AIM:To explore the methylation status of MSH6 in retinoblastoma(RB)and its impact on clinicopathological features and diagnosis.METHODS:Differentially expressed genes were identified through bioinformatics screening o...AIM:To explore the methylation status of MSH6 in retinoblastoma(RB)and its impact on clinicopathological features and diagnosis.METHODS:Differentially expressed genes were identified through bioinformatics screening of the GSE24673 and GSE125903 datasets,combined with GeneCards database analysis.A total of 102 RB patients and 62 traumaenucleated controls between January 2018 and December 2023 were enrolled,with their clinicopathological data and retinal tissues collected.The mRNA and methylation levels of MSH6 in retinal tissues were detected using real-time quantitative polymerase chain reaction(PCR)and methylation-specific PCR.Western blot analysis was conducted in one pair of RB and control tissues for preliminary protein-level validation of MSH6 expression.Based on the methylation status of MSH6,RB patients were categorized into two groups:low-methylation and highmethylation.Both univariate and multivariate analyses were conducted to identify independent factors influencing the methylation levels using clinicopathological data.Receiver operating characteristic(ROC)curves were applied to evaluate the diagnostic potential of MSH6 methylation in RB.RESULTS:Bioinformatics analysis of public datasets revealed that MSH6 expression was downregulated across multiple cancers,RB.Consistently,in clinical RB tissues,MSH6 mRNA expression was significantly lower than that in control retinal tissues,whereas the promoter methylation level of MSH6 was markedly higher(both P<0.001),indicating that promoter hypermethylation may contribute to transcriptional silencing of MSH6 in RB.Patients with higher MSH6 methylation levels showed more advanced pathological classification and a higher frequency of metastasis.Multivariate logistic regression confirmed that metastatic status(P=0.008,OR=3.51)and pathological classification(P=0.005,OR=3.7)were independent factors associated with MSH6 methylation.Receiver operating characteristic(ROC)analysis demonstrated that MSH6 methylation could effectively distinguish RB tissues from non-tumorous controls(AUC=0.847,sensitivity=78.43%,specificity=80.65%),suggesting that MSH6 hypermethylation may serve as a potential diagnostic biomarker for RB.CONCLUSION:The methylation level of the MSH6 gene may be a key factor in RB pathogenesis.The methylation status of the MSH6 gene is closely associated with clinicopathological features and shows diagnostic potential.展开更多
Background:Constitutional mismatch repair deficiency(CMMRD)is a rare disorder resulting from biallelic germline pathogenic variants in mismatch repair genes.This study described the molecular profile of two metachrono...Background:Constitutional mismatch repair deficiency(CMMRD)is a rare disorder resulting from biallelic germline pathogenic variants in mismatch repair genes.This study described the molecular profile of two metachronous brain tumors and a patient-derived xenograft(PDX)from a Brazilian child with CMMRD.Methods:After PDX development,methylation array,whole exome sequencing,and Nano String techniques were applied to describe the genetic landscape of CMMRD.Results:A 6½-year-old girl was diagnosed with Sonic Hedgehog(SHH)-activated medulloblastoma and somatic TP53-mutant.After surgery and radiochemotherapy,she remained free of disease progression.At 10 years and 3 months,she developed a diffuse pediatric-type high-grade glioma(dp HGG).The child had a family history of cancer,and subsequent investigation revealed a biallelic germline variant on MSH6(c.3556+1G>A)with the absence of protein expression in both normal and tumor tissue.A PDX model of the dp HGG was developed.The methylation profile confirmed the diagnosis of both brain tumors and PDX,refining the classification of dp HGG,Rtk1 subtype,subclass A,with an actionable alteration on Platelet-derived growth factor receptor A(PDGFRA).Exome analysis showed high tumor mutational burden,with 3019,540,and 1049 pathogenic variants in the medulloblastoma,dp HGG,and PDX,respectively.Only the medulloblastoma exhibited microsatellite instability.The CD24,CD47,and CD276 immune checkpoints had elevated messenger RNA levels,yet no programmed death ligand 1 expression was observed in CMMRD-derived tumors.Conclusion:We report an extensive molecular profile of a CMMRD patient,and the developed PDX model can be applied to explore new therapeutic approaches for CMMRD-associated brain tumors.展开更多
黑色素合成受多种基因和miRNAs的调控,为了研究miR-186-5p与α-MSH协同作用对绵羊黑素细胞黑色素生成的影响。本研究在绵羊黑素细胞中转染miR-186-5p表达载体,同时添加α-MSH,通过实时荧光PCR (quantitative real time polymerase chain...黑色素合成受多种基因和miRNAs的调控,为了研究miR-186-5p与α-MSH协同作用对绵羊黑素细胞黑色素生成的影响。本研究在绵羊黑素细胞中转染miR-186-5p表达载体,同时添加α-MSH,通过实时荧光PCR (quantitative real time polymerase chain reaction, qRT-PCR)和蛋白质免疫印迹(Western blotting)检测MITF、TYR、TYRP1和TYRP2 4种可能与之相关的基因表达情况;利用免疫组化检测MITF蛋白在黑素细胞中的表达和亚细胞定位;通过分光光度法测定黑色素含量变化;利用划痕试验测定细胞迁移情况,试验分为miR-186-5p转染组、miR-186-5p+α-MSH互作组和对照组,每组3个重复。结果显示,miR-186-5p能够抑制绵羊黑素细胞中MITF、TYR、TYRP1和TYRP2的表达,并最终抑制黑色素的生成。而添加α-MSH能缓解miR-186-5p对MITF、TYR、TYRP1和TYRP2表达的抑制作用,进而在一定程度上恢复黑色素的含量。另外,miR-186-5p还能抑制细胞分裂,并阻碍细胞的迁移,而α-MSH无法抵消miR-186-5p产生的这种负面影响。上述结果表明,在绵羊黑素细胞中,miR-186-5p和α-MSH均参与调控黑色素合成途径,其中,miR-186-5p主要起负调控作用,而α-MSH主要参与相关位点的正调控,并能部分恢复miR-186-5p导致的黑色素含量下降。值得注意的是,miR-186-5p还参与调控细胞的增殖和迁移,而α-MSH不参与相关调控。展开更多
文摘AIM:To explore the methylation status of MSH6 in retinoblastoma(RB)and its impact on clinicopathological features and diagnosis.METHODS:Differentially expressed genes were identified through bioinformatics screening of the GSE24673 and GSE125903 datasets,combined with GeneCards database analysis.A total of 102 RB patients and 62 traumaenucleated controls between January 2018 and December 2023 were enrolled,with their clinicopathological data and retinal tissues collected.The mRNA and methylation levels of MSH6 in retinal tissues were detected using real-time quantitative polymerase chain reaction(PCR)and methylation-specific PCR.Western blot analysis was conducted in one pair of RB and control tissues for preliminary protein-level validation of MSH6 expression.Based on the methylation status of MSH6,RB patients were categorized into two groups:low-methylation and highmethylation.Both univariate and multivariate analyses were conducted to identify independent factors influencing the methylation levels using clinicopathological data.Receiver operating characteristic(ROC)curves were applied to evaluate the diagnostic potential of MSH6 methylation in RB.RESULTS:Bioinformatics analysis of public datasets revealed that MSH6 expression was downregulated across multiple cancers,RB.Consistently,in clinical RB tissues,MSH6 mRNA expression was significantly lower than that in control retinal tissues,whereas the promoter methylation level of MSH6 was markedly higher(both P<0.001),indicating that promoter hypermethylation may contribute to transcriptional silencing of MSH6 in RB.Patients with higher MSH6 methylation levels showed more advanced pathological classification and a higher frequency of metastasis.Multivariate logistic regression confirmed that metastatic status(P=0.008,OR=3.51)and pathological classification(P=0.005,OR=3.7)were independent factors associated with MSH6 methylation.Receiver operating characteristic(ROC)analysis demonstrated that MSH6 methylation could effectively distinguish RB tissues from non-tumorous controls(AUC=0.847,sensitivity=78.43%,specificity=80.65%),suggesting that MSH6 hypermethylation may serve as a potential diagnostic biomarker for RB.CONCLUSION:The methylation level of the MSH6 gene may be a key factor in RB pathogenesis.The methylation status of the MSH6 gene is closely associated with clinicopathological features and shows diagnostic potential.
基金Brazilian National Program of Genomics and Precision Health-Genomas Brasil,Grant/Award Number:MS-SECTICS-Decit/CNPq 16/2023São Paulo Research Foundation,Grant/Award Number:FAPESP-2021/07957-5+5 种基金Barretos Cancer Hospital,Grant/Award Number:13/2021National Oncology Care Support Program (PRONON),CNPq,Grant/Award Number:444217/2023-1Public Ministry of Labor Campinas (Research, Prevention, and Education of Occupational Cancer)Brazilian Ministry of Health (MoH)National Council for Scientific and Technological DevelopmentCNPq Productivity
文摘Background:Constitutional mismatch repair deficiency(CMMRD)is a rare disorder resulting from biallelic germline pathogenic variants in mismatch repair genes.This study described the molecular profile of two metachronous brain tumors and a patient-derived xenograft(PDX)from a Brazilian child with CMMRD.Methods:After PDX development,methylation array,whole exome sequencing,and Nano String techniques were applied to describe the genetic landscape of CMMRD.Results:A 6½-year-old girl was diagnosed with Sonic Hedgehog(SHH)-activated medulloblastoma and somatic TP53-mutant.After surgery and radiochemotherapy,she remained free of disease progression.At 10 years and 3 months,she developed a diffuse pediatric-type high-grade glioma(dp HGG).The child had a family history of cancer,and subsequent investigation revealed a biallelic germline variant on MSH6(c.3556+1G>A)with the absence of protein expression in both normal and tumor tissue.A PDX model of the dp HGG was developed.The methylation profile confirmed the diagnosis of both brain tumors and PDX,refining the classification of dp HGG,Rtk1 subtype,subclass A,with an actionable alteration on Platelet-derived growth factor receptor A(PDGFRA).Exome analysis showed high tumor mutational burden,with 3019,540,and 1049 pathogenic variants in the medulloblastoma,dp HGG,and PDX,respectively.Only the medulloblastoma exhibited microsatellite instability.The CD24,CD47,and CD276 immune checkpoints had elevated messenger RNA levels,yet no programmed death ligand 1 expression was observed in CMMRD-derived tumors.Conclusion:We report an extensive molecular profile of a CMMRD patient,and the developed PDX model can be applied to explore new therapeutic approaches for CMMRD-associated brain tumors.
文摘黑色素合成受多种基因和miRNAs的调控,为了研究miR-186-5p与α-MSH协同作用对绵羊黑素细胞黑色素生成的影响。本研究在绵羊黑素细胞中转染miR-186-5p表达载体,同时添加α-MSH,通过实时荧光PCR (quantitative real time polymerase chain reaction, qRT-PCR)和蛋白质免疫印迹(Western blotting)检测MITF、TYR、TYRP1和TYRP2 4种可能与之相关的基因表达情况;利用免疫组化检测MITF蛋白在黑素细胞中的表达和亚细胞定位;通过分光光度法测定黑色素含量变化;利用划痕试验测定细胞迁移情况,试验分为miR-186-5p转染组、miR-186-5p+α-MSH互作组和对照组,每组3个重复。结果显示,miR-186-5p能够抑制绵羊黑素细胞中MITF、TYR、TYRP1和TYRP2的表达,并最终抑制黑色素的生成。而添加α-MSH能缓解miR-186-5p对MITF、TYR、TYRP1和TYRP2表达的抑制作用,进而在一定程度上恢复黑色素的含量。另外,miR-186-5p还能抑制细胞分裂,并阻碍细胞的迁移,而α-MSH无法抵消miR-186-5p产生的这种负面影响。上述结果表明,在绵羊黑素细胞中,miR-186-5p和α-MSH均参与调控黑色素合成途径,其中,miR-186-5p主要起负调控作用,而α-MSH主要参与相关位点的正调控,并能部分恢复miR-186-5p导致的黑色素含量下降。值得注意的是,miR-186-5p还参与调控细胞的增殖和迁移,而α-MSH不参与相关调控。
