High CD44 Expression Research Articles

Abstract 4123674: The role of CD34+ PI16+ fibroblast progenitor cells in transplant arteriosclerosis

Background: Transplantation arteriosclerosis is one of the major complications for the mid- and long-term survival of recipients with organ transplantation. Although previous studies suggest that CD34 stem/progenitor cells are involved in this process, the heterogeneity and potential adverse effects of CD34 + SPCs have not been fully determined. Methods and Results: A mouse model of transplant arteriosclerosis was established by using Balb/c, C57BL/6J, CD34-CreERT2, R26-tdTomato, Rosa26-iDTR, CD34-Dre, PI16-CreERT2, CAG-LSL-RSR-tdTomato-2A-DTR mice. Using single-cell RNA-seq and the innovative application of genetic lineage tracing with dual recombinases, we identified a subpopulation of fibroblast progenitor cells marked by high CD34 and PI16 expression. Interestingly, this progenitor cell group gave rise to a distinct chemotactic fibroblast subset. Based on chemokine antibody microarray assay and transcriptome analysis, the subgroup with increased CD34 expression and decreased PI16 expression promoted intimal hyperplasia, acting through the paracrine release of a specific chemokine CCL11 (eotaxin-1). Moreover, the binding of CCL11 to its receptor CCR3 triggered the PI3K-AKT signaling pathway in smooth muscle cells, promoting their proliferation and migration to form neointimal lesions. Overexpression of CCL11 by adeno-associated virus can promote neointimal hyperplasia in vivo, while neutralization of CCL11 or inhibition of receptor CCR3 can alleviate neointimal lesions. Conclusion: Our findings identified CD34 + /PI16 + fibroblast progenitors able to differentiate into specific chemotactic fibroblasts that release chemokines pivotal for neointima formation, implicating a therapeutic potential targeting the chemotactic behavior of these cells.

Expression of CD44 in Triple Negative Breast Cancer and its Correlation with Prognostic Parameters

Background: The study aims to evaluate CD44 expression as a cancer stem cell marker in Triple-negative breast cancer (TNBC) and its correlation with prognostic parameters. Evaluation of CD44 immunoexpression in TNBC is vital for understanding tumour aggressiveness and determining its prognostic value. Methods: A hospital based cross sectional study of 50 cases of primary triple negative breast cancer patients. The tissue sections were subjected to immunohistochemical examination using CD44 antigen marker. The proportion and intensity of CD44 immunostaining was assessed and correlation with prognostic markers such as histological grade, tumor size and nodal status. Results: CD44 expression was observed in 40% of the total cases with a statistically significant association with histological grade (p-value= 0.002). Higher CD44 expression was noticed with increasing tumour grade. However, no statistical significance was observed with respect to tumour size and nodal status. Conclusion: The study suggests that CD44 immunoexpression may serve as a surrogate marker of BCSCs and may hold prognostic value in TNBC patients. However, further studies on larger samples are required to fully understand its role.

Targeting Hypoxia-Inducible Factor-1α in Pancreatic Cancer: siRNA Delivery Using Hyaluronic Acid-Displaying Nanoparticles

Background/Objectives: Conventional anticancer therapies often lack specificity, targeting both cancerous and normal cells, which reduces efficacy and leads to undesired off-target effects. An additional challenge is the presence of hypoxic regions in tumors, where the Hypoxia Inducible Factor (HIF) transcriptional system drives the expression of pro-survival and drug resistance genes, leading to radio- and chemo-resistance. This study aims to explore the efficacy of targeted nanoparticle (NP)-based small interfering RNA (siRNA) therapies in downregulating these genes to enhance treatment outcomes in pancreatic cancer, a tumor type characterized by high CD44 expression and hypoxia. Methods: We utilized hyaluronic acid (HA)-displaying nanoparticles composed of positively charged chitosan (CS) complexed with siRNA to target and knock down HIF-1α in pancreatic cancer cells. Two NP formulations were prepared using either low molecular weight (LMW) or high molecular weight (HMW) CS. These formulations were evaluated for their internalization by cells and their effectiveness in gene silencing, both in vitro and in vivo. Results: The study found that the molecular weight (MW) of CS influenced the interaction between HA and CD44, as well as the release of siRNA upon internalization. The LMW CS formulation shows faster uptake kinetics, while HMW CS is more effective in gene knockdown across different cell lines in vitro. In vivo, both were able to significantly knockdown HIF-1α and some of its downstream genes. Conclusions: The results suggest that HMW and LMW CS-based NPs exhibit distinct characteristics, showing that both MWs have potential for targeted pancreatic cancer therapy by influencing different aspects of delivery and gene silencing, particularly in the hypoxic tumor microenvironment.

Abstract B080: A porcine model of pancreatic ductal adenocarcinoma for human scale translational cancer research

Abstract Pancreatic ductal adenocarcinoma (PDAC) remains a highly fatal form of cancer, requiring urgent advancements in diagnostic and therapeutic strategies. Although PDAC mouse models have been crucial in advancing our comprehension of the disease, they present some limitations in replicating key human PDAC aspects. In this study, we present the development of the first large animal model of pancreatic cancer via Cre activatable mutations in the endogenous KRAS and TP53 genes 1,2. In order to activate these mutations in the pancreas, two Cre driver pig lines expressing Cre recombinase from PTF1A 3 and PDX1 were created. Crossing both Cre lines with pigs carrying latent KRAS G12D and TP53 R167H alleles produced double (KC) and triple (KPC) genetically modified animals. Pathological analyses revealed the presence of inter- and intralobular fibrosis with multifocal acinar-to-ductal metaplasia (ADM), some low-grade PanINs, dysplasia, inflammation and duct obstruction in most of the KPC pigs between 3 to 6 months of age. Interestingly, the majority of these pigs already exhibited local metastasis in the lymph nodes, suggesting that the metastatic potential is established early in the tumorigenic process. Age-matched KC pigs exhibited mainly ADM with dysplasia. Flow cytometry and RNA expression analyses of the established pancreatic tumour primary cells revealed a pronounced epithelial-to-mesenchymal transition (EMT). Moreover, both bulk tumour samples and primary tumour cells showed high expression of the pancreatic cancer stem cell marker CD44, with differential expression of its isoforms, including the major isoform and variants 6 and 9. In addition, histological and molecular analyses revealed notable similarities between pig and human PDAC, including molecular subtypes, neuronal invasion and loss of acinar identity. These findings highlight the unique advantage of the pig PDAC model, that allows longitudinal and multi-regional tumour sampling in the absence of any therapeutic interventions. This makes it a valuable tool for developing new diagnostic and therapeutic approaches that can greatly improve patient outcomes in the long run.

CD24 affects the immunosuppressive effect of tumor-infiltrating cells and tumor resistance in a variety of cancers

BackgroundCluster of differentiation 24 (CD24) is a highly glycosylated glycosylphosphatidylinositol (GPI)-anchored surface protein, expressed in various tumor cells, as a "don't eat me" signaling molecule in tumor immune. This study aimed to investigate the potential features of CD24 in pan-cancer.MethodsThe correlations between 22 immune cells and CD24 expression were using TIMER analysis. R package “ESTIMATE” was used to predict the proportion of immune and stromal cells in pan-cancer. Spearman's correlation analysis was performed to evaluate the relationships between CD24 expression and immune checkpoints, chemokines, mismatch repair, tumor mutation burden and microsatellite instability, and qPCR and western blot were conducted to assess CD24 expression levels in liver hepatocellular carcinoma (LIHC). In addition, loss of function was performed for the biological evaluation of CD24 in LIHC.ResultsCD24 expression was positively correlated with myeloid cells, including neutrophils and myeloid-derived suppressor cells, in various tumors, such as BLCA, HNSC-HPV, HNSC, KICH, KIRC, KIRP, TGCT, THCA, THYM, and UCEC. In contrast, anti-tumor NK cells and NKT cells showed a negative association with CD24 expression in BRCA-Her2, ESCA, HNSC-HPV, KIRC, THCA, and THYM. The top three tumors with the highest correlation between CD24 and ImmuneScore were TGCT, THCA, and SKCM. Functional enrichment analysis revealed CD24 expression was negatively associated with various immune-related pathways. Immune checkpoints and chemokines also exhibited inverse correlations with CD24 in CESC, CHOL, COAD, ESCA, READ, TGCT, and THCA. Additionally, CD24 was overexpressed in most tumors, with high CD24 expression in BRCA, LIHC, and CESC correlating with poor prognosis. The TIDE database indicated tumors with high CD24 expression, particularly melanoma, were less responsive to PD1/PD-L1 immunotherapy. Finally, CD24 knockdown resulted in impaired proliferation and cell cycle progression in LIHC.ConclusionCD24 participates in regulation of immune infiltration, influences patient prognosis and serves as a potential tumor marker.

Inhibition of JAK/STAT3 Expression by Acute Myeloid Leukemia-Targeted Nanoliposome for Chemotherapy Enhancement.

Acute myeloid leukemia (AML) is a relatively common malignant hematological disease whose development is mostly associated with abnormal activation of the JAK/STAT3 signaling pathway. Our previous study revealed that SAR317461, a novel JAK2/STAT3 inhibitor, can effectively inhibit the activation of the JAK2/STAT3 signaling pathway and has significant damaging and pro-apoptotic effects on AML cell lines. This project aims to build upon our prior research to enhance the application of SAR317461 in AML. The surface modification of liposomes with the CD34 antibody, along with the inclusion of the SAR317461 and cytarabine (a common AML chemotherapeutic agent), is observed. Due to the high expression of CD34 on the surface of AML cells, the nanoliposome could target AML cells specifically, further achieving an effective treatment for AML through the synergistic effect of JAK2/STAT3 inhibitors and chemotherapeutic agents. The implementation of this project will provide more theoretical support and ideas for the clinical application of JAK/STAT3 inhibitors in malignant tumors and for overcoming chemotherapy resistance.

Integrated Analysis of Phagocytic and Immunomodulatory Markers in Cervical Cancer Reveals Constellations of Potential Prognostic Relevance.

Despite improvements in vaccination, screening, and treatment, cervical cancer (CC) remains a major healthcare problem on a global scale. The tumor microenvironment (TME) plays an important and controversial role in cancer development, and the mechanism of the tumor's escape from immunological surveillance is still not clearly defined. We aim to investigate the expression of CD68 and CD47 in patients with different histological variants of CC, tumor characteristics, and burden. This is a retrospective cohort study performed on paraffin-embedded tumor tissues from 191 patients diagnosed with CC between 2014 and 2021 at the Medical University Pleven, Bulgaria. Slides for immunohistochemical (IHC) evaluation were obtained, and the expression of CD68 was scored in intratumoral (IT) and stromal (ST) macrophages (CD68+cells) using a three-point scoring scale. The CD47 expression was reported as an H-score. All statistical analyses were performed using R v. 4.3.1 for Windows. Infiltration by CD68-IT cells in the tumor depended on histological type and the expression of CD47. Higher levels of the CD47 H-score were significantly more frequent among patients in the early stage. Higher levels of infiltration by CD68-ST cells were associated with worse prognosis, and the infiltration of CD68-IT cells was associated with reduced risk of death from neoplastic disease. TME is a complex ecosystem that has a major role in the growth and development of tumors. Macrophages are a major component of innate immunity and, when associated with a tumor process, are defined as TAM. Tumor cells try to escape immunological surveillance in three ways, and one of them is reducing immunogenicity by the overexpression of negative coreceptors by T-lymphocytes and their ligands on the surface of tumor cells. One such mechanism is the expression of CD47 in tumor cells, which sends a "don't eat me" signal to the macrophages and, thus, prevents phagocytosis. To our knowledge, this is the first study that has tried to establish the relationship between the CD47 and CD68 expression levels and some clinicopathologic features in CC. We found that the only clinicopathological feature implicating the level of CD68 infiltration was the histological variant of the tumor, and only for CD68-IT-high levels were these observed in SCC. High levels of CD47 expression were seen more frequently in pT1B than pT2A and pT2B in the FIGO I stage than in the FIGO II and III stages. Infiltration by large numbers of CD68-IT cells was much more common among patients with a high expression of CD47 in tumor cells. A high level of infiltration by CD68-ST cells was associated with a worse prognosis, and a high level of infiltration by CD68-ST cells was associated with a lower risk of death from cancer.

Immunohistochemical expression of CD44 in invasive breast carcinoma

Background: In India, breast cancer forms the most common malignancy, accounting for 28.2% of all female cancers. Breast cancer consists of phenotypically diverse group of diseases. Due to different relapse abilities, doubling times, and different infiltrative capacities, it is important to identify potential biomarkers that could be used to screen high-risk patient and predict breast cancer prognosis in conjunction with classical pathological parameters. Aims and Objectives: The present study was conducted to evaluate immunohistochemical expression of CD44 in breast carcinoma and to correlate CD44 expression with other clinicopathological parameters and molecular classification of carcinoma breast. Materials and Methods: The present study was a prospective descriptive study conducted on 100 cases of carcinoma breast diagnosed on modified radical mastectomy specimens that were submitted to the Department of Pathology, Pt. B. D. Sharma, PGIMS, Rohtak, Haryana, over the period of 2 years. Results: Out of 100, 64 cases (64%) were CD44 positive. Out of these 64 cases, 9 (9%) cases were 1+, 34 (34%) cases were 2+, and 21 (21%) cases showed 3+ positive expression of CD44 in tumor cells. Loss of CD44 expression was seen in 36 (36%) cases. A statistically significant association of CD44 was seen with multifocality of the tumor, negative estrogen receptor/progesterone receptor (ER/PR) expression, and molecular subtypes. No statistically significant association of CD44 was seen with age, side of tumor, lymph node metastasis, lymphovascular invasion, ductal carcinoma in situ and Ki67, and HER2neu expression. Conclusion: A high CD44 expression in breast carcinoma correlates with aggressive tumor characteristics such as multifocality, negative ER/PR expression, and belonging to the basal subtype which is associated with poor prognosis. Conversely, low CD44 expression is linked to Luminal A and Luminal B subtypes which have good prognosis. These indicate the role of CD44 as a prognostic biomarker in the carcinoma breast.

Single-Cell Analysis Reveals That CD47 mRNA Expression Correlates with Immune Cell Activation, Antiviral Isgs, and Cytotoxicity.

Immune cells are reported to upregulate CD47 during infection, however, the role of CD47 in innate and adaptive immune cells remains unclear. To bridge this knowledge gap, we analysed our single cell (sc)-RNA dataset along with other publicly available sc-RNA datasets from healthy controls, people with HIV-1 (PWH) and COVID-19 patients. We characterized each immune cell based on low, intermediate, and high expression of CD47 . Our analyses revealed that CD47 high pDCs and monocytes exhibited relatively higher expression of IFN-α regulatory genes, antiviral interferon-stimulated genes (ISGs) and MHC-I associated genes compared to CD47 inter. and CD47 low cells. Furthermore, CD47 high NK and CD8+ T cells showed higher expression of antiviral ISGs, as well as genes encoding for cytotoxic markers like granzyme B, perforin, granulysin, interferon gamma and NKG7. Additionally, CD47 high CD8+ T cells expressed higher levels of PD-1 and LAG-3 genes. Lastly, we found that CD47 high B cells had enriched expression of genes involved in cell activation and humoral responses. Overall, our analyses revealed that innate and adaptive immune cells expressing elevated activation and functional gene signatures also express higher CD47 levels.

Concise review: breast cancer stems cells and their role in metastases.

Breast cancer stem cells (BCSCs) have been suggested to be responsible for the development of Breast cancer (BC). The aim of this study was to evaluate BCSCs and the target organs microenvironment immunophenotyping markers in common BC metastases, and therapeutic targets regarding to the mentioned criteria. This narrative review involved searching international databases; PubMed, Google Scholar using predetermined keywords including breast cancer, breast cancer stem cells, breast cancer metastases, immunophenotyping, immunohistochemistry and metastases. The search results were assessed based on the title, abstract, and full text of the articles, and relevant findings were included in the review. BCSCs express high amounts of aldehyde dehydrogenase 1 (ALDH1), Ganglioside 2 (GD2), CD44 and CD133 but are negative for CD24 marker. CXCR4 and OPN have high expression in the cells and may contribute in BC metastasis to the bone. Nestin, CK5, prominin-1 (CD133) markers in BCSCs have been reported to correlate with brain metastasis. High expression of CD44 in BCSCs and CXCL12 expression in the liver microenvironment may contribute to BC metastasis to the liver. Aberrantly expressed vascular cell adhesion molecule-1 (VCAM-1) that binds to collagen and elastin fibers on pulmonary parenchyma, and CXCR4 of BCSCs and CXCL12 in lung microenvironment may promote the cells homing and metastasis to lung. As in various types of BC metastases different markers that expressed by the cells and target organ microenvironment are responsible, BCSCs immunophenotyping can be used as target markers to predict the disease prognosis and treatment.

Association of CD133, ALDH1, CD117 and OCT4 expression with prognosis of patients with cervical cancer.

Cancer stem cells (CSC), a small population of neoplastic cells, are associated with worse prognosis. The aim of this study was to evaluate the expression of ALDH1, CD117, CD133 and OCT4; potential markers of CSC; and their associations with the prognosis of women diagnosed with cervical cancer. This retrospective cohort study included 126 women diagnosed with cervical cancer whose biopsies were analyzed by immunohistochemistry. Median values of marked cells were used to define cutoff points for low and high expression. For specific survival, multivariate analyses showed statistical significance for lymph node metastases (HR 8.15; 95% CI 3.00-22.18) and borderline significance for high CD133 expression (p = 0.058). For overall survival, multivariate analyses showed statistical significance for IIA-IVB staging (HR 4.60; 95% CI 1.46-14.56), lymph node metastases (HR 5.13; 95% CI 12.02-13.03) and high CD133 expression (2.67; 95% CI 1.11-6.43). Considering only women with SCC, the same clinicopathological variables were associated with worse specific and overall survival in univariate analyses. However, higher expression of CD 133 (HR 11.10; 95% CI 2.42-50.94 and 6.00; 95% CI 2.02-17.87) and staging IIA-IVB (HR 5.96; 95% CI 1.30-27.34 and HR 12.47; 95% CI 2.45-63.54) respectively impacted negatively specific and overall survival, as multivariate analyses showed. Secondarily, it was observed that ALDH1 expression was associated with adenocarcinoma and CD117 expression with squamous cells carcinoma. Higher expression of CD133 was associated with worse specific and overall survival, indicating that it could have relevance as a clinical marker and therapeutic target.

Impact of CD151 overexpression on prognosis and therapy in non-small cell lung cancer patients lacking EGFR mutations.

This study investigates CD151, a protein linked to cancer progression, in non-small cell lung cancer (NSCLC) patients without epidermal growth factor receptor (EGFR) mutations. These patients often have limited treatment options. The study used retrospective analysis to examine 157 adenocarcinoma biopsy specimens and 199 patient cases from The Cancer Genome Atlas, correlating CD151 expression with patient survival. Cellular studies revealed that CD151 interacts with EGFR, influencing epidermal growth factor (EGF)-induced cell proliferation and the effectiveness of the EGFR inhibitor, erlotinib. A strong association was found between CD151 expression and EGFR mutation status. High CD151 expression in the absence of EGFR mutations is correlated with poorer survival outcomes. Biological assays showed that CD151 colocalizes and associates with EGFR, playing a crucial role in regulating EGF-induced cell proliferation via the AKT and ERK1/2 pathways. Importantly, CD151 expression was found to influence the anti-proliferative effects of the EGFR tyrosine kinase inhibitor, erlotinib. High CD151 expression, in the absence of EGFR mutations, was associated with poorer survival outcomes. It could serve as a potential prognostic marker and influence cellular responses to EGFR-targeted treatments. This study highlights CD151 as a potential novel target for therapeutic intervention in NSCLC, especially in populations lacking EGFR mutations.

Immunohistochemical Expression of CD47 and CD68 in Breast Carcinoma and Their Prognostic Value.

Cluster of differentiation 47 (CD47) has been identified as a new immune checkpoint. The exact role of CD47 in prognosis of breast cancer remains unclear. This study aims to evaluate immunohistochemical (IHC) expression of CD47 in breast cancer, and to measure the density of tumor associated macrophages (TAMs) infiltration by CD68 IHC staining. Furthermore, assessing the relations of CD47 and CD68 expression to different clinicopathological variables and evaluating the prognostic role of CD47 and CD68 in breast cancer cases. This retrospective cohort study included 200 diagnosed primary breast cancer cases who underwent surgical resection at the Oncology Center of Mansoura University (OCMU), Faculty of Medicine, Egypt. Clinicopathological and survival data were collected. IHC for CD47 and CD68 was performed. Among 200 breast cancer cases, high CD47 expression was detected in 89 cases (44.5%). CD47 high expression was significantly associated with presence of distant metastasis (P=0.04), advanced TNM stage (P=0.02), ER & PR negativity (P=0.04 & 0.004 respectively), and molecular subtype (P=0.03). Their was a statistically significant association between CD47 and CD68 expression (P=0.002). CD47 high expression was found to predict poor overall survival, but it is not considered alone as independent poor prognostic factor by multivariate analysis. Multivariate analysis spotted combined high expression of CD47 and CD68 as an independent prognostic predictor for shorter OS in breast cancer patients (P=0.002). CD47 high expression is related to poor prognosis in breast cancer patients especially when associated with high CD68+TAMs infiltration. Therefore, CD47 is a promising prognostic and therapeutic target in breast carcinoma that may direct selection of patients for immunotherapy.

Immunohistochemical Expression and Histopathological Role of CD47 in Colorectal Cancer in Iraqi Patients

Background: Bowel cancer is the most prevalent digestive system cancer and is the 4th largest cause of cancer-related death worldwide. In Iraq, colon and rectal cancer (CRC) is the 6th most common malignancy in males and the 5th in females. This cancer is sluggish in growth, which gives a window of opportunity to screen for both precursor lesions and early cancer. The Cluster of Differentiation 47 (CD47) protein is a type of transmembrane glycoproteins found on nearly all human cells, including non-hematopoietic and hematopoietic cells. CD47 promotes CRC growth by triggering angiogenesis and apoptosis of tumor cell. Objectives: To evaluate the immunohistochemical expression of (CD47) in various colorectal samples from Iraqi patients with CRC by immunohistochemistry (IHC) assay. Specimens and methods: A total of 45 paraffin-embedded CRC tissue specimens and clinical data were obtained from the Medical City Teaching Hospital in Baghdad and a number of private laboratories in Baghdad, Iraq. In addition, 30 control colon and rectum tissues with no significant pathology were collected from the Forensic Medicine Department for comparison purposes after taking the official approvals. Results: The results revealed a high expression of CD47 in CRC cases, but with no significant correlation with clinicopathological features. Also, the result of figures in this study revealed negative membranous expression of CD47 (score 0), strong membranous expression of CD47 (score 3), moderately membranous expression of CD47 (score 2), and weak membranous expression of CD47 (score 1) Conclusion: Patients with CRC had high CD47 expression, allowing tumor cells to modulate CD47SIRP inhibitory signaling and prevent immune cell attack.

High CD90 Expression is A Predictor of Axillary Nodal Metastasis in Breast Carcinoma

High CD90 Expression is A Predictor of Axillary Nodal Metastasis in Breast Carcinoma

High levels of soluble CD73 unveil resistance to BRAF inhibitors in melanoma cells

Melanoma cells express high levels of CD73 that produce extracellular immunosuppressive adenosine. Changes in the CD73 expression occur in response to tumor environmental factors, contributing to tumor phenotype plasticity and therapeutic resistance. Previously, we have observed that CD73 expression can be up-regulated on the surface of melanoma cells in response to nutritional stress. Here, we explore the mechanism by which melanoma cells release soluble CD73 under low nutrient availability and whether this might be affected by agents targeting the proto-oncogene B-Raf (BRAF). We found that starved melanoma cells can release high levels of CD73, able to convert AMP into adenosine, and this activity is abrogated by selective CD73 inhibitors, APCP or PSB-12489. The release of CD73 from melanoma cells is mediated by the matrix metalloproteinase MMP-9. Indeed, MMP-9 inhibitors significantly reduce the levels of CD73 released from the cells, while its surface levels increase. Of relevance, melanoma cells, harboring an activating BRAF mutation, upon treatment with dabrafenib or vemurafenib, show a strong reduction of CD73 cell expression and reduced levels of CD73 released into the extracellular space. Conversely, melanoma cells resistant to dabrafenib show high expression of membrane-bound CD73 and soluble CD73 released into the culture medium. In summary, our data indicate that CD73 is released from melanoma cells. The expression of CD73 is associated with response to BRAF inhibitors. Melanoma cells developing resistance to dabrafenib show increased expression of CD73, including soluble CD73 released from cells, suggesting that CD73 is involved in acquiring resistance to treatment.

Effect of tumorspheres cultured from circulating cancer stem cells on the innate checkpoint CD47 in patients with breast cancer.

e13113 Background: Circulating cancer cells, and in particular their very rare subpopulation, circulating cancer stem cells (cCSCs), are responsible for recurrence and metastasis. The exact role of cCSCs in escape of cancer from immunosurveillance is still unknown, but recent studies reported that increased expression of CD47 enable cancer cells to evade phagocytosis by macrophages and promote the cancer stem cell phenotype. Understanding the mechanisms behind this CD47 overexpression in cancer stem cells is critical for developing more effective immunotherapy. Therefore, in the current study, we evaluated the incidence and clinical relevance of tumorspheres cultured from cCSCs expressing CD47 in breast cancer patients. Methods: 110 patients with breast cancer in different stages of disease were included in this study. The determination of cCSCs was performed using the sphere-forming assay. Additionally, anti-CD47 antibody staining was applied to examine CD47 expression on breast tumorspheres. Results: We have developed an innovative in vitro platform for detection of cCSCs from peripheral blood of cancer patients. The number of tumorspheres was associated with disease progression and aggressiveness of primary tumor. Patients with metastatic disease had statistically more tumorspheres as compared to patients without metastasis (30 vs 10/100µl blood, p<0.05). Patients with multiple metastasis had more tumorspheres compared to patients with single metastases (60 vs 30/100µl blood, p<0.05). CD47 was highly expressed in tumorspheres, which are enriched from circulating cancer stem cells and associated with triple-negative tumors. We also observed high heterogeneity of CD47 expression between the tumorspheres of a patient and between the patients. Conclusions: The number of tumorspheres cultured from peripheral blood directly reflects aggressiveness and proliferation capacity of primary tumor. The presence of tumorspheres with high expression of CD47 might suggest their immunoregulatory potential. Better understanding of the interaction between cCSCs and tumor immunology may improve outcome especially in high-risk patients in part by attacking cCSCs and disinhibiting innate immunity.

QUIC: Phase 2 study of gemcitabine, cisplatin, quemliclustat (AB680), and zimberelimab (AB122) during first-line treatment of advanced biliary tract cancers (BTC)—Big Ten Cancer Research Consortium study BTCRC-GI22-564.

TPS4195 Background: Despite recent approvals of immune checkpoint inhibitors with chemotherapy in the first-line setting, the median overall survival (mOS) for patients with advanced biliary tract cancer (BTC) remains less than 15 months. CD73 is a key enzyme responsible for the conversion of extracellular adenosine 5’-monophosphate into adenosine and may play an important role in creating an immunosuppressed tumor microenvironment. High expression of CD73 in BTC is associated with decreased OS. Quemliclustat (Q) is a potent, selective, reversible inhibitor of CD73. Q in combination with chemotherapy has demonstrated promising activity in patients with advanced pancreatic cancer without significant increase in adverse events. The BTCRC-GI22-564 study evaluates safety and preliminary efficacy of Q in combination with zimberelimab (Z), a monoclonal antibody targeting human PD-1, with gemcitabine and cisplatin (GC) as first-line therapy for patients with advanced BTC, QUIC (Q and Immunotherapy in Cholangiocarcinoma). Methods: This is an open label, single arm, phase II multi-site trial, evaluating Q and Z in combination with GC in patients with advanced BTC who have not received systemic treatment for advanced disease or who completed adjuvant therapy > 6 months prior to development of recurrent disease. Chemotherapy is given on days 1, 8, 22 and 29 of each 42-day cycle as per local standards. Z is administered at a fixed dose of 360 mg via IV infusion every 3 weeks. Q is administered via IV infusion on days 1, 15, and 29. A safety run-in portion built into the study is planned to enroll 6 subjects to ensure there are no dose limiting toxicities (DLT). If a study defined DLT is observed, Q, gemcitabine and cisplatin will be reduced by 1 dose level, and an additional 6 subjects will be enrolled in the safety run-in portion. The primary efficacy endpoint is median progression free survival (mPFS) with null and alternative survival of 6.0 and 10.0 months, respectively. Based on an accrual rate of 3 patients per month, we expect to accrue 33-39 patients which will provide at least 83% power with a one-sided alpha of 0.1. Secondary endpoints include mOS, disease control rate, overall response rate, and duration of response. Correlative endpoints will assess clinical outcomes with immune infiltration within tumor microenvironment, CD73 and PD-L1 expression. The QUIC study is currently open to enrollment through BTCRC. Clinical trial information: NCT06048133 .

Enhanced immunosuppressive capability of mesenchymal stem cell-derived small extracellular vesicles with high expression of CD73 in experimental autoimmune uveitis

BackgroundAutoimmune uveitis is an inflammatory disease triggered by an aberrant immune response. Mesenchymal stem cell-derived small extracellular vesicles (MSC-sEVs) are emerging as potential therapeutic agents for this condition. CD73, an ectoenzyme present on MSC-sEVs, is involved in mitigating inflammation by converting extracellular adenosine monophosphate into adenosine. We hypothesize that the inhibitory effect of MSC-sEVs on experimental autoimmune uveitis (EAU) could be partially attributed to the surface expression of CD73.MethodsTo investigate novel therapeutic approaches for autoimmune uveitis, we performed lentiviral transduction to overexpress CD73 on the surface of MSC-sEVs, yielding CD73-enriched MSC-sEVs (sEVs-CD73). Mice with interphotoreceptor retinoid-binding protein (IRBP)-induced EAU were grouped randomly and treated with 50 µg MSC-sEVs, vector infected MSC-sEVs, sEVs-CD73 or PBS via single tail vein injection. We evaluated the clinical and histological features of the induced mice and analyzed the proportion and functional capabilities of T helper cells. Furthermore, T-cells were co-cultured with various MSC-sEVs in vitro, and we quantified the resulting inflammatory response to assess the potential therapeutic benefits of sEVs-CD73.ResultsCompared to MSC-sEVs, sEVs-CD73 significantly alleviates EAU, leading to reduced inflammation and diminished tissue damage. Treatment with sEVs-CD73 results in a decreased proportion of Th1 cells in the spleen, draining lymph nodes, and eyes, accompanied by an increased proportion of regulatory T-cells (Treg cells). In vitro assays further reveal that sEVs-CD73 inhibits T-cell proliferation, suppresses Th1 cells differentiation, and enhances Treg cells proportion.ConclusionOver-expression of CD73 on MSC-sEVs enhances their immunosuppressive effects in EAU, indicating that sEVs-CD73 has the potential as an efficient immunotherapeutic agent for autoimmune uveitis.

LKB1 Loss Correlates with STING Loss and, in Cooperation with β-Catenin Membranous Loss, Indicates Poor Prognosis in Patients with Operable Non-Small Cell Lung Cancer.

To investigate the incidence and prognostically significant correlations and cooperations of LKB1 loss of expression in non-small cell lung cancer (NSCLC), surgical specimens from 188 metastatic and 60 non-metastatic operable stage I-IIIA NSCLC patients were analyzed to evaluate their expression of LKB1 and pAMPK proteins in relation to various processes. The investigated factors included antitumor immunity response regulators STING and PD-L1; pro-angiogenic, EMT and cell cycle targets, as well as metastasis-related (VEGFC, PDGFRα, PDGFRβ, p53, p16, Cyclin D1, ZEB1, CD24) targets; and cell adhesion (β-catenin) molecules. The protein expression levels were evaluated via immunohistochemistry; the RNA levels of LKB1 and NEDD9 were evaluated via PCR, while KRAS exon 2 and BRAFV600E mutations were evaluated by Sanger sequencing. Overall, loss of LKB1 protein expression was observed in 21% (51/248) patients and correlated significantly with histotype (p < 0.001), KRAS mutations (p < 0.001), KC status (concomitant KRAS mutation and p16 downregulation) (p < 0.001), STING loss (p < 0.001), and high CD24 expression (p < 0.001). STING loss also correlated significantly with loss of LKB1 expression in the metastatic setting both overall (p = 0.014) and in lung adenocarcinomas (LUACs) (p = 0.005). Additionally, LKB1 loss correlated significantly with a lack of or low β-catenin membranous expression exclusively in LUACs, both independently of the metastatic status (p = 0.019) and in the metastatic setting (p = 0.007). Patients with tumors yielding LKB1 loss and concomitant nonexistent or low β-catenin membrane expression experienced significantly inferior median overall survival of 20.50 vs. 52.99 months; p < 0.001 as well as significantly greater risk of death (HR: 3.32, 95% c.i.: 1.71-6.43; p <0.001). Our findings underscore the impact of the synergy of LKB1 with STING and β-catenin in NSCLC, in prognosis.