Triple-negative breast cancer (TNBC) represents a distinctive subtype, characterized by the absence of estrogen receptors, progesterone receptors, and human epidermal growth factor receptor 2 (HER2). Due to its high inter-tumor and intra-tumor heterogeneity, TNBC poses significant chanllenges for personalized diagnosis and treatment. The advant of clustered regular interspaced short palindromic repeats (CRISPR) technology has profoundly enhanced our understanding of the structure and function of the TNBC genome, providing a powerful tool for investigating the occurrence and development of diseases. This review focuses on the application of CRISPR/Cas technology in the personalized diagnosis and treatment of TNBC. We begin by discussing the unique attributes of TNBC and the limitations of current diagnostic and treatment approaches: conventional diagnostic methods provide limited insights into TNBC, while traditional chemotherapy drugs are often associated with low efficacy and severe side effects. The CRISPR/Cas system, which activates Cas enzymes through complementary guide RNAs (gRNAs) to selectively degrade specific nucleic acids, has emerged as a robust tool for TNBC research. This technology enables precise gene editing, allowing for a deeper understanding of TNBC heterogeneity by marking and tracking diverse cell clones. Additionally, CRISPR facilitates high-throughput screening to promptly identify genes involved in TNBC growth, metastasis, and drug resistance, thus revealing new therapeutic targets and strategies. In TNBC diagnostics, CRISPR/Cas was applied to develop molecular diagnostic systems based on Cas9, Cas12, and Cas13, each employing distinct detection principles. These systems can sensitively and specifically detect a variety of TNBC biomarkers, including cell-specific DNA/RNA and circulating tumor DNA (ctDNA). In the realm of precision therapy, CRISPR/Cas has been utilized to identify key genes implicated in TNBC progression and treatment resistance. CRISPR-based screening has uncovered potential therapeutic targets, while its gene-editing capabilities have facilitated the development of combination therapies with traditional chemotherapy drugs, enhancing their efficacy. Despite its promise, the clinical translation of CRISPR/Cas technology remains in its early stages. Several clinical trials are underway to assess its safety and efficacy in the treatment of various genetic diseases and cancers. Challenges such as off-target effects, editing efficiency, and delivery methods remain to be addressed. The integration of CRISPR/Cas with other technologies, such as 3D cell culture systems, human induced pluripotent stem cells (hiPSCs), and artificial intelligence (AI), is expected to further advance precision medicine for TNBC. These technological convergences can offer deeper insights into disease mechanisms and facilitate the development of personalized treatment strategies. In conclusion, the CRISPR/Cas system holds immense potential in the precise diagnosis and treatment of TNBC. As the technology progresses and becomes more costs-effective, its clinical relevance will grow, and the translation of CRISPR/Cas system data into clinical applications will pave the way for optimal diagnosis and treatment strategies for TNBC patients. However, technical hurdles and ethical considerations require ongoing research and regulation to ensure safety and efficacy.

Currently, transcatheter intervention is the preferred treatment for patients with anatomically suitable atrial septal defects. However, the use of nickel-titanium alloy occluders in interventional procedures results in lifelong presence of the implant in the body, leading to complications such as metal allergies and arrhythmias in some patients. To overcome the short-term and long-term complications associated with the presence of metal, and to avoid radiation exposure and metal toxicity, this paper reports a case of successful transcatheter closure of atrial septal defect in a pediatric patient with metal allergies using fully biodegradable occluder under ultrasound guidance, achieving excellent results by interventional therapy.

Objective To reveal the molecular mechanism by which nuclear epidermal growth factor receptor(nEGFR)synergistically regulates the expression of cell migration-inducing protein(CEMIP)by forming a complex with the transcription factor Yin Yang 1(YY1),and to investigate the biological functions of the nEGFR-YY1-CEMIP signaling axis in invasion of hepatocellular carcinoma(HCC).Methods After HCC cells were serum-starved for 24 h,the cells were treated with 100 ng/mL EGF.Thus,the cells were divided into a control group and EGF-treated groups at different time points.Nuclear expression and localization changes of EGFR were detected by Western blotting and immunofluorescence(IF).To investigate the interaction between nEGFR and YY1,their nuclear colocalization and interaction were examined by IF and co-immunoprecipitation(Co-IP),respectively.Transcriptional profiling was performed using RNA sequencing(RNA-seq)to identify differentially expressed genes at the genome-wide level.Combined with Gene Ontology(GO)functional enrichment analysis and transcription factor binding profiles via using the JASPAR database,CEMIP was identified as a candidate target gene.To validate the regulatory mechanism,the following experimental groups were established,Control,EGF,siYY1,and siYY1+EGF.The expression of CEMIP at protein and mRNA levels was detected by Western blotting and RT-qPCR.To elucidate the molecular mechanism of nEGFR/YY1 binding to the CEMIP promoter,the control and EGF-treated groups were established.Chromatin immunoprecipitation followed by quantitative PCR(ChIP-qPCR)was performed to assess the enrichment of nEGFR/YY1 at the CEMIP promoter region.Luciferase reporter assay was conducted following transfection with either wild-type EGFR(EGFR-WT),nuclear localization-deficient mutant(EGFR-dNLS),YY1 overexpression plasmid(YY1-OE),or dominant-negative YY1 mutant(YY1-DN)to evaluate changes in promoter activity.Subsequently,cell migration and invasion capabilities were evaluated using scratch wound healing assay and Transwell assay,while hyaluronic acid(HA)level was quantified by ELISA.The expression of matrix metalloproteinases(MMP2/9)was analyzed via Western blotting to assess the regulatory role of the nEGFR/YY1-CEMIP axis in the migration and invasion of HCC cells.By analyzing the CEMIP expression profiles in HCC patients from National Center for Biotechnology Information(NCBI)public databases,its potential association with tumor metastasis risk was validated.Results Western blotting and IF demonstrated that EGF treatment significantly induced nuclear translocation of EGFR,peaking at 30 min(P<0.001).Co-IP and IF assays indicated both physical interaction and nuclear co-localization between nEGFR and YY1.RNA-seq analysis identified CEMIP as a significantly differentially expressed gene.GO enrichment analysis revealed that CEMIP was significantly enriched in biological processes related to cell invasion promotion.JASPAR prediction identified conserved YY1 potential binding region within the CEMIP promoter region.Western blot and RT-qPCR analyses confirmed that EGF treatment up-regulated CEMIP at both protein and mRNA levels(P<0.05).Notably,YY1 knockdown significantly suppressed CEMIP expression,while exogenous EGF supplementation restored CEMIP level in YY1-deficient cells(P<0.05).ChIP-qPCR analysis demonstrated specific enrichment of the nEGFR/YY1 complex at the CEMIP promoter region,with EGF stimulation significantly enhancing its binding affinity(P<0.001).Luciferase reporter assay confirmed that nEGFR/YY1 robustly enhanced CEMIP promoter activity(P<0.01),while either the EGFR-dNLS or the YY1-DN substantially attenuated this transcriptional activation.Functional phenotyping showed that the nEGFR/YY1-CEMIP axis significantly enhanced the migration and invasion of HCC cells by promoting HA catabolism and up-regulating MMP2/9 expression(P<0.05).Analysis of NCBI datasets revealed that CEMIP expression was significantly up-regulated in HCC tumor tissues than adjacent normal tissues(P<0.001).Moreover,HCC patients with elevated CEMIP expression exhibited higher risk of metastasis(P<0.001).Conclusion nEGFR promotes HCC invasion by forming a transcriptional complex with YY1 to cooperatively activate CEMIP expression.

Objective To reveal the mechanism by which the programmed death-ligand 1(PD-L1)-protein tyrosine phosphatase 1B(PTP1B)-focal adhesion kinase(FAK)signaling axis promotes the progression of hepatocellular carcinoma(HCC)and elucidate its effector functions in HCC.Methods GEPIA database was used to plot a 10-year survival curve for PD-L1 and FAK expression levels in HCC patients.Immunohistochemical(IHC)staining was utilized to analyze the relative expression levels of PD-L1 and FAK phosphorylated at the Y397 site[p-FAK(Y397)]in HCC tissues,and the results were compared to those in the adjacent non-tumor tissues.Subsequently,endogenous PD-L1 expression was detected with Western blotting in HCC cell lines with low(SNU-387)and high(Hep3B)PD-L1 expression levels.After lentivirus-transduced SNU-387PDL1+and Hep3BPDL1-cells were constructed,the effect of high and low expression of PD-L1 on the expression of p-FAK(Y397)with Western blotting.To elucidate the functional mechanism of FAK in HCC,functional rescue experiments were performed by administering a FAK inhibitor to SNU-387PDL1+cells and a FAK activator to Hep3BPDL1-cells,combined with wound healing scratch assay,Transwell invasion assay,EdU proliferation assay,and colony formation assay to evaluate tumor malignant effects.The GENEMANIA database predicted functional interactions between protein tyrosine phosphatase 1B(PTP1B),PD-L1,and FAK.IHC staining was performed to analyze the correlation among PD-L1,PTP1B,and p-FAK(Y397)expression.Co-immunoprecipitation(Co-IP)and indirect immunofluorescence(IF)were applied to validate the interaction between PD-L1 and PTP1B.Western blotting was utilized to confirm the regulatory relationship between PD-L1 and PTP1B.In vitro PTP1B phosphatase activity assay measured the changes in PTP1B activity.Subsequently,Western blotting was used to screen cell lines with high endogenous PTP1B expression(SNU-387)and low endogenous PTP1B expression(Hep3B).Furthermore,Hep3BPTP1B+and SNU-387PTP1B-cell lines were generated,and then p-FAK(Y397)levels were then detected in these modified cell lines,and the aforementioned functional effect assays(migration,invasion,proliferation and colony formation)and rescue experiments were repeated.Furthermore,Western blotting was employed to detect changes in downstream signaling pathways following enhancement or attenuation of p-FAK(Y397)in SNU-387 and Hep3B cells.Results IHC staining revealed a positive correlation between PD-L1 and p-FAK(Y397)expression in HCC tissues(95%CI:1.065～3.801,P<0.01).In SNU-387PDL1+cells,PD-L1 overexpression significantly enhanced phosphorylation at the FAK Y397 site(P<0.01)and increased cell migration,invasion,proliferation,and colony formation capabilities(P<0.01),and these effects could be reversed by FAK inhibitor treatment(P<0.05).Conversely,in Hep3BPDL1-cells,PD-L1 knockdown significantly reduced FAK Y397 phosphorylation(P<0.01)and decreased cell migration,invasion,proliferation,and colony formation abilities(P<0.01),and these effects were restored by FAK activator treatment(P<0.05).IHC staining further showed a negative correlation between PTP1B expression and both PD-L1 and p-FAK(Y397)in HCC tissues(95%CI:1.886～3.514,P<0.05).Co-IP and IF assays confirmed a direct interaction between PD-L1 and PTP1B,with PD-L1 suppressing PTP1B expression level and reducing its activity(P<0.01).In SNU-387PTP1B-cells,PTP1B knockdown significantly increased FAK Y397 phosphorylation(P<0.01)and enhanced cell migration,invasion,proliferation,and colony formation(P<0.01),and these effects were reversed by FAK inhibitor(P<0.05).While in Hep3BPTP1B+cells,PTP1B overexpression significantly decreased FAK Y397 phosphorylation(P<0.01)and reduced cell migration,invasion,proliferation,and colony formation(P<0.01),and those effects were restored by FAK activator treatment(P<0.05).Furthermore,enhanced phosphorylation at the FAK Y397 site in SNU-387 cells activated downstream PI3K/AKT and MEK/ERK signaling pathways(P<0.01),whereas inhibition of FAK(Y397)phosphorylation in Hep3B cells attenuated the activation of these signaling pathways(P<0.01).Conclusion PD-L1 activates FAK by suppressing PTP1B,thereby promoting migration,invasion,and proliferation in HCC.

Objective:To explore the genetic and clinical characteristics of epilepsy related with ATP6V1A gene heterozygous variants.Methods:A case series study was conducted. The clinical data of 10 children of epilepsy associated with ATP6V1A gene variants who were admitted to the Children′s Medical Center, Peking University First Hospital from January 2019 to December 2024 was collected. The characteristics of children′ gene variation, clinical phenotype, auxiliary examination results, treatment and prognosis were analyzed.Results:Among the 10 children, there were 4 boys and 6 girls. All 10 children with ATP6V1A gene variants were de novo heterozygous variants, including 1 case of mosaic variant. A total of 9 different variants were identified and 7 variants have not been reported previously. The age at epilepsy onset was 28 (9, 48) months. Five children experienced their first seizure as a fever induction. The types of epileptic seizures included focal seizures in 6 children, epileptic spasms in 5 children, tonic spasms and atonic seizures in 1 child respectively. Three children had 2 seizure types. Global developmental delays were exhibited in 8 children, 2 of whom manifested autism spectrum disorder phenotypes. Two children showed normal development. Electroencephalography revealed slowed background activity in 5 children. Interictal epileptiform discharges were recorded in 9 cases, including hypsarrhythmia, focal, multifocal or generalized discharges. Clinical seizures were captured in 4 children. Brain magnetic resonance imaging abnormalities were found in 4 children, including frontotemporal cortical dysplasia, prominent sulci, delayed myelination of white matter, dysplasia of the corpus callosum, bilateral ventricular enlargement, and cerebral atrophy. Five children were diagnosed with developmental and epileptic encephalopathy (DEE), and 4 of them were diagnosed with infantile epileptic spasms syndrome. At the last follow-up, the age was 78 (25, 120) months. Seizures were controlled in 6 children, while 4 children had uncontrolled seizures despite treatment with ≥3 anti-seizure medications. Conclusions:All children with ATP6V1A gene related epilepsy harbored de novo heterozygous missense variants, with few showing mosaic variants. Seizure onset age ranged widely from the neonatal period to childhood. The predominant seizure types were focal seizures and epileptic spasms. The phenotypic spectrum may exhibit DEE, while a minority maintain normal development.

Objective:To investigate the characteristics of hand dysfunction and its associated factors in patients with rheumatoid arthritis (RA).Methods:A cross-sectional study. Patients with RA were recruited from January 2019 to April 2024 at the Department of Rheumatology and Immunology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University. Demographic and clinical data were collected, including age, gender, active smoking, disease duration, time of morning stiffness, rheumatoid factor and anti-cyclic citrullinated peptide antibody, disease activity, radiographic indicators, and hand function assessment. Hand function was assessed by grip strength measures and self-reported items related to hand function in the Stanford Health Assessment Questionnaire. Factors related to hand function were analyzed by logistic regression analyses.Results:A total of 1 079 RA patients were recruited [mean age: (53.0±12.6) years]. Overall, 72.6% (783/1 079) patients experienced a decrease in grip strength, 57.2% (617/1 079) patients experienced a decreased grip strength in both hands, with the average grip strength of the left and right hands decreasing by 16.3% and 14.1%, respectively, compared to normal values; 39.9% (430/1 079) patients had self-reported hand dysfunction. There were 185 (17.1%) older RA patients (age ≥65 years). The proportion of older RA patients with decreased grip strength [89.7% (166/185) vs. 69.0% (617/894)] and degree of decrease in grip strength compared to normal values (left hand:-35.3%±30.6% vs. -12.3%±38.6%; right hand:-32.6%±32.3% vs. -10.3%±42.1%) were significantly higher than that in young patients, and the proportion of older patients with self-reported hand dysfunction was also significantly higher [53.0% (98/185) vs. 37.1% (332/894), all P<0.001]. Multivariate logistic regression analysis showed that pain visual analogue scale ( OR=1.375, 95% CI 1.020-1.854) was independently associated with grip strength decrease in older RA patients, while the 28-joint tender joint count ( OR=1.151, 95% CI 1.063-1.246) and provider global assessment of disease activity ( OR=1.381, 95% CI 1.171-1.628) were associated with self-reported hand dysfunction. Conclusions:Hand dysfunction is common in RA patients, especially among older RA patients, which is related to pain, joint tenderness and provider global assessment of disease activity. This result implies the importance of pain management in RA patients.

Objective:To summarize the genotype and clinical phenotype characteristics of children with epilepsy associated with the SCN1B gene encoding the sodium channel β1 subunit. Methods:The genotypes and clinical phenotypes of patients with SCN1B variants among suspected genetic epilepsy cases treated at the Children′s Medical Center of Peking University First Hospital between May 2016 and July 2024 were analyzed. These variants were identified using next-generation sequencing and subsequently validated by Sanger sequencing or quantitative polymerase chain reaction methods. Results:A total of 17 patients were analyzed, including 8 males and 9 females. Ten cases of missense variations (including 2 with the same variations), 4 cases of deletion variations, and 1 case each of nonsense variations, splice site variations, and exons 4-5 deletions were identified. Among them, 6 cases had novel SCN1B variations. The variants in 11 cases were inherited from 1 parent. Eleven types of gene variants have not been reported yet. Onset of epilepsy ranged from 3 months to 5 years and 3 months old (median age: 14 months). Types of seizures included generalized tonic-clonic seizures (GTCS) in 14 cases, focal seizures in 9 cases, myoclonic seizures in 3 cases, atypical absence seizures in 2 cases and epilepsy spasms, tonic seizures and atonic seizures in 1 case each. Eleven cases had diverse seizure types. Fourteen cases (14/17) demonstrated fever sensitivity. Electroencephalography revealed focal discharges in 3 cases, coinciding with focal and generalized discharges in 3 additional cases, and multifocal discharges in 6 cases. Seizures were identified in 4 cases: 1 case of myoclonic seizures, 1 case of GTCS, 1 case of atypical absence seizures, and 1 case exhibiting both myoclonic and tonic seizures. Nine cases (9/17) were diagnosed with genetic epilepsy with febrile seizures plus, 1 case diagnosed with myoclonic epilepsy in infancy and 1 diagnosed with infant epileptic spasms syndrome. There were 2 cases of nonspecific developmental epileptic encephalopathy, while the remaining 4 cases could not be diagnosed with a specific epileptic syndrome. Effective antiseizure medications (ASMs) included valproate in 8 cases, levetiracetam in 5 cases, topiramate in 3 cases, clobazam in 2 cases, clonazepam and vigabatrin in 1 case each. Sodium channel blockers exacerbated seizures in 3 cases, specifically oxcarbazepine in 2 cases and lamotrigine in 1 case. At the last follow-up, seizures were controlled for at least 6 months in 14 patients (14/17), while seizures remained uncontrolled in 3 patients despite trialing 2 or more ASMs. Thirteen patients exhibited normal development, while 4 experienced developmental delays. Conclusions:The heterozygous variants in children with SCN1B gene-related epilepsy include missense, deletion, nonsense, splice site variants, and exon deletions. The correlation between different genetic variants and clinical phenotypes remains unclear. These variants are associated with epilepsy onset from infancy to early childhood, presenting with various seizure types, with GTCS being the most common. Phenotypic manifestations can vary significantly in severity, ranging from benign febrile seizures or febrile seizures plus to developmental epileptic encephalopathy. Valproic acid demonstrates the highest effectiveness rate, while the use of sodium channel blockers may worsen seizures in certain patients, necessitating cautious administration.

Objective:To summarize the clinical phenotype and genetic features of patients with relapsing encephalopathy with cerebellar ataxia (RECA) caused by ATP1A3 gene R756 variants. Methods:A retrospective analysis was performed on patients carrying the ATP1A3 gene R756 variants, identified by whole-exome sequencing of family members, at Capital Center for Children′s Health, Capital Medical University and Children's Medical Center, Peking University First Hospital from August 2005 to February 2024. Their clinical, laboratory, neuroimaging, electrophysiological and genetic characteristics were summarized. Results:A total of 13 RECA patients were enrolled in this study, including 8 males and 5 females. The age of onset was 8 months to 5 years, with a median age of onset of 18 months. All of 13 patients presented paroxysmal episodes of neurological decompensations triggered by fever and residual symptoms following the acute phase. During acute attack stage, ataxia was observed in all 13 cases, muscle weakness in 12 cases, dysarthria in 12 cases, altered consciousness in 10 cases, dysphagia in 10 cases, dystonic episodes in 4 cases, abnormal eye movement in 2 cases, choreoathetosis in 2 cases, and epileptic seizures in 1 case. All 13 patients had residual symptoms during the nonparoxysmal period, of whom 9 patients had ataxia, 9 patients had dysarthria, 4 patients had dystonia, 3 patients had cognitive disorders, and 1 patient had epileptic seizures. All 13 cases had ATP1A3 missense variants, and variant c.2266C>T/p.R756C was found in 6 cases, c.2267G>A/p.R756H in 5 cases, and c.2267G>T/p.R756L in 2 cases. Nine cases carried de novo variants, 4 with inherited variants. Conclusions:RECA caused by variants of ATP1A3 in residue 756 typically presents with an acute onset during infancy or early childhood, precipitated by febrile episodes and characterized by recurrent episodes of ataxia, with bulbar paralysis, muscle weakness and altered consciousness. Recurrence is common, and the most common persistent symptoms are cerebellar ataxia and dysarthria. A few patients have cognitive impairment. Three types of ATP1A3 gene variants R756C, R756H and R756L are related with RECA, and R756C is the most common variant.

ObjectiveTo investigate the mechanism of action of Huangqi Guizhi Wuwutang （HGWT） against cerebral ischemia-reperfusion injury （CIRI） based on bioinformatics and experimental validation. MethodsBiological informatics methods were used to screen for active components of HGWT and their targets. The GEO database was utilized to obtain CIRI-related differentially expressed genes （DEGs）， and platforms such as GeneCards were used to identify disease targets. Venn diagram analysis was conducted to identify overlapping targets， followed by protein-protein interaction （PPI）， gene ontology （GO）， and Kyoto Encyclopedia of Genes and Genomes （KEGG） enrichment analysis， as well as immune infiltration and immune cell differential analysis. Core genes （Hub genes） were screened using LASSO regression and ROC curves， and molecular docking was used to validate the binding efficiency between the active components of the drug and the core targets. A rat CIRI model was established， with rats randomly divided into five groups （n=10）： Sham surgery group （Sham）， model group （MG）， and low-dose （LD，5.3 g·kg^-1）， medium-dose （MD，10.6 g·kg^-1）， and high-dose （HD，21.2 g·kg^-1） HGWT groups. From 3 days before modeling to 7 days after surgery， oral administration was performed daily： Sham and MG groups received physiological saline， while each drug group received the corresponding dose of HGWT. Hematoxylin-eosin （HE） staining， Nissl staining， and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling （TUNEL staining） were used to assess the repair effects of HGWT on neural damage. Western blot analysis was used to detect B-cell lymphoma-2 protein （Bcl-2）， Bcl-2-associated X protein （Bax）， signal transducer and activator of transcription 3 （STAT3）， phosphorylated STAT3 ［p-STAT3 （Tyr705）］， protein kinase B1 （Akt1）， and phosphorylated Akt1 ［p-Akt1 （Ser473）］， among other target proteins. ResultsAfter screening， 56 common target points of DEGs-disease-drug were obtained. GO and KEGG analyses indicated that HGWT primarily functions in pathways such as apoptosis， oxidative stress， and inflammatory responses. Immune infiltration analysis revealed a significant association between HGWT's anti-CIRI activity and immune cells such as Th17 cells and myeloid-derived suppressor cells （MDSCs） （P0.01）. LASSO-ROC analysis identified Akt1， Caspase-3， glycogen synthase kinase-3β （GSK-3β）， and STAT3 as core genes. Molecular docking confirmed that Hub genes exhibit significant binding affinity with the active components of HGWT （binding energy ≤ -5 kJ·mol^-1）（1 cal≈4.186 J）. Animal experiment results showed that compared with the sham group， the MG group exhibited significant neuronal necrosis， nuclear condensation， and vacuolar degeneration in rat brains， with a significant decrease in Nissl body density （P0.01） and increased neuronal apoptosis in rat brains as indicated by TUNEL staining （P0.01）. Compared with the MG， the LD， MD， and HD groups showed reduced neuronal necrosis， nuclear condensation， and vacuolar degeneration in rat brain neurons， increased Nissl body density， and reduced apoptosis （P0.01）， with significant differences among the drug groups （P0.01）. Western blot results showed that compared with the sham group， the MG group had reduced Bcl-2 and p-Akt1 （P0.01） and increased Bax and p-STAT3 （P0.01）. Compared with the MG group， the drug groups showed increased Bcl-2 and p-Akt1 （P0.01） and decreased Bax and p-STAT3 （P0.01）. There were no significant changes in total Akt1 and STAT3 protein levels among the groups. ConclusionBased on network pharmacology and experimental verification， HGWT may exert its neuroprotective effects by regulating the phosphorylation levels of Akt1 and STAT3， thereby alleviating cell apoptosis， inflammatory responses， and oxidative stress in rat brain tissue following CIRI. This provides theoretical support for the clinical treatment of CIRI.

Objective: To establish an ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method based on solid-phase extraction column purification for simultaneous determination of cyromazine and melamine in poultry eggs and meat. Methods: Eggs, quail eggs, and chicken were collected from markets. After homogenization, the sample was extracted with 0.5% formic acid in acetonitrile, subjected to solid-phase extraction using an MCX cartridge, and eluted with 5% ammonia in methanol. The eluate was collected, evaporated to near dryness under nitrogen, and reconstituted in a 10% aqueous methanol solution. Separated using TSK gel Amide-80 column (2.0 mm×150 mm, 5 μm), cyromazine and melamine were simultaneously detected in positive ion multiple reaction monitoring mode via tandem mass spectrometry, with quantification achieved by isotope dilution internal standard methods. Efficiency was enhanced and matrix interference minimized by optimizing conditions such as sample extraction, solid-phase extraction cartridge selection, and instrumental parameters. Calibration curves were constructed, and detection limits, quantification limits, spiked recoveries, and relative standard deviations for (RSD) of cyromazine and melamine were calculated. Results: After method optimization, matrix effects for cyromazine and melamine ranged from 0.97 to 1.04, indicating no significant matrix suppression or enhancement. Both cyromazine and melamine exhibited excellent linearity within the concentration range of 1.0-200.0 ng/mL, with correlation coefficients ≥0.999 5. The limits of detection were 0.3 μg/kg for cyromazine and 0.5 μg/kg for melamine, the quantification limits were 1.0 and 1.5 μg/kg, respectively. At spiked levels of 1.0, 20.0, and 150.0 μg/kg, the average recoveries ranged from 78.6% to 103.1%, with RSD between 3.5% and 6.3%. Among 95 samples tested, cyromazine was detected in 6 samples and melamine in 5 samples; neither cyromazine nor melamine was detected in chicken samples. Conclusion The UPLC-MS/MS method established in this study enables simultaneous detection and accurate quantification of cyromazine and melamine in poultry eggs and meat.