Efficacy and safety of PD-1/PD-L1 immune checkpoint inhibitors in the treatment of recurrent ovarian cancer: A systematic review and meta-analysis.

BACKGROUND: Recurrent ovarian cancer (OC) presents a significant therapeutic challenge with limited treatment success. Programmed cell death protein 1 (PD-1/PD-L1) immune checkpoint inhibitors have emerged as a potential treatment avenue, necessitating a systematic review and meta-analysis to evaluate their efficacy and safety. METHODS: Adhering to preferred reporting items for systematic reviews and meta-analyses guidelines, we conducted a comprehensive literature search across PubMed, Embase, Web of Science, and Cochrane Library, culminating in the inclusion of studies focusing on the treatment of recurrent OC with PD-1/PD-L1 inhibitors. Studies were evaluated using the Newcastle-Ottawa Scale and analyzed using fixed or random effects models depending on heterogeneity levels. RESULTS: Our search yielded 1215 articles, with 6 meeting the inclusion criteria for final analysis. Studies varied in size and reported median age, overall survival (OS), progression-free survival (PFS), and adverse events. The meta-analysis showed improved Objective Response Rates (ORR), Disease Control Rate (DCR), and PFS in patients treated with PD-1/PD-L1 inhibitors. The overall adverse event rate was 17.9%, indicating a need for careful patient selection and monitoring. No significant publication bias was detected, enhancing the reliability of our findings. CONCLUSIONS: PD-1/PD-L1 inhibitors offer a promising treatment option for recurrent OC, improving ORR, DCR, and PFS. However, the higher incidence of adverse events necessitates a cautious approach to their use. Future research should focus on long-term outcomes, biomarker identification, and optimal combination therapies.

Immunoglobulins and serum proteins impair anti-tumor NK cell effector functions in malignant ascites.

Introduction: Malignant ascites indicates ovarian cancer progression and predicts poor clinical outcome. Various ascites components induce an immunosuppressive crosstalk between tumor and immune cells, which is poorly understood. In our previous study, imbalanced electrolytes, particularly high sodium content in malignant ascites, have been identified as a main immunosuppressive mechanism that impaired NK and T-cell activity. Methods: In the present study, we explored the role of high concentrations of ascites proteins and immunoglobulins on antitumoral NK effector functions. To this end, a coculture system consisting of healthy donor NK cells and ovarian cancer cells was used. The anti-EGFR antibody Cetuximab was added to induce antibody-dependent cellular cytotoxicity (ADCC). NK activity was assessed in the presence of different patient ascites samples and immunoglobulins that were isolated from ascites. Results: Overall high protein concentration in ascites impaired NK cell degranulation, conjugation to tumor cells, and intracellular calcium signaling. Immunoglobulins isolated from ascites samples competitively interfered with NK ADCC and inhibited the conjugation to target cells. Furthermore, downregulation of regulatory surface markers CD16 and DNAM-1 on NK cells was prevented by ascites-derived immunoglobulins during NK cell activation. Conclusion: Our data show that high protein concentrations in biological fluids are able to suppress antitumoral activity of NK cells independent from the mechanism mediated by imbalanced electrolytes. The competitive interference between immunoglobulins of ascites and specific therapeutic antibodies could diminish the efficacy of antibody-based therapies and should be considered in antibody-based immunotherapies.

Profiling of Tumour-Infiltrating Lymphocytes and Tumour-Associated Macrophages in Ovarian Epithelial Cancer-Relation to Tumour Characteristics and Impact on Prognosis.

Early evidence suggests a strong impact of tumour-infiltrating lymphocytes (TILs) on both the prognosis and clinical behaviour of ovarian cancer. Proven associations, however, have not yet translated to successful immunotherapies and further work in the field is urgently needed. We aimed to analyse the tumour microenvironment of a well-characterised cohort of ovarian cancer samples. Tumour markers were selected owing to their comparative underrepresentation in the current literature. Paraffin-embedded, formalin-fixed tumour tissue blocks of 138 patients representative of the population and including early stage disease were identified, stained for CD3, CD20, CD68 and CD163 and analysed for both the stromal and intertumoral components. Data were statistically analysed in relation to clinical details, histological subtype, borderline vs. malignant status, survival and management received. Mean stromal CD3, total CD3 count, mean stromal CD20 and total CD20 count all correlated negatively with survival. Malignant ovarian tumours consistently demonstrated significantly higher infiltration of all analysed immune cells than borderline tumours. Assessment of the stromal compartment produced a considerably higher proportion of significant results when compared to the intra-tumoural infiltrates. Customary assessment of solely intra-tumoural cells in advanced stage disease patients undergoing primary debulking surgery should be challenged, with recommendations for future scoring systems provided.

Serum anti-CFL1, anti-EZR, and anti-CYPA autoantibody as diagnostic markers in ovarian cancer.

The purpose of this study was to identify novel autoantibodies against tumor-associated antigens (TAAs) and explore a diagnostic panel for Ovarian cancer (OC). Enzyme-linked immunosorbent assay was used to detect the expression of five anti-TAA autoantibodies in the discovery (70 OC and 70 normal controls) and validation cohorts (128 OC and 128 normal controls). Machine learning methods were used to construct a diagnostic panel. Serum samples from 81 patients with benign ovarian disease were used to identify the specificity of anti-TAA autoantibodies for OC. In both the discovery and validation cohorts, the expression of anti-CFL1, anti-EZR, anti-CYPA, and anti-PFN1 was higher in patients with OC than that in normal controls. The area under the receiver operating characteristic curve, sensitivity, and specificity of the panel containing anti-CFL1, anti-EZR, and anti-CYPA were 0.762, 55.56%, and 81.31%. The panel identified 53.06%, 53.33%, and 51.11% of CA125 negative, HE4 negative and the Risk of Ovarian Malignancy Algorithm negative OC patients, respectively. The combination of the three anti-TAA autoantibodies can serve as a favorable diagnostic tool for OC and has the potential to be a complementary biomarker for CA125 and HE4 in the diagnosis of ovarian cancer.

Prospects and challenges of CAR-T in the treatment of ovarian cancer.

Ovarian cancer ranks as the seventh most prevalent cancer among women and is considered the most lethal gynecological malignancy on a global scale. The absence of reliable screening techniques, coupled with the insidious onset of nonspecific symptoms, often results in a delayed diagnosis, typically at an advanced stage characterized by peritoneal involvement. Management of advanced tumors typically involves a combination of chemotherapy and cytoreductive surgery. However, the therapeutic arsenal for ovarian cancer patients remains limited, highlighting the unmet need for precise, targeted, and sustained-release pharmacological agents. Genetically engineered T cells expressing chimeric antigen receptors (CARs) represent a promising novel therapeutic modality that selectively targets specific antigens, demonstrating robust and enduring antitumor responses in numerous patients. CAR T cell therapy has exhibited notable efficacy in hematological malignancies and is currently under investigation for its potential in treating various solid tumors, including ovarian cancer. Currently, numerous researchers are engaged in the development of novel CAR-T cells designed to target ovarian cancer, with subsequent evaluation of these candidate cells in preclinical studies. Given the ability of chimeric antigen receptor (CAR) expressing T cells to elicit potent and long-lasting anti-tumor effects, this therapeutic approach holds significant promise for the treatment of ovarian cancer. This review article examines the utilization of CAR-T cells in the context of ovarian cancer therapy.

Tim4 enables large peritoneal macrophages to cross-present tumor antigens at early stages of tumorigenesis.

Receptors controlling the cross-presentation of tumor antigens by macrophage subsets in cancer tissues are poorly explored. Here, we show that TIM4+ large peritoneal macrophages efficiently capture and cross-present tumor-associated antigens at early stages of peritoneal infiltration by ovarian cancer cells. The phosphatidylserine (PS) receptor TIM4 promotes maximal uptake of dead cells or PS-coated artificial targets and triggers inflammatory and metabolic gene programs in combination with cytoskeletal remodeling and upregulation of transcriptional signatures related to antigen processing. At the cellular level, TIM4-mediated engulfment induces nucleation of F-actin around nascent phagosomes, delaying the recruitment of vacuolar ATPase, acidification, and cargo degradation. In vivo, TIM4 deletion blunts induction of early anti-tumoral effector CD8 T cells and accelerates the progression of ovarian tumors. We conclude that TIM4-mediated uptake drives the formation of specialized phagosomes that prolong the integrity of ingested antigens and facilitate cross-presentation, contributing to immune surveillance of the peritoneum.

Targeting the GPI transamidase subunit GPAA1 abrogates the CD24 immune checkpoint in ovarian cancer.

CD24 is frequently overexpressed in ovarian cancer and promotes immune evasion by interacting with its receptor Siglec10, present on tumor-associated macrophages, providing a "don't eat me" signal that prevents targeting and phagocytosis by macrophages. Factors promoting CD24 expression could represent novel immunotherapeutic targets for ovarian cancer. Here, using a genome-wide CRISPR knockout screen, we identify GPAA1 (glycosylphosphatidylinositol anchor attachment 1), a factor that catalyzes the attachment of a glycosylphosphatidylinositol (GPI) lipid anchor to substrate proteins, as a positive regulator of CD24 cell surface expression. Genetic ablation of GPAA1 abolishes CD24 cell surface expression, enhances macrophage-mediated phagocytosis, and inhibits ovarian tumor growth in mice. GPAA1 shares structural similarities with aminopeptidases. Consequently, we show that bestatin, a clinically advanced aminopeptidase inhibitor, binds to GPAA1 and blocks GPI attachment, resulting in reduced CD24 cell surface expression, increased macrophage-mediated phagocytosis, and suppressed growth of ovarian tumors. Our study highlights the potential of targeting GPAA1 as an immunotherapeutic approach for CD24+ ovarian cancers.

Machine learning developed a CD8+ exhausted T cells signature for predicting prognosis, immune infiltration and drug sensitivity in ovarian cancer.

CD8+ exhausted T cells (CD8+ Tex) played a vital role in the progression and therapeutic response of cancer. However, few studies have fully clarified the characters of CD8+ Tex related genes in ovarian cancer (OC). The CD8+ Tex related prognostic signature (TRPS) was constructed with integrative machine learning procedure including 10 methods using TCGA, GSE14764, GSE26193, GSE26712, GSE63885 and GSE140082 dataset. Several immunotherapy benefits indicators, including Tumor Immune Dysfunction and Exclusion (TIDE) score, immunophenoscore (IPS), TMB score and tumor escape score, were used to explore performance of TRPS in predicting immunotherapy benefits of OC. The TRPS constructed by Enet (alpha = 0.3) method acted as an independent risk factor for OC and showed stable and powerful performance in predicting clinical outcome of patients. The C-index of the TRPS was higher than that of tumor grade, clinical stage, and many developed signatures. Low TRPS score indicated a higher level of CD8+ T cell, B cell, macrophage M1, and NK cells, representing a relative immunoactivated ecosystem in OC. OC patients with low risk score had a higher PD1&CTLA4 immunophenoscore, higher TMB score, lower TIDE score and lower tumor escape score, suggesting a better immunotherapy response. Moreover, higher TRPS score indicated a higher score of cancer-related hallmarks, including angiogenesis, EMT, hypoxia, glycolysis, and notch signaling. Vitro experiment showed that ARL6IP5 was downregulated in OC tissues and inhibited tumor cell proliferation. The current study constructed a novel TRPS for OC, which could serve as an indicator for predicting the prognosis, immune infiltration and immunotherapy benefits for OC patients.

Interferon epsilon and ovarian cancer.

Most biologists know of the interferons IFNα, IFNß, and IFNγ and their roles in immunity and infection, but they may not have heard of IFNε. A recent study in Nature suggests that IFNε can act as a tumor suppressor in serous ovarian cancers.

[Solid Tumors With Cold Agglutinins:Report of Two Cases and Literature Review].

Cold agglutinins(CA),autoantibodies against the antigen I or i on the surface of red blood cells,are mainly of IgM class,and the majority have κ light chains.They can lead to red blood cell agglutination at decreased body temperature and are usually associated with infections,drug reactions,autoimmune diseases,and hematological malignancies.However,solid tumors with CA are rare.We reported two cases of CA in the peripheral blood of patients with solid tumors.Peripheral complete blood cell count of the patients at admission showed reduced erythrocyte count and hematocrit,mismatching between erythrocyte count and hemoglobin,abnormally elevated levels of mean corpuscular hemoglobin and mean cell hemoglobin concentration.Peripheral blood smear showed erythrocyte aggregation.After the sample was preheated at 37 ℃ for 30 min,the reversibility of red blood cell aggregation was observed,and the erythrocyte parameters were corrected.

Interferon-ε is a tumour suppressor and restricts ovarian cancer.

High-grade serous ovarian cancers have low survival rates because of their late presentation with extensive peritoneal metastases and frequent chemoresistance1, and require new treatments guided by novel insights into pathogenesis. Here we describe the intrinsic tumour-suppressive activities of interferon-ε (IFNε). IFNε is constitutively expressed in epithelial cells of the fallopian tube, the cell of origin of high-grade serous ovarian cancers, and is then lost during development of these tumours. We characterize its anti-tumour activity in several preclinical models: ovarian cancer patient-derived xenografts, orthotopic and disseminated syngeneic models, and tumour cell lines with or without mutations in Trp53 and Brca genes. We use manipulation of the IFNε receptor IFNAR1 in different cell compartments, differential exposure status to IFNε and global measures of IFN signalling to show that the mechanism of the anti-tumour activity of IFNε involves direct action on tumour cells and, crucially, activation of anti-tumour immunity. IFNε activated anti-tumour T and natural killer cells and prevented the accumulation and activation of myeloid-derived suppressor cells and regulatory T cells. Thus, we demonstrate that IFNε is an intrinsic tumour suppressor in the female reproductive tract whose activities in models of established and advanced ovarian cancer, distinct from other type I IFNs, are compelling indications of potential new therapeutic approaches for ovarian cancer.

Tumor immune microenvironment changes are associated with response to neoadjuvant chemotherapy and long-term survival benefits in advanced epithelial ovarian cancer: A pilot study.

Little is known about the association between efficacy of neoadjuvant chemotherapy (NACT)/survival and the dynamic change of tumor immune environment (TIME) during treatment in epithelial ovarian cancer (EOC). This study investigated the TIME landscape of treatment-naive EOC tumors using multiplex immunofluorescence and associated the TIME before and after platinum-based NACT with treatment efficacy and prognosis in 33 patients with advanced EOC. NACT significantly increased the density of CD8+ T cells (P = 0.033), CD20+ B cells (P = 0.023), CD56 NK cells (P = 0.041), PD-1+ cells (P = 0.042), and PD-L1+CD68+ macrophages (P = 0.005) in the tissue specimens. Response to NACT was evaluated using CA125 response and chemotherapy response score (CRS). Compared with the non-responders, the responders displayed a larger proportion of tumors showing increase in the infiltration of CD20+ cells (P = 0.046) and in the M1/M2 ratio (P = 0.038) as well as fewer tumors showing increase in the infiltration of CD56bright cells (P = 0.041). No association was found between pre-NACT TIME and response to NACT. Density of pre-NACT CD8+ cells was positively associated with longer progression-free survival (PFS) (P = 0.011) and overall survival (OS) (P = 0.048). Post-NACT CD20+ and CD163+ macrophages (M2) infiltrates were associated with prolonged (P = 0.005) and shortened PFS (P = 0.021), respectively. Increase in the density of CD4+ T cells was predictive for longer PFS (P = 0.022) and OS (P = 0.023). In the multivariate analysis, high density of CD8+ cells pre-NACT (P = 0.042) were independently associated with improved OS.

TIPE2 acts as a tumor suppressor and correlates with tumor microenvironment immunity in epithelial ovarian cancer.

BACKGROUND: Epithelial ovarian cancer (EOC) is one of the deadliest gynecologic cancers. The etiology of EOC has still not been elucidated thoroughly. Tumor necrosis factor-α-induced protein 8-like2 (TNFAIP8L2, TIPE2), an important regulator of inflammation and immune homeostasis, plays a critical role in the progression of various cancers. This study aims to investigate the role of TIPE2 in EOC. METHODS: Expression of TIPE2 protein and mRNA in EOC tissues and cell lines was examined using Western blot and quantitative real-time PCR (qRT-PCR). The functions of TIPE2 in EOC were investigated by cell proliferation assay, colony assay, transwell assay, and apoptosis analysis in vitro. To further investigate the regulatory mechanisms of TIPE2 in EOC, RNA-seq and western blot were performed. Finally, the CIBERSORT algorithm and databases including Tumor Immune Single-cell Hub (TISCH), Tumor Immune Estimation Resource (TIMER), Tumor-Immune System Interaction (TISIDB), and The Gene Expression Profiling Interactive Analysis (GEPIA) were used to elucidate its potential role in regulating tumor immune infiltration in the tumor microenvironment (TME). RESULTS: TIPE2 expression was shown to be considerably lower in both EOC samples and cell lines. Overexpression of TIPE2 suppressed EOC cell proliferation, colony formation, and motility in vitro. Mechanistically, TIPE2 suppressed EOC by blocking the PI3K/Akt signaling pathway, according to bioinformatics analysis and western blot in TIPE2 overexpression EOC cell lines, and the anti-oncogenic potentials of TIPE2 in EOC cells could be partially abrogated by the PI3K agonist, 740Y-P. Finally, TIPE2 expression was positively associated with various immune cells and possibly involved in the regulation of macrophage polarization in ovarian cancer. CONCLUSIONS: We detail the regulatory mechanism of TIPE2 in EOC carcinogenesis, as well as how it correlates with immune infiltration, emphasizing its potential as a therapeutic target in ovarian cancer.

Propranolol reduces IFN-γ driven PD-L1 immunosuppression and improves anti-tumour immunity in ovarian cancer.

The immune system plays an important role in controlling epithelial ovarian cancer (EOC). EOC is considered to be a "cold tumour," a tumour that has not triggered a strong response by the immune system. However, tumour infiltrating lymphocytes (TILs) and the expression of programmed cell death ligand (PD-L1) are used as prognostic indicators in EOC. Immunotherapy such as PD-(L)1 inhibitors have shown limited benefit in EOC. Since the immune system is affected by behavioural stress and the beta-adrenergic signalling pathway, this study aimed to explore the impact of propranolol (PRO), a beta-blocker, on anti-tumour immunity in both in vitro and in vivo EOC models. Noradrenaline (NA), an adrenergic agonist, did not directly regulate PD-L1 expression but PD-L1 was significantly upregulated by IFN-γ in EOC cell lines. IFN-γ also increased PD-L1 on extracellular vesicles (EVs) released by ID8 cells. PRO significantly decreased IFN-γ levels in primary immune cells activated ex vivo and showed increased viability of the CD8+ cell population in an EV-immune cell co-incubation. In addition, PRO reverted PD-L1 upregulation and significantly decreased IL-10 levels in an immune-cancer cell co-culture. Chronic behavioural stress increased metastasis in mice while PRO monotherapy and the combo of PRO and PD-(L)1 inhibitor significantly decreased stress-induced metastasis. The combined therapy also reduced tumour weight compared to the cancer control group and induced anti-tumour T-cell responses with significant CD8 expression in tumour tissues. In conclusion, PRO showed a modulation of the cancer immune response by decreasing IFN-γ production and, in turn, IFN-γ-mediated PD-L1 overexpression. The combined therapy of PRO and PD-(L)1 inhibitor decreased metastasis and improved anti-tumour immunity offering a promising new therapy.

Ovarian cancer mutational processes drive site-specific immune evasion.

High-grade serous ovarian cancer (HGSOC) is an archetypal cancer of genomic instability1-4 patterned by distinct mutational processes5,6, tumour heterogeneity7-9 and intraperitoneal spread7,8,10. Immunotherapies have had limited efficacy in HGSOC11-13, highlighting an unmet need to assess how mutational processes and the anatomical sites of tumour foci determine the immunological states of the tumour microenvironment. Here we carried out an integrative analysis of whole-genome sequencing, single-cell RNA sequencing, digital histopathology and multiplexed immunofluorescence of 160 tumour sites from 42 treatment-naive patients with HGSOC. Homologous recombination-deficient HRD-Dup (BRCA1 mutant-like) and HRD-Del (BRCA2 mutant-like) tumours harboured inflammatory signalling and ongoing immunoediting, reflected in loss of HLA diversity and tumour infiltration with highly differentiated dysfunctional CD8+ T cells. By contrast, foldback-inversion-bearing tumours exhibited elevated immunosuppressive TGFß signalling and immune exclusion, with predominantly naive/stem-like and memory T cells. Phenotypic state associations were specific to anatomical sites, highlighting compositional, topological and functional differences between adnexal tumours and distal peritoneal foci. Our findings implicate anatomical sites and mutational processes as determinants of evolutionary phenotypic divergence and immune resistance mechanisms in HGSOC. Our study provides a multi-omic cellular phenotype data substrate from which to develop and interpret future personalized immunotherapeutic approaches and early detection research.

Cancer-associated fibroblasts-derived FMO2 as a biomarker of macrophage infiltration and prognosis in epithelial ovarian cancer.

OBJECTIVE: Recent molecular profiling revealed that cancer-associated fibroblasts (CAFs) are essential for matrix remodeling and tumor progression. Our study aimed to investigate the role of flavin-containing monooxygenase 2 (FMO2) in epithelial ovarian cancer (EOC) as a novel CAF-derived prognostic biomarker. METHODS: Primary fibroblasts were isolated from EOC samples. Microdissection and single-cell RNA sequencing (scRNA-seq) datasets (including TCGA, GSE9891, GSE63885, GSE118828 and GSE178913) were retrieved to determine the expression profiles. Gene set enrichment analysis (GSEA) was used to explore the correlation between FMO2 and stromal activation as well as immune infiltration. The predictive value of FMO2 and combined macrophage infiltration level was verified in an independent EOC cohort (n = 113). RESULTS: We demonstrated that FMO2 was upregulated in tumor stroma and correlated with fibroblast activation. Besides, FMO2 had the predictive power for worse clinical outcome of EOC patients. In the mesenchymal subtype of EOC, the FMO2-defined signature revealed that FMO2 contributed to infiltration of tumor-infiltrating lymphocytes. Moreover, we confirmed the positive correlation between FMO2 and CD163+ cell infiltration level in EOC tissues, and showed that combination of FMO2 expression with CD163+ cell infiltration level in the tumor stroma could predict poor overall survival (HR = 3.63, 95% CI = 1.93-6.84, p = 0.0008). Additionally, FMO2 also predicted the prognosis of patients with ovarian cancer based on the expression of immune checkpoints (such as PD-L1 and PD1). CONCLUSION: Our results address the tumor-supporting role of FMO2 in EOC and its association with immune components, and it might be a prospective target for stroma-oriented therapies against EOC.

Downregulation of LEMD1-AS1 and Its Influences on the Diagnosis, Prognosis, and Immune Infiltrates of Epithelial Ovarian Cancer.

Previous studies have confirmed long noncoding RNA LEMD1-AS1 (LEMD1-AS1) as a functional factor in several tumors. The present work is aimed at exploring the prognostic and diagnostic values of LEMD1-AS1 in patients with epithelial ovarian cancer (EOC). We examined the expressions of LEMD1-AS1 in pan-cancer from TCGA microarray datasets and GTEx Project. The expressions of LEMD1-AS1 were detected by qRT-PCR in EOC specimens and normal ovarian specimens from 30 EOC patients. The χ 2 test was applied to compare the clinicopathological characteristics of different groups. ROC curves were established to determine the diagnostic values of LEMD1-AS1 in screening EOC tissues. The association of LEMD1-AS1 expression with clinical outcome was determined by the Kaplan-Meier methods and COX assays. A decreased expression of LEMD1-AS1 was observed in EOC tissues compared to matched normal specimens (p < 0.01). Low LEMD1-AS1 expression could be used to distinguish EOC from adjacent normal specimens. A clinical study revealed that patients with low LEMD1-AS1 expression have a shorter overall survival (p = 0.035) and progress-free interval (p = 0.041) than those with high LEMD1-AS1 expression. The Spearman correlation test revealed that LEMD1-AS1 expressions were negatively associated with the expressions of neutrophil and myeloid dendritic cell. Overall, our finding suggested that LEMD1-AS1 may have potential roles as a potential biomarker and/or a therapeutic target in EOC.

Oncolytic adenovirus with MUC16-BiTE shows enhanced antitumor immune response by reversing the tumor microenvironment in PDX model of ovarian cancer.

The improved survival rate of ovarian cancer (OC) is related to the action of infiltrating cytotoxic T lymphocytes (CTLs). Recently, oncolytic adenoviruses (OAds) have emerged as a key player in treating solid tumors; however, the immunosuppressive tumor microenvironment (TME) and the body-mediated antiviral immune response limit their therapeutic effect. In this study, we tested the hypothesis that bispecific T-cell engagers (BiTEs) could activate and redirect CTLs to increase the anti-tumor effect of OAds. We modified the parental OAd to express a MUC16-targeting BiTE antibody (OAd-MUC16-BiTE), which retained its oncolytic properties and replication ability in vitro. This BiTE secreted from infected tumor cells into the microenvironment binds to MUC16 on target cells and cross-links them to CD3 on T cells, leading to activation, proliferation, and toxicity of T cells against MUC16+ tumor cells. In cell coculture assays, OAd-MUC16-BiTE-mediated oncolysis enhanced T-cell-mediated tumor cell killing and bystander effect. In ex vivo tumor cultures freshly derived from OC patients, OAd-MUC16-BiTE overcame the suppressed immune TME, achieving stronger toxicity than the parental virus. Moreover, in the cell-derived xenograft and patient-derived xenograft model, OAd-MUC16-BiTE showed stronger antitumor activity and increased the number of CTLs, compared with the parental virus. Further, we demonstrated that the OAd-MUC16-BiTE-mediated anti-tumor activity is related to the reversal of the TME and improved MHC I antigen presentation. Overall, our results show how arming OAds with BiTE can overcome limitations in oncolytic virotherapy, yielding a potent therapy that is ready for clinical assessment.

An Integrative Analysis Revealing ZFHX4-AS1 as a Novel Prognostic Biomarker Correlated with Immune Infiltrates in Ovarian Cancer.

Ovarian cancer (OC) is the main cause of deaths worldwide in female reproductive system malignancies. Growing studies have indicated that eRNAs could regulate cellular activities in various tumors. Yet the potential roles of eRNAs in OC progression have not been elucidated. Thus, comprehensive assays were needed to screen the critical eRNAs and to explore their possible function in OC. We used Kaplan-Meier methods to identify survival-associated eRNAs in OC based on TCGA datasets. The levels of ZFHX4-AS1 were examined using TCGA datasets. Further exploration was carried out based on the following assays: clinical and survival assays, GO terms, and KEGG assays. TIMER was applied to delve into the relationships between ZFHX4-AS1 and tumor immune infiltration. In this research, we observed 71 survival-related eRNAs in OC patients. ZFHX4-AS1 was highly expressed in OC specimens and predicted a poor prognosis of OC patients. In addition, high ZFHX4-AS1 expression was positively related to the advanced stages of OC specimens. Multivariate assays revealed that ZFHX4-AS1 was an independent prognostic factor for overall survival of OC patients. KEGG analysis indicated that ZFHX4-AS1 may play a regulatory effect on TGF-beta signaling, PI3K-Akt signaling, and proteoglycans in cancer. The pan-cancer validation indicated that ZFHX4-AS1 was related to survival in eight tumors, namely, UCEC, STAD, SARC, OV, ACC, KICH, KIRC, and BLCA. The expression of ZFHX4-AS1 was correlated with the levels of B cells, T cell CD8+, neutrophil, macrophage, and myeloid dendritic cells. Simultaneously, ZFHX4-AS1 may be a prognostic biomarker and a distinctly immunotherapy-related eRNA in OC.

Genome-scale CRISPR-Cas9 screen reveals novel regulators of B7-H3 in tumor cells.

BACKGROUND: Despite advances in B7 homolog 3 protein (B7-H3) based immunotherapy, the development of drug resistance remains a major clinical concern. The heterogeneity and emerging loss of B7-H3 expression are the main causes of drug resistance and treatment failure in targeted therapies, which reveals an urgent need to elucidate the mechanism underlying the regulation of B7-H3 expression. In this study, we identified and explored the crucial role of the transcription factor SPT20 homolog (SP20H) in B7-H3 expression and tumor progression. METHODS: Here, we performed CRISPR/Cas9-based genome scale loss-of-function screening to identify regulators of B7-H3 in human ovarian cancer cells. Signaling pathways altered by SP20H knockout were revealed by RNA sequencing. The regulatory role and mechanism of SP20H in B7-H3 expression were validated using loss-of-function and gain-of-function assays in vitro. The effects of inhibiting SP20H on tumor growth and efficacy of anti-B7-H3 treatment were evaluated in tumor-bearing mice. RESULTS: We identified SUPT20H (SP20H) as negative and eIF4E as positive regulators of B7-H3 expression in various cancer cells. Furthermore, we provided evidence that either SP20H loss or TNF-α stimulation in tumor cells constitutively activates p38 MAPK-eIF4E signaling, thereby upregulating B7-H3 expression. Loss of SP20H upregulated B7-H3 expression both in vitro and in vivo. Additionally, deletion of SP20H significantly suppressed tumor growth and increased immune cells infiltration in tumor microenvironment. More importantly, antibody-drug conjugates targeting B7-H3 exhibited superior antitumor performance against SP20H-deficient tumors relative to control groups. CONCLUSIONS: Activation of p38 MAPK-eIF4E signaling serves as a key event in the transcription initiation and B7-H3 protein expression in tumor cells. Genetically targeting SP20H upregulates target antigen expression and sensitizes tumors to anti-B7-H3 treatment. Collectively, our findings provide new insight into the mechanisms underlying B7-H3 expression and introduce a potential synergistic target for existing antibody-based targeted therapy against B7-H3.