Detection and genotyping of human papillomaviruses and their role in the development of ovarian carcinomas

High-Grade Serous Ovarian Cancer-A Risk Factor Puzzle and Screening Fugitive

High-grade serous ovarian cancer (HGSOC) is the most lethal tumor of the female genital tract. Despite extensive studies and the identification of some precursor lesions like serous tubal intraepithelial cancer (STIC) or the deviated mutational status of the patients (BRCA germinal mutation), the pathophysiology of HGSOC and the existence of particular risk factors is still a puzzle. Moreover, a lack of screening programs results in delayed diagnosis, which is accompanied by a secondary chemo-resistance of the tumor and usually results in a high recurrence rate after the primary therapy. Therefore, there is an urgent need to identify the substantial risk factors for both predisposed and low-risk populations of women, as well as to create an economically and clinically justified screening program. This paper reviews the classic and novel risk factors for HGSOC and methods of diagnosis and prediction, including serum biomarkers, the liquid biopsy of circulating tumor cells or circulating tumor DNA, epigenetic markers, exosomes, and genomic and proteomic biomarkers. The novel future complex approach to ovarian cancer diagnosis should be devised based on these findings, and the general outcome of such an approach is proposed and discussed in the paper.

Human Papillomaviruses as Infectious Agents in Gynecological Cancers. Oncogenic Properties of Viral Proteins

Human papillomaviruses (HPVs), which belong to the Papillomaviridae family, constitute a group of small nonenveloped double-stranded DNA viruses. HPV has a small genome that only encodes a few proteins, and it is also responsible for 5% of all human cancers, including cervical, vaginal, vulvar, penile, anal, and oropharyngeal cancers. HPV types may be classified as high- and low-risk genotypes (HR-HPVs and LR-HPVs, respectively) according to their oncogenic potential. HR-HPV 16 and 18 are the most common types worldwide and are the primary types that are responsible for most HPV-related cancers. The activity of the viral E6 and E7 oncoproteins, which interfere with critical cell cycle points such as suppressive tumor protein p53 (p53) and retinoblastoma protein (pRB), is the major contributor to HPV-induced neoplastic initiation and progression of carcinogenesis. In addition, the E5 protein might also play a significant role in tumorigenesis. The role of HPV in the pathogenesis of gynecological cancers is still not fully understood, which indicates a wide spectrum of potential research areas. This review focuses on HPV biology, the distribution of HPVs in gynecological cancers, the properties of viral oncoproteins, and the molecular mechanisms of carcinogenesis.

Human papillomavirus and ovarian cancer (review of literature and meta-analysis)

Many factors are involved in carcinogenesis of the ovary, such human genetic and physiological characteristics as lifestyle, existing diseases of the reproductive system, and, as suggested, the human papillomavirus (HPV). It is well known that the human papillomavirus virus of high carcinogenic risk (HCR) plays a crucial role in the onset and development of cervical cancer, as well as cases of HPV positive breast cancer and endometrial cancer. The data on the presence of HPV in ovarian cancer are ambiguous: the researchers claim that there is no complete effect of the virus on the development of this type of cancer, and the detection of HPV in 60-80% of tumors. In this regard, there is a need to systematize the currently available research results on this controversial issue and conduct a meta-analysis of the association of HPV infection with the risk of ovarian cancer.

Prevalence of human papillomavirus detection in ovarian cancer: a meta-analysis

We conducted a meta-analysis of published data to update and estimate the prevalence of HPV in ovarian cancer. A comprehensive literature search was performed according to the PRISMA guidelines. Eligible articles published from 1989 until 2020 by searching Web of Sciences, Pubmed, Embase, and the Cochrane Library Central databases were gathered. A pooled estimation of HPV prevalence with a 95% confidence interval (CI) was calculated based on a random effect model. Quantitative assessment of heterogeneity was explored using Cochrane test and I². Additionally, publication bias, sensitivity, meta-regression, and subgroup analyses were also performed. Twenty-nine studies involving 2280 patients with ovarian cancer were included. The statistical heterogeneity was high (I² = 88%, P<0.0001). The pooled prevalence of HPV in ovarian cancer cases was 15.9% (95% CI, 11–22). In subgroup analyses, the highest prevalence of HPV was reported by studies from Asia (30.9%; 95% CI, 20–44) and Eastern Europe (29.3%; 95% CI, 4.4–78). Furthermore, the most frequently detected HPV genotype was HPV16 (54%; 95% CI, 27.9–55), followed by HPV18 (23.2%; 95% CI, 18.8–28.2). Our meta-analysis suggests a great difference in the prevalence of HPV detected in ovarian cancer by different studies, which is not seen in strongly HPV-associated cancers such as cervical cancer. However, the prevalence varied markedly by geographic region. Considering the substantial heterogeneity found, more studies with control groups and precise assays measuring HPV mRNA expression are needed to further evaluate the link and causative aetiology between HPV and ovarian cancer.

Association of Human Papilloma Virus and Epstein-Barr Virus with Ovarian Cancer in Shiraz, Southwestern Iran

Background & Objective:

Ovarian cancer is one of the most common cancers amongst women. The association of Human papillomavirus (HPV) and Epstein-Barr virus (EBV) with ovarian cancer is inconclusive; therefore, the aims of this study were to evaluate the frequency of HPV and EBV in malignant, borderline, benign and normal ovarian tissues.

Methods:

In this case-control study, 205 Paraffin-embedded ovarian tissue specimens including 68 malignant, 27 borderline, 65 benign, and 45 normal tissues were included from December 2014 to January 2018 and subjected to DNA extraction. The β-globin gene was amplified using PCR to confirm the quality of the extracted DNA. The genomes of HPV (genotypes 16 and 18) and EBV were identified, using specific primers by PCR.

Results:

The mean age of participants was 43.42 ± 15.4 years. The frequency of HPV was statistically significant between malignant versus benign (P=0.02) and control groups (P=0.002), but not with borderline tumor group (P=0.78). Amongst HPV infected samples, 1 (4.5%) and 14 (63.6%) samples were infected with types 16 and 18, respectively. Also 4 (18.2 %) samples were infected with both genotypes. Eleven samples including 7(10.3%) malignant, 1 (3.7%) borderline, 3 (4.6%) benign and none (0%) of normal control groups were infected with EBV, which was statistically different between malignant and the normal control group (P=0.03).

Conclusion:

The results of our study showed the possible role of high risk HPVs as well as EBV in pathogenesis of ovarian cancer, and further studies are recommended to confirm these findings.

Factors in Oncogenesis: Viral Infections in Ovarian Cancer

Ovarian cancer (OC) is one of the leading causes of cancer death in women, with high-grade serous ovarian cancer (HGSOC) being the most lethal gynecologic malignancy among women. This high fatality rate is the result of diagnosis of a high number of new cases when cancer implants have already spread. The poor prognosis is due to our inadequate understanding of the molecular mechanisms preceding ovarian malignancy. Knowledge about the site of origination has been improved recently by the discovery of tube intraepithelial cancer (TIC), but the potential risk factors are still obscure. Due to high tumoral heterogeneity in OC, the establishment of early stage biomarkers is still underway. Microbial infection may induce or result in chronic inflammatory infection and in the pathogenesis of cancers. Microbiome research has shed light on the relationships between the host and microbiota, as well as the direct roles of host pathogens in cancer development, progression, and drug efficacy. While controversial, the detection of viruses within ovarian malignancies and fallopian tube tissues suggests that these pathogens may play a role in the development of OC. Genomic and proteomic approaches have enhanced the methods for identifying candidates in early screening. This article summarizes the existing knowledge related to the molecular mechanisms that lead to tumorigenesis in the ovary, as well as the viruses detected in OC cases and how they may elevate this process.

Detection and genotyping of CMV and HPV in tumors and fallopian tubes from epithelial ovarian cancer patients

Viral and bacterial infections are detected in epithelial ovarian cancer (EOC) tissues. Since the fallopian tubes are often affected by pelvic inflammatory disease (PID) and the majority of serous EOCs appear to originate from dysplastic lesions in the distal tube, it is relevant to consider the potential role that infectious agents may play in ovarian carcinogenesis. We sought to analyze the prevalence of human papillomavirus (HPV) and cytomegalovirus (CMV) in EOC tissue and fallopian tube specimens obtained at tumor resection. Ovarian cancer and fallopian tube tissue samples obtained from patients with EOC were analyzed by both qualitative and quantitative PCR to detect and quantify viral DNA. The presence of CMV and HPV DNA was detected in 70% and 74% cancerous ovarian tissues, respectively, and was significantly higher in EOC than in benign tumor cases (P ≤ 0.01). CMV or HPV infection was observed also in the fallopian tube samples. Infection with HPV16 was determined in 70% of EOC cases. Almost two thirds of EOC patients demonstrated coinfection with CMV and HPV in the pathological samples. The results revealed that the presence of CMV and HPV in EOC samples is common. CMV and HPV infections can be potential risks for EOC development.

The ovarian cancer oncobiome

Humans and other mammals are colonized by microbial agents across the kingdom which can represent a unique microbiome pattern. Dysbiosis of the microbiome has been associated with pathology including cancer. We have identified a microbiome signature unique to ovarian cancers, one of the most lethal malignancies of the female reproductive system, primarily because of its asymptomatic nature during the early stages in development. We screened ovarian cancer samples along with matched, and non-matched control samples using our pan-pathogen array (PathoChip), combined with capture-next generation sequencing. The results show a distinct group of viral, bacterial, fungal and parasitic signatures of high significance in ovarian cases. Further analysis shows specific viral integration sites within the host genome of tumor samples, which may contribute to the carcinogenic process. The ovarian cancer microbiome signature provides insights for the development of targeted therapeutics against ovarian cancers.

The potential role of infectious agents and pelvic inflammatory disease in ovarian carcinogenesis

Background

The etiological cause of ovarian cancer is poorly understood. It has been theorized that bacterial or viral infection as well as pelvic inflammatory disease could play a role in ovarian carcinogenesis.

Aim

To review the literature on studies examining the association between ovarian cancer and bacterial or viral infection or pelvic inflammatory disease.

Methods

Database search through MEDLINE, applying the medical subject headings: “Ovarian neoplasms”, AND “Chlamydia infections”, “Neisseria gonorrhoeae”, “Mycoplasma genitalium”, “Papillomaviridae”, or “pelvic inflammatory disease”. Corresponding searches were performed in EMBASE, and Web of Science. The literature search identified 935 articles of which 40 were eligible for inclusion in this review.

Results

Seven studies examined the association between bacterial infection and ovarian cancer. A single study found a significant association between chlamydial infection and ovarian cancer, while another study identified Mycoplasma genitalium in a large proportion of ovarian cancer cases. The remaining studies found no association. Human papillomavirus detection rates varied from 0 to 67% and were generally higher in the Asian studies than in studies from Western countries. Cytomegalovirus was the only other virus to be detected and was found in 50% of cases in a case-control study. The association between ovarian cancer and pelvic inflammatory disease was examined in seven epidemiological studies, two of which, reported a statistically significant association.

Conclusions

Data indicate a potential association between pelvic inflammatory disease and ovarian cancer. An association between ovarian cancer and high-risk human papillomavirus genotypes may exist in Asia, whereas an association in Western countries seems unlikely due to the low reported prevalence. Potential carcinogenic bacteria were found, but results were inconsistent, and further research is warranted.

Electronic supplementary material

The online version of this article (doi:10.1186/s13027-017-0134-9) contains supplementary material, which is available to authorized users.

Human Papillomavirus Genotypes and Methylation of CADM1, PAX1, MAL and ADCYAP1 Genes in Epithelial Ovarian Cancer Patients

Background:

High-risk types of human papillomavirus (HR-HPV) may play a role in the development of epithelial ovarian cancer (EOC). The aim of this study was to determine any HPV genotypes and correlations to CADM1, PAX1, MAL and ADCYAP1 gene methylation in Egyptian EOC patients.

Materials and methods:

The prevalence of HR-HPV in 100 formalin fixed paraffin embedded EOC tissues was determined using nested polymerase chain reaction (PCR) with MY09/MY11 and GP5+/GP6 + primers to amplify a broad spectrum of HPV genotypes in a single reaction. DNA sequencing was applied to identify HPV genotypes for the positive samples. All samples negative for HPV were re-analyzed for HR-HPV and low-risk HPV subtypes using type specific primers.

Results:

The prevalence of HPV was 10% in our EOC cases. HPV-16 and HPV-18 were the predominant genotypes followed by HPV−33, all being associated with advanced stages. Other HR-HPV and low risk HPV genotypes were not found. CADM1 was hypermethylated in 100% of patients infected with HPV-16 and HPV-33 and in 75% of patients infected with HPV-18. Hypermethylation of PAX1 was evident in 80% and in 75% of patients infected with HPV-16 and HPV-18 while MAL was hypermethylated in 100% and ADCYAP1 was hypermethylated in 60% and in 75%, respectively.

Conclusion:

The presence of high risk HPV genotypes among epithelial ovarian carcinoma may reflect an importance of infection in the pathogenesis of EOC. In HR-HPV infected cancers, DNA methylation may be one of the mechanisms triggering the alteration in CADM1, PAX1, MAL and ADCYAP1 gene expression levels.

Progress in the Research on the Relationship between Infection with Human Papillomavirus and Tumorigenesis

Human papillomavirus (HPV) is a DNA virus that infects the skin and mucous membranes of the human body. Approximately 80% of sexually active women are likely infected with HPV. Cervical cancer is one of the most common malignant tumors and is second in incidence only to breast cancer. Infection with high-risk HPV types is the main risk factor for cervical cancer, which is currently the only malignant tumor with a clearly defined etiology. HPV infection is also closely related to the incidence and development of other malignant tumors. In addition to cervical cancer, HPV can cause other urogenital tumors, as well as tumors in the digestive tract, lungs, eyes, skin, and other organ systems. This paper provides a review of the progress in HPV infection-related research and provides novel ideas for the study of tumor etiology and mechanisms.

High-risk HPV is not associated with epithelial ovarian cancer in a Caucasian population

Background

High-risk human papillomavirus (HPV) has been suspected to play a role in the carcinogenesis of epithelial ovarian cancer (EOC). However, results from previous studies are conflicting. In most of these studies, the number of tissue samples was small. The current study was therefore undertaken to examine the prevalence of high-risk HPV DNA in EOC in a large series of patients.

Method

Formalin-fixed, paraffin-imbedded tumor tissue samples from 198 cases consecutively included in the Danish Pelvic Mass Study were analyzed. The material included 163 serous adenocarcinomas, 15 endometrioid adenocarcinomas, 11 mucinous adenocarcinomas and nine clear-cell carcinomas. Genotyping for high-risk HPV DNA was performed by real-time Polymerase chain reaction (PCR) using an in-house TaqMan singleplex assay targeting the E6/E7 region of the HPV 16 and 18 genomes. Additionally, 20 random samples without HPV 16 and/or 18 infections were reanalyzed for HPV subtypes 31, 33, 35, 39, 45, 51 and 52.

Results

The quality criteria were fulfilled in 191 samples. HPV 18 DNA was detected in one sample only, while the rest tested negative. The subgroup analysis for seven additional high-risk HPV subtypes was also negative.

Conclusions

Only one in 191 samples was positive for HPV DNA. We therefore conclude that high risk HPV is unlikely to be associated with EOC in a Caucasian population. Future studies should focus on other microorganisms as possible etiological factors in EOC carcinogenesis.

Electronic supplementary material

The online version of this article (doi:10.1186/s13027-016-0087-4) contains supplementary material, which is available to authorized users.

Synthesis, characterization and biological evaluation of novel Ru(II)-arene complexes containing intercalating ligands

Three new ruthenium(II)-arene complexes, namely [(η(6)-p-cymene)Ru(Me2dppz)Cl]PF6 (1), [(η(6)-benzene)Ru(Me2dppz)Cl]PF6 (2) and [(η(6)-p-cymene)Ru(aip)Cl]PF6 (3) (Me2dppz=11,12-dimethyldipyrido[3,2-a:2',3'-c]phenazine; aip=2-(9-anthryl)-1H-imidazo[4,5-f] [1,10] phenanthroline) have been synthesized and characterized using different spectroscopic techniques including elemental analysis. The complexes were found to be well soluble and stable in DMSO. The biological activity of the three complexes was tested in three different human cancer cell lines (A549, MDA-MB-231 and HeLa) and in one human non-cancerous cell line (MRC-5). Complexes 1 and 3, carrying η(6)-p-cymene as the arene ligand, were shown to be toxic in all cell lines in the low micromolar/subnanomolar range, with complex 1 being the most cytotoxic complex of the series. Flow cytometry analysis revealed that complex 1 caused concentration- and time-dependent arrest of the cell cycle in G2-M and S phases in HeLa cells. This event is followed by the accumulation of the sub-G1 DNA content after 48h, in levels higher than cisplatin and in the absence of phosphatidylserine externalization. Fluorescent microscopy and acridine orange/ethidium bromide staining revealed that complex 1 induced both apoptotic and necrotic cell morphology characteristics. Drug-accumulation and DNA-binding studies performed by inductively coupled plasma mass spectrometry in HeLa cells showed that the total ruthenium uptake increased in a time- and concentration-dependent manner, and that complex 1 accumulated more efficiently than cisplatin at equimolar concentrations. The introduction of a Me2dppz ligand into the ruthenium(II)-p-cymene scaffold was found to allow the discovery of a strongly cytotoxic complex with significantly higher cellular uptake and DNA-binding properties than cisplatin.

Methylation of SFRPs and APC genes in ovarian cancer infected with high risk human papillomavirus

BACKGROUND

Secreted frizzled-related protein (SFRP) genes, new tumor suppressor genes, are negative regulators of the Wnt pathway whose alteration is associated with various tumors. In ovarian cancer, SFRPs genes promoter methylation can lead to gene inactivation. This study investigated mechanisms of SFRP and adenomatous polyposis coli (APC) genes silencing in ovarian cancer infected with high risk human papillomavirus.

MATERIALS AND METHODS

DNA was extracted from 200 formalin-fixed paraffin-embedded ovarian cancer and their normal adjacent tissues (NAT) and DNA methylation was detected by methylation specific PCR (MSP). High risk human papillomavirus (HPV) was detected by nested PCR with consensus primers to amplify a broad spectrum of HPV genotypes.

RESULTS

The percentages of SFRP and APC genes with methylation were significantly higher in ovarian cancer tissues infected with high risk HPV compared to NAT. The methylated studied genes were associated with suppression in their gene expression.

CONCLUSION

This finding highlights the possible role of the high risk HPV virus in ovarian carcinogenesis or in facilitating cancer progression by suppression of SFRP and APC genes via DNA methylation.

Human papillomavirus genotyping and integration in ovarian cancer Saudi patients

Background

Human papillomavirus (HPV) is associated with different malignancies but its role in the pathogenesis of ovarian cancer is controversial. This study investigated the prevalence, genotyping and physical state of HPV in ovarian cancer Saudi patients.

Methods

Hundred formalin fixed paraffin embedded (FFPE) ovarian carcinoma tissues and their normal adjacent tissues (NAT) were included in the study. HPV was detected by nested polymerase chain reaction (PCR) using degenerated HPVL1 consensus primer pairs MY09/MY11 and GP5+/GP6 + to amplify a broad spectrum of HPV genotypes in a single reaction. The HPV positive samples were further genotyped using DNA sequencing. The physical state of the virus was identified using Amplification of Papillomavirus Oncogene Transcripts (APOT) assay in the samples positive for HPV16 and/or HPV18.

Results

High percentage of HPV (42%) was observed in ovarian carcinoma compared to 8% in the NAT. The high-risk HPV types 16, 18 and 45 were highly associated with the advanced stages of tumor, while low-risk types 6 and 11 were present in NAT. In malignant tissues, HPV-16 was the most predominant genotype followed by HPV-18 and -45. The percentage of viral integration into the host genome was significantly high (61.1%) compared to 38.9% episomal in HPV positive tumors tissues. In HPV18 genotype the percentage of viral integration was 54.5% compared to 45.5% episomal.

Conclusion

The high risk HPV genotypes in ovarian cancer may indicate its role in ovarian carcinogenesis. The HPV vaccination is highly recommended to reduce this type of cancer.

Prevalence of human papillomavirus in epithelial ovarian cancer tissue. A meta-analysis of observational studies

OBJECTIVE

The role of human papillomavirus (HPV) in the pathogenesis of ovarian cancer is controversial, and conflicting results have been published. We conducted a systematic review and meta-analysis to estimate the prevalence of HPV in epithelial ovarian cancer tissue.

MATERIAL AND METHODS

Observational studies published until 4 March 2013 were identified in PubMed and Embase. We adhered to MOOSE guidelines and included 22 studies (case-control, cross-sectional studies). A pooled estimate of the HPV prevalence with corresponding 95% confidence interval (CI) was calculated based on a random effect model. In a meta-regression analysis we examined the contribution of different factors to heterogeneity. Furthermore, publication bias was evaluated.

RESULTS

The pooled HPV prevalence in ovarian cancer tissue was 15.5%, but wide variation was found (0-66.7%). After stratification by geographical region, publication year, tissue type and method of HPV detection, we found that the prevalence of HPV varied most markedly by geographical area, the prevalence being 45.6% (95% CI, 31.0-60.3) in Asia, 18.5% (95% CI, 8.5-28.6) in Eastern Europe, 1.1% (95% CI, -1.6 to 3.8) in Western Europe and zero in North America. A meta-regression analysis revealed that the difference between geographical regions could not be explained by HPV detection method or type of tissue.

CONCLUSIONS

Great geographical variation exists in HPV prevalence in ovarian cancer tissue, which is not explained by different HPV detection methods. The results suggest that HPV is unlikely to play an important role in Western European and American women, but cannot reject a role of HPV in other populations.