Role of CD47 in tumor immunity: a potential target for combination therapy

Translating CD47-targeted therapy in gastrointestinal cancers: Insights from preclinical to clinical studies

This review presents a thorough investigation of the role of CD47 in gastrointestinal cancers. We performed a comprehensive, in-depth review of over 100 preclinical and clinical studies focused on inhibiting CD47. The research highlights the potential of targeted CD47 to enhance existing treatments by boosting the immune response to cancer cells. Considering the essential need to balance the toxicity and efficacy of CD47 inhibition, our review emphasizes the need to optimize CD47 inhibitors. We also demonstrate the necessity of combining CD47 antibodies with conventional chemotherapy, radiotherapy, or other targeted therapies to enhance treatment effectiveness. Finally, we propose the integration of CD47-targeted therapies into treatment plans as a promising approach to reshape the therapeutic landscape of gastrointestinal cancers. Continued research in this field holds great potential for improving the outcomes of gastrointestinal cancer patients and overcoming the challenges associated with this formidable spectrum of diseases.

Prognostic implication of CD47 and CTLA-4 expressions in endometrial carcinoma

BACKGROUND

CD47 is an immune-regulatory protein that belongs to the immunoglobulin family. It inhibits the phagocytic ability of immune cells. So, it is related to an unfavorable outcome in leukemia and various solid tumors. One of the immune checkpoint molecules is cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) which interferes with anticancer immunity and has an important role in anti-cancer surveillance. This study aimed to investigate CD47 and CTLA-4 mRNA and protein expressions in relation to P53 mutation and different clinicopathological parameters in endometrial carcinoma (EC). We also investigated the relation between CD47 and CTLA-4 expressions in EC.

SUBJECT & METHOD

This study included sixty-eight patients with EC. Tissue samples of the tumor with adequate safety margin were obtained. Part of the tissues was preserved in formalin for histopathological and immunohistochemical examination while the other part was kept frozen at -80 °C for molecular profile.

RESULTS

CD47 and CTLA-4 gene expressions were upregulated in the tissues of EC in comparison with the adjacent control tissues. Significantly higher CD47 and CTLA-4 gene expressions were detected in the serous type, higher stage, muscle invasion ≥50 %, higher grade, LN metastasis, and distant metastasis. CD47 gene expression was a good marker of P53 mutation at a cut-off of 1.65. It showed a high sensitivity of 84 %, a high specificity of 75.3 %, an average PPV of 65.6 %, a high NPV of 88.9 %, and an accuracy of 77.9 % (P < 0.001). Similarly, CTLA-4 gene expression was a good marker of P53 mutation at a cut-off of 3.75. It showed a sensitivity of 88 %, a specificity of 74.3 %, a PPV of 66.7 %, an NPV of 91.4 %, and an accuracy of 79.4 % (P < 0.001).

CONCLUSION

CD47 and CTLA-4 expressions can be considered possible diagnostic and prognostic markers in EC. They were good markers of P53 mutation, and higher tumor grades and stages.

CD40 agonist engineered immunosomes modulated tumor microenvironment and showed pro-immunogenic response, reduced toxicity, and tumor free survival in mice bearing glioblastoma

CD40 agonist antibodies (αCD40) have shown promising anti-tumor response in both preclinical and early clinical studies. However, its systemic administration is associated with immune- and hepato-toxicities which hampers its clinical usage. In addition, αCD40 showed low tumor retention and induced PD-L1 expression which makes tumor microenvironment (TME) immunosuppressive. To overcome these issues, in this study, we have developed a multifunctional Immunosome where αCD40 is conjugated on the surface and RRX-001, a small molecule immunomodulator was encapsulated inside it. Immunosomes showed higher tumor accumulation till 96 h of administration and displayed sustained release of αCD40 in vivo. Immunosomes significantly delayed tumor growth and showed tumor free survival in mice bearing GL-261 glioblastoma by increasing the population of CD45+CD8+ T cells, CD45+CD20+ B cells, CD45+CD11c+ DCs and F4/80+CD86+ cells in TME. Immunosome significantly reduced the population of T-regulatory cells, M2 macrophage, and MDSCs and lowered the PD-L1 expression. Moreover, Immunosomes significantly enhanced the levels of Th1 cytokines (IFN-γ, IL-6, IL-2) over Th2 cytokines (IL-4 and IL-10) which supported anti-tumor response. Most interestingly, Immunosomes averted the in vivo toxicities associated with free αCD40 by lowering the levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), IL-6, IL-1α and reduced the degree of liver damage. In addition, Immunosomes treated long-term surviving mice showed tumor specific immune memory response which prevented tumor growth upon rechallenge. Our results suggested that this novel formulation can be further explored in clinics to improve in vivo anti-tumor efficacy of αCD40 with long-lasting tumor specific immunity while reducing the associated toxicities.

The Prognostic Significance of CD47, CD68, and CD163 Expression Levels and Their Relationship with MLR and MAR in Locally Advanced and Oligometastatic Nasopharyngeal Carcinoma

BACKGROUND

This study aimed to assess the prognostic and predictive implications of CD47, CD68, and CD163, biomarkers of tumor-associated macrophages (TAMs), on the treatment efficacy and clinical outcomes of nasopharyngeal carcinoma (NPC). Additionally, the prognostic value of TAM-related indices, such as the monocyte-to-lymphocyte ratio (MLR) and monocyte-to-albumin ratio (MAR), was evaluated.

METHODS

A retrospective cohort of 54 patients with locally advanced or oligometastatic NPC treated with concurrent chemoradiotherapy (CCRT), with or without induction chemotherapy, was analyzed. Patients were categorized based on the cumulative expression scores for CD47, CD68, and CD163: negative/low (0-3 points) and high (4-6 points). MLR and MAR were also stratified as low MLR (<0.545) vs. high MLR (≥0.545) and low MAR (<16.145) vs. high MAR (≥16.145). The primary endpoint was overall survival (OS).

RESULTS

High CD47, CD68, and CD163 expression levels were correlated with advanced clinical stage, reduced CCRT response, and elevated MLR and MAR. These TAM biomarkers were linearly correlated with each other and with established risk factors such as advanced age and elevated EBV-DNA levels. Kaplan-Meier analysis revealed that patients with low TAM expression had significantly longer OS and progression-free survival (PFS) than those with high TAM expression. Multivariate analysis identified high CD163, MLR, and MAR levels as independent adverse prognostic factors for OS. Elevated MLR is an independent risk factor for both OS and PFS in patients with NPC.

CONCLUSIONS

CD47, CD68, and CD163 are significant prognostic markers in NPC, with higher levels being associated with poorer OS and PFS. Elevated MLR and MAR values also predict worse outcomes, underscoring their value as prognostic tools. CD163 and MLR are particularly strong predictors, highlighting the crucial role of TAMs in NPC management and suggesting that CD163 is a potential therapeutic target within the immune checkpoint pathway.

CD47 in Osteosarcoma: Correlation with Metastasis and Macrophage-Mediated Phagocytosis

CD47 is expressed on cell surfaces and acts as a "don't eat me" signal by interacting with signal-regulatory protein-α on the macrophage surface. Some cancer cells express CD47 protein and can evade macrophage phagocytosis. Herein, we evaluated the feasibility of targeting CD47 for osteosarcoma by analyzing its expression patterns, clinicopathological correlations, and immunotherapeutic potential. We performed a retrospective analysis on 24 biopsy samples from patients with osteosarcoma to investigate correlations between CD47 protein positivity and clinicopathological characteristics. CD47 protein expression was detected in 20.8% of the biopsy samples. CD47 positivity correlated with metastasis at diagnosis. Patients with CD47-positive tumors were older than those with CD47-negative tumors. However, CD47 protein expression was not associated with sex, tumor size, or histologic response to preoperative chemotherapy. In vitro, CD47 antibody (B6H12) did not affect osteosarcoma cell viability or apoptosis. In a wound-healing assay, CD47 inhibited the migration of osteosarcoma cells. Differentiated macrophages exhibited higher phagocytic activity against osteosarcoma cells when pretreated with B6H12 compared with the isotype control. Our preliminary data suggest a possible interaction between CD47 protein and macrophage phagocytosis in osteosarcoma metastasis. A better understanding of the role of CD47 is necessary to develop an innovative immunotherapeutic approach against osteosarcoma.

Diffuse Gastric Cancer: A Comprehensive Review of Molecular Features and Emerging Therapeutics

Diffuse-type gastric cancer (DGC) accounts for approximately one-third of gastric cancer diagnoses but is a more clinically aggressive disease with peritoneal metastases and inferior survival compared with intestinal-type gastric cancer (IGC). The understanding of the pathogenesis of DGC has been relatively limited until recently. Multiomic studies, particularly by The Cancer Genome Atlas, have better characterized gastric adenocarcinoma into molecular subtypes. DGC has unique molecular features, including alterations in CDH1, RHOA, and CLDN18-ARHGAP26 fusions. Preclinical models of DGC characterized by these molecular alterations have generated insight into mechanisms of pathogenesis and signaling pathway abnormalities. The currently approved therapies for treatment of gastric cancer generally provide less clinical benefit in patients with DGC. Based on recent phase II/III clinical trials, there is excitement surrounding Claudin 18.2-based and FGFR2b-directed therapies, which capitalize on unique biomarkers that are enriched in the DGC populations. There are numerous therapies targeting Claudin 18.2 and FGFR2b in various stages of preclinical and clinical development. Additionally, there have been preclinical advancements in exploiting unique therapeutic vulnerabilities in several models of DGC through targeting of the focal adhesion kinase (FAK) and Hippo pathways. These preclinical and clinical advancements represent a promising future for the treatment of DGC.

Cell autonomous functions of CD47 in regulating cellular plasticity and metabolic plasticity

CD47 is a ubiquitously expressed cell surface receptor, which is widely known for preventing macrophage-mediated phagocytosis by interacting with signal regulatory protein α (SIRPα) on the surface of macrophages. In addition to its role in phagocytosis, emerging studies have reported numerous noncanonical functions of CD47 that include regulation of various cellular processes such as proliferation, migration, apoptosis, differentiation, stress responses, and metabolism. Despite lacking an extensive cytoplasmic signaling domain, CD47 binds to several cytoplasmic proteins, particularly upon engaging with its secreted matricellular ligand, thrombospondin 1. Indeed, the regulatory functions of CD47 are greatly influenced by its interacting partners. These interactions are often cell- and context-specific, adding a further level of complexity. This review addresses the downstream cell-intrinsic signaling pathways regulated by CD47 in various cell types and environments. Some of the key pathways modulated by this receptor include the PI3K/AKT, MAPK/ERK, and nitric oxide signaling pathways, as well as those implicated in glucose, lipid, and mitochondrial metabolism. These pathways play vital roles in maintaining tissue homeostasis, highlighting the importance of understanding the phagocytosis-independent functions of CD47. Given that CD47 expression is dysregulated in a variety of cancers, improving our understanding of the cell-intrinsic signals regulated by this molecule will help advance the development of CD47-targeted therapies.

Targeting CD47 and Angiogenesis Demonstrates Effective Anti-Tumor Effect in Bladder Cancer

Background: Although immunotherapy has shown potential in cancer treatment, current immunotherapeutics for bladder cancer are limited by a low response rate. Therefore, it is necessary to investigate other suitable immunotherapeutic targets and strategies for bladder cancer. Methods: To evaluate whether CD47 could be a suitable target for bladder cancer immunotherapy, CD47 protein expression levels in 116 bladder cancer tissue samples were assessed by IHC staining. In vitro anti-tumor effect of blocking CD47 was examined by phagocytosis assays. In vivo anti-tumor effects of targeting CD47 and angiogenesis were experimented in the HSPCs-CDX model. Results: We find that CD47 is highly expressed in bladder cancer samples and is associated with poor prognosis. Blocking CD47 could enhance the human PBMC-derived macrophages' phagocytosis of T24 (from 10.40% to 29.70%) and 5637 (from 5.31% to 33.52%) human bladder cancer cells, as well as demonstrate anti-tumor effects in the HSPCs-CDX model (tumor growth inhibition rate, TGI: 33.05%). During CD47 treatment, we observed that the level of angiogenesis increased after CD47 blockade, and it might undermine the effect of CD47 immunotherapy. We then combined CD47 blockade with anti-angiogenic drugs to treat bladder cancer and discovered that inhibiting angiogenesis could further improve the anti-tumor effect of CD47 blockade (TGI: 76.39%). Finally, we tested the anti-tumor effect of co-targeting CD47 and angiogenesis using a bispecific fusion protein, SIRPα-VEGFR1, which successfully inhibited tumor growth to a similar extent as a combination therapy. Conclusions: Our study suggests that targeting CD47 could inhibit the growth of bladder cancer by promoting macrophage-mediated anti-tumor immunity. Moreover, blocking CD47 and angiogenesis could achieve a potent anti-tumor effect and could be an effective immunotherapy strategy for bladder cancer.

Tumor-associated mesenchymal stromal cells modulate macrophage phagocytosis in stromal-rich colorectal cancer via PD-1 signaling

CMS4 colorectal cancer (CRC), based on the consensus molecular subtype (CMS), stratifies patients with the poorest disease-free survival rates. It is characterized by a strong mesenchymal stromal cell (MSC) signature, wound healing-like inflammation and therapy resistance. We utilized 2D and 3D in vitro, in vivo, and ex vivo models to assess the impact of inflammation and stromal cells on immunosuppression in CMS4 CRC. RNA sequencing data from untreated stage II/III CRC patients showed enriched TNF-α signatures in CMS1 and CMS4 tumors. Secretome from TNF-α treated cancer cells induced an immunomodulatory and chemotactic phenotype in MSC and cancer-associated fibroblasts (CAFs). Macrophages in CRC tumours migrate and preferentially localise in stromal compartment. Inflammatory CRC secretome enhances expression of PD-L1 and CD47 on both human and murine stromal cells. We demonstrate that TNF-α-induced inflammation in CRC suppresses macrophage phagocytosis via stromal cells. We show that stromal cell-mediated suppression of macrophage phagocytosis is mediated in part through PD-1 signaling. These data suggest that re-stratification of CRC by CMS may reveal patient subsets with microsatellite stable tumors, particularly CMS4-like tumors, that may respond to immunotherapies.

Noncoding Ribonucleic Acids (RNAs) May Improve Response to Immunotherapy in Pancreatic Cancer

Pancreatic ductal adenocarcinoma (PDAC) is the seventh most common cause of cancer-related mortality. Despite different methods of treatment, nearly more than 90% of patients with PDAC die shortly after diagnosis. Contrary to promising results in other cancers, immune checkpoint inhibitors (ICIs) showed limited success in PDAC. Recent studies have shown that noncoding RNAs (ncRNAs) are extensively involved in PDAC cell-immune cell interaction and mediate immune evasion in this vicious cancer. PDAC cells recruit numerous ncRNAs to widely affect the phenotype and function of immune cells through various mechanisms. For instance, PDAC cells upregulate miR-301a and downregulate miR-340 to induce M2 polarization of macrophages or overexpress miR-203, miR-146a, and miR-212-3p to downregulate toll-like receptor 4 (TLR4), CD80, CD86, CD1a, major histocompatibility complex (MHC) II, and CD83, thereby evading recognition by dendritic cells. By downregulating miR-4299 and miR-153, PDAC cells can decrease the expression of NK group 2D (NKG2D) and MHC class I chain-related molecules A and B (MICA/B) to blunt the natural killer (NK) cell response. PDAC cells also highly express lncRNA AL137789.1, hsa_circ_0046523, lncRNA LINC00460, and miR-155-5p to upregulate immune checkpoint proteins and escape T cell cytotoxicity. On the other hand, ncRNAs derived from suppressive immune cells promote proliferation, invasion, and drug resistance in PDAC cells. ncRNAs can be applied to overcome resistance to ICIs, monitor the immune microenvironment of PDAC, and predict response to ICIs. This Review article comprehensively discusses recent findings regarding the roles of ncRNAs in the immune evasion of PDAC.

Polyester nanoparticles delivering chemotherapeutics: Learning from the past and looking to the future to enhance their clinical impact in tumor therapy

Polymeric nanoparticles (NPs), specifically those comprised of biodegradable and biocompatible polyesters, have been heralded as a game-changing drug delivery platform. In fact, poly(α-hydroxy acids) such as polylactide (PLA), poly(lactide-co-glycolide) (PLGA), and poly(ε-caprolactone) (PCL) have been heavily researched in the past three decades as the material basis of polymeric NPs for drug delivery applications. As materials, these polymers have found success in resorbable sutures, biodegradable implants, and even monolithic, biodegradable platforms for sustained release of therapeutics (e.g., proteins and small molecules) and diagnostics. Few fields have gained more attention in drug delivery through polymeric NPs than cancer therapy. However, the clinical translational of polymeric nanomedicines for treating solid tumors has not been congruent with the fervor or funding in this particular field of research. Here, we attempt to provide a comprehensive snapshot of polyester NPs in the context of chemotherapeutic delivery. This includes a preliminary exploration of the polymeric nanomedicine in the cancer research space. We examine the various processes for producing polyester NPs, including methods for surface-functionalization, and related challenges. After a detailed overview of the multiple factors involved with the delivery of NPs to solid tumors, the crosstalk between particle design and interactions with biological systems is discussed. Finally, we report state-of-the-art approaches toward effective delivery of NPs to tumors, aiming at identifying new research areas and re-evaluating the reasons why some research avenues have underdelivered. We hope our effort will contribute to a better understanding of the gap to fill and delineate the future research work needed to bring polyester-based NPs closer to clinical application. This article is categorized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease Nanotechnology Approaches to Biology > Nanoscale Systems in Biology Therapeutic Approaches and Drug Discovery > Emerging Technologies.

Antigen presenting cells in cancer immunity and mediation of immune checkpoint blockade

Antigen-presenting cells (APCs) are pivotal mediators of immune responses. Their role has increasingly been spotlighted in the realm of cancer immunology, particularly as our understanding of immunotherapy continues to evolve and improve. There is growing evidence that these cells play a non-trivial role in cancer immunity and have roles dependent on surface markers, growth factors, transcription factors, and their surrounding environment. The main dendritic cell (DC) subsets found in cancer are conventional DCs (cDC1 and cDC2), monocyte-derived DCs (moDC), plasmacytoid DCs (pDC), and mature and regulatory DCs (mregDC). The notable subsets of monocytes and macrophages include classical and non-classical monocytes, macrophages, which demonstrate a continuum from a pro-inflammatory (M1) phenotype to an anti-inflammatory (M2) phenotype, and tumor-associated macrophages (TAMs). Despite their classification in the same cell type, each subset may take on an immune-activating or immunosuppressive phenotype, shaped by factors in the tumor microenvironment (TME). In this review, we introduce the role of DCs, monocytes, and macrophages and recent studies investigating them in the cancer immunity context. Additionally, we review how certain characteristics such as abundance, surface markers, and indirect or direct signaling pathways of DCs and macrophages may influence tumor response to immune checkpoint blockade (ICB) therapy. We also highlight existing knowledge gaps regarding the precise contributions of different myeloid cell subsets in influencing the response to ICB therapy. These findings provide a summary of our current understanding of myeloid cells in mediating cancer immunity and ICB and offer insight into alternative or combination therapies that may enhance the success of ICB in cancers.

Characterizing the immune tumor microenvironment in ALK fusion-positive lung cancer: state-of-the-art and therapeutical implications

INTRODUCTION

Approximately 5% of non-small cell lung cancer (NSCLC), exhibits anaplastic lymphoma kinase (ALK) rearrangements. EML4-ALK fusions account for over 90% of ALK rearrangements in NSCLC. The advent of treatment targeting ALK has significantly improved survival rates in patients with advanced ALK-positive NSCLC. However, the emergence of resistance mechanisms and the subsequent progression disease inevitably occurs. The tumor immune microenvironment (TIME) plays a pivotal role in lung cancer, influencing disease development, patient's outcomes, and response to treatments.

AREAS COVERED

The aim of this review is to provide a comprehensive characterization of the TIME in ALK rearranged NSCLC and its intrinsic plasticity under treatment pressure.

EXPERT OPINION

Recognizing the fundamental role of the TIME in cancer progression has shifted the paradigm from a tumor cell-centric perspective to the understanding of a complex tumor ecosystem. Understanding the intricate dynamics of the TIME, its influence on treatment response, and the potential of immunotherapy in patients with ALK-positive NSCLC are currently among the primary research objectives in this patient population.

Blockade of SIRPα-CD47 axis by anti-SIRPα antibody enhances anti-tumor activity of DXd antibody-drug conjugates

Signal regulatory protein alpha (SIRPα) is an immune inhibitory receptor on myeloid cells including macrophages and dendritic cells, which binds to CD47, a ubiquitous self-associated molecule. SIRPα-CD47 interaction is exploited by cancer cells to suppress anti-tumor activity of myeloid cells, therefore emerging as a novel immune checkpoint for cancer immunotherapy. In blood cancer, several SIRPα-CD47 blockers have shown encouraging monotherapy activity. However, the anti-tumor activity of SIRPα-CD47 blockers in solid tumors seems limited, suggesting the need for combination therapies to fully exploit the myeloid immune checkpoint in solid tumors. Here we tested whether combination of SIRPα-CD47 blocker with antibody-drug conjugate bearing a topoisomerase I inhibitor DXd (DXd-ADC) would enhance anti-tumor activity in solid tumors. To this end, DS-1103a, a newly developed anti-human SIRPα antibody (Ab), was assessed for the potential combination benefit with datopotamab deruxtecan (Dato-DXd) and trastuzumab deruxtecan (T-DXd), DXd-ADCs targeting human trophoblast cell-surface antigen 2 and human epidermal growth factor receptor 2, respectively. DS-1103a inhibited SIRPα-CD47 interaction and enhanced antibody-dependent cellular phagocytosis of Dato-DXd and T-DXd against human cancer cells. In a whole cancer cell vaccination model, vaccination with DXd-treated cancer cells led to activation of tumor-specific T cells when combined with an anti-mouse SIRPα (anti-mSIRPα) Ab, implying the benefit of combining DXd-ADCs with anti-SIRPα Ab on anti-tumor immunity. Furthermore, in syngeneic mouse models, both Dato-DXd and T-DXd combination with anti-mSIRPα Ab showed stronger anti-tumor activity over the monotherapies. Taken together, this study provides a preclinical rationale of novel therapies for solid tumors combining SIRPα-CD47 blockers with DXd-ADCs.

Current Landscape of Cancer Immunotherapy: Harnessing the Immune Arsenal to Overcome Immune Evasion

Cancer immune evasion represents a leading hallmark of cancer, posing a significant obstacle to the development of successful anticancer therapies. However, the landscape of cancer treatment has significantly evolved, transitioning into the era of immunotherapy from conventional methods such as surgical resection, radiotherapy, chemotherapy, and targeted drug therapy. Immunotherapy has emerged as a pivotal component in cancer treatment, harnessing the body's immune system to combat cancer and offering improved prognostic outcomes for numerous patients. The remarkable success of immunotherapy has spurred significant efforts to enhance the clinical efficacy of existing agents and strategies. Several immunotherapeutic approaches have received approval for targeted cancer treatments, while others are currently in preclinical and clinical trials. This review explores recent progress in unraveling the mechanisms of cancer immune evasion and evaluates the clinical effectiveness of diverse immunotherapy strategies, including cancer vaccines, adoptive cell therapy, and antibody-based treatments. It encompasses both established treatments and those currently under investigation, providing a comprehensive overview of efforts to combat cancer through immunological approaches. Additionally, the article emphasizes the current developments, limitations, and challenges in cancer immunotherapy. Furthermore, by integrating analyses of cancer immunotherapy resistance mechanisms and exploring combination strategies and personalized approaches, it offers valuable insights crucial for the development of novel anticancer immunotherapeutic strategies.

Immune checkpoint inhibitors in the treatment of hepatocellular carcinoma

Despite advances in cancer treatment, hepatocellular carcinoma (HCC), the most common form of liver cancer, remains a major public health problem worldwide. The immune microenvironment plays a critical role in regulating tumor progression and resistance to therapy, and in HCC, the tumor microenvironment (TME) is characterized by an abundance of immunosuppressive cells and signals that facilitate immune evasion and metastasis. Recently, anti-cancer immunotherapies, therapeutic interventions designed to modulate the immune system to recognize and eliminate cancer, have become an important cornerstone of cancer therapy. Immunotherapy has demonstrated the ability to improve survival and provide durable cancer control in certain groups of HCC patients, while reducing adverse side effects. These findings represent a significant step toward improving cancer treatment outcomes. As demonstrated in clinical trials, the administration of immune checkpoint inhibitors (ICIs), particularly in combination with anti-angiogenic agents and tyrosine kinase inhibitors, has prolonged survival in a subset of patients with HCC, providing an alternative for patients who progress on first-line therapy. In this review, we aimed to provide an overview of HCC and the role of the immune system in its development, and to summarize the findings of clinical trials involving ICIs, either as monotherapies or in combination with other agents in the treatment of the disease. Challenges and considerations regarding the administration of ICIs in the treatment of HCC are also outlined.

A comprehensive analysis of CD47 expression in various histological subtypes of soft tissue sarcoma: exploring novel opportunities for macrophage-directed treatments

PURPOSE

The CD47 molecule, often referred to as the "do not eat me" signal, is frequently overexpressed in tumor cells. This signaling pathway limits phagocytosis by macrophages. Our objective was to determine CD47 abundance in various soft tissue sarcomas (STS) to investigate whether it could serve as a potential evasion mechanism for tumor cells. Additionally, we aimed to assess the prognostic value of CD47 expression by examining its association with different clinicopathological factors. This study aimed to elucidate the significance of CD47 in the context of emerging anti-tumor targeting approaches.

METHODS

In this retrospective study, formalin-fixed paraffine-embedded (FFPE) tumor tissues of 55 treatment-naïve patients were evaluated by immunohistochemistry for the abundance of CD47 molecule on tumor cells. The categorization of CD47 positivity was as follows: 0 (no staining of tumor cells), 1 + (less than 1/3 of tumor area positive), 2 + (between 1/3 and 2/3 of tumor area positive), and 3 + (more than 2/3 of tumor area positive for CD47). Next, we compared CD47 abundance between different tumor grades (G1-3). We used Kaplan-Meier survival curves with log-rank test to analyze the differences in survival between patients with different CD47 expression. Moreover, we performed Cox proportional hazards regression model to evaluate the clinical significance of CD47.

RESULTS

CD47 is widely prevalent across distinct STS subtypes. More than 80% of high grade undifferentiated pleiomorphic sarcoma (UPS), 70% of myxofibrosarcoma (MFS) and more than 60% of liposarcoma (LPS) samples displayed a pattern of moderate-to-diffuse positivity. This phenomenon remains consistent regardless of the tumor grade. However, there was a tendency for higher CD47 expression levels in the G3 group compared to the combined G1 + G2 groups when all LPS, MFS, and UPS were analyzed together. No significant associations were observed between CD47 abundance, death, and metastatic status. Additionally, high CD47 expression was associated with a statistically significant increase in progression-free survival in the studied cohort of patients.

CONCLUSION

This study highlights the potential of the CD47 molecule as a promising immunotherapeutic target in STS, particularly given its elevated expression levels in diverse sarcoma types. Our data showed a notable trend linking CD47 expression to tumor grade, while also suggesting an interesting correlation between enhanced abundance of CD47 expression and a reduced hazard risk of disease progression. Although these findings shed light on different roles of CD47 in STS, further research is crucial to assess its potential in clinical settings.

Engagement of CD99 Activates Distinct Programs in Ewing Sarcoma and Macrophages

Ewing sarcoma (EWS) is the second most common pediatric bone tumor. The EWS tumor microenvironment is largely recognized as immune-cold, with macrophages being the most abundant immune cells and their presence associated with worse patient prognosis. Expression of CD99 is a hallmark of EWS cells, and its targeting induces inhibition of EWS tumor growth through a poorly understood mechanism. In this study, we analyzed CD99 expression and functions on macrophages and investigated whether the concomitant targeting of CD99 on both tumor and macrophages could explain the inhibitory effect of this approach against EWS. Targeting CD99 on EWS cells downregulated expression of the "don't eat-me" CD47 molecule but increased levels of the "eat-me" phosphatidyl serine and calreticulin molecules on the outer leaflet of the tumor cell membrane, triggering phagocytosis and digestion of EWS cells by macrophages. In addition, CD99 ligation induced reprogramming of undifferentiated M0 macrophages and M2-like macrophages toward the inflammatory M1-like phenotype. These events resulted in the inhibition of EWS tumor growth. Thus, this study reveals what we believe to be a previously unrecognized function of CD99, which engenders a virtuous circle that delivers intrinsic cell death signals to EWS cells, favors tumor cell phagocytosis by macrophages, and promotes the expression of various molecules and cytokines, which are pro-inflammatory and usually associated with tumor regression. This raises the possibility that CD99 may be involved in boosting the antitumor activity of macrophages.

CD133, CD47, and PD-L1 Expression in Ovarian High-grade Serous Carcinoma and Its Association with Metastatic Disease: A Cross-sectional Study

INTRODUCTION

Ovarian cancer is a primary cause of cancer-related death in women. At the time of diagnosis, the majority of ovarian malignancies had metastasized. It is believed that cancer stem cells (CSCs) and immune evasion play a crucial role in the metastatic process. The objective of this study was to describe the expression profiles of cluster of differentiation (CD)133, CD47, and programmed death ligand 1 (PD-L1) in high-grade serous ovarian cancer (HGSC) as commonly utilized markers for CSCs and immune evasion.

MATERIAL AND METHODS

Using an immunohistochemical procedure, 51 HGSC tissue samples were stained with anti-CD133, anti-CD47, and anti-PDL1 antibodies. The samples contained 31 HGSC with metastases and 20 HGSC absent metastases. The expression of CD133, CD47, and PD-L1 was compared between groups.

RESULTS

Strong expression of CD133 and CD47 was seen in 52% and 66% of tissue samples, respectively. Twenty of the thirty-one patients with metastases had a significant level of CD133 expression, with a p-value of 0.039. CD47 expression was increased in 26 of 31 samples with metastatic disease. A 62.7 percent of samples were negative for PD-L1 expression, significantly inversely correlated with HGSC metastatic disease (p=0.023). Although there was no significant association between CD133, CD47, or PD-L1 expression and age, Tumor Infiltrating Lymphocytes demonstrated a significantly varied relationship.

CONCLUSION

Our findings suggested that expression of CD133, CD47, and PD-L1 may have dynamically increased as the primary lesion progressed to the metastatic lesion, implying that these proteins may be involved in the progression of high-grade serous ovarian cancer from the primary to the metastatic stage.

Opportunities and challenges of CD47-targeted therapy in cancer immunotherapy

Cancer immunotherapy has emerged as a promising strategy for the treatment of cancer, with the tumor microenvironment (TME) playing a pivotal role in modulating the immune response. CD47, a cell surface protein, has been identified as a crucial regulator of the TME and a potential therapeutic target for cancer therapy. However, the precise functions and implications of CD47 in the TME during immunotherapy for cancer patients remain incompletely understood. This comprehensive review aims to provide an overview of CD47's multifaced role in TME regulation and immune evasion, elucidating its impact on various types of immunotherapy outcomes, including checkpoint inhibitors and CAR T-cell therapy. Notably, CD47-targeted therapies offer a promising avenue for improving cancer treatment outcomes, especially when combined with other immunotherapeutic approaches. The review also discusses current and potential CD47-targeted therapies being explored for cancer treatment and delves into the associated challenges and opportunities inherent in targeting CD47. Despite the demonstrated effectiveness of CD47-targeted therapies, there are potential problems, including unintended effects on healthy cells, hematological toxicities, and the development if resistance. Consequently, further research efforts are warranted to fully understand the underlying mechanisms of resistance and to optimize CD47-targeted therapies through innovative combination approaches, ultimately improving cancer treatment outcomes. Overall, this comprehensive review highlights the significance of CD47 as a promising target for cancer immunotherapy and provides valuable insight into the challenges and opportunities in developing effective CD47-targeted therapies for cancer treatment.

Site-Specific Modification of Single Domain Antibodies by Enzyme-Immobilized Magnetic Beads

Nanobodies as imaging agents and drug conjugates have shown great potential for cancer diagnostics and therapeutics. However, site-specific modification of a nanobody with microbial transglutaminase (mTGase) encounters problems in protein separation and purification. Here, we describe a facile yet reliable strategy of immobilizing mTGase onto magnetic beads for site-specific nanobody modification. The mTGase immobilized on magnetic beads (MB-mTGase) exhibits catalytic activity nearly equivalent to that of the free mTGase, with good reusability and universality. Magnetic separation simplifies the protein purification step and reduces the loss of nanobody bioconjugates more effectively than size exclusion chromatography. Using MB-mTGase, we demonstrate site-specific conjugation of nanobodies with fluorescent dyes and polyethylene glycol molecules, enabling targeted immunofluorescence imaging and improved circulation dynamics and tumor accumulation in vivo. The combined advantages of MB-mTGase method, including high conjugation efficiency, quick purification, less protein loss, and recycling use, are promising for site-specific nanobody functionalization and biomedical applications.

Design of siRNA Bioconjugates for Efficient Control of Cancer-Associated Membrane Receptors

Research on siRNA delivery has seen tremendous growth over the past few decades. As one of the major delivery strategies, siRNA bioconjugates offer the potential to enhance and extend the pharmacological properties of siRNAs while minimizing toxicity. In this paper, we suggest the development of a siRNA conjugate platform with peptides and proteins that are ligands of target receptors for cancer treatment. The siRNA bioconjugates target and block the receptor membrane proteins, enter the cells through receptor-mediated endocytosis, and inhibit the expression of that same target membrane receptor, thereby doubly controlling the function of the membrane proteins. The three kinds of bioconjugates targeting CD47, PD-L1, and EGFR were synthesized via two different copper-free click chemistry reactions. Results showed the cellular uptake of each conjugate, reduction of target gene expression, and efficient functional control of receptor proteins. This platform provides an effective approach for regulating membrane proteins in various diseases beyond cancer.

CD47 blockade enhances phagocytosis of cardiac cell debris by neutrophils

CD47 is a cell surface protein controlling phagocytotic activity of innate immune cells. CD47 blockade was investigated as an immune checkpoint therapy in cancer treatment, enhancing phagocytosis of tumor cells by macrophages. Anti-CD47 treatment also reduced injury size during reperfused acute myocardial infarction (repAMI) by enhancing phagocytotic acitivity of macrophages. Little is known about the impact of CD47 blockade on neutrophils, representing the main portion of early infiltrating immune cells after repAMI. Therefore, we performed 45 min of cardiac ischemia followed by 24 h of reperfusion, observing a decreased cardiac injury size measured by triphenyl tetrazolium chloride (TTC) Evan's blue staining. We were able to detect this effect with an innovative three-dimensional method based on light sheet fluorescence microscopy (LSFM). This further allowed us a simultaneous analysis of neutrophil infiltration, showing an unaltered amount of injury-associated neutrophils with reduced cardiac injury volume from repAMI. This observation suggests modulated phagocytosis of cell debris by neutrophils. Therefore, we performed flow cytometry analysis, revealing an increased phagocytotic activity of neutrophils in vitro. These findings highlight that CD47 blockade also enhances phagocytosis of cardiac cell debris by neutrophils, which might be an additional protective effect of anti-CD47 treatment after repAMI.

Comprehensive analysis and validation of SNX7 as a novel biomarker for the diagnosis, prognosis, and prediction of chemotherapy and immunotherapy response in hepatocellular carcinoma

BACKGROUND

Studies have demonstrated that Sorting nexin 7 (SNX7) functions as an anti-apoptotic protein in liver tissue and plays a crucial role in the survival of hepatocytes during early embryonic development. However, its diagnostic and prognostic value as well as the predictive value of chemotherapy and immunotherapy have not been reported in hepatocellular carcinoma (HCC).

METHODS

SNX7 mRNA expression and its diagnostic efficacy were examined in GEO datasets, and the findings were further confirmed in TCGA, ICGC cohorts, and cell lines. The protein level of SNX7 was determined using CPTAC and HPA databases, and the results were validated through immunohistochemistry (IHC). Survival analyses were performed in TCGA and ICGC cohorts, and the results were subsequently validated via Kaplan-Meier Plotter. The response to chemotherapy and immunotherapy was predicted via GDSC dataset and TIDE algorithm, respectively. R packages were employed to explore the relationship between SNX7 expression and immune infiltration, m6A modification, as well as the functional enrichment of differentially expressed genes (DEGs).

RESULTS

The expression of SNX7 at both mRNA and protein levels was significantly upregulated in HCC tissues. SNX7 exhibited superior diagnostic efficacy compared to AFP alone for HCC detection, and combining it with AFP improved the diagnostic accuracy for HCC. High SNX7 was associated with unfavorable outcomes, including poor overall survival, disease-specific survival, progression-free survival, and advanced pathological stage, in patients with HCC, and SNX7 was identified as an independent risk factor for HCC. Moreover, elevated SNX7 expression was positively correlated with increased sensitivity to various chemotherapy drugs, including sorafenib, while it was associated with resistance to immunotherapy in HCC patients. Correlation analysis revealed a relationship between SNX7 and multiple m6A-related genes and various immune cells. Finally, enrichment analysis demonstrated strong associations of SNX7 with critical biological processes, such as cell cycle regulation, cellular senescence, cell adhesion, DNA replication, and mismatch repair pathway in HCC.

CONCLUSIONS

Our study highlights the association of SNX7 with the immune microenvironment and its potential influence on HCC progression. SNX7 emerges as a promising novel biomarker for the diagnosis, prognosis, and prediction of response to chemotherapy and immunotherapy in patients with HCC.

Harnessing prostaglandin E2 signaling to ameliorate autoimmunity

The etiology of most autoimmune diseases remains unknown; however, shared among them is a disruption of immunoregulation. Prostaglandin lipid signaling molecules possess context-dependent immunoregulatory properties, making their role in autoimmunity difficult to decipher. For example, prostaglandin E2 (PGE2) can function as an immunosuppressive molecule as well as a proinflammatory mediator in different circumstances, contributing to the expansion and activation of T cell subsets associated with autoimmunity. Recently, PGE2 was shown to play important roles in the resolution and post-resolution phases of inflammation, promoting return to tissue homeostasis. We propose that PGE2 plays both proinflammatory and pro-resolutory roles in the etiology of autoimmunity, and that harnessing this signaling pathway during the resolution phase might help prevent autoimmune attack.

Narrative review: immunotherapy in anaplastic lymphoma kinase (ALK)+ lung cancer-current status and future directions

Background and Objective

Patients with metastatic anaplastic lymphoma kinase (ALK)+ non-small cell lung cancer (NSCLC) often experience years of disease control on targeted therapies but the disease eventually develops resistance and progresses. Multiple clinical trial efforts to incorporate PD-1/PD-L1 immunotherapy into the treatment paradigm for ALK+ NSCLC have resulted in significant toxicities without clear improvement in patient outcomes. Observations from clinical trials, translational studies, and preclinical models suggest the immune system interacts with ALK+ NSCLC and this interaction is heightened with the initiation of targeted therapy. The objective of this review is to summarize knowledge to date about current and potential immunotherapy approaches for patients with ALK+ NSCLC.

Methods

To identify the relevant literature and clinical trials the databases PubMed.gov and ClinicalTrials.gov were queried with keywords "ALK" and "lung cancer". PubMed search was further refined with terms such as "immunotherapy", "tumor microenvironment or TME", "PD-1", and "T cells". The search for clinical trials was limited to interventional studies.

Key Content and Findings

In this review, the current status of PD-1/PD-L1 immunotherapy for ALK+ NSCLC is updated and alternative immunotherapy approaches are highlighted in the context of available patient level and translational data on the ALK+ NSCLC tumor microenvironment (TME). An increase in CD8+ T cells within the ALK+ NSCLC TME has been observed with targeted therapy initiation across multiple studies. Therapies to augment this including tumor infiltrating lymphocyte (TIL) therapy, modified cytokines, and oncolytic viruses are reviewed. Furthermore, the contribution of innate immune cells in TKI mediated tumor cell clearance is discussed as a future target for novel immunotherapy approaches that promote cancer cell phagocytosis.

Conclusions

Immune modulating strategies derived from current and evolving knowledge of the ALK+ NSCLC TME may have a role in ALK+ NSCLC beyond PD-1/PD-L1 based immunotherapy.

CD47 Expression Predicts Unfavorable Prognosis in Clear Cell Renal Cell Carcinoma after Curative Resection

The role of CD47 expression as a ‘do not eat me’ signal that inhibits phagocytosis of tumor cells by macrophages is well established. Immune checkpoint therapy that targets CD47 has been successful in preclinical trials and is currently undergoing clinical investigation for various human malignancies. Here, the clinicopathological correlation with CD47 expression in clear cell renal cell carcinoma (ccRCC) was explored. CD47 expression was evaluated by immunohistochemical staining in tissue microarray sections of 235 ccRCC tissues. CD47 expression was observed in 28 (11.9%) of 235 ccRCC tissues and was significantly associated with higher WHO/ISUP grade (p = 0.001), frequent lymphovascular invasion (p = 0.036), frequent renal vein thrombus (p = 0.018), frequent sinus fat invasion (p = 0.004), frequent sarcomatous change (p = 0.001), higher pT stage (p = 0.002), higher pN stage (p = 0.002), higher pM stage (p < 0.001), and advanced American Joint Committee on Cancer stage (p = 0.002). In the survival analyses, positive CD47 expression was associated with cancer-specific survival (p = 0.003). However, positive CD47 expression was not associated with recurrence-free survival. In conclusion, CD47 expression was associated with adverse clinicopathological parameters and cancer-specific survival in patients with ccRCC.