Surface Of Cancer Cells Research Articles

Cytofluorometric assessment of calreticulin exposure on CD38+ plasma cells from the human bone marrow.

Exposure of the endoplasmic reticulum chaperone calreticulin (CALR) on the surface of stressed and dying cells is paramount for their effective engulfment by professional antigen-presenting cells such as dendritic cells (DCs). Importantly, this is required (but not sufficient) for DCs to initiate an adaptive immune response that culminates with an effector phase as well as with the establishment of immunological memory. Conversely, the early exposure of phosphatidylserine (PS) on the outer layer of the plasma membrane is generally associated with the rapid engulfment of stressed and dying cells by tolerogenic macrophages. Supporting the clinical relevance of the CALR exposure pathway, the spontaneous or therapy-driven translocation of CALR to the surface of malignant cells, as well as intracellular biomarkers thereof, have been associated with improved disease outcome in patients affected by a variety of neoplasms, with the notable exception of multiple myeloma (MM). Here, we describe an optimized protocol for the flow cytometry-assisted quantification of surface-exposed CALR and PS on CD38+ plasma cells from the bone marrow of patients with MM. With some variations, we expect this method to be straightforwardly adaptable to the detection of CALR and PS on the surface of cancer cells isolated from patients with neoplasms other than MM.

Anticancer approach by targeted activation of a global inhibitor of sialyltransferases with acrolein

Chemical regulation of glycan synthesis at the targeted cancer cell surface in mice leading to significant anticancer effects without side effects.

TAMs and PD-1 Networking in Gastric Cancer: A Review of the Literature.

Gastric cancer (GC) is one of the most common and aggressive types of cancer. Immune checkpoint inhibitors (ICIs) have proven effective in treating various types of cancer. The use of ICIs in GC patients is currently an area of ongoing research. The tumor microenvironment (TME) also seems to play a crucial role in cancer progression. Tumor-associated macrophages (TAMs) are the most abundant population in the TME. TAMs are capable of displaying programmed cell death protein 1 (PD-1) on their surface and can form a ligand with programmed death ligand 1 (PD-L1), which is found on the surface of cancer cells. Therefore, it is expected that TAMs may significantly influence the immune response related to immune checkpoint inhibitors (ICIs). Understanding the role of TAMs and PD-1/PD-L1 networking in GC. A systematic review of published data was performed using MEDLINE (PubMed), Embase, and Cochrane databases. We retrieved articles investigating the co-existence of TAMs and PD-1 in GC and the prognosis of patients expressing high levels of PD-1+ TAMs. Ten articles with a total of 2277 patients were included in the systematic review. The examined data suggest that the expression of PD-L1 has a positive correlation with the infiltration of TAMs and that patients who express high levels of PD-1+ TAMs may have a worse prognosis than those who express low levels of PD-1+ TAMs. TAMs play a pivotal role in the regulation of PD-1/PD-L1 networking and the progression of GC cells. Nevertheless, additional studies are needed to better define the role of TAMs and PD-1/PD-L1 networking in GC.

Antibody engineering to generate anti-tumor-associated glycoprotein 72 mouse recombinant CC49 IgG with improved solubility, purity, and thermal stability

Tumor-associated glycoprotein 72 (TAG-72) is a mucin that is overexpressed heterogeneously on the surface of cancer cells, and is a potential target for immunotherapies for various cancer types. As a tumor marker, TAG-72 is measured with the cancer antigen (CA) 72–4 immunoassay. The murine monoclonal antibody (mAb) CC49 is a second-generation IgG that targets an antigen on TAG-72; however, CC49 has an unfavorable propensity to aggregate, which results in antibody impurity, instability, and low solubility and thus low potency and efficacy for therapeutic and diagnostic applications. Sequence analysis of CC49 revealed aggregation-prone motifs in the variable domain of the light chain. Using antibody engineering approaches, we developed three aggregation-resistant CC49 mIgG2a mutants (CC49M1, CC49M2, and CC49M3). The engineered CC49 mIgG2a mutants retained compatible binding performance with a significantly higher thermal stability. The CC49 mIgG2a mutants also demonstrated an almost 15-fold improvement in solubility, with 97% purity vs 70% purity of the parent molecule at 0.3 mg/mL. The enhanced stability and improved solubility of engineered CC49 could have significant advantages for diagnostic and therapeutic applications.

Ezurpimtrostat, A Palmitoyl-Protein Thioesterase-1 Inhibitor, Combined with PD-1 Inhibition Provides CD8+ Lymphocyte Repopulation in Hepatocellular Carcinoma.

Palmitoyl-protein thioesterase-1 (PPT1) is a clinical stage druggable target for inhibiting autophagy in cancer. We aimed to determine the cellular and molecular activity of targeting PPT1 using ezurpimtrostat, in combination with an anti-PD-1 antibody. In this study we used a transgenic immunocompetent mouse model of hepatocellular carcinoma. Herein, we revealed that inhibition of PPT1 using ezurpimtrostat decreased the liver tumor burden in a mouse model of hepatocellular carcinoma by inducing the penetration of lymphocytes into tumors when combined with anti-programmed death-1 (PD-1). Inhibition of PPT1 potentiates the effects of anti-PD-1 immunotherapy by increasing the expression of major histocompatibility complex (MHC)-I at the surface of liver cancer cells and modulates immunity through recolonization and activation of cytotoxic CD8+ lymphocytes. Ezurpimtrostat turns cold tumors into hot tumors and, thus, could improve T cell-mediated immunotherapies in liver cancer.

Cytotoxic and Anticancer Activity of Pharmacological Pairs of C115H Methionine–Gamma-lyase and S-Propyl-L-Cysteine Sulfoxide

BACKGROUND: One of the alternate ways to developing novel medication is to use pharmacological pairs: an enzyme and a non-toxic prodrug that, under certain conditions, releases cytotoxic substances within or on the surface of the cancer cells, allowing the drug to be delivered precisely to the cancer cells.
 AIM: To evaluate cytotoxic and anticancer effects of the pharmacological pair of C115H methionine-γ-lyase (C115H MGL), conjugated with daidzein (C115H MGL-Dz), and S-propyl-L-cysteine sulfoxide (propiin) against different kinds of solid tumors in vitro and in vivo.
 METHODS: MTT-test was performed to determine the cytotoxicity of C115H MGL-Dz in the presence of propiin in vitro against human embryonic kidney (HEK-293), human placenta, breast cancer (MCF7, SKBR3, and T47D), colon cancer (HT29 and COLO205), pancreatic cancer (MIA PaCa-2) and prostate cancer (DU145, and PC3) cells. The anticancer activity of the pharmacological pair "C115H MGL-Dz + propiin" against SKBR3, MIA PaCa-2, and HT29 in vivo was investigated using subcutaneous xenografts in BALB/c nude mice.
 RESULTS: In comparison to dipropylthiosulfinate generated in vitro using the pharmacological pairs "C115H MGL + propiin", targeted delivery of C115H MGL-Dz as a component of a pharmacological pair "C115H MGL-Dz + propiin" to generate dipropylthiosulfinate directly on the surface of cancer cells enhances cytotoxicity in all cancer cells. The study of the antitumor activity of the pharmacological pair "C115H MGL-Dz + propiin" in vivo revealed a suppression of tumor volume growth in xenografts SKBR3 (tumor growth inhibition, TGI=89%, p=0.004), MIA PaCa-2 (TGI=50%, p=0.011), and HT29 (TGI=52%, p=0.04) vs control.
 CONCLUSIONS: On several cancer cells, the cytotoxicity and anticancer activity of dipropylthiosulfinate produced by the pharmacological pair "C115H MGL-Dz + propiin" was observed. Our findings may stimulate more study into the role of pharmacological pairs as a novel strategy to cancer treatment.

Dual Role of Vitamin C-Encapsulated Liposomal Berberine in Effective Colon Anticancer Immunotherapy.

The aim of the study was to achieve effective colon anticancer immunotherapy using the alkaloid berberine. In the presented paper we attempt to develop a formulation of berberine loaded into liposomal carriers using the vitamin C gradient method, characterized by efficient drug encapsulation, high stability during long-term storage, low drug release in human plasma with specific cytotoxicity towards colon cancer cells. Liposomal berberine was responsible for the induction of oxidative stress, the presence of Ca2+ ions in the cytosol, the reduction of Δψm, and ATP depletion with a simultaneous lack of caspase activity. Moreover, treatment with liposomal berberine led to CRT exposure on the surface of cancer cells, extracellular ATP, and HMGB1 release. The above-described mechanism of action was most likely associated with ICD induction, contributing to the increased number of phagocytic cancer cells. We have shown that cancer cells treated with liposomal berberine were phagocytosed more frequently by macrophages compared to the untreated cancer cells. What is more, we have shown that macrophage pre-treatment with liposomal berberine led to a 3-fold change in the number of phagocytosed SW620 cancer cells. The obtained results provide new insights into the role of berberine in maintaining the immune response against colorectal cancer.

Functionalized Carbon Nano-Onions as a Smart Drug Delivery System for the Poorly Soluble Drug Carmustine for the Management of Glioblastoma.

The drug delivery system for transporting anticancer agents to targeted tissues in the body is a challenging issue. In search of a suitable biocompatible carrier having controlled and sustained drug release properties of poorly soluble drugs, carbon nano-onions (CNOs) were loaded with an anticancer drug, bis-chloroethyl nitrosourea (BCNU/carmustine). CNOs being autofluorescent, drug-loaded functionalized CNOs (f-CNO-BCNU) can be detected in vivo. Transmission electron microscopy (TEM) and differential light scattering (DLS) techniques were used to analyze the sizes of these f-CNOs. The molecular study revealed that the f-CNO-BCNU readily and noncovalently binds with the folate receptors present on the cancer cell surface in excess. Computer modeling and molecular dynamics simulation followed by binding free energy calculation shows f-CNOs have -29.9 kcal/mol binding free energy, and it noncovalently binds the receptor FRα using loop dynamics of three essential loops present in the protein along with polar stabilization interactions provided by Asp55 and Glu86 residues present in the active site. The f-CNO effectively decreased cancer cell viability with a low IC50 value (the concentration that led to 50% killing of the cells). The cell-based Franz diffusion assay was performed to study the drug release profile. The f-CNO-BCNUs also decreased the mitochondrial membrane potential of U87 cells, increased reactive oxygen species release, and caused a loss of mitochondrial membrane integrity. The f-CNOs also increased the percentage of apoptotic cells observed by the Annexin V assay. Based on observed results, it can be concluded that the f-CNO-BCNU efficiently targets the cancer cells, enhances the bioavailability of carmustine, and can be used as a smart chemotherapeutic agent. This strategy offers better patient compliance and greater bioavailability of the drug.

Trogocytosis-Resistant CAR T Cells Exhibit Increased Persistence and Prevent Antigen Escape

Chimeric Antigen Receptor (CAR) T cell therapy is a highly effective treatment for cancer patients in which T cells are genetically modified to express a CAR targeting an antigen expressed on the surface of cancer cells. While CAR T cells have shown remarkable efficacy, many patients receiving CAR T cell therapy relapse within five years of treatment. It has recently been shown that tumor cells can escape killing by CAR T cells using a mechanism called trogocytosis. CAR-mediated trogocytosis (CMT) involves the transfer of cell surface proteins from tumor cells to CAR T cells. Antigen transfer by CMT results in antigen-negative tumor cells and reduced CAR T cell persistence due to increased CAR T cell exhaustion and fratricide. To date, the molecular processes causing CMT remain poorly understood and there are currently no approaches to therapeutically target CMT. To track CMT in real-time, we first developed a custom luciferase complementation assay with a detection limit of approximately 100 CAR T cells displaying the target antigen (CompLuc). Using this assay, we found that CMT is effector-target ratio and time-dependent and can be modulated by inhibiting actin polymerization, a process essential for key T cell functions including vesicle formation, protein transport, and target cell killing. To develop a universal approach to inhibit CMT in CAR T cells without altering tumor cell killing, we investigated the effect of inhibiting adhesion, endocytosis, vesicle formation, and proteolytic degradation using various small-molecule inhibitors. We found that inhibition of the cysteine protease Cathepsin B with the small molecule inhibitor Ca-074-Me significantly reduced CMT as determined by CompLuc assay and flow cytometry. Performing a luciferase-based cytotoxicity assay, we found that Cathepsin B inhibition does not affect tumor cell killing. Based on these data, we hypothesized that Cathepsin B inhibition could be a potential therapeutic approach to limit CMT. Cathepsin B activity in human cells is regulated by the human proteins Cystatin A and Cystatin B. Structural data of Cathepsin B in complex with Ca-074-Me or Cystatin A show that both molecules appear to sterically block access of substrates to the active site cysteine of Cathepsin B. We therefore explored if overexpression of cystatins in CAR T cells could be an efficient approach to inhibit CMT. We found that overexpression of Cystatin A significantly reduced Cathepsin B activity in CAR T cells and limited transfer of tumor antigen to CAR T cells. We also observed that cystatin overexpression reduced loss of antigen from the tumor cell surface, indicating that Cathepsin B inhibition blocks CMT at an early stage of the trogocytic process. Importantly, Cystatin A overexpression did not alter CAR T cell expansion, tumor cell killing, or CAR T cell phenotype, indicating that this approach selectively inhibits CMT and that key CAR T cell functions remain intact. Cystatin overexpression also led to significantly increased tumor-specific CAR T cell numbers (78% of non-targeting CAR T cells) compared to wild-type CAR T cells (61% of non-targeting CAR T cells, p = 0.0298) after 24 h exposure to tumor cells, indicating that selective inhibition of CMT prevents CAR T cell fratricide and/or exhaustion. To further reduce presence of antigen on CAR T cells following CMT, we next developed a system to actively degrade the trogocytosed protein in CAR T cells. Specifically, we developed a fusion protein combining the SH2 domain of the Src kinase Lyn, which binds with high affinity to the intracellular domain of CD19, with the von Hippel-Lindau E3 ubiquitin ligase. We show that expression of this fusion protein within CAR T cells rapidly targets trogocytosed CD19 for degradation and eliminates its presence on the surface of CAR T cells. Trogocytosed antigen degradation also increased CAR T cell survival at the end of in vitro co-culture, indicating reduced CAR T cell fratricide and/or exhaustion. Taken together, we provide the first preclinical proof-of-concept that, using a fully human genetic engineering approach, CMT can be targeted without compromising essential CAR T cell functions. This represents a promising approach to improve CAR T cell efficacy and limit the occurrence of relapse in patients receiving CAR T cell therapy.

Smart Nanomedicine Targeting Endocytosis Mediated by Cancer Cell Surface Neuraminidase‐1

Human neuraminidase‐1 (NEU1) plays a much more profound function in human cancers than previously considered. It is demonstrated that cancer cell surface NEU1 is a desired gatekeeper for an innovative anticancer therapeutic nanomedicine enabling active drug‐targeting delivery by specific endocytosis into the cytoplasm. Nanosome, an antiadhesive nanoparticular shuttle, carrying multiple suicide substrates for NEU1 confers potent and universal inhibitory effects on the proliferation of human cancer cells, such as hepatocellular carcinoma (HCC) (HepG2, IC50 = 13.5 nM), lung cancer (A549, IC50 = 9.57 nM), and colon cancer (HT‐29, IC50 = 11.1 nM), in which irreversible inactivation of cell surface NEU1 is essential for the intracellular trafficking and subsequent lysosomal membrane permeabilization by nanosomal aggregation due to the formation of “sialidase corona” through irreversible inactivation of NEU1–NEU4 residing in lysosome. Nanomedicine targeting membrane‐tethered NEU1 allows efficient delivery of hydrophobic sorafenib (Nexavar), a RAF family kinase inhibitor for the treatment of advanced renal cell carcinoma and unresectable HCC at the recommended dose of 400 mg orally twice daily, into endolysosome, resulting in a potent and sustainable inhibition (IC50 = 3.1–6.2 nM at 24–96 h after coincubation) against HepG2 cell growth.

Bombesins: A New Frontier in Hybrid Compound Development.

Recently, bombesin (BN) and its analogs have attracted much attention as excellent anticancer agents because they interact with specific receptors widely distributed on the surface of various cancer cells. However, their biological properties proceed far beyond this, given a broad spectrum of activity. Bombesin receptor ligands are effective drugs for the treatment of rheumatoid arthritis or gastrointestinal diseases. However, most diseases are complex, and the use of polytherapy may lead to pharmacokinetic and pharmacodynamic drug-drug interactions, resulting in side effects. Therefore, there is a need to develop effective compounds that also contain BN or its analogs, which are combined with other structural entities, thus generating a so-called hybrid drug. Hybrid drugs that contain bombesin pharmacophore(s) may be proposed as a solution to the problem of polytherapy or the lack of an effective cure. Such structures have now demonstrated the desired efficacy, though information on these aforementioned compounds is relatively scarce. Therefore, our paper aims to encourage researchers to focus on bombesins. Herein, we indicate that the hybrid approach should also be firmly applied to bombesins and the BN receptor family. This paper's structure is divided into two main sections demonstrating bombesins and their properties, as well as recent data on bombesin-based hybrid compounds and their potential usefulness in medicine. Overall, it refers to the discovery and synthesis of modified bombesin-based hybrid compounds.

A Novel pH-Responsive Iron Oxide Core-Shell Magnetic Mesoporous Silica Nanoparticle (M-MSN) System Encapsulating Doxorubicin (DOX) and Glucose Oxidase (Gox) for Pancreatic Cancer Treatment.

This study developed a pancreatic cancer targeted drug delivery system that responds to changes in acidity. The system was based on iron oxide core-shell magnetic mesoporous silica nanoparticles (M-MSNs) to treat pancreatic cancer through combined chemotherapy and starvation therapy. Glucose oxidase (Gox) was coupled to the cancer cell surface to reduce glucose availability for cancer cells, exacerbating the heterogeneity of the tumor microenvironment. Reduced pH accelerated the depolymerization of pH-sensitive polydopamine (PDA), thereby controlling the spatial distribution of Gox and release of doxorubicin (DOX) within tumor cells. Characterization results showed the successful synthesis of DG@M-MSN-PDA-PEG-FA (DG@NPs) with a diameter of 66.02 ± 3.6 nm. In vitro data indicated DG@NPs were highly effective and stable with good cellular uptake shown by confocal laser scanning microscopy (CLSM). DG@NPs exhibited high cytotoxicity and induced apoptosis. Additionally, in vivo experiments confirmed DG@NPs effectively inhibited tumor growth in nude mice with good biosafety. The combination of starvation therapy and chemotherapy facilitated drug release, suggesting DG@NPs as a novel drug delivery system for pancreatic cancer treatment. This study successfully constructed a doxorubicin release system responsive to acidity changes for targeted delivery in pancreatic cancer, providing a new strategy for combination therapy.

Synthetic Receptors for Early Detection and Treatment of Cancer.

Over recent decades, synthetic macrocyclic compounds have attracted interest from the scientific community due to their ability to selectively and reversibly form complexes with a huge variety of guest moieties. These molecules have been studied within a wide range of sensing and other fields. Within this review, we will give an overview of the most common synthetic macrocyclic compounds including cyclodextrins, calixarenes, calixresorcinarenes, pillarenes and cucurbiturils. These species all display the ability to form a wide range of complexes. This makes these compounds suitable in the field of cancer detection since they can bind to either cancer cell surfaces or indeed to marker compounds for a wide variety of cancers. The formation of such complexes allows sensitive and selective detection and quantification of such guests. Many of these compounds also show potential for the detection and encapsulation of environmental carcinogens. Furthermore, many anti-cancer drugs, although effective in in vitro tests, are not suitable for use directly for cancer treatment due to low solubility, inherent instability in in vivo environments or an inability to be adsorbed by or transported to the required sites for treatment. The reversible encapsulation of these species in a macrocyclic compound can greatly improve their solubility, stability and transport to required sites where they can be released for maximum therapeutic effect. Within this review, we intend to present the use of these species both in cancer sensing and treatment. The various macrocyclic compound families will be described, along with brief descriptions of their synthesis and properties, with an outline of their use in cancer detection and usage as therapeutic agents. Their use in the sensing of environmental carcinogens as well as their potential utilisation in the clean-up of some of these species will also be discussed.

Targeted delivery of cathepsin-activatable near-infrared fluorescence probe for ultrahigh specific imaging of peritoneal metastasis

Inadequate cytoreductive surgery (CRS) has been identified as a prognostic factor for poor patient outcomes in cases of peritoneal metastasis. While imaging probes are used to identify peritoneal metastasis to facilitate CRS, many of these probes exhibit high background signals, resulting in a significant delay in achieving a satisfactory tumor-to-normal ratio (TNR) due to prolonged clearance time. In this study, we designed a novel fluorescent probe named Tras-AA-Cy NH2, which enables the relatively rapid imaging of subcutaneous tumors and peritoneal tumors while maintaining a high TNR. Mechanistically, Tras-AA-Cy NH2 exhibits selective targeting towards the Human epidermal growth factor receptor 2 on the surface of cancer cells. Following internalization, it undergoes enzymatic cleavage catalyzed by the overexpressed cathepsin, leading to the subsequent release of near-infrared fluorophores. Consequently, Tras-AA-Cy NH2 achieved a TNR of 7.8 at 6 h and 21.4 at 24 h in subcutaneous tumor mice. Even after 522 h of in vivo circulation, the TNR remained above 5, indicating an ultralong imaging time window. It is noteworthy that Tras-AA-Cy NH2 has demonstrated successful utilization for peritoneal tumor-specific imaging and further affirmed its tumor tissue-specific recognition capability using human resected tissues. In summary, these findings underscore the rational design of Tras-AA-Cy NH2 for visualizing peritoneal tumors.

AS1411aptamer conjugated liposomes for targeted delivery of arsenic trioxide in mouse xenograft model of melanoma cancer

Development of AS1411aptamer-conjugated liposomes for targeted delivery of arsenic trioxide is the primary goal of this study. AS1411aptamer was used as ligand to target nucleolin, which is highly expressed on the surface of melanoma cancer cells. The targeted liposomes were constructed by the thin film method, and arsenic trioxide was loaded as cobalt (II) hydrogen arsenite (CHA) to increase the loading efficiency and stability of the liposomes. The liposomal structure was characterized by Fourier Transform Infrared Spectroscopy (FT-IR) and field emission scanning electron microscopy (FESEM). In addition, particle sizes and zeta potential of the CHA-loaded liposomes (CHAL) and aptamer-functionalized CHA-loaded liposomes (AP-CHAL) were determined. In vitro cytotoxicity of CHAL and AP-CHAL were evaluated using MTT assay in murine melanoma (B16) and mouse embryonic fibroblast (MEF) cell lines. The encapsulation efficiency of CHAL and AP-CHAL was reported as 60.2 ± 6.5% and 58.7 ± 4.2%, respectively. In vivo antitumor activity of CHAL and AP-CHAL in the B16 tumor-xenograft mouse model was dramatically observed. All mice of both groups survived until the end of treatment and showed body weight gain. The tumor protrusion completely disappeared in 50% of the mice in these groups. Furthermore, histopathology studies demonstrated that CHAL and AP-CHAL did not induce significant toxicity in healthy mice tissues. However, unlike the CHAL group, which showed an initial increase in tumor volume, a specific antitumor effect was observed in the AP-CHAL group from the beginning of treatment. The results showed that AP-CHAL can be used as an effective drug delivery system with high potential in the treatment of solid tumors.

A CRISPR activation screen identifies MUC-21 as critical for resistance to NK and T cell-mediated cytotoxicity

BackgroundImmunotherapy has significantly advanced cancer treatments, but many patients do not respond to it, partly due to immunosuppressive mechanisms used by tumor cells. These cells employ immunosuppressive ligands to evade detection and elimination by the immune system. Therefore, the discovery and characterization of novel immunosuppressive ligands that facilitate immune evasion are crucial for developing more potent anti-cancer therapies.MethodsWe conducted gain-of-function screens using a CRISPRa (CRISPR activation) library that covered the entire human transmembrane sub-genome to identify surface molecules capable of hindering NK-mediated cytotoxicity. The immunosuppressive role and mechanism of MUC21 were validated using NK and T cell mediated cytotoxicity assays. Bioinformatics tools were employed to assess the clinical implications of mucin-21 (MUC21) in cancer cell immunity.ResultsOur genetic screens revealed that MUC21 expression on cancer cell surfaces inhibits both the cytotoxic activity of NK cells and antibody-dependent cellular cytotoxicity, but not affecting complement-dependent cytotoxicity. Additionally, MUC21 expression hinders T cell activation by impeding antigen recognition, thereby diminishing the effectiveness of the immune checkpoint inhibitor, anti-PD-L1. Moreover, MUC21 expression suppress the antitumor function of both CAR-T cells and CAR-NK cells. Mechanistically, MUC21 facilitates immune evasion by creating steric hindrance, preventing interactions between cancer and immune cells. Bioinformatics analysis revealed elevated MUC21 expression in lung cancer, which correlated with reduced infiltration and activation of cytotoxic immune cells. Intriguingly, MUC21 expression was higher in non-small cell lung cancer (NSCLC) tumors that were non-responsive to anti-PD-(L)1 treatment compared to responsive tumors.ConclusionsThese findings indicate that surface MUC21 serves as a potent immunosuppressive ligand, shielding cancer cells from NK and CD8+T cell attacks. This suggests that inhibiting MUC21 could be a promising strategy to improve cancer immunotherapy.

Hapten/Myristoyl Functionalized Poly(propyleneimine) Dendrimers as Potent Cell Surface Recruiters of Antibodies for Mediating Innate Immune Killing.

Recruiting endogenous antibodies to the surface of cancer cells using antibody-recruiting molecules has the potential to unleash innate immune effector killing mechanisms against antibody-bound cancer cells. The affinity of endogenous antibodies is relatively low, and many currently explored antibody-recruiting strategies rely on targeting over-expressed receptors, which have not yet been identified in most solid tumors. Here, both challenges are addressed by functionalizing poly(propyleneimine) (PPI) dendrimers with both multiple dinitrophenyl (DNP) motifs, as anti-hapten antibody-recruiting motifs, and myristoyl motifs, as universal phospholipid cell membrane anchoring motifs, to recruit anti-hapten antibodies to cell surfaces. By exploiting the multivalency of the ligand exposure on the dendrimer scaffold, it is demonstrated that dendrimers featuring ten myristoyl and six DNP motifs exhibit the highest antibody-recruiting capacity in vitro. Furthermore, it is shown that treating cancer cells with these dendrimers in vitro marks them for phagocytosis by macrophages in the presence of anti-hapten antibodies. As a proof-of-concept, it is shown that intratumoral injection of these dendrimers in vivo in tumor-bearing mice results in the recruitment of anti-DNP antibodies to the cell surface in the tumor microenvironment. These findings highlight the potential of dendrimers as a promising class of novel antibody-recruiting molecules for use in cancer immunotherapy.

Cancer-derived non-coding RNAs endow tumor microenvironment with immunosuppressive properties.

Non-coding RNAs (ncRNAs) have attracted extensive attention due to their vital roles in tumorigenesis and progression, especially in the immunotherapy resistance. Tumor immunotherapy resistance is a crucial factor hindering the efficacy of tumor treatments, which can be largely attributed to the immunosuppressive properties of tumor microenvironment. Current studies have revealed that cancer-derived ncRNAs are involved in the formation of tumor immunosuppressive microenvironment (TIME) through multiple ways. They not only promote the expression of immune checkpoint ligands (e.g., PD-L1, CD47, Gal-9, and CD276) on cancer cell surfaces, but also enhance the secretion of immunosuppressive cytokines (e.g., TGF-β, IL-6, IL-10, VEGF, and chemokines). Cancer-derived ncRNAs could also be transferred into surrounding immune-related cells through extracellular vesicles, thereby inhibiting the cytotoxicity of CD8+ T cells and NK cells, restraining the DC-mediated antigen presentation, inducing the immunosuppressive phenotype transformation of TAMs and CAFs, and enhancing the immunosuppressive functions of Tregs and MDSCs. Herein, we summarize the roles of cancer-derived ncRNAs in regulating TIME formation and further explore their potential applications as prognostic biomarkers and immunotherapeutic targets, which will help us to address the TIME-mediated immunotherapy resistance in the future. This article is categorized under: RNA in Disease and Development > RNA in Disease Regulatory RNAs/RNAi/Riboswitches > Regulatory RNAs.

The utility of a deep learning-based approach in Her-2/neu assessment in breast cancer

IntroductionHER-2/neu is a protein present on the surface of specific cancer cells and has been linked to the development and progression of certain cancer types. It is present in 15 to 20% of breast cancers and is clinically significant due to the availability of multiple anti-Her2 treatment options. Immunohistochemistry (IHC) is the most commonly used method to evaluate and quantify the expression of Her-2/neu. Although IHC is well-standardized in clinical practice, it is still subjected to inter-observer variability. Automating Her-2/neu scoring can improve accuracy, efficiency, consistency, and cost-effectiveness while reducing pathologists' workload. Materials and MethodsA deep learning-based automatic framework was utilized for the automatic detection of Her-2/neu score from whole slide images (WSI). The framework consists of three phases: identification of tumor patches, scoring of tumor patches, and Her-2/neu score prediction for whole slide images (WSI) based on the distribution of each score. This work used the dataset from the University of Warwick HER2 challenge contest. Two expert pathologists evaluated all 86 WSIs and assigned Her-2/neu scores to them. In addition, patches were generated from 50 WSIs and annotated individually by the pathologists. A total of 6641 extracted patches were generated out of which, 947 were labeled as 0, 327 as 1+, 1401 as 2+, 2950 as 3+, and 1016 were marked for discarding. Four pre-trained image classification models, namely DenseNet201, GoogleNet, MobileNet_v2, and a Vision Transformer based model, were fine-tuned, and tested on the generated patches. In order to predict the Her-2/neu score of the entire WSI, a random forest classifier was trained to predict the Her-2/neu score from the percentages of patches of each score present in the whole slide image. ResultsIn patch classification performances, the vision transformer-based model outperformed the other models by achieving an accuracy of 92.6% on tumor patch classification and 91.15% on patch score classification. The random forest classifier achieved an accuracy of 88% on four score classification (0, 1+, 2 + and 3 + ) and 96% on three score classification (0/1+, 2 + and 3 + ). ConclusionThe proposed deep learning-based framework for the automatic detection and evaluation of Her-2/neu expression in breast cancer obtained encouraging results. This framework has the potential to be used as a prognostic tool, providing a cost-effective and time-efficient alternative for generating clinically relevant results. However, additional research is required to assess the applicability of this pipeline in different contexts.

Anti-cancer Effects of a Chitosan Based Nanoformulation Expressing miR-340 on 4T1 Breast Cancer Cells

MicroRNAs (miRNAs) have a crucial role in the regulation of gene expression in tumor development, invasion, and metastasis. Herein, miRNA-340 (miR-340) has been shown to play tumor suppressor activity in breast cancer (BC). However, the clinical applications of miRNAs request the development of safe and effective delivery systems capable of protecting nucleic acids from degradation. In this study, biodegradable chitosan nanoparticles incorporating miR-340 plasmid DNA (pDNA) (miR-340 CNPs) were synthesized and characterized. Then, the anti-tumor effects of miR-340 CNPs were investigated using 4T1 BCE cells. The spherical nanoparticles (NPs) with an appropriate mean diameter of around 266 ± 9.3 nm and zeta potential of +17 ± 1.8 mV were successfully prepared. The NPs showed good stability, high entrapment efficiency and a reasonable release behavior, meanwhile their high resistance against enzymatic degradation was verified. Furthermore, NPs demonstrated appropriate transfection efficiency and could induce apoptosis, so had toxicity in 4T1 BCE cells. Also, CD47 expression on the surface of cancer cells was significantly reduced after treatment with miR-340 CNPs. The results showed that miR-340 CNPs augmented the expression of P-27 in BC cells. Furthermore, miR-340 CNPs caused down-regulation of BRP-39 (breast regression protein-39) increasingly suggested as a prognostic biomarker for neoplastic diseases like BC. In conclusion, our data show that miR-340 CNPs can be considered as a promising new platform for BC gene therapy.