Covalent assembly-based two-photon fluorescent probes for in situ visualizing nitroreductase activities: From cancer cells to human cancer tissues.

Nitroreductase (NTR) is widely regarded as a biomarker whose enzymatic activity correlates with the degree of hypoxia in solid malignant tumors. Herein, we utilized 2-dimethylamino-7-hydroxynaphthalene as fluorophore linked diverse nitroaromatic groups to obtain four NTR-activatable two-photon fluorescent probes based on covalent assembly strategy. With the help of computer docking simulation and in vitro assay, the sulfonate-based probe XN3 was proved to be able to identify NTR activity with best performances in rapid response, outstanding specificity, and sensitivity in comparison with the other three probes. Furthermore, XN3 could detect the degree of hypoxia by monitoring NTR activity in kinds of cancer cells with remarkable signal-to-noise ratios. In cancer tissue sections of the breast and liver in mice, XN3 had the ability to differentiate between healthy and tumorous tissues, and possessed excellent fluorescence stability, high tissue penetration and low tissue autofluorescence. Finally, XN3 was successfully utilized for in situ visualizing NTR activities in human transverse colon and rectal cancer tissues, respectively. The findings suggested that XN3 could directly identify the boundary between cancer and normal tissues by monitoring NTR activities, which provides a new method for imaging diagnosis and intraoperative navigation of tumor tissue.

Homologous Tumor Cell-Derived Biomimetic Nano-Trojan Horse Integrating Chemotherapy with Genetherapy for Boosting Triple-Negative Breast Cancer Therapy.

Triple-negative breast cancer (TNBC) is a subtype of breast cancer that carries the worst prognosis and lacks specific therapeutic targets. To achieve accurate "cargos" delivery at the TNBC site, we herein constructed a novel biomimetic nano-Trojan horse integrating chemotherapy with gene therapy for boosting TNBC treatment. Briefly, we initially introduce the diselenide-bond-containing organosilica moieties into the framework of mesoporous silica nanoparticles (MONs), thereby conferring biodegradability to intratumoral redox conditions in the obtained MONSe. Subsequently, doxorubicin (Dox) and therapeutic miR-34a are loaded into MONSe, thus achieving the combination of chemotherapy and gene-therapy. After homologous tumor cell membrane coating, the ultimate homologous tumor cell-derived biomimetic nano-Trojan horse (namely, MONSe@Dox@miR-34a@CM) can selectively enter the tumor cells in a stealth-like fashion. Notably, such a nanoplatform not only synergistically eradicated the tumor but also inhibited the proliferation of breast cancer stem-like cells (BCSCs) in vitro and in vivo. With the integration of homologous tumor cell membrane-facilitated intratumoral accumulation, excellent biodegradability, and synergistic gene-chemotherapy, our biomimetic nanocarriers hold tremendous promise for the cure of TNBC in the future.

Clinical application of FIGO 2023 staging system of endometrial cancer in a Chinese cohort.

OBJECTIVE: The International Federation of Gynecology and Obstetrics (FIGO) 2023 staging system for endometrial cancer (EC) was released with incorporating histology, lympho-vascular space invasion, and molecular classification together. Our objective is to further explore the clinical utility and prognostic significance of the 2023 FIGO staging system in China. METHODS: A retrospective analysis was conducted for patients who received standard surgeries and underwent genetic testing using multigene next-generation sequencing (NGS) panels between December 2018 and December 2023 at Fudan University Shanghai Cancer Center, Shanghai, China. The genomic and clinical data of all patients were analyzed, and stages were determined by both the 2009 and 2023 FIGO staging systems. Kaplan-Meier estimators and Cox proportional hazards models were used for survival analysis. RESULTS: A total of 547 patients were enrolled in the study. After the restaged by the FIGO 2023 staging system, stage shifts occurred in 147/547 (26.9%) patients. In patients with early stages in FIGO 2009 (stage I-II), 63 cases were rearranged to IAmPOLEmut and 53 cases to IICmp53abn due to the molecular classification of POLEmut and p53abn. Altogether 345 cases were in stage I, 107 cases in stage II, 69 cases in stage III, and 26 cases in stage IV according to the FIGO 2023 staging criteria. For stage I diseases, the 3-year PFS rate was 92.7% and 95.3% in 2009 and 2023 FIGO staging systems, respectively. The 3-year PFS of stage II in 2023 FIGO was lower than that of FIGO 2009 (3-year PFS: 85.0% versus 90.9%), especially in substage IIC and IICmp53abn. Three cases (12%) of stage IIIA in FIGO 2009 were shifted to stage IA3 FIGO 2023, with 3-year PFS rates of 90.9% versus 100%, respectively. In NGS analysis, the most prevalent gene alterations were observed in PTEN and PIK3CA. CONCLUSION: The FIGO 2023 staging system was proved to be a good predictor of survival for EC patients with enhanced precision compared to FIGO 2009. Predominant stage shifts were observed in early-stage diseases. Distinct gene alterations of different subtypes may help to explore more accurate target therapies.

A near-infrared fluorescent probe with two-photon excitation for in situ imaging of NQO1 in human colorectum cancer tissue.

Colorectum cancer has become one of the most fatal cancer diseases, in which NAD(P)H: quinone oxidoreductase 1 (NQO1) plays a role in intracellular free radical reduction and detoxification and has been linked to colorectum cancer and chemotherapy resistance. Therefore, rational design of optical probe for NQO1 detection is urgent for the early diagnosis of colorectum cancer. Herein, we have developed a novel two-photon fluorescent probe, WHFD, which is capable of selectively detecting of intracellular NQO1 with two-photon (TP) absorption (800 nm) and near-infrared emission (620 nm). Combination with a substantial Stokes shift (175 nm) and biocompatibility, we have assessed its suitability for in vivo imaging of endogenous NQO1 activities from HepG2 tumor-bearing live animals with high tissue penetration up to 300 µm. Particularly, we for the first time used the probe to image NQO1 activities from human colorectum cancer samples by using TP microscopy, and proving our probe possesses reliable diagnostic performance to directly in situ imaging of cancer biomarker and can clearly distinguish the boundary between human colorectum cancer tissue and their surrounding normal tissue, which shows great potential for the intraoperative navigation.

Current and Future of "Turn-On" Based Small-Molecule Copper Probes for Cuproptosis.

Increasing evidence shows that abnormal copper (Cu) metabolism is highly related to many diseases, such as Alzheimer's disease, Wilson's disease, hematological malignancies and Menkes disease. Very recently, cuproptosis, a Cu-dependent, programmed cell death was firstly described by Tsvetkov et al. in 2022. Their findings may provide a new perspective for the treatment of related diseases. However, the concrete mechanisms of these diseases, especially cuproptosis, remain completely unclear, the reason of which may be a lack of reliable tools to conduct highly selective, sensitive and high-resolution imaging of Cu in complex life systems. So far, numerous small-molecular fluorescent probes have been designed and utilized to explore the Cu signal pathway. Among them, fluorescence turn-on probes greatly enhance the resolution and accuracy of imaging and may be a promising tool for research of investigation into cuproptosis. This review summarizes the probes developed in the past decade which have the potential to study cuproptosis, focusing on the design strategies, luminescence mechanism and biological-imaging applications. Besides, we put forward some ideas concerning the design of next-generation probes for cuproptosis, aiming to tackle the main problems in this new field. Furthermore, the prospect of cuproptosis in the treatment of corresponding diseases is also highlighted.

A light-activated magnetic bead strategy utilized in spatio-temporal controllable exosomes isolation.

Tumor-derived exosomes are considered as a key biomarker in the field of liquid biopsy. However, conventional separation techniques such as ultracentrifugation, co-precipitation and column chromatography cannot isolate samples with high throughput, while traditional immunomagnetic separation techniques, due to steric effect of magnetic beads, reducing sensitivity of exosomes optical detection. Herein, we provide a novel and simple nanoplatform for spatiotemporally controlling extraction and elution of exosomes via magnetic separation and light-activated cargo release. In this system, magnetic beads are co-modified by photoresponsive groups -nitrobenzyl group and aptamers that are compatible with CD63-a highly expressed exosomal surface-specific protein. Through exosomes extracted from cell model and nude mice xenograft tumor model morphological characterization and proteomic analysis, results showed that our novel magnetic bead system outperformed current ultracentrifugation in serum exosome extraction in terms of extraction time, yield, and proportion of populations with high CD63 expression. This strategy may be a powerful tool for exosome isolation in clinical liquid biopsies of cancer disease.

Two-Photon Small-Molecule Fluorogenic Probes for Visualizing Endogenous Nitroreductase Activities from Tumor Tissues of a Cancer Patient.

Nitroreductase (NTR), a common enzymatic biomarker of hypoxia, is widely used to evaluate tumor microenvironments. To date, numerous optical probes have been reported for NTRs detection. Approaches capable of concisely guiding the probe design of NTRs suitable for deep-tissue imaging, however, are still lacking. As such, direct optical imaging of endogenous NTR activities from tumors derived from cancer patients is thus far not possible. Herein, aided by computational calculations, the authors have successfully developed a series of two-photon (TP) small-molecule fluorogenic probes capable of sensitively detecting general NTR activities from various biological samples; by optimizing the distance between the recognition moiety and the reactive site of NTRs from different sources, the authors have discovered and experimentally proven that X4 displays the best performance in both sensitivity and selectivity. Furthermore, X4 shows excellent TP excited fluorescence properties capable of directly monitoring/imaging endogenous NTR activities from live mammalian cells, growing zebrafish, and tumor-bearing mice. Finally, with an outstanding TP tissue-penetrating imaging property, X4 is used, for the first time, to successfully detect endogenous NTR activities from the liver lysates and cardia tissues of a cancer patient. The work may provide a universal strategy to design novel TP small-molecule enzymatic probes in future clinical applications.

Simultaneously Detecting Monoamine Oxidase A and B in Disease Cell/Tissue Samples Using Paper-Based Devices.

As enzymes in the outer membrane of the mitochondrion, monoamine oxidases (MAOs) can catalyze the oxidative deamination of monoamines in the human body. According to different substrates, MAOs can be divided into MAO-A and MAO-B. The imbalance of the MAO-A is associated with neurological degeneration, while excess MAO-B activity is closely connected with Parkinson's disease (PD) and Alzheimer's disease (AD); therefore, detection of MAOs is of great significance for the diagnosis and treatment of these diseases. This work reports the multiplexed detection of MAO-A and MAO-B using paper-based devices based on chemiluminescence (CL). The detection limits were 5.01 pg/mL for MAO-A and 8.50 pg/mL for MAO-B in human serum. In addition, we used paper-based devices to detect MAOs in human cells and tissue samples and found that the results of paper-based detection and Western blotting (WB) showed the same trend. While only one antibody can be incubated on the same membrane by WB, multiple antibodies incubated on the same paper enabled simultaneous detection of MAO-A and MAO-B by paper-based devices. The paper-based assay could be used for preliminary early screening of clinical samples for MAOs and can be extended as an alternative to WB for multiplexed detection of various proteins in disease cell or tissue samples.

Rational Design of a Two-Photon Fluorogenic Probe for Visualizing Monoamine Oxidase†A Activity in Human Glioma Tissues.

Monoamine oxidases have two functionally distinct but structurally similar isoforms (MAO-A and MAO-B). The ability to differentiate them by using fluorescence detection/imaging technology is of significant biological relevance, but highly challenging with available chemical tools. Herein, we report the first MAO-A-specific two-photon fluorogenic probe (F1), capable of selective imaging of endogenous MAO-A enzymatic activities from a variety of biological samples, including MAO-A-expressing neuronal SY-SY5Y cells, the brain of tumor-bearing mice and human Glioma tissues by using two-photon fluorescence microscopy (TPFM) with minimal cytotoxicity.

A novel naphthofluorescein-based probe for ultrasensitive point-of-care testing of zinc(II) ions and its bioimaging in living cells and zebrafishes.

The combination of fluorescence method with paper-based diagnostic device is quite suitable in point-of-care testing (POCT). Herein, we designed a novel hybrid fluorescein-based probe ZN-2 and investigated its fluorescent properties thoroughly in the detection of Zn2+. In comparison with the fluorescein-based probe ZN-1, ZN-2 displayed better sensitivity, long-wavelength and faster response to Zn2+ within 20 min. Interestingly, we could achieve ultrasensitive, high-throughput and visual detection in the POCT analysis of Zn2+ by anchoring this probe ZN-2 on the paper-based device. This device with satisfied performance for Zn2+ detection was achieved in real samples including cytochylema, serum and lake water. Finally, the probe ZN-2 was further applied to visualize and monitor the level changes of Zn2+ in the living cells and zebrafishes.

A novel pyrimidine based deep-red fluorogenic probe for detecting hydrogen peroxide in Parkinson's disease models.

Parkinson's disease (PD) severely affects life quality of patients and has brought huge economic burden to health system worldwide. Previous studies have shown that the abnormal expression of hydrogen peroxide (H2O2) in the brain is closely related to the development of neurodegenerative diseases such as PD. Herein, we designed a novel deep-red H2O2 fluorogenic probe PB1 to detect the level of H2O2in vivo. PB1 showed a highly selectivity response to H2O2 over other reactants such as reactive oxygen/nitrogen species, biothiols and various ions in aqueous solution at physiological pH. We have demonstrated that PB1 possesses an excellent response to H2O2 in the cells and in the brain tissue of drosophila from confocal fluorescence imaging. These results suggested that PB1 holds great potential in the study of the relationship between H2O2 overexpression and PD.

Non-viral nanocarriers for intracellular delivery of microRNA therapeutics.

MicroRNAs are small regulatory noncoding RNAs that regulate various biological processes associated with neurological disorders, cardiovascular diseases, cancer and viral infection. MiRNA-based therapeutics have broad applications including cancer immunotherapy, genomic engineering and protein replacement therapy. Until now, a variety of materials have been proved to be promising as non-viral nanocarriers for intracellular delivery of miRNAs, such as polymeric nanoparticles, lipid nanocapsules, and inorganic nanoparticles, etc. In this review, we will present the strategies for intracellular miRNA delivery, and specially focus on rationally designed routes, their mechanisms of action, and potential therapeutics used in the host cells or in vivo studies. Futhermore, we will also make a conclusion based on the current development. The perspective on the new generation of delivery systems toward the emerging area of miRNA-based therapeutics will be discussed as well.

The use of proteomic technologies to study molecular mechanisms of multidrug resistance in cancer.

Multidrug resistance (MDR), defined as the cross-resistance of cancer cells toward a broad range of chemotherapeutic agents, is a universal and intractable problem in chemotherapy. The understanding of MDR mechanisms is essential to discover the potential biomarkers for predicting multidrug resistance and more importantly, tackling and preventing multidrug resistance. Multiple technologies have been used to study MDR mechanisms including comparative genomic hybridization, DNA array, differential display RT-PCR and various immunoassays. Compared with these approaches, proteomic technologies allow a high through-put analysis of protein detection, protein quantification and protein interaction with high accuracy. With the rapid development of proteomic studies in recent years, proteomic technologies have made substantial contributions to the characterization of MDR mechanisms including MDR-related protein detection and quantification, as well as the characterization of drug-transporter binding sites. This review offers a comprehensive illustration of MDR, proteomic technologies and the discoveries made in understanding MDR mechanisms using proteomic approaches.

Fast response two-photon fluorogenic probe based on Schiff base derivatives for monitoring nitric oxide levels in living cells and zebrafish.

Numerous excellent fluorogenic probes for NO detection based on NO-mediated reactions have been developed. However, some of them still suffer from limitations such as low selectivity, slow response, and a short excitation wavelength (<500 nm). Herein, a novel two-photon fluorogenic probe (XNO1) based on a Schiff base derivative has been reported for the first time. This new mechanism with a Schiff base structure as the specific response moiety towards NO endows the probe with fast responsibility, high selectivity and pH-independent properties. Furthermore, XNO1 has been demonstrated to be lysosome-targeted and to successfully monitor exogenous/endogenous NO in living cells and zebrafishes with one- and two-photon fluorescence imaging.

Nanoquencher-Based Selective Imaging of Protein Glutathionylation in Live Mammalian Cells.

Changes in the cellular levels of glutathione (GSH) and protein S-glutathionylation (PSSG) are closely associated with a number of human diseases. Despite recent advances, few thiol-reactive, small-molecule GSH sensors could selectively detect GSH over other endogenous thiols, and none was capable of detecting PSSG in live mammalian cells. By using a dye-loaded mesoporous silica nanoquencher (qMSN) capped with anti-GSH antibody capable of highly selective binding toward GSH and glutathionylated proteins over other molecules, we have successfully developed a fluorescence GSH/PSSG nanosensor, which showed unprecedented selectivity toward PSSG even in the presence of GSH, had amplifiable and programmable fluorescence Turn-ON properties, and could be used to image endogenous PSSG in live mammalian cells under stimulated conditions for the first time.

MSN-on-a-Chip: Cell-Based Screenings Made Possible on a Small-Molecule Microarray of Native Natural Products.

Standard small-molecule microarrays (SMMs) are not well-suited for cell-based screening assays. Of the few attempts made thus far to render SMMs cell-compatible, all encountered major limitations. Here we report the first mesoporous silica nanoparticle (MSN)-on-a-chip platform capable of allowing high-throughput cell-based screening to be conducted on SMMs. By making use of a glass surface on which hundreds of MSNs, each encapsulated with a different native natural product, were immobilized in spatially defined manner, followed by on-chip mammalian cell growth and on-demand compound release, high-content screening was successfully carried out with readily available phenotypic detection methods. By combining this new MSN-on-a-chip system with small interfering RNA technology for the first time, we discovered that (+)-usniacin possesses synergistic inhibitory properties similar to those of olaparib (an FDA-approved drug) in BRCA1-knockdown cancer cells.

Intracellular Delivery of Functional Native Antibodies under Hypoxic Conditions by Using a Biodegradable Silica Nanoquencher.

Antibodies are important biopharmaceuticals, but almost all existing antibody-based drugs are limited to targeting antigens located at the cell exterior because of the inability of antibodies to enter the cell interior. Available methods for intracellular delivery of antibodies have major shortcomings. Herein, we report an approach to encapsulate native antibodies in a biodegradable silica nanoquencher (BS-qNP), which could undergo efficient cellular uptake and intracellular degradation to release antibodies only under hypoxic conditions. By coating the surface of BS-qNP with cell-penetrating poly(disulfide)s (CPD), the delivered antibodies (or other proteins) avoided endolysosomal trapping. Doping of the silica coating with a fluorescent dye and a dark hole quencher further endowed BS-qNP with hypoxia-responsive fluorescence turn-on property. Our antibody delivery system thus provides the first platform capable of stable encapsulation, efficient uptake, on-demand antibody release, and imaging of release/cell state.

Simultaneous Imaging of Endogenous Survivin mRNA and On-Demand Drug Release in Live Cells by Using a Mesoporous Silica Nanoquencher.

The design of multifunctional drug delivery systems capable of simultaneous target detection, imaging, and therapeutics in live mammalian cells is critical for biomedical research. In this study, by using mesoporous silica nanoparticles (MSNs) chemically modified with a small-molecule dark quencher, followed by sequential drug encapsulation, MSN capping with a dye-labeled antisense oligonucleotide, and bioorthogonal surface modification with cell-penetrating poly(disulfide)s, the authors have successfully developed the first mesoporous silica nanoquencher (qMSN), characterized by high drug-loading and endocytosis-independent cell uptake, which is able to quantitatively image endogenous survivin mRNA and release the loaded drug in a manner that depends on the survivin expression level in tumor cells. The authors further show that this novel drug delivery system may be used to minimize potential cytotoxicity encountered by many existing small-molecule drugs in cancer therapy.

Cell-Penetrating Poly(disulfide) Assisted Intracellular Delivery of Mesoporous Silica Nanoparticles for Inhibition of miR-21 Function and Detection of Subsequent Therapeutic Effects.

The design of drug delivery systems capable of minimal endolysosomal trapping, controlled drug release, and real-time monitoring of drug effect is highly desirable for personalized medicine. Herein, by using mesoporous silica nanoparticles (MSNs) coated with cell-penetrating poly(disulfide)s and a fluorogenic apoptosis-detecting peptide (DEVD-AAN), we have developed a platform that could be uptaken rapidly by mammalian cells via endocytosis-independent pathways. Subsequent loading of these MSNs with small molecule inhibitors and antisense oligonucleotides resulted in intracellular release of these drugs, leading to combination inhibition of endogenous miR-21 activities which was immediately detectable by the MSN surface-coated peptide using two-photon fluorescence microscopy.

A fluorescent probe for simultaneous discrimination of GSH and Cys/Hcy in human serum samples via distinctly-separated emissions with independent excitations.

Biothiols like Cys, Hcy and GSH play important roles in various physiological and pathological processes, and it is still challenging to simultaneously and discriminatively detect GSH and Cys/Hcy due to their similar structures and reaction activities. Hence, it would be highly desirable to design a fluorescent probe for simultaneously discriminating GSH and Cys/Hcy in biological samples with no spectral crosstalk, few interferences and rapid response. Herein, through coupling two fluorophores with biothiol-sensitive linker, we developed a fluorescent probe, which has two biothiol-responsive and distinctly-separated emissions via independent visible-light excitations, for simultaneously discriminating GSH and Cys/Hcy with near-infrared and green emissions. The probe is operable in human serum samples, thus holding promise for diagnostic-related applications. Moreover, the probe shows quite good properties. First, it exhibits a rapid response (within a few minutes) with highly selective and sensitive detection for GSH and Cys/Hcy. Second, it offers an apparent colorimetric and two fluorescence emission signals without spectral crosstalk. Third, it shows low cytotoxicity. Therefore, it would provide a useful method for further elucidating the roles of biothiols as well as for conducting pathological analysis for diseases involving biothiols.