Human cytomegalovirus in high grade serous ovarian cancer possible implications for patients survival

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.

Prevalence of active cytomegalovirus infection at diagnosis of ovarian cancer and during chemotherapy and subsequent changes in cognitive functioning

PURPOSE

One of the most frequently reported effects of cancer and its treatments is cancer-related cognitive impairment (CRCI). Viral infections may affect inflammation and immune function and therefore may influence patient symptoms, including CRCI. The goal of this study was to describe the prevalence of cytomegalovirus (CMV) infections at diagnosis, during, and after chemotherapy in individuals with ovarian cancer and explore CMV infection at diagnosis with cancer-related cognitive impairment (CRCI) following chemotherapy.

METHODS

We recruited adults newly diagnosed with ovarian, primary peritoneal or fallopian tube cancer at a single academic cancer center into two prospective studies. In Study 1 (N = 71), participants provided blood samples at diagnosis. In Study 2 (N = 18), participants provided blood samples and completed symptom surveys before, during and after front-line adjuvant chemotherapy. Serum CMV DNA levels were assessed using digital PCR; >100 copies/mL of serum was considered positive for active CMV infection (CMV+). CRCI was measured using the Functional Assessment of Cancer Therapy - Cognitive Function (FACT-Cog) questionnaire. Changes in FACT-Cog scores were compared by CMV status at diagnosis using t-tests at each time point.

RESULTS

At diagnosis, 29.2% were CMV+ (28.2% in Study 1, 33.3% in Study 2). Following three cycles of chemotherapy (Study 2), CMV positivity rose to 60.0% and then back down to 31.3% after chemotherapy. We observed significant differences in CRCI following chemotherapy by CMV status at diagnosis.

CONCLUSION

Our data suggest that active CMV infection is common among patients undergoing treatment for ovarian cancer and may contribute to symptoms of CRCI.

Polyploidy, EZH2 upregulation, and transformation in cytomegalovirus-infected human ovarian epithelial cells

Human cytomegalovirus (HCMV) infection has been implicated in epithelial ovarian cancer (OC). Polyploidy giant cancer cells (PGCCs) have been observed in high-grade serous ovarian carcinoma (HGSOC); they possess cancer stem cell-like characteristics and give rise to progeny cells expressing epithelial-mesenchymal transition (EMT) markers. EZH2 plays a potential oncogenic role, correlating with high proliferative index and tumor grade in OC. Herein, we present the experimental evidence for HCMV as a reprogramming vector that elicited human ovarian epithelial cells (OECs) transformation leading to the generation of "CMV-transformed Ovarian cells" (CTO). The infection with the two high-risk clinical strains, namely HCMV-DB and BL provoked a distinct cellular and molecular mechanisms in infected OECs. EZH2 upregulation and cellular proliferation were curtailed by using EZH2 inhibitors. The HGSOC biopsies were characterized by an elevated EZH2 expression, possessing a strong positive correlation between the aforementioned marker and HCMV. From HGSOC biopsies, we isolated three HCMV clinical strains that transformed OECs generating CTO cells which displayed proliferative potentials in addition to EZH2 upregulation and PGCCs generation; these features were reduced upon EZH2 inhibition. High-risk HCMV strains transformed OECs confirming an HCMV-induced epithelial ovarian cancer model and highlighting EZH2 tumorigenic properties. Our findings might be highly relevant in the pathophysiology of ovarian tumors thereby nominating new targeted therapeutics.

Human cytomegalovirus in cancer: the mechanism of HCMV-induced carcinogenesis and its therapeutic potential

Cancer is one of the leading causes of death worldwide. Human cytomegalovirus (HCMV), a well-studied herpesvirus, has been implicated in malignancies derived from breast, colorectal muscle, brain, and other cancers. Intricate host-virus interactions are responsible for the cascade of events that have the potential to result in the transformed phenotype of normal cells. The HCMV genome contains oncogenes that may initiate these types of cancers, and although the primary HCMV infection is usually asymptomatic, the virus remains in the body in a latent or persistent form. Viral reactivation causes severe health issues in immune-compromised individuals, including cancer patients, organ transplants, and AIDS patients. This review focuses on the immunologic mechanisms and molecular mechanisms of HCMV-induced carcinogenesis, methods of HCMV treatment, and other studies. Studies show that HCMV DNA and virus-specific antibodies are present in many types of cancers, implicating HCMV as an important player in cancer progression. Importantly, many clinical trials have been initiated to exploit HCMV as a therapeutic target for the treatment of cancer, particularly in immunotherapy strategies in the treatment of breast cancer and glioblastoma patients. Taken together, these findings support a link between HCMV infections and cellular growth that develops into cancer. More importantly, HCMV is the leading cause of birth defects in newborns, and infection with HCMV is responsible for abortions in pregnant women.

Human Cytomegalovirus Protein Expression Is Correlated with Shorter Overall Survival in Breast Cancer Patients: A Cohort Study

Background: Human cytomegalovirus (HCMV) is increasingly suggested to be involved in human carcinogenesis and onco-modulation due to its ability to contribute to all hallmarks of cancer. Growing evidence demonstrates a link between HCMV infection and various malignancies, including breast cancer, which incidence and mortality are still on the rise. The etiology of breast cancer remains mostly unclear, leaving 80% of breast cancer cases considered to be sporadic. Identifying novel risk- and prognostic factors for improved breast cancer treatment and increased survival rates, were the objectives of this study. Methods: Automated immunohistochemical staining results for HCMV proteins in 109 breast tumors and lymph node metastasis were correlated with clinical follow-up data (>10 years). Statistical analyses for median Overall Survival (OS) were performed. Results: Survival analyses revealed shorter median OS for patients with HCMV-IE positive tumors of 118.4 months compared to 202.4 months for HCMV-IE negative tumors. A higher number of HCMV-LA positive cells in the tumors was also associated with a shorter OS in patients (146.2 months vs. 151.5 months). Conclusions: Our findings suggest a link between HCMV-infections and breast cancer prognosis, which paves the way for potential novel clinical intervention and targeted therapy that may prolong the overall survival of selected patients with breast cancer.

Human cytomegalovirus alters immune cell profile with potential implications for patient survival in head and neck cancer

Cytomegalovirus (CMV) is a highly prevalent human herpes virus that exerts a strong influence on immune repertoire which may influence cancer risk. We have tested whether CMV immunoglobulin G (IgG) serostatus is associated with immune cell proportions (n = 132 population controls), human papillomavirus (HPV) co-infection and head and neck cancer risk (n = 184 cancer cases and 188 controls) and patient survival. CMV status was not associated with the proportion of Natural Killer cells, B cells or the neutrophil-to-lymphocyte ratio. However, CD8+ T cells increased with increasing categories of IgG titers (P =1.7 × 10-10), and titers were inversely associated with the CD4:CD8 ratio (P = 5.6 × 10-5). Despite these differences in T cell proportions, CMV was not associated with HPV16 co-infection. CMV seropositivity was similar in cases (52%) and controls (47%) and was not associated with patient survival (hazard ratio [HR] 1.14, 95% confidence interval [CI]: 0.70 to 1.86). However, those patients with the highest titers had the worst survival (HR 1.91, 95% CI: 1.13 to 3.23). Tumor-based data from The Cancer Genome Atlas demonstrated that the presence of CMV transcripts was associated with worse patient survival (HR 1.79, 95% CI: 0.96 to 2.78). These findings confirm that a history of CMV infection alters T cell proportions, but this does not translate to HPV16 co-infection or head and neck cancer risk. Our data suggest that high titers and active CMV virus in the tumor environment may confer worse survival.

CMV Seropositive Status Increases Heparanase SNPs Regulatory Activity, Risk of Acute GVHD and Yield of CD34+ Cell Mobilization

Heparanase is an endo-β-glucuronidase that is best known for its pro-cancerous effects but is also implicated in the pathogenesis of various viruses. Activation of heparanase is a common strategy to increase viral spread and trigger the subsequent inflammatory cascade. Using a Single Nucleotide Polymorphisms (SNP)-associated approach we identified enhancer and insulator regions that regulate HPSE expression. Although a role for heparanase in viral infection has been noticed, the impact of HPSE functional SNPs has not been determined. We investigated the effect of cytomegalovirus (CMV) serostatus on the involvement of HPSE enhancer and insulator functional SNPs in the risk of acute graft versus host disease (GVHD) and granulocyte-colony stimulating factor related CD34⁺ mobilization. A significant correlation between the C alleles of insulator rs4364254 and rs4426765 and CMV seropositivity was found in healthy donors and patients with hematological malignancies. The risk of developing acute GVHD after hematopoietic stem cell transplantation was identified only in CMV-seropositive patients. A significant correlation between the enhancer rs4693608 and insulator rs28649799 and CD34⁺ cell mobilization was demonstrated in the CMV-seropositive donors. It is thus conceivable that latent CMV infection modulates heparanase regulatory regions and enhances the effect of functional SNPs on heparanase function in normal and pathological processes.

Detection of Human Cytomegalovirus Proteins in Paraffin-Embedded Breast Cancer Tissue Specimens-A Novel, Automated Immunohistochemical Staining Protocol

Emerging evidence supports a significant association between human cytomegalovirus (HCMV) and human malignancies, suggesting HCMV as a human oncomodulatory virus. HCMV gene products are found in >90% of breast cancer tumors and seem to be correlated with more aggressive disease. The definitive diagnosis of HCMV relies on identification of virus inclusions and/or viral proteins by different techniques including immunohistochemical staining. In order to reduce biases and improve clinical value of HCMV diagnostics in oncological pathology, automation of the procedure is needed and this was the purpose of this study. Tumor specimens from 115 patients treated for primary breast cancer at Akershus University Hospital in Norway were available for the validation of the staining method in this retrospective study. We demonstrate that our method is highly sensitive and delivers excellent reproducibility for staining of HCMV late antigen (LA), which makes this method useful for future routine diagnostics and scientific applications.

Potential Impact of Human Cytomegalovirus Infection on Immunity to Ovarian Tumours and Cancer Progression

Ovarian cancer (OC) is one of the most common, and life-threatening gynaecological cancer affecting females. Almost 75% of all OC cases are diagnosed at late stages, where the 5-year survival rate is less than 30%. The aetiology of the disease is still unclear, and there are currently no screening method nor effective treatment strategies for the advanced disease. A growing body of evidence shows that human cytomegalovirus (HCMV) infecting more than 50% of the world population, may play a role in inducing carcinogenesis through its immunomodulatory activities. In healthy subjects, the primary HCMV infection is essentially asymptomatic. The virus then establishes a life-long chronic latency primarily in the hematopoietic progenitor cells in the bone marrow, with periodic reactivation from latency that is often characterized by high levels of circulating pro-inflammatory cytokines. Currently, infection-induced chronic inflammation is considered as an essential process for OC progression and metastasis. In line with this observation, few recent studies have identified high expressions of HCMV proteins on OC tissue biopsies that were associated with poor survival outcomes. Active HCMV infection in the OC tumour microenvironment may thus directly contribute to OC progression. In this review, we highlight the potential impact of HCMV infection-induced immunomodulatory effects on host immune responses to OC that may promote OC progression.

The Relevant Participation of Prolactin in the Genesis and Progression of Gynecological Cancers

Prolactin (PRL) is a hormone produced by the pituitary gland and multiple non-pituitary sites, vital in several physiological processes such as lactation, pregnancy, cell growth, and differentiation. However, PRL is nowadays known to have a strong implication in oncogenic processes, making it essential to delve into the mechanisms governing these actions. PRL and its receptor (PRLR) activate a series of effects such as survival, cellular proliferation, migration, invasion, metastasis, and resistance to treatment, being highly relevant in developing certain types of cancer. Because women produce high levels of PRL, its influence in gynecological cancers is herein reviewed. It is interesting that, other than the 23 kDa PRL, whose mechanism of action is endocrine, other variants of PRL have been observed to be produced by tumoral tissue, acting in a paracrine/autocrine manner. Because many components, including PRL, surround the microenvironment, it is interesting to understand the hormone's modulation in cancer cells. This work aims to review the most important findings regarding the PRL/PRLR axis in cervical, ovarian, and endometrial cancers and its molecular mechanisms to support carcinogenesis.

Cytomegalovirus and systemic inflammation at time of surgery is associated with worse outcomes in serous ovarian cancer

OBJECTIVES

Cytomegalovirus (CMV) is a common infection that establishes latency in healthy people. CMV has been associated with alterations of the immune compartment leading to improved responses, while inflammation has been shown to adversely impact outcomes. We investigated whether CMV serostatus predicts outcomes in ovarian cancer in the presence or absence of inflammation.

METHODS

A total of 106 patients with serous ovarian cancer from 2006 to 2009 were analyzed. CMV and systemic inflammation was measured using CMV immunoglobulin G (IgG) and C-reactive protein (CRP), respectively, in serum collected prior to cytoreduction. Patients were stratified by CMV IgG (non-reactive, reactive/borderline) and CRP (≤10, >10 mg/L) status. Overall survival (OS) and recurrence-free survival (RFS) were compared by group using log-rank tests and Cox proportional hazards regression models adjusting for age at surgery.

RESULTS

Of 106 eligible patients, 40 (37.7%) were CMV+/CRP+, 24 (22.6%) CMV+/CRP-, 19 (17.9%) CMV-/CRP+, and 23 (21.7%) CMV-/CRP-. CRP+ had higher CA-125 levels (P = 0.05) and higher rates of suboptimal debulking (P = 0.03). There were no other significant differences in demographic, surgical, or pathologic factors between groups. CMV+/CRP+ patients median RFS and OS were 16.9 months (95% CI: 9.0-21.1) and 31.7 months (95% CI: 25.0-48.7), respectively, with a significantly worse RFS (aHR: 1.85, 95% CI: 1.05-3.24, P = 0.03) and OS (aHR: 2.12, 95% CI: 1.17-3.82, P = 0.01) compared to CMV-/CRP- (RFS = 31.2 months (95% CI: 16.0-56.4) and OS = 63.8 months (95% CI: 50.7-87.0)). CMV+/CRP- group displayed the longest OS (89.3 months).

CONCLUSIONS

Previous exposure to CMV and high CRP at surgery portended worse RFS and OS compared to women who tested negative. The CMV+/CRP- group had the longest OS, indicating that CMV status alone, in the absence of inflammation, may be protective.

Valganciclovir as Add-on to Standard Therapy in Glioblastoma Patients

PURPOSE

Several groups have reported a prevalence of human cytomegalovirus (CMV) in glioblastoma close to 100%. Previously, we reported that treatment with the antiviral drug valganciclovir as an add-on to standard therapy significantly prolonged survival in 50 patients with glioblastoma. Here, we present an updated retrospective analysis that includes an additional 52 patients.

EXPERIMENTAL DESIGN

From December 2006 to November 2019, 102 patients with newly diagnosed glioblastoma received valganciclovir as an add-on to standard therapy. No additional toxicity was observed. Contemporary controls were 231 patients with glioblastoma who received similar baseline therapy.

RESULTS

Patients with newly diagnosed glioblastoma receiving valganciclovir had longer median overall survival (OS 24.1 vs. 13.3 months, P < 0.0001) and a 2-year survival rate (49.8% vs. 17.3%) than controls. Median time-to-tumor progression was also longer than in controls; 9.9 (0.7-67.5 months) versus 7.3 (1.2-49 months), P = 0.0003. Valganciclovir improved survival in patients with radical or partial resection and an unmethylated or methylated MGMT promoter gene.

CONCLUSIONS

Valganciclovir prolonged median OS of patients with newly diagnosed glioblastoma (with methylated or unmethylated MGMT promoter gene) and was safe to use.

Detection of human cytomegalovirus in patients with epithelial ovarian cancer and its impacts on survival

Background

The cause of epithelial ovarian cancer (EOC) is not elucidated. Viral infection may induce chronic inflammatory infection and play a role in the pathogenesis of cancers. Some viruses are considered to be oncomodulatory, modulating cellular pathways such as cell proliferation, tumor progression, vascular disease development, and immune evasion. Human cytomegalovirus (HCMV) has been detected in several types of cancers including ovarian cancer. However, the role of HCMV in ovarian carcinogenesis remains controversial.

Objective

To investigate the potential role of HCMV infection in EOC, we evaluated the prevalence of HCMV proteins in EOC tissue and its impacts on patients’ survival.

Methods

Formalin-fixed paraffin-embedded tissues from 66 patients with EOC and 30 patients with benign ovarian cystadenoma were studied. Specimens were analyzed for expression of HCMV immediate early protein (IE) and HCMV tegument protein (pp65) by immunohistochemistry.

Results

HCMV-IE protein expression was detected in 82% of EOC and 36% of benign tumors; pp65 was detected in 97% of EOC and 63% of benign tumors. Extensive HCMV-IE protein expression was associated with higher stage of EOC. Reactivation of latent HCMV within the tumor at interval debulking surgery may be induced by neoadjuvant chemotherapy before surgery. Extensive HCMV-IE expression was associated with shorter median overall survival than focal or negative expression (39 versus 41 months, P = 0.03). Multivariate analysis indicated that HCMV-IE expression was an independent prognostic factor for overall survival (P = 0.034).

Conclusions

This study demonstrate a high prevalence of HCMV proteins in tissue sections from patients with EOC. HCMV infection can be potential risk factor for EOC development. Extensive HCMV-IE expression indicated a poor prognosis. The relationship between HCMV and clinical outcomes highlight the need for further researches on the oncomodulatory role of HCMV in ovarian cancer.

Cytomegalovirus and cancer-related mortality in the national health and nutritional examination survey

PURPOSE

Cytomegalovirus (HCMV) is a common viral infection that shapes lifelong immunity. A history of infection with HCMV has been associated with many chronic diseases, including cancer. In addition, prospective cohort studies have established that HCMV is associated with all-cause mortality. However, there are limited data regarding HCMV and cancer mortality.

METHODS

Data were obtained from the National Health and Nutrition Examination Survey (NHANES) III study (1988-1994): subjects aged 18 to 98, who had HCMV serology results, did not report having cancer at baseline, and were eligible for mortality follow-up (n = 14,498). Mortality was ascertained until December 2011 using National Death Index (NDI) linkage.

RESULTS

The unadjusted risk of all-cancer mortality was higher in HCMV seropositive individuals (HR 2.74, 95% CI 2.05-3.64). This association was attenuated after adjusting for age (HR 1.39, 95% CI 1.02-1.92), and other covariates (age, sex, race/ethnicity, smoking status, BMI, education, and C-reactive protein (CRP); HR 1.21, 95% CI 0.91-1.81). There was a statistically significant interaction between HCMV and sex (p = 0.01): HCMV seropositivity was associated with increased cancer mortality in men (HR 1.65, 95% CI 0.99-2.73) but not in women (HR 0.95, 95% CI 0.59-1.54).

CONCLUSION(S)

Consistent with prior reports, HCMV seropositivity may be associated with an increased risk of cancer-related mortality but the association is partially driven by socioeconomic status and other risk factors. Future research is needed to determine whether HCMV is a risk factor for cancer, as well as identify the specific cancer types where HCMV increases mortality.

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.

Human Cytomegalovirus Infection Induces High Expression of Prolactin and Prolactin Receptors in Ovarian Cancer

One of the potential biomarkers for ovarian cancer patients is high serum level of prolactin (PRL), which is a growth factor that may promote tumor cell growth. The prolactin receptor (PRLR) and human cytomegalovirus (HCMV) proteins are frequently detected in ovarian tumor tissue specimens, but the potential impact of HCMV infection on the PRL system have so far not been investigated. In this study, HCMV’s effects on PRL and PRLR expression were assessed in infected ovarian cancer cells (SKOV3) by PCR and Western blot techniques. The levels of both PRL and PRLR transcripts as well as the corresponding proteins were highly increased in HCMV-infected SKOV3 cells. Tissue specimens obtained from 10 patients with ovarian cancer demonstrated high expression of PRLR, HCMV-IE, and pp65 proteins. Extensive expression of PRLR was detected in all examined ovarian tumor tissue specimens except for one from a patient who had focal expression of PRLR and this patient was HCMV-negative in her tumor. In conclusion, PRL and PRLR were induced to high levels in HCMV-infected ovarian cancer cells and PRLR expression was extensively detected in HCMV-infected ovarian tissue specimens. Highly induced PRL and PRLR by HCMV infection may be of relevance for the oncomodulatory role of this virus in ovarian cancer.

Human alpha and beta herpesviruses and cancer: passengers or foes?

Based on seroepidemiological studies, human herpes simplex virus types 1 and 2 (HSV-1, HSV-2) are put in relation with a number of cancer diseases; however, they do not appear to play a direct role, being only considered cofactors. Their ability to transform the cells in vitro could be demonstrated experimentally by removing their high lytic ability by a certain dose of UV radiation or by photoinactivation in the presence of photosensitizers, such as neutral red or methylene blue, or culturing under conditions suppressing their lytic activity. However, recent studies indicate that UV irradiated or photoinactivated HSV-1 and HSV-2, able to transform non-transformed cells, behave differently in transformed cells suppressing their transformed phenotype. Furthermore, both transforming and transformed phenotype suppressing activities are pertaining only to non-syncytial virus strains. There are some proposed mechanisms explaining their transforming activity. According to the "hit and run" mechanism, viral DNA induces only initiation of transformation by interacting with cellular DNA bringing about mutations and epigenetic changes and is no longer involved in other processes of neoplastic progression. According to the "hijacking" mechanism, virus products in infected cells may activate signalling pathways and thus induce uncontrolled proliferation. Such a product is e.g. a product of HSV-2 gene designated ICP10 that encodes an oncoprotein RR1PK that activates the Ras pathway. In two cases of cancer, in the case of serous ovarian carcinoma and in some prostate tumours, virus-encoded microRNAs (miRNAs) were detected as a possible cofactor in tumorigenesis. And, recently described herpes virus-associated growth factors with transforming and transformation repressing activity might be considered important factors playing a role in tumour formation. And finally, there is a number of evidence that HSV-2 may increase the risk of cervical cancer after infection with human papillomaviruses. A similar situation is with human cytomegalovirus; however, here, a novel mechanism named oncomodulation has been proposed. Oncomodulation means that HCMV infects tumour cells and modulates their malignant properties without having a direct effect on cell transformation.

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.

Cytomegalovirus is a tumor-associated virus: armed and dangerous

Human cytomegalovirus (HCMV) gene products are present in multiple human malignancies, often in specific association with tumor cells and tumor vasculature. Emerging evidence from human and mouse models of CMV infection in cancer indicate that CMV can transform epithelial cells, promote epithelial to mesenchymal transition (EMT) and mesenchymal to epithelial (MET) in tumor cells, promote tumor angiogenesis and proliferation and incapacitate the host anti-CMV immune response. This review will discuss the increasing role of HCMV in human cancer by demonstrating how HCMV is well suited for impacting major themes in oncogenesis including initiation, promotion, progression, metastasis and immune evasion. What emerges is a picture of an extremely versatile pathogen that may play a significant role in human cancer progression and death.

The emerging role of human cytomegalovirus infection in human carcinogenesis: a review of current evidence and potential therapeutic implications

It is well-established that infections with viruses harboring oncogenic potential increase the cancer risk. Virus induced oncogenic processes are influenced by a complex and unique combination of host and environmental risk factors that are currently not fully understood. Many of the oncogenic viruses exhibit a prolonged, asymptomatic latency after a primary infection, and cause cancer in only a minority of carriers. From an epidemiologic point of view, it is therefore difficult to determine their role in cancer development. However, recent evidence suggests a neoplastic potential of one additional ubiquitous virus; human Cytomegalovirus (HCMV). Emerging data presents HCMV as a plausible cancer-causing virus by demonstrating its presence in >90% of common tumor types, while being absent in normal tissue surrounding the tumor. HCMV targets many cell types in tumor tissues, and can cause all the ten proposed hallmarks of cancer. This virus exhibits cellular tumor-promoting and immune-evasive strategies, hijacks proangiogenic and anti-apoptotic mechanisms and induces immunosuppressive effects in the tumor micro-environment. Recognizing new cancer-causing mechanisms may increase the therapeutic potential and prophylactic options for virus associated cancer forms. Such approaches could limit viral spread, and promote anti-viral and immune controlling strategies if given as add on to standard therapy to potentially improve the prognosis of cancer patients. This review will focus on HCMV-related onco-viral mechanisms and the potential of HCMV as a new therapeutic target in HCMV positive cancer forms.

The prevalence of EBV and CMV DNA in epithelial ovarian cancer

Background

The underlying cause of epithelial ovarian cancer (EOC) is unknown. It has been theorized that infectious agents could contribute to ovarian tumorigenesis.

Objective

To investigate the potential role of oncogenic viral infection in EOC, we examined the prevalence of Epstein-Barr Virus (EBV) DNA and cytomegalovirus (CMV) DNA in EOC tissue samples.

Methods

Formalin-fixed, paraffin-imbedded (FFPE) tumor tissue samples from 198 patients included in the Danish Pelvic Mass Study were studied: 163 with serous adenocarcinomas, 15 with endometrioid adenocarcinomas, 11 with mucinous adenocarcinomas, and nine with clear-cell carcinomas. For controls in the EBV analysis, we used 176 tissue samples from patients diagnosed with benign mucinous cystadenomas. EBV and CMV genotyping was performed by real-time polymerase chain reaction with CMV and EBV CE-IVD approved kits. In-situ hybridization (ISH) was performed on the EBV positive samples.

Results

Sufficient DNA material was obtained in 191 and 174 tissue samples from cases and controls, respectively. Ten of 191 case samples (5.2%) and one of 174 control samples (0.5%) were positive for EBV DNA (P value = 0.011). CMV DNA was detected in only one case sample (0.5%). ISH confirmed that three of the samples were of stromal origin, while the remaining seven tested negative for EBV.

Conclusions

This study is the first to demonstrate a higher prevalence of EBV DNA in tissue samples from patients with EOC than in a benign control group. However, the cellular origin of seven of the samples could not be determined by ISH analysis. Our study did not support an association between CMV and EOC.

Impact of human cytomegalovirus on glioblastoma cell viability and chemotherapy treatment

The relationship between human cytomegalovirus (HCMV) and tumours has been extensively investigated, mainly in glioblastoma multiforme (GBM), a malignant tumour of the central nervous system with low overall survival rates. Several reports have demonstrated the presence of HCMV in GBM, although typically restricted to a low number of cells, and studies have indicated that viral proteins have the ability to dysregulate cellular processes and increase tumour malignancy. Treatment of GBM involves the use of the chemotherapeutic agents temozolomide (TMZ) and carmustine (bis-chloroethylnitrosourea, BCNU), which lead to the attachment of adducts to the DNA backbone, causing errors during replication and consequent cell death. It is known that HCMV infection can modulate DNA repair pathways, but what effects the virus may exhibit during chemotherapy are unknown. Here we approach this question by analysing HCMV infection and viral protein accumulation in GBM cell lines with different genotypes and their response to TMZ and BCNU in the presence of the virus. We demonstrate that A172, TP365MG and U251MG GBM cells are efficiently infected by both low-passage (TB40E) and high-passage (AD169) HCMV strains. However, the GBM cell lines vary widely in their permissiveness to viral gene expression and exhibit very different patterns of immediate early, early and late protein accumulation. HCMV reduces the viability of permissive GBM cells in a multiplicity-dependent manner in both the absence and presence of TMZ or BNCU. In sum, we demonstrate that GBM cell lines are equally susceptible but differentially permissive to infection by both low- and high-passage strains of HCMV. This observation not only indicates that viral replication is largely controlled by cellular factors in this system, but also provides a possible explanation for why viral gene products are only found in a subset of cells in GBM tumours. Furthermore, we conclude that the virus does not confer increased resistance to chemotherapeutic drugs in various GBM cell lines, but instead reduces tumour cell viability. These results highlight that the oncomodulatory potential of HCMV is not limited to cancer-promoting activities, but also includes adverse effects on tumour cell proliferation or survival.