Sensitivity Of Cells Research Articles

Enhancing the radiosensitivity of colorectal cancer cells by reducing spermine synthase through promoting autophagy and DNA damage

BACKGROUND Colorectal cancer (CRC), the third most common cancer worldwide, has increasingly detrimental effects on human health. Radiotherapy resistance diminishes treatment efficacy. Studies suggest that spermine synthase (SMS) may serve as a potential target to enhance the radiosensitivity. AIM To investigate the association between SMS and radiosensitivity in CRC cells, along with a detailed elucidation of the underlying mechanisms. METHODS Western blot was adopted to assess SMS expression in normal colonic epithelial cells and CRC cell lines. HCT116 cells were transfected with control/SMS-specific shRNA or control/pcDNA3.1-SMS plasmids. Assessments included cell viability, colony formation, and apoptosis via MTT assays, colony formation assays, and flow cytometry. Radiosensitivity was studied in SMS-specific shRNA-transfected HCT116 cells post-4 Gy radiation, evaluating cell viability, colony formation, apoptosis, DNA damage (comet assays), autophagy (immunofluorescence), and mammalian target of rapamycin (mTOR) pathway protein expression (western blot). RESULTS Significant up-regulation of SMS expression levels was observed in the CRC cell lines. Upon down-regulation of SMS expression, cellular viability and colony-forming ability were markedly suppressed, concomitant with a notable increase in apoptotic indices. Furthermore, attenuation of SMS expression significantly augmented the sensitivity of HCT116 cells to radiation therapy, evidenced by a pronounced elevation in levels of cellular DNA damage and autophagy. Importantly, down-regulation of SMS corresponded with a marked reduction in the expression levels of proteins associated with the mTOR signaling pathway. CONCLUSION Knocking down SMS attenuates the mTOR signaling pathway, thereby promoting cellular autophagy and DNA damage to enhance the radiosensitivity of CRC cells.

Islet-derived exosomal miR-204 accelerates insulin resistance in skeletal muscle by suppressing sirtuin 1: An in vivo study in a mouse model of high-fat diet-induced obesity.

The interaction between pancreatic islets and skeletal muscle plays a pivotal role in the development of insulin resistance. The present study aimed to elucidate the impact of non-hormonal molecules from islets on the insulin sensitivity of skeletal muscle cells. We developed a mouse model of obesity through a high-fat diet, assessing glucose tolerance and conducting miRNA sequencing on skeletal muscle samples. An in vitro model was established by treating cells with palmitic acid, and exosomes in the supernatant were characterized using scanning electron microscopy and CD63 expression analysis. Intracellular miR-204-5p levels were quantified by RT-PCR. Our in vivo model demonstrated a robust correlation between miR-204-5p level alterations and obesity-induced insulin resistance. Elevated fatty acid levels were observed to increase miR-204-5p in both skeletal muscle and islets. In cellular studies, palmitic acid increased miR-204-5p in MIN-6 islet β-cells but not in C2C12 skeletal muscle cells. Exosomes containing miR-204-5p, secreted by palmitic acid-treated MIN6 cells, were identified through morphological examination, immunoblotting for the exosomal marker CD63, and intraexosomal miR-204-5p level measurement. C2C12 cells were shown to uptake islet-derived miR-204-5p exosomes, as evidenced by the uptake of Exo-Red labeled exosomes. TargetScan analysis identified a highly conserved binding site for miR-204-5p in the 3' UTR of Sirt mRNA. Functional studies indicated that miR-204-5p overexpression reduced glucose consumption and uptake in C2C12 cells, decreased Sirt expression, and impaired insulin signaling, as evidenced by reduced Akt phosphorylation and membrane Glut4 levels. Our findings reveal that miR-204-5p contributes to the development of insulin resistance in obesity and acts as a signaling molecule in the crosstalk between pancreatic islets and skeletal muscle.

Honing CAR T cells to tackle acute myeloid leukemia.

Acute myeloid leukemia (AML) remains a dismal disease with poor prognosis, particularly in the relapsed/refractory (r/r) setting. Chimeric antigen receptor (CAR) therapy has yielded remarkable clinical results in other leukemias and thus has, in principle, the potential to achieve similar outcomes in r/r AML. Re-directing the approved CD19-specific CAR designs against the myeloid antigens CD33, CD123 or CLEC12A has occasionally yielded morphological leukemia-free states (MLFS) but has so far been marred by threatening myeloablation and early relapses. These safety and efficacy limitations owe in large part to the challenge of identifying suitable target antigens and designing adequate receptors for effective recognition and safe elimination of AML. Building on lessons learned from the initial clinical attempts, a new wave of CAR strategies relying on alternative target antigens and innovative CAR designs is about to enter clinical evaluation. Adapted multi-antigen targeting, logic-gating and emerging cell engineering solutions offer new possibilities to better direct T cell specificity and sensitivity towards AML. Pharmacologic modulation and genetic epitope engineering may extend these approaches by augmenting target expression in AML cells or minimizing target expression in normal hematopoietic cells. On/off switches or CAR T cell depletion may curb excessive or deleterious CAR activity. Investigation of AML-intrinsic resistance and leukemic microenvironmental factors is poised to reveal additional targetable AML vulnerabilities. We summarize here the findings, challenges and new developments of CAR therapy for AML. These illustrate the need to specifically adapt CAR strategies to the complex biology of AML to achieve better therapeutic outcomes.

Coptisine enhances the sensitivity of chemoresistant breast cancer cells by inhibiting the function and expression of ABC transporters

BackgroundMultidrug resistance (MDR), mainly caused by ATP-binding cassette transporters (ABCTs) efflux, makes it difficult for many anticancer drugs to treat breast cancer (BC). Phytochemicals can reverse cancer’s MDR by modifying ABC transporter expression and function, as well as working synergistically with anticancer drugs to target other molecules. The reversal effect of the isoquinoline alkaloid coptisine (COP) was assessed on four breast cell lines; Two sensitive MCF-7 cell lines with positive estrogen, androgen, progesterone, and glucocorticoid receptors, as well as MDB-MB-231 cells with negative estrogen, progesterone, and HER2 receptors, and two doxorubicin-resistant cell lines, MCF-7/ADR and MDB-MB-231/ADR.MethodsThe cytotoxicity of COP and its ability to improve doxorubicin (DOX) cytotoxicity were assessed using the MTT assay. The effectiveness of COP in reversing DOX resistance was evaluated by calculating resistance ratio (RR) values, combination index (CI), and isobologram (IB). The inhibitory effect of COP on ABCT efflux function in comparison to verapamil (VER) was evaluated by measuring the cellular accumulation of Rho123 using flow cytometry. The impact of COP, either alone or in combination with DOX, on the gene expression of ABCTs (P-gp/MDR1, BCRP, and MRP1) of investigated cell lines was assessed by RT-PCR.ResultsThe COP showed modest cytotoxicity on the examined cell lines. In MCF-7/ADR and MDA-MB-231/ADR cells, COP (31 μM) enhanced DOX cytotoxicity with CI (0.77 and 0.75), RR (2.58 and 3.33), and IB suggesting synergism. COP significantly inhibits ABCT function in resistant BC cell lines, increases Rho123 accumulation, and decreases efflux more than VER; 2.1 and 1.2-fold, respectively. The combination of COP and DOX had a strong inhibitory effect on ABCT function (3.1 and 3.9 times VER, P< 0.001) and downregulated the genes and protein expression of ABCT.ConclusionCOP reversed ABCT-mediated multidrug resistance in vitro, indicating its potential as a multidrug resistance-reversing agent in cancer chemotherapy.

Carcinoma-Astrocyte Gap Junction Interruption by a Dual-Targeted Biomimetic Liposomal System to Attenuate Chemoresistance and Treat Brain Metastasis.

Brain metastasis contributes substantially to the morbidity and mortality of various malignancies and is characterized by high chemoresistance. Intracellular communication between carcinoma cells and astrocytes through gap junctions, which are assembled mainly by the connexin 43 protein, has been shown to play a vital role in this process. However, effectively blocking the gap junctions between the two cell types remains extremely challenging because of insufficient drug delivery to the target site. Herein, we designed a connexin blocker-carbenoxolone (CBX)-loaded biomimetic liposomal system with artificial liposomes fused with brain metastatic cell and reactive astrocyte membranes (LAsomes) to block gap junctions and attenuate chemoresistance. LAsomes effectively penetrated the blood-brain barrier via semaphorin 4D (SEMA 4D)─Plexin B1 interactions and actively migrated to their source cells via homotypic recognition. Consequently, LAsomes effectively inhibited material transfer and Ca2+ flow from metastatic cells to astrocytes via gap junctions, thereby markedly increasing the sensitivity of metastatic tumor cells to chemotherapy. These results reveal that closing the gap junctions may be a promising therapeutic strategy for intractable brain metastasis.

Metamodel-based Hybrid Parametric Optimization with Static Prototype Validation for a Six-Axle Wheel Load Cell Design

The accurate measurement of forces and torques acting on a vehicle’s chassis, originating from wheel-pavement interactions, is essential for optimizing suspension systems, axles, and other structural components. A critical challenge in optimizing wheel load cell (WLC) design is to enhance sensitivity without compromising mechanical robustness. To address this question, this study developed a six-axis load cell designed to decouple force and torque measurements, achieving high sensitivity and reliability. The objective was to design an optimized WLC for multi-axis force measurement by maximizing sensitivity through a metamodel-based hybrid optimization framework. The methodology began with a fractional factorial Design of Experiments (DOE) to identify key parameters affecting load cell sensitivity and to define the optimization search space. This was followed by a dual-step parametric optimization process, utilizing the finite element method (FEM) to evaluate load cell performance and an inner-point optimization algorithm for convergence. After completing the DOE and FEM stages, the load cell was physically constructed and calibrated using a universal testing machine MTS 810, where experimental data closely matched simulation results, validating the design’s effectiveness. The main findings indicate that the optimized load cell can reliably measure six components, with a sensitivity increase of 14% compared to conventional designs. Numerical results from FEM analyses showed stress levels at 215 MPa, displacements around 0.16 mm, and a first-mode vibration frequency of 1351 Hz, meeting all structural integrity and performance requirements. Calibration confirmed minimal cross-talk effects, supporting the robustness of the final design. The developed load cell met optimal design criteria, showing substantial improvements in sensitivity and accuracy over existing designs, with potential applications in automotive, aerospace, and engineering testing.

Anticancer potential of osthole: targeting gynecological tumors and breast cancer.

Gynecological tumors, such as ovarian, endometrial, and cervical cancers, alongside breast cancer, represent significant malignancies that pose serious threats to women's health worldwide. Standard treatments, including surgery, chemotherapy, radiotherapy, and targeted therapies, are commonly utilized in clinical practice. However, challenges such as high recurrence rates, drug resistance, and adverse side effects underscore the urgent need for more effective therapeutic options. Osthole, a natural coumarin compound derived from Chinese herbal medicine, has demonstrated remarkable antitumor activity against various cancers. Emerging evidence indicates that osthole can inhibit the proliferation, invasion, and metastasis of gynecological and breast cancer cells through various mechanisms, including inducing apoptosis and autophagy, regulating the tumor microenvironment, inhibiting tumor angiogenesis, and enhancing the sensitivity of cancer cells to chemotherapy and radiotherapy. This review highlights the recent advancements in osthole research within the context of gynecological and breast cancers, focusing on its molecular mechanisms, and offers a theoretical foundation for its potential development as an anticancer agent.

Transcription factor PRRX1-activated ANXA6 facilitates EGFR-PKCα complex formation and enhances cisplatin sensitivity in bladder cancer

BackgroundTumor resistance to cisplatin represents a major clinical challenge, particularly in bladder cancer (BC). ANXA6 is a member of annexin family, and its role in cisplatin resistance remains unclear. This study explores ANXA6's role in promoting cisplatin sensitivity. MethodsBioinformatics analyses and clinical specimen verifications assessed the correlation between ANXA6 and cisplatin treatment. A series of assays, including CCK-8, clone formation assay, flow cytometry assays for reactive oxygen species (ROS) and apoptosis, and comet assays, were used to confirm ANXA6's role in enhancing cisplatin sensitivity and re-sensitizing resistant BC cells. Mass spectrometry, immunofluorescence, and co-immunoprecipitation experiments elucidated ANXA6's role in enhancing PKCα/EGFR complex formation and inhibiting the EGFR pathway. ChIP-PCR and dual-luciferase assays determined PRRX1's regulatory role on ANXA6 transcription. Finally, the impact of ANXA6 in vivo was evaluated using xenograft models. ResultsBioinformatics analyses showed a significant correlation between ANXA6 expression and cisplatin sensitivity. In vitro and in vivo experiments confirmed that ANXA6 was a new target for cisplatin treatment. ANXA6 overexpression not only enhanced cell viability inhibition, DNA damage and apoptosis caused by cisplatin, but also re-sensitized cisplatin-resistant cells. Mechanistically, ANXA6 promotes PKCα/EGFR complex formation, inhibiting EGFR phosphorylation and downstream AKT and ERK1/2. Moreover, PRRX1 was identified as a transcription factor promoting ANXA6 expression, thereby augmenting the cytotoxic effects of cisplatin. ConclusionOur study reveals the mechanism by which ANXA6 enhances cisplatin sensitivity and re-sensitizes resistant cells. The roles of PRRX1 and ANXA6 in cisplatin resistance offer new therapeutic targets to overcome cisplatin resistance in clinical practice.

CEA-Induced PI3K/AKT Pathway Activation through the Binding of CEA to KRT1 Contributes to Oxaliplatin Resistance in Gastric Cancer

BackgroundThe serum level of carcinoembryonic antigen (CEA) has prognostic value in patients with gastric cancer (GC) receiving oxaliplatin-based chemotherapy. As the molecular functions of CEA are increasingly uncovered, its role in regulating oxaliplatin resistance in GC attracts attention. MethodsThe survival analysis adopted the KaplanMeier method. Effects of CEA on proliferative capacity were investigated using CCK8, colony formation, and xenograft assays. Oxaliplatin sensitivity was identified through IC50 detection, apoptosis analysis, comet assay, organoid culture model, and xenograft assay. Multi-omics approaches were utilized to explore CEA’s downstream effects. The binding of CEA to KRT1 was confirmed through proteomic analysis and Co-IP, GST pull-down, and immunofluorescence colocalization assays. Furthermore, small molecule inhibitors were identified using virtual screening and surface plasmon resonance. ResultsStarting from clinical data, we confirmed that CEA demonstrated superior ability to predict the prognosis of patients with GC who received oxaliplatin-based chemotherapy, particularly in predicting recurrence-free survival based on serum CEA level. In vitro and in vivo experiments revealed CEAhigh GC cells presented increased proliferative capacity and decreased oxaliplatin sensitivity. The resistance phenotype was transmitted through secreted CEA. Multi-omics analysis revealed that CEA activated the PI3K/AKT pathway by binding to KRT1, leading to oxaliplatin resistance. Finally, the small molecule inhibitor evacetrapib, which competitively inhibits the CEA-KRT1 interaction, was identified and validated in vitro. ConclusionsIn summary, the CEA-KRT1-PI3K/AKT axis regulates oxaliplatin sensitivity in GC cells. Treatment with small molecule inhibitors such as evacetrapib to inhibit this interaction constitutes a novel therapeutic strategy.

Purification, characterization, and hypoglycemic activity of exopolysaccharides from Lactiplantibacillus plantarum MY04

As natural polymers, Lactiplantibacillus plantarum exopolysaccharides (EPS) possess a wide range of bioactivities but suffer from low yields and unclear relationships between functional activity and structure. To this end, the chemical structure and bioactive properties of EPS from Lactiplantibacillus plantarum MY04 were investigated. As a result, three polysaccharide fractions (EPS-1, EPS-2, EPS-3) were separated and purified, of which EPS-2 had better antioxidant activity and α-glucosidase inhibitory ability. More importantly, EPS-2 can significantly enhance insulin sensitivity in HepG2 cells by upregulating enzyme activities in the glycolytic pathway and mitigating oxidative stress-induced damage. In addition, the structural characterization of EPS-2 was also comprehensively elucidated. It was found that EPS-2 was mainly composed of mannose with a molecular weight of 2.3 × 106 Da, and its main chain structure is →3)-Manp-(1 → 2)-Manp-(1 → 2,6)-Manp-(1 → 2,6)-Manp-(1→, providing a theoretical basis for understanding the relationship between structure and function of polysaccharides.

Whole mount preparation and analysis of rabbit mammary gland

The mammary gland undergoes dynamic structural and compositional changes throughout life, influenced significantly by hormonal fluctuations and environmental factors. From embryonic development through menopause, this tissue adapts to accommodate phases such as postnatal expansion, pregnancy-induced lactation, and post-weaning involution. Hormones, growth factors, cytokines, and exogenous factors regulate these innate processes, affecting mammary epithelial cell proliferation and sensitivity, particularly in terminal end buds (TEB) and lobules, which are highly susceptible to endocrine disruption. Rodent models have provided invaluable insights into mammary gland biology, yet differences exist compared to human development, prompting the exploration of alternative models like rabbits. Additionally, there is momentum to move away from the use of nonhuman primates in safety assessments, increasing the need for evaluation tools for all tissues in the rabbit model. Rabbit mammary glands exhibit similarities to humans, making them promising for studying breast biology and pathology. However, protocols for whole-mount analysis of rabbit mammary glands are lacking due to the technical challenges of working with thicker tissue than rodent mammary glands. Here, we developed a methodology modified from rodent studies for preparing and analyzing rabbit mammary gland whole mounts, which is essential for advancing research in mammary gland biology and understanding the effects of hormonal and toxicant-induced disruption of mammary gland growth and function.

Fifty-hertz magnetic fields induce DNA damage through activating mPTP associated mitochondrial permeability transition in senescent human fetal lung fibroblasts

With the rapid development and using of electromagnetic technology, artificial electromagnetic fields (EMFs) have become an emerging environmental factor in our daily life. Extremely-low-frequency (ELF) magnetic fields (MFs), generally generated by power lines and various electric equipment, is one of the most common EMFs in the environment which were concerned for the potential impact on human health. Base on limited evidence, ELF-MFs have been classified as possible carcinogen to human by International Agency for Research on Cancer (IARC), but the mechanisms have not been fully elucidated. Senescent cells are a group of special cells, characterized by cell cycle arrest, senescence-associated secretory phenotype (SASP), accumulation of macromolecular damage, and metabolic disturbance, play important role in fetal development, tissue aging, and even carcinogenesis. Thus, EMFs may promote carcinogenesis by affecting senescent cells, however, there are few studies. In this study, we found that exposure to 50 Hz MFs at 1.0 mT for 24 h could induce significant DNA damage in senescent but not non-senescent human fetal lung fibroblast suggested that senescent cells are more sensitive to 50 Hz MFs on DNA damage, and further results revealed that reactive oxygen species (ROS) generation mediated by mitochondrial permeability transition pore (mPTP) activation play critical role in this process. Our results indicated that cellular senescence can lead to cell sensitivity to the DNA damage effect of 50 Hz MFs, however, whether this play important role in mediating the carcinogenesis of EMFs await further study.

The Utilization of Anthocyanin Extract from Parijoto (Medinilla speciosa) as a Sensitizer in Dye-Sensitized Solar Cells (DSSC)

The Utilization of Anthocyanin Extract from Parijoto (Medinilla speciosa) as a Sensitizer in Dye-Sensitized Solar Cells (DSSC)

Unveiling the degradation mechanisms in silicon heterojunction solar cells under accelerated damp-heat testing

Silicon heterojunction (SHJ) solar cells have become one of the mainstream solar cells in the current photovoltaic market due to their high efficiency. Still, concerns about their long-term reliability are seen as a potential issue restricting further marketisation. In particular, the sensitivity of silicon heterojunction solar cells to high temperatures and moisture is a concern. Sodium (Na) in combination with humidity is widely considered one of the causes of degradation in silicon heterojunction solar cells. Yet, a comprehensive understanding of the mechanisms behind Na-induced decay remains lacking. This study will investigate humidity-induced degradation of industrial SHJ solar cells at elevated temperatures using various sodium-containing salts [sodium bicarbonate (NaHCO3), sodium chloride (NaCl), and sodium nitrate (NaNO3)] to improve our fundamental understanding of Na-induced degradation. We will show that SHJ solar cells exposed to NaHCO3 and NaCl show a significant reduction in efficiency, while solar cells exposed to NaNO3 show minimal degradation. Further analysis indicates that NaHCO3 may interact with the transparent conductive oxide (TCO) layer, leading to a reduction in surface passivation and a deterioration of the metal-TCO interface. NaCl primarily affects the Ag contact, resulting in a reduction of the adhesion of the screen-printed contact. Moreover, the TCO composition, particularly the oxygen content, influences its chemical tolerance. These results show that Na-related degradation is more complicated than initially thought. The chemistry is strongly influenced by the negative ions, as well as the composition of TCO and metal paste. These factors are determined by the bill of materials and the contaminants introduced during cell/module fabrication and operation of the SHJ module. The findings of this paper may lead to the development of new accelerated testing protocols for SHJ technology to ascertain long-term reliability in the field.

A mathematical framework for comparison of intermittent versus continuous adaptive chemotherapy dosing in cancer

Chemotherapy resistance in cancer remains a barrier to curative therapy in advanced disease. Dosing of chemotherapy is often chosen based on the maximum tolerated dosing principle; drugs that are more toxic to normal tissue are typically given in on-off cycles, whereas those with little toxicity are dosed daily. When intratumoral cell-cell competition between sensitive and resistant cells drives chemotherapy resistance development, it has been proposed that adaptive chemotherapy dosing regimens, whereby a drug is given intermittently at a fixed-dose or continuously at a variable dose based on tumor size, may lengthen progression-free survival over traditional dosing. Indeed, in mathematical models using modified Lotka-Volterra systems to study dose timing, rapid competitive release of the resistant population and tumor outgrowth is apparent when cytotoxic chemotherapy is maximally dosed. This effect is ameliorated with continuous (dose modulation) or intermittent (dose skipping) adaptive therapy in mathematical models and experimentally, however, direct comparison between these two modalities has been limited. Here, we develop a mathematical framework to formally analyze intermittent adaptive therapy in the context of bang-bang control theory. We prove that continuous adaptive therapy is superior to intermittent adaptive therapy in its robustness to uncertainty in initial conditions, time to disease progression, and cumulative toxicity. We additionally show that under certain conditions, resistant population extinction is possible under adaptive therapy or fixed-dose continuous therapy. Here, continuous fixed-dose therapy is more robust to uncertainty in initial conditions than adaptive therapy, suggesting an advantage of traditional dosing paradigms.

The oncogenic role and prognostic value of PXDN in human stomach adenocarcinoma

Stomach adenocarcinoma (STAD) is known for its high prevalence and poor prognosis, which underscores the need for novel therapeutic targets. Peroxidasin (PXDN), an enzyme with peroxidase activity, has been linked to cancer development in previous studies. However, its specific role in STAD is not well understood. In our study, we used public databases and clinical specimens to determine that PXDN expression is significantly elevated in STAD tissues and serves as an independent prognostic marker for patient outcomes. Our in vitro assays demonstrated that silencing PXDN significantly reduced STAD cell proliferation, invasion, and migration. Mechanistically, we found that PXDN promotes epithelial‒mesenchymal transition and angiogenesis in STAD cells and may be regulated by the PI3K/AKT pathway. Further analysis revealed that PXDN levels affect the sensitivity of STAD cells to various chemotherapeutic and small molecule drugs. Additionally, we observed a significant association between PXDN levels and the abundances of various immune cell types in patients with STAD. Our study highlighted a strong link between PXDN levels and the tumor immune microenvironment (TIM), suggesting that PXDN is a useful metric for evaluating the response to immune checkpoint inhibitors. Moreover, we found that PXDN is significantly associated with multiple immune checkpoints. In summary, our findings indicate that PXDN plays a critical role in STAD and that its level could serve as a potential prognostic biomarker. Thus, targeting PXDN may represent an effective treatment strategy for STAD.

Cerebral organoid research for pediatric patients with neurological disorders.

Cerebral organoids derived from human induced pluripotent stem cells offer a groundbreaking foundation for the analysis of pediatric neurological diseases. Unlike organoids from other somatic systems, cerebral organoids present unique challenges, such as the high sensitivity of neuronal cells to environmental conditions and the complexity of replicating brain-specific architectures. Cerebral organoids replicate the human brain development and pathology, enabling research on conditions such as microcephaly, Rett syndrome, autism spectrum disorders, and brain tumors. This review explores the utility of cerebral organoids for modeling diseases and testing therapeutic interventions. Despite current limitations such as variability and lack of vascularization, recent technological advancements have improved the reliability and application of such interventions. Cerebral organoids provide valuable insight into the mechanisms underlying complex neural disorders and hold promise as novel treatment strategies for pediatric neurological diseases.

Electrochemical Biosensor for the Assessment of Cell Viability Using Methylene Blue. Application to the Detection of Ciguatoxins in Fish from the Canary Islands.

Cell-based biosensors (CBBs) for the detection of marine neurotoxins such as ciguatoxins (CTXs) are of high interest due to the composite toxicological response they can provide and the low limits of quantification (LOQs) they can achieve with the use of sensitive neural cells. However, the development and validation of CBBs are challenging due to the use of living material and the need for appropriate signal transduction strategies. In this work, Neuro-2a cells have been immobilized on thin-film gold electrodes, and their viability after exposure to CTX1B has been evaluated with light optical microscopy as well as cyclic voltammetry (CV) and differential pulse voltammetry (DPV) using methylene blue (MB) as a redox indicator. An LOQ of 0.93 pg CTX1B/mL has been obtained. The CBB has been applied to the analysis of fish samples from the Canary Islands, one of them implicated in a ciguatera poisoning (CP) outbreak, and results have been compared with those obtained with a conventional cell-based assay (CBA), showing a very good agreement. The combination of the benefits of cells with those provided by biosensor platforms in terms of ease of use, miniaturization, automatization, and portability could result in the ideal analytical tool for CP management. Additionally, this is the first time MB is used as a cell viability indicator in a CBB, providing a new versatile approach for multiple applications.

Discovery, Validation and Mechanistic Study of XPO1 Inhibition in the Treatment of Triple-Negative Breast Cancer

Background/Objectives: Triple-negative breast cancer (TNBC) is an aggressive form of breast cancer with limited treatment options. The nuclear export protein XPO1 has emerged as a potential therapeutic target in cancer, but its role in TNBC has not been fully characterized. This study investigates the potential of repurposing selinexor, an FDA-approved XPO1 inhibitor, as a novel therapeutic options for TNBC. Methods: A computational drug repurposing pipeline was used to predict patient tumor responses to hundreds of drugs. We identified XPO1 inhibitors as a candidate drug and validated its efficacy on an independent patient dataset and across various TNBC cell lines. RNA-sequencing after longitudinal XPO1 inhibition and further mechanistic studies were performed to explore and confirm the leading causes of TNBC cell sensitivity to XPO1 inhibition. Results: Selinexor significantly reduce the viability of a variety of TNBC cell lines. Mechanistically, selinexor induces TNBC cell death by inhibiting the NF-kB pathway through nuclear retention of NFKBIA. This effect was consistent across multiple TNBC cell lines. Conclusions: XPO1 inhibitors show promise as targeted therapies for TNBC patients. New mechanistic insight into the causes leading to TNBC sensitivity to XPO1-inhibition-mediated cell death warrant further clinical trials to evaluate the safety and efficacy in TNBC.

Targeting STK26 and ATG4B: miR-22-3p as a modulator of autophagy and tumor progression in HCC

Drug-induced protective autophagy significantly affects the efficacy of anticancer therapies. Enhancing tumor cell sensitivity to treatment by inhibiting autophagy is essential for effective cancer therapy. Our study, analyzing data from The Cancer Genome Atlas (TCGA) public database, HCC cell lines, and liver cancer tissue samples, found that miR-22-3p is expressed at low levels in HCC and is significantly associated with clinicopathological features and patient prognosis. Functional assays and xenograft models demonstrated that miR-22-3p suppresses HCC progression. Moreover, Western blot analysis and the LC3B double reporter (mRFP1-EGFP-LC3B) confirmed that miR-22-3p inhibits autophagy in HCC cells. Further investigation identified Sterile 20-like kinase 26 (STK26) and Autophagy Related 4B Cysteine Peptidase (ATG4B) as targets of miR-22-3p. STK26, which is overexpressed in HCC, promotes malignant characteristics such as proliferation, migration, and invasion. Additionally, STK26 facilitates autophagy in HCC by phosphorylating ATG4B at serine 383. miR-22-3p inhibits autophagy by targeting STK26 and ATG4B, thus preventing the phosphorylation of ATG4B at serine 383. Sorafenib treatment increases the levels and phosphorylation of STK26 and ATG4B, inducing protective autophagy. The combination of miR-22-3p with sorafenib demonstrated enhanced antitumor effects both in vitro and in vivo. In conclusion, our findings suggest that miR-22-3p inhibits HCC progression by regulating the expression of STK26 and ATG4B, potentially through autophagy inhibition, thereby increasing sensitivity to sorafenib treatment. This offers a new therapeutic approach for effective HCC