Immune Profiling of Vulvar Squamous Cell Cancer Discovers a Macrophage-rich Subtype Associated with Poor Prognosis.

The incidence rates of vulvar squamous cell cancer (VSCC) have increased over the past decades, requiring personalized oncologic approaches. Currently, lymph node involvement is a key factor in determining prognosis and treatment options. However, there is a need for additional immune-related biomarkers to provide more precise treatment and prognostic information. Here, we used IHC and expression data to characterize immune cells and their spatial distribution in VSCC. Hierarchical clustering analysis identified distinct immune subtypes, of which the macrophage-rich subtype was associated with adverse outcome. This is consistent with our findings of increased lymphogenesis, lymphatic invasion, and lymph node involvement associated with high macrophage infiltration. Further in vitro studies showed that VSCC-associated macrophages expressed VEGF-A and subsequently induced VEGF-A in the VSCC cell line A-431, providing experimental support for a pro-lymphangiogenic role of macrophages in VSCC. Taken together, immune profiling in VSCC revealed tumor processes, identified a subset of patients with adverse outcome, and provided a valuable biomarker for risk stratification and therapeutic decision making for anti-VEGF treatment, ultimately contributing to the advancement of precision medicine in VSCC. SIGNIFICANCE: Immunoprofiling in VSCC reveals subtypes with distinct clinical and biological behavior. Of these, the macrophage-rich VSCC subtype is characterized by poor clinical outcome and increased VEGF-A expression, providing a biomarker for risk stratification and therapeutic sensitivity.

AHRR and SFRP2 in primary versus recurrent high-grade serous ovarian carcinoma and their prognostic implication.

BACKGROUND: The aim of this study was to analyse transcriptomic differences between primary and recurrent high-grade serous ovarian carcinoma (HGSOC) to identify prognostic biomarkers. METHODS: We analysed 19 paired primary and recurrent HGSOC samples using targeted RNA sequencing. We selected the best candidates using in silico survival and pathway analysis and validated the biomarkers using immunohistochemistry on a cohort of 44 paired samples, an additional cohort of 504 primary HGSOCs and explored their function. RESULTS: We identified 233 differential expressed genes. Twenty-three showed a significant prognostic value for PFS and OS in silico. Seven markers (AHRR, COL5A2, FABP4, HMGCS2, ITGA5, SFRP2 and WNT9B) were chosen for validation at the protein level. AHRR expression was higher in primary tumours (p < 0.0001) and correlated with better patient survival (p < 0.05). Stromal SFRP2 expression was higher in recurrent samples (p = 0.009) and protein expression in primary tumours was associated with worse patient survival (p = 0.022). In multivariate analysis, tumour AHRR and SFRP2 remained independent prognostic markers. In vitro studies supported the anti-tumorigenic role of AHRR and the oncogenic function of SFRP2. CONCLUSIONS: Our results underline the relevance of AHRR and SFRP2 proteins in aryl-hydrocarbon receptor and Wnt-signalling, respectively, and might lead to establishing them as biomarkers in HGSOC.

N6-methyladenosine RNA modification (m6A) is of prognostic value in HPV-dependent vulvar squamous cell carcinoma.

BACKGROUND: Vulvar squamous cell carcinoma (VSCC) is an uncommon gynecologic malignancy but with an increasing incidence in recent years. Etiologically, VSCC is classified into two subtypes: HPV-dependent and HPV-independent. Localized VSCC is treated surgically and/or with radiation therapy, but for advanced, metastatic or recurrent disease, therapeutic options are still limited. N6-methyladenosine (m6A) is the most prevalent post-transcriptional messenger RNA (mRNA) modification and involved in many physiological processes. The group of m6A proteins can be further divided into: 'writers' (METTL3, METTL4, METTL14, WTAP, KIAA1429), 'erasers' (FTO, ALKBH5), and 'readers' (HNRNPA2B1, HNRNPC, YTHDC1, YTHDF1-3). Dysregulated m6A modification is implicated in carcinogenesis, progression, metastatic spread, and drug resistance across various cancer entities. Up to date, however, only little is known regarding the role of m6A in VSCC. METHODS: Here, we comprehensively investigated protein expression levels of a diverse set of m6A writers, readers and erasers by applying immunohistochemical staining in 126 patients with primary VSCC. RESULTS: In the entire study cohort, dominated by HPV-independent tumors, m6A protein expression was not associated with clinical outcome. However, we identified enhanced protein expression levels of the 'writers' METTL3, METTL14 and the 'reader' YTHDC1 as poor prognostic markers in the 23 patients with HPV-dependent VSCC. CONCLUSION: Our study suggests dysregulated m6A modification in HPV-associated VSCC.

Diverse mutational landscapes in human lymphocytes.

The lymphocyte genome is prone to many threats, including programmed mutation during differentiation1, antigen-driven proliferation and residency in diverse microenvironments. Here, after developing protocols for expansion of single-cell lymphocyte cultures, we sequenced whole genomes from 717 normal naive and memory B and T cells and haematopoietic stem cells. All lymphocyte subsets carried more point mutations and structural variants than haematopoietic stem cells, with higher burdens in memory cells than in naive cells, and with T cells accumulating mutations at a higher rate throughout life. Off-target effects of immunological diversification accounted for approximately half of the additional differentiation-associated mutations in lymphocytes. Memory B cells acquired, on average, 18 off-target mutations genome-wide for every on-target IGHV mutation during the germinal centre reaction. Structural variation was 16-fold higher in lymphocytes than in stem cells, with around 15% of deletions being attributable to off-target recombinase-activating gene activity. DNA damage from ultraviolet light exposure and other sporadic mutational processes generated hundreds to thousands of mutations in some memory cells. The mutation burden and signatures of normal B cells were broadly similar to those seen in many B-cell cancers, suggesting that malignant transformation of lymphocytes arises from the same mutational processes that are active across normal ontogeny. The mutational landscape of normal lymphocytes chronicles the off-target effects of programmed genome engineering during immunological diversification and the consequences of differentiation, proliferation and residency in diverse microenvironments.

COOBoostR: An Extreme Gradient Boosting-Based Tool for Robust Tissue or Cell-of-Origin Prediction of Tumors.

We present here COOBoostR, a computational method designed for the putative prediction of the tissue- or cell-of-origin of various cancer types. COOBoostR leverages regional somatic mutation density information and chromatin mark features to be applied to an extreme gradient boosting-based machine-learning algorithm. COOBoostR ranks chromatin marks from various tissue and cell types, which best explain the somatic mutation density landscape of any sample of interest. A specific tissue or cell type matching the chromatin mark feature with highest explanatory power is designated as a potential tissue- or cell-of-origin. Through integrating either ChIP-seq based chromatin data, along with regional somatic mutation density data derived from normal cells/tissue, precancerous lesions, and cancer types, we show that COOBoostR outperforms existing random forest-based methods in prediction speed, with comparable or better tissue or cell-of-origin prediction performance (prediction accuracy-normal cells/tissue: 76.99%, precancerous lesions: 95.65%, cancer cells: 89.39%). In addition, our results suggest a dynamic somatic mutation accumulation at the normal tissue or cell stage which could be intertwined with the changes in open chromatin marks and enhancer sites. These results further represent chromatin marks shaping the somatic mutation landscape at the early stage of mutation accumulation, possibly even before the initiation of precancerous lesions or neoplasia.

RNA sequence analysis reveals macroscopic somatic clonal expansion across normal tissues.

How somatic mutations accumulate in normal cells is poorly understood. A comprehensive analysis of RNA sequencing data from ~6700 samples across 29 normal tissues revealed multiple somatic variants, demonstrating that macroscopic clones can be found in many normal tissues. We found that sun-exposed skin, esophagus, and lung have a higher mutation burden than other tested tissues, which suggests that environmental factors can promote somatic mosaicism. Mutation burden was associated with both age and tissue-specific cell proliferation rate, highlighting that mutations accumulate over both time and number of cell divisions. Finally, normal tissues were found to harbor mutations in known cancer genes and hotspots. This study provides a broad view of macroscopic clonal expansion in human tissues, thus serving as a foundation for associating clonal expansion with environmental factors, aging, and risk of disease.

Widespread Chromosomal Losses and Mitochondrial DNA Alterations as Genetic Drivers in Hürthle Cell Carcinoma.

Hürthle cell carcinoma of the thyroid (HCC) is a form of thyroid cancer recalcitrant to radioiodine therapy that exhibits an accumulation of mitochondria. We performed whole-exome sequencing on a cohort of primary, recurrent, and metastatic tumors, and identified recurrent mutations in DAXX, TP53, NRAS, NF1, CDKN1A, ARHGAP35, and the TERT promoter. Parallel analysis of mtDNA revealed recurrent homoplasmic mutations in subunits of complex I of the electron transport chain. Analysis of DNA copy-number alterations uncovered widespread loss of chromosomes culminating in near-haploid chromosomal content in a large fraction of HCC, which was maintained during metastatic spread. This work uncovers a distinct molecular origin of HCC compared with other thyroid malignancies.

Tumoral PD-L1 expression defines a subgroup of poor-prognosis vulvar carcinomas with non-viral etiology.

Vulvar cancer is rare but incidence rates are increasing due to an aging population and higher frequencies of young women being affected. In locally advanced, metastatic or recurrent disease prognosis is poor and new treatment modalities are needed. Immune checkpoint blockade of the PD-1/PD-L1 pathway is one of the most important advancements in cancer therapy in the last years. The clinical relevance of PD-L1 expression in vulvar cancer, however, has not been studied so far. We determined PD-L1 expression, numbers of CD3+ T cells, CD20+ B cells, CD68+ monocytes/macrophages, Foxp3+ regulatory T cells and CD163+ tumor-associated macrophages by immunohistochemistry in 103 patients. Correlation analysis with clinicopathological parameters was undertaken; the cause-specific outcome was modeled with competing risk analysis; multivariate Cox regression was used to determine independent predictors of survival. Membranous PD-L1 was expressed in a minority of tumors, defined by HPV-negativity. Its presence geographically correlated with immunocyte-rich regions of cancer islets and was an independent prognostic factor for poor outcome. Our data support the notion that vulvar cancer is an immunomodulatory tumor that harnesses the PD-1/PD-L1 pathway to induce tolerance. Accordingly, immunotherapeutic approaches might have the potential to improve outcome in patients with vulvar cancer and could complement conventional cancer treatment.

A mutational signature reveals alterations underlying deficient homologous recombination repair in breast cancer.

Biallelic inactivation of BRCA1 or BRCA2 is associated with a pattern of genome-wide mutations known as signature 3. By analyzing ∼1,000 breast cancer samples, we confirmed this association and established that germline nonsense and frameshift variants in PALB2, but not in ATM or CHEK2, can also give rise to the same signature. We were able to accurately classify missense BRCA1 or BRCA2 variants known to impair homologous recombination (HR) on the basis of this signature. Finally, we show that epigenetic silencing of RAD51C and BRCA1 by promoter methylation is strongly associated with signature 3 and, in our data set, was highly enriched in basal-like breast cancers in young individuals of African descent.

Individual management of cervical cancer in pregnancy.

PURPOSE: The management of cervical cancer in pregnancy persists to be challenging. Therefore, identification of factors that influence the choice of therapeutic management is pivotal for an adequate patient counseling. METHODS: We present a literature review of 26 studies reporting 121 pregnancies affected by cervical cancer. Additionally, we add a retrospective case series of five patients with pregnancy-associated cervical cancer diagnosed and treated in our clinic between 2006 and 2013. RESULTS: The literature review revealed that the therapeutic management during pregnancy varies according to the gestational age at diagnosis, while in the postpartum period no influence on the treatment choice could be detected. Also in our case series the choice of oncologic therapy was influenced by the gestational age, the wish to continue the pregnancy and the risks of delaying definitive treatment. CONCLUSIONS: There are no standardized procedures concerning the treatment of cervical cancer in pregnancy. Therefore, in consultation with the patient and a multidisciplinary team, an adequate individualized treatment plan should be determined.

Sequence-specific activation of the DNA sensor cGAS by Y-form DNA structures as found in primary HIV-1 cDNA.

Cytosolic DNA that emerges during infection with a retrovirus or DNA virus triggers antiviral type I interferon responses. So far, only double-stranded DNA (dsDNA) over 40 base pairs (bp) in length has been considered immunostimulatory. Here we found that unpaired DNA nucleotides flanking short base-paired DNA stretches, as in stem-loop structures of single-stranded DNA (ssDNA) derived from human immunodeficiency virus type 1 (HIV-1), activated the type I interferon-inducing DNA sensor cGAS in a sequence-dependent manner. DNA structures containing unpaired guanosines flanking short (12- to 20-bp) dsDNA (Y-form DNA) were highly stimulatory and specifically enhanced the enzymatic activity of cGAS. Furthermore, we found that primary HIV-1 reverse transcripts represented the predominant viral cytosolic DNA species during early infection of macrophages and that these ssDNAs were highly immunostimulatory. Collectively, our study identifies unpaired guanosines in Y-form DNA as a highly active, minimal cGAS recognition motif that enables detection of HIV-1 ssDNA.

Accumulation of ALDH1-positive cells after neoadjuvant chemotherapy predicts treatment resistance and prognosticates poor outcome in ovarian cancer.

Although ovarian cancer is a highly chemosensitive disease, it is only infrequently cured. One of the major reasons lies in the presence of drug-resistant cancer stem-like cells, sufficient to fuel recurrence. We phenotyped cancer stem-like cells by flow cytometry and immunohistochemistry in 55 matched samples before and after taxane/platinum-based neoadjuvant chemotherapy. All used markers of stemness (ALDH1, CD24, CD117, CD133) isolated low frequencies of malignant cells. ALDH1 was the most valuable marker for tracking stemness in vivo. The enrichment of ALDH1 expression after treatment was associated with a poor response to chemotherapy, with platinum resistance and independently prognosticated unfavorable outcome. Our results suggest that increased ALDH1 expression after treatment identifies patients with aggressive tumor phenotypes.

c-myc copy number gain is a powerful prognosticator of disease outcome in cervical dysplasia.

Cervical carcinoma develops from preneoplasia by a multistep process. Although most low-grade dysplastic lesions will regress without intervention and even high-grade changes exhibit a substantial rate of regression, a small percentage of dysplasia will progress over time. Thus, indicators are needed to estimate the biological risk and to help avoid overtreatment in women who desire to preserve fertility. In addition to the classical biomarkers, PCR-ELISA-determined HPV genotype and immunohistochemically assessed p16INK4a and Ki-67 expression, cells with integrated HPV and copy number gain of TERC and c-myc were quantified in a panel of 104 benign, intraepithelial neoplastic (CIN I, II, III) and cancerous lesions using fluorescence in situ hybridization. Optimal cut-off values were calculated; Kaplan-Meier curves and a Cox proportional hazard regression model were used to evaluate prognostic signatures. The assay reliably identified HPV integration, TERC and c-myc copy number gain as determined by comparisons with established biomarkers. All biomarker levels increased with the progression of the disease. However, only c-myc copy number gain independently prognosticated a low probability of dysplastic regression. Our results suggest that c-myc plays a key role in the process of dysplastic transformation and might thus be exploited for treatment and follow-up decision-making of cervical dysplasia.

Prognostic significance of tumor-associated macrophages in endometrial adenocarcinoma.

OBJECTIVE: Endometrial adenocarcinoma is one of the most common gynecologic malignancies worldwide and in stages confined to the uterus considered to have an excellent prognosis. However, in advanced or recurrent cases when surgery fails to achieve disease control other treatment options are less effective. Thus, new therapeutic avenues are needed. METHODS: To provide the rationale for the use of novel agents that target immune checkpoints 163 type I endometrial cancer samples were immunohistochemically screened for the presence of CD163(+) tumor-associated macrophages and Foxp3(+) regulatory T cells. Further, a D2-40-based evaluation of lymph vessel density and lymphovascular space invasion was carried out. Correlation analysis with clinicopathological parameters was performed; Kaplan-Meier curves were generated; multivariate analysis was undertaken as appropriate. RESULTS: A substantial amount of tumor-associated macrophages and regulatory T cells was detected in all specimens characterizing endometrial cancer as an immunogenic tumor. However, only the increased infiltration of tumor-associated macrophages was proportionally associated with advanced FIGO stages, high tumor grade, increased lymph vessel density, lymphovascular space invasion and lymph node metastasis. Thus, the presence of tumor-associated macrophages indicates aggressive tumor behavior and appeared to be an independent prognostic factor for recurrence-free survival. CONCLUSIONS: Our results make future therapeutic approaches that target tumor-associated macrophages reasonable to improve the outcome of women with advanced or recurrent endometrial adenocarcinoma.

Interval debulking surgery in patients with Federation of Gynecology and Obstetrics (FIGO) stage IIIC and IV ovarian cancer.

BACKGROUND: The feasibility of neoadjuvant chemotherapy (NAC) and the outcome in patients with Federation of Gynecology and Obstetrics (FIGO) IIIC and IV ovarian cancer were assessed. PATIENTS AND METHODS: 67 patients undergoing interval debulking surgery (IDS) and ≥ 4 courses of platinum-based NAC were analyzed for survival, perioperative morbidity and mortality. RESULTS: The median follow-up was 30 months. The median progression-free survival (PFS) was 17 months, the overall survival (OS) 34 months. The PFS of patients without residual disease (n = 23; 34.3%) was 31 months (p = 0.003), the OS 65 months (p = 0.001). PFS and OS were significantly longer in patients with no residual disease than in patients with 1-10 mm (n = 34; 47.9%) (p = 0.005 and p = 0.0001, respectively) residual disease. No survival benefit was seen for patients with 1-10 mm compared to > 1 cm (n = 12; 16.9%) residual disease (PFS p = 0.518; OS p = 0.077). 1 patient (1.4%) died; 12 patients needed interventional treatment or operation (16.9%) within the first 30 days postoperatively. Out of these, 5 patients (7.0%) had residual or lasting disability. CONCLUSIONS: NAC and IDS are safe and feasible in this series of patients with unfavorable prognosis. IDS does not change the goal of complete cytoreduction and therefore does not compensate for a less radical surgical approach.

Cardiorenal syndrome is present in human fetuses with severe, isolated urinary tract malformations.

OBJECTIVE: We analyzed the association between renal and cardiovascular parameters in fetuses with isolated severe urinary tract malformations. METHODS: 39 fetuses at a mean gestational age of 23.6 weeks with nephropathies or urinary tract malformations and markedly impaired or absent renal function were prospectively examined. Fetal echocardiography was performed, and thicknesses of the interventricular septum, and left and right ventricular wall were measured. Blood flow velocity waveforms of the umbilical artery, middle cerebral artery, and ductus venosus were obtained by color Doppler ultrasound. Concentrations of circulating n-terminal pro-B-type natriuretic peptide (nt-proBNP), cystatin C, ß2-microglobulin, and hemoglobin were determined from fetal blood samples. RESULTS: Malformations included 21 cases of obstructive uropathy, 10 fetuses with bilateral nephropathy, and 8 cases of bilateral renal agenesis. Marked biventricular myocardial hypertrophy was present in all cases. The ratio between measured and gestational age-adjusted normal values was 2.01 (interventricular septum), 1.85, and 1.78 (right and left ventricular wall, respectively). Compared to controls, levels of circulating nt-proBNP were significantly increased (median (IQR) 5035 ng/L (5936 ng/L) vs. 1874 ng/L (1092 ng/L); p<0.001). Cystatin C and ß2-microglobulin concentrations were elevated as follows (mean ± SD) 1.85±0.391 mg/L and 8.44±2.423 mg/L, respectively (normal range 1.66±0.202 mg/L and 4.25±0.734 mg/L, respectively). No correlation was detected between cardiovascular parameters and urinary tract morphology and function. Despite increased levels of nt-proBNP cardiovascular function was preserved, with normal fetal Doppler indices in 90.2% of cases. CONCLUSION: Urinary tract malformations resulting in severe renal impairment are associated with biventricular myocardial hypertrophy and elevated concentrations of circulating nt-proBNP during fetal life. Cardiovascular findings do not correlate with kidney function or morphology.

Circulating N-terminal pro-B-type natriuretic peptide in fetal anemia before and after treatment.

BACKGROUND: N-terminal pro-B-type natriuretic peptide (ntproBNP) is an established marker of heart failure in adult cardiology. We analyzed nt-proBNP in the circulation of fetuses with increased volume load secondary to anemia and investigated the effect of treatment on nt-proBNP concentration. METHODS: Fetuses undergoing intrauterine transfusion (IUT) were examined. nt-proBNP was measured before IUT and correlated with hemoglobin concentrations, ultrasonographic findings, and Doppler measurements of the peak systolic velocity of the middle cerebral artery (MCA-PSV). RESULTS: A total of 27 patients (7 with hydrops) and 78 controls were examined. nt-proBNP was markedly elevated in anemia (P < 0.001). Concentrations were highest in hydropic fetuses (P < 0.03); no differences were present in hemoglobin and MCA-PSV values between hydropic and nonhydropic cases. In fetuses undergoing multiple IUTs nt-proBNP normalized after the third IUT, whereas hemoglobin and MCA-PSV remained abnormal. CONCLUSION: Levels of circulating nt-proBNP correlate well with the degree of myocardial workload in the hyperdynamic state of fetal anemia. We hypothesize that normalization of nt-proBNP after serial transfusions is an indicator of myocardial adjustment to chronic anemia. nt-proBNP measurement may be useful in the management of fetal anemia, particularly in cases at risk of hydrops and fetuses requiring multiple transfusions.

N-terminal pro-B-type natriuretic peptide in the circulation of fetuses with cardiac malformations.

Cardiac malformations with impact on loading patterns have the potential to progress to irreversible loss of ventricular function during human fetal life. N-terminal pro-B-type natriuretic peptide (nt-proBNP) is a marker of cardiac dysfunction and involved in cardiac remodeling and fibrosis. We evaluated nt-proBNP levels in the circulation of human fetuses with cardiac defects. A total of 45 cases and 75 controls during the second half of gestation were recruited. Nt-proBNP concentrations were determined in venous specimens obtained by fetal blood sampling. Results were correlated to echocardiography and Doppler studies. Mean gestational age was 26.9 weeks (range 21.0-33.4 weeks). Levels of circulating nt-proBNP were elevated in fetuses with cardiac defects (mean 6,896 ng/L (range 595-42,479 ng/L) vs. 1,867 ng/L (73-3,751 ng/L), p < 0.001). In the presence of abnormal Doppler indices a further increase was detected (mean 11,287 ng/L (range 1,403-42,479 ng/L) vs. 4,659 ng/L (595-30,848 ng/L), p = 0.021). No difference was found in fetuses with co-existing growth restriction. Malformations were classified according to their hemodynamic effect. Compared to shunt defects nt-proBNP concentrations were significantly higher in left or right ventricular outflow tract obstruction with intact ventricular septum (mean 15,639 ng/L (range 2,301-42,479 ng/L) vs. 3,891 ng/L (595-13,752 ng/L), p = 0.013), and corresponded to the degree of ventricular dysfunction. In the circulation of human fetuses with cardiac defects levels of circulating nt-proBNP are elevated. Concentrations correlate with the type of myocardial wall stress. This finding supports a role for nt-proBNP as early indicator of intrauterine cardiovascular dysfunction and cardiac remodeling.

Immunogenic cell death of human ovarian cancer cells induced by cytosolic poly(I:C) leads to myeloid cell maturation and activates NK cells.

Owing to high rates of tumor relapse, ovarian cancer remains a fatal disease for which new therapeutic approaches are urgently needed. Accumulating evidence indicates that immune stimulation may delay or even prevent disease recurrence in ovarian cancer. In order to elicit proinflammatory signals that induce or amplify antitumor immune reactivity, we mimicked viral infection in ascites-derived ovarian cancer cells. By transfection or electroporation we targeted the synthetic double-stranded RNA poly(I:C) intracellularly in order to activate melanoma differentiation-associated gene-5 (MDA-5), a sensor of viral RNA in the cytosol of somatic cells. Cancer cells reacted with enhanced expression of HLA-class I, release of CXCL10, IL-6, and type I IFN as well as tumor cell apoptosis. Monocytes and monocyte-derived DCs (MoDCs) engulfed MDA-5-activated cancer cells, and subsequently upregulated HLA-class I/II and costimulatory molecules, and secreted CXCL10 and IFN-α. Further, this proinflammatory milieu promoted cytolytic activity and IFN-γ secretion of NK cells. Thus, our data suggest that the engagement of MDA-5 in a whole tumor cell vaccine is a promising approach for the immunotherapy of ovarian cancer.

Targeted activation of RNA helicase retinoic acid-inducible gene-I induces proimmunogenic apoptosis of human ovarian cancer cells.

Most malignant cells are poorly immunogenic and fail to elicit an effective antitumor immune response. In contrast, viral infections of cells are promptly detected and eliminated by the immune system. Viral recognition critically hinges on cytosolic nucleic acid receptors that include the proinflammatory RNA helicase retinoic acid-inducible gene-I (RIG-I). Here, we show that targeted delivery of RIG-I agonists induced ovarian cancer cells to upregulate HLA class I and to secrete the proinflammatory cytokines CXCL10, CCL5, interleukin-6, tumor necrosis factor-alpha, and IFN-beta. Ovarian cancer cells stimulated via RIG-I became apoptotic and were readily phagocytosed by monocytes and monocyte-derived dendritic cells, which in turn upregulated HLA class I/II and costimulatory molecules and released CXCL10 and IFN-alpha. Our findings offer proof of principle that mimicking viral infection in ovarian cancer cells triggers an immunogenic form of tumor cell apoptosis that may enhance immunotherapy of ovarian cancer.