Search Results (33)

Protein self-interaction to form homodimers and higher-order homo-oligomers is a ubiquitous phenomenon fundamental to living organisms. Recent structural, system-level, and computational insights reveal that self-interacting proteins dictate the specificity, rewiring, and topological complexity of cellular signaling networks and macromolecular assemblies. Beyond their physiological roles, aberrant or dysregulated homotypic interactions disrupt cellular proteostasis, driving the formation of toxic non-native oligomers, pathological amyloid fibrillization, or aberrant liquid–liquid phase separation transitions linked to neurodegenerative and systemic diseases. This review provides a comprehensive overview of the state-of-the-art experimental methodologies, including proximity labeling, as well as the advanced computational frameworks, such as deep learning architectures and protein language models, used to map the structural dynamics of SIPs. Furthermore, we dissect the evolutionary trajectories of SIPs within protein–protein interaction networks, which are underpinned by dosage-balance constraints, and highlight their diverse functional advantages, ranging from allosteric modulation to biomolecular condensation. Finally, we summarize the molecular mechanisms linking pathological self-associations to human disorders, underscoring the emerging paradigm of targeting homotypic interfaces as a promising frontier for precision therapeutics. Full article

Background: Glioblastoma (GBM) has emerged as a model of resistance to immunotherapy because of the immunosuppressive tumor microenvironment (TME), which is closely associated with tryptophan metabolism. Inhibiting the expression of indoleamine 2,3-dioxygenase-1 (IDO1, a key enzyme in tryptophan metabolism) is a promising strategy for improving the immunosuppressive TME. Meanwhile, Gasdermin B (GSDMB)-mediated pyroptosis is a newly identified mechanism for activating the immune response. Methods: We prepared a GBM cell membrane (CM)-modified lipid nanoparticle (CMLNP) to deliver CRISPR/Cas9 components and mRNA encoding the N-terminal domain of GSDMB (GSDMB^NT mRNA). Results: The CM modification endowed the LNP with a tumor homing/homotypic targeting effect. Then, CRISPR/Cas9 components realized the knockdown of the IDO1 gene, thus remodeling the TME. GSDMB^NT mRNA triggers pyroptosis, thus eliciting an immune response. Conclusions: This system generated potent antitumor immunity and offered a novel strategy for GBM immunotherapy. Full article

Background/Objectives: Triple-negative breast cancer (TNBC) is an aggressive breast cancer subtype associated with poor prognosis and limited targeted therapeutic options. Natural products, rich in bioactive phytochemicals, represent a potential source of novel anticancer agents. This study examined the phytochemical profile and anticancer activity of an ethanolic bulb extract of Cyclamen persicum (CPE), with a primary focus on TNBC. Methods: The phytochemical composition of CPE was analyzed by liquid chromatography–mass spectrometry (LC–MS). Antioxidant activity was evaluated using DPPH radical scavenging assay. The anticancer effects of CPE were assessed mainly in MDA-MB-231 TNBC cells using MTT cell viability assays, Ki-67 immunoblotting, Western blot analysis of signaling proteins, wound healing migration assays, Matrigel invasion assays, adhesion assays and cell–cell aggregation assays. Antiproliferative activity was also examined in 22RV1 (prostate), Capan-2 (pancreatic), and HCT116 (intestinal) cancer cell lines using MTT assays. Results: LC–MS analysis indicated that the extract contains multiple polyphenolic and organic acid constituents commonly associated with bioactivity. Consistent with this profile, CPE demonstrated strong antioxidant activity. In MDA-MB-231 cells, CPE significantly reduced cell viability and proliferation, accompanied by decreased Ki-67 expression. Treatment was associated with modulation of proteins involved in proliferative and survival signaling, induction of apoptosis-related markers, and reduced migratory and invasive capacities. CPE also promoted cell–cell homotypic aggregation, suggesting a shift toward a less aggressive phenotype. These effects were associated with reduced phosphorylation of p65, indicating possible modulation of NF-κB signaling. Additionally, CPE decreased proliferation in 22RV1, Capan-2, and HCT116 cancer cell lines. Conclusions: Collectively, these findings indicate that C. persicum bulb extract exerts multimodal anticancer effects in vitro, particularly in TNBC cells, and highlights its potential as a source of bioactive compounds warranting further mechanistic and translational investigation. Full article

Burkholderia pseudomallei complex and B. cepacia complex are two evolutionary distinct clades of pathogens causing human disease. Most vaccine efforts have focused on the former group largely due to their biothreat status and global disease burden. It has been proposed that a vaccine could be developed that simultaneously protects against both groups of Burkholderia by specifically targeting conserved antigens. Only a few studies have set out to identify which antigens may be optimal targets for such a vaccine. We have previously assessed the ability of three highly conserved B. pseudomallei antigens, namely OmpA1, OmpA2, and Pal, coupled to gold nanoparticle vaccines, to protect mice against a homotypic B. pseudomallei challenge. Here, we have expanded our study by demonstrating that antibodies to each of these proteins show varying levels of reactivity to homologues in B. cepacia complex, with OmpA2 antibodies exhibiting the highest cross-reactivity. Remarkably, some nanovaccine immunized mice, particularly those that received OmpA2, produced antibodies that bind Pseudomonas aeruginosa, which harbors distantly related homologous proteins. T cells elicited to Pal and OmpA2 responded to stimulation with B. cepacia complex-derived homologues. Our study supports incorporation of these antigens, particularly OmpA2, for the development of a pan-Burkholderia vaccine. Full article

Background: Norovirus is a leading cause of epidemic acute gastroenteritis worldwide, associated with significant morbidity, mortality, and economic loss. Despite its global impact, no licensed vaccine is currently available, and vaccine development remains challenging. Methods: We explored avian immunoglobulin Y (IgY) antibodies as a low-cost countermeasure against norovirus infection. We generated recombinant protruding (P) domain proteins from the capsid protein (VP1) of noroviruses, representing two GII.4 variants and the GII.6 genotype. These were combined into a single immunogen to immunize laying hens to produce norovirus VP1-specific IgY antibodies. Results: Immunization of laying hens with the P domain proteins elicited high-titer (>1:450,000) P domain-specific IgY antibodies. The yolk-derived IgY effectively inhibited binding of various norovirus P particles to their histo-blood group antigen ligands, with 50% blocking titers (BT50) up to 1:8533 against homotypic GII.4 and 1:667 against heterotypic G1.1 Norwalk virus P particles. Importantly, the IgY neutralized replication of GII.4 norovirus in the human intestinal enteroid (HIE) system at a high titer of over 1:2500, equivalent to 0.70 µg/mL of total IgY. We also produced norovirus shell (S) domain proteins and corresponding IgY antibodies, which neutralized GII.4 norovirus replication in the HIE model at a titer of ~1:800, equivalent to 2.98 µg/mL of total IgY. This provides the first evidence that the S domain contains neutralizing epitopes. Conclusions: Our findings support the potential of IgY targeting norovirus P or S domains as a scalable, cost-effective strategy for preventing norovirus infection and disease. Full article

Background/Objectives: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can naturally infect a broad spectrum of animal species, with cats, minks, and ferrets being highly susceptible. There is a potential risk that infected animals could transmit viruses to humans. Moreover, SARS-CoV-2 continues to evolve via mutation and genetic recombination, resulting in the continuous emergence of new variants that have triggered a wave of reinfection. Therefore, safe and effective corona virus disease 2019 (COVID-19) vaccines for animals are still being sought. Methods: We generated three recombinant Modified vaccinia virus Ankara (MVAs) expressing the prefusion-stabilized S proteins, S6P, DS6P, and BA2S6P, targeting the full-length S protein genes of the ancestral, Delta, and Omicron BA.2 strains of SARS-CoV-2. Subsequently, the safety, immunogenicity, and protective efficacy of these MVA-based oral COVID-19 vaccine candidates were assessed in mice, minks, and cats. Results: These recombinant MVAs are safe in mice, minks, and cats. Oral or intramuscular vaccination with rMVA-S6P induced a robust SARS-CoV-2 neutralizing antibody (NA) response and conferred complete protection against the SARS-CoV-2 challenge in mice. Meanwhile, oral or intramuscular administration of these recombinant MVAs in combination induced a potent and durable NA response against homotypic SARS-CoV-2 pseudovirus in mice, minks, and cats, respectively. Conclusions: These findings suggest that the MVA-vectored vaccines are promising oral COVID-19 vaccine candidates for animals, and that the combined vaccination approach is an effective administration strategy for such vaccines. Full article

Glioblastoma (GB) is an aggressive brain cancer with high microvascular proliferation. The pathological angiogenesis leads to accelerated tumour invasion and diffused infiltration into the surrounding brain tissues, with a tragically short survival rate. Various transmembrane proteins, which are embedded on the glioblastoma cancer cell surface, interact with diverse extracellular ligands/molecules present in the tumor micro-environment. These ligands play a crucial role in the development, progression, and therapeutic resistance. In the present study, we systematically screened multiple transmembrane protein receptors, and their extracellular ligands involved/implicated in GB cancer cell progression. Additionally, we analyzed the homotypic and heterotypic protein associations within glioblastoma cancer cells to better understand their role in tumor development. Ten well-known and clinically approved GB cancer drugs were selected and retrieved from online databases for molecular docking analyses with extracellular proteins. Among the different ligands analyzed, computational analysis revealed a strong interaction between fibronectin (PDB ID: 3VI4) and the majority of GB surface receptors. Furthermore, molecular docking studies between GB-approved drugs and fibronectin demonstrated the strongest binding interaction with Irinotecan, followed by Etoposide, Vincristine, etc. In conclusion, identification of ligand-drugs interactions provides valuable insights into the mechanisms underlying GB cancer cell development and potential avenues for therapeutic inhibition strategies. Our study demonstrated that Irinotecan, Etoposide, and Vincristine exhibit strong binding interactions with fibronectin, effectively disrupting its interaction with surface receptor(s). Since fibronectin receptor interactions play a crucial role in GB tumor progression, these findings suggest that targeting fibronectin could present a promising strategy to inhibit GB cell proliferation and invasion. Full article

Background/Objectives: Homotypic targeting refers to the ability of cells to preferentially interact with other cells of the same type. An understanding of how cells use homotypic targeting (self-homing) characteristics for tumor-targeting purposes may aid in the effective delivery of radionuclides or other drugs for imaging or therapeutic applications. Additionally, studies investigating the targeting properties of cells from the same lineage may shed light on this interesting mechanism, allowing it to be harnessed for other applications. The objective of this study was to assess the tumor-self targeting potential of PC3 prostate cancer and 4T1 breast cancer cells using a direct cell labeling technique, with a focus on evaluation of cellular labeling efficiency, cell viability, cellular efflux, and in vivo tumor-self targeting capability using both identical and dissimilar tumor models. Methods: [⁸⁹Zr]Zr-oxine was prepared and utilized for the labeling of PC3 and 4T1 cells. Following the assessment of cell labeling efficacy, viability, and efflux, PET/CT imaging and biodistribution studies were conducted with [⁸⁹Zr]Zr-oxine labeled PC3 and 4T1 cells in PC3 and 4T1 tumor-bearing mice models. Results: Both PC3 cells and 4T1 cells were radiolabeled with [⁸⁹Zr]oxine, with PC3 cells illustrating a higher labeling efficiency (86.55 ± 0.38%) than 4T1 cells (46.95 ± 1.47%). Notably, radiolabeled PC3 cells illustrated significant uptake in PC3 tumors (7.54 ± 1.07%ID/gram at 24 h and 6.95 ± 3.56%ID/gram at 48 h) with lower tumor uptake in the 4T1 xenograft model (1.79 ± 0.29%ID/gram at 24 h and 1.42 ± 0.71%ID/gram at 48 h), illustrating the potential of self-targeting. Conclusions: Both PC3 and 4T1 cells followed a similar pattern of biodistribution, with labeled PC3 cells demonstrating lower blood retention and reduced uptake in non-target organs such as lungs and heart. Taken together, these results may indicate that PC3 cells illustrate homotypic targeting, warranting further investigation of this phenomenon. Full article

Cancer-associated fibroblasts (CAFs) constitute a heterogeneous population of cells within the tumor microenvironment and are associated with cancer development and drug resistance. The absence of a universal classification for CAFs hinders their research and therapeutic targeting. To define CAF phenotypes, we developed patient-derived cell cultures of breast cancer (BC) and validated and characterized four distinct CAF subtypes (S1–S4) by Costa’s classification. Three out of five primary cell cultures of BC demonstrated different functional features rather than fixed cellular states due to the plasticity of the CAF phenotype. CAF crosstalk with cancer cells supported their survival in the presence of anticancer drugs. Based on the analysis of the cytotoxic effect of doxorubicin, cisplatin and tamoxifen, it was demonstrated that CAF-S4 and CAF-S1 cells were sensitive to the action of all drugs investigated, despite the fact that they possessed different mechanisms of action. CAF-S2 cells exhibited the highest level of resistance to the antitumour agents. Homotypic and heterotypic spheroids with CAFs could be used to model the fibrotic area of BC in vitro. The patient-derived cell cultures of CAFs formed spheroids. Hypoxia-activated CAF-S4 have been shown to stimulate the metastatic potential of triple-negative BC cells in a heterotypic spheroid model. Consequently, this study could be a starting point for the development of novel therapeutic strategies that target CAFs and their interactions with cancer cells. Full article

Cancer cell spheroids autonomously form in the ascites fluid and are considered a conduit for epithelial ovarian cancer metastasis within the peritoneal cavity. Spheroids are homotypic, avascular 3D structures that acquire resistance to anoikis to remain viable after cellular detachment. We used in vitro spheroid model systems to interrogate pathways critical for spheroid cell proliferation, distinct from those driving monolayer cancer cell proliferation. Using the 105C and KOC-7c human ovarian clear cell carcinoma (OCCC) cell lines, which have distinct proliferative phenotypes as spheroids but the same prototypical OCCC gene mutation profile of constitutively activated AKT signaling with the loss of ARID1A, we revealed therapeutic targets that efficiently kill cells in spheroids. RNA-seq analyses compared the transcriptome of 3-day monolayer and spheroid cells from these lines and identified the characteristics of dormant spheroid cell survival, which included the G2/M checkpoint, autophagy, and other stress pathways induced in 105C spheroids, in sharp contrast to the proliferating spheroid cells of the KOC-7c cell line. Next, we assessed levels of various G2/M checkpoint regulators and found a consistent reduction in steady-state levels of checkpoint regulators in dormant spheroid cells, but not proliferative spheroids. Our studies showed that proliferative spheroid cells were sensitive to Wee1 inhibition by AZD1775, but the dormant spheroid cells showed a degree of resistance to AZD1775, both in terms of EC50 values and spheroid reattachment abilities. Thus, we identified biomarkers of dormant spheroids, including the G2/M checkpoint regulators Wee1, Cdc25c, and PLK1, and showed that, when compared to proliferating spheroid cells, the transcriptome of dormant OCCC spheroids is a source of therapeutic targets. Full article

The field of nanomedicine has been fruitful in creating novel drug delivery ideas to battle hematologic cancers. However, one persistent barrier to efficient nanoparticle treatment is phagocytic uptake or the clearance of nanoparticles by immune cells. To prevent this immune uptake, scientists have utilized biomimicry, the emulation of natural structures for engineered applications, to create particles that are able to remain unrecognized by immune cells. This method aims to improve the overall circulation time of nanoparticles by decreasing the amount of particles filtered out of the blood. It can even lead to homotypic cancer cell targeting, decreasing cancer cell vitality. This review summarizes recent in vivo and in vitro studies to prove that biomimetic cargo delivery is a unique and tenable way of increasing survival outcomes in patients with hematologic cancers. Full article

It was found that the serine protease inhibitors BmSPI38 and BmSPI39 in silkworm can strongly inhibit the activity of porcine pancreatic elastase, which has potential applicational value in the drug research and development of lung diseases, inflammatory diseases, and skin aging caused by the excessive release of elastase. Previous studies have shown that homotypic multimers obtained by tandem expression can significantly enhance the antifungal activity and structural homogeneity of BmSPI38 and BmSPI39, while the effect of the tandem expression of these two inhibitors, with different combinations, on the total activity and expression levels of multimers remains unclear. The aim of this study is to explore whether it is possible to obtain the combination of BmSPI38 and BmSPI39 with strong total expression activity by protein engineering. In this study, 40 tandem multimer expression vectors with different combinatorial forms of BmSPI38 and BmSPI39 were constructed by the isocaudomer method, and recombinant proteins were obtained by the prokaryotic expression system. The target proteins were separated by SDS-PAGE to analyze the expression levels of multimer proteins with different combinatorial forms. The total activity of the recombinant expression products with different tandem forms was investigated using the in-gel activity staining technique of protease inhibitors. The SDS-PAGE results show that the expression levels of tandem multimers containing the BmSPI39 module at the carboxyl terminus were generally higher in the Escherichia coli supernatant than that of the tandem multimers containing the BmSPI38 module at the carboxyl terminus. The activity staining results indicate that compared with BmSPI38 and BmSPI39 homotypic multimers, the total activity of some recombinant expression products with different tandem forms was stronger. Furthermore, the total activity level was relatively higher when the carboxyl terminus of the multimer was a BmSPI39 module, such as the tandem dimers SPIAB and SPIaB and the tandem trimers SPIabB, SPIaaB, and SPIbaB. In this study, the expression of tandem fusion proteins with different combinations of the silkworm protease inhibitors BmSPI38 and BmSPI39 in E. coli was successfully achieved. It was confirmed that the tandem of different combinatorial forms, based on protein engineering, was an effective way to enhance the total activity of the fusion proteins of BmSPI38 and BmSPI39 and to improve their expression levels. Additionally, a number of multimer proteins with strong total activity and high exogenous expression levels were also screened, for example, SPIbaA, SPIbbA, SPIbbB, SPIabB, SPIaaB, and SPIbaB. This study not only lays the foundation for the exogenous production and development of BmSPI38 and BmSPI39 but also provides a reference for the construction of tandem and multimerization exploration of other protease inhibitors. Full article

Transcription factors (TFs) are the main regulators of eukaryotic gene expression. The cooperative binding of at least two TFs to genomic DNA is a major mechanism of transcription regulation. Massive analysis of the co-occurrence of overrepresented pairs of motifs for different target TFs studied in ChIP-seq experiments can clarify the mechanisms of TF cooperation. We categorized the target TFs from M. musculus ChIP-seq and A. thaliana ChIP-seq/DAP-seq experiments according to the structure of their DNA-binding domains (DBDs) into classes. We studied homotypic pairs of motifs, using the same recognition model for each motif. Asymmetric and symmetric pairs consist of motifs of remote and close recognition scores. We found that asymmetric pairs of motifs predominate for all TF classes. TFs from the murine/plant ‘Basic helix–loop–helix (bHLH)’, ‘Basic leucine zipper (bZIP)’, and ‘Tryptophan cluster’ classes and murine ‘p53 domain’ and ‘Rel homology region’ classes showed the highest enrichment of asymmetric homotypic pairs of motifs. Pioneer TFs, despite their DBD types, have a higher significance of asymmetry within homotypic pairs of motifs compared to other TFs. Asymmetry within homotypic CEs is a promising new feature decrypting the mechanisms of gene transcription regulation. Full article

As nanocarriers of a new generation, biomimetic nanovesicles are an emerging class of therapeutic tools whose surface is integrated or fabricated with biomaterials capable of mimicking the biological features and functions of native cells. Thanks to this, biomimetic nanovesicles, in particular, those made by plasma membrane moieties, possess greatly improved biocompatibility, high target specificity, a long retention time, and minimal undesired immune responses. For these reasons, a multitude of progenitor cells including cancer ones were employed as templates to generate biomimetic or membrane-camouflaged nanovesicles hosting different therapeutic compounds. In this contribution, different membrane-derived biomimetic vesicles (M-NVs) were generated by osmotic lysis or plasma membrane isolation approaches from normal and cancer cell lines and assayed against in vitro models of human glioblastoma. M-NVs were compared in their cellular internalization degrees of DNA and proteins, morphologically and molecularly characterized, expressing an extracellular membrane-associated marker. Then, Rose Bengal (RB), a photoactivable drug characterized by a relatively low cellular uptake, was incorporated into nascent glioblastoma-derived M-NVs and finally administered to homotypic receiving cells, showing an increased degree of internalization as well as induced cytotoxic effects, even in the absence of photodynamic direct stimulation. Similar results were also obtained assaying lyophilized M-NVs loaded with RB. In conclusion, M-NVs generated by cell membranes effectively deliver several cargoes, including therapeutic molecules, maintain functionality after lyophilization, and show significant internalization effects, making them a promising strategy for therapeutic applications against human glioblastoma cells. Full article

Poor prognosis in high-grade gliomas is mainly due to fatal relapse after surgical resection in the absence of efficient chemotherapy, which is severely hampered by the blood–brain barrier. However, the leaky blood–brain–tumour barrier forms upon tumour growth and vascularization, allowing targeted nanocarrier-mediated drug delivery. The homotypic targeting ability of cell-membrane fragments obtained from cancer cells means that these fragments can be exploited to this aim. In this experimental work, injectable nanoemulsions, which have a long history of safe clinic usage, have been wrapped in glioma-cell membrane fragments via co-extrusion to give targeted, homogeneously sized, sterile formulations. These systems were then loaded with three different chemotherapeutics, in the form of hydrophobic ion pairs that can be released into the target site thanks to interactions with physiological components. The numerous assays performed in two-dimensional (2D) and three-dimensional (3D) cell models demonstrate that the proposed approach is a versatile drug-delivery platform with chemo-tactic properties towards glioma cells, with adhesive interactions between the target cell and the cell membrane fragments most likely being responsible for the effect. This approach’s promising translational perspectives towards personalized nanomedicine mean that further in vivo studies are foreseen for the future. Full article