Receptor Targeting Research Articles

Cucumeropsis mannii seed oil mitigates bisphenol-A-induced sperm and hormonal damages in F1-generation of F0-exposed male rats: An in-vivo and in-silico analysis

Exposure to endocrine-disrupting chemicals such as bisphenol A (BPA) has been linked to the sharp drop in male fertility observed worldwide. This study evaluates the protective benefits of Cucumeropsis mannii seed oil (CMSO) against BPA-induced transgenerational sperm indices and reproductive hormone disruptions in rats. Twenty-four F0-male rats (aged 4–5 weeks) were randomly assigned to six groups (n = 4 each) after CMSO characterization for flavonoids. Group A received 1 ml of olive oil. Group B received 100 mg/kg body weight (BW) of BPA whereas Group C had a BW of 7.5 ml/kg CMSO. Groups D, E, and F were administered 100 mg/kg_BW of BPA in addition to 7.5, 5.0, and 2.5 ml/kg_BW of CMSO, respectively. After two weeks of treatment, four mature female rats were introduced to each group and allowed to stay together with male rats for seven days to confirm mating. Thereafter, the pregnant female rats were separated from the male according to their groups and allowed to give birth after 21 days of gestation period. At six weeks, the F1-male rats were isolated from each group and sacrificed for biochemical analysis. In-silico, CMSO flavonoids were assessed for drug-likeness and oral absorbability, followed by molecular docking to study their androgen receptor targeting mechanisms. Results showed that total flavonoids were 17.3652 ± 8.85 g/100 g. In-vivo, BPA significantly (p < 0.005) dysregulated sperm indices and male fertility hormones in F1 rats, but co-administration with CMSO restored these dysregulations in F1 rats. In-silico, the druglike molecules exhibited stronger binding affinities (−6.2 to −8.5 kcal/mol) for the androgen receptor than BPA (−6.1 kcal/mol) within the binding pockets. We postulated that CMSO mitigates transgenerational sperm indices and male fertility hormone disruption in F1 male offspring following F0 male exposure to BPA perhaps by utilizing androgen receptor signaling.

Mesalamine may be a Plausible Therapeutic Agent for the Management of Diabetic Wounds: A Computational Approach

Aim: Validation of mesalamine (MS) as a potential therapeutic agent in treating diabetic wound (DW) healing using in silico approach. Background: Diabetic wound (DW) is a serious consequence of diabetes that frequently results in the amputation of the affected organ. Maggot therapy, pressure off-loading, surgical intervention, glucose control, hyperbaric oxygen therapy, wound debridement, and other treatments are currently available for DW. However, the majority of people do not meet all DW requirements due to significant pathology and the high expense of the solutions. Objective: To address the issues with current conventional therapy, we reasoned that repurposing existing medication (MS) to a target receptor that plays a significant role in the progression of DW might be advantageous. Mesalamine (MS), also known as Mesalazine or 5- Aminosalicylic acid, is an aminosalicylate anti-inflammatory used to treat inflammatory bowel disease (IBD), ulcerative colitis (UC), inflamed anus or rectum. The complicated pathophysiology of DW, which includes prolonged inflammation, increased infection, decreased cell proliferation, and migration, is a serious issue. As a result, we chose the MMP-9, TNF-α, MurC, ParE, and GSK-3β receptors as a universal target for treating the complex pathogenesis of DW. The use of MS as a therapeutic modulator on MMP-9, TNF-α, MurC, ParE, and GSK-3β receptors was studied in the current hypothetical investigation. Methods: Computational studies such as molecular docking and MMGBSA were performed by using the Schrödinger suite. Results: Computational investigations, such as molecular docking and MMGBSA were used to test our theory. It is clear from the in silico methods that MS has a higher binding affinity for the designated receptors. Hence, it is predicted that MS may be a good therapeutic agent to use in the treatment of DW. Conclusion: As a result of our findings, MS appears to be a unique therapeutic drug for the treatment of DW. However, further studies are highly required to take MS into clinical use.

Real-time platelet P2Y12 receptor occupancy as a promising pharmacodynamics biomarker for bridging the gap between PK/PD of clopidogrel therapy

Clopidogrel effectively inhibits platelet aggregation in response to ADP by irreversibly binding to the platelet P2Y12 receptor through its active metabolite. However, the observed discrepancies between the pharmacokinetics (PK) and pharmacodynamics (PD) of clopidogrel present substantial challenges in individualizing of antiplatelet therapy. To address these challenges, a robust liquid chromatography–tandem mass spectrometry method has been developed to facilitate the real-time assessment of platelet P2Y12 receptor occupancy. This method has been validated in animal models, providing a reliable link between individual PK profiles and PD effects. Target receptor occupancy offers a comprehensive overview of interindividual variations in clopidogrel metabolism, regulation of P2Y12 receptor expression, and platelet turnover. Moreover, it directly correlates with the inhibitory effect on platelet aggregation. The levels of platelet P2Y12 occupancy accurately reflect the extent of clinical factors influencing the PD of clopidogrel, including dosage, drug–drug interactions (DDI), and type 2 diabetes mellitus (T2DM). As a normalized metric, platelet P2Y12 occupancy not only serves potential as a diagnostic tool for personalized clopidogrel therapy but also aids in elucidating the role of the P2Y12 signaling pathway in cases of abnormal on-treatment platelet reactivity.

Standardized Production of Anti-Desmoglein 3 Antibody AK23 for Translational Pemphigus Vulgaris Research.

Antibody-mediated receptor activation is successfully used to develop medical treatments. If the activation induces a pathological response, such antibodies are also excellent tools for defining molecular mechanisms of target receptor malfunction and designing rescue therapies. Prominent examples are naturally occurring autoantibodies inducing the severe blistering disease pemphigus vulgaris (PV). In the great majority of patients, the antibodies bind to the adhesion receptor desmoglein 3 (Dsg3) and interfere with cell signaling to provoke severe blistering in the mucous membranes and/or skin. The identification of a comprehensive causative signaling network downstream of antibody-targeted Dsg3 receptors (e.g., shown by pharmacological activators or inhibitors) is currently being discussed as a basis to develop urgently needed first-line treatments for PV patients. Although polyclonal PV IgG antibodies have been used as proof of principle for pathological signal activation, monospecific anti-Dsg3 antibodies are necessary and have been developed to identify pathological Dsg3 receptor-mediated signal transduction. The experimental monospecific PV antibody AK23, produced from hybridoma cells, was extensively tested in our laboratory in both in vitro and in vivo models for PV and proved to recapitulate the clinicopathological features of PV when generated using the standardized production and purification protocols described herein. © 2024 The Author(s). Current Protocols published by Wiley Periodicals LLC. Basic Protocol 1: Bovine IgG stripping from FBS and quality control Basic Protocol 2: AK23 hybridoma expansion and IgG production Basic Protocol 3: AK23 IgG purification Basic Protocol 4: AK23 IgG quality control Support Protocol 1: Detection of endotoxin levels Support Protocol 2: Detection and removal of mycoplasma.

Molecular Docking of Brazilin from Secang Wood Plant (Caesalpinia sappan L.) as an Anti-Breast Cancer

Breast cancer is a disease characterized by abnormal cell growth, which can invade adjacent tissues or metastasize to other organs. Secang (Caesalpinia sappan L.) is a plant that has been used as an alternative medicine for a variety of health conditions, including some types of cancer. This study aims to determine whether the brazilin compound found in secang wood can interact with the target receptors estrogen alpha, 17-β-HSD-1, and NUDT5, potentially serving as an anticancer candidate. Molecular docking simulations were employed to identify the molecular interactions of brazilin against estrogen receptor alpha (ERα) (PDB ID: 3ERT), 17β-HSD-1 (PDB ID: 3HB5), and NUDT5 (PDB ID: 5NQR) using AutoDockTools software. The results showed that the best free-binding energy (ΔG) value obtained for brazilin against the 17-β-HSD-1 receptor was -9.16 kcal/mol, with an inhibition constant of 192.45 nM. The ΔG value of brazilin with estrogen alpha was -6.68 kcal/mol, and the ΔG value for brazilin against NUDT5 was -4.8 kcal/mol. Brazilin has a higher potency compared to innate ligands based on the docking result of estrogen alpha receptor and NUDT5. Some structural similarities and interactions occurred between the amino acids GLY186 and TYR155 in brazilin with the binding of amino acids formed in the innate ligand against the 17-β-HSD-1 receptor, thus showing similar affinity to the 17-β-HSD1 receptor. In silico approaches provided valuable insights into the potential of brazilin as an anti-breast cancer agent.

From birth to bite: the evolutionary ecology of India's medically most important snake venoms

BackgroundSnake venoms can exhibit remarkable inter- and intraspecific variation. While diverse ecological and environmental factors are theorised to explain this variation, only a handful of studies have attempted to unravel their precise roles. This knowledge gap not only impedes our understanding of venom evolution but may also have dire consequences on snakebite treatment. To address this shortcoming, we investigated the evolutionary ecology of venoms of Russell’s viper (Daboia russelii) and spectacled cobra (Naja naja), India’s two clinically most important snakes responsible for an alarming number of human deaths and disabilities.MethodologySeveral individuals (n = 226) of D. russelii and N. naja belonging to multiple clutches (n = 9) and their mothers were maintained in captivity to source ontogenetic stage-specific venoms. Using various in vitro and in vivo assays, we assessed the significance of prey, ontogeny and sex in driving venom composition, function, and potency.ResultsConsiderable ontogenetic shifts in venom profiles were observed in D. russelii, with the venoms of newborns being many times as potent as juveniles and adults against mammalian (2.3–2.5 ×) and reptilian (2–10 ×) prey. This is the first documentation of the ontogenetic shift in viperine snakes. In stark contrast, N. naja, which shares a biogeographic distribution similar to D. russelii, deployed identical biochemical cocktails across development. Furthermore, the binding kinetics of cobra venom toxins against synthetic target receptors from various prey and predators shed light on the evolutionary arms race.ConclusionsOur findings, therefore, provide fascinating insights into the roles of ecology and life history traits in shaping snake venoms.

Dissecting the neuroprotective interaction between the BH4 domain of BCL-w and the IP3 receptor

BCL-w is a BCL-2 family protein that promotes cell survival in tissue- and disease-specific contexts. The canonical anti-apoptotic functionality of BCL-w is mediated by a surface groove that traps the BCL-2 homology 3 (BH3) α-helices of pro-apoptotic members, blocking cell death. A distinct N-terminal portion of BCL-w, termed the BCL-2 homology 4 (BH4) domain, selectively protects axons from paclitaxel-induced degeneration by modulating IP3 receptors, a noncanonical BCL-2 family target. Given the potential of BCL-w BH4 mimetics to prevent or mitigate chemotherapy-induced peripheral neuropathy, we sought to characterize the interaction between BCL-w BH4 and the IP3 receptor, combining "staple" and alanine scanning approaches with molecular dynamics simulations. We generated and identified stapled BCL-w BH4 peptides with optimized IP3 receptor binding and neuroprotective activities. Point mutagenesis further revealed the sequence determinants for BCL-w BH4 specificity, providing a blueprint for therapeutic targeting of IP3 receptors to achieve neuroprotection.

Biochemical characterization of Prokineticin 2 binding to Prokineticin receptor 1 in zebrafish

Prokineticin 2 (PK2) binds to prokineticin receptor 1 and prokineticin receptor 2 (PKR1 and PKR2, respectively), two G protein-coupled receptors (GPCRs) that can mediate multiple signalling pathways by promoting the elevation of intracellular calcium and cAMP levels, phosphorylation of Akt and activation of ERK and STAT3. This work aims to evidence the conservation of protein sequence and the mechanism of PK2 binding to PKR1 to use the zebrafish model for the identification of new drugs as targets of prokineticin receptors. To this end, we first demonstrated that the zebrafish genes pk2 and pkr1 are phylogenetically related to orthologous mammalian genes by constructing evolutionary trees and performing syntenic analyses. Subsequently, by comparing the amino acid sequences, we showed that the interaction sites with PK2 are conserved in the zPKR1. Using GST pull-down and cross-linking experiments, we demonstrated the crucial role of the N-terminal region of zPKR1 for binding to the PK2. Finally, by expressing zPKR1 in CHO cells, we demonstrated the ability of zPKR1 to induce the activation of ERK and STAT3.

ScHyper: reconstructing cell-cell communication through hypergraph neural networks.

Cell-cell communications is crucial for the regulation of cellular life and the establishment of cellular relationships. Most approaches of inferring intercellular communications from single-cell RNA sequencing (scRNA-seq) data lack a comprehensive global network view of multilayered communications. In this context, we propose scHyper, a new method that can infer intercellular communications from a global network perspective and identify the potential impact of all cells, ligand, and receptor expression on the communication score. scHyper designed a new way to represent tripartite relationships, by extracting a heterogeneous hypergraph that includes the source (ligand expression), the target (receptor expression), and the relevant ligand-receptor (L-R) pairs. scHyper is based on hypergraph representation learning, which measures the degree of match between the intrinsic attributes (static embeddings) of nodes and their observed behaviors (dynamic embeddings) in the context (hyperedges), quantifies the probability of forming hyperedges, and thus reconstructs the cell-cell communication score. Additionally, to effectively mine the key mechanisms of signal transmission, we collect a rich dataset of multisubunit complex L-R pairs and propose a nonparametric test to determine significant intercellular communications. Comparing with other tools indicates that scHyper exhibits superior performance and functionality. Experimental results on the human tumor microenvironment and immune cells demonstrate that scHyper offers reliable and unique capabilities for analyzing intercellular communication networks. Therefore, we introduced an effective strategy that can build high-order interaction patterns, surpassing the limitations of most methods that can only handle low-order interactions, thus more accurately interpreting the complexity of intercellular communications.

Multi Receptor Targeting of Potential Bioactive Compound Obtained from Chloroform Extract of Asparagus racemosus by GC-MS Analysis: A in silico Based Approach

Multi Receptor Targeting of Potential Bioactive Compound Obtained from Chloroform Extract of Asparagus racemosus by GC-MS Analysis: A in silico Based Approach

Identification of phytochemicals as potential inhibitors of Candida albicans SAP3: An in-silico approach

Background: Candida albicans is a major threat to human health, causing a variety of diseases. Candida albicans can overgrow and trigger infections like thrush, diaper rash, and vaginal yeast infections. Therefore, finding potential inhibitors of C. albicans from plant sources has become important, recently.Methods: This study investigated the interaction of natural compounds (N = 450) from the ZINC database with the C. albicans SAP3 protein. PyRx tools were used to conduct molecular docking analyses, which included ligand and target receptor preparation, data analysis, and visualization.Result: The binding energies between the natural compounds and SAP3 ranged from -8.8 to -7.8 kcal/mol, indicating that the interactions were predominantly strong. Among the compounds screened, ZINC000252509014, ZINC000252509722, ZINC000253389136, ZINC000251981944, and ZINC000252480871 were extensively explored in this study because they were found to be the best among others. Furthermore, these compounds showed favorable drug-like properties.Conclusion: These findings lay the groundwork for future research aimed at developing potent SAP3 inhibitors to treat C. albicans infections.Keywords: Candida albicans; SAP3 protein; Natural compounds; Virtual screening; Drug-likeness

Lipid nanoparticle-mediated hepatocyte delivery of siRNA and silibinin in metabolic dysfunction-associated steatotic liver disease

Lipid nanoparticle-mediated co-delivery of siRNA and small molecule holds a great potential to treat metabolic dysfunction-associated steatotic liver disease (MASLD). However, targeted delivery of therapeutics to hepatocytes remains challenging. Taking the advantage of rising low density lipoprotein receptor/very-low density lipoprotein receptor (LDLR/VLDR) levels in MASLD, the biological fate of dinonylamine-ethylene glycol chlorophosphate-1-nonanol (DNNA-COP-NA) based lipid nanoparticles (LNPs) was oriented to liver tissues via apolipoprotein E (ApoE)-LDLR/VLDLR pathway. We then adopted a three-round screening strategy to optimize the formulation with both high potency and selectivity to deliver siRNA-HIF-1α (siHIF1α) and silibinin (SLB) payloads to hepatocytes. The optimized SLB/siHIF1α-LNPs mediates great siRNA delivery and transfection of hepatocytes. In high fat diet (HFD)- and carbon tetrachloride (CCl4)-induced mouse models of MASLD, SLB/siHIF1α-LNPs enabled the silencing of hypoxia inducible factor-1α (HIF-1α), a therapeutic target primarily expressed by hepatocytes, leading to significantly reduced inflammation and liver fibrosis synergized with SLB. Moreover, it is demonstrated the hepatocyte-targeting delivery of SLB/siHIF1α-LNPs has the potential to restore the immune homeostasis by modulating the population of Tregs and cytotoxic T cells in spleen. This proof-of-concept study enable siRNA and small molecule co-delivery to hepatocytes through intrinsic variation of targeting receptors for MASLD therapy.

Ketamine alleviates NMDA receptor hypofunction through synaptic trapping

Activity-dependent modulations of N-methyl-D-aspartate glutamate receptor (NMDAR) trapping at synapses regulate excitatory neurotransmission and shape cognitive functions. Although NMDAR synaptic destabilization has been associated with severe neurological and psychiatric conditions, tuning NMDAR synaptic trapping to assess its clinical relevance for the treatment of brain conditions remains a challenge. Here, we report that ketamine (KET) and other clinically relevant NMDAR open channel blockers (OCBs) promote interactions between NMDAR and PDZ-domain-containing scaffolding proteins and enhance NMDAR trapping at synapses. We further show that KET-elicited trapping enhancement compensates for depletion in synaptic receptors triggered by autoantibodies from patients with anti-NMDAR encephalitis. Preventing synaptic depletion mitigates impairments in NMDAR-mediated CaMKII signaling and alleviates anxiety- and sensorimotor-gating-related behavioral deficits provoked by autoantibodies. Altogether, these findings reveal an unexpected dimension of OCB action and stress the potential of targeting receptor anchoring in NMDAR-related synaptopathies.

Natural Product-Inspired Dopamine Receptor Ligands.

Due to their evolutionary bias as ligands for biologically relevant drug targets, natural products offer a unique opportunity as lead compounds in drug discovery. Given the involvement of dopamine receptors in various physiological and behavioral functions, they are linked to numerous diseases and disorders such as Parkinson's disease, schizophrenia, and substance use disorders. Consequently, ligands targeting dopamine receptors hold considerable therapeutic and investigative promise. As this perspective will highlight, dopamine receptor targeting natural products play a pivotal role as scaffolds with unique and beneficial pharmacological properties, allowing for natural product-inspired drug design and lead optimization. As such, dopamine receptor targeting natural products still have untapped potential to aid in the treatment of disorders and diseases related to central nervous system (CNS) and peripheral nervous system (PNS) dysfunction.

Cheminformatics-based identification of phosphorylated RET tyrosine kinase inhibitors for human cancer.

Rearranged during transfection (RET), an oncogenic protein, is associated with various cancers, including non-small-cell lung cancer (NSCLC), papillary thyroid cancer (PTC), pancreatic cancer, medullary thyroid cancer (MTC), breast cancer, and colorectal cancer. Dysregulation of RET contributes to cancer development, highlighting the importance of identifying lead compounds targeting this protein due to its pivotal role in cancer progression. Therefore, this study aims to discover effective lead compounds targeting RET across different cancer types and evaluate their potential to inhibit cancer progression. This study used a range of computational techniques, including Phase database creation, high-throughput virtual screening (HTVS), molecular docking, molecular mechanics with generalized Born surface area (MM-GBSA) solvation, assessment of pharmacokinetic (PK) properties, and molecular dynamics (MD) simulations, to identify potential lead compounds targeting RET. Initially, a high-throughput virtual screening of the ZINC database identified 2,550 compounds from a pool of 170,269. Subsequent molecular docking studies revealed 10 compounds with promising negative binding scores ranging from -8.458 to -7.791kcal/mol. MM-GBSA analysis further confirmed the potential of four compounds to exhibit negative binding scores. MD simulations demonstrated the stability of CID 95842900, CID 137030374, CID 124958150, and CID 110126793 with the target receptors. These findings suggest that these selected four compounds have the potential to inhibit phosphorylated RET (pRET) tyrosine kinase activity and may represent promising candidates for the treatment of various cancers.

Antibacterial activities, PASS prediction and ADME analysis of phytochemicals from Curcubita moschata, Curcubita maxima, and Irvingia gabonensis: insights from in silico studies.

Microbial infection management and treatment are crucial as a result of the prevalent antimicrobial resistance issue. Progressive studies are being carried out on how to develop drugs that can mitigate the resistance trends of these microorganisms. Secondary metabolites of plants can also be employed and accessed for this role, as the current study examines the antibacterial activities of phytochemicals from three (3) plants (Cucubita moschata, Cucubita maxima, and Irvingia gabonesis) through computational approaches. Molecular docking studies were carried out to show the binding affinities of the phytochemicals against two target receptors (DNA gyrase and Penicillin Binding Protein 3). In addition, drug likeness analysis, bioactivity and oral-bioavailability properties, absorption, distribution, metabolism, and excretion (ADME) profiling, as well as prediction of activity spectra for substances (PASS) using online tools like SwissADME, PASS online, AdmetSAR2, and Discovery Studio, were also performed. The results obtained identified isochlorogenic acid and apigenin-7-O-glucoside for DNA gyrase (1KZN) and apigenin-7-O-glucoside for Penicillin Binding Protein 3 (4BJP), which were further subjected to molecular dynamics simulation (MDS) and therefore recommended as the lead compounds.

Benzothiazole‐Piperazine Hybrids Effectively Target C4‐2 Castration‐Resistant Prostate Cancer Cells in vitro Implicated through Computational Studies

AbstractA series of new analogs based on benzothiazole‐piperazine conjugates were synthesized and assessed to investigate their anticancer properties using in vitro and in silico techniques. The compounds 3 a–3 h were tested against prostate (C4‐2) cancer cells, and the results revealed that all the compounds showed significant inhibitory activity against C4‐2 cells (&gt;50 % inhibition at 20 μM). Among all, 2‐(4‐(pyrimidin‐2‐yl) piperazin‐1‐yl) benzo[d]thiazole demonstrated the most prominent activity in the cell viability assay conducted displaying an IC50 value of 19.98 μM. In vitro studies have demonstrated that the compound can selectively target the androgen receptor (AR) and reduce the expression of several androgen‐responsive genes, including EAF2, ELL2, PSA and CALR genes, in castration‐resistant prostate cancer cells. Molecular docking results also revealed that all the compounds exhibited good energy binding scores against the androgen receptor target (PB ID: 2PNU) particularly compound 3 g which showed a maximum binding energy of −9.87 kcal/mol followed by other compounds as well as the established prostate cancer drug, enzalutamide, with a binding energy of −5.66 kcal/mol. Docking results were further supported by MD simulation studies, which confirmed that the ligand+protein complex was in stable conformation throughout the simulation time of 100 nanoseconds. Collectively, the present results, stemming from a combination of in vitro and in silico examinations, demonstrate that compound 3 g displays notable anti‐cancer characteristics, implying its viability as a prospective anti‐cancer pharmaceutical subject to clinical validation and subsequent development.

A Comprehensive Review of HER2 in Cancer Biology and Therapeutics.

Human epidermal growth factor receptor 2 (HER2), a targetable transmembrane glycoprotein receptor of the epidermal growth factor receptor (EGFR) family, plays a crucial role in cell proliferation, survival, and differentiation. Aberrant HER2 signaling is implicated in various cancers, particularly in breast and gastric cancers, where HER2 overexpression or amplification correlates with aggressive tumor behavior and poor prognosis. HER2-activating mutations contribute to accelerated tumorigenesis and metastasis. This review provides an overview of HER2 biology, signaling pathways, mechanisms of dysregulation, and diagnostic approaches, as well as therapeutic strategies targeting HER2 in cancer. Understanding the intricate details of HER2 regulation is essential for developing effective targeted therapies and improving patient outcomes.

Improved Biological Impacts of Anti-EGFR Monoclonal Antibody in KRAS-Mutant Colorectal Cancer Cells by Silica-Coated Magnetic Nanoparticle Conjugation

Background: The therapeutic potential of epidermal growth factor receptor (EGFR) targeting in colorectal cancer (CRC) is hindered by the presence of KRAS codon 12 activating mutations, prevalent in approximately 25% of advanced CRC cases. This study investigates the role of reactive oxygen species (ROS) in conferring resistance to anti-EGFR monoclonal antibodies in KRAS mutant CRC cells, focusing on ROS-mediated apoptosis induction using cetuximab-PEGylated silica-coated magnetic nanoparticles (MNPs). Methods: MNPs were synthesized and surface-coated with silica, followed by functionalization and stabilization with polyethylene glycol (PEG). Cetuximab (Cet) was covalently conjugated to generate EMNP-PEG-Cet. Structural and compositional analyses were performed using scanning electron microscopy (SEM), dynamic light scattering (DLS), UV-vis spectroscopy, and Fourier transform infrared (FTIR) analysis. Apoptosis induction, chromatin condensation, and ROS production were evaluated in KRAS mutant SW-480 CRC cells. Results: Successful synthesis of EMNP-PEG-Cet was confirmed, revealing a particle size of 67 nm and a surface charge of -8.3 mV. The conjugate exhibited significant cytotoxicity against CRC cells, with notable apoptosis induction and ROS generation in EGFR-positive/KRAS mutant SW-480 cells, surpassing the effects observed with bare Cet and EMNP-PEG controls. The nuclear factor erythroid 2-related factor 2/Kelch-like ECH-related protein 1 (Nrf2-Kaep1) gene expression analysis by real-time PCR showed that cells treated with EMNP-PEG-Cet exhibited a noteworthy decrease in Nrf2 expression and a simultaneous increase in Keap1 expression compared to those treated with free Cet. Conclusion: These findings highlight the potential of ROS-mediated apoptosis induction to enhance the cytotoxicity of Cet in EGFR-positive/KRAS mutant CRC cells, offering new avenues for overcoming drug resistance mechanisms in metastatic CRC.

Tumor Regression Following Engineered Polyomavirus-Specific T Cell Therapy in Immune Checkpoint Inhibitor-Refractory Merkel Cell Carcinoma.

Although immune check-point inhibitors (CPIs) revolutionized treatment of Merkel cell carcinoma (MCC), patients with CPI-refractory MCC lack effective therapy. More than 80% of MCC express T-antigens encoded by Merkel cell polyomavirus, which is an ideal target for T-cell receptor (TCR)-based immunotherapy. However, MCC often repress HLA expression, requiring additional strategies to reverse the downregulation for allowing T cells to recognize their targets. We identified TCRMCC1 that recognizes a T-antigen epitope restricted to human leukocyte antigen (HLA)-A*02:01. Seven CPI-refractory metastatic MCC patients received CD4 and CD8 T cells transduced with TCRMCC1 (TTCR-MCC1) preceded either by lymphodepleting chemotherapy or an HLA-upregulating regimen (single-fraction radiation therapy (SFRT) or systemic interferon gamma (IFNγ)) with concurrent avelumab. Two patients who received preceding SFRT and IFNγ respectively experienced tumor regression. One experienced regression of 13/14 subcutaneous lesions with 1 'escape' lesion and the other had delayed tumor regression in all lesions after initial progression. Although TTCR-MCC1 cells with an activated phenotype infiltrated tumors including the 'escape' lesion, all progressing lesions transcriptionally lacked HLA expression. While SFRT/IFNγ did not immediately upregulate tumor HLA expression, a secondary endogenous antigen-specific T cell infiltrate was detected in one of the regressing tumors and associated with HLA upregulation, indicating in situ immune responses have the potential to reverse HLA downregulation. Indeed, supplying a strong co-stimulatory signal via a CD200R-CD28 switch receptor allows TTCR-MCC1 cells to control HLA-downregulated MCC cells in a xenograft mouse model, upregulating HLA expression. Our results demonstrate the potential of TCR gene therapy for metastatic MCC and propose a next strategy for overcoming epigenetic downregulation of HLA in MCC.