High CD44 Expression Research Articles

Hyaluronic acid-coated liposomes for enhanced in vivo efficacy of neogambogic acid via active tumor cell targeting and prolonged systemic exposure

Neogambogic acid (NGA), which possesses a variety of anticancer activities, is visualized as an anticancer bioactive ingredient. However, the huge vascular stimulation, poor aqueous solubility, and short half-life restricted its clinical use. In this work, an effective nanocarrier was explored to reduce toxicity and enhance the tumor-targeted delivery. Two liposomal formulations, neogambogic acid liposomes (NGA-L), and hyaluronic acid-coated neogambogic acid liposomes (HA-NGA-L) were prepared and characterized with high encapsulation efficiency, slow pattern of drug release, narrow size distribution and higher stability. The cytotoxicity and cellular uptake of HA-NGA-L were higher than those of NGA-L in MDA-MB-231 cells (high CD44 expression), while no obvious differences in MCF-7 cells with (low CD44 expression), suggesting the CD44-mediated cellular internalization of hyaluronic acid-modified liposomes enhanced the cytotoxicity. Mechanistically, elevation of Bax and caspase-3 as well as downregulation of Bcl-2 led to cell apoptosis. Besides, the vascular stimulation and the hemolysis test indicated good safety of HA-NGA-L. In addition, HA-NGA-L was the effective nanocarrier to repress tumor proliferation in MDA-MB-231 tumor xenograft mouse through CD44 mediated active targeting without any obvious histopathological abnormities on major organs. Immunohistochemistry analysis revealed the enhanced elevation of Bax and caspase-3, and reduced expression of Bcl-2 contribute to apoptosis in tumors. Meanwhile, HA-NGA-L increased the AUC and t1/2 by 5.34-fold and 3.94-fold, respectively. In summary, the present study shows that HA-NGA-L may be safe and effective for the tumor-targeted delivery of neogambogic acid.

Targeting SIGLEC15 as an emerging immunotherapy for anaplastic thyroid cancer

Anaplastic thyroid carcinoma (ATC) is the most aggressive subtype of thyroid cancer with few effective therapies. Though immunotherapies such as targeting PD-1/PD-L1 axis have benefited patients with solid tumor, the druggable immune checkpoints are quite limited in ATC. In our study, we focused on the anti-tumor potential of sialic acid-binding Ig-like lectins (Siglecs) in ATC. Through screening by integrating microarray datasets including 216 thyroid-cancer tissues and single-cell RNA-sequencing, SIGLEC family members CD33, SIGLEC1, SIGLEC10 and SIGLEC15 were significantly overexpressed in ATC, among which SIGLEC15 increased highest and mainly expressed on cancer cells. SIGLEC15high ATC cells are characterized by high expression of serine protease PRSS23 and cancer stem cell marker CD44. Compared with SIGLEC15low cancer cells, SIGLEC15high ATC cells exhibited higher interaction frequency with tumor microenvironment cells. Further study showed that SIGLEC15high cancer cells mainly interacted with T cells by immunosuppressive signals such as MIF-TNFRSF14 and CXCL12-CXCR4. Notably, treatment of anti-SIGLEC15 antibody profoundly increased the cytotoxic ability of CD8+ T cells in a co-culture model and zebrafish-derived ATC xenografts. Consistently, administration of anti-SIGLEC15 antibody significantly inhibited tumor growth and prolonged mouse survival in an immunocompetent model of murine ATC, which was associated with increase of M1/M2, natural killer (NK) cells and CD8+ T cells, and decrease of myeloid-derived suppressor cells (MDSCs). SIGLEC15 inhibited T cell activation by reducing NFAT1, NFAT2, and NF-κB signals. Blocking SIGLEC15 increased the secretion of IFN-γ and IL-2 in vitro and in vivo. In conclusion, our finding demonstrates that SIGLEC15 is an emerging and promising target for immunotherapy in ATC.

Construction of glutathione-responsive paclitaxel prodrug nanoparticles for image-guided targeted delivery and breast cancer therapy.

Paclitaxel (PTX) remains an essential drug in the treatment of breast cancer. To improve metabolic stability and real-time monitoring of drug location, we develop a visualized nano-prodrug. Novel hyaluronic acid (HA)-coated glutathione (GSH)-sensitive chitosan (CS)-based nano-prodrug (HA/TPE-CS-SS-PTX NPs) with aggregation-induced emission effects (AIE) were accomplished. The prodrug NPs (drug loading 29.32%, particle size 105 nm, regular sphericity) exhibit excellent fluorescence stability. The prodrug NPs could target tumor cells with high expression of CD44 and decompose in the presence of high concentrations of glutathione. In vitro evaluations revealed that the prodrug NPs have significant cytotoxicity on 4T1 cells, and due to their excellent AIE characteristics, their position in cells can be tracked. Moreover, the prodrug NPs also shown superior anti-tumor effects in vivo experimental. Overall, the HA/TPE-CS-SS-PTX NPs we constructed have excellent bio-imaging capabilities and can be served as a potential nanomedicine for PTX delivery against breast cancer.

Study on the mechanism of quercetin inducing mesenchymal stem cells to differentiate into fibroblasts through TGF-β1 and IGF-1

BackgroundStem cell differentiation has opened up new avenues for disease treatment, tissue repair, and drug development in the study of regenerative medicine, and has huge application prospects. This study aimed to explore the mechanism of quercetin on the differentiation of mesenchymal stem cells (MSCs) into fibroblasts. MethodsIn this study, cell differentiation experiments and flow cytometry were used to detect the successful isolation of bone marrow MSCs from SD rats. Quercetin at 5, 10, and 20 μM was used as low, medium, and high doses to intervene in MSCs. The cell viability changes of ligament fibroblasts at 24, 48, and 72 hours after quercetin treatment were detected using a CCK-8 cell counting kit. Cell proliferative capacity was determined by flow cytometry. RT-qPCR measured the relative expression levels of TGF-β1, IGF-1, COL-Ⅰ, COL-Ⅲ, FN (fibronectin), and TNMD (Tenomodulin) in different experimental groups. Molecular docking experiments were conducted to explore the binding effect of quercetin on TGF-β1 and IGF-1 proteins. ResultsFlow cytometry verified the successful isolation of MSCs, which had high expression of CD29 and CD73, while lower expression of CD90 and CD45. Experimental results show that low and medium doses of quercetin can enhance cell proliferation, while high doses have no significant effect on cells. Detection of cell proliferation through flow cytometry yielded similar results to CCK-8. Transwell experiments have shown that low and medium doses of quercetin can increase cell migration ability. In addition, RT-qPCR detection showed that quercetin can increase the mRNA expression of TGF-β1 and IGF-1, and promote the expression of COL-Ⅰ, COL-Ⅲ, FN, and TNMD genes in ligament fibroblasts. Molecular docking results showed that quercetin can bind firmly to TGF-β1 and IGF-1. ConclusionOverall, this study revealed the morphological characteristics and identification of MSCs, as well as the regulatory mechanism of quercetin on the behavior of ligament fibroblasts. Quercetin affects the proliferation and gene expression of ligament fibroblasts by regulating the expression of TGF-β1 and IGF-1, which may provide a new perspective for biomedical research on the skeletal system.

Progress in cancer research on the regulator of phagocytosis CD47, which determines the fate of tumor cells (Review).

Cluster of differentiation 47 (CD47) is a transmembrane protein that is widely and moderately expressed on the surface of various cells and can have an essential role in mediating cell proliferation, migration, phagocytosis, apoptosis, immune homeostasis and other related responses by binding to its ligands, integrins, thrombospondin-1 and signal regulatory protein α. The poor prognosis of cancer patients is closely associated with high expression of CD47 in glioblastoma, ovarian cancer, breast cancer, bladder cancer, colon cancer and hepatocellular carcinoma. Upregulation of CD47 expression facilitates the growth of numerous types of tumor cells, while downregulation of its expression promotes phagocytosis of tumor cells by macrophages, thereby limiting tumor growth. In addition, blocking CD47 activates the cyclic GMP-AMP (cGAMP) synthase/cGAMP/interferon gene stimulating factor signaling pathway and initiates an adaptive immune response that kills tumor cells. The present review describes the structure, function and interactions of CD47 with its ligands, as well as its regulation of phagocytosis and tumor cell fate. It summarizes the therapeutics, mechanisms of action, research advances and challenges of targeting CD47. In addition, this paper provides an overview of the latest therapeutic options for targeting CD47, such as chimeric antigen receptor (CAR) T-cells, CAR macrophages and nanotechnology-based delivery systems, which are essential for future clinical research on targeting CD47.

Co-targeting CD47 and VEGF elicited potent anti-tumor effects in gastric cancer

BackgroundCD47, serving as an intrinsic immune checkpoint, has demonstrated efficacy as an anti-tumor target in hematologic malignancies. Nevertheless, the clinical relevance of CD47 in gastric cancer and its potential as a therapeutic target remains unclear.MethodsThe expression of CD47 in clinical gastric cancer tissues was assessed using immunohistochemistry and Western blot. Patient-derived cells were obtained from gastric cancer tissues and co-cultured with macrophages derived from human peripheral blood mononuclear cells. Flow cytometry analyses were employed to evaluate the rate of phagocytosis. Humanized patient-derived xenografts (Hu-PDXs) models were established to assess the efficacy of anti-CD47 immunotherapy or the combination of anti-CD47 and anti-VEGF therapy in treating gastric cancer. The infiltrated immune cells in the xenograft were analyzed by immunohistochemistry.ResultsIn this study, we have substantiated the high expression of CD47 in gastric cancer tissues, establishing a strong association with unfavorable prognosis. Through the utilization of SIRPα-Fc to target CD47, we have effectively enhanced macrophage phagocytosis of PDCs in vitro and impeded the growth of Hu-PDXs. It is noteworthy that anti-CD47 immunotherapy has been observed to sustain tumor angiogenic vasculature, with a positive correlation between the expression of VEGF and CD47 in gastric cancer. Furthermore, the successful implementation of anti-angiogenic treatment has further augmented the anti-tumor efficacy of anti-CD47 therapy. In addition, the potent suppression of tumor growth, prevention of cancer recurrence after surgery, and significant prolongation of overall survival in Hu-PDX models can be achieved through the simultaneous targeting of CD47 and VEGF using the bispecific fusion protein SIRPα-VEGFR1 or by combining the two single-targeted agents.ConclusionsOur preclinical studies collectively offer substantiation that CD47 holds promise as a prospective target for gastric cancer, while also highlighting the potential of anti-angiogenic therapy to enhance tumor responsiveness to anti-CD47 immunotherapy.

CD44 and CD133 protein expression might serve as a prognostic factor for early occurrence castration-resistant prostate cancer.

The occurrence of castration-resistant prostate cancer (CRPC) varies in patients with advanced prostate cancer (PCa) undergoing androgen deprivation therapy (ADT). The rate of occurrence of CRPC may be related to the presence of prostate cancer stem cells (CSC). Thus, this study aims to evaluate the presence of CSC markers (CD44 and CD133) in histopathology tissue at the time of diagnosis and their correlation with the occurrence of CRPC in patients with advanced PCa within 2 years of ADT. A retrospective case-control study was conducted to evaluate the incidence of CRPC within 2 years. The inclusion criteria were patients with PCa who had received treatment with ADT and a first-generation anti-androgen (AA) for 2 years. We classified patients based on whether they developed CRPC within 2 years (CRPC) of the therapy or did not experience CRPC within 2 years (non-CRPC) of the therapy. We performed immunohistochemical (IHC) staining for CD44 and CD133 on the prostate biopsy tissue samples. Data were collected from records spanning 2011-2019. We analyzed a total of 65 samples, including 22 patients with CRPC and 43 patients with non-CRPC who had received treatment with LHRH agonists and AA for up to 2 years. Our findings showed a significant H-score difference in CD44 protein expression between CRPC prostate adenocarcinoma samples 869 (200-1329) and non-CRPC 524 (154-1166) (p = 0.033). There was no significant difference in CD133 protein expression between the two groups (p = 0.554). However, there was a significant difference in the nonoccurrence of CRPC between the high expressions of both CD44 and CD133 groups with other expressions of CD44/CD133 groups (25% vs. 75%; p = 0.011; odds ratio = 4.29; 95% confidence interval [1.34, 13.76]). This study found a low expression of at least one CD44/CD133 protein in the patients without early occurrence of CRPC. This result might suggest that CD44/CD133 may function as a potential prognostic marker for PCa, especially in a low expression, to identify patients who have a better prognosis regarding the occurrence of early CRPC.

Abstract 2520: CD133 expression is associated with less DNA repair, better response to chemotherapy, and survival in ER-positive/ER-negative breast cancer

Abstract Introduction: Cancer stem cells (CSC) constitute only 0.1-1% of all the cells in a bulk tumor, yet they play a crucial role in treatment resistance and relapses. Its role in breast cancer (BC) has been studied but a consensus remains elusive. We focused on gene expression of a CSC marker CD133 and studied its clinical significance in ER-positive/HER2-negative (ER+/HER2-) BC, the most prevalent subtype. We utilized multiple independent large patient cohorts of gene expression and clinical variables for transcriptome analysis. Methods: A total of 2969 patients from The Cancer Genome Atlas (TCGA, n=1065) and the Molecular Taxonomy of Breast Cancer International Consortium (METABRIC, n=1904) BC cohorts, as well as BC patients who underwent neoadjuvant chemotherapy (NAC; GSE25066, GSE20194, GSE32646 cohorts) were analyzed. Results: By analyzing SCP1039 and SCP1106 single-cell sequencing cohorts, we found that epithelial cells were the predominant source of CD133 gene expression in the tumor microenvironment. High expression of CD133 in ER+/HER2- BC correlated with elevated gene expressions of the other CSC markers; CD24, NOTCH1, DLL1, and ALDH1A1 (all p<0.001), and significantly enriched WNT/β-Catenin, Hedgehog, and Notch signaling (all FDR<0.25), which are all known pathways related with CSC in TCGA and validated in METABRIC cohort. Consistent with CSC phenotype, CD133-high BC was negatively enriched with Hallmark cell proliferation-related gene sets, such as E2F Targets, G2M Checkpoint, MYC Targets V1, Ki67 gene expression and proliferation score (FDR<0.25 and p<0.001, respectively) in both cohorts. CD133-high BC was negatively associated with DNA repair genes, such as BRCA1, E2F7 in both cohorts (all p<0.001). In agreement, CD133-high BC was associated with less homologous recombination deficiency, lower silent and non-silent mutation rates. Surprisingly, CD133-high BC exhibited a proinflammatory microenvironment, as represented by higher cytolytic activity in the METABRIC and higher lymphocyte infiltrations, TGF-beta response, and TCR richness in TCGA (both p<0.001), but less Th1 cells, M1 macrophages and dendritic cell infiltrations consistently in both cohorts. It also enriched signaling pathways related to inflammation and immune responses such as inflammatory response, allograft rejection, TNF-alpha, IL-6, TGF-beta signaling, and complement signaling (all FDR<0.25). CD133-high tumors had better pathological complete response after NAC in GSE25066 cohort and improved Disease-Free Survival and Overall Survival in both TCGA and METABRIC cohorts (all p<0.05). Conclusion: CD133-high ER+/HER2- BC is associated with CSC phenotype, reduced cell proliferation, and impaired DNA repair, but enhanced inflammation, potentially explaining the better response to NAC and favorable patient prognosis. Citation Format: Takumi Sato, Masanori Oshi, Jing Lee, Arya M. Roy, Kohei Chida, Itaru Endo, Masato Obayashi, Kazuaki Takabe. CD133 expression is associated with less DNA repair, better response to chemotherapy, and survival in ER-positive/ER-negative breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2520.

Abstract 3017: Lack of MCPIP1 enzymatic activity leads to neoplastic transformation of normal kidney cells

Abstract Introduction: The MCPIP1 protein (Monocyte Chemotactic Protein-1 Induced Protein) is involved in the negative regulation of inflammation due to its RNase activity. A growing number of publications suggest that the MCPIP1 protein may influence the development of cancer by regulation of factors involved in angiogenesis, proliferation and cell death. We believe, that MCPIP1 may be a potential tumor suppressor. Our recent results show that lack of enzymatic activity of MCPIP1 leads to increased tumor growth, angiogenesis and metastasis. The main aim of our research is to study the importance of MCPIP1 for neoplastic transformation of normal, epithelial kidney cells, as well as acquirement of stemness features. Material and Methods: To examine the effect of MCPIP1 in normal epithelial cell lines TCMK-1, RPTEC-Tert1 and HK-2 were transduced to overexpress mutated, inactive form of MCPIP1 (pLIX D141N) with proper control (pLIX PURO). We analyzed cells clonogenicity, as well as the levels of CSCs markers by western blot, NGS and qPCR. Next, cells were injected subcutaneously into NOD-SCID mice to check if mutation of MCPIP1 will induce tumor growth in vivo. Mice blood was analyzed for the presence of circulating tumor cells (CTCs), and secretion of cytokines by Proteome Profiler assay. Tumors were evaluated by multiple IHC stainings, as well as western blot and qPCR. Results and Discussion: We have shown that the mutation of MCPIP1 increases the clonogenicity of kidney cells. Moreover, pLIX D141N cells were characterized by higher levels of the c-Met receptor, vimentin, Twist, CD44 and c-Myc, which are the markers of epithelial to mesenchymal transition and cancer stemness. The obtained results suggest that the loss of the MCPIP1 protein causes the acquisition of the characteristics of neoplastic cells. Next, we checked whether MCPIP1 mutation in normal cells predisposes them to proliferate when administered to mice. We found that, D141N mutation caused the growth of large tumors with higher expression of Cd44, Klf4 and Myc and number of CTCs, while the control cells injected into mice developed only local fibrosis with high expression of aSMA. pLIX D141N tumors secreted CXCL16 into mice plasma, and were characterized by increased phosphorylation of c-Met, Src kinase and c-Myc. Conclusions: We believe that the MCPIP1 protein may be a marker of tumor initiation and play a key role in neoplastic transformation by regulating the changes in cell phenotype and levels of CSCs markers. This study was supported by National Science Center grants no. 2022/47/B/NZ5/02724, 2022/45/B/NZ5/01973 and MNS 15/2021. Citation Format: Paulina Marona, Iga Piasecka, Judyta Gorka, Oliwia Kwapisz, Rafal Myrczek, Ewelina Pospiech, Jolanta Jura, Katarzyna Miekus. Lack of MCPIP1 enzymatic activity leads to neoplastic transformation of normal kidney cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3017.

Abstract 2781: GBM cells mimic regulatory T cell function to protect the CSC pool from immune surveillance in recurrent GBM

Abstract Glioblastoma (GBM) is the most lethal and aggressive form of brain cancer, with incredibly high recurrence rates and virtually no long-term survival. Despite our growing understanding of GBM at the molecular level, we still don’t fully comprehend the molecular mechanisms driving recurrence in GBM. Current knowledge indicates that Glioma Stem Cells (GSCs) drive a resistant cell phenotype in GBM. Understanding the molecular events coordinated by GSCs leading to therapy-resistance can provide key advancements on how we treat recurrent GBM (rGBM). Mechanisms of GSC immune escape are considered fundamental to clinical GBM growth and recurrence. The cross talk between cancer cells and the immune system is now classified as a hallmark of cancer. The current dogma is that cancer cells, including GSCs, influence recruitment of immune-suppressive cell subsets to tumor tissue, however how subsets of GSCs mimic this immune-suppressive effect within the tumor microenvironment remains to be elucidated. Single-cell RNA sequencing analysis of GBM neurospheres revealed a previously unrecognized Oct4/Sox2high/FOXP3− cell subpopulation with high expression of TGFβ1, CD39, CD73, PD-L1, and Galectin-1, a gene expression fingerprint typically associated with regulatory T cell (Tregs) and their immune suppressive functions within the tumor microenvironment. Bioinformatics analysis of public databases shows that the above-mentioned genes are enriched in the mesenchymal GBM subtype and highly correlated with TGFβ type II receptor (TGFBR2) expression in clinical GBM. Mechanistically, we show that blocking TGFBR2 or XBP1 signaling, key intermediary of this process, counteracts the immune-suppressive phenotype of rGBM cells by restoring CD4 and CD8 tumor killing capacity and reversing exhaustion in co-culture experiments. siRNA-mediated knock-down of TGFBR2 in rGBM cells also decreased CD206 expression and reduced release of anti-inflammatory chemokines in THP1 cells. By combining miRNA-based network analysis and advanced nanoparticle formulation for miRNA delivery we show that miR-16/124-3p effectively target all nodes of this immunosuppressive axis successfully blocking the immunosuppressive nature of rGBM cells. This research provides the first description of such neoplastic cells in any malignancy and has high potential translational impact since targeting these tumor cell subsets and their immunosuppressive mechanisms may be critical to the successful development of GBM immunotherapies. Citation Format: Hernando Lopez-Bertoni, Sophie Sall, Harmon Khela, Jack Korleski, Katherine Luly, Maya Johnson, Bachchu Lal, Amanda Johnson, Stephany Tzeng, Jordan Green, John Laterra. GBM cells mimic regulatory T cell function to protect the CSC pool from immune surveillance in recurrent GBM [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2781.

Abstract 4652: Combined inhibition of MCL-1 and MEK reduces tumor growth in a triple-negative/inflammatory breast cancer, MEK-resistant xenograft mouse model

Abstract Background: Triple-negative breast cancer (TNBC) and inflammatory breast cancer (IBC) are highly aggressive subtypes of invasive breast cancer. Our previous work showed that the MEK inhibitor (MEKi) selumetinib (AZD6244) prevents lung metastasis in a xenograft model. However, clinical studies have shown that MEKi’s as single agents have only modest activity against solid tumors. Using a genome-wide synthetic lethal siRNA screening, we identified myeloid cell leukemia-1 (MCL1) as a potential contributor to selumetinib resistance. MCL-1 is an anti-apoptotic protein associated with cell immortalization, transformation, and chemoresistance in numerous cancers. We hypothesized that MCL-1 promotes MEKi resistance in TNBC/IBC and inhibition of MCL-1 in the presence of AZD6244 overcomes this MEKi resistance. Methods & Results: To understand MCL1’s role in MEKi resistance, we established two AZD6244 -resistant TNBC/IBC cell lines: MDA-MB-231-R and SUM149-R. These cells showed increased cell viability, colony formation, migration, cells in G1 phase, CD44+CD24low, mammosphere count, anchorage-independent growth and high MCL-1 expression. MCL-1’s biological role was evaluated by transient and stably knock down (KD) of MCL-1 in the resistant cells which showed decreased cell viability, colony formation, and increased apoptosis. To understand the mechanism mediating apoptosis, we examined the expression of MCL-1’s binding partners in the MCL-1-KD-R cells in the presence of AZD6244. These cells showed a high expression of the PUMA, NOXA, BAK, and BAX in the presence of AZD6244. Further, we treated resistant cells with MEKi AZD6244 and an MCL-1i (AZD5991) that confirmed restoration of MEK sensitivity in both resistant cell lines, resulting in decreased cell viability, colony formation and increased apoptosis. We compared tumor formation capability between SUM149 parental and SUM149 resistant cells by injecting them in nu/nu mice and observed a time-dependent increase (avg. 4-fold) in tumor growth with SUM149-R cells compared to parental cells (P≤0.0001). Moreover, IHC analysis showed high expression of MCL-1 (P≤0.01), Ki67 (ns), CD44 (P≤0.0001), and ALDHA1 (P≤0.0001) in the mammary gland tumor tissues of SUM149-R-injected mice compared to SUM149-P-injected mice. Next, we evaluated the therapeutic effect of AZD6244 in mice harboring SUM149-R - MCL-1-deficient tumors. AZD6244 treatment significantly reduced tumor development in mice harboring SUM149-R - MCL-1-KD tumors compared to control mice (P<0.0001), suggesting that MCL-1 mediates MEK resistance in triple-negative/inflammatory breast cancer. Conclusion: Our results suggest that MCL-1 is important for inducing acquired MEK resistance and combining an MCL-1i with a MEKi could improve treatment outcomes of patients with TNBC or IBC who have developed resistance to single-agent MEKi. Citation Format: Mohd Mughees, Alex Tan, Lakesla Iles, Michael White, Debu Tripathy, Savitri Krishnamurthy, Jian Wang, Wendy A. Woodward, Geoffrey Bartholomeusz, Chandra Bartholomeusz. Combined inhibition of MCL-1 and MEK reduces tumor growth in a triple-negative/inflammatory breast cancer, MEK-resistant xenograft mouse model [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4652.

Abstract 5409: Phosphorylated focal adhesion kinase by mild reduction of cell surface proteins inhibits integrin α5β1-dependent patient- derived cancer cell migration and invasion

Abstract Although head and neck squamous cell carcinomas (HNSCCs), including tongue, vocal cord, and buccal cancers, are one of the most common cancers worldwide with a mortality rate of more than 40%, there have been no solid standard biomarkers for effectively diagnosing HNSCCs at early stages and no effective protocols available to support in vitro expansion of HNSCC cells. To establish a cell culture method to support in vitro self-renewal of HNSCC cells, patient-derived tumor was enzymatically digested, and the tongue cancer epithelial cells were seeded onto feeder cells with the Rho kinase inhibitor (Y-27632). Additionally, to test our hypothesis that free thiol groups in the cells, generated by a mild reduction of cell surface proteins using the reducing agent tris(2-carboxyethyl) phosphine hydrochloride (TCEP), would modulate cancer cell adhesion and migration, we assessed the expression levels of integrins, focal adhesion kinase (FAK), and phosphorylated FAK (pFAK) of tongue cancer epithelial cells cultured on both soft and rigid polyacrylamide (PAAm) hydrogel-based cell culture substrates. Patient-derived tongue cancer epithelial cells exhibited self-renewal ability and maintained cancerous phenotypes, with high expressions of P53, Ki67, E-cadherin, CD44, and AHDH1A1. Treatment with the reducing agent (TCEP) increased the degree of cell adhesion through the significantly upregulated integrin α5β1-mediated phosphorylation of FAK, resulting in inhibited single-cell and collective cell migration as well as invasion. Additionally, when these cells were cultured on stiff PAAm hydrogels mimicking the tumor microenvironment, the cells exhibited accelerated cell migration behaviors, compared to cells on soft hydrogels. These results highlight the synergetic contributions of feeder cells and Rho kinase inhibitor to support long-term self-renewal of tongue cancer patient-derived epithelial cells. Citation Format: Joo Hyun Kim, Laurensia D. Anggradita, Sung Sik Hur, Jae Hong Park, Sang-Heon Kim, Myung Jin Ban, Yongsung Hwang. Phosphorylated focal adhesion kinase by mild reduction of cell surface proteins inhibits integrin α5β1-dependent patient- derived cancer cell migration and invasion [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5409.

Abstract 1097: CD73 contributes to the pathogenesis of fusion-negative rhabdomyosarcoma through the purinergic signaling pathway

Abstract Rhabdomyosarcoma (RMS) is the most common type of soft tissue sarcoma in children and adolescents. Fusion-Negative RMS (FN-RMS) accounts for more than 80% of all RMS cases. The long-term event-free survival rate for patients with high grade FN-RMS is below 30%, highlighting the need for improved therapeutic strategies. CD73 is a 5’ ectonucleotidase that hydrolyzes AMP to adenosine and regulates the purinergic signaling pathway. We found that CD73 is elevated in FN-RMS tumors that express high levels of TWIST2. While high expression of CD73 contributes to the pathogenesis of multiple cancers, its role in FN-RMS has not been investigated. We found that CD73 knockdown decreased FN-RMS cell growth while upregulating the myogenic differentiation program. Moreover, mutation of the catalytic residues of CD73 rendered the protein enzymatically inactive and abolished its ability to stimulate FN-RMS growth. Overexpression of wildtype CD73, but not the catalytically inactive mutant, in CD73 knockdown FN-RMS cells, restored their growth capacity. Likewise, treatment with an adenosine receptor A2A-B agonist partially rescued FN-RMS cell proliferation and bypassed the CD73 knockdown defective growth phenotype. These results demonstrate that the catalytic activity of CD73 contributes to the pathogenic growth of FN-RMS through the activation of the purinergic signaling pathway. Therefore, targeting CD73 and the purinergic signaling pathway represents a potential therapeutic approach for FN-RMS patients. Citation Format: Karla Gabriela Cano Hernandez, Akansha Shah, Victor Lopez, Vincent Tagliabracci, Kenian Chen, Lin Xu, Rhonda Bassel-Duby, Eric Olson, Ning Liu. CD73 contributes to the pathogenesis of fusion-negative rhabdomyosarcoma through the purinergic signaling pathway [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1097.

Potential Role of Lymphocyte CD44 in Determining Treatment Selection Between Stereotactic Body Radiation Therapy and Surgery for Early-Stage Non-Small Cell Lung Cancer

Background: Stereotactic body radiotherapy (SBRT) versus surgery for operable early-stage non-small-cell lung cancer (ES-NSCLC) remains highly debated. Herein, we utilized spatial proteomics to identify whether any molecular biomarker(s) associate with the efficacy of either modality, in efforts to optimize treatment selection between surgery or SBRT for this population. Methods: We evaluated biopsy tissue samples from 44 ES-NSCLC patients treated with first-line SBRT (cohort 1) by GeoMx Digital Spatial Profiling (DSP) with a panel of 70 proteins in five spatial molecular compartments: tumor (panCK+), leukocyte (CD45+), lymphocyte (CD3+), macrophage (CD68+), and stroma (α-SMA+). To validate the findings in cohort 1, biopsy samples from 52 ES-NSCLC patients who received SBRT (cohort 2) and 62 ES-NSCLC patients who underwent surgery (cohort 3) were collected and analyzed by multiplex immunofluorescence (mIF). Results: In cohort 1, higher CD44 expression in the lymphocyte compartment was associated with poorer recurrence-free survival (RFS) (DSP: P<0.001; mIF: P<0.001) and higher recurrence rate (DSP: P=0.001; mIF: P=0.004). mIF data from cohort 2 validated these findings (P<0.05 for all). From cohort 3, higher lymphocyte CD44 predicted higher RFS after surgery (P=0.003). Inter-modality comparisons demonstrated that SBRT was associated with significantly higher RFS over surgery in CD44-low patients (P<0.001), but surgery was superior to SBRT in CD44-high cases (P=0.016). Conclusions: Lymphocyte CD44 may not only be a predictor of SBRT efficacy in this population, but also an important biomarker (pending validation by large prospective data) that could better sharpen selection for SBRT vs. surgery in ES-NSCLC.

Siglec10 Expression on Tumor-associated Macrophages Is an Independent Prognostic Factor in Stage I Lung Adenocarcinoma.

Prognostic indicators for postoperative lung adenocarcinoma are elusive. The interaction between CD24 on tumor cells and sialic-acid-binding Ig-like lectin 10 (Siglec10) on tumor-associated macrophages (TAMs) is implicated in immune evasion in distinct tumors. However, the therapeutic significance of phagocytic checkpoints in lung adenocarcinoma remains unknown. We aimed to investigate the clinical relevance and prognostic significance of phagocytosis checkpoints mediated by Siglec10 in TAMs of patients with lung adenocarcinoma who underwent curative resection. In this single-center retrospective study, we analyzed the data of 423 patients with stage I lung adenocarcinoma resected between 1999 and 2016. Tissue microarrays were constructed, and CD24, CD68, and Siglec10 immunohistochemistry was performed. Additionally, we assessed the clinical significance and prognostic associations of these markers. CD24 expression was higher in the Siglec10-high expression group than that in the -low expression group. Multivariate analysis showed that combined high Siglec10 and CD24 expression was an independent predictor of recurrence-free probability. The combined high Siglec10 and CD68 expression was a significant independent predictor of overall survival. Univariate analysis demonstrated that the 5-year probability of post-recurrence survival of patients with combined high Siglec10 and CD68 expression was lower than that of the other patients. High TAM Siglec10 expression and tumor CD24 expression are correlated, and the high Siglec10+CD24 combination is a major risk factor for recurrence. CD68+Siglec10 TAMs are important prognostic factors. Siglec10 expression on TAMs is essential for tumor microenvironment immunoregulation and offers a promising new immunotherapeutic approach for lung adenocarcinoma.

High CD133 expression in proximal tubular cells in diabetic kidney disease: good or bad?

BackgroundProximal tubular cells (PTCs) play a critical role in the progression of diabetic kidney disease (DKD). As one of important progenitor markers, CD133 was reported to indicate the regeneration of dedifferentiated PTCs in acute kidney disease. However, its role in chronic DKD is unclear. Therefore, we aimed to investigate the expression patterns and elucidate its functional significance of CD133 in DKD.MethodsData mining was employed to illustrate the expression and molecular function of CD133 in PTCs in human DKD. Subsequently, rat models representing various stages of DKD progression were established. The expression of CD133 was confirmed in DKD rats, as well as in human PTCs (HK-2 cells) and rat PTCs (NRK-52E cells) exposed to high glucose. The immunofluorescence and flow cytometry techniques were utilized to determine the expression patterns of CD133, utilizing proliferative and injury indicators. After overexpression or knockdown of CD133 in HK-2 cells, the cell proliferation and apoptosis were detected by EdU assay, real-time cell analysis and flow analysis. Additionally, the evaluation of epithelial, progenitor cell, and apoptotic indices was performed through western blot and quantitative RT-PCR analyses.ResultsThe expression of CD133 was notably elevated in both human and rat PTCs in DKD, and this expression increased as DKD progressed. CD133 was found to be co-expressed with CD24, KIM-1, SOX9, and PCNA, suggesting that CD133+ cells were damaged and associated with proliferation. In terms of functionality, the knockdown of CD133 resulted in a significant reduction in proliferation and an increase in apoptosis in HK-2 cells compared to the high glucose stimulus group. Conversely, the overexpression of CD133 significantly mitigated high glucose-induced cell apoptosis, but had no impact on cellular proliferation. Furthermore, the Nephroseq database provided additional evidence to support the correlation between CD133 expression and the progression of DKD. Analysis of single-cell RNA-sequencing data revealed that CD133+ PTCs potentially play a role in the advancement of DKD through multiple mechanisms, including heat damage, cell microtubule stabilization, cell growth inhibition and tumor necrosis factor-mediated signaling pathway.ConclusionOur study demonstrates that the upregulation of CD133 is linked to cellular proliferation and protects PTC from apoptosis in DKD and high glucose induced PTC injury. We propose that heightened CD133 expression may facilitate cellular self-protective responses during the initial stages of high glucose exposure. However, its sustained increase is associated with the pathological progression of DKD. In conclusion, CD133 exhibits dual roles in the advancement of DKD, necessitating further investigation.

Efficacy and Mechanism of Highly Active Umbilical Cord Mesenchymal Stem Cells in the Treatment of Osteoporosis in Rats.

A rat model of osteoporosis was induced with dexamethasone sodium phosphate. Highly active umbilical cord mesenchymal stem cells (HA-UCMSCs) and UCMSCs were isolated, cultured, identified, and infused intravenously once at a dose of 2.29 × 106 cells/kg. In the 4th week of treatment, bone mineral density (BMD) was evaluated via cross-micro-CT, tibial structure was observed via HE staining, osteogenic differentiation of bone marrow mesenchymal stem cells (BMMSCs) was examined via alizarin red staining, and carboxy-terminal cross-linked telopeptide (CTX), nuclear factor-κβ ligand (RANKL), procollagen type 1 N-terminal propeptide (PINP) and osteoprotegerin (OPG) levels were investigated via enzyme-linked immunosorbent assays (ELISAs). BMMSCs were treated with 10-6 mol/L dexamethasone and cocultured with HA-UCMSCs and UCMSCs in transwells. The osteogenic and adipogenic differentiation of BMMSCs was subsequently examined through directional induction culture. The protein expression levels of WNT, β-catenin, RUNX2, IFN-γ and IL-17 in the bone tissue were measured via Western blotting. The BMD in the healthy group was higher than that in the model group. Both UCMSCs and HA-UCMSCs exhibited a fusiform morphology; swirling growth; high expression of CD73, CD90 and CD105; and low expression of CD34 and CD45 and could differentiate into adipocytes, osteoblasts and chondrocytes, while HA-UCMSCs were smaller in size; had a higher nuclear percentage; and higher differentiation efficiency. Compared with those in the model group, the BMD increased, the bone structure improved, the trabecular area, number, and perimeter increased, the osteogenic differentiation of BMMSCs increased, RANKL expression decreased, and PINP expression increased after UCMSC and HA-UCMSC treatment for 4 weeks. Furthermore, the BMD, trabecular area, number and perimeter, calcareous nodule counts, and OPG/RANKL ratio were higher in the HA-UCMSC treatment group than in the UCMSC treatment group. The osteogenic and adipogenic differentiation of dexamethasone-treated BMMSCs was enhanced after the coculture of UCMSCs and HA-UCMSCs, and the HA-UCMSC group exhibited better effects than the UCMSC coculture group. The protein expression of WNT, β-catenin, and runx2 was upregulated, and IFN-γ and IL-17 expression was downregulated after UCMSC and HA-UCMSC treatment. HA-UCMSCs have a stronger therapeutic effect on osteoporosis compared with that of UCMSCs. These effects include an improved bone structure, increased BMD, an increased number and perimeter of trabeculae, and enhanced osteogenic differentiation of BMMSCs via activation of the WNT/β-catenin pathway and inhibition of inflammation.</p>.

Role of CD44 and CD24 Expression on 2-years Disease Free Survival in Patients with Advanced Epithelial Ovarian Carcinoma.

Ovarian cancer is one of the most common cancers with a high mortality rate worldwide. Despite optimal surgical therapy and chemotherapy, recurrence is still common. Cancer stem cells expressing CD44 and CD24 are thought to be contributing factors in recurrence. A cohort retrospective study with survival analysis was carried out on advanced ovarian cancer patients who underwent optimal debulking surgery followed by 6 cycles of chemotherapy at Cipto Mangunkusumo General Hospital and Fatmawati General Hospital from January 2019 to March 2023. Immunohistochemical examination was performed on tumor tissue with CD44 and CD24 expression were assessed using the H-Score method then determined the cut off-point expression level using the ROC curve. Furthermore, the relationship between these expression levels with the disease-free survival was assessed using the survival curve. There were 48 subjects who were included in the study. There were high expression levels of CD44 in 47.9% and CD24 in 50% of cases. High CD44 expression had mean and median survival of 13.2 ± 1.8 and 11 months (HR 5.05, 95% CI 1.84- 13.85). High CD24 expression had mean and median survival of 13.5 ± 2.4 and 7 months (HR 7.73, 95% CI 2.58 - 23.15). The combination of the two high expressions had mean and median survival of 10.44 ± 1.88 and 7 months. High expression of CD44 and CD24 will shorten the disease-free survival of patients with advanced ovarian cancer.

Expression of CD151 in Gastric Cancer Tissues and Its Clinical Significance

Objective: To explore the expression of CD151 in gastric cancer tissues and its clinical significance. Methods: Immunohistochemistry was employed to detect the expression of CD151 in gastric cancer tissues and adjacent normal tissues.The relationship between CD151 expression and the clinicopathological characteristics of gastric cancer was analyzed. Results: The expression of CD151 in gastric cancer tissues was significantly higher than in adjacent normal tissues (P &lt;0.05). It was associated with the degree of differentiation, depth of invasion, lymph node metastasis, and TNM staging ofgastric cancer. The survival time of patients with high CD151 expression was significantly shorter than that of those withlow expression (P &lt; 0.05). Conclusion: High expression of CD151 in gastric cancer tissues is correlated with the malignantbiological behavior of gastric cancer and can serve as an indicator for evaluating the prognosis of gastric cancer.

Exosomes from ectoderm mesenchymal stem cells inhibits lipopolysaccharide-induced microglial M1 polarization and promotes survival of H2O2-exposed PC12 cells by suppressing inflammatory response and oxidative stress

To investigate the potential value of exosomes derived from rat ectoderm mesenchymal stem cells (EMSCs-exo) for repairing secondary spinal cord injury. EMSCs-exo were obtained using ultracentrifugation from EMSCs isolated from rat nasal mucosa, identified by transmission electron microscope, nanoparticle tracking analysis (NTA), and Western blotting, and quantified using the BCA method. Neonatal rat microglia purified by differential attachment were induced with 100 μg/L lipopolysaccharide (LPS) and treated with 37.5 or 75 mg/L EMSCs-exo. PC12 cells were exposed to 400 μmol/L H2O2 and treated with EMSCs-exo at 37.5 or 75 mg/L. The protein and mRNA expressions of Arg1 and iNOS in the treated cells were determined with Western blotting and qRT- PCR, and the concentrations of IL- 6, IL-10, and IGF-1 in the supernatants were measured with ELISA. The viability and apoptosis of PC12 cells were detected using CCK-8 assay and flow cytometry. The isolated rat EMSCs showed high expressions of nestin, CD44, CD105, and vimentin. The obtained EMSCs-exo had a typical cup-shaped structure under transmission electron microscope with an average particle size of 142 nm and positivity for CD63, CD81, and TSG101 but not vimentin. In LPS-treated microglia, EMSCs-exo treatment at 75 mg/L significantly increased Arg1 protein level and lowered iNOS protein expression (P < 0.05). EMSCs-exo treatment at 75 mg/L, as compared with the lower concentration at 37.5 mg/L, more strongly increased Arg1 mRNA expression and IGF-1 and IL-10 production and decreased iNOS mRNA expression and IL-6 production in LPS-induced microglia, and more effectively promoted cell survival and decreased apoptosis rate of H2O2-induced PC12 cells (P < 0.05). EMSCs-exo at 75 mg/L can effectively reduce the proportion of M1 microglia and alleviate neuronal apoptosis under oxidative stress to promote neuronal survival, suggesting its potential in controlling secondary spinal cord injury.