Intrathecal topotecan with systemic checkpoint inhibitor therapy for gastroesophageal cancer with leptomeningeal involvement: two case reports and review of the literature.

Background: Leptomeningeal metastases (LM) in gastroesophageal (GE) malignancies are exceedingly rare. Historically, treatment for LM has included steroids, radiation, chemotherapy, and intrathecal (IT) chemotherapy. However, the outcomes in GE malignancies with LM remain poor. Unfortunately, clinical trials in GE malignancies have traditionally excluded those with LM, limiting advances in therapeutic strategies. Given that LM poses potentially devastating neurologic and psychologic sequelae, there is an urgent need for more effective treatments. Case Description: Patient 1 is a 44-year-old woman with localized esophageal adenocarcinoma who undergoes neoadjuvant chemoradiation followed by esophagectomy. Seven months following surgery, she develops ataxia, weakness, and nausea/vomiting. Magnetic resonance imaging (MRI) reveals intracranial disease that is subsequently successfully resected and then treated with gamma knife (GK) radiation. Pathology confirms metastases. Three months later she is found to have LM. She receives palliative whole brain radiation therapy as well as focal radiation to the spine. Following this she transitioned to concurrent IT topotecan plus intravenous (IV) ipilumumab/nivolumab with durable response beyond 14 months. Patient 2 is a 71-year-old man with de novo metastatic esophageal adenocarcinoma with durable response to 5-fluorouracil plus irinotecan. Asymptomatic intracranial metastases are detected on surveillance scans 2 years after initial diagnosis for which he receives GK. Follow up MRI identifies new LM. As such, to treat the LM, he was transitioned to IT topotecan and IV pembrolizumab with good response for 6 months until death from a gastrointestinal bleed. Conclusions: We present two cases of LM in patients with GE adenocarcinoma who had longer survival than what has been reported. They were treated with combination IT topotecan and IV checkpoint inhibition. Further studies evaluating the central nervous system tumor immune-microenvironment can help expand our understanding of how this combination has worked well in our patients and how to care for others with similar scenarios.

Senescence-related signatures predict prognosis and response to immunotherapy in colon cancer.

Background: Colorectal cancer (CRC) is one of the most common cancers. Cellular senescence plays a vital role in carcinogenesis by activating many pathways. In this study, we aimed to identify biomarkers for predicting the survival and recurrence of CRC through cellular senescence-related genes. Methods: Utilizing The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases, RNA-sequencing data and clinical information for CRC were collected. A risk model for predicting overall survival was established based on five differentially expressed genes using least absolute shrinkage and selection operator-Cox regression (LASSO-Cox regression), receiver operating characteristic (ROC), and Kaplan-Meier analyses. The study also delved into both the tumor microenvironment and the response to immunotherapy. Moreover, we gathered clinical sample data from our center in order to confirm the findings of public database analysis. Results: Through ROC and Kaplan-Meier analyses, a risk model was developed using five cellular senescence-related genes [i.e., CDKN2A, SERPINE1, SNAI1, CXCL1, and ETS2] to categorize patients into high- and low-risk groups. In the TCGA-colon adenocarcinoma (COAD) and GEO-COAD cohorts, the high-risk group was associated with a bleaker forecast (P<0.05), immune cell inactivation, and insensitivity to immunotherapy in IMvigor210 database (http://research-pub.gene.com/IMvigor210CoreBiologies/). Clinical samples were then used to confirm that ETS2 and CDKN2A could serve as independent prognostic biomarkers in CRC. Conclusions: Gene signatures related to cellular senescence, specifically involving CDKN2A and ETS2, are emerging as promising biomarkers for predicting CRC prognosis and guiding immunotherapy.

Role of TAP1 in the identification of immune-hot tumor microenvironment and its prognostic significance for immunotherapeutic efficacy in gastric carcinoma.

Background: Gastric cancer (GC), a multifaceted gastrointestinal malignancy, is the fourth most prevalent contributor to cancer-related fatalities globally. As a member of the ATP-binding cassette (ABC) family, transporter associated with antigen processing 1 (TAP1) is crucial for conveying antigen peptides from the cytoplasm to the lumen of the endoplasmic reticulum and subsequently loading them onto the major histocompatibility complex (MHC) class I molecules. Recent studies have established the biological significance of TAP1 in upholding tumor survival and facilitating immune evasion by remodeling the tumor microenvironment (TME) and orchestrating immune infiltration. The study was conducted to elucidate the association of TAP1 expression with immunological characteristics, and sought to exploit the value of TAP1 as a biomarker reflecting the inflamed TME and immunotherapeutic response. Methods: RNA-sequencing profiles and clinical annotations were obtained from The Cancer Genome Atlas-stomach adenocarcinoma (TCGA-STAD) cohort and Gene Expression Omnibus (GEO) portal. Preprocessing was conducting using the limma package. Weighted gene co-expression network analysis (WGCNA) was used to identify gene modules and TAP1 co-expressed genes (CEGs) based on correlation patterns. Consensus clustering and silhouette analysis determined the optimal number of TAP1-related groups. Gene expression profiles were integrated and classified using the pamr package. The Estimation of STromal and Immune cells in MAlignant Tumors using Expression data (ESTIMATE) algorithm and single-sample gene set enrichment analysis (ssGSEA) were used to evaluate immunological characteristics. Differential expression analysis was conducted using the limma package. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were performed. Single-cell RNA sequencing (scRNA-seq) datasets were analyzed using the Seurat toolkit to characterize cell types. Results: Within this investigation, no significant differences in TAP1 expression were observed among patients exhibiting various clinicopathological features, indicating that TAP1 expression was not specific to molecular subtypes. Subsequent analysis revealed a positive correlation between TAP1 and diverse immunological traits, encompassing immunomodulators, tumor-infiltrating immune cells, as well as immune checkpoints across multiple datasets. Besides, within a GC immunotherapy cohort, individuals displaying high TAP1 expression demonstrated an increased likelihood of achieving complete remission (CR) post-treatment, suggesting heightened sensitivity to immunotherapy. In the clinical cohort, TAP1 overexpression in GC patients was positively correlated with CD8. Conclusions: TAP1 appears linked to an inflamed TME and serves as a prospective biomarker for discerning immunological attributes and gauging immunotherapeutic responses in GC, particularly in identifying immune-reactive tumors.

Safety and short-term outcomes of esophagectomy after neoadjuvant immunotherapy combined with chemotherapy or chemoradiotherapy for locally advanced esophageal squamous cell cancer: analysis of two phase-II clinical trials.

Background: Preoperative chemotherapy (CT) or chemoradiotherapy (CRT) show survival benefits in patients with locally advanced esophageal squamous cell carcinoma (ESCC); however, ESCC patients still have a dismal prognosis. We conducted two phase-II, single-armed clinical trials to assess the potential benefits, efficacy, feasibility, and safety of esophagectomy after combining preoperative CT or CRT and neoadjuvant programmed cell death protein 1 (PD-1) inhibitors in the treatment of ESCC. Methods: Patients were included with histologically confirmed ESCC (clinical stage II-IVA according to the American Joint Committee on Cancer 8th staging system) from two phase-II, single-arm trials (NCT04506138 and NCT03940001). Patients underwent two doses of intravenous PD-1 inhibitor (either camrelizumab or sintilimab) every 3 weeks, combined with two cycles of either CT or CRT. The primary endpoint of the study was the safety and short-term outcomes of esophagectomy as measured by the risk of developing complications within 30 days, after the combination of preoperative PD-1 inhibitor and CT or CRT Secondary endpoint was to evaluate the pCR rates (pT0N0), primary tumor pCR rates (pT0), operation time, postoperative stay, and 30-day mortality rate between both groups. Results between both groups were compared using a multivariable log-binomial regression model to obtain the adjusted relative risk ratios (RRs). Results: Between May 2019 and June 2022, 55 patients were included. All patients completed neoadjuvant therapy. Age, sex, performance status, clinical stage, histologic subtype, procedure type, operative time, and blood loss volume were similar between the two groups. The primary tumor pCR rates were 52.9% in the nICRT group and 21.6% in the nICT group (P=0.03), while the postoperative pCR rates were 41.2% in the nICRT group and 21.6% in the nICT group (P=0.19). The minimally invasive surgery rates were 89.2% (33/37) in the nICT group and 94.1% (16/17) in the nICRT group. The risk of developing pulmonary, anastomotic, or other complications were similar between the two groups. Conclusions: Esophagectomy was safe after the addition of the PD-1 inhibitor to preoperative CT or CRT in ESCC neoadjuvant therapies. Follow-up and the exploratory endpoints, including biomarkers analyses, are ongoing.

Synthetic lethal CRISPR screen identifies a cancer cell-intrinsic role of PD-L1 in regulation of vulnerability to ferroptosis.

Despite the success of programmed cell death 1 (PD-1)/programmed death ligand 1 (PD-L1) inhibition in tumor therapy, many patients do not benefit. This failure may be attributed to the intrinsic functions of PD-L1. We perform a genome-wide CRISPR synthetic lethality screen to systematically explore the intrinsic functions of PD-L1 in head and neck squamous cell carcinoma (HNSCC) cells, identifying ferroptosis-related genes as essential for the viability of PD-L1-deficient cells. Genetic and pharmacological induction of ferroptosis accelerates cell death in PD-L1 knockout cells, which are also more susceptible to immunogenic ferroptosis. Mechanistically, nuclear PD-L1 transcriptionally activates SOD2 to maintain redox homeostasis. Lower reactive oxygen species (ROS) and ferroptosis are observed in patients with HNSCC who have higher PD-L1 expression. Our study illustrates that PD-L1 confers ferroptosis resistance in HNSCC cells by activating the SOD2-mediated antioxidant pathway, suggesting that targeting the intrinsic functions of PD-L1 could enhance therapeutic efficacy.

Survival trends among patients with metastatic non-small cell lung cancer before and after the approval of immunotherapy in the United States: A Surveillance, Epidemiology, and End Results database-based study.

BACKGROUND: In 2015, the US Food and Drug Administration approved nivolumab as the first immunotherapy for patients with advanced non-small cell lung cancer (NSCLC). However, population-based survival benefit studies after the introduction of immunotherapy in lung cancer are lacking. This study examined overall survival (OS) and cancer-specific survival in patients with NSCLC in the pre immunotherapy and immunotherapy eras. METHODS: This study used the Surveillance, Epidemiology, and End Results database, which spanned 17 registries from 2000 to 2020. Two cohorts were delineated: preimmunotherapy (2010-2014) and immunotherapy (2015-2020), which coincided with nivolumab's approval. RESULTS: This study included 191,802 patients, 90,807 in the preimmunotherapy era and 100,995 in the immunotherapy era. OS was significantly higher in the immunotherapy era, as shown by Kaplan-Meier curves (1-year OS, 40.1% vs. 33.5%; 3-year OS, 17.8% vs. 11.7%; 5-year OS, 10.7% vs. 6.8%; median OS, 8 vs. 7 months; p < .001 by log-rank test). Similarly, cancer-specific survival improved in the immunotherapy era (1-year survival, 44.0% vs. 36.8%; 3-year survival, 21.7% vs. 14.4%; 5-year survival, 14.3% vs. 9.0%; median OS, 10 vs. 8 months; p < .001 by log-rank test). Survival rates were significantly better in the immunotherapy era, as confirmed by multivariate analysis with a Cox proportional hazards model after adjusting for age, sex, race, income, and geographical area (adjusted hazard ratio, 0.830; 95% CI, 0.821-0.840; p < .001). CONCLUSIONS: In summary, the survival rate of patients with metastatic NSCLC has improved since the introduction of immunotherapy.

Less is more: Exploring neoadjuvant immunotherapy as a de-escalation strategy in head and neck squamous cell carcinoma treatment.

Head and neck squamous cell carcinoma (HNSCC) constitutes a significant global cancer burden, given its high prevalence and associated mortality. Despite substantial progress in survival rates due to the enhanced multidisciplinary approach to treatment, these methods often lead to severe tissue damage, compromised function, and potential toxicity. Thus, there is an imperative need for novel, effective, and minimally damaging treatment modalities. Neoadjuvant treatment, an emerging therapeutic strategy, is designed to reduce tumor size and curtail distant metastasis prior to definitive intervention. Currently, neoadjuvant chemotherapy (NACT) has optimized the treatment approach for a subset of HNSCC patients, yet it has not produced a noticeable enhancement in overall survival (OS). In the contemporary cancer therapeutics landscape, immunotherapy is gaining traction at an accelerated pace. Notably, neoadjuvant immunotherapy (NAIT) has shown promising radiological and pathological responses, coupled with encouraging efficacy in several clinical trials. This potentially paves the way for a myriad of possibilities in treatment de-escalation of HNSCC, which warrants further exploration. This paper reviews the existing strategies and efficacies of neoadjuvant immune checkpoint inhibitors (ICIs), along with potential de-escalation strategies. Furthermore, the challenges encountered in the context of the de-escalation strategies of NAIT are explored. The aim is to inform future research directions that strive to improve the quality of life (QoL) for patients battling HNSCC.

[Systemic therapeutic strategies for hepatocellular carcinoma: current status and prospects].

Hepatocellular carcinoma (HCC) is a common type of poorly prognosticated malignant tumor. Surgical resection is the preferred treatment method for early-stage HCC. However, at the time of the initial diagnosis, fewer than 30% of patients with liver cancer are suitable for radical therapy. Systemic therapy plays an important role in the treatment process of patients with intermediate- to advanced-stage HCC, as it can effectively extend patients' survival time. With an emphasis on the status and role of systemic therapy for comprehensive management of HCC, this article summarizes the latest progress at home and abroad in the past five years, including first-line combined immunotherapy for advanced-stage HCC, second-line therapy selection, perioperative systemic therapy application, and combined therapy of systemic and local. Currently, the treatment model combined with local therapy has already become a new research hotspot in the treatment of advanced-stage HCC. Nevertheless, in the future, individualized and precise systemic therapeutic strategies will need further exploration.

Rejection resistant CD30.CAR-modified Epstein-Barr virus-specific T cells as an off-the-shelf platform for CD30+ lymphoma.

Off-the-shelf (OTS) adoptive T cell therapies have many benefits such as immediate availability, improved access and reduced cost, but face the major challenges of graft-vs-host disease (GVHD) and graft rejection, mediated by alloreactive T cells present in the graft and host, respectively. We have developed a platform for OTS T cell therapies by using Epstein-Bar virus (EBV)-specific T cells (EBVSTs) expressing a chimeric antigen receptor (CAR) targeting CD30. Allogeneic EBVSTs have not caused GVHD in several clinical trials, while the CD30.CAR, that is effective for the treatment of lymphoma, can also target alloreactive T cells that upregulate CD30 on activation. Although EBVSTs express high levels of CD30, they were protected from fratricide in cis, by the CD30.CAR. Hence, they could proliferate extensively and maintained function both through their native EBV-specific T cell receptor and the CD30.CAR. The CD30.CAR enabled EBVSTs to persist in co-cultures with naive and primed alloreactive T cells and eliminate activated natural killer cells that can also be alloreactive. In conclusion, we show that CD30.CAR EBVSTs have the potential to be an effective OTS therapy against CD30+ tumors and, if successful, could then be used as a platform to target other tumor antigens.

Case report: Splenic inflammatory pseudotumor-like follicular dendritic cell sarcoma (IPT-like FDCS): a trial of immunotherapy and review of the literature.

Inflammatory pseudotumor-like follicular dendritic cell sarcoma (IPT-like FDCS) is a rare malignancy with fewer than 150 cases in the literature. IPT-like FDCS follows an indolent course with most cases definitively managed with surgical resection. We present a case of IPT-like FDCS with multiple recurrences with a trial of immunotherapy. The patient initially presented with splenic involvement requiring splenectomy, subsequently recurring in the liver requiring hepatic resections. Afterwards, there was recurrence with pelvic/small bowel involvement for which treatment was trialed with ipilimumab and nivolumab. The patient progressed despite dual immune checkpoint inhibitor therapy requiring a small bowel resection. To date, this is the first case of immunotherapy use in IPT-like FDCS. Therefore, more evidence is needed to support additional treatments in recurrent IPT-like FDCS after resection.

Promising immunotherapeutic approaches for primary effusion lymphoma.

Primary effusion lymphoma (PEL) is a large B-cell neoplasm usually presenting as a serious effusion in body cavities without detectable tumor masses. It is an AIDS-related non-Hodgkin's lymphoma (HL) with human herpes virus 8 (HHV8)/Kaposi sarcoma-associated herpes virus (KSHV) infection. A combination antiretroviral therapy (cART) prolongs the lifespan of AIDS and AIDS-related malignant lymphoma patients, but PEL continues to have a dismal prognosis. PEL showed disappointing outcomes with standard chemotherapy such as CHOP or CHOP-like regimens. A PEL status highlights the urgent need for new therapeutic approaches and treatment strategies and improve clinical outcomes. This review discusses the current knowledge and some recent clinical trials for PEL in the platform of immunotherapy as well as promising future immunotherapeutic approaches for PEL.

Immunotherapy in thymic epithelial tumors: tissue predictive biomarkers for immune checkpoint inhibitors.

Thymic epithelial tumors (TETs) are rare malignant neoplasms arising in the thymus gland. Nevertheless, TETs, including thymomas (TMs), thymic carcinomas (TCs), and thymic neuroendocrine neoplasms (TNENs), are the most common mediastinal malignancies overall. A multidisciplinary approach is required for the appropriate diagnostic and therapeutic management of TETs. To date, the main therapeutic strategies are largely depended on the stage of the tumor and they include surgery with or without neoadjuvant or adjuvant therapy, represented by platinum-based chemotherapy, radiotherapy or chemoradiotherapy. Immune checkpoint inhibitors (ICIs) are ongoing under evaluation in the advanced or metastatic diseases despite the challenges related to the very low tumor mutation burden (TMB) and the high incidence of immune-related adverse events in TETs. In this regard, predictive impact of tissue biomarkers expression such as programmed cell death ligand-1 (PD-L1), and other emerging biomarkers, as well as their optimal and shared interpretation are currently under evaluation in order to predict response rates to ICIs in TETs.

Exploiting gender-based biomarkers and drug targets: advancing personalized therapeutic strategies in hepatocellular carcinoma.

This review systematically examines gender differences in hepatocellular carcinoma (HCC), identifying the influence of sex hormones, genetic variance, and environmental factors on the disease's epidemiology and treatment outcomes. Recognizing the liver as a sexually dimorphic organ, we highlight how gender-specific risk factors, such as alcohol consumption and obesity, contribute differently to hepatocarcinogenesis in men and women. We explore molecular mechanisms, including the differential expression of androgen and estrogen receptors, which mediate diverse pathways in tumor biology such as cell proliferation, apoptosis, and DNA repair. Our analysis underscores the critical need for gender-specific research in liver cancer, from molecular studies to clinical trials, to improve diagnostic accuracy and therapeutic effectiveness. By incorporating a gender perspective into all facets of liver cancer research, we advocate for a more precise and personalized approach to cancer treatment that acknowledges gender as a significant factor in both the progression of HCC and its response to treatment. This review aims to foster a deeper understanding of the biological and molecular bases of gender differences in HCC and to promote the development of tailored interventions that enhance outcomes for all patients.

Single cell RNA-sequencing in uveal melanoma: advances in heterogeneity, tumor microenvironment and immunotherapy.

Uveal melanoma (UM) is a highly aggressive and fatal tumor in the eye, and due the special biology of UM, immunotherapy showed little effect in UM patients. To improve the efficacy of immunotherapy for UM patients is of great clinical importance. Single-cell RNA sequencing(scRNA-seq) provides a critical perspective for deciphering the complexity of intratumor heterogeneity and tumor microenvironment(TME). Combing the bioinformatics analysis, scRNA-seq could help to find prognosis-related molecular indicators, develop new therapeutic targets especially for immunotherapy, and finally to guide the clinical treatment options.

The biological function of Serpinb9 and Serpinb9-based therapy.

Recent breakthroughs in discovering novel immune signaling pathways have revolutionized different disease treatments. SERPINB9 (Sb9), also known as Proteinase Inhibitor 9 (PI-9), is a well-known endogenous inhibitor of Granzyme B (GzmB). GzmB is a potent cytotoxic molecule secreted by cytotoxic T lymphocytes and natural killer cells, which plays a crucial role in inducing apoptosis in target cells during immune responses. Sb9 acts as a protective mechanism against the potentially harmful effects of GzmB within the cells of the immune system itself. On the other hand, overexpression of Sb9 is an important mechanism of immune evasion in diseases like cancers and viral infections. The intricate functions of Sb9 in different cell types represent a fine-tuned regulatory mechanism for preventing immunopathology, protection against autoimmune diseases, and the regulation of cell death, all of which are essential for maintaining health and responding effectively to disease challenges. Dysregulation of the Sb9 will disrupt human normal physiological condition, potentially leading to a range of diseases, including cancers, inflammatory conditions, viral infections or other pathological disorders. Deepening our understanding of the role of Sb9 will aid in the discovery of innovative and effective treatments for various medical conditions. Therefore, the objective of this review is to consolidate current knowledge regarding the biological role of Sb9. It aims to offer insights into its discovery, structure, functions, distribution, its association with various diseases, and the potential of nanoparticle-based therapies targeting Sb9.

Report of case series: Correlation between pathological and radiological evaluation and clinical course of three cases of metastatic renal cell carcinoma with cytoreductive nephrectomy after combined immuno-oncology therapy.

Introduction: The pathologic evaluation and clinical course of cytoreductive nephrectomy after combined immuno-oncology therapy were reviewed to understand the benefits of cytoreductive nephrectomy. Case presentation: Three patients with clear cell carcinoma underwent tumor biopsy before combined immuno-oncology therapy. Case 1 was found to have a sarcomatoid component upon nephrectomy and continued with combined immuno-oncology therapy. Case 2 discontinued combined immuno-oncology therapy due to adverse events but maintained tumor shrinkage. The patient was found to have viable cells in most nephrectomy specimens but has had no recurrence after combined immuno-oncology therapy was discontinued. In case 3, the residual tumor was deemed resectable with combined immuno-oncology therapy, and nephrectomy and metastasectomy were performed. No viable cells were observed in either specimen, and the patient has had no recurrence. Conclusion: Cytoreductive nephrectomy after combined immuno-oncology therapy may be useful to allow pathologic evaluation of treatment and provide an indicator for subsequent treatment.

Antibody-Decorated Nanoplatform to Reprogram Macrophage and Block Immune Checkpoint LSECtin for Effective Cancer Immunotherapy.

Repolarizing tumor-associated macrophages (TAMs) into tumor-inhibiting M1 macrophages has been considered a promising strategy for enhanced cancer immunotherapy. However, several immunosuppressive ligands (e.g., LSECtin) can still be highly expressed on M1 macrophages, inducing unsatisfactory therapeutic outcomes. We herein developed an antibody-decorated nanoplatform composed of PEGylated iron oxide nanoparticles (IONPs) and LSECtin antibody conjugated onto the surface of IONPs via the hydrazone bond for enhanced cancer immunotherapy. After intravenous administration, the tumor microenvironment (TME) pH could trigger the hydrazone bond breakage and induce the disassociation of the nanoplatform into free LSECtin antibodies and IONPs. Consequently, the IONPs could repolarize TAMs into M1 macrophages to remodel immunosuppressive TME and provide an additional anticancer effect via secreting tumoricidal factors (e.g., interlukin-12). Meanwhile, the LSECtin antibody could further block the activity of LSECtin expressed on M1 macrophages and relieve its immunosuppressive effect on CD8+ T cells, ultimately leading to significant inhibition of tumor growth.

Dendritic cells pulsed with penetratin-OLFM4 inhibit the growth and metastasis of melanoma in mice.

Cancer stem cells (CSCs) can self-renew and differentiate, contributing to tumor heterogeneity, metastasis, and recurrence. Their resistance to therapies, including immunotherapy, underscores the importance of targeting them for complete remission and relapse prevention. Olfactomedin 4 (OLFM4), a marker associated with various cancers such as colorectal cancer, is expressed on CSCs promoting immune evasion and tumorigenesis. However, its potential as a target for CSC-specific immunotherapy remains underexplored. The primary aim of this study is to evaluate the effectiveness of targeting OLFM4 with dendritic cell (DC)-based vaccines in inhibiting tumor growth and metastasis. To improve antigen delivery and immune response, OLFM4 was conjugated with a protein-transduction domain (PTD) from the antennapedia of Drosophila called penetratin, creating a fusion protein (P-OLFM4). The efficacy of DCs pulsed with P-OLFM4 (DCs [P-OLFM4]) was compared to DCs pulsed with OLFM4 (DCs [OLFM4]) and PBS (DCs [PBS]). DCs [P-OLFM4] inhibited tumor growth by 91.2 % and significantly reduced lung metastasis of OLFM4+ melanoma cells by 97 %, compared to the DCs [PBS]. DCs [OLFM4] also demonstrated a reduction in lung metastasis by 59.7 % compared to DCs [PBS]. Immunization with DCs [P-OLFM4] enhanced OLFM4-specific T-cell proliferation, interferon-γ production, and cytotoxic T cell activity in mice. The results indicate that OLFM4 is a viable target for CSC-focused immunotherapy. DC [P-OLFM4] vaccines can elicit robust immune responses, significantly inhibiting tumor growth and metastasis. This strategy holds promise for developing more effective cancer treatments that specifically target CSCs, potentially leading to better patient outcomes by reducing the likelihood of tumor relapse and metastasis.

Progestogen-driven B7-H4 contributes to onco-fetal immune tolerance.

Immune tolerance mechanisms are shared in cancer and pregnancy. Through cross-analyzing single-cell RNA-sequencing data from multiple human cancer types and the maternal-fetal interface, we found B7-H4 (VTCN1) is an onco-fetal immune tolerance checkpoint. We showed that genetic deficiency of B7-H4 resulted in immune activation and fetal resorption in allogeneic pregnancy models. Analogously, B7-H4 contributed to MPA/DMBA-induced breast cancer progression, accompanied by CD8+ T cell exhaustion. Female hormone screening revealed that progesterone stimulated B7-H4 expression in placental and breast cancer cells. Mechanistically, progesterone receptor (PR) bound to a newly identified -58 kb enhancer, thereby mediating B7-H4 transcription via the PR-P300-BRD4 axis. PR antagonist or BRD4 degrader potentiated immunotherapy in a murine B7-H4+ breast cancer model. Thus, our work unravels a mechanistic and biological connection of a female sex hormone (progesterone) to onco-fetal immune tolerance via B7-H4 and suggests that the PR-P300-BRD4 axis is targetable for treating B7-H4+ cancer.