Search Results (2,218)

Introduction: Gastrointestinal stromal tumors (GISTs) are primarily driven by mutations in KIT (KIT proto-oncogene receptor tyrosine kinase) or PDGFRA (platelet-derived growth factor receptor alpha), but resistance to tyrosine kinase inhibitors (TKIs) such as imatinib remains a major clinical challenge. Alterations in fibroblast growth factor receptor 2 (FGFR2), although rare, are emerging as important contributors to tumor progression and drug resistance. This review evaluates the molecular mechanisms, expression profiles, detection methods, and therapeutic implications of FGFR2 in GIST. Methods: We searched PubMed, Web of Science, Google Scholar, and ClinicalTrials.gov for studies published between January 2010 and June 2025, using combinations of keywords related to FGFR2, gastrointestinal stromal tumor, resistance mechanisms, gene fusion, amplification, polymorphisms, and targeted therapy. Eligible studies were critically assessed to distinguish GIST-specific data from evidence extrapolated from other cancers. Results:FGFR2 is expressed in multiple normal tissues and at variable levels in mesenchymal-derived tumors, including GIST. Its alterations occur in approximately 1–2% of GIST cases, most commonly as gene fusions (e.g., FGFR2::TACC2, <1%) or amplifications (1–2%); point mutations and clinically significant polymorphisms are extremely rare. These alterations activate the MAPK/ERK and PI3K/AKT pathways, contribute to bypass signaling, and enhance DNA damage repair, thereby promoting TKI resistance. Beyond mutations, mechanisms such as amplification, ligand overexpression, and microenvironmental interactions also play roles. FGFR2 alterations appear mutually exclusive with KIT/PDGFRA mutations but occasional co-occurrence has been reported. Current clinical evidence is largely limited to small cohorts, basket trials, or case reports. Conclusions:FGFR2 is an emerging oncogenic driver and biomarker of resistance in a rare subset of GISTs. Although direct evidence remains limited, particularly regarding DNA repair and polymorphisms, FGFR2-targeted therapies (e.g., erdafitinib, pemigatinib) show potential, especially in combination with TKIs or DNA-damaging agents. Future research should prioritize GIST-specific clinical trials, the development of FGFR2-driven models, and standardized molecular diagnostics to validate FGFR2 as a therapeutic target. Full article

CRISPR (clustered regularly interspaced short palindromic repeats)-Cas (CRISPR-associated protein) nucleases enable precise genome editing, but off-target cleavage remains a critical challenge. Here, we report the development of MAD7_HF, a high-fidelity variant of the MAD7 nuclease engineered through a bacterial screening system leveraging the DNA gyrase-targeting toxic gene ccdB. This system couples survival to efficient on-target cleavage and minimal off-target activity, mimicking the transient action required for high-precision editing. Through iterative selection and sequencing validation, we identified MAD7_HF, harboring three substitutions (R187C, S350T, K1019N) that enhanced discrimination between on- and off-target sites. In Escherichia coli assays, MAD7_HF exhibited a >20-fold reduction in off-target cleavage across multiple mismatch contexts while maintaining on-target efficiency comparable to wild-type MAD7. Structural modeling revealed that these mutations stabilize the guide RNA-DNA hybrid at on-target sites and weaken interactions with mismatched sequences. This work establishes a high-throughput bacterial screening strategy that allows the identification of Cas12a variants with improved specificity at a given target site, providing a useful framework for future efforts to develop precision genome-editing tools. Full article

Objective: The classification of hereditary spastic paraplegia (HSP) is based on genetics, and the number of genetic loci continues to increase with new genetic descriptions. Additionally, the number of new variants in known mutations continues to increase. In this paper, we aim to report our experience with genetically confirmed HSPs. Methods: We retrospectively evaluated 10 consecutive children with genetically confirmed HSPs. Results: In this study, we identified six novel mutations, including spastic paraplegia 11 (SPG11), glucosylceramidase beta 2 (GBA2), chromosome 19 open reading frame 12 (C19orf12), 1 in each of the Cytochrome P450 family 7 subfamily B member 1 (CYP7B1) genes, and two different mutations in the intropomyosin-receptor kinase fused gene (TFG) gene. We also identified different clinical phenotypes associated with known mutations. Conclusions: Heterozygous mutations with GBA2 and SPG11 mutation-related HSP are reported for the first time, expanding the known inheritance patterns. We report a novel homozygous chromosome 19 open reading frame 12 (C19orf12) mutation resulting in iron accumulation in the brain, broadening the genetic variants and clinical findings. We determine the first Turkish patients with carnitine palmitoyltransferase IC (CPT1C) and TFG gene mutation-related pure HSP. A pure form of HSP with two novel TFG gene mutations is also identified for the first time. We report the first Turkish patient with kinase D-interacting substrate of 220 kDa (KIDINS220) gene, broadening the clinical spectrum of KIDINS220 variant-related disorders to encompass certain HSPs. Moreover, a novel variant in the oxysterol7-hydroxylase (CYP7B1) gene is reported, expanding the genetic variants and clinical findings relating to SPG5. Full article

Background and Clinical Significance: In hepatocellular carcinoma (HCC), numerous signaling pathways become aberrantly regulated, resulting in sustained cellular proliferation and enhanced metastatic potential. Tumors that lack PYGO2 may not show the same types of tissue remodeling or regenerative features driven by the Wnt/β-catenin pathway, which could make the tumor behave differently from others that are Wnt-positive. PIK3CA-positive tumors are often associated with worse prognosis due to the aggressive nature of the PI3K/AKT pathway activation. This is linked to higher chances of metastasis, recurrence, and resistance to therapies that do not target this pathway. Case presentation: In this paper we present a rare case of hepatocellular carcinoma with PIK3CA-positive and PYGO2-negative signaling pathways, several key aspects of the tumor’s behavior, prognosis, and treatment options. Although alpha-fetoprotein (AFP) levels were significantly elevated, the CT and MRI examination showed characteristics of malignancy, HCC with secondary hepatic lesions and associated perfusion disturbances. The case particularities and immunohistochemistry features are highlighted in the context of literature review, the PIK3CA mutation suggesting the activation of the PI3K/AKT/mTOR pathway, a critical signaling pathway involved in cell survival, proliferation, and metabolism. Conclusions: Due to the aggressive nature of PIK3CA mutations, close monitoring and consideration of immunotherapy and targeted treatments are of crucial importance. Full article

Candida auris has emerged as a global public health threat due to its high mortality rates, multidrug resistance, and rapid transmission in healthcare settings. This study reports the first documented cases of C. auris candidemia in Portugal, comprising eight isolates from candidemia and colonised patients admitted to a major hospital in northern Portugal in 2023. Whole-genome sequencing (WGS) was performed to determine the phylogenetic relationships of the isolates, which were classified as belonging to Clade I. Genome sequencing also enabled the detection of missense mutations in antifungal resistance genes, which were correlated with antifungal susceptibility profiles determined according to EUCAST (European Committee on Antimicrobial Susceptibility Test) protocols and guidelines. All isolates exhibited resistance to fluconazole and amphotericin B according to the recently established EUCAST epidemiological cut-offs (ECOFFs). Most of the isolates showed a resistant phenotype to anidulafungin and micafungin. All isolates were resistant to caspofungin. Missense mutations identified included Y132F in ERG11, E709D in CDR1, A583S in TAC1b, K52N and E1464K in SNQ2, K74E in CIS2, M192I in ERG4, a novel mutation S237T in CRZ1, and variants in GCN5, a gene involved in chromatin remodelling and stress-response regulation. Identifying known and novel mutations highlights the evolution of antifungal resistance mechanisms in C. auris. These findings underscore the need for further research to understand C. auris resistance pathways and to guide effective clinical management strategies. Full article

Leghemoglobin (LegH), a plant-derived hemoprotein, is engineered for the first time as a standalone biocatalyst for carbene N–H insertion. Through semi-rational design, the K65P mutation in the heme pocket significantly enhances catalytic efficiency. Under mild aqueous conditions (PBS buffer, 25 °C), the K65P variant achieves 92% yield in the model reaction between benzylamine and ethyl α-diazoacetate—surpassing wild-type LegH by >1.6-fold in initial reaction rate. The mutant also exhibits markedly improved thermostability. This work establishes engineered LegH as a high-performance, cofactor-free biocatalyst for C–N bond formation, providing a sustainable platform for synthesizing chiral amine derivatives. The catalytic proficiency and inherent stability of the K65P mutant demonstrate the potential of plant hemoproteins in non-natural carbene transfer reactions without requiring immobilization supports. Full article

To address the challenge of coordinating economic cost control and low-carbon objectives in microgrid scheduling, while overcoming the performance limitations of the traditional Zebra Optimization Algorithm (ZOA) in complex problems, this paper proposes a Synergistic Zebra Optimization Algorithm (SZOA) and integrates it with innovative management concepts to enhance the microgrid scheduling process. The SZOA incorporates three core strategies: a multi-population cooperative search mechanism to strengthen global exploration, a vertical crossover–mutation strategy to meet high-dimensional scheduling requirements, and a leader-guided boundary control strategy to ensure variable feasibility. These strategies not only improve algorithmic performance but also provide technical support for innovative management in microgrid scheduling. Extensive experiments on the CEC2017 (d = 30) and CEC2022 (d = 10, 20) benchmark sets demonstrate that the SZOA achieves higher optimization accuracy and stability compared with those of nine state-of-the-art algorithms, including IAGWO and EWOA. Friedman tests further confirm its superiority, with the best average rankings of 1.20 for CEC2017 and 1.08/1.25 for CEC2022 (d = 10, 20). To validate practical applicability, the SZOA is applied to grid-connected microgrid scheduling, where the system model integrates renewable energy sources such as photovoltaic (PV) generation and wind turbines (WT); controllable sources including fuel cells (FC), microturbines (MT), and gas engines (GS); a battery (BT) storage unit; and the main grid. The optimization problem is formulated as a bi-objective model minimizing both economic costs—including fuel, operation, pollutant treatment, main-grid interactions, and imbalance penalties—and carbon emissions, subject to constraints on generation limits and storage state-of-charge safety ranges. Simulation results based on typical daily data from Guangdong, China, show that the optimized microgrid achieves a minimum operating cost of USD 5165.96, an average cost of USD 6853.07, and a standard deviation of only USD 448.53, consistently outperforming all comparison algorithms across economic indicators. Meanwhile, the SZOA dynamically coordinates power outputs: during the daytime, it maximizes PV utilization (with peak output near 35 kW) and WT contribution (30–40 kW), while reducing reliance on fossil-based units such as FC and MT; at night, BT discharges (−20 to −30 kW) to cover load deficits, thereby lowering fossil fuel consumption and pollutant emissions. Overall, the SZOA effectively realizes the synergy of “economic efficiency and low-carbon operation”, offering a reliable and practical technical solution for innovative management and sustainable operation of microgrid scheduling. Full article

Background: Treatment failure continues to play a role in HIV-related morbidity in Mozambique. Antiretroviral therapy (ART) regimen switches are decided empirically, as HIV genotypic resistance testing (HIV-GT) is unavailable in Mozambique’s public health system. Since 2016, Médecins Sans Frontières (MSF) and I-TECH have provided access to HIV-GT at Alto Maé Health Center, Maputo. We describe the cohort of people with virologic failure (VF) that underwent HIV-GT and analyze dolutegravir (DTG) resistance (R) patterns. Methods: This cross-sectional assessment of routine programmatic data between July 2020 and February 2024 was conducted to guide future program enhancements. People living with HIV (PLWH) receiving ART beyond the first line with confirmed VF were included. Mutations were interpreted according to the Stanford HIVdb algorithm. We applied Bayesian bootstrapping for analysis, and the threshold for significance of effects was defined as a probability of 95%. Results: A total of 106 persons underwent HIV-GT following a structured adherence strategy, 62 (58.5%) of whom were on a DTG-based regimen. Fifty-seven of the 62 samples from persons on a DTG-based regimen were sequenced, and 51 (89.5% [95% CrI: 80.7, 96.2]) had confirmed resistance to DTG; the mean DTG-R score was 70.2 (95% CrI: 62.2, 78). Samples with DTG-R had a median of three INSTI mutations (IQR 1–4). Major DTG-associated mutations were found in 46 out of 57 samples: G118R (n = 28), R263K (n = 15), and Q148RK (n = 7). None of the people on the protease inhibitor regimen had an INSTI mutation. Conclusions: In contexts with limited access to resistance testing, the introduction of algorithms to identify PLWH at risk of developing drug resistance is strongly recommended. The proposed algorithm incorporates adherence reinforcement strategies, as recommended in national policies, followed by a short, supervised antiretroviral therapy (ART) support strategy. This approach has shown a high predictive value for identifying PLWH with resistance mutations to dolutegravir (DTG), thereby allowing the continuation of the effective DTG regimen without unnecessary regimen switches. Full article

Background: Differentiated thyroid cancer (DTC) is commonly treated with radioactive iodine (RAI), but resistance to RAI remains a significant clinical challenge. The molecular mechanisms driving dedifferentiation and RAI refractoriness, particularly in BRAF^V600E-mutated tumors, are not fully understood. Methods: RNA sequencing was conducted on BRAF^V600E-mutated DTC and RAIR-DTC tissue samples to identify differentially expressed genes. Gadd45B was identified as significantly downregulated in RAIR-DTC. Functional studies including overexpression and knockdown experiments were performed in thyroid cancer cell lines and xenograft models. Downstream targets, including MAP3K4 and MYCBP, were evaluated through co-immunoprecipitation, luciferase assays, and Western blot. The therapeutic efficacy of recombinant Gadd45B protein in combination with BRAF^V600E and TERT inhibitors was assessed in patient-derived xenograft (PDX) models. Results: Gadd45B overexpression suppressed MAPK pathway activity by interacting with MAP3K4 and downregulated c-MYC stability through competition with MYCBP. These interactions enhanced the expression of iodine-metabolism genes (NIS, TPO, Tg), increased RAI uptake, and reversed tumor dedifferentiation. In vivo, Gadd45B restoration reduced tumor burden and improved RAI uptake. Combined treatment with Gadd45B protein, PLX4720, and BIBR1532 produced synergistic therapeutic effects in PDX models. Conclusions: Gadd45B plays a pivotal role in regulating the differentiation status and RAI sensitivity of BRAF^V600E-mutated thyroid cancer. These findings identify Gadd45B as a promising therapeutic target for restoring RAI responsiveness in RAIR-DTC patients. Full article

Ovarian cancer (OCa) remains the most lethal gynecologic malignancy in the United States, with low-grade serous and mucinous subtypes frequently driven by KRAS mutations. These mutations activate downstream MAPK and PI3K/AKT signaling pathways, contributing to tumor progression and resistance to therapy. Although the MEK inhibitor trametinib is used to target these pathways, its efficacy is limited in KRAS-mutant OCa due to compensatory activation of the leukemia inhibitory factor (LIF)/LIF receptor (LIFR) axis. In this study, we evaluated the therapeutic potential of combining trametinib with EC359, a selective LIFR inhibitor, in Ras/Raf-driven OCa models. EC359 significantly reduced cell viability, clonogenic survival, and induced cell death via ferroptosis in vitro. Mechanistic studies revealed that EC359 suppressed trametinib-induced activation of LIFR downstream signaling. RNA-seq analysis showed that combination therapy downregulated mitochondrial translation and MYC target genes while upregulating apoptosis-related genes. In vivo, EC359 and trametinib co-treatment significantly reduced tumor growth in xenograft and PDX models without inducing toxicity. Our studies identify LIFR signaling as a critical vulnerability in Ras/Raf-mutant and low grade serous OCa. Further, it provides strong preclinical rationale for EC359 and trametinib combination therapy as a new therapeutic strategy for treating Ras/Raf-driven OCa and low-grade serous OCa. Full article

Inorganic pyrophosphatase (PPase) is an enzyme that catalyzes the hydrolysis of pyrophosphate (PPi) into two phosphates. Ton1914, a thermophilic inorganic pyrophosphatase derived from Thermococcus onnurineus NA1, has good thermal stability and an extremely high optimum temperature and has been shown to reduce pyrophosphate inhibition. In this study, eight sites were selected based on sequence alignment and software calculations, and multiple single mutants were successfully constructed. After saturation and superposition mutations, six superior mutants were obtained. The enzyme activities of E97Y, D101K and L42F were increased 2.57-, 2.47- and 2.15-fold, respectively, while those of L42F/E97Y, L42F/D101K and E97Y/D101K were increased 2.60-, 2.63- and 1.88-fold, respectively, relative to the wild-type enzyme. Compared to Ton1914, all mutants more effectively increased PCR product quantity, reduced the number of qPCR cycles required to reach the threshold, and improved the efficiency of gene amplification. In the UDP-Galactose (UDP-Gal) synthesis reaction, the addition of mutants could further improve yield. When Ton1914 and mutants with the same activity were added, the yield of UDP-Gal was almost identical, effectively reducing the dosage of pyrophosphatase. Overall, the mutants showed greater prospects for industrial application. Full article

Xylanase, an essential enzyme for breaking down xylan, faces limitations in its industrial applications due to the relatively low catalytic activity of the wild type. Directed evolution was used to enhance the catalytic efficiency of xylanase that originated from the Dickeya dadantii DCE-01. A xylanase variant (Xyn-ep) was obtained with improved catalytic activity by random mutant library employing two rounds of error-prone PCR. The results showed that the Xyn-ep demonstrated enzyme activity 1.6 times higher than that of wild-type xylanase. Sequencing analysis pinpointed key mutation sites at S159P, K212N, and N397S, respectively. Homology modeling was used to analyze the location of the mutation sites and to investigate the mechanism of the improved catalytic performance. The mutant Xyn-ep showed improved catalytic performance by error-prone PCR. Additionally, the increased flexibility of the loop of the mutant may contribute to the enhanced activity. These findings indicate that error-prone PCR is an effective method for enhancing enzyme activity and that the mutant Xyn-ep may be a new GH30 xylanase, being a potential candidate for industrial applications such as bast fiber bio-degumming, cotton bio-refinery, paper making, and so on. Full article

Polyamines, particularly spermidine, have emerged as key dietary factors with roles in cellular health, autophagy, and longevity. However, strategies for scalable production of polyamine-rich food ingredients remain limited. Here, we report the development of a high-spermidine-producing Saccharomyces cerevisiae strain, 3L63, obtained via ultraviolet mutagenesis of the K7 strain. This strain exhibited a 5.9-fold increase in the total polyamine content, with spermidine being the most abundant. A scalable fermentation system of up to 10⁴ L was established, yielding a dried yeast product that met food safety criteria. Whole-genome sequencing identified mutations in central metabolic pathways, including ARG3, and functional enrichment analysis suggested broad metabolic rewiring, supporting an enhanced biosynthetic capacity, including polyamines. Free amino acid profiling revealed higher arginine levels in 3L63 than in K7, which is consistent with its role as a polyamine precursor. The 3L63 yeast-derived product was enriched in essential amino acids and polyamines. Functionally, this strain promoted the proliferation of normal and senescent human dermal fibroblasts, and its autophagy-inducing activity exceeded that of equivalent concentrations of pure spermidine, suggesting synergistic effects of yeast-derived bioactive compounds. This study demonstrates a non-genetically modified, high-spermidine yeast strain as a promising functional food ingredient with potential applications in healthy aging. Full article

The Ataxin-2-like (ATXN2L) protein is required to survive embryonic development, as documented in mice with the constitutive absence of the ATXN2L Lsm, LsmAD, and PAM2 domains due to knock-out (KO) of exons 5–8 with a frameshift. Its less abundant paralog, Ataxin-2 (ATXN2), has an extended N-terminus, where a polyglutamine domain is prone to expansions, mediating vulnerability to the polygenic adult motor neuron disease ALS (Amyotrophic Lateral Sclerosis) or causing the monogenic neurodegenerative processes of Spinocerebellar Ataxia Type 2 (SCA2), depending on larger mutation sizes. Here, we elucidated the physiological function of ATXN2L by deleting the LsmAD and PAM2 motifs via loxP-mediated KO of exons 10–17 with a frameshift. Crossing heterozygous floxed mice with constitutive Cre-deleter animals confirmed embryonic lethality among offspring. Crossing with CamK2a-CreERT2 mice and injecting tamoxifen for conditional deletion achieved chimeric ATXN2L absence in CamK2a-positive frontal cortex neurons and reduced spontaneous horizontal movement. Global proteome profiling of frontal cortex homogenate showed ATXN2L levels decreased to 75% and dysregulations enriched in the alternative splicing pathway. Nuclear proteins with Sm domains are critical to performing splicing; therefore, our data suggest that the Like-Sm (Lsm, LsmAD) domains in ATXN2L serve a role in splice regulation, despite their perinuclear location. Full article

Breast cancer is the most common malignancy and leading cause of cancer-related mortality among women worldwide. Oestrogen receptor (ER)-positive disease accounts for the majority of cases, where endocrine and targeted therapies have substantially improved survival. Nevertheless, resistance to therapy remains inevitable, emphasising the need for precision strategies informed by molecular profiling. The molecular landscape of ER-positive breast cancer is increasingly complex, characterised by diverse genomic alterations driving resistance and progression. Advances in next-generation sequencing and circulating tumour DNA (ctDNA) technologies enable the dynamic assessment of tumour heterogeneity and clonal evolution, informing prognostication and guiding biomarker-driven therapy. Uniquely, this review integrates molecular phenotyping with clinical treatment algorithms for advanced ER-positive breast cancer, providing a practical framework to translate genomic insights into patient care. Key genomic alterations and targeted strategies with demonstrated clinical benefit, including oral selective ER degraders (SERDs) and PI3K/AKT/mTOR inhibitors in selected biomarker populations, are highlighted. Emerging targets, such as human epidermal growth factor 2 (HER2) mutations, and the potential of ctDNA monitoring to detect resistance and guide therapeutic escalation are also discussed. Incorporating molecular profiling, as recommended by international guidelines, into routine clinical decision making can personalise therapy and optimise patient outcomes. Addressing real-world challenges, including cost and accessibility, will be critical to achieving equitable implementation of precision oncology for patients with ER-positive breast cancer worldwide. Full article