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
Early gastric carcinomas may develop with a molecular profile differing from sporadic carcinomas occurring at a later age. In this study, we analyzed a retrospective series of 88 patients with gastric adenocarcinoma d...Early gastric carcinomas may develop with a molecular profile differing from sporadic carcinomas occurring at a later age. In this study, we analyzed a retrospective series of 88 patients with gastric adenocarcinoma diagnosed before the age of 45 years for the presence of TP53 mutations, clinicopathological features and immunohistochemistry to evaluate the expression of markers considered to be important in gastric carcinogenesis (E-cadherin, β-catenin, MUC1, MUC2, MUC5AC, MUC6 and p53). The majority of proportion of tumors were diffuse-type (70%) and advanced stage (56%). Familial history of cancer was positive in 21% of the cases. There was a significant association between altered expression of E-cadherin and β-catenin, and between p53 expression and perineural invasion. TP53 mutations were detected in 14.5% of evaluated cases, including a germline mutation (p.R337H) in a 12-year old patient. Overall survival analysis showed significant differences in relation with tumor stage and histopathology. The evaluated biomarkers did not present prognostic value in non-exploratory multivariate analyses. The low frequency of TP53 mutations in this series suggests these alterations are not a major molecular event in gastric cancer occurring at early age, although the identification of a case with germline p.R337H mutation is consistent with the hypothesis that a small proportion of early, apparently sporadic gastric cancer, may be associated with widespread Brazilian founder mutations. Further studies are needed to evaluate the prognostic significance of markers for specific groups of patients according to tumor histology and familial history.展开更多
Adenocarcinomas of the gastrointestinal tract(esophagus,stomach,and colon)represent a heterogeneous group of diseases with distinct etiology,clinical features,treatment approaches,and prognosis.Studies are ongoing to ...Adenocarcinomas of the gastrointestinal tract(esophagus,stomach,and colon)represent a heterogeneous group of diseases with distinct etiology,clinical features,treatment approaches,and prognosis.Studies are ongoing to isolate molecular genetic subtypes,perform complete biological characterization of the tumor,determine prognostic groups,and find predictive markers to the effectiveness of therapy.Separate molecular genetic classifications were created for esophageal adenocarcinoma[The Cancer Genome Atlas(TCGA)],stomach cancer(TCGA,Asian Cancer Research Group),and colon cancer(Colorectal Cancer Subtyping Consortium).In 2018,isolation of TCGA molecular genetic subtypes for adenocarcinomas of the gastrointestinal tract(esophagus,stomach,and colon)highlighted the need for further studies and clinical validation of subtyping of gastrointestinal adenocarcinomas.However,this approach has limitations.The aim of our work was to critically analyze integration of molecular genetic subtyping of gastrointestinal adenocarcinomas in clinical practice.展开更多
BACKGROUND Adenomatous polyposis confers an increased risk of developing colorectal cancer.APC and MUTYH are the major genes investigated in patients suspected of having polyposis.In addition to APC and MUTYH genes,ot...BACKGROUND Adenomatous polyposis confers an increased risk of developing colorectal cancer.APC and MUTYH are the major genes investigated in patients suspected of having polyposis.In addition to APC and MUTYH genes,other genes,such as POLE,POLD1,NTHL1,MBD4,MSH3 and MLH3,have recently been associated with polyposis phenotypes,conferring heterogeneity in terms of the clinical,etiological and heritable aspects of patients with polyposis.AIM To investigate the underlying variant landscape in patients with suspected polyposis who lack variants in the APC and MUTYH genes using whole-exome sequencing.METHODS Twenty-seven participants were included in the study and subjected to germline whole-exome sequencing.In addition,their clinical-pathological,personal,and family history data were collected.RESULTS The mean age at diagnosis was 51 years,and most participants had attenuated forms of polyposis(88.9%),with 63.0%diagnosed with a primary tumor,mostly colorectal cancer(76.5%).Among the variants identified,17 were classified as pathogenic or likely pathogenic(in 12 participants),including variants in genes involved in the Wnt/β-catenin signaling pathway,such as ST7 L,A1CF,and DKK4,and variants in DNA-repair genes,such as NTHL1,PNKP,and PMS2,as well as a variant found at the FRK gene identified in a patient with classic polyposis at age 19 and with a family history of polyps.CONCLUSION This study identified novel genes potentially associated with polyposis in patients lacking germline pathogenic variants in the APC and MUTYH genes.These findings support the use of next-generation sequencing for screening,expanding the scope of polyposis-related variants beyond these two genes.展开更多
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Early gastric carcinomas may develop with a molecular profile differing from sporadic carcinomas occurring at a later age. In this study, we analyzed a retrospective series of 88 patients with gastric adenocarcinoma diagnosed before the age of 45 years for the presence of TP53 mutations, clinicopathological features and immunohistochemistry to evaluate the expression of markers considered to be important in gastric carcinogenesis (E-cadherin, β-catenin, MUC1, MUC2, MUC5AC, MUC6 and p53). The majority of proportion of tumors were diffuse-type (70%) and advanced stage (56%). Familial history of cancer was positive in 21% of the cases. There was a significant association between altered expression of E-cadherin and β-catenin, and between p53 expression and perineural invasion. TP53 mutations were detected in 14.5% of evaluated cases, including a germline mutation (p.R337H) in a 12-year old patient. Overall survival analysis showed significant differences in relation with tumor stage and histopathology. The evaluated biomarkers did not present prognostic value in non-exploratory multivariate analyses. The low frequency of TP53 mutations in this series suggests these alterations are not a major molecular event in gastric cancer occurring at early age, although the identification of a case with germline p.R337H mutation is consistent with the hypothesis that a small proportion of early, apparently sporadic gastric cancer, may be associated with widespread Brazilian founder mutations. Further studies are needed to evaluate the prognostic significance of markers for specific groups of patients according to tumor histology and familial history.
文摘Adenocarcinomas of the gastrointestinal tract(esophagus,stomach,and colon)represent a heterogeneous group of diseases with distinct etiology,clinical features,treatment approaches,and prognosis.Studies are ongoing to isolate molecular genetic subtypes,perform complete biological characterization of the tumor,determine prognostic groups,and find predictive markers to the effectiveness of therapy.Separate molecular genetic classifications were created for esophageal adenocarcinoma[The Cancer Genome Atlas(TCGA)],stomach cancer(TCGA,Asian Cancer Research Group),and colon cancer(Colorectal Cancer Subtyping Consortium).In 2018,isolation of TCGA molecular genetic subtypes for adenocarcinomas of the gastrointestinal tract(esophagus,stomach,and colon)highlighted the need for further studies and clinical validation of subtyping of gastrointestinal adenocarcinomas.However,this approach has limitations.The aim of our work was to critically analyze integration of molecular genetic subtyping of gastrointestinal adenocarcinomas in clinical practice.
基金Supported by the National Oncology Care Support Program,No.25000.056766/2015-64.
文摘BACKGROUND Adenomatous polyposis confers an increased risk of developing colorectal cancer.APC and MUTYH are the major genes investigated in patients suspected of having polyposis.In addition to APC and MUTYH genes,other genes,such as POLE,POLD1,NTHL1,MBD4,MSH3 and MLH3,have recently been associated with polyposis phenotypes,conferring heterogeneity in terms of the clinical,etiological and heritable aspects of patients with polyposis.AIM To investigate the underlying variant landscape in patients with suspected polyposis who lack variants in the APC and MUTYH genes using whole-exome sequencing.METHODS Twenty-seven participants were included in the study and subjected to germline whole-exome sequencing.In addition,their clinical-pathological,personal,and family history data were collected.RESULTS The mean age at diagnosis was 51 years,and most participants had attenuated forms of polyposis(88.9%),with 63.0%diagnosed with a primary tumor,mostly colorectal cancer(76.5%).Among the variants identified,17 were classified as pathogenic or likely pathogenic(in 12 participants),including variants in genes involved in the Wnt/β-catenin signaling pathway,such as ST7 L,A1CF,and DKK4,and variants in DNA-repair genes,such as NTHL1,PNKP,and PMS2,as well as a variant found at the FRK gene identified in a patient with classic polyposis at age 19 and with a family history of polyps.CONCLUSION This study identified novel genes potentially associated with polyposis in patients lacking germline pathogenic variants in the APC and MUTYH genes.These findings support the use of next-generation sequencing for screening,expanding the scope of polyposis-related variants beyond these two genes.
