Chlamydia trachomatis, Pelvic Inflammatory Disease, and Epithelial Ovarian Cancer.

Epidemiologic, clinical, molecular and translational research findings support an interrelationship between Chlamydia trachomatis, pelvic inflammatory disease (PID), and epithelial ovarian cancer (EOC). Overall, the link between C. trachomatis, PID, and EOC seems to be relatively weak, although nondifferential misclassification bias may have attenuated the results. The predominant tubal origin of EOC and the role of chronic inflammation in tumorigenesis suggest that the association is biologically plausible. Thus, C. trachomatis and PID may represent potential risk factors or risk markers for EOC. However, many steps in this chain of events are still poorly understood and need to be addressed in future studies. Research gaps include time of exposure in relation to the long-term consequences and lag time to EOC. Data of differential risk for EOC between chlamydial and nonchlamydial PID is also needed. Another major research gap has been the absence of high-performance biomarkers for C. trachomatis, PID, and EOC, as well as EOC precursors. Biomarkers for C. trachomatis and PID leading to increased risk of EOC should be developed. If the association is confirmed, C. trachomatis and PID prevention efforts may play a role in reducing the burden of EOC.

Probing the impact of nairovirus genomic diversity on viral ovarian tumor domain protease (vOTU) structure and deubiquitinase activity.

Post-translational modification of host and viral proteins by ubiquitin (Ub) and Ub-like proteins, such as interferon stimulated gene product 15 (ISG15), plays a key role in response to infection. Viruses have been increasingly identified that contain proteases possessing deubiquitinase (DUB) and/or deISGylase functions. This includes viruses in the Nairoviridae family that encode a viral homologue of the ovarian tumor protease (vOTU). vOTU activity was recently demonstrated to be critical for replication of the often-fatal Crimean-Congo hemorrhagic fever virus, with DUB activity suppressing the type I interferon responses and deISGylase activity broadly removing ISG15 conjugated proteins. There are currently about 40 known nairoviruses classified into fourteen species. Recent genomic characterization has revealed a high degree of diversity, with vOTUs showing less than 25% amino acids identities within the family. Previous investigations have been limited to only a few closely related nairoviruses, leaving it unclear what impact this diversity has on vOTU function. To probe the effects of vOTU diversity on enzyme activity and specificity, we assessed representative vOTUs spanning the Nairoviridae family towards Ub and ISG15 fluorogenic substrates. This revealed great variation in enzymatic activity and specific substrate preferences. A subset of the vOTUs were further assayed against eight biologically relevant di-Ub substrates, uncovering both common trends and distinct preferences of poly-Ub linkages by vOTUs. Four novel X-ray crystal structures were obtained that provide a biochemical rationale for vOTU substrate preferences and elucidate structural features that distinguish the vOTUs, including a motif in the Hughes orthonairovirus species that has not been previously observed in OTU domains. Additionally, structure-informed mutagenesis provided the first direct evidence of a second site involved in di-Ub binding for vOTUs. These results provide new insight into nairovirus evolution and pathogenesis, and further enhances the development of tools for therapeutic purposes.

Evidence of human cytomegalovirus infection and expression of 5-lipoxygenase in borderline ovarian tumors.

Borderline ovarian tumors (BOTs) belong to a group of tumors that are distinctly different from ovarian carcinomas. There is an increased risk of BOTs in patients with pelvic inflammatory disease. Human cytomegalovirus (HCMV) has been detected in ovarian cancer tissue specimens. This virus favors the inflammatory milieu by inducing expression of the potent inflammatory factor 5-lipoxygenase (5LO), which stimulates cellular viability, cellular proliferation and activates antiapoptotic signaling pathways. Here, we aimed to examine presence of HCMV and 5LO in BOTs. Expression levels of HCMV proteins (IE and pp65) and 5LO were examined in paraffin embedded BOT tissue sections by immunohistochemistry staining and HCMV immunoglobulin M and immunoglobulin G (IgG) levels were determined by serology in blood samples obtained from 15 patients with BOTs identified in a prospective study at Karolinska University Hospital. Extensive expression of HCMV-IE, pp65, and 5LO were detected in 87%, 40%, and 90% of examined BOT tissue sections, respectively. HCMV-IgG prevalence and antibody levels were significantly higher in patients with BOT compared to age matched healthy women (83.3% vs. 65,6%, respectively, p = .01). Whether HCMV can induce inflammation and affect the pathogenesis of BOTs should therefore be further investigated.

A phase 1b study of intraperitoneal oncolytic viral immunotherapy in platinum-resistant or refractory ovarian cancer.

OBJECTIVE: Our objective was to assess safety and adverse events associated with intraperitoneal Olvi-Vec virotherapy in patients with platinum-resistant or refractory ovarian cancer (PRROC). Secondary objectives included objective response rate (ORR) per RECIST 1.1 and progression-free survival (PFS). METHODS: Olvi-Vec is a modified vaccinia virus that causes oncolysis and immune activation. An open-label phase 1b trial using a 3 + 3 dose escalation was conducted. Intraperitoneal Olvi-Vec was given as monotherapy in two consecutive daily doses. Translational analyses included anti-virus antibody levels, viral shedding, circulating tumor cells (CTCs) and T cells. RESULTS: Twelve patients (median age: 69 years, range: 45-77) with median 5 prior therapies (range: 2-10) and 2 prior platinum lines (range: 1-5) were enrolled. There were three dose level cohorts: 3 × 109 (n = 6), 1 × 1010 (n = 5), and 2.5 × 1010 (n = 1) plaque forming units (PFU)/day on two consecutive days. Treatment-related adverse events (TRAEs) included G1/G2 nausea (n = 6), fever (n = 6), abdominal distention (n = 5), and abdominal pain (n = 4). There were no Grade 4 TRAEs, no dose relationship to TRAEs, and no deaths attributed to Olvi-Vec. The ORR was 9% (1/11). Stable disease (SD) was 64% (7/11), and SD ≥15 weeks was 46% (5/11). Median PFS was 15.7 weeks (95%CI: 5.7-34.5), including extended PFS in four patients (23.2, 34.5, 59.4+ and 70.8 weeks). Three patients had extended overall survival (deceased 33.6 months, and alive with disease at 54 and 59 months). CTCs diminished in 6/8 (75%) baseline-positive patients. Immune activation was demonstrated from virus-enhanced tumor infiltration of CD8+ T-cells and activation of tumor-specific T-cells in peripheral blood. CONCLUSIONS: Oncolytic viral therapy with intraperitoneal Olvi-Vec showed promising safety, clinical activities, and immune activation in patients with PRROC, warranting further clinical investigation.

The relationship of human papillomavirus and cytology co-testing results with endometrial and ovarian cancer diagnoses.

BACKGROUND: To investigate whether routine cervical screening using human papillomavirus (HPV) and cytology co-testing effectively identifies women with endometrial (EC) or ovarian (OvC) cancer. METHODS: In 2003, Kaiser Permanente Northern California implemented triennial co-testing in women aged ≥30 years. Index screening results (n = 2,385,729) were linked to subsequent EC (n = 3434) and OvC (n = 1113) diagnoses from January 1, 2003 to December 31, 2017. EC were categorized as type 1 or 2, and, selectively, EC and OvC diagnoses were stratified on whether symptoms were present at the time of the co-test. Fractions and absolute risks of EC or OvC of each co-testing result were calculated. RESULTS: Most EC (82.18%) and OvC (88.68%) were preceded by a negative HPV and negative cytology co-test. More EC were preceded by atypical squamous cells of undetermined significance (ASC-US) or more severe (ASC-US+) cytology and negative HPV test (n = 290) (8.44% of EC) compared to a negative cytology and a positive HPV test (n = 31) (0.89% of EC) (p < 0.001). The absolute risk of any EC diagnosis following ASC-US+ and negative HPV test was 0.48%. Atypical glandular cells (AGC) cytology and a negative HPV result preceded 6.92% of any EC diagnosis, with an absolute risk of 4.02%, but preceded only 1.13% of type 2 EC cases, with an absolute risk of 0.24%, in asymptomatic women. AGC cytology and a negative HPV result preceded 1.44% of OvC, with an absolute risk of 0.28%. CONCLUSIONS: Abnormal cervical screening tests, even AGC cytology, rarely precedes and poorly predict women with EC or OvC.

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.

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.

Anti-tumor effect of a dual cancer-specific recombinant adenovirus on ovarian cancer cells.

BACKGROUND: Apoptin can specifically kill cancer cells but has no toxicity to normal cells. Human telomerase reverse transcriptase (hTERT) acts as a tumor-specific promoter, triggering certain genes to replicate or express only in tumor cells, conferring specific replication and killing abilities. This study aimed at investigating the anticancer potential of the recombinant adenovirus Ad-apoptin-hTERTp-E1a (Ad-VT) in ovarian cancer treatment. METHODS: Crystal Violet staining and WST-1 assays were used to analyze the inhibitory effect of Ad-VT on ovarian cancer SKOV3 and OVCAR-3 cells. Ad-VT-induced apoptosis of ovarian cancer cells, was detected using Hoechst, Annexin V-FITC/PI, JC-1 staining. Cell migration and invasion of ovarian cancer cells were detected using cell-scratch and Transwell assays. The pGL4.51 plasmid was used to transfect and to generate SKOV3-LUC cells, that stably express luciferase. The in vivo tumor inhibition effect of Ad-VT was subsequently confirmed using a tumor-bearing nude mouse model. RESULTS: Ad-VT had a strong apoptosis-inducing effect on SKOV3 and OVCAR-3 cells, that was mainly mediated through the mitochondrial apoptotic pathway. The Ad-VT could significantly increase the inhibition of ovarian cancer cell migration and invasion. The Ad-VT also can inhibit tumor growth and reduce toxicity in vivo. CONCLUSIONS: The recombinant adenovirus, comprising the apoptin protein and the hTERTp promoter, was able to inhibit the growth of ovarian cancer cells and promote their apoptosis.

Serologic markers of Chlamydia trachomatis and other sexually transmitted infections and subsequent ovarian cancer risk: Results from the EPIC cohort.

A substantial proportion of epithelial ovarian cancer (EOC) arises in the fallopian tube and other epithelia of the upper genital tract; these epithelia may incur damage and neoplastic transformation after sexually transmitted infections (STI) and pelvic inflammatory disease. We investigated the hypothesis that past STI infection, particularly Chlamydia trachomatis, is associated with higher EOC risk in a nested case-control study within the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort including 791 cases and 1669 matched controls. Serum antibodies against C. trachomatis, Mycoplasma genitalium, herpes simplex virus type 2 (HSV-2) and human papillomavirus (HPV) 16, 18 and 45 were assessed using multiplex fluorescent bead-based serology. Conditional logistic regression was used to estimate relative risks (RR) and 95% confidence intervals (CI) comparing women with positive vs. negative serology. A total of 40% of the study population was seropositive to at least one STI. Positive serology to C. trachomatis Pgp3 antibodies was not associated with EOC risk overall, but with higher risk of the mucinous histotype (RR = 2.30 [95% CI = 1.22-4.32]). Positive serology for chlamydia heat shock protein 60 (cHSP60-1) was associated with higher risk of EOC overall (1.36 [1.13-1.64]) and with the serous subtype (1.44 [1.12-1.85]). None of the other evaluated STIs were associated with EOC risk overall; however, HSV-2 was associated with higher risk of endometrioid EOC (2.35 [1.24-4.43]). The findings of our study suggest a potential role of C. trachomatis in the carcinogenesis of serous and mucinous EOC, while HSV-2 might promote the development of endometrioid disease.

Prevalence and impact of hepatitis B virus infection in ovarian cancer patients in an endemic area-A retrospective cohort study.

Hepatitis B virus (HBV) infection is associated with many extrahepatic malignancies, but its association with and impact on ovarian cancer has not been examined. We therefore examined the prevalence of HBV infection among women with primary ovarian carcinoma in an endemic area, and whether this impacts the presentation and survival of these patients. In a retrospective study, we reviewed 523 patients presenting with primary ovarian cancer and known HBV status between 1 January 2006 and 31 December 2017. Patients were divided into HBV-positive and negative groups for the comparison of the patient characteristics and presentation, including staging and histological types, and short term (2 years) mortality from ovarian cancer. Among the 10.1% (53/523) patients screened positive for HBV, more of them presented with advanced staging at FIGO stage 3 or above (OR 1.378, 95% CI 1.063-1.787), although there were no significant differences in patient characteristics. Within 24 months from presentation, there were more deaths due to malignancy in the HBV-positive group (73.3% vs 44.2%, OR 1.659, 95% CI 1.135-2.425). On multivariate analysis after adjusting for nulliparity status, previous use of oestrogens, presence of metastases, histological type (epithelial or others) and grading (high grade or not), whether optimal debulking was performed, and chemotherapy, HBV infection was independently associated with increased death within 24 months of presentation (aOR 2.683, 95% CI 1.015-7.091). In conclusion, the findings of this study suggested an adverse effect of chronic HBV infection on survival within two years of presentation in patients with primary ovarian cancer.

Management of patients with ovarian cancer in the COVID-19 era.

At the beginning of 2020, coronavirus disease 2019 (COVID-19) spreads worldwide. Patients with ovarian cancer should be considered at high-risk of developing severe morbidity related to COVID-19. Most of them are diagnosed in advanced stages of disease, and they are fragile. Here, we evaluated the major impact of COVID-19 on patients with ovarian cancer, discussing the effect of the outbreak on medical and surgical treatment.

Transtubal Spread of a Superficially Invasive Cervical Adenocarcinoma to the Ovaries After 11 Years.

We report a 55-yr-old woman who presented with bilateral ovarian masses, 11 yr after hysterectomy for superficially invasive stage IA1 cervical adenocarcinoma of usual (human papillomavirus-associated) type. The bilateral ovarian tumors were composed of glands lined by malignant mucinous epithelium and these tumors were metastases from her previous cervical adenocarcinoma, based on morphology, immunophenotype, and positive in situ hybridization for human papillomavirus. In addition, there was extensive involvement of the mucosa of the left fallopian tube by malignant mucinous epithelium. The patient is alive and well 2 yr after the ovarian recurrence. The phenomenon of minimally invasive cervical adenocarcinoma metastasizing to the ovary has been described previously; the extrauterine disease is typically limited to the ovaries and associated with a relatively favorable prognosis. The presence of fallopian tube involvement by cervical adenocarcinoma has rarely been reported, and suggests transtubal spread of tumor. Unique to this case is the >11 yr interval between diagnosis of the cervical and ovarian disease, with previously described cases showing up to a 7 yr latency period. This case demonstrates that spread of cervical adenocarcinoma to the ovaries, via the fallopian tube lumen, can occur after a very long latent period and this possibility must be considered when examining adnexal mass(es) in women who have previously had a hysterectomy for cervical adenocarcinoma.

Cloning of carrier cells infected with oncolytic adenovirus driven by midkine promoter and biosafety studies.

BACKGROUND: A549 carrier cells infected with oncolytic adenovirus can induce complete tumor reduction of subcutaneous ovarian tumors but not intraperitoneal disseminated ovarian tumors. This appears to be a result of the insufficient antitumor effect of A549 carrier cells. Therefore, in the present study, we cloned a novel carrier cell with the aim of improving the antitumor effects. METHODS: Carrier cells infected with oncolytic adenovirus AdE3-midkine with a midkine promoter were cloned by limiting dilution. We examined the antitumor effects of these cells on subcutaneous and intraperitoneal OVHM ovarian tumors in a syngeneic mouse model. Biosafety tests were conducted in beagle dogs and rabbits. RESULTS: We cloned EHMK-51-35 carrier cells with 10-fold higher antitumor effects compared to A549 carrier cells in vitro. EHMK-51-35 carrier cells co-infected with AdE3-midkine and Ad-mGM-CSF induced a 100% complete tumor reduction in subcutaneous tumors and a 60% reduction of intraperitoneal disseminated tumors. Single-dose acute toxicity test on beagle dogs with EHMK-51-35 carrier cells co-infected with AdE3-midkine and Ad-cGM-CSF showed no serious side effects. Biologically active adenoviruses were not detected in the blood, saliva, feces, urine or whole organs. In a chronic toxicity test, VX2 tumors in rabbits were injected five times with EHMK-51-35 carrier cells infected with AdE3-midkine and these rabbits showed no serious side effects. CONCLUSIONS: Significant antitumor effects and safety of cloned EHMK-51-35 carrier cells were confirmed in intraperitoneal ovarian tumors and toxicity tests, respectively. These findings will be extended to preclinical efficacy studies using dogs and cats, with the aim of conducting human clinical trials on refractory solid tumors.

HPV DNA integration site as proof of the origin of ovarian metastasis from endocervical adenocarcinoma: three case reports.

BACKGROUND: Most endocervical adenocarcinomas are human papillomavirus (HPV)-related cancers associated with p16 immunostaining. Ovarian metastasis from cervical cancer is a rare phenomenon, the mechanism of dissemination remains unclear. The diagnosis of metastasis may be difficult to establish when the ovarian neoplasm presents features consistent with primary tumor. Immunohistochemical expression of p16 in ovarian tumors can guide the diagnosis of metastasis from HPV-related cervical cancer, but p16 positivity is nonspecific. Identical HPV genotype in the paired endocervical and ovarian tumors is a better marker for cervical origin, which may also be confirmed by identical HPV integration site. CASE PRESENTATION: Two women presented with HPV18 cervical adenocarcinoma. No signs of disease were visible on MRI after treatment. After several years of follow-up, mucinous ovarian tumors were discovered in both patients. Molecular analyses showed that the ovarian lesions were HPV18-positive; indicating a primary cervical origin. A third woman was diagnosed with grade 1 ovarian endometrioid carcinoma with no peritoneal carcinomatosis. Final histological examination and HPV genotyping revealed HPV18-related in situ endometrioid adenocarcinoma in the endocervix and HPV18-related invasive endometrioid adenocarcinoma in the endometrium and both ovaries. Additional molecular analyses performed in two patients identified the same HPV integration sites in both the ovarian and cervical tumors, confirming that the ovarian mass was a metastasis from the cervical adenocarcinoma. CONCLUSION: We report three new cases of ovarian neoplasia in which the diagnosis of metastasis from cervical cancer was supported by the same HPV genotype and the same integration site in the paired cervical and ovarian tumors. To our knowledge, this is the first report of molecular evidence of the cervical origin of an ovarian metastasis. HPV screening should be performed in ovarian tumors for all patients with history of cervical neoplasia.

Spatial and temporal epithelial ovarian cancer cell heterogeneity impacts Maraba virus oncolytic potential.

BACKGROUND: Epithelial ovarian cancer exhibits extensive interpatient and intratumoral heterogeneity, which can hinder successful treatment strategies. Herein, we investigated the efficacy of an emerging oncolytic, Maraba virus (MRBV), in an in vitro model of ovarian tumour heterogeneity. METHODS: Four ovarian high-grade serous cancer (HGSC) cell lines were isolated and established from a single patient at four points during disease progression. Limiting-dilution subcloning generated seven additional subclone lines to assess intratumoral heterogeneity. MRBV entry and oncolytic efficacy were assessed among all 11 cell lines. Low-density receptor (LDLR) expression, conditioned media treatments and co-cultures were performed to determine factors impacting MRBV oncolysis. RESULTS: Temporal and intratumoral heterogeneity identified two subpopulations of cells: one that was highly sensitive to MRBV, and another set which exhibited 1000-fold reduced susceptibility to MRBV-mediated oncolysis. We explored both intracellular and extracellular mechanisms influencing sensitivity to MRBV and identified that LDLR can partially mediate MRBV infection. LDLR expression, however, was not the singular determinant of sensitivity to MRBV among the HGSC cell lines and subclones. We verified that there were no apparent extracellular factors, such as type I interferon responses, contributing to MRBV resistance. However, direct cell-cell contact by co-culture of MRBV-resistant subclones with sensitive cells restored virus infection and oncolytic killing of mixed population. CONCLUSIONS: Our data is the first to demonstrate differential efficacy of an oncolytic virus in the context of both spatial and temporal heterogeneity of HGSC cells and to evaluate whether it will constitute a barrier to effective viral oncolytic therapy.

Monitoring of biodistribution and persistence of conditionally replicative adenovirus in a murine model of ovarian cancer using capsid-incorporated mCherry and expression of human somatostatin receptor subtype 2 gene.

A significant limiting factor to the human clinical application of conditionally replicative adenovirus (CRAd)-based virotherapy is the inability to noninvasively monitor these agents and their potential persistence. To address this issue, we proposed a novel imaging approach that combines transient expression of the human somatostatin receptor (SSTR) subtype 2 reporter gene with genetic labeling of the viral capsid with mCherry fluorescent protein. To test this dual modality system, we constructed the Ad5/3Δ24pIXcherry/SSTR CRAd and validated its capacity to generate fluorescent and nuclear signals in vitro and following intratumoral injection. Analysis of 64Cu-CB-TE2A-Y3-TATE biodistribution in mice revealed reduced uptake in tumors injected with the imaging CRAd relative to the replication-incompetent, Ad-expressing SSTR2 but significantly greater uptake compared to the negative CRAd control. Optical imaging demonstrated relative correlation of fluorescent signal with virus replication as determined by viral genome quantification in tumors. Positron emission tomography/computed tomography studies demonstrated that we can visualize radioactive uptake in tumors injected with imaging CRAd and the trend for greater uptake by standardized uptake value analysis compared to control CRAd. In the aggregate, the plasticity of our dual imaging approach should provide the technical basis for monitoring CRAd biodistribution and persistence in preclinical studies while offering potential utility for a range of clinical applications.

Gemcitabine enhances the efficacy of reovirus-based oncotherapy through anti-tumour immunological mechanisms.

BACKGROUND: Reovirus preferentially infects and kills cancer cells and is currently undergoing clinical trials internationally. While oncolysis is the primary mode of tumour elimination, increasing evidence illustrates that reovirus additionally stimulates anti-tumour immunity with a capacity to target existing and possibly relapsing cancer cells. These virus-induced anti-tumour immune activities largely determine the efficacy of oncotherapy. On the other hand, anti-viral immune responses can negatively affect oncotherapy. Hence, the strategic management of anti-tumour and anti-viral immune responses through complementary therapeutics is crucial to achieve the maximum anti-cancer benefits of oncotherapy. METHODS: Intra-peritoneal injection of mouse ovarian surface epithelial cells (ID8 cells) into wild-type C57BL/6 mice was treated with a therapeutic regimen of reovirus and/or gemcitabine and then analysed for prolonged survival, disease pathology, and various immunological parameters. Furthermore, in vitro analyses were conducted to assess apoptosis, viral spread, and viral production during reovirus and/or gemcitabine treatment. RESULTS: We demonstrate that reovirus and gemcitabine combination treatment postpones peritoneal carcinomatosis development and prolongs the survival of cancer-bearing hosts. Importantly, these anti-cancer benefits are generated through various immunological mechanisms, including: (1) inhibition of myeloid-derived suppressor cells recruitment to the tumour microenvironment, (2) downmodulation of pro-MDSC factors, and (3) accelerated development of anti-tumour T-cell responses. CONCLUSION: The complementation of reovirus with gemcitabine further potentiates virus-initiated anti-cancer immunity and enhances the efficacy of oncotherapy. In the context of ongoing clinical trials, our findings represent clinically relevant information capable of enhancing cancer outcomes.

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.