Search Results (40)

Cytarabine is a cornerstone of acute myeloid leukemia (AML) therapy; however, acquired resistance remains a major clinical challenge. FMS-like tyrosine kinase 3 internal tandem duplication (FLT3-ITD), a common genetic alteration in AML, is associated with high relapse rates and poor outcomes. Here, we investigated the cellular and molecular mechanisms of acquired cytarabine resistance in FLT3-ITD AML. Cytarabine-resistant MV4-11-CR and MOLM-13-CR cells were generated from parental MV4-11 and MOLM-13 cells, respectively, by stepwise drug selection. Both models exhibited markedly elevated cytarabine IC₅₀ values and enhanced proliferation. FLT3 expression and activation increased in MV4-11-CR cells but decreased in MOLM-13-CR cells. Midostaurin pretreatment failed to restore cytarabine sensitivity, indicating that altered FLT3 signaling is not a shared mechanism of resistance. Cytogenetic analyses and interphase FISH revealed greater numerical and structural chromosomal heterogeneity in the resistant cells than in their parental counterparts, including the presence of polyploid and near-tetraploid subpopulations. RNA sequencing identified common transcriptional alterations, with DCK among the most significantly downregulated genes. Reduced DCK expression was confirmed at the mRNA and protein levels. DCK knockdown in parental MV4-11 cells attenuated cytarabine-induced cytotoxicity, whereas its re-expression in MV4-11-CR cells partially restored cytarabine sensitivity, supporting the functional contribution of DCK downregulation to acquired resistance. Gene set enrichment analysis demonstrated shared enrichment of G2/M checkpoint and mitotic spindle pathways. Notably, combined TTK/Mps1 and FLT3 inhibition with luvixasertib and midostaurin synergistically suppressed cell viability in both resistant cell lines. These findings identify divergent FLT3 regulation, DCK downregulation, increased chromosomal heterogeneity, and enrichment of mitotic regulatory programs as key features associated with acquired cytarabine resistance. They also support the combined inhibition of TTK/Mps1 and FLT3 as a potential therapeutic strategy for cytarabine-resistant FLT3-ITD AML. Full article

Mulberry leaves are used as functional food materials, but drought can reduce leaf production and physiological stability. This study evaluated whether foliar sodium selenite application could partially alleviate drought injury while increasing total selenium and selected functional-quality indicators in mulberry (Morus alba L.) leaves. Seedlings were assigned to four treatments: normal water supply with the surfactant-containing control spray (CK), normal water supply with sodium selenite application (Se), drought stress with the control spray (D+CK), and drought stress with sodium selenite application (D+Se). Drought reduced plant growth, leaf water status, leaf pigment status, gas exchange, and PSII photochemical performance while increasing oxidative damage and membrane injury. Under drought stress, sodium selenite application partially maintained growth, water status, photosynthetic performance, and antioxidant enzyme activities and was associated with lower oxidative-damage indicators. Drought alone increased several stress-responsive secondary metabolites but reduced biomass, polysaccharides, and soluble protein, indicating a trade-off rather than a uniform improvement in leaf quality. Compared with D+CK, D+Se increased total selenium, several functional compounds, and in vitro antioxidant capacity. Overall, foliar application of 10 μM sodium selenite was associated with partial drought-stress alleviation and higher functional-quality indicators under controlled pot conditions. Further studies are required to optimize the application dose and evaluate selenium speciation, bioaccessibility, intake safety, and field performance. Full article

Gemcitabine-based chemotherapy has long served as a standard treatment for urothelial carcinoma (UC), particularly in perioperative and metastatic settings. However, therapeutic efficacy is frequently limited by intrinsic or acquired resistance. Gemcitabine functions as a prodrug whose activity depends on coordinated processes involving cellular uptake, intracellular activation, metabolic inactivation, and nucleotide metabolism. Increasing evidence suggests that resistance in UC is mediated by multiple interconnected mechanisms beyond alterations in gemcitabine transport, activation, and inactivation alone. Key molecular determinants include human equilibrative nucleoside transporter 1 (hENT1), deoxycytidine kinase (dCK), cytidine deaminase (CDA), and ribonucleotide reductase regulatory subunit M1 (RRM1), which is involved in nucleotide pool maintenance and DNA synthesis. In addition, replication stress responses, apoptosis evasion pathways, and tumor microenvironment-associated factors also contribute to gemcitabine resistance. Stress-adaptive pathways involving Y-box binding protein 1 (YB-1), hypoxia-inducible factor-1 alpha (HIF-1α), and autophagy-related mechanisms may further promote survival under chemotherapy-induced stress conditions. In addition, extracellular mucin-associated mechanisms may alter intratumoral drug accessibility and contribute to resistance. In this review, we summarize UC-specific evidence regarding gemcitabine resistance and discuss how these pathways collectively shape an integrated resistant phenotype. Full article

Nucleoside analogs (NAs) play a central role in cancer therapy, either through direct cytotoxicity or epigenome reprogramming. They are clinically effective but have shortcomings in their long-term effectiveness because of variable patient responses and the emergence of resistance. There is growing evidence that DNA methylation, histone modifications, chromatin remodeling, and non-coding RNAs (ncRNAs) are key factors that determine sensitivity and resistance to NAs. This review summarizes existing evidence on the epigenetic control of cytotoxic and epigenetic nucleoside analogs, discusses predictive biomarkers of human Equilibrative Nucleoside Transporter 1 (hENT1) and deoxycytidine kinase (dCK) promoter methylation, histone modifications, and ncRNA signatures, and assesses the emerging strategies of multi-omic integration. Improvements in detection methods, such as high-resolution sequencing, single-cell profiling, and liquid biopsy, are addressed, along with the issues of reproducibility, tumor heterogeneity, and clinical translation. Epigenetic biomarkers are promising for patient stratification in clinical trials, although a lack of uniformity in technical and methodological approaches currently constrains their full potential. The future focus will be on standardized panels of biomarkers, real-time monitoring, rational combination strategies, and biomarker-directed clinical trial designs. Overall, epigenetic biomarkers are capable of changing nucleoside analog therapy into a more precise, durable, and personalized treatment approach. Full article

To address the challenges of low land use efficiency, soil degradation, and high management costs in Ilex asprella cultivation, this study established an I. asprella–Grona styracifolia intercropping system and systematically evaluated its effects on soil nutrient cycling, microbial communities, and crop growth. Field experiments were conducted in Yunfu City, Guangdong Province, with monoculture (LCK for I. asprella, DCK for G. styracifolia) and three intercropping densities (HDT, LDT, MDT). Combining 16S rRNA sequencing and metagenomics, we analyzed the functional profile of the rhizosphere microbiome. The results showed that intercropping significantly increased the biomass of G. styracifolia, with the medium-density (MDT) treatment increasing plant length and fresh weight by 41.2% and 2.4 times, respectively, compared to monoculture. However, high-density intercropping suppressed the accumulation of medicinal compounds. In terms of soil properties, intercropping significantly enhanced soil organic carbon (SOC), total nitrogen (TN), total phosphorus (TP), and available nitrogen (AN) in the rhizosphere of both plants. Specifically, AN in the I. asprella rhizosphere increased by 18.9%. Soil urease and acid phosphatase activities were also elevated, while pH decreased. Microbial analysis revealed that intercropping reshaped the rhizosphere microbial community structure, significantly increased the Shannon diversity index of bacteria in the G. styracifolia rhizosphere, and enhanced the complexity of the microbial co-occurrence network. Metagenomic analysis further confirmed that intercropping enriched functional genes related to carbon fixation, nitrogen cycling (nitrogen fixation, assimilatory nitrate reduction), and organic phosphorus mineralization (the phoD gene), thereby driving the transformation and availability of soil nutrients. These findings demonstrate that the I. asprella–G. styracifolia intercropping system, particularly at medium density, effectively improves soil fertility and land use efficiency by regulating rhizosphere microbial functions, providing a theoretical basis for the sustainable ecological cultivation of I. asprella. Full article

Background/Objectives: Triple-negative breast cancer (TNBC) is an aggressive subtype lacking ER, PR, and HER2 expression, with limited targeted therapies and poor outcomes. Epigenetic dysregulation, particularly aberrant DNA methylation, is a key driver. Decitabine, a DNA methyltransferase inhibitor (DNMTi), shows promise by reactivating silenced tumor suppressor genes and modulating immune responses. This systematic review evaluates preclinical and clinical evidence on decitabine’s efficacy, mechanisms, and translational potential in TNBC. Methods: A PRISMA-2020 compliant search of PubMed, EBSCO, Web of Science, and Semantic Scholar was conducted up to April 2025. Included studies assessed decitabine alone or in combination in TNBC preclinical or clinical settings. Risk of bias was assessed using QUIPS and RoB 2.0 tools. Results: Twenty-five studies were included. In vitro, decitabine-induced growth inhibition, apoptosis, and re-expression of silenced genes (such as BRCA1 and CDH1). In vivo, it reduced tumor burden and enhanced anti-tumor immunity through MHC-I, PD-L1, and STING pathway upregulation. Synergy was noted with anti-PD-1, HDAC inhibitors, and chemotherapy. Resistance mechanisms included persistent DNMT activity, low DCK, and miRNA-driven escape (miR-155–TSPAN5). Conclusions: Decitabine demonstrates strong preclinical and early clinical potential in TNBC via epigenetic reprogramming and immune activation. Future strategies should focus on biomarker-based selection and resistance mitigation. Full article

Resistance to cytarabine (Ara-C) remains a major obstacle to the successful treatment of acute myeloid leukemia (AML). Therefore, modulating Ara-C resistance is indispensable for improving clinical outcomes. We previously demonstrated that sodium caseinate (SC), a salt derived from casein, the principal milk protein, inhibits proliferation and modulates the expression of Ara-C resistance-related genes in chemoresistant cells. However, it remains unclear whether the combination of SC with antineoplastic agents enhances apoptosis, modulates chemoresistance-related genes, and prolongs the survival of tumor-bearing mice implanted with chemoresistant cells. Here, we investigated the effects of SC in combination with Ara-C or daunorubicin (DNR) on cell proliferation, apoptosis, the expression of chemoresistance-associated genes, and the survival of tumor-bearing mice. Crystal violet assays, quantitative reverse transcription polymerase chain reaction (qRT-PCR), immunofluorescence, flow cytometry, and Kaplan–Meier survival curves were used to evaluate the effects of combinations in chemoresistant cells. We demonstrate that the IC₂₅ concentration of SC, when combined with antileukemic agents, increases the sensitivity of chemoresistant WEHI-CR50 cells to Ara-C by downregulating SIRT1 and MDR1, upregulating the expression of ENT1 and dCK, enhancing apoptosis, and prolonging the survival of WEHI-CR50 tumor-bearing mice. Our data suggest that SC in combination with antileukemic agents could be an effective adjuvant for Ara-C-resistant AML. Full article

The backbone of therapy for elderly patients with myelodysplastic syndromes and acute myeloid leukemia consists of hypomethylating agents 5-aza-2’-deoxycytidine (DAC) and 5-azacytidine (AZA). However, resistance frequently emerges during treatment. To investigate the mechanisms of resistance, we generated DAC-resistant variants of the acute myeloid leukemia cell lines, MOLM-13 and SKM-1, through their prolonged cultivation in increasing concentrations of DAC. The resistant cell variants, MOLM-13/DAC and SKM-1/DAC, exhibited cross-resistance to cytarabine and gemcitabine, but remained sensitive to AZA. Existing studies have suggested that the loss of deoxycytidine kinase (DCK) may play an important role in DAC resistance. DCK is critical for DAC activation, but the precise mechanisms of its downregulation remain incompletely understood. We identified a novel point mutation (A180P) in DCK, which results in acquired DAC resistance. Although the DCK mRNA was actively transcribed, the mutant protein was not detected in DAC-resistant cells. The transfection of HEK293 cells with the mutant DCK, combined with proteasomal inhibition, revealed rapid proteasomal degradation, establishing a mechanistic link between the A180P mutation and DCK loss, not previously described. This highlights the importance of also evaluating DCK at the protein and/or enzymatic activity levels in patients. The loss of functional DCK impairs the phosphorylation of deoxynucleosides, conferring resistance to DAC, gemcitabine, and cytarabine, but AZA, phosphorylated by uridine–cytidine kinase, remains effective and may represent a therapeutic alternative for patients with acquired DAC resistance. Full article

Background: Several pancreatic adenocarcinoma (PA) biomarkers beyond the traditional carbohydrate antigen (CA)19-9 have been identified but are lacking large-scale prospective validation. This prospective cohort study evaluated the prognostic impact of potential PA biomarkers. Methods: We enrolled 238 of 288 patients with histologically proven PA. We assessed candidate biomarkers, including CA19-9, germline BRCA1/2, and ATM mutations, as well as mutant KRAS circulating tumor DNA (ctDNA) in blood samples. Additionally, we evaluated the expression of SLC29A1 (hENT1), DCK, CES2, and GATA6. We examined the association of candidate biomarkers with progression-free survival (PFS) and overall survival (OS). Results: We analyzed biomarker efficacy in 200 (median age 65 years; 55% male) of the enrolled patients who received chemotherapy. A high mutant KRAS ctDNA concentration (hazard ratio [HR]: 1.508 and 95% confidence interval [CI]: 1.052–2.161 for PFS; HR: 1.796 and 95% CI: 1.203–2.681 for OS) and high CA19-9 level (HR: 1.647 and 95% CI: 1.177–2.306 for PFS; HR: 1.803 and 95% CI: 1.248–2.605 for OS) were associated with poor prognosis. High GATA6 RNA expression was linked to longer PFS (HR: 0.336 and 95% CI: 0.195–0.582) and OS (HR: 0.304 and 95% CI: 0.165–0.560). Conclusions: Plasma mutant KRAS ctDNA concentrations and GATA6 expression could serve as significant prognostic biomarkers in patients with PA, potentially guiding therapeutic decisions and prognostication. Full article

Objective: The poultry industry is significantly impacted by viral infections, particularly Newcastle Disease Virus (NDV), which leads to substantial economic losses. It is essential to comprehend how the sequence of development affects biological pathways and how early exposure to infections might affect immune responses. Methods: This study employed transcriptome analysis to investigate host–pathogen interactions by analyzing gene expression changes in NDV-infected chicken embryos’ lungs. Result: RNA-Seq reads were aligned with the chicken reference genome (Galgal7), revealing 594 differentially expressed genes: 264 upregulated and 330 downregulated. The most overexpressed genes, with logFC between 8.15 and 8.75, included C8A, FGG, PIT54, FETUB, APOC3, and FGA. Notably, downregulated genes included BPIFB3 (−4.46 logFC) and TRIM39.1 (−4.26 logFC). The analysis also identified 29 novel transcripts and 20 lncRNAs that were upregulated. Gene Ontology and KEGG pathways’ analyses revealed significant alterations in gene expression related to immune function, metabolism, cell cycle, nucleic acid processes, and mitochondrial activity due to NDV infection. Key metabolic genes, such as ALDOB (3.27 logFC), PRPS2 (2.66 logFC), and XDH (2.15 logFC), exhibited altered expression patterns, while DCK2 (−1.99 logFC) and TK1 (−2.11 logFC) were also affected. Several immune-related genes showed significant upregulation in infected lung samples, including ALB (6.15 logFC), TLR4 (1.86 logFC), TLR2 (2.79 logFC), and interleukin receptors, such as IL1R2 (3.15 logFC) and IL22RA2 (1.37 logFC). Conversely, genes such as CXCR4 (−1.49 logFC), CXCL14 (−2.57 logFC), GATA3 (−1.51 logFC), and IL17REL (−2.93 logFC) were downregulated. The higher expression of HSP genes underscores their vital role in immune responses. Conclusion: Comprehension of these genes’ interactions is essential for regulating viral replication and immune responses during infections, potentially aiding in the identification of candidate genes for poultry breed improvement amidst NDV challenges. Full article

Background: Acute myeloid leukemia (AML) is a hematological neoplasm of rapid and progressive onset, and is the most common form of leukemia in adults. Chemoresistance to conventional treatments such as cytarabine (Ara-C) and daunorubicin is a main cause of relapse, recurrence, metastasis, and high mortality in AML patients. It is known that sodium caseinate (SC), a salt derived from casein, a milk protein, inhibits growth and induces apoptosis in acute myeloid leukemia cells but not in normal hematopoietic cells. However, it is unknown whether SC retains its antileukemic effect in cytarabine-resistant AML cell lines. Objective: To evaluate the antineoplastic effect of SC in cytarabine-resistant leukemia models. Methods: The SC inhibits the growth and induces apoptosis in parental WEHI-3 AML cells. Here, we generated two cytarabine-resistant sublines, WEHI-CR25 and WEHI-CR50, which exhibit 6- and 16-fold increased resistance to cytarabine, respectively, compared to the parental WEHI-3 cells. Thus, these sublines mimic a chemoresistant model. Results: We demonstrate that WEHI-CR25 and WEHI-CR50 cells retain sensitivity to SC, similar to parental WEHI-3 cells. This sensitivity results in inhibited cell proliferation, induced apoptosis, and increased expression of ENT1 and dCK, molecules involved in the entry and metabolism of Ara-C, while decreasing MDR1 expression. Additionally, we observed that SC prolonged the survival of WEHI-CR50 tumor-bearing mice, despite their resistance to Ara-C. Conclusion: This is the first evidence that SC, a milk protein, may inhibit proliferation and induce apoptosis in cytarabine-resistant cells. Full article

Broad-spectrum antibiotics are frequently used to treat bacteria-induced infections, but the overuse of antibiotics may induce the gut microbiota dysbiosis and disrupt gastrointestinal tract function. Probiotics can be applied to restore disturbed gut microbiota and repair abnormal intestinal metabolism. In the present study, two strains of Enterococcus faecium (named DC-K7 and DC-K9) were isolated and characterized from the fecal samples of infant dogs. The genomic features of E. faecium DC-K7 and DC-K9 were analyzed, the carbohydrate-active enzyme (CAZyme)-encoding genes were predicted, and their abilities to produce short-chain fatty acids (SCFAs) were investigated. The bacteriocin-encoding genes in the genome sequences of E. faecium DC-K7 and DC-K9 were analyzed, and the gene cluster of Enterolysin-A, which encoded a 401-amino-acid peptide, was predicted. Moreover, the modulating effects of E. faecium DC-K7 and DC-K9 on the gut microbiota dysbiosis induced by antibiotics were analyzed. The current results demonstrated that oral administrations of E. faecium DC-K7 and DC-K9 could enhance the relative abundances of beneficial microbes and decrease the relative abundances of harmful microbes. Therefore, the isolated E. faecium DC-K7 and DC-K9 were proven to be able to alter the gut microbiota dysbiosis induced by antibiotic treatment. Full article

Cytarabine (Ara-C) is a synthetic isomer of cytidine that differs from cytidine and deoxycytidine only in the sugar. The use of arabinose instead of deoxyribose hinders the formation of phosphodiester linkages between pentoses, preventing the DNA chain from elongation and interrupting the DNA synthesis. The minor structural alteration (the inversion of hydroxyl at the 2′ positions of the sugar) leads to change of the biological activity from anti-depressant and DNA/RNA block builder to powerful anti-cancer. Our study aimed to determine the molecular nature of this phenomenon. Three ¹H-¹⁴N NMR-NQR experimental techniques, followed by solid-state computational modelling (Quantum Theory of Atoms in Molecules, Reduced Density Gradient and 3D Hirshfeld surfaces), Quantitative Structure–Property Relationships, Spackman’s Hirshfeld surfaces and Molecular Docking were used. Multifaceted analysis—combining experiments, computational modeling and molecular docking—provides deep insight into three-dimensional packing at the atomic and molecular levels, but is challenging. A spectrum with nine lines indicating the existence of three chemically inequivalent nitrogen sites in the Ara-C molecule was recorded, and the lines were assigned to them. The influence of the structural alteration on the NQR parameters was modeled in the solid (GGA/RPBE). For the comprehensive description of the nature of these interactions several factors were considered, including relative reactivity and the involvement of heavy atoms in various non-covalent interactions. The binding modes in the solid state and complex with dCK were investigated using the novel approaches: radial plots, heatmaps and root-mean-square deviation of the binding mode. We identified the intramolecular OH···O hydrogen bond as the key factor responsible for forcing the glycone conformation and strengthening NH···O bonds with Gln97, Asp133 and Ara128, and stacking with Phe137. The titular butterfly effect is associated with both the inversion and the presence of this intramolecular hydrogen bond. Our study elucidates the differences in the binding modes of Ara-C and cytidine, which should guide the design of more potent anti-cancer and anti-viral analogues. Full article

In order to investigate physiological and molecular mechanisms underlying the impacts of organic selenium and nanoselenium on the drought stress of pak choi (Brassica chinensis var. pekinensis. cv. ‘Suzhouqing’), we sprayed 20 mL of 0, 5, 10, 20 mg L⁻¹ concentrations of organic selenium (DCK, DO5, DO10, DO20) and nanoselenium (DN5, DN10, DN20). We measured photosynthetic pigment, antioxidant and nutritional quality, performed transcriptome sequencing of leaves using RNA-seq technology, obtained 297,176,114 clean sequences, and identified differential expressed genes. Organic selenium and nanoselenium increased the photosynthetic capacity by upregulating light-trapping pigment proteins, regulated reactive oxygen species homeostasis by activating the antioxidant system through the upregulation of glutathione S-transferase, and maintained water homeostasis through glutathione oxidase activity, thus enhancing weight. They contributed to the elevated total selenium content by increasing expression levels of ABC transporter, adenylate kinase, and cysteine desulphurase. Additionally, hub genes related to these metabolic pathways were identified using a weighted gene coexpression network analysis. The consistent results with the upregulated genes identified in the Kyoto Encyclopedia of Genes and Genomes pathway confirmed the accuracy and reliability of the transcriptome sequencing data. This study provides scientific reference to further in-depth research on the molecular effect of selenium on crops under drought stress conditions. Full article

The aryl hydrocarbon receptor (AHR) is a transcription factor that is commonly upregulated in pancreatic ductal adenocarcinoma (PDAC). AHR hinders the shuttling of human antigen R (ELAVL1) from the nucleus to the cytoplasm, where it stabilises its target messenger RNAs (mRNAs) and enhances protein expression. Among these target mRNAs are those induced by gemcitabine. Increased AHR expression leads to the sequestration of ELAVL1 in the nucleus, resulting in chemoresistance. This study aimed to investigate the interaction between AHR and ELAVL1 in the pathogenesis of PDAC in vitro. AHR and ELAVL1 genes were silenced by siRNA transfection. The RNA and protein were extracted for quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot (WB) analysis. Direct binding between the ELAVL1 protein and AHR mRNA was examined through immunoprecipitation (IP) assay. Cell viability, clonogenicity, and migration assays were performed. Our study revealed that both AHR and ELAVL1 inter-regulate each other, while also having a role in cell proliferation, migration, and chemoresistance in PDAC cell lines. Notably, both proteins function through distinct mechanisms. The silencing of ELAVL1 disrupts the stability of its target mRNAs, resulting in the decreased expression of numerous cytoprotective proteins. In contrast, the silencing of AHR diminishes cell migration and proliferation and enhances cell sensitivity to gemcitabine through the AHR-ELAVL1-deoxycytidine kinase (DCK) molecular pathway. In conclusion, AHR and ELAVL1 interaction can form a negative feedback loop. By inhibiting AHR expression, PDAC cells become more susceptible to gemcitabine through the ELAVL1-DCK pathway. Full article