human papilloma viral load and MPP2 gene expression.

MATERIAL AND METHODS

We performed an observational comparative case-control study in Department of Obstetric and Gynecology, Mansoura University Hospitals over women presented with spontaneous preterm labor, besides females admitted for giving birth at full term to detect conserved sequence in HPV-L1 gene (GP5/GP6) followed by genotype detection of high- and low-risk HPVs with quantification of the viral load and the MMP2 gene expression using real-time polymerase chain reaction (PCR).

RESULTS

The prevalence of HPV was 18.1% in preterm females, but only 4% in full-term women (p value = 0.019*). Twenty percent were PCR positive for HPV 16 and 40% for HPV 18 whereas none of the control was positive for any of the studied high-risk genotypes. Thirty percent were PCR positive for HPV 6 and 10% were positive for HPV 11. MMP2 gene expression was significantly higher in preterm than full term. Human papilloma viral load was found to be positively correlated to the rate of MMP2 expression and the gestational age was significantly related to the viral load and the rate of expression of MMP2 gene.

CONCLUSION

Human pabilloma virus especially high-risk genotypes was correlated to spontaneous preterm labor in Egyptian females through increasing early expression of MMP2 gene. The time of occurrence of preterm labor was affected by the viral load and so the rate of expression of MMP2 gene.

Elevated Expression of Ox2R in Cervical Cancers and Placentas of Uyghur Women in Xinjiang, China

Objective:

Cervical cancer is one of the major causes of mortality of Uyghur women in Xinjiang, China. Although increased expression of orexin receptor (OxR), known to be strongly expressed in human placenta, has a proven relation to some cancers, there have been few studies of cervical cancer. Thus, we explored this question by evaluating the expression of orexin receptor as a biomarker for screening early stage of cervical cancer in Uyghur women with highest occurrence rate of cervical cancer in China.

Study Design:

We used polymerase chain reaction (PCR) and immunohistochemical staining to determine the expression of both Ox1R and Ox2R in cervical cancer and cervicitis biopsies collected from Uyghur women infected with human papilloma virus (HPV)16. The expression rate was compared between cervical cancers of low, intermediate and high differentiation and cervicitis.

Results:

Although there was no significant difference in the expression rate of Ox1R between groups, Ox2R was significantly overexpressed in cervical cancer patients when compared to the cervicitis group. Ox1R was negative in normal human placenta while Ox2R was positive.

Conclusions:

While expression of Ox1R had no correlation with invasion or metastatic potential, Ox2R demonstrated elevation in cervical cancer with heterogeneity in groups with different metastatic potential, in the human placenta as well, implying that it might serve as an indicator of invasive capacity along with other indices.

Human Papillomavirus (HPV) - structure, epidemiology and pathogenesis

The number of cancers is constantly increasing. An important role in the etiology of many of them is played by the viral factor, by oncogenic viruses, such as the Human Papillomavirus. The article shows current epidemiological situation and describes the structure of the virus and modes of transmission. It also explains the role of HPV infection in cancer with particular emphasis on oropharynx and head and neck cancer. Summarizing, HPV infection plays an important role in carcinogenesis of the oropharynx tumors. The presence of viral genetic material in the tumor may influence prognosis and treatment method choices.

High-risk human papillomavirus infection in different histological subtypes of renal cell carcinoma

Limited data exist regarding whether a high-risk human papillomavirus (HR-HPV) infection increases the risk of developing renal cell carcinoma. The aim of this study was to investigate whether HPV infection has a role in the pathogenesis or development of a certain histological subtype of renal cell carcinoma. Formalin-fixed paraffin-embedded (FFPE) specimens of 122 patients with histopathologically proven renal cell carcinoma and their respective peritumoral tissues were examined. The presence of HPV-DNA was determined by a combination of MY/GP+ consensus primers and HPV-16/18 type specific nested PCRs followed by direct sequencing. Catalyzed signal-amplified colorimetric in situ hybridization (CSAC-ISH) technique was applied to determine the physical status of viral genome. The expression of p16INK4a and HPV L1 capsid proteins was evaluated using immunohistochemistry. HPV genome was detected in 37 (30.3%) tumor specimens and their four (4.1%) corresponding peritumoral tissues. HPV-18 was the most common viral type identified followed by HPV-16 and 58. Immunoexpression of p16INK4a was detected in 24 (20.3%) cases. Data analysis showed a significant correlation between p16INK4a expression and the presence of HR-HPV DNA (P < 0.001). CSAC-ISH analysis confirmed HR-HPV infection in 45% of tumors, which were previously tested positive for HPV-DNA. Diffuse signal pattern was identified in 15 (83.3%) samples whereas a mixed pattern of diffuse and punctate signals was only detectable in three cases. The results indicate an association of HR-HPV types with renal cell carcinoma. It is proposed that HPV infection in high-grade tumors might precede disease progression in a number of tumors, particularly of the papillary subtype.

Reduced expression of members of the mhc-i antigen processing machinery in ethnic Uighur women with cervical cancer in the Xinjiang region of China

OBJECTIVE

Cervical cancer is a major cause of mortality in Uighur women compared with Han women in the Xinjiang region of China. Although a reduction in the class i major histocompatibility complex (mhc-i) antigen processing machinery (apm) is associated with the development of cervical cancer, the mhc-i apm has not been studied in this particular group of women, who have the highest incidence rate of cervical cancer in China.

STUDY DESIGN

We used immunohistochemical staining and polymerase chain reaction amplification of viral dna from infection with the human papilloma virus (hpv) to study the expression of members of the mhc-i apm in cervical cancer sections collected from Uighur and Han women and in cervicitis samples from age-matched counterparts.

RESULTS

Expression of the molecules of interest was compared between two ethnic groups, and expression of transporter associated with antigen processing 1 and 2, heat shock protein 90, and calnexin were found to be reduced even more significantly in Han women with cervical cancer than in Uighur women with same disease. However, compared with Han women, Uighur women had a higher rate of infection with hpv 16.

CONCLUSIONS

The mhc-i apm were reduced in cervical cancer, with heterogeneity in the two ethnic groups. The reduction was more pronounced in Han women, who less frequently had hpv 16 infection, suggesting possible differences in the roles of members of the mhc-i apm and in the mechanisms of cervical cancer development in these two ethnic groups despite residence in the same region of China.

Lack of schmallenberg virus in ruminant brain tissues archived from 1961 to 2010 in Germany

Schmallenberg virus (SBV) is an orthobunyavirus of the family Bunyaviridae that is associated with stillbirth and malformations in ruminants. The infection has been identified in many European countries since August 2011. The present study investigated retrospectively the occurrence of SBV infection in ruminants using immunohistochemistry and in-situ hybridization in brain tissues archived between 1961 and 2010 (112 cattle, 57 sheep, 16 goats and 27 wild ruminants). Eighty-five animals with inflammatory brain lesions and 47 animals with malformations were included. Due to the lack of SBV protein and RNA detection, SBV appears to have been introduced recently into Northern parts of Europe from tropical or subtropical regions.

Is human papillomavirus associated with prostate cancer survival?

The role of human papillomavirus (HPV) in prostate carcinogenesis is highly controversial: some studies suggest a positive association between HPV infection and an increased risk of prostate cancer (PCa), whereas others do not reveal any correlation. In this study, we investigated the prognostic impact of HPV infection on survival in 150 primary PCa patients. One hundred twelve (74.67%) patients had positive expression of HPV E7 protein, which was evaluated in tumour tissue by immunohistochemistry. DNA analysis on a subset of cases confirmed HPV infection and revealed the presence of genotype 16. In Kaplan-Meier analysis, HPV-positive cancer patients showed worse overall survival (OS) (median 4.59 years) compared to HPV-negative (median 8.24 years, P = 0.0381). In multivariate analysis age (P < 0.001), Gleason score (P < 0.001), nuclear grading (P = 0.002), and HPV status (P = 0.034) were independent prognostic factors for OS. In our cohort, we observed high prevalence of HPV nuclear E7 oncoprotein and an association between HPV infection and PCa survival. In the debate about the oncogenic activity of HPV in PCa, our results further confirm the need for additional studies to clarify the possible role of HPV in prostate carcinogenesis.

Expression of 17β-hydroxysteroid dehydrogenase type 1 in gastric cancer

There are several findings suggesting the protective role of estrogens in gastric carcinogenesis. Extragonadal 17β-estradiol (E2) may be formed during estrone (E1) reduction to E2 by 17-β-hydroxysteroid dehydrogenase type 1 (HSD17B1). Therefore, we studied the HSD17B1 transcript and protein levels in primary nontumoral and tumoral gastric tissue from the same 21 patients with gastric cancer (GC). We also assessed the effect of 5-Aza-2'-deoxycytidine (5-dAzaC), on the methylation status of HSD17B1 and its expression and conversion of E1 to E2 in HGC-27 and EPG 85-257 GC cells. We identified the presence of HSD17B1 transcript and protein in HGC-27 and EPG 85-257 GC cells as well as in primary nontumoral and tumoral tissues from patients with GC. Moreover, we found that 5-dAzaC significantly up-regulated the HSD17B1 transcript and protein levels, which is associated with increased conversion of E1 to E2 in HGC-27 and EPG 85-257 GC cells. The changes in HSD17B1 expression in both HGC-27 and EPG 85-257 cells were accompanied by 5-dAzaC induced DNA demethylation in the 5' flanking region. Our results demonstrated that HSD17B1 expression and its ability to convert the weak estrogen E1 to the more potent E2 can be associated with DNA methylation in the 5' flanking region in GC cells.

Laboratory-developed L1 sequencing and type-specific, real-time polymerase chain reaction for the detection and typing of human papillomaviruses in formalin-fixed, paraffin-embedded tissues

CONTEXT

The detection and typing of high-risk and low-risk human papillomavirus (HPV) in archival formalin-fixed, paraffin-embedded tissues by nucleic acid amplification testing is an important adjunct to immunohistochemical staining in evaluation of squamous cell proliferations of the oropharynx, larynx, and anal canal.

OBJECTIVE

To evaluate semiautomated, xylene-free extraction from formalin-fixed, paraffin-embedded tissues combined with laboratory-developed HPV L1 sequencing and type-specific HPV 6, 11, 16, and 18 real-time polymerase chain reaction for identification and typing of HPV in the clinical laboratory.

DESIGN

We evaluated the adequacy of extraction using β-globin amplification and compared L1 sequencing and real-time polymerase chain reaction methods for typing accuracy using 68 formalin-fixed, paraffin-embedded tissues, including 56 anorectal biopsy or surgical resection specimens and 12 laryngeal papilloma specimens from patients with recurrent respiratory papillomatosis.

RESULTS

Adequate DNA was obtained from 68 of 68 specimens analyzed and all were HPV positive. In 47 cases where L1 sequencing demonstrated that the predominant HPV type was 6, 11, 16, or 18, type-specific, real-time polymerase chain reaction provided concordant results. Sequencing revealed additional low-risk (HPV 40) and high-risk HPV types (HPV 31, 33, 56, and 58) in anorectal specimens, whereas HPV 6 or 11 were the types found in laryngeal papillomas.

CONCLUSION

Both L1 sequencing and type-specific, real-time polymerase chain reaction are suitable methods for routine HPV testing of formalin-fixed, paraffin-embedded tissues in a clinical laboratory setting.

Urothelial carcinoma with prominent squamous differentiation in the setting of neurogenic bladder: role of human papillomavirus infection

Squamous cell carcinomas of the urinary bladder are rare in the Western world; the majority of cases are reported in countries endemic to Schistosoma parasitic infections. Unlike squamous tumors of the uterine cervix or oropharynx, the human papillomavirus (HPV) is not commonly associated with bladder squamous cell carcinomas. We report on two cases of HPV-positive urothelial carcinomas of the urinary bladder with extensive squamous differentiation showing the typical basaloid, poorly differentiated morphology of HPV-associated tumors. These occurred in patients with neurogenic bladders who had long-standing histories of self-catheterization with tumors that tested positive for HPV by in situ hybridization. A retrospective review of our institutional database revealed four additional patients with bladder tumors showing squamous differentiation arising in the setting of neurogenic bladder. Review of these cases showed the more common well-differentiated keratinizing appearance of squamous cell carcinomas of the bladder. These tumors showed only patchy positivity for p16 immunohistochemical stain (not the diffuse strong staining seen in HPV-positive tumors), and the one tested case was negative for HPV by in situ hybridization. HPV infection and neurogenic bladder have been independently associated with increased risk of developing carcinoma in the urinary bladder; however, this is the first report of squamous tumors arising in the setting of concurrent neurogenic bladder and HPV infection. The morphology of these tumors is similar to that of other high-risk HPV-associated squamous carcinomas with a basaloid, poorly differentiated appearance and little to no keratin formation.

A novel multiplex real-time PCR assay for the detection and quantification of HPV16/18 and HSV1/2 in cervical cancer screening

Infection with human papillomavirus (HPV), particularly HPV16 and HPV18, is the main cause of invasive cervical cancer, although other factors such as herpes simplex virus (HSV) may act in conjunction with HPV in this context. To explore the possibility of developing a system for rapid diagnosis and clinical screening of cervical cancer, we developed a multiplex real-time PCR assay that can simultaneously detect and quantify HPV16/18 and HSV1/2. To evaluate its possibilities and practical uses, 177 samples collected from patients with suspected HPV and HSV infection in exfoliated cervical cells, genital herpes or labial herpes were tested by multiplex real-time PCR and compared with results obtained by DNA sequencing. Each virus was detected over a range from 1.0 × 10(1) to 1.0 × 10(7) copies/reaction. The clinical sensitivity was 100% for HPV16/18 and HSV1/2. The clinical specificity was 97.1% for HPV16, 98.1% for HPV18, 97.0% for HSV1 and 96.0% for HSV2. The kappa value was 0.96 for HPV16, 0.92 for HPV18, 0.94 for HSV1 and 0.93 for HSV2, when DNA sequencing was used as the reference standard. In summary, this novel multiplex real-time PCR allows the rapid and specific detection of HPV16/18 and HSV1/2, as well as coinfection with HPV and HSV, in clinical samples. In the future, this multiplex real-time PCR assay will assist in cervical cancer screening, viral treatment evaluation and epidemiological studies in which high throughput analysis is required.

Expression pattern of class I histone deacetylases in vulvar intraepithelial neoplasia and vulvar cancer: a tissue microarray study

BACKGROUND

Epigenetic regulation is an important mechanism leading to cancer initiation and promotion. Histone acetylation by histone deacetylases (HDACs) represents an important part of it. The development of HDAC inhibitors has identified the utility of HDACs as a therapeutic target. Little is known about the epigenetic regulation of vulvar intraepithelial neoplasia (VIN) and vulvar squamous cell cancer (VSCC). In this study, the expression of class I HDACs (HDAC 1, 2 and 3) was compared in a series of VIN and VSCC tissues.

METHODS

A tissue micro array (TMA) with specimens from 106 patients with high-grade VIN and 59 patients with vulvar cancer was constructed. The expression of HDACs 1, 2 and 3 were analyzed with immunohistochemistry (IHC). The nuclear expression pattern was evaluated in terms of intensity and percentage of stained nuclei and was compared between vulvar preinvasive lesions and vulvar cancer.

RESULTS

HDAC 2 expression was significantly higher in VIN than in VSCC (p < 0.001, Fisher's test). Also, 88.7% (n = 94/106) of VIN samples and only 54.5% (n = 31/57) of VSCC samples were scored at the maximum level. Conversely, HDAC 3 expression was significantly higher in VSCC (93%, 53/57) compared to VIN (73.6%, 78/106, p = 0.003), whereas only a small difference in the expression of HDAC 1 was found between these two entities of vulvar neoplasia.

CONCLUSIONS

These results suggest that epigenetic regulation plays a considerable role in the transformation of VIN to invasive vulvar neoplasia.

Evaluation of two commercialised in situ hybridisation assays for detecting HPV-DNA in formalin-fixed, paraffin-embedded tissue

INTRODUCTION

The role of human papilloma virus (HPV) in the pathogenesis of anogenital dysplasia is now conclusive. However, HPV detection in formalin-fixed and paraffin-embedded tissues remains controversial. Therefore, the aim of this study was to evaluate morphological changes directly in tissue specimens using a HPV-DNA detection system involving HPV in situ hybridisation.

MATERIALS AND METHODS

Samples from patients with cervical carcinoma were analysed using the GenPoint HPV DNA Probe Cocktail (Dako, Glostrup, Denmark) and the ZytoFast HPV Screening CISH-Kit (Zytomed, Berlin, Germany). Three cervical carcinoma cell lines with a well-defined HPV copy number per cell (SiHa, HeLa, and CaSki) served as positive controls for sensitivity testing, while two HPV-negative cell lines (AC-1M32, MCF-7) and brain tissue samples served as negative controls. Moreover, to assess the validity of the in situ hybridisation, the expression of HPV-16 DNA in cell lines was demonstrated by HPV-16 E6-specific PCR.

RESULTS

Both HPV-screening assays revealed strong signals of episomal and integrated HPV-DNA at a HPV copy number of more than 50 copies/cell. All cervical carcinoma samples were positive in the Dako assay, which identifies 13 high-risk HPV genotypes, whereas HPV-DNA could be detected in 9/10 cervical carcinoma samples using the Zytofast assay, identifying HPV 16, 18, 31, 33, and 35.

CONCLUSION

HPV in situ hybridisation is a convenient and powerful tool for detecting HPV-DNA in formalin-fixed and paraffin-embedded tissue samples. Therefore, this technique is suitable for analysis of a potential HPV infection using archival pathological slides.

Comparative analysis of four methods to extract DNA from paraffin-embedded tissues: effect on downstream molecular applications

Background

A large portion of tissues stored worldwide for diagnostic purposes is formalin-fixed and paraffin-embedded (FFPE). These FFPE-archived tissues are an extremely valuable source for retrospective (genetic) studies. These include mutation screening in cancer-critical genes as well as pathogen detection. In this study we evaluated the impact of several widely used DNA extraction methods on the quality of molecular diagnostics on FFPE tissues.

Findings

We compared 4 DNA extraction methods from 4 identically processed FFPE mammary-, prostate-, colon- and lung tissues with regard to PCR inhibition, real time SNP detection and amplifiable fragment size. The extraction methods, with and without proteinase K pre-treatment, tested were: 1) heat-treatment, 2) QIAamp DNA-blood-mini-kit, 3) EasyMAG NucliSens and 4) Gentra Capture-Column-kit.

Amplifiable DNA fragment size was assessed by multiplexed 200-400-600 bp PCR and appeared highly influenced by the extraction method used. Proteinase K pre-treatment was a prerequisite for proper purification of DNA from FFPE. Extractions with QIAamp, EasyMAG and heat-treatment were found suitable for amplification of fragments up to 400 bp from all tissues, 600 bp amplification was marginally successful (best was QIAamp). QIAamp and EasyMAG extracts were found suitable for downstream real time SNP detection. Gentra extraction was unsuitable. Hands-on time was lowest for heat-treatment, followed by EasyMAG.

Conclusions

We conclude that the extraction method plays an important role with regard to performance in downstream molecular applications.

Rapid, sensitive, type specific PCR detection of the E7 region of human papillomavirus type 16 and 18 from paraffin embedded sections of cervical carcinoma

Human papillomavirus (HPV) infection, and in particularly infection with HPVs 16 and 18, is a central carcinogenic factor in the uterine cervix. We established and optimized a PCR assay for the detection and discrimination of HPV types 16 and 18 in archival formaldehyde fixed and paraffin embedded (FFPE) sections of cervical cancer.

Tissue blocks from 35 cases of in situ or invasive cervical squamous cell carcinoma and surrogate FFPE sections containing the cell lines HeLa and SiHa were tested for HPV 16 and HPV18 by conventional PCR using type specific primers, and for the housekeeping gene β-actin. Using HPV 16 E7 primers, PCR products with the expected length were detected in 18 of 35 of FFPE sections (51%). HPV 18 E7 specific sequences were detected in 3 of 35 FFPE sections (9%).

In our experience, the PCR technique is a robust, simple and sensitive way of type specific detection of HPV16 and HPV18 genes in FFPE tissue. That makes this technique applicable to routine practices of HPV detection.

Human papillomavirus genotypes in anal intraepithelial neoplasia and anal carcinoma as detected in tissue biopsies

Human papillomavirus (HPV) infection strongly correlates with the development of anal intraepithelial neoplasias and carcinomas; however, few studies have characterized the distribution of the specific subtypes of the virus in the varying grades of dysplasia. This report characterizes the distribution of HPV 16/18 in surgical specimens with anal intraepithelial neoplasia (AIN) I-III and histological variants of anal carcinoma. A total of 111 anal surgical specimens with no dysplasia (10), AIN I-III (53), and anal carcinomas (48) were evaluated for the presence of high-risk HPV infection and subtyped by nested PCR or the Invader Assay. High-risk virus types were detected in progressively greater number of anal intraepithelial lesions from 56% in low grade to 88% in high grade. Type 16 was the prevalent subtype and was noted in 28% of low grade and 68% of high-grade lesions. Moderate dysplasias showed type 16 in 20%, a prevalence similar to that in low-grade lesions. The non-16/18 subtypes of the virus predominated and were present in 50% of the cases. Most (89%) squamous carcinomas were associated with high-risk viruses, 68% with type 16, a prevalence similar to that noted in high-grade dysplasia. Non-16/18 subtypes were encountered more frequently in squamous carcinomas from immunodeficient individuals (57% cases) as compared with immunocompetent individuals (18% cases). The similarity in the prevalence of type 16 in high-grade dysplasia and squamous carcinomas suggests that anal intraepithelial lesion III is the true precursor of squamous carcinoma and warrants aggressive management. Anal intraepithelial lesions II showed a virus distribution that was similar to low-grade dysplasia. In addition, a subset of these that were associated with type 16 or 18 showed progression, whereas those associated with non-16/18 subtypes regressed, thereby raising the possibility of conservative management for these lesions.

GP5+/6+ SYBR Green methodology for simultaneous screening and quantification of human papillomavirus

BACKGROUND

Detection and quantification of human papillomavirus (HPV) may help in predicting the evolution of HPV infection and progression of associated lesions.

OBJECTIVES

We propose a novel protocol using consensus primers GP5+/6+ in a SYBR Green quantitative real-time (Q-RT) polymerase chain reaction (PCR). The strategy permits screening for HPV infection and viral load quantification simultaneously.

STUDY DESIGN

DNA from 153 archived cervical samples, previously tested for HPV detection by GP5+/6+ PCR and typed by EIA-RLB (enzyme immunoassay-reverse line blot) or sequence analysis, was analysed using SYBR Green Q-RT PCR. Melting temperature assay (T(m)) and cycle threshold (C(t)) were used to evaluate HPV positivity and viral load. The T(m) in the range of 77-82 degrees C was considered to be positive for HPV-DNA. HPV results generated through GP5+/6+ conventional PCR were considered the gold standard against which sensitivity and specificity of our assay were measured.

RESULTS

Out of 104 HPV positive samples, 100 (96.2%) were also determined as positive by SYBR Green Q-RT PCR; of the 49 HPV-negative samples, all were determined as negative. There was an excellent positivity agreement (kappa=0.94) between the SYBR Green Q-RT and the previous methods employed. The specificity and sensitivity were 100% and 96.2%, respectively. Comparison of SYBR Green Q-RT and TaqMan oligo-probe technologies gave an excellent concordance (rho(c)=0.95) which validated the proposed strategy.

CONCLUSIONS

We propose a sensitive and easy-to-perform technique for HPV screening and viral load quantification simultaneously.

BD ProEx C immunostaining in extramammary Paget's disease and perineal melanoma

The differential diagnosis of perineal biopsies can include squamous intraepithelial lesions, extramammary Paget's disease, and melanoma. Less frequently two of these lesions coexist. BD ProEx C is a recently developed immunoassay that targets expression of two genes shown to be associated with cervical cancer. Immunostaining for ProEx C has been validated in cervical cytology and positive staining has also been shown to be strongly associated with human papilloma virus (HPV)-induced cervical and anal intraepithelial neoplasia in biopsies. We observed positive staining for ProEx C in Paget cells in all of 26 cases of Paget's disease irrespective of tissue site (extramammary, mammary) and in melanoma cells in all of 12 cases of primary perineal melanoma with immunostaining in >50% of malignant cells in 73% of Paget disease cases and 43% of perineal melanoma cases. Positive staining was heterogeneous and exclusively nuclear in all cases. In situ hybridization was negative for low-risk and high-risk HPV subtypes in all Paget and melanoma cases that were tested. Currently neither of these lesions is known to be HPV related although according to the literature the possibility of a role for HPV in melanoma is still unsettled. Relevant literature is reviewed.

HPV in situ hybridization signal patterns as a marker for cervical intraepithelial neoplasia progression

OBJECTIVE

HPV-DNA integration is one factor for malignant transformation and can be identified using in situ hybridization (ISH), where a diffuse signal represents episomal HPV and punctate, integrated. The aim is to verify if a punctate pattern could be a marker of CIN1 that progresses.

METHODS

74 CIN1 biopsies were studied. In the follow up, a second biopsy was performed and 65% showed CIN1 or no lesion (group without progression) and 35% CIN2/3 (with progression). ISH was carried out with HR-HPV GenPoint in the first biopsy looking for the positive distribution in epithelium regions (basal, intermediate, superficial) and reaction pattern (diffuse and punctate). The Mann-Whitney and Fisher tests were used to compare the groups (p<or=0.05).

RESULTS

The mean age of patients without progression was 26 and, with progression 31 (p=0.02). ISH was positive in 22 cases, 8 with CIN2/3 in the second biopsy. The punctate signal was observed in all epithelial layers, and the mean coefficient between the number of cells with punctate and diffuse signals was 3.5 times more common in the progression group (p=0.08). The average percentage of punctate nuclei patterns in the basal region in cases without progression was 0.5% and 11% in those with progression (p=0.05). However, in superficial layer this was not correlated with progression.

CONCLUSION

Progression was observed in 35% of CIN1 and associated with age; 30% of the cases were positive by ISH, but must be carefully interpreted. Punctate signals were related to progression only in basal cells, identifying CIN1 with potentially aggressive behavior.

Human papillomavirus DNA and e6/e7 mRNA status in relation to survival of patients treated for cervical squamous cell carcinoma

The prognostic significance of human papillomavirus (HPV) DNA and E6/E7 mRNA, the presence of specific types, and the physical state of HPV DNA, were studied in 202 cervical squamous cell carcinomas. Absence or non-detectable levels of high-risk (types 16, 18, 31, 33, 35, 45, 52 and 58) E6/E7 mRNA, using the real-time nucleic acid sequence based amplification (NASBA) assay, and absence of HPV high-risk/HPV 6, 26, 66, 69, 73 (all methods collectively) were associated with poor overall survival in univariate analysis (P = 0.04 and P = 0.03, respectively) and had independent prognostic value in multivariate analysis (P = 0.01 and P = 0.03, respectively) including FIGO stage and age. Based on the individual results of type-specific PCR and in situ hybridization (ISH), the presence of HPV DNA was not found to be a prognostic factor. Likewise, concerning the presence of specific HPV types and the HPV integration status (determined by ISH), no prognostic significance was found. Mutation analyses of the TP53 gene revealed mutations in 3 of the 6 HPV negative samples (50%).

Tobacco smoking and chewing as risk factors for multiple human papillomavirus infections and cervical squamous intraepithelial lesions in two countries (Côte d'Ivoire and Finland) with different tobacco exposure

Our objective was to compare the association between tobacco smoking and chewing and the risk of multiple human papillomavirus (HPV) infections and cervical squamous intraepithelial lesions (SILs) in two populations with different tobacco exposure. We studied 2,162 women from Côte d'Ivoire, West Africa, and 419 women from Finland, Northern Europe, with baseline data on cervical screening, HPV DNA status and smoking and chewing habits. The proportion of women who smoked and/or chewed tobacco was higher in Finland (36.8%) than in Côte d'Ivoire (3.7%), where tobacco chewing (2.6%) was more common than tobacco smoking (1.4%). Having multiple HPV infections was common in HPV16 and/or 18-infected women (60.4% in Finland and 47.2% in Côte d'Ivoire). There was no increased risk of multiple HPV infections among tobacco consumers. We found that women >or=30 years of age exposed to tobacco through smoking in Finland (OR: 2.2, 95% CI: 0.5-8.7) and chewing in Côte d'Ivoire (OR: 5.5, 95% CI: 2.1-14) had a moderately or highly increased risk of high-grade SIL, respectively. In the latter, the risk was statistically significant. Our findings emphasize the need for health initiatives targeted to prevent tobacco smoking or chewing among women especially in less industrialized countries.

Critical evaluation of HPV16 gene copy number quantification by SYBR green PCR

BACKGROUND

Human papilloma virus (HPV) load and physical status are considered useful parameters for clinical evaluation of cervical squamous cell neoplasia. However, the errors implicit in HPV gene quantification by PCR are not well documented. We have undertaken the first rigorous evaluation of the errors that can be expected when using SYBR green qPCR for quantification of HPV type 16 gene copy numbers. We assessed a modified method, in which external calibration curves were generated from a single construct containing HPV16 E2, HPV16 E6 and the host gene hydroxymethylbilane synthase in a 1:1:1 ratio.

RESULTS

When testing dilutions of mixed HPV/host DNA in replicate runs, we observed errors in quantifying E2 and E6 amplicons of 5-40%, with greatest error at the lowest DNA template concentration (3 ng/microl). Errors in determining viral copy numbers per diploid genome were 13-53%. Nevertheless, in cervical keratinocyte cell lines we observed reasonable agreement between viral loads determined by qPCR and Southern blotting. The mean E2/E6 ratio in episome-only cells was 1.04, but with a range of 0.76-1.32. In three integrant-only lines the mean E2/E6 ratios were 0.20, 0.72 and 2.61 (values confirmed by gene-specific Southern blotting). When E2/E6 ratios in fourteen HPV16-positive cervical carcinomas were analysed, conclusions regarding viral physical state could only be made in three cases, where the E2/E6 ratio was < or = 0.06.

CONCLUSION

Run-to-run variation in SYBR green qPCR produces unavoidable inaccuracies that should be allowed for when quantifying HPV gene copy number. While E6 copy numbers can be considered to provide a useable indication of viral loads, the E2/E6 ratio is of limited value. Previous studies may have overestimated the frequency of mixed episomal/integrant HPV infections.