Single cell imaging reveals cisplatin regulating interactions between transcription (co)factors and DNA

Biomimetic Sealing of Cisplatin by Cancer Cell Membranes to Achieve Nucleophile Resistance and Tumor Targeting for Improved Cancer Therapy

Platinum-based anticancer drugs (PBCs), particularly cisplatin, play a key role in over 70% of cancer treatment protocols. PBCs suffer from their strong affinity with numerous nucleophiles present in the body, leading to significant systematic toxicity and rapid drug inactivation. The cell membrane's selective and energy-dependent transport properties, inherent to its unique biological structure, offer a strategic opportunity for employing cell membranes (CMs) in the development of PBC delivery systems that repel nucleophiles. To prove this idea, we harness cancer CMs to develop a dual-package approach for sealing cisplatin in a nanoformulation that is both nucleophile-resistant and tumor-targeted without the need for synthetic materials. The dual-package process begins by conjugating cisplatin to cancer CMs, creating positively charged nanoparticles. These isolated nanoparticles are then recomplexed with cancer CMs. Our strategy, which tightly seals cisplatin within the cancer CMs, ensures that cisplatin is safely sequestered from reactive molecules in the body while simultaneously guiding it specifically to homologous tumors. The resulting nanoformulation demonstrates immune evasion and a prolonged circulation time due to the native-like identity conferred by cancer CMs. The biomimetic sealing of cisplatin within CMs prevented the transmembrane attack of nucleophiles, including not only macromolecular proteins but also small-molecule compounds such as glutathione, thereby ensuring a high level of cytotoxicity when challenged by these nucleophiles. It also displays precise targeting at homologous tumors, ensures sustained drug release, and achieves significant tumor suppression. These features together adumbrate the nanoformulation's potential as a revolutionary tool in cisplatin cancer therapy. Given the prevalence of metal ion-based drugs and their common susceptibility to nucleophile-associated issues, the strategy presented in this study may offer a widely applicable solution to developing nucleophile-resistant metal-ion-based medications.

MECOM and the PRDM gene family in uterine endometrial cancer: bioinformatics and experimental insights into pathogenesis and therapeutic potentials

To elucidate the expression profiles, methylation states, and clinicopathological significance of the PRDM gene family, focusing on the MECOM gene's role in uterine endometrial cancer (UCEC) and its molecular interactions with the TGF-beta signaling pathway. Our methodology combined detailed bioinformatics analyses using UALCAN and GEPIA with in vitro assessments in HEC-1-A cells. Techniques included CRISPR-Cas9 for gene editing and various cellular assays (CCK-8, flow cytometry, Transwell) to evaluate the effects of MECOM on cell proliferation, migration, and apoptosis, alongside Western blot analysis for protein regulation in the TGF-beta pathway. MECOM was upregulated in UCEC tissues, influencing tumor cell behavior significantly. Knockout studies demonstrated reduced proliferation and migration and increased apoptosis, while overexpression showed reverse effects. Mechanistically, MECOM modulated critical proteins within the TGF-beta pathway, impacting cell cycle dynamics and apoptotic processes. The PRDM gene family, particularly MECOM, plays a crucial role in the pathogenesis and progression of UCEC, suggesting its utility as a target for novel therapeutic interventions. Our findings offer valuable insights for future research and potential clinical application in managing uterine endometrial cancer.

Metal-detection based techniques and their applications in metallobiology

Metals are essential for human health and play a crucial role in numerous biological processes and pathways. Gaining a deeper insight into these biological events will facilitate novel strategies for disease prevention, early detection, and personalized treatment. In recent years, there has been significant progress in the development of metal-detection based techniques from single cell metallome and proteome profiling to multiplex imaging, which greatly enhance our comprehension of the intricate roles played by metals in complex biological systems. This perspective summarizes the recent progress in advanced metal-detection based techniques and highlights successful applications in elucidating the roles of metals in biology and medicine. Technologies including machine learning that couple with single-cell analysis such as mass cytometry and their application in metallobiology, cancer biology and immunology are also emphasized. Finally, we provide insights into future prospects and challenges involved in metal-detection based techniques, with the aim of inspiring further methodological advancements and applications that are accessible to chemists, biologists, and clinicians.

Dual mass spectrometry imaging and spatial metabolomics to investigate the metabolism and nephrotoxicity of nitidine chloride

Evaluating toxicity and decoding the underlying mechanisms of active compounds are crucial for drug development. In this study, we present an innovative, integrated approach that combines air flow-assisted desorption electrospray ionization mass spectrometry imaging (AFADESI-MSI), time-of-flight secondary ion mass spectrometry (ToF-SIMS), and spatial metabolomics to comprehensively investigate the nephrotoxicity and underlying mechanisms of nitidine chloride (NC), a promising anti-tumor drug candidate. Our quantitive AFADESI-MSI analysis unveiled the region specific of accumulation of NC in the kidney, particularly within the inner cortex (IC) region, following single and repeated dose of NC. High spatial resolution ToF-SIMS analysis further allowed us to precisely map the localization of NC within the renal tubule. Employing spatial metabolomics based on AFADESI-MSI, we identified over 70 discriminating endogenous metabolites associated with chronic NC exposure. These findings suggest the renal tubule as the primary target of NC toxicity and implicate renal transporters (organic cation transporters, multidrug and toxin extrusion, and organic cation transporter 2 (OCT2)), metabolic enzymes (protein arginine N-methyltransferase (PRMT) and nitric oxide synthase), mitochondria, oxidative stress, and inflammation in NC-induced nephrotoxicity. This study offers novel insights into NC-induced renal damage, representing a crucial step towards devising strategies to mitigate renal damage caused by this compound.

Trichostatin A Promotes Cytotoxicity of Cisplatin, as Evidenced by Enhanced Apoptosis/Cell Death Markers

Trichostatin A (TSA), a histone deacetylase (HDAC) inhibitor, promotes the cytotoxicity of the genotoxic anticancer drug cisplatin, yet the underlying mechanism remains poorly understood. Herein, we revealed that TSA at a low concentration (1 μM) promoted the cisplatin-induced activation of caspase-3/6, which, in turn, increased the level of cleaved PARP1 and degraded lamin A&C, leading to more cisplatin-induced apoptosis and G2/M phase arrest of A549 cancer cells. Both ICP-MS and ToF-SIMS measurements demonstrated a significant increase in DNA-bound platinum in A549 cells in the presence of TSA, which was attributable to TSA-induced increase in the accessibility of genomic DNA to cisplatin attacking. The global quantitative proteomics results further showed that in the presence of TSA, cisplatin activated INF signaling to upregulate STAT1 and SAMHD1 to increase cisplatin sensitivity and downregulated ICAM1 and CD44 to reduce cell migration, synergistically promoting cisplatin cytotoxicity. Furthermore, in the presence of TSA, cisplatin downregulated TFAM and SLC3A2 to enhance cisplatin-induced ferroptosis, also contributing to the promotion of cisplatin cytotoxicity. Importantly, our posttranslational modification data indicated that acetylation at H4K8 played a dominant role in promoting cisplatin cytotoxicity. These findings provide novel insights into better understanding the principle of combining chemotherapy of genotoxic drugs and HDAC inhibitors for the treatment of cancers.

Novel mechanism of cisplatin resistance in head and neck squamous cell carcinoma involving extracellular vesicles and a copper transporter system

BACKGROUND

Cisplatin (CDDP) plays a central role in chemotherapy for head and neck squamous cell carcinoma (HNSCC), but drug resistance in HNSCC chemotherapy remains a problem, and the mechanism of CDDP resistance is unclear. We investigated CDDP-resistance mechanisms mediated by extracellular vesicles (EVs) and ATPase copper transporting beta (ATP7B) in HNSCC.

METHODS

We established CDDP-resistant sublines of HNSCC cells and verified their ATP7B expression. We used an EV secretion inhibitor (GW4869) and ATP7B short hairpin (sh)RNA transfection to examine the correlation between EV secretion and ATP7B expression.

RESULTS

The CDDP-resistant HNSCC sublines showed decreased CDDP sensitivity and increased ATP7B expression. GW4869 suppressed ATP7B expression, and ATP7B shRNA transfection suppressed EV secretion. The suppressions of EV secretion and ATP7B expression both enhanced CDDP's cell-killing effect.

CONCLUSIONS

EVs were involved in the ATP7B-mediated mechanism underlying CDDP resistance. Further clarification of the EV-induced CDDP-resistance mechanism may lead to novel therapeutic strategies for HNSCC.

Advancements in ToF-SIMS imaging for life sciences

In the last 2 decades, Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) has gained significant prominence as a powerful imaging technique in the field of life sciences. This comprehensive review provides an in-depth overview of recent advancements in ToF-SIMS instrument technology and its applications in metabolomics, lipidomics, and single-cell analysis. We highlight the use of ToF-SIMS imaging for studying lipid distribution, composition, and interactions in cells and tissues, and discuss its application in metabolomics, including the analysis of metabolic pathways. Furthermore, we review recent progress in single-cell analysis using ToF-SIMS, focusing on sample preparation techniques, in situ investigation for subcellular distribution of drugs, and interactions between drug molecules and biological targets. The high spatial resolution and potential for multimodal analysis of ToF-SIMS make it a promising tool for unraveling the complex molecular landscape of biological systems. We also discuss future prospects and potential advancements of ToF-SIMS in the research of life sciences, with the expectation of a significant impact in the field.

Recent advances in mass spectrometry imaging of single cells

Mass spectrometry imaging (MSI) is a sensitive, specific, label-free imaging analysis technique that can simultaneously obtain the spatial distribution, relative content, and structural information of hundreds of biomolecules in cells and tissues, such as lipids, small drug molecules, peptides, proteins, and other compounds. The study of molecular mapping of single cells can reveal major scientific issues such as the activity pattern of living organisms, disease pathogenesis, drug-targeted therapy, and cellular heterogeneity. Applying MSI technology to the molecular mapping of single cells can provide new insights and ideas for the study of single-cell metabolomics. This review aims to provide an informative resource for those in the MSI community who are interested in single-cell imaging. Particularly, we discuss advances in imaging schemes and sample preparation, instrumentation improvements, data processing and analysis, and 3D MSI over the past few years that have allowed MSI to emerge as a powerful technique in the molecular imaging of single cells. Also, we highlight some of the most cutting-edge studies in single-cell MSI, demonstrating the future potential of single-cell MSI. Visualizing molecular distribution at the single-cell or even sub-cellular level can provide us with richer cell information, which strongly contributes to advancing research fields such as biomedicine, life sciences, pharmacodynamic testing, and metabolomics. At the end of the review, we summarize the current development of single-cell MSI technology and look into the future of this technology.

Discriminant Principal Component Analysis of ToF-SIMS Spectra for Deciphering Compositional Differences of MSC-Secreted Extracellular Matrices

Identifying characteristic extracellular matrix (ECM) variants is a key challenge in mechanistic biology, bioengineering, and medical diagnostics. The reported study demonstrates the potential of time-of-flight secondary ion mass spectrometry (ToF-SIMS) to detect subtle differences between human mesenchymal stromal cell (MSC)-secreted ECM types as induced by exogenous stimulation or emerging pathology. ToF-SIMS spectra of decellularized ECM samples are evaluated by discriminant principal component analysis (DPCA), an advanced multivariate analysis technique, to decipher characteristic compositional features. To establish the approach, signatures of major ECM proteins are determined from samples of pre-defined mixtures. Based on that, sets of ECM variants produced by MSCs in vitro are analyzed. Differences in the content of collagen, fibronectin, and laminin in the ECM resulting from the combined supplementation of MSC cultures with polymers that induce macromolecular crowding and with ascorbic acid are detected from the DPCA of ToF-SIMS spectra. The results are verified by immunostaining. Finally, the comparative ToF-SIMS analysis of ECM produced by MSCs of healthy donors and patients suffering from myelodysplastic syndrome display the potential of the novel methodology to reveal disease-associated alterations of the ECM composition.

Multi-target activity of copper complexes: Antibacterial, DNA binding, and molecular docking with SARS-CoV-2 receptor

A series of pendant-armed mixed-ligand copper(II) complexes of the type [CuL^1-3(diimine)] (1-6) have been synthesized by the reaction of pendant-armed ligands N,N-bis(2-(((E)-2-hydroxy-5-methylbenzylidene)amino)ethyl)benzamide (H₂L¹), N,N-bis(2-(((E)-2-hydroxy-5-methylbenzylidene)amino)ethyl)-4-nitrobenzamide (H₂L²) and N,N-bis(2-(((E)-2-hydroxy-5-methylbenzylidene)amino)ethyl)-3,5-dinitrobenzamide (H₂L³) with diimine = 2,2'-bipyridyl (bpy) or 1,10-phenanthroline (phen) in the presence of copper(II) chloride and analyzed using various spectroscopic methods. All the spectroscopic results support that the complexes adopt a pentagonal-bipyramidal shape around the copper ion. Gram-positive and Gram-negative bacteria were used to test all the complexes for antibacterial activity and all the complexes had greater potency against gram-negative pathogens. DNA-binding experiments of complexes with calf thymus DNA revealed a major-groove binding pattern, further supported by molecular docking studies. Complexes have significantly interacted with SARS-CoV-2 receptor via π-π, π-σ, π-alkyl, π-anion, π-cation, alkyl, hydrogen bond, van der Waals, and electrostatic interactions. The estimated binding energy and inhibition constant of these complexes are higher than standard drugs, chloroquine, and molnupiravir.

Applications of spatially resolved omics in the field of endocrine tumors

Endocrine tumors derive from endocrine cells with high heterogeneity in function, structure and embryology, and are characteristic of a marked diversity and tissue heterogeneity. There are still challenges in analyzing the molecular alternations within the heterogeneous microenvironment for endocrine tumors. Recently, several proteomic, lipidomic and metabolomic platforms have been applied to the analysis of endocrine tumors to explore the cellular and molecular mechanisms of tumor genesis, progression and metastasis. In this review, we provide a comprehensive overview of spatially resolved proteomics, lipidomics and metabolomics guided by mass spectrometry imaging and spatially resolved microproteomics directed by microextraction and tandem mass spectrometry. In this regard, we will discuss different mass spectrometry imaging techniques, including secondary ion mass spectrometry, matrix-assisted laser desorption/ionization and desorption electrospray ionization. Additionally, we will highlight microextraction approaches such as laser capture microdissection and liquid microjunction extraction. With these methods, proteins can be extracted precisely from specific regions of the endocrine tumor. Finally, we compare applications of proteomic, lipidomic and metabolomic platforms in the field of endocrine tumors and outline their potentials in elucidating cellular and molecular processes involved in endocrine tumors.

Bioimaging approaches for quantification of individual cell behavior during cell fate decisions

Tracking individual cells has allowed a new understanding of cellular behavior in human health and disease by adding a dynamic component to the already complex heterogeneity of single cells. Technically, despite countless advances, numerous experimental variables can affect data collection and interpretation and need to be considered. In this review, we discuss the main technical aspects and biological findings in the analysis of the behavior of individual cells. We discuss the most relevant contributions provided by these approaches in clinically relevant human conditions like embryo development, stem cells biology, inflammation, cancer and microbiology, along with the cellular mechanisms and molecular pathways underlying these conditions. We also discuss the key technical aspects to be considered when planning and performing experiments involving the analysis of individual cells over long periods. Despite the challenges in automatic detection, features extraction and long-term tracking that need to be tackled, the potential impact of single-cell bioimaging is enormous in understanding the pathogenesis and development of new therapies in human pathophysiology.

OUP accepted manuscript

Pyridostatin (PDS) is a well-known G-quadruplex (G4) inducer and stabilizer, yet its target genes have remained unclear. Herein, applying MS proteomics strategy, we revealed PDS significantly downregulated 22 proteins but upregulated 16 proteins in HeLa cancer cells, of which the genes both contain a number of G4 potential sequences, implying that PDS regulation on gene expression is far more complicated than inducing/stabilizing G4 structures. The PDS-downregulated proteins consequently upregulated 6 proteins to activate cyclin and cell cycle regulation, suggesting that PDS itself is not a potential anticancer agent, at least toward HeLa cancer cells. Importantly, SUB1, which encodes human positive cofactor and DNA lesion sensor PC4, was downregulated by 4.76-fold. Further studies demonstrated that the downregulation of PC4 dramatically promoted the cytotoxicity of trans-[PtCl₂(NH₃)(thiazole)] (trans-PtTz) toward HeLa cells to a similar level of cisplatin, contributable to retarding the repair of 1,3-trans-PtTz crosslinked DNA lesion mediated by PC4. These findings not only provide new insights into better understanding on the biological functions of PDS but also implicate a strategy for the rational design of novel multi-targeting platinum anticancer drugs via conjugation of PDS as a ligand to the coordination scaffold of transplatin for battling drug resistance to cisplatin.

Interactions of HMGB Proteins with the Genome and the Impact on Disease

High Mobility Group Box (HMGB) proteins are small architectural DNA binding proteins that regulate multiple genomic processes such as DNA damage repair, nucleosome sliding, telomere homeostasis, and transcription. In doing so they control both normal cellular functions and impact a myriad of disease states, including cancers and autoimmune diseases. HMGB proteins bind to DNA and nucleosomes to modulate the local chromatin environment, which facilitates the binding of regulatory protein factors to the genome and modulates higher order chromosomal organization. Numerous studies over the years have characterized the structure and function of interactions between HMGB proteins and DNA, both biochemically and inside cells, providing valuable mechanistic insight as well as evidence these interactions influence pathological processes. This review highlights recent studies supporting the roles of HMGB1 and HMGB2 in global organization of the genome, as well as roles in transcriptional regulation and telomere maintenance via interactions with G-quadruplex structures. Moreover, emerging models for how HMGB proteins function as RNA binding proteins are presented. Nuclear HMGB proteins have broad regulatory potential to impact numerous aspects of cellular metabolism in normal and disease states.